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Liquid deposition modeling is an energy-efficient, additive manufacturing process for pasty materials. Physical material properties were determined for a water-based paste consisting of the binder carboxymethyl cellulose and wood flour. A continuously operating dual screw extruder was developed, which was used to manufacture a table frame with a height of 18 cm.
Based on a real-world application in the semiconductor industry, this article models and discusses a hybrid flow shop problem with time dependencies and priority constraints. The analyzed problem considers a production where a large number of heterogeneous jobs are processed by a number of machines. The route that each job has to follow depends upon its type, and, in addition, some machines require that a number of jobs are combined in batches before starting their processing. The hybrid flow model is also subject to a global priority rule and a “same setup” rule. The primary goal of this study was to find a solution set (permutation of jobs) that minimizes the production makespan. While simulation models are frequently employed to model these time-dependent flow shop systems, an optimization component is needed in order to generate high-quality solution sets. In this study, a novel algorithm is proposed to deal with the complexity of the underlying system. Our algorithm combines biased-randomization techniques with a discrete-event heuristic, which allows us to model dependencies caused by batching and different paths of jobs efficiently in a near-natural way. As shown in a series of numerical experiments, the proposed simulation-optimization algorithm can find solutions that significantly outperform those provided by employing state-of-the-art simulation software.
The role accomlished by Major Histocompatibility Complex (MHC) molecules in initiating and regulating immune respouses, binding short pepticles and displaying them on the cell surface for recoguition by Tiell receptors, is of the atmost importance in immunlogogy. However, only a subset of peptider is capable of binding to any particular MHC molecule. The study was undertaken to rationalize MHC/ peptide interactions in terms of molecular structural requirements for the prediction of class I MHC buding peptides. Prediction of buding activities by means of computational methods can minimize experimental assays, and lead to the development of vaceines and immune-therapeutie drugs.
BIM (Building information modeling) is becoming a reliable method for the planning, design, implementation, and maintenance stages of construction projects due to its ability to improve the quality of project stages, reduce project time, and ensure costs. From 2000 onwards, the trend of using BIM method increased in the world. And in the last decade, many developed countries have introduced BIM as a reasonable and efficient method with the aim of optimizing project stages, and many employers have paid attention to training and persuading consulting and contracting companies.
In the meantime, the BIM method is constantly being updated. Many researchers are looking to modify existing sub-methods to help the project achieve all of the great BIM goals.
Although BIM has great goals such as those mentioned, in some cases, projects are not able to achieve all of them for various reasons.
This thesis has put its hypothesis on the existence of deficiencies in the content of the EIR (Employer's Information Requirements) document and its writing methods.
This document, which is a kind of project guide in BIM format, is compiled by the client and its task is to announce the needs of the client to the members involved in the project and to clarify the different stages of the project. In many construction projects, due to the complexity of the EIR, the employer's lack of attention to some information, or the failure to include the opinions and views of the project's stakeholders in the writing of this document, the EIR cannot fulfill its key role with its maximum potential performance in the project.
This thesis is written with the aim of finding a comprehensive solution to maximize the power of the BIM method in a project through correct and complete document writing.
Also, this thesis seeks to prove its claims by focusing on the ABS 38 project as a case study. In addition, a literature review on important and key issues in the field of BIM and EIR documents has been done. After that, a scoring system (Relative rating method) was used to find the best variant and compare it to prove the proposed hypothesis.
Since Carbon emissions are soaring all over the atmosphere, the world suffers from significant problems daily. It has become apparent that reliance on single occupancy vehicle transportation is unsustainable, expensive, and primarily harmful to humankind. Rural areas are frequently abandoned while expanding
transportation infrastructure as urbanisation grows. In rural areas, a lack of adequate and inexpensive transportation options leads to seclusion and restricted access to products, facilities, and job opportunities.
This study explores the potential of alternative transportation methods to improve mobility in rural areas. The objectives of the research are to expand knowledge on sustainable alternative transportation in rural regions and to offer practical solutions for enhancing accessibility and mobility for rural residents.
The study employed a mixed-method approach, including a literature review, a survey, and interviews with participants in two rural regions, Mosel and Oberrothenbach. The findings suggest that the transportation challenges faced by rural inhabitants can be effectively and sustainably addressed through walking and by using alternative transportation modes, such as cycling and public transit. This thesis provides a range of ideas and strategies to improve regulations, programs, and infrastructure related to alternative transportation modes in rural areas. This study dives into the characteristics and requirements
of these places using a combination of quantitative and qualitative surveys done in representative two rural regions to recommend successful alternative transportation solutions of On-Demand Transport Services and Electric or Trolley bus Services for daily commutes. The findings underline the need for flexible, multimodal, and on-demand transit choices, as well as the need for community participation and technology integration.
A novel approach to consider triaxial tensile stresses within the framework of a failure criterion
(2022)
For use in micromechanical simulations of continuous fiber reinforced polymers, a more general form of the paraboloid failure criterion by Stassi‐D'Alia for matrix failure was developed with explicit consideration of the hydrostatic tension strength. Regarding polymers, limits for hydrostatic tensile strength based on isotropic linear elasticity could be derived. The comparison of the newly developed extended paraboloid criterion with experimental data for yielding as well as for material separation (fracture) shows good agreement.
The purpose of this article is to revise the literature on how theories have been utilized in investigating third-parties (for example, Non-Governmental Organizations, certifying organizations, among others) in Sustainable Supply Chain Management. Based on that, we derive future research directions. For revising the literature in a structured manner, the articles use the systematic literature review as the method of choice. Only half of the identified articles utilize theories for investigating third-parties in Sustainable Supply Chain Management. In addition, major theories are overweighed. This predomination leads to influencing the conceptualization of third-parties in Sustainable Supply Chain Management. Future research opportunities exist in broadening the utilization of theories and methods applied in the field, investing in under-explored aspects and broadening the scope of testing and building frameworks. Based on the synthesizing, propositions supplement future research directions. The novelty of this article lies in its investigation of how theories have been used in investigating and conceptualizing third-parties in Sustainable Supply Chain Management. By that, it contributes with a state-of-the-art view on the important topic of sustainability and how third-parties could solve sustainability challenges. With that, the article is a first attempt and step for extending the academic literature and practice with rethinking classic ways of managing sustainability and utilize out of the box ideas.
Despite lacking sufficient evidence, the shift to automated mobility has often been regarded as progress towards a safer road transport system. Following the introduction of the first production car that has been officially certified as Level 3 earlier in 2022, the driver can shift their role to only as a fallback when the automated driving system reaches its limit of the Operational Design Domain. In the event of an accident, though, the matter will only get even more complicated, especially in the process of unravelling the party that was performing the Dynamic Driving Task at the time of the collision. An accident investigation is done to provide insight into how it occurred and uncover the liable parties. This thesis reviews various methods reconstructing an accident scene, such as photogrammetry and laser scanning, as well as elaborating the relevant data that has already available in the vehicle and from the infrastructure. Recommendations are also presented on for the future data collection, specifically in the scenario of automated driving, to improve such practice.
Active Traffic Management Systems – Developing a Package of Measurements for the City of Füssen
(2021)
Intelligent Transportation Systems (ITS) and Active Transportation and Demand Management (ATDM) are new commanders in the world of transportation engineering. The combination of ATDM and ITS has created a concept called “Active Traffic Management (ATM)”. The world’s ATM is getting a higher point for major technological changes that have been bringing new ways in public and private transport managing, decision making, smart cities, traffic control, safety and environment.
The management, control, influence of travel demand and traffic flow in transportation facilities is referred to as ATM. Actions are taken in real time to improve system performance, such as preventing or delaying breakdown conditions, enhancing safety, encouraging sustainable travel modes or cutting emissions, using archived data and or/predictive methods.
In this Master's thesis, it has been exanimated the prominent different areas of Active Traffic Management in traffic engineering with a special focus on the sections of traffic management, signal control, and simulations with the program VISSIM. To discuss this issue, this paper begins with a brief introduction of the names and concepts of the current technologies in ATM, followed by an example. Important data and challenges for the study case of the city of Füssen in Germany will be presented in the text, subsequent to some results, conclusions and recommendations. In addition, the current and alternative scenarios with their respective level of service are researched according to German regulations. A simulation of different nodes has been modeled to observe the respective delays, level of services and emissions of the intersections selected in the city.
Keywords
Traffic Engineering, Intelligent Transportation Systems (ITS), Active Traffic Management (ATM), Level of Service (LOS) and Traffic Simulation.
As one of the key technologies involved in communication networks, all-optical switching has witnessed many research efforts during the last decade. This work presents a detailed investigation of the properties and attractive interaction of spatial solitons in nematic liquid crystals for all-optical switching devices. This includes a description of basic properties such as their multimode behavior, as well as their power dependent interactions and signal steering. Furthermore, the temporal performance of an all-optical switching setup is analyzed and discussed. Thanks to their long-range, phase and wavelength independent interactions at milliwatts powers, and despite their slow response time in switching applications, nematicons proved to be an extremely promising testbed for soliton-based devices, including signal waveguides and power-dependent spatial steering devices.
Structures made of the thermoplastic polymer polyether ether ketone (PEEK) are widely used in dynamically-loaded applications due to their high-temperature resistance and high mechanical properties. To design these dynamic applications, in addition to the well-known stiffness and strength properties the vibration-damping properties at the given frequencies are required. Depending on the application, frequencies from a few hertz to the ultrasonic range are of interest here. To characterize the frequency-dependent behavior, an experimental approach was chosen and applied to a sample polymer PEEK. The test setup consists of a piezoelectrically driven base excitation of the polymeric specimen and the non-contact measurement of the velocity as well as the surface temperature. The beam’s bending vibrations were analyzed by means of the Timoshenko theory to determine the polymer’s storage modulus. The mechanical loss factor was calculated using the half-power bandwidth method. For PEEK and a considered frequency range of 1 kHz to 16 kHz, a storage modulus between 3.9 GPa and 4.2 GPa and a loss factor between 9 × 10−3 and 17 × 10−3 were determined. For the used experimental parameters, the resulting mechanical properties were not essentially influenced by the amplitude of excitation, the duration of excitation, or thermal degrad.ation due to self-heating, but rather slightly by the clamping force within the fixation area.
Analgesic drug use of recreational and competitive badminton players: Starting points for prevention
(2021)
Analysis of a Film Forming Process through Coupled Image Correlation and Infrared Thermography
(2022)
The aim of the present investigation was to determine the dependence of the material and process parameters of the bending process of thermoplastic films. In this context, parameter combinations leading to high resulting forming ratios were identified. To measure the relevant parameters within the hot bending process, a coupled evaluation of infrared thermography (IRT) and deformation measurement using digital image correlation (DIC) was performed. The coupled measurement enables the identification of the actual mechanically stressed bending area of the film as a result of the bending process. This allows for the specification of the local forming temperatures required for the desired forming ratios. Furthermore, the mechanical and thermal strain along the defined measuring sections and their deviation in individual tests as well as the effect of thermal strain on process control on a larger scale were determined. Based on the results, a process window was defined for the film materials investigated, which will serve as a starting point for future efforts to develop a continuous manufacturing process.
The use of fossil resources must be phased out during the next decades in order to stay below a well below 2°C trajectory adopted with the Paris Agreement. The growing threat of climate changes arises large uncertainties concerning natural and social systems and induced changes on economic activities and human welfare in the 21st century. As recent climate negotiations failed to achieve significant progress to stop the climate change, GHG emissions fragmented the international communities. Total carbon dioxide (CO2) concentration is at the highest levels ever recorded. Since, it is very important to differentiate the total CO2 and its origin.
Evidently, CO2 has been identifed as the most important GHG because it contributes the largest share to the anthropogenic increase of radiative forcing and grows fastest. Anthropogenic sources of CO2 emissions are fossilfuel combustion (FFC), cement production, traditional biomass combustion and land use change, which contain chlorouorocarbons, hydrochlorouorocarbons and others. Where Biogenic CO2 emission sources are fermentation, biogas and other biological process. Compare to atropogenicsource with high purity.
The thesis provides an improved overview of R&D, pilot, demonstration and commercial projects that capture CO2 from biogas plants and other biogenic sources and subsequently put this carbon to further use. Best practices in terms of business models and GHG saving potentials are described. The CO2 emissions mitigation are related to the innovation, technologies, investment and moreover the strong policies from the Government
With the launch of a new vehicle model Rolls-Royce Motorcars had to face a dramatic volume increase from 300% more cars being build in existing structure and facilities in the Test and Finish Area. This massive volume increase required a revisiting of the process flow of cars through this Test and Finish Area to show optimisation potential and possible improvements to work packages and sequence of operation. Furthermore it will be necessary to implement those improvements to cope increased future throughput targets. To find optimisation and improvement potentials it was essential to analyse the entire area. In doing so every single station and work package was analysed. In addition to this a simulation model was used to confirm the highlighted problems and bottlenecks. Furthermore it was possible to investigate the influence of certain measures. In a following step it was the aim to show a way how a permanent and stable vehicle flow is achievable. According to that an action plan was developed, which shows clear measures to cope not only future but also the current production volume. In doing so it was possible to gain a transparency into the processes. Furthermore the process flow was optimised into a pull strategy to improve respectively implement a takt adherence.
Analysis of Traffic Management using Microscopic Simulation and Markov chain Modeling in Hyderabad
(2022)
Many developing countries around the world have been affected by globalization. India is one of the countries that has gained the most benefits. Hyderabad is the capital of the Indian state of Telangana. Because of population growth and the migration of people from rural to urban areas, traffic in Hyderabad is rapidly expanding. With commercial enterprise quarters, purchasing departmental stores, schools, and hospitals, Hyderabad has evolved into a financial hub. As a result, the number of people who own and use automobiles is increasing. Traffic congestion and regular traffic jams have become widespread in central areas, as they have traffic gridlocks on major corridors. The majority of the city’s transportation needs are currently met by bus transit (42 percent), the Multimodal Transport System (MMTS) based on the rail (1.5 percent), vehicles with three and seven seats (8 percent), and two and four-wheeled private automobiles (48.5 percent). Hyderabad is located at a crossroads of three national highways that connect it to six other states. The primary purpose of this article is to understand the city’s existing traffic challenges, find solutions that have been effectively adopted in established cities, and discuss the many projects and actions undertaken by local authorities to manage traffic congestion issues.
Traffic congestion can occur in any mode of transportation, but we focused on traffic congestion on the road network caused by vehicles. Lower velocity, lengthier travels, and car queuing for an extended period are some of the characteristics that distinguish street networks. In this paper, the causes of traffic congestion are identified, including illegal parking, traffic rules, seasonal factors, pavement failures, encroaching on footpaths, the passage of heavy goods vehicles on narrow roads, accidents, and incorrect lane management, as well as remedial measures to reduce congestion at the study location of Hyderabad.
The thesis analysis the car parks’ elements and the factors that influence the drivers’ behaviour on them. Then makes an approach to the definition of the strategy of how the car drivers search for free parking spaces. The reason for it is that there is a need to assess car parks’ design parameters in the terms of their performance. One of the decisive factors is also the drivers’ behaviour. A car park simulation based on the environment of matrices is designed and implemented in MATLAB. The algorithm for searching for the parking spaces is designed and implemented within that as well. The results of the simulation are presented.
This paper provides a critical reading of Janek Wasserman’s The Marginal Revolutionaries: How Austrian Economists Fought the War of Ideas. Wasserman depicts the evolution of the Austrian School from the 1860s until today, a particularly illuminating narrative for the readers of this journal. The breadth of portrayed economists, their cultural embeddedness in Austrian and US contexts, and the complexity of configurations across the school’s generations create a rich and readable story. The last third of the book suffers from allegations about the ideological agenda and institutional power of the Austrian economists which sometimes lack sufficient substantiation. The paper indicates how both in their theorizing and in their political activities, the Austrian economists can be seen as reformers instead of revolutionaries, and as constitutionalists instead of anti-democrats. Despite these disagreements, Wasserman’s portrayals evoke largely fair and challenging impulses both to scholars working in the Austrian research program and to those interested in the Austrian School’s long history, regardless of one’s ideological positions.
The traffic calming measures aim to slow down traffic speed, accident frequency, and reduction of through traffic caused mainly by motorized vehicles in residential areas. These measures are primarily addressed to the specific streets and lead the necessary or remaining traffic to drive in a restrained or considerate manner. While these measures are designed to prevent conflicts between pedestrians and motorists, they impose unstable traffic patterns and are sometimes unable to accommodate the increasing motor vehicle flows, as they are concentrated only on certain streets.
This paper investigates area-wide urban traffic calming techniques from existing projects. It explains how traffic regulatory and structural measures link together or separately to restrict the movement of motor vehicles traveling through neighborhood streets and divert them to main roads. The implemented sample measures were illustrated and described with photos of their current locations.
In this thesis, the district Äußere Neustadt was defined as a model area in Dresden to analyze and redesign the existing mobility plan in order to reduce the MIV flows with the main objectives of giving space for pedestrians, cyclists, and public transport. The district's street infrastructure is heavily impacted by the presence of parked vehicles, raising challenges to the safe movement of both bicyclists and oncoming motor vehicles. In the frame of the model project initiative - "Woche des guten Lebens", the volunteer team has designed a traffic experiment and carried out an online survey to assess citizens' opinions of the Äußere Neustadt. The analyses demonstrate and emphasize the necessity of political support and interactive communication with citizens regarding the area-wide radical sustainable mobility plan. Considering the positive feedback of the citizens, the new mobility plan was realized in this paper.
Area-specific traffic calming techniques such as diagonal or cross barriers, zone speed limits, offsets, one-way streets, etc. were analyzed from the implemented projects to determine the appropriate solutions for the specified streets. The district's existing traffic network and the new solutions offered were visualized using QGIS software.
The implemented new traffic plan will lead to more space for pedestrians and bicycle traffic and a reduction in traffic noise.
Objective: Sagittal balance (SB) plays important role in the successful treatment of spinal disorders. Segmental lordosis is an important SB parameter in spinal surgery and diagnosis, which can help to ensure proper surgical planning and better postoperative outcomes. The manual measurement of segmental lordosis is associated with problems such as time-consuming procedures, high error rates, and poor reproducibility.
The bachelor thesis proposes a solution by exploring and evaluating a more efficient and reliable AI-based method for determining segmental lordosis in preoperative patients, which is compared to measurements made by experienced physicians.
Methods: hidden due to a non-disclosure agreement.
Results: hidden due to a non-disclosure agreement.
Conclusions: hidden due to a non-disclosure agreement.
Hypotrochoidal profile contours have been produced in industrial applications in recent years using two-spindle processes, and they are considered effective high-quality solutions for form-fit shaft and hub connections. This study mainly concerns analytical approaches to determine the stresses and deformations in hypotrochoidal profile shafts due to pure bending loads. The formulation was developed according to bending principles using the mathematical theory of elasticity and conformal mappings. The loading was further used to investigate the rotating bending behaviour. The stress factors for the classical calculation of maximum bending stresses were also determined for all those profiles presented and compiled in the German standard DIN3689-1 for practical applications. The results were also compared with the corresponding numerical and experimental results, and very good agreement was observed. Additionally, based on previous work, the stress factor was determined for the case of torsional loading to calculate the maximum torsional stresses in the standardised profiles, and the results are listed in a table. This study contributes to the further refinement of the current DIN3689 standard.
This paper presents an analytical method for determining the bending stresses and deformations in prismatic, noncircular profile shafts with trochoidal cross sections. The so-called higher trochoids can be used as form-fit shaft-hub connections. Hybrid (mixed) higher trochoids (M-profiles) were developed for the special application as a profile contour for the form-fit shaft and hub connections in an earlier work by the author. M-profiles combine the advantages of the two standardised polygonal and spline contours, which are used as shaft-hub connections for the transmission of high torques. In this study, the geometric and mechanical properties of the higher hybrid trochoids were investigated using complex functions to simplify the calculations. The pure bending stress and shaft deflection were determined for M-profiles using bending theory based on the theory of mathematical elasticity. The loading cases consisted of static and rotating bends. Analytical, numerical, and experimental results agreed well. The calculation formulas developed in this work enable reliable and low-cost dimensioning with regard to the stresses and elastic deformations of profile shafts subjected to bending loads.
Between Clash of Civilizations and Global Identity - the Interdependence of Culture and Economics
(2019)
Our life is becoming faster, more connected and more global - this developments have a lot of positive but also negative effects. Being fearful towards the "different" is a growing phenomenon and the question arises of we heading towards a global identity or a clash of civilizations, which factors play the important parts and how did they come into existence. By using North African immigration in France as an example, an approach is made to put this topic in a smaller context in order to see where the scenario is heading to and what is conducive and/or detrimental.
Railways is one of the most important ways of transporting people and goods from place to another in the whole world. In Germany, it comes as the second most used way of transport. The German railways network is so big and covers the whole maps of Germany. That is why it is so important to develop and improve the performance of it. At this thesis work, the performance of every route at the German railways is calculated using a digital model which is created in PTV Visum software using the programming language python. Furthermore, the workload of every node (junction) at the German Railways is calculated, and according to that, recommendations to build an overpass structure at the overloaded Junctions is suggested to improve the capacity of this Junctions.
Die Diplomarbeit umfasst die Analyse der für den Prüfstand notwendigen Geräte, den Aufbau des Prüfstandes und die Programmierung von kundenspezifischen Applikationen mittels LabVIEW.
The objective of this work is to provide some useful tools to foreign investors intentioned to make business in Turkey, giving a general overview of the country. Political, economic, social as well as environmental characteristics are described in order to give a global point of view on this emerging market. Besides, four selected industrial sectors are analyzed and possible business opportunities for each sector have been indicated. In this sense, some considerations on the potentialities of Turkish market are given on the basis of two chances and risks profiles, one in the case that Turkey will become a full member of the European Union and the other in the case that it will maintain the actual status of simply associated partner.
Certifying Fully Dynamic Algorithms for Recognition and Hamiltonicity of Threshold and Chain Graphs
(2023)
Solving problems on graphs dynamically calls for algorithms to function under repeated modifications to the graph and to be more efficient than solving the problem for the whole graph from scratch after each modification. Dynamic algorithms have been considered for several graph properties, for example connectivity, shortest paths and graph recognition. In this paper we present fully dynamic algorithms for the recognition of threshold graphs and chain graphs, which are optimal in the sense that the costs per modification are linear in the number of modified edges. Furthermore, our algorithms also consider the addition and deletion of sets of vertices as well as edges. In the negative case, i.e., where the graph is not a threshold graph or chain graph anymore, our algorithms return a certificate of constant size. Additionally, we present optimal fully dynamic algorithms for the Hamiltonian cycle problem and the Hamiltonian path problem on threshold and chain graphs which return a vertex cutset as certificate for the non-existence of such a path or cycle in the negative case.
This thesis will examine the process of internationalization which generates international changes and growth, entry into new markets and the creation of new businesses. Projecting this on the sports industry, businessmen tend to take more risks than a few decades ago in the interest of becoming more competitive. The sports industry is used to transmit multiple messages as it reaches global audiences. The term sports covers much more than the physical activity. The term also comprises possibilities for lucrative business actions, sponsoring and image creation. Furthermore, it induces a pooling of diverse cultures. Thanks to this boundary-spanning connection of sportsmen and arising opportunities to increase sales, managers have decided to go international and to expand their company
This work aimed to apply the Floating Film Transfer Method (FTM), developed by Kaneto et.al., as a new way of coating planar and nonplanar substrates with photoresist. Focus laid on the creation of a workflow to coat the substrate and process it by UV-Lithography and Nanoimprint lithography. Conventional coating methods like spin-, spray- or dip coating are well established in today’s industry but are limited in their capabilities to coat curved and structured surfaces. FTM offers the possibility to overcome these limitations. Therefore, two negative resists AR N 4400 and AR N 4600 10 as well as two positive resists AR P 3110 and AZ MIR 701 were drop cast on deionized water. The resist spreads into a thin film that can be transferred to a planar or curved substrate. Profilometric and ellipsometric measurements were conducted to evaluate the topography of the resist. A non-uniform thickness distribution was found depending on the resist and parameters like solid content, water temperature, and the amount of surfactant. UV-Lithography and Nanoimprintl ithography were successfully performed with these films. Resolutions as low as 2,3±0,4 µm were achieved by UV-Lithography of AR P 3110. A periodic pattern with a pitch of 1,51 µm was transferred by thermal nanoimprint lithography to AR N 4400 10. As proof of concept Laser Direct Writing was performed to structure AZ MIR 701coated on a glass vial.
This work is aimed to study the effect of two types of stresses/corrosion on different materials used in making of disc brake rotors, atmospheric corrosion and thermal fatigue. The materials chosen were steel (100Cr6), nodular cast iron (GJS-400-15) and Aluminium reinforced silicon carbide (F3S-20S). Specimens of the each material will be subjected to an induced atmospheric corrosion using the salt spray (fog) chamber for two different test durations to simulate atmospheric corrosion. Other specimens of the chosen materials will be subjected to a thermal fatigue test through a repeated heating-cooling cycle. The effects on the materials will be measured by the difference in the values of coefficient of friction and the wear rate before and after the tests are carried out. Analysis of the induced corrosion and thermal fatigue products will be carried out by XRD analysis and microscopic photos of the surfaces. A comparison between the different tested materials will also be performed.
China
(2015)
Within this Bachelor Thesis the Chinese economic development with begin of the economic boom until today are described. With focus on the Austrian Business Cycle Theory by Ludwig von Mises and Friedrich Hayek the questions why and how economic bubbles develop are investigated and similarities between countries who experienced economic bubbles in the past and China analysed. The conclusion of the research is that the Chinese real estate market has indeed been caught in a boom-and-bust cycle and is at the moment going through recession. A future reoccurence of an economic bubble in China is possible.
The thesis explains the economic and political motivation of China's drive towards Africa, the political framework for this and the approach to the African continent via trade, investment and aid. The Sino-African cooperation is exemplified by the countries Angola, Sudan, Zimbabwe, Nigeria, Kenya and South Africa. Finally several points of criticism and the perceptions of the Western world towards China's engagement with Africa will be examined.
This master's thesis focuses on developing a robust framework for co-simulating microscopic traffic scenarios and vehicle dynamics, leveraging the capabilities of SUMO and CARLA. The essence of this research lies in its meticulous analysis of existing simulation tools, leading to identifying the most effective co-simulation strategies and intercommunication methods. A comparative study elucidates the strengths and limitations of these methodologies, guiding the selection of an optimal approach.
Central to the methodology is a thorough understanding and application of SUMO and CARLA, enhanced by the strategic implementation of intercommunication methods. The detailed integration of these tools and the introduction of test automation significantly boost simulation efficacy. The framework's reliability and accuracy are rigorously validated through well-defined procedures and metrics, ensuring fidelity in simulation results.
Key to this research is the design of experimental scenarios that reflect real-world traffic conditions underpinned by carefully chosen simulation parameters. These scenarios are pivotal in validating the co-simulation framework's performance, supplemented by a performance cost analysis focusing on processing efficiency. The thesis culminates with a critical discussion of the findings, addressing the research objectives and posing solutions to identified challenges. Potential areas for future enhancements are explored, highlighting the framework's limitations.
In conclusion, this thesis contributes significantly to the field of traffic simulation for autonomous driving technologies. It presents a comprehensive co-simulation framework, offering researchers and engineers a sophisticated tool for advanced testing and validation. The insights and recommendations provided are instrumental for ongoing research and development in this rapidly evolving domain.
Abstract: Duplex steels are used for applications that require high strength and ductility combined with good corrosion resistance. An economical welding technology to handle these steels is achieved by combining the MIG and TIG arc processes. The aim is to improve welding speed and quality by utilizing a TIG-MIG hybrid welding process to join 1.4462 duplex steel with a thickness of 2 mm. The interaction between the two arcs, caused by the blowing effect, is an enormous challenge that can be counteracted with a defined torch position and current modulation. For this purpose, a variation of the MIG (pulsed and AC pulsed arc) and TIG process (AC and pulsed DC) took place. The influence of electrical parameters on process stability and material transfer was investigated. For analysis, an evaluation of high-speed recordings (5000 frames per second) and synchronized measured current/voltage curves (200 kHz) is carried out. Based on a number of selected specimens, a welding procedure test according to ISO 15614-1 is performed to determine the welding seam quality. The test includes the characterization by tensile and hardness testing and macroscopic and microscopic examination. Additionally, the specimens are examined according to ISO 5817.
At first an indroduction is given to lidar, atmospheric basics, include scattering and absorption, and different experiments using lidar in space. Then it's shown how you can determine aerosol layers using LITE data. Two different kinds of Color Rations will analyzed on these aerosol layers. To calculate Color Rations it's necessary to calibrate the LITE data in the 352 nm and the 1064 nm wavelength. A calibration ratio is used, because of problems with the calabration in the 1064 nm channel.<br> The Attenued Totel Color Ration can be used to distinguish betweeen clouds and aerosols. This will be done for the Orbit 55 on single shot and averaged shot data, and for more averaged shot data in other Orbits. On the other hand the Particle Color Ratio, which is analyzed from the top of the layer with the Top Skimming Technique, can be used to find out what kind of particle is it.
Turbidity currents play a significant role within the global sediment cycle, and are important for environmental processes as well as the formation of hydrocarbon reservoirs. A special kind of turbidity currents are tubidity currents with reversing buoy- ancy. Hyperpycnal flows are one kind of turbidity currents with reversing buoyancy. There exist numerous experimental studies of these flows but no simulations. This thesis deals with reversing-buoyancy turbidity currents. The propagation of the flow front over time and the later lift-off are investigated on the basis of the results from Sparks et al. (1993). Furthermore the interaction of the current with obstacles is analyzed by means of the work from Stevenson & Peakall (2010). Hereby a closer look at deposit patterns caused by various obstacle positions and dimensions, is taken. Towards this end a highly parallel three-dimensional Navier-Stokes Direct Numerical Simulation code is used.
Automotive transportation plays an important role in everyday urban life. The motorization is increasing along with rising population every year. The constant increase of cars causes various problems in big cities. One of the major problems is parking. Parking search traffic contributes to about 30% of the traffic volume in city centers. This leads to problems like congestion, road accidents, increase of fuel emission due to the circling of cars inside the city looking for parking facilities, environmental pollution etc. Most of the cities face this problem not because of the unavailability of parking spots in parking facilities but rather because drivers don't have the right information on where to park. This can be solved by providing proper guidance about the parking facilities to the drivers. For this, efficient parking space management including the design of a suitable parking guidance system is required. The Entsorgungs and Vekehrsbetrieb (EVB) Wismar has been responsible for the parking space management in the city since 2012 and is implementing the parking space concept in Wismar that was approved by the town council. So far, there is a static parking guidance system in Wismar, which consists of 20 locations with signs pointing to six parking facilities. The Entsorgungs und Vekehrsbetrieb (EVB) intends to replace the static parking guidance system of the Hanseatic City of Wismar with a dynamic parking guidance system (DPGS). The aim of my master thesis is to create a concept for the development of a dynamic parking guidance system in the Hanseatic city of Wismar, including the technical operation and possible implementation, taking autonomous driving into account.
Conceptual Approach to an AI-Based Adaptive Study Support System for Individualized Higher Education
(2023)
In the context of the digital transformation, the targeted implementation of AI-based or AI-supported technologies in "teaching & learning" as well as "administration & service" holds considerable potential for organizational change and quality enhancement for higher education institutions. The use of AI in higher education teaching and services lags behind the level in research. Therefore, holistic solutions must be planned and implemented in unity of teaching and research for the AI-based support of the stakeholders’ inclusive administration, the further development or the establishment of new digital study programs and offers as well as the prospective qualification of university staff in the field of AI. The solutions must be analyzed, systematized, and structured to generate a conceptual approach via an integrated architecture with adaptive services.
This paper is an evolution of the concept presented at the Learning Ideas Conference 2022 and includes, in addition to explanations of the current state of the arts, the presentation of a systems-oriented approach for AI in higher education as well as the conception of the student lifecycle management at the author’s university. The paper ends with the presentation of a concept regarding a decision support system for individualized studying.
Conceptual design of load balanced streaming of multimedia data within shared web applications
(2011)
In this master's thesis it has been researched the possibility of a network of shared web applications in a server-supported (hybrid) peer-to-peer network where peers retransmit specified parts of the progressively download (streamed) multimedia data, with focus on economically bandwidth usage. A conceptual design of a real-world peer-to-peer video-on-demand service, controlled by a central server, was developed, including a payment procedure for commercial use. Different network overlay scenarios were proposed and their advantages and disadvantages were discussed. Bandwidth calculations have supported those predications. Algorithms for dynamically handling changes in the network structure were developed. Communication protocols were conceptualized accordant to the needs of the proposed shared applications. Methods for keeping the quality of experience high were discussed. A zipper mode, higher-level slice structure for the data was proposed, and enhanced to a multiple-stream system for sending and receiving data. Error and data loss handling procedures were designed.
The sysWORXX CTR-700 is a versatile edge controller solution developed by SYSTEC electronic AG and sold since 2017. The embedded device is designed for industrial environments to control other machines and equipment connected to it
over Ethernet network, CAN bus or a set of digital and analog input/output pins.
As a central controller in such automated environments, security is an important aspect. Especially integrity of all devices as well as confidentiality of stored and processed data must be ensured. Furthermore, provable authenticity of hardware is crucial to secure the controller's environment and prevent counterfeit hardware.
The sysWORXX CTR-700 has a built-in cryptographic co-processor ATECC508A from Microchip Inc. This ac:HSM provides hardware support for algorithms based on elliptic curve cryptography as well as secured slots for cryptographic keys and other confidential secrets.
This thesis analyses requirements for secure hardware verification and license management supported by the ac:HSM to enhance the existing solutions by leveraging military-grade cryptography standard algorithms and processes. Over
the course of this document, security principles are presented, relevant cryptographic systems and algorithms are explained to build a strong foundation and understanding.
Furthermore, the ATECC508A is introduced with its capabilities and prerequisites for secure confidential operation.
The proposed solution is a form of a vendor acrlong:PKI system. Technical and organizational policies for the ac:PKI are covered. They are accompanied by a detailed process description for provisioning the sysWORXX CTR-700 and the integrated ac:HSM. The process is supported by a set of custom-built tools for managing licenses and devices.
The purpose of this study is to bring China closer to the audience, especially from the marketing perspective. The automotive industry, textile industry, technological industry, food, and beverage industries and much more have developed themselves in the Chinese market. Subsequently, the writer chose one sector of the technology industry, which are smartphones. The focus of this thesis is already available smartphone brands in China. The perception of smartphone brands should help in determining how the producing country is looked at, if the image clouds the judgment and if consumers are loyal to brands. These insights allow us to draw conclusions and recommendations for the communication and design of smartphone brands.
As corporate social responsibility (CSR) is becoming increasingly important in China, this bachelor thesis examines the current state, problems and challenges of corporate social responsibility in China. Based on the analysis of the CSR strategies of Apple and Huawei in China, the thesis reveals lessons and guidelines for companies that want to implement a CSR strategy and integrate CSR operations into their business in China.
Abstract
This article presents a cost-effective ultraviolet-ozone cleaner (UV/O3 Cleaner) for surface pre-treatment of substrates in the field of semiconductor technology. The cleaner consists of two chambers, the upper one contains the electronics, including the time counter. The lower chamber contains the two UV sterilisation lamps and a UV reflector of anodized aluminium, which confines the area of high Ozone concentration in the area of interest. The device is successfully used for surface cleaning and modification of different materials. To this end, the two important wavelengths 253.7 nm (excitation of organic residues) and 184.9 nm (production of ozone from the atmospheric environment as a strong oxidant) were first detected. The effectiveness of UV/O3 cleaning is demonstrated by improving the properties of indium tin oxide (ITO) for OLED fabrication. The contact angle of water to ITO could be reduced from 90° to 3° and for diiodomethane, it was reduced from 55° to 31° within the 10 min of irradiation. This greatly improved wettability for polar and non-polar liquids can increase the flexibility in further process control. In addition, an improvement in wettability is characterized by measuring the contact angles for titanium dioxide (TiO2) and polydimethylsiloxane (PDMS). The contact angle of water to TiO2 decreased from 70° to 10°, and that of diiodomethane to TiO2 from 54° to 31°. The wettability of PDMS was also greatly increased. Here, the contact angle of water was reduced from 109° to 24° and the contact angle to diiodomethane from 89° to 49°.
Article Highlights
We report a cost-effective dry-cleaning device for surface cleaning and modification based on ultraviolet-ozone irradiation.
Contact angle measurements show an increase of wettability for different materials due to surface modification.
The UVO3 pre-treatment improves layer formation and optoelectrical properties of OLEDs.
ABSTRACT:
Multimodal transportation system which is also called as Combined transportation system. This type of transportation is seen in two methods i.e., movement of passengers from one place to another and movement of cargo using different types of transportation vehicles (Trains, trams, metro, bus, ship, truck, bicycle, airplane and air cargos). This type of system can also be derived
as single ticket (passengers) and single contract (freight) transportation. This will help in reducing the travel time, air pollution, economy, environmental changes, and unorganized journey. The main goal of the thesis is to bring ease in the multi-modal transportation system in India and to make people choose public transport over private and to provide end to end transportation facilities for people, so that people opt for public transportation as it is budget friendly as well. For instance, prevailing the single ticket (passengers) and single contract (freight) transportation system in Germany could be implemented in India. A single transport operator system is needed to meet the desired target in implementing multi-modal transportation
system feasibly. The main issue lies in the implementation of this system in Indian conditions which can be fulfilled by integration of various institutions involved in it for instance linking up the network channels of various modes of transport (end to end transportation). The rising concerns of funding by Indian government can be resolved by the implementation of this system
in the form of subsidies.
My research paper also includes the phases of MMTS, how it was earlier and how it has been in contemporary times. Major Factors like total cost, reliability, transportation capability, total time and security drive forward to developing multi-modal transportation system. This system is helpful in the growth of a nation's economy and is energy-efficient. Reliability of this system shall be based on the funding from the government because the absence of multi-modal transportation system leads to pollution, and ill health. The amount of funding plays a vital role in determining country to country (MMTS) development. Having been considering the advantages and uses of this system it is important to look into the disadvantages of the system.
For instance, How can implementing multi-modal transportation system in India be feasible?
The aim of this bachelor thesis is to investigate how cultural differences of countries can be used to make assumptions on what kind of financial product might be the most efficient one based on the culture of a country. By using re-search that is trying to explain market performance differences and consumer behavior differences based on culture of a country. This thesis is trying to link those researches in order to create a cultural assessment framework that can be used to make predictions about a country
The book is the first of four volumes on data science and artificial intelligence. This first volume covers fundamentals of data science: an introduction to Python programming, software libraries for data management, techniques for working with big data. It contains many exercises and projects with real-world data.
The book is the second of four volumes on data science and artificial intelligence. This second volume covers data visualization tool and techniques as well as fundamentals of supervised machine learning: linear regression, artificial neural networks, support-vector machines, decision trees, ensemble methods and more.
Der General
(2022)
Natural Language Processing (NLP) is a wide area in computer science and software engineering that finds its application not only in such fields as machine learning or artificial intelligence, but also has very quickly become a very popular solution to various questions and issues raised in the academic field. Those issues include information classification, text analysis, performing a so-called “smart search”, information grouping, providing feedback to academic papers, and many more. The application designed and implemented for this thesis targets solving a similar problem, which is described in details below.
The faculty of Physical Engineering and Informatics at the Westsächsische Hochschule Zwickau uses a software tool called “Quest”. The “Quest” serves as an online platform that enables students to ask questions regarding the module material introduced by the teaching professors. The professors can use these questions in order to keep track of the topics rising the most amount of uncertainty, as well as to clarify those questions during the lectures. Since the modules repeat over time, similar or identical questions are frequently asked by students.
The current functionality of the “Quest” tool, however, does not provide grouping or clustering questions with a similar content into one category. The reason why this is important is because in the future phases of the improvement of the functionality of the “Quest”, professors want to be able to link similar questions with a learning material or online resources that the students can benefit from. This, however, is only possible when each incoming question is labeled with a certain category, and all previously inputted questions associated with this category become visible through the UI of the tool. That would allow students to review the questions referring to the same category that were previously asked by others, as well as to get access to the study materials or resources associated with that category.
The functionality described above would significantly improve the study process and therefore a solution to this problem is needed. One way to solve this issue would be to perform a manual classification of existing questions into associated categories, which given the large size of the question database would be quite time- and effort-consuming. Another option would be to build an application that would be able to analyze the existing dataset of questions and, with the help of the NLP techniques, classify new questions asked by students and identify the similar ones from an existing database.
The tool implemented for the above-mentioned purposes aims to serve as text analytics and classification application that would be able to find and categorize similar text and questions provided by students and/or professors at the Westsächsische Hochschule Zwickau.
This bachelor thesis demonstrates the process of building a software tool using certain NLP techniques, such as tokenization, model training, categorization, NER (Named Entity Recognition), and POS (Parts of Speech tagging), which are defined and described in Chapter 2: “Literature Overview”. The relevance of these techniques in terms of the classification tool built in the context of this thesis is discussed in the section “Selection of NLP tools and techniques” of the “Methodology” chapter.
The aim of this thesis is to describe the methods and software tools used to develop a restful API for text classification, as well as to compare and analyze the effectiveness of two common NLP classifiers – the Naïve Bayes and Logistic Regression (Entropy Model) algorithms.
Models of artificial root canals are used in several fields of endodontic investigations and pre-clinical endodontic training. They allow the physical testing of dental treatments, the operating of instruments used and the interaction between these instruments and the tissues. Currently, a large number of different artificial root canal models exist whose geometry is created either on the basis of selected natural root canal systems or to represent individual geometrical properties. Currently, only a few geometric properties such as the root canal curvature or the endodontic working width are taken into consideration when generating these models. To improve the representational capability of the artificial root canal models, the aim of the current study is therefore to generate an artificial root canal based on the statistical evaluation of selected natural root canals. Here, the approach introduced by Kucher for determining the geometry of a root canal model is used, which is based on the measurement and statistical evaluation of the root canal center line’s curvatures and their cross-sectional dimensions. Using the example of unbranched distal root canals of mandibular molars (n = 29), an artificial root canal model representing the mean length, curvature, torsion and cross-sectional dimensions of these teeth could be derived.
WHO estimates that 1.25 million people worldwide pass away in traffic accidents each year. Accidental damage to the economy costs USD 520 per year. Road traffic accidents account for 2.1% of all fatalities worldwide. In total, 50,000 people die in Europe each year. One of the most significant economic and social issues, traffic accidents result in thousands of fatalities and serious injuries each year in Germany and around the world. Whenever there is an accident involving vehicles, trucks, motorized two-wheelers, bicycles, or pedestrians that results in casualties or property damage, the questions of what caused the accident and how it could have been prevented naturally arises: whether it was due to human factors (e.g., carelessness, speeding, or drinking), vehicular flaw (e.g., faulty brakes, a faulty chassis, or old tires), road surface, poor visibility, and so on. The list of possible explanations is really long. The problem is to implement effective steps to prevent accidents from happening in the first place, regardless of what caused the mishap.
The German federal states of Sachsen, Sachsen-Anhalt, Brandenburg, Hessen, and cities of Hamburg, and Bremen are examined in this study's analysis of accidents. This study aims to (i) identify the human factors, environmental factors, and road/infrastructural factors that lead to human failures which cause road accidents, and (ii) explore ways of mitigating these accidents.
Developing of a marketing-mix for Duerr Ecoclean for the modified Spray Cleaning Machine "Jeto 84W". Duerr Ecoclean already established its business within the Chinese Automotive Industry and is now trying to touch the Chinese Component Industry. Therefore, they are looking for a suitable strategy to enter this market. The thesis included an analysis of the market environment, customer base, and competitor structure to develop a fitting marketing-mix to implement the Spray Cleaning Machine "Jeto 84W".
Development and Characterization of a Dispersion-Encoded Method for Low-Coherence Interferometry
(2022)
This Open Access book discusses an extension to low-coherence interferometry by dispersion-encoding. The approach is theoretically designed and implemented for applications such as surface profilometry, polymeric cross-linking estimation and the determination of thin-film layer thicknesses. During a characterization, it was shown that an axial measurement range of 79.91 µm with an axial resolution of 0.1 nm is achievable. Simultaneously, profiles of up to 1.5 mm in length were obtained in a scan-free manner. This marked a significant improvement in relation to the state-of-the-art in terms of dynamic range. Also, the axial and lateral measurement range were decoupled partially while functional parameters such as surface roughness were estimated. The characterization of the degree of polymeric cross-linking was performed as a function of the refractive index. It was acquired in a spatially-resolved manner with a resolution of 3.36 x 10-5. This was achieved by the development of a novel mathematical analysis approach.
Development and testing of a measuring system for recording mechanical loads on industrial batteries
(2019)
Sometimes cranioplasty is necessary to reconstruct skull bone defects after a neurosurgical operation. If an autologous bone is unavailable, alloplastic materials are used. The standard technical approach for the fabrication of cranial implants is based on 3D imaging by computed tomography using the defect and the contralateral site. A new approach uses 3D surface scans, which accurately replicate the curvature of the removed bone flap. For this purpose, the removed bone flap is scanned intraoperatively and digitized accordingly. When using a design procedure developed for this purpose creating a patient-specific implant for each bone flap shape in short time is possible. The designed skull implants have complex free-form surfaces analogous to the curvature of the skull, which is why additive manufacturing is the ideal manufacturing technology here. In this study, we will describe the intraoperative procedure for the acquisition of scanned data and its further processing up to the creation of the implant.
Level crossings represent high risk for both rail and road users due to the severe consequences of any possible accident. Between 2011-2020, a total of 1602 accidents occurred at level crossings in Germany and resulted in 344 fatalities. Therefore, elimination of accident risk through consolidation of level crossings becomes a priority. However, due to the scarcity of financial resources in comparison to the high costs that level crossings consolidation or safety upgrade projects require, there is a need for the creation of tools that prioritize the level crossings for consolidation projects based on several criteria that is not related to safety only but to social, economic and environmental aspects as well. Such tool would be particularly useful for authorities and decision-makers in Germany to improve the resource allocation process and increase overall safety at German level crossings. In this project, the level crossing prioritization and consolidation models that are applied all over the world are reviewed and analyzed to benefit from the international experiences in this field. Additionally, a literature review to determine the most influencing factors on level crossing safety was performed. After that, a points-based priority score for German level crossings was developed based on analytic hierarchy process (AHP) methodology after a pairwise comparison survey was conducted to a selected level crossing group of experts. The developed model assigns a priority score from 1000 points to each level crossing. Crossings could be ranked according to their priority for consolidation and safety upgrade based on the points received as crossings with the highest priority score have a higher priority for elimination.
Unnoticed by many, a congenital cardiac anomaly is in existence, which can be found in over a quarter of the total population. It is associated with the occurrence of strokes, migraine with and without an aura and feelings of faintness.This refers to the atrial septal defect (ASD) or one of its forms, the patent foramen ovale (PFO). Eventhough this illness, depended on the manifestation, can remain without any symptoms, it should still be considered to treat the condition, to prevent possible complications in a higher age. In recent years, based on several studies, a closure of ASDs and PFOs has been established as the preferred approach and is therefore increasingly replacing the medicinal treatment. In the context of this Master
In the scope of this thesis a novel minimal invasive medical device was developed and manufactured. It is used to treat mitral regurgitation, which is one of the most common cardiovascular diseases. It prevents a perfect closure of the mitral leaflets and causes blood to flow back and cause different symptoms, from dyspnea to sometimes death. For this purpose, two versions of new treatment devices were developed that suture the Mitral valve leaflets together resulting in a better closure. Various state of the art Software and machines were used to design and manufacture the Prototypes. This thesis provides the basis of putting those devices onto the Market and to help physicians and patients with an easier treatment and faster recovery time.
The SuperStitch is a suture-based closure device for the use during minimally invasive surgical procedures. The aim is to close a vessel or wound site in an open setting. The project is dealing with the further development of an already proven product pf the HeartStitch company. In the process, adaptation and fining solutions based on new requirements are discussed. These aim to perform surgery in the area of the human heart. The new field of application is mostly meant to deal with the closure of PFO's, ASD II and occurring residual shunts.
This bachelor thesis is about the development and design of the suture-based HeartStitch MR device for functional restoration of the mitral valve when a mitral regurgitation is present. The mitral valve is one of the four existing heart valves and due to their load, the mitral valve is most commonly affected by valve defects. In case of a mitral regurgitation, the leaflets of the mitral valve are not closing tight enough, which causes a reflux of the oxygenated blood from the left ventricle into the left atrium. As consequence, the human body won't be sufficiently supplied with oxygen anymore, which results in a disproportionate cardiac output. Untreated, this can lead to respiratory dis-tress, cardiac arrhythmias and stroke or even to death. In this case, a heart surgery is essential to improve the patient
The here presented work is about the development of an atom pair descriptor based virtual screening system. In the beginning the fundamentals are explained which are the base of the following chapters. The chemical data file formats, the term descriptor as well as the enrichment factor and the process of benchmarking is discussed. In the main part the development of the virtual screening system is explained and afterwards the results on the bcr-abl kinase target protein are interpreted. For the development of the virtual screening system the realization of the atom pair descriptor, the different similarity methods and their selection is discussed. Also the clustering and the functio-nality of the virtual screening system are explained. Afterwards the results of the bcr-abl kinase screening are discussed and the functionality of the virtual screening system is evaluated. Finally a conclusion is given where set goals and achieved outcomes are compared and an outlook for possible future projects is presented.
To improve the quality of education in applied laser physics, a new and innovative educational platform was designed, realized and tested. The system focusses on the improvement of the theoretical, experimental and numerical skills in the topics of ultra-short pulsed fiber based laser systems and related measurement techniques. The main content of the platform is the fundamental understanding of the technologies of an ytterbium-doped fiber based Master-Oscillator Power-Amplifier and a 2nd order intensity autocorrelator. A wide range of system parameters are variable and metrologically accessible. Thus the underlying physical mechanisms are illustrated and, by this the fundamental understanding of the system, improved. To transfer actual industrial and scientific topics into the experimental education of students, the complex lab course aims for a full characterization of the system by experimental work and a numerical analysis by simulating the system dynamics. A state-of-the-art educational tool was created to demonstrate current industrial sys-tems. An amplification of 37.2 dB was achieved. The pulses with a temporal width of 30.6 picoseconds possessed a pulse peak power of 14.2 kW. By the analysis of the material specific spectral properties, the rate equation model can be applied and im-portant system parameters determined.
The Faculty of Languages at the University of Applied Sciences Zwickau has a knowledge
base on critical incidents. Critical incidents capture and structure insights from critical situations in international mobility [Fet15]. With the rapid development of data and information, the
research platform CIs to Go has a clear need for a central search infrastructure that will allow
users to find and discover more relevant critical incidenst (or intercultural experinces as named
in the research platform CIs to Go). The data and information about critical incidents are stored
in open-source relational database management system PostgreSQL.
Nowadays it is inconceivable to use traditional RDBMS tools to analyze the data as they
grow very fast. The amount of information has steadily increased for years. Big Data provides
a solution for analyzing large amounts of data. Many search engine providers offer the solution
for analyzing large volumes of data, and companies are looking for open source solutions that
can quickly and reliably search, analyze, and evaluate large volumes of data. Elasticsearch
is a Lucene based search engine. Elasticsearch uses the concept of indexing to speed up the
search. This search engine provides a variety of options for free text queries, fuzzy matching
and indexing data. First, search engines and NLP toolkits are reviewed. This thesis also defines
the functional requirements of these tools. Then, an evaluation is given by indicating the positive
and negative aspects of the tools.
This thesis presents a complete search engine to be deployed on the research platform CIs
to Go as a new visual tool that helps in the process of searching for and finding intercultural
experiences.
In the surgery of the pituitary gland and other related areas of the skull base, the endoscopic endonasal surgery has established oneself as today's operation method. Although the surgeon is able to look around corners with the aid of an endoscope, the dissection in these areas is limited. Current suction devices are limited in their size, shape, bending and prone to kinking because of the narrow suction channel. The work with such inadequate instruments increase the risk of life-threatening complications, prolong the operation and limit the quality of a complete tumor resection. The ideal suction device would be adaptable to numerous surgery situations, easy to bend, maintain its lumen, adequate in their ratio of rigidity and formability, ergonomic and reformable to its original shape. In the following bachelor thesis, it is shown that this can be achieved with a suction device with shape memory alloy. After the development of a comfortable hand sample, the suction device went into preparation and a risk analysis was performed. The results of the evaluation process are reductions in operative risk, time and cost if this bendable suction device would be applied. Therefore, approval for the international market should be sought, to provide an opportunity for safer and more effective surgical procedures.
Es wird ein neuartiges, interferometrisches Verfahren zur Analyse dünner Filme beschrieben.
Dissipation energy based parameter identification of anisotropic linear viscoelastic composites
(2020)
The current work presents a relaxation analysis based procedure to identify effective material parameters of the multiaxial generalized Maxwell model (GMM) by a numerical homogenization of the microscopic dissipation energy density for anisotropic linear viscoelastic composites. The employed GMM enables the derivation of a thermodynamically consistent constitutive law and a function of the dissipation energy density for direction‐dependent viscoelastic materials. The identity of this energy function to the microstructure's homogenized dissipation energy density is utilized for the identification of effective relaxation times. Furthermore, the identified relaxation times enable a simple determination of the remaining stiffness parameters. Finally, the presented procedure is demonstrated and evaluated for a randomly endless fibre‐reinforced plastic with a polymer matrix exhibiting a significant viscoelastic behaviour.
Effect of acoustic excitation on fiber-reinforced polypropylene and the influence on melt viscosity
(2021)
The paper describes a novel technological approach to influencing the rheological properties of thermoplastic materials exposed to acoustic energy. The flow behavior of polypropylene with different mass percentages of glass fibers is investigated in a parallel plate rheometer under high-frequency longitudinal excitation. The influence of oscillation frequency on the melt viscosity is explained by means of shear thinning criteria. The dependence of the oscillation shape using sinusoidal excitation on shear thinning as a function of different fiber reinforcement percentages is also investigated. A phenomenological view describes the mutually influencing parameters with regard to different material compositions and different excitation frequencies over the time course of the rheometric measurement. Interacting relationships are analyzed and discussed and the potential of the actuator system to influence the plastic melt is worked out. Based on this, a technological approach follows which describes the transfer of an oscillating mold surface to plastics processing methods, which, especially in the case of energy-intensive injection molding technology, leads to the expectation of possible resource efficiency in energy and material.
The aim of this study was to investigate the antimicrobial efficacy of different disinfection protocols in a novel Enterococcus faecalis biofilm model based on a visualization method and to evaluate the potential alteration of dentinal surface. A total of 120 extracted human premolars were allocated to 6 groups with different irrigation protocols. The assessment of the effectiveness of each protocol and the alteration of dentinal surface were visualized by using SEM and fluorescence microscopy (DAPI). A dense E. faecalis biofilm with a penetration depth of 289 μm (medial part of the root canal) and 93 μm (apical part) validated that the biofilm model had been successfully implemented. A significant difference between the 3% NaOCl groups and all the other groups in both observed parts of the root canal (p < 0.05) was detected. However, the SEM analysis revealed that the dentinal surface in the 3% NaOCl groups was severely altered. The established biofilm model and the visualization method based on DAPI are appropriate for bacterial quantification and evaluation of the depth effect of different disinfection protocols in the root canal system. The combination of 3% NaOCl with 20% EDTA or MTAD with PUI allows the decontamination of deeper dentine zones within the root canal but simultaneously alters the dentinal surface.
Abstract: This article reconstructs the path of the German economist Friedrich A. Lutz (1901–75) to American economics. The correspondence with his former teacher Walter Eucken, the founder of the Freiburg school, constitutes a crucial yet unexplored source for the article. Through Lutz's case, this article demonstrates the growing gulf between German and Anglo-Saxon economics during the late 1930s. In his native Germany, Lutz was trained in methodologically and institutionally focused economics, which differed fundamentally from the mathematical economics dominating Anglo-Saxon academia. He realized that an academic career in the United States would be impossible if he did not adapt to the new methods and if he did not abandon the methods of the German tradition. This gave rise to his internal Methodenstreit. After his emigration in 1938, he constantly experienced doubts and tensions because he was convinced that without considering institutions, mathematical economics could never explain the occurrence and essence of macroeconomic phenomena. Despite his stellar career at Princeton, it was only after his move to Zurich in 1953, where he taught history and theory of socioeconomics for the rest of his life, that Lutz could reconcile this internal Methodenstreit.
Electrical and thermal measurements were conducted during the plasma electrolytic polishing (PEP) of cemented tungsten carbide (WC-Co) materials to characterize energetic aspects of the process in relation to the temporal development of the gaseous layer near the workpiece. The power transferred to the workpiece is determined using a calorimetric probe and employing the time derivative of the temperature curve. It shows distinct heating phases due to the generation of the gaseous layer. At the beginning of the process, a typical power of 367 ± 17 W is transferred to the workpiece of a surface area of 14 cm2. At longer process times, a stabilized gaseous layer limits the power transferred to the workpiece to 183 ± 3 W. In an attempt to describe the heat transferred to the electrolyte, the electrolyte temperature was measured using a thermocouple situated 15 mm away from the workpiece. The local electrolyte temperature increases from 70 to 81 °C for an immersion depth of 20 mm. Moreover, the spatiotemporal development of the electrolyte temperature was obtained by 2D-hydrodynamic modeling using COMSOL Multiphysics®. The modeling results for the local temporal temperature development are in excellent agreement with the experimental values when the turbulent model is applied up to t = 65 s. Afterward, the laminar model leads to a better agreement. Furthermore, line scan x-ray photoelectron spectroscopy revealed that aliphatic carbon was preferentially removed. Only a slight compositional gradient in the vertical direction after the PEP process was observed.
Stereo matching methods are usually relying on rectified images to calculate disparities. If the rectification is inaccurate or not present at all most stereo matching algorithms will produce distorted disparity maps. In this thesis an approach is described that overcomes this issue for the PatchMatch Stereo algorithm. As groundwork for stereo matching four rectification procedures namely Bouget
Cloud Computing has had an impact on the computer science in recent years. Instead of the traditional way, where the using and providing of hardware resources and software are inflexible, Cloud Computing represents a pool of scalable, on-demand and easily available Cloud Services. These are differentiated by infrastructure, platform or software and are provided by a Cloud Service provider. An example of a service provider is a business software provider. Due to this of business software customers are increasingly are interested in a shift to Cloud Computing. Customers want to appreciate the advantages of Cloud Computing, such as the reduction of business expenditures generally or make business more flexible. This Bachelor Thesis analyses Cloud Computing's possibilities and advantages, especially Cloud Services, to forming the basis of expanding business software providers' product portfolio. The analyses results the concept for providing existing software components as a Cloud Service, without radically altering component configuration. This is used by a number of actors types and points out the advantage of using Cloud Services in different ways. Finally, a prototype implementation analysis the technical feasibility of the concept and represents a basis for conclusion and outlook
The title of this thesis is the development of a Standardized Process Controlling and a method for the measurement of plant flexibility using the example of the Automotive Aftermarket (AA) division of the Robert Bosch GmbH. Developing the Standardized Process Controlling based on literature review and an analysis of existing procedures at the company. The approach consists of an instruction for process development and a reporting tool to control it after implementation. It is tested on three already existing processes as well as on the development of the Plant Flexibility process; establishing the Plant Flexibility measurement on the four aspects of line, volume, time and personnel capacity flexibility. In the application of the Standardized Process Controlling identified problems are used to improve and finalize the approach. As a result an easier implementation of processes as well as an evaluation of their current performance is possible.
Radiation measurements have been employed in research for close to a century and over the last years a growing interest for application in workshops has developed. However, some problems of standardization mainly pertaining to room acoustics arise, which make measurement results comparable only to those conducted under the same circumstances. Our aim is to modify measurement procedure and rig design in such a way, that comparable results can be attained even in acoustically non-ideal spaces. A specialized rig for violin radiation measurements was constructed leaning on partial automation to allow for the application of thick curtains as a means of decoupling measurements from the surrounding room. Trial runs in an acoustically challenging space - our living room - as well as in a small studio environment were conducted.
Improvements of measurement results were obtained for frequencies above 800 Hz, measurements were influenced significantly by the surrounding room below that threshold. As a result, calculated features were heavily skewed by the environment, rendering obtained data useless for statistical purposes. Therefore additional measurements of six instruments were performed in a small studio environment and features as defined in the literature calculated. Correlations with listening test results concerning the evenness of sound as well as structural instrument parameters were obtained. Listening test results were inconclusive, which is proposed to be attributed to the narrow range of instrument quality available for trials. Some interesting correlations of measurement features with structural parameters could be obtained and further vetted through the comparison with a second set of data. Three correlations were found which were significant or approaching significance in both groups, giving a more complete connection from instrument making to sound perception. Furthermore we have found some interesting correlations of structural parameters, giving insights into maker decisions and corroborating some workshop wisdoms.
This paper presents numerical analysis of the discrete fundamental solution of the discrete Laplace operator on a rectangular lattice. Additionally, to provide estimates in interior and exterior domains, two different regularisations of the discrete fundamental solution are considered. Estimates for the absolute difference and lp‐estimates are constructed for both regularisations. Thus, this work extends the classical results in the discrete potential theory to the case of a rectangular lattice and serves as a basis for future convergence analysis of the method of discrete potentials on rectangular lattices.
The world of engineering has changed significantly over the last years. Increased time to market, cost and produce variety constraints lead, next to the introduction of new engineering technologies and tools, to the implementation of new engineering processes, such as Simultaneous Engineering. The Rover Group started with the implementation of Simultaneous Engineering Principles within their development departments at the beginning of the 90's. The requirements towards the realisation of Simultaneous Engineering within their development projects changed when the Rover Group started working and developing products with BMW in 1994. Within this Diploma the intake manifold development process for the NG4 engine, the first joint developed combustion engine between the Powertrain sections of BMW and Rover, will be analysed. The basis for the analysed. The basis for the analysis of the Simultaneous Engineering Process are SE-Principles, based on literature research, which will be estimated on their degree of realisation within the development process. In the final part of the Diploma some recommendations regarding the creation of future Powertrain Engineering processes are given, in particular, focus on the improvement of the international co-operation between the development departments of BMW and Rover Group. It is to note, a lot of basic project information used for the analysis and recommendation within this Diploma are based on UK development sources. Not all statements given within this Diploma might be valid for the Munich based BMW departments or the manufacturing section. <!-- #h:dissdiplDevelopment.doc# -->
Traffic signal priority for Public Transit vehicle is considered as an effective strategy to reduce the delay times and increase service reliability. This strategy is implemented to stop the vicious cycle of traffic congestion due to excess utilization of private vehicle. Though this is an attractive alternative for a private vehicle, this strategy can be implemented without opting for any new transportation infrastructure. On doing so the concern towards sustainable mobility solutions is also addressed. Therefore, prioritizing public transport is the best possible way to adapt to the increasing mobility demands in urban areas. Along with the technological advancements, these priority strategies are also being developed.
With these advancements in priority strategies, more research towards Estimated Time of Arrival of transit vehicles a key parameter in Transit signal priority has been observed. One such new traffic signal priority is with C-ITS message profiles CAM and SREM. Though this advanced priority method is considered to outperform the existing traffic signal priority strategies, how much better they can perform is not yet determined. This thesis focuses on this aspect by comparing the existing Transit signal priority method with the advanced CAM and SREM Transit signal priority, in four different scenarios. Signal Control tool LISA and Simulation tool VISSIM are used for the whole design and evaluation process. Delay time, waiting time,and average speed evaluation parameters are considered for comparing and determining the performance of two Transit Signal priority methods.