1NF模糊时态数据库数据模型技术应用

为了使时态数据库能够更准确的表达现实世界事物的模糊属性,使之更加符合人们对客观事物的分析判断习惯,提高据库数据模型的映射能力,优化不同种类数据的相互转换过程,符合广泛用户定义的要求,我们针对同时具有时态性和模糊性的复杂数据,着手于时态数据库模型,建立起一个能够反映模糊时态数据的1NF模糊时态数据库数据模型,以对确定的及不确定的模糊时态数据做出模拟表达,同时还做了相关规则及操作元素的语义演算和分析,并从理论上对运算模型及模糊时态映射关系进行了数学论证,从而利用模糊的时态数据将事件的不确定性映射出来,提高了时态数据库有关模糊时态信息的直观性。     

时态逻辑形式化描述并发系统性质

时态逻辑是一种描述反应式(并发)系统中状态迁移序列的形式化方法，用于刻画并发系统所需验证的性质，是模型检测的基础．阐述了时态逻辑CTL及其子逻辑CTL、LTL的语法及语义，然后分析运用时态逻辑描述并发系统性质，最后给出一个应用实例。     

时态地理信息系统研究

时态地理信息系统的研究是现代空间信息系统的前景．它有重要的理论和实践的意义。这篇论文根据科学发展和社会需求，分析了时空数据模型当前研究的问题和进展，说明了时态地理信息系统发展的必要性．并提出取其构成特征作为基础的时空模型．和基于传感器机理、时空分析和时空推论的时空模型。所有这些工作会促进时态地理信息系统的新发展。     

基于时态元素的知识表示模型

本文建立了一种基于时态元素的时态知识表示方法，它能描述不同粒度世界中事件的时态方面。     

基于间断区间的1NF时态元组演算语言

Ｓ．Ｇａｄｉａ的ＴＣＡＬ时态元组演算语言及我们建立的时态元组演算语言均是Ｎ１ＮＦ的，它有进槽和出槽的麻顽。本文建立一个基于间断区间的１ＮＦ时态元组演算语言，它与我们建立的基于间断区间的１ＮＦ时态关系代数是等价的。     

时态推理中的若干问题研究

介绍了在时态推理方面的一些研究工作，包括基于间断区间的时态知识表示及其推理，以及模糊数学中两个基本操作的一些注记。     

一个模糊的1NF时态元组演算语言

考虑到模糊的Ｎ１ＮＦ时态关系存在进槽和出槽的麻烦，建立了一个基于间断区间的模糊的１ＮＦ时态元组演算语言，它能操作带时间的模糊数据。     

相似发现技术在时态数据挖掘中的应用

现实生活中,随处可见的Web的访问、股市交易的指数、气象的观测等等都是时态数据,所谓的时态数据的挖掘就是关注数据动态的特性,而相似发现技术在时态数据挖掘中的应用则关注数据的发展变化状况,并从其发展变化中试图发现事物动态所演化的相似性规律。通过阐述相似发现技术的3个主要任务,并以网络短文本舆情热点为研究对象,对相似发现技术在时态数据挖掘中的应用进行具体深入的分析和介绍。     

有效时间不确定性研究

时态数据库中的有效时间中引入了时态变量Now。本文主要介绍now产生的复杂语义,进而分析复杂语义带来的查询结果的时态不确定问题以及现有处理模型及其不足,最后建立now复杂语义不确定性时态数据模型。     

时态信息处理中的一些问题研究

讨论了时态信息处理面临的几个问题：“ＮＯＷ的处理，事件爆炸，事件在不同粒度世界中的描述。     

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.     

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.……     

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...     

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.     

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.……     

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.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...