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The properties of diamond make it an attractive material for MEMS and sensor devices. We present the feasibility to fabricate membranes and cantilevers made of nano-(micro-) crystalline diamond films grown on Si/SiO2 substrates using microwave chemical vapour deposition (MWCVD). The patterning of micromechanical structures was performed by a combined process of femtosecond laser ablation and wet etching. We designed cantilever structures with varying lengths and widths (25, 50, 100, 200 and 300 μm). The cantilevers were made in a symmetric left- and right-hand configuration. An additional laser treatment was used to modify the mechanical properties of the left-hand cantilever. The deflection of the laser-treated, and non-treated sections was measured. The global mechanical system properties were simulated and corresponded with high accuracy to the measured results of deflection.
Purpose: Although there is an apparent potential in using data for advanced services in manufacturing environments, SMEs are reluctant to share data with their ecosystem partners, which prevents them from leveraging this potential. Therefore, the purpose of this paper is to analyse the reasons behind these resistances. The argumentation paves the way for elaborating countermeasures that are adequate for the specific situation and the typical capabilities of SMEs.
Design/Methodology/Approach: The analysis is based on literature research and in-depth interviews with management representatives of 15 companies in manufacturing service ecosystems. Half of these are manufacturers and the other half technology or service providers for manufacturers. They are SMEs or partly larger companies operating in structures that are typical for SMEs.
Findings: Data sharing hurdles are investigated in the five dimensions, 1. quantifying the value of data, 2. willingness to share data and trust, 3. organizational culture and mindset, 4. legal aspects, and 5. security and privacy. The ability to quantify the value of data is a necessary but not sufficient precondition for data sharing, which must be enabled by adequate measures in the other four dimensions.
Originality/Value: The findings of this empirical study and the solution approach provide an SME-specific framework to analyze hurdles that must be overcome for sharing data in an ecosystem.
Manufacturing SMEs can apply the framework to overcome the hurdles by specific insights and solution approaches. Furthermore, the analysis illustrates the future research direction of the project towards a comprehensive solution approach for data sharing in a manufacturing ecosystem.
The design and development of smart products and services with data science enabled solutions forms a core topic of the current trend of digitalisation in industry. Enabling skilled staff, employees, and students to use data science in their daily work routine of designing such products and services is a key concern of higher education institutions, including universities, company workshop providers and in further education. The scope and usage scenario of this paper is to assess software modules (‘tools’) for integrated data and analytics as service (DAaaS). The tools are usually driven by machine learning, may be deployed in cloud infrastructures, and are specifically targeted at particular needs of the industrial manufacturing, production, or supply chain sector.
The paper describes existing theories and previous work, namely methods used in didactics, work done for visually designing and using machine learning algorithms (no-code / low- code tools), as well as combinations of these two topics. For tools available on the market, an extended assessment of their suitability for a set of learning scenarios and personas is discussed.
Smart services disrupt business models and have the potential to stimulate the circular economy transition of regions, enabling an environmentally friendly atmosphere for sustainable and innovation-driven growth of regions. Although smart services are powerful means for deploying circular economy goals in industrial practices, there is little systematic guidance on how the adoption of smart services could improve resource efficiency and stimulate smart regional innovation-driven growth, enabled through circular design. Implemented in the scope of Vorarlberg’s smart specialization strategy, this paper contributes to the literature on the circular economy and regional innovation-driven growth by assessing critical factors of the value creation and value capture implemented within the scope of the quadruple helix system. By identifying the main challenges and opportunities of collaborative value creation and value capture in setting-up smart circular economy strategies and by assessing the role of innovation actors within the quadruple helix innovation system, the study provides recommendations and set of guidelines for managers and public authorities in managing circular transition. Finally, based on the analysis of the role of actors in creating shared value and scaling-up smart circular economy practices in the quadruple helix innovation systems, the paper investigates the role of banks as enablers of circular economy innovation-driven regional growth and smart value creation.
Small and medium-sized enterprises often face resource deficits and there- fore depend on cooperating with other actors to stay innovative in a competitive environment. Establishing and maintaining actual co-creation and service inter- action strategies however is challenging. A reason for this is the complexity of finding methodologies and tools to create valuable outcome and the lack of knowledge of collaboration toolsets, also in virtual environments. This paper introduces an Innovation-Method-Framework consisting of innovation methods for increased service interaction and value co-creation among service stakeholders. Also, toolsets for the framework’s practical application are provided.
Recent developments in the area of Natural Language Processing (NLP) increasingly allow for the extension of such techniques to hitherto unidentified areas of application. This paper deals with the application of state-of-the-art NLP techniques to the domain of Product Safety Risk Assessment (PSRA). PSRA is concerned with the quantification of the risks a user is exposed to during product use. The use case arises from an important process of maintaining due diligence towards the customers of the company OMICRON electronics GmbH.
The paper proposes an approach to evaluate the consistency of human-made risk assessments that are proposed by potentially changing expert panels. Along the stages of this NLP-based approach, multiple insights into the PSRA process allow for an improved understanding of the related risk distribution within the product portfolio of the company. The findings aim at making the current process more transparent as well as at automating repetitive tasks. The results of this paper can be regarded as a first step to support domain experts in the risk assessment process.
The production of liquid-gas dispersions places high demands on the process technology, which requires knowledge of the bubble formation mechanisms, as well as the phase parameters of the media combinations used. To obtain the bubble sizes introduced to a flow not knowing the phase parameters, different process parameters are investigated. Their quality and applicability are evaluated. The results obtained make it possible to simplify long design processes of dispersion processes in manufacturing plants and to ensure the product quality of the products manufactured, by reducing waste.
In previous studies of linear rotary systems with active magnetic bearings, parametric excitation was introduced as an open-loop control strategy. The parametric excitation was realized by a periodic, in-phase variation of the bearing stiffness. At the difference between two of the eigenfrequencies of the system, a stabilizing effect, called anti-resonance, was found numerically and validated in experiments. In this work, preliminary results of further exploration of the parametric excitation are shared. A Jeffcott rotor with two active magnetic bearings and a disk is investigated. Using Floquet theory, a deeper insight into the dynamic behavior of the system is obtained. Aiming at a further increase of stability, a phase difference between excitation terms is introduced.
Bachground: Worldwide, more than 79.5 million people are forcibly displaced, including a significant number of migrant and refugee families with children. Migration and refugeedom affect these families in different dimensions, such as mental, physical and spiritual health. Identifying family needs and enhancing parenting skills can improve family cohesion and health, as well as smooth integration into the host country. This review is part of the Erasmus+ funded project- IENE 8 (Intercultural Education for Nurses in Europe) aiming at empowering migrant and refugee families regarding parenting skills.
Methods: This was a scoping review of literature. The IENE 8 partner countries (Cyprus, Germany, Greece, Italy, Romania, and United Kingdom) searched for peer reviewed papers, grey literature and mass media reports at international, European and national level. The time period for the search of scientific and grey literature was between2013-2018, and for mass media, it was between 2016 and 2018. Results: 124 relevant sources were identified. They included 33 Peer reviewed papers, 47 Grey literature documents and 44 mass media reports. This revealed the importance of understanding the needs of migrant families with children. Conclusion: It is evident from the literature that there is a need to support refugee parents to adjust their existing skill and to empower them to develop new ones. Healthcare and social services professionals have an essential role in improving the refugees' parenting skills. This can be done by developing and implementing family-centered and culturally-sensitive intervention programs.
Highly-sensitive single-step sensing of levodopa by swellable microneedle-mounted nanogap sensors
(2022)
Microneedle (MN) sensing of biomarkers in interstitial fluid (ISF) can overcome the challenges of self-diagnosis of diseases by a patient, such as blood sampling, handling, and measurement analysis. However, the MN sensing technologies still suffer from poor measurement accuracy due to the small amount of target molecules present in ISF, and require multiple steps of ISF extraction, ISF isolation from MN, and measurement with additional equipment. Here, we present a swellable MN-mounted nanogap sensor that can be inserted into the skin tissue, absorb ISF rapidly, and measure biomarkers in situ by amplifying the measurement signals by redox cycling in nanogap electrodes. We demonstrate that the MN-nanogap sensor measures levodopa (LDA), medication for Parkinson disease, down to 100 nM in an aqueous solution, and 1 μM in both the skin-mimicked gelatin phantom and porcine skin.
The paper shows concepts of optical splitting based on three dimensional (3D) optical splitters based on multimode interference principle. This paper is focused on the design, fabrication and characterization of 3D MMI splitter with formed output waveguides based on IP-Dip polymer for direct application on optical fiber. The MMI optical splitter was simulated and fabricated using direct laser writing process. Output characteristics were characterized by highly resolved near-field scanning optical microscope (NSOM) and compared with 3D MMI splitter without output waveguides.
We present 256-channel, 25-GHz AWG designed for ultra-dense wavelength division multiplexing. For the design two in-house developed tools were used: AWG-Parameters tool for the calculation of input design parameters and AWGAnalyser tool, used to evaluate the simulated transmission characteristics. The AWG structure was designed for AWG central wavelength of 1550 nm and simulated with PHASAR tool from Optiwave. To keep the size of AWG structure as small as possible the number of waveguides in the phased array was tested. The simulations show that there is a certain minimum number of phased array waveguides necessary to reach sufficient AWG performance. After optimization, the AWG structure reached 10 cm x 11 cm in size and satisfying optical properties.
This paper describes two different designs of 1×8 passive optical splitters. The first splitter consists of cascade arranged directional waveguide branches (Y-branch splitter) with (0.8×0.16) µm2 waveguide cross-section. The second splitter is based on multimode interference occurring in a large MMI coupler, which uses a self-imaging effect for beam propagation, exhibiting the same waveguide core size as a Y-branch splitter. The waveguide channel profile, used in both approaches, is based on a silicon nitride material platform, with a refractive index of core being nc = 1.925 and a refractive index of cladding ncl = 1.4575. The splitters are designed as a planar structure for a medical operating wavelength 850 nm. Design, simulation, and optimization of passive optical components are performed by a commercial photonic software tool BeamPROP simulation engine by RSoft Photonics Suite tool, employing beam propagation method. This work aims to find the minimum physical dimensions of the designed splitters with the satisfactory optical performance. According to the minimum insertion loss and minimum non-uniformity, the optimum length of the splitters is determined. Finally, the optical properties of splitters for both approaches are discussed and compared with each other.
Calls for decolonising global health have intensified in recent years. The Austrian NGO plan:g Partnership for Global Health has taken several steps to decolonise its work and to find new ways of communicating and engaging in equitable partnerships. Decolonising global health cooperation is however not without its challenges.
Due to the increasing trend of photonic element miniaturisation and the need for optical splitting, we propose and simulate a new type of three-dimensional (3D) optical splitter based on multimode interference (MMI) for the wavelength of 1550 nm. We present various designs and simulations of various parameters for the optimized MMI splitter. We focus on the possibility of its integration on an optical fiber. The design is focused on a possible production process using 3D laser lithography for the prepared experiments. The MMI splitter was prepared by laser lithography using direct writing process and finally investigated by output characterisation by the near-field measurement.
In this paper, we document optical splitters based on Y-branch and also on MMI splitting principle. The 1×4 Y-branch splitter was prepared in 3D geometry fully from polymer approaching the single mode transmission at 1550 nm. We also prepared new concept of 1×4 MMI optical splitter. Their optical properties and character of output optical field were measured by near-field scanning optical microscope. Splitting properties and optical outputs of both splitters are very promising and increase an attractiveness of presented 3D technology and polymers.
The paper deals with the optimization of 2x2 optical switch for photonic integrated circuits based on two 2x2 MMI splitters and two phase-modulators. The optical switch was modelled in the RSoftCAD with the simulation tool BeamPROP. The optimization was done to minimise the insertion losses and broaden the spectral band at 1550 nm by using linear tapers in a 2x2 MMI splitter topology. The 2x2 optical switch is a common element for creating more complex 1xN or NxN optical switches in all-optical signal processing.
Design, simulation, and optimization of the 1×4 optical three-dimensional multimode interference splitter using IP-Dip polymer as a core and polydimethylsiloxane (PDMS) Sylgard 184 as a cladding is demonstrated. The splitter was simulated by using beam propagation method in BeamPROP simulation module of RSoft photonic tool and optimized for an operating wavelength of 1.55 μm . According to the minimum insertion loss, the dimensions of the splitter were optimized for a waveguide with a core size of 4×4 μm2 . The objective of the study is to create the design for fabrication by three-dimensional direct laser writing optical lithography.
In this paper we present various educational activities with Photonics Explorer, an educational kit developed by the photonics research team B - PHOT at VUB (Vrije Universiteit Brussel) for students at secondary schools. The concept is a ‘lab-in-a-box’ that enables students of the 2 nd and 3 rd grade to do photonics experiments themselves at school with lasers, LEDs, lenses, optical fibers, and other high-tech components. Even though, the kit was developed for the secondary schools, we use experiments from the kit also for some other teaching activities such as lectures at the university, photonics workshops for teachers and children at primary/secondary schools or for events such as children's/youth's university or the night of sciences. In the frame of Austrian based project Phorsch! we have organized most of these activities which will be presented here.
A new software tool, called AWG-Channel-Spacing, is developed to calculate accurate channel spacing of an arrayed waveguide gratings (AWG) optical multiplexer/demultiplexer. This tool has been developed with the application framework QT in the programming language C++. The tool was evaluated with a design of 20-channel 200 GHz AWG. The achieved simulated transmission characteristics prove the correct functionality of the tool.
A new software tool, called AWG-Wuckler, is developed to calculate geometric parameters of arrayed waveguide grating structures for telecommunication and medical applications. These parameters are crucial for a AWG layout which will be created and simulated using commercial photonic design tools. The design process of AWG is very complex because its geometric dimensions depend on a large number of input design parameters and other input design parameters. Often geometric constraints require an adjustment of the input design parameters and vice versa. Calculation and adjustment of the geometric parameters is a time-consuming process that is currently not fully supported by any commercial photonic tool. AWG-Wuckler tool overcomes this issue and offers a fast and easy to use solution. The tool was already applied in various AWG designs and is technologically well proven.
This paper aims to study the design, simulation, and optimization of low-loss Y-branch passive optical splitters up to 64 output ports for telecommunication applications. For a waveguide channel profile, the standard material silica-on-silicon is used. The Y-splitters are designed and simulated at telecommunication operating wavelength, λ = 1550 nm. Except for the lengths of the used Y-branches, and a core size of the waveguides, design parameters such as port pitch between the waveguides and simulation parameters for all splitters are considered fixed. The simulation results are analyzed to determine the optimum length of the splitters and the optimum core size. Based on this optimization the total length of the highest designed 1×64 Y-branch splitter was reduced by 41.14 % for a waveguide core (5×5) μm2 compared to the length of splitter with a standard (6×6) μm2 core size.
Vast amounts of oily wastewater are byproducts of the petrochemical and the shipping industry and to this day frequently discharged into water bodies either without or after insufficient treatment. To alleviate the resulting pollution, water treatment processes are in great demand. Bubble column humidifiers (BCHs) as part of humidification–dehumidification systems are predestined for such a task, since they are insensitive to different feed liquids, simple in design and have low maintenance requirements. While humidification in a bubble column has been investigated plentiful for desalination, a systematic investigation of oily wastewater treatment is missing in literature. We filled this gap by analyzing the treatment of an oil–water emulsion experimentally to derive recommendations for future design and operation of BCHs. Our humidity measurements indicate that the air stream is always saturated after humidification for a liquid height of only 10 cm. A residual water mass fraction of 3.5 wt% is measured after a batch run of six hours. Furthermore, continuous measurements show that an increase in oil mass fraction leads to a decrease in system productivity especially for high oil mass fractions. This decrease is caused by the heterogeneity of the liquid temperature profile. A lower liquid height mitigates this heterogeneity, therefore decreasing the heat demand and improving the overall efficiency. The oil content of the produced condensate is below 15 ppm, allowing discharge into various water bodies. The results of our systematic investigation prove suitability and indicate a strong future potential for the use of BCHs in oily wastewater treatment.
Industrial demand side management has shown significant potential to increase the efficiency of industrial energy systems via flexibility management by model-driven optimization methods. We propose a grey-box model of an industrial food processing plant. The model relies on physical and process knowledge and mass and energy balances. The model parameters are estimated using a predictive error method. Optimization methods are applied to separately reduce the total energy consumption, total energy costs and the peak electricity demand of the plant. A viable potential for demand side management in the plant is identified by increasing the energy efficiency, shifting cooling power to low price periods or by peak load reduction.
A trend from centralized to decentralized production is emerging in the manufacturing domain leading to new and innovative approaches for long-established production methods. A technology supporting this trend is Cloud Manufacturing, which adapts technologies and concepts known from cloud computing to the manufacturing domain. A core aspect of Cloud Manufacturing is representing knowledge about manufacturing, e.g., machine capabilities, in a suitable form. This knowledge representation should be flexible and adaptable so that it fits across various manufacturing domains, but, at the same time, should also be specific and exhaustive. We identify three core capabilities that such a platform has to support, i.e., the product, the process and the production.We propose representing this knowledge in semantically specified knowledge graphs, essentially creating three through features interconnected ontologies each representing a facet of manufacturing. Finally, we present an exemplary implementation of a Cloud Manufacturing platform using this representation and its advantages.
In the current international business environment employees are spending large amounts of their time in meetings. More than ever these meetings take place remotely and often have the problem that individuals in the meeting do not share information or opinions. Employees often stay in muted in meetings and allow one or two participants to drive the conversation. This habit is especially troublesome for problem solving meetings. Problem solving meetings invite individuals from different disciplines to share and brainstorm possible causes for issues related to poor company outcomes. Active and open contribution from all members is required to achieve the group goals. This study aims to find methods that will increase contribution amongst meeting participants in regular meetings as well as problem solving meetings. The study tested sixteen topics for their influence on contribution in meetings. This was done in a survey, that was distributed within a multination engineering corporation, and on LinkedIn. There was a total of 68 responses. These responses were then separated by above average and below average participation in problem solving meetings. Hypothesis testing was done on the total group and separately on the problem-solving group. Employee participation in decision making and psychological safety were found to correlate highly with Contribution in meetings for both groups. Psychological safety was found to be of even greater importance to problem solving group. This study demonstrates that to increase contribution in meetings, leaders should provide a psychologically safe climate where employees share in the decision making. Furthermore, a psychologically safe environment is critical in problem solving meetings where members of different disciplines with low familiarity take part.
This master thesis investigates drivers and barriers of innovation workshops for an intercultural participant group. Actively dealing with innovation management is considered vital for companies which are acting on competing markets. An innovation workshop is a useful tool in order to foster innovation ability, develop innovative ideas and drive innovation forward. Intercultural participant groups are not only a common challenge in today's business world but also entail several benefits as they incorporate diverse knowledge bases and perspectives and hence contribute to the ideation and innovation process. Within the master thesis a broad variety of barriers and drivers are evaluated. Main barriers of innovation workshops for an intercultural participant group are high conflict potential, miscommunication, language barriers, a lack of management support, no agreement on workshop objectives as well as poor workshop preparation, organization and facilitation. Main drivers of innovation workshops for an intercultural participant group are a heterogeneous group composition, intercultural competence of the facilitator, the opening up of mindset silos, an intensive workshop preparation and empathetic facilitation. These drivers and barriers build the basis for the determination of success factors and recommendations for action for organizers and facilitators of an innovation workshop for an intercultural participant group. In the further course of the paper an exemplary workshop design will be presented as a guideline and framework for managerial practice
Data is the new oil,” said British Mathematician and Tesco marketing mastermind Clive Humbly1. Data has also been described as the backbone of digital retail enterprises2 and the currency of the digital age. Whether these statements live up to be true is debatable, but what is certain is the fact that the internet age has contributed to the avalanche of data witnessed today. In a century dominated by predictive analysis and artificial intelligence, it is no surprise that by the end of the last decade, data companies Apple, Amazon and Microsoft closed as the world´s first trillion-dollar companies, with their revenues dwarfing economies of several countries across the globe.3The recognition of the importance of data in today´s economy bears with it the responsibility to protecting its owners. While this intricate balance has long been the subject of legal analysis the General Data Protection Regulation, 2018, is hailed as the world´s most comprehensive and strict data protection regime currently in force. In addition to protecting the personal data of persons from its member countries, the Regulation also seeks to ensure the same protection accompanies any data transferred out of the European Union to other countries. It is almost 5 years since the Regulation was passed and process of implementation into business operations an important topic of discussion. Of importance to this study are the Modernized Standard Contractual Clauses, a tool of data transfer to countries outside the EU, which replace the three sets of SCCs adopted by the now repealed Data Protection Directive 94/46. These Standard Contractual Clauses came into effect on 27th September 2021, and companies have until 27th September 2022 to rely on the old set of clauses. With this deadline coming up, how far have the clauses been integrated into operations by businesses in Austria and the EU?
The rapidly evolving nature of Industry 4.0 has confronted corporates with the challenge of being able to react rapidly and nimbly (Van Solingen, 2020). Hence, many corporates need to embark on a journey of adaptation toward becoming agile organisations (Schmitz, 2018). However, this adaptation can only be achieved if employees fully commit to changing to an agile posture, and the required commitment is simply not forthcoming without proper corporate initiatives (Neves & Caetano, 2009). As there is no holistic summary of corporate initiatives required to boost employees' commitment to change when approaching an agile transformation, this study supplements the current research. The initiatives are derived from the existing literature and from unique insights given into a European automotive supplier that is currently managing a global agile transformation. Employees’ perceptions of the transformation in Austria and China were recorded and conclusions regarding what drives employees’ commitment to change and what led to job terminations were determined.
Fear of failure is a major factor influencing entrepreneurial actions. Since the female quota for startups and self-employment is still lower than for men, the aim is to determine the extent to which the fear of failure is incorporated into the entrepreneurial actions of women in Austria. The trailblazer and pioneer in female entrepreneurship America is used as an international benchmark for evaluation. A quantitative survey was conducted among women from Austria and America on their fears of failure related to self-employment and their aspirations to become self-employed. There were significant differences in the quantitative study between self-employed and non-self-employed women, irrespective of their country of origin. As a result, recommendations for action were created to reduce the influence of Fear of Failure on entrepreneurial actions of Austrian women.
The impact of organizational citizenship behavior for the environment on corporate sustainability
(2022)
Today, many businesses increasingly engage in pro-environmental activities to face environmental challenges such as pollution or climate change. In addition to formal management practices, employees are impacting environmental advances with voluntary pro-environmental activities, also known as Organizational Citizenship Behavior for the Environment. The purpose of this master thesis is to explore factors that could influence employees’ engagement in Organizational Citizenship Behavior for the Environment. For this aim, five semi-structured interviews were carried out with multinational corporations from the DACHL region. The results show that certain leadership styles, corporate culture, a sustainability-driven mindset, environmental concern, communication and motivation can influence employees’ engagement in Organizational Citizenship Behavior for the Environment. In addition, the cumulative effect of small initiatives seems to considerably impact environmental sustainability. In contrast to past research on this topic, this study takes a qualitative approach to explore different influencing factors of Organizational Citizenship Behavior for the Environment. In addition, the study focuses on businesses located in the DACHL region.
Projects, in which software products, services, systems and solutions are developed, all rely on the right requirements to be established. Software requirements are the expression of user wants or needs that have to be addressed, business objectives that have to be met, as well as capabilities and functionality that has to be developed. Meanwhile, practice shows that very often incorrect, unclear or incomplete requirements are established, which causes major problems for such projects. It could lead to budget overruns, missed deadlines and overall failure in worst-case scenarios.
The field of requirements engineering emerged as an answer to these shortcomings, aiming to systematize and streamline the process that
establishes requirements. Requirements elicitation is a key component of this process, and one of its starting points. The current thesis attempts to outline best practices in requirements elicitation, as well as what issues, obstacles and challenges are currently faced, and then present this through the lens of national culture. In this way its effects on the practice, if any, could be highlighted and studied further. The way this was achieved was by interviewing practitioners from two nations, which are shown to be
culturally different, and then comparing and contrasting the findings.
Meanwhile, the validity of those findings was enhanced by comparisons with existing literature.
Even though the findings were not compelling enough to form generalizations or concrete conclusions about the effects of national culture on requirements elicitation, these findings revealed patterns that could be worth exploring further. When it comes to requirements elicitation itself, it was observed to benefit from a structured and systematic approach, and be
most effective with one-on-one, instead of group interactions. The main pain points of the process stem from the complexity of communication, but are not always obvious. Practitioners are also advised to carefully plan the gathering of requirements, as the source may not have them readily available, and could even be unclear about what exactly is needed. Overall, this thesis research could be considered successful in its goal to shed a modicum of light on the issue at hand from a different, underexplored angle. By following a systematic and methodical approach, this research has also been made easier to expand or replicate.
Power cables play an important role in power grids. Insulation faults in cables can have adverse effects on the operating behaviour. These effects can be assessed through an AC withstand test by using a very-low frequency high voltage generator. This generator produces a sinusoidal voltage waveform at 0.1Hz with high voltage levels up to 65kV peak. During the quality assessment, the power cable is repeatedly charged and discharged. The discharging process is done by a discharging circuit where the energy is dissipated thermally. But to reuse the dissipated energy a novel extension in form of an energy storage system is presented. This thesis, therefore, describes the design process of an energy storage system that allows the temporary storage of the discharge energy. The developed system is composed of a bidirectional DC/DC converter and an aluminium electrolytic capacitor as storage type. Based on the maximum VLF system ratings the energy storage unit is dimensioned and sized. The effective power flow control between the storage system and the available discharge energy is done by a synchronous buck-boost converter. This bidirectional converter works in continuous conduction mode over the complete charging phase. Together with a theoretical analysis of the underlying problem and the use of converter analysis methods the selected synchronous buck-boost converter is dimensioned and sized. In addition, a state space AC modeling of the converter with its electrical uncertainties is conducted. With the converters AC model, the controller is designed. A closed-loop input converter current control scheme based on a proportional-integral controller is implemented. The system assessment is done by a model-based hardware implementation in Matlab Simulink and Plecs Blockset. The system is rated to store discharge energies up to 4.3kJ in a short charging period of 2.5s. The maximum peak power during the charging phase is 2.7kW. The digital proportional-integral controller is implemented through an emulation process of the designed analog controller. Based on a C-code implementation of the digital controller the gap between the real hardware is reduced. During the design process theoretical calculations are made and reveal that designing a capacitor storage unit has a direct impact on the peak system currents and also impose also limitations on permissible DC voltage ranges on electrical components. The developed energy storage system and its power flow control strategy were investigated through simulation studies. The results show proper charging of the energy storage medium. In addition, also a statement of the final technical feasibility is made. In total, this work summarizes a detailed design process of the energy storage system. This proof of concept is intended to further advance the system integration.
Development of a low pressure syringe pump for detecting cannabinoids through liquid chromatography
(2022)
The following thesis covers the miniaturization and characterization of a pneumatic syringe pump, which is used for applications in low-pressure liquid chromatography. For this purpose, the components of the prototype are dealt with in the first section. These include the membrane pump and the cylinder for pressure and force generation, the syringe used for sample preparation and the construction of the test column. Furthermore, the pressure preparation on the cylinder, the friction losses of the syringe and then the behavior of the syringe in various application scenarios are considered. In the second section, the focus is on the different behaviors when using water and ethanol as a solvent. Tests in normal applications, as well as with air pockets or leaking seals, show the different behavior and the resulting deviations in the test pressure of the column. In addition, the maximum forces that can be applied to the syringe are worked out in several tests and the different maximum pressures, which depend on the solvent contained, are evaluated. These different maximum pressures, which are due to the different sealing behavior in connection with the surface tension of the liquid, will be discussed in conclusion. An outlook follows, up to which test pressures the system can be used and how these can be achieved.
This master’s thesis provides an overview of a more efficient, future-oriented living concept in Dornbirn, Austria. The use of a combined heat and power unit (CHP), in combination with a thermal storage, as a heating system is specifically investigated. In order to make this heating system more attractive for the consumer, the sale of the generated electricity from the CHP is considered. The more efficient use of energy for heating increases the attractiveness by a minimisation of the living space. This master’s thesis aims to draw attention to the issue and to achieve a rethinking in the planning of future living space. For the research and elaboration of this thesis, statistics and trustworthy literature were used, and physical modelling was applied. This Master’s thesis can be assigned to the fields of energy technology, mechatronics, architecture and civil engineering. It contributes for students, researchers, and other interested person in these sectors.
The detection of glucose is an essential part of diabetes management and can help to prevent secondary diseases, that can occur as a result of diabetes. For this reason, it is important to improve the current glucose monitoring by developing novel sensors with high efficiency, low cost and compact design. The use of microelectrodes with interdigitated array (IDA) structures reduces the total detector size while providing benefits such as large currents, high sensitivity, and fast response. The aim of this thesis is to develop a novel sensor based on platinum interdigitated array (IDA) electrodes and to investigate which method is most effective for the detection of glucose. This work is divided into two parts. The first part is focused on the design and the fabrication of the sensor chips. The second part is concerned with the electrochemical characterisation of the sensors. Two distinct sensor designs are created, each consisting of a four-electrode system arranged as an interdigitated array. For the fabrication of the sensors, two different manufacturing processes are used. A lift-off process is used to fabricate the 2 μm-Gap sensor chips, whereas a lift-off free process is applied to produce the nanogap sensor chips. The electrochemical characterisation of both sensor chips is achieved by the immobilisation of the enzyme glucose oxidase (GOx) on the electrode surface. This thesis investigates the immobilisation of GOx by reduction of diazonium salts and the direct immobilisation of GOx by cyclic voltammetry. As a result of this work, it has been demonstrated that glucose detection by reduction of diazonium salts is error-prone due to modification with a multi-step procedure and is not suitable for our sensors based on platinum IDA electrodes. The direct immobilisation of GOx by cyclic voltammetry, by contrast, demonstrates the successful detection of glucose. In glucose solutions ranging from 5 mM to 20 mM, a direct correlation between the glucose concentration and the measured current is obtained. The reproducibility of direct immobilization is demonstrated by repeated performance with various sensors.
In today’s world, fiber optic networks for data transmission are an essential technology. This technology provides multiple advantages compared to conventional electrical data transmission. The simultaneous transmission of multiple optical signals in a single fiber is one of the main benefits of fiber optic cable. This is accomplished by directing the different optical signals into a single fibre and splitting them up after the transmission in order to obtain the individual signals. Arrayed Waveguide Gratings (AWGs) are used for this purpose in modern optical networks. Design and evaluation process are two components of AWG development. During the evaluation of several simulated and already manufactured AWGs for telecommunication applications, it was discovered that the channel spacing parameter does not conform telecommunication standards. The correct shift of the geometric parameter ”separation of the output waveguides” leads to the standard-conform channel spacing.
According to the current state of the art, no commercial tool is available which calculates the shift of this parameter correctly. The aim of this thesis is the development of a software tool to calculate the accurate shifting of the geometric parameter ”separation of the output waveguides” of an AWG. This tool operates as an interface between the design and evaluation processes and must be able to import the data format of the evaluation process and returns the data in a suitable data format for the design process. The Vorarlberg University of Applied Sciences uses three different methods for the shifting of the geometric parameter ”separation of the output waveguides”. These methods are evaluated and optimised as part of this thesis. Additionally, it has been determined that the shift of the geometric parameter ”separation of the output waveguides” has no significant impact on the performance of the AWG.
Erosion due to cavitation is a common problem for any kind of water turbine. Most of the currently used techniques to detect cavitation are using an Acoustic Emission (AE) sensor and highspeed cameras during operation. For the pelton wheel which is subject of this thesis it is impossible to take pictures during operation, because of the splashing water and the mist. Therefore this thesis aims to explore possibilities in detecting erosion on the buckets of the pelton wheel on images taken during manual inspections. Since the provided images are snapshots taken with a mobile phone camera without a tripod, a lot of effort was invested in the preprocessing of the images. For the main task, the classification of the erosion, two methods were evaluated: Local Binary Patterns (LBP) + kN-earest neighbor classification and the classification with a Convolutional Neural Network (CNN). The given 2405 images, contained 4810 buckets on which the erosion was graded from zero to four. This means the baseline for the classification accuracy is 20%. LBP + kNearest neighbor classification scored 32.03%. The chosen CNN model, a light version of the Xception architecture outperformed the LBP + kNearest classification with 58,29%. The biggest issue found during research is the variance of the erosion grading by the maintainance personnel. Reasons for this are: no objective grading critera like the area of erosion in mm2, classification by different employees, a shift in grading from overall bucket condition to erosion from cavitation and too many classes for grading. The mentioned reasons were confirmed by the manual classification experiment were an IllwerkeVKW employee had to perform the grading on images of the dataset. The contestants accuracy score was 36% for this task. The result of 58,29% classification accuracy indicates that an automated grading of erosion by cavitation is feasible.
Skiing is one of the most popular winter sports in the world and especially in the alps. As the skiers enjoy their time on the slopes the most annoying thing that could happen is long waiting times at a lift. Unfortunately, because of climate changes, this happens more regularly because smaller skiing areas at lower altitudes have to close and the number of good skiing days decreases as well. This leads to a increase in the number of skiers in the skiing areas which inevitably leads to longer waiting times and dissatisfied skiers. To prevent this from happening, the carriers of the skiing areas have to manage the skiers flow and distribution and what better way to analyse the current situation and possible changes then by simulating the whole area. A simulation has the advantage of being flexible with regards to time as well as configuration. Be it simulating a skiing day and look into detail of the behaviour of a single skier and how it moves in the area by simulating in real time or setting the focus to the whole area and find out when and where queues are forming throughout the whole day by speeding up the time and simulate the day in only seconds, everything is possible. Even simulating a scenario where some part of the area is closed and the skiers cannot take specific lifts due to some technical error or some slopes because of to less snow. By simulating and analysing all these scenarios not only does the experts of the skiing area gain valuable statistical information about the area but can also simulate changes to the system like a crowd fl ow control or an increase or decrease in capacity of a lift. The simulation built in context with this work for the skiing area of Mellau shows all those applications but can also be used as a basis for further improvements of the skiing area or be expanded to other areas like Damüls. The simulation was implemented using the Anylogic simulation environment and the statistical evaluation was also performed in this program.
Systems are constantly increasing in complexity. This poses challenges to managing and using system knowledge. The Systems Modeling Language (SysML) is a modeling language specifically for systems, while Machine Learning (ML) is a tool to tackle complex problems. Currently, no bridge between systems modelled in SysML and ML regarding said systems has been proposed in literature. This thesis presents an approach that uses Model-driven Software Engineering (MDSE) and Template-based Code Generation (TBCG) to generate a ML IPython Notebook (IPYNB) from a SysML model. A mapping configuration using JavaScript Object Notation (JSON) allows the definition of mappings between SysML elements and template variables, enabling configuration and user-supplied templates. To test the approach, a SysML model describing ML to predict the weather based on data is created. Python ML templates are supplied and template variables mapped with the JSON mapping configuration are proposed in the thesis. The outcome is an executable IPYNB that contains all information from the SysML model and follows the modelled workflow. The findings of the work show that model-driven ML using SysML as a modeling language is beneficial due to the representation of ML knowledge in a general-purpose modeling language and the reusability of SysML model elements. It further shows that TBCG and a mapping configuration allow for more flexible code generation without changing the source implementation.
Offline speech to text engine for delimited context in combination with an offline speech assistant
(2022)
The inatura museum in Dornbirn had planned an interactive speech assistant-like exhibit. The concept was that visitors could ask the exhibit several questions that they would like to ask a flower. Solution requirements regarding the functionalities were formulated, such as the capacity to run offline because of privacy reasons. Due to the similarity of the exhibit, open-source offline Speech To Text (STT) engines and speech assistants were examined. Proprietary cloud-based STT engines associated with the corresponding speech assistants were also researched. The aim behind this was to evaluate the hypothesis of whether an open-source offline STT engine can compete with a proprietary cloud-based STT engine. Additionally, a suitable STT engine or speech assistant would need to be evaluated. Furthermore, analysis regarding the adaption possibilities of the STT models took place. After the technical analysis, the decision in favour of the STT engines called "Vosk" was made. This analysis was followed by attempts to adapt the model of Vosk. Vosk was compared to proprietary cloud-based Google Cloud Speech to Text to evaluate the hypothesis. The comparison resulted in not much of a significant difference between Vosk and Google Cloud Speech to Text. Due to this result, a recommendation to use Vosk for the exhibit was given. Due to the lack of intent parsing functionality, two algorithms called "text matching algorithm" and "text and keyword matching algorithm" were implemented and tested. This test proved that the text and keyword matching algorithm performed better, with an average success rate of 83.93 %. Consequently, this algorithm was recommended for the intent parsing of the exhibit. In the end, potential adaption possibilities for the algorithms were given, such as using a different string matching library. Some improvements regarding the exhibit were also presented.
The demand for managing data across multiple domains for product creation is steadily increasing. Model-Driven Systems Engineering (MDSE) is a solution for this problem. With MDSE, domain-specific data is formalized inside a model with a custom language, for example, the Unified Modelling Language (UML). These models can be created with custom editors, and specialized domains can be integrated with extensions to UML, e.g., the Systems Modeling Language (SysML). The most dominant editor in the open-source sector is Eclipse Papyrus SysML 1.6 (Papyrus), an editor to create SysML diagrams for MDSE.
In the pursuit of creating a model and diagrams, the editor does not support the user appropriately or even hinders them. Therefore, paradigms from the diagram modelling and Human Computer Interaction (HCI) domains, as well as perceptual and design theory, are applied to create an editor prototype from scratch. The changes fall into the categories of hierarchy, aid in the diagram composition, and navigation. The prototype is compared with Papyrus in a user test to determine if the changes have the effect of improving usability.
The study involved 10 participants with different knowledge levels of UML, ranging from beginners to experts. Each participant was tested on a navigation and modelling task in both the newly created editor, named Modelling Studio, and Papyrus. The study was evaluated through a questionnaire and analysis of the diagrams produced by the tasks.
The findings are that Modelling Studio’s changes to the hierarchical elements improved their rating. Furthermore, aid for diagram composition could be reinforced by changes to the alignment helper tool and adjustments to the default arrow behaviour of a diagram. Lastly, model navigation adjustments improve a link’s visibility and rating of a specialized link (best practice). The introduction of breadcrumbs had limited success in bettering navigation usability. The prototype deployed a broad spectrum of changes that found improvement already, which can, however, be further improved and tested more thoroughly.
With the rise of people wearing smartwatches and the ever-lasting issue of stress, there has been an interest in detecting stress with wearables in real-time. This allows for interventions that take place exactly when stress occurs. However, many situations require all of our attention, making them unsuitable for any interventions. Additionally, many approaches currently do not factor in this aspect, running the risk of offering users undesirable interventions.
This thesis examines how contextual user information can be incorporated into a stress intervention system to reduce undesirable intervention timings. The system is split into detecting stress using heart rate variability (HRV) metrics obtained from a photoplethysmography (PPG) signal, and inferring user context from available sensor data. It is evaluated with a simulation-based approach using daily schedules of created personas and randomly sampled stressors during daily life.
The results obtained indicate the benefit of adding contextual user information to a stress intervention system. Depending on the busyness of the schedule, it can greatly decrease the number of received interventions. However, as these findings are attained without performing a user testing, it is unclear how they compare to results from real-world usage.
The alarming degradation of the natural environment is leading many consumers to increasingly demand sustainable products. Since 2017, the global purchase intention of such products has increased by 63%. To respond to the increasing demand, more and more companies have started producing products from sustainable materials such as recycled products. However, purchase intention does not always result in actual behavior and can vary due to different products and in country-specific contexts. Hence, it is the purpose of this study to determine which factors influence the purchase intention of recycled products and whether these factors differ between a developed country such as Germany and a developing country such as South Africa. Furthermore, the study aims to discover whether there are differences in purchase intention with regard to different product categories, whether there is an intention-behavior gap, and whether there are country-specific differences. Finally, target groups of the corresponding countries will be derived. To answer the research questions, a quantitative study was conducted using an online questionnaire in Germany (n = 603) and South Africa (n = 692). The findings demonstrate that the purchase intention for recycled products is significantly higher in South Africa than in Germany, but no significant difference in the factors influencing the purchase intention could be found. However, the factors differ in terms of the extent of their influence. Thus, the factor “Attitude / Environmental Concern” has the strongest influence in South Africa, while the factor “Value / Accessibility” has the strongest influence in Germany. Likewise, a difference could be found concerning the products, with the purchase intention for mobile phones generally smaller than for t-shirts and toilet paper. In a country-specific comparison, however, purchase intention for t-shirts is significantly higher in South Africa than in Germany. An intention-behavior gap was identified for the sample, and it was found that the age groups 25 to 49 have the strongest purchase intentions and that the purchase intention increases significantly with increasing education level.
Today, industrial B2B manufacturers face a rapidly changing environment, exacerbated by increasing globalization and associated shifts in the competitive landscape. Digital transformation and the emergence of new innovations and technologies are forcing companies to rethink their business models and offerings to integrate digital services to strengthen competitive advantages. Suppliers are becoming more deeply involved in customer processes through digital after-sales services, with the aim of exploiting efficiencies. Following the servitization transformation, companies intend to change their purpose from focusing on the pure physical product to becoming a service provider with emphasis on value creation and the capture of the customer.
To investigate how customer and supplier perspectives agree and what requirements each side has for digital after-sales services, exploratory qualitative research was conducted with customers and suppliers by means of one-on-one interviews. The thesis aimed to assess the status, progress, and future possibilities of implementing digital after-sales services and business models based on them. Research shows that the far-reaching establishment of product-accompanying services with strong connectivity and customer-centricity is primarily relevant. Disruptive business models still require a mind-shift and organizational readiness on the part of both customers and suppliers. In principle, digitization in after-sales interaction is beneficial and should be steadily advanced to make customer processes as well as further developments at the supplier level more efficient and well-founded through the analysis of real data. Overall, this thesis outlines important aspects that need to be considered while developing digital service innovations to deal with customer demands appropriately.
Keywords: Servitization, Digital After-Sales Services, Predictive Maintenance, Remote Monitoring, Digital Interaction, Digital Service Innovation, Digital Service Innovation Process
The presented master thesis of the study subject International Marketing and Sales at the Fachhochschule Vorarlberg in Dornbirn deals with the influence of emotions on the attitude toward hydrogen cars and their purchase intention. For this purpose, an empirical analysis with a correlation analysis was conducted in order to be able to determine the correlations of the individual parameters.
At the beginning of the thesis the hydrogen technology was presented in more detail and by means of suitable criteria it was shown that the hydrogen car represents a certain potential, however, in comparison to the combustion cars and electric cars, the hydrogen car is currently in third place. The relatively long range, the fast-refueling and the sustainability were identified as advantages, while the current high price and the poorly developed refueling station network are currently the biggest ob-stacles to a hydrogen car. It can be seen that research and development of hydrogen cars is being driven forward in many countries around the world, including by the gov-ernment side through the provision of various subsidies. For this reason, the future development of the driving technology remains exciting and simultaneously uncertain.
In the second step of the work, emotions were examined in more detail. The aim was to find out which emotions exist and which of them are predominant when buying a car, and then to find out what influence emotions have on the cognitive process, the attitude, and the purchase intention. It turned out that the majority of the population is highly involved in the purchase of a car and therefore tries to make rational decisions, which makes the influence of emotions more difficult, but not impossible.
By presenting suitable marketing tools for measuring emotions, it was shown that measuring emotions is a difficult undertaking. Measurement is often difficult or expen-sive and involves a great deal of effort. For this reason, beside the presentation of marketing tools, the strategic approach for a marketing campaign was also presented.
Based on the conducted empirical analysis, the influence of emotions on attitude and purchase intention could not be significantly confirmed but it could be proven that the knowledge about hydrogen cars is currently low. One inside is that an increase in awareness increases the purchase intention of hydrogen cars. Furthermore, a signifi-cant correlation between the sustainable attitude and the purchase intention could be proven. In addition, people who like to follow new trends are more likely to buy a hy-drogen car than others. This paper concludes with a brief summary of the findings and an outlook on the potential for improvement of the hydrogen car market.
Keywords: Hydrogen Cars, Sustainability, Emotions in Marketing, Purchase Inten-tion, Attitude, Marketing Tool
In recent years, more and more companies have become aware that a brand also has a social dimension, and with the advent of social media platforms, brand communities have experienced a shift from a traditional offline to more of an online presence. Brands of innovative consumer durables have also recognized social media brand communities as a very significant marketing strategy. It is therefore important to understand the influence of these communities on members' purchase intentions.
This master’s thesis has the goal of demonstrating to enterprises what aspects of a social media brand community will influence the purchase intention of its members and what should be considered in order to enhance it. This will ultimately lead to the following research question: How do social media brand communities influence the diffusion process of innovative consumer durables in the DACH region?
To answer this, a quantitative study has been conducted that has targeted people who are participating in a social media brand community of innovative consumer durables in the DACH region. This involved testing various criteria of a social media brand community and their impact on the diffusion process (purchase intention).
The findings of the study revealed that increased positive electronic word-of-mouth leads to enhanced purchase intention of members. Furthermore, the research has shown that higher identification with a social media brand community, greater engagement, increased entertainment value, faster corporate responsiveness, and reduced occurrence of social spam, do not have a positive effect on the diffusion process of innovative consumer durables.
The research focused on the wood pellet market for private consumers in Germany and has the objective to understand the factors affecting the purchase decisions of wood pellets buy-ers. The aims of the research were achieved by applying the Engel, Kollat, Blackwell model of consumer behaviour, by conducting in-depth interviews and deriving the grounded theory. The application of EKB model revealed that the following groups of factors may influence the con-sumers: cultural (culture and social class), social (family influence), personal (age and lifecycle stage), psychological (believes, motives, attitudes) and unexpected circumstances. In-depth interviews with the buyers of wood pellets helped specify the influencing factors to finally an-swer the research question. The analysis showed that the buyers of wood pellets are influ-enced by family, personal believes and attitudes, and the unexpected circumstances. The most important factors for the buyers are the quality of the pellets and reliability of the supplier. If they are satisfied with the quality of product and service, they will be reluctant to look for an alternative. And on the opposite side, in case the quality of the product or the service is unsat-isfactory this is a limiting factor and will stop the buyer from purchasing this product. Price is an important factor for the buyers of pellets in bags. However, in the situation of volatile mar-ket and exploding prices, the price factor will play a bigger role. Thus, the strategic factors for marketing of pellets is to concentrate on quality and price communication, and to focus on the quality of pellet delivery service.
Nowadays, online marketing is becoming increasingly important not only in the B2C but also in the B2B sector, as evidenced by marketing budget expenditures. Companies pursue overarching goals involving visibility and attention from prospective customers in order to raise brand awareness and as a result, outperform increasing market competition. This begs the question of whether online marketing is appropriate for increasing brand awareness.
The master´s thesis topic developed from both a personal as well as a professional perspective. Private research increased the author´s interest in the topic of online marketing. Furthermore, brands, whose level of awareness needs to be improved, are becoming a more common topic of professional debates. In this way, the research of the current master´s thesis was created.
The aim of this master's thesis was to discover how online marketing can be used to increase awareness of a brand. This will be analyzed by using the brand turn to zero, which offers consulting services for B2B customers in the sustainability industry. In this context, suitable and visible online marketing channels for increasing brand awareness are to be identified. In addition to this, suitable content for the company´s own as well as paid online marketing channels need to be collected. Furthermore, the influence that online marketing has on creating brand image awareness is to be presented.
Research questions are defined in order to achieve the described objectives. Within the scope of the master thesis, one main research question, as well as three sub-research questions, are to be answered based on the literature as well as the generated output resulting from the empirical part. Eight existing B2B customers of turn to zero, originating from com-mercial and industrial sectors, were interviewed in the empirical part. The interview findings were evaluated by using qualitative content analysis according to Mayring.
Research results showed that targeted combinations of online marketing channels are contributing to increase brand awareness. In addition, the research succeeded in determining suitable communication content for various online marketing channels. Furthermore, the in-fluence of online marketing could be investigated more closely in terms of brand image.
Startups usually have high growth ambitions but only limited resources. Therefore, they are looking for efficient and effective methods to grow their business. However, if they go interna-tional, challenging changes will likely be made if the company is not focused on the global market. The aim of this work is therefore to support startups in the internationalization of their business and to provide guidance from the beginning by using strategic marketing elements to facilitate this process. To achieve this, a qualitative method of analysis was chosen. First, a literature review was conducted on the relevant topics of a startup, strategic marketing, and internationalization. Five success factors emerged from the literature: commitment, strategy, research, marketing mix adaptation, and organization and network. These were then ana-lyzed in more detail in expert interviews. The analysis of the interview results shows that for the internationalization of startups, the commitment to internationalization and a global mindset is of great importance from the very beginning. This is because they influence all supporting and strategic marketing elements.
The number of electric vehicles will increase rapidly in the coming years. Studies suggest that most owners prefer to charge their electric vehicle at home, which will fuel the need for charging stations in residential complexes where vehicles can be charged overnight. Currently, there already are over 100 such residential complexes, with another 70 added every year in Vorarlberg alone. In most existing residential complexes, however, the grid connections are not sufficient to charge all vehicles at the same time with maximum power. In addition, it is also desirable for grid operators and electricity producers that the power demand be as smooth and predictable as possible. To achieve this, ways to manage flexible loads need to be found, which can operate within the technical constraints. Therefore, the most common scenarios how the load can be made grid-friendly with the help of optional battery storage and/or photovoltaics using optimization methods of linear and stochastic programming were examined. At the same time, the needs of the vehicle owners for charging comfort - namely to find their vehicles reliably charged at the time of their respective departure - were addressed by combining both objectives using suitable weights. The algorithms determined were verified in practice on an existing Vlotte prototype installation. For this purpose, the necessary programs were implemented in Python, so that the data obtained during the test operation, which lasted one month, could be subjected to a well-founded analysis. In addition, simulation studies helped to further reveal the influence of PV and BESS sizing on the achievable optimums and confirm that advanced optimization algorithms such as the ones discussed are a vital contribution in reducing the charging stations’ peak load while at the same time maintaining high satisfaction levels.
To create a map of an unknown area, autonomous robots must follow a strategy to explore the area without knowing the optimal paths to reduce the time needed to map the whole area. To reduce the time to accomplish this task, multiple robots can work together to create a map in a more efficient way. However, without proper coordination, the time a team of autonomous robots needs to explore the unknown area can exceed the time needed by a single robot. To counteract the challenges, a shared infrastructure is needed which extracts useful information for the individual robots out of the shared information of all robots so the exploration can be coordinated. These measures introduce new challenges to the system, concerning the load of the communication infrastructure as well as the overall task of exploring and mapping becoming dependent on the correct communication and robustness of the shared team infrastructure. Therefore, the amount of communication and dependency of each individual robot of the rest of the other robots of the team must be reduced to ensure that the robots can continue working even if the communication with the shared infrastructure fails.
Bubble column humidifiers (BCHs) are frequently used for the humidification of air in various water treatment applications. A potential but not yet profoundly investigated application of such devices is the treatment of oily wastewater. To evaluate this application, the accumulation of an oil-water emulsion using a BCH is experimentally analyzed. The amount of evaporating water vapor can be evaluated by measuring the humidity ratio of the outlet air. However, humidity measurements are difficult in close to saturated conditions, as the formation of liquid droplets on the sensor impacts the measurement accuracy. We use a heating section after the humidifier, such that no liquid droplets are formed on the sensor. This enables us a more accurate humidity measurement. Two batch measurement runs are conducted with (1) tap water and (2) an oil-water emulsion as the respective liquid phase. The humidity measurement in high humidity conditions is highly accurate with an error margin of below 3 % and can be used to predict the oil concentration of the remaining liquid during operation. The measured humidity ratio corresponds with the removed amount of water vapor for both tap water and the accumulation of an oil-water emulsion. Our measurements show that the residual water content
in the oil-water emulsion is below 4 %.
Grid-scale electrical energy storage (EES) is a key component in cost-effective transition scenarios to renewable energy sources. The requirement of scalability favors EES approaches such as pumped-storage hydroelectricity (PSH) or compressed-air energy storage (CAES), which utilize the cheap and abundant storage materials water and air, respectively. To overcome the site restriction and low volumetric energy densities attributed to PSH and CAES, liquid-air energy storage (LAES) has been devised; however, it suffers from a rather small round-trip efficiency (RTE) and challenging storage conditions. Aiming to overcome these drawbacks, a novel system for EES is developed using solidified air (i.e., clathrate hydrate of air) as the storable phase of air. A reference plant for solidified-air energy storage (SAES) is conceptualized and modeled thermodynamically using the software CoolProp for water and air as well as empirical data and first-order approximations for the solidified air (SA). The reference plant exhibits a RTE of 52% and a volumetric storage density of 47 kWh per m3 of SA. While this energy density relates to only one half of that in LAES plants, the modeled RTE of SAES is comparable already. Since improved thermal management and the use of thermodynamic promoters can further increase the RTEs in SAES, the technical potential of SAES is in place already. Yet, for a successful implementation of the concept - in addition to economic aspects - questions regarding the stability of SA must be first clarified and challenges related to the processing of SA resolved.
As the boundary between real and virtual life is becoming increasingly blurred, researchers and practitioners are looking for ways to integrate the two intending to improve human lives in a plethora of domains. A cutting-edge concept is the design of Digital Twins (DT), having a broad range of implications and applications, spanning from education, training, as well as safety and productivity in the workplace. An emergent approach for implementing DTs is the usage of mixed reality (MR) and augmented reality (AR), which are well aligned with merging real and virtual objects to enhance the human’s ability to interact with and manage DTs. Yet, this is still a novel area of research and, as such, a grounded understanding of the current state, challenges, and open questions is still lacking. Towards this, we conducted a PRISMA-based literature review of scientific articles and book chapters dealing with the use of MR and AR for digital twins. After a thorough screening phase and eligibility check, 25 papers were analyzed, sorted and compared by different categories like research topic (e.g., visualization, guidance), domain (e.g., manufacturing, education), paper type (e.g., design study, evaluation), evaluation type (user study, case study or none), used hardware (e.g., Microsoft HoloLens, mobile devices) as well as the different outcomes (result type and topic, problems, outlook). The major finding of this research survey is the predominant focus of the reviewed papers on the technology itself and the neglect of factors regarding the users. We, therefore, encourage researchers in this area to keep the importance of ease and joy of use in mind and include users in multiple stages of their work.
PV hosting capacity provides utilities the knowledge of the maximum amount of solar installations possible to accommodate in low voltage grids such that no operational problems arise. As the quantification of the hosting capacity requires data collection, grid modelling, and often time-consuming simulations, simplified estimations for large-scale applications are of interest. In this paper, Bayesian statistical inference is applied to estimate the hosting capacities of more than 5000 real feeders in Austria. The results show that the hosting capacity of 95% of the total feeders can be estimated with a mean error below 20% by only having knowledge of a random sample of 5%. Moreover, the hosting capacity estimation at a regional level shows a maximum error below 9%, also relying on a random sample of 5% of the total feeders. Furthermore, the approach proposed provides a methodology to assess new parameters aiming to improve the accuracy of the hosting capacity estimation at a feeder level.
The impact of global warming and climate change has forced countries to introduce strict policies and decarbonization goals toward sustainable development. To achieve the decarbonization of the economy, a substantial increase of renewable energy sources is required to meed energy demand and to transition away from fossil fuels. However, renewables are sensitive to environmental conditions, which may lead to imbalances between energy supply and demand. Battery energy storage systems are gaining more attention for balancing energy systems in existing grid networks at various levels such as bulk power management, transmission and distribution, and for end-users. Integrating battery energy storage systems with renewables can also solve reliability issues related to transient energy production and be used as a buffer source for electrical vehicle fast charging. Despite these advantages, batteries are still expensive and typically built for a single application – either for an energy- or power-dense application – which limits economic feasibility and flexibility. This paper presents a theoretical approach of a hybrid energy storage system that utilizes both energy- and power-dense batteries serving multiple grid applications. The proposed system will employ second use electrical vehicle batteries in order to maximise the potential of battery waste. The approach is based on a survey of battery modelling techniques and control methods. It was found that equivalent circuit models as well as unified control methods are best suited for modelling hybrid energy storages for grid applications. This approach for hybrid modelling is intended to help accelerate the renewable energy transition by providing reliable energy storage.
Increasing electric vehicle penetration leads to undesirable peaks in power if no proper coordination in charging is implemented. We tested the feasibility of electric vehicles acting as flexible demands responding to power signals to minimize the system peaks. The proposed hierarchical autonomous demand side management algorithm is formulated as an optimal power tracking problem. The distribution grid operator determines a power signal for filling the valleys in the non-electric vehicle load profile using the electric vehicle demand flexibility and sends it to all electric vehicle controllers. After receiving the control signal, each electric vehicle controller re-scales it to the expected individual electric vehicle energy demand and determines the optimal charging schedule to track the re-scaled signal. No information concerning the electric vehicles are reported back to the utility, hence the approach can be implemented using unidirectional communication with reduced infrastructural requirements. The achieved results show that the optimal power tracking approach has the potential to eliminate additional peak demands induced by electric vehicle charging and performs comparably to its central implementation. The reduced complexity and computational overhead permits also convenient deployment in practice.
Violation-mitigation-based method for PV hosting capacity quantification in low voltage grids
(2022)
Hosting capacity knowledge is of great importance for distribution utilities to assess the amount of PV capacity possible to accommodate without troubling the operation of the grid. In this paper, a novel method to quantify the hosting capacity of low voltage grids is presented. The method starts considering a state of fully exploited building rooftop solar potential. A downward process is proposed - from the starting state with expected violations on the grid operation to a state with no violations. In this process, the installed PV capacity is progressively reduced. The reductions are made sequentially and selectively aiming to mitigate specific violations: nodes overvoltage, lines overcurrent and transformer overloading. Evaluated on real data of fourteen low voltage grids from Austria, the method proposed exhibits benefits in terms of higher hosting capacities and lower computational costs compared to stochastic methods. Furthermore, it also quantifies hosting capacity expansions achievable by overcoming the effect of the violations. The usage of a potential different from solar rooftops is also presented, demonstrating that a user-defined potential allows to quantify the hosting capacity in a more general setting with the method proposed.
Gaming as a cultural commons
(2022)
Traditional power grids are mainly based on centralized power generation and subsequent distribution. The increasing penetration of distributed renewable energy sources and the growing number of electrical loads is creating difficulties in balancing supply and demand and threatens the secure and efficient operation of power grids. At the same time, households hold an increasing amount of flexibility, which can be exploited by demand-side management to decrease customer cost and support grid operation. Compared to the collection of individual flexibilities, aggregation reduces optimization complexity, protects households’ privacy, and lowers the communication effort. In mathematical terms, each flexibility is modeled by a set of power profiles, and the aggregated flexibility is modeled by the Minkowski sum of individual flexibilities. As the exact Minkowski sum calculation is generally computationally prohibitive, various approximations can be found in the literature. The main contribution of this paper is a comparative evaluation of several approximation algorithms in terms of novel quality criteria, computational complexity, and communication effort using realistic data. Furthermore, we investigate the dependence of selected comparison criteria on the time horizon length and on the number of households. Our results indicate that none of the algorithms perform satisfactorily in all categories. Hence, we provide guidelines on the application-dependent algorithm choice. Moreover, we demonstrate a major drawback of some inner approximations, namely that they may lead to situations in which not using the flexibility is impossible, which may be suboptimal in certain situations.
This paper sought to identify and analyze what are the barriers towards women career’s development as business leaders in Brazil and Nicaragua when it comes to the country societal variables. In order to comprehend these barriers through women’s perception, qualitative data was chosen for this investigation, which was gathered through one-to-one interviews within businesswomen from Brazil and Nicaragua that have experience in leadership positions. The results of this research confirm that societal, economic, and political factors have great influence at gender equality and in how it affects women’s progress as business leaders. Thus, it can vary considerably between countries, even when they have similar culture backgrounds. Furthermore, it is imperative to comprehend these differences in order to close any gender gap in the field.
Observing the ratios of the rail usage in terms of passenger travelled per km and per capita, we see that there are huge differences between countries, so some railway systems are performing better in catching passengers than others. By analysing the factors that make the railways attractive for users, and setting standard values for these factors, we can analyse how well a system is performing. This paper has investigated those factors and developed an assessment tool that will inform about the required improvements, so in a later stage specific strategies can be developed to increase the performance in order to attract more passengers. Spain will be used as case study, since the country has specially low passenger rail usage compared to other countries even though the large investments in high speed lines the country undertook in the last decades.
The e-commerce market has been growing for years and this trend seems to be continuing. Online stores for clothing are very successful. It seems that hardly any company can afford not to have a digital presence. This goes hand in hand with the fact that the range of products on offer to customers is getting bigger and bigger. But it's not just the range that's getting bigger, it's also the effort customers have to make to find the right product. For this reason, many successful online stores are already relying on AI. In doing so, companies are creating opportunities for customers that an employee could hardly manage. Implemented on the website, AI can check inventory, update it in real time, predict trends and evaluate customer or user data and make suitable recommendations. This is important for the customer because with the huge choice available, for one thing, personalization is increasingly important and being presented with a relevant selection. A central question is whether the recommendations are trustworthy and whether they can be equated with a real salesperson advising the customer. After all, trust is relevant in longterm customer relationships in that it leads to loyalty and satisfaction, which in turn increases the intention to repurchase. The recommendation tools mentioned are also of particular interest for another reason. On the one hand, they help customers to get a relevant selection of the offer and thus to get faster to the desired one. On the other hand, they are relevant for companies not only because of customer satisfaction, but also because of the chance to reduce returns. The large online stores for clothing offer their customers very generous opportunities to return the goods free of charge. In doing so, the companies have responded to customer wishes, because hardly anything is more important to them when it comes to online shopping: free returns. In this way, customers have minimized the risk of having to keep goods that do not fit or please them. This thesis examines whether recommendation tools can help customers to better assess the sizes and properties of clothing, so that they receive more suitable clothing and do not even feel the need to order several sizes of the same item of clothing. It can therefore be assumed that trust in the recommendations of the AI tools reduces uncertainty, which in turn should reduce the intention to return goods. Another assumption to be tested is that of the perceived usefulness of the recommendation tools. As a prerequisite to get an assessment of these assumptions is the usage of the tools. Therefore, a survey was initiated in the DACH region to assess the extent to which usage influences the factors mentioned. It was found by means of a regression analysis that the frequency of online purchases, mediated by perceived usefulness, explains the influence on trust.
In recent years, numerous studies around the world have examined the environmental potential of biochar to determine whether it can help address climate challenges. Several of these studies have used the Life Cycle Assessment (LCA) method to evaluate the environmental impacts of biochar systems. However, studies focus mainly on biochar obtained from pyrolysis, while the number of studies on biochar from gasification is small.
To contribute to the current state of LCA research on biochar from gasification, LCA was performed for biochar, electricity, and heat from a wood gasification plant in Vorarlberg, Austria. Woodchips from local woods are used as biomass feedstock to produce energy, i.e., electricity and heat. Thereby, biochar is obtained as a side product from gasification. The production of syngas and biochar takes place in a floating fixed-bed gasifier. Eventually, the syngas is converted to electricity in a gas engine and fed to the power grid. Throughout different stages within the gasification process, heat is obtained and fed into local heat grid to be delivered to customers. The biochar produced complies with the European Biochar Industry (EBI) guidelines and is used on a nearby farm for manure treatment and eventually for soil application. Thereby, the effect of biochar used for manure treatment is considered to reduce emissions occurring from manure, i.e., nitrogen monoxide (N2O). Further, the CO2 sequestration potential of biochar, i.e., removal of CO2 from the atmosphere and long-term storage, is considered. Several constructions, such as the construction of the gasification system and the heating grid, are included in the evaluation.
As input related reference flow, 1 kg of woodchips with water content of 40 % is used. Three functionals units are eventually obtained, i.e., 0.17 kg of biochar applied to soil, 4.47 MJ of heat and 2.82 MJ of electricity, each per reference flow. The results for Global Warming Potential (GWP) for biochar is – 274.7*10 - 3 kg CO2eq per functional unit, which corresponds to – 1.6 kg CO2eq per 1 kg biochar applied to soil. The GWP for heat results in 17.1*10 - 3 CO2eq per functional unit, which corresponds to 3.6*10 - 3 kg CO2eq per 1 MJ. For electricity, a GWP of 38.1*10 - 3 kg CO2eq per functional unit is obtained, which is equivalent to 13.5*10 - 3 kg CO2eq per 1 MJ.
The calculation was performed using SimaPro Version 9.1 and the ReCiPe method with hierarchist perspective.
Bubble columns are recently used for the humidification of air in water treatment systems and fuel cells. They are well applicable due to their excellent heat and mass transfer and their low technical complexity. To design and operate such devices with high efficiency, the humidification process and the impact of the operating parameters need to be understood to a sufficient degree. To extend this knowledge, we use a refined and novel method to determine the volumetric air–liquid heat and mass transfer coefficients and the humidifier efficiency for various parametric settings. The volumetric transfer coefficients increase with both of the superficial air velocity and the liquid temperature. It is further shown that the decrease of vapor pressure with an increase of the salinity results in a corresponding decrease in the outlet humidity ratio. In contrast to previous studies, liquid heights smaller than 0.1 m are investigated and significant changes in the humidifier efficiency are seen in this range. We present the expected humidifier efficiency with respect to the superficial air velocity and the liquid height in an efficiency chart, such that optimal operating conditions can be determined. Based on this efficiency chart, recommendations for industrial applications as well as future scientific challenges are drawn.
The electricity demand due to the increasing number of EVs presents new challenges for the operation of the electricity network, especially for the distribution grids. The existing grid infrastructure may not be sufficient to meet the new demands imposed by the integration of EVs. Thus, EV charging may possibly lead to reliability and stability issues, especially during the peak demand periods. Demand side management (DSM) is a potential and promising approach for mitigation of the resulting impacts. In this work, we developed an autonomous DSM strategy for optimal charging of EVs to minimize the charging cost and we conducted a simulation study to evaluate the impacts to the grid operation. The proposed approach only requires a one way communicated incentive. Real profiles from an Austrian study on mobility behavior are used to simulate the usage of the EVs. Furthermore, real smart meter data are used to simulate the household base load profiles and a real low voltage grid topology is considered in the load flow simulation. Day-ahead electricity stock market prices are used as the incentive to drive the optimization. The results for the optimum charging strategy is determined and compared to uncontrolled EV charging. The results for the optimum charging strategy show a potential cost saving of about 30.8% compared to uncontrolled EV charging. Although autonomous DSM of EVs achieves a shift of load as pursued, distribution grid operation may be substantially affected by it. We show that in the case of real time price driven operation, voltage drops and elevated peak to average powers result from the coincident charging of vehicles during favourable time slots.
If left uncontrolled, electric vehicle charging poses severe challenges to distribution grid operation. Resulting issues are expected to be mitigated by charging control. In particular, voltage-based charging control, by relying only on the local measurements of voltage at the point of connection, provides an autonomous communication-free solution. The controller, attached to the charging equipment, compares the measured voltage to a reference voltage and adapts the charging power using a droop control characteristic. We present a systematic study of the voltage-based droop control method for electric vehicles to establish the usability of the method for all the currently available residential electric vehicle charging possibilities considering a wide range of electric vehicle penetrations. Voltage limits are evaluated according to the international standard EN50160, using long-term load flow simulations based on a real distribution grid topology and real load profiles. The results achieved show that the voltage-based droop controller is able to mitigate the under voltage problems completely in distribution grids in cases either deploying low charging power levels or exhibiting low penetration rates. For high charging rates and high penetrations, the control mechanism improves the overall voltage profile, but it does not remedy the under voltage problems completely. The evaluation also shows the controller’s ability to reduce the peak power at the transformer and indicates the impact it has on users due to the reduction in the average charging rates. The outcomes of the paper provide the distribution grid operators an insight on the voltage-based droop control mechanism for the future grid planning and investments.
In recent years, ultrashort pulsed lasers have increased their applicability for industrial requirements, as reliable femtosecond and picosecond laser sources with high output power are available on the market. Compared to conventional laser sources, high quality processing of a large number of material classes with different mechanical and optical properties is possible. In the field of laser cutting, these properties enable the cutting of multilayer substrates with changing material properties. In this work, the femtosecond laser cutting of phosphor sheets is demonstrated. The substrate contains a 230 micrometer thick silicone layer filled with phosphor, which is embedded between two glass plates. Due to the softness and thermal sensitivity of the silicone layer in combination with the hard and brittle dielectric material, the separation of such a material combination is challenging for both mechanical separation processes and cutting with conventional laser sources. In our work, we show that the femtosecond laser is suitable to cut the substrate with a high cutting edge quality. In addition to the experimental results of the laser dicing process, we present a universal model that allows predicting the final cutting edge geometry of a multilayer substrate.
Entangled photon generation at 1550 nm in the telecom C-band is of critical importance as it enables the realization of quantum communication protocols over long distance using deployed telecommunication infrastructure. InAs epitaxial quantum dots have recently enabled on-demand generation of entangled photons in this wavelength range. However, time-dependent state evolution, caused by the fine-structure splitting, currently limits the fidelity to a specific entangled state. Here, we show fine-structure suppression for InAs quantum dots using micromachined piezoelectric actuators and demonstrate generation of highly entangled photons at 1550 nm. At the lowest fine-structure setting, we obtain a maximum fidelity of 90.0 ± 2.7% (concurrence of 87.5 ± 3.1%). The concurrence remains high also for moderate (weak) temporal filtering, with values close to 80% (50%), corresponding to 30% (80%) of collected photons, respectively. The presented fine-structure control opens the way for exploiting entangled photons from quantum dots in fiber-based quantum communication protocols.
Arrayed Waveguide Grating (AWG) is a passive optical component, which have found applications in a wide range of photonic applications including telecommunications and medicine. Silica-on-Silicon (SoS) based AWGs use a low refractive-index contrast between the core (waveguide) and the cladding which leads to some significant advantages such as low propagation losses and low fiber coupling losses between the AWG waveguides and the fibres. Therefore, they are an attractive DWDM solution offering higher channel count technology and good performance characteristics compared to other methods. However, the very low refractive-index contrast means the bending radius of the waveguides needs to be very large (on the order of several millimeters) and may not fall below a particular critical value to suppress bending losses. As a result, silica-based waveguide devices usually have a very large size that limits the integration density of SiO2-based photonic integrated devices. High-index contrast AWGs (such as silicon, silicon nitride or polymer-based waveguide devices) feature much smaller waveguide size compared to low index contrast AWGs. Such compact devices can easily be implemented on a chip and have already found applications in emerging applications such as optical sensors, devices for DNA diagnostics and optical spectrometers for infrared spectroscopy.In this work, we present the design, simulation, technological verification and applications of both, the low-index contrast and high-index contrast AWGs. For telecommunication applications AWG-MUX/Demux with up to 128-channels will be presented. For medical applications the AWG-spectrometer with up to 512-channels will be presented.This work was carried out in the framework of the projects: ADOPT No. SK-AT-20-0012, NOVASiN No. SK-AT-20-0017 and AUTOPIC No. APVV-17-0662 from Slovak research and development agency of Ministry of Education, Science, Research and Sport of the Slovak Republic and No. SK 07/2021 and SK 08/2021 from Austrian Agency for International Cooperation in Education and Research (OeAD-GmbH); and project PASTEL, no. 2020-10-15-001, funded by SAIA.
A Telecom optical fibers are still being the best transmission medium of digital data and analogue signals for long distance applications. Progress in integrated photonics enables development of photonic chips with new unique properties, circuits of the future, and overcomes current limits in information and communication technologies. The packaging of photonic chips is necessary for taking them out of research laboratories into real implementation in the information and communication technology applications. One important step of packaging is effective coupling of optical radiation between telecom optical fiber with ten microns core dimension and photonic chip optical waveguide with submicron dimensions. For complex photonic chips, it is necessary to couple not one optical fiber but several optical fibers, which are arranged in fiber arrays. In this case, it is necessary to use a 6D positioning system, which allows to optimally adjust the relative position of the photonic chip and the fiber arrays. After setting the optimal relative position of the photonic chip and the fiber array, the process of their fixation follows. One possibility of fixation is gluing with an adhesive in the optical path between the photonic chip and an array of optical fibers with a refractive index close to the refractive index of the optical fiber core. This paper is focused on the experimental test set-up for the temperature characterization of fiber array to photonics chip butt coupling at 1310 nm and 1550 nm wavelengths fixed themselves by UV adhesive in the optical path. The main aims of this works are selection of better adhesive from two types for gluing of photonic chip and fiber array in packaging process of photonics chips and validation of gluing process developing. The coupling and alignment of fiber arrays to photonics chip were done by automated active alignments system and they were fixed themselves by curable epoxy adhesive. Temperature changes of coupling insertion losses are measured and investigated for two different UV adhesives during three temperature cycles from -40 °C to 80 °C in climatic chamber according to Telcordia. Spectral dependence of insertion losses were measured and compared before and after three temperature cycles for 1530 nm to 1570 nm spectral range at room temperature.
This work was supported by the Slovak Research and Development Agency under the contracts APVV-17-0662 and SK-AT-20-0017 and by the COST Action “European Network for High Performance Integrated Microwave Photonics” (EUIMWP) CA16220.
In this paper, design of 1×8 multimode interference passive optical splitter is proposed. The structure of the splitter is designed based on a silicon nitride material platform. This work aims to find the minimum physical dimensions of the designed splitters with the satisfactory optical performance. According to the minimum insertion loss and minimum non-uniformity, the optimum length of the splitters is determined.
Femtosecond laser ablation on Si generates 2D ripple structures, known as laser induced periodic surface structures (LIPSS) and pinholes. We fabricated membranes with 20 to 50 μm thickness perforated by an array of tapered pinholes up to 5 μm in diameter and 10 to 20 μm spacing. Within several micrometer the pinholes transform into hollow photonic waveguides with constant diameter from 1μm to 2μm. Such structures offer a 3D photonic coupling device for polymer Y-branch- and MMI-splitter. We measured a considerable change of electrical resistivity for 500 ppm H2 in air using Si/SiO2/TiO2 substrates with 2D LIPSS. We propose to investigate 3D waveguide arrays also for photonic-chemical sensors.
In this paper we report on the experimental test set-up for the temperature characterization of fiber array to photonics chip butt coupling at 1310 nm and 1550 nm wavelengths. The alignment and gluing of fiber arrays to photonics chip were done by automated active alignments system and they were fixed themselves by UV curable epoxy adhesive. Temperature changes of coupling insertion losses are measured and investigated for two different UV adhesives during three temperature cycles from -40 °C to 80 °C in climatic chamber. Spectral dependence of insertion losses was measured and compared before and after three temperature cycles for 1530 nm to 1570 nm spectral range at room temperature.
We present design, simulation and optimization of polymer based 16-channel, 100-GHz AWG designed for central wavelength of 1550 nm. The input design parameters were calculated applying AWG-Parameters tool. The simulations were performed applying a commercial photonic tool PHASAR from Optiwave. The achieved transmission characteristics were evaluated by AWG-Analyzer tool and show a satisfying agreement between designed and simulated AWG optical properties. Finally, the influence of the number of phased array (PA) waveguides on the AWG performance was studied. The results show that there is a certain minimum number of PA waveguides necessary to reach sufficient AWG performance.