Refine
Departments, institutes and facilities
- Fachbereich Wirtschaftswissenschaften (1241)
- Fachbereich Informatik (1148)
- Fachbereich Angewandte Naturwissenschaften (766)
- Fachbereich Ingenieurwissenschaften und Kommunikation (636)
- Institut für funktionale Gen-Analytik (IFGA) (584)
- Institut für Technik, Ressourcenschonung und Energieeffizienz (TREE) (485)
- Präsidium (404)
- Fachbereich Sozialpolitik und Soziale Sicherung (402)
- Institute of Visual Computing (IVC) (313)
- Institut für Cyber Security & Privacy (ICSP) (307)
Document Type
- Article (2430)
- Conference Object (1806)
- Part of a Book (942)
- Book (monograph, edited volume) (452)
- Part of Periodical (411)
- Report (201)
- Contribution to a Periodical (118)
- Doctoral Thesis (106)
- Working Paper (94)
- Preprint (90)
Year of publication
Keywords
- Lehrbuch (88)
- Deutschland (34)
- Nachhaltigkeit (30)
- Controlling (25)
- Unternehmen (25)
- Management (20)
- Corporate Social Responsibility (18)
- Betriebswirtschaftslehre (17)
- Digitalisierung (17)
- Machine Learning (17)
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.
This paper gives an overview of the development of Fair Trade in six European countries: Austria, France, Germany, the Netherlands, Switzerland and the United Kingdom. After the description of the food retail industry and its market structures in these countries, the main European Fair Trade organizations are analyzed regarding their role within the Fair Trade system. The following part deals with the development of Fair Trade sales in general and with respect to the products coffee, tea, bananas, fruit juice and sugar. An overview of the main activities of national Fair Trade organizations, e.g. public relation activities, completes the analysis. This study shows the enormous upswing of Fair Trade during the last decade and the reasons for this development. Nevertheless, it comes to the conclusion that Fair Trade is still far away from being an essential part of the food retail industry in Europe.
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.
The phenomenon of the deviation between purchase attitudes and actual buying behaviour of responsible consumers 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. The last three barriers are mainly of a psychological nature. Especially the low-involvement feature of food products due to daily purchase routines and relatively low prices tends to result in fast, automatic and subconscious decisions based on a so-called human mental system 1, derived from Daniel Kahneman’s (Nobel-Prize laureate in Behavioural Economics) model in behavioural psychology. In contrast, the human mental system 2 is especially important for the transformations of individual behaviour towards a more sustainable consumption. Decisions based on the human mental system 2 are slow, logical, rational, conscious and arduous. This so-called dual action model also influences the reliability of responses in consumer surveys. It seems that the consumer behaviour is the most unstable and unpredictable part of the entire supply chain and requires special attention. Concrete measures to influence consumer behaviour towards sustainable consumption are highly complex. Reviews of interdisciplinary research literature on behavioural psychology, behavioural economics and consumer behaviour and an empirical analysis of selected countries worldwide with a view to sustainable food are presented. The example of Denmark serves as a ‘best practice’ case study to illustrate how sustainable food consumption can be encouraged. It demonstrates that common efforts and a shared responsibility of consumers, business, interdisciplinary researchers, mass media and policy are needed. It takes pioneers of change who succeed in assembling a ‘critical mass’ willing to increase its ‘sustainable’ behaviour. Considering the strong psychological barriers of consumers and the continuing low market share of organic food, proactive policy measures would be conducive to foster the personal responsibility of the consumers and offer incentives towards a sustainable production. Also, further self-obligations of companies (Corporate Social Responsibility – CSR) as well as more transparency and simplification of reliable labels and certifications are needed to encourage the process towards a sustainable development.
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.
Macht in Unternehmen
(2012)
Kaum ein Begriff ist so diskreditiert wie der der Macht. Sie wird mit Missbrauch, Willkür und Irrationalität verbunden, allein das Streben danach gilt als verdächtig. Dabei ist die regulierende und gestaltende Funktion der Macht für und in Organisationen aus dem Blick geraten, aber auch die Frage nach den Ursprüngen und den Regulativen von Macht. Das Buch untersucht diese Thematik aus der Perspektive von Wissenschaftlern verschiedener Disziplinen und von "Praktikern der Macht" aus Unternehmen und Politik.
Warum wir tun, was andere wollen: Psychologische Determinanten informeller Macht in Organisationen
(2012)
Solar energy is one option to serve the rising global energy demand with low environmental impact.1 Building an energy system with a considerable share of solar power requires long-term investment and a careful investigation of potential sites. Therefore, understanding the impacts from varying regionally and locally determined meteorological conditions on solar energy production will influence energy yield projections. Clouds are moving on a short term timescale and have a high influence on the available solar radiation, as they absorb, reflect and scatter parts of the incoming light.2 However, the impact of cloudiness on photovoltaic power yields (PV) and cloud induced deviations from average yields might vary depending on the technology, location and time scale under consideration.
Solar energy is one option to serve the rising global energy demand with low environmental Impact [1]. Building an energy system with a considerable share of solar power requires long-term investment and a careful investigation of potential sites. Therefore, understanding the impacts from varying regionally and locally determined meteorological conditions on solar energy production will influence energy yield projections. Clouds are moving on a short term timescale and have a high influence on the available solar radiation, as they absorb, reflect and scatter parts of the incoming light [2]. However, modeling photovoltaic (PV) power yields with a spectral resolution and local cloud information gives new insights on the atmospheric impact on solar energy.
Hand speed is particularly important in boxing both for protection against incoming blows and delivering blows. Sixteen amateur boxers (10 male, 6 female) with varying levels of experience from a boxing gym performed 20 jabs and 20 cross punches in air. The movement was recorded with a small wrist mounted accelerometer under the glove. The maximum velocity of each punch was determined from the RMS acceleration profile. The mean values of the jab maximal velocity was higher than the cross maximal velocity for 9 participants. The cross showed some dependence on reach (Spearman's correlation coefficient r = 0.57) and the jab dependence on experience (Spearman's correlation coefficient r = 0.56). The accelerometer technique has some promise for routine assessment of fist speed.
Virtual reality environments are increasingly being used to encourage individuals to exercise more regularly, including as part of treatment in those with mental health or neurological disorders. The success of virtual environments likely depends on whether a sense of presence can be established, where participants become fully immersed in the virtual environment. Exposure to virtual environments is associated with physiological responses, including cortical activation changes. Whether the addition of a real exercise within a virtual environment alters sense of presence perception, or the accompanying physiological changes, is not known. In a randomized and controlled study design, trials of moderate-intensity exercise (i.e. self-paced cycling) and no-exercise (i.e. automatic propulsion) were performed within three levels of virtual environment exposure. Each trial was 5-min in duration and was followed by post-trial assessments of heart rate, perceived sense of presence, EEG, and mental state. Changes in psychological strain and physical state were generally mirrored by neural activation patterns. Furthermore these change indicated that exercise augments the demands of virtual environment exposures and this likely contributed to an enhanced sense of presence.
Traffic simulations are typically concerned with modeling human behavior as closely as possible to create realistic results. In conventional traffic simulations used for road planning or traffic jam prediction only the overall behavior of an entire system is of interest. In virtual environments, like digital games, simulated traffic participants are merely a backdrop to the player’s experience and only need to be “sufficiently realistic”. Additionally, restricted computational resources, typical for virtual environment applications, usually limit the complexity of simulated behavior in this field. More importantly, two integral aspects of real-world traffic are not considered in current traffic simulations from both fields: misbehavior and risk taking of traffic participants. However, for certain applications like the FIVIS bicycle simulator, these aspects are essential.
Traditionally traffic simulations are used to predict traffic jams, plan new roads or highways, and estimate road safety. They are also used in computer games and virtual environments. There are two general concepts of modeling traffic: macroscopic and microscopic modeling. Macroscopic traffic models take vehicle collectives into account and do not consider individual vehicles. Parameters like average velocity and density are used to model the flow of traffic. In contrast, microscopic traffic models consider each vehicle individually. Therefore, vehicle specific parameters are of importance, e.g. current velocity, desired velocity, velocity difference to the lead vehicle, individual time gap.
In this paper, we introduce an optical sensor system, which is integrated into an industrial push-button. The sensor allows to classify the type of material that is in contact with the button when pressed into different material categories on the basis of the material's so called "spectral signature". An approach for a safety sensor system at circular table saws on the same base has been introduced previously on SIAS-2007. This contactless working sensor is able to distinguish reliably between skin, textiles, leather and various other kinds of materials. A typical application for this intelligent push-button is the use at possibly dangerous machines, whose operating instructions include either the prohibition or the obligation to wear gloves during the work at the machine. An exemple of machines at which no gloves are allowed are pillar drilling machines, because of the risk of getting caught in the drill chuck and being turned in by the machine. In many cases this causes very serious hand injuries. Depending on the application needs, the sensor system integrated into the push-button can be configured flexibly by software to prevent the operator from accidentally starting a machine with or without gloves, which can decrease the risk of severe accidents significantly. Especially two-hand controls are incentive to manipulation for easier handling. By equipping both push-buttons of a two-hand control with material classification properties, the user is forced to operate the controls with his bare fingers. That limitation disallows the manipulation of a two-hand control by a simple rodding device.
Computers will soon be powerful enough to simulate consciousness. The artificial life community should start to try to understand how consciousness could be simulated. The proposal is to build an artificial life system in which consciousness might be able to evolve. The idea is to develop internet-wide artificial universe in which the agents can evolve. Users play games by defining agents that form communities. The communities have to perform tasks, or compete, or whatever the specific game demands. The demands should be such that agents that are more aware of their universe are more likely to succeed. The agents reproduce and evolve within their user’s machine, but can also sometimes transfer to other machine across the internet. Users will be able to choose the capabilities of their agents from a fixed list, but may also write their own powers for their agents.
A novel approach to produce 2D designs by adapting the HyperNEAT algorithm to evolve non-uniform rational basis splines (NURBS) is presented. This representation is proposed as an alternative to previous pixel-based approaches primarily motivated by aesthetic interests, and not designed for optimization tasks. This spline representation outperforms previous pixel-based approaches on target matching tasks, performing well even in matching irregular target shapes. In addition to improved evolvability in the face of a well defined fitness metric, a NURBS representation has the added virtues of being continuous rather than discrete, as well as being intuitive and easily modified by graphic and industrial designers.
Nowadays, we input text not only on stationary devices, but also on handheld devices while walking, driving, or commuting. Text entry on the move, which we term as nomadic text entry, is generally slower. This is partially due to the need for users to move their visual focus from the device to their surroundings for navigational purposes and back. To investigate if better feedback about users' surroundings on the device can improve performance, we present a number of new and existing feedback systems: textual, visual, textual & visual, and textual & visual via translucent keyboard. Experimental comparisons between the conventional and these techniques established that increased ambient awareness for mobile users enhances nomadic text entry performance. Results showed that the textual and the textual & visual via translucent keyboard conditions increased text entry speed by 14% and 11%, respectively, and reduced the error rate by 13% compared to the regular technique. The two methods also significantly reduced the number of collisions with obstacles.
Software repository data, for example in issue tracking systems, include natural language text and technical information, which includes anything from log files via code snippets to stack traces. However, data mining is often only interested in one of the two types e.g. in natural language text when looking at text mining. Regardless of which type is being investigated, any techniques used have to deal with noise caused by fragments of the other type i.e. methods interested in natural language have to deal with technical fragments and vice versa. This paper proposes an approach to classify unstructured data, e.g. development documents, into natural language text and technical information using a mixture of text heuristics and agglomerative hierarchical clustering. The approach was evaluated using 225 manually annotated text passages from developer emails and issue tracker data. Using white space tokenization as a basis, the overall precision of the approach is 0.84 and the recall is 0.85.
IT-Offshoring ist lediglich ein zur Zeit viel diskutierter Spezialfall des IT-Outsourcings, d. h. der Verlagerung von Aufgaben im Zusammenhang mit der Planung, Entwicklung und dem Betrieb von Informationssystemen auf Dritte. Insbesondere geht es um die Verlagerung von Programmier- und Testaufgaben aber auch um den Betrieb von Rechenzentren oder Hotlines für Endanwender. Wurden zunächst einfachere Aufgaben wie die Programmierung von mathematischen Algorithmen oder grafischen Anwendungen verlagert, werden zunehmend auch komplexere Tätigkeiten mit hoher Wertschöpfung wie z. B. die Entwicklung von ERP-Systemen in Betracht gezogen.
Viele Controller verzeichnen steigende IT-Kosten, die zum Teil durch Lizenzkosten verursacht werden. Oft werden Kosteneinsparungen durch ineffizientes oder fehlendes Lizenzmanagement nicht realisiert, zudem sehen sich zahlreiche Unternehmen zusehends mit dem Problem nicht budgetierter Nachlizenzierungen, aufgrund steigender Aktivitäten der Softwarehersteller im Bereich der Lizenzierungsüberprüfung, konfrontiert. Der Beitrag zeigt die Problematik des IT-Lizenzmanagements und grundsätzliche Lösungsmöglichkeiten auf. Ein Referenzmodell demonstriert, wie im praktischen Anwendungsfall eine Kostensenkung und Prozessverbesserung realisiert werden kann.
Digitales Geld
(2015)
Industrie 4.0: Digitale Wirtschaft – Herausforderung und Chance für Unternehmen und Arbeitswelt
(2015)
Seit Mitte der 1990er Jahre werden neue Informations- und Kommunikationstechnologien in der Arbeitswelt genutzt, in wachsendem Ausmaß und mit wachsender Bedeutung. Die verstärkte Digitalisierung verändert sowohl die Wirtschaft als auch die Gesellschaft. Es wird sogar von der "vierten industriellen Revolution" gesprochen, denn traditionelle Geschäftsmodelle geraten unter Druck.
We explore the potential of stereoscopic 3D (S3D) vision in offering distinct gameplay using an S3D-specific game called Deepress3D. Our game utilizes established S3D design principles for optimizing GUI design, visual comfort and game mechanics which rely on depth perception in time-pressured spatial conflicts. The game collects detailed S3D player metrics and allows players to choose between different, evenly matched strategies. We conducted a between subjects study comparing S3D and monoscopic versions of Deepress3D that examined player behavior and performance and measured user-reported data on presence, simulator sickness, and game experience.
Deep Gaming
(2014)
How to create a distinct user experience of Stereo 3D in Interactive Entertainment & Virtual Reality Gaming Stereoscopic 3D (S3D) vision offers spatial visual perception by presenting two separate and different This article or re envision the, creative economy different versions of games in it up. By authors behind the same sheet, of primary medical dental and operator. If I gently rubbed miles chest wouldn't know. Listing infohere at a way through, sixth grade level by the layout and memory. Hats off adjust the bass and restart automatic benefit. Try to be fooled into serious topics by playing with a lot. Creating general many other people, with new digital games allow their impact! The hunt for example my google, searches has learned. These badges this development phases to work it is in my year.
The topic of this PhD project is in the context of cross-reality, a term that defines mixed reality environments that tunnel dense real-world data acquired through the use of sensor/actuator device networks into virtual worlds. It is part of the ongoing academia and industry efforts to achieve interoperability between virtual and real devices and services.
This paper describes the development of a Pedelec controller whose performance level (PL) conforms to European standard on safety of machinery [9] and whose soft- ware is verified to conform to EPAC standard [6] by means of a software verification technique called model checking. In compliance with the standard [9] the hardware needs to implement the required properties corresponding to categories “C” and “D”. The latter is used if the breaks are not able to bring the velomobile with a broken motor controller to a full stop. Therefore the controller needs to implement a test unit, which verifies the functionality of the components and, in case of an emergency, shuts the whole hardware down to prevent injuries of the cyclist. The MTTFd can be measured through a failure graph, which is the result of a FMEA analysis, and can be used to proof that the Pedelec controller meets the regulations of the system specification. The analysis of the system in compliance with [9] usually treats the software as a black box thus ignoring its inner workings and validating its correctness by means of testing. In this paper we present a temporal logic specification according to [6], based on which the software for the Pedelec controller is implemented, and verify instead of only testing its functionality. By means of model checking [1] we proof that the software fulfills all requirements which are regulated by its specification.
Designing stereoscopic information visualization for 3D-TV: What can we learn from S3D gaming?
(2012)
This paper explores graphical design and spatial alignment of visual information and graphical elements into stereoscopically filmed content, e.g. captions, subtitles, and especially more complex elements in 3D-TV productions. The method used is a descriptive analysis of existing computer- and video games that have been adapted for stereoscopic display using semi-automatic rendering techniques (e.g. Nvidia 3D Vision) or games which have been specifically designed for stereoscopic vision. Digital games often feature compelling visual interfaces that combine high usability with creative visual design. We explore selected examples of game interfaces in stereoscopic vision regarding their stereoscopic characteristics, how they draw attention, how we judge effect and comfort and where the interfaces fail. As a result, we propose a list of five aspects which should be considered when designing stereoscopic visual information: explicit information, implicit information, spatial reference, drawing attention, and vertical alignment. We discuss possible consequences, opportunities and challenges for integrating visual information elements into 3D-TV content. This work shall further help to improve current editing systems and identifies a need for future editing systems for 3DTV, e.g., live editing and real-time alignment of visual information into 3D footage.
We present a study that investigates user performance benefits of playing video games using 3D motion controllers in 3D stereoscopic vision in comparison to monoscopic viewing. Using the PlayStation 3 game console coupled with the PlayStation Move Controller, we explored five different games that combine 3D stereo and 3D spatial interaction. For each game, quantitative and qualitative measures were taken to determine if users performed better and learned faster in the experimental group (3D stereo display) than in the control group (2D display). A game expertise pre-questionnaire was used to classify participants into beginners and expert game player categories to analyze a possible impact on performance differences. The results show two cases where the 3D stereo display did help participants perform significantly better than with a 2D display. For the first time, we can report a positive effect on gaming performance based on stereoscopic vision, although reserved to isolated tasks and depending on game expertise. We discuss the reasons behind these findings and provide recommendations for game designers who want to make use of 3D stereoscopic vision and 3D motion control to enhance game experiences.
Recent advances in digital game technology are making stereoscopic games more popular. Stereoscopic 3D graphics promise a better gaming experience but this potential has not yet been proven empirically. In this paper, we present a comprehensive study that evaluates player experience of three stereoscopic games in comparison with their monoscopic counterparts. We examined 60 participants, each playing one of the three games, using three self-reporting questionnaires and one psychophysiological instrument. Our main results are (1) stereoscopy in games increased experienced immersion, spatial presence, and simulator sickness; (2) the effects strongly differed across the three games and for both genders, indicating more affect on male users and with games involving depth animations; (3) results related to attention and cognitive involvement indicate more direct and less thoughtful interactions with stereoscopic games, pointing towards a more natural experience through stereoscopy.
MySAP CRM
(2004)
Für eine erfolgreiche Strategie im Bereich Customer Relationship Management (CRM) ist ein solches Integrationsniveau notwendig – schließlich endet die Interaktion mit dem Kunden nicht mit dem Auftrag. Vertriebs- und Serviceanwendungen für den Kundenkontakt mit Backoffice-Prozessen in Finanz- und Supply-Chain-Management-Lösungen zu verbinden ist lediglich der Anfang eines durchgängigen Prozesses, in den auch Vertriebspartner und Wiederverkäufer einbezogen werden müssen.
mySAP CRM
(2004)
MySAP CRM
(2002)
We present a model checking algorithm for ∀CTL (and full CTL) which uses an iterative abstraction refinement strategy.
It terminates at least for all transition systems M that have a finite simulation or bisimulation quotient. In contrast to other abstraction refinement algorithms, we always work with abstract models whose sizes depend only on the length of the formula θ (but not on the size of the system, which might be infinite).
In der vorliegenden Arbeit werden Verfahren vorgestellt, die geeignet sind, Modelle des menschlichen kardiovaskulären Systems an individuelle Kreislaufreaktionen anzupassen. Allgemeine Kreislaufmodelle des menschlichen kardiovaskulären Systems sind in der Regel nichtlineare Differentialgleichungssysteme, für die es keine effizienten Optimierungsverfahren gibt. Durch die Einschränkung auf relevante Aspekte (bzgl. der Individualisierungsaufgabe) wird ein solches Modell auf Modelle einfacherer Struktur projiziert, die eine Approximation durch Funktionsapproximatoren erlauben, für welche wiederum effiziente Optimierungsalgorithmen existieren. In Abhängigkeit von der Struktur der Individualisierungsaufgabe kommt zusätzlich ein modifiziertes BFGS-Verfahren zum Einsatz, das Approximationen solcher Modellaspekte verwendet um die Konvergenz der Modellindividualisierung zu verbessern.
The SAP R/3 system
(2000)
Information spielt in jeder arbeitsteilig organisierten Volkswirtschaft eine wichtige Rolle. Nur durch den Austausch von Informationen ist eine Koordination von Leistungserstellungs- und Allokationsprozessen möglich. "Alles das, was ... geteilt, gespalten oder weiter untergliedert – mit einem Wort: was aufgelöst worden ist, muß durch ein System von Information und Kommunikation wieder verbunden werden" (1). Ein Betrieb ist ohne Informationsfluß im Inneren und nach außen schlichtweg nicht funktionsfähig.
Das System SAP R/3
(1994)
Information
(1993)
Towards a Generalization of Production Theory - "Soft" Production Functions Using Fuzzy Set Theory
(1992)
Virtuelle Maschinen
(1985)
Extraction of text information from visual sources is an important component of many modern applications, for example, extracting the text from traffic signs on a road scene in an autonomous vehicle. For natural images or road scenes this is a unsolved problem. In this thesis the use of histogram of stroke widths (HSW) for character and noncharacter region classification is presented. Stroke widths are extracted using two methods. One is based on the Stroke Width Transform and another based on run lengths. The HSW is combined with two simple region features– aspect and occupancy ratios– and then a linear SVM is used as classifier. One advantage of our method over the state of the art is that it is script-independent and can also be used to verify detected text regions with the purpose of reducing false positives. Our experiments on generated datasets of Latin, CJK, Hiragana and Katakana characters show that the HSW is able to correctly classify at least 90% of the character regions, a similar figure is obtained for non-character regions. This performance is also obtained when training the HSW with one script and testing with a different one, and even when characters are rotated. On the English and Kannada portions of the Chars74K dataset we obtained over 95% correctly classified character regions. The use of raycasting for text line grouping is also proposed. By combining it with our HSW-based character classifier, a text detector based on Maximally Stable Extremal Regions (MSER) was implemented. The text detector was evaluated on our own dataset of road scenes from the German Autobahn, where 65% precision, 72% recall with a f-score of 69% was obtained. Using the HSW as a text verifier increases precision while slightly reducing recall. Our HSW feature allows the building of a script-independent and low parameter count classifier for character and non-character regions.
Advanced driver assistance systems (ADAS) are technology systems and devices designed as an aid to the driver of a vehicle. One of the critical components of any ADAS is the traffic sign recognition module. For this module to achieve real-time performance, some preprocessing of input images must be done, which consists of a traffic sign detection (TSD) algorithm to reduce the possible hypothesis space. Performance of TSD algorithm is critical.
One of the best algorithms used for TSD is the Radial Symmetry Detector (RSD), which can detect both Circular [7] and Polygonal traffic signs [5]. This algorithm runs in real-time on high end personal computers, but computational performance of must be improved in order to be able to run in real-time in embedded computer platforms.
To improve the computational performance of the RSD, we propose a multiscale approach and the removal of a gaussian smoothing filter used in this algorithm. We evaluate the performance on both computation times, detection and false positive rates on a synthetic image dataset and on the german traffic sign detection benchmark [29].
We observed significant speedups compared to the original algorithm. Our Improved Radial Symmetry Detector is up to 5.8 times faster than the original on detecting Circles, up to 3.8 times faster on Triangle detection, 2.9 times faster on Square detection and 2.4 times faster on Octagon detection. All of this measurements were observed with better detection and false positive rates than the original RSD.
When evaluated on the GTSDB, we observed smaller speedups, in the range of 1.6 to 2.3 times faster for Circle and Regular Polygon detection, but for Circle detection we observed a decreased detection rate than the original algorithm, while for Regular Polygon detection we always observed better detection rates. False positive rates were high, in the range of 80% to 90%.
We conclude that our Improved Radial Symmetry Detector is a significant improvement of the Radial Symmetry Detector, both for Circle and Regular polygon detection. We expect that our improved algorithm will lead the way to obtain real-time traffic sign detection and recognition in embedded computer platforms.
Der Einsatz von Agentensystemen ist vielfältig, dennoch sind aktuelle Realisierungen lediglich in der Lage primär regelkonformes oder aber „geskriptetes“ Verhalten auch unter Einsatz von randomisierten Verfahren abzubilden. Für eine realistische Repräsentation sind jedoch auch Abweichungen von den Regeln notwendig, die nicht zufällig sondern kontextbedingt auftreten. Im Rahmen dieses Forschungsprojektes wurde ein realitätsnaher Straßenverkehrssimulator realisiert, der mittels eines detailliert definierten Systems für kognitive Agenten auch diese irregulären Verhaltensweisen generiert und somit ein realistisches Verkehrsverhalten für die Verwendung in VR-Anwendungen simuliert. Durch das Erweitern der Agenten mit psychologischen Persönlichkeitsprofilen, basierend auf dem „Fünf-Faktoren-Modell“, zeigen die Agenten individualisierte und gleichzeitig konsistente Verhaltensmuster. Ein dynamisches Emotionsmodell sorgt zusätzlich für eine situationsbedingte Adaption des Verhaltens, z.B. bei langen Wartezeiten. Da die detaillierte Simulation kognitiver Prozesse, der Persönlichkeitseinflüsse und der emotionalen Zustände erhebliche Rechenleistungen verlangt, wurde ein mehrschichtiger Simulationsansatz entwickelt, der es erlaubt den Detailgrad der Berechnung und Darstellung jedes Agenten während der Simulation stufenweise zu verändern, so dass alle im System befindlichen Agenten konsistent simuliert werden können. Im Rahmen diverser Evaluierungsiterationen in einer bestehenden VR-Anwendung – dem FIVIS-Fahrradfahrsimulator des Antragstellers - konnte eindrucksvoll nachgewiesen werden, dass die realisierten Konzepte die ursprünglich formulierten Forschungsfragestellung überzeugend und effizient lösen.