Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241)最新文献_第5页

On analyzing the errors in a selectivity estimation method using a multidimensional file structure 基于多维文件结构的选择性估计方法误差分析

Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241) Pub Date : 1998-08-19 DOI: 10.1109/CMPSAC.1998.716635

Sang-Wook Kim, Whan-Kyu Whang, K. Whang

{"title":"On analyzing the errors in a selectivity estimation method using a multidimensional file structure","authors":"Sang-Wook Kim, Whan-Kyu Whang, K. Whang","doi":"10.1109/CMPSAC.1998.716635","DOIUrl":"https://doi.org/10.1109/CMPSAC.1998.716635","url":null,"abstract":"In this paper, we discuss the errors in selectivity estimation using the multilevel grid file (MLGF), a multidimensional file structure. We first analyze the cause of the estimation errors, and then investigate five factors affecting the accuracy of estimation: (1) the data distribution in a region, (2) the number of records stored in the MLGF, (3) the page size, (4) the query region size, and (5) the level of the MLGF directory. Next, we present through extensive experiments the tendency of estimation errors when the value for each factor changes. The results show that the errors decrease when (1) the distribution of records in a region becomes closer to the uniform one, (2) the number of records in the MLGF increases, (3) the page size decreases, (4) the query region size increases, and (5) the level of the MLGF directory containing data distribution information becomes lower. We define the granule ratio, the core formula representing the basic relationship between the estimation error and the above five factors, and finally examine the change of estimation errors in relation with the change of the granule ratio through experiments. The results indicate that with a specific value for the granule ratio, errors tend to be similar regardless of different values for the five factors.","PeriodicalId":252030,"journal":{"name":"Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131350537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Transformations on hierarchical predicate transition nets: refinements and abstractions 层次谓词转换网络上的转换:改进与抽象

Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241) Pub Date : 1998-08-19 DOI: 10.1109/CMPSAC.1998.716652

Xudong He

引用次数: 1

A general framework for interconnecting annotations of software systems 软件系统注释互连的通用框架

Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241) Pub Date : 1998-08-19 DOI: 10.1109/CMPSAC.1998.716690

Michael Stein, M. Heimdahl, J. Riedl

引用次数: 2

A generic discretionary access control system for reuse frameworks 一种用于重用框架的通用自主访问控制系统

Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241) Pub Date : 1998-08-19 DOI: 10.1109/CMPSAC.1998.716680

L. K. Wei, S. Jarzabek

引用次数: 1

Component-based integrated systems development: a model for the emerging procurement-centric approach to software development 基于组件的集成系统开发:用于新兴的以采购为中心的软件开发方法的模型

Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241) Pub Date : 1998-08-19 DOI: 10.1109/CMPSAC.1998.716648

V. Tran

{"title":"Component-based integrated systems development: a model for the emerging procurement-centric approach to software development","authors":"V. Tran","doi":"10.1109/CMPSAC.1998.716648","DOIUrl":"https://doi.org/10.1109/CMPSAC.1998.716648","url":null,"abstract":"The continuing increase of interest in Component-based Software Engineering (CBSE) signifies the emergence of a new development trend within the software industry. Unlike preceding software engineering models, CBSE heavily relies on the utilization of commercial off-the-shelf (COTS) products as the underlying foundation for new product development. Its emphasis is on the acquisition of reusable products to develop complex integrated solutions over their development from scratch. Compared to traditional development-centric approaches, CBSE promises a more efficient and effective means to deliver software solutions to the market. However, underestimating the risks associated with the acquisition of these software components has resulted in longer schedule delay and higher development/maintenance cost. The paper describes a procurement-centric model that we have utilized to effectively support the development of a CBSE project at the Mitsubishi Consumer Electronics Engineering Center (CEEC). The Component-based Integrated Systems Development (CISD) model identifies key engineering phases and their sub-phases that are often ignored, or merely implicit, in existing development-centric models. The paper also presents the various lessons learned implementing CBSE at the CEEC.","PeriodicalId":252030,"journal":{"name":"Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126077588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Object-oriented software specification in programming language design and implementation 面向对象软件规范中的编程语言设计与实现

Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241) Pub Date : 1998-08-19 DOI: 10.1109/CMPSAC.1998.716685

B. Bryant, V. Vaidyanathan

引用次数: 3

Application development process-a pipeline framework 应用程序开发过程—管道框架

Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241) Pub Date : 1998-08-19 DOI: 10.1109/CMPSAC.1998.716628

C. Yerrapragada

引用次数: 0

Using multi-attribute predicates for mining classification rules 使用多属性谓词挖掘分类规则

Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241) Pub Date : 1998-08-19 DOI: 10.1109/CMPSAC.1998.716745

Ming-Syan Chen

引用次数: 9

Tools for the knowledge analyst: an information superiority visionary demonstration 知识分析师的工具:一种信息优势的前瞻性论证

Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241) Pub Date : 1998-08-19 DOI: 10.1109/CMPSAC.1998.716700

M. Maybury

引用次数: 1

Provably efficient non-preemptive task scheduling with Cilk 证明有效的非抢占任务调度与Cilk

Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241) Pub Date : 1998-08-19 DOI: 10.1109/CMPSAC.1998.716733

V.-B. Vee, W. Hsu

{"title":"Provably efficient non-preemptive task scheduling with Cilk","authors":"V.-B. Vee, W. Hsu","doi":"10.1109/CMPSAC.1998.716733","DOIUrl":"https://doi.org/10.1109/CMPSAC.1998.716733","url":null,"abstract":"We consider the problem of scheduling static task graphs by using Cilk, a C based runtime system for multithreaded parallel programming. We assume no preemption of task execution and no prior knowledge of the task execution times. Given a task graph G, the output of the scheduling algorithm is a Cilk program P which, when executed initiates the tasks in consistence with the precedence requirements of G. We show that the Cilk model has restrictions in implementing optimal schedules for certain types of task graphs; however, the restriction does not fundamentally hinder the practical applications of Cilk, as it is possible to produce reasonably good quality schedules (in the sense of expected execution time). Our algorithm identifies a minimal number of stages, assigns tasks to these stages, and bundles parallel tasks of the same stage into one Cilk procedure. By using Tarjan's algorithm (for set operations) to implement the bundling process, we demonstrate that the parallel schedule can be derived in O(n+e) time for all practical purposes, where n and e denote the number of nodes and edges in the task graph G. With P processors, the expected completion time for the scheduled tasks is bounded by Tp=O(T/sub 1//P+S), where T/sub 1/ denotes the total work, i.e., the time required for executing all tasks on a single processor, and S denotes the sum (over all stages) of the longest execution time of the tasks at each stage. When the execution times of tasks are relatively homogeneous, the quality of the schedule generated by using our approach is nearly optimal.","PeriodicalId":252030,"journal":{"name":"Proceedings. The Twenty-Second Annual International Computer Software and Applications Conference (Compsac '98) (Cat. No.98CB 36241)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115188399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1