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.

A Large-scale Analysis of the Mnemonic Password Advice.

Abstract: How to choose a strong but still easily memorable password? An often recommended advice is to memorize a random sentence (the mnemonic) and to concatenate the words’ initials: a so-called mnemonic password. The paper in hand analyzes the effectiveness of this advice—in terms of the obtained password strength—and sheds light on various related aspects. While it is infeasible to obtain a sufficiently large sample of human-chosen mnemonics, the password strength depends only on the distribution of certain character probabilities. We provide several pieces of evidence that these character probabilities are approximately the same for human-chosen mnemonics and sentences from a web crawl and exploit this connection for our analyses. The presented analyses are independent of cracking software, avoid privacy concerns, and allow full control over the details of how passwords are generated from sentences. In particular, the paper introduces the following original research contributions: (1) construction of one of the largest corpora of human-chosen mnemonics, (2) construction of two web sentence corpora from the 27.3 TB ClueWeb12 web crawl, (3) demonstration of the suitability of web sentences as substitutes for mnemonics in password strength analyses, (4) improved estimation of password probabilities by position-dependent language models, and (5) analysis of the obtained password strength using web sentence samples of different sentence complexity and using 18 generation rules for mnemonic password construction. Our findings include both expected and less expected results, among others: mnemonic passwords from lowercase letters only provide comparable strength to mnemonic passwords that exploit the 7-bit visible ASCII character set, less complex mnemonics reduce password strength in offline scenarios by less than expected, and longer mnemonic passwords provide more security in an offline but not necessarily in an online scenario. When compared to passwords generated by uniform sampling from a dictionary, distributions of mnemonic passwords can reach the same strength against offline attacks with less characters.

Managing Urban Resilience: Stream Processing Platform for Responsive Cities

Abstract: Good governance is necessary to make cities resilient and sustainable. To achieve this, we propose the Responsive City, in which citizens, enabled by technology, take on an active role in urban planning processes. Adequate planning of Responsive Cities requires a change and evolvement of the role of policy-makers, government experts, urban planners, and architects. A key factor is hereby the understanding of urban dynamics. In this paper we present a method to model the dynamics of the city from the viewpoint of the urban metabolism as a system of stocks and flows. Understanding these flows helps to identify the main characteristics of the city and advances the knowledge of relationships between different stocks and flows in the system. Big Data can inform and support this process with evidence by taking advantage of behavioural data from infrastructure sensors and crowdsourcing initiatives. They can be overlaid with spatial information in order to respond to events in decreasing time spans by automating the response process partially, which is a necessity for any resilient city management.

An Extended Cell-Based Smoothed Three-Node Mindlin Plate Element (XCS-MIN3) for Free Vibration Analysis of Cracked FGM Plates

Abstract: A cell-based smoothed three-node Mindlin plate element (CS-MIN3) was recently proposed and proven to be robust for static and free vibration analyses of Mindlin plates. The method improves significantly the accuracy of the solution due to softening effect of the cell-based strain smoothing technique. In addition, it is very flexible to apply for arbitrary complicated geometric domains due to using only three-node triangular elements which can be easily generated automatically. However so far, the CS-MIN3 has been only developed for isotropic material and for analyzing intact structures without possessing internal cracks. The paper hence tries to extend the CS-MIN3 by integrating itself with functionally graded material (FGM) and enriched functions of the extended finite element method (XFEM) to give a so-called extended cell-based smoothed three-node Mindlin plate (XCS-MIN3) for free vibration analysis of cracked FGM plates. Three numerical examples with different conditions are solved and compared with previous published results to illustrate the accuracy and reliability of the XCS-MIN3 for free vibration analysis of cracked FGM plates.

Analysis of Building Damage during the 8 October 2005 Earthquake in Pakistan

Abstract: The strongest earthquake in the history of Pakistan jolted the northern region at 08:50 local time (03:50 UTC) 8 October 2005. The epicenter of the earthquake was determined by the U.S. Geological Survey (USGS) to be 34.493°N and 73.629°E. This location is in the northern portion of Muzaffarabad district. It had a magnitude of 7.6 with a depth of 26 km. The earthquake caused extensive damage, destruction, and loss of life over a wide region (almost 30,000-km2) including Muzaffarabad, Mansehra, Batagram, Bagh, and Poonch (see figure 1). The impact of the main shock was felt as far away as Lahore (350 km from epicenter). About 90,000 people died, 79,000 were injured, and more than 3.5 million were rendered homeless. More than 1,200 aftershocks were recorded through 7 November 2005. According to government figures, 19,000 children died in the earthquake, most due to the collapse of school buildings. The earthquake affected more than 500,000 families. More than 400,000 buildings were damaged. The destruction of about 7,000 school buildings and several hospitals caused further difficulties in relief operations and social rehabilitation. Adobe, stone masonry, concrete block masonry, brick masonry, and timber structures are the dominant building types in the region. Reinforced concrete frame structures usually are constructed only in urban areas. Figure 1. Epicenter, most affected area and selected seismic recording station. This article is the outcome of a field visit made just after the event. The field visit was supported by the German Task Force for Earthquakes (GeoForschungsZentrum, Potsdam) and Earthquake Damage Analysis Center (EDAC), Weimar (Maqsood et al. 2006). ### Regional Seismic History Figure 2 shows the past seismicity in and around Pakistan. There was no major event recorded in the recent past in the epicentral area before the 8 October 2005 earthquake. But very high seismic activity was seen after the main event, …

Intelligent Road Inspection with Advanced Machine Learning; Hybrid Prediction Models for Smart Mobility and Transportation Maintenance Systems

Abstract: Prediction models in mobility and transportation maintenance systems have been dramatically improved through using machine learning methods. This paper proposes novel machine learning models for intelligent road inspection. The traditional road inspection systems based on the pavement condition index (PCI) are often associated with the critical safety, energy and cost issues. Alternatively, the proposed models utilize surface deflection data from falling weight deflectometer (FWD) tests to predict the PCI. Machine learning methods are the single multi-layer perceptron (MLP) and radial basis function (RBF) neural networks as well as their hybrids, i.e., Levenberg-Marquardt (MLP-LM), scaled conjugate gradient (MLP-SCG), imperialist competitive (RBF-ICA), and genetic algorithms (RBF-GA). Furthermore, the committee machine intelligent systems (CMIS) method was adopted to combine the results and improve the accuracy of the modeling. The results of the analysis have been verified through using four criteria of average percent relative error (APRE), average absolute percent relative error (AAPRE), root mean square error (RMSE), and standard error (SD). The CMIS model outperforms other models with the promising results of APRE=2.3303, AAPRE=11.6768, RMSE=12.0056, and SD=0.0210.