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Moderne als Geschichte
(2015)
Das Software-System MODES ist ein Programmwerkzeug zur Planung und Optimierung von Energieversorgungsanlagen bezüglich Auslegung und Energiemanagement. Es ermöglicht die integrierte Betrachtung von Wärme- und Elektroenergie unter Einschluss von erneuerbaren Energieträgern. Da für die Eingabeparameter nicht nur feste Werte, sondern auch Unschärfebereiche eingegeben werden können, ist ein stochastische Behandlung der Ergebnisse möglich. Neben der technischen erfolgt ebenfalls die in der Praxis unumgängliche wirtschaftliche Simulation. Damit ist mit Hilfe von MODES eine numerische, mehrkriterielle technische und energiewirtschaftliche Bewertung von Energieversorgungssystemen möglich. Es handelt sich um den Abschlußbericht des entsprechenden Projektes für das Bundesministerium für Bildung und Forschung, Förderkennzeichen 1707499. Vertrauliche Stellen wurden aus dem vorliegenden Text herausgenommen.
Domain-specific modeling is more and more understood as a comparable solution compared to classical software development. Textual domain-specific languages (DSLs) already have a massive impact in contrast tographical DSLs, they still have to show their full potential. The established textual DSLs are normally generated from a domain specific grammar or maybe other specific textual descriptions. And advantage of textual DSLs is that they can be development cost-efficient.
In this paper, we describe asimilar approach for the creation of graphical DSLs from textual descriptions. We present a set of specially developed textual DSLs to fully describe graphical DSLs based on node and edge diagrams. These are, together with an EMF meta-model, the input for a generator that produces an eclipse-based graphical Editor. The entire project is available as open source under the name MoDiGen.
Monitor Energiewende 2015
(2015)
In der Region Konstanz setzen sich zahlreiche Akteure - von Unternehmen über Energieversorger, Bildungsinstitutionen und Stadtverwaltungen bis zu Umweltschutzverbänden - dafür ein, durch konkrete Projekte die Energiewende vor Ort voranzubringen. Das Forschungsprojekt „Kompetenzzentrum
Energiewende Region Konstanz“ an der Hochschule Konstanz unterstützt diese Aktivitäten - u.a. mit einem jährlichen Monitor zum Stand der Energiewende in der Region Konstanz. Im Monitor 2015 wurden erstmals landkreisbezogene Daten zur Energiewende zusammengefasst und in den Kontext der landesweiten Ziele gestellt. Stand: Januar 2015
Monitor Energiewende 2016
(2016)
Monitor Energiewende 2017
(2017)
Im Monitor 2017 wurde der Stand der Energiewende im Landkreis Konstanz aktualisiert und erweitert. Dabei lag ein Fokus zum einen auf der Frage, wie sich die ungewöhnlich hohe Bevölkerungszunahme in den Jahren 2014 und 2015 sowie die prognostizierte Bevölkerungsentwicklung bis zum Jahr 2035 auf den Energiebedarf, die erneuerbaren Energiepotenziale und die Treibhausgasemissionen des Landkreises auswirken. Zum anderen wurde untersucht, welche Stellschrauben sich eignen, um den Energiebedarf und die Treibhausgasemissionen trotz des Bevölkerungswachstums in dem angestrebten Umfang zu reduzieren.
Monitor Energiewende 2020
(2021)
Sleep is extremely important for physical and mental health. Although polysomnography is an established approach in sleep analysis, it is quite intrusive and expensive. Consequently, developing a non-invasive and non-intrusive home sleep monitoring system with minimal influence on patients, that can reliably and accurately measure cardiorespiratory parameters, is of great interest. The aim of this study is to validate a non-invasive and unobtrusive cardiorespiratory parameter monitoring system based on an accelerometer sensor. This system includes a special holder to install the system under the bed mattress. The additional aim is to determine the optimum relative system position (in relation to the subject) at which the most accurate and precise values of measured parameters could be achieved. The data were collected from 23 subjects (13 males and 10 females). The obtained ballistocardiogram signal was sequentially processed using a sixth-order Butterworth bandpass filter and a moving average filter. As a result, an average error (compared to reference values) of 2.24 beats per minute for heart rate and 1.52 breaths per minute for respiratory rate was achieved, regardless of the subject’s sleep position. For males and females, the errors were 2.28 bpm and 2.19 bpm for heart rate and 1.41 rpm and 1.30 rpm for respiratory rate. We determined that placing the sensor and system at chest level is the preferred configuration for cardiorespiratory measurement. Further studies of the system’s performance in larger groups of subjects are required, despite the promising results of the current tests in healthy subjects.
Measuring the natural frequency of buildings and bridges is a possibility to get information about the stiffness of the construction. Decreasing stiffness can be detected be repeatedly measurements. Damaged parts of the construction or too high wood moisture can be reasons for decreasing stiffness. The earlier the failure is detected the better is the chance to repair it with low costs. The method of monitoring by repeatedly measuring the natural frequency is applied at timber bridges, especially on footbridges. As damages due to high wood moisture cannot be seen easily, measuring the natural frequency is a good possibility to detect them and then to repair them. Equations to calculate the natural frequencies regarding the damaged parts are shown and applied to a simple supported beam.
The Montgomery multiplication is an efficient method for modular arithmetic. Typically, it is used for modular arithmetic over integer rings to prevent the expensive inversion for the modulo reduction. In this work, we consider modular arithmetic over rings of Gaussian integers. Gaussian integers are subset of the complex numbers such that the real and imaginary parts are integers. In many cases Gaussian integer rings are isomorphic to ordinary integer rings. We demonstrate that the concept of the Montgomery multiplication can be extended to Gaussian integers. Due to independent calculation of the real and imaginary parts, the computation complexity of the multiplication is reduced compared with ordinary integer modular arithmetic. This concept is suitable for coding applications as well as for asymmetric key cryptographic systems, such as elliptic curve cryptography or the Rivest-Shamir-Adleman system.
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.
Im diesem Beitrag geht es darum zu zeigen, dass die spezifisch ethische Dimension der Go-vernanceethik als kohärentistische Ethikauffassung gedeutet - und begründungstheoretisch unterfüttert - werden kann. Mein Blick richtet sich also vor allem auf die Frage, wie ethisches Nachdenken kohärentistisch konzeptualisiert werden kann und, im zweiten Schritt, in welchem Sinne es m.E. eine strukturelle Parallele bzw. Anschlussfähigkeit von Kohärentismus und Governanceethik gibt. Es geht also im Folgenden weder darum, die Governanceethik als bereichsspezifische wirtschafts- und unternehmensethische Theorie zu untersuchen noch darum, bestimmte Referenzpunkte des Wielandschen Governanceethik-Modells1 wie z.B. ihre systemtheoretischen Prämissen zu diskutieren. Beginnen werde ich mit einer Bestimmung ethischen Nachdenkens als einer Orientierungsreflexion, die nicht letzte Prinzipien begründen, sondern vernünftige Selbstorientierung moralischer Akteure ermöglichen soll. Vor diesem Hintergrund wird das Theoriemodell des ethischen Kohärentismus entfaltet, um abschließend zu zeigen, dass dieses wesentliche Prämissen hinsichtlich der Auffassung über die Funktion ethischen Nachdenkens mit der Governanceethik teilt.
Motion safety for vessels
(2015)
The improvement of collision avoidance for vessels in close range encounter situations is an important topic for maritime traffic safety. Typical approaches generate evasive trajectories or optimise the trajectories of all involved vessels. The idea of this work is to validate these trajectories related to guaranteed motion safety, which means that it is not sufficient for a trajectory to be collision-free, but it must additionally ensure that an evasive manoeuvre is performable at any time. An approach using the distance and the evolution of the distance to the other vessels is proposed. The concept of Inevitable Collision States (ICS) is adopted to identify the states for which no evasive manoeuvre exist. Furthermore, it is implemented into a collision avoidance system for recreational crafts to demonstrate the performance.
Recently published nonlinear model-based control
approaches achieve impressive performances in complex real-
world applications. However, due to model-plant mismatches
and unforeseen disturbances, the model-based controller’s per-
formance is limited in full-scale applications. In most applica-
tions, low-level control loops mitigate the model-plant mismatch
and the sensitivity to disturbances. But what is the influence
of these low-level control loops? In this paper, we present
the model predictive path integral (MPPI) control of a self-
balancing vehicle and investigate the influence of subordinate
control loops on closed-loop performance. Therefore, simulation
and full-scale experiments are performed and analyzed. Subor-
dinate control loops empower the MPPI controller because they
dampen the influence of disturbances, and thus improve the
model’s accuracy. This is the basis for the successful application
of model-based control approaches in real-world systems. All
in all, a model is used to design a low-level controller, then
its closed-loop behavior is determined, and this model is used
within the superimposed MPPI control loop – modeling for
control and vice versa.
In extended object tracking, a target is capable to generate more than one measurement per scan. Assuming the target being of elliptical shape and given a point cloud of measurements, the Random Matrix Framework can be applied to concurrently estimate the target’s dynamic state and extension. If the point cloud contains also clutter measurements or origins from more than one target, the data association problem has to be solved as well. However, the well-known joint probabilistic data association method assumes that a target can generate at most one detection. In this article, this constraint is relaxed, and a multi-detection version of the joint integrated probabilistic data association is proposed. The data association method is then combined with the Random Matrix framework to track targets with elliptical shape. The final filter is evaluated in the context of tracking smaller vessels using a high resolution radar sensor. The performance of the filter is shown in simulation and in several experiments.
Offline handwriting recognition systems often use LSTM networks, trained with line- or word-images. Multi-line text makes it necessary to use segmentation to explicitly obtain these images. Skewed, curved, overlapping, incorrectly written text, or noise can lead to errors during segmentation of multi-line text and reduces the overall recognition capacity of the system. Last year has seen the introduction of deep learning methods capable of segmentation-free recognition of whole paragraphs. Our method uses Conditional Random Fields to represent text and align it with the network output to calculate a loss function for training. Experiments are promising and show that the technique is capable of training a LSTM multi-line text recognition system.
Multi-faceted stresses of social, environmental, and economic nature are increasingly challenging the existence and sustainability of our societies. Cities in particular are disproportionately threatened by global issues such as climate change, urbanization, population growth, air pollution, etc. In addition, urban space is often too limited to effectively develop sustainable, nature-based solutions while accommodating growing populations. This research aims to provide new methodologies by proposing lightweight green bridges in inner-city areas as an effective land value capture mechanism. Geometry analysis was performed using geospatial and remote sensing data to provide geometrically feasible locations of green bridges. A multi-criteria decision analysis was applied to identify suitable locations for green bridges investigating Central European urban centers with a focus on German cities as representative examples. A cost-benefit analysis was performed to assess the economic feasibility using a case study. The results of the geometry analysis identified 3249 locations that were geometrically feasible to implement a green bridge in German cities. The sample locations from the geometry analysis were proved to be validated for their implementation potential. Multi-criteria decision analysis was used to select 287 sites that fall under the highest suitable class based on several criteria. The cost-benefit analysis of the case study showed that the market value of the property alone can easily outweigh the capital and maintenance costs of a green bridge, while the indirect (monetary) benefits of the green space continue to increase the overall value of the green bridge property including its neighborhood over time. Hence, we strongly recommend light green bridges as financially sustainable and nature-based solutions in cities worldwide.
This work introduces new signal constellations based on Eisenstein integers, i.e., the hexagonal lattice. These sets of Eisenstein integers have a cardinality which is an integer power of three. They are proposed as signal constellations for representation in the equivalent complex baseband model, especially for applications like physical-layer network coding or MIMO transmission where the constellation is required to be a subset of a lattice. It is shown that these constellations form additive groups where the addition over the complex plane corresponds to the addition with carry over ternary Galois fields. A ternary set partitioning is derived that enables multilevel coding based on ternary error-correcting codes. In the subsets, this partitioning achieves a gain of 4.77 dB, which results from an increased minimum squared Euclidean distance of the signal points. Furthermore, the constellation-constrained capacities over the AWGN channel and the related level capacities in case of ternary multilevel coding are investigated. Simulation results for multilevel coding based on ternary LDPC codes are presented which show that a performance close to the constellation-constrained capacities can be achieved.
Autonomous moving systems require very detailed information about their environment and potential colliding objects. Thus, the systems are equipped with high resolution sensors. These sensors have the property to generate more than one detection per object per time step. This results in an additional complexity for the target tracking algorithm, since standard tracking filters assume that an object generates at most one detection per object. This requires new methods for data association and system state filtering.
As new data association methods, in this thesis two different extensions of the Joint Integrated Probabilistic Data Association (JIPDA) filter to assign more than one detection to tracks are proposed.
The first method that is introduced, is a generalization of the JIPDA to assign a variable number of measurements to each track based on some predefined statistical models, which will be called Multi Detection - Joint Integrated Probabilistic Data Association (MD-JIPDA).
Since this scheme suffers from exponential increase of association hypotheses, also a new approximation scheme is presented. The second method is an extension for the special case, when the number and locations of measurements are a priori known. In preparation of this method, a new notation and computation scheme for the standard Joint Integrated Data Association is outlined, which also enables the derivation of a new fast approximation scheme called balanced permanent-JIPDA.
For state filtering, also two different concepts are applied: the Random Matrix Framework and the Measurement Generating Points. For the Random Matrix framework, first an alternative prediction method is proposed to account for kinematic state changes in the extension state prediction as well. Secondly, various update methods are investigated to account for the polar to Cartesian noise transformation problem. The filtering concepts are connected with the new MD-JIPDA and their characteristics analyzed with various Monte Carlo simulations.
In case an object can be modeled by a finite number of fixed Measurement Generating Points (MGP), also a proposition to track these object via a JIPDA filter is made. In this context, a fast Track-to-Track fusion algorithm is proposed as well and compared against the MGP-JIPDA.
The proposed algorithms are evaluated in two applications where scanning is done using radar sensors only. The first application is a typical automotive scenario, where a passenger car is equipped with six radar sensors to cover its complete environment.
In this application, the location of the measurements on an object can be considered stationary and that is has a rectangular shape. Thus, the MGP based algorithms are applied here. The filters are evaluated by tracking especially vehicles on nearside lanes.
The second application covers the tracking of vessels on inland waters. Here, two different kind of Radar systems are applied, but for both sensors a uniform distribution of the measurements over the target's extent can be assumed. Further, the assumption that the targets have elliptical shape holds, and so the Random Matrix Framework in combination with the MD-JIPDA is evaluated.
Exemplary test scenarios also illustrate the performance of this tracking algorithm.
Multistakeholder-Analyse zur Evaluation der KiCG Anforderungen an Compliance-Management-Systeme
(2015)
This paper focuses on the multivariable control of a drawing tower process. The nature of the process together with the differences in measurement noise levels that affect the variables to be controlled motivated the development of a new MPC algorithm. An extension of a multivariable predictive control algorithm with separated prediction horizons is proposed. The obtained experimental results show the usefulness of the proposed algorithm..
Mutual Information Analysis for Generalized Spatial Modulation Systems With Multilevel Coding
(2022)
Generalized Spatial Modulation (GSM) enables a trade-off between very high spectral efficiencies and low hardware costs for massive MIMO systems. This is achieved by transmitting information via the selection of active antennas from a set of available antennas besides the transmission of conventional data symbols. GSM systems have been investigated concerning various aspects like suitable signal constellations, efficient detection algorithms, hardware implementations, spatial precoding, and error control coding. On the other hand, determining the capacity of GSM is challenging because no closed-form expressions have been found so far. This paper investigates the mutual information for different GSM variants. We consider a multilevel coding approach, where the antenna selection and IQ modulation are encoded independently. Combined with multistage decoding, such an approach enables low-complexity capacity-achieving coded modulation. The influence of the data symbols on the mutual information is illuminated. We analyze the portions of mutual information related to antenna selection and the IQ modulation processes which depend on the GSM variant and the signal constellation. Moreover, the potential of spatial modulation for massive MIMO systems with many transmit antennas is investigated. Especially in systems with many transmit antennas much information can be conveyed by antenna selection.
Bedingt durch den fortwährenden Ausbau erneuerbarer Energien steigt die Bedeutung von regelenergiebereitstellenden Technologien kontinuierlich an. Prinzipiell können bereits heute Laufwasserkraftwerke mittels einer Durchlaufspeicherung Regelenergie bereitstellen. Bislang gibt es jedoch keinen einheitlichen Kriterienkatalog, der die technische Durchführbarkeit einer Durchlaufspeicherung bewertet. Im vorliegenden Beitrag wird ein solcher Katalog vorgestellt und am Beispiel des Unteren Neckars angewandt. Unter rein technischen Gesichtspunkten ist eine Durchlaufspeicherung zwar prinzipiell denkbar, allerdings unterbinden schifffahrtsbedingte Restriktionen eine solche Bereitstellung von Regelenergie. Es wird daher empfohlen, eine Durchlaufspeicherung generell an Gewässern ohne strikte Auflagen durch die Schifffahrt zu betreiben. Außerdem ist der Zusammenschluss von mehreren Staustufen zu einem virtuellen Kraftwerk sinnvoll, um zusätzlich generierbare Strommengen gebündelt anbieten zu können.
Der Bericht dokumentiert die Aktivitäten, die ich während des Wintersemesters 2023/24 im Rahmen meines Fortbildungssemesters durchgeführt habe. Der Forschungsschwerpunkt lag dabei auf der Umsetzung eines gemeinschaftlichen Projekts zur Bewertung mündlicher Prüfungen. Zusätzlich erfolgten Aufenthalte zur Förderung der internationalen Kooperationen an Partnerhochschulen.
A post-growth economy is a comparatively new paradigm in the tourism discourse. The aim of this article is to find out the commonalities between this concept and Māori tourism and in which way the latter can contribute to a post-growth economy. A qualitative mixed method approach, including in-depth-interviews, participant observation, and secondary analysis is applied. The results show that there is a lot of overlap between Māori tourism and a post-growth economy. Differences are visible, as well, regarding the value approach of Māori tourism and the indicator approach of a post-growth economy. Especially the social innovation created in Aotearoa New Zealand at the instigation of Māori groups of granting legal personhood to parts of nature may serve as a driver for a form of tourism that is in line with the idea of a post-growth economy.
Nachhaltigkeit
(2009)
Im Rahmen der Lehrveranstaltung "Nachhaltigkeit im industriellen Umfeld" im Masterstudiengang Umwelt- und Verfahrenstechnik der Hochschulen Konstanz und Ravensburg-Weingarten wurde 2015 eine studentische Fachkonferenz durchgeführt.
Die Studierenden entwickelten in Einzelarbeit oder als Zweierteam Konferenzbeiträge zu folgenden Themen:
- Innovationen und Spannendes aus dem Bereich der Energieerzeugung und -wandlung
- Aspekte der Schließung von Stoffkreisläufen und Vermeidung von Schadstoffeinträgen in die Umwelt
- Chancen und Herausforderungen Nachwachsender Rohstoffe bei verschiedenen Einsatzmöglichkeiten sowie Themen der Nachhaltigkeit in der Landwirtschaft
- verschiedene Blickwinkel auf das Thema Wasser (von der Abwasserreinigung bis zum Wasserkonsum der Konsumenten)
- die Betrachtung spezifischer Industrien und Unternehmen sowie deren Werkzeuge zur Umsetzung von Nachhaltigkeit
Die Ergebnisse der studentischen Fachkonferenz zur „Nachhaltigkeit im industriellen Umfeld“ werden in der vorliegenden Publikation präsentiert.
Im Rahmen der Lehrveranstaltung "Nachhaltigkeit im industriellen Umfeld" im Masterstudiengang Umwelt- und Verfahrenstechnik der Hochschulen Konstanz und Ravensburg-Weingarten fand im Dezember 2016 eine studentische Fachkonferenz statt. Die Studierenden entwickelten in Einzelarbeit oder als Zweierteam
Konferenzbeiträge zu folgenden Themen:
- Spannendes aus dem Bereich der Energieerzeugung und der Grauen Energie
- Aspekte der Kreislaufwirtschaft
- Ökosysteme - ihre Belastung und Erhalt
- Spezifische Wirtschaftszweige und Nachhaltigkeit
Die Ergebnisse der studentischen Fachkonferenz zur „Nachhaltigkeit im
industriellen Umfeld“ werden in der vorliegenden Publikation präsentiert.
Nachhaltige Entwicklung umfasst verschieden weite Definitionen und konzeptionelle Zugänge. Im Zentrum der Diskussion steht die zukünftige Entwicklungsfähigkeit von Biosphäre und Anthroposphäre im Sinne einer Koevolution. Thematisiert werden die zunehmende Eingriffstiefe in die Natur sowie die intersystemische Konkurrenz zwischen diesen beiden Sphären. Das evolutorische Verständnis der naturalen Produktion unterscheidet sich vom herkömmlichen Produktionsverständnis der Ökonomik. Aus diesen verschiedenen Zugängen ergibt sich ein Problemlösungsspektrum, das sich über eine integrative Verknüpfung der drei Strategieansätze und Handlungsfelder Effizienz, Konsistenz und Suffizienz erstreckt.
Nachhaltiges Wirtschaften und insbesondere nachhaltigerer Konsum sind längst als zentrale Herausforderung des 21. Jahrhunderts erkannt worden. Unternehmen und Verbraucher/innen sind dabei gleichermaßen gefordert, sich gegenseitig in Prozessen gemeinsamer Wertschöpfung zu befähigen. Das Potential dieser Prozesse liegt jedoch nicht alleine in einer klugen Mäßigung der Akteure, sondern in einer sichtbaren Aufwertung der vielfältigen nachhaltigen Konsumoptionen. Eine Möglichkeit, dies zu erreichen, liegt darin, Nachhaltigkeit als Qualität für ein breites Spektrum von Konsumgütern erkennbar und erlebbar werden zu lassen. Eine Nachhaltigkeitsdeklarierung kann dabei weit mehr leisten als nur eine weitere visuelle Auszeichnung. Unternehmen können die kulturellen Kontexte von Verbraucher/innen erkennen und zielgerichtet agieren. Dabei können die vielfältigen Möglichkeiten digitaler Medien hilfreich sein. Die vorliegende Arbeit schlägt vor, dies stets mit Blick auf die lebendige Realität auf Anbieter- und Nachfragerseite zu tun.
Navigation on the Danube
(2016)
This report contains two parts: The first part presents an overview on studies concerning the Danube, inland navigation or the impact of climate change on either of those. The second part gives a more detailed analysis of inland navigation on the Danube, partly based on studies presented in part one. Part two covers the current situation along the Danube by covering the topic of bottlenecks and other limitations for shipping along the Danube. Based on these informations, an estimation of the economic impacts of low water periods on inland navigation is made. As a last step, measures to reduce the impact of low water on inland navigations are presented. The report shows, that inland navigation still is an important transport mode, along the Danube as well as in other european regions. Especially in Romania, inland navigation still has a large share of more than 20% and rising in total transport. However, inland navigation depends strongly on good conditions of its infrastructure. These good conditions are limited mainly by two factors: one are the so called bottlenecks. Those are areas with sub-optimal shipping conditions e.g. due to solid rock formations in the river that lead to a reduced water depths. The other factor is the weather (and, on a longer time scale, the climate) which, mostly depending on precipitation and evaporation, can lead to low water levels seasonally. In addition to these two natural factors, laws which e.g. regulate the maximum number of barges allowed. Human build structures like locks limit the size of vessels as well as the speed they can travel with. These limiting factors are identified and located in the first chapter of part two of this report, before the water depth needed by several ship sizes as well as the cargo fleet available along the Danube are presented. One of the targets of this report is to estimate the economic impact of low water periods. All the factors named above as well as the freight prices charged for connections along the Danube are used to each this target in chapter II.4. To estimate the impact of low water periods on the freight prices, a method developed by Jonkeren et al. (2007) for the Rhine is transfered to the Danube. By transfering Jonkeren et al. (2007) method, regression equations for several transport connections along the Danube are identified that give a first estimate for the connection of freight prices and water levels. With the help of these regression equations, an estimation of the total expenses for transport via inland navigation for several years is possible. The yearly and seasonal variability is identified as well as the additional expenses due to water levels below 280cm. But additional expenses are not the only impact of changing water levels on inland navigation. Another is, that while the demand for transport stays at the same level, sometimes the water levels are not sufficient enough to use the full capacity of the fleet. Therefore, the (theoretical) amount of cargo that could not be transported due to low water levels is calculated as well and presented in chapter II.5. Finally, some measures to overcome some of the here named problems of inland navigation due to low water levels are presented. These are separated into two general approches: change the ship or change the river. Both methods have their advantages and disadvantages due to technical as well as regulatory and other factors. The list presented here however is incomplete and only gives a few ideas of how some problems can be overcome. In the end, an individual mix for the different regions along the river and sometimes for the individual companies must be found.
Cyberspace: a world at war. Our privacy, freedom of speech, and with them the very foundations of democracy are under attack. In the virtual world frontiers are not set by nations or states, they are set by those, who control the flows of information. And control is, what everybody wants.
The Five Eyes are watching, storing, and evaluating every transmission. Internet corporations compete for our data and decide if, when, and how we gain access to that data and to their pretended free services. Search engines control what information we are allowed - or want - to consume. Network access providers and carriers are fighting for control of larger networks and for better ways to shape the traffic. Interest groups and copyright holders struggle to limit access to specific content. Network operators try to keep their networks and their data safe from outside - or inside - adversaries.
And users? Many of them just don’t care. Trust in concepts and techniques is implicit. Those who do care try to take back control of the Internet through privacy-preserving techniques.
This leads to an arms race between those who try to classify the traffic, and those who try to obfuscate it. But good or bad lies in the eye of the beholder, and one will find himself fighting on both sides.
Network Traffic Classification is an important tool for network security. It allows identification of malicious traffic and possible intruders, and can also optimize network usage. Network Traffic Obfuscation is required to protect transmissions of important data from unauthorized observers, to keep the information private. However, with security and privacy both crumbling under the grip of legal and illegal black hat crackers, we dare say that contemporary traffic classification and obfuscation techniques are fundamentally flawed. The underlying concepts cannot keep up with technological evolution. Their implementation is insufficient, inefficient and requires too much resources.
We provide (1) a unified view on the apparently opposed fields of traffic classification and obfuscation, their deficiencies and limitations, and how they can be improved. We show that (2) using multiple classification techniques, optimized for specific tasks improves overall resource requirements and subsequently increases classification speed. (3) Classification based on application domain behavior leads to more accurate information than trying to identify communication protocols. (4) Current approaches to identify signatures in packet content are slow and require much space or memory. Enhanced methods reduce these requirements and allow faster matching. (5) Simple and easy to implement obfuscation techniques allow circumvention of even sophisticated contemporary classification systems. (6) Trust and privacy can be increased by reducing communication to a required minimum and limit it to known and trustworthy communication partners.
Our techniques improve both security and privacy and can be applied efficiently on a large scale. It is but a small step in taking back the Web.
Das hier vorgestellte Netzoptimierungstool kann dem Verteilnetzbetreiber bei einem Störfall im Netz in Echtzeit eine Lösung zur Steuerung seiner Betriebsmittel vorschlagen. Dadurch kann das bestehende Netz optimal genutzt werden und ein kostenintensiver Netzausbau im Mittel- und Niederspannungsnetz verringert oder sogar verhindert werden. Als Grundlage für den Netzoptimierer dient ein künstliches neuronales Netz (KNN). Zum Training des KNN wurden Störfälle generiert, die auf reellen Erzeugungs- und Lastprofilen aus dem CoSSMic-Projekt basieren [1]. Für jeden Störfall wurde aus allen möglichen und sinnvollen Netzkonfigurationen eine optimierte Netztopologie anhand von Lastflussberechnungen ermittelt. Durch die Variation der Stufenschalter der Transformatoren und der Stellungen aller installierten Schalter im Netz wurde berechnet, wie der Stromfluss gelenkt werden muss, damit keines der Betriebsmittel die zulässigen Belastungsgrenzen mehr überschreitet. Für ein virtuelles Testnetz konnte mit einem trainierten KNN zu 90 Prozent die optimale Lösung des jeweiligen Störfalls erkannt werden. Durch die Anwendung der N-Best Methode konnte die Vorhersagewahrscheinlichkeit auf annähernd 99 Prozent erhöht werden.
Der Einsatz von Keramiken erfolgt oft bei hohen Temperaturen oder großen Temperaturgradienten. Deshalb ist die thermo-mechanische Beständigkeit von keramischen und feuerfesten Werkstoffen wichtig für die Materialauswahl und das Bauteildesign. Das Werkstoffverhalten wird durch die Thermoschock- bzw. Temperaturwechselbeständigkeit beschrieben. Etablierte Werkstoffprüfungen zu ihrer Ermittlung sind komplex und aufwendig. Das Potenzial von anwendungsnaher Werkstoffprüfung in Kombination mit modellbildender Simulation wird beschrieben.
Large persistent memory is crucial for many applications in embedded systems and automotive computing like AI databases, ADAS, and cutting-edge infotainment systems. Such applications require reliable NAND flash memories made for harsh automotive conditions. However, due to high memory densities and production tolerances, the error probability of NAND flash memories has risen. As the number of program/erase cycles and the data retention times increase, non-volatile NAND flash memories' performance and dependability suffer. The read reference voltages of the flash cells vary due to these aging processes. In this work, we consider the issue of reference voltage adaption. The considered estimation procedure uses shallow neural networks to estimate the read reference voltages for different life-cycle conditions with the help of histogram measurements. We demonstrate that the training data for the neural networks can be enhanced by using shifted histograms, i.e., a training of the neural networks is possible based on a few measurements of some extreme points used as training data. The trained neural networks generalize well for other life-cycle conditions.
Der Prozess der Optimierung ist in Bereichen wie der Mathematik, Wirtschaft sowie sämtlichen Ingenieurswissenschaften ein zentrales und nicht mehr wegzudenkendes Werkzeug. Mit der Motivation der Nachhaltigkeit, Effizienz und Kosteneinsparung wird im Bauwesen ein optimaler Einsatz der Materialien gefordert unter Einhaltung der geforderten statischen Nachweise.
Die Methode der Verformungsreduzierung durch Materialumverteilung (kurz: MVM) greift die Anforderung auf, Material möglichst effizient einzusetzen. Diese Methode basiert darauf, die Steifigkeiten innerhalb eines geometrisch festgelegten und bereits vordimensionierten Tragwerkes durch Materialumverteilung in einem iterativen Prozess neu zu positionieren, wodurch die Verformung an einem vorab definierten kritischen Punkt reduziert wird und gleichzeitig die Verteilung der Ausnutzung vergleichmäßigt wird.
Ziel dieser Bachelorarbeit ist es, das in einer vorherigen Abschlussarbeit bereits entwickelte Grasshopper-Skript für eine praxisbezogene Anwendung zu optimieren und zu erweitern. Dieses Grasshopperskript soll neu strukturiert und auf Fehler untersucht werden. Ebenso soll ein Abbruchkriterium implementiert werden, das die Optimierung automatisch abbricht, sobald keine nennenswerte Reduzierung der Verformung infolge der Materialumverteilung mehr erfolgt. Dabei soll stetig die Tragfähigkeit aller Stäbe eingehalten sein.
Das optimierte Tool soll abschließend anhand geeigneter praxisorientierter Beispiele angewandt und validiert werden.
Product development and product manufacturing are entering a new era, namely an era where engineering tasks are executed under collaboration of all involved parties. Engineers and potential customers work together mainly in a virtual world for the design and realization of the product. We address this so called “crowdsourcing” trend in the automotive industry that lowers cost and accelerates production of new car. Current practice and prior studies fail to handle data management and collaboration aspects in sufficient detail. We propose a PLM based crowdsourcing platform that applies best practices to the established approach and adapt it with new methods for handling specific requirements. Our work provides a basis for establishing an improved collaboration platform to support a Gig Economy in the automotive industry.
This paper presents the current state of development and selected technological challenges in the application of ecologically and economically sustainable nets for aquaculture based on ongoing development projects. These aim at the development of a new material system of high-strength stainless steel wires as net material with environmentally compatible antifouling properties for nearshore and offshore aquacultures. Current plastic netting materials will be replaced with high-strength stainless steel to provide a more environmentally friendly system that can withstand more severe mechanical stresses (waves, storms, tides and predators). A new antifouling strategy is expected to solve current challenges, such as ecological damage (e.g., due to pollution from copper-containing antifouling substances or microplastics), high maintenance costs (e.g., cleaning and repairs), and shorter service life. Approaches for the next development steps are presented based on previous experience as well as calculation models based on this experience.
Codes over quotient rings of Lipschitz integers have recently attracted some attention. This work investigates the performance of Lipschitz integer constellations for transmission over the AWGN channel by means of the constellation figure of merit. A construction of sets of Lipschitz integers that leads to a better constellation figure of merit compared to ordinary Lipschitz integer constellations is presented. In particular, it is demonstrated that the concept of set partitioning can be applied to quotient rings of Lipschitz integers where the number of elements is not a prime number. It is shown that it is always possible to partition such quotient rings into additive subgroups in a manner that the minimum Euclidean distance of each subgroup is strictly larger than in the original set. The resulting signal constellations have a better performance for transmission over an additive white Gaussian noise channel compared to Gaussian integer constellations and to ordinary Lipschitz integer constellations. In addition, we present multilevel code constructions for the new signal constellations.