检索结果-内蒙古大学图书馆

Integration of small world networks with multi-agent systems for simulating epidemic spatiotemporal transmission

Chinese Science Bulletin 2010年第13期55卷 1285-1293页

作者： LIU Tao LI Xia LIU XiaoPing School of Geography and Planning Sun Yat-sen University Guangzhou 510275 China

This study proposes an integrated model based on small world network (SWN) and multi-agent system (MAS) for simulating epidemic spatiotemporal transmission. In this model, MAS represents the process of spatiotemporal interactions among individuals, and SWN describes the social relation network among agents. The model is composed of agent attribute definitions, agent movement rules, neighborhoods, construction of social relation network among agents and state transition rules. The construction of social relation network and agent state transition rules is essential for implementing the proposed model. The decay effects of infection "memory", distance and social relation between agents are introduced into the model, which are unavailable in traditional models. The proposed model is used to simulate the transmission process of flu in Guangzhou City based on the swarm software platform. The integration model has better performance than the traditional SEIR model and the pure MAS based epidemic model. This model has been applied to the simulation of the transmission of epidemics in real geographical environment. The simulation can provide useful information for the understanding, prediction and control of the transmission of epidemics.

关键词：小世界网络传播模拟疫情传播网络传输多代理时空统集成综合模型

来源：评论

学校读者我要写书评

暂无评论

Top-Down Gaze Movement Control in Target Search Using Population Cell Coding of Visual Context

引用

IEEE TRANSACTIONS ON AUTONOMOUS MENTAL development 2010年第3期2卷 196-215页

作者： Miao, Jun Qing, Laiyun Zou, Baixian Duan, Lijuan Gao, Wen Chinese Acad Sci Inst Comp Technol Key Lab Intelligent Informat Proc Beijing 100190 Peoples R China Chinese Acad Sci Sch Informat Sci & Engn Grad Univ Beijing 100049 Peoples R China Beijing Union Univ Dept Informat Sci & Technol Coll Arts & Sci Beijing 100083 Peoples R China Beijing Univ Technol Coll Comp Sci & Technol Beijing 100124 Peoples R China Peking Univ Inst Digital Media Beijing 100871 Peoples R China

Visual context plays an important role in humans' top-down gaze movement control for target searching. Exploring the mental development mechanism in terms of incremental visual context encoding by population cells is an interesting issue. This paper presents a biologically inspired computational model. The visual contextual cues were used in this model for top-down eye-motion control on searching targets in images. We proposed a population cell coding mechanism for visual context encoding and decoding. The model was implemented in a neural network system. A developmental learning mechanism was simulated in this system by dynamically generating new coding neurons to incrementally encode visual context during training. The encoded context was decoded with population neurons in a top-down mode. This allowed the model to control the gaze motion to the centers of the targets. The model was developed with pursuing low encoding quantity and high target locating accuracy. Its performance has been evaluated by a set of experiments to search different facial objects in a human face image set. Theoretical analysis and experimental results show that the proposed visual context encoding algorithm without weight updating is fast, efficient and stable, and the population-cell coding generally performs better than single-cell coding and k-nearest-neighbor (k-NN)-based coding.

关键词： Gaze movement control neural encoding and decoding population cell coding target search visual context

来源：评论

学校读者我要写书评

暂无评论

Study on the dehydrogenation kinetics and thermodynamics of Ca(BH₄)₂

引用

JOURNAL OF ALLOYS AND COMPOUNDS 2010年第2期500卷 200-205页

作者： Mao, Jianfeng Guo, Zaiping Poh, Chung Kiak Ranjbar, Abbas Guo, Yanhui Yu, Xuebin Liu, Huakun Univ Wollongong Inst Superconducting & Elect Mat Wollongong NSW 2522 Australia Univ Wollongong Sch Mech Mat & Mechatron Engn Wollongong NSW 2522 Australia Fudan Univ Dept Mat Sci Shanghai 200433 Peoples R China

Ca(BH4)(2) is a promising hydrogen storage material due to its high gravimetric hydrogen density of 11.5 wt%. In this work, the dehydrogenation kinetics and thermodynamics of Ca(BH4)(2) were systematically investigated by differential thermal analysis (DTA), thermal analysis mass spectrometry (TA/MS), temperature-programmed desorption (TPD), X-ray diffraction (XRD) and pressure, composition, and temperature (PCT) measurements. DTA, TA/MS, TPD and XRD results indicate that the dehydrogenation process of Ca(BH4)(2) is a two-step reaction. The dehydriding reaction of Ca(BH4)(2) starts at approximately 320 degrees C, and about 9.6% of hydrogen is desorbed through the two-step reaction. The apparent activation energy (E-a) of about 225.37 and 280.51 kJ/mol for the first-step and second-step dehydrogenation, respectively, were determined by Kissinger's method. The activation energy for the first-step dehydrogenation was further confirmed by the Arrhenius equation. As a result of in-depth kinetic investigations, a geometrical contraction-controlled kinetic mechanism has been identified for the first-step dehydrogenation by analyzing isothermal hydrogen desorption curves with a linear plot method. Finally, the thermodynamic parameters for the dehydrogenation are estimated based on the results of the PCT measurements: enthalpy of reaction Delta H = 87 kJ/mol-H-2, and entropy of reaction Delta S = 158 J/K mol-H-2. The relatively high activation energy and change in enthalpy indicate that a kinetic and thermodynamic barrier needs to be overcome for Ca(BH4)(2) to be suitable as a hydrogen storage material for mobile applications. (C) 2010 Elsevier B.V. All rights reserved.

关键词： Hydrogen storage Ca(BH4)(2) Kinetics Thermodynamics

来源：评论

学校读者我要写书评

暂无评论

development of controllable two-way self-locking mechanism for micro in-pipe robot

Development of controllable two-way self-locking mechanism f...

引用

3rd International Conference on Intelligent Robotics and Applications, ICIRA 2010

作者： Yong, Xue Jian-Zhong, Shang Zi-Rong, Luo Jin-Wei, Qiao Chen, Cheng Department of Mechatronics Engineering National University of Defense Technology Changsha 410073 China

ISBN: (纸本)3642165834

A controllable two-way self-locking mechanism was developed in this paper to improve the tractive ability of inchworm micro In-pipe robot and reverse its moving direction. Firstly, the robot structure was proposed and its relevant locomotive functions were introduced. Then the mechanism was analyzed and its mathematical model was built to deduce the conditions of direction reversing and diameter variation adapting. Finally a robot prototype was developed based on the results derived above, and its related experiments were carried to test these conditions. © 2010 Springer-Verlag.

关键词： Locks (fasteners)

来源：评论

学校读者我要写书评

暂无评论

Novel Antibiotic-Free Plasmid Selection System Based on Complementation of Host Auxotrophy in the NAD De Novo Synthesis Pathway

引用

APPLIED AND ENVIRONMENTAL MICROBIOLOGY 2010年第7期76卷 2295-2303页

作者： Dong, Wei-Ren Xiang, Li-Xin Shao, Jian-Zhong Zhejiang Univ Coll Life Sci Hangzhou 310058 Zhejiang Peoples R China Zhejiang Univ Key Lab Cell & Gene Engn Zhejiang Prov Hangzhou 310058 Zhejiang Peoples R China Zhejiang Univ Key Lab Anim Epidem Etiol & Immunol Prevent Minist Agr Hangzhou 310058 Zhejiang Peoples R China

The use of antibiotic resistance genes in plasmids causes potential biosafety and clinical hazards, such as the possibility of horizontal spread of resistance genes or the rapid emergence of multidrug-resistant pathogens. This paper introduces a novel auxotrophy complementation system that allowed plasmids and host cells to be effectively selected and maintained without the use of antibiotics. An Escherichia coli strain carrying a defect in NAD de novo biosynthesis was constructed by knocking out the chromosomal quinolinic acid phosphoribosyltransferase (QAPRTase) gene. The resistance gene in the plasmids was replaced by the QAPRTase gene of E. coli or the mouse. As a result, only expression of the QAPRTase gene from plasmids can complement and rescue E. coli host cells in minimal medium. This is the first time that a vertebrate gene has been used to construct a nonantibiotic selection system, and it can be widely applied in DNA vaccine and gene therapy. As the QAPRTase gene is ubiquitous in species ranging from bacteria to mammals, the potential environmental biosafety problems caused by horizontal gene transfer can be eliminated.

关键词： OPERATOR-REPRESSOR TITRATION hiGH-LEVEL EXPRESSION ESCHERIChiA-COLI STABLE MAINTENANCE COPY NUMBER VACCINE STRAIN CLONED GENES PRotEIN VECTOR MARKER

来源：评论

学校读者我要写书评

暂无评论

Denial of Service Detection with Hybrid Fuzzy Set Based Feed Forward Neural Network

Denial of Service Detection with Hybrid Fuzzy Set Based Feed...

引用

7th International Symposium on Neural Networks

作者： Wang, Yong Gu, Dawu Wen, Mi Xu, Jianping Li, Haiming Shanghai Univ Elect Power Dept Comp Sci & Technolgy Shanghai 20090 Peoples R China Shanghai Jiao Tong Univ Dept Comp Sci & Technolgy Shanghai 200240 Peoples R China

ISBN: (纸本)9783642133176

The paper presents a Denial of Service (DoS) intrusion detection method with hybrid fuzzy set based feed forward neural network from KDD cup 99 records. The data are pre-processed by fuzzy set, which transform record string attributes to double types and find the data record internal rules. After data pre-process, about 60 percent of selected KDD 99 64633 records are selected for training and each 20 percent for validation and test in the neural network. all the training, validation and test results show 99.6 percent correctly classified cases and only 0.4 percent misclassified cases. The experiment results show that the design is effective.

关键词： Denial of Service Neural Network Fuzzy Set DoS IDS

来源：评论

学校读者我要写书评

暂无评论

Saddlepoint approximation based line sampling method for uncertainty propagation in fuzzy and random reliability analysis

引用

Science china(technological Sciences) 2010年第8期53卷 2252-2260页

作者： LI LuYi,LU ZhenZhou &SONG ShuFang School of Aeronautics,Northwestern Polytechnical University,Xi’an 710072,china 1. School of Aeronautics Northwestern Polytechnical University Xi’an 710072 China

For structural system with random basic variables as well as fuzzy basic variables,uncertain propagation from two kinds of basic variables to the response of the structure is investigated.A novel algorithm for obtaining membership function of fuzzy reliability is presented with saddlepoint approximation(SA)based line sampling *** the presented method,the value domain of the fuzzy basic variables under the given membership level is firstly obtained according to their membership *** the value domain of the fuzzy basic variables corresponding to the given membership level,bounds of reliability of the structure response satisfying safety requirement are obtained by employing the SA based line sampling method in the reduced space of the random *** this way the uncertainty of the basic variables is propagated to the safety measurement of the structure,and the fuzzy membership function of the reliability is *** to the direct Monte Carlo method for propagating the uncertainties of the fuzzy and random basic variables,the presented method can considerably improve computational efficiency with acceptable *** presented method has wider applicability compared to the transformation method,because it doesn't limit the distribution of the variable and the explicit expression of performance function, and no approximation is made for the performance function during the computing ***,the presented method can easily treat the performance function with cross items of the fuzzy variable and the random variable,which isn't suitably approximated by the existing transformation *** examples are provided to illustrate the advantages of the presented method.

关键词： membership function fuzzy reliability fuzzy variable random variable saddlepoint approximation based line sampling method

来源：评论

学校读者我要写书评

暂无评论

Characteristics of nuclease activity of the SbcCD complex from Deinococcus radiodurans

引用

JOURNAL OF BIOCHEMISTRY 2010年第3期147卷 307-315页

作者： Hu, Yihuai Tian, Bing Xu, Guangzhi Yin, Longfei Hua, Xiaoting Lin, Jun Hua, Yuejin Zhejiang Univ Key Lab Chinese Minist Agr Nucl Agr Sci Inst Nucl Agr Sci Hangzhou 310029 Zhejiang Peoples R China Zhejiang Univ Coll Life Sci Hangzhou 310029 Zhejiang Peoples R China Huaiyin Inst Technol Coll Life Sci & Chem Engn Huaian 223001 Peoples R China

The bacterium Deinococcus radiodurans is extremely resistant to the intense ionizing irradiation which causes extensive DNA double-strand breaks (DSBs). The deinococcal SbcCD complex (drSbcCD) is required for DSB repair. The drSbcC and drSbcD genes were cloned and overexpressed in Escherichia coli cells, respectively. The nearly homogeneous drSbcC and drSbcD proteins were purified and reconstituted to form a stable complex in vitro. The drSbcCD complex has an ATP-independent 3'5' exonuclease activity to cleave both dsDNA and ssDNA substrates in the presence of either Mn2+ or Mg2+ ion. The drSbcCD complex also has an ATP-independent endonuclease activity. It can cleave the circular ssDNA, nick the supercoiled circular dsDNA, cleave the 3' flap DNA substrate at the site of the single-strand branch adjacent to duplex DNA, and cleave the hairpin DNA taking no account of the DNA end free or not. It is a kind of secondary structure-specific endonuclease. The drSbcCD complex still has a 3'5' exonuclease activity when the DNA termini are blocked by the proteins. These results suggest that the drSbcCD complex takes part in the metabolism of DNA, and its nuclease activities may play important roles in DNA repair process.

关键词： Deinococcus radiodurans nuclease activity SbcCD

来源：评论

学校读者我要写书评

暂无评论

Characterization of antibodies specific for hemagglutinin and neuraminidase proteins of the 1918 and 2009 pandemic H1N1 viruses

引用

VACCINE 2010年第2期29卷 183-190页

作者： Liu, Yuan Liu, Xiaoqing Fang, Jing Shen, Xiaona Chen, Wei Lin, Xiaojing Li, Huaifang Tan, Wenjie Wang, Yue Zhao, Ping Qi, Zhongtian China Ctr Dis Control & Prevent Natl Inst Viral Dis Control & Prevent State Key Lab Mol Virol & Genet Engn Beijing 100052 Peoples R China Second Mil Med Univ Shanghai Key Lab Med Biodef Dept Microbiol Shanghai 200433 Peoples R China Ctr Dis Control & Prevent Fujian Prov Fuzhou 350001 Fujian Peoples R China Tongji Univ Tongji Hosp Dept Obstet & Gynaecol Shanghai 200065 Peoples R China

Serologic studies have detected protective immunity against 2009 pandemic H1N1 influenza virus (H1N1-2009) in some people. However, further study of preexisting immunity has been complicated by the complexity of the human immunological background. Here, we immunized mice with HA- and NA-encoding plasmids. The cross-neutralizing activity of the anti-HA antisera and the effect of the anti-NA antisera on viral infectivity were evaluated using H1N1-1918- and 2009-pseudotyped particles (pps) and an H1N1-2009 isolate. Antibodies to H1N1-2009 HA (09HA) neutralized pps harboring 09HA or H1N1-1918 HA (18HA): similarly, antibodies to 18HA neutralized pps harboring 18HA or 09HA. Antibodies to 09HA and 18HA also neutralized the H1N1-2009 virus with high efficiency. Antibodies to H1N1-1918 NA (18NA) or H1N1-2009 NA (09NA) both enhanced the infectivity of pps harboring 09NA and 18NA. Although anti-09NA and -18NA antibodies significantly reduced cytopathic effects in multiple-cycle infection assays, conversely, these antibodies enhanced the infectivity of H1N1-2009 in single-cycle infection assays. Our study demonstrates the existence of cross-protection between antibodies against these two antigenically related virus strains and shows that anti-NA antibodies have a dual effect that requires reexamination of their role in human immunity. (C) 2010 Elsevier Ltd. All rights reserved.

关键词： Preexisting immunity Cross-neutralizing Effect of anti-NA antisera

来源：评论

学校读者我要写书评

暂无评论

Combined Effects of Water Quality and Furrow Gradient on Runoff and Soil Erosion in North china

引用

PEDOSPHERE 2010年第1期20卷 35-42页

作者： Li Fa-Hu Zhang Li-Jun State Key Lab Soil Eros & Dryland Farming Loess P Yangling 712100 Shaanxi Peoples R China China Agr Univ Coll Water Resources & Civil Engn Beijing 100083 Peoples R China Changchun Engn Coll Fac Water Resources & Environm Engn Changchun 130012 Jilin Peoples R China

Irrigation-induced soil erosion seriously affects the sustainability of irrigated agriculture. The effects of irrigation water quality and furrow gradient on runoff and soil loss were studied under simulated furrow irrigation in laboratory using a soil collected from an experimental station of china Agricultural University, North china. The experimental treatments were different combinations of irrigation water salt concentrations of 5, 10, 20, and 30 mmol(c) L-1, sodium adsorption ratios (SAR.) of 0.5, 5.0, and 10.0 (mmol(c) L-1)(0.5), and furrow gradients of 1%, 3%, and 5%, with distilled water for irrigation at 3 furrow gradients as controls. The experimental data indicated that total runoff amount, sediment concentration in runoff, and total soil loss amount generally decreased with increasing salt;concentration in irrigation water but increased with its sodicity and furrow gradient. The effects of water quality and furrow gradient on soil loss were greater than those on runoff, and the increase of furrow gradient decreased the influence of water quality on soil loss. When the salt concentration increased from 5 to 30 mmol(c) L-1 at SAR of 10.0 (mmol(c) L-1)(0.5), total runoff amount, sediment concentration, and total soil loss amount decreased by 3.89%, 52.1%, and 53.92%, and 10.57%, 38.86%, and 42.03% at the furrow gradients of 1% and 5%, respectively. However, they respectively increased by 3.37%, 45.34%, and 55.36%, and :3.86%, 10.77%, and 13.91% when SAR, increased from 0.5 to 10.0 (mmol(c) L-1)(0.5) at the salt concentration of 5 mmol(c) L-1. Irrigation water quality and furrow gradient should be comprehensively considered in the planning and management of furrow irrigation practices to decrease soil loss and improve water utilization efficiency.

关键词： salt concentration sediment concentration sodium adsorption ratio (SAR) soil dispersion soil loss

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：