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This article is on a university course called Engineering Conferences. It has been developed by the authors and installed as a mandatory part of the curriculum in three master’s degree programs for engineering students. The participants of the course are postgraduates with different nationalities, mostly German, and different technical backgrounds. They study Mechanical Engineering, Simulation and Experimental Technology, or International Business Engineering. The basic idea of the course concept goes far beyond simply teaching the standards of academic writing and skills for using scientific publications. By using a learnercentered approach, the students get engaged in typical activities around an active attendance of a real conference. Students learn to locate the field of their bachelor thesis or project report in the world of research communities, scientific journals and engineering conferences. They learn about conferences matching their bachelor/project topic. They write a paper complying with common academic standards, submit it to a mock-up conference, and review submissions of their fellow students. Students also produce a poster and have to defend it in a poster session held publicly on the campus. Engineering Conferences is a course on scientific communication and presentation that also aims at the development of other skills and competences needed in the world of modern engineering.
A chatspace was developed that allows conversation with 3D sound using networked streaming in a shared virtual environment. The system provides an interface to advanced audio features, such as a "whisper function" for conveying a confided audio stream. This study explores the use of spatial audio to enhance a user's experience in multiuser virtual environments.
Actors in virtual studio productions are faced with the challenge that they have to interact with invisible virtual objects because these elements are rendered separately and combined with the real image later in the production process. Virtual sets typically use static virtual elements or animated objects with predefined behavior so that actors can practice their performance and errors can be corrected in the post production. With the demand for inexpensive live recording and interactive TV productions, virtual objects will be dynamically rendered at arbitrary positions that cannot be predicted by the actor. Perceptive aids have to be employed to support a natural interaction with these objects. In our work we study the effect of haptic feedback for a simple form of interaction. Actors are equipped with a custom built haptic belt and get vibrotactile feedback during a small navigational task (path following). We present a prototype of a wireless vibrotactile feedback device and a small framework for evaluating haptic feedback in a virtual set environment. Results from an initial pilot study indicate that vibrotactile feedback is a suitable non-visual aid for interaction that is at least comparable to audio-visual alternatives used in virtual set productions.
In this paper we describe a prototypical system for live musical performance in a virtual studio environment. The performer stands in front of the studio camera and interacts with an infrared-laser-based multi-touch device. The final TV image shows the performer interacting with a virtual screen which is augmented in front of herself. To overcome the problem of the performer not seeing this virtual screen in reality, we use a special hexagonal grid to facilitate the performer's awareness of this novel Theremin-like virtual musical instrument.
Refractive power measurements serve as the primary quality standard in the automotive glazing industry. In the light of autonomous driving new optical metrics are becoming more and more popular for specifying optical quality requirements for the windshield. Nevertheless, the link between those quantities and the refractive power needs to be established in order to ensure a holistic requirement profile for the windshield. As a consequence, traceable high-resolution refractive power measurements are still required for the glass quality assessment. Standard measurement systems using Moiré patterns for refractive power monitoring in the automotive industry are highly resolution limited, wherefore they are insufficient for evaluating the camera window area. Consequently, there is a need for more sophisticated refractive power measurement systems that provide a higher spatial resolution. In addition, a calibration procedure has to be developed in order to guarantee for comparability of the measurement results. For increasing the resolution, a measurement setup based on an auto-correlation algorithm is tested in this paper. Furthermore, a calibration procedure is established by using a single reference lens with a nominal refractive power of 100 km-1. For the calibration of the entire measurement range of the system, the lens is tilted by an inclination angle orthogonal to the optical axis. The effective refractive power is then given by the Kerkhof model. By adopting the measurement and calibration procedure presented in this paper, glass suppliers in the automotive industry will be able to detect relevant manufacturing defects within the camera window area more accurately paving the way for a holistic quality assurance of the windshield for future advanced driver-assistance system (ADAS) functionalities. Concurrently, the traceability of the measurement results is ensured by establishing a calibration chain based on a single reference lens, which is traced back to international standards.
Despite the higher uptake of digital media also in older age groups, there are still challenges for people of high ages and with cognitive or motoric problems, which prevent them from learning and using devices like smartphones or tablets. Tangible user interfaces provide an opportunity to connect these people to social media, thereby increasing their digital participation in society and reducing loneliness. In this paper, we discuss the challenges of intergenerational communication and research the opportunities affiliated with tangible technologies to overcome technology barriers for adults of high ages. We present a hybrid system for social media interactions between young smartphone users and their old relatives, who do not use mobile technologies. The system consists of a tangible user interface designed specifically for old adults that connects to a standard mobile messenger service. TAMI was designed in a user-centered process to fulfill the needs of older adults and tested in a longer-term field study with pairs of young and old relatives.
Computational models for the personalized analysis of human femurs contain uncertainties in bone material properties and loads, which affect the simulation results. To quantify the influence we developed a probabilistic framework based on polynomial chaos (PC) that propagates stochastic input variables through any computational model. We considered a stochastic E-ρ relationship and a stochastic hip contact force, representing realistic variability of experimental data. Their influence on the prediction of principal strains (ϵ1 and ϵ3) was quantified for one human proximal femur, including sensitivity and reliability analysis. Large variabilities in the principal strain predictions were found in the cortical shell of the femoral neck, with coefficients of variation of ≈40%. Between 60 and 80% of the variance in ϵ1 and ϵ3 are attributable to the uncertainty in the E-ρ relationship, while ≈10% are caused by the load magnitude and 5-30% by the load direction. Principal strain directions were unaffected by material and loading uncertainties. The antero-superior and medial inferior sides of the neck exhibited the largest probabilities for tensile and compression failure, however all were very small (pf<0.001). In summary, uncertainty quantification with PC has been demonstrated to efficiently and accurately describe the influence of very different stochastic inputs, which increases the credibility and explanatory power of personalized analyses of human proximal femurs.
A 3-stage model of a low pressure steam turbine has been equipped with extensive instrumentation to assess aerodynamic performance and for validation of numerical methods. Emphasis was placed on detailed measurements at the inlet and exit of the last stage guide vane. Two configurations were examined – the first used a guide vane with lean in the last stage and a the second used a guide vane combining both lean and sweep. The experimental results from the two configurations have been compared with data from various design methods, ranging from through-flow to 3D multistage viscous simulations with mixing planes. Despite the challenges in modelling complex rotating blades in a wet steam environment, good agreement between the numerical and experimental results was obtained, and the new stator vane combining lean and sweep achieved the desired increase in reaction at the hub section.
Load Matching and Grid Interaction of Net Zero Energy Buildings. EuroSun Conference 2010, Graz
(2010)
“Net Zero Energy Building” has become a prominent wording to describe the synergy of energy efficient building and renewable energy utilization to reach a balanced energy budget over a yearly cycle. Taking into account the energy exchange with a grid infrastructure overcomes the limitations of seasonal energy storage on-site. Even though the wording “Net Zero Energy Building” focuses on the annual energy balance, large differences may occur between solution sets in the amount of grid interaction needed to reach the goal. The paper reports on the analysis of example buildings concerning the load matching and grid interaction. Indices to describe both issues are proposed and foreseen as part of a harmonized definition framework. The work is part of subtask A of the IEA SHCP Task40/ECBCS Annex 52: “Towards Net Zero Energy Solar Buildings”.
“Net Zero-Energy Building” has become a popular catchphrase to describe the synergy between energy-efficient building and renewable energy utilisation to achieve a balanced energy budget over an annual cycle. Taking into account the energy exchange with a grid overcomes the limitations of energy-autonomous buildings with the need for seasonal energy storage on-site. Although the expression, “Net Zero-Energy Building,” appears in many energy policy documents, a harmonised definition or a standardised balancing method is still lacking. This paper reports on the background and the various effects influencing the energy balance approach. After discussing the national energy code framework in Germany, a harmonised terminology and balancing procedure is proposed. The procedure takes not only the energy balance but also energy efficiency and load matching into account.
Musicians and music professionals are often considered to be expert listeners for listening tests on room acoustics. However, these tests often target acoustic parameters other than those typically relevant in music such as pitch, rhythm, amplitude, or timbre. To assess the expertise in perceiving and understanding room acoustical phenomena, a listening test battery was constructed to measure the perceptual sensitivity and cognitive abilities in the identification of rooms with different reverberation times and different spectral envelopes. Performance in these tests was related to data from the Goldsmiths Musical Sophistication Index, self-reported previous experience in music recording and acoustics, and academic knowledge on acoustics. The data from 102 participants show that sensory and cognitive abilities are both correlated significantly with musical training, analytic listening skills, recording experience, and academic knowledge on acoustics, whereas general interest in and engagement with music do not show any significant correlations. The regression models, using only significantly correlated criteria of musicality and professional expertise, explain only small to moderate amounts (11%–28%) of the variance in the “room acoustic listening expertise” across the different tasks of the battery. Thus, the results suggest that the traditional criteria for selecting expert listeners in room acoustics are only weak predictors of their actual performances.
The study examined whether the extent of negative body-related thoughts and emotions evoked by looking in a mirror can be changed by cognitive-behavioural body image therapy (BIT) and whether any remaining cognitive and affective responses dropped faster after the treatment. Females with eating disorders (n = 17) looked in a mirror for 40 minutes under standardised conditions before and after BIT. A control group (CG) (n = 24) was also exposed to their own bodies twice. Cognitive and affective reactions were assessed four times during the session. Hierarchical Linear Modelling revealed that among eating-disordered patients, the entrance levels of negative thoughts and feelings were lower at post compared to pre-BIT, whereas they remained stable in the CG. The extent of reduction of the remaining body image distress was not changed after the treatment. BIT seems to be a potent treatment of negative emotions and cognitions in an in vivo situation.
The groupuscularization of neo-Nazism in Germany: the case of the Aktionsbüro Norddeutschland
(2004)
Sporting Aces and the Military: Performance, Discipline, and Nationalism in the Fields of Honor
(2009)
Vibrotactile feedback via body-worn vibrating belts is a common means of direction signalization - e.g. for navigational tasks. Consequently such feedback devices are used to guide blind or visually impaired people but can also be used to support other wayfinding tasks - for instance, guiding actors in virtual studio productions. Recent effort has been made to simplify this task by integrating vibrotactile feedback into virtual studio applications. In this work we evaluate the accuracy of an improved direction signalization technique, utilizing a body-worn vibrotactile belt with a limited number of tactors, and compare it to other work. The results from our user study indicate that it is possible to signalize different directions accurately, even with a small number of tactors spaced by 90°.
The soundscape approach highlights the role of situational factors in sound evaluations; however, only a few studies have applied a multi‐domain approach including sound‐related, person‐related, and time‐varying situational variables. Therefore, we conducted a study based on the Experience Sampling Method to measure the relative contribution of a broad range of potentially relevant acoustic and non‐auditory variables in predicting indoor soundscape evaluations. Here we present the comprehensive dataset for which 105 participants reported temporally (rather) stable trait variables such as noise sensitivity, trait affect, and quality of life. They rated 6.594 situations regarding the soundscape standard dimensions, perceived loudness, and the saliency of its sound components and evaluated situational variables such as state affect, perceived control, activity, and location. To complement these subject‐centered data, we additionally crowdsourced object‐centered data by having participants make binaural measurements of each indoor soundscape at their homes using a low‐(self‐)noise recorder. These recordings were used to compute (psycho‐)acoustical indices such as the energetically averaged loudness level, the A‐weighted energetically averaged equivalent continuous sound pressure level, and the A‐weighted five‐percent exceedance level. This complex hierarchical data can be used to investigate time‐varying non‐auditory influences on sound perception and to develop soundscape indicators based on the binaural recordings to predict soundscape evaluations.
This article describes the possibilities and problems that occur using the SteamVR tracking 2.0 system as a camera tracking system in a virtual studio and explains an approach for implementation and calibration within a professional studio environment. The tracking system allows for cost effective deployment. Relevant application fields are also mixed reality recording and streaming of AR and VR experiences.
Forums such as Stack Overflow are used by many software developers to find a solution for a given coding problem. Found solutions, i.e. forum posts containing relevant source code, are utilized in a copy and paste manner. This behavior carries the risk that vulnerabilities contained in the source code of the forum posts are spread. Software developers should be able to identify vulnerable source code at an early stage, thereby preventing copying the corresponding source code. In this paper, we introduce the tool CopypastaVulGuard that identifies vulnerable source code in forum posts and allows software developers to omit the source code by marking the forum posts as dangerous. Our tool consists of a browser extension and a management application capable to address as examples SQL injections, remote code executions and deprecated functions based on a dump of the archive.org Stack Overflow data set. We present an evaluation of our tool's possible impact and relevance considering pros/cons and selected research questions.
Towards a Model of Early Entrepreneurial Education: Appreciation, Facilitation and Evaluation
(2019)
Magnetic Resonance (MR) elastography is a method for measuring tissue elasticity via phase images acquired with an MR scanner. The propagation of periodic mechanical waves through the tissue can be captured by means of a modified phase contrast sequence. These waves are generated with a mechanical oscillator (actuator) and coupled into the tissue through the skin. The actuator must be capable of generating a sinusoidal excitation with excellent phase and amplitude stability, while not disturbing the MR imaging process. In this work, an actuator based on a piezoelectric principle was developed. Based on the imaging evaluation of several material samples, the housing for the piezoelectric ceramic was constructed of aluminum. Smaller parts of the housing were manufactured from brass and titanium to fulfill the mechanical constraints. A lever was used to transfer the oscillation generated by the piezoelectric ceramic to the point of excitation. The lever amplifies the piezoelectric motion, allowing for a more compact design. Three different lever designs were characterized by an acceleration sensor both outside and inside the magnet. It was shown that the rigidity of the lever, as determined by its material and form, was decisive in determining the resonant frequency of the system and therefore the maximum practical frequency of operation. It was also shown that the motion of the oscillator is unaffected by the electromagnetic fields of the MR imager. The final design can be placed directly in the magnet bore within a few centimeters of the tissue volume to be imaged without generating significant artifacts. An amplitude range of 0–1 mm in the frequency range from 0 to over 300 Hz was achieved, sufficient for performing most MR elastography applications. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 239–254, 2002
Differentiable Compound Optics and Processing Pipeline Optimization for End-to-end Camera Design
(2021)
Most modern commodity imaging systems we use directly for photography‐-or indirectly rely on for downstream applications‐-employ optical systems of multiple lenses that must balance deviations from perfect optics, manufacturing constraints, tolerances, cost, and footprint. Although optical designs often have complex interactions with downstream image processing or analysis tasks, today’s compound optics are designed in isolation from these interactions. Existing optical design tools aim to minimize optical aberrations, such as deviations from Gauss’ linear model of optics, instead of application-specific losses, precluding joint optimization with hardware image signal processing (ISP) and highly parameterized neural network processing. In this article, we propose an optimization method for compound optics that lifts these limitations. We optimize entire lens systems jointly with hardware and software image processing pipelines, downstream neural network processing, and application-specific end-to-end losses. To this end, we propose a learned, differentiable forward model for compound optics and an alternating proximal optimization method that handles function compositions with highly varying parameter dimensions for optics, hardware ISP, and neural nets. Our method integrates seamlessly atop existing optical design tools, such as Zemax. We can thus assess our method across many camera system designs and end-to-end applications. We validate our approach in an automotive camera optics setting‐-together with hardware ISP post processing and detection‐-outperforming classical optics designs for automotive object detection and traffic light state detection. For human viewing tasks, we optimize optics and processing pipelines for dynamic outdoor scenarios and dynamic low-light imaging. We outperform existing compartmentalized design or fine-tuning methods qualitatively and quantitatively, across all domain-specific applications tested.
The study “lidA – leben in der Arbeit. German cohort study on work, age and health” was a two-wave panel study funded by the Federal Ministry of Education and Research and examines the relationship between work, health and work participation among aging employees from an interdisciplinary perspective (www.lida-studie.de). The lidA study was carried out by an interdisciplinary consortium consisting of the Institute for Safety Technology at Bergische University Wuppertal, the Institute for Employment Research (IAB), Nuremberg, the Institute of Social Medicine and Health Economics at Otto-von-Guericke-University Magdeburg, the Institute of the History, Philosophy and Ethics of Medicine at Ulm University, infas Institute for Applied Social Sciences, Bonn and the Federal Institute for Occupational Safety and Health (BAuA), Berlin, as an associated partner. lidA contains a representative sample of persons belonging to the 1959 and 1965 birth cohorts and employed on the reference date for sampling, 31 December 2009. They were interviewed personally (CAPI) in 2011 (wave 1; N=6,585) and 2014 (wave 2; N=4,244). The data contain information about work and current employment relationship characteristics, work demands, workloads, subjective health indicators, socioeconomic status, household context and allow both cross-sectional and longitudinal analysis. This dataset is now available as a Scientific Use File for the scientific community via the Research Data Centre of the Federal Employment Agency at the Institute for Employment Research. The report contains information on data collection, data editing, anonymisation and the description of the variables of the two waves.
Employment trajectories of German baby boomers and their effect on statutory pension entitlements
(2016)
Objective Vocational rehabilitation measures support youth and young adults with disabilities to obtain vocational training and to enter the labor market. In Germany, a growing number of young people with psychological disabilities in vocational rehabilitation can be observed. The study at hand focuses on this group and examines their (un-)unemployment biographies before vocational rehabilitation, their access to vocational rehabilitation and identifies their individual challenges within the process of vocational rehabilitation. Methods Using a multi-methods approach, we analyze representative administrative data of the German Federal Employment Agency as well as biographical interviews conducted with young rehabilitants. We compare the population of young rehabilitants with psychological disorders to those with other disabilities in terms of vocational rehabilitation and initial labor market entry in order to get a representative picture about their school to work transitions. Since rehabilitants with psychological disabilities tend to be older than the remaining population, analyses are stratified by age groups. In addition, qualitative in-depth interviews provide an additional and deeper understanding of specific employment barriers youth with psychological disorders have to overcome. Furthermore, the individual perspective gives insight on how the crucial transition from school to work is perceived by the population under study. Results The pathway into vocational rehabilitation of youth with psychological disorders is often characterized by obstacles in their transition from school to work. During rehabilitation, it appears essential to provide psychological stabilization along with vocational training. Although their average level of education is higher than those of other rehabilitants, labor market transition after (often company-external) vocational training challenges many young people with psychological disabilities, leaving many of them with comparatively poor labor market prospects. Conclusions Young persons with psychological disabilities, who come from regular schools or dropped out from regular school or university, seem to find their way to vocational rehabilitation more indirectly. Furthermore, vocational rehabilitation itself is often prolonged for those with psychological disabilities possibly due to a corresponding stabilization process. However, vocational rehabilitation can be a core element within the stabilization process of a psychological disease.
Gender-specific differences in the frequency of depression to the disadvantage of women have been known for decades. In Germany, there is evidence that the prevalence of mental disorders also differs by occupation. The present study investigates whether for women working in male-dominated occupations and for men working in female-dominated occupations is related to depressive symptoms independently from other factors like work stress and work-family conflict. Special attention is paid to gender differences. Moreover, women are distinguished according to their working time (full-time or not). We use data from the first wave of the lidAstudy for our analyses. We make use of the applied Beck Depression Inventory, the effort-reward imbalance scales as well as the work-family conflict scale. Occupational gender segregation is defined as a share of 80 % of men and women per occupation, respectively. For women, the results of the multivariate analyses show an independent relationship between depressive symptoms and working in male-dominated occupations. Furthermore, significant interactions between occupational gender segregation and work stress are observed in both men and women regarding depressive symptoms.
Cliffhanger-VR
(2018)
The audio design for virtual environments includes simulation of acoustical room properties besides specifing sound sources and sinks and their behavior. Virtual environments supporting room reverberation not only gain realism but also provide additional information to the user about surrounding space. Catching the different sound properties by the different spaces requires partitioning the space by the properties of aural spaces. We define soundscape and aural attributes as an application and multimedia content interface. Calculated data on an abstract level is sent to spatialization backends. Part of this research was the implementation of a device driver for the Roland Sound Space Processor. This device not only directionalizes sound sources, but also controls room effects like reverberation.