并行MLFMA分布层的构造及其负载均衡

研究了并行多层快速多极子算法（MLFMA）的分布层,提出了一种衡量其负载不均衡程度的方法,并在此基础上提出了分布树的一种新的构造算法。通过预先估算按分布层的不同层均分所得分布层的负载不均衡度,选取了一种负载不均衡度较小的方法来构造分布树。实验结果表明,该算法相比传统的按分布层的最细层均分所得分布树的算法,能更为有效地提高整个多层快速多极子算法的并行效率。     

AVL树在FAT文件系统中的应用与研究

FAT文件系统是一种适用于各种应用的优秀文件系统管理模式.通过深入分析FAT文件系统簇的组织管理模式,剖析其在实时性能上的不足之处,提出了利用AVL树来组织管理FAT文件系统内连续空闲块信息的新方法,并在此基础实现了文件读写等一系列优化算法.通过仿真测试,优化后的FAT文件系统在保持其兼容性的前提下,能有效地提高文件操作响应的实时性.     

基于流密码的可重构处理结构及其专用指令集研究

在对多种流密码算法生成结构进行分析的基础上,提出一种基于流密码的可重构处理结构,并在总结重构流密码算法使用频率较高的基本操作类型的基础上,为该流密码可重构处理结构设计了一种专用指令集。描述了指令的具体格式,并对指令性能进行了评估。结果表明,该指令集作用在该流密码可重构结构上可灵活高效地实现多种流密码算法。     

磷化工工艺决策支持系统的构建

将决策支持系统(DSS)理论与磷化工工艺技术结合,建立磷化工工艺决策支持系统.介绍了该系统的基本理论、建立步骤、组成和数据处理框架的构成和功能,并利用层次分析法(AHP)、线性加权法和基于估计相对位置的方案排队法3种多属性决策方法实现辅助决策过程.磷化工工艺决策支持系统能够对磷矿资源合理利用、工艺优化选择提供决策辅助评判.     

苯与羰基钼相互作用的密度泛函研究

用密度泛函理论在B3LYP/LANL2DZ基组水平上自由优化(η~x-C_6H_6)Mo(CO)_n(x=1-6;n=1-5)复合物体系的可能构型及计算相互作用能,探索不同羰基数对复合物稳定性、苯和羰基钼相互作用的影响,并分析苯和羰基钼相互作用的NBO。结论(1)苯以η~6与Mo(CO)_n(n=1-3)配位形成的复合物比较稳定,但η~6配位复合物CO的个数越多,则越不稳定;(2)复合物1、2、3和10中,Mo(CO)_n与苯的相互作用拉动电荷由苯的π键电子向Mo(CO)_n的σ_(Mo-CO)~*键转移,而在复合物7中,苯的π键电子向Mo(CO)_n中Mo的孤对电子轨道d转移。     

人工免疫动态克隆调节策略在分馏装置塔板效率确定中的应用

在石油化工领域中,分馏过程是流程模拟计算中重要的模块之一,在分馏过程模拟的主要输入参数中,塔盘效率无法直接获得,因此确定合适的塔盘效率是分馏模拟成功与否的关键因素,探索合适的方法确定板效率是精馏模拟的重要课题。本文在板效率确定方面,引入人工免疫动态克隆优化调节策略DCAS,与传统的智能优化算法相比,该算法的特点为:自动调整搜索空间及克隆规模;采用多尺度变异策略;有机结合全局与局部搜索能力。在实验中,通过建立分馏装置的机理模型,并采集装置的实际工况数据和各流股质量组成的分析数据,对所采集的数据依据稳态过程的物料守恒方程等进行剔除和校正处理,采用校正后的工况数据作为模型的输入,分别用经验法、遗传算法GA及人工免疫动态调整策略DCAS确定分馏装置的塔板效率,使模型与实际装置达到最大程度的吻合。研究结果表明,用DCAS确定的塔板效率,能够使分馏塔的关键塔板温度分布及分馏塔塔顶、塔釜主要产品的产出与实际吻合得最好,表明用DCAS搜索的塔板效率建立的分馏塔模型能够较好地描述实际分馏塔的生产过程,可以用来指导分馏装置的过程模拟及优化操作。     

Cr(CO)_n(n=1-5)与C_6 H_6相互作用的密度泛函研究

用密度泛函理论在B3LYP/LANL2DZ基组水平上对(η~x-C_6H_6)Cr(CO)_n(x=1-6;n=1-5)复合物体系的可能构型进行了自由优化及相互作用能的计算,研究了不同羰基数对复合物稳定性、苯和羰基铬相互作用的影响,并对苯和羰基铬相互作用进行了NBO分析。得到以下结论:(1)当n≤3时,苯与Cr(CO)_n以η~6配位;当n≥4时,苯与Cr(CO)_n以η~2配位;(2)最稳定复合物中随羰基数的增加Cr-C_(benzene)平均键长增长,最大二面角H-C-C-H偏离碳环的角度随复合物对称性降低而逐渐增大;(3)当n为奇数时,复合物相互作用主要表现为苯C-C键的π轨道和Cr-CO键的σ反键轨道;当n为偶数时,复合物相互作用主要表现为苯C-C键的π轨道或π~*轨道与Cr的孤对电子轨道;(4)复合物羰基数越多,最稳定复合物的相互作用能数值越大,稳定性越小。     

3D-freehand-pose initialization based on operator’s cognitive behavioral models

Tracking, recognition and interaction based on 3D freehand are a part of our virtual assembly system, in which monocular camera is used to input online freehand videos and the hand pose tracker requires a reliable initial pose in the first frame. A novel approach to initializing 3D pose and position of freehand is put forward in this paper visualization of 3D hand model and modeling the operators’ cognitive behaviors. Our approach is composed of three phases: hand posture recognition, coarse-tuning and fine-tuning. The operator moves his/her hand onto the to meet the needs of our virtual assembly system. The main contribution of this paper is that the three core techniques are for the first time integrated together, including human–computer interaction (HCI) in the process of initializing, projection of the 3D hand model in the period of coarse-tuning time. Then, the computer repeatedly fine-tunes the 3D hand model until the projection of the 3D hand model is completely superimposed onto the operator’s hand image. We focus on exploring and modeling cognitive behavior of operator’s hand upon which we design our initialization algorithm. Our research shows that cognitive behavioral models are not only beneficial to reducing cognitive loads for operators, because it makes the computers cater for the changes of the operators’ hand poses, but also helpful to address high dimensionality of articulated 3D hand model. Our experimental results also show that the approach presented in this paper is easier, more pleasurable and satisfactory experience for the operators. Our initialization system has successfully been applied to our 3D freehand tracking system and a simulation virtual assembly system.     

A fully geometric approach for developable cloth deformation simulation

We present a new method for simulation of inextensible cloth subjected to a conservative force (e.g., the gravity) and collision-free constraint. Traditional algorithms for cloth simulation are all physically-based in which cloth is treated as an elastic material with some stiffness coefficient(s). These algorithms break down ultimately if one tries to set this stiffness coefficient to infinite which corresponds to inextensible cloth. The crux of the method is an algorithm for interpolating a given set of arbitrary points or space curves by a smooth developable mesh surface. We formulate this interpolation problem as a mesh deformation process that transforms an initial developable mesh surface, e.g., a planar figure, to a final mesh surface that interpolates the given points (called anchor points). During the deformation process, all the triangle elements in the intermediate meshes are kept isometric to their initial shapes, while the potential energy due to the conservative force is reduced gradually. The collision problem is resolved by introducing dynamic anchor points owing to the collision during the deformation. Notwithstanding its simplicity, the proposed method has shown some promising efficacy for simulation of inextensible cloth.     

BASE: A bacteria foraging algorithm for cell formation with sequence data

A cellular manufacturing system (CMS) is considered an efficient production strategy for batch type production. A CMS relies on the principle of grouping machines into machine cells and grouping parts into part families on the basis of pertinent similarity measures. The bacteria foraging algorithm (BFA) is a newly developed computation technique extracted from the social foraging behavior of Escherichia coli (E. coli) bacteria. Ever since Kevin M. Passino invented the BFA, one of the main challenges has been employment of the algorithm to problem areas other than those for which the algorithm was proposed. This research work studies the first applications of this emerging novel optimization algorithm to the cell formation (CF) problem considering the operation sequence. In addition, a newly developed BFA-based optimization algorithm for CF based on operation sequences is discussed. In this paper, an attempt is made to solve the CF problem, while taking into consideration the number of voids in the cells and the number of inter-cell travels based on operational sequences of the parts visited by the machines. The BFA is suggested to create machine cells and part families. The performance of the proposed algorithm is compared with that of a number of algorithms that are most commonly used and reported in the corresponding scientific literature, such as the CASE clustering algorithm for sequence data, the ACCORD bicriterion clustering algorithm and modified ART1, and using a defined performance measure known as group technology efficiency and bond efficiency. The results show better performance of the proposed algorithm.