Bauhaus University, Weimar

About: Bauhaus University, Weimar is a education organization based out in Weimar, Thüringen, Germany. It is known for research contribution in the topics: Finite element method & Isogeometric analysis. The organization has 1421 authors who have published 2998 publications receiving 104454 citations. The organization is also known as: Bauhaus-Universität Weimar & Hochschule für Architektur und Bauwesen.

Weimar-DM: a highly secure double-length compression function

Abstract: We present Weimar-DM, a double length compression function using two calls to a block cipher with 2n-bit key and n-bit block size to compress a 3n-bit string to a 2n-bit one. For Weimar-DM, we show that for n=128, no adversary asking less than 2n−1.77=2126.23 queries can find a collision with probability greater than 1/2. This is the highest collision security bound ever shown for such a compression function. Even more important, our security analysis is much simpler than that for comparable functions as, e.g., Tandem-DM, Abreast-DM or Hirose-DM. We also give a preimage security analysis of Weimar-DM showing a near-optimal bound of 22n−5=2251 queries. Our security bounds are asymptotically optimal.

Error Analysis of Clay-Rock Water Content Estimation with Broadband High-Frequency Electromagnetic Sensors—Air Gap Effect

Abstract: Broadband electromagnetic frequency or time domain sensor techniques present high potential for quantitative water content monitoring in porous media. Prior to in situ application, the impact of the relationship between the broadband electromagnetic properties of the porous material (clay-rock) and the water content on the frequency or time domain sensor response is required. For this purpose, dielectric properties of intact clay rock samples experimental determined in the frequency range from 1 MHz to 10 GHz were used as input data in 3-D numerical frequency domain finite element field calculations to model the one port broadband frequency or time domain transfer function for a three rods based sensor embedded in the clay-rock. The sensor response in terms of the reflection factor was analyzed in time domain with classical travel time analysis in combination with an empirical model according to Topp equation, as well as the theoretical Lichtenecker and Rother model (LRM) to estimate the volumetric water content. The mixture equation considering the appropriate porosity of the investigated material provide a practical and efficient approach for water content estimation based on classical travel time analysis with the onset-method. The inflection method is not recommended for water content estimation in electrical dispersive and absorptive material. Moreover, the results clearly indicate that effects due to coupling of the sensor to the material cannot be neglected. Coupling problems caused by an air gap lead to dramatic effects on water content estimation, even for submillimeter gaps. Thus, the quantitative determination of the in situ water content requires careful sensor installation in order to reach a perfect probe clay rock coupling.

Algorithms and Corpora for Persian Plagiarism Detection

Abstract: The task of plagiarism detection is to find passages of text-reuse in a suspicious document. This task is of increasing relevance, since scholars around the world take advantage of the fact that information about nearly any subject can be found on the World Wide Web by reusing existing text instead of writing their own. We organized the Persian PlagDet shared task at PAN 2016 in an effort to promote the comparative assessment of NLP techniques for plagiarism detection with a special focus on plagiarism that appears in a Persian text corpus. The goal of this shared task is to bring together researchers and practitioners around the exciting topic of plagiarism detection and text-reuse detection. We report on the outcome of the shared task, which divides into two subtasks: text alignment and corpus construction. In the first subtask, nine teams participated, whereas the best result achieved was a PlagDet score of 0.92. For the second subtask of corpus construction, five teams submitted a corpus, which were evaluated using the systems submitted for the first subtask. The results show that significant challenges remain in evaluating newly constructed corpora.

The interface strength and delamination of fiber-reinforced composites using a continuum modeling approach

Abstract: A closed-form expression of the interface strength between a fiber and a matrix is obtained using a continuum approach based on van der Waals interactions. The explicit solution of the interface delamination of fiber-reinforced composites with functionally graded interphase under three-dimensional load is derived. The present analytical results indicate that the delamination behavior of the fiber-reinforced composites highly depends upon the interphase thickness, the fiber radius, the Young's moduli and Poisson's ratio of the fiber and the matrix. The present analytical solution provides a sufficient support for the later research on the mechanical behaviors of fiber-reinforced composites and finally for developing new micro-composites.