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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.
At the University of Applied Sciences Konstanz, Germany, a modern electronically controlled dynamometer and several cars are available for tests. Numerous studies have been carried out, and the latest results will be presented. The paper is intended to explain different tests under load. One focus is the driving cycle WLTC (Worldwide harmonized Light vehicles Test Cycle) and the requirements for the proper conduct of investigation with this driving cycle. Two and three wheelers have a great importance for mobility in various Asian countries. But also in other countries, this segment is very important for the so-called First or Last Mile Vehicles. Because of this, a short explanation of the driving cycle WMTC (Worldwide harmonized Motorcycle Emissions Certification/Test Procedure) is given. The various possibilities for the operation of the dynamometer and for carrying out various experiments are shown.
Other important figures that can be determined on a dynamometer are the wheel power, the power losses and eventually the engine performance. With the brake specific torque, the traction force at the propelled wheels, the maximum acceleration or maximum gradeability of a car can be determined.
As well the slippage related to load can be measured on the dynamometer. The dynamic wheel radius of the driven wheels has a significant influence on the slippage. Because of the temperature increase of the tires during the tests the tire pressure increases. A rise of tire temperature, tire pressure, and wheel speed results in an increase of the dynamic wheel radius and slippage. Equations for the determination of the dynamic wheel radius are presented.
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.
It is well known that signal constellations which are based on a hexagonal grid, so-called Eisenstein constellations, exhibit a performance gain over conventional QAM ones. This benefit is realized by a packing and shaping gain of the Eisenstein (hexagonal) integers in comparison to the Gaussian (complex) integers. Such constellations are especially relevant in transmission schemes that utilize lattice structures, e.g., in MIMO communications. However, for coded modulation, the straightforward approach is to combine Eisenstein constellations with ternary channel codes. In this paper, a multilevel-coding approach is proposed where encoding and multistage decoding can directly be performed with state-of-the-art binary channel codes. An associated mapping and a binary set partitioning are derived. The performance of the proposed approach is contrasted to classical multilevel coding over QAM constellations. To this end, both the single-user AWGN scenario and the (multiuser) MIMO broadcast scenario using lattice-reduction-aided preequalization are considered. Results obtained from numerical simulations with LDPC codes complement the theoretical aspects.
This paper presents a new likelihood-based partitioning method of the measurement set for the extended object probability hypothesis density (PHD) filter framework. Recent work has mostly relied on heuristic partitioning methods that cluster the measurement data based on a distance measure between the single measurements. This can lead to poor filter performance if the tracked extended objects are closely spaced. The proposed method called Stochastic Partitioning (StP) is based on sampling methods and was inspired by a former work of Granström et. al. In this work, the StP method is applied to a Gaussian inverse Wishart (GIW) PHD filter and compared to a second filter implementation that uses the heuristic Distance Partitioning (DP) method. The performance is evaluated in Monte Carlo simulations in a scenario where two objects approach each other. It is shown that the sampling based StP method leads to an improved filter performance compared to DP.
Assistive environments are entering our homes faster than ever. However, there are still various barriers to be broken. One of the crucial points is a personalization of offered services and integration of assistive technologies in common objects and therefore in a regular daily routine. Recognition of sleep patterns for the preliminary sleep study is one of the health services that could be performed in an undisturbing way. This article proposes the hardware system for the measurement of bio-vital signals necessary for initial sleep study in a non-obtrusive way. The first results confirm the potential of measurement of breathing and movement signals with the proposed system.
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.
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.
Autism spectrum disorders (ASD) affect a large number of children both in the Russian Federation and in Germany. Early diagnosis is key for these children, because the sooner parents notice such disorders in a child and the rehabilitation and treatment program starts, the higher the likelihood of his social adaptation. The difficulties in raising such a child lie in the complexity of his learning outside of children's groups and the complexity of his medical care. In this regard, the development of digital applications that facilitate medical care and education of such children at home is important and relevant. The purpose of the project is to improve the availability and quality of healthcare and social adaptation at home of children with ASD through the use of digital technologies.
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.
The investigation of stress requires to distinguish between stress caused by physical activity and stress that is caused by psychosocial factors. The behaviour of the heart in response to stress and physical activity is very similar in case the set of monitored parameters is reduced to one. Currently, the differentiation remains difficult and methods which only use the heart rate are not able to differentiate between stress and physical activity, without using additional sensor data input. The approach focusses on methods which generate signals providing characteristics that are useful for detecting stress, physical activity, no activity and relaxation.
Nachhaltigkeit stellt seit 2018 einen der bedeutsamsten Trends in der Modeindustrie da. Die Missstände innerhalb der Textil- und Bekleidungsindustrie wurden seit dem Einsturz einer Textilfabrik in Bangladesch im Jahre 2013 zu einer öffentlichen Diskussion. Die global ausgerichtete Industrie produziert vermehrt Textilien in kürzester Zeit, um beständig das Angebot an aktuellen Modetrends anbieten zu können. Die sogenannte Fast-Fashion wird von großen Markenkonzernen wie ZARA und Hennes & Mauritz (H&M) zu niedrigen Preisen der breiten Masse zugänglich gemacht. Sie wird als einer der größten Gründe für Überkonsum von Bekleidung und sinkender Wertschätzung dieser Waren bezeichnet. Die Gegenbewegung Slow-Fashion möchte hingegen die Konsumenten davon überzeugen, ihre Bekleidung wieder wertzuschätzen. Slow-Fashion steht für Bekleidung, die unter umweltverträglichen und menschenwürdigen Bedingungen produziert wird. Durch die Gewährleistung von Transparenz hinsichtlich der Produktionsbedingungen und Lieferketten ermöglicht Slow-Fashion einen bewussteren Konsum von Mode.
Durch Slow-Fashion kann die Integration von Nachhaltigkeit in die Bekleidungsindustrie als einen Modetrend des vergangenen Jahres angesehen werden. Allerdings verstehen nachhaltige Bekleidungsmarken Slow-Fashion nicht als zeitgemäßen Trend, sondern vielmehr als Grundbedingung ihrer angebotenen Waren. Dieses Prinzip lässt sich auf Marken sämtlicher Branchen übertragen, sodass sie als ‚nachhaltige Marken‘ tituliert werden könnten. Bislang mangelt es allerdings an einer einheitlichen Definition für nachhaltige Marken. Das Ziel dieser Arbeit ist daher die Erarbeitung eines Definitionsvorschlags. Dabei muss die Bedeutung von Marken und das Prinzip der Nachhaltigkeit voneinander isoliert erörtert werden. Anschließend soll die Schuhmarke ZWEIGUT, die als ein Beispiel aus der Bekleidungsindustrie dient, daraufhin überprüft werden, ob sie dem Anspruch der ausgearbeiteten Definition einer nachhaltigen Marke gerecht wird. Im Laufe dieser Markenanalyse sollen zugleich die Erfolgsbausteine der Marke ZWEIGUT bestimmt werden.
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.
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.
Compliance Management ist längst zu einem Thema in mittelständischen Unternehmen geworden. Aber was ist der richtige Ansatz, um Regeleinhaltung, Rechtschaffenheit und verantwortliches Wirtschaften als Unternehmer oder Unternehmenslenker wirksam und effizient zu organisieren? Welche Rolle spielen die Führungskräfte? Ausgehend von der Frage, was ein mittelständisch geprägtes Unternehmen im Bereich der Compliance tun kann und soll und dem dazu gehörenden Compliance Management System, wird in diesem Beitrag knapp umrissen, worauf es bei der Implementierung und Umsetzung von Maßnahmen im Unternehmensalltag besonders ankommt. Dabei wird der Schulung der Führungskräfte mittels qualitativ hochwertiger Dilemma-Trainings ein ebenso hoher Stellenwert eingeräumt, wie der auch dadurch sukzessive zu entwickelnden ethischen Unternehmenskultur.
Low temperature carburizing of a series of austenitic stainless with various combinations of chromium and nickel equivalents was performed. The investigation of the response towards low temperature carburized for three stainless steels with various Cr- and Ni-equivalents showed that the carbon uptake depends significantly on the chemical composition of the base material. The higher carbon content in the expanded austenite layer of specimen 6 (1.4565) and specimen 4 (1.4539/AISI 904L) compared to specimen 2 (1.4404/AISI 316L) is assumed to be mainly related to the difference in the specimens’ chromium content. More chromium leads to more lattice expansion. Along with the higher carbon content, higher hardness values and higher compressive residual stresses in the expanded austenite zone are introduced than for low temperature carburized AISI 316L. The residual stresses obtained from X-ray diffraction lattice strain investigation depend strongly on the chosen X-ray elastic constants. Presently, no values are known for carbon (or nitrogen) stabilized expanded austenite. Nevertheless, first principle elastic constants for γ′&minus Fe4C appear to provide realistic residual stress values. Magnetic force microscopy and measurement with an eddy current probe indicate that austenitic stainless steels can become ferromagnetic upon carburizing, similar for low temperature nitriding. The apparent transition from para- to ferromagnetism cannot be attributed entirely to the interstitially dissolved carbon content in the formed expanded austenite layer but appears to depend also on the metallic composition of the alloy, in particular the Ni content.
Das Potential der Offshore-Windenergie, welches hauptsächlich auf hohe mittlere Windgeschwindigkeiten zurückzuführen ist, kann nicht ignoriert werden. Trotzdem zeigt die Betrachtung der aktuell installierten Leistung und der Stromgestehungskosten, dass zusätzliche Risiko- und Kostenfaktoren existieren. Diese sind vor allem auf die Installation, die Energiewandlersysteme und die Netzanbindung zurückzuführen. Getriebeschäden sind einer dieser großen Kostenfaktoren. Aus diesem Grund gewinnen getriebelosen Windkraftanlagen mit permanentmagneterregten Synchrongeneratoren immer mehr an Relevanz. In der Netzanbindung von ganzen Offshore-Windparks überwiegt die Hochspannungs-Gleichstrom-Übertragung (HGÜ) ab einer Übertragungsdistanz von 80 km. Diese Tendenz ist sinkend. Steigende windparkinterne Spannungen auf 66 kV fördern zusätzlich den Verzicht auf Umspannplattformen, welche für die HGÜ-Technik aktuell sinnvoll sind. Diese und weitere bereits in Aussicht stehenden Entwicklungen führen zu einer Einschränkung der Risiko- und Kostenfaktoren. Es wird demnach davon ausgegangen, dass die Offshore-Windenergie, als Ergänzung zur Onshore-Windenergie, eine wichtige Rolle im Rahmen der Energiewende einnimmt.