DigitalNachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
Matthias Huber, D. Dimkova, T. Hamacher
Integration of wind and solar power in Europe: Assessment of flexibility requirements
Energy, vol. 69, no. 1 May 2014, pp. 236-246
2014
DOI: 10.1016/j.energy.2014.02.109
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Flexibility is the ability of a power system to respond to changes in power demand and generation. Integrating large shares of variable renewable energy sources, in particular wind and solar, can lead to a strong increase of flexibility requirements for the complementary system, traditionally hydrothermal, which has to balance the fluctuations of variable generation. We quantify these flexibility requirements at the operational timescale of 1–12 hours and different spatial scales across Europe. Our results indicate that three major factors determine the ramping flexibility needed in future power systems: the penetration of variable renewables, their mix and the geographic system size. Compared to the variability of load, flexibility requirements increase strongly in systems with combined wind and PV (photovoltaics) contribution of more than 30% of total energy and a share of PV in the renewables mix above 20–30%. In terms of extreme ramps, the flexibility requirements of a geographically large, transnational power system are significantly lower than of smaller regional systems, especially at high wind penetration.
GesundEuropan Campus Rottal-InnZeitschriftenartikel
T. Lorenz, Vlaskamp, B. N. S., Anna-Maria Kasparbauer, A. Mörtl, S. Hirche
Dyadic Movement Synchronization While Performing Incongruent Trajectories Requires Mutual Adaptation
Frontiers in Human Neuroscience, no. June
2014
DOI: 10.3389/fnhum.2014.00461
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Unintentional movement synchronization is often emerging between interacting humans. In the present study, we investigate the extent to which the incongruence of movement trajectories has an influence on unintentional dyadic movement synchronization. During a target-directed tapping task, a participant repetitively moved between two targets in front of another participant who performed the same task in parallel but independently. When the movement path of one participant was changed by placing an obstacle between the targets, the degree of their unintentional movement synchronization was measured. Movement synchronization was observed despite of their substantially different movement trajectories. A deeper investigation of the participant's unintentional behavior shows, that although the actor who cleared the obstacle puts unintentional effort in establishing synchrony by increasing movement velocity—the other actor also unintentionally adjusted his/her behavior by increasing dwell times. Results are discussed in the light of joint action, movement interference and obstacle avoidance behavior.
DigitalAngewandte InformatikZeitschriftenartikel
J. Li, Marcus Barkowsky, P. Callet
Visual discomfort of stereoscopic 3D videos: Influence of 3D motion
Displays, vol. 35, no. 1, pp. 49-57
2014
DOI: 10.1016/j.displa.2014.01.002
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Visual discomfort is one of the most frequent complaints of the viewers while watching 3D images and videos. Large disparity and large amount of motion are two main causes of visual discomfort. To quantify this influence, three objectives are set in this paper. The first one is the comparative analysis on the influence of different types of motion, i.e., static stereoscopic image, planar motion and in-depth motion, on visual discomfort. The second one is the investigation on the influence factors for each motion type, for example, the disparity offset, the disparity amplitude and velocity. The third one is to propose an objective model for visual discomfort. Thirty-six synthetic stereoscopic video stimuli with different types of motion are used in this study. In the subjective test, an efficient paired comparison method called Adaptive Square Design (ASD) was used to reduce the number of comparisons for each observer and keep the results reliable. The experimental results showed that motion does not always induce more visual discomfort than static conditions. The in-depth motion generally induces more visual discomfort than the planar motion. The relative disparity between the foreground and the background, and the motion velocity are identified as main factors for visual discomfort. According to the subjective results, an objective model for comparing visual discomfort induced by different types of motion is proposed which shows high correlation with the subjective perception.
DigitalAngewandte InformatikZeitschriftenartikel
P. Le Callet, Marcus Barkowsky
On viewing distance and visual quality assessment in the age of Ultra High Definition TV
VQEG (Video Quality Expert Group) eLetter, vol. 1, no. 1, pp. 25-30
2014
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The consumer video market is largely driven by the introduction of new formats(e.g.,new pixel resolution). Each time,the story remains the same: what is the optimal viewing distance? Ultra High Definition TV is not an exception. This simple question is of crucial importance when it comes to the issue of quality and the added value of a new technology. In this letter, werevisit the topic,starting from bestpractices and then raising open questions.
DigitalAngewandte InformatikZeitschriftenartikel
J. Li, Marcus Barkowsky, P. Le Callet
Validation of reliable 3DTV subjective assessment methodology ‐ Establishing a Ground Truth Database
VQEG (Video Quality Expert Group) eLetter, vol. 1, no. 2
2014
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Quality of Experience (QoE) in 3DTV is a multi-dimensional concept which includes image quality, depth quality, and visual comfort. How to measure this multi-dimensional concept is a challenging issue nowadays. In this letter, we introduce a Ground Truth database which is targeted for the standardization of subjective methodologies for QoE in 3DTV.
DigitalAngewandte InformatikZeitschriftenartikel
Marcus Barkowsky, I. Sedano, K. Brunnström, M. Leszczuk, N. Staelens
Hybrid video quality prediction: reviewing video quality measurement for widening application scope
Multimedia Tools and Applications, vol. 74, pp. 323-343
2014
DOI: 10.1007/s11042-014-1978-2
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A tremendous number of objective video quality measurement algorithms have been developed during the last two decades. Most of them either measure a very limited aspect of the perceived video quality or they measure broad ranges of quality with limited prediction accuracy. This paper lists several perceptual artifacts that may be computationally measured in an isolated algorithm and some of the modeling approaches that have been proposed to predict the resulting quality from those algorithms. These algorithms usually have a very limited application scope but have been verified carefully. The paper continues with a review of some standardized and well-known video quality measurement algorithms that are meant for a wide range of applications, thus have a larger scope. Their individual artifacts prediction accuracy is usually lower but some of them were validated to perform sufficiently well for standardization. Several difficulties and shortcomings in developing a general purpose model with high prediction performance are identified such as a common objective quality scale or the behavior of individual indicators when confronted with stimuli that are out of their prediction scope. The paper concludes with a systematic framework approach to tackle the development of a hybrid video quality measurement in a joint research collaboration.
Angewandte WirtschaftswissenschaftenZeitschriftenartikel
Wolfgang Nagl
Better safe than sorry? The Effects of Income Risk and Unemployment Risk on Wages
Labour: Review of Labour Economics and Industrial Relations, vol. 28, no. 3, pp. 251-268
2014
DOI: 10.1111/labr.12033
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The idea of this paper was developed during a research visit to the University of Bergen. I thank the University of Bergen and especially Kjell Vaage and Espen Bratberg for their great hospitality. I also thank E.ON Ruhrgas for financial support of my research stay in Bergen. Furthermore, I thank Robert Lehmann, Christian Ochsner, Marcel Thum, Michael Weber and the participants of the 2013 Annual Conferences of the Royal Economic Society, the Scottish Economic Society and the European Regional Science Association as well as the participants of the seminars and workshops at the TU Dresden, at the University of Leipzig and at the Ifo Institute for very helpful comments and suggestions.