The Key Laboratory of Urban Security and Disaster Engineering

Beijing, China

The Key Laboratory of Urban Security and Disaster Engineering

Beijing, China
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Jing X.,University of Science and Technology of China | Liu Z.,University of Science and Technology of China | Yang M.,University of Science and Technology of China | Bao Y.,The Key Laboratory of Urban Security and Disaster Engineering
Electronics, Communications and Networks IV - Proceedings of the 4th International Conference on Electronics, Communications and Networks, CECNet2014 | Year: 2015

Remote sensing classification is an effective technical means to obtain ground cover information, and its quality directly influences the application effectiveness of remote sensing data. Therefore, it is very important to research the precision of remote sensing image classification. However, sampling method and sample size have a relatively large impact on accuracy evaluation using the confusion matrix. In the paper, classification uncertainty of remote sensing image was evaluated based on rough set theory. Firstly, the remote sensing image was classified using SVM (Support Vector Machine) method on the basis of image processing. And then the probability vector after classification is used in this paper as the basis in defining upper and lower approximation sets for remote sensing image classification uncertainty evaluation model. Finally, MRED (Modified Rough Entropy Model) is applied to evaluating the uncertainty of classification results. The results showed the MRED measured the classification uncertainty at the scale of land cover classes are more reasonably and accurately. © 2015 Taylor & Francis Group, London.


Li Y.,The Key Laboratory of Urban Security and Disaster Engineering | Yu P.,The Key Laboratory of Urban Security and Disaster Engineering | Liu J.,The Key Laboratory of Urban Security and Disaster Engineering | Li H.,The Key Laboratory of Urban Security and Disaster Engineering
Beijing Gongye Daxue Xuebao/Journal of Beijing University of Technology | Year: 2017

In order to get more suitable hydraulic lime materials for stone and earthen historical relics reinforcement conservation, the slag, admixtures and polyvinyl alcohol fiber modified hydraulic lime mixture proportion optimization design, physical mechanical properties, mechanism of hydration hardening and durability were studied in this paper. The researches show that adding slag, admixtures and polyvinyl alcohol fiber can significantly improve the samples' physical mechanical properties and durability. The flexural strength, compressive strength and pull strength of the modified hydraulic lime sample D had reached at 3.27, 15.45 and 0.61 MPa, respectively. Moreover, after the water, salt and dry-wet cycle tests, the sample D still keeps high mechanical properties, which have important implications for conservation and restoration of the stone and earthen historical relics. © 2017, Editorial Department of Journal of Beijing University of Technology. All right reserved.


Zhang Q.-X.,The Key Laboratory of Urban Security and Disaster Engineering | Zhang Q.-X.,Beijing University of Technology | Li J.-H.,The Key Laboratory of Urban Security and Disaster Engineering | Li J.-H.,Beijing University of Technology
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2010

According to the theoretical and practical experience, the affected areas of destruction soil under the foundation is closer to circular slip surface, further less than the logarithmic spiral of traditional theory. This article assumed that the center of series the arc-shaped sliding surface were in the bottom, then according to the minimum security and stability coefficient, the determined center of a circle at the edge of the base of the foundation is the most dangerous slip surface when the overall instability of the foundation. With limit equilibrium method, the author deduce a new theory formula for calculating the bearing capacity of strip foundation. And it is taken to compare with several existing calculation methods of foundation bearing capacity to evaluate it the legitimacy and applicability of engineering practice.


Li Y.,The Key Laboratory of Urban Security and Disaster Engineering | Li Y.,Beijing University of Technology | Li J.,University of California at Berkeley | Guo H.,The Key Laboratory of Urban Security and Disaster Engineering | Guo H.,Beijing University of Technology
Materials and Design | Year: 2015

Polymethylmethacrylate (PMMA) optical fibers with two types of diameters were uniformly arranged in sulfoaluminate mortar by different methods. Light transmitting sulfoaluminate cement-based materials (LTSCM) were prepared. Optical and mechanical properties of LTSCM were studied. The compressive strength decreased linearly with increasing volume fraction of optical fiber in LTSCM. Compressive strength of specimen after 80. °C water bath was larger than that of specimen under standard curing conditions. According to CCD technology, brightness of optical fiber in different positions of LTSCM can be exhibited clearly. Light transmitting performance of LTSCM was tested by optical power method. Transmittance of specimen decreased with increasing spacing between the detector and specimen. Optical power increased with increasing number of fiber and with increasing diameter of fiber. Transmittance of fiber was weakened due to water bath at high temperature. Voids existed between the fiber and matrix. © 2015 Elsevier Ltd.

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