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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.
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
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.
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.
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.
The aim of this paper is to examine the impact of sustainability communication in the fashion industry on the customers’ behavior with a focus on consumers’ perception regarding websites with sustainability-specific content. Based on a profound literature review, a projective method in form of two dummy websites is developed. Both websites illustrate sustainability communication with comprehensive and transparent information demonstrating a credible, trustful and serious commitment. Additionally, both sites have the same structure and an appealing, visualized website design as well as a customer oriented communication. While each website consists of almost the same aspects such as Vision & Mission, Value chain, Corporate Commitment, Working Conditions, Environment, Social Commitment and documents such as a Sustainability Report and Code of Conduct, they differ enormously in the sustainability-specific content. For instance, website 1 represents a sustainable and responsible company communicating sustainable issues about eco-friendly materials, fair working conditions, ecological production and their social commitment. It further includes eco-friendly wash and care advices as seen by reformation to remember consumers to take care of the environment, e.g. to wash cold or by using ecological detergents. In contrast, website 2 does not represent a sustainable and responsible fashion brand. It also does not communicate sustainable efforts or a sustainable engagement. Rather it is about offering trendy, low-priced fast- fashion products, produced under unfair working conditions with wages and working hours as usual terms in production countries with a focus on style and design. Regarding website 2, all raw materials have been produced conventionally in developing countries and are therefore not eco-friendly, resulting in a pollution of the environment due to long transport routes. Additionally, the website voices the wish to improve the chances for developing animal protection only minimally, showing that the company is not socially committed. Although website 2 focuses on transparency and a customer-oriented communication, it is not sustainable. Both websites are tested via an online survey. A total of 90 fashion students participated in the sample.
Scheduled flexibility and individualization of knowledge transfer in foundations of computer science
(2017)
The opening of the German higher education system for new target groups involves a heterogeneous composition of students as never before and face up the universities to new challenges. Due to different educational biographies, the students don't show a homogeneous level of knowledge. Furthermore, their access to course content and their individual learning methods are very diverse. The existing lack of knowledge and the very unequal study speed have a significant influence on the learning behavior and learning motivation. During the first semesters, the dropout rate is appreciably higher. The reform project gives an overview of a didactic restructuring from a formerly conventional teaching and learning concept to a stronger combination of digital offers, combined with classical lectures in the basic modules of computer science. The teaching content is adjusted to the individual requirements and knowledge. Students with different previous knowledge get the possibility to increase their knowledge in different levels of abstraction. The aim of the reform project has to point out the possibilities, also the challenges of the digital process in higher education. At the same time the question has to be explored, how far does an accompanied and self-directed learning in own speed and in own individual depth of knowledge have a positive impact on the motivation and on the study success of a learner.
The demonstration project Virtual Power Plant Neckar-Alb is constructing a Virtual Power Plant (VPP) demonstration site at the Reutlingen University campus. The VPP demonstrator integrates a heterogeneous set of distributed energy resources (DERs) which are connected to control the infrastructure and an energy management system. This paper describes the components and the architecture of the demonstrator and presents strategies for demonstration of multiple optimization and control systems with different control paradigms.
The purpose of this article is to provide insight of a new simple forecasting method based on a state-estimation algorithm known as the Kalman filter. While the accuracy of such algorithm is not comparable to state-of-the-art forecasting algorithms for PV-power production it does not require any internet connection, eyefish cameras or time intensive training. The algorithm was tested with several months of real high-resolution data with adequate results for the intended applications. The minimization of the necessary spinning reserve on a PV-diesel hybrid system to increase the solar fraction and reduce diesel consumption.
Learning factories present a promising environment for education, training and research, especially in manufacturing related areas which are a main driver for wealth creation in any nation. While numerous learning factories have been built in industry and academia in the last decades, a comprehensive scientific overview of the topic is still missing. This paper intends to close this gap establishing the state of the art of learning factories. The motivations, historic background, and the didactic foundations of learning factories are outlined. Definitions of the term learning factory and the corresponding morphological model are provided. An overview of existing learning factory approaches in industry and academia is provided, showing the broad range of different applications and varying contents. The state of the art of learning factories curricula design and their use to enhance learning and research as well as potentials and limitations are presented. Conclusions and an outlook on further research priorities are offered.
In this paper we claim that a competitive analysis with new players entering a market requires a specific and systems-based analysis. System dynamics provides such an approach. We infer from our study that established premium automobile manufacturers could have identified a possible threat by a newcomer like Tesla earlier with using system dynamics. In particular, we postulate that a feedback view supports decision makers to better understand the significance of competitive information and perceive information faster and more reliably.
This paper contributes to the automatic detection of perioperative workflow by developing a binary endoscope localization. Automated situation recognition in the context of an intelligent operating room requires the automatic conversion of low level cues into more abstract high level information. Imagery from a laparoscope delivers rich content that is easy to obtain but hard to process. We introduce a system which detects if the endoscope's distal tip is inside or outsiede the patient based on the endoscope video. This information can be used as one parameter in a situation recognition pipeline. Our localization performs in real-time at a video resolution of 1280x720 and 5-fold cross validation yields mean F1-scores of up to 0,94 on videos of 7 laparoscopies.
The fashion industry is well documented for causing significant environmental impact. Product-service systems (PSS) present a promising way to solve this challenge. PSS shift the focus toward complementary service offers, which decouples customer satisfaction from material consumption and entails dematerialization. However, PSS are not ecoefficient by nature but need to be accompanied by corporate environmental management (CEM) practices. The objective of this article is to examine the potential of PSS to contribute to the environmental sustainability of today's fashion industry by investigating if fashion firms with a positive attitude toward PSS implementation also pursue goals related to the ecological environment. For this purpose, analysis of variance (ANOVA) is conducted to analyze data of 102 fashion firms. Results reveal that the diffusion of PSS in today's fashion industry is low and few firms consider implementing PSS. Results, furthermore, demonstrate that PSS implementation is positively related to CEM. This indicates that existing structures of CEM favor PSS implementation and unlock the eco-efficient potential of implemented PSS in the fashion industry.
The fluorescence of monomeric photosystem II core complexes (mPSIIcc) of the cyanobacterium Thermosynechococcus elongatus, originating from redissolved crystals, is investigated by using single-molecule spectroscopy (SMS) at 1.6 K. The emission spectra of individual mPSIIcc are dominated by sharp zero-phonon lines, showing the existence of different emitters compatible with the F685, F689, and F695 bands reported formerly. The intensity of F695 is reduced in single mPSIIcc as compared to single PSIIcc-dimers (dPSIIcc). Crystal structures show that one of the β-carotene (β-Car) cofactors located at the monomer–monomer interface in dPSIIcc is missing in mPSIIcc. This β-Car in dPSIIcc is in van der Waals distance to chlorophyll (Chl) 17 in the CP47 subunit. We suggest that this Chl contributes to the F695 emitter. A loss of β-Car cofactors in mPSIIcc preparations will lead to an increased lifetime of the triplet state of Chl 17, which can explain the reduced singlet emission of F695 as observed in SMS.
The Football World Cup 2014
(2017)
International sporting events such as the Football World Cup constitute the ideal platform for companies to implement their target-group-specific marketing communications. Therefore, sporting event organisers sell exclusive marketing rights for their events to official sponsors. In return, these sponsors acquire exclusive opportunities to utilise the event for their own marketing purposes.
Ambush marketing is the method used by companies that do not actually hold marketing rights to an event, but still use marketing activities in diverse ways to establish a connection to it. The philosophy of ambush marketing consists of achieving conventional marketing objectives using unconventional methods. However, it creates the risk of fines or punishment, since companies that use these strategies even though they do not have sponsorship rights are violating legal requirements.
This case study introduces and analyses the marketing communications tools of sports sponsorship and ambush marketing.
The third Digital Enterprise Computing Conference DEC 17 at the Herman Hollerith Center in Böblingen brings together students, researchers, and practitioners to discuss solutions, experiences, and future developments for the digital transformation. Digitization of business and IT defines the conference agenda: digital models & architecture, digital marketing, agility & innovation.
Induced by a societal decision to phase out conventional energy production - the so-called Energiewende (energy transition) - the rise of distributed generation acts as a game changer within the German energy market. The share of electricity produced from renewable resources increased to 31,6% in 2015 (UBA, 2016) with a targeted share of renewable resources in the electricity mix of 55%-60% in 2035 (RAP, 2015), opening perspectives for new products and services. Moreover, the rapidly increasing degree of digitization enables innovative and disruptive business models in niches at the grid's edge that might be the winners of the future. It also stimulates the market entry of newcomers and competitors from other sectors, such as IT or telecommunication, challenging the incumbent utilities. For example, virtual and decentral market places for energy are emerging; a trend that is likely to speed up considerably by blockchain technology, if the regulatory environment is adjusted accordingly. Consequently, the energy business is turned upside down, with customers now being at the wheel. For instance, more than one-third of the renewable production capacities are owned by private persons (Trendsearch, 2013). Therefore, the objective of this chapter is to examine private energy consumer and prosumer segments and their needs to derive business models for the various decentralized energy technologies and services. Subsequently, success factors for dealing with the changing market environment and consequences of the potentially disruptive developments for the market structure are evaluated.
Indium tin oxide (ITO) particle coatings are known for high transparency in the visible, good conductive properties and near-infrared absorption. These properties depend on ITO particle's stiochiometric composition, defects and size. Here we present a method to gradually change ITO particle's optical properties by a simple and controlled laser irradiation process. The defined irradiation process and controlled energy dose input allows one to engineer the absorption and transsmission of coatings made from these particles. We investigate the role of the surrounding solvent, influence of laser fluence and the specific energy dose targeting modification of the ITO particle's morphology and chemistry by stepwise laser irradiation in a free liquid jet. TEM, SEM, EDX, XPS, XRD and Raman are used to elucidate the structural, morphological and chemical changes of the laser-induced ITO particles. On the basis of these results the observed modification of the optical properties is tentatively attributed to chemical changes, e.g. laser-induced defects or partial reduction.
We report the temperature dependence of metal-enhanced fluorescence (MEF) of individual photosystem I (PSI) complexes from Thermosynechococcus elongatus (T. elongatus) coupled to gold nanoparticles (AuNPs). A strong temperature dependence of shape and intensity of the emission spectra is observed when PSI is coupled to AuNPs. For each temperature, the enhancement factor (EF) is calculated by comparing the intensity of individual AuNP-coupled PSI to the mean intensity of ‘uncoupled’ PSI. At cryogenic temperature (1.6 K) the average EF was 4.3-fold. Upon increasing the temperature to 250 K the EF increases to 84-fold. Single complexes show even higher EFs up to 441.0-fold. At increasing temperatures the different spectral pools of PSI from T. elongatus become distinguishable. These pools are affected differently by the plasmonic interactions and show different enhancements. The remarkable increase of the EFs is explained by a rate model including the temperature dependence of the fluorescence yield of PSI and the spectral overlap between absorption and emission spectra of AuNPs and PSI, respectively.
Propofol is an intravenous anesthetic. Currently, it is not possible to routinely measure blood concentration of the drug in real time. However, multi-capillary column ion-mobility spectrometry of exhaled gas can estimate blood propofol concentration.Unfortunately, adhesion of volatile propofol on plastic materials complicates measurements. Therefore, it is necessary to consider the extent to which volatile propofol adheres to various plastics used in sampling tubing. Perfluoralkoxy (PFA), polytetrafluorethylene (PTFE), polyurethane (PUR), silicone, and Tygon tubing were investigated in an experimental setting using a calibration gas generator (HovaCAL). Propofol gas was measured for one hour at 26 °C, 50 °C, and 90 °C tubing temperature. Test tubing segments were then flushed with N2 to quantify desorption. PUR and Tygon sample tubing absorbed all volatile propofol. The silicone tubing reached the maximum propofol concentration after 119 min which was 29 min after propofol gas exposure stopped. The use of PFAor PTFE tubing produced comparable and reasonably accurate propofol measurements. The desaturation time for the PFA was 10 min shorter at 26 °C than for PTFE. PFA tubing thus seems most suitable for measurement of volatile propofol,with PTFE as an alternative.
The management of football brands : brand identity management illustrated by Borussia Dortmund
(2017)
Despite a growing awareness of the importance of the management of trademarks at the club level, there is a significant delay regarding the professional management of the brand within the Bundesliga clubs. So far, the principles of brand identity management were rarely applied, and most clubs have given up, despite a high economic potential, the ability to create competitive advances in economic terms, but also in sports terms. In this chapter, we will study the success factors of the management of brand identity of professional football clubs from the actual case of Borussia Dortmund.
Green fashion retail
(2017)
This book focuses on sustainability in fashion retail, which is fast becoming the pivot point of future fashion retail strategies. Chapters in the book provide theoretical and practical insight on how going green may positively influence the strategy of fashion retailers and marketers, who have to react to the changing society and customer needs. Structured in four main parts, and based on distinct research questions, readers will be able to dig deep into the individual levers for possible adaptions. It thus provides a solid understanding on how to integrate green aspects into any fashion retailers business model.