This paper presents an automatic non-photorealistic rendering approach to generating technical illustration from 3D models. It first decomposes the 3D object into a set of CSG primitives, and then performs the hidden surface removal based on the prioritized list, in which the rendition order of CSG primitives is sorted out by depth. Then, each primitive is illustrated by the pre-defined empirical lighting model, and the system mimics the stroke-drawing by user-specified style. In order to artistically and flexibly modulate the illumination, the empirical lighting model is defined by three major components: parameters of multi-level lighting intensities, parametric spatial occupations for each lighting level, and an interpolation method to calculate the lighting distribution over primitives. The stylized illustration is simulated by a grid-based method, in which we ‘fill’ the desirable pictorial units into the spatial occupation of CSG primitives, instead of “pixel-by-pixel” painting. This region-by-region shading facilitates the simulation of illustration styles.
单个Web服务难以满足实际应用的需求,如何组合已有的服务,形成新的服务,已成为此领域的研究热点。现在的组合方法极少考虑服务质量QoS(Quality of Service)。对于一些提供相似功能的Web服务,服务质量是判断是否选择此服务的关键因素,组合服务的质量必须满足用户的需求。本文基于SOA的服务开发思想,针对当前服务组合存在的问题,提出了一种基于QoS的服务组合方法,并给出了构建基于QoS的Web服务组合及选择最佳服务的策略,通过整合单个服务的质量以得到最终组合服务的整体最佳质量。在满足用户组合服务的功能需求的同时,也满足了用户对服务质量QoS的需求,实现了需求服务的优化。
Recently service orientation is becoming a mainstream approach for building large scale software systems. A key requirement in service-oriented design is the de- pendability of service. It stipulates that the behavior of services is controllable. Formal models can aid in constructing software in a dependable manner. They can describe ser- vices precisely and compose them together consistently. This paper presents a strategy for service realization based on a novel layered formal model. When a service is provided or required via internet, the semantic consistency becomes critical issue. Our architecture tackles the issue by proposing a novel scheme: defining contract of a service to keep semantic information. Although service-oriented design is our prime target, the contract models, to a large extent, are independent of the framework of design and therefore ap- plicable to large scale software design in general.
