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In this contribution, we describe the activities and promotion programs installed at the Bonn-Rhein-Sieg University as an institution and at the Department of Computer Science respectively for increasing the total number of computer science students and in particular the female rate. We report about our experiences in addressing gender aspects in education and try to evaluate the outcome of our programs with respect to our equal rights for women strategy. We propose a closer look at mental self-theories enabled by E-portfolios to address also gender issues in Computer Science. Moreover, reasons are identified and discussed which may be responsible for the reduced interest in particular of female young adults to choose a computer science study program.
In interactive graphics it is often necessary to introduce large changes in the image in response to updated information about the state of the system. Updating the local state immediately would lead to a sudden transient change in the image, which could be perceptually disruptive. However, introducing the correction gradually using smoothing operations increases latency and degrades precision. It would be beneficial to be able to introduce graphic updates immediately if they were not perceptible. In the paper the use of saccade-contingent updates is exploited to hide graphic updates during the period of visual suppression that accompanies a rapid, or saccadic, eye movement. Sensitivity to many visual stimuli is known to be reduced during a change in fixation compared to when the eye is still. For example, motion of a small object is harder to detect during a rapid eye movement (saccade) than during a fixation. To evaluate if these findings generalize to large scene changes in a virtual environment, gaze behavior in a 180 degree hemispherical display was recorded and analyzed. This data was used to develop a saccade detection algorithm adapted to virtual environments. The detectability of trans-saccadic scene changes was evaluated using images of high resolution real world scenes. The images were translated by 0.4, 0.8 or 1.2 degrees of visual angle during horizontal saccades. The scene updates were rarely noticeable for saccades with a duration greater than 58 ms. The detection rate for the smallest translation was just 6.25%. Qualitatively, even when trans-saccadic scene changes were detectible, they were much less disturbing than equivalent changes in the absence of a saccade.
In this contribution a machine vision inspection system is presented which is designed as a length measuring sensor. It is developed to be applied to a range of heat shrink tubes, varying in length, diameter and color. The challenges of this task were the precision and accuracy demands as well as the real-time applicability of the entire approach since it should be realized in regular industrial line production. In production, heat shrink tubes are cut to specific sizes from a continuous tube. A multi-measurement strategy has been developed, which measures each individual tube segment several times with sub pixel accuracy while being in the visual field. The developed approach allows for a contact-free and fully automatic control of 100% of produced heat shrink tubes according to the given requirements with a measuring precision of 0.1mm. Depending on the color, length and diameter of the tubes considered, a true positive rate of 99.99% to 100% has been reached at a true negative rate of > 99.7.
GL-Wrapper for Stereoscopic Rendering of Standard Applications for a PC-based Immersive Environment
(2007)
In this paper we present an ongoing research work dedicated to a Virtual-Reality-based product customization application development. The work is addressing the problem of flexible and quick customization of products from a great number of parts. Our application is an effective instrument that can be simultaneously used by two users for rapid assembly tasks, allowing engineers and designers to work collaboratively. Furthermore, it is directly connected to a manufacturing environment, which is able to produce the product right after customization. In the paper we describe the architecture of the application, our interaction and assembly techniques, and explain how the system can be integrated into a manufacturing environment.
Video Surveillance is in the center of research due to high importance of safety and security issues. Usually, humans have to monitor an area and often they have to do this for 24 hours a day. Thus, it would be desirable to have automatic surveillance systems that support this job automatically. The system described in this paper is such an automatic surveillance system that has been developed to detect several dangerous situations in a subway station. This paper discusses the high-level module of the system. Herein, an expert system is used to detect events.
A Low-Cost Based 6 DoF Head Tracker for Usability Application Studies in Virtual Environments
(2008)
3D tracking using multiple Nintendo Wii Remotes: a simple consumer hardware tracking approach
(2009)
An easy to build and cost-effective 3D tracking solution is presented, using Nintendo Wii Remotes acting as cameras. As the hardware differs from usual tracking cameras, the calibration and tracking process has to be adapted accordingly. The tracking approach described could be used for tracking the user's motions in video games based upon physical activity (sports, fighting or dancing games), allowing the player to interact with the game in a more intuitive way than by just pressing buttons.
How Does Self-Perception Influence the Choice of Study? E-Portfolio and Gender Issues in Informatics
(2009)
The perceived distance of self motion induced in a stationary observer by optic flow is overestimated (Redlick et al., Vis Res. 2001 41: 213). Here we assessed how different components of translational optic flow contribute to perceived distance traveled. Subjects sat on a stationary bicycle in front of a virtual reality display that extended beyond 90deg on each side. They monocularly viewed a target presented in a virtual hallway wallpapered with stripes that changed colour to prevent tracking individual stripes. Subjects then looked centrally or 30, 60 or 90° eccentrically while their view was restricted to an ellipse with faded edges (25 x 42deg) centered on their fixation. Subjects judged when they had reached the target’s remembered position. Perceptual gain (perceived/actual distance traveled) was highest when subjects were looking in a direction that depended on the simulated speed of motion. Results were modeled as the sum of separate mechanisms sensitive to radial and laminar optic flow. In our display distances were perceived as compressed. However, there was no correlation between perceptual compression and perceived speed of motion. These results suggest that visually induced self motion in virtual displays can be subject to large but predictable error.
This contribution presents an easy to implement 3D tracking approach that works with a single standard webcam. We describe the algorithm and show that it is well suited for being used as an intuitive interaction method in 3D video games. The algorithm can detect and distinguish multiple objects in real-time and obtain their orientation and position relative to the camera. The trackable objects are equipped with planar patterns of five visual markers. By tracking (stereo) glasses worn by the user and adjusting the in-game camera's viewing frustum accordingly, the well-known immersive "screen as a window" effect can be achieved, even without the use of any special tracking equipment.
This contribution describes an optical laser-based user interaction system designed for virtual reality (VR) environments. The project's objective is to realize a 6-DoF user input device for interaction with VR applications running in CAVE-type visualization environments with flat projections walls. In case of a back-projection VR system, in contrast to optical tracking systems, no camera has to be placed within the visualization environment. Instead, cameras observe patterns of laser beam projections from behind the screens. These patterns are emitted by a hand-held input device. The system is robust with respect to partial occlusion of the laser pattern. An inertial measurement unit is integrated into the device in order to improve robustness and precision.
Interactive Distributed Rendering of 3D Scenes on Multiple Xbox 360 Systems and Personal Computers
(2012)
This paper compares the memory allocation of two Java virtual machines, namely Oracle Java HotSpot VM 32-bit (OJVM) and Jamaica JamaicaVM (JJVM). The basic difference of the architectures in both machines is that the JamaicaVM uses fixed-size blocks for allocating objects on the heap. The basic difference of the architectures is that the JJVM uses fixed size block allocation on the heap. This means that objects have to be split into several connected blocks if they are bigger than the specified block-size. On the other hand, for small objects a full block must be allocated. The paper contains both theoretical and experimental analysis on the memory-overhead. The theoretical analysis is based on specifications of the two virtual machines. The experimental analysis is done with a modified JVMTI Agent together with the SPECjvm2008 Benchmark.
Für die prototypische Erstellung von Virtual Reality (VR) Szenen auf Grundlage realer Umgebungen bieten sich Daten aus aktuellen Panorama-Kameras an. Diese Daten eignen sich jedoch nicht unmittelbar für die Integration in eine Game Engine. Wir stellen daher ein projektionsbasiertes Verfahren vor, mit dem Bilder und Videos im Fischaugenformat, wie sie z.B. die 360 Kamera Ricoh Theta erstellt, ohne Konvertierung in Echtzeit mit Hilfe der Unity Game Engine visualisiert werden können. Es wird weiterhin gezeigt, dass ein Panoramabild mit diesem Verfahren leicht manuell um grobe Tiefeninformation erweitert werden kann, sodass bei einer Darstellung in VR ein grober räumlicher Eindruck der Szene für einfach prototypische Umsetzungen ermöglicht wird.
Simulating eye movements for virtual humans or avatars can improve social experiences in virtual reality (VR) games, especially when wearing head mounted displays. While other researchers have already demonstrated the importance of simulating meaningful eye movements, we compare three gaze models with different levels of fidelity regarding realism: (1) a base model with static fixation and saccadic movements, (2) a proposed simulation model that extends the saccadic model with gaze shifts based on a neural network, and (3) a user's real eye movements recorded by a proprietary eye tracker. Our between-groups design study with 42 subjects evaluates impact of eye movements on social VR user experience regarding perceived quality of communication and presence. The tasks include free conversation and two guessing games in a co-located setting. Results indicate that a high quality of communication in co-located VR can be achieved without using extended gaze behavior models besides saccadic simulation. Users might have to gain more experience with VR technology before being able to notice subtle details in gaze animation. In the future, remote VR collaboration involving different tasks requires further investigation.
Traffic simulations for virtual environments are concerned with the behavior of individual traffic participants. The complexity of behavior in these simulations is often rather simple to abide by the constraints of processing resources. In sophisticated traffic simulations, the behavior of individual traffic participants is also modeled, but the focus lies on the overall behavior of the entire system, e.g. to identify possible bottle necks of traffic flow [8].
Integration of Multi-modal Cues in Synthetic Attention Processes to Drive Virtual Agent Behavior
(2017)
Grailog embodies a systematics to visualize knowledge sources by graphical elements. Its main benefit is that the resulting visual presentations are easier to read for humans than the original symbolic source code. In this paper we introduce a methodology to handle the mapping from Datalog RuleML, serialized in XML, to an SVG representation of Grailog, also serialized in XML, via eXtensible Stylesheet Language Transformations (XSLT) 2.0/XML; the SVG is then rendered visually by modern Web browsers. This initial mapping is realized to target Grailog's "fully node copied" normal form. Elements can thus be translated one at a time, separating the fundamental Datalog-to-SVG translation concern from the concern of merging node copies for optimal (hyper)graph layout and avoiding its high computational complexity in this online tool. The resulting open source Grailog Knowledge-Source Visualizer (Grailog KS Viz) supports Datalog RuleML with positional relations of arity n>1. The on-the-fly transformation was shown to run on all recent major Web browsers and should be easy to understand, use, and extend.
Gone But Not Forgotten: Evaluating Performance and Scalability of Real-Time Mesoscopic Agents
(2020)
Traffic simulations are generally used to forecast traffic behavior or to simulate non-player characters in computer games and virual environments. These systems are usually modeled in such a way that traffic rules are strictly followed. However, rule violations are a common part of real-life traffic and thus should be integrated into such models.
A cost-efficient alternative to outside-in tracking systems for pointing interaction with large displays is to equip the pointing device with a camera, whose images are matched to display content. This work presents the Dynamic Marker Camera Tracking (DMCT) framework for display-based camera tracking. It accounts for typical display characteristics and uses dynamic on-screen markers overlaid to the display content that follow the camera. An example marker implementation and a tracking recovery method are presented. DMCT can measure pointing locations with sub-millimeter precision in large tracking volumes and computes 6-DoF camera poses for 3D interaction. 60 Hz update rate and 24 ms latency were achieved. DMCT's main limitation is the visible marker interfering with display content. In pointing effciency, the prototype is comparable to an OptiTrack system.
Realism and plausibility of computer controlled entities in entertainment software have been enhanced by adding both static personalities and dynamic emotions. Here a generic model is introduced that allows findings from real-life personality studies to be transferred to a computational model. Adaptive behavior patterns are enabled by introducing dynamic event-based emotions. The advantages of this model have been validated using a four-way crossroad in a traffic simulation. Driving agents using the introduced model enhanced by dynamics were compared to agents based on static personality profiles and simple rule-based behavior. The results show that adding a dynamic factor to agents improves perceivable plausibility and realism.
Perception is one of the most important cognitive capabilities of an entity since it determines how an entity perceives its environment. The presented work focuses on providing cost efficient but realistic perceptual processes for intelligent virtual agents (IVAs) or NPCs with the goal of providing a sound information basis for the entities' decision making processes. In addition, an agent-central perception process should rovide a common interface for developers to retrieve data from the IVAs' environment. The overall process is evaluated by applying it to a scenario demonstrating its benefits. The evaluation indicates, that such a realistically simulated perception process provides a powerful instrument to enhance the (perceived) realism of an IVA's simulated behavior.
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.
Motion parameters estimation of moving objects and ego motion applying an active camera system
(2004)
Populating virtual worlds with intelligent agents can drastically improve a user's sense of presence. Applying these worlds to virtual training, simulations, or (serious) games, often requires multiple agents to be simulated in real time. The process of generating believable agent behavior starts with providing a plausible perception and attention process that is both efficient and controllable. We describe a conceptual framework for synthetic perception that specifically considers the mentioned requirements: plausibility, real-time performance, and controllability. A sample implementation will focus on sensing, attention, and memory to demonstrate the framework's capabilities in a real-time game engine scenario. A combination of dynamic geometric sensing and false coloring with static saliency information is provided to exemplify the collection of environmental stimuli. The subsequent attention process handles both bottom-up processing and task-oriented, top-down factors. Behavioral results can be influenced by controlling memory and attention The example case is demonstrated and discussed alongside future extensions.
In the presented project, new approaches for the prevention of hand movements leading to hazards and for non-contact detection of fingers are intended to permit comprehensive and economical protection on circular saws. The basic principles may also be applied to other machines with manual loading and/or unloading. Two new detection principles are explained. The first is the distinction between skin and wood or other material by spectral analysis in the near infrared region. Using LED and photodiodes it is possible to detect fingers and hands reliable. With a kind of light curtain the intrusion into the dangerous zone near the blade can be prevented. The second principle is video image processing to detect persons, arms and fingers. In the first stage of development the detection of upper limb extremities within a defined hazard area by means of a computer based video image analysis is investigated.