The current mathematical models for the storage assignment problem are generally established based on the traveling salesman problem(TSP),which has been widely applied in the conventional automated storage and retri...The current mathematical models for the storage assignment problem are generally established based on the traveling salesman problem(TSP),which has been widely applied in the conventional automated storage and retrieval system(AS/RS).However,the previous mathematical models in conventional AS/RS do not match multi-tier shuttle warehousing systems(MSWS) because the characteristics of parallel retrieval in multiple tiers and progressive vertical movement destroy the foundation of TSP.In this study,a two-stage open queuing network model in which shuttles and a lift are regarded as servers at different stages is proposed to analyze system performance in the terms of shuttle waiting period(SWP) and lift idle period(LIP) during transaction cycle time.A mean arrival time difference matrix for pairwise stock keeping units(SKUs) is presented to determine the mean waiting time and queue length to optimize the storage assignment problem on the basis of SKU correlation.The decomposition method is applied to analyze the interactions among outbound task time,SWP,and LIP.The ant colony clustering algorithm is designed to determine storage partitions using clustering items.In addition,goods are assigned for storage according to the rearranging permutation and the combination of storage partitions in a 2D plane.This combination is derived based on the analysis results of the queuing network model and on three basic principles.The storage assignment method and its entire optimization algorithm method as applied in a MSWS are verified through a practical engineering project conducted in the tobacco industry.The applying results show that the total SWP and LIP can be reduced effectively to improve the utilization rates of all devices and to increase the throughput of the distribution center.展开更多
In this paper, the system bgMath/OLAP for warehousing and online analytical processing bibliographic data is proposed. The implemented system can be useful for the users maintaining their electronic libraries with pub...In this paper, the system bgMath/OLAP for warehousing and online analytical processing bibliographic data is proposed. The implemented system can be useful for the users maintaining their electronic libraries with publications in order to monitoring, evaluating and comparing the scientific development of particular researchers, entire research groups, certain scientific fields and problems.展开更多
Enterprises in today's fast-paced business environment are always puzzled with billions of bytes of data flowing into their computers. In this paper, the new technology to solve this problem called "data warehousing...Enterprises in today's fast-paced business environment are always puzzled with billions of bytes of data flowing into their computers. In this paper, the new technology to solve this problem called "data warehousing" is introduced. Benefits which can be achieved from this technology for enterprises are also discussed. In addition, this paper describes "SAP Business Information Warehouse" (SAP BW), especially its characteristics, which is the data warehousing solution from SAP. Finally, advantages and shortcomings of SAP BW are given.展开更多
The Qinhuangdao Bonded Warehousing Company, approved by MOFTEC and the Customs Administration, is the only company handling bonded warehousing business in Hebei. Founded in 1992, the company owns RMB14.9369 million in...The Qinhuangdao Bonded Warehousing Company, approved by MOFTEC and the Customs Administration, is the only company handling bonded warehousing business in Hebei. Founded in 1992, the company owns RMB14.9369 million in assets, and has large-scale, modern bonded warehouses and two cooperative economic entities.展开更多
In recent years,the transformation of warehousing enterprises has garnered widespread attention.The integration of industry and finance in management accounting can provide financial management support for the transfo...In recent years,the transformation of warehousing enterprises has garnered widespread attention.The integration of industry and finance in management accounting can provide financial management support for the transformation of warehousing enterprises,deliver accurate and effective financial and business information,facilitate managers’decision-making,and achieve the benign development of enterprises.This paper discusses the problems in the application of industry-finance integration in warehousing enterprises,including the low degree of informatization,inefficient internal cost control,and mismatched staff quality,and then proposes corresponding measures,such as establishing and improving information systems,establishing a comprehensive budget management system,and establishing management measures for the integration of industry and finance in warehousing enterprises,so as to strengthen the application of industry-finance integration in warehousing enterprises.展开更多
At present Coal Bed Methane (CBM) has become the important part of clean energy in China. and will optimize the energy structure in China unceasingly. However, warehousing and transportation of CBM become one of the...At present Coal Bed Methane (CBM) has become the important part of clean energy in China. and will optimize the energy structure in China unceasingly. However, warehousing and transportation of CBM become one of the core factors that restrain its exploitation and utilization at present, due to the space-time character of natural deposit and modem utilization of CBM. In this paper, according to the character of CBM and the expanding trend of its utilization, the necessity of constructing the CBM's warehousing and transportation management system demonstrated. Index system that influence CBM's warehousing and transportation is established. And CBM's warehousing and transportation model is established by Voronoi diagram. In light of above research, CBM's warehousing and transportation management system based on Geography Information System (GIS) is designed, Using this system, CBM's warehousing and allocation center in one mining area is optimized. Research shows that to reinforce CBM's warehousing and transportation management is one of the key factors for coordinating the development of its development and utilization, thereby ensuring its sustainable development and utilization.展开更多
Cloud warehousing service (CWS) has emerged as a promising third-party logistics service paradigm driven by the widespread use of e-commerce. The current CWS billing method is typically based on a fixed rate in a coar...Cloud warehousing service (CWS) has emerged as a promising third-party logistics service paradigm driven by the widespread use of e-commerce. The current CWS billing method is typically based on a fixed rate in a coarse-grained manner. This method cannot reflect the true service value under the fluctuating e-commerce logistics demand and is not conducive to CWS resilience management. Accordingly, a floating mechanism can be considered to introduce more flexible billing. A CWS provider lacks sufficient credibility to implement floating mechanisms because it has vested interests in terms of fictitious demand. To address this concern, this report proposes a blockchain-enabled floating billing management system as an overall solution for CWS providers to enhance the security, credibility, and transparency of CWS. A one-sided Vickrey–Clarke–Groves (O-VCG) auction mechanism model is designed as the underlying floating billing mechanism to reflect the real-time market value of fine-grained CWS resources. A blockchain-based floating billing prototype system is built as an experimental environment. Our results show that the O-VCG mechanism can effectively reflect the real-time market value of CWSs and increase the revenue of CWS providers. When the supply of CWS providers remains unchanged, allocation efficiency increases when demand increases. By analyzing the performance of the O-VCG auction and comparing it with that of the fixed-rate billing model, the proposed mechanism has more advantages. Moreover, our work provides novel managerial insights for CWS market stakeholders in terms of practical applications.展开更多
It is common in industrial construction projects for data to be collected and discarded without being analyzed to extract useful knowledge. A proposed integrated methodology based on a five-step Knowledge Discovery in...It is common in industrial construction projects for data to be collected and discarded without being analyzed to extract useful knowledge. A proposed integrated methodology based on a five-step Knowledge Discovery in Data (KDD) model was developed to address this issue. The framework transfers existing multidimensional historical data from completed projects into useful knowledge for future projects. The model starts by understanding the problem domain, industrial construction projects. The second step is analyzing the problem data and its multiple dimensions. The target dataset is the labour resources data generated while managing industrial construction projects. The next step is developing the data collection model and prototype data ware-house. The data warehouse stores collected data in a ready-for-mining format and produces dynamic On Line Analytical Processing (OLAP) reports and graphs. Data was collected from a large western-Canadian structural steel fabricator to prove the applicability of the developed methodology. The proposed framework was applied to three different case studies to validate the applicability of the developed framework to real projects data.展开更多
This paper investigates how to integrate Web data into a multidimensional data warehouse (cube) for comprehensive on-line analytical processing (OLAP) and decision making. An approach for Web data-based cube const...This paper investigates how to integrate Web data into a multidimensional data warehouse (cube) for comprehensive on-line analytical processing (OLAP) and decision making. An approach for Web data-based cube construction is proposed, which includes Web data modeling based on MIX ( Metadam based Integration model for data X-change ), generic and specific mapping rules design, and a transformation algorithm for mapping Web data to a multidimensional array. Besides, the structure and implementation of the prototype of a Web data base cube are discussed.展开更多
Discipline of informatics must contain one of the significant issues that need to develop for especially processing systems of large-scale enterprises. At this point, a well-designed business intelligence (BI) syste...Discipline of informatics must contain one of the significant issues that need to develop for especially processing systems of large-scale enterprises. At this point, a well-designed business intelligence (BI) system, which includes a structure of regular business activities and analyses within whole an enterprise, requires to manage stored data and transform the data into information as an output and forecasting targets and provide sustainable growth for an enterprise or an organization. Information systems (IS) support to constitute these processes by using the information technologies (IT) that cause to capture data which will be transformed into information and integrate whole subsystems that need to develop for all departments of the enterprise. BI tools organize all parts of these business analysis and processes and effect on the top management level of enterprises or organizations. Decision makers at the top-level of management must use these information and knowledge to orient future decisions for the enterprise that includes investments, company policies, precautions for the future negations, etc. This study shows that the BI is not only an IS, but also reinforcement for strategic decisions of the enterprises and/or organizations.展开更多
Biomedical questions are usually complex and regard several different life science aspects. Numerous valuable and he- terogeneous data are increasingly available to answer such questions. Yet, they are dispersedly sto...Biomedical questions are usually complex and regard several different life science aspects. Numerous valuable and he- terogeneous data are increasingly available to answer such questions. Yet, they are dispersedly stored and difficult to be queried comprehensively. We created a Genomic and Proteomic Data Warehouse (GPDW) that integrates data provided by some of the main bioinformatics databases. It adopts a modular integrated data schema and several metadata to describe the integrated data, their sources and their location in the GPDW. Here, we present the Web application that we developed to enable any user to easily compose queries, although complex, on all data integrated in the GPDW. It is publicly available at http://www.bioinformatics.dei.polimi.it/GPKB/. Through a visual interface, the user is only required to select the types of data to be included in the query and the conditions on their values to be retrieved. Then, the Web application leverages the metadata and modular schema of the GPDW to automatically compose an efficient SQL query, run it on the GPDW and show the extracted requested data, enriched with links to external data sources. Performed tests demonstrated efficiency and usability of the developed Web application, and showed its and GPDW relevance in supporting answering biomedical questions, also difficult.展开更多
Radio frequency identification (RFID) is a contactless form of automatic identification and data capture (AIDC) technology. This paper explores the use of RFID in the new field of manufacturing automation and quality ...Radio frequency identification (RFID) is a contactless form of automatic identification and data capture (AIDC) technology. This paper explores the use of RFID in the new field of manufacturing automation and quality control. This paper consists of five parts. The first part gives a brief background and introduction of technology. The proposed use of RFID technology in the field of manufacturing automation and quality control is discussed in second part. The third part covers its use in the field of warehouse management system. Part four is a local review and analysis of RFID technology in manufacturing and warehousing which would support the potential use of this technology locally at China. The last part of paper gives concluding remarks about the RFID technology with recommendations of RFID use in these areas.展开更多
A conceptual,data-driven framework for organizing the data analytics and control functions in an electrical distribution network is proposed in this paper.The framework is built such that it tightly corresponds to the...A conceptual,data-driven framework for organizing the data analytics and control functions in an electrical distribution network is proposed in this paper.The framework is built such that it tightly corresponds to the naturally existing physical hierarchy of typical radial distribution networks,allowing for an organized and highly-localized set of data storage and analytics processes,which in turn correspond well to likely control commands.By utilizing this structure,the computational entities in the framework are endowed with persistent local situational awareness.However,the framework also permits,through a series of tiered communications,the operation of a centralized authority for overall system observability and controllability.展开更多
Database system is the infrastructure of the modern information system. The R&D in the database system and its technologies is one of the important research topics in the field. The database R&D in China took off la...Database system is the infrastructure of the modern information system. The R&D in the database system and its technologies is one of the important research topics in the field. The database R&D in China took off later but it moves along by giant steps. This report presents the achievements Renmin University of China (RUC) has made in the past 25 years and at the same time addresses some of the research projects we, RUC, are currently working on. The National Natural Science Foundation of China supports and initiates most of our research projects and these successfully conducted projects have produced fruitful results.展开更多
QC-Tree is one of the most storage-efficient structures for data cubes in an MOLAP system. Although QC- Tree can achieve a high compression ratio, it is still a fully materialized data cube. In this paper, an improved...QC-Tree is one of the most storage-efficient structures for data cubes in an MOLAP system. Although QC- Tree can achieve a high compression ratio, it is still a fully materialized data cube. In this paper, an improved structure PMC is presented allowing us to materialize only a part of the cells in a QC-Tree to save more storage space. There is a notable difference between our partially materialization algorithm and traditional materialized views selection algorithms. In a traditional algorithm, when a view is selected, all the cells in this view are to be materialized. Otherwise, if a view is not selected, all the cells in this view will not be materialized. This strategy results in the unstable query performance. The presented algorithm, however, selects and materializes data in cell level, and, along with further reduced space and update cost, it can ensure a stable query performance. A series of experiments are conducted on both synthetic and real data sets. The results show that PMC can further reduce storage space occupied by the data cube, and can shorten the time to update the cube.展开更多
The results of data cube will occupy huge amount of disk space when the base table is of a large number of attributes. A new type of data cube, compact data cube like condensed cube and quotient cube, was proposed to ...The results of data cube will occupy huge amount of disk space when the base table is of a large number of attributes. A new type of data cube, compact data cube like condensed cube and quotient cube, was proposed to solve the problem. It compresses data cube dramatically. However, its query cost is so high that it cannot be used in most applications. This paper introduces the semi-closed cube to reduce the size of data cube and achieve almost the same query response time as the data cube does. Semi-closed cube is a generalization of condensed cube and quotient cube and is constructed from a quotient cube. When the query cost of quotient cube is higher than a given threshold, semi-closed cube selects some views and picks a fellow for each of them. All the tuples of those views are materialized except those closed by their fellows. To find a tuple of those views, users only need to scan the view and its fellow. Thus, their query performance is improved. Experiments were conducted using a real-world data set. The results show that semi-closed cube is an effective approach of data cube.展开更多
Data warehouse (DW) modeling is a complicated task, involving both knowledge of business processes and familiarity with operational information systems structure and behavior. Existing DW modeling techniques suffer ...Data warehouse (DW) modeling is a complicated task, involving both knowledge of business processes and familiarity with operational information systems structure and behavior. Existing DW modeling techniques suffer from the following major drawbacks -- data-driven approach requires high levels of expertise and neglects the requirements of end users, while demand-driven approach lacks enterprise-wide vision and is regardless of existing models of underlying operational systems. In order to make up for those shortcomings, a method of classification of schema elements for DW modeling is proposed in this paper. We first put forward the vector space models for subjects and schema elements, then present an adaptive approach with self-tuning theory to construct context vectors of subjects, and finally classify the source schema elements into different subjects of the DW automatically. Benefited from the result of the schema elements classification, designers can model and construct a DW more easily.展开更多
The logistics routes allocation discusses optimal routing from origin to destination through distribution center (DC) on condition that both transport and distribution cost should be taken into account. The problem ...The logistics routes allocation discusses optimal routing from origin to destination through distribution center (DC) on condition that both transport and distribution cost should be taken into account. The problem can be solved by the iterative non-linear programming (INLP), in which the transport cost and distribution cost are assumed to be linear and non-linear, respectively. The method works well in most situations. However, when the distribution cost predominates in the total cost, the method falls, and the solution given by the method is not a global minimum but a local minimum. Further study reveals that the INLP method is still a kind of transport routing method like vehicle routing problem (VRP), and the failure of the method must happen when the distribution cost is a major one. On such a condition, further computation on other extreme points, which physically means forcing all routes to pass through one DC one by one, should be carried out. By comparing values on these extreme points, the global optimal solution can be got. The method has both theoretical and practical meaning. In theoretical field, it might force us to seek new method; in practice, it reminds us to do such kind of check when the transport distance is short and warehousing work is major that often happens in local consolidation center or de-vanning center.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.661403234)Shandong Provincial Science and Techhnology Development Plan of China(Grant No.2014GGX106009)
文摘The current mathematical models for the storage assignment problem are generally established based on the traveling salesman problem(TSP),which has been widely applied in the conventional automated storage and retrieval system(AS/RS).However,the previous mathematical models in conventional AS/RS do not match multi-tier shuttle warehousing systems(MSWS) because the characteristics of parallel retrieval in multiple tiers and progressive vertical movement destroy the foundation of TSP.In this study,a two-stage open queuing network model in which shuttles and a lift are regarded as servers at different stages is proposed to analyze system performance in the terms of shuttle waiting period(SWP) and lift idle period(LIP) during transaction cycle time.A mean arrival time difference matrix for pairwise stock keeping units(SKUs) is presented to determine the mean waiting time and queue length to optimize the storage assignment problem on the basis of SKU correlation.The decomposition method is applied to analyze the interactions among outbound task time,SWP,and LIP.The ant colony clustering algorithm is designed to determine storage partitions using clustering items.In addition,goods are assigned for storage according to the rearranging permutation and the combination of storage partitions in a 2D plane.This combination is derived based on the analysis results of the queuing network model and on three basic principles.The storage assignment method and its entire optimization algorithm method as applied in a MSWS are verified through a practical engineering project conducted in the tobacco industry.The applying results show that the total SWP and LIP can be reduced effectively to improve the utilization rates of all devices and to increase the throughput of the distribution center.
文摘In this paper, the system bgMath/OLAP for warehousing and online analytical processing bibliographic data is proposed. The implemented system can be useful for the users maintaining their electronic libraries with publications in order to monitoring, evaluating and comparing the scientific development of particular researchers, entire research groups, certain scientific fields and problems.
文摘Enterprises in today's fast-paced business environment are always puzzled with billions of bytes of data flowing into their computers. In this paper, the new technology to solve this problem called "data warehousing" is introduced. Benefits which can be achieved from this technology for enterprises are also discussed. In addition, this paper describes "SAP Business Information Warehouse" (SAP BW), especially its characteristics, which is the data warehousing solution from SAP. Finally, advantages and shortcomings of SAP BW are given.
文摘The Qinhuangdao Bonded Warehousing Company, approved by MOFTEC and the Customs Administration, is the only company handling bonded warehousing business in Hebei. Founded in 1992, the company owns RMB14.9369 million in assets, and has large-scale, modern bonded warehouses and two cooperative economic entities.
文摘In recent years,the transformation of warehousing enterprises has garnered widespread attention.The integration of industry and finance in management accounting can provide financial management support for the transformation of warehousing enterprises,deliver accurate and effective financial and business information,facilitate managers’decision-making,and achieve the benign development of enterprises.This paper discusses the problems in the application of industry-finance integration in warehousing enterprises,including the low degree of informatization,inefficient internal cost control,and mismatched staff quality,and then proposes corresponding measures,such as establishing and improving information systems,establishing a comprehensive budget management system,and establishing management measures for the integration of industry and finance in warehousing enterprises,so as to strengthen the application of industry-finance integration in warehousing enterprises.
基金Acknowledgments: This work was supported by the National Natural Science Foundation of China (Grant No. 70971129) and Soft Science Project (Grant No. 2008041036-02). The authors would like to thank anonymous reviewers for their helpful comments.
文摘At present Coal Bed Methane (CBM) has become the important part of clean energy in China. and will optimize the energy structure in China unceasingly. However, warehousing and transportation of CBM become one of the core factors that restrain its exploitation and utilization at present, due to the space-time character of natural deposit and modem utilization of CBM. In this paper, according to the character of CBM and the expanding trend of its utilization, the necessity of constructing the CBM's warehousing and transportation management system demonstrated. Index system that influence CBM's warehousing and transportation is established. And CBM's warehousing and transportation model is established by Voronoi diagram. In light of above research, CBM's warehousing and transportation management system based on Geography Information System (GIS) is designed, Using this system, CBM's warehousing and allocation center in one mining area is optimized. Research shows that to reinforce CBM's warehousing and transportation management is one of the key factors for coordinating the development of its development and utilization, thereby ensuring its sustainable development and utilization.
基金supported by the National Natural Science Foundation of China(Grant Nos.52005218 and 72071093)RGC TRS Project(Grant No.T32-707-22-N)the Guangdong Basic and Applied Basic Research Foundation(Guangdong Natural Science Fund,Grant No.2019A1515110296).
文摘Cloud warehousing service (CWS) has emerged as a promising third-party logistics service paradigm driven by the widespread use of e-commerce. The current CWS billing method is typically based on a fixed rate in a coarse-grained manner. This method cannot reflect the true service value under the fluctuating e-commerce logistics demand and is not conducive to CWS resilience management. Accordingly, a floating mechanism can be considered to introduce more flexible billing. A CWS provider lacks sufficient credibility to implement floating mechanisms because it has vested interests in terms of fictitious demand. To address this concern, this report proposes a blockchain-enabled floating billing management system as an overall solution for CWS providers to enhance the security, credibility, and transparency of CWS. A one-sided Vickrey–Clarke–Groves (O-VCG) auction mechanism model is designed as the underlying floating billing mechanism to reflect the real-time market value of fine-grained CWS resources. A blockchain-based floating billing prototype system is built as an experimental environment. Our results show that the O-VCG mechanism can effectively reflect the real-time market value of CWSs and increase the revenue of CWS providers. When the supply of CWS providers remains unchanged, allocation efficiency increases when demand increases. By analyzing the performance of the O-VCG auction and comparing it with that of the fixed-rate billing model, the proposed mechanism has more advantages. Moreover, our work provides novel managerial insights for CWS market stakeholders in terms of practical applications.
文摘It is common in industrial construction projects for data to be collected and discarded without being analyzed to extract useful knowledge. A proposed integrated methodology based on a five-step Knowledge Discovery in Data (KDD) model was developed to address this issue. The framework transfers existing multidimensional historical data from completed projects into useful knowledge for future projects. The model starts by understanding the problem domain, industrial construction projects. The second step is analyzing the problem data and its multiple dimensions. The target dataset is the labour resources data generated while managing industrial construction projects. The next step is developing the data collection model and prototype data ware-house. The data warehouse stores collected data in a ready-for-mining format and produces dynamic On Line Analytical Processing (OLAP) reports and graphs. Data was collected from a large western-Canadian structural steel fabricator to prove the applicability of the developed methodology. The proposed framework was applied to three different case studies to validate the applicability of the developed framework to real projects data.
基金The National Natural Science Foundation of China (No.60573165)
文摘This paper investigates how to integrate Web data into a multidimensional data warehouse (cube) for comprehensive on-line analytical processing (OLAP) and decision making. An approach for Web data-based cube construction is proposed, which includes Web data modeling based on MIX ( Metadam based Integration model for data X-change ), generic and specific mapping rules design, and a transformation algorithm for mapping Web data to a multidimensional array. Besides, the structure and implementation of the prototype of a Web data base cube are discussed.
文摘Discipline of informatics must contain one of the significant issues that need to develop for especially processing systems of large-scale enterprises. At this point, a well-designed business intelligence (BI) system, which includes a structure of regular business activities and analyses within whole an enterprise, requires to manage stored data and transform the data into information as an output and forecasting targets and provide sustainable growth for an enterprise or an organization. Information systems (IS) support to constitute these processes by using the information technologies (IT) that cause to capture data which will be transformed into information and integrate whole subsystems that need to develop for all departments of the enterprise. BI tools organize all parts of these business analysis and processes and effect on the top management level of enterprises or organizations. Decision makers at the top-level of management must use these information and knowledge to orient future decisions for the enterprise that includes investments, company policies, precautions for the future negations, etc. This study shows that the BI is not only an IS, but also reinforcement for strategic decisions of the enterprises and/or organizations.
文摘Biomedical questions are usually complex and regard several different life science aspects. Numerous valuable and he- terogeneous data are increasingly available to answer such questions. Yet, they are dispersedly stored and difficult to be queried comprehensively. We created a Genomic and Proteomic Data Warehouse (GPDW) that integrates data provided by some of the main bioinformatics databases. It adopts a modular integrated data schema and several metadata to describe the integrated data, their sources and their location in the GPDW. Here, we present the Web application that we developed to enable any user to easily compose queries, although complex, on all data integrated in the GPDW. It is publicly available at http://www.bioinformatics.dei.polimi.it/GPKB/. Through a visual interface, the user is only required to select the types of data to be included in the query and the conditions on their values to be retrieved. Then, the Web application leverages the metadata and modular schema of the GPDW to automatically compose an efficient SQL query, run it on the GPDW and show the extracted requested data, enriched with links to external data sources. Performed tests demonstrated efficiency and usability of the developed Web application, and showed its and GPDW relevance in supporting answering biomedical questions, also difficult.
文摘Radio frequency identification (RFID) is a contactless form of automatic identification and data capture (AIDC) technology. This paper explores the use of RFID in the new field of manufacturing automation and quality control. This paper consists of five parts. The first part gives a brief background and introduction of technology. The proposed use of RFID technology in the field of manufacturing automation and quality control is discussed in second part. The third part covers its use in the field of warehouse management system. Part four is a local review and analysis of RFID technology in manufacturing and warehousing which would support the potential use of this technology locally at China. The last part of paper gives concluding remarks about the RFID technology with recommendations of RFID use in these areas.
基金supported by the Science and Technology Program of the State Grid Corporation of China(DZB51201403772)the National Natural Science and Technology Fund of China(51261130472).
文摘A conceptual,data-driven framework for organizing the data analytics and control functions in an electrical distribution network is proposed in this paper.The framework is built such that it tightly corresponds to the naturally existing physical hierarchy of typical radial distribution networks,allowing for an organized and highly-localized set of data storage and analytics processes,which in turn correspond well to likely control commands.By utilizing this structure,the computational entities in the framework are endowed with persistent local situational awareness.However,the framework also permits,through a series of tiered communications,the operation of a centralized authority for overall system observability and controllability.
基金Supported by the National Natural Science Foundation of China. Acknowledgements The National Science Foundation of China supported these works. Thanks to NSFC and all the members of the research groups in Renmin University of China.
文摘Database system is the infrastructure of the modern information system. The R&D in the database system and its technologies is one of the important research topics in the field. The database R&D in China took off later but it moves along by giant steps. This report presents the achievements Renmin University of China (RUC) has made in the past 25 years and at the same time addresses some of the research projects we, RUC, are currently working on. The National Natural Science Foundation of China supports and initiates most of our research projects and these successfully conducted projects have produced fruitful results.
基金Supported by the National Key Scientific and Technological Project: Research on the Management of the Railroad Fundamental Information (Grant No.2002BA407B01-2) and the Science Foundation of Beijing Jiaotong University (Grant No.2003SZ003).
文摘QC-Tree is one of the most storage-efficient structures for data cubes in an MOLAP system. Although QC- Tree can achieve a high compression ratio, it is still a fully materialized data cube. In this paper, an improved structure PMC is presented allowing us to materialize only a part of the cells in a QC-Tree to save more storage space. There is a notable difference between our partially materialization algorithm and traditional materialized views selection algorithms. In a traditional algorithm, when a view is selected, all the cells in this view are to be materialized. Otherwise, if a view is not selected, all the cells in this view will not be materialized. This strategy results in the unstable query performance. The presented algorithm, however, selects and materializes data in cell level, and, along with further reduced space and update cost, it can ensure a stable query performance. A series of experiments are conducted on both synthetic and real data sets. The results show that PMC can further reduce storage space occupied by the data cube, and can shorten the time to update the cube.
文摘The results of data cube will occupy huge amount of disk space when the base table is of a large number of attributes. A new type of data cube, compact data cube like condensed cube and quotient cube, was proposed to solve the problem. It compresses data cube dramatically. However, its query cost is so high that it cannot be used in most applications. This paper introduces the semi-closed cube to reduce the size of data cube and achieve almost the same query response time as the data cube does. Semi-closed cube is a generalization of condensed cube and quotient cube and is constructed from a quotient cube. When the query cost of quotient cube is higher than a given threshold, semi-closed cube selects some views and picks a fellow for each of them. All the tuples of those views are materialized except those closed by their fellows. To find a tuple of those views, users only need to scan the view and its fellow. Thus, their query performance is improved. Experiments were conducted using a real-world data set. The results show that semi-closed cube is an effective approach of data cube.
基金Supported by the National Natural Science Foundation of China under Grant No. 60403041, the Project of National "10th Five-Year Plan" of China under Grant No. 2001BA102A01, and the National Grand Fundamental Research 973 Program of China under Grant No. 1999032705. Acknowledgements The first author is very thankful to Jian Liu, Bo Yu, Peng Zhang and Ling-Fu Li for their valuable suggestions on this paper. The authors are also grateful to anonymous reviewers for their insightful comments on this paper, which have helped to improve the manuscript.
文摘Data warehouse (DW) modeling is a complicated task, involving both knowledge of business processes and familiarity with operational information systems structure and behavior. Existing DW modeling techniques suffer from the following major drawbacks -- data-driven approach requires high levels of expertise and neglects the requirements of end users, while demand-driven approach lacks enterprise-wide vision and is regardless of existing models of underlying operational systems. In order to make up for those shortcomings, a method of classification of schema elements for DW modeling is proposed in this paper. We first put forward the vector space models for subjects and schema elements, then present an adaptive approach with self-tuning theory to construct context vectors of subjects, and finally classify the source schema elements into different subjects of the DW automatically. Benefited from the result of the schema elements classification, designers can model and construct a DW more easily.
基金the National Science Foundation,Ministry of Education and Science, Japan (No. 17330089)
文摘The logistics routes allocation discusses optimal routing from origin to destination through distribution center (DC) on condition that both transport and distribution cost should be taken into account. The problem can be solved by the iterative non-linear programming (INLP), in which the transport cost and distribution cost are assumed to be linear and non-linear, respectively. The method works well in most situations. However, when the distribution cost predominates in the total cost, the method falls, and the solution given by the method is not a global minimum but a local minimum. Further study reveals that the INLP method is still a kind of transport routing method like vehicle routing problem (VRP), and the failure of the method must happen when the distribution cost is a major one. On such a condition, further computation on other extreme points, which physically means forcing all routes to pass through one DC one by one, should be carried out. By comparing values on these extreme points, the global optimal solution can be got. The method has both theoretical and practical meaning. In theoretical field, it might force us to seek new method; in practice, it reminds us to do such kind of check when the transport distance is short and warehousing work is major that often happens in local consolidation center or de-vanning center.