Unsupervised intrinsic calibration from a single frame using a "plumb-line" approach

in International Conference on Computer Vision (ICCV) (2013, December)

A very good triple of operads

E-print/Working paper (2013)

56. Aktualisierungslieferung - §§ 14, 43, 52b, 62, 64 RStV

Book published by Jehle-Rehm (2013)

Optimization of hard fusion based spectrum sensing for energy-constrained cognitive radio networks

in Physical Communication (2013), 9

The detection reliability of a cognitive radio network improves by employing a cooperative spectrum sensing scheme. However, increasing the number of cognitive radios entails a growth in the cooperation ... [more ▼]

The detection reliability of a cognitive radio network improves by employing a cooperative spectrum sensing scheme. However, increasing the number of cognitive radios entails a growth in the cooperation overhead of the system. Such an overhead leads to a throughput degradation of the cognitive radio network. Since current cognitive radio networks consist of low-power radios, the energy consumption is another critical issue. In this paper, throughput optimization of the hard fusion based sensing using the k-out-of-N rule is considered. We maximize the throughput of the cognitive radio network subject to a constraint on the probability of detection and energy consumption per cognitive radio in order to derive the optimal number of users, the optimal k and the best probability of false alarm. The simulation results based on the IEEE 802.15.4/ZigBee standard, show that the majority rule is either optimal or almost optimal in terms of the network throughput. [less ▲]

Les marques modales dans les chats: étude sémiotique et pragmatique des interjections et des émoticônes dans un corpus de conversations synchrones en ligne

Doctoral thesis (2013)

The purpose of this thesis is to study subjectivity markers in an online chat corpus : interjections and emoticons. First, we will study the semiotic and pragmatic specificities of this type of online ... [more ▼]

The purpose of this thesis is to study subjectivity markers in an online chat corpus : interjections and emoticons. First, we will study the semiotic and pragmatic specificities of this type of online conversation ; then we will propose a semiotic and pragmatic approach of interjections and emoticons. We will show that, even if there are a few differences between those two types of signs – interjections are definitely part of verbal language, whereas emoticons are iconic imitations of gestures and mimics – they share numerous traits. The study of those signs will lead us to wonder about their semiotic status, from icon to index, but also about their pragmatic functions : how they allow to perform, to show instead of describing, how they allow the users to express their subjectivity regarding a propositional content, etc. We hope that this study will contribute to enlarge the knowledge we have of emoticons, but also the views researchers have on the relationships between language and gestures / mimics, which, according to us, should be brought closer, and not further apart. [less ▲]

SNR Estimation for Multi-dimensional Cognitive Receiver under Correlated Channel/Noise

in IEEE Transactions on Wireless Communications (2013), 12(12), 6392-6405

In addition to Spectrum Sensing (SS) capability required by a Cognitive Radio (CR), Signal to Noise Ratio (SNR) estimation of the primary signals at the CR receiver is crucial in order to adapt its ... [more ▼]

In addition to Spectrum Sensing (SS) capability required by a Cognitive Radio (CR), Signal to Noise Ratio (SNR) estimation of the primary signals at the CR receiver is crucial in order to adapt its coverage area dynamically using underlay techniques. In practical scenarios, channel and noise may be correlated due to various reasons and SNR estimation techniques with the assumption of white noise and uncorrelated channel may not be suitable for estimating the primary SNR. In this paper, firstly, we study the performance of different eigenvaluebased SS techniques in the presence of channel or/and noise correlation. Secondly, we carry out detailed theoretical analysis of the signal plus noise hypothesis to derive the asymptotic eigenvalue probability distribution function (a.e.p.d.f.) of the received signal’s covariance matrix under the following two cases: (i) correlated channel and white noise, and (ii) correlated channel and correlated noise, which is the main contribution of this paper. Finally, an SNR estimation technique based on the derived a.e.p.d.f is proposed in the presence of channel/noise correlation and its performance is evaluated in terms of normalized Mean Square Error (MSE). It is shown that the PU SNR can be reliably estimated when the CR sensing module is aware of the channel/noise correlation. [less ▲]

Sprachen und Nationalbewusstsein (1913-1923)

in Scuto, Denis; Lesch, Paul; Steichen, Yves (Eds.) Un Journal dans son siècle (2013)

Suburbaner Raum im Lebenszyklus

Report (2013)

The central part of the study deals with the question of how to approach the temporarily differentiated development dynamics of suburban spaces within a systematic, conceptual analysis framework. The ... [more ▼]

The central part of the study deals with the question of how to approach the temporarily differentiated development dynamics of suburban spaces within a systematic, conceptual analysis framework. The temporal variation and trajectory analysis however remains descriptive in this study, as the method still has not been developed into an autonomous explanatory system. The study concentrates on the integration of the particular phases and cycles into a broader context of the suburban system and - as far as possible - to describe interdependencies of trigger factors as well as of the local and regional framework. This makes the approach different to a static spatial analysis. Those phases contain, in most cases, the Growth, Maturity, Transition and Resiliency. The latter describes the capability of a system to encounter decline or even to reach a development turn. The phases develop into cycles when temporal periodic changes occur, following a certain logic determined by definable factors and strategies. [less ▲]

Improving Portfolio Selection Using Option-Implied Volatility and Skewness

in Journal of Financial and Quantitative Analysis (2013), 48(06), 1813-1845

Our objective in this paper is to examine whether one can use option-implied information to improve the selection of mean-variance portfolios with a large number of stocks, and to document which aspects ... [more ▼]

Our objective in this paper is to examine whether one can use option-implied information to improve the selection of mean-variance portfolios with a large number of stocks, and to document which aspects of option-implied information are most useful to improve their out-of-sample performance. Portfolio performance is measured in terms of volatility, Sharpe ratio, and turnover. Our empirical evidence shows that using option-implied volatility helps to reduce portfolio volatility. Using option-implied correlation does not improve any of the metrics. Using option-implied volatility, risk premium, and skewness to adjust expected returns leads to a substantial improvement in the Sharpe ratio, even after prohibiting short sales and accounting for transaction costs. [less ▲]

Advances in Applied Mechanics

Book published by Elsevier (2013)

Advances in Applied Mechanics draws together recent significant advances in various topics in applied mechanics. Published since 1948, Advances in Applied Mechanics aims to provide authoritative review ... [more ▼]

Advances in Applied Mechanics draws together recent significant advances in various topics in applied mechanics. Published since 1948, Advances in Applied Mechanics aims to provide authoritative review articles on topics in the mechanical sciences, primarily of interest to scientists and engineers working in the various branches of mechanics, but also of interest to the many who use the results of investigations in mechanics in various application areas, such as aerospace, chemical, civil, environmental, mechanical and nuclear engineering. [less ▲]