A consulting system for data base design

This paper proposes a methodology for automated data base design based on a set of managerial reports. We introduce the notion of report schemata, specified in terms of record types and binary relations, as a framework for analyzing report structures and interactions among reports. Four classes of binary relations are identified, each being characteristic of a certain type of elementary report. Multiple binary relations are used to specify more complex reports. We also discuss concepts such as report covering and the maximal members for transforming reports to a parsimonious representation for data base design. Finally, we formulate this report-driven data base design methodology as an expert consulting system in Artificial Intelligence.     

Logical data base design: A management-oriented approach

A logical data base consists of data definitions and data relationships. It is typically very large and complex even for a small organization, but it is generally designed in an ad hoc manner. However, several approaches have recently been proposed that allow for a systematic logical data base design.To make a data base more useful to the managers, it is imperative to encourage and obtain their involvement in the initial phase of the logical data base design. “Surface semantic models” are used in the logical data base design process to increase this involvement. A special type of this, called a “hierarchical external view model”, is proposed. It has been successfully used to develop a logical data base for the Department of Aging in Pennsylvania.     

Applying and evaluating concern-sensitive design heuristics

Manifestation of crosscutting concerns in software systems is often an indicative of design modularity flaws and further design instabilities as those systems evolve. Without proper design evaluation mechanisms, the identification of harmful crosscutting concerns can become counter-productive and impractical. Nowadays, metrics and heuristics are the basic mechanisms to support their identification and classification either in object-oriented or aspect-oriented programs. However, conventional mechanisms have a number of limitations to support an effective identification and classification of crosscutting concerns in a software system. In this paper, we claim that those limitations are mostly caused by the fact that existing metrics and heuristics are not sensitive to primitive concern properties, such as either their degree of tangling and scattering or their specific structural shapes. This means that modularity assessment is rooted only at conventional attributes of modules, such as module cohesion, coupling and size. This paper proposes a representative suite of concern-sensitive heuristic rules. The proposed heuristics are supported by a prototype tool. The paper also reports an exploratory study to evaluate the accuracy of the proposed heuristics by applying them to seven systems. The results of this exploratory analysis give evidences that the heuristics offer support for: (i) addressing the shortcomings of conventional metrics-based assessments, (ii) reducing the manifestation of false positives and false negatives in modularity assessment, (iii) detecting sources of design instability, and (iv) finding the presence of design modularity flaws in both object-oriented and aspect-oriented programs. Although our results are limited to a number of decisions we made in this study, they indicate a promising research direction. Further analyses are required to confirm or refute our preliminary findings and, so, this study should be seen as a stepping stone on understanding how concerns can be useful assessment abstractions. We conclude this paper by discussing the limitations of this exploratory study focusing on some situations which hinder the accuracy of concern-sensitive heuristics.     

A distributed medical data base: Network software design

This paper describes the software design aspects of a distributed medical data base, to be implemented on a homogeneous minicomputer loop network of PDP-11/45s, using the UNIX operating system. Eash user at a node, operating within a virtual user machine, is seen to interact with the file machines of either the local or distant node(s), through his local virtual network access machine. This last resource has two logical components: a switch, which routes messages, and a network interface.     

An integer programming formulation of computer data base design problems

Traditionally, computer data base design has been handled intuitively without the assistance of quantitative techniques. A systematic approach to data base design consists of these phases: (1) a mathematical problem statement; (2) problem reduction; (3) mathematical solution. This paper addresses the first phase (associated work on the other phases is briefly discussed) and demonstrates that certain data base design problems can be formulated as nonlinear, zero-one programs. The decision variables state which logical data base elements (entities and attributes) are represented in each subdivision (subfile) of the physical data base. Computational experience using cluster analysis for problem reduction and branch and bound for mathematical solution is reported. It is shown that a planned subdivision of the physical data base can yield noticeable operating cost improvements over conventional data base designs.     

Relational heuristics for the design of deterministic programs

Summary It has been shown that the design of deterministic programs can be formulated as the resolution of relational equations. Because relational calculi are not sufficiently structured, there are no algorithmic solutions to relational equations. In this paper, we formulate some heuristic solutions to these equations.Part of this work was carried out while the first and second author were at Laval University in Québec. Canada: it was supported by the National Research Council of Canada through a research grant to the first author and a scholarship to the second author. Presently, this research is supported by a grant to the first and third authors from the Tunisian Council on Scientific and Technical Research     

A comprehensive data base for the design of manual materials handling

The main objective of the present paper is to provide a comprehensive data base of the material handling capabilities of the industrial work force. The data base encompasses the following: (1) five different types of manual materials handling activities, namely, lifting, lowering, carrying, pushing, and pulling, (2) worker variables (e.g., sex), and (3) task variables (e.g., frequency, and container size). The data base was developed for the IBM personal computer using the software package DBASE III PLUS.     

The introduction of a design heuristics extraction method

This paper introduces a novel method for analyzing conceptual design data. Given a database of previous designs, this method identifies relationships between design components within this database. Further, the method transforms these relationships into explicit design knowledge that can be used to generate a ‘heuristic-based’ model of the design domain for use at the conceptual stage. This can be viewed as a knowledge extracting method for the conceptual design stage. Such a method is particularly interesting, as the conceptual stage typically lacks explicit models to describe the trade-offs that must be made when designing. The method uses either principal components analysis or self-organizing maps to identify the relationships, and this paper describes all the elements required by the method to successfully extract and verify design knowledge from design databases.     

化工基础课堂教学及实验教学数据处理的窗体化设计

为解决化工基础课堂教学和实验教学中的数据处理难题,可利用Visual Basic6.0语言编写出处理其数据的程序。通过简单的窗体操作和程序运行,即可计算有关过程及作图,打印出所需的结果和图表。本程序可在Win9X操作平台下独立运行,操作简便、直观、图像清晰、误差小。     

Learning page-independent heuristics for extracting data from Web pages

One bottleneck in implementing a system that intelligently queries the Web is developing `wrappers' — programs that extract data from Web pages. Here we describe a method for learning general, page-independent heuristics for extracting data from HTML documents. The input to our learning system is a set of working wrapper programs, paired with HTML pages they correctly wrap. The output is a general procedure for extracting data that works for many formats and many pages. In experiments with a collection of 84 constrained but realistic extraction problems, we demonstrate that 30% of the problems can be handled perfectly by learned extraction heuristics, and around 50% can be handled acceptably. We also demonstrate that learned page-independent extraction heuristics can substantially improve the performance of methods for learning page-specific wrappers.     

The design of a Bills of Material Processor using a relational data base

This paper describes the development of a Bills of Material Processor (BOM) and shows how a relational data base system could greatly simplify the design and implementation of the processor on a computer. It describes the steps leading to the structuring of the data files based on data obtained from a manufacturing industry. Examples used in the discussion are real in that they refer to the actual development of a BOM processor using the RAPPORT relational data management system.     

MILP-based heuristics for the design of rural community electrification projects

Wind–photovoltaic systems are a suitable option to provide electricity to isolated communities autonomously. To design these systems, there are recent mathematical models that solve the location and type of each of the electrification components and the design of the possible distribution microgrids. When the amount of demand points to electrify increases, solving the mathematical model requires a computational time that becomes infeasible in practice. To speed up the solving process, three heuristic methods based on mixed integer linear programming (MILP) are presented in this paper: Relax and Fix heuristics, heuristics based on a Corridor Method and Increasing Radius heuristics. In all algorithms first a relaxed MILP is solved to obtain a base solution and then it is used as a starting point to find a feasible solution by searching in a reduced search space. For each type of heuristic several options to relax and to reduce the solution space are developed and tested. Extensive computational experiments based on real projects are carried out and results show that the best heuristic vary according to the size of instances.     

A comparison of optimization heuristics for the data mapping problem

In the paper we compare the performance of six heuristics with suboptimal solutions for the data distribution of two dimensional meshes that are used for the numerical solution of partial differential equations (PDEs) on multicomputers. The data mapping heuristics are evaluated with respect to seven criteria covering load balancing, interprocessor communication, flexibility and ease of use for a class of single-phase iterative PDE solvers. Our evaluation suggests that the simple and fast block distribution heuristic can be as effective as the other five complex and computational expensive algorithms. © 1997 by John Wiley & Sons, Ltd.