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The paper presents a new control strategy of management of transport companies operating in completive transport environment. It is aimed to optimise the headway of transport companies to provide the balance between costs and benefits of operation under competition. The model of transport system build using AnyLogic comprises agent-based and discrete-event techniques. The model combined two transport companies was investigated under condition of the competition between them. It was demonstrated that the control strategy can ensure the balance of interests of transport companies trying to find compromise between cost of operation and quality of service.
Work in progress: Starter-project for first semester students to survey their engineering studies
(2015)
In education, finding the appropriate learning pace that fits to the members of a large group is a challenging task. This becomes especially evident when teaching multidisciplinary subjects such as epidemiology in medicine or computer science in most study programs, since lecturers have to face a very heterogeneous state of previous knowledge. Approaching this issue requires an individual supervision of each and every student, which is obviously bounded by the available resources. Moreover, when referring back to the second example, writing computer programs requires a complex installation and configuration of development tools. Many beginning programmers already become stuck at this entry stage. This paper introduces WHELP, a Web-based Holistic E-Learning Platform, which provides an integrated environment enabling the learning and teaching of computer science topics without the need to install any software. Moreover, WHELP includes an interactive feedback system for each programming exercise, where lecturers or tutors can supply comments, improvements, code assistance or tips helping the students to accomplish their tasks. Furthermore, WHELP offers a statistical analysis module as well as a real-time classroom polling system both promoting an overview of the state of knowledge of a course. In addition to that, WHELP enables collaborative working including code-sharing and peer-to-peer learning. This feature enables students to work on exercises simultaneously at distinct places. WHELP has been successfully deployed in the winter term 2013 at the Cologne University of Applied Sciences supporting the 120 students and 3 lecturers to learn and teach basic topics of computer science in an engineering study program.
Although much effort is made to prevent risks arising from food, food-borne diseases are an ever present-threat to the consumers’ health. The consumption of fresh food that is contaminated with pathogens like fungi, viruses or bacteria can cause food poisoning that leads to severe health damages or even death. The outbreak of Shiga Toxin-producing enterohemorrhagic E. coli (EHEC) in Germany and neighbouring countries in 2011 has shown this dramatically. Nearly 4.000 people were reported of being affected and more than 50 people died during the so called EHEC-crisis. As a result the consumers’ trust in the safety of fruits and vegetables decreased sharply.
In this paper, a set of micro-benchmarks is proposed to determine basic performance parameters of single-node mainstream hardware architectures for High Performance Computing. Performance parameters of recent processors, including those of accelerators, are determined. The investigated systems are Intel server processor architectures as well as the two accelerator lines Intel Xeon Phi and Nvidia graphic processors. Results show similarities for some parameters between all architectures, but significant differences for others.
This paper gives necessary foundations to understand the mechanism of warning processing and summarizes the state of the art in warning development. That includes a description of tools, researchers use to work in this scientific field. In detail these are models that describes the human way of processing warnings and mental models. Both are presented detailed with relevant examples. The paper tells how these tools are connected and how they are used to improve the effectiveness of warnings.
Softwareentwickelnde kleine und mittlere Unternehmen (KMU) erkennen zunehmend, dass die nutzerzentrierte Gestaltung ein wichtiges, oft entscheidendes Kriterium für die Benutzerfreundlichkeit und damit den Erfolg ihrer Produkte ist. Stolpersteine auf dem Weg zum erfolgreichen Usability- und User Experience-Engineering sind dabei allerdings häufig die Unkenntnis der passenden Methoden bzw. die Befürchtung zu hohen Aufwands an Ressourcen und von Verzögerungen in der Produktentwicklung (vgl. Stade et al., 2013; Reckin & Brandenburg, 2013; Woywode et al., 2011).
The study of locomotion in virtual environments is a diverse and rewarding research area. Yet, creating effective and intuitive locomotion techniques is challenging, especially when users cannot move around freely. While using handheld input devices for navigation may often be good enough, it does not match our natural experience of motion in the real world. Frequently, there are strong arguments for supporting body-centered self-motion cues as they may improve orientation and spatial judgments, and reduce motion sickness. Yet, how these cues can be introduced while the user is not moving around physically is not well understood. Actuated solutions such as motion platforms can be an option, but they are expensive and difficult to maintain. Alternatively, within this article we focus on the effect of upper-body tilt while users are seated, as previous work has indicated positive effects on self-motion perception. We report on two studies that investigated the effects of static and dynamic upper body leaning on perceived distances traveled and self-motion perception (vection). Static leaning (i.e., keeping a constant forward torso inclination) had a positive effect on self-motion, while dynamic torso leaning showed mixed results. We discuss these results and identify further steps necessary to design improved embodied locomotion control techniques that do not require actuated motion platforms.
Understanding the Internet of Things: A Conceptualisation of Business-to-Thing (B2T) Interactions
(2015)
Despite the lack of standardisation for building REST-ful HTTP applications, the deployment of REST-based Web Services has attracted an increased interest. This gap causes, however, an ambiguous interpretation of REST and induces the design and implementation of REST-based systems following proprietary approaches instead of clear and agreed upon definitions. Issues arising from these shortcomings have an influence on service properties such as the loose coupling of REST-based services via a unitary service contract and the automatic generation of code. To overcome such limitations, at least two prerequisites are required: the availability of specifications for implementing REST-based services and auxiliaries for auditing the compliance of those services with such specifications. This paper introduces an approach for conformance testing of REST-based Web Services. This appears conflicting at the first glance, since there are no specifications available for implementing REST by, e.g., t he prevalent technology set HTTP/URI to test against. Still, by providing a conformance test tool and leaning it on the current practice, the exploration of service properties is enabled. Moreover, the real demand for standardisation gets explorable by such an approach. First investigations conducted with the developed conformance test system targeting major Cloud-based storage services expose inconsistencies in many respects which emphasizes the necessity for further research and standardisation.
The Whole Is More than the Sum of Its Parts - On Culture in Education and Educational Culture
(2015)
The Learning Culture Survey investigates learners’ expectations towards and perceptions of education on international level with the aim to make culture in the context of education better understandable and support educators to prevent and solve intercultural conflicts in education. So far, we found that culture-related expectations differ between educational settings, depend on the age of the learners, and that a nationally homogenous educational culture is rather an exception than the rule. The results of our recently completed longitudinal study provided evidence that educational culture on the institutional level actually is persistent, at least over a term of four years. After a brief introduction of the general background, we will subsume the steps taken during the past seven years and achieved general insights regarding educational culture. Last, we will introduce a method for the determination of conflict potential, which bases on the understanding of culture as the level to w hich people within a society accept deviations from the usual. We close with demonstrating the method’s functionality on examples from the Learning Culture Survey.
Introduction: After cellulose, lignin represents the most abundant biopolymer on earth that accounts for up to 18-35 % by weight of lignocellulose biomass. Today, it is a by-product of the paper and pulping industry. Although lignin is available in huge amounts, mainly in form of so called black liquor produced via Kraft-pulping, processes for the valorization of lignin are still limited [1]. Due to its hyperbranched polyphenol-like structure, lignin gained increasing interest as biobased building block for polymer synthesis [2]. The present work is focused on extraction and purification of lignin from industrial black liquor and synthesis of lignin-based polyurethanes.
Sustainable development needs sustainable production and sustainable consumption. During the last decades the encouragement of sustainable production has been the focus of research and policy makers under the implicit assumption that the observable increasing ‘green’ values of consumers would also entail a growing sustainable consumption. However, it has been found that the actual purchasing behaviour often deviates from ‘green’ attitudes. This phenomenon is called the attitude-behaviour gap. It is influenced by individual, social and situational factors. The main purchasing barriers for sustainable (organic) food are price, lack of immediate availability, sensory criteria, lack or overload of information as well as the low-involvement feature of food products in conjunction with well-established consumption routines, lack of transparency and trust towards labels and certifications.
Roughness by Residuals
(2015)
Rough set theory (RST) focuses on forming posets of equivalence relations to describe sets with increasing accuracy. The connection between modal logics and RST is well known and has been extensively studied in their relation algebraic (RA) formalisation. RST has also been interpreted as a variant of intuitionistic or multi-valued logics and has even been studied in the context of logic programming.
So far, sustainable HCI has mainly focused on the domestic context, but there is a growing body of work looking at the organizational context. As in the domestic context, these works still rest on psychological theories for behaviour change used for the domestic context. We supplement this view with an organizational theory-informed approach that adopts organizational roles as a key element. We will show how a role-based analysis could be applied to uncover information needs and to give em-ployee’s eco-feedback, which is linked to their tasks at hand. We illustrate the approach on a qualitative case study that was part of a broader, ongoing action research conducted in a German production company.
Binary relations with certain properties such as biorders, equivalences or difunctional relations can be represented as particular matrices. In order for these properties to be identified usually a rearrangement of rows and columns is required in order to reshape it into a recognisable normal form. Most algorithms performing these transformations are working on binary matrix representations of the underlying relations. This paper presents an approach to use the RLE-compressed matrix representation as a data structure for storing relations to test whether they are biorders in a hopefully more efficient way.
IT-accessiblity is often treated as an orphan in companies. Even though the proportion of disabled people is substantial and people become older and more susceptible to disabilities. Besides cost factors, companies often do not have a plan how to implement and control IT-accessibility successfully. However, most companies are familiar with IT-maturity frameworks to evaluate and improve their own IT-infrastructure. It would facilitate dealing with IT-accessibility, if IT-maturity frameworks consider IT-accessibility and provide recommendations and solutions for a successful implementation. Therefore, this article conducts a review of an acknowledged IT-maturity framework with regard to its capability to enable implementation of IT-accessibility in an organization. The first part of this article will illustrate the motivation and background for the authors concern with such a topic. Afterwards the authors will introduce the reader to the reviewed IT-maturity framework and provide basic knowledge on IT-accessibility. The main part of the article will deal with the review of the applied IT-maturity framework and outline examples of critical capabilities for successfully implementing IT-accessibility in an organization. The final section will derive implications and close with planned future research activities in this field.
Die Rückkehr ins Erwerbsleben (Return to Work, RTW) wird für onkologische Rehabilitanden zunehmend zum zentralen Behandlungsziel, wodurch auch die Bereitstellung spezifischer berufsorientierter Maßnahmen an Bedeutung gewinnt (z. B. Mehnert, Koch, 2012). Die Überprüfung der Behandlungsergebnisse solcher Maßnahmen stellt einen wichtigen Baustein des Qualitätsmanagements der Rehabilitationseinrichtungen dar. Im Rahmen der „Reha-QM-Outcome-Studie“ des Qualitätsverbundes Gesundheit und der Deutschen Rentenversicherung Baden-Württemberg (Nübling et al., 2014) wurde daher ein besonderes Augenmerk auf das Outcome und die RTW-Quote der onkologischen Patienten, auch im Vergleich zu anderen Hauptindikationen, gelegt.
[Context and motivation] Communication in distributed software development is usually supported by issue tracking systems. Within these systems, most of the communication is stored as unstructured natural language text. The natural language text, however, contains much information with respect to requirements management, e.g. discussion, clarification and prioritization of features, bugs, and refactorings. [Question] This paper investigates the information stored in the issue tracking systems of four different open-source projects. It categorizes the text and reports on the distribution of issue types and information types. [Principal ideas/results] A manual analysis of 80 issues, using a grounded approach, is conducted to derive a taxonomy of issue types and information types. Subsequently, the taxonomy is used as a codebook, to manually categorize and structure the text in another 120 issues. [Contribution] The first contribution of this paper is the taxonomy of issue and information types and the second contribution is an in-depth analysis of the natural language data and the communication. This analysis showed, for example, that information with respect to prioritization and scheduling can be found in natural language data, whether the ITS supports such tasks in a structured way or not.
Despite the opportunities and benefits of OER, research and practice has shown how the OER repositories have a hard time in reaching an active user-base. The opportunities of experience exchange and simple feedback mechanisms of social software have been realized for improving the situation and many are basing or transforming their OER offerings towards socially powered environments. Research on social software has shown how knowledge-sharing barriers in online environments are highly culture and context-specific and require proper investigation. It is crucial to study what challenges might arise in such environments and how to overcome them, ensuring a successful uptake. A large-scale (N = 855) cross-European investigation was initiated in the school context to determine which barriers teachers and learners perceive as critical. The study highlights barriers on cultural distance, showing how those are predicted by nationality and age of the respondents. The paper concludes with recommendations for overcoming those barriers.
Quality Management in Education: Business Process Modelling in Interdisciplinary Environments
(2015)
Secure vehicular communication has been discussed over a long period of time. Now,- this technology is implemented in different Intelligent Transportation System (ITS) projects in europe. In most of these projects a suitable Public Key Infrastructure (PKI) for a secure communication between involved entities in a Vehicular Ad hoc Network (VANET) is needed. A first proposal for a PKI architecture for Intelligent Vehicular Systems (IVS PKI) is given by the car2car communication consortium. This architecture however mainly deals with inter vehicular communication and is less focused on the needs of Road Side Units. Here, we propose a multi-domain PKI architecture for Intelligent Transportation Systems, which considers the necessities of road infrastructure authorities and vehicle manufacturers, today. The PKI domains are cryptographically linked based on local trust lists. In addition, a crypto agility concept is suggested, which takes adaptation of key length and cryptographic algorithms during PKI operation into account.
Die psychische Komorbidität bei chronisch körperlichen Erkrankungen gilt als weitgehend belegt. Je nach Indikationsbereich variiert der Anteil zusätzlich psychisch erkrankter Patienten zwischen 16 und 24 % (4-Wochen-Prävalenz) bzw. zwischen 29 und 41 % (1-Jahres- Prävalenz; Härter et al., 2007). Aktuelle Konzepte legen eine stärkere Fokussierung auf psychosoziale, vor allem psychologische, psychotherapeutische und pädagogische Behandlungsbausteine innerhalb der stationären Rehabilitation nahe (Bengel et al., 2014; Seiter et al., 2012). Zusätzlich werden gezielte Nachsorgekonzepte entwickelt und erprobt (z. B. Deck, Hüppe, 2014). Der vorliegende Beitrag geht auf der Grundlage einer aktuellen Versichertenstichprobe der Frage nach, wie psychische Beeinträchtigung, Behandlungsempfehlung und nachfolgende Inanspruchnahme ambulanter psychotherapeutischer Leistungen zusammenhängen und mit welchen Behandlungsergebnissen sie assoziiert sind.
Die Vorteile, Nutzer aktiv, früh und langfristig in ntwicklungsprozesse zu integrieren, um Fehlentwicklungen zu vermeiden und Nutzerbedürfnisse zu adressieren, sind nicht nur in der akademischen Forschung bekannt. Prozesse und Strukturen in Unternehmen der IKT-Branche sind bereits häufig agil implementiert. Dennoch schaffen es kleine und mittlere Unternehmen (KMU) oftmals nicht, die Potentiale einer Nutzerintegration konsequent auszuschöpfen. In Fallstudien wurden drei unterschiedliche KMU analysiert, wie sie die Stimme des Nutzers im Entwicklungsprozess berücksichtigen. Unterschiedliche Strategien der Nutzerintegration, die sich in Rollen und Werkzeugen, in Anforderungen und Problemen an das Nutzersample, Methoden und Datenaufbereitung widerspiegeln, werden beleuchtet. Unser Beitrag soll helfen, Herausforderungen und Probleme von KMU auf der Suche nach angemessenen und passgenauen Wegen der Nutzerintegration zu verstehen und Lösungen zu gestalten.
Reducing energy consumption is one of the most pursued economic and ecologic challenges concerning societies as a whole, individuals and organizations alike. While politics start taking measures for energy turnaround and smart home energy monitors are becoming popular, few studies have touched on sustainability in office environments so far, though they account for almost every second workplace in modern economics. In this paper, we present findings of two parallel studies in an organizational context using behavioral change oriented strategies to raise energy awareness. Next to demonstrating potentials, it shows that energy feedback needs must fit to the local organizational context to succeed and should consider typical work patterns to foster accountability of consumption.
This paper proposes an Artificial Plasmodium Algorithm (APA) mimicked a contraction wave of a plasmodium of physarum polucephalum. Plasmodia can live using the contracion wave in their body to communicate to others and transport a nutriments. In the APA, each plasmodium has two information as the wave information: the direction and food index. We apply the APA to 4 types of mazes and confirm that the APA can solve the mazes.
Durch Dotierung eines nematischen Flüssigkristalles mit einer chiralen Substanz wird eine helikal strukturierte Phase induziert, die in der Lage ist, einfallendes Licht wellenlängenselektiv zu reflektieren. Bei der Reaktion des Dotiermittels mit einem gasförmigen Analyten verändern sich die Ganghöhe dieser Struktur und damit die reflektierte Wellenlänge. Liegt diese im Bereich des sichtbaren Lichts, ist eine Farbänderung mit dem menschlichen Auge zu beobachten. Es ist dabei sinnvoll den Flüssigkristall z.B. in einem Polymer einzukapseln, um ihn vor mechanischen Einflüssen und Umwelteinflüssen zu schützen. Eine Möglichkeit zur Einkapselung ist das koaxiale Elektrospinnen. Vorteile sind unter anderem die Realisierung einer großen Oberfläche und einer sehr geringen Wanddicke der schützenden Schale, die die Diffusion von Gasen durch die Wand hindurch ermöglicht. Um die Funktionsfähigkeit eines solchen Sensors zu testen, wurde ein CO2-sensitiver Flüssigkristall verwendet. Dieser wurde in eine Schale aus Polyvinylpyrrolidon (PVP) versponnen und die Reaktion mit CO2 spektroskopisch analysiert.
Managing the needs of learners is crucial in order to support their motivation and keep dropout rates on a low level. With the constantly growing level of internationalization in classrooms, the variety of different context-specific requirements from learners increase; without a profound understanding of the learners’ contexts, successfully maintaining a culture-sensitive and learner-focussed education is impossible. A solution to reach this understanding is the open exchange of experiences and knowledge amongst educators of the different contexts. In this paper, we will briefly introduce the two European projects “Open Discovery Space” (ODS) and “Inspiring Science Education” (ISE), which have the aim to foster the establishment and improvement of Open Educational Practices in the context of school education. The purpose of this paper is to attract and invite potential partners to affiliate with, contribute to, and profit from the projects.