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Die wenigen Literaturangaben zu Sorptionsisothermen von mineralischen Estrichen beziehen sich im Wesentlichen auf Calciumsulfatestriche und genormte Zementestriche, sowie i.d.R. nur auf eine festgesetzte Lufttemperatur (= 20 Grad C). Daher war es das Anliegen der im Beitrag beschriebenen Untersuchung, die Feuchtigkeitseigenschaften von Estrichen bei unterschiedlichen Klimaten mithilfe von Sorptionsisothermen zu charakterisieren. Ergänzend sollten die seit ca. 20 Jahren marktüblichen ternären Schnellzemente mit untersucht und die baupraktisch interessanten Temperaturen von 15 Grad C und 25 Grad C einbezogen werden. Ebenso wurden die Auswirkungen der Klimabedingungen auf der Baustelle (Jahreszeit, Luftfeuchtigkeit, Temperatur) auf den Hydratationsvorgang der Estriche untersucht. In Kombination mit den Ergebnissen der Gefügeuntersuchungen (u.a. Hg-Porosimetrie) wird belegt, weshalb sich die zement- und schnellzementgebundenen Estriche vollkommen anders verhalten als die calciumsulfatgebundenen Estriche. Dieses unterschiedliche Verhalten ist auch einer der Gründe, warum Estriche mit der KRL-Methode in Bezug auf ihren Feuchtegehalt nicht bewertet werden können. Deshalb folgt ein Vergleich der Materialfeuchtemessungen "KRL-Methode" mit der handwerksüblichen und seit Jahrzehnten in der Praxis bewährten "CM-Methode".
Von wegen Bauschutt
(2020)
RC-Betone sind keine Neu-Entwicklungen, aber sie erleben seit circa 15 Jahren in Deutschland eine Renaissance mit Materialzusammensetzungen, die den heutigen Anforderungen an Normalbetone gerecht werden. Es gab immer wieder Abschnitte in der (Bau-)Geschichte, in denen Gebäude aus Ziegelsplitt-Betonen errichtet wurden, wie das Max-Kade-Studentenwohnheim in Stuttgart und das Technische Rathaus in Tübingen. Beide stammen aus der Nachkriegszeit und weisen einen guten Erhaltungszustand auf. Sie sind Beispiele für die Bewährung "historischer" Ziegelsplitt-Betone in der Baupraxis und ihre lange technische Lebensdauer.
Kleine und mittelständische Unternehmen (KMU) sind bekannt für ihre Innovationskraft und bilden das Rückgrat der deutschen Wirtschaft. Wie Studien zeigen sind sie in Bezug auf Compliance-Maßnahmen im Vergleich zu
kapitalmarktorientierten Unternehmen jedoch im Rückstand. Eine gesonderte Betrachtung der IT-Compliance erfolgt dabei in den Studien in der Regel nicht. Auch wenn zu den Gründen und Motiven fehlender IT-Compliance-Strukturen in KMU kaum Forschungsergebnisse vorliegen, zeigen doch die vielen Publikationen, die sich mit Teilaspekten von Compliance und KMU beschäftigen, dass Handlungsbedarf besteht. Insbesondere die aktuellen Veränderungen unter dem Stichwort Digitalisierung deuten auf eine gesteigerte Bedeutung von IT-Compliance-Maßnahmen vor allem in mittelständischen Unternehmen. In dieser Arbeit sollen daher mithilfe einer Literaturrecherche die aktuell behandelten Themen in Bezug auf IT-Compliance und KMU analysiert sowie aktuelle Themenschwerpunkte herausgearbeitet werden.
The expansion of a given multivariate polynomial into Bernstein polynomials is considered. Matrix methods for the calculation of the Bernstein expansion of the product of two polynomials and of the Bernstein expansion of a polynomial from the expansion of one of its partial derivatives are provided which allow also a symbolic computation.
Let A = [a_ij] be a real symmetric matrix. If f:(0,oo)-->[0,oo) is a Bernstein function, a sufficient condition for the matrix [f(a_ij)] to have only one positive eigenvalue is presented. By using this result, new results for a symmetric matrix with exactly one positive eigenvalue, e.g., properties of its Hadamard powers, are derived.
In this thesis, the recognition problem and the properties of eigenvalues and eigenvectors of matrices which are strictly sign-regular of a given order, i.e., matrices whose minors of a given order have the same strict sign, are considered. The results are extended to matrices which are sign-regular of a given order, i.e., matrices whose minors of a given order have the same sign or are allowed to vanish. As a generalization, a new type of matrices called oscillatory of a specific order, are introduced. Furthermore, the properties for this type are investigated. Also, same applications to dynamic systems are given.
Totally nonnegative matrices, i.e., matrices having all their minors nonnegative, and matrix intervals with respect to the checkerboard partial order are considered. It is proven that if the two bound matrices of such a matrix interval are totally nonnegative and satisfy certain conditions, then all matrices from this interval are also totally nonnegative and satisfy the same conditions.
For a long time, the use of intermediate products in production has been growing more rapidly in most countries than domestic production. This is a strong indication of more interdependency in production. The main purpose of input-output analysis is to study the interdependency of industries in an economy. Often the term interindustry analysis is also used. Therefore, the exchange of intermediate products is a key issue of input-output analysis. We will use input–output data for this study that the author prepared for the new ‘Handbook on Supply, Use and Input–Output Tables with Extensions and Applications’ of the United Nations. The supply use and input–output tables contain separate valuation matrices for trade margins, transport margins, value added tax, other taxes on products and subsidies on products. For the study, two input–output models were developed to evaluate the impact of fuel subsidy and taxation reform on output, gross domestic product, inflation and trade. Six scenarios are discussed covering different aspects of the reform.
Multi-dimensional spatial modulation is a multipleinput/ multiple-output wireless transmission technique, that uses only a few active antennas simultaneously. The computational complexity of the optimal maximum-likelihood (ML) detector at the receiver increases rapidly as more transmit antennas or larger modulation orders are employed. ML detection may be infeasible for higher bit rates. Many suboptimal detection algorithms for spatial modulation use two-stage detection schemes where the set of active antennas is detected in the first stage and the transmitted symbols in the second stage. Typically, these detection schemes use the ML strategy for the symbol detection. In this work, we consider a suboptimal detection algorithm for the second detection stage. This approach combines equalization and list decoding. We propose an algorithm for multi-dimensional signal constellations with a reduced search space in the second detection stage through set partitioning. In particular, we derive a set partitioning from the properties of Hurwitz integers. Simulation results demonstrate that the new algorithm achieves near-ML performance. It significantly reduces the complexity when compared with conventional two-stage detection schemes. Multi-dimensional constellations in combination with suboptimal detection can even outperform conventional signal constellations in combination with ML detection.
Many resource-constrained systems still rely on symmetric cryptography for verification and authentication. Asymmetric cryptographic systems provide higher security levels, but are very computational intensive. Hence, embedded systems can benefit from hardware assistance, i.e., coprocessors optimized for the required public key operations. In this work, we propose an elliptic curve cryptographic coprocessors design for resource-constrained systems. Many such coprocessor designs consider only special (Solinas) prime fields, which enable a low-complexity modulo arithmetic. Other implementations support arbitrary prime curves using the Montgomery reduction. These implementations typically require more time for the point multiplication. We present a coprocessor design that has low area requirements and enables a trade-off between performance and flexibility. The point multiplication can be performed either using a fast arithmetic based on Solinas primes or using a slower, but flexible Montgomery modular arithmetic.
In this work, we investigate a hybrid decoding approach that combines algebraic hard-input decoding of binary block codes with soft-input decoding. In particular, an acceptance criterion is proposed which determines the reliability of a candidate codeword. For many received codewords the stopping criterion indicates that the hard-decoding result is sufficiently reliable, and the costly soft-input decoding can be omitted. The proposed acceptance criterion significantly reduces the decoding complexity. For simulations we combine the algebraic hard-input decoding with ordered statistics decoding, which enables near maximum likelihood soft-input decoding for codes of small to medium block lengths.
The ballistocardiography is a technique that measures the heart rate from the mechanical vibrations of the body due to the heart movement. In this work a novel noninvasive device placed under the mattress of a bed estimates the heart rate using the ballistocardiography. Different algorithms for heart rate estimation have been developed.
NAND flash memory is widely used for data storage due to low power consumption, high throughput, short random access latency, and high density. The storage density of the NAND flash memory devices increases from one generation to the next, albeit at the expense of storage reliability.
Our objective in this dissertation is to improve the reliability of the NAND flash memory with a low hard implementation cost. We investigate the error characteristic, i.e. the various noises of the NAND flash memory. Based on the error behavior at different life-aging stages, we develop offset calibration techniques that minimize the bit error rate (BER).
Furthermore, we introduce data compression to reduce the write amplification effect and support the error correction codes (ECC) unit. In the first scenario, the numerical results show that the data compression can reduce the wear-out by minimizing the amount of data that is written to the flash. In the ECC scenario, the compression gain is used to improve the ECC capability. Based on the first scenario, the write amplification effect can be halved for the considered target flash and data model. By combining the ECC and data compression, the NAND flash memory lifetime improves three fold compared with uncompressed data for the same data model.
In order to improve the data reliability of the NAND flash memory, we investigate different ECC schemes based on concatenated codes like product codes, half-product codes, and generalized concatenated codes (GCC). We propose a construction for high-rate GCC for hard-input decoding. ECC based on soft-input decoding can significantly improve the reliability of NAND flash memories. Therefore, we propose a low-complexity soft-input decoding algorithm for high-rate GCC.
This document presents a new complete standalone system for a recognition of sleep apnea using signals from the pressure sensors placed under the mattress. The developed hardware part of the system is tuned to filter and to amplify the signal. Its software part performs more accurate signal filtering and identification of apnea events. The overall achieved accuracy of the recognition of apnea occurrence is 91%, with the average measured recognition delay of about 15 seconds, which confirms the suitability of the proposed method for future employment. The main aim of the presented approach is the support of the healthcare system with the cost-efficient tool for recognition of sleep apnea in the home environment.
Which testing formats are most appropriate for assessing academic language skills? Christian Krekeler addresses this question for informal language assessment in the classroom. In the first part of this chapter discrete items, isolated tests of writing, and integrated tests, three formats which are frequently used in standardised assessment, are investigated and their usefulness for classroom assessment, where diagnosis, achievement and learning are important test functions, is discussed. Because academic language use is cognitively demanding, it is argued that assessment of academic language skills should include authentic and complex tasks as well as subject specific content. The resulting tensions between complex, authentic and context sensitive tasks and the requirements of language assessment methodology are discussed in the second part of the chapter.
This paper examines the corporate organisational aspects of the implementation of Industry 4.0. Industry 4.0 builds on new technologies and appears as a disruptive innovation to manufacturing firms. Although we do have a good understanding of the technical components, the implementation of the management and organisational aspects of Industry 4.0 is under-researched. It is challenging to find qualitative empirical evidence which provides comprehensive insights about real implementation cases. Based on a case study in a German high value manufacturing firm, we explore the corporate organisation and implementation of Industry 4.0. By using the framework of Complex Adaptive System (CAS), we have identified three key factors which facilitate the implementation of Industry 4.0 namely 1.) Organisational structure changes such as the foundation of a central department for digital transformation, 2.) The election of a Chief Digital Officer as a personnel change, and 3.) Corporate opening up towards cooperating with partners as a cultural change. We have furthermore found that Lean Management is an important enabler that ensures readiness for the adoption of Industry 4.0.
Uncertainty about the future requires companies to create discontinuous innovations. Established companies, however, struggle to do so; whereas independent startups seem to better cope with this. Consequently, established companies set up entrepreneurial initiatives to make use of startups' benefits. Consequently, this led-amongst others-to great interest in socalled corporate entrepreneurship (CE) programs and to the development and characterization of several different forms. Their processes to achieve certain objectives, yet, are still rather ineffective. Thus, considerations of the actions performed in preparation for and during CE programs could be one approach to improve this but are still absent today. Furthermore, the increasing use of several CE programs in parallel seems to bear the potential for synergies and, thus, more efficient use of resources. Aiming to provide insights to both issues, this study analyzes actions of CE programs, by looking at interviews with managers of seven corporate incubators and accelerator programs of five established German tech-companies.
Digitalization is one of the most frequently discussed topics in industry. New technologies, platform concepts and integrated data models do enable disruptive business models and drive changes in organization, processes, and tools. The goal is to make a company more efficient, productive and ultimately profitable. However, many companies are facing the challenge of how to approach digital transformation in a structured way and to realize these potential benefits. What they realize is that Product Lifecycle Management plays a key role in digitalization intends, as object, structure and process management along the life cycle is a foundation for many digitalization use cases. The introduced maturity model for assessing a firm’s capabilities along the product lifecycle has been used almost two hundred times. It allows a company to compare its performance with an industry specific benchmark to reveal individual strengths and weaknesses. Furthermore, an empirical study produced multidimensional correlation coefficients, which identify dependencies between business model characteristics and the maturity level of capabilities.
Globalization has increased the number of road trips and vehicles. The result has been an intensification of traffic accidents, which are becoming one of the most important causes of death worldwide. Traffic accidents are often due to human error, the probability of which increases when the cognitive ability of the driver decreases. Cognitive capacity is closely related to the driver’s mental state, as well as other external factors such as the CO2 concentration inside the vehicle. The objective of this work is to analyze how these elements affect driving. We have conducted an experiment with 50 drivers who have driven for 25 min using a driving simulator. These drivers completed a survey at the start and end of the experiment to obtain information about their mental state. In addition, during the test, their stress level was monitored using biometric sensors and the state of the environment (temperature, humidity and CO2 level) was recorded. The results of the experiment show that the initial level of stress and tiredness of the driver can have a strong impact on stress, driving behavior and fatigue produced by the driving test. Other elements such as sadness and the conditions of the interior of the vehicle also cause impaired driving and affect compliance with traffic regulations.
In previous studies, we used a method for detecting stress that was based exclusively on heart rate and ECG for differentiation between such situations as mental stress, physical activity, relaxation, and rest. As a response of the heart to these situations, we observed different behavior in the Root Mean Square of the Successive differences heartbeats (RMSSD). This study aims to analyze Virtual Reality via a virtual reality headset as an effective stressor for future works. The value of the Root Mean Square of the Successive Differences is an important marker for the parasympathetic effector on the heart and can provide information about stress. For these measurements, the RR interval was collected using a breast belt. In these studies, we can observe the Root Mean Square of the successive differences heartbeats. Additional sensors for the analysis were not used. We conducted experiments with ten subjects that had to drive a simulator for 25 minutes using monitors and 25 minutes using virtual reality headset. Before starting and after finishing each simulation, the subjects had to complete a survey in which they had to describe their mental state. The experiment results show that driving using virtual reality headset has some influence on the heart rate and RMSSD, but it does not significantly increase the stress of driving.
In modern fruit processing technology, non-destructive quality measuring techniques aresought for determining and controlling changes in the optical, structural, and chemical properties of theproducts. In this context, changes inside the product can be measured during processing. Especiallyfor industrial use, fast, precise, but robust methods are particularly important to obtain high-qualityproducts. In this work, a newly developed multi-spectral imaging system was implemented andadapted for drying processes. Further it was investigated if the system could be used to link changesin the surface spectral reflectance during mango drying with changes in moisture content andcontents of chemical components. This was achieved by recovering the spectral reflectance frommulti-spectral image data and comparing the spectral changes with changes of the total soluble solids(TSS), pH-value and the relative moisture contentxwbof the products. In a first step, the camera wasmodified to be used in drying, then the changes in the spectra and quality criteria during mangodrying were measured. For this, mango slices were dried at air temperatures of 40–80◦C and relativeair humidities of 5%–30%. Samples were analyzed and pictures were taken with the multi-spectralimaging system. The quality criteria were then predicted from spectral data. It could be shown thatthe newly developed multi-spectral imaging system can be used for quality control in fruit drying.There are strong indications as well, that it can be employed for the prediction of chemical qualitycriteria of mangoes during drying. This way, quality changes can be monitored inline during theprocess using only one single measuring device.
What drives entrepreneurial action to create a lasting impact? The creation of new ventures that aim at having an impact beyond their financial performance face additional challenges: achieving economic sustainability and at the same time addressing social or environmental issues. Little is known on how these new hybrid organizations, aiming for multiple impact dimensions, manage to be congruent with their blended values. A dataset of 4,125 early-stage ventures is used to gain insights into how blended values are converted into financial, social and environmental impacts, giving shape to different types of hybrid organizations. Our findings suggest new hybrid organizations might opt to sacrifice financial impact to achieve social impact, yet this is not the case when they aim to generate environmental or sustainable impact. Therefore, the tensions and sacrifices related to holding blended values are not homogeneous across all types of new hybrid organizations.
Three-dimensional ship localization with only one camera is a challenging task due to the loss of depth information caused by perspective projection. In this paper, we propose a method to measure distances based on the assumption that ships lie on a flat surface. This assumption allows to recover depth from a single image using the principle of inverse perspective. For the 3D ship detection task, we use a hybrid approach that combines image detection with a convolutional neural network, camera geometry and inverse perspective. Furthermore, a novel calculation of object height is introduced. Experiments show that the monocular distance computation works well in comparison to a Velodyne lidar. Due to its robustness, this could be an easy-to-use baseline method for detection tasks in navigation systems.
Mapping of tree seedlings is useful for tasks ranging from monitoring natural succession and regeneration to effective silvicultural management. Development of methods that are both accurate and cost-effective is especially important considering the dramatic increase in tree planting that is required globally to mitigate the impacts of climate change. The combination of high-resolution imagery from unmanned aerial vehicles and object detection by convolutional neural networks (CNNs) is one promising approach. However, unbiased assessments of these models and methods to integrate them into geospatial workflows are lacking. In this study, we present a method for rapid, large-scale mapping of young conifer seedlings using CNNs applied to RGB orthomosaic imagery. Importantly, we provide an unbiased assessment of model performance by using two well-characterised trial sites together containing over 30,000 seedlings to assemble datasets with a high level of completeness. Our results showed CNN-based models trained on two sites detected seedlings with sensitivities of 99.5% and 98.8%. False positives due to tall weeds at one site and naturally regenerating seedlings of the same species led to slightly lower precision of 98.5% and 96.7%. A model trained on examples from both sites had 99.4% sensitivity and precision of 97%, showing applicability across sites. Additional testing showed that the CNN model was able to detect 68.7% of obscured seedlings missed during the initial annotation of the imagery but present in the field data. Finally, we demonstrate the potential to use a form of weakly supervised training and a tile-based processing chain to enhance the accuracy and efficiency of CNNs applied to large, high-resolution orthomosaics.
This paper presents the goals, service design approach, and the results of the project “Accessible Tourism around Lake Constance”, which is currently run by different universities, industrial partners and selected hotels in Switzerland, Germany and Austria. In the 1st phase, interviews with different persons with disabilities and elderly persons have been conducted to identify the barriers and pains faced by tourists who want to spend their holidays in the region of Lake Constance as well as possible assistive technologies that help to overcome these barriers. The analysis of the interviews shows that one third of the pains and barriers are due to missing, insufficient, wrong or inaccessible information about the
accessibility of the accommodation, surroundings, and points of interests during the planning phase of the holidays. Digital assistive technologies hence play a
major role in bridging this information gap. In the 2nd phase so-called Hotel-Living-Labs (HLL) have been established where the identified assistive technologies
can be evaluated. Based on these HLLs an overall service for accessible holidays has been designed and developed. In the last phase, this service has been implemented
based on the HLLs as well as the identified assistive technologies and is currently field tested with tourists with disabilities from the three participated countries.
Im vorliegenden Beitrag wird der Einfluss der Modellierung des Kellergeschosses auf die Querkraft und die Verformungen von im Kellergeschoss eingespannten Stahlbeton‐Aussteifungswänden untersucht. Der Querkraftverlauf der Wand und die Verschiebung am Kopf der Wand werden mit den entsprechenden, am vereinfachten Kragwandmodell ermittelten Werten verglichen, bei dem die Wand auf Höhe der Kellerdecke voll eingespannt ist und die Weiterleitung der Schnittkräfte im Kellergeschoss nicht näher betrachtet wird. Für die Berücksichtigung des Kellergeschosses wird zunächst eine gelenkige Festhaltung durch die Kellerdecke und die Bodenplatte betrachtet, wodurch sich eine unrealistisch große Wandquerkraft im Kellergeschoss ergibt. Danach wird ein verfeinertes Modell mit Teileinspannung in der Bodenplatte und nachgiebiger Halterung durch die Kellerdecke untersucht. Es werden Empfehlungswerte für die Federkonstante der Drehfeder auf Höhe der Bodenplatte und der horizontalen Translationsfeder auf Höhe der Kellerdecke angegeben, die in der Praxis Anwendung finden können. Es wird besonders der Frage nachgegangen, welche Einflüsse die Berücksichtigung des Kellergeschosses bei der Erdbebenbemessung der Aussteifungswände hat. Dabei wird einerseits die Systemsteifigkeit, von der die Erdbebenersatzlasten abhängen, und andererseits die mögliche Verschiebungsduktilität, von der der mögliche Verhaltensbeiwert q abhängt, betrachtet.
Location-aware mobile devices are becoming increasingly popular and GPS sensors are built into nearly every portable unit with computational capabilities. At the same time, the emergence of location-aware virtual services and ideas calls for new efficient spatial real-time queries. Communication latency in mobile environments interacting with high decentralization and the need of scalability in high-density systems with immense client counts leads to major challenges. In this paper we describe a decentralized architecture for continuous range queries in settings in which both, the requested and the requesting clients, are mobile. While prior works commonly use a request-response approach we provide a stream-based adaptive grid solution dealing with arbitrary high client counts and improving communication latency that meets given hard real-time constraints.
Die Nibelungenbrücke Worms
(2020)
The transformation to an Industry 4.0, which is in general seen as a solution to increasing market challenges, is forcing companies to radically change their way of thinking and to be open to new forms of cooperation. In this context, the opening-up of the innovation process is widely seen as a necessity to meet these challenges, especially for small and medium enterprises (SMEs). The aim of the study therefore is to analyze how cooperation today can be characterized, how this character has changed since the establishment of the term Industry 4.0 at Hanover Fair in 2011 and which cooperation strategies have proven successful. The analysis consists of a quantitative, secondary data analysis that includes country-specific data from 35 European countries of 2010 and 2016 collected by the European Commission and the OECD. The research, focusing on the secondary sector, shows that multinational enterprises MNEs still tend to cooperate more than SMEs, with a slight overall trend towards protectionism. Nevertheless, there is a clear tendency towards the opening-up of SMEs. In this regard, especially universities, competitors and suppliers have become increasingly attractive as cooperation partners for SMEs.
Probabilistic Short-Term Low-Voltage Load Forecasting using Bernstein-Polynomial Normalizing Flows
(2021)
The transition to a fully renewable energy grid requires better forecasting of demand at the low-voltage level. However, high fluctuations and increasing electrification cause huge forecast errors with traditional point estimates. Probabilistic load forecasts take future uncertainties into account and thus enables various applications in low-carbon energy systems. We propose an approach for flexible conditional density forecasting of short-term load based on Bernstein-Polynomial Normalizing Flows where a neural network controls the parameters of the flow. In an empirical study with 363 smart meter customers, our density predictions compare favorably against Gaussian and Gaussian mixture densities and also outperform a non-parametric approach based on the pinball loss for 24h-ahead load forecasting for two different neural network architectures.
Sustainable technologies are being increasingly used in various areas of human life. While they have a multitude of benefits, they are especially useful in health monitoring, especially for certain groups of people, such as the elderly. However, there are still several issues that need to be addressed before its use becomes widespread. This work aims to clarify the aspects that are of great importance for increasing the acceptance of the use of this type of technology in the elderly. In addition, we aim to clarify whether the technologies that are already available are able to ensure acceptable accuracy and whether they could replace some of the manual approaches that are currently being used. A two-week study with people 65 years of age and over was conducted to address the questions posed here, and the results were evaluated. It was demonstrated that simplicity of use and automatic functioning play a crucial role. It was also concluded that technology cannot yet completely replace traditional methods such as questionnaires in some areas. Although the technologies that were tested were classified as being “easy to use”, the elderly population in the current study indicated that they were not sure that they would use these technologies regularly in the long term because the added value is not always clear, among other issues. Therefore, awareness-raising must take place in parallel with the development of technologies and services.
Generalized Concatenated Codes over Gaussian and Eisenstein Integers for Code-Based Cryptography
(2021)
The code-based McEliece and Niederreiter cryptosystems are promising candidates for post-quantum public-key encryption. Recently, q-ary concatenated codes over Gaussian integers were proposed for the McEliece cryptosystem together with the one-Mannheim error channel, where the error values are limited to Mannheim weight one. Due to the limited error values, the codes over Gaussian integers achieve a higher error correction capability than maximum distance separable (MDS) codes with bounded minimum distance decoding. This higher error correction capability improves the work factor regarding decoding attacks based on information-set decoding. The codes also enable a low complexity decoding algorithm for decoding beyond the guaranteed error correction capability. In this work, we extend this coding scheme to codes over Eisenstein integers. These codes have advantages for the Niederreiter system. Additionally, we propose an improved code construction based on generalized concatenated codes. These codes extent the rate region where the work factor is beneficial compared to MDS codes. Moreover, generalized concatenated codes are more robust against structural attacks than ordinary concatenated codes.
Das Ziel dieser Arbeit war die Konzeption eines untergeordneten Stadtbusnetzes der Stadt Konstanz. Dabei wurde auf einem bereits entwickelten Entwurf eines übergeordneten Netzes aufgesetzt. Durch die Kombination dieser beiden entstand ein Gesamtbusnetz.
Im ersten Schritt wurde eine breit gefächerte Bestandsanalyse durchgeführt, inbegriffen war dabei eine Analyse des übergeordneten Busnetzes. Die gebündelten Ergebnisse gaben den Rahmen für die Konzeption vor. Danach folgte der schrittweise Entwurf der einzelnen Linien des untergeordneten Netzes. Im letzten Schritt der Konzeption wurden die Linien an wichtigen Umsteigeknoten und Parkräumen aufeinander abgestimmt.
Aus der genannten Analyse resultierten diverse Anforderungen für die Konzeption eines neuen Busnetzes. Hierbei konnte die Anbindung an die Bahn und das neu entstehende Mobilitätszentrum besonders hervorgehoben werden. Das Ergebnis der Konzeption waren elf Buslinien, die dem untergeordneten Netz zugewiesen werden können. Gemeinsam mit den fünf Linien des übergeordneten Entwurfs bilden sie ein Gesamtstadtbusnetz. Dabei wurden die Streckenverläufe der Linien aufeinander abgestimmt, sodass ein breitgefächertes Netz an Direktverbindungen entstehen konnte. Mithilfe der Abstimmung an Umsteigeknoten konnten sinnvolle Umsteigerelationen geschaffen werden, wodurch die Direktverbindungen zu einer flächendeckenden Anbindung der Stadtteile an relevante Ziele im Stadtgebiet erweitert wurden.
Auf theoretischer Ebene wurde hier aufgezeigt, wie ein neues Buskonzept der Stadt Konstanz gestaltet sein kann. Das vorliegende Konzept sollte in einer separaten Arbeit auf eine tatsächliche Umsetzbarkeit geprüft werden.
Optimierungsansätze zur Verbesserung der Leistungsbeschreibungen bei öffentlichen Bauvorhaben
(2021)
Elbphilharmonie, BER, Bischofsresistenz Limburg, Stuttgart 21, Alter Elbtunnel Hamburg. Alles bekannte deutsche Bauprojekte der letzten 20 Jahre. Alle mit einer Gemeinsamkeit: Exorbitante Kostenexplosionen und Bauzeitenverzögerungen.
In dieser Arbeit wird aufgezeigt, weshalb solche Kostenexplosionen auch aufgrund von Unklarheiten bzw. Fehlern in Leistungsbeschreibungen entstehen und welches enorme Potential klare und erschöpfende Leistungsbeschreibungen haben, um bereits im Vorfeld eines Bauvorhabens die Weichen für einen reibungslosen und erfolgreichen Projektverlauf zu stellen.
Many countries offer state credit guarantees to support credit-constrained exporters. The policy instrument is commonly justified by governments as a means to mitigating adverse outcomes of financial market frictions for exporting firms. Accumulated returns to the German state credit guarantee scheme deriving from risk-compensating premia have outweighed accumulated losses over the past 60 years. Why do private financial agents not step in and provide insurance given that the state-run program yields positive returns? We argue that costs of risk diversification, liquidity management, and coordination among creditors limit the ability of private financial agents to offer comparable insurance products. Moreover, we suggest that the government’s greater effectiveness in recovering claims in foreign countries endows the state with a cost advantage in dealing with the risks involved in large export projects. We test these hypotheses using monthly firm-level data combined with official transaction-level data on covered exports of German firms and find suggestive evidence that positive effects on trade are due to mitigated financial constraints: State credit guarantees benefit firms that are dependent on external finance, if the value at risk which they seek to cover is large, and at times when refinancing conditions on the private financial market are tight.
Modular arithmetic over integers is required for many cryptography systems. Montgomeryreduction is an efficient algorithm for the modulo reduction after a multiplication. Typically, Mont-gomery reduction is used for rings of ordinary integers. In contrast, we investigate the modularreduction over rings of Gaussian integers. Gaussian integers are complex numbers where the real andimaginary parts are integers. Rings over Gaussian integers are isomorphic to ordinary integer rings.In this work, we show that Montgomery reduction can be applied to Gaussian integer rings. Twoalgorithms for the precision reduction are presented. We demonstrate that the proposed Montgomeryreduction enables an efficient Gaussian integer arithmetic that is suitable for elliptic curve cryptogra-phy. In particular, we consider the elliptic curve point multiplication according to the randomizedinitial point method which is protected against side-channel attacks. The implementation of thisprotected point multiplication is significantly faster than comparable algorithms over ordinary primefields.
Beim data-driven learning (DDL) werden Lernerinnen und Lerner angeleitet, sprachliche Muster mit Hilfe von Korpuswerkzeugen zu entdecken und eigene Korpusabfragen durchzuführen. Am Beispiel einer Unterrichtseinheit für den Wirtschaftsdeutsch-Unterricht wird der Einsatz von DDL erläutert. Es wird deutlich, welche Chancen korpuslinguistische Verfahren bieten, aber auch, welche Probleme beim DDL auftreten können. Vor allem für die Planung des Fachsprachenunter-richts können korpuslinguistische Analysen hilfreich sein: Zu nennen sind die Bedarfsermittlung, die Auswahl von Materialien, die Identifizierung von typischem Wortschatz und häufigen Mustern sowie die Erstellung von Übungsmaterialien. Das Praxisbeispiel, das auf andere Kontexte übertragen werden kann, illustriert, wie sich korpuslinguistische Verfahren und DDL auf die Unterrichtsplanung und -durchführung auswirken: Sprache wird als Datenmenge betrachtet; der Fokus liegt auf sprachlichen Mustern; Fragen nach der Korrektheit bzw. der Angemessenheit werden thematisiert.
The McEliece cryptosystem is a promising candidate for post-quantum public-key encryption. In this work, we propose q-ary codes over Gaussian integers for the McEliece system and a new channel model. With this one Mannheim error channel, errors are limited to weight one. We investigate the channel capacity of this channel and discuss its relation to the McEliece system. The proposed codes are based on a simple product code construction and have a low complexity decoding algorithm. For the one Mannheim error channel, these codes achieve a higher error correction capability than maximum distance separable codes with bounded minimum distance decoding. This improves the work factor regarding decoding attacks based on information-set decoding.
Zur Erfassung von Veränderungen der Produkteigenschaften während der Trocknung von Lebensmitteln werden zerstörungsfreie Qualitätsmesstechniken gefordert, mit denen Veränderungen im Inneren des Produkts bestimmt werden können. Gerade im industriellen Einsatz sind schnelle, präzise, und gleichzeitig robuste Verfahren besonders wichtig, um qualitativ hochwertige Produkte zu erhalten.
In dieser Arbeit wurde zur optischen Qualitätsmessung ein neuartiges multispektrales Kamerasystem eingesetzt, um von Veränderungen der spektralen Oberflächenreflexion bei der Mango- und Ananastrocknung mit Veränderungen der Produktfeuchte, sowie mechanischen und chemischen Eigenschaften zu verknüpfen. Diese Verknüpfung wurde mit maschinellem Lernen erreicht.
In einem ersten Schritt wurde ein neues Kameraprinzip, eine multispektrale Flächenkamera mit vier Objektiven und Vorsatzfiltern, entwickelt und speziell auf den Einsatz in der Obsttrocknung angepasst. Anschließend wurden die Änderungen der Spektren und der Qualitätskriterien während der Trocknung gemessen. Dazu wurden Mango- und Ananasscheiben in einem Einzelschichttrockner bei Lufttemperaturen zwischen 40 °C und 80 °C und relativen Luftfeuchtigkeiten von 5 % bis 30 % getrocknet. Während der gesamten Trocknungsdauer wurde die Produktfeuchte der Proben gemessen, und Bilder mit der multispektralen Flächenkamera aufgenommen. Zur Analysen von nur ausgewählten Bereichen von Interesse in den Bildern wurde ein Softwarefilter entwickelt. Aus Spektraldaten und Prozessdaten konnte mit Algorithmen des maschinellen Lernens die Produktfeuchte zu jedem Zeitpunkt sehr genau vorhergesagt werden (Bestimmtheitsmaß R² von 0,98 bis 0,99). Die Kombination aus dem Prinzip der multispektralen Flächenkamera und maschinellem Lernen wurde in einem anderen Trocknungsprozess und mit weiteren Qualitätskriterien getestet. Dafür wurden Mangoscheiben in einem Schranktrockner getrocknet und deren Produkteigenschaften anhand der Spektraldaten und der Prozessdaten vorhergesagt. Bei der Vorhersage der Farbwerte Δa*, Δb* und ΔE00 sowie des Gehalts an gesamtlöslichen Feststoffen im Rehydrierungswasser wurden Bestimmtheitsmaße R² zwischen 0,56 und 0,94 erzielt).
Es konnte gezeigt werden, dass die Kombination aus dem neu entwickelten Multispektralkamerasystem und maschinellem Lernen zur Vorhersage der Produktfeuchte und anderer Qualitätskriterien der Produkte eingesetzt werden kann. Auf diese Weise können Qualitätsänderungen während des Prozesses mit nur wenigen Messgeräten inline überwacht werden.
In diesem Beitrag wird zunächst ein einführender Überblick über die Thematik eines Marketing-Controlling spezifischen Rechtsrahmens gegeben. Da die Datenerhebung, -verarbeitung und -analyse stets die Hauptfunktionsmerkmale eines Marketing-Controllings sind, stehen nach diesem Überblick die Rechtsgrundlagen eines Datenschutzes im Mittelpunkt der folgenden Ausführungen.
Dieses Forschungsvorhaben zielt darauf ab, individuelle Entrepreneure hinsichtlich ihrer Veränderungstendenzen zur Nutzung der Entscheidungslogik Effectuation und Causation zu untersuchen – insbesondere während des Gründungsprozesses. Basierend auf einem qualitativen Fallstudiendesign zeigen sowohl fallinterne als auch fallübergreifende Analysen, wie Entrepreneure zunächst an der effektuativen Logik festhalten und im Gründungsverlauf zu hybriden Logikformen übergehen. Der Beitrag zur Weiterentwicklung der Forschung zielt in drei Richtungen: Erstens schließt die Arbeit Lücken in der Effectuation-Forschung, indem sie Entscheidungsfindung von Unternehmensgründern auf individueller Ebene spezifiziert. Zweitens ermöglicht die Fokussierung auf die einzelnen Gründungsphasen ein besseres Verständnis der Veränderungstendenzen einschließlich der Kausalzusammenhänge (wann, wie und warum). Insbesondere werden Erkenntnisse zur Auffälligkeit von Veränderungssprüngen von einer Phase zur anderen geliefert. Drittens kann durch die Beleuchtung der verschiedenen Subdimensionen von Effectuation und Causation ihre zunehmend hybride Verwendung im Zeitverlauf der Gründung das Verständnis für transformative Prozesse entwickeln.
This paper introduces the concept of Universal Memory Automata (UMA) and automated compilation of Verilog Hardware Description Language (HDL) code at Register Transfer Level (RTL) from UMA graphs for digital designs. The idea is based on the observation that Push Down Automata (PDA) are able to process the Dyk-Language - commonly known as the balanced bracket problem - with a finite set of states while Finite State Machines (FSM) require an infinite set of states. Since infinite sets of states are not applicable to real designs, PDAs appear promising for types of problems similar to the Dyk-Language. PDAs suffer from the problem that complex memory operations need to be emulated by a specific stack management. The presented UMA therefore extends the PDA by other types of memory, e.g. Queue, RAM or CAM. Memories that are eligible for UMAs are supposed to have at least one read and one write port and a one-cycle read/write latency. With their modified state-transfer- and output-function, UMAs are able to operate user-defined numbers, configurations and types of memories. Proof of concept is given by an implementation of a cache coherency protocol, i.e. a practical problem in microprocessor design.
Botswana is a country in southern Africa with rich mineral resources, which has built its economy on mining. Due to challenges in the upcoming years caused by climate and demographic change, it aims to move away from a resource-based economy to a knowledge-based economy in the long term. In order to support the
process, the Maun Science Park, a centre for research and development is planned to be created in Maun, a town on the edge of the Okavango Delta. The project is initiated by the “International Resilience and Sustainability Partnership” (inRES), a non-governmental organization. The project is currently in the initiation phase.
The purpose of this thesis is to determine a cost framework with exemplary developer calculation and sensitivity analysis for the Maun Science Park Project in Botswana. Therefor, a source research was performed in a first step. Based on this, interviews were conducted with members of the inRES. Based on the data
obtained and further assumptions, a cost framework for the different project phases of the MSP project was established. Subsequently, a developer calculation
was exemplarily carried out on the basis of the project phase 2 and a sensitivity analysis was performed.
During the interviews, data was collected on the different project phases. It became clear that the interview partners had partly inconsistent perceptions
about different project phases. The calculation can be used as a basis for further calculation at the time of concretization of the planning data.
Urban car-free mobility
(2021)
Across the globe, urban areas experience the phenomena of rising road-congestion, air pollution and car accidents. These are just a few popular quantified effects that arise due to rapid, uncoordinated urbanization on a car-centric city layout. There is an urgent need to consider new concepts of urban mobility development to combat these negative effects. Car-free mobility is one notion adopted in diverse formats by numerous cities to create a more inclusive, just, healthy and sustainable urban life. The focus of this thesis is to ex- amine whether a car-free mobility concept is applicable to the Maun Science Park, Bot- swana. Therefore, the idea of car-free mobility, its positive aspects as well as its con- straints, are described first. This illustrates the complexity of urban transport planning as it is intertwined with urban land-use, political vision and people’s perceptions and behav- iors. Secondly, examples and strategies on how to change existing structures are pre- sented. Following this, the smart developments in the field of sustainable urban mobility are considered to provide an insight into their assets and drawbacks. Then the local mo- bility conditions are examined before the car-free concept is exemplarily applied to the Maun Science Park via scenario construction. These scenarios give a first vision of how a car-free concept can be applied to the MSP and additionally provide a starting point for future strategic planning as well as inspiration for other cities to follow along.
The present work proposes the use of modern ICT technologies such as smartphones, NFCs, internet, and web technologies, to help patients in carrying out their therapies. The implemented system provides a calendar with a reminder of the assumptions, ensures the drug identification through NFC, allows remote assistance from healthcare staff and family members to check and manage the therapy in real-time. The system also provides centralized information on the patient's therapeutic situation, helpful in choosing new compatible therapies.
A nonlinear mathematical model for the dynamics of permanent magnet synchronous machines with interior magnets is discussed. The model of the current dynamics captures saturation and dependency on the rotor angle. Based on the model, a flatness-based field-oriented closed-loop controller and a feed-forward compensation of torque ripples are derived. Effectiveness and robustness of the proposed algorithms are demonstrated by simulation results.
With the increasing challenges of the 21st century, such as a rapidly growing population, increasing hunger and the destruction of the environment, the demand for sustainable and future-oriented ways of living is growing. To meet this demand, a residential district named Maun Science Park is being built in Botswana to develop a resilient society. In addition to the application of modern technology to optimise the use of resources, the environmentally friendly construction of the buildings is another goal of the project. This thesis investigates the prefabrication of rammed earth in terms of implementation and profitability for the Maun Science Park.
For this purpose, the specific properties, handling, as well as the application of the building material in prefabrication are first discussed.
This is followed by an investigation of how the work processes of prefabrication can be implemented in the Maun Science Park. Based on this, a profitability test is carried out using a break-even and sensitivity analysis.
The analyses showed that the investment in prefabrication is not profitable within the assumed production volume, which is due to the high fixed costs. These are primarily generated by the two main cost drivers, consisting of the new construction of the production hall and the rental of heavy construction equipment.
Lastly, recommendations for action were formulated that provide for a cost reduction in both the two main cost drivers as well as for other decisive factors.
In Maun, Botswana, a self-sufficient, sustainable and future-oriented district will be created, the Maun Science Park. Within this project, several 5-8 storey smart homes shall be built in sustainable construction. The aim of this thesis is to develop a sustainable structural concept for those homes of the Maun Science Park. In a first step, the general basics for tall building structures and sustainable construction were established. Based on those fundamentals, criteria for the structural requirements, the ecological as well as the social sustainability of a structural design could be defined. Subsequently, four structural systems were drafted: a concrete core structure, a steel shear frame structure, a rammed earth shear wall structure and a wooden diagrid structure. In addition to the pre-dimensioning of the systems, a life cycle assessment was set up to evaluate the ecological sustainability of the designs. With the help of a utility value analysis, the wooden diagrid structure was determined as the preferred variant. The comparison of the designs also allows to draw general conclusions for the development of sustainable tall building structures. The results of the life cycle assessment show the advantage of wood as an ecological building material over industrially manufactured building materials, such as steel and concrete. Whereas rammed earth, a likewise ecological building material, is not convincing due to its low strength. In general, a balance is created in the life cycle assessment between ecological and industrially manufactured products in regard of strength and environmental impact. In terms of social sustainability, the design of the structure system can significantly influence the flexibility and use of local resources. However, due to the diversity of sustainable construction, the development of a structural system should be linked to an overarching sustainability concept that takes architecture and stakeholders into account.
Ballistocardiography (BCG) can be used to monitor heart rate activity. Besides, the accelerometer should have high sensitivity and minimal internal noise; a low-cost approach was taken into consideration. Several measurements have been executed to determine the optimal positioning of a sensor under the mattress to obtain a signal strong enough for further analysis. A prototype for an unobtrusive accelerometer-based measurement system has been developed and tested in a conventional bed without any specific extras. The influence of the human sleep position for the output accelerometer data was tested. The obtained results indicate the potential to capture BCG signals using accelerometers. The measurement system can detect heart rate in an unobtrusive form in the home environment.
We compared vulnerable and fixed versions of the source code of 50 different PHP open source projects based on CVE reports for SQL injection vulnerabilities. We scanned the source code with commercial and open source tools for static code analysis. Our results show that five current state-of-the-art tools have issues correctly marking vulnerable and safe code. We identify 25 code patterns that are not detected as a vulnerability by at least one of the tools and 6 code patterns that are mistakenly reported as a vulnerability that cannot be confirmed by manual code inspection. Knowledge of the patterns could help vendors of static code analysis tools, and software developers could be instructed to avoid patterns that confuse automated tools.
Einsatz von Bankettbeton bei schmalen und stark beanspruchten Ortsverbindungs- und Kreisstraßen
(2021)
The Global Sanctions Data Base (GSDB): an update that includes the years of the Trump presidency
(2021)
In der Nachhaltigkeits-Diskussion spielen anthropogene Treibhausgasemissionen durch den von ihnen hervorgerufenen Klimawandel eine entscheidende Rolle. Im Zuge dessen entscheidet sich die Hochschule Technik, Wirtschaft und Gestaltung in Konstanz (HTWG), eine jährliche Treibhausgasbilanzierung zu erstellen. Durch die jährliche Erfassung der hochschulbezogenen Emissionen erfolgt das Monitoring (dt.: Überwachung).
Die Bilanzierung und Überwachung der durch die Hochschule und ihren Betrieb verursachten Treibhausgasemissionen (THG-Emissionen) dienen als Ausgangspunkt für lokalen Klima-schutz. Die wesentlichen Handlungsfelder werden durch das Identifizieren der Hauptursachen für Treibhausgasemissionen ermittelt und setzen den Startpunkt für die Planung, Auswahl und Umsetzung von Klimaschutzaktivitäten. Durch eine langfristige und regelmäßige Überwachung der Emissionen trägt die HTWG auch über ihre lokalen Systemgrenzen hinaus zum gesellschaftlichen Umweltbewusstsein bei.
Um das Erreichen dieses Ziels zu unterstützen, wird im Rahmen der vorliegenden Abschlussarbeit ein Pflichtenheft erstellt. Dieses enthält eine Ausarbeitung über die erforderlichen Organisations- und Arbeitsstrukturen für das Monitoring der THG-Emissionen. Des Weiteren erfolgt mit der Status-Quo-Abschätzung der THG-Emissionen des festgelegten Basisjahres 2019 die erste exemplarische Praxisanwendung des Pflichtenheftes. Das Monitoring wird mit der Zielsetzung einer maßnahmen- und umsetzungsorientierten Anwendung konzeptioniert, dessen jährliche Erhebung mit einem vertretbaren Aufwand zu realisieren ist.
Der Inhalt dieser Arbeit befasst sich mit der Verwendung von regionalen Ressourcen in Form von Erde. Diese soll als Baumaterial unter Anwendung der Stampflehmbauweise für
ökologischeres Bauen dienen. Damit der Baustoff den Ansprüchen heutiger Bauaufgaben gerecht wird, wird untersucht, mit welchen nachhaltigen Methoden die Erde stabilisiert werden kann. Darüber hinaus wird nach einem zukunftsweisenden Fertigungsverfahren
für den Stampflehmbau gesucht. Die Nutzung und Kombination dieser Aspekte bezeichnen wir als Erdbau 4.0, welcher unter anderem für das Maun Sciene Park Projekt in Botswana infrage kommen könnte.
The last decades have shown that the volume of tourism, in general, is constantly increasing (with some justified exceptions). To offer a possibility of travel for all groups of people, it is necessary to pay attention to accessibility. One of the possibilities for increasing accessibility is digital technologies, which could assist in planning and the implementation and completion of trips. To make a selection of technologies, first, a study of barriers was conducted, which was then analyzed, and finally, some technologies were made available in a test setup. A focus on two technologies was made: 360°-Tours and mobile app with the travel information. The two technologies were implemented and presented to the test subjects.
The evaluation results showed that both technologies could increase accessibility if some essential aspects (such as usability, completeness, relevance, etc.) are considered during the implementation.
The development of home health systems can provide continuous and user-friendly monitoring of key health parameters. This project aims to create a concept for such a system, implement it on a test basis, and evaluate it. Three health areas were selected for this purpose:
Sleep, Stress, and Rehabilitation. Appropriate devices were installed in the homes of test subjects and used by them for two weeks. Besides, relevant questionnaires were completed to obtain a complete picture. Finally, the implemented system was evaluated, and the results of the conducted study showed that home health systems have great potential. However, it is necessary to consider some points to increase the usability of the system and the motivation of the users. Among others, ease of use of the equipment is of extreme importance.
Health monitoring in a home environment can have broader use since it may provide continuous control of health parameters with relatively minor intrusiveness into regular life. This work aims to verify if it is possible to replace the typical in some sleep medicine areas subjective questioning by an objective measurement using electronic devices. For this purpose, a study was conducted with ten subjects, in which objective and subjective measurement of relevant sleep parameters took place. The results of both measurement methods were evaluated and analyzed. The results showed that while for some measures, such as Total Time in Bed, there is a high agreement between objective and subjective measurements, for others, such as sleep quality, there are significant differences. For this reason, currently, a combination of both measurement methods may be beneficial and provide the most detailed results, while a partial replacement can already reduce the number of questions at the subjective measurement by measurement through electronic devices.
Twenty-first century infrastructure needs to respond to changing demographics, becoming climate neutral, resilient, and economically affordable, while remaining a driver for development and shared prosperity. However, the infrastructure sector remains one of the least innovative and digitalized, plagued by delays, cost overruns, and benefit shortfalls. The authors assessed trends and barriers in the planning and delivery of infrastructure based on secondary research, qualitative
interviews with internationally leading experts, and expert workshops. The analysis concludes that the root-cause of the industry’s problems is the prevailing fragmentation of the infrastructure value chain and a lacking long-term vision for infrastructure. To help overcome these challenges, an integration of the value chain is needed. The authors propose that this could be achieved through a use-case-based, as well as vision and governance-driven creation of federated digital platforms applied to infrastructure projects and outline a concept. Digital platforms enable full-lifecycle participation and responsible governance guided by a shared infrastructure vision. This paper has contributed as policy recommendation to the Group of Twenty (G20) in 2021.
Introduction. Despite its high accuracy, polysomnography (PSG) has several drawbacks for diagnosing obstructive sleep apnea (OSA). Consequently, multiple portable monitors (PMs) have been proposed. Objective. This systematic review aims to investigate the current literature to analyze the sets of physiological parameters captured by a PM to select the minimum number of such physiological signals while maintaining accurate results in OSA detection. Methods. Inclusion and exclusion criteria for the selection of publications were established prior to the search. The evaluation of the publications was made based on one central question and several specific questions. Results. The abilities to detect hypopneas, sleep time, or awakenings were some of the features studied to investigate the full functionality of the PMs to select the most relevant set of physiological signals. Based on the physiological parameters collected (one to six), the PMs were classified into sets according to the level of evidence. The advantages and the disadvantages of each possible set of signals were explained by answering the research questions proposed in the methods. Conclusions. The minimum number of physiological signals detected by PMs for the detection of OSA depends mainly on the purpose and context of the sleep study. The set of three physiological signals showed the best results in the detection of OSA.
Identifikation von Schlaf- und Wachzuständen durch die Auswertung von Atem- und Bewegungssignalen
(2021)
In this paper, a novel measurement model based on spherical double Fourier series (DFS) for estimating the 3D shape of a target concurrently with its kinematic state is introduced. Here, the shape is represented as a star-convex radial function, decomposed as spherical DFS. In comparison to ordinary DFS, spherical DFS do not suffer from ambiguities at the poles. Details will be given in the paper. The shape representation is integrated into a Bayesian state estimator framework via a measurement equation. As range sensors only generate measurements from the target side facing the sensor, the shape representation is modified to enable application of shape symmetries during the estimation process. The model is analyzed in simulations and compared to a shape estimation procedure using spherical harmonics. Finally, shape estimation using spherical and ordinary DFS is compared to analyze the effect of the pole problem in extended object tracking (EOT) scenarios.
SyNumSeS is a Python package for numerical simulation of semiconductor devices. It uses the Scharfetter-Gummel discretization for solving the one dimensional Van Roosbroeck system which describes the free electron and hole transport by the drift-diffusion model. As boundary conditions voltages can be applied to Ohmic contacts. It is suited for the simulation of pn-diodes, MOS-diodes, LEDs (hetero junction), solar cells, and (hetero) bipolar transistors.
This paper describes the rationale and the development of a structured digital approach for measuring corporate environmental sustainability using performance metrics.
It is impossible to imagine today's age without the preservation of our environment, not even in the corporate environment. Currently, sustainability is mostly only rudimentarily considered in companies, mostly only with written down phrases on the website. This will no longer be sufficient in the future, which is why companies should record sustainability on a numerical basis. Based on the development of a workable concept for companies, a small empirical study was carried out, which can be used to numerically measure the sustainability performance of companies. Two utility analyses were completed.
One of them was supplemented by expert interviews. Well-known practitioners from the business world were interviewed and asked for their assessment of ecological performance indicators. The result of the research is an indicator-based concept that can be applied in corporate practice to determine ecological sustainability performance.
Im Zuge zunehmender Effizienzbestrebungen in produzierenden Unternehmen spielt auch die Optimierung von indirekten Wertschöpfungsprozessen eine immer größere Rolle. Neben einer ansteigenden Aufgabenvielfalt stellt ein parallel wachsender Kostendruck eine doppelte Herausforderung dar. Dies gilt insbesondere für Einkaufsbereiche entsprechender Organisationen, welche an der Schnittstelle zwischen der unternehmensinternen und -externen Wertschöpfungskette operieren und an dieser einen essenziellen Beitrag auch im Sinne des Informationsflusses zur Unterstützung eines integrierten Supply Chain Managements darstellen. Um diesen zu begegnen, ist es notwendig, die relevanten Kernprozesse der Einkaufsbereiche stetig im Blick zu halten und Verbesserungsmöglichkeiten zu identifizieren und umzusetzen. Dieser Beitrag will zu einem Überblick für die Prozessoptimierung mithilfe des Einsatzes digitaler Technologien speziell in Einkaufsbereichen beitragen. Es werden die Spezifika des Einkaufs vorgestellt, relevante Kernaufgaben beschrieben und exemplarisch technologische Ansätze zur Prozessoptimierung anhand von Process Mining, Robotic Process Automation und künstlicher Intelligenz aufgezeigt.
Das produzierende Gewerbe in Deutschland erlebt aufgrund von Technologiewandel im Automobilbau, der Anpassung von Lieferketten und der digitalen Transformation grundlegende Veränderungen. Diese als Chance für künftiges Wachstum zu begreifen ist essenziell und eine zwingende Voraussetzung für den Wirtschaftsstandort Deutschland. Anhand eines konkreten Unternehmensbeispiels werden hierfür zentrale Aspekte für Transformation eines mittelständischen produzierenden Blechbearbeitungsunternehmens hin zu einem netzwerkbasierten Geschäftsmodell betrachtet. Auf Basis der Analyse von Referenzbeispielen webbasierter Vertriebsplattformen in der Blechbearbeitung werden erfolgsrelevante Aspekte für die Ausgestaltung und die Umsetzung für ein Onlineplattformmodell beschrieben. Hierbei wird exemplarisch dargelegt, wie mittels digitaler Vertriebsplattformen in Verbindung mit digitalen Auftragsmanagementprozessen neue Wege für Wachstum ermöglicht werden können.
InnoCrowd, a Product Classification System for Design Decision in a Crowdsourced Product Innovation
(2021)
System engineering focuses on how to design and manage complex systems. Meanwhile, in the era of Industry 4.0 and Internet of Things (IoT), systems are getting more complex. Contributors to higher complexity include the usage of modern components (e.g. mechatronics), new manufacturing technologies (e.g. 3D Print) and new engineering product development processes, e.g. open innovation. Open innovation is enabled by IoT, where people and devices are easily connected, and it supports development of more innovative products through ideas gained from predecessors and collaborators world wide. Some researchers suggest this approach is up to three times faster and five times cheaper than conventional approaches [Gassmann, 2012], [Howe, 2008], [Kusumah, 2018]. Because open innovation is relatively new, many managers do not know how to employ it effectively in some phases of product development [Schenk, 2009], [Afuah, 2017], including requirements definition, design and engineering processes (task assignment) through quality assurance. Also, they have trouble estimating and controlling development time and cost [Nevo, 2020], [Thanh, 2015]. As a consequence, the acceptance of this new approach in the industry is limited. Research activities addressing this new approach mainly address high-level and qualitive issues. Few effective methods are available to estimate project risk and to decide whether to initiate a project.
We propose InnoCrowd, a decision support system that uses an improved method to support these tasks and make decisions about crowdsourced engineering product development.
InnoCrowd uses natural language processing and machine learning to build a knowledgebase of crowdsourced product developments. InnoCrowd presents a manager with results of similar projects to show which practices led to good results. A manager of a new project can use this guidance to employ best practices for product requirements definition, project schedule, and other aspects, thereby reducing risk and increasing chances for success.
Background:
One of the most promising health care development areas is introducing telemedicine services and creating solutions based on blockchain technology. The study of systems combining both these domains indicates the ongoing expansion of digital technologies in this market segment.
Objective:
This paper aims to review the feasibility of blockchain technology for telemedicine.
Methods:
The authors identified relevant studies via systematic searches of databases including PubMed, Scopus, Web of Science, IEEE Xplore, and Google Scholar. The suitability of each for inclusion in this review was assessed independently. Owing to the lack of publications, available blockchain-based tokens were discovered via conventional web search engines (Google, Yahoo, and Yandex).
Results:
Of the 40 discovered projects, only 18 met the selection criteria. The 5 most prevalent features of the available solutions (N=18) were medical data access (14/18, 78%), medical service processing (14/18, 78%), diagnostic support (10/18, 56%), payment transactions (10/18, 56%), and fundraising for telemedical instrument development (5/18, 28%).
Conclusions:
These different features (eg, medical data access, medical service processing, epidemiology reporting, diagnostic support, and treatment support) allow us to discuss the possibilities for integration of blockchain technology into telemedicine and health care on different levels. In this area, a wide range of tasks can be identified that could be accomplished based on digital technologies using blockchains.
Die fortschreitende Urbanisierung sowie die voranschreitende digitale Transformation stellen viele Städte vor großen Herausforderungen. Um den wirtschaftlichen und gesellschaftlichen Veränderungsprozessen gerecht zu werden, braucht es innovative Lösungen. Die Nutzung digitaler Technologien und Daten eröffnen Städten neue Möglichkeiten, um sich zukunftsfähig zu gestalten. So wird die Stadt der Zukunft eine Stadt der Daten sein. Sie ist smart, vernetzt und entwickelt intelligente, digitale Lösungen für sich und ihre Bürger. Digitale, offene föderierte Plattformen bilden hierbei das Herzstück. Als zentraler Zugangspunkt zu Daten schaffen sie eine grenzenlose Vernetzung und generieren einen Mehrwert für Stadt, Bürger und Wirtschaft. Sie vereinen smarte Dienste und Services, verbessern die digitale Teilhabe und erhöhen die Lebensqualität in einer Stadt.
Das Ziel in der vorliegenden Arbeit ist die Entwicklung von Anwendungsfällen aus dem Bereich der Bauwirtschaft für offene, föderierte digitale Plattformen. Der Fokus liegt hierbei auf der Online-Plattform für sogenannte digitale Zwillinge, die ein virtuelles Abbild der Realität erschaffen. Der virtuelle Stadtzwilling bildet das Fundament zahlreicher Smart City-Konzepte. Er ist ein Smart City-Werkzeug, das aufgrund seiner vielfältigen Einsatzfähigkeit für Städte großes Potenzial bietet.
Der Stadt Konstanz eröffnen sich mit der Etablierung eines digitalen Stadtzwillings neue Möglichkeiten für eine resiliente und umweltschonende Gestaltung ihres urbanen Raums. Der digitale Zwilling findet in den unterschiedlichsten Feldern Anwendung. So kann er beispielsweise für die Entwicklung klimaoptimierter Bebauungsszenarien eingesetzt oder für intelligent vorausschauende Verkehrsleitsysteme genutzt werden. Darüber hinaus ermöglicht er neue Formen mit der Öffentlichkeit zu interagieren, indem er geplante Bauvorhaben und deren Auswirkungen realitätsgetreu abbildet. Dennoch stellt die Etablierung und die vollumfängliche Nutzung des digitalen Zwillings die Stadt Konstanz vor großen Herausforderungen. So setzt die Anwendung smarter städtischer Lösungen einen ausreichenden Datenschutz voraus. Darüber hinaus ist die digitale Transformation ein zeitintensiver und kostenaufwendiger Prozess, für den entsprechende Ressourcen benötigt werden. Zudem bedarf es einen gesellschaftsübergreifenden Paradigmenwechsel, der bislang nur langsam voranschreitet. Dennoch ist es unerlässlich, dass die Stadt Konstanz die Herausforderungen annimmt und die Chancen ergreift, um zu einer zukunftsfähigen und digitalen Stadt zu werden. Denn der digitale Zwilling bildet einen zentralen Baustein auf dem Weg zu einer Smart City.
Specific climate adaptation and resilience measures can be efficiently designed and implemented at regional and local levels. Climate and environmental databases are critical for achieving the sustainable development goals (SDGs) and for efficiently planning and implementing appropriate adaptation measures. Available federated and distributed databases can serve as necessary starting points for municipalities to identify needs, prioritize resources, and allocate investments, taking into account often tight budget constraints. High-quality geospatial, climate, and environmental data are now broadly available and remote sensing data, e.g., Copernicus services, will be critical. There are forward-looking approaches to use these datasets to derive forecasts for optimizing urban planning processes for local governments. On the municipal level, however, the existing data have only been used to a limited extent. There are no adequate tools for urban planning with which remote sensing data can be merged and meaningfully combined with local data and further processed and applied in municipal planning and decision-making. Therefore, our project CoKLIMAx aims at the development of new digital products, advanced urban services, and procedures, such as the development of practical technical tools that capture different remote sensing and in-situ data sets for validation and further processing. CoKLIMAx will be used to develop a scalable toolbox for urban planning to increase climate resilience. Focus areas of the project will be water (e.g., soil sealing, stormwater drainage, retention, and flood protection), urban (micro)climate (e.g., heat islands and air flows), and vegetation (e.g., greening strategy, vegetation monitoring/vitality). To this end, new digital process structures will be embedded in local government to enable better policy decisions for the future.
Twenty-first century infrastructure needs to respond to changing demographics, becoming climate neutral, resilient and economically affordable, while remaining a driver for development and shared prosperity. However, the infrastructure sector remains one of the least innovative and digitalised, plagued by delays, cost overruns and benefit shortfalls (Cantarelli et al. 2008; Flyvbjerg, 2007; Flyvbjerg et al., 2003; Flyvbjerg et al., 2004). The root cause is the prevailing fragmentation of the infrastructure sector (Fellows and Liu, 2012). To help overcome these challenges, integration of the value chain is needed. This could be achieved through a use-case-based creation of federated ecosystems connecting open and trusted data spaces and advanced services applied to infrastructure projects. Such digital platforms enable full-lifecycle participation and responsible governance guided by a shared infrastructure vision. Digital federation enables secure and sovereign data exchange and thus collaboration across the silos within the infrastructure sector and between industries as well as within and between countries. Such an approach to infrastructure technology policy would not rely on technological solutionism but proposes the development of open and trusted data alliances. Federated data spaces provide access to the emerging data economy, especially for SMEs, and can foster the innovation of new digital services. Such responsible digital governance can help make the infrastructure sector more resilient, efficient and aligned with the realisation of ambitious decarbonisation and environmental protection targets. The European Union and the United States have already developed architectures for sovereign and secure data exchange.
Preliminary results of homomorphic deconvolution application to surface EMG signals during walking
(2021)
Homomorphic deconvolution is applied to sEMG signals recorded during walking. Gastrocnemius lateralis and tibialis anterior signals were acquired according to SENIAM recommendation. MUAP parameters like amplitude and scale were estimated, whilst the MUAP shape parameter was fixed. This features a useful time-frequency representation of sEMG signal. Estimation of scale MUAP parameter was verified extracting the mean frequency of filtered EMG signal, extracted from the scale parameter estimated with two different MUAP shape values.
Normal breathing during sleep is essential for people’s health and well-being. Therefore, it is crucial to diagnose apnoea events at an early stage and apply appropriate therapy. Detection of sleep apnoea is a central goal of the system design described in this article. To develop a correctly functioning system, it is first necessary to define the requirements outlined in this manuscript clearly. Furthermore, the selection of appropriate technology for the measurement of respiration is of great importance. Therefore, after performing initial literature research, we have analysed in detail three different methods and made a selection of a proper one according to determined requirements. After considering all the advantages and disadvantages of the three approaches, we decided to use the impedance measurement-based one. As a next step, an initial conceptual design of the algorithm for detecting apnoea events was created. As a result, we developed an activity diagram on which the main system components and data flows are visually represented.
Respiratory diseases are leading causes of death and disability in the world. The recent COVID-19 pandemic is also affecting the respiratory system. Detecting and diagnosing respiratory diseases requires both medical professionals and the clinical environment. Most of the techniques used up to date were also invasive or expensive.
Some research groups are developing hardware devices and techniques to make possible a non-invasive or even remote respiratory sound acquisition. These sounds are then processed and analysed for clinical, scientific, or educational purposes.
We present the literature review of non-invasive sound acquisition devices and techniques.
The results are about a huge number of digital tools, like microphones, wearables, or Internet of Thing devices, that can be used in this scope.
Some interesting applications have been found. Some devices make easier the sound acquisition in a clinic environment, but others make possible daily monitoring outside that ambient. We aim to use some of these devices and include the non-invasive recorded respiratory sounds in a Digital Twin system for personalized health.
Ferromagnetism is of increasing importance in the growing field of electromobility and data storage. In stable austenitic steels, the occurrence of ferromagnetism is not expected and would also interfere with many applications. However, ferromagnetism in austenitic stainless steels after low-temperature nitriding has already been shown in the past. Herein, the presence of ferromagnetism in austenitic steels is discovered after low-temperature carburization (Kolsterizing), which represents a novel and unique finding. A zone of expanded austenite is established on various austenitic stainless steels by low-temperature carburization and the respective ferromagnetism is investigated in relation to the alloy composition. The ferromagnetism occurring is determined by means of a commercial magnetoinductive sensor (Feritscope). Ferromagnetic domains are visualized by magnetic force microscopy and a ferrofluid. X-ray diffraction measurements indicate a clear difference in the lattice expansion of the different alloys. Furthermore, a different appearance of the magnetizable microstructure regions (magnetic domain structure) is detected depending on the grain orientation determined by electron backscatter diffraction (EBSD). Strongly pronounced magnetic domains show no linear lattice defects, whereas in small magnetizable areas linear lattice defects are detected by electron channeling contrast imaging and EBSD.