A Generic Pigment Model for Digital Painting

We propose a generic pigment model suitable for digital painting in a wide range of genres including traditional Chinese painting and water-based painting. The model embodies a simulation of the pigment-water solution and its interaction with the brush and the paper at the level of pigment particles; such a level of detail is needed for achieving highly intricate effects by the artist. The simulation covers pigment diffusion and sorption processes at the paper surface, and aspects of pigment particle deposition on the paper. We follow rules and formulations from quantitative studies of adsorption and diffusion processes in surface chemistry and the textile industry. The result is a pigment model that spans a continuum from the very wet to the very dry brush stroke effects. We also propose a new pigment mixing method based on machine learning techniques to emulate pigment mixing in real life as well as to support the creation of new artificial pigments. To experiment with the proposed model, we embedded the model in a sophisticated digital brush system. The combined system exhibits interactive speed on a modest PC platform. http://www.cs.hku.hk/~songhua/pigment provides supplementary materials for this paper.     

The operational semantics of user-defined relationships in object oriented database systems

In semantic data models, abstract relationship (e.g. generalization, aggregation, etc.) semantics are defined, specifying how insertion, deletion and modification operations made at a higher level of abstraction can affect the objects abstracted over and vice versa. These semantics, also known as structural constraints, are expressed through so-called update rules. This perspective has been somewhat lost in most object-oriented systems, where user-defined relationships are supported as simple pointers and their semantics are embedded, distributed and replicated within the operations accessing these pointers. This paper inherits and extends the treatment of relationships found in semantic data models to behavioural object-oriented models by presenting an approach to uniformly capture the update rules for user-defined relationships. The stress is not on supporting relationships as first-class objects, but on describing their update rules (or operational semantics) through a set of constructors namely, reaction, anticipation, delegation and exception. The approach has been borne out by an implementation in an active object-oriented database system.     

动态Cache技术在网站性能设计中的应用

本文主要讲述如何利用Cache技术,来有效的提高网站性能。以ASP.NET为基础,展示ASP.NET中使用Cache的新特性,主要应用了Databasedependencies技术。     

面向对象的管理信息系统分析与设计

本文对面向对象方法（ＯＯ）应用于ＭＩＳ系统开发中的诸多问题进行了较详尽的讨论，提出了ＯＯ对象在管理应用领域存在管理生命周期（ＭＬＣ）的新思想，并将该思想应用到面向对象的ＭＩＳ系统分析与设计中，取得了较好的效果。     

电视节目资料管理及节目编排系统

系统采用XENIX操作系统和FoxBASE~+关系型数据库。本文简要介绍了该系统设计的基本原理、系统功能,并比较了XENIX多用户系统与DOS单用户系统的优缺点。     

一种基于Google Maps的土地利用信息发布平台

目前常见的Web地图服务仅支持浏览和查询,不支持矢量数据的发布.文章提出一种基于Google Maps的WebGIS构建方法,支持多种浏览器的矢量数据互操作及空间分析.针对郑州市土地利用信息发布需求,采用B/S架构,借助Google Maps API和AJAX技术,实现了土地利用信息系统化,标准化发布平台.该平台响应速度快,面向多种用户,支持数据共享,能更好的为土地利用变化研究及土地整理决策提供服务.     

基于GIS的房地产批量评估数据库构建研究-以深圳市为例

与传统单宗房地产评估不同,房地产批量评估需要建立在强大详实的数据库基础上,如何构建高可靠性、高扩展性以及高集成性的批量评估数据库成为一项关键任务。在对房地产批量评估数据进行分析的基础上,基于GIS技术提出了房地产批量评估数据库构建的技术路线,设计了数据库的总体结构,并研究了房地产批量评估数据集成的方法,最后以深圳市为例说明了该方法的有效性。     

数据库应用系统逻辑结构设计初探

数据库应用系统的逻辑设计是建立数据库应用系统过程中最为重要的一环。主要就如何科学合理地进行数据库系统逻辑设计,从E—R图向数据模型的转换、关系模式的规范化、改善优化数据库性能、存储空间的调整等四个方面进行分析和讨论。     

移动终端智能应答系统的实现

本系统针对当前移动手机用户在不方便接听、不愿意接听电话例如在开会、开车等各种各样的情形下．通过委婉的方式表达个人处境,达到礼貌告知对方的目的而开发的智能应答系统。业务的基本模式就是捕获到用户忙的事件,如果可能还需要区分是用户通话忙还是拒接忙,然后通过USSD向被叫推送一个提示如何回复用户的操作菜单,最后通过被叫用户的选择,给主叫用户一个答复,例如一个预定义的短信、IVR放音、转接语音信箱等多种方式。     

Access数据库的三个教学案例设计

针对初学者在学习Access数据库中遇到的困难,设计了三个教学案例,介绍报表中计算控件的使用、if语句的语法格式和通配符“？”和“’,的使用．对于提高Access数据库的教学效果有一定的参考价值。