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Results from the EU-project iStoppFalls : feasibility, effectiveness, approach for fall prevention
(2016)
Autonomous mobile robots comprise of several hardware and software components. These components interact with each other continuously in order to achieve autonomity. Due to the complexity of such a task, a monumental responsibility is bestowed upon the developer to make sure that the robot is always operable. Hence, some means of detecting faults should be readily available. In this work, the aforementioned fault-detection system is a robotic black box (RBB) attached to the robot which acquires all the relevant measurements of the system that are needed to achieve a fault-free robot. Due to limited computational and memory resources on-board the RBB, a distributed diagnosis is proposed. That is, the fault diagnosis task (detection and isolation) is shared among an on-board component (the black box) and an off-board component (an external computer). The distribution of the diagnosis task allows for a non-intrusive method of detecting and diagnosing faults, in addition to the ability of remotely diagnosing a robot and potentially issuing a repair command. In addition to decomposing the diagnosis task and allowing remote diagnosability of the robot, another key feature of this work is the addition of expert human knowledge to aid in the fault detection process.
Domestic Robotics
(2016)
Gleichlaufgelenke als Teil der Antriebswellen (Seitenwellen und Längswellen) sind in allen maßgeblichen Triebstrangkonfigurationen im direkten Leistungsfluss angeordnet. Ihre Hauptfunktion ist die Übertragung einer Antriebsleistung unter Ermöglichung von Abbeugung und Axialverschiebung. Dieser Beitrag soll einen Überblick zu den wesentlichen, auf dem heutigen Markt verbreiteten Bauweisen und ihren jeweiligen Einsatzgebieten geben. Besonders berücksichtigt werden hierbei neue Gelenkkonzepte, die sich aufgrund ihrer besonderen Gestaltung durch deutlich höhere Wirkungsgrade auszeichnen. Der Einfluss auf den Energieverbrauch soll quantifiziert werden, hierzu wird ein neuartiger Berechnungsansatz vorgestellt, der eine einfache Abschätzung des Einflusses von Wirkungsgradverbesserungen auf den Energieverbrauch für verschiedener Antriebskonzepte (ICE / Hybrid / E-Fahrzeuge) erlaubt.
Förderpreise 2016
(2016)
Der zunehmende Wunsch der Verbraucher nach einem natürlichen Lebensstil führt unter anderem zu einem erhöhten Konsum von Rohmilch und Milchprodukten aus unpasteurisierter Milch (Hudopisk et al., 2013). Rohmilchkonsumenten bevorzugen Rohmilch zum Einen wegen des subjektiven Eindrucks eines besseren Geschmacks und zum Anderen versprechen sie sich gesundheitliche Vorteile, wie eine reduzierte Empfindlichkeit gegen Allergien und eine bessere Qualität der enthaltenen Nährstoffe, durch den Verzehr unbehandelter Milch (Claeys et al., 2014). Mit dem Konsum von Rohmilch gehen allerdings mikrobiologische Risiken einher, da Rohmilch aufgrund ihres neutralen pH-Wertes, dem hohen Nährstoffgehalt und der hohen Wasseraktivität einen guten Nährboden für mikrobielles Wachstum darstellt. Das Wachstum von verschiedenen Mikroorganismen wird dabei größtenteils durch die Temperatur, die kompetitive Begleitflora und die Anwesenheit von Hemmstoffen beeinflusst (Claeys et al., 2013).Mögliche Kontaminationen der Rohmilch resultieren entweder aus einer direkten Abgabe von Mikroorganismen durch das Euter, als Konsequenz von Entzündungen oder durch eine indirekte Kontamination während des Melkvorgangs oder der späteren Handhabung (EFSA, 2015).
Simulating free-surface and pressurised flow is important to many fields of application, especially in network approaches. Modelling equations to describe flow behaviour arising in these problems are often expressed by one-dimensional formulations of the hyperbolic shallow water equations. One established approach to realise their numerical computation is the method of lines based on semi-discretisation in space (Steinebach and Rentrop, An adaptive method of lines approach for modeling flow and transport in rivers. In: Vande Wouwer, Saucez, Schiesser (eds) Adaptive method of lines, pp 181–205. Chapman & Hall/CRC, Boca Raton, London, New York, Washington, DC, 2001; Steinebach and Weiner, Appl Numer Math 62:1567–1578, 2012; Steinebach et al., Modeling and numerical simulation of pipe flow problems in water supply systems. In: Martin, Klamroth, et al. (eds) Mathematical optimization of water networks. International series of numerical mathematics, vol 162, pp 3–15. Springer, Basel, 2012). It leads to index-one DAE systems as algebraic constraints are required to realise coupling and boundary conditions of single reaches.Linearly implicit ROW schemes proved to be effective to solve these DAE systems (Steinebach and Rentrop, An adaptive method of lines approach for modeling flow and transport in rivers. In: Vande Wouwer, Saucez, Schiesser (eds) Adaptive method of lines, pp 181–205. Chapman & Hall/CRC, Boca Raton, London, New York, Washington, DC, 2001). However, under certain conditions an extended partial explicit time-integration of the shallow water equations could be worthwhile to save computational effort. To restrict implicit solution by ROW schemes to stiff components while using explicit solution by RK methods for remaining terms, we adapt ROW method ROS34PRW (Rang, J Comput Appl Math 262:105–114, 2014) to an AMF and IMEX combining approach (Hundsdorfer and Verwer, Numerical solution of time-dependent advection-diffusion-reaction equations. Springer, Berlin, Heidelberg, New York, 2003). Applied to first test problems regarding open channel flow, efficiency is analysed with respect to flow behaviour. Results prove to be advantageous especially concerning dynamical flow.
Do remittances and social assistance transfers have different impacts on household’s expenditure patterns? While two separate strands of literature have looked at how social assistance or remittances have been spent, few studies have compared them directly. Using data from a household survey conducted in Moldova in 2011, this paper assesses the impact both types of transfers have on household expenditure patterns. Contrary to the common assumption that money is fungible, we find that social assistance and remittances have different impacts on expenditure patterns (having controlled for potential endogeneity). In other words, where the income comes from can determine how it is spent. As such, different sources of income may have different poverty impacts. In our sample, the two types of transfers are received by different, but slightly overlapping population groups. The fact that the two transfers are spent in different ways means that, to some extent, social assistance and remittances are complements rather than substitutes.
Noch sind sich die Experten nicht einig, wie schnell Blockchain das Internet revolutionieren wird. Dass das Potenzial dafür riesig ist, ist sich Professor Jens Böcker sicher. Er unterhält eine Professur für Betriebswirtschaftslehre und Marketing an der Hochschule Bonn-Rhein-Sieg und forscht zu diesem Thema.
Background: Falls are common in older adults and can result in serious injuries. Due to demographic changes, falls and related healthcare costs are likely to increase over the next years. Participation and motivation of older adults in fall prevention measures remain a challenge. The iStoppFalls project developed an information and communication technology (ICT)-based system for older adults to use at home in order to reduce common fall risk factors such as impaired balance and muscle weakness. The system aims at increasing older adults’ motivation to participate in ICT-based fall prevention measures. This article reports on usability, user-experience and user-acceptance aspects affecting the use of the iStoppFalls system by older adults.
Methods: In the course of a 16-week international multicenter study, 153 community-dwelling older adults aged 65+ participated in the iStoppFalls randomized controlled trial, of which half used the system in their home to exercise and assess their risk of falling. During the study, 60 participants completed questionnaires regarding the usability, user experience and user acceptance of the iStoppFalls system. Usability was measured with the System Usability Scale (SUS). For user experience the Physical Activity Enjoyment Scale (PACES) was applied. User acceptance was assessed with the Dynamic Acceptance Model for the Re-evaluation of Technologies (DART). To collect more detailed data on usability, user experience and user acceptance, additional qualitative interviews and observations were conducted with participants.
Results: Participants evaluated the usability of the system with an overall score of 62 (Standard Deviation, SD 15.58) out of 100, which suggests good usability. Most users enjoyed the iStoppFalls games and assessments, as shown by the overall PACES score of 31 (SD 8.03). With a score of 0.87 (SD 0.26), user acceptance results showed that participants accepted the iStoppFalls system for use in their own home. Interview data suggested that certain factors such as motivation, complexity or graphical design were different for gender and age.
Conclusions: The results suggest that the iStoppFalls system has good usability, user experience and user acceptance. It will be important to take these along with factors such as motivation, gender and age into consideration when designing and further developing ICT-based fall prevention systems.
In this paper an overview on modelling techniques and numerical methods applied to problems in water network simulation is given. The considered applications cover river alarm systems (Rentrop and Steinebach, Surv Math Ind 6:245–265, 1997), water level forecast methods (Steinebach and Wilke, J CIWEM 14(1):39–44, 2000) up to sewer and water supply networks (Steinebach et al., Mathematical Optimization of Water Networks Martin. Springer, Basel, 2012).
The hyperbolic modelling equations are derived from mass and momentum conservation laws. A typical example are the well known Saint-Venant equations. For their numerical solution a conservative semi-discretisation in space by finite differences is proposed. A new well-balanced space discretisation scheme is presented which improves the local Lax-Friedrichs approach applied so far. Higher order discretisations are achieved by WENO methods (Kurganov and Levy, SIAM J Sci Comput 22(4):1461–1488, 2000).
Together with appropriate boundary and coupling conditions this method of lines approach leads to an index-one DAE system. Efficient solution of the DAE system is the topic of Jax and Steinebach (ROW methods adapted to network simulation for fluid flow, in preparation).
Marketing und Recht kompakt
(2016)
"Marketing und Recht - was soll das denn?" So oder ähnlich wird der eine oder andere auf den Titel des vorliegenden Buches spontan reagieren. Das verwundert nicht, ist die Buch-Landschaft doch vor allem dadurch geprägt, dass Marketing-Werke und Abhandlungen zu marketingrelevanten Rechtsthemen am Büchermarkt stets "getrennt marschieren". Wer Marketingkonzepte entwirft, Vorhaben im Rahmen der Marketingforschung durchführen will oder beabsichtigt, Entscheidungen im Rahmen des Marketings zu treffen, sollte unseres Erachtens möglichst frühzeitig die gängigen "juristischen Fallstricke" erkennen und in seinen Überlegungen berücksichtigen.
Within qualitative interviews we examine attitudes towards driverless cars in order to investigate new mobility services and explore the impact of such services on everyday mobility. We identified three main issues that we would like to discuss in the workshop: (I) Designing beyond a driver-centric approach; (II) Developing mobility services for cars which drive themselves; and (III) Exploring self-driving practices.
Mobilitäts- und Nachhaltigkeitsforscher sehen sich bei der Erforschung des Mobilitätsverhaltens von Personen mit einer bunten Palette an Erhebungsmethoden konfrontiert. Erweitert wird diese Vielfalt in der letzten Zeit durch die Möglichkeit, dieses Verhalten direkt über die Smartphones der Probanden zu erfassen. Um die Auswahl geeigneter Methoden zu erleichtern, liefert die vorliegende Literaturstudie einen detaillierten Überblick zu Fragestellungen, Daten und Erhebungsmethoden, die im Bereich der Mobilitätsforschung zur Erfassung von Alltagsmobilität eingesetzt werden.
Dieser Artikel stützt sich auf das vom 13.10.2015 bis 12.01.2016 gemeinsam durchgeführten Praxisprojekt von ORBIT und der Hochschule Bonn-Rhein-Sieg. Thema des Projekts waren die Methodenevaluation und Automatisierung von Auswertungsprozessen. Speziell ging es um die Überprüfung der von ORBIT entwickelten Methodik zur Anforderungsanalyse und Standortbestimmung – dem ORBIT-Navigator.
SpMV Runtime Improvements with Program Optimization Techniques on Different Abstraction Levels
(2016)
The multiplication of a sparse matrix with a dense vector is a performance critical computational kernel in many applications, especially in natural and engineering sciences. To speed up this operation, many optimization techniques have been developed in the past, mainly focusing on the data layout for the sparse matrix. Strongly related to the data layout is the program code for the multiplication. But even for a fixed data layout with an accommodated kernel, there are several alternatives for program optimizations. This paper discusses a spectrum of program optimization techniques on different abstraction layers for six different sparse matrix data format and kernels. At the one end of the spectrum, compiler options can be used that hide from the programmer all optimizations done by the compiler internally. On the other end of the spectrum, a multiplication kernel can be programmed that use highly sophisticated intrinsics on an assembler level that ask for a programmer with a deep understanding of processor architectures. These special instructions can be used to efficiently utilize hardware features in processors like vector units that have the potential to speed up sparse matrix computations. The paper compares the programming effort and required knowledge level for certain program optimizations in relation to the gained runtime improvements.
A deployment of the Vehicle-to-Vehicle communication technology according to ETSI is in preparation in Europe. Currently, a Public Key Infrastructure policy for Intelligent Transport Systems in Europe is in discussion to enable V2V communication. This policy set aside two classes of keys and certificates for ITS vehicle stations: long term authentication keys and pseudonymous keys and certificates. We show that from our point of view the periodic sent Cooperative Awareness Messages with extensive data have technical limitations and together with the pseudonym concept cause privacy problems.
With the rising interest in vehicular communication systems many proposals for secure vehicle-to-vehicle commu- nication were made in recent years. Also, several standard- ization activities concerning the security and privacy measures in these communication systems were initiated in Europe and in US. Here, we discuss some limitations for secure vehicle- to-infrastructure communication in the existing standards of the European Telecommunications Standards Institute. Next, a vulnerability analysis for roadside stations on one side and security and privacy requirements for roadside stations on the other side are given. Afterwards, a proposal for a multi-domain public key architecture for intelligent transport systems, which considers the necessities of road infrastructure authorities and vehicle manufacturers, is introduced. The domains of the public key infrastructure 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.
RPSL meets lightning: A model-based approach to design space exploration of robot perception systems
(2016)
The design space of a robotic application defines at a meta level what are all of its possible implementations. Those possibilities are called design alternatives and differ on many different aspects, one being preferred to the other depending on how, where, when or what the application should do. Design Space Exploration (DSE) is the process of reviewing those design alternatives, prior to their implementation, with intention to verify that the set of all design alternatives to be implemented covers all the possible scenarios in which the application is to be executed. In this paper we address two challenges related to DSE, namely, (1) the formal definitions of design spaces, a non-trivial task due to the many dimensions to be taken into consideration, and (2) the automatisation of DSE, that is, enabling a domain expert to review design alternatives corresponding to a given design space effortlessly. In this paper, we address those challenges in the context of robot perception software systems by combining two already existing technologies, namely RPSL for the specification of robot perception system's design spaces and Lightning, a language workbench that we use to formalise RPSL and obtain, from RPSL specifications, corresponding design alternatives.
We present an analysis of eye tracking data produced during a quality-focused user study of our own foveated ray tracing method. Generally, foveated rendering serves the purpose of adapting actual rendering methods to a user’s gaze. This leads to performance improvements which also allow for the use of methods like ray tracing, which would be computationally too expensive otherwise, in fields like virtual reality (VR), where high rendering performance is important to achieve immersion, or fields like scientific and information visualization, where large amounts of data may hinder real-time rendering capabilities. We provide an overview of our rendering system itself as well as information about the data we collected during the user study, based on fixation tasks to be fulfilled during flights through virtual scenes displayed on a head-mounted display (HMD). We analyze the tracking data regarding its precision and take a closer look at the accuracy achieved by participants when focusing the fixation targets. This information is then put into context with the quality ratings given by the users, leading to a surprising relation between fixation accuracy and quality ratings.
Software development for robots is a knowledgeintensive exercise. To capture this knowledge explicitly and formally in the form of various domain models, roboticists have recently employed model-driven engineering (MDE) approaches. However, these models are merely seen as a way to support humans during the robot's software design process. We argue that the robots themselves should be first-class consumers of this knowledge to autonomously adapt their software to the various and changing run-time requirements induced, for instance, by the robot's tasks or environment. Motivated by knowledge-enabled approaches, we address this problem by employing a graph-based knowledge representation that allows us not only to persistently store domain models, but also to formulate powerful queries for the sake of run time adaptation. We have evaluated our approach in an integrated, real-world system using the neo4j graph database and we report some lessons learned. Further, we show that the graph database imposes only little overhead on the system's overall performance.
IT-Controlling
(2016)
Die Klausur: VWL
(2016)
