Software Engineering for Spreadsheets

Spreadsheets are popular end-user programming tools. Many people use spreadsheet-computed values to make critical decisions, so spreadsheets must be correct. Proven software engineering principles can assist the construction and maintenance of dependable spreadsheets. However, how can we make this practical for end users? One way is to exploit spreadsheets' idiosyncratic structure to translate software engineering concepts such as type checking and debugging to an end-user programming domain. The simplified computational model and the spatial embedding of formulas, which provides rich contextual information, can simplify these concepts, leading to effective tools for end users.     

Evolution of Appropriate Crossover and Mutation Operators in a Genetic Process

Traditional genetic algorithms use only one crossover and one mutation operator to generate the next generation. The chosen crossover and mutation operators are critical to the success of genetic algorithms. Different crossover or mutation operators, however, are suitable for different problems, even for different stages of the genetic process in a problem. Determining which crossover and mutation operators should be used is quite difficult and is usually done by trial-and-error. In this paper, a new genetic algorithm, the dynamic genetic algorithm (DGA), is proposed to solve the problem. The dynamic genetic algorithm simultaneously uses more than one crossover and mutation operators to generate the next generation. The crossover and mutation ratios change along with the evaluation results of the respective offspring in the next generation. By this way, we expect that the really good operators will have an increasing effect in the genetic process. Experiments are also made, with results showing the proposed algorithm performs better than the algorithms with a single crossover and a single mutation operator.     

基于新变异算子的改进粒子群优化算法

粒子群优化算法(PSO)是一种基于群体智能的优化算法。本文在介绍PSO算法基本原理和流程的基础上,分析了该算法在处理一些复杂问题时容易出现的早熟收敛、收敛效率低和精度不高等问题,提出了一种基于新变异算子的改进粒子群优化算法(NMPSO)。NMPSO算法将产生的变异粒子与当前粒子进行优劣比较,选择较优的粒子,增强了种群的多样性,有效地避免算法收敛早熟。用5个常用基准测试函数对两种算法进行对比实验,结果表明:新提出的NMPSO算法增强了全局搜索能力,提高了收敛速度和收敛精度。     

Spreadsheets with Incremental Queries as a user interface for logic programming

We believe that currently marketed programs leave unexploited much of the potential of the spreadsheet interface. The purpose of our work is to obtain suggestions for wider application of this interface by showing how to obtain its main features as a subset of logic programming. Our work is based on two observations. The first is that spreadsheets would already be a useful enhancement to interactive languages such as APL and Basic. Although Prolog is also an interactive language, this interface cannot be used in the same direct way. Hence our second observation: the usual query mechanism of Prolog does not provide the kind of interaction this application requires. But it can be provided by the Incremental Query, a new query mechanism for Prolog. The two observations together yield the spreadsheet as a display of the state of the substitution of an incremental query in Prolog. Recalculation of dependent cells is achieved by automatic modification of the query in response to a new increment that would make it unsolvable without the modification.     

一种基于POI的Web表格生成

互联网技术的飞速发展使得基于Web的应用越来越普遍,同时也更加复杂。基于Web的动态Excel表格就是一个典型的实例。随着开发技术的不断发展,一些开源项目凭借其公开、自由以及免费等众多优势产生了越来越大的影响,很多项目都采用了开源技术。文中介绍了一种开源的基于Java的Excel报表开发组件POI引擎,阐述了其表格显示原理。通过在Web上实现动态Excel表格,给出了一种典型应用,并结合一个实际项目中的例子进行了分析,探索出了一种开发Web动态Excel表格的方法。     

一种基于POI的Web表格生成

互联网技术的飞速发展使得基于Web的应用越来越普遍,同时也更加复杂.基于Web的动态Excel表格就是一个典型的实例.随着开发技术的不断发展,一些开源项目凭借其公开、自由以及免费等众多优势产生了越来越大的影响,很多项目都采用了开源技术.文中介绍了一种开源的基于Java的Excel报表开发组件POI引擎,阐述了其表格显示原理.通过在Web上实现动态Excel表格,给出了一种典型应用,并结合-个实际项目中的例子进行了分析,探索出了一种开发Web动态Excel表格的方法.     

Modal Operators for Coequations

We present the dual to Birkhoff's variety theorem in terms of predicates over the carrier of a cofree coalgebra. We then discuss the dual to Birkhoff's completeness theorem, showing how closure under deductive rules dualizes to yield two modal operators acting on coequations. We discuss the properties of these operators and show that they commute, and we prove the invariance theorem, which is the formal dual of the completeness theorem.     

变精度覆盖近似算子与覆盖近似算子的关系

变精度覆盖粗糙集模型是在放宽了覆盖标准的前提下给出的,因而导致近似算子发生了变化,但其变化有一定的规律。在介绍了覆盖粗糙集模型和变精度覆盖粗糙集模型的概念的基础上,给出并证明了变精度覆盖粗糙近似算子与覆盖粗糙近似算子之间的关系,即定理1、定理2及其推论。     

Boundary Procedures for Summation-by-Parts Operators

Four different methods of imposing boundary conditions for the linear advection-diffusion equation and a linear hyperbolic system are considered. The methods are analyzed using the energy method and the Laplace transform technique. Numerical calculations are done, considering in particular the case when the initial data and boundary data are inconsistent.     

一种基于关系数据库的Fix工控系统报表生成方法

本文通过分析当前在Fix工控系统报表制作过程中存在的问题，提出基于关系数据库和Fix Real-TimeODBC SQL接口的报表制作方法，并将这种方法在实践中加以运用，取得了良好的效果。     

Reducing Error in Spreadsheets: Example Driven Modeling Versus Traditional Programming

This article presents experimental data supporting an alternative approach to developing decision support spreadsheets using a Programming by Demonstration paradigm. This technique is coined “Example Driven Modeling” and uses example data (attribute classifications) in combination with inductive machine learning to create decision support models as an alternative to spreadsheet programming. This experiment examines whether participants can define attribute classifications (“example-giving”) satisfactorily and describe benefits and limitations this method offers through statistical analysis of the experimental results. The article then considers the wider implications of this research in traditional programming.     

Operators of preference composition for CP-nets

Now the handling of user preference is becoming an increasingly important issue in database fields where they capture soft criteria for queries. A broader category of qualitative preferences with dependent relations among multiple attributes is widely existing, which is CP-nets. In this article, we focus on designing the operators of preference composition for CP-nets. Firstly, we extend Pareto composition to our model by including equivalence relation ≈, incomparability relation ∥ and conflicting relation ⊥, which can preserve a strict partial order and conditional associativity. On this basis, two questions are solved: (a) the generation of satisfiability sequences for CP-nets, (b) the top-k queries of relational database with CP-nets preference. For (a), a CP-net is induced into multiple tables, consequently the strong dominance tests between outcomes can be solved by using preference composition instead of using induced preference graph of CP-nets. For (b), we adopt the concept of Query Lattice to provide a natural semantics for the block sequence answering a preference query, where two algorithms (called QOCP and IQOCP) are introduced. These questions are solved efficiently and effectively at the perspective of combination of graph model and relational database.     

粒计算中粒度转换的运算符

粒计算三元论模型将现有粒计算研究成果的共性抽象出来,为问题求解提供了统一的方法论,而三元论模型是以多层次、多视角的粒结构为基础的。基于图的粒结构首先定义了图上的粒和层次,然后基于半序关系定义了图上的粒结构。在基于图的粒结构基础上,给出了实现不同粒度之间转换的“细化”、“粗化”运算符。“细化”运算处理从粗粒度到细粒度的转换,将粗粒度层次中的粒转换为细粒度层次中的粒,将粗粒度层次转换为细粒度层次。“粗化”运算处理从细粒度到粗粒度的转换,将细粒度层次中的粒转换为粗粒度层次中的粒,将细粒度层次转换为粗粒度层次。通过粒结构和“细化”、“粗化”运算,可以在不同的粒度上分析同一问题并使其在不同粒度之间自由转换。     

Isospectral Domains for Discrete Elliptic Operators

Concerning the Laplace operator with homogeneous Dirichlet boundary conditions, the classical notion of isospectrality assumes that two domains are related when they give rise to the same spectrum. In two dimensions, non isometric, isospectral domains exist. It is not known however if all the eigenvalues relative to a specific domain can be preserved under suitable continuous deformation of its geometry. We show that this is possible when the 2D Laplacian is replaced by a finite dimensional version and the geometry is modified by respecting certain constraints. The analysis is carried out in a very small finite dimensional space, but it can be extended to more accurate finite-dimensional representations of the 2D Laplacian, with an increase of computational complexity. The aim of this paper is to introduce the preliminary steps in view of more serious generalizations.     

替固网运营商排忧

本世纪初,在西方国家电信业步履维艰之时,我国电信业继续保持着快速增长、不断满足社会需求、推进经济增长的良好势头,但主体电话业务已经步入平缓增长期,固网电信运营商正面临着“增量不增收”、ARPU值(平均每用户收入)下降、宽带业务上升缓慢的挑战。于是,彷徨与担忧接踵而来。那么,固网运营商的前景究竟如何?一、话音业务不是夕阳产业话音业务是固网运营商的主体业务和主要收入来源。然而,从全球看,固定电话用户数长期以来一直徘徊在4%到7%的年增长率,话音业务收入所占百分比也在慢慢下降,网上的话音流量已经低于数据流量。但是必须看…     

Foot Pedal Forces for Seated Operators

The foot controls of spot welding machines were orgonomicnlly evaluated, and redesign recammondations put forward. Ten male and ten female subjects were tested to dotermine the maximum isometric force that a seated operator could exert on a horizontal foot pedal. The experimental results showed no significant strength differences between right arid left legs and mole legs strengths were 9% to 50% greater than female leg strengths depending on the position of the foot pedal.     

Linear Differential Operators for Polynomial Equations

Given a squarefree polynomial P ∈ k₀[ x,y ], k₀a number field, we construct a linear differential operator that allows one to calculate the genus of the complex curve defined by P =  0 (when P is absolutely irreducible), the absolute factorization of P over the algebraic closure of k₀, and calculate information concerning the Galois group of P over ___ k₀(x) as well as overk₀ (x).