高层结构方案实例库系统及其在结构智能选型中应用

从结构方案设计的角度,建立了工程实例信息的统一表征模型,收集获取了国内外1008个高层结构工程实例信息。在此基础上,利用关系数据库技术建造了高层结构实例库及其管理系统,实现了实例数据录入、修改、删除、查询、统计和知识发现等功能。最后结合高层结构智能选型的实际,给出了基于实例库的定量型与模糊型结构选型规则的挖掘过程与方法,同时还构建了定量属性的模糊区间划分及其模糊化方法,分析探讨了基于Apriori算法的关联分析方法在工程智能设计等方面的可能应用。上述工作为挖掘与充分利用已有工程实例中的知识信息,提高结构设计效率、质量与智能化水平等提供了新的途径、方法与手段等的支持。     

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.     

基于知识工程复杂产品开发过程的模型研究

 为了提高复杂产品开发的效率,驾驭复杂产品开发过程各个环节相互关联的复杂性,提出一种基于知识工程的复杂产品开发过程新模型.该模型把知识工程理论融入复杂产品开发全生命周期过程中,通过知识推理技术从数据库和知识库中获取相应开发阶段的知识和数据来驱动和指导整个复杂产品开发过程,以更好地重用设计知识.研究了该模型的关键技术,包括复杂产品开发知识处理技术和基于知识的CAD/CAM/CAE/CAPP集成技术,提出了两种知识处理方法,即基于规则-对象-框架的知识处理方法和基于规则-实例的知识处理方法,并研究了相应的推理算法;以知识库、数据库、规则库和实例库为基础,通过PDM,STEP中型文件、规则、实例和知识等,实现CAD/CAM/CAE/CAPP集成.最后,通过数据库技术、编程语言VC# . NET和CATIA软件实现了隧道掘进机（TBM）主机的快速设计系统,有效地减少了隧道掘进机主机开发的复杂性和缩短开发周期,以TBM主机为应用实例进一步介绍该模型的合理性和有效性.     

失效分析专家系统

对系统结构、失效分析知识的获取和表达及计算机推理进行了研究.该系统包括六个主要功能模块:知识库及其管理系统、知识获取、数据库及其管理系统、字典库及其管理系统、推理机、人机交互界面.失效分析知识的获取采用了通过文本及机器学习方法;知识的表达采用了框架、规则及面向对象综合表达方式.计算机推理则采用不确定性推理方法,具体采用了置信度方法.     

可拓知识库系统及其应用

知识库系统是一种专门存储、管理大量知识的机构。文章以可拓学的理论和方法为指导,提出可拓知识表示法和可拓知识库系统的特点与构架。给出了可拓知识表示的形式化语义,其基本单元是知识物元;阐述了矛盾问题求解的形式表示,其核心是问题的物元模型,通过可拓算子把不相容问题转化为相容问题;相关方式推理是可拓知识库系统推理机的特点,是传统规则推理的推广。可拓知识库采用可拓知识表示方法,是传统知识库的一个超集;可拓知识库系统由目标库、条件库、公用知识库、分类知识库、推理机与知识库管理系统组成。     

基于知识库的知识发现（KDK）的结构模型与挖掘算法研究

从知识库中发现新知识KDK (knowledge discovery in knowledgebase) 是一个新课题，它的成功将直接作用于大型知识库的构建，并将为解决目前机器学习的瓶颈问题——知识获取起到重要影响。笔者的主要工作是：基于知识库中事实的KDK归纳结构、算法及其验证；基于知识库中规则的KDK归纳结构、算法及其验证。     

热障涂层知识库系统的设计和构建

设计并建立了热障涂层知识库系统,采用多用户的管理模式由知识库管理系统统管整个知识库系统.系统采用问答方式进行询问回答,并给出相应建议和具体的实例说明.建立了临时库,方便用户自行添加规则进行推理.     

一类基于认知心理特征的知识发现新模型

为克服数据挖掘过程中的"数据海量,算法复杂"的困扰,建立了两个用于在知识发现系统与过程中模拟认知心理特征的协调器--启发型协调器和维护型协调器,从而实现了系统自主地发现知识短缺和进行知识库的实时维护;创建了双库协同机制,它揭示了数据库与知识库在特定构造下,两个范畴间的等价关系(即结构对应定理);并将这两个协调器和双库协同机制融入经典的数据库中的知识发现(KDD)过程模型,诱导出新的知识发现过程模型--KDD和基于数据库和知识库双库数据挖掘(KD (D&K))过程模型,实现了"定向搜索"与"定向挖掘".最后通过实例验证了其有效性与先进性.     

知识库构建工具软件的设计与实现

人工智能研究领域之一的专家系统在工程设备上的应用需求较为广泛,但满足用户需求的应用实例很少,主要原因在于知识库构建复杂且困难,其质量得不到保障。针对这个问题,研究了知识获取存在的问题,开发了以故障树为核心表达方式的知识库构建工具软件,实现了故障诊断功能。根据工程实际需要,采用J2EE技术开发了一套B/S（browser/server,浏览器/服务器）模式知识库构建工具软件,并对知识库各模块进行了需求分析设计,包括知识模型的数据结构设计和业务层逻辑方法的设计。此外,还探讨了知识模型的多样性表达,以3种命名方式来表达完整的故障树。最后,通过实例说明了该知识库构建工具软件的可行性。研究结果表明：知识获取模块采用故障树表达方式,有利于知识库质量的提高;选择网页Web形式,可以实现多用户/多工位知识编辑和输入,显著提高知识获取效率。该知识获取辅助系统具有强通用性,为领域专家和工程师构建知识库提供了有力支持。     

产品基因及其在能量转换功能求解中的应用

 提出了能量转换型原理解的产品基因模型,构造了能量型产品基因知识库,建立了基于产品基因的启发式原理方案求解模型,并给出了求解实例。     

Bridging customer knowledge to innovative product development: a data mining approach

In the big data era, firms are inundated with customer data, which are valuable in improving services, developing new products, and identifying new markets. However, it is not clear how companies apply data-driven methods to facilitate customer knowledge management when developing innovative new products. Studies have investigated the specific benefits of applying data-driven methods in customer knowledge management, but failed to systematically investigate the specific mechanics of how firms realised these benefits. Accordingly, this study proposes a systematic approach to link customer knowledge with innovative product development in a data-driven environment. To mine customer needs, this study adopts the Apriori algorithm and C5.0 in addition to the association rule and decision tree methodologies for data mining. It provides a systematic and effective method for managers to extract knowledge ‘from’ and ‘about’ customers to identify their preferences, enabling firms to develop the right products and gain competitive advantages. The findings indicate that the knowledge-based approach is effective, and the knowledge extracted is shown as a set of rules that can be used to identify useful patterns for both innovative product development and marketing strategies.     

A three‐dimensional finite element method with arbitrary polyhedral elements

The ‘variable‐element‐topology finite element method’ (VETFEM) is a finite‐element‐like Galerkin approximation method in which the elements may take arbitrary polyhedral form. A complete development of the VETFEM is given here for both two and three dimensions. A kinematic enhancement of the displacement‐based formulation is also given, which effectively treats the case of near‐incompressibility. Convergence of the method is discussed and then illustrated by way of a 2D problem in elastostatics. Also, the VETFEM's performance is compared to that of the conventional FEM with eight‐node hex elements in a 3D finite‐deformation elastic–plastic problem. The main attraction of the new method is its freedom from the strict rules of construction of conventional finite element meshes, making automatic mesh generation on complex domains a significantly simpler matter. Copyright © 2006 John Wiley & Sons, Ltd.     

Efficient approximation concepts using second order information

The primary goal of this paper is to show how second derivative information can be used in an effective way in structural optimization problems. The basic idea is to generate such an information at the expense of only one more ‘virtual load case’ in the sensitivity analysis part of the finite element code. To achieve this goal a primal–dual approach is employed, that can also be interpreted as a sequential quadratic programming method. Another objective is to relate the proposed method to the well known family of approximation concepts techniques, where the primary optimization problem is transformed into a sequence of non-linear explicit subproblems. When restricted to diagonal second derivatives, the new approach can be viewed as a recursive convex programming method, similar to the ‘Convex Linearization’ method (CONLIN), and to its recent generalization, the ‘Method of Moving Asymptotes’ (MMA). This new method has been successfully tested on simple problems that can be solved in closed form, as well as on sizing optimization of trusses. In all cases the method converges faster than CONLIN, MMA or other approximation techniques based on reciprocal variables.     

Detection of nanostructural anomalies in hydrated cement systems

Monitoring the flow of helium gas into the structure of hydrated cement systems has proven to be a useful method for following nanostructural changes in the C–S–H phase of hydrated cement systems. The method is sensitive to changes that occur on removal of structural water from the layered silicates. The helium-inflow method was applied, in this study, to normally hydrated low-water–cement ratio (w/c) Portland cement pastes (w/c < 0.38) and to low w/c autoclaved cement systems containing fly ash and elemental sulfur. Unusually, high amounts and rates of inflow were observed for these pastes. It was postulated that inflow occurred into both interlayer and other spaces in the latter. The inflow into the other or ‘trapped’ space was unexpected and considered anomalous in absence of a widely accepted explanation. The structural differences which were observed at the nanoscale for the low w/c preparations were consistent with behavioral aspects for published structural models of layered C–S–H. These include the models of Richardson and Jennings and concepts involving the existence of two types of C–S–H. Arguments for the existence of ‘trapped’ space between aggregates of C–S–H layers are advanced. Evidence for the preservation of C–S–H structures (similar to those formed during normal hydration) for the autoclaved systems containing fly ash and sulfur is presented. The evidence is compatible with the existence of ‘trapped’ space within layered agglomerates and the collapse of C–S–H structure on removal of water from interlayer space, typical of normally hydrated pastes.     

Fatigue of composite materials under spectrum loading

A method to predict fatigue of composites under spectrum loading is proposed. It is based on a recently developed approach for constant amplitude loading where the cycles to failure are determined using the cycle-by-cycle probability of failure under a given loading. Failure under spectrum loading occurs when the residual strength equals the applied maximum (or minimum) stress. Closed-form expressions are obtained and compared to Miner’s rule. It is shown that the present method results in a damage law which, depending on the case, can sum to more or less than unity unlike Miner’s rule which always sums up to unity. Comparison of the predictions with test results show very good agreement with minor exceptions that are discussed. The present method does not need any semi-empirical curve-fitting. All the parameters used in the model can be derived from the characteristics of the static strength distribution of the structure.     

Symmetricability of pressure stiffness matrices for shells with loaded free edges

For the case of free edges which are loaded, follower forces remaining normal to the middle surface of a shell throughout the deformation history do not have a load potential. In finite element analysis, this results in an unsymmetric pressure stiffness matrix. Depending on the structure of the available computer program, implementation of an equation solver permitting solution of unsymmetric simultaneous systems of algebraic equations may be a tedious task. This explains the significance of the topic of symmetricability of pressure stiffness matrices, turning out to be of special importance in the case of static buckling under the assumption of a linear prebuckling path. At first, incremental equations for tracing the nonlinear load–displacement path are derived. Thereafter, the buckling condition is deduced. Then, it is demonstrated that symmetrization of the pressure stiffness matrix is admissible if the so-obtained ‘buckling pressure’ differs ‘very little’ from the ‘buckling pressure’ resulting from an alternative symmetric ‘buckling matrix’, as is shown to be the case for a simply supported cylindrical shell with a free upper edge, subjected to hydrostatic external pressure. The alternative symmetric ‘buckling matrix’ is a consequence of deleting the virtual work term, causing the unsymmetry of the pressure stiffness matrix, in the expression for the external virtual work. A mechanical interpretation of this virtual work term is given. It is shown to be equal to the difference of virtual work of the original pressure load and of a ‘substitute pressure-field’, of the form of a Fourier series of the former. This explains why, normally, the buckling coefficient resulting from the ‘substitute pressure-field’ represents a good approximation to the buckling coefficient stemming from the original pressure load.     

Use invention of a chemical substance

The Japanese Patent Law defines the patentable subject matter and considers the following types or categories of inventions ‘a thing (substance)’, ‘a method’ and ‘a method of producing a thing (substance)’; however ‘use’ as a category is lacking. Although a discovery per se is unpatentable, the discovery of a new use of a product is practically patentable in a claim within the category of ‘a thing’ or ‘a method’.Two or more use inventions are deemed to be identical if those uses are substantially undistinguishable from one another with respect to ‘the range within which they are applied’, ‘means of application of the use’ and ‘time of application of such use’, even when the intended uses are different. An invention of use in the field of pharmaceutical products is patentable in the form of a claim: ‘substance or composition coupled with the indication of the intended pharmaceutical use’. Under the ‘Guidelines for practice in examining pharmaceutical inventions’ two or more inventions of pharmaceutical uses of one product are regarded as being identical if (A) the pharmacological effects are based on the same or closely related pharmacological action, or if (B) they are substantially undistinguishable in ‘the range of applications’. Actually, the guideline is not practised so strictly, particulary with respect to the standpoint (B).Problems are also left unsolved in Japan in pharmaceutical use inventions with respect to the entity of the patent right granted and to the preservation of right and further how to judge infringement, due to the fact that the subjects of application are human beings.For solving these problems some means can be contrived: ‘method of curing disease’ is deemed to be patentable subject matter, or a generic claim is granted on the first use and a specific claim is granted on the second use. Also in Japan various opinions exist as to whether the so-called second use should be patentable subject matter or not and in which form the second use, if patentable, should be patented.     

Finite element method for piezoelectric vibration

A finite element formulation which includes the piezoelectric or electroelastic effect is given. A strong analogy is exhibited between electric and elastic variables, and a ‘stiffness’ finite element method is deduced. The dynamical matrix equation of electroelasticity is formulated and found to be reducible in form to the well-known equation of structural dynamics, A tetrahedral finite element is presented, implementing the theorem for application to problems of three-dimensional electroelasticity.     

Evolutionary paths of change of emerging nanotechnological innovation systems: the case of ZnO nanostructures

This paper puts forward a quantitative approach aimed at the understanding of the evolutionary paths of change of emerging nanotechnological innovation systems. The empirical case of the newly emerging zinc oxide one-dimensional nanostructures is used. In line with other authors, ‘problems’ are visualized as those aspects guiding the dynamics of innovation systems. It is argued that the types of problems confronted by an innovation system, and in turn its dynamics of change, are imprinted on the nature of the underlying knowledge bases. The latter is operationalized through the construction of co-citation networks from scientific publications. We endow these co-citation networks with directionality through the allocation of a particular problem, drawn from a ‘problem space’ for nanomaterials, to each network node. By analyzing the longitudinal, structural and cognitive changes undergone by these problem-attached networks, we attempt to infer the nature of the paths of change of emerging nanotechnological innovation systems. Overall, our results stress the evolutionary mechanisms underlying change in a specific N&N subfield. It is observed that the latter may exert significant influence on the innovative potentials of nanomaterials.