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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.
Praxisorientierte, wissenschaftliche Lehre und Forschung in enger Zusammenarbeit mit Unternehmen, Organisationen und gesellschaftlichen Gruppierungen ist das zentrale Leitbild des Fachbereichs Wirtschaftswissenschaften an der Hochschule Bonn-Rhein-Sieg.
Sweet sorghum (Sorghum bicolor (L.) moench), a crop that is grown by subsistence farmers in Zimbabwe was used to extract silica gel in order to assess its possible use as a raw material for the production of silica-based products. The gel was prepared from sodium silicate extracted from sweet sorghum bagasse ash by sodium hydroxide leaching. Results show that maximum yield can be obtained at pH 5 and with 3 M sodium concentration. The silica gel prepared at optimum pH 5 had a bulk density of 0.5626 g/cm3 and anestimated porosity of 71.87%. Silica gel aged over 10 h had improved moisture adsorption properties. X-ray fluorescence (XRF) determinations show that the silica content in the ash is 40.1%. Characterization of sweet sorghum ash and silica gels produced at pH 5, 7 and 8.5 by Fourier Transform Infrared spectroscopy gave absorption bands similar to those reported by other researchers.Transmission electron micrographs show that silica prepared under optimum conditions is amorphous and consisted of irregular particles. Sweet sorghum proved to be a potential low cost raw material for the production of silica gel.
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.
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.
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.
It is know that mesenchymal stem cells (MSCs) actively secretemultiple biologically-active factors during their process of differentiation which gives rise to a variey of cytotypes including bone and fatcells. It is also acknowledged that the chemokines secreted throughoutMSC differentiation may play an important role in the development and growth of tumor cells, although literature data appear somewhat indeterminate due to the contradictory evidence often found.
Digitalisierung eines Pen-&-Paper-Rollenspiels mit Übertragung von Interaktionen in die reale Welt
(2015)
Das hier vorliegende Werk ist eine Zusammenführung des Masterprojekts und der darauf aufbauenden Masterarbeit von Antony Konstantinidis und Nicolas Kopp. Diese Arbeiten sind in den Jahren 2013 und 2014 entstanden und ergeben zusammen ein umfassendes Bild der Software- und Spielenentwicklung, der Konzeption von Echtzeitanwendungen und vermitteln Hintergründe aus den verschiedensten Bereichen der Mixed Reality, des Storytelling, der Netzwerkkonzeption und der künstlichen Intelligenz.
Alles dreht sich um's Denken im gerade erschienenen Jahresbericht 2014.
Im Interview erörtern Hochschulpräsident Hartmut Ihne und 3Sat-Moderator Gert Scobel den Denkbegriff - "Dürfen wir unsere Autonomie aus freien Stücken an Algorithmen abgeben?".
James Chamberlain, Leiter des Sprachenzentrums der H-BRS, geht der Frage auf den Grund, in wieweit sich das Denken in unterschiedlichen Sprachen unterscheidet.
Professor Paul Plöger vom Fachbereich Informatik erklärt, warum Roboter große Probleme damit haben, komplexe Zusammenhänge in offenen Umgebungen zu verstehen.
Der knapp 90 Seiten starke Jahresbericht verknüpft sein großes Thema mit der enormen Vielfalt von Leben, Forschung und Lehre an der H-BRS und wirft nicht nur einen Blick in die Zukunft der Hochschule.
This book chapter describes application examples of gas chromatography/mass spectrometry and pyrolysis – gas chromatography/mass spectrometry in failure analysis for the identification of chemical materials like mineral oils and nitrile rubber gaskets. Furthermore, failure cases demanding identification of polymers/copolymers in fouling on the compressor wall of a car air conditioner and identification of fouling on the surface of a bearing race from the automotive industry are demonstrated. The obtained analytical results were then used for troubleshooting and remedial action of the technological process.
Annual Report 2013 - 2014
(2015)
An Empirical Evaluation of the Received Signal Strength Indicator for fixed outdoor 802.11 links
(2015)
For the evaluation of the received signal strength indication (RSSI) a different methodology compared to previous publications is introduced in this paper by exploiting a spectral scan feature of recent Qualcomm Atheros WiFi NICs. This method is compared to driver reports and to an industrial grade spectrum analyzer. During the conducted outdoor experiments a decreased scattering of the RSSI compared to previous publications is observed. By applying well-known mathematical tests for normality it is possible to show that the RSSI does not follow a normal distribution in a line-of-sight outdoor environment. The evaluated spectral scan features offers additional possibilities to develop interference classifiers which is an important step for frequency allocation in long-distance 802.11 networks.
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.
The steadily decreasing prices of display technologies and computer graphics hardware contribute to the increasing popularity of multiple-display environments, like large, high-resolution displays. It is therefore necessary that educational organizations give the new generation of computer scientists an opportunity to become familiar with this kind of technology. However, there is a lack of tools that allow for getting started easily. Existing frameworks and libraries that provide support for multi-display rendering are often complex in understanding, configuration and extension. This is critical especially in educational context where the time that students have for their projects is limited and quite short. These tools are also rather known and used in research communities only, thus providing less benefit for future non-scientists. In this work we present an extension for the Unity game engine. The extension allows – with a small overhead – for implementation of applications that are apt to run on both single-display and multi-display systems. It takes care of the most common issues in the context of distributed and multi-display rendering like frame, camera and animation synchronization, thus reducing and simplifying the first steps into the topic. In conjunction with Unity, which significantly simplifies the creation of different kinds of virtual environments, the extension affords students to build mock-up virtual reality applications for large, high-resolution displays, and to implement and evaluate new interaction techniques and metaphors and visualization concepts. Unity itself, in our experience, is very popular among computer graphics students and therefore familiar to most of them. It is also often employed in projects of both research institutions and commercial organizations; so learning it will provide students with qualification in high demand.