Showing papers by "Renmin University of China published in 2003"
TL;DR: The prevalence of genital chlamydial and gonococcal infections in China is substantial and patterns of infection by subgroup and behavioral patterns suggest potential avenues for intervention.
Abstract: ContextSexually transmitted diseases are increasing rapidly in China. Surveillance
data imperfectly indicate current prevalence and risk factors.ObjectivesTo estimate the prevalence of genital chlamydial and gonococcal infections
and to describe patterns of infection by subgroup and behavioral patterns.Design, Setting, and ParticipantsA national stratified probability sample of 3426 Chinese individuals
(1738 women and 1688 men) aged 20 to 64 years, who were interviewed between
August 1999 and August 2000, completed a computer-administered survey, and
provided a urine specimen (69% total participation rate).Main Outcome MeasurePositive test result for chlamydial or gonococcal infections.ResultsThe overall prevalence per 100 population of chlamydial infection was
2.6 (95% confidence interval [CI], 1.6-4.1) for women and 2.1 (95% CI, 1.3-3.3)
for men. For gonococcal infection, the overall prevalence per 100 population
was 0.08 (95% CI, 0.02-0.4) for women and 0.02 (95% CI, 0.005-0.1) for men.
Risk factors for chlamydial infection among men aged 20 to 44 years were unprotected
sex with a commercial sex worker (odds ratio [OR], 8.24; 95% CI, 3.51-19.35),
less education (OR, 7.20; 95% CI, 2.31-22.37), and recent sex with their spouse
or other steady partner (OR, 7.73; 95% CI, 2.70-22.10). Among women aged 20
to 44 years, risk factors for chlamydial infection were having less education
(OR, 2.82; 95% CI, 1.01-7.91) and living in a city (OR, 3.46; 95% CI, 1.67-7.18)
or along the southern coast (OR, 2.16; 95% CI, 1.29-3.63) and having a spouse
or other steady sexual partner who earned a high income (OR, 2.85; 95% CI,
1.11-7.29), who socialized often (OR, 2.79; 95% CI, 1.08-7.19), or who traveled
less than 1 week per year (OR, 5.40; 95% CI, 1.44-20.3).ConclusionsThe prevalence of chlamydial infection in China is substantial. The
patterns of infection suggest potential avenues for intervention.
269 citations
TL;DR: Wang et al. as discussed by the authors argue that from the beginning of the reform of restructuring China state-owned enterprises into public listed companies, the concern about the potential loss of state assets made the ownership split into three different type of shares, with only a small fraction of A-shares are tradable, and the state keeps on holding the controlling share stakes.
117 citations
07 Nov 2003
TL;DR: This paper proposes a novel schema-guided approach to the problem of automatic wrapper maintenance, based on the observation that despite various page changes, many important features of the pages are preserved, such as syntactic patterns, annotations, and hyperlinks of the extracted data items.
Abstract: Extracting data from Web pages using wrappers is a fundamental problem arising in a large variety of applications of vast practical interests. There are two main issues relevant to Web-data extraction, namely wrapper generation and wrapper maintenance. In this paper, we propose a novel schema-guided approach to the problem of automatic wrapper maintenance. It is based on the observation that despite various page changes, many important features of the pages are preserved, such as syntactic patterns, annotations, and hyperlinks of the extracted data items. Our approach uses these preserved features to identify the locations of the desired values in the changed pages, and repair wrappers correspondingly by inducing semantic blocks from the HTML tree. Our intensive experiments on real Web sites show that the proposed approach can effectively maintain wrappers to extract desired data with high accuracies.
84 citations
TL;DR: In this paper, returns and volatilities transmission across four emerging stock markets and three developed international markets, Tokyo, London, and New York, were investigated using daily open and close price data from 1994 to 2001.
Abstract: This study investigates returns and volatilities transmission across Greater China's four emerging stock markets and three developed international markets, Tokyo, London, and New York. Using daily open and close price data from 1994 to 2001, we provide empirical evidence that the overnight returns on all the Greater China stock indices can be estimated by using information from at least one of the three developed markets' daytime returns. The contemporaneous return spillovers are in general unidirectional from more advanced major international markets to the Chinese markets. However, split-sample analysis suggests that there is also evidence of bi-directional return spillovers after the 1997 Asian financial crisis. We also find that there are no one-period lagged return spillover effects from the three advanced markets to the Chinese markets, except for Taiwan. Finally, Mainland China's two stock markets are not affected by contemporaneous nor delayed "bad news".
64 citations
TL;DR: In this article, a cheap commercially available and efficient hemicellulase was used to degrade partially N-acetylated chitosan and the degradation was monitored by gel permeation chromatography.
60 citations
TL;DR: In this article, the capability of three models to estimate the evapotranspiration of catchments with complex topography and land-use classification is investigated, and the models are applied to two catchments for several representative years.
Abstract: In large river basins, there may be considerable variations in both climate and land use across the region. The evapotranspiration that occurs over a basin may be drastically different from one part of the region to another. The potential influence of these variations in evapotranspiration estimated for the catchment is weakened by using a spatially based distributed hydrological model in such a study. Areal evapotranspiration is estimated by means of approaches requiring only meteorological data: the combination equation (CE) model and the complementary relationship approach—the complementary relationship areal evapotranspiration (CRAE) and advection–aridity (AA) models. The capability of three models to estimate the evapotranspiration of catchments with complex topography and land-use classification is investigated, and the models are applied to two catchments with different characteristics and scales for several representative years. Daily, monthly, and annual evapotranspiration are estimated with different accuracy. The result shows that the modified CE model may underestimate the evapotranspiration in some cases. The CRAE and AA models seem to be two kinds of effective alternatives for estimating catchment evapotranspiration. Copyright © 2003 John Wiley & Sons, Ltd.
37 citations
09 Sep 2003
TL;DR: This chapter discusses a schema based native XML storage system, and an evaluation of the alternative non-native storage strategies is presented.
Abstract: Publisher Summary This chapter discusses a schema based native XML storage system. The increasing number of XML repositories has provided the impetus to design and develop systems that can store and query XML data efficiently. Research to improve system performance has been largely concentrated on indexing paths and optimizing XML queries. The storage configuration of XML data on disk also has an impact on the efficiency of an XML data management system. Existing XML storage strategies can be classified into two categories: native XML storage and non-native XML storage. The main distinction between them is their data model. The former is based on the XML Data Models such as document object model (DOM), and object exchange model (OEM), while the latter is based on the traditional relational data model, or object-oriented data model. An evaluation of the alternative non-native storage strategies is presented.
32 citations
TL;DR: In this paper, a stochastic model for daily streamflow generation at multiple sites by integrating random occurrences of wet and dry spells is formulated and verified with a case study at Wupper River in Germany.
25 citations
23 citations
TL;DR: In this article, the authors examined Chinese companies that issue both A-shares in mainland China and H-Shares in Hong Kong, and found that H-share exhibit significant exposure to Hong Kong market factors and behave more like Hong Kong stocks than mainland Chinese stocks.
Abstract: We examine Chinese companies that issue both A-shares in mainland China and H-shares in Hong Kong. A-shares are restricted to mainland Chinese investors, while H-shares are available to Hong Kong and international investors. We find that H-shares exhibit significant exposure to Hong Kong market factors and behave more like Hong Kong stocks than mainland Chinese stocks. However, H-shares retain significant exposure to their domestic market and therefore provide foreign investors with diversification opportunities. We find a large time-varying H-share price discount relative to A-shares, and this discount is highly correlated with domestic and foreign market factors and relative market illiquidity.
18 citations
TL;DR: In this paper, runoff data were analyzed from the 21.2 km² Goodwin Creek Experimental Watershed (GCEW) in northern Mississippi to examine watershed response over a range of scales.
Abstract: Runoff data were analyzed from the semihumid 21.2 km² Goodwin Creek Experimental Watershed (GCEW) in northern Mississippi to examine watershed response over a range of scales. Runoff is monitored at the GCEW outlet and in 13 subcatchments, ranging in area from 0.06 to 17.6 km². Previous data-based studies have shown that simple scaling theory fails to describe scaling of flood quantiles in large watersheds, and there is a fundamental change in scaling behavior in semihumid watersheds at an area of approximately 100 km². It has been found that flood quantiles in nearly all subbasins in the GCEW are self-similar as described by simple scaling theory. It has also been found that expected values of peak flows during single runoff events are described by a power law function of catchment area. The primary reasons why flood quantiles are self-similar on Goodwin Creek are that precipitation is relatively uniform over the basin; peak discharges in smaller catchments are highly correlated with rainfall rates; nearly the entire watershed regularly contributes to runoff and; the groundwater table plays little role in runoff production.
TL;DR: This paper focuses on how to support target objects' attainability information when dealing with Location Dependent Queries, and presents the Reachability Graph to index static target objects for supporting attainability.
TL;DR: In this paper, concepts of g-supersolution, g-manrtingale, gsupermartingale are introduced, which are related to BSDE with Brownian motion and Poisson point process, and a strict comparison theorem, monotonic limit theorem related to this type of BSDE are also discussed.
Abstract: Concepts of g-supersolution, g-manrtingale, g-supermartingale are introduced, which are related to BSDE with Brownian motion and Poisson point process. A strict comparison theorem, monotonic limit theorem related to this type of BSDE are also discussed. As an application of these results, a nonlinear Doob-Meyer decomposition theorem is obtained.
01 Sep 2003
TL;DR: Wang et al. as discussed by the authors proposed a new moving objects database model, Discrete Spatio-Temporal Trajectory Based Moving Objects Database (DSTTMOD) model, which represents dynamic attributes of moving objects, including the past, current, and future location information.
Abstract: In this paper, a new moving objects database model – Discrete Spatio-Temporal Trajectory Based Moving Objects Database (DSTTMOD) model, is put forward. Trajectories are used to represent dynamic attributes of moving objects, including the past, current, and future location information. Moving objects can submit moving plans of different length according to their moving patterns. Moreover, they can divide the whole moving plan into multiple sections, and submit each section only when it is about to be used. Different moving objects can set up different threshold to trigger location updates. When a location update occurs to a moving object, not only its future trajectory is updated, but also the corresponding index records are adjusted. The model can support three kinds of queries (point queries, range queries, and K-nearest neighbor (KNN) queries) for location information in not only the near future, but also the far future. In order to evaluate the performance of the DSTTMOD model, a prototype system is developed and a series of experiments are conducted which show promising performance.
03 Nov 2003
TL;DR: A user-friendly interface is provided that allows users to define the schema of the data to be extracted, and specifies mappings from a HTML page to the target schema, and the system can automatically generate an extraction rule to extract data from the page.
Abstract: Extracting data from Web pages using wrappers is a fundamental problem arising in a large variety of applications of vast practical interest. In this paper, we propose a novel schema-guided approach to wrapper generation. We provide a user-friendly interface that allows users to define the schema of the data to be extracted, and specifies mappings from a HTML page to the target schema. Based on the mappings, the system can automatically generate an extraction rule to extract data from the page. Our approach to wrapper generation can significantly reduce the work of human beings in this process. And the user never has to deal with the internal extraction rule, or even familiarity with the details of HTML.
Journal Article•
TL;DR: The making and implementing of strategic decisions involve many sides, which need to be well organized in order to shape an efficient division-cooperation system.
Abstract: The making and implementing of strategic decisions involve many sides, which need be well organized in order to shape an efficient division-cooperation system. Early researches on strategy-managing organizations pay more attention to the implementations and have the idea that structure should follow strategy. While the practical firms do face the relationship that structure follows strategy, the reverse one, which is now an important topic, is also faced.
TL;DR: In this paper, the authors address the little researched topic of cross-cultural differences in college students' use of social support and find that both Israeli and Chinese students rated the importance and availabi...
Abstract: This exploratory study addresses the little researched topic of cross-cultural differences in college students' use of social support. Israeli and Chinese students rated the importance and availabi...
21 Mar 2003
TL;DR: A central problem in good text classification for IF/IR is the high dimensionality of the data and a technique using Rough Sets theory to alleviate this situation is proposed, which locates a minimal set of co-ordinate keywords to distinguish between classes of documents.
Abstract: A central problem in good text classification for IF/IR is the high dimensionality of the data. To cope with this problem, we propose a technique using Rough Sets theory to alleviate this situation. Given corpora of documents and a training set of examples of classified documents, the technique locates a minimal set of co-ordinate keywords to distinguish between classes of documents, reducing the dimensionality of the keyword vectors. Besides, we generate several reduct bases for the classification of new object, hoping that the combination of answers of the multiple reduct bases result in better performance. To get the tidy and effective rules, we use the value reduction as the final rules. This paper describes the proposed technique and provides experimental results.
26 Mar 2003
TL;DR: A novel spatio-temporal index based on PMR quadtree, which is called Future Trajectory Quadtree (FT-Quadtree), which adopts a trajectory segment shared structure and depicts an efficient update algorithm.
Abstract: Recently, more research has been conducted on moving object databases (MOD). Typically, there are three kinds of data for dynamic attributes in MOD, i.e., historical, current and future. Although many index structures have been developed for the former two types of data, there is not much work to deal with the future data. In particular, the problem of index update has not been addressed with efficient methods. This paper proposes a novel spatio-temporal index based on PMR quadtree, which is called Future Trajectory Quadtree (FT-Quadtree). FT-Quadtree adopts a trajectory segment shared structure and depicts an efficient update algorithm. The performance studies have shown that FT-Quadtree has superiority to the traditional one in index maintenance.
TL;DR: In this paper, a research agenda on integrated management and services for urban development records, archives, and information is introduced, which is supported by the National Natural Science Foundation of China.
Abstract: This paper introduces a research agenda on “integrated management and services for urban development records, archives and information”, a national research project supported by the National Natural Science Foundation of China. It discusses seven aspects of the agenda: background to the research, the research aims, the research objectives and questions, focuses and hypothesis of the project, analytical framework and methodology of the project, research plans, and the expected outcomes for the study.
Proceedings Article•
01 Jan 2003TL;DR: A novel schema-guided approach for wrapper maintenance is proposed, called SG-WRAM, which is based on a schema- guided wrapper generation system (SG-WRAP), which can generate a wrapper to extract data from an HTML document to produce an XML document conforming to the user-defined Schema.
Abstract: The World Wide Web has become one of the most important connections to various sources of information. A large proportion of the data is embedded in HTML documents. This language serves the visual presentation of data in Internet browser, but does not provide semantic information for the data presented. This form of data presentation is, therefore, inappropriate for the demands of automated, computer assisted information management system. In particular, if data from different sources needs to be combined, it is necessary to develop special and often complex programs to automate the data extraction. Wrappers are specialized program routines to fulfil such tasks. They automatically extract data from Internet web sites and convert the information into a structured format. As the manual coding of wrappers is timeconsuming and error-prone process, different methods [1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12] have been proposed to automate the wrapper generation process. As a rule, however, a specially developed wrapper is required for each individual data source, because of the different and unique structures of web sites. The WWW is also extremely dynamic and continually evolving, which results in frequent changes in the structures of web documents. Consequently, wrappers may stop working when the structures of the corresponding documents are changed no matter how they have been generated. It is often necessary to constantly update or even completely rewrite existing wrappers, in order to maintain the desired data extraction capabilities. The simplest way to maintain wrappers is to re-create wrappers using the new HTML documents. Obviously, this method is inefficient in that the maintenance depends mostly on the system developers. In this demo, we propose a novel schema-guided approach for wrapper maintenance, called SG-WRAM, which is based on our previous work, a schema-guided wrapper generation system (SG-WRAP[8,9]). SG-WRAP can generate a wrapper to extract data from an HTML document to produce an XML document conforming to the user-defined Schema. Although changes of HTML documents are extremely various, some features of desired information in previous document, e.g. syntactic features, data pattern, notation and underlying schemas are still preserved in the changed one. Syntactic features, data pattern and notation can be easily obtained from schemas, previous rules and extracting results. Therefore, it is feasible to recognize data items in the changed document using these features. Based on these observations, we fulfill the maintenance following four sequential steps. At First, syntactic features, data pattern and notation are obtained from the schema, previous rule and extracted results, then they are used to recognize the data items. After that, they are grouped according to the given schema. Each group is an instance of the given schema. At last, the representative instances are selected to re-induce the extraction rule. We name these four steps as features discovery, item recovery, block configuration and wrapper reparation respectively. Our schema guided method for wrapper maintenance has several unique features comparing to the related work. We make good use of schema, which is given by user during the process of wrapper generation, to assist the procedures of item recovery and block configuration; Our experience with real-life web documents shows that our method can deal with the changes from simple to complex including context shift, structural shift [12] and hybrid changes; In our system, we give different method for simple changes in which condition a part of the rule is disabled and the complex changes in which condition most of the rule is disabled. That makes the re-inducted rule more accurate and complete.
01 Jan 2003
TL;DR: This paper proposes a novel spatio-temporal index based on PMR quadtree, which is called Future Trajectory Quadtree (FT-Quadtree), which adopts a trajectory segment shared structure and depicts an efficient update algorithm.
Abstract: Recently, more research has been conducted on moving object databases (MOD). Typically, there are three kinds of data for dynamic attributes in MOD, i.e., historical, current and future. Although many index structures have been developed for the former two types of data, there is not much work to deal with the future data. In particular, the problem of index update has not been addressed with efficient methods. This paper proposes a novel spatio-temporal index based on PMR quadtree, which is called Future Trajectory Quadtree (FT-Quadtree). FT-Quadtree adopts a trajectory segment shared structure and depicts an efficient update algorithm. The performance studies have shown that FT-Quadtree has superiority to the traditional one in index maintenance.
TL;DR: Based on system dynamics approach, SDMUWEIC model is developed in order to evaluate future dynamics of urban water infrastructure development in China as discussed by the authors, focusing on water infrastructure's dynamic relationships with population increase, economic development, water resources shortage and water conservation practices.
Abstract: Based on system dynamics approach, SDMUWEIC model is developed in order to evaluate future dynamics of urban water infrastructure development in China. Firstly, this paper presents the basic structure and characteristics of the model, focusing on water infrastructure’s dynamic relationships with population increase, economic development, water resources shortage and water conservation practices. Secondly, model veracity and robustness tests based on behavior reproduction and uncertainty analyses are illustrated. Thirdly, based on the model, future patterns of China’s urban water infrastructure investment requirements are simulated, and effectiveness of two different policy scenarios are evaluated. Finally, conclusions and policy implications are drawn, allowing insights into China’s sustainable water infrastructure policies and managements.
TL;DR: Both geographical parameter database and unit population database are able to offer sufficient conditions for quantitative analysis and will have important role in the research fields of data mining (DM), Decision-making Support Systems (DSS), and regional sustainable development.
Abstract: Now GIS is turning into a good tool in handling geographical, economical, and population data, so we can obtain more and more information from these data. On the other hand, in some cases, for a calamity, such as hurricane, earthquake, flood, drought etc., or a decision-making, such as setting up a broadcasting transmitter, building a chemical plant etc., we have to evaluate the total population in the region influenced by a calamity or a project. In this paper, a method is put forward to evaluate the population in such special region. Through exploring the correlation of geographical parameters and the distribution of people in the same region by means of quantitative analysis and qualitative analysis, unit population database (1km × 1km) is established. In this way, estimating the number of people in a special region is capable by adding up the population in every grid involved in this region boundary. The geographical parameters are obtained from topographic database and DEM database on the scale of 1:250 000. The fundamental geographical parameter database covering county administrative boundaries and 1km × 1km grid is set up and the population database at county level is set up as well. Both geographical parameter database and unit population database are able to offer sufficient conditions for quantitative analysis. They will have important role in the research fields of data mining (DM), Decision-making Support Systems (DSS), and regional sustainable development.
TL;DR: In this paper, the relation between the inseparable prime C*-algebras and primitive C *-algesbras was studied, and it was shown that prime AW*-Algebraic C*algebraic structures are all primitive C* algebra structures.
Abstract: The relation between the inseparable prime C*-algebras and primitive C*-algebras is studied, and we prove that prime AW*-algebras are all primitive C*-algebras.
Journal Article•
TL;DR: In this paper, the authors discuss the main factors that affect the regional collocation of land consolidation target in China with regard to the international development trend of land re-arrangement and the nationwide regional distribution of target.
Abstract: Land consolidation is the very important path to realize sustainable land utilization, and its targets include many aspects and many levels. There is different target of land consolidation in different regions. Based on building up the target system of land consolidation, this essay is intended to discuss the main factors that affect the regional collocation of land consolidation target in China with regard to the international development trend of land re-arrangement and the nationwide regional distribution of land re-arrangement target.
01 Jan 2003
TL;DR: Wang et al. as mentioned in this paper defined Confucian philosop hy as the theoretical expounding of Confucians beliefs, which experienced three different stages: the study of confucian classics in the two Han Dynasties, metaphysics in the Wei and Jin dynasties and the idealist philosophy in the Song and Ming Dynas ties.
Abstract: Confucianism is religion whereas Confucian study is not reli gion. The latter is the theorization and systematization of the former. Confucian philosop hy is the theoretical expounding of Confucian beliefs, which experienced three s tages: the study of Confucian classics in the two Han Dynasties, metaphysics in the Wei and Jin dynasties and the idealist philosophy in the Song and Ming Dynas ties.
Journal Article•
TL;DR: In this paper, characteristics of netizens' behaviour in the period of SARS outbreak from three aspects are discussed, i.e., behaviour change, behavior change, and behavior change.
Abstract: The paper discusses characteristics of netizens' behaviour in the period of SARS outbreak from three aspects.
Journal Article•
TL;DR: From the analysis of2000census datas and other datas, the author makes a brief introduction of the situation and the de-development trend of population aging in BeiJing, and find the main features of the old person, then tells us the pressure and the main problems that we have as discussed by the authors.
Abstract: From the analysis of2000census datas and other datas,the author makes a brief introduction of the situation and the de-velopment trend of population aging in BeiJing,and find the main features of the old person,then tells us the pressure and the main problems that we have.
17 Aug 2003
TL;DR: This paper proposes an effective way of data partition, to solve the problem of computing multiple reducts in text classification and maintains the classification accuracy.
Abstract: Text classification based on Rough Sets theory is an effective method for the automatic document classification problem. However, the computing multiple reducts is a problem in this method. When the number of training document is large, it takes much time and large memory for the computation. It is very hard to be applied in the real application system. In this paper, we propose an effective way of data partition, to solve the above problem. It reduces the computing time of generating reducts and maintains the classification accuracy. This paper describes our approach and experimental result.