Asian Agricultural Research(ISSN1943-9903),founded in 2009,is a monthly comprehensive agricultural academic journal published and approved by the Library of Congress of the United States of America.
Recent studies have addressed that the cache be havior is important in the design of main memory index structures. Cache-conscious indices such as the CSB^＋-tree are shown to outperform conventional main memory indic...Recent studies have addressed that the cache be havior is important in the design of main memory index structures. Cache-conscious indices such as the CSB^＋-tree are shown to outperform conventional main memory indices such as the AVL-tree and the T-tree. This paper proposes a cacheconscious version of the T-tree, CST-tree, defined according to the cache-conscious definition. To separate the keys within a node into two parts, the CST-tree can gain higher cache hit ratio.展开更多
Urban air pollution is a prominent problem related to the urban development in China, especially in the densely populated urban agglomerations. Therefore, scientific examination of regional variation of air quality an...Urban air pollution is a prominent problem related to the urban development in China, especially in the densely populated urban agglomerations. Therefore, scientific examination of regional variation of air quality and its dominant factors is of great importance to regional environmental management. In contrast to traditional air pollution researches which only concentrate on a single year or a single pollutant, this paper analyses spatiotemporal patterns and determinants of air quality in disparate regions based on the air quality index(AQI) of the Yangtze River Delta region(YRD) of China from 2014 to 2016. Results show that the annual average value of the AQI in the YRD region decreases from 2014 to 2016 and exhibit a basic characteristic of ‘higher in winter, lower in summer and slightly high in spring and autumn'. The attainment rate of the AQI shows an apparently spatial stratified heterogeneity, Hefei metropolitan area and Nanjing metropolitan area keeping the worst air quality. The frequency of air pollution occurring in large regions was gradually decreasing during the study period. Drawing from entropy method analysis, industrialization and urbanization represented by per capita GDP and total energy consumption were the most important factors. Furthermore, population agglomeration is a factor that cannot be ignored especially in some mega-cities. Limited to data collection, more research is needed to gain insight into the spatiotemporal pattern and influence mechanism in the future.展开更多
The journal of Meteorological and Environmental Research [ISSN: 2152-3940] has been included and stored by the following famous databases: CA, CABI, CSA, EBSCO, UPD, AGRIS, EA, Chinese Science and Technology Periodica...The journal of Meteorological and Environmental Research [ISSN: 2152-3940] has been included and stored by the following famous databases: CA, CABI, CSA, EBSCO, UPD, AGRIS, EA, Chinese Science and Technology Periodical Database, and CNKI, as well as Library of Congress, United States.展开更多
In this paper, we propose a new method based on index to realize IR-style Chinese keyword search with ranking strategies in relational databases. This method creates an index by using the related information of tuple ...In this paper, we propose a new method based on index to realize IR-style Chinese keyword search with ranking strategies in relational databases. This method creates an index by using the related information of tuple words and presents a ranking strategy in terms of the nature of Chinese words. For a Chinese keyword query, the index is used to match query search words and the tuple words in index quickly, and to compute similarities between the query and tuples by the ranking strategy, and then the set of identifiers of candidate tuples is generated. Thus, we retrieve top-N results of the query using SQL selection statements and output the ranked answers according to the similarities. The experimental results show that our method is efficient and effective.展开更多
There are several indexing techniques that can optimize system performances. The choice of the right index type in a schema can improve the DB performances by up to 80%. Unfortunately the illustrations of the various ...There are several indexing techniques that can optimize system performances. The choice of the right index type in a schema can improve the DB performances by up to 80%. Unfortunately the illustrations of the various techniques are scattered over a number of texts and manuals, and the courses for database designers are often somewhat incomplete. The present paper shows a didactical experience which tackles this kind of limitations. In particular, the authors have prepared a textbook that includes twenty-one different index formats; it discusses advantages and disadvantages of each indexing technique, and has been positively validated during advanced courses on relational database design.展开更多
The forest stand database of Bilahe Forestry Bureau, Inner Mongolia of China was taken as an example to demonstrate the whole process of building a temporal geodatabase by means of reengineering. The process was compo...The forest stand database of Bilahe Forestry Bureau, Inner Mongolia of China was taken as an example to demonstrate the whole process of building a temporal geodatabase by means of reengineering. The process was composed of establishing a conceptual data model from the initial database, constructing a logical database by means of mapping, and building a temporal geodatabase with the help of Computer-Aided Software Engineering （CASE） tool and Unified Markup Language （UML）. The results showed that as the reengineered forest stand geodatabase was dynamic, it could easily store the historical data and answer time related questions by Structured Query Language （SQL）, meanwhile, it maintains the integrity of database and eliminates the redundancy.展开更多
Guizhou Province is an important karst area in the world and a fragile ecological area in China. Ecological risk assessment is very necessary to be conducted in this region. This study investigates different character...Guizhou Province is an important karst area in the world and a fragile ecological area in China. Ecological risk assessment is very necessary to be conducted in this region. This study investigates different characteristics of the spatial-temporal changes of vegetation cover in Guizhou Province of Southern China using the data set of SPOT VEGETATION(1999–2015) at spatial resolution of 1-km and temporal resolution of 10-day. The coefficient of variation, the Theil-Sen median trend analysis, and the Mann-Kendall test are used to investigate the spatial-temporal change of vegetation cover and its future trend. Results show that: 1) the spatial distribution pattern of vegetation cover in Guizhou Plateau is high in the east whereas low in the west. The average annual normalized difference vegetation index(NDVI) from west to east is higher than that from south to north. 2) Average annual NDVI improved obviously in the past 17 years. The growth rate of average annual NDVI is 0.028/10 yr, which is slower than that of vegetation in the country(0.048/10 yr) from 1998 to 2007. Average annual NDVI in karst area is lower than that in non-karst area. However, the growing rate of average annual NDVI in karst area(0.030/10 yr) is faster than that in non-karst area(0.023/10 yr), indicating that vegetation coverage increases more rapidly in karst area. 3) Vegetation coverage in the study area is stable overall, but fluctuates in the local scales. 4) Vegetation coverage presents a continuous increasing trend. The Hurst exponent of NDVI in different vegetation types has an obvious threshold in various elevations. 5) The proportion of vegetation cover with sustainable increase is higher than that of vegetation cover with sustainable decrease. The improvement in vegetation cover may expand to most parts of the study area.展开更多
An outsource database is a database service provided by cloud computing companies.Using the outsource database can reduce the hardware and software＇s cost and also get more efficient and reliable data processing capa...An outsource database is a database service provided by cloud computing companies.Using the outsource database can reduce the hardware and software＇s cost and also get more efficient and reliable data processing capacity.However,the outsource database still has some challenges.If the service provider does not have sufficient confidence,there is the possibility of data leakage.The data may has user＇s privacy,so data leakage may cause data privacy leak.Based on this factor,to protect the privacy of data in the outsource database becomes very important.In the past,scholars have proposed k-anonymity to protect data privacy in the database.It lets data become anonymous to avoid data privacy leak.But k-anonymity has some problems,it is irreversible,and easier to be attacked by homogeneity attack and background knowledge attack.Later on,scholars have proposed some studies to solve homogeneity attack and background knowledge attack.But their studies still cannot recover back to the original data.In this paper,we propose a data anonymity method.It can be reversible and also prevent those two attacks.Our study is based on the proposed r-transform.It can be used on the numeric type of attributes in the outsource database.In the experiment,we discussed the time required to anonymize and recover data.Furthermore,we investigated the defense against homogeneous attack and background knowledge attack.At the end,we summarized the proposed method and future researches.展开更多
Background Based on the China-VHD database,this study sought to develop and validate a Valvular Heart Disease-specific Age-adjusted Comorbidity Index(VHD-ACI)for predicting mortality risk in patients with VHD.Methods&...Background Based on the China-VHD database,this study sought to develop and validate a Valvular Heart Disease-specific Age-adjusted Comorbidity Index(VHD-ACI)for predicting mortality risk in patients with VHD.Methods&Results The China-VHD study was a nationwide,multi-centre multi-centre cohort study enrolling 13,917 patients with moderate or severe VHD across 46 medical centres in China between April-June 2018.After excluding cases with missing key variables,11,459 patients were retained for final analysis.The primary endpoint was 2-year all-cause mortality,with 941 deaths(10.0%)observed during follow-up.The VHD-ACI was derived after identifying 13 independent mortality predictors:cardiomyopathy,myocardial infarction,chronic obstructive pulmonary disease,pulmonary artery hypertension,low body weight,anaemia,hypoalbuminaemia,renal insufficiency,moderate/severe hepatic dysfunction,heart failure,cancer,NYHA functional class and age.The index exhibited good discrimination(AUC,0.79)and calibration(Brier score,0.062)in the total cohort,outperforming both EuroSCORE II and ACCI(P<0.001 for comparison).Internal validation through 100 bootstrap iterations yielded a C statistic of 0.694(95%CI:0.665−0.723)for 2-year mortality prediction.VHD-ACI scores,as a continuous variable(VHD-ACI score:adjusted HR(95%CI):1.263(1.245-1.282),P<0.001)or categorized using thresholds determined by the Yoden index(VHDACI≥9 vs.<9,adjusted HR(95%CI):6.216(5.378-7.184),P<0.001),were independently associated with mortality.The prognostic performance remained consistent across all VHD subtypes(aortic stenosis,aortic regurgitation,mitral stenosis,mitral regurgitation,tricuspid valve disease,mixed aortic/mitral valve disease and multiple VHD),and clinical subgroups stratified by therapeutic strategy,LVEF status(preserved vs.reduced),disease severity and etiology.Conclusion The VHD-ACI is a simple 13-comorbidity algorithm for the prediction of mortality in VHD patients and providing a simple and rapid tool for risk stratification.展开更多
Interpretation results of RS images were taken as the foundation, ETM RS images of July 15, 2009 as the data source, ENVI was applied for the preprocessing, Arc GIS used to finish the interpretation, master data obtai...Interpretation results of RS images were taken as the foundation, ETM RS images of July 15, 2009 as the data source, ENVI was applied for the preprocessing, Arc GIS used to finish the interpretation, master data obtained, and VB used to complete program development. 12 representative landscape pattern indexes were selected, Excel data used to create Access database, and VB used to complete the program development. Selection of landscape pattern indexes, program development process and program usage were summarized, through comparing its results with Excel calculation results, it was found that calculation results of this program were correct, the usage was convenient, so needs of most users could be satisfied.展开更多
Frontiers of Nursing is a nursing academic journal,CN 14-1395/R,ISSN 2097-5368.Size A4,quarterly publication,color printing,public offerings at home and abroad which is managed by the First Hospital of Shanxi Medical ...Frontiers of Nursing is a nursing academic journal,CN 14-1395/R,ISSN 2097-5368.Size A4,quarterly publication,color printing,public offerings at home and abroad which is managed by the First Hospital of Shanxi Medical University,sponsored by Shanxi Nursing Association and Shanxi Medical Periodical Press Co.,Ltd.Frontiers of Nursing has been indexed by databases including Scopus,Google Scholar,DOAJ,Baidu Scholar,CNKI,VIP,Wanfang,Chaoxing,and so on.展开更多
Baosteel Technical Research has been indexed in many databases such as ProQuest CSA,Реферативныйжурнал(VINITI),China National Knowledge Infrastructure(CNKI),Wanfang Data,VIP Information,Airiti Librar...Baosteel Technical Research has been indexed in many databases such as ProQuest CSA,Реферативныйжурнал(VINITI),China National Knowledge Infrastructure(CNKI),Wanfang Data,VIP Information,Airiti Library,and Superstar Journals Database.These databases have obtained permission to digitally copy,compile,distribute,and disseminate the works of Baosteel Technical Research within their networks.The copyright usage fees are covered by the remuneration paid to the authors by Baosteel Technical Research.All authors submitting articles for publication in Baosteel Technical Research are hereby requested to conform to the above arrangement.If anyone has any objections,please inform regarding the same while submitting the manuscript so that the article is appropriately handled by Baosteel Technical Research.展开更多
文摘Asian Agricultural Research(ISSN1943-9903),founded in 2009,is a monthly comprehensive agricultural academic journal published and approved by the Library of Congress of the United States of America.
基金Supported bythe National High Technology of 863Project (2002AA1Z2308 ,2002AA118030)
文摘Recent studies have addressed that the cache be havior is important in the design of main memory index structures. Cache-conscious indices such as the CSB^＋-tree are shown to outperform conventional main memory indices such as the AVL-tree and the T-tree. This paper proposes a cacheconscious version of the T-tree, CST-tree, defined according to the cache-conscious definition. To separate the keys within a node into two parts, the CST-tree can gain higher cache hit ratio.
基金Under the auspices of Key Projects of the National Social Science Fund(No.16AJL015)Youth Project of Natural Science Foundation of Jiangsu Province(No.BK20170440)+1 种基金Open Foundation of Key Laboratory of Watershed Geographical Science(No.WSGS2017004)Project of Nantong Key Laboratory(No.CP12016005)
文摘Urban air pollution is a prominent problem related to the urban development in China, especially in the densely populated urban agglomerations. Therefore, scientific examination of regional variation of air quality and its dominant factors is of great importance to regional environmental management. In contrast to traditional air pollution researches which only concentrate on a single year or a single pollutant, this paper analyses spatiotemporal patterns and determinants of air quality in disparate regions based on the air quality index(AQI) of the Yangtze River Delta region(YRD) of China from 2014 to 2016. Results show that the annual average value of the AQI in the YRD region decreases from 2014 to 2016 and exhibit a basic characteristic of ‘higher in winter, lower in summer and slightly high in spring and autumn'. The attainment rate of the AQI shows an apparently spatial stratified heterogeneity, Hefei metropolitan area and Nanjing metropolitan area keeping the worst air quality. The frequency of air pollution occurring in large regions was gradually decreasing during the study period. Drawing from entropy method analysis, industrialization and urbanization represented by per capita GDP and total energy consumption were the most important factors. Furthermore, population agglomeration is a factor that cannot be ignored especially in some mega-cities. Limited to data collection, more research is needed to gain insight into the spatiotemporal pattern and influence mechanism in the future.
文摘The journal of Meteorological and Environmental Research [ISSN: 2152-3940] has been included and stored by the following famous databases: CA, CABI, CSA, EBSCO, UPD, AGRIS, EA, Chinese Science and Technology Periodical Database, and CNKI, as well as Library of Congress, United States.
文摘In this paper, we propose a new method based on index to realize IR-style Chinese keyword search with ranking strategies in relational databases. This method creates an index by using the related information of tuple words and presents a ranking strategy in terms of the nature of Chinese words. For a Chinese keyword query, the index is used to match query search words and the tuple words in index quickly, and to compute similarities between the query and tuples by the ranking strategy, and then the set of identifiers of candidate tuples is generated. Thus, we retrieve top-N results of the query using SQL selection statements and output the ranked answers according to the similarities. The experimental results show that our method is efficient and effective.
文摘There are several indexing techniques that can optimize system performances. The choice of the right index type in a schema can improve the DB performances by up to 80%. Unfortunately the illustrations of the various techniques are scattered over a number of texts and manuals, and the courses for database designers are often somewhat incomplete. The present paper shows a didactical experience which tackles this kind of limitations. In particular, the authors have prepared a textbook that includes twenty-one different index formats; it discusses advantages and disadvantages of each indexing technique, and has been positively validated during advanced courses on relational database design.
基金China Scholarship (2004836052)‘Voyage Project’ of Jiangxi Province(2007)
文摘The forest stand database of Bilahe Forestry Bureau, Inner Mongolia of China was taken as an example to demonstrate the whole process of building a temporal geodatabase by means of reengineering. The process was composed of establishing a conceptual data model from the initial database, constructing a logical database by means of mapping, and building a temporal geodatabase with the help of Computer-Aided Software Engineering （CASE） tool and Unified Markup Language （UML）. The results showed that as the reengineered forest stand geodatabase was dynamic, it could easily store the historical data and answer time related questions by Structured Query Language （SQL）, meanwhile, it maintains the integrity of database and eliminates the redundancy.
基金Under the auspices of National Key Research Program of China(No.2016YFC0502300,2016YFC0502102,2014BAB03B00)National Key Research and Development Program(No.2014BAB03B02)+3 种基金Agricultural Science and Technology Key Project of Guizhou Province of China(No.2014-3039)Science and Technology Plan Projects of Guiyang Municipal Bureau of Science and Technology of China(No.2012-205)Science and Technology Plan of Guizhou Province of China(No.2012-6015)Guangxi Natural Science Foundation of China(No.2014GXNSFBA118221)
文摘Guizhou Province is an important karst area in the world and a fragile ecological area in China. Ecological risk assessment is very necessary to be conducted in this region. This study investigates different characteristics of the spatial-temporal changes of vegetation cover in Guizhou Province of Southern China using the data set of SPOT VEGETATION(1999–2015) at spatial resolution of 1-km and temporal resolution of 10-day. The coefficient of variation, the Theil-Sen median trend analysis, and the Mann-Kendall test are used to investigate the spatial-temporal change of vegetation cover and its future trend. Results show that: 1) the spatial distribution pattern of vegetation cover in Guizhou Plateau is high in the east whereas low in the west. The average annual normalized difference vegetation index(NDVI) from west to east is higher than that from south to north. 2) Average annual NDVI improved obviously in the past 17 years. The growth rate of average annual NDVI is 0.028/10 yr, which is slower than that of vegetation in the country(0.048/10 yr) from 1998 to 2007. Average annual NDVI in karst area is lower than that in non-karst area. However, the growing rate of average annual NDVI in karst area(0.030/10 yr) is faster than that in non-karst area(0.023/10 yr), indicating that vegetation coverage increases more rapidly in karst area. 3) Vegetation coverage in the study area is stable overall, but fluctuates in the local scales. 4) Vegetation coverage presents a continuous increasing trend. The Hurst exponent of NDVI in different vegetation types has an obvious threshold in various elevations. 5) The proportion of vegetation cover with sustainable increase is higher than that of vegetation cover with sustainable decrease. The improvement in vegetation cover may expand to most parts of the study area.
文摘An outsource database is a database service provided by cloud computing companies.Using the outsource database can reduce the hardware and software＇s cost and also get more efficient and reliable data processing capacity.However,the outsource database still has some challenges.If the service provider does not have sufficient confidence,there is the possibility of data leakage.The data may has user＇s privacy,so data leakage may cause data privacy leak.Based on this factor,to protect the privacy of data in the outsource database becomes very important.In the past,scholars have proposed k-anonymity to protect data privacy in the database.It lets data become anonymous to avoid data privacy leak.But k-anonymity has some problems,it is irreversible,and easier to be attacked by homogeneity attack and background knowledge attack.Later on,scholars have proposed some studies to solve homogeneity attack and background knowledge attack.But their studies still cannot recover back to the original data.In this paper,we propose a data anonymity method.It can be reversible and also prevent those two attacks.Our study is based on the proposed r-transform.It can be used on the numeric type of attributes in the outsource database.In the experiment,we discussed the time required to anonymize and recover data.Furthermore,we investigated the defense against homogeneous attack and background knowledge attack.At the end,we summarized the proposed method and future researches.
基金supported by the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(No.2017-12M-3-002)the National Key R&D Program of China(No.2020YFC2008100).
文摘Background Based on the China-VHD database,this study sought to develop and validate a Valvular Heart Disease-specific Age-adjusted Comorbidity Index(VHD-ACI)for predicting mortality risk in patients with VHD.Methods&Results The China-VHD study was a nationwide,multi-centre multi-centre cohort study enrolling 13,917 patients with moderate or severe VHD across 46 medical centres in China between April-June 2018.After excluding cases with missing key variables,11,459 patients were retained for final analysis.The primary endpoint was 2-year all-cause mortality,with 941 deaths(10.0%)observed during follow-up.The VHD-ACI was derived after identifying 13 independent mortality predictors:cardiomyopathy,myocardial infarction,chronic obstructive pulmonary disease,pulmonary artery hypertension,low body weight,anaemia,hypoalbuminaemia,renal insufficiency,moderate/severe hepatic dysfunction,heart failure,cancer,NYHA functional class and age.The index exhibited good discrimination(AUC,0.79)and calibration(Brier score,0.062)in the total cohort,outperforming both EuroSCORE II and ACCI(P<0.001 for comparison).Internal validation through 100 bootstrap iterations yielded a C statistic of 0.694(95%CI:0.665−0.723)for 2-year mortality prediction.VHD-ACI scores,as a continuous variable(VHD-ACI score:adjusted HR(95%CI):1.263(1.245-1.282),P<0.001)or categorized using thresholds determined by the Yoden index(VHDACI≥9 vs.<9,adjusted HR(95%CI):6.216(5.378-7.184),P<0.001),were independently associated with mortality.The prognostic performance remained consistent across all VHD subtypes(aortic stenosis,aortic regurgitation,mitral stenosis,mitral regurgitation,tricuspid valve disease,mixed aortic/mitral valve disease and multiple VHD),and clinical subgroups stratified by therapeutic strategy,LVEF status(preserved vs.reduced),disease severity and etiology.Conclusion The VHD-ACI is a simple 13-comorbidity algorithm for the prediction of mortality in VHD patients and providing a simple and rapid tool for risk stratification.
基金Supported by Social Development Program of Lianyungang Bureau of Science and Technology,Jiangsu Province:RS-based Research on the Eco-environment Evolution of Coastal Regions in Lianyungang(SH0811)~~
文摘Interpretation results of RS images were taken as the foundation, ETM RS images of July 15, 2009 as the data source, ENVI was applied for the preprocessing, Arc GIS used to finish the interpretation, master data obtained, and VB used to complete program development. 12 representative landscape pattern indexes were selected, Excel data used to create Access database, and VB used to complete the program development. Selection of landscape pattern indexes, program development process and program usage were summarized, through comparing its results with Excel calculation results, it was found that calculation results of this program were correct, the usage was convenient, so needs of most users could be satisfied.
文摘Frontiers of Nursing is a nursing academic journal,CN 14-1395/R,ISSN 2097-5368.Size A4,quarterly publication,color printing,public offerings at home and abroad which is managed by the First Hospital of Shanxi Medical University,sponsored by Shanxi Nursing Association and Shanxi Medical Periodical Press Co.,Ltd.Frontiers of Nursing has been indexed by databases including Scopus,Google Scholar,DOAJ,Baidu Scholar,CNKI,VIP,Wanfang,Chaoxing,and so on.
文摘Baosteel Technical Research has been indexed in many databases such as ProQuest CSA,Реферативныйжурнал(VINITI),China National Knowledge Infrastructure(CNKI),Wanfang Data,VIP Information,Airiti Library,and Superstar Journals Database.These databases have obtained permission to digitally copy,compile,distribute,and disseminate the works of Baosteel Technical Research within their networks.The copyright usage fees are covered by the remuneration paid to the authors by Baosteel Technical Research.All authors submitting articles for publication in Baosteel Technical Research are hereby requested to conform to the above arrangement.If anyone has any objections,please inform regarding the same while submitting the manuscript so that the article is appropriately handled by Baosteel Technical Research.
