分布式本体库存储模型的设计与优化

针对如何高效地构建用于语义交互的分布式本体库展开了研究。首先,分析了基于本体的语义交互平台的通用体系结构,进而明确分布式本体库在平台中的作用,提出了一种分布式本体库存储模型。围绕该模型,详细讨论了网络本体库与本地本体库的映射方法,语义数据的编码方法,然后详细分析了该模型中指令分发和数据演化组件的工作机制,最后通过实验验证了:在集群存储模式下,对于大数据量查询,网络数据传输对查询时间开销的影响远远小于查询本身,从而为分布式本体库存储效率的优化奠定了基础,即在本体库中采用分布式集群存储可以达到优化检索效率的目的。该存储模型已经在STASIS平台中得到应用。     

基于结构相似性的轴类零件加工特征可拓关联方法

在现有轴类零件相似性检索方法的基础上,将轴类零件的信息模型划分为结构特征层和加工工艺层,并利用可拓基元方法进行形式化描述.提出从轴类零件结构和加工工艺两方面进行相似性检索的方法:首先基于结构矩阵表达方法,对轴类零件的结构特征进行相似性检索,从实例库中检索出2~5个相似实例,然后以可拓综合关联函数进行加工特征的相似度匹配,得出与新零件最相似的零件.通过实例验证,该方法具有可行性,并且可在检索过程中动态调整系数水平,具有检索适应性强的优点.     

基于用户兴趣本体的数字图书馆个性化检索研究

为满足数字图书馆信息检索中用户个性化需求,本文描述了一个基于用户兴趣本体的个性化检索模型．该模型将用户兴趣本体应用于图书馆检索,包括用户兴趣模型的构建、用户兴趣查询扩展以及个性化检索结果排序等。在用户访问数字图书馆过程中,利用用户兴趣本体来匹配和扩展用户关键词,实现语义化的检索,满足用户个性化需求。     

民机客户服务标准化信息系统研究

本文分析了民机客户服务本体的构建方法,提出了基于本体的标准资料表示模型和检索算法,对标准体系管理、标准化工作流程管理、标准贯彻,以及标准信息服务等内容进行了探讨,并通过原型系统实现了上述功能,提高了标准资料的利用效率和客户服务标准化工作的效率。     

玉米雌穗几何造型研究

通过对玉米雌穗形态结构的观测分析,提出了基于形态结构特征参数的玉米雌穗三维形态教学模型和可视化实现方法.根据玉米雌穗结构特征,雌穗建模过程包括雌穗轴线设计、果穗柄造型、穗轴造型、苞叶造型和籽粒造型5个阶段.对于不同玉米品种,通过设置模型参数,即可在计算机上实现雌穗的三维显示,具有较强的真实感效果.该模型可控性强,易于操作,可满足玉米雌穗数字化设计的需要.     

一种基于向量空间模型的质谱谱库检索算法

本文基于向量空间模型,提出了一种质谱谱库检索算法。该算法将质谱图数据向量化,并定义一个质量数向量空间,质谱图被表示成质量数空间内的一组向量,并利用向量间的相似性计算方法,实现质谱谱库的检索。并且,将(m/e)m.In作为权重进行质谱图相似性的计算,而不仅仅是(m/e)。通过试验,该算法的检索结果与NIST 05检索软件的检索结果一致。     

基于Tversky特征相似度的谱库检索算法

针对传统谱库检索效率低,提出了一种基于Tversky特征相似度的谱库检索算法。它优化了基于向量空间模型的谱库检索算法,并在准确定性分析化合物的前提下,通过大幅度减少原有相似度算法中的乘积运算来缩短谱库检索的时间。实验表明,该算法的检测结果和NIST 11的结果完全一样,并且谱库检索的时间缩短了5.22%,具有一定的检索优势。     

基于形状拆分的机械零件三维模型检索

提出一种基于形状拆分的机械零件三维模型检索方法.首先根据零件名称和功能,将机械零件模型库按传统方式划分为四大类,即轴套类、盘盖类、叉架类和箱体类,三维模型之间的匹配在同一类模型中进行;随后进行三维模型外轮廓扫描,将整个三维模型拆分成若干平面体、回转体和曲面体,根据同一型体之间特征数量和参数的不同,进行单一型体之间的匹配;最后根据单一型体的数量和匹配对的相似度,综合计算整个模型的相似度.单一型体的定义和整个匹配算法均是围绕着形状和工艺相似进行的.通过实例验证了该方法的有效性.     

本体概念分类的遗传算法

提出了一种基于遗传算法的本体概念分类规则学习方法(GAOCL).该方法从已有的本体库或知识库中获取实例作为训练样本,通过遗传算法获取相关的概念分类规则,实现概念实例的有效分类,以达到扩充和丰富本体的目的.首先,在编码过程中采用了可变长度的规则集合作为个体,以满足不同概念对分类规则数目的不同要求.其次,定义了规则集相对覆盖率,并以此作为适应值函数,评估个体对概念实例的分类效果,实现优化迭代.最后,给出了基于遗传算法的本体分类规则学习算法.利用一组标准样本集对该算法与同类算法进行了比较,实验结果表明该算法具有很好的收敛性,并且能获得较好的分类效果.     

基于临床路径与CBR的单病种成本预测研究

单病种成本估计是医院成本管理中的重要环节,分析了单病种成本估算中存在的问题,提出了基于临床路径与事例推理(CBR)的单病种成本预测方法,运用CBR技术从病例库中检索最相似病例来预测新病例的单病种成本。重点研究了基于医院信息系统(HIS)的病例库组织模型和基于模拟退火算法的特征权重优化方法,提高了病例的检索效率和准确度。最后通过一个实例证明了该方法的有效性,能够大大提高医院成本管理工作的及时性。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.