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18th International Conference on Nuclear Engineering, ICONE18

作者： Jun, Liu Bo, Yan Naibin, Jiang Department of Engineering Mechanics Chongqing University Chongqing 400044 China National Key Laboratory of Science and Technology on Reactor System Design Technology Nuclear Power Institute of China Chengdu Sichuan China

ISBN: (纸本)9780791849330

The determination of crack-opening-area (COA) is very important in the application of LBB technique. A numerical method based on coupled finite element-meshless Galerkin method (FEM/EFG) is proposed to calculate the crack-opening-area of cracked pipes in nuclear power station. By means of the method by which the meshless nodes are used in the vicinity of crack front and the finite elements are applied in remained zone, the resolved domain is numerically discreted. This technique can speed up the set up of the numerical model and improve the computational precise. Based on the displacement field determined by the coupled FEM/EFG, a kind of surface integral method is used to accurately calculate the crack-opening-area. The correctness and validity of the presented method are demonstrated by comparing the COA results of centre-cracked panel under uniform load determined by the presented method with those from theoretic formula. Subsequently the numerical method for cracked panel is employed to calculate the crack-opening-area of nuclear pressure pipe. The numerical COA results are compared with those determined by engineering methods. It is shown that for thick-wall or middle-thick-wall pipes, the COA results obtained by the presented method are more conservative than those by the engineering methods, whereas for thin-wall pipes, the results by the later one are more conservative than those by the former. © 2010 by ASME.

关键词： Numerical methods

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Research on control and operation support integrated system for nuclear power plants

Research on control and operation support integrated system ...

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2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010

作者： Zhi, Chen Yao, Zhang Chen, Deng-Ke Ren, Yu National Key Laboratory of Design Technology of Nuclear Reactor System Nuclear Power Institute of China Chengdu China Department of Nuclear Power Science and Engineering Naval University of Engineering Wuhan China

ISBN: (纸本)9781424479566

At present, the information and control system (I&C) and operation support system (OSS) of the nuclear power plants (NPPs) are designed separately;their structures and functions are independent. So, the compatibility, availability and dependability of them are not desirable, and the comprehensive advantages of them are not to exert fully. In order to resolve these problems, this paper presents a new idea that designing and developing the I&C and the OSS coordinately, so that their structures and functions are integrated. Firstly, this paper reviewed the evolution and application status of the OSS. And then, the realization methods and forms for the integrated system are analyzed. At last, the hierarchy and architecture of the integrated system which have the double-functions of the I&C and OSS is founded. Analysis and study is also carried out in terms of the hierarchy and characteristics of the integrated system. © 2010 IEEE.

关键词： Nuclear power plants

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Generalized coarse-mesh finite difference acceleration for the method of characteristics

Generalized coarse-mesh finite difference acceleration for t...

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International Conference on the Physics of reactors 2010, PHYSOR 2010

作者： Chai, Xiaoming Yao, Dong Wang, Kan National Key Laboratory of Science and Technology on Reactor System Design Technology in China P. O. Box 622-509 Chengdu 610041 China Department of Engineering Physics Tsinghua University Beijing 100084 China

ISBN: (纸本)9781617820014

Based on generalized coarse mesh rebalance (GCMR) method, this paper proposes a new acceleration method for the method of characteristics (MOC) in unstructured meshes: the generalized coarse-mesh finite difference (GCMFD) method. The GCMFD method, which applies equivalent width of coarse mesh to establish the finite difference discretization, can use unstructured coarse meshes composed of adjacent fine meshes to speed up the MOC iteration. The convergence property of the GCMFD method is controlled by width factor. However, the optimal width factor cannot be given a priori. Method of adjusting width factor automatically is proposed in this paper. Finally, the GCMFD method is adopted in the 3-D neutron transport MOC code TCM. Numerical tests show that the GCMFD, using generalized-geometry coarse meshes, can accelerate the MOC iteration with good speedup.

关键词： Iterative methods

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Modeling and Analysis of Novel Integrated Radial Hybrid Magnetic Bearing for Magnetic Bearing Reaction Wheel

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Chinese Journal of Mechanical Engineering 2010年第5期23卷 655-662页

作者： HAN Bangcheng Key Laboratory of Novel Inertial Instrument ＆ Navigation System Technology of Fundamental Science for National Defense Beihang University Beijing 100191 China School of Instrument Science and Opto-electronics Engineering Beihang University Beijing 100191 China

Conventional ball bearing reaction wheel used to control the attitude of spacecraft can＇t absorb the centrifugal force caused by imbalance of the wheel rotor,and there will be a torque spike at zero speed,which seriously influences the accuracy and stability of spacecraft attitude *** with traditional ball-bearing wheel,noncontact and no lubrication are the remarkable features of the magnetic bearing reaction wheel,and which can solve the high precision problems of *** general,two radial magnetic bearings are needed in magnetic bearing wheel,and the design results in a relatively large axial dimension and smaller momentum-to-mass *** this paper,a new type of magnetic bearing reaction wheel（MBRW） is introduced for satellite attitude control,and a novel integrated radial hybrid magnetic bearing（RHMB） with permanent magnet bias is designed to reduce the mass and minimize the size of the MBRW,*** equivalent magnetic circuit model for the RHMB is presented and a solution is *** stiffness model is also presented,including current stiffness,position negative stiffness,as well as tilting current stiffness,tilting angular position negative stiffness,force and moment equilibrium *** design parameters of the RHMB are given according to the requirement of the MBRW with angular momentum of 30 N ？ m ？ s when the rotation speed of rotor reaches to 5 kr/*** nonlinearity of the RHMB is shown by using the characteristic curves of force-control current-position,current stiffness,position stiffness,moment-control current-angular displacement,tilting current stiffness and tilting angular position stiffness considering all the rotor position within the clearance space and the control *** proposed research ensures the performance of the radial magnetic bearing with permanent magnet bias,and provides theory basis for design of the magnetic bearing wheel.

关键词： magnetic bearing reaction wheel radial hybrid magnetic bearing equivalent magnetic circuit current stiffness position negative stiffness tilting current stiffness tilting angular position stiffness

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Loading pattern optimization cooperatively using two new algorithms

Loading pattern optimization cooperatively using two new alg...

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International Conference on the Physics of reactors 2010, PHYSOR 2010

作者： Gong, Zhaohu Wang, Kan Yao, Dong Department of Engineering Physics Tsinghua University Beijing 100084 China National Key Laboratory of Science and Technology on Reactor System Design Technology Nuclear Power Institute of China P.O.Box 622-501 Chengdu Sichuan 610041 China

ISBN: (纸本)9781617820014

Loading pattern optimization (LPO) for a PWR in nuclear power plant contains three parts: fuel assembly location optimization, burnable poison placement optimization, and used fuel assembly orientation optimization. To solve the former two parts, this paper devises an innovative stochastic evolutionary algorithm - Interval Bound Algorithm (IBA), which can optimize fuel assembly location and burnable poison placement together. IBA just uses the fuel assembly's infinite multiplication factor to get rid of unfavorable patterns and to explore new promising solution space. To solve the last part, this paper applies Estimation of Distribution Algorithms (EDAs), which also belong to evolutionary algorithms. These three parts depend on each other, so it is better not to solve them separately. In order to optimize these parts in a coupled way, we use Symbiotic Co-evolutionary Algorithm (SCA) to incorporate IBA and EDAs. This technique could reflect the real optimization process. Based on these algorithms, the corresponding LPO code of IBALPO is developed. To avoid search direction to offset for inconsistency between the LP search code and the design code, IBALPO directly adopts production core design code to evaluate LPs in a parallel computation environment. Finally, this code system is used to solve a realistic reload problem to show its performance. Obtained results have illustrated that IBALPO is efficient and robust. It can find satisfying LPs in two days using 18 CPUs after evaluating about 10000 LPs for a core containing 157 assemblies.

关键词： Nuclear power plants

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Finite element analysis for effects of stochastic properties of particles on ratcheting of SiCP/6061Al composites

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Fuhe Cailiao Xuebao/Acta Materiae Compositae Sinica 2010年第3期27卷 128-133页

作者： Shao Xuejiao Kang, Guozheng Guo, Sujuan Zhang, Juan School of Mechanics and Engineering Southwest Jiaotong University Chengdu 610031 China National Key Laboratory of Science and Technology on Reactor System Design Technology Design of Nuclear Power Institute of China Chengdu 610041 China

Based on the mesoscopic finite element model of particle reinforced composites, the effects of stochastic properties of SiC particles on the ratcheting behavior of SiCP/6061Al composites were numerically analyzed by employing a 3D multi-particulate unit cell and using an advanced cyclic plastic constitutive model. In the simulation, a 3D multi-particle unit cell containing the stochastic particle properties was first generated by the random sequential adsorption (RSA) method, and then the effects of the number of particles, the particle arrangement, shape, size and their stochastic distributions on the ratcheting of the composites were discussed by the numerical simulations. The results show that the smaller the particulate size and the higher the proportion of the particles distributing near the surface of matrix as well as the more the number of particulates contained in the unit cell, the higher the resistance to the ratcheting deformation. Meanwhile, the modeled composite with uniform distribution of particle size and location presents higher resistance to the ratcheting deformation than that with random distribution. The assumptions of spherical particle and its uniform distributions in size and location in the 3D unit cell can provide a reasonable simulation to the ratcheting of the particle reinforced metal matrix composites.

关键词： Finite element method

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Implicit detection of stealth software with a local-booted Virtual machine

Implicit detection of stealth software with a local-booted V...

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3rd International Conference on Information sciences and Interaction sciences, ICIS 2010

作者： Wen, Yan Huang, Minhuan Zhao, Jinjing Kuang, Xiaohui Beijing Institute of System Engineering Beijing China National Key Laboratory of Science and Technology on Information System Security Beijing China Department of Computer Science and Technology Tsinghua University Beijing China

ISBN: (纸本)9781424473854

Resource hiding is commonly used by stealth malware to evade detection by anti-malware scanners. In this paper, we present the design, implementation, and evaluation of Libra, a new VM-based anti-stealth-malware approach. By introducing the novel local-booting technology of our previous work called Secure Virtual Execution Environment, Libra VM just boots from the underlying host OS but not a newly installed OS image. Consequently, Libra accurately reproduces the software environment of the underlying preinstalled OS within the Libra VM. In addition, with proposing a set of unique techniques to implicitly construct the trusted OS-level semantic view of resource from within the virtualized hardware layer, Libra is decoupled with the guest information which is subvertable to the privileged guest malware. Thus, Libra provides a promising way to detect the existing stealth malware in the host OS. We have implemented a prototype of Libra on Windows platforms and our evaluation results with real-world rootkits demonstrate the practicality and effectiveness of our approach.

关键词： Malware

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Intensity model with blur effect on GPUs applied to large-scale star simulators

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Ruan Jian Xue Bao/Journal of Software 2011年第SUPPL. 2期22卷 172-181页

作者： Li, Chao Zhang, Yun-Quan Zheng, Chang-Wen Hu, Xiao-Hui National Key Laboratory of Integrated Information System Technology Institute of Software Chinese Academy of Sciences Beijing 100190 China Laboratory of Parallel Software and Computational Science Institute of Software Chinese Academy of Sciences Beijing 100190 China Graduate University Chinese Academy of Sciences Beijing 100049 China

Intensity model with blur effect is widely employed to accurately simulate the imaging process of star simulator used for attitude determination and guiding feedback. It imposes great demands of computing power for realistic domains, and modern Graphics Processing Units (GPUs) have demonstrated to be a powerful accelerator for this kind of computationally intensive simulations. This paper presents a parallel design and implementation of the intensity model applied to large-scale star simulators on GPUs using the compute unified device architecture (CUDA) programming model. The study analyzes the double parallel nature inherent in this model and use the CUDA framework to efficiently exploit the potential fine-grain data parallelism. Two versions of simulator are designed and studied: One is sequential simulator used as the baseline simulator, and another is parallel simulator using CUDA. In parallel strategy, model, and GPU implementation level, the study employs specific optimized strategies to efficiently improve the parallel performance. Finally, two benchmarks corresponding with the double parallelism are developed to fully evaluate the performance behavior of our simulators. The result analysis demonstrates the efficiency of the CUDA simulators and also illustrates the restriction and bottlenecks presented in this simulator. ©2011 Journal of Software.

关键词： Graphics processing unit

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RETRACTED ARTICLE: The research and development of worm defense strategies

RETRACTED ARTICLE: The research and development of worm defe...

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作者： Liu, Qi Ma, Guoqing State Key Laboratory of Information Security Graduate University Chinese Academy of Science Beijing China National Key Laboratory of Science and Technology on Information System Security Beijing China

ISBN: (纸本)9781424455386

The deterioration of worm propagation on internet in recent years has pushed the research in the field of worm defense, as a result there are coming up plenty of worm defense strategies. This paper refers to make the systematic study of the complete worm defense strategies and provide taxonomy of worm defense system strategies according to the key factors of each defense category. As guideline for the design of worm defense, we compare the present evaluation of the worm defense strategies, and give a highlight on the trendy of worm defense in the future at the end. © 2010 IEEE.

关键词： Network security

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Nodal SP3 method for solving neutron transport equation

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Hedongli Gongcheng/Nuclear Power Engineering 2010年第SUPPL. 2期31卷 73-78+91页

作者： Li, Yun-Zhao Wu, Hong-Chun Cao, Liang-Zhi Yao, Dong School of Nuclear Science and Technology Xi'an Jiaotong University Xi'an 710049 China Science and Technology on Reactor System Design Technology Laboratory Chengdu 610041 China

This paper establishes a nodal method to solve the two coupled equations transformed from the transport equation by SP3 method. In the nodal method, diffusion equation is discretized into average fluxes in the nodes and partial currents on the nodal boundaries. Nodal response relationship is obtained by expanding the detailed nodal flux into a sum of exponential functions. Numerical results demonstrates that the nodal SP3 method can treat polygonal meshes in different shapes with good parallel property, and that it can provide a similar accuracy while runs about six times faster than the nodal-SN (N=4) method DNTR under the same mesh.

关键词： Exponential functions

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