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Pitting susceptibility of metastable austenitic stainless steels as a function of surface conditions
(2019)
Fachvortrag auf der 10th International European Stainless Steel Conference and 6th European Duplex Stainless Steel Conference (ESSC & DUPLEX 2019), 30.09. – 02.10.2019, Vienna, Austria
Fachvortrag auf dem Swiss Tribology Symposium, 12.11.2019, Hightechzentrum Aargau, Brugg, Schweiz
Pitting susceptibility of metastable austenitic stainless steels as a function of surface conditions
(2019)
The influence of surface roughness and local defects on pitting susceptibility of type 304 (UNS S30400) and type 301 (UNS S30100) in chloride solution were investigated. Because the mechanical properties can be regarded as decisive for the achieved surface quality, different properties of the base material were obtained by cold rolling the metastable austenites. This was done before the surfaces were finished. Therefor the surfaces were treated by different grinding parameters to generate different surface conditions and different defects. As a reference, different standardised surface finishes were used.
By using and comparing different methods for the characterization of surface roughness and surface texture, it is possible to find a relationship between the quantity and characteristics of local defects on the one hand and pitting susceptibility on the other hand. For the machining parameters used, a ranking of the influencing factors on the corrosion resistance achieved could be determined.
The automated application of software-based solutions for estimating the pitting susceptibility of machined surfaces and components will be discussed using concrete examples.
The exposure to the light has a great influence on human beings in their everyday life. Various lighting sources produce light that reaches the human eye and influences a rhythmic release of melatonin hormone, that is a sleep promoting factor.
Since the development of new technologies provides more control over illuminance, this work uses an IoT based lighting system to set up dim and bright scenarios. A small study has been performed on the influence of illuminance on sleep latency. The system consists of different light bulbs, sensors and a central bridge which are interconnected like a mesh network. Also, a mobile app has been developed, that allows to adjust the lighting in various rooms. With the help of a ferro-electret sensor, like applied in sleep monitoring systems, a subject’s sleep was monitored. The sensor is placed below the mattress and it collects data, which is stored and processed in a cloud or in other alternative locations.
The research was conducted on healthy young subjects after being previously exposed to the preconfigured illuminance for at least three hours before bedtime. The results indicate correlation between sleep onset latency and exposure to different illuminance before bedtime. In a dimmed environment, the subject fell asleep in average 28% faster compared to the brighter environment.
One important skill for engineers is the ability of optimizing their experiments. On their job they will often spend a lot more time designing and improving an experimental setup compared to running the actual experiment itself. Is it possible to teach this complex task in physics labs? A method for reaching this goal is proposed an example is given and discussed.
BIM im Membranbau
(2019)
Die fortschreitende Digitalisierung wird zurzeit zu einem der wichtigsten Themen und zugleich zu einer der größten Herausforderungen für die Bauwirtschaft. Building Information Modeling (BIM) kommt eine immer größere Bedeutung zu.
Es ist sicherlich richtig, dass derzeit nur wenige Projekte im Bauwesen den geforderten BIM-Anforderungen der Bauherrschaft genügen. Es ist zu erwarten, dass in den kommenden Jahren auch an Membranbauprojekte immer mehr Anforderungen bezüglich BIM gestellt werden. Aus diesem Grund ist es wichtig, dass sich Planungsbüros für leichte Flächentragwerke mit dem Thema BIM befassen.
Ziel dieser Arbeit ist die Ausarbeitung eines Konzepts für die effiziente durchgehende Umsetzung der Building Information Modeling-Arbeitsmethode bei der Tragwerksplanung im Membranbau.
Es werden vorhandene Funktionalitäten untersucht und alternative Interoperabilitätskomponenten entwickelt. Aufbauend auf den möglichen Werkzeugketten werden verschiedene Einsatzverfahren vorgeschlagen. Darauffolgend wird eines der möglichen Verfahren an einem realen Tragwerk implementiert. Die erhaltenen Ergebnisse werden einer kritischen Analyse unterzogen.
Abschließende Rückschlüsse, Beurteilung der angewandten Planungsmethoden und Ausblick fassen das behandelte Thema zusammen.
Bei der Arbeit verwendete Methoden schließen den parametrischen Entwurf, manuelle Modellierung in zwei verschiedenen Softwareumgebungen und textliche Programmierung mit C#-Sprache ein.
Die Relevanz des untersuchten Themas erstreckt sich überwiegend auf praktisch tätige Ingenieure aus den Bereichen leichte Flächentragwerke, Sondertragwerke, Membranbau, wird aber auch für wissenschaftliche Mitarbeiter der Forschungsinstitutionen, BIM-Spezialisten und Produkthersteller von Interesse sein.
A growing share of modern trade policy instruments is shaped by non-tariff barriers (NTBs). Based on a structural gravity equation and the recently updated Global Trade Alert database, we empirically investigate the effect of NTBs on imports. Our analysis reveals that the implementation of NTBs reduces imports of affected products by up to 12%. Their trade dampening effect is thus comparable to that of trade defence instruments such as anti-dumping duties. It is smaller for exporters that have a free trade agreement with the importing country. Different types of NTBs affect trade to a different extent. Finally, we investigate the effect of behind-the-border measures, showing that they significantly lower the importer’s market access.
This paper analyses international cooperation in alternative energy production research and development. Therefore, patents of the technological domain, registered at the European Patent Office from 1997 until 2016, are analysed. International cooperation is considered when patents involve co-assignment or co-inventorship comprising two or more different countries. Generally, international R&D cooperation tends to be increasing over time in alternative energy production. In total, 2234 co-patents from 87 countries are identified. Through social network analysis the cooperative relationships between countries are examined. The most significant states of the network are the United States of America and Germany. Innovative clusters and strong partnerships are identified. Alternative energy technologies that involve international cooperation most extensively are harnessing energy from manmade waste, solar energy and bio-fuels. The paper clarifies which countries are cooperating with each other for what purpose. The findings can be used for establishing R&D strategies in the domain of alternative energy production.
Extracting suitable features from acquired data to accurately depict the current health state of a system is crucial in data driven condition monitoring and prediction. Usually, analogue sensor data is sampled at rates far exceeding the Nyquist-rate containing substantial amounts of redundancies and noise, imposing high computational loads due to the subsequent and necessary feature processing chain (generation, dimensionality reduction, rating and selection). To overcome these problems, Compressed Sensing can be used to sample directly to a compressed space, provided the signal at hand and the employed compression/measurement system meet certain criteria. Theory states, that during this compression step enough information is conserved, such that a reconstruction of the original signal is possible with high probability. The proposed approach however does not rely on reconstructed data for condition monitoring purposes, but uses directly the compressed signal representation as feature vector. It is hence assumed that enough information is conveyed by the compression for condition monitoring purposes. To fuse the compressed coefficients into one health index that can be used as input for remaining useful life prediction algorithms and is limited to a reasonable range between 1 and 0, a logistic regression approach is used. Run-to-failure data of three translational electromagnetic actuators is used to demonstrate the health index generation procedure. A comparison to the time domain ground truth signals obtained from Nyquist sampled coil current measurements shows reasonable agreement. I.e. underlying wear-out phenomena can be reproduced by the proposed approach enabling further investigation of the application of prognostic methods.
Die Studienanfänger in den technischen Studiengängen der Hochschulen für angewandte Wissenschaften haben nicht nur in Mathematik sondern auch in Physik sehr unterschiedliche Vorkenntnisse. Obwohl diese Fächer für das grundlegende Verständnis technischer Vorgänge von großer Bedeutung sind, kann die Ausbildung in diesen Bereichen angesichts der begrenzten dafür im Verlauf des Studiums zur Verfügung stehenden Zeitfenster nicht bei Null anfangen. Für Mathematik wurde daher von der Arbeitsgruppe cosh ein Mindestanforderungskatalog zusammengestellt und 2014 veröffentlicht. Er beschreibt Kenntnisse und Fertigkeiten, die Studienanfänger zur erfolgreichen Aufnahme eines WiMINT-Studiums (Wirtschaft, Mathematik, Informatik, Naturwissenschaft, Technik) an einer Hochschule benötigen. Inzwischen hat sich nun eine Arbeitsgruppe von Physikerinnen und Physikern an Hochschulen in Baden-Württemberg gebildet, deren Ziel es ist, einen analogen Mindestanforderungskatalog für den Bereich Physik zu erstellen. Hier wird der aktuell erreichte Stand der Arbeiten vorgestellt.
The business model canvas (BMC) and the lean start-up manifesto (LSM) have been changing both the entrepreneurial education and, on the practical side, the mindset in setting up innovative ventures since the burst of the dot-com bubble. However, few empirical insights on the business model implementation patterns that distinguish between digital and non-digital innovative ventures exist. Connecting practical management tools to network theory as well as to the theory of organizational learning, this paper investigates evolution patterns of digital and non-digital business models out of the deal flow of an innovation intermediary. For this purpose, a multi-dimensional quantitative content analysis research design is applied to 242 ventures' business plans. The measured strength of transaction relations to customers, suppliers, people, and financiers has been combined with performance indicators of the sampled ventures. The results indicate that in order to succeed, digital ventures iterate their business on the market early and search for investment afterwards. Contrariwise, non-digital ventures already need financial investments in the early stages to set up a product ready to be tested on the market. In both groups we found strong evidence that specific evolutionary patterns relate to higher rates of success.
Entrepreneurial employees
(2019)
Volatile markets and accelerating innovation cycles progressively force established companies to adopt alternative innovation strategies such as entrepreneurship. Due to the key role entrepreneurial employees play for strengthening the company's abilities for innovation and change, various concepts have emerged like corporate entrepreneurship or intrapreneurship. While the extant literature has increasingly examined only specific issues of entrepreneurial employees, an overall view on it lacks investigation. Therefore, the purpose of this paper is to structurally present current research on entrepreneurial employees by conducting a broad systematic literature review. The resulting research streams contribute to a clearer justification for future research and are a first step towards a comprehensive research view related to intrapreneurship.
Due to the rising need for palliative care in Russia, it is crucial to provide timely and high-quality solutions for patients, relatives, and caregivers. A methodology for remote monitoring of patients in need of palliative care and the requirements will be developed for a hardware-software complex for remote monitoring of patients' health at home.
The Lake Constance region is due to its scenic attractiveness one of the most visited destinations in German-speaking countries. Scenic attractiveness as well as so-called landscape stereotypes also play a decisive role in tourism marketing. Tour operators reproduce supra-individual landscape concepts and establish mental geographies that ultimately influence the choice of destinations. A growing trend in tourism is the emergence of creative narratives in tourism marketing and tourism offers induced by creative companies. By means of a discourse-analytical investigation, whose theoretical and conceptual frame of reference is the hegemony and discourse theory of Laclau and Mouffe (1985), recurring landscape stereotypes are identified in tourist promotional material for the destination Bodensee. Based on these results as well as expert interviews with regional tourism stakeholders, a discussion of the creative economic potential for regional tourism marketing will take place. The investigation shows that these potentials are currently not being exhausted. At the same time, creative tourism can help a rural region, such as Lake Constance, to position itself as an alternative to city tourism, while at the same time addressing the lucrative target group 60plus.
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.
We present an alternative approach to grid management in low voltage grids by the use of artificial intelligence. The developed decision support system is based on an artificial neural network (ANN). Due to the fast reaction time of our system, real time grid management will be possible. Remote controllable switches and tap changers in transformer stations are used to actively manage the grid infrastructure. The algorithm can support the distribution system operators to keep the grid in a safe state at any time. Its functionality is demonstrated by a case study using a virtual test grid. The ANN achieves a prediction rate of around 90% for the different grid management strategies. By considering the four most likely solutions proposed by the ANN, the prediction rate increases to 98.8%, with a 0.1 second increase in the running time of the model.
Autismus-Spektrum-Störungen (ASD) bei Kindern werden häufig zu spät diagnostiziert und die Begleitung der chronischen Krankheit gestaltet sich schwierig. Der vorgestellte Ansatz erlaubt die Behandlung der Kinder in dem bekannten häuslichen Umfeld und versucht die Beziehungen zwischen Schlaf und Verhalten herauszuarbeiten. Die gewonnenen Erkenntnisse sollen die Lebensqualität der Patienten verbessern und den Eltern Hilfestellung geben. Die notwendige infrastrukturelle Unterstützung wird durch medizinisches Fachpersonal geleistet, das auf einen web-basierten Service zurückgreifen kann, der sämtliche Prozesse (Diagnostik, Datenerfassung, -aufzeichnung und Training etc.) begleitet. Die anonymisierten Daten werden in einem Diagnosesystem zentral abgelegt und können so für zukünftige Behandlungsstrategien nutzbar sein. Die umfassende Lösung setzt auf zentrale Elemente von Smart-Homes und AAL auf.
This article describes a research project that aims at investigating individual entrepreneurial founders concerning their shift tendencies of decision-making logics - especially during the respective phases of the venture creating process. Prior studies found that team founders show a hybrid perspective on strategic decision-making. They not only combine causation (planning-based) and effectuation (flexible) logics but also show logic shifts and also re-shifts over time. Due to the fact, that founders' social identity shapes early structuring processes, this article describes the necessity of elimination of in-group influences of multi-founding ventures and focus on individuals in order to make specific assessments on logic shifts and re-shifts. Based on an extensive literature review, a pre-selection-test and a qualitative case study design from the empirical body of the paper. Insofar, this study applies a qualitative design of a process research approach to investigate shifts of decision-making logics of individual founders in new venture creation over time.
Leichtbauwerkstoffe bewegen sich im Spannungsfeld neuer Werkstoffkombinationen, Herstellungs- und Fügetechnologien sowie von Lebensdauer und Nachhaltigkeit. Besondere Aufmerksamkeit sollte daher hybriden CFK-Metallverbunden gelten. Gefördert von der Internationalen Bodensee Hochschule IBH untersucht etwa das Werkstoffprüflabor der Hochschule Konstanz (HTWG) in einem internationalen Forschungsprojekt die Festigkeit von Sandwich-Verbunden aus Aluminium und CFK.
A new thermal shock application-oriented testing method for ceramic components and refractories
(2019)
Ceramics and refractories are often used in high-temperature applications like industrial furnaces. Therefore, thermomechanical and heat resistance of ceramic and refractory materials are important. The material behaviour is described by thermal stress resistance. Established material tests to determine thermal shock behaviour are complex and do not yield key figures. The potential of application-related material testing in combination with simulations with transfer from ceramics to refractories is described below. The combination of model-based simulation with applied material testing offers numerous advantages. On the one hand, the design of the test setup is supported by the simulation, which results in a goal and application-oriented test setup. On the other hand, the iterative approach allows the model verification with the help of the applied material testing. The simulation shows that the transfer from ceramics to refractory material is possible and results according to literature. The design reliability of the components is thereby improved, since initially different loads can be simulated in the model in combination with a variety of materials and geometries, and thereby substitute complex and expensive preliminary tests. As a result, verified models offer a great savings potential in terms of time to market, development expenses and use of raw materials. Very important is, that the method is suitable for technical ceramics and refractory materials.
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.
Ceramics are often used in high-temperature applications. Therefore, thermomechanical and heat resistance of ceramic and refractory materials are important. The material behaviour is described by thermal stress resistance. Established material tests to determine thermal shock behaviour are complex. The potential of application-related material testing in combination with simulations is described below.
If the process contains a delay (dead time), the Nyquist criterion is well suited to derive a PI or PID tuning rule because the delay is taken into account without approximation. The tuning of the speed of the closed loop enters naturally by the crossover frequency. The goal of robustness and performance is translated into the phase margin.
Thermochemical surface hardening is used to overcome the weak mechanical performance of austenitic and duplex stainless steels. Both low-temperature carburizing and nitrocarburizing can improve the hardness, wear, galling, and cavitation resistance, while maintaining their good corrosion resistance. Therefore, it is crucial to not form chromium-rich precipitates during hardening as these can deteriorate the passivity of the alloy. The hardening parameters, the chemical composition of the steel, and the manufacturing route of a component determine whether precipitates are formed. This article gives an overview of suitable alloys for low-temperature surface hardening and the performance under corrosive loading.
While existing resource extraction debates have contributed to a better understanding of national economic and political dilemmas and institutional responses, there are flaws in understanding the specific relevance of the various types of mining schemes for rural households to deal with the various problems they are confronted with. Our paper examines the perceptions of gold mining effects on households in Northern Burkina Faso. The findings of our survey across six districts representing different mining schemes (industrial, artisanal, no mining) highlight the fact that artisanal gold mining can generate job opportunities and cash income for local households; whereas industrial gold mining widely fails to do so. However, the general economic and environmental settings exert a much stronger influence on the household state. Gold mining effects are perceived as being less advantageous in districts where people are suffering from a lack of education, a higher vulnerability to drought and poor market access. Our findings provide empirical support for those who back the enhanced formalization of artisanal and small-scale mining (ASM) and policies that entail more rigorous state monitoring of mining concessions, especially in economic and environmentally disadvantaged contexts. Effectively addressing communal and pro-poor development requires greater attention to the political economy of ASM and corporate mining. It also calls for a greater inclusion of local mining stakeholders and a more effective alignment of international regulatory and advocacy efforts.
The introduction of multi level cell (MLC) and triple level cell (TLC) technologies reduced the reliability of flash memories significantly compared with single level cell (SLC) flash. The reliability of the flash memory suffers from various errors causes. Program/erase cycles, read disturb, and cell to cell interference impact the threshold voltages. With pre-defined fixed read thresholds a voltage shift increases the bit error rate (BER). This work proposes a read threshold calibration method that aims on minimizing the BER by adapting the read voltages. The adaptation of the read thresholds is based on the number of errors observed in the codeword protecting a small amount of meta-data. Simulations based on flash measurements demonstrate that this method can significantly reduce the BER of TLC memories.
The goal of this paper pretends to show how a bed system with an embedded system with sensor is able to analyze a person’s movement, breathing and recognizing the positions that the subject is lying on the bed during the night without any additional physical contact. The measurements are performed with sensors placed between the mattress and the frame. An Intel Edison board was used as an endpoint that served as a communication node from the mesh network to external service. Two nodes and Intel Edison are attached to the bottom of the bed frame and they are connected to the sensors.
Rheumatoid arthritis is an autoimmune disease that causes chronic inflammation of synovial joints, often resulting in irreversible structural damage. The activity of the disease is evaluated by clinical examinations, laboratory tests, and patient self-assessment. The long-term course of the disease is assessed with radiographs of hands and feet. The evaluation of the X-ray images performed by trained medical staff requires several minutes per patient. We demonstrate that deep convolutional neural networks can be leveraged for a fully automated, fast, and reproducible scoring of X-ray images of patients with rheumatoid arthritis. A comparison of the predictions of different human experts and our deep learning system shows that there is no significant difference in the performance of human experts and our deep learning model.
This work proposes a suboptimal detection algorithm for generalized multistream spatial modulation. 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. For multistream spatial modulation with large signal constellations the second detection step typically dominates the detection complexity. With the proposed detection scheme, the modified Gaussian approximation method is used for detecting the antenna pattern. In order to reduce the complexity for detecting the signal points, we propose a combined equalization and list decoding approach. Simulation results demonstrate that the new algorithm achieves near-maximum-likelihood performance with small list sizes. It significantly reduces the complexity when compared with conventional two-stage detection schemes.
CO2 compensation measures, in particular the compensation of flights, are becoming more and more popular. Carbon offsetting is defined as measures financed by donations that save greenhouse gases previously emitted elsewhere through climate protection projects.
CO2 abatement costs are often low in developing countries. This is why most offset projects are implemented there. Nevertheless, this does not mean that the holiday resort and the project country are in any way related to each other.
By linking carbon offset projects with the destination country, the tourist is able to get an impression of the co-financed project. In case such projects are realized in cooperation with the hotel, the hotel operator obtains a new tourist attraction and can demonstrate its efforts to climate protection in a PR-effective way.
Methodology
(2019)
Chapter three introduces the methodology of the study and the research design. Its nested, multi-layered methodological concept constitutes one of the major innovations of the book and enables us to map and measure peacebuilding activities of Christian church actors in the conflicts of Mindanao and Maluku (Ambon). The methodological concept draws from Katzenstein’s “analytic eclecticism,” which transcends the rigidity of existing research schools and seeks to fuse elements of several approaches into a new research agenda. The nested, multi-layered analysis of this book seamlessly combines process tracing, discourse analysis, statistical analysis of primary data generated in two field surveys, Qualitative Comparative Analysis (QCA), and statistical regression analysis.
The cornerstone of cognitive systems is environment awareness which enables agile and adaptive use of channel resources. Whitespace prediction based on learning the statistics of the wireless traffic has proven to be a powerful tool to achieve such awareness. In this paper, we propose a novel Hidden Markov Model (HMM) based spectrum learning and prediction approach which accurately estimates the exact length of the whitespace in WiFi channels within the shared industrial scientific medical ISM) bands. We show that extending the number of hidden states and formulating the prediction problem as a maximum likelihood (ML) classification leads to a substantial increase in the prediction horizon compared to classical approaches that predict the immediate (short-term) future. We verify the proposed algorithm through simulations which utilize a model for WiFi traffic based on extensive measurement campaigns.
The Lempel-Ziv-Welch (LZW) algorithm is an important dictionary-based data compression approach that is used in many communication and storage systems. The parallel dictionary LZW (PDLZW) algorithm speeds up the LZW encoding by using multiple dictionaries. The PDLZW algorithm applies different dictionaries to store strings of different lengths, where each dictionary stores only strings of the same length. This simplifies the parallel search in the dictionaries for hardware implementations. The compression gain of the PDLZW depends on the partitioning of the address space, i.e. on the sizes of the parallel dictionaries. However, there is no universal partitioning that is optimal for all data sources. This work proposes an address space partitioning technique that optimizes the compression rate of the PDLZW using a Markov model for the data. Numerical results for address spaces with 512, 1024, and 2048 entries demonstrate that the proposed partitioning improves the performance of the PDLZW compared with the original proposal.
The Lempel–Ziv–Welch (LZW) algorithm is an important dictionary-based data compression approach that is used in many communication and storage systems. The parallel dictionary LZW (PDLZW) algorithm speeds up the LZW encoding by using multiple dictionaries. This simplifies the parallel search in the dictionaries. However, the compression gain of the PDLZW depends on the partitioning of the address space, i.e. on the sizes of the parallel dictionaries. This work proposes an address space partitioning technique that optimises the compression rate of the PDLZW. Numerical results for address spaces with 512, 1024, and 2048 entries demonstrate that the proposed address partitioning improves the performance of the PDLZW compared with the original proposal. These address space sizes are suitable for flash storage systems. Moreover, the PDLZW has relative high memory requirements which dominate the costs of a hardware implementation. This work proposes a recursive dictionary structure and a word partitioning technique that significantly reduce the memory size of the parallel dictionaries.
The Burrows–Wheeler transformation (BWT) is a reversible block sorting transform that is an integral part of many data compression algorithms. This work proposes a memory-efficient pipelined decoder for the BWT. In particular, the authors consider the limited context order BWT that has low memory requirements and enable fast encoding. However, the decoding of the limited context order BWT is typically much slower than the encoding. The proposed decoder pipeline provides a fast inverse BWT by splitting the decoding into several processing stages which are executed in parallel.
Today, many resource-constrained systems, such as embedded systems, still rely on symmetric cryptography for authentication and digital signatures. Asymmetric cryptography provide a higher security level, but software implementations of public-key algorithms on small embedded systems are extremely slow. Hence, such embedded systems require hardware assistance, i.e. crypto coprocessors optimized for public key operations. Many such coprocessor designs aim on high computational performance. In this work, an area efficient elliptic curve cryptography (ECC) coprocessor is presented for applications in small embedded systems where high performance coprocessors are too costly. We propose a simple control unit with a small instruction set that supports different ECC point multiplication (PM) algorithms. The control unit reduces the logic and number of registers compared with other implementations of ECC point multiplications.