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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.
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.
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
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.
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 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.
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.
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.
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.
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.
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.
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.
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.
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
Experimental and theoretical investigation of mechanical stresses in Through-Silicon-Vias (TSV)
(2007)
In the work an experimental and theoretical investigation of the influence on the wafer bending of Through-Silicon-Vias (TSV) and their processing is presented. In a first step the influence of the anisotropic material properties of silicon and the thicknesses of an oxide hard mask and a tungsten film were analyzed at room temperature and as a function of the temperature up to 500 °C. For this purpose, the wafer bow was determined experimentally. In a second step, the analysis was extended to structured wafers. Wafers with Through-Silicon-Vias were etched and coated subsequently with several films. The wafer bow at room temperature was monitored stepwise. The theoretical analysis of bow and stress was done by using the Finite-Element-Program ANSYS. Models for unstructured wafers with various films were developed and the results compared with the experimental bow. For structured wafers, a model of a single via was generated; local deformations, stresses and the stress distribution were determined. To attempt the simulation of fully structured wafers, an effective medium model was developed as first step approximation.
This work analyzes and evaluates different approaches to translate UML state machines into C++ code. The first part of this thesis covers the ground of transforming information of a source language to a target language. It addresses the basics of language theory and different approaches of language transformation. The second part examines the properties and formalisms of state machines to value their characteristics for further reuse in the development cycle. The third part disassembles the programming language C++ with all its quirks and oddities. The last part puts all mentioned pieces together. Beyond this approach the thesis tries to point out several concepts of language engineering to ease the use of software languages for the language user as well as the language engineer. It scrutinizes diverging solutions with the resulting consequences.
LEGO robotics sets are a well established tool for teaching programming in undergraduate courses. Starting with the now outdated EV3 set LEGO provided a Python programming interface and (inofficial) Linux support. The current LEGO Spike Prime set still provides Python programming, but no direct support for Linux.
In this report we collect and extend information on controlling Spike Prime robots from Linux hosts. We cover access to a robot's Python interpreter and code transfer as well as bidirectional robot-to-host communication via USB and Bluetooth. Results may be extended to robot-to-robot communication via Bluetooth.
The NobleStitchTM EL Cardiovascular Suturing System can be used in general surgical, interventional and endoscopic procedures, such as Patent foramen ovale (PFO) closure, transapical ventricular closure, carotid arterial closure, mitral annuloplasty or edge-to-edge mitral valve repair. The System is used through an access device or in an open setting. For applying suture to a wound site, one Device of the NobleStitchTM EL Cardiovascular Suturing System, called the NobleStitchTM EL (S)
Integrating Message-Based Load Distribution for Asynchronous Processes in an Enterprise Application
(2011)
With the ever-growing need for more scalable and fault-tolerant enterprise-level intranet and extranet solutions, application vendors are trying to prepare their products for multiple-machine environments. Apart from the traditional clustering approach of balancing and distributing user requests equally over several nodes, applications can be designed to handle greater loads by allowing designated background processes to run independently and be scaled separately from the main business logic and client request handling processes. Liferay Portal, a web-based enterprise-level portal and CMS solution developed by the company of the same name, already offers support for modeling a multi-node setup by utilizing well-known clustering paradigms in the manner of search index replication or cache invalidation as well as taking the application server's session replication mechanisms into account. Its upcoming release, however, will introduce long-running, CPU-bound features like creating document previews and encoding video or audio files , which will intensify the need for a concept that allows for queuing and equally distributing processor time
In this project we develop an intelligent water meter based on software solutions offered by the IOTA Foundation. The water meter allows the customer to map water usage in real-time and pay water on demand, as well as the water provider to map water usage on a greater scale, regulate water supply during low- demand phases and offers regulatory functions to prepare for drought or humid climate, and to incentivise sustainable water usage in high-demand fields like agriculture. This functionality is phrased into a research issue:
Invention of a working prototype to demonstrate the IOTA Streams and Wallet protocols for a meter with additional focus on economic efficiency and the technical preparation of scalability.
Utilizing the IOTA streams protocol, a next generation secure data connection is established between the water meter and a server-sided software application. On this connection, water consumption is mapped into a data bench, and informative data and commands are issued to the graphical interface of the meter.
The IOTA wallet library is leveraged to provide customer accounts corresponding to their meter. IOTA tokens can be send to the account, which grants access to water in a matter of seconds. Depending on the regulatory scenario, water flow can be stopped as soon as the account is exhausted (i.e. public well), or an overdraw can be established in order to guarantee fulfilment of basic human rights (i.e. private households).
Since pricing data can be calculated server-sided and water consumption is mapped in very narrow intervals of as low as 4 seconds, the price can be used as tool to regulate consumption.
The physical components include an electrical ball valve to shut down water flow automatically, a command line interface to provide informative data,, a Raspberry Pi running the client-sided software application, and a water meter with MBus-Interface, as well as a Controlling Board to connect the Raspberry Pi with both peripheral devices.
The finished prototype shows, that water consumption can be mapped on a highly secure level, in near real-time, from afar, flexible for most applications.
The Jupyter ecosystem with JupyterHub and JupyterLab as its most prominent members is the de-facto standard for teaching Python programming and also for research in machine learning and data science. Although the Jupyter project is well documented, there are lots of settings and situations requiring deep knowledge of the internal workings of Jupyter, Linux and related software tools. This report describes three problems and possible solutions arising when installing and configuring a Jupyter-based teaching environment. These three problems are the installation and setup of the autograding tool nbgrader, the interplay between JupyterHub and Linux PAM, and providing access to WebDAV resources for users of JupyterHub.
The book 'Reinforcment Learning: An Introduction' by Sutton and Barto is the standard text book for introductory courses to reinforcement learning. Next to concrete algorithms and extensive examples the book contains several fundamental results related to Markov decision processes (MDPs) and Bellman equations in Chapters 3 and 4. Unfortunately some proofs are missing, some theorems lack precise formulation, and for some results the line of arguments is quite garbled.
In this note we provide all missing proofs, give precise formulations of theorems and untangle the line of arguments. Further, we avoid using random variables and their expected values. Since we (like Sutton/Barto) restrict our attention to finite MDPs all expected values can be made explicit avoiding overloaded notation and murky conclusions.
This article bridges the gap between introductory literature like Sutton/Barto and research literature containing exact formulations and proofs of relevant results, but being less accessible to beginners due to higher generality and complexity.
Subject of the thesis is the development and testing of a laboratory setup for test measurements of acoustic neutrino detectors in ice environments. The preparation of clear ice was one major part of the thesis. Different sound sources, piezos and lasers, have been used as sound sources. The development of a directed sound source, basing on a parabolic reflector, is described in the thesis. Finally, the temperature behavior of acoutic neutrino detectors was investigated.
Ferroelectric doped hafnium oxide might be able to revive the ferroelectric memory as a candidate for future non-volatile memories. Recent publications have reported ferroelectricity in HfO2 films deposited via physical vapor deposition (PVD) and thermal atomic layer deposition (ALD). Within this thesis, such layers have been fabricated by a plasma enhanced ALD process for the first time. Using an O2 remote plasma to oxidize TEMAHf and TMAl, respectively, Al:HfO2 stacks with different compositions have been deposited. Sputter deposited TiN was used as bottom and top electrode to form metal-insulator-metal capacitors. Compared to the PVD or thermal ALD films reported in literature, the plasma enhanced ALD films exhibited one to two orders higher leakage current at 1 V. The root of this higher leakage are oxygen vacancies as well as carbon and nitrogen impurities in the range of several at%. Despite the consequential perturbing effects, the main trends reported earlier are discernable. Just these perturbing effects turn out to substantiate the current explanation of a ferroelectric phase as route source for the observed electrical behavior.
Boron-doped diamond (BDD) electrodes offer some excellent electrochemical properties, including the widest potential window in aqueous solutions, low background currents and good chemical and mechanical stability. They can also be produced transparent and could offer a great potential for spectroelectrochemical (SEC) experiments. However, to reach the mentioned electrical properties for such optically transparent electrodes (OTE), heavy doping is needed to increase conductivity. The introduction of boron in return reduces the transparency significantly. This work investigates the effect of introducing an alternative path for electrons in the form of an highly conductive get transparent interlayer which could increase the conductivity without increasing the BDD film or the doping level supporting high transparency in the visible (Vis) and ultraviolet (UV) regime. This work furthermore investigates possible interlayers for this application and implements four of them in two BDD OTE samples which are extensively studied by electrical, optical and electrochemical methods. An ultra-thin metal film (UTMF) of titanium (Ti) is shown to decrease the electrochemical resistance by 2.4kOhms while decreasing the transparency of a BDD OTE by only 11%.
Qualification of tool to tool matching of a color image inspection system for wafer backsides
(2010)
This diploma thesis deals with the qualification of the color image inspection of a wafer backside inspection system as a means of defect detection. Currently, the color image is used to provide a quick overview and visual impression of the wafer backside. The goal of the diploma thesis is to qualify the color image inspection to comply with all requirements of tool to tool matching. As a given standard, the existing hardware design of the wafer backside inspection system can not be altered and has to be used in its current state. Potential causes of uncertainty introduced by this hardware design will be accounted for. The main focus of the diploma thesis will be the investigation of the three main factors influencing the color image inspection. These factors are the detected intensity, the contrast and the image sharpness. Their adjustability, repeatability, reproducibility and effect on the tool to tool matching are going to be quantified, necessary improvements will be formulated and the implementation of these improvements is going to be tested. Additionally, new and existing software factors influencing defect detection will be investigated with regard to their effect on the tool to tool matching. Lastly, based on the findings of the diploma thesis, a series of suggestions will be formulated. They will help to plan additional qualification steps, if necessary, and provide the basis for composing a guideline to achieve tool to tool matching for all systems in the field.
In this study more than 150 kg real waste from electrical and electronic equipment (WEEE) shredder residues from different European dismantling plant were treated by laserspectroscopic flouroescence and solvent-based recycling process. Currently, the samples used are excluded from material recycling and remain as side streams in state-of-the-art plastic recycling plants. The main reason why the waste streams are not currently recycled is due to the fact that they contain flame retardants that are already banned by different EU regulations (e.g. REACH, POP) and must be removed before the recyclates produced can be used again in products on the market. Conventional recycling technologies cannot separate these hazardous flame retardants from the polymers, therefore the solvent-based recycling process was used for this study. The focus within this work was the upscaling of the CreaSolv® Process from the laboratory scale to the small technical scale to provide larger quantities of recyclates. Sensor-based sorting process and CreaSolv® Process were combined to achieve easier handling and better yields of recyclates. By means of safe solvents a significant decrease of halogen content of (up to 98%) was achieved within the applied methods. Mass balances were determined, and gas chromatography-electron capture detector (GC-ECD) as well as energy dispersive X-ray fluorescence (EDXRF) measurements provided data on the different flame retardants and halogen content of each recyclate. As a result, the recyclates produced comply with the limit values of the EU directives (e.g. POPs, REACH). Melt flow analysis and differential scanning calorimetry (DSC) were carried out on the recyclates for a quality evaluation and revealed that the recyclates have similar properties to virgin materials. Based on this work, the upscaling of the CreaSolv® Process is able to recycle WEEE containing pollutants and at the same time produce recyclates with good mechanical properties.
Prussian blue (PB) layers were electrodeposited for the fabrication of Au/PB/Ag stacks to study the resistive switching effect. The PB layers were characterized by different techniques to prove the homogeneity, composition, and structure. Electrical measurements confirmed the bipolar switching behavior with at least 3 orders of magnitude in current and the effect persisting for the 200 cycles tested. The low resistance state follows the ohmic conduction with an activation energy of 0.2 eV.
Routing games over time are widely studied due to various applications, e.g., transportation, road and air traffic control, logistic in production systems, communication networks like the internet, and financial flows. In this article, we present a new competitive packet routing game with edge priorities motivated by traffic and transportation. In this model a set of selfishly acting players travels through the network over time. If the number of players who want to enter an edge at the same time exceeds the inflow capacity of this edge, then edge priorities with respect to the preceding edge are used to resolve these conflicts, which is similar to right-of-way rules in traffic. We analyze the efficiency of pure Nash equilibria, present an efficient algorithm for computing equilibria in symmetric games, and show that it is NP-hard to decide whether a Nash equilibrium exists in an asymmetric game. Furthermore, we address the problem of constructing optimal priorities.
The birefringence of single crystal diamonds is quantified using a birefringence measurement setup and a Matlab program for the calculation. The theoretical backgrounds of the polarization of light and polarization changing equipment is used for selecting a plane polariscope measurement method. Here, a birefringent sample is placed between two optical polarizers. The equipment, as well as its theoretical and practical behavior in the measurement setup is discussed. The equations for birefringence measurements are given and a practical Matlab program is introduced to simplify the birefringence calculation for the user. Possible influences on the birefringence value due to inaccuracies of the laser, the polarizers, the diamond sample, the magnification lenses and the camera are discussed and taken into account. Intensity fluctuations and polarization changes of the laser beam are studied. The direction of the transmission axis of the polarizer and the analyzer is examined. A retarder is inserted into the measurement setup to check the accuracy of the birefringence measurement since a retarder has a known phase retardation. This retarder measurement should qualify the measurement setup to quantify birefringence of the diamond sample. The measurement results show that intensity fluctuations of the laser and the handling inaccurracies of the polarizers have a major influence on the accurracy of the birefringence measurement. This measurement setup is not qualitfied to measure birefringence accurate yet. Steps to improve the measurement setup and the birefringence calculation are discussed.
Speech-controlled Home Shopping in Virtual Reality (Investigation and Prototypical Realization)
(2019)
In order to discover and to identify possible improvements in the interaction between humans
and computers, research in speech recognition in combination with virtual reality provides
an opportunity to learn about scientific fields such as human-computer interaction. For the aim
of reaching a new level of interactivity between users and systems, the research in virtual reality
contributes to several innovative ideas for researchers to discover inventive features. The idea
beyond prototyping speech controlled home shopping in virtual reality is to overcome some
technical limitations in virtual reality and to serve direct interaction between the user and the
virtual reality environment through speech commands.
Sodium iron hexacyanoferrate (NaFeHCF) films were electrodeposited on Au/Cr/Si for the study of growth behavior and physical properties. The NaFeHCF films were studied by different analytical methods to prove the chemical composition, morphology and crystal structure. The grains of the film grow with a cubic structure with an average lattice parameter of 10.10 Å and the preferential growth direction along the [111] direction of the cubic cell. The films show a repeatable bipolar resistive switching behavior accompanied by high current changes (up to a factor of ~105). The different resistive states in the materials are dominated by ohmic conduction.
The electrical conduction mechanism of resistive switching Prussian white (PW) thin films obtained by the electrodeposition method was examined by AC impedance spectroscopy and DC current–voltage measurements. Using an electrode tip to contact PW grown over Au, robust unipolar resistive switching was observed with a current change of up to three orders of magnitude, high repeatability, and reproducibility. Moreover, electrical impedance spectroscopy showed that the resistive switching comes from small conductive filaments formed by potassium ions before the establishment of larger conductive channels. Both voltammetry and EIS measurements suggest that the electrical properties and conductive filament formation are influenced by defects and ions present in the grain boundaries. Thus, PW is a potential material for the next generation of ReRAM devices.
Methods of analyzing the structural integrity of compound materials under stressed conditions becoming more importantly. Not merely safety and economic reasons demanding a good monitoring of e.g. wind turbine blades or aircraft wings but also ecological ones. The existing strategy for the blades is to replace them at a certain schedule, resulting in unnecessary downtimes and high cost. Several possibilities of an optical structural health monitoring system been examined in this thesis. Both free-space and fiber-based setups are tested and evaluated in their usability. The methods were tested with the objective of embedding them into large-scale polymer structures such as the mentioned fields of application.
Abstract:
Background: Proctoring represents a cornerstone in the acquisition of state‐of‐the‐art cardiovascular interventions. Yet, travel restrictions and containment measures during the COVID‐19 pandemic limited on‐site proctoring for training and expert support in interventional cardiology.
Methods and Results: We established a teleproctoring setup for training in a novel patent foramen ovale closure device system (NobleStitch EL, HeartStitch Inc, Fountain Valley, CA) at our institution using web‐based real‐time bidirectional audiovisual communication. A total of 6 patients with prior paradoxical embolic stroke and a right‐to‐left shunt of grade 2 or 3 were treated under remote proctorship after 3 cases were performed successfully under on‐site proctorship. No major device/procedure‐related adverse events occurred, and none of the patients had a residual right‐to‐left shunt of grade 1 or higher after the procedure. Additionally, we sought to provide an overview of current evidence available for teleproctoring in interventional cardiology. Literature review was performed identifying 6 previous reports on teleproctoring for cardiovascular interventions, most of which were related to the current COVID‐19 pandemic. In all reports, teleproctoring was carried out in similar settings with comparable setups; no major adverse events were reported.
Conclusions: Teleproctoring may represent a feasible and safe tool for location‐independent and cost‐effective training in a novel patent foramen ovale closure device system. Future prospective trials comparing teleproctoring with traditional on‐site proctoring are warranted.
With the help of the Laser-Speckle phenomenon different in-vivo diagnostic applications can be performed at the surfaces of different tissues such as the skin, the retinal skin and the cerebral cortex. In this study the Laser light scattering phenomenon is used to measure blood flow and hemoglobin concentration change. There are a lot of different approaches to perform these investigations for example with single-mode or multi-mode fibers. A comparison between the two illumination systems is presented together with an experimental setup. The results show that both of the approaches are feasible under specific conditions. Both fiber illumination systems have their advantages and limitations in fulfilling different tasks. The two approaches are tested and evaluated to propose specific applications for every illumination system. With these results future uses of the proposed methods are encouraged.
Context
VR as an application to enhance well-being is sparsely researched in the elderly population. The aim of the pilot study was to analyze the effect of 360° videos of different categories on the state of mind of seniors in nursing facilities. Furthermore, for the implementation in everyday life, the usability of the system and the experience for seniors should be evaluated.
Methods
The VR experience was used as a supplement to existing care services in three facilities on eight subjects. Mood state was assessed using the Questionnaire for the Assessment of Happiness before and after the intervention. Demographic data and technology acceptance were collected beforehand. After the intervention, subjects were interviewed about confounding factors and side effects, and nursing home staff were interviewed about the usability of the system and the organizational concept of implementation.
Results
There was a positive effect on state of mind. Gender and spatial mobility turned out to be influencing factors. Categories containing people, animals and action achieved the highest increases in the state of mind. Interest in using technical devices correlated negatively with the change in mood state. None of the subjects found the VR goggles distracting or reported motion sickness. Very good usability was indicated by the employees.
Conclusion
A very high willingness to use this technology was found among nursing staff and residents. The tendencies of the positive effect of 360° videos on the state of mind, as well as differentiation based on the mentioned characteristics gender and spatial mobility, should be verified by a larger sample to empirically validate the use of this technology to increase the quality of life.
In this paper, we propose cache replacement strategies based on the machine learning methods. As part of this work, we analyse the data provided for caching, design, and train Random Forest Regression and Gradient Boosting Decision Trees to predict the popularity of web objects. Finally we compare the proposed strategies with policies traditionally used for cache replacement to evaluate their applicability.