关于钣金部件设计中CAD技术探究与开发

介绍了数控冲床钣金加工CAD/CAM系统设计过程中遇到的模具自动匹配、夹钳位置设定与干涉检查、冲压禁区规避规划、特殊对象冲压计算、不规则曲线内阵列冲压计算等关键问题,研究并提出了有效的解决方案.     

组织项目管理成熟度(OPM3)模型构建

目前,在经济全球化的环境中,越来越多的组织已经把项目管理作为一种在当今高度竞争的商务环境中维持竞争优势的关键战略,并以各种努力去开发自己的项目管理能力,为其发展战略服务.组织项目管理成熟度模型(Organization Project Management Maturity Model,OPM3)作为一种全新的理念,它为组织项目管理能力的提升提供了一个评估与改进的框架.     

现代通信技术发展探析

适应社会和市场的需求是现代通信技术一务重要的发展原则.本文根据无线电通信技术的特点,对现代通信技术发展进行了分析.对通信技术发展的趋势进行了分析,最后提出了现代通信技术发展的对策,提出了自己的思考.     

用回溯法解决八皇后问题

八皇后问题是计算机科学中一个较经典的题目.本文提出用回溯法来解决八皇后问题,并给出了逻辑结构清晰、可读性强的递归算法,用C语言加以实现,得到了八皇后问题的12个真正不同的解.     

Supervised classification of share price trends

Share price trends can be recognized by using data clustering methods. However, the accuracy of these methods may be rather low. This paper presents a novel supervised classification scheme for the recognition and prediction of share price trends. We first produce a smooth time series using zero-phase filtering and singular spectrum analysis from the original share price data. We train pattern classifiers using the classification results of both original and filtered time series and then use these classifiers to predict the future share price trends. Experiment results obtained from both synthetic data and real share prices show that the proposed method is effective and outperforms the well-known K-means clustering algorithm.     

Type-2 fuzzy Gaussian mixture models

This paper presents a new extension of Gaussian mixture models (GMMs) based on type-2 fuzzy sets (T2 FSs) referred to as T2 FGMMs. The estimated parameters of the GMM may not accurately reflect the underlying distributions of the observations because of insufficient and noisy data in real-world problems. By three-dimensional membership functions of T2 FSs, T2 FGMMs use footprint of uncertainty (FOU) as well as interval secondary membership functions to handle GMMs uncertain mean vector or uncertain covariance matrix, and thus GMMs parameters vary anywhere in an interval with uniform possibilities. As a result, the likelihood of the T2 FGMM becomes an interval rather than a precise real number to account for GMMs uncertainty. These interval likelihoods are then processed by the generalized linear model (GLM) for classification decision-making. In this paper we focus on the role of the FOU in pattern classification. Multi-category classification on different data sets from UCI repository shows that T2 FGMMs are consistently as good as or better than GMMs in case of insufficient training data, and are also insensitive to different areas of the FOU. Based on T2 FGMMs, we extend hidden Markov models (HMMs) to type-2 fuzzy HMMs (T2 FHMMs). Phoneme classification in the babble noise shows that T2 FHMMs outperform classical HMMs in terms of the robustness and classification rate. We also find that the larger area of the FOU in T2 FHMMs with uncertain mean vectors performs better in classification when the signal-to-noise ratio is lower.     

GPU-based rendering for deformable translucent objects

In this paper we introduce an approximate image-space approach for real-time rendering of deformable translucent models by flattening the geometry and lighting information of objects into textures to calculate multi-scattering in texture spaces. We decompose the process into two stages, called the gathering and scattering corresponding to the computations for incident and exident irradiance respectively. We derive a simplified illumination model for the gathering of the incident irradiance, which is amenable for deformable models using two auxiliary textures. In the scattering stage, we adopt two modes for efficient accomplishment of the view-dependent scattering. Our approach is implemented by fully exploiting the capabilities of graphics processing units (GPUs). It achieves visually plausible results and real-time frame rates for deformable models on commodity desktop PCs.     

VICUR: A human-vision-based algorithm for curve reconstruction

In this paper, a new algorithm, named VICUR, is presented for curve reconstruction problem. From a set of unorganized points, the proposed algorithm can construct curves that look natural to human vision. The VICUR algorithm is based on two connectivity criteria: proximity and good continuation from the prominent Gestalt principles of perception. Experimental results are presented to show the effectiveness of VICUR.     

Dynamic composition and optimization of Web services

Process-based composition of Web services has recently gained significant momentum for the implementation of inter-organizational business collaborations. In this approach, individual Web services are choreographed into composite Web services whose integration logics are expressed as composition schema. In this paper, we present a goal-directed composition framework to support on-demand business processes. Composition schemas are generated incrementally by a rule inference mechanism based on a set of domain-specific business rules enriched with contextual information. In situations where multiple composition schemas can achieve the same goal, we must first select the best composition schema, wherein the best schema is selected based on the combination of its estimated execution quality and schema quality. By coupling the dynamic schema creation and quality-driven selection strategy in one single framework, we ensure that the generated composite service comply with business rules when being adapted and optimized.     

基于Matlab/Simulink的TMS320F2812代码开发

TMS320F2812 DSP是运动控制系统很好的硬件支撑平台,但传统的DSP代码开发周期较长,效率不高。Matlab公司的Embedded Target for TI C2000 DSP可解决上述问题,用户通过使用该模块,不仅可以进行电路的系统级仿真,还可编译生成相应的C语言代码,进行算法的探索与设计思路的验证。文章以三相异步电动机的VVVF结合SVPWM控制算法的开环控制系统为例,给出了Matlab/Simulink平台上DSP代码开发的设计流程。