Pseudo-Kernelization: A Branch-then-Reduce Approach for FPT Problems

Pseudo-kernelization is introduced in this paper as a new strategy for improving fixed-parameter algorithms. This new technique works for bounded search tree algorithms by identifying favorable branching conditions whose absence could be used to reduce the size of corresponding problem instances. Pseudo-kernelization applies well to hitting set problems. It can be used either to improve the search tree size of a 3-Hitting-Set algorithm from O^*(2.179^k) to O^*(2.05^k), or to improve the kernel size from k³ to 27k. In this paper the parameterized 3-Hitting-Set and Face Cover problems are used as typical examples.     

Positive and negative aspects of the work of information technology personnel: an exploratory analysis

This paper re-analyses data gathered in a 1989 research among Dutch information technology personnel. Working from Karasek's job stress model, we use exploratory multiple correspondence analyses on the aggregated data matrix of occupations and work items. We employed two models: one that emphasised the negative evaluations of job aspects, and one that emphasised positive evaluations. The structuring of positive evaluations of job aspects proved most meaningful. Occupations could be distinguished into three groups. The first and largest group is characterised by a fairly balanced degree of autonomy and workload. A second group comprised of middle management occupations is characterised by unfavourable judgement on workload, matched by insufficient autonomy; as such, employees in these occupations appear at risk of overburdening. A third group of computer specialists report a workload that is too slight given their degree of autonomy; this group appears to be at risk of underburdening.     

Positive and negative aspects of the work of information technology personnel: An exploratory analysis

This paper re-analyses data gathered in a 1989 research among Dutch information technology personnel. Working from Karasek's job stress model, we use exploratory multiple correspondence analyses on the aggregated data matrix of occupations and work items. We employed two models: one that emphasised the negative evaluations of job aspects, and one that emphasised positive evaluations. The structuring of positive evaluations of job aspects proved most meaningful. Occupations could be distinguished into three groups. The first and largest group is characterised by a fairly balanced degree of autonomy and workload. A second group comprised of middle management occupations is characterised by unfavourable judgement on workload, matched by insufficient autonomy; as such, employees in these occupations appear at risk of overburdening. A third group of computer specialists report a workload that is too slight given their degree of autonomy; this group appears to be at risk of underburdening.     

User support: revealing structure instead of surface

Abstract

The development of different help systems and the application of numerous approaches to user support have shown (a) that end-users may encounter insuperably complex use situations, and (b) that it is possible to assist users significantly by implementing computerized help systems. There are many approaches to the realization of user support, varying from the use of natural language to user modelling. However, the current help systems seem to focus on relatively technical data processing issues, ignoring the organizational context in which the use takes place. It is asserted in this paper that it is relevant for users to perceive the organizational context and that it is possible to reflect the context in a support system. Representing the context in a support system is made possible by introducing a context database. A context database is parallel to the actual database and contains information about task flows, task-connected information objects and the like. Therefore the analysis of work and information systems has to be based on related areas. The areas of inquiry are (a) tasks, (b) job design, (c) organization of work, (d) computer applications and (e) information media. The following kinds of mappings can be incorporated within the context database: [organizational unit Ol]-T_person PI in job]-[job task Tl]-[task-connected information Il]-[task-connected information 12]-[job task T2]-[person in job P2]-[organizational unit O2], This type of chain (or parts of it) can then be visualized as context support.     

基于．NET环境下ADO．NET访问数据库技术的研究

ADO．NET是微软针对ADO的缺陷而重新设计的一种全新的数据库访问模型,它支持工业标准,集合了所有用于数据处理的类。该文研究了ADO．NET的体系结构和数据绑定技术,创新性的对利用ADO．NET访问数据库的不同方式进行了探究．对于软件开发人员连接数据库具有一定的指导意义。     

基于.NET环境下ADO.NET访问数据库技术的研究

ADO.NET是微软针对ADO的缺陷而重新设计的一种全新的数据库访问模型,它支持工业标准,集合了所有用于数据处理的类。该文研究了ADO.NET的体系结构和数据绑定技术,创新性的对利用ADO.NET访问数据库的不同方式进行了探究,对于软件开发人员连接数据库具有一定的指导意义。     

User support: revealing structure instead of surface

The development of different help systems and the application of numerous approaches to user support have shown (a) that end-users may encounter insuperably complex use situations, and (b) that it is possible to assist users significantly by implementing computerized help systems. There are many approaches to the realization of user support, varying from the use of natural language to user modelling. However, the current help systems seem to focus on relatively technical data processing issues, ignoring the organizational context in which the use takes place. It is asserted in this paper that it is relevant for users to perceive the organizational context and that it is possible to reflect the context in a support system. Representing the context in a support system is made possible by introducing a context database. A context database is parallel to the actual database and contains information about task flows, task-connected information objects and the like. Therefore the analysis of work and information systems has to be based on related areas. The areas of inquiry are (a) tasks, (b) job design, (c) organization of work, (d) computer applications and (e) information media. The following kinds of mappings can be incorporated within the context database: [organizational unit Ol]-T_person PI in job]-[job task Tl]-[task-connected information Il]-[task-connected information 12]-[job task T2]-[person in job P2]-[organizational unit O2], This type of chain (or parts of it) can then be visualized as context support.     

Scheduling two jobs with fixed and nonfixed routes

The shop-scheduling problem with two jobs andm machines is considered under the condition that the machine order is fixed in advance for the first job and nonfixed for the second job. The problems of makespan and mean flow time minimization are proved to be NP-hard if operation preemption is forbidden. In the case of preemption allowance for any given regular criterion theO(n _*) algorithm is proposed. Here,n _* is the maximum number of operations per job.     

基于ASP.NET/C#的Web应用程序关键技术研究与实现

本文首先介绍了.NET下Web数据库开发技术,在此基础上讨论了在ASP.NET下Web应用程序中的基于ADO.NET的数据访问方法和动态数据绑定技术,采用的Form-Based验证机制实现了对数据库页面的安全调用,分析了访问数据库的代码后置和使用存储过程的技术,同时对如何动态绑定TreeView控件、DataGrid控件和DropDownList控件进行了介绍.     

软件技术专业.NET实训课程教学设计与探索

软件技术专业.NET方向开设的实训类课程应当具有较强的综合性,为此设计了实践性很强的课程体系,主要由C#程序设计、数据库设计、UML建模、.NET多层架构设计、ASP.NET动态Web开发技术等专业课程组成,其教学以典型的企业化项目为载体,系统、全面的训练学生综合系统开发、设计与编码能力;遵照企业标准和岗位流程培养学生项目设计、编码以及团队合作开发能力,为其定岗实习和就业打下基础。     

基于VB.NET的ADO.NET对象与数据库的交互

当今世界对数据的需求越来越迫切,无论采用任何软件编写程序访问数据库,都必须事先建立好数据库,用VB.NET访问数据库也是如此。在VB.NET中,微软推出了新的数据访问模型ADO.NET,它将成为构建数据感知.NET应用程序的基础。     

基于.NET平台通用数据库组件的设计与实现

基于现实IT工程的需求,在研究国内通用数据库引擎的情况下,结合.NET自身开放性的特点,利用XML技术设计了一种基于.NET平台新的通用数据库组件访问方案,提供了一套跨平台快速访问多个数据库的统一接口,从而进一步扩充了.NET对数据进行操作的能力.利用该技术,不仅克服了.NET对单一数据库的操作,而且能够快速查找并定位数据接口的功能,优化对大量不同类型数据操作的性能,提高系统工作的效率.     

WoLMIS: a labor market intelligence system for classifying web job vacancies

In the last decades, an increasing number of employers and job seekers have been relying on Web resources to get in touch and to find a job. If appropriately retrieved and analyzed, the huge number of job vacancies available today on on-line job portals can provide detailed and valuable information about the Web Labor Market dynamics and trends. In particular, this information can be useful to all actors, public and private, who play a role in the European Labor Market. This paper presents WoLMIS, a system aimed at collecting and automatically classifying multilingual Web job vacancies with respect to a standard taxonomy of occupations. The proposed system has been developed for the Cedefop European agency, which supports the development of European Vocational Education and Training (VET) policies and contributes to their implementation. In particular, WoLMIS allows analysts and Labor Market specialists to make sense of Labor Market dynamics and trends of several countries in Europe, by overcoming linguistic boundaries across national borders. A detailed experimental evaluation analysis is also provided for a set of about 2 million job vacancies, collected from a set of UK and Irish Web job sites from June to September 2015.     

基于.NET的Web Service技术的分布式异构数据库的集成

本文分析了Web Service的特点,提出了一种基于Microsoft.NET的Web Service技术访问分布异构数据库的体系结构,并采用.NET技术实现了原型系统.在原型系统中,使用Web Service将分布于Internet上不同的数据库系统中的数据集成,向访问数据库的应用程序提供统一的数据操作接口,实现了分布式数据库的透明访问.     

基于C#的ADO.NET访问数据库技术

ADO.NET是微软针对ADO的缺陷而重新设计的一种全新的数据库访问模型,它支持工业标准,集合了所有用于数据处理的类。文章论述了ADO.NET的结构和其中的主要对象,探讨了利用ADO.NET技术访问数据库的方式。同时对如何绑定DataGrid控件、TextBox控件进行了介绍。     

基于C#的ADO．NET访问数据库技术

ADO．NET是微软针对ADO的缺陷而重新设计的一种全新的数据库访问模型，它支持工业标准，集合了所有用于数据处理的类。文章论述了ADO．NET的结构和其中的主要对象，探讨了利用ADO．NET技术访问数据库的方式。同时对如何绑定DataGrid控件、TextBox控件进行了介绍。     

Parallel algorithms for arrangements

We give the first efficient parallel algorithms for solving the arrangement problem. We give a deterministic algorithm for the CREW PRAM which runs in nearly optimal bounds ofO (logn log^* n) time andn ²/logn processors. We generalize this to obtain anO (logn log^* n)-time algorithm usingn ^d /logn processors for solving the problem ind dimensions. We also give a randomized algorithm for the EREW PRAM that constructs an arrangement ofn lines on-line, in which each insertion is done in optimalO (logn) time usingn/logn processors. Our algorithms develop new parallel data structures and new methods for traversing an arrangement.This work was supported by the National Science Foundation, under Grants CCR-8657562 and CCR-8858799, NSF/DARPA under Grant CCR-8907960, and Digital Equipment Corporation. A preliminary version of this paper appeared at the Second Annual ACM Symposium on Parallel Algorithms and Architectures [3].     

Dynamic Programming for Minimum Steiner Trees

We present a new dynamic programming algorithm that solves the minimum Steiner tree problem on graphs with k terminals in time O^*(c^k) for any c > 2. This improves the running time of the previously fastest parameterized algorithm by Dreyfus-Wagner of order O^*(3^k) and the so-called "full set dynamic programming" algorithm solving rectilinear instances in time O^*(2.38^k).     

Multimedia Indexing with the SMART system

The storage and retrieval of multimedia data is a crucial problem in multimedia information systems due to the huge storage requirements. It is necessary to provide an efficient methodology for the indexing of multimedia data for rapid retrieval. The aim of this paper is to introduce a methodology to represent, simplify, store, retrieve and reconstruct an image from a repository. An algebraic representation of the spatio-temporal relations present in a document is constructed from an equivalent graph representation and used to index the document. We use this representation to simplify and later reconstruct the complete index. This methodology has been tested by implementation of a prototype system called Simplified Modeling to Access and ReTrieve multimedia information (SMART). Experimental results show that the complexity of an index of a 2D document is O (n^*(n−1)/k) with k≥2 as opposed to the O (n^*(n−1)/2) known so far. Since k depends on the number of objects in an image more complex documents have lower overall complexity.     

P2-Packing问题参数算法的改进

P₂-Packing问题是一个典型的NP难问题.目前这个问题的最好结果是时间复杂度为O^*(2^5.301k)的参数算法,其核的大小为15k.通过对P₂-packing问题的结构作进一步分析,提出了改进的核心化算法,得到大小为7k的核,并在此基础上提出了一种时间复杂度为O^*(2^4.142k)的参数算法,大幅度改进了目前文献中的最好结果.