期刊文献+
共找到32,121篇文章
< 1 2 250 >
每页显示 20 50 100
Target Controllability of Multi-Layer Networks With High-Dimensional Nodes
1
作者 Lifu Wang Zhaofei Li +1 位作者 Ge Guo Zhi Kong 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第9期1999-2010,共12页
This paper studies the target controllability of multilayer complex networked systems,in which the nodes are highdimensional linear time invariant(LTI)dynamical systems,and the network topology is directed and weighte... This paper studies the target controllability of multilayer complex networked systems,in which the nodes are highdimensional linear time invariant(LTI)dynamical systems,and the network topology is directed and weighted.The influence of inter-layer couplings on the target controllability of multi-layer networks is discussed.It is found that even if there exists a layer which is not target controllable,the entire multi-layer network can still be target controllable due to the inter-layer couplings.For the multi-layer networks with general structure,a necessary and sufficient condition for target controllability is given by establishing the relationship between uncontrollable subspace and output matrix.By the derived condition,it can be found that the system may be target controllable even if it is not state controllable.On this basis,two corollaries are derived,which clarify the relationship between target controllability,state controllability and output controllability.For the multi-layer networks where the inter-layer couplings are directed chains and directed stars,sufficient conditions for target controllability of networked systems are given,respectively.These conditions are easier to verify than the classic criterion. 展开更多
关键词 high-dimensional nodes inter-layer couplings multi-layer networks target controllability
下载PDF
Hepatitis B Surface Antigen and Hepatitis C Virus Antibodies among Drug Users in Burkina Faso
2
作者 Sylvie Zida Kadari Cissé +13 位作者 Odette Ky-Zerbo Dinanibè Kambiré Serge Théophile Soubeiga Simon Tiendrebéogo Fatou Sissoko Issa Sory Célestine Ki-Toé Solange Dioma Djeneba Zorom Adama Ouédraogo Cedric Dimitri Axon Hien Mahamoudou Sanou Seni Kouanda Henri Gautier Ouédraogo 《Advances in Microbiology》 CAS 2024年第1期92-104,共13页
Introduction: The epidemiology of both hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among drug users (DUs) is little known in West Africa. The study aimed to assess the prevalence of hepatitis B and ... Introduction: The epidemiology of both hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among drug users (DUs) is little known in West Africa. The study aimed to assess the prevalence of hepatitis B and C viruses among drug users in Burkina Faso. Methodology: This was a cross-sectional biological and behavioral survey conducted between June and August 2022, among drug users in Ouagadougou and Bobo Dioulasso, the two main cities of Burkina Faso. A respondent-driven sampling (RDS) was used to recruit drug users. Hepatitis B surface antigen was determined using lateral flow rapid test kits and antibodies to hepatitis C virus in serum determined using an Enzyme-Linked Immunosorbent Assay. Data were entered and analyzed using Stata 17 software. Weighted binary logistic regression was used to identify the associated factors of hepatitis B and C infections and a p-value Results: A total of 323 drug users were recruited with 97.5% males. The mean age was 32.7 years old. The inhaled or smoked mode was the most used by drug users. The adjusted hepatitis B and hepatitis C prevalence among study participants were 11.1% and 2.3% respectively. The marital status (p = 0.001), and the nationality (p = 0.011) were significantly associated with hepatitis B infection. The type of drug used was not significantly associated with hepatitis B infection or hepatitis C infection. Conclusion: The prevalence of HBsAg and anti-HCV antibodies among DUs are comparable to those reported in the general population in Burkina Faso. This result suggests that the main routes of contamination by HBV and HCV among DUs are similar to those in the population, and could be explained by the low use of the injectable route by DUs in Burkina Faso. 展开更多
关键词 Drug users Hepatitis C Hepatitis B PREVALENCE Burkina Faso
下载PDF
Multi-Objective Equilibrium Optimizer for Feature Selection in High-Dimensional English Speech Emotion Recognition
3
作者 Liya Yue Pei Hu +1 位作者 Shu-Chuan Chu Jeng-Shyang Pan 《Computers, Materials & Continua》 SCIE EI 2024年第2期1957-1975,共19页
Speech emotion recognition(SER)uses acoustic analysis to find features for emotion recognition and examines variations in voice that are caused by emotions.The number of features acquired with acoustic analysis is ext... Speech emotion recognition(SER)uses acoustic analysis to find features for emotion recognition and examines variations in voice that are caused by emotions.The number of features acquired with acoustic analysis is extremely high,so we introduce a hybrid filter-wrapper feature selection algorithm based on an improved equilibrium optimizer for constructing an emotion recognition system.The proposed algorithm implements multi-objective emotion recognition with the minimum number of selected features and maximum accuracy.First,we use the information gain and Fisher Score to sort the features extracted from signals.Then,we employ a multi-objective ranking method to evaluate these features and assign different importance to them.Features with high rankings have a large probability of being selected.Finally,we propose a repair strategy to address the problem of duplicate solutions in multi-objective feature selection,which can improve the diversity of solutions and avoid falling into local traps.Using random forest and K-nearest neighbor classifiers,four English speech emotion datasets are employed to test the proposed algorithm(MBEO)as well as other multi-objective emotion identification techniques.The results illustrate that it performs well in inverted generational distance,hypervolume,Pareto solutions,and execution time,and MBEO is appropriate for high-dimensional English SER. 展开更多
关键词 Speech emotion recognition filter-wrapper high-dimensional feature selection equilibrium optimizer MULTI-OBJECTIVE
下载PDF
An Efficient Reliability-Based Optimization Method Utilizing High-Dimensional Model Representation and Weight-Point Estimation Method
4
作者 Xiaoyi Wang Xinyue Chang +2 位作者 Wenxuan Wang Zijie Qiao Feng Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1775-1796,共22页
The objective of reliability-based design optimization(RBDO)is to minimize the optimization objective while satisfying the corresponding reliability requirements.However,the nested loop characteristic reduces the effi... The objective of reliability-based design optimization(RBDO)is to minimize the optimization objective while satisfying the corresponding reliability requirements.However,the nested loop characteristic reduces the efficiency of RBDO algorithm,which hinders their application to high-dimensional engineering problems.To address these issues,this paper proposes an efficient decoupled RBDO method combining high dimensional model representation(HDMR)and the weight-point estimation method(WPEM).First,we decouple the RBDO model using HDMR and WPEM.Second,Lagrange interpolation is used to approximate a univariate function.Finally,based on the results of the first two steps,the original nested loop reliability optimization model is completely transformed into a deterministic design optimization model that can be solved by a series of mature constrained optimization methods without any additional calculations.Two numerical examples of a planar 10-bar structure and an aviation hydraulic piping system with 28 design variables are analyzed to illustrate the performance and practicability of the proposed method. 展开更多
关键词 Reliability-based design optimization high-dimensional model decomposition point estimation method Lagrange interpolation aviation hydraulic piping system
下载PDF
Censored Composite Conditional Quantile Screening for High-Dimensional Survival Data
5
作者 LIU Wei LI Yingqiu 《应用概率统计》 CSCD 北大核心 2024年第5期783-799,共17页
In this paper,we introduce the censored composite conditional quantile coefficient(cC-CQC)to rank the relative importance of each predictor in high-dimensional censored regression.The cCCQC takes advantage of all usef... In this paper,we introduce the censored composite conditional quantile coefficient(cC-CQC)to rank the relative importance of each predictor in high-dimensional censored regression.The cCCQC takes advantage of all useful information across quantiles and can detect nonlinear effects including interactions and heterogeneity,effectively.Furthermore,the proposed screening method based on cCCQC is robust to the existence of outliers and enjoys the sure screening property.Simulation results demonstrate that the proposed method performs competitively on survival datasets of high-dimensional predictors,particularly when the variables are highly correlated. 展开更多
关键词 high-dimensional survival data censored composite conditional quantile coefficient sure screening property rank consistency property
下载PDF
Evaluation of an Autonomous Vehicle User Interface for Sensory Impaired Users
6
作者 Elena Angeleska Linda Lüchtrath Paolo Pretto 《Journal of Transportation Technologies》 2024年第4期570-589,共20页
Autonomous vehicles (AVs) hold immense promises in revolutionizing transportation, and their potential benefits extend to individuals with impairments, particularly those with vision and hearing impairments. However, ... Autonomous vehicles (AVs) hold immense promises in revolutionizing transportation, and their potential benefits extend to individuals with impairments, particularly those with vision and hearing impairments. However, the accommodation of these individuals in AVs requires developing advanced user interfaces. This paper describes an explorative study of a multimodal user interface for autonomous vehicles, specifically developed for passengers with sensory (vision and/or hearing) impairments. In a driving simulator, 32 volunteers with simulated sensory impairments, were exposed to multiple drives in an autonomous vehicle while freely interacting with standard and inclusive variants of the infotainment and navigation system interface. The two user interfaces differed in graphical layout and voice messages, which adopted inclusive design principles for the inclusive variant. Questionnaires and structured interviews were conducted to collect participants’ impressions. The data analysis reports positive user experiences, but also identifies technical challenges. Verified guidelines are provided for further development of inclusive user interface solutions. 展开更多
关键词 Autonomous Vehicles user Interface Inclusive Design Wizard of Oz Simulation
下载PDF
Reform of the Irrigation Sector and Creation of Functional and Sustainable Irrigation Water Users Associations (AUEI) in Niger: Capitalization of the Experience of the Konni AHA
7
作者 Saidou Abdoulkarimou Illou Mahamadou 《Agricultural Sciences》 2024年第2期209-229,共21页
During the 1980s, as part of a policy of liberalization, following budgetary cuts linked to the implementation of structural adjustment programs, management responsibilities for AHAs were transferred from ONAHA to coo... During the 1980s, as part of a policy of liberalization, following budgetary cuts linked to the implementation of structural adjustment programs, management responsibilities for AHAs were transferred from ONAHA to cooperatives concerned. Due to lack of financial resources, but also because of poor management, everywhere in Niger we are witnessing an accelerated deterioration of the irrigation infrastructure of hydro-agricultural developments. Institutional studies carried out on this situation led the State of Niger to initiate a reform of the governance of hydro-agricultural developments, by streng-thening the status of ONAHA, by creating an Association of Irrigation Water Users (AUEI) and by restructuring the old cooperatives. Indeed, this research aims to analyze the creation of functional and sustainable Irrigation Water User Associations (AUEI) in Niger in a context of reform of the irrigation sector, and based on the experience of the Konni AHA. It is based on a methodological approach which takes into account documentary research and the collection of data from 115 farmers, selected by reasoned choice and directly concerned by the management of the irrigated area. The data collected was analyzed and the results were analyzed using the systemic approach and the diagnostic process. The results show that the main mission of the AUEI is to ensure better management of water, hydraulic equipment and infrastructure on the hydro-agricultural developments of Konni. The creation of the Konni AUEI was possible thanks to massive support from the populations and authorities in the implementation process. After its establishment, the AUEI experienced a certain lethargy for some time due to the rehabilitation work of the AHA but currently it is functional and operational in terms of associative life and governance. Thus, the constraints linked to the legal system, the delay in the completion of the work, the uncertainties of access to irrigation water but also the problems linked to the change in mentality of certain ONAHA agents constitute the challenges that must be resolved in the short term for the operationalization of the Konni AUEI. 展开更多
关键词 Konni (Niger) Hydro-Agricultural Developments Association of Irrigation Water users GOVERNANCE
下载PDF
Design Method for Optimizing the Interactive Interface of Live Broadcasting Platform for the Elderly Users
8
作者 WEI Bi-ze FAN Wei DUAN Ying-ke 《印刷与数字媒体技术研究》 CAS 北大核心 2024年第4期167-178,共12页
In the era of network live broadcasting for everyone,the development of live broadcasting platforms is also more intelligent and diversified.However,in the face of a large group of elderly users,the interface interact... In the era of network live broadcasting for everyone,the development of live broadcasting platforms is also more intelligent and diversified.However,in the face of a large group of elderly users,the interface interaction design mode used is still mainly based on the interaction mode for young groups,and is not designed for elderly users.Therefore,a design method for optimizing the interaction interface of live broadcasting platform for elderly users was proposed in this study.Firstly,the case study method and Delphi expert survey method were used to determine the design needs of elderly users and the design mode was analysed.Secondly,the orthogonal design principle was used to design a test sample of the interactive interface of live broadcasting platform applicable for the elderly users,and then a user evaluation system was established to calculate the weights of the design elements using hierarchical analysis,and then the predictive relationship between the design mode of the interactive interface of live broadcasting platform and the elderly users was established by Quantitative Theory I.Finally,Genetic Algorithm was applied to generate the optimized design scheme.The results showed that the design method based on the Genetic Algorithm and the combination of Quantitative Theory can scientifically and effectively optimize the design of the interactive interface of the live broadcasting platform for the elderly users,and improve the experience of the elderly users. 展开更多
关键词 Live broadcasting platform Interaction design Elderly users Genetic Algorithm Quantitative Theory I
下载PDF
Optimal Estimation of High-Dimensional Covariance Matrices with Missing and Noisy Data
9
作者 Meiyin Wang Wanzhou Ye 《Advances in Pure Mathematics》 2024年第4期214-227,共14页
The estimation of covariance matrices is very important in many fields, such as statistics. In real applications, data are frequently influenced by high dimensions and noise. However, most relevant studies are based o... The estimation of covariance matrices is very important in many fields, such as statistics. In real applications, data are frequently influenced by high dimensions and noise. However, most relevant studies are based on complete data. This paper studies the optimal estimation of high-dimensional covariance matrices based on missing and noisy sample under the norm. First, the model with sub-Gaussian additive noise is presented. The generalized sample covariance is then modified to define a hard thresholding estimator , and the minimax upper bound is derived. After that, the minimax lower bound is derived, and it is concluded that the estimator presented in this article is rate-optimal. Finally, numerical simulation analysis is performed. The result shows that for missing samples with sub-Gaussian noise, if the true covariance matrix is sparse, the hard thresholding estimator outperforms the traditional estimate method. 展开更多
关键词 high-dimensional Covariance Matrix Missing Data Sub-Gaussian Noise Optimal Estimation
下载PDF
The Intersection of Privacy by Design and Behavioral Economics: Nudging Users towards Privacy-Friendly Choices
10
作者 Vivek Kumar Agarwal 《Journal of Information Security》 2024年第4期557-563,共7页
This paper conducts a comprehensive review of existing research on Privacy by Design (PbD) and behavioral economics, explores the intersection of Privacy by Design (PbD) and behavioral economics, and how designers can... This paper conducts a comprehensive review of existing research on Privacy by Design (PbD) and behavioral economics, explores the intersection of Privacy by Design (PbD) and behavioral economics, and how designers can leverage “nudges” to encourage users towards privacy-friendly choices. We analyze the limitations of rational choice in the context of privacy decision-making and identify key opportunities for integrating behavioral economics into PbD. We propose a user-centered design framework for integrating behavioral economics into PbD, which includes strategies for simplifying complex choices, making privacy visible, providing feedback and control, and testing and iterating. Our analysis highlights the need for a more nuanced understanding of user behavior and decision-making in the context of privacy, and demonstrates the potential of behavioral economics to inform the design of more effective PbD solutions. 展开更多
关键词 Privacy by Design Behavioral Economics Nudges user-Centric Design Data Protection Cognitive Biases HEURISTICS
下载PDF
Enable Excel-Based Basic Cybersecurity Features for End Users by Using Python-Excel Integration
11
作者 Mohamed Breik Osama Magdy +2 位作者 Essam Amin Tarek Aly Mervat Gheith 《Journal of Software Engineering and Applications》 2024年第6期522-529,共8页
In the digital age, the global character of the Internet has significantly improved our daily lives by providing access to large amounts of knowledge and allowing for seamless connections. However, this enormously int... In the digital age, the global character of the Internet has significantly improved our daily lives by providing access to large amounts of knowledge and allowing for seamless connections. However, this enormously interconnected world is not without its risks. Malicious URLs are a powerful menace, masquerading as legitimate links while holding the intent to hack computer systems or steal sensitive personal information. As the sophistication and frequency of cyberattacks increase, identifying bad URLs has emerged as a critical aspect of cybersecurity. This study presents a new approach that enables the average end-user to check URL safety using Microsoft Excel. Using the powerful VirusTotal API for URL inspections, this study creates an Excel add-in that integrates Python and Excel to deliver a seamless, user-friendly interface. Furthermore, the study improves Excel’s capabilities by allowing users to encrypt and decrypt text communications directly in the spreadsheet. Users may easily encrypt their conversations by simply typing a key and the required text into predefined cells, enhancing their personal cybersecurity with a layer of cryptographic secrecy. This strategy democratizes access to advanced cybersecurity solutions, making attentive digital integrity a feature rather than a daunting burden. 展开更多
关键词 Python End-user Approach EXCEL Excel Add-In CYBERSECURITY URL Check API Virustotal API Encryption Decryption Vigenère Cipher Python-Excel Integration
下载PDF
Survey of HIV Infection among Injection Drug Users in Guangdong, China 被引量:1
12
作者 林鹏 刘勇鹰 +5 位作者 王晔 付笑冰 许锐恒 万卓越 颜瑾 赵茜茜 《Chinese Journal of Sexually Transmitted Infections》 2005年第1期5-9,共5页
Objective: To understand the prevalence and behavioral risk factors of HIV infection among injection drug users in the Pearl River Delta Region (PRDR) of Guangdong province, and to provide evidence for establishing... Objective: To understand the prevalence and behavioral risk factors of HIV infection among injection drug users in the Pearl River Delta Region (PRDR) of Guangdong province, and to provide evidence for establishing effective intervention strategies. Methods: Face to face interviews were conducted and serum samples from injection drug users from detoxification centers and the community were collected for HIV screening. Results: 655 drug users were recruited and interviewed. The HIV seropositive rate was 29.0%. 99.5 % of subjects were injection drug users (IDUs), of whom,75.4% reported sharing injection equipment. Conclusion: HIV prevalence among injection drug users is high in the PRDR of Guangdong. Injection drug use is the principal behavioral risk factor for HIV transmission. Pragmatic harm reduction programs should be implemented to prevent the spread of HIV infection. 展开更多
关键词 HIV/AIDS risk behavior drug users
下载PDF
Study on Guidance of Users’Point of View to Construction of Urban Park in China——Inspiration by "Reflection on Urban Park:Public Space and Multi-culture"
13
作者 王璐艳 刘克成 《Journal of Landscape Research》 2010年第8期14-16,20,共4页
New idea studying urban parks was opened up by "Reflection on Urban Park:Public Space and Multi-culture". By introducing anthropology into planning and design methodology of urban public space, it provided a... New idea studying urban parks was opened up by "Reflection on Urban Park:Public Space and Multi-culture". By introducing anthropology into planning and design methodology of urban public space, it provided a new research method for the planning of urban park in our country. Through introduction and assessment of the book, existing problems and suggestions of the construction of our urban parks were proposed. In the perspective of urban parks' users, by the method of ethnology and anthropology, cultural diversity of urban public space would be investigated, paying attention to the usage behavior and different cultural characteristics, thinking about how to respect ecology and environmental construction of parks and coordinate the relation between culture and ecology while cultural diversity was respected. What should be considered in the construction of urban parks was not only culture but also ecological environment protection when culture was respected and citizens' interests during environment construction. These were also the fundamental problems needed to be considered and solved in parks' planning, construction and operation. 展开更多
关键词 Urban PARK users Planning Culture ECOLOGY
下载PDF
Proxy-Users系统收入分配的Stackelberg模型及解的存在性
14
作者 韩海山 斯琴 《内蒙古民族大学学报(自然科学版)》 2005年第2期121-124,共4页
用对策论的Stackelberg平衡理论研究了Proxy-Users系统中Proxy和Users之间分配收入问题.对Proxy和Users的地位不平等且Proxy不能按到达率提供服务的情况,建立了收入分配的Stackelberg策略模型,得到了一个双层规划模型,并证明了模型的解... 用对策论的Stackelberg平衡理论研究了Proxy-Users系统中Proxy和Users之间分配收入问题.对Proxy和Users的地位不平等且Proxy不能按到达率提供服务的情况,建立了收入分配的Stackelberg策略模型,得到了一个双层规划模型,并证明了模型的解的存在性. 展开更多
关键词 对策 Stackelberg策略 Proxy—users通信系统 双层规划 收入分配
下载PDF
Server-Proxy-Users系统收入分配的对策论模型及解的存在性
15
作者 韩海山 陈荣江 斯琴 《工程数学学报》 CSCD 北大核心 2005年第8期63-66,共4页
用对策论研究了Server-Proxies-Users系统中Server、Proxies和Users之间的收入分配问题,建立了收入分配的对策论模型,得到了三层规划模型。根据三层规划模型的特殊性,把它分解成两个双层规划模型,同时证明了模型的解的存在性。
关键词 对策论 Server-Proxies-users系统 三层规划 收入分配
下载PDF
Server-Agents-Users通信系统的Stackelberg模型
16
作者 韩海山 夏尊铨 《大连理工大学学报》 EI CAS CSCD 北大核心 2004年第3期334-336,共3页
在多媒体通信系统中引入代理服务器,使其成为Server-Agents-Users系统,并用对策论的Stackelberg理论研究该系统.针对Server、Agents和Users地位不平等的情况,建立了该系统的Stackelberg策略模型,得到一个三层规划模型.
关键词 Server-Agents-users通信系统 对策论 Slackelberg策略 三层规划模型 多媒体通信 代理服务器 服务质量
下载PDF
The Research on E-mail Users' Behavior of Participating in Subjects Based on Social Network Analysis 被引量:3
17
作者 ZHANG Lejun ZHOU Tongxin +2 位作者 Qi Zhixin GUO Lin XU Li 《China Communications》 SCIE CSCD 2016年第4期70-80,共11页
The e-mail network is a type of social network. This study analyzes user behavior in e-mail subject participation in organizations by using social network analysis. First, the Enron dataset and the position-related in... The e-mail network is a type of social network. This study analyzes user behavior in e-mail subject participation in organizations by using social network analysis. First, the Enron dataset and the position-related information of an employee are introduced, and methods for deletion of false data are presented. Next, the three-layer model(User, Subject, Keyword) is proposed for analysis of user behavior. Then, the proposed keyword selection algorithm based on a greedy approach, and the influence and propagation of an e-mail subject are defined. Finally, the e-mail user behavior is analyzed for the Enron organization. This study has considerable significance in subject recommendation and character recognition. 展开更多
关键词 E-MAIL NETWORK social NETWORK ANALYSIS user BEHAVIOR ANALYSIS KEYWORD selection
下载PDF
Guaranteed Cost Consensus for High-dimensional Multi-agent Systems With Time-varying Delays 被引量:8
18
作者 Zhong Wang Ming He +2 位作者 Tang Zheng Zhiliang Fan Guangbin Liu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第1期181-189,共9页
Guaranteed cost consensus analysis and design problems for high-dimensional multi-agent systems with time varying delays are investigated. The idea of guaranteed cost con trol is introduced into consensus problems for... Guaranteed cost consensus analysis and design problems for high-dimensional multi-agent systems with time varying delays are investigated. The idea of guaranteed cost con trol is introduced into consensus problems for high-dimensiona multi-agent systems with time-varying delays, where a cos function is defined based on state errors among neighboring agents and control inputs of all the agents. By the state space decomposition approach and the linear matrix inequality(LMI)sufficient conditions for guaranteed cost consensus and consensu alization are given. Moreover, a guaranteed cost upper bound o the cost function is determined. It should be mentioned that these LMI criteria are dependent on the change rate of time delays and the maximum time delay, the guaranteed cost upper bound is only dependent on the maximum time delay but independen of the Laplacian matrix. Finally, numerical simulations are given to demonstrate theoretical results. 展开更多
关键词 Guaranteed cost consensus high-dimensional multi-agent system time-varying delay
下载PDF
Prevalence of hepatitis C infection among intravenous drug users in Shanghai 被引量:3
19
作者 Yan-Lin Tao Yu-Fan Tang +4 位作者 Jian-Ping Qiu Xiao-Feng Cai Xiao-Ting Shen Ya-Xin Wang Xue-Tao Zhao 《World Journal of Gastroenterology》 SCIE CAS 2013年第32期5320-5325,共6页
AIM:To characterize the prevalence of hepatitis C virus(HCV)infection among Chinese intravenous drug users(IDUs).METHODS:A total of 432 adult IDUs(95 women and337 men)in Shanghai were included in the study.The third-g... AIM:To characterize the prevalence of hepatitis C virus(HCV)infection among Chinese intravenous drug users(IDUs).METHODS:A total of 432 adult IDUs(95 women and337 men)in Shanghai were included in the study.The third-generation Elecsys Anti-HCV assay(Roche Diagnostics GmbH,Sandhofer Strasse 116,D-68305,Mannheim,Germany)was used to screen for antibodies against HCV.The RIBA strip,a supplemental antiHCV test with high specificity,was performed on all of the samples that tested positive during the initial screening.All of the anti-HCV positive samples were analyzed with a Cobas TaqMan 48 Analyzer(Roche Diagnostics)for direct detection of HCV RNA.All of the HCV RNA-positive samples were sequenced for genotype determination.RESULTS:The preliminary screening identified 262(60.6%)subjects who were seropositive for HCV.Of the 62 females and 200 males seropositive subjects,16(16.7%)and 65(19.3%),respectively,were confirmed by RIBA,yielding an overall HCV seropositive rate of18.8%.Four female(6.5%)and 14 male(7.0%)subjects tested positive for HCV RNA,indicating an active infection rate of 4.2%for the entire study population.The 18 HCV RNA-positive serum samples were genotyped.Seven individuals were genotype 1b,and four were genotype 1a.One individual each was infected with genotypes 2a,2b and 3a.Four subjects were coinfected with multiple strains:two with genotypes 1a and 2a,and two with genotypes 1b and 2a.The active infection rate among HCV-seropositive individuals was22.2%,which was significantly lower than most estimates.CONCLUSION:The prevalence of HCV is relatively low among IDUs in Shanghai,with a spontaneous recovery rate much higher than previous estimates. 展开更多
关键词 HEPATITIS C Anti-hepatitis C VIRUS ANTIBODIES PREVALENCE of HEPATITIS C VIRUS Active infection rate INTRAVENOUS drug users
下载PDF
USERS′ PERCEPTION OF KOWLOON PARK, HONG KONG:VISITING PATTERNS AND SCENIC ASPECTS 被引量:6
20
作者 WONG Koon-kwai Manfred DOMROES 《Chinese Geographical Science》 SCIE CSCD 2004年第3期269-275,共7页
Hong Kong is a hyper-dense city with 7x10(6) people living in an area of 1100km(2). One way to improve the livability of compacted and congested cities like Hong Kong is through the provision of urban parks, an aspect... Hong Kong is a hyper-dense city with 7x10(6) people living in an area of 1100km(2). One way to improve the livability of compacted and congested cities like Hong Kong is through the provision of urban parks, an aspect that has largely been under-researched. This study focuses on how users perceive and utilize various facilities in the Kowloon Park. The findings revealed that the Kowloon Park is one of the most preferred parks in Hong Kong for both local residents and tourists. Users were quite satisfied with the park's facilities. Notably, the most important component of an urban park is its greenery. This is followed by water elements, seating places, and facilities for various recreational activities. The improvements users would like to see in urban parks include good design and management, meeting users' needs, overcoming barriers to use, and providing a high quality and varied experience for different groups in the community. The findings of this study provide a good basis to address park management issues from the users' perspective. In particular, parks should provide easy access, encourage optimum usage and enable complimentary improvements to the environment. 展开更多
关键词 urban park visiting pattern user perception urban park management
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部