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Due to rapidly changing technologies and business contexts, many products and services are developed under high uncertainties. It is often impossible to predict customer behaviors and outcomes upfront. Therefore, product and service developers must continuously find out what customers want, requiring a more experimental mode of management and appropriate support for continuously conducting experiments. We have analytically derived an initial model for continuous experimentation from prior work and matched it against empirical case study findings from two startup companies. We examined the preconditions for setting up an experimentation system for continuous customer experiments. The resulting RIGHT model for Continuous Experimentation (Rapid Iterative value creation Gained through High-frequency Testing) illustrates the building blocks required for such a system and the necessary infrastructure. The major findings are that a suitable experimentation system requires the ability to design, manage, and conduct experiments, create so-called minimum viable products or features, link experiment results with a product roadmap, and manage a flexible business strategy. The main challenges are proper, rapid design of experiments, advanced instrumentation of software to collect, analyse, and store relevant data, and integration of experiment results in the product development cycle, software development process, and business strategy. This summary refers to the article The RIGHT Model for Continuous Experimentation, published in the Journal of Systems and Software [Fa17].
First International Workshop on Hybrid dEveLopmENt Approaches in Software Systems Development
(2017)
A software process is the game plan to organize project teams and run projects. Yet, it still is a challenge to select the appropriate development approach for the respective context. A multitude of development approaches compete for the users’ favor, but there is no silver bullet serving all possible setups. Moreover, recent research as well as experience from practice shows companies utilizing different development approaches to assemble the bestfitting approach for the respective company: a more traditional process provides the basic framework to serve the organization, while project teams embody this framework with more agile (and/or lean) practices to keep their flexibility. The first HELENA workshop aims to bring together the community to discuss recent findings and to steer future work.
The ability to develop and deploy high-quality software at a high speed gets increasing relevance for the comptetitiveness of car manufacturers. Agile practices have shown benefits such as faster time to market in several application domains. Therefore, it seems to be promising to carefully adopt agile practices also in the automotive domain. This article presents findings from an interview-based qualitative survey. It aims at understanding perceived forces that support agile adoption. Particularly, it focuses on embedded software development for electronic control units in the automotive domain.
Software and system development faces numerous challenges of rapidly changing markets. To address such challenges, companies and projects design and adopt specific development approaches by combining well-structured comprehensive methods and flexible agile practices. Yet, the number of methods and practices is large, and available studies argue that the actual process composition is carried out in a fairly ad-hoc manner. The present paper reports on a survey on hybrid software development approaches. We study which approaches are used in practice, how different approaches are combined, and what contextual factors influence the use and combination of hybrid software development approaches. Our results from 69 study participants show a variety of development approaches used and combined in practice. We show that most combinations follow a pattern in which a traditional process model serves as framework in which several fine-grained (agile) practices are plugged in. We further show that hybrid software development approaches are independent from the company size and external triggers. We conclude that such approaches are the results of a natural process evolution, which is mainly driven by experience, learning, and pragmatism.
The digital transformation of the automotive industry has a significant impact on how development processes need to be organized in future. Dynamic market and technological environments require capabilities to react on changes and to learn fast. Agile methods are a promising approach to address these needs but they are not tailored to the specific characteristics of the automotive domain like product line development. Although, there have been efforts to apply agile methods in the automotive domain for many years, significant and widespread adoptions have not yet taken place. The goal of this literature review is to gain an overview and a better understanding of agile methods for embedded software development in the automotive domain, especially with respect to product line development. A mapping study was conducted to analyze the relation between agile software development, embedded software development in the automotive domain and software product line development. Three research questions were defined and 68 papers were evaluated. The study shows that agile and product line development approaches tailored for the automotive domain are not yet fully explored in the literature. Especially, literature on the combination of agile and product line development is rare. Most of the examined combinations are customizations of generic approaches or approaches stemming from other domains. Although, only few approaches for combining agile and software product line development in the automotive domain were found, these findings were valuable for identifying research gaps and provide insights into how existing approaches can be combined, extended and tailored to suit the characteristics of the automotive domain.
Seit über 50 Jahren dominiert die neoklassische Kapitalmarkttheorie unser Verständnis für die Abläufe an Finanzmärkten. Sie hat eine Vielzahl von Theorien und Konzepten (z.B. Portfoliotheorie, Capital Asset Pricing Model oder Value-at-Risk) hervorgebracht und basiert auf der Annahme eines streng rationalen Homo Oeconomicus.
Das vorliegende Buch möchte Praktikern die Türe öffnen zu einer neu entstehenden, verhaltenswissenschaftlichen Sicht auf die Finanzmärkte, in der ein realitätsnäherer Homo Oeconomicus Humanus an den Märkten agiert. Er setzt bei der Entscheidungsfindung begrenzt rationale Heuristiken ein und lässt sich von emotionalen Einflüssen lenken.
Die Autoren schlagen zunächst den Bogen von der neoklassischen Sicht der Finanzmärkte zur Behavioral Finance. Anschließend werden spekulative Blasen, von der Tulpenmanie bis zur Subprime Hypothekenblase, als Anzeichen für begrenzte Rationalität an Finanzmärkten ausführlich vorgestellt. Danach stehen die Heuristiken bei Anlageentscheidungen an Wertpapiermärkten im Vordergrund. Die dadurch ausgelösten Verzerrungen werden ntsprechend ihrer Risiko-/Renditeschädlichkeit im Rahmen des RRS-Index® eingeordnet. Abschließend werden Beispiele für die Anwendung der Behavioral-Finance-Erkenntnisse im Wealth Management und Corporate Governance diskutiert und es wird ein Blick auf aktuelle Entwicklungen der Neuro-Finance und Emotional Finance geworfen.
In dieser Auflage neu hinzugekommen ist Financial Nudging, eine besonders vielversprechende Anwendung von Behavioral Finance-Erkenntnissen.
Afrika ist aufgrund überdurchschnittlicher Wirtschaftswachstumsraten und als die weltweit letzten unbearbeiteten Märkte seit einigen Jahren ein populäres Thema der Wirtschaft. Deutsche Unternehmen sind allerdings mit ihrem Engagement auf den afrikanischen Märkten sehr zurückhaltend. So schwankt der Anteil der deutschen Exporte nach Afrika an den deutschen Gesamtexporten seit zehn Jahren um die zwei Prozent; betrachtet man nur Subsahara‐Afrika, so waren es sogar nur 0,5 % in 2014 (Allafi und Koch 2015, S. 3). Bezüglich der Direktinvestitionen (nur Beteiligungskapital, ohne Direktinvestitionskredite) spielt Afrika eine noch geringere Rolle mit nur 1,5 % aller deutschen Investitionen in 2014, wobei hiervon so gut wie alle nach Nordafrika und Südafrika geflossen sind (Deutsche Bundesbank 2015, S. 12 f.). Neben den Standardgründen wie beispielsweise politischen Risiken, schlechter Infrastruktur, schwacher institutioneller Rahmenbedingungen und Governance‐Problemen (vgl. zum Beispiel World Bank 2016a), ist ein gängiges Markteintrittsproblem die fehlende Verfügbarkeit von lokalen Partnern in den Bereichen Vertrieb, Logistik und teilweise auch Produktion (vgl. zum Beispiel Carlowitz und Röndigs 2016). Aktuell ist ein Markteintritt in Afrika ohne lokalen Partner aufgrund der völlig anderen und schwierigen Rahmenbedingungen fast unmöglich.
Incubators in multinational corporations : development of a corporate incubator operator model
(2017)
This paper analyzes the components of a corporate incubator operator model in multinational companies. Thereby, three relevant phases were identified: pre incubation, incubation, and exit. Each phase contains different criteria that represent critical success factors for a corporate incubator, which are based on theoretical findings and lessons learned from practice. During the pre-incubation phase companies should define their need for a corporate incubator, the origin of ideas and the selection criteria for incubator tenants. The actual phase of incubation refers to the incubator program, which should be flexible with respect to each tenant. Furthermore, resource allocation plays an important role during the incubator program. Exit options after a successful incubation differ according to internal ideas and external start-ups, as well as the objective of the incubator. The research is based on a comprehensive screening of existing incubator literature and a qualitative content analysis of statements from eight experts of international corporate incubators.
Gallium nitride high electron mobility transistors (GaN-HEMTs) have low capacitances and can achieve low switching losses in applications where hard turn-on is required. Low switching losses imply a fast switching; consequently, fast voltage and current transients occur. However, these transients can be limited by package and layout parasitics even for highly optimized systems. Furthermore, a fast switching requires a fast charging of the input capacitance, hence a high gate current.
In this paper, the switching speed limitations of GaN-HEMTs due to the common source inductance and the gate driver supply voltage are discussed. The turn-on behavior of a GaN-HEMT is simulated and the impact of the parasitics and the gate driver supply voltage on the switching losses is described in detail. Furthermore, measurements are performed with an optimized layout for a drain-source voltage of 500 V and a drain-source current up to 60 A.
A device including a first and second monitoring unit, the first monitoring unit detecting a first voltage potential and the second monitoring unit detecting a second voltage potential, the monitoring units comparing the first voltage potential and the second voltage potential to the value of the supply voltage and activate a control unit as a function of the comparisons, the control unit determining a switching point in time of a second power transistor, and an arrangement being present which generates current when the second power transistor is being switched on, the current changing the first voltage potential, and the control unit activates a first power transistor when the first voltage potential has the same value as the supply voltage, so that the first power transistor is de-energized.
Modern power semiconductor devices have low capacitances and can therefore achieve very fast switching transients under hard-switching conditions. However, these transients are often limited by parasitic elements, especially by the source inductance and the parasitic capacitances of the power semiconductor. These limitations cannot be compensated by conventional gate drivers. To overcome this, a novel gate driver approach for power semiconductors was developed. It uses a transformer which accelerates the switching by transferring energy from the source path to the gate path.
Experimental results of the novel gate driver approach show a turn-on energy reduction of 78% (from 80 μJ down to 17 μJ) with a drain-source voltage of 500V and a drain current of 60 A. Furthermore, the efficiency improvement is demonstrated for a hard-switching boost converter. For a switching frequency of 750 kHz with an input voltage of 230V and an output voltage of 400V, it was possible to extend the output power range by 35%(from 2.3kW to 3.1 kW), due to the reduction of the turn-on losses, therefore lowering the junction temperature of the GaN-HEMT.
Um sich im Kommunikationswettbewerb zu profilieren und Streuverluste zu minimieren, bedienen sich Unternehmen vermehrt den sogenannten "nicht klassischen" Kommunikationsinstrumenten. Sponsoring stellt dabei einen erfolgsversprechenden Ansatz dar, da Sponsoring in einem attraktiven, emotional- aufgeladenen und nicht -kommerziellen Umfeld stattfindet. Aufgrund der zunehmenden Reizüberflutung der Konsumenten erscheint die Erreichung gesteckter Sponsoringziele durch bloße Sichtbarkeit jedoch nicht mehr zufriedenstellend realisierbar. Der vorliegende Beitrag behandelt das Thema Aktuelle Trends im Sponsoring im Sport. Die Analyse der aktuellen Entwicklungen zeigt, dass sich die Wirkungsvoraussetzungen des Sponsoring im Zeitverlauf verändert haben. Es bedarf neuer und innovativer Aktivierungsmaßmahmen, um die Reizüberflutung der Konsumenten zu überwinden und die Potentiale des Sponsorings zu nutzen. Die Darstellung praktischer Beispiele aus dem Sportmarketing zeigt, dass die handelnden Akteure die neuen Herausforderungen des Sponsorings erkannt haben. Es werden die aktuellen Entwicklungen hinsichtlich Digitalisierung, Internationalisierung, Professionalisierung und unkonventionaller Aktivierung aufgezeigt.
Within the scope of the present cumulative doctoral thesis six scientific papers were published which illustrates that modern reaction model-free (=isoconversional) kinetic analysis (ICKA) methods represents a universal and effective tool for the controlled processing of thermosetting materials. In order to demonstrate the universal applicability of ICKA methods, the thermal cure of different thermosetting materials having a very broad range of chemical composition (melamine-formaldehyde resins, epoxy resins, polyester-epoxy resins, and acrylate/epoxy resins) were analyzed and mathematically modelled. Some of the materials were based on renewable resources (an epoxy resin was made from hempseed oil; linseed oil was modified into an acrylate/epoxy resin). With the aid of ICKA methods not only single-step but also complex multi-step reactions were modelled precisely. The analyzed thermosetting materials were combined with wood, wood-based products, paper, and plant fibers which are processed to various final products. Some of the thermosetting materials were applied as coating (in form of impregnated décor papers or powder and wet coatings respectively) on wood substrates and the epoxy resin from hempseed oil was mixed with plant fibers and processed into bio-based composites for lightweight applications. From the final products mechanical, thermal, and surface properties were determined. The activation energy as function of cure conversion derived from ICKA methods was utilized to predict accurately the thermal curing over the course of time for arbitrary cure conditions. Furthermore the cure models were used to establish correlations between the cross-linking during processing into products and the properties of the final products. Therewith it was possible to derive the process time and temperature that guarantee optimal cross-linking as well as optimal product properties
The presented wide-Vin step-down converter introduces a parallel-resonant converter (PRC), comprising an integrated 5-bit capacitor array and a 300 nH resonant coil, placed in parallel to a conventional buck converter. Unlike conventional resonant concepts, the implemented soft-switching control eliminates input voltage dependent losses over a wide operating range. This ensures high efficiency across a wide range of Vin= 12-48V, 100-500mA load and 5V output at up to 15MHz switching frequency. The peak efficiency of the converter is 76.3 %. Thanks to the low output current ripple, the output capacitor can be as small as 50 nF, while the inductor tolerates a larger ESR, resulting in small component size. The proposed PRC architecture is also suitable for future power electronics applications using fast-switching GaN devices.
Instead of waiting for and constantly adapting to details of political interventions, utilities need to focus on their environment from a holistic perspective. The unique position of the company - be it a local utility, a bigger player, or an international utility specializing in specitic segments - has to be the basis of goals and strategies. But without consistent translation of these goals and strategies into processes, structures, and company culture, a strategy remains pure theory. Companies need to engage in a continuing learning process. This means being willing to pass on strategies, to slow down or speed up, to work from a different angle etc.
Saving energy and road safety became important in the last decades, hence several driving assistant systems were developed that help to improve the driving behaviour. However, these driving systems cover the area of either energy-efficiency or safety. Furthermore, they do not consider the reaction of the driver to a shown recommendation and the driver stress level. In this paper, the decision process of showing a recommendation to the driver in an energy-efficient and safety relevant driving system is presented. The decision process considers the driver's reaction to a shown recommendation and the driver stress in order to increase the user acceptance and the road safety. The results of the evaluation showed that the driving system was able to show recommendations when needed, while suppressing recommendations when the driver ignored a recommendation repeatedly or when the driver was in stress.
More and more power electronics applications utilize GaN transistors as they enable higher switching frequencies in comparison to conventional Si devices. Faster switching shrinks down the size of passives and enables compact solutions in applications like renewable energy, electrical cars and home appliances. GaN transistors benefit from ~10× smaller gate charge QG and gate drive voltages in the range of typically 5V vs. ~15V for Si.
Modern power transistors are able to switch at very high transition speed, which can cause EMC violations and overshoot. This is addressed by a gate driver with variable gate current, which is able to control the transition speed. The key idea is that the gate driver can influence the di/dt and dv/dt transition separately and optimize whichever transition promises the highest improvement while keeping switching losses low. To account for changes in the load current, supply voltage, etc., a control loop is required in the driver to ensure optimized switching. In this paper, an efficient control scheme for an automotive gate driver with variable output current capability is presented. The effectiveness of the control loop is demonstrated for a MOSFET bridge consisting of OptiMOS-T2™devices with a total gate charge of 39nC. This bridge setup shows dv/dt transitions between 50 to 1000ns, depending on driving current. The driver is able to switch between gate current levels of 1 to 500mA in 10/15ns (rising/falling transition). With the implemented control loop the driver is measured to significantly reduce the ringing and thereby reduce device stress and electromagnetic emissions while keeping switching losses 52% lower than with a constant current driver.
A concept for a slope shaping gate driver IC is proposed, used to establish control over the slew rates of current and voltage during the turn-on and turn off switching transients.
It combines the high speed and linearity of a fully-integrated closed-loop analog gate driver, which is able to perform real-time regulation, with the advantages of digital control, like flexibility and parameter independency, operating in a predictive cycle-bycycle regulation. In this work, the analog gate drive integrated circuit is partitioned into functional blocks and modeled in the small-signal domain, which also includes the non-linearity of parameters. An analytical stability analysis has been performed in order to ensure full functionality of the system controlling a modern generation IGBT and a superjunction MOSFET. Major parameters of influence, such as gate resistor and summing node capacitance, are investigated to achieve stable control. The large-signal behavior, investigated by simulations of a transistor level design, verifies the correct operation of the circuit. Hence, the gate driver can be designed for robust operation.
In a digitally controlled slope shaping system, reliable detection of both voltage and current slope is required to enable a closed-loop control for various power switches independent of system parameters. In most state-of-the-art works, this is realized by monitoring the absolute voltage and current values. Better accuracy at lower DC power loss is achieved by sensing techniques for a reliable passive detection, which is achieved through avoiding DC paths from the high voltage network into the sensing network. Using a high-speed analog-to-digital converter, the whole waveform of the transient derivative can be stored digitally and prepared for a predictive cycle-by-cycle regulation, without requiring high-precision digital differentiation algorithms. To gain an accurate representation of the voltage and current derivative waveforms, system parasitics are investigated and classified in three sections: (1) component parasitics, which are identified by s-parameter measurements and extraction of equivalent circuit models, (2) PCB design issues related to the sensing circuit, and (3) interconnections between adjacent boards.
The contribution of this paper is an optimized sensing network on the basis of the experimental study supporting fast transition slopes up to 100 V/ns and 1 A/ns and beyond, making the sensing technique attractive for slope shaping of fast switching devices like modern generation IGBTs, CoolMOSTM and SiC mosfets. Measurements of the optimized dv/dt and di/dt setups are demonstrated for a hard switched IGBT power stage.
Introducing continuous experimentation in large software-intensive product and service organisations
(2017)
Software development in highly dynamic environments imposes high risks to development organizations. One such risk is that the developed software may be of only little or no value to customers, wasting the invested development efforts.Continuous experiment ation, as an experiment-driven development approach, may reduce such development risks by iteratively testing product and service assumptions that are critical to the success of the software. Although several experiment-driven development approaches are available, there is little guidance available on how to introduce continuous experimentation into an organization. This article presents a multiple-case study that aims at better understanding the process of introducing continuous experimentation into an organization with an already established development process. The results from the study show that companies are open to adopting such an approach and learning throughout the introduction process. Several benefits were obtained, such as reduced development efforts, deeper customer insights, and better support for development decisions. Challenges included complex stakeholder structures, difficulties in defining success criteria, and building experimen- tation skills. Our findings indicate that organizational factors may limit the benefits of experimentation. Moreover, introducing continuous experimentation requires fundamental changes in how companies operate, and a systematic introduction process can increase the chances of a successful start.
Empirical software engineering experts on the use of students and professionals in experiments
(2018)
Using students as participants remains a valid simplification of reality needed in laboratory contexts. It is an effective way to advance software engineering theories and technologies but, like any other aspect of study settings, should be carefully considered during the design, execution, interpretation, and reporting of an experiment. The key is to understand which developer population portion is being represented by the participants in an experiment. Thus, a proposal for describing experimental participants is put forward.
Medical applications are becoming increasingly important in the current development of health care and therefore a crucial part of the medical industry. The work focuses on the analysis of requirements and the challenges arisen from designing mobile medical applications in relation to the user interface. The paper describes the current status in the development of mobile medical apps and illustrates the development of e-health market. The author will explain the requirements and will illustrate the hurdles and problems. He refers to the German market which is similar to the European and compares that with the market in the USA.
To assess the quality of a person’s sleep, it is essential to examine the sleep behaviour by identifying the several sleep stages, their durations and sleep cycles. The established and gold standard procedure for sleep stage scoring is overnight polysomnography (PSG) with the Rechtschaffen and Kales (R-K) method. Unfortunately, the conduct of PSG is time-consuming and unfamiliar for the subjects and might have an impact of the recorded data. To avoid the disadvantages with PSG, it is important to make further investigations in low-cost home diagnostic systems. For this intention it is necessary to find suitable bio vital parameters for classifying sleep stages without any physical impairments at the same time. Due to the promising results in several publications we want to analyse existing methods for sleep stage classification based on the parameters body movement,
heartbeat and respiration. Our aim was to find different behaviour patterns in the several sleep stages. Therefore, the average values of 15 whole-night PSG recordings -obtained from the ‘DREAMS
Subjects Database’- where analysed in the light of heartbeat, body movement and respiration with 10 different methods.
Sleep quality and in general, behavior in bed can be detected using a sleep state analysis. These results can help a subject to regulate sleep and recognize different sleeping disorders. In this work, a sensor grid for pressure and movement detection supporting sleep phase analysis is proposed. In comparison to the leading standard measuring system, which is Polysomnography (PSG), the system proposed in this project is a non invasive sleep monitoring device. For continuous analysis or home use, the PSG or wearable actigraphy devices tends to be uncomfortable. Besides this fact, they are also very expensive. The system represented in this work classifies respiration and body movement with only one type of sensor and also in a non invasive way. The sensor used is a pressure sensor. This sensor is low cost and can be used for commercial proposes. The system was tested by carrying out an experiment that recorded the sleep process of a subject. These recordings showed the potential for classification of breathing rate and body movements. Although previous researches show the use of pressure sensors in recognizing posture and breathing, they have been mostly used by positioning the sensors between the mattress and bedsheet. This project however, shows an innovative way to position the sensors under the mattress.
To evaluate the quality of sleep, it is important to determine how much time was spent in each sleep stage during the night. The gold standard in this domain is an overnight polysomnography (PSG). But the recording of the necessary electrophysiological signals is extensive and complex and the environment of the sleep laboratory, which is unfamiliar to the patient, might lead to distorted results. In this paper, a sleep stage detection algorithm is proposed that uses only the heart rate signal, derived from electrocardiogram (ECG), as a discriminator. This would make it possible for sleep analysis to be performed at home, saving a lot of effort and money. From the heart rate, using the fast Fourier transformation (FFT), three parameters were calculated in order to distinguish between the different sleep stages. ECG data along with a hypnogram scored by professionals was used from Physionet database, making it easy to compare the results. With an agreement rate of 41.3%, this approach is a good foundation for future research.
Zukünftige Montagearbeitsplätze müssen veränderten Herausforderungen, wie z. B. der zunehmenden Anzahl von Mensch Roboter-Kollaborationen, gerecht werden. Die Virtual Reality (VR)-Technik bietet im Rahmen der Arbeitsplatzgestaltung neue Möglichkeiten, diesen veränderten Planungsherausforderungen gerecht zu werden. Die Ausarbeitung stellt eine Methode zur Bewertung des sinnvollen Einsatzes der VR-Technik für einen spezifischen Arbeitsplatz vor. Außerdem wird aufgezeigt, wie die VR-Technik in den Prozess der Arbeitsplatzgestaltung integriert werden kann.
46 Prozent der Arbeitsplätze in der Automobilindustrie sind bis 2030 durch Automatisierung und Digitalisierung bedroht – die Tätigkeiten werden dann nicht mehr von Menschen, sondern von intelligenten Robotern und Systemen erledigt. Das ist das zentrale Ergebnis unserer Studie „Digitale Transformation – Der Einfluss der Digitalisierung auf die Workforce in der Automobilindustrie“, die wir gemeinsam mit dem Herman Hollerith Lehr- und Forschungszentrum an der Hochschule Reutlingen erstellt haben.
LDMOS transistors in integrated power technologies are often subject to thermo-mechanical stress, which degrades the on-chip metallization and eventually leads to a short. This paper investigates small sense lines embedded in the LDMOS metallization. It will be shown that their resistance depends strongly on the stress cycle number. Thus, they can be used as aging sensors and predict impending failures. Different test structures have been investigated to identify promising layout configurations. Such sensors are key components for resilient systems that adaptively reduce stress to allow aggressive LDMOS scaling without increasing the risk of failure.
A gate driver approach is presented for the reduction of turn-on losses in hard switching applications. A significant turn-on loss reduction of up to 55% has been observed for SiCMOSFETs. The gate driver approach uses a transformer which couples energy from the power path back into the gate path during switching events, providing increased gate driver current and thereby faster switching speed.
The gate driver approach was tested on a boost converter running at a switching frequency up to 300 kHz. With an input voltage of 300V and an output voltage of 600V, it was possible to reduce the converter losses by 8% at full load. Moreover, the output power range could be extended by 23% (from 2.75kW to 3.4 kW) due to the reduction of the turn-on losses.
Die weiterhin hohen Schulden in einigen Staaten der Europäischen Wirtschafts- und Währungsunion lassen nach wie vor staatliche Insolvenzen befürchten. Um die entstandenen Probleme zu bewältigen, aber auch damit eine solche Situation erst gar nicht eintritt, hält der Autor eine staatliche Insovenzordnung – mit Bail-out durch die anderen Mitgliedstaaten nur in Notfällen – für erforderlich. Er schlägt einen staatlichen Abwicklungsmechanismus für überschuldete Euro-Länder vor, der auf einem Konzept des Sachverständigenrates für Wirtschaft von 2016 beruht.
In order to decouple economic growth from global material consumption it is necessary to implement material efficiency strategies at the level of single enterprises and their supply chains, and to implement circular economy aspects. Manufacturing firms face multiple implementation challenges like cost limitations, competition, innovation and stakeholder pressure, and supplier and customer relationships, among others. Taking as an example a case of a medium-sized manufacturing company, opportunities to realise material efficiency improvements within the company borders - on the supply chain and by using circular economy measures - are assessed. Deterministic calculations and simulations, performed for the supply chain of this company, show that measures to increase material efficiency in the supply chain are important. However, they need to be complemented by efforts to return waste and used products to the economic cycle, which requires rethinking the traditional linear economic system.
IT platforms as the foundation of digitized processes and products are vital in a digital economy. However, many companies’ platforms are liabilities, not strategic assets because of their complexity. Consequently, companies initiate IT complexity reduction programs. But these technology-centric programs at best provide temporary relief. Soon after, companies’ platforms become just as complex as before. Based on four case studies, we identify three non-technical drivers of platform complexity: (1) Lacking awareness of consequences business decisions have on platform complexity, (2) Lacking motivation to avoid platform complexity, (3) Lacking authority to protect platforms from complexity. We propose measures to address these drivers that can help achieve more sustainable impact on platform complexity: (1) Removing information asymmetries between those creating complexity and those dealing with complexity, (2) Redefining incentives to include long-term effects on platform complexity, (3) Redressing power imbalances between those who create complexity and those who have to manage it.
Electric freight vehicles have the potential to mitigate local urban road freight transport emissions, but their numbers are still insignificant. Logistics companies often consider electric vehicles as too costly compared to vehicles powered by combustion engines. Research within the body of the current literature suggests that increasing the driven mileage can enhance the competitiveness of electric freight vehicles. In this paper we develop a numeric simulation approach to analyze the cost-optimal balance between a high utilization of medium-duty electric vehicles – which often have low operational costs – and the common requirement that their batteries will need expensive replacements. Our work relies on empirical findings of the real-world energy consumption from a large German field test with medium-duty electric vehicles. Our results suggest that increasing the range to the technical maximum by intermediate (quick) charging and multi-shift usage is not the most cost-efficient strategy in every case. A low daily mileage is more cost-efficient at high energy prices or consumptions, relative to diesel prices or consumptions, or if the battery is not safeguarded by a long warranty. In practical applications our model may help companies to choose the most suitable electric vehicle for the application purpose or the optimal trip length from a given set of options. For policymakers, our analysis provides insights on the relevant parameters that may either reduce the cost gap at lower daily mileages, or increase the utilization of medium-duty electric vehicles, in order to abate the negative impact of urban road freight transport on the environment.
Though bioprinting is a forward-looking approach in bone tissue engineering, the development of bioinks which are on the one hand processable with the chosen printing technique, and on the other hand possess the relevant mechanical as well as osteoconductive features remains a challenge. In the present study, polymer solutions based on methacrylated gelatin and methacrylated hyaluronic acid modified with hydroxyapatite (HAp) particles (5 wt%) were prepared. Encapsulation of primary human adipose derived stem cells in the HAp-containing gels and culture for 28 d resulted in a storage moduli significantly increased to 126% ± 9.6% compared to the value on day 1 by the sole influence of the HAp. Additional use of osteogenic media components resulted in an increase of storage module up to 199% ± 27.8%. Similarly, the loss moduli was increased to 370% ± 122.1% under the influence of osteogenic media components and HAp. Those changes in rheological material characteristics indicate a distinct change in elastic and viscous hydrogel properties, and are attributed to extensive matrix production in the hydrogels by the encapsulated cells, what could also be proven by staining of bone matrix components like collagen I, fibronectin, alkaline phosphatase and osteopontin. When using the cell-laden polymer solutions as bioinks to build up relevant geometries, the ink showed excellent printability and the printed grid structure's integrity remained intact over a culture time of 28 d. Again, an intense matrix formation as well as upregulation of osteogenic markers by the encapsulated cells could be shown. In conclusion, we demonstrated that our HAp-containing bioinks and hydrogels on basis of methacrylated gelatin and hyaluronic acid are on the one hand highly suitable for the build up of relevant three-dimensional geometries with microextrusion bioprinting, and on the other hand exhibit a significant positive effect on bone matrix development and remodeling in the hydrogels, as indicated by rheological measurements and staining of bone components. This makes the developed composite hydrogels an excellent material for bone bioprinting approaches.
Understanding the factors that influence the accuracy of visual SLAM algorithms is very important for the future development of these algorithms. So far very few studies have done this. In this paper, a simulation model is presented and used to investigate the effect of the number of scene points tracked, the effect of the baseline length in triangulation and the influence of image point location uncertainty. It is shown that the latter is very critical, while the other all play important roles. Experiments with a well known semi-dense visual SLAM approach are also presented, when used in a monocular visual odometry mode. The experiments show that not including sensor bias and scale factor uncertainty is very detrimental to the accuracy of the simulation results.
In this work we investigate the behavior of MIS- and Schottky-gate AlGaN/GaN HEMTs under high-power pulsestress. A special setup capable of applying pulses of constant power is used to evaluate the electro-thermal response in different operating points. For both types of devices, the time to failure was found to decrease with increasing drain-source voltage. Overall, the Schottky-gate device displays a higher pulse robustness. The pulse withstand time of the MIS-gate device is limited by the occurrence of a thermal instability at approximately 240°C while the Schottky-gate device displays a rapid increase of the gate leakage current prior to failure. The mechanism responsible for this gate current is further investigated by static and transient temperature measurements and yielded activation energies of 0.6 eV and 0.84 eV.
This paper studies whether a monetary union can be managed solely by a rule based approach. The Five Presidents’ Report of the European Union rejects this idea. It suggests a centralisation of powers. We analyse the philosophy of policy rules from the vantage point of the German economic school of thought. There is evidence that a monetary union consisting of sovereign states is well organised by rules, together with the principle of subsidiarity. The root cause of the euro crisis is rather the weak enforcement of rules, compounded by structural problems. Therefore, we suggest a genuine rule-based paradigm for a stable future of the Economic and Monetary Union.
Under update intensive workloads (TPC, LinkBench) small updates dominate the write behavior, e.g. 70% of all updates change less than 10 bytes across all TPC OLTP workloads. These are typically performed as in-place updates and result in random writes in page-granularity, causing major write-overhead on Flash storage, a write amplification of several hundred times and lower device longevity.
In this paper we propose an approach that transforms those small in-place updates into small update deltas that are appended to the original page. We utilize the commonly ignored fact that modern Flash memories (SLC, MLC, 3D NAND) can handle appends to already programmed physical pages by using various low-level techniques such as ISPP to avoid expensive erases and page migrations. Furthermore, we extend the traditional NSM page-layout with a delta-record area that can absorb those small updates. We propose a scheme to control the write behavior as well as the space allocation and sizing of database pages.
The proposed approach has been implemented under Shore- MT and evaluated on real Flash hardware (OpenSSD) and a Flash emulator. Compared to In-Page Logging it performs up to 62% less reads and writes and up to 74% less erases on a range of workloads. The experimental evaluation indicates: (i) significant reduction of erase operations resulting in twice the longevity of Flash devices under update-intensive workloads; (ii) 15%-60% lower read/write I/O latencies; (iii) up to 45% higher transactional throughput; (iv) 2x to 3x reduction in overall write
amplification.
In the present paper we demonstrate the novel technique to apply the recently proposed approach of In-Place Appends – overwrites on Flash without a prior erase operation. IPA can be applied selectively: only to DB-objects that have frequent and relatively small updates. To do so we couple IPA to the concept of NoFTL regions, allowing the DBA to place update-intensive DB-objects into special IPA-enabled regions. The decision about region configuration can be (semi-)automated by an advisor analyzing DB-log files in the background.
We showcase a Shore-MT based prototype of the above approach, operating on real Flash hardware. During the demonstration we allow the users to interact with the system and gain hands-on experience under different demonstration scenarios.
In the present paper we demonstrate a novel approach to handling small updates on Flash called In-Place Appends (IPA). It allows the DBMS to revisit the traditional write behavior on Flash. Instead of writing whole database pages upon an update in an out-of-place manner on Flash, we transform those small updates into update deltas and append them to a reserved area on the very same physical Flash page. In doing so we utilize the commonly ignored fact that under certain conditions Flash memories can support in-place updates to Flash pages without a preceding erase operation.
The approach was implemented under Shore-MT and evaluated on real hardware. Under standard update-intensive workloads we observed 67% less page invalidations resulting in 80% lower garbage collection overhead, which yields a 45% increase in transactional throughput, while doubling Flash longevity at the same time. The IPA outperforms In-Page Logging (IPL) by more than 50%.
We showcase a Shore-MT based prototype of the above approach, operating on real Flash hardware – the OpenSSD Flash research platform. During the demonstration we allow the users to interact with the system and gain hands on experience of its performance under different demonstration scenarios. These involve various workloads such as TPC-B, TPC-C or TATP.
This article is a review of the book "Brain computation as hierarchical abstraction" by Dana H. Ballard published by MIT press in 2015. The book series computational neuroscience familiarizes the reader with the computational aspects of brain functions based on neuroscientific evidence. It provides an excellent introduction of the functioning, i.e. the structure, the network and the routines of the brain in our daily life. The final chapters even discuss behavioral elements such as decision-making, emotions and consciousness. These topics are of high relevance in other sciences such as economics and philosophy. Overall, Ballard’s book stimulates a scientifically well-founded debate and, more importantly, reveals the need of an interdisciplinary dialogue towards social sciences.
The purpose of this paper is to study the impact of transparency on the political budget cycle (PBC) over time and across countries. So far, the literature on electoral cycles finds evidence that cycles depend on the stage of an economy. However, the author shows – for the first time – a reliance of the budget cycle on transparency. The author uses a new data set consisting of 99 developing and 34 Organization for Economic Cooperation and Development countries. First, the author develops a model and demonstrates that transparency mitigates the political cycles. Second, the author confirms the proposition through the econometric assessment. The author uses time series data from 1970 to 2014 and discovers smaller cycles in countries with higher transparency, especially G8 countries.
Die Europäische Währungs- und Wirtschaftsunion (EWWU) bedarf einer weiteren Stabilisierung, da die institutionellen Regelungen langfristig keine hinreichende Bindekraft auf die Mitgliedsländer entfalten. Die Herausforderung ist die Rückgewinnung der verlorengegangenen Glaubwürdigkeit in das Regelwerk im Zuge der europäischen Staatsverschuldungskrise seit dem Jahr 2010. Um die Währungsunion zu erhalten, muss einerseits im Primärrecht das "No Bailout" in Art. 125 AEUV glaubwürdig angewandt werden können und andererseits die Regelungen im Sekundärrecht, u.a. der Stabilitäts- und Wachstumspakt, der Fiskalpakt oder das europäische Semester, unabhängiger und schneller rechtsverbindlich vollzogen werden. Der hier vorgeschlagene und klug in den europäischen Rahmen eingepasste "staatliche Insolvenzmechanismus", verbunden mit einer im Ultima Ratio rechtsverbindlichen "Austrittsklausel" wäre ein Lösungsansatz. Ein Scheitern der EWWU ist abwendbar, aber der fehlende Reformwille könnte dem Zerfall der Währungsunion Vorschub leisten.
Ein wesentliches Ziel der unter dem Schlagwort Industrie 4.0 gebündelten neuen Entwicklungen ist die Vernetzung intelligenter Komponenten in industriellen Anlagen, um Prozesse transparenter und effizienter zu gestalten. Ein weiteres Ziel ist das Condition Monitoring, d.h. die Überwachung des Zustands der Komponenten während der Laufzeit und die Abschätzung der Restlebensdauer, damit die gesamte Lebensdauer der Komponente ausgenutzt und Wartungsintervalle besser geplant werden können. Die Bewertung des Komponentenzustands erfolgt anhand von Messgrößen, die entweder durch zusätzlich in den Prozess eingebrachte Sensoren erfasst werden oder durch Prozessdaten, die in den Regel- und Steuereinrichtungen verfügbar sind. Diese Messdaten werden ausgewertet und das Ergebnis wird dem Anwender angezeigt.
Der vorliegende Beitrag gibt einen kurzen Überblick über verwendete Messgrößen sowie verwendete Auswerteverfahren. Darüber hinaus wird ein Verfahren erläutert, das die Schwierigkeiten bei der Beurteilung der üblicherweise verwendeten Frequenzspektren vermeidet.
This paper describes a new method for condition monitoring of a roller chain. In contrast to conventional methods, no additional accelerometers are used to measure and interpret frequency spectra but the chain condition is evaluated using an easy to interpret similarity measure based on correlation functions using the driving motor torque. An additional clustering of current data and reference measurements yields an easy to understand representation of the chain condition.
Using the damage area as a quantification method for the Martindale test is a promising method to compare textile finishes without the need to test to full destruction. In addition, it could be shown that the results of Martindale tests performed with different pressure loads can be scaled to identical functional shape. If these results can be verified, this method would be a simplification of abrasive testing for different application areas.
Im Zuge von REACH wurden gängige hocheffektive halogenierte Flammschutzmittel verboten, da diese unter dem Verdach stehen, kanzerogen, mutagen und teratogen zu sein. Zur Zeit fehlen entsprechende Alternativen. Daher werden am DTNW neue umweltfreundliche und halogenfreie Flammschutzmittel auf der Basis von Phosphor- und Stickstoffverbindungen entwickelt, um einen entsprechenden Flammschutz zu gewährleisten. Neue Möglichkeiten werden im Rahmen dieses Artikels vorgestellt.
Es wird eine Möglichkeit zur Quantifizierung der Schädigung von Geweben bei der Martindale-Flachscheuerung vorgestellt, die eine interessante Möglichkeit darstellt, vergleichende Untersuchungen durchzuführen, auch wenn die Gewebe nicht bis zu einem Fadenbruch gescheuert werden. Die Untersuchungen deuten außerdem eine Skalierbarkeit der Scheuerversuche bei unterschiedlichen Anpressdrücken an. Sollte sich diese Beobachtung in weiteren Untersuchungen bestätigen, würde dies eine grundlegende Vereinfachung der Scheuerprüfung für verschiedene Anwendungen bedeuten.
In this paper we describe the design and development process of an electromagnetic picker for rivets. These rivets are used in a production process of leather or textile design objects like riveted waist belts or purses. The picker is designed such that it replaces conventional mechanical pickers thus avoiding mechanical wear problems and increasing the process quality. The paper illustrates the challenges in the design process of this mechatronic system. The design process was based on both simulation and experiments leading to a prototype that satisfies the requirements.
In retail environments, consumers commonly evaluate products while standing on some type of flooring and concurrently being exposed to music; however, no study has examined the interaction of these two atmospheric cues. To bridge this gap, this research examines whether retailers can benefit from creating multisensory atmospheric congruent rather than incongruent retail environments of flooring and music. The results of an experiment in a real retail store reveal positive effects of multisensory congruent retail environments (e.g., soft music combined with soft flooring) on product evaluations. This study provides a new process explanation with consumers’ purchase-related self-confidence mediating these effects. Specifically, consumers in congruent rather than incongruent retail environments experience more purchase-related self confidence, which in turn leads to more favorable product evaluations. Furthermore, this study shows that consumers with a low rather than a high preference for haptic information are influenced more by multisensory atmospheric congruence when evaluating a product haptically.
As the market penetration of alternative fuel vehicles is still uncertain, defining green design cues for their design is of specific relevance to target environmentally conscious customers. This paper is a review of the existing literature aiming at summarizing the market penetration scenarios of alternative fuel vehicles over the next years, consumer demand for sustainable materials, and present methodologies to represent characteristics of eco-friendly mobility in the interior of alternative fuel vehicles. In particular, present attempts to correlate materials with green design cues are explored. Finally, projections for the future of the field are suggested, posing enchanting research questions to further unify the field of environmentally conscious design with the domain of product personality.
Werkstoffkundeunterricht wird in den allermeisten Fällen als reiner Frontalunterricht abgehalten. Ergänzender Laborunterricht zur Werkstoffkunde findet teilweise statt, nur beziehen sich hier die durchgeführten Experimente größtenteils auf sehr wenige Teilgebiete, wie z.B. den Zugversuch. Im Curriculum mancher Studiengänge ist für derartige im Labor druchgeführte Experimente gar keine Zeit vorgesehen. Das Wissen muss komplett im Unterricht vermittelt werden.
Ziel von ExperiMat ist es, praxistaugliche Schauexperimente für den werkstoffkundlichen Unterricht zu beschreiben.
Das vorliegende Buch ist als eine zusammenfassende Bearbeitung der über viele Jahre gesammelten Erkenntnisse im Bereich der Schussfadenzugkraftmessung entstanden. Für die Schusseintragstechniken mit Greifern, Projektilen und Luftstrahl ist es gelungen, Formeln zur Berechnung der Schussfadenzugkräfte zu erarbeiten, die es auch dem Weberei-Praktiker ermöglichen, die maximalen Schussfadenzugkräfte mit guter Genauigkeit voraus zu berechnen. Ausgehend von diesen Ergebnissen kann über einen Vergleich mit dem Schwachstellenniveau des Schussgarns die Entscheidung über die Einsatzfähigkeit des Schussgarns auf der vorgesehenen Webmaschine oder über die Einsatzfähigkeit der vorgesehenen Webmaschine selbst bei der gewünschten Drehzahl herbeigeführt werden.
Das vorliegende Taschenbuch fasst die bekannten Berechnungsformeln und Erkenntnisse aus der betrieblichen Praxis und aus wissenschaftlichen Untersuchungen im Bereich des Weberei-Vorwerks und der Weberei zusammen. Die bei der Gewebeherstellung notwendigen Entscheidungsprozesse sollen damit erleichtert werden.
Mit dieser Formelsammlung lassen sich jedoch nicht nur die optimalen Fertigungsvorschriften für Gewebe praxisgerecht erstellen, sondern auch die wichtigsten technischen und physikalischen Grundlagen des Fabrikbetriebs werden in der gebotenen Kürze dargestellt.
- Die zunehmende Digitalisierung stellt sowohl Unternehmen als auch deren Mitarbeiter vor viele neue Herausforderungen und bietet zugleich ein hohes Chancenpotenzial.
- Die Chance, das mit der Digitalisierung verbundene Potenzial zu heben, ist abhängig von der Konsequenz der Umsetzung der Digitalisierung.
- Voraussetzung für eine erfolgreiche Umsetzung ist eine Digitalisierungsstrategie, die den Weg und die Ziele für alle Beteiligten transparent, nachvollziehbar und erstrebenswert macht.
- Eine gelebte und von allen mitgetragene Digitalisierungsstrategie impliziert eine Kulturveränderung im Unternehmen.
Nachdem Unternehmen Klarheit über das Kundenverhalten und die damit zusammenhängenden Determinanten haben, gilt es, in einem zweiten Schritt eine Strategie auszuarbeiten, die die bestmögliche Befriedigung der Kundenbedürfnisse in den Mittelpunkt des Handelns setzt. Je besser dieses den Unternehmen gelingt, umso besser lassen sich damit deren eigene Ziele verwirklichen. Dabei gilt es zunächst, einen Marketingplan zu entwickeln.
Marketing ist allgegenwärtig! Es begegnet Ihnen im Supermarkt, in Onlineshops und in sozialen Medien. Doch was steckt konkret hinter dem Marketing und wie gestalten Unternehmen es erfolgreich? Auf diese und weitere Fragen geht das Buch im Detail ein. Zu Beginn vermittelt es Grundlagen zum Konsumentenverhalten, zum Kaufprozess und zur persönlichen Kaufentscheidung. Vor diesem Hintergrund erläutert es Ziele und Maßnahmen der strategischen Marketingplanung. Darauf aufbauend präsentiert es Aspekte einer operativen Marketingplanung und diskutiert die Marken-, Produkt-, Distributions-, Kommunikations- sowie Preispolitik ausführlich. Marketingprofis geben Einblicke in die Praxis. Ein Best Practice-Beispiel macht das Gelernte schnell (be)greifbar.
Radiofrequency ablation is an ablation technique to treat tumors with focused heat. Computer tomography, ultrasound and magnetic resonance imaging (MRI) are imaging modalities which can be used for image-guided procedures. MRI offers several advantages in comparison to the other imaging modalities, such as radiation-free fluoroscopic imaging, temperature mapping, a high-soft-tissue contrast and free selection of imaging planes. This work addresses the application of 3Dcontrollers for controlling interventional, fluoroscopic MR sequences at the scenario of MR guided radiofrequency ablation of hepatic malignancies. During this procedure, the interventionalist can monitor the targeting of the tumor with near-real time fluoroscopic sequences. In general, adjustments of the imaging planes are necessary during tumor targeting, which is performed by an assistant in the control room. Therefore, communication between the interventionalist in the scanner room and the assistant in the control room is essential. However, verbal communication is impaired due to the loud scanning noises. Alternatively, non-verbal communication between the two persons is possible, however limited to a few gestures and susceptible to misunderstandings. This work is analyzing different 3D-controllers to enable control of interventional MR sequences during MR-guided procedures directly by the interventionalist. Leap Motion, Wii Remote, SpaceNavigator, Phantom Omni and Foot Switch were selected. For that a simulation was built in C++ with VTK to feign the real scenario for test purposes. Previous results showed that Leap Motion is not suitable for the application while Wii Remote and Foot Switch are possible input devices. Final evaluation showed a generally time reduction with the use of 3D-controllers. Best results were reached with Wii Remote in 34 seconds. Handholding input devices like Wii Remote have further potential to integrate them in real environment to reduce intervention time.
Digitization of societies changes the way we live, work, learn, communicate, and collaborate. In the age of digital transformation IT environments with a large number of rather small structures like Internet of Things (IoT), microservices, or mobility systems are emerging to support flexible and agile digitized products and services. Adaptable ecosystems with service oriented enterprise architectures are the foundation for self-optimizing, resilient run-time environments and distributed information systems. The resulting business disruptions affect almost all new information processes and systems in the context of digitization. Our aim are more flexible and agile transformations of both business and information technology domains with more flexible enterprise information systems through adaptation and evolution of digital enterprise architectures. The present research paper investigates mechanisms for decision-controlled digitization architectures for Internet of Things and microservices by evolving enterprise architecture reference models and state of the art elements for architectural engineering for micro-granular systems.
Digitization fosters the development of IT environments with many rather small structures, like Internet of Things (IoT), microservices, or mobility systems. They are needed to support flexible and agile digitized products and services. The goal is to create service-oriented enterprise architectures (EA) that are self optimizing and resilient. The present research paper investigates methods for decision-making concerning digitization architectures for Internet of Things and microservices. They are based on evolving enterprise architecture reference models and state of the art elements for architectural engineering for microgranular systems. Decision analytics in this field becomes increasingly complex and decision support, particularly for the development and evolution of sustainable enterprise architectures, is sorely needed. The challenging of the decision processes can be supported with in a more flexible and intuitive way by an architecture management cockpit.
Digital enterprise architecture management in tourism : state of the art and future directions
(2018)
The advance of information technology impacts tourism more than many other industries, due to the service character of its products. Most offerings in tourism are immaterial in nature and challenging in coordination. Therefore, the alignment of IT and strategy and digitization is of crucial importance to enterprises in tourism. To cope with the resulting challenges, methods for the management of enterprise architectures are necessary. Therefore, we scrutinize approaches for managing enterprise architectures based on a literature research. We found many areas for future research on the use of enterprise architecture in tourism.
Digitization transforms business process models and processes in many enterprises. However, many of them need guidance, how digitization is impacting the design of their information systems. Therefore, this paper investigates the influence of digitization on information system design. We apply a two-phase research method applying a literature review and an exploratory case study. The case study took place in the IT service provider of a large insurance enterprise. The study’s results suggest that a number of areas of information system design are affected, such as architecture, processes, data and services.
In a time of digital transformation, the ability to quickly and efficiently adapt software systems to changed business requirements becomes more important than ever. Measuring the maintainability of software is therefore crucial for the long-term management of such products. With service-based systems (SBSs) being a very important form of enterprise software, we present a holistic overview of such metrics specifically designed for this type of system, since traditional metrics – e.g. object oriented ones – are not fully applicable in this case. The selected metric candidates from the literature review were mapped to 4 dominant design properties: size, complexity, coupling, and cohesion. Microservice-based systems (μSBSs) emerge as an agile and fine grained variant of SBSs. While the majority of identified metrics are also applicable to this specialization (with some limitations), the large number of services in combination with technological heterogeneity and decentralization of control significantly impacts automatic metric collection in such a system. Our research therefore suggests that specialized tool support is required to guarantee the practical applicability of the presented metrics to μSBSs.
Towards a practical maintainability quality model for service- and microservice-based systems
(2017)
Although current literature mentions a lot of different metrics related to the maintainability of service-based systems (SBSs), there is no comprehensive quality model (QM) with automatic evaluation and practical focus. To fill this gap, we propose a Maintainability Model for Services (MM4S), a layered maintainability QM consisting of service properties (SPs) related with automatically collectable Service Metrics (SMs). This research artifact created within an ongoing Design Science Research (DSR) project is the first version ready for detailed evaluation and critical feedback. The goal of MM4S is to serve as a simple and practical tool for basic maintainability estimation and control in the context of BSs and their specialization
microservice-based systems (μSBSs).
Im Rahmen des Forschungsprojektes sollten die Möglichkeiten und Grenzen des Einsatzes von Sol-Gel-Ausrüstung für die Verbesserung der Scheuer-/Abrasionsbeständigkeit für Gewebe aus unterschiedlichen Fasermaterialien untersucht werden. Dabei lag der Schwerpunkt auf Textilien für die Bereiche Bekleidung- /Berufsbekleidung sowie Bezugsstoffe (Möbel, Automotive, Personentransport).
Kleider machen Drummer
(2018)
Nicht nur Songs machen Musiker bekannt, sondern auch ihr Look: David Bowie, Kurt Cobain, Madonna, Elvis Presley haben durch ihre Musik und ihren Kleidungsstil ganze Generationen geprägt. Viele Drummer legen sehr viel Wert auf Technik - doch wenn man in der Musikbranche erfolgreich sein will, sollte man sich auch seiner Wirkungsweis bewusst sein.
Structural and functional thermosetting composite materials are exposed to different kinds of stress which can damage the polymer matrix, thus impairing the intended properties. Therefore, self-healing materials have attracted the attention of many research groups over the last decades in order to provide satisfactory material properties and outstanding product durability. The present article provides a critical overview of promising self-healing strategies for crosslinked thermoset polymers. It is organized in two parts: an overview about the different approaches to self-healing is given in the first part, whereas the second part focuses on the specific chemistries of the main strategies to achieve self-healing through crosslinking. It is attempted to provide a comprehensive discussion of different approaches which are described in the scientific literature. By comparison of the advantages and disadvantages, the authors wish to provide helpful insights on the assessment of the potential to transfer the extensive present knowledge about self-healing materials and methods to surface varnishing thermoset coatings.
This article provides a general overview of the most promising candidates of bio based materials and deals with the most important issues when it comes to their incorporation into PF resins. Due to their abundance on Earth, much knowledge of lignin-based materials has already been gained and uses of lignin in PF resins have been studied for many decades. Other natural polyphenols that are less frequently considered for impregnation are covered as well, as they do also possess some potential for PF substitution.
High quality decorative laminate panels typically consist of two major types of components: the surface layers comprising décor and overlay papers that are impregnated with melamine-based resins, and the core which is made of stacks of kraft papers impregnated with phenolic (PF) resin. The PF-impregnated layers impart superior hydrolytic stability, mechanical strength and fire-resistance to the composite. The manufacturing involves the complex interplay between resin, paper and impregnation/drying processes. Changes in the input variables cause significant alterations in the process characteristics and adaptations of the used materials and specific process conditions may, in turn, be required. This review summarizes the main variables influencing both processability and technological properties of phenolic resin impregnated papers and laminates produced therefrom. It is aimed at presenting the main influences from the involved components (resin and paper), how these may be controlled during the respective process steps (resin preparation and paper production), how they influence the impregnation and lamination conditions, how they affect specific aspects of paper and laminate performance, and how they interact with each other
(synergies).
Eine Vielzahl einzelner Personalmanagementaktivitäten ist in Forschungseinrichtungen bereits etabliert. Im Rahmen eines Nachhaltigkeitsmanagements ist jedoch ein systematisches und strategisches Vorgehen bei der Konzeption, Planung und Implementierung von Personalmanagementaktivitäten notwendig. Ein an einem Nachhaltigkeitsmanagement orientiertes Personalmanagement richtet Personalmaßnahmen an der Strategie und den Organisationszielen der Forschungseinrichtung aus. Nachhaltiges Personalmanagement in Forschungsorganisationen bedeutet, dass die Forschenden ihr kreatives wissenschaftliches Potential entfalten und einsetzen können; die Expertise des wissenschaftsunterstützenden Personals ist dabei ein wichtiger Partner und Begleiter.
Trotz der oft schwierigen Rahmenbedingungen auf den Märkten Subsahara Afrikas ist es möglich, ein erfolgreiches Geschäft aufzubauen, sofern man die adäquate Markteintrittsform wählt und darüber hinaus bereit ist, das eigene Geschäftsmodell an die lokalen Gegebenheiten anzupassen. Eine Herausforderung ist die politische, wirtschaftliche und kulturelle Heterogenität in Subsahara Afrika, die es unmöglich macht, den Kontinent als einen Markt zu bearbeiten. Allerdings gibt es seit Jahrzehnten regionale Integrationsabkommen, die jedoch erst in den letzten Jahren wiederbelebt und vorangetrieben wurden, wie z. B. die ECOWAS (Economic Community of West African States), die EAC (East African Community) und die SADC (South African Development Corporation). Inzwischen funktionieren diese Initiativen soweit, dass einige ausländische Unternehmen beginnen, Teile des Geschäftes regional und nicht mehr national zu organisieren, also die Länder als gemeinsamen Markt zu bearbeiten. In der Regel sind die kulturellen Unterschiede in Nachbarländern nicht so groß. Aus diesen Gründen besteht Wachstumspotential für geschäftlich interessante Märkte in Subsahara Afrika.
Context: Development of software intensive products and services increasingly occurs by continuously deploying product or service increments, such as new features and enhancements, to customers. Product and service developers must continuously find out what customers want by direct customer feedback and usage behaviour observation. Objective: This paper examines the preconditions for setting up an experimentation system for continuous customer experiments. It describes the RIGHT model for Continuous Experimentation (Rapid Iterative value creation Gained through High-frequency Testing), illustrating the building blocks required for such a system. Method: An initial model for continuous experimentation is analytically derived from prior work. The model is matched against empirical case study findings from two startup companies and further developed. Results: Building blocks for a continuous experimentation system and infrastructure are presented. Conclusions: A suitable experimentation system requires at least the ability to release minimum viable products or features with suitable instrumentation, design and manage experiment plans, link experiment results with a product roadmap, and manage a flexible business strategy. The main challenges are proper, rapid design of experiments, advanced instrumentation of software to collect, analyse, and store relevant data, and the integration of experiment results in both the product development cycle and the software development process.
Software engineering education is under constant pressure to provide students with industry-relevant knowledge and skills. Educators must address issues beyond exercises and theories that can be directly rehearsed in small settings. Industry training has similar requirements of relevance as companies seek to keep their workforce up to date with technological advances. Real-life software development often deals with large, software-intensive systems and is influenced by the complex effects of teamwork and distributed software development, which are hard to demonstrate in an educational environment. A way to experience such effects and to increase the relevance of software engineering education is to apply empirical studies in teaching. In this paper, we show how different types of empirical studies can be used for educational purposes in software engineering. We give examples illustrating how to utilize empirical studies, discuss challenges, and derive an initial guideline that supports teachers to include empirical studies in software engineering courses. Furthermore, we give examples that show how empirical studies contribute to high-quality learning outcomes, to student motivation, and to the awareness of the advantages of applying software engineering principles. Having awareness, experience, and understanding of the actions required, students are more likely to apply such principles under real-life constraints in their working life.
In vitro composed vascularized adipose tissue is and will continue to be in great demand e.g. for the treatment of extensive high-graded burns or the replacement of tissue after tumor removal. Up to date, the lack of adequate culture conditions, mainly a culture medium, decelerates further achievements. In our study, we evaluated the influence of epidermal growth factor (EGF) and hydrocortisone (HC), often supplemented in endothelial cell (EC) specific media, on the co-culture of adipogenic differentiated adipose derived stem cells (ASCs) and microvascular endothelial cells (mvECs). In ASCs, EGF and HC are thought to inhibit adipogenic differentiation and have lipolytic activities. Our results showed that in indirect co-culture for 14 days, adipogenic differentiated ASCs further incorporated lipids and partly gained an univacuolar morphology when kept in media with low levels of EGF and HC. In media with high EGF and HC levels, cells did not incorporate further lipids, on the contrary, cells without lipid droplets appeared. Glycerol release, to measure lipolysis, also increased with elevated amounts of EGF and HC in the culture medium. Adipogenic differentiated ASCs were able to release leptin in all setups. MvECs were functional and expressed the cell specific markers, CD31 and von Willebrand factor (vWF), independent of the EGF and HC content as long as further EC specific factors were present. Taken together, our study demonstrates that adipogenic differentiated ASCs can be successfully co-cultured with mvECs in a culture medium containing low or no amounts of EGF and HC, as long as further endothelial cell and adipocyte specific factors are available.
Die Internationalität muss das Markenzeichen und ein wesentlicher Bestandteil des Leitbildes einer Hochschule sein. Für die Strategieentwicklung und -umsetzung bedarf es der notwendigen Strukturen an einer Hochschule sowie der Vernetzung mit weiteren nationalen und internationalen Partnern. Keine Hochschulleitung würde dieses Erfordernis in Zweifel ziehen. Und doch unterschätzen noch immer Rektorate und Präsidien diesen "Dauer-Marathon". Eine Internationalisierungsstrategie wird vielfach und damit gleichzeitig unkorrekt mit einem Perpetuum mobile
verglichen. Einmal verabschiedet, geht es weiter - es gibt keinen Stillstand. Aber das passendere Bild - auch für die Hochschule Reutlingen - ist die Strategie, die einem "kontinuierlichen Verbesserungsprozess" gleicht.
Curriculum design for the German language class in the double-degree programme business engineering
(2017)
This paper aims to give an overview on how German is taught as a foreign language to students enrolled in the Bachelor of Business Engineering, a double-degree programme offered in Universiti Malaysia Pahang. The double degree students have the opportunity to complete their first two years of study in Malaysia and their last two years in Germany. Taking the TestDaF examination is compulsory for double-degree students. Hence, the German Language curriculum has been meticulously planned to ensure the students would be competent in the language. As such, the settings of the language class are discussed thoroughly in this paper. Additionally, it also discusses the challenges faced in teaching German as foreign language. This paper ends with some suggestions for improvement.
Decreasing batch sizes in production in line with Industrie 4.0 will lead to tremendous changes of the control of logistic processes in future production systems. Intelligent bins are crucial enablers to establish decentrally controlled material flow systems in value chain networks as well as at the intralogistics level. These intelligent bins have to be integrated into an overall decentralized monitoring and control approach and have to interact with humans and other entities just like other cyber-physical systems (CPS) within the cyber-physical production system (CPPS). To realize a decentralized material supply following the overall aim of a decentralized control of all production and logistics processes, an intelligent bin system is currently developed at the ESB Logistics Learning Factory. This intelligent bin system will be integrated into the self developed, cloud-based and event-oriented SES system (so-called “Self Execution System”) which goes beyond the common functionalities and capabilities of traditional manufacturing execution systems (MES).
To ensure a holistic integration of the intelligent bin for different material types into the SES framework, the required hard- and software components for the decentrally controlled bin system will be split into a common and an adaptable component. The common component represents the localization and network layer which is common for every bin, whereas the flexible component will be customizable to different requirements, like to the specific characteristics of the parts.
Close and safe interaction of humans and robots in joint production environments is technically feasible, however should not be implemented as an end in itself but to deliver improvement in any of a production system’s target dimensions. Firstly, this paper shows that an essential challenge for system integrators during the design of HRC applications is to identify a suitable distribution of available tasks between a robotic and a human resource. Secondly, it proposes an approach to determine task allocation by considering the actual capabilities of both human and robot in order to improve work quality. It matches those capabilities with given requirements of a certain task in order to identify the maximum congruence as the basis for the allocation decision. The approach is based on a study and subsequent generic description of human and robotic capabilities as well as a heuristic procedure that facilities the decision making process.
Technologies for mapping the “digital twin“ have been under development for approximately 20 years. Nowadays increasingly intelligent, individualized products encourages companies to respond innovatively to customer requirements and to handle the rising product variations quickly.
An integrated engineering network, spanning across the entire value chain, is operated to intelligently connect various company divisions, and to generate a business ecosystem for products, services and communities. The conditions for the digital twin are thereby determined in which the digital world can be fed into the real, and the real world back into the digital to deal such intelligent products with rising variations.
The term digital twin can be described as a digital copy of a real factory, machine, worker etc., that is created and can be independently expanded, automatically updated as well as being globally available in real time. Every real product and production site is permanently accompanied by a digital twin. First prototypes of such digital twins already exist in the ESB Logistics Learning Factory on a cloud- and app based software that builds on a dynamic, multidimensional data and information model. A standardized language of the robot control systems via software agents and positioning systems has to be integrated. The aspect of the continuity of the real factory in the digital factory as an economical means of ensuring continuous actuality of digital models looks as the basis of changeability.
For the indoor localization sensor combinations that in addition to the hardware already contain the software required for the sensor data fusion should be used. Processing systems, scenario-live-simulations and digital shop floor management results in a mandatory procedural combination. Essential to the digital twin is the ability to consistently provide all subsystems with the latest state of all required information, methods and algorithms.
This paper presents a novel multi-modal CNN architecture that exploits complementary input cues in addition to sole color information. The joint model implements a mid-level fusion that allows the network to exploit cross modal interdependencies already on a medium feature-level. The benefit of the presented architecture is shown for the RGB-D image understanding task. So far, state-of-the-art RGB-D CNNs have used network weights trained on color data. In contrast, a superior initialization scheme is proposed to pre-train the depth branch of the multi-modal CNN independently. In an end-to-end training the network parameters are optimized jointly using the challenging Cityscapes dataset. In thorough experiments, the effectiveness of the proposed model is shown. Both, the RGB GoogLeNet and further RGB-D baselines are outperformed with a significant margin on two different tasks: semantic segmentation and object detection. For the latter, this paper shows how to extract object level groundtruth from the instance level annotations in Cityscapes in order to train a powerful object detector.
Rational strain engineering requires solid testing of phenotypes including productivity and ideally contributes thereby directly to our understanding of the genotype-phenotype relationship. Actually, the test step of the strain engineering cycle becomes the limiting step, as ever advancing tools for generating genetic diversity exist. Here, we briefly define the challenge one faces in quantifiying phenotypes and summarize existing analytical techniques that partially overcome this challenge. We argue that the evolution of volatile metabolites can be used as proxy for cellular metabolism. In the simplest case, the product of interest is a volatile (e.g., from bulk alcohols to special fragrances) that is directly quantified over time. But also nonvolatile products (e.g., from bulk long-chain fatty acids to natural products) require major flux rerouting that result potentially in altered volatile production. While alternative techniques for volatile determination exist, rather few can be envisaged for medium to high-throughput analysis required for phenotype testing. Here, we contribute a detailed protocol for an ion mobility spectrometry (IMS) analysis that allows volatile metabolite quantification down to the ppb range. The sensivity can be exploited for small-scale fermentation monitoring. The insights shared might contribute to a more frequent use of IMS in biotechnology, while the experimented aspects are of general use for researchers interested in volatile monitoring.
Despite the significant potential offered by the powder coating process for finishing wood-based materials, until now it has been used almost exclusively for coating Medium Density Fiber Board (MDF). A research project aims to develop processes and substrate materials that will allow lightweight boards to be powder coated.
§ 303 Schuldenkonsolidierung
(2018)
Ein zukunfts- und innovationsfähiges Personalmanagement stellt sicher, dass der Organisation in qualitativer und quantitativer Hinsicht das erforderliche Personal zur Verfügung steht, um die organisationalen Ziele zu erreichen. Vor dem Hintergrund zunehmend dynamischer Umfelder gelingt dies mit den bislang etablierten Arbeitsweisen, Praktken und Instrumenten des Personalmanagements künftig nicht mehr. Daher muss das Personalmanagement permanent neue Arbeitsweisen, innovative Praktiken und neue Instrumente entwickeln (Exploration). Gleichzeitig hat es jedoch auch die bisherigen "Routineaufgaben" zunehmend effizienter zu erledigen (Exploitation). Diese Herausforderung des beidhändigen Agierens zwischen Exploration und Exploitation verlangt nach dezidierten Innovationsstrukturen, Praktiken und Fähigkeiten im Personalmanagement. Der vorliegende Beitrag plädiert daher für eine organisatorisch aufgehängte "Forschung und Entwicklung" im Personalbereich, die neue Themen innerhalb und außerhalb der Organisation aufgreift, um daraus innovative Personalpraktiken zu generieren.
Es gibt viele und teilweise sehr unterschiedliche Vorgehensweisen für die Planung von Materialflusssysstemen in der Produktionslogisitk. Ein spezifisches Vorgehensmodell für die Planung der Produktionsversorgung in der Montage im engeren Sinne existiert nicht. Im Folgenden wird ein solches Vorgehensmodell dargestellt, das sich auf die Planung der Produktionsversorgung fokussiert.
Produktionsversorgungssysteme für die variantenreiche Fließfertigung. - (Berichte aus der Logistik)
(2017)
Angestoßen durch das Lean Management wurden Produktionsabläufe in den letzten Jahrzehnten kontinuierlich optimiert und weiterentwickelt. Der Fokus lag dabei auf der Reduzierung von Prozesszeiten und der Eliminierung nicht wertschöpfender Tätigkeiten im Produktionsprozess. Diese Tätigkeiten, häufig aus dem Bereich der Materialbereitstellung, wurden aus dem Produktionsprozess in die Logistik verlagert. Die Weiterentwicklung und Optimierung der Logistik fand aber nicht in gleichem Maße statt, sodass heute viele Unternehmen in den Bereichen der Produktionslogistik und insbesondere bei der Materialversorgung erhebliche Effektivitäts- und Effizienzdefizite haben. Das Buch stellt mit einzelnen Artikeln zu Themenschwerpunkten der Materialversorgung und Materialbereitstellung auf Basis eines in der Fahrzeugbauindustrie realisierten Projektes Möglichkeiten für die Produktionslogistikoptimierung und -weiterentwicklung vor.
Management virtueller, internationaler Engineering-Prozesse. - (Berichte aus dem Maschinenbau)
(2017)
Die Internationalisierung von Geschäftsprozessen hat dazu geführt, dass in den Engineering-Prozessen, z.B. Produktentwicklung, Produktionsplanung etc., zunehmend in virtuellen, internationalen Teams gearbeitet wird. Die Prozesse und Methoden wurden aber oft nicht entsprechend weiterentwickelt, dass die virtuellen, internationalen Engineering-Prozesse effektiv und effizient ausgeführt werden. In Rahmen einer fragebogenbasierten Unternehmensbefragung in Deutschland wird untersucht, wie Unternehmen mit Kernfragen der Gestaltung virtueller, internationaler Engineering-Prozesse umgehen und welche Vorgehensweisen, Methoden und Werkzeuge, insbesondere Informations- und Kommunikationstechnologien, sie einsetzen. Dabei werden neben dem Nutzen auch die Risiken thematisiert, die nach der neuen DIN EN ISO 9001:2015 stärker in den unternehmerischen Fokus rücken müssen.
Layout generators, commonly denoted as PCells (parameterized cells), play an important role in the layout design of analog ICs (integrated circuits). PCells can automatically create parts of a layout, whose properties are controlled by the PCell parameters. Any layout, whether hand-crafted or automatically generated, has to be verified against design rules using a DRC (design rule check) in order to assure proper functionality and producibility. Due to the growing complexity of today’s PCells it would be beneficial if a PCell itself could be ensured to produce DRC clean layouts for any allowed parameter values, i.e. a formal verification of the PCell’s code rather than checking all possible instances of the PCell. In this paper we demonstrate the feasibility of such a formal PCell verification for a simple NMOS transistor PCell. The set from which the parameter values can be chosen was found during the verification process.
We present a new methodology for automatic selection and sizing of analog circuits demonstrated on the OTA circuit class. The methodology consists of two steps: a generic topology selection method supported by a “part-sizing” process and subsequent final sizing. The circuit topologies provided by a reuse library are classified in a topology tree. The appropriate topology is selected by traversing the topology tree starting at the root node. The decision at each node is gained from the result of the part-sizing, which is in fact a node-specific set of simulations. The final sizing is a simulation-based optimization. We significantly reduce the overall simulation effort compared to a classical simulation-based optimization by combining the topology selection with the part-sizing process in the selection loop. The result is an interactive user friendly system, which eases the analog designer’s work significantly when compared to typical industrial practice in analog circuit design. The topology selection method and sizing process are implemented as a tool into a typical analog design environment. The design productivity improvement achievable by our method is shown by a comparison to other design automation approaches.
A new method for the analysis of movement dependent parasitics in full custom designed MEMS sensors
(2017)
Due to the lack of sophisticated microelectromechanical systems (MEMS) component libraries, highly optimized MEMS sensors are currently designed using a polygon driven design flow. The strength of this design flow is the accurate mechanical simulation of the polygons by finite element (FE) modal analysis. The result of the FE-modal analysis is included in the system model together with the data of the (mechanical) static electrostatic analysis. However, the system model lacks the dynamic parasitic electrostatic effects, arising from the electric coupling between the wiring and the moving structures. In order to include these effects in the system model, we present a method which enables the quasi dynamic parasitic extraction with respect to in-plane movements of the sensor structures. The method is embedded in the polygon driven MEMS design flow using standard EDA tools. In order to take the influences of the fabrication process into account, such as etching process variations, the method combines the FE-modal analysis and the fabrication process simulation data. This enables the analysis of dynamic changing electrostatic parasitic effects with respect to movements of the mechanical structures. Additionally, the result can be included into the system model allowing the simulation of positive feedback of the electrostatic parasitic effects to the mechanical structures.
This paper introduces a novel placement methodology for a common-centroid (CC) pattern generator. It can be applied to various integrated circuit (IC) elements, such as transistors, capacitors, diodes, and resistors. The proposed method consists of a constructive algorithm which generates an initial, close to the optimum, solution, and an iterative algorithm which is used subsequently, if the output of constructive algorithm does not satisfy the desired criteria. The outcome of this work is an automatic CC placement algorithm for IC element arrays. Additionally, the paper presents a method for the CC arrangement evaluation. It allows for evaluating the quality of an array, and a comparison of different placement methods.