摘要：XML data can be represented by a tree or graph and the query processing for XML data requires the structural information among nodes. Designing an efficient labeling scheme for the nodes of Order-Sensitive XML trees is one of the important methods to obtain the excellent management of XML data. Previous labeling schemes such as region and prefix often sacrifice updating performance and suffer increasing labeling space when inserting new nodes. To overcome these limitations, in this paper we propose a new labeling idea of separating structure from order. According to the proposed idea, a novel Prime-based Middle Fraction Labeling Scheme(PMFLS) is designed accordingly, in which a series of algorithms are proposed to obtain the structural relationships among nodes and to support updates. PMFLS combines the advantages of both prefix and region schemes in which the structural information and sequential information are separately expressed. PMFLS also supports Order-Sensitive updates without relabeling or recalculation, and its labeling space is stable. Experiments and analysis on several benchmarks are conducted and the results show that PMFLS is efficient in handling updates and also significantly improves the performance of the query processing with good scalability.

摘要：Former knowledge engineering research aimed at boosting automatic *** recent knowledge management research focused on promoting the knowledge sharing and reusing among the *** of the different aims between the two directions,former knowledge representation schemata,such as rule based representation,frame from knowledge engineering research does not fit to the current knowledge management *** this paper,for the purpose of building knowledge management systems for product design enterprises,knowledge items are classified into seven types based on the semantics of their *** their representations are discussed *** on the above classification,a knowledge representation meta-model and a basic domain ontology reference model for cooperative knowledge management systems are put *** reference model is an abstraction that can be reused and extended in knowledge management systems of different ***,the patterns of knowledge acquisition processes in cooperative knowledge management scenarios of product design processes are studied.

摘要：可视化语言技术比一维文本语言在描述软件组成方面具有优越性.由于图表和图形概念在系统建模中的广泛使用,可视化语言可以应用于需求分析、设计、测试和维护等软件开发的各个阶段.除了具有直观易见的特点之外,图文法在计算机上的精确建模和验证能力,为设计可视化语言提供了一个坚实的理论基础.讨论了可视化语言的形式理论基础,回顾了相关的可视化图形编程环境.特别提出了一种空间图文法,并且用该图文法定义了统一建模语言的行为语义.基于空间图文法,开发了一种基于模式驱动的框架,以帮助软件架构与设计.

摘要：The radial deformation design of turbine disk seriously influences the control of gas turbine high pressure turbine(HPT) blade-tip radial running clearance(BTRRC). To improve the design of BTRRC under continuous operation, the nonlinear dynamic reliability optimization of disk radial deformation was implemented based on extremum response surface method(ERSM), including ERSM-based quadratic function(QF-ERSM) and ERSM-based support vector machine of regression(SR-ERSM). The mathematical models of the two methods were established and the framework of reliability-based dynamic design optimization was developed. The numerical experiments demonstrate that the proposed optimization methods have the promising potential in reducing additional design samples and improving computational efficiency with acceptable precision, in which the SR-ERSM emerges more obviously. Through the case study, we find that disk radial deformation is reduced by about 6.5×10–5 m; δ=1.31×10–3 m is optimal for turbine disk radial deformation design and the proposed methods are verified again. The presented efforts provide an effective optimization method for the nonlinear transient design of motion structures for further research, and enrich mechanical reliability design theory.

摘要：Fuzzy entropy was designed for non convex fuzzy membership function using well known Hamming distance *** proposed fuzzy entropy had the same structure as that of convex fuzzy membership *** procedure of fuzzy entropy was proposed by considering fuzzy membership through distance measure,and the obtained results contained more flexibility than the general fuzzy membership ***,characteristic analyses for non convex function were also *** on the mutual information were carried out through the proposed fuzzy entropy and similarity measure,which was also dual structure of fuzzy *** the illustrative example,mutual information was discussed.

摘要：改进真实感图形绘制性能是计算机图形系统的一个基本问题 文中探讨了一些几何压缩算法对真实感图形绘制性能的影响 ,这些算法是为了优化使用形体顶点高速缓冲存储器而设计的 ;研究了这些算法和计算机芯片上纹理高速缓冲存储器的相互作用 ;提出了一个基于三角条形的简单方法 ,以通过平衡使用形体顶点和纹理高速缓冲存储器而改进真实感图形绘制性能 最后 。

摘要：Aspect-oriented modeling can uncover potential design faults, yet most existing work fails to achieve both separation and composition in a natural and succinct way. This study presents an aspect-oriented modeling and analysis approach with hierarchical Coloured Petri Nets(HCPN). HCPN has sub-models and well-defined semantics combining a set of submodels. These two characteristics of HCPN are nicely integrated into aspect oriented modeling. Submodels are used to model aspects while the combination mechanism contributes to aspects weaving. Furthermore, the woven aspect oriented HCPN model can be simulated and analyzed by the CPN Tools. A systematic web application case study is conducted. The results show the system original properties are satisfied after weaving aspects and all design flaws are revealed. As such, the approach can support web application design and analysis in an aspect-oriented fashion concisely and effectively.

摘要：With the significant advancement in emerging processor, memory, and networking technologies, exascale systems will become available in the next few years （2020 2022）. As the exascale systems begin to be deployed and used, there will be a continuous demand to run next-generation applications with finer granularity, finer time-steps, and increased data sizes. Based on historical trends, next-generation applications will require post-exascale systems during 2025-2035. In this study, we focus on the networking and communication challenges for post-exascale systems. Firstly, we present an envisioned architecture for post-exascale systems. Secondly, the challenges are summarized from different perspectives： heterogeneous networking technologies, high-performance eonmmnication and synchronization protocols, integrated support with accelerators and field-programmable gate arrays, fault-tolerance and quality-of-service support, energy-aware communication schemes and protocols, software- defined networking, and scalable communication protocols with heterogeneous memory and storage. Thirdly, we present the challenges in designing efficient programming model support for high-performance computing, big data, and deep learning on these systems. Finally, we emphasize the critical need for co-designing runtime with upper layers on these systems to achieve the maximum performance and scalability.

摘要：A mathematical approach was proposed to investigate the impact of high penetration of large-scale photovoltaic park(LPP) on small-signal stability of a power network and design of hybrid controller for these units.A systematic procedure was performed to obtain the complete model of a multi-machine power network including *** damping of oscillations focusing on inter-area oscillatory modes,a hybrid controller for LPP was *** performance of the suggested controller was tested using a 16-machine 5-area *** results indicate that the proposed hybrid controller for LPP provides sufficient damping to the low-frequency modes of power system for a wide range of operating *** method presented in this work effectively indentifies the impact of increased PV penetration and its controller on dynamic performance of multi-machine power network containing *** results demonstrate that the model presented can be used in designing of essential controllers for LPP.

摘要：To describe the design approaches of IND-CCA2 （adaptive chosen ciphertext attack） secure public key encryption schemes systematically, the gaps between different kinds of intractable problems and IND-CCA2 security are studied. This paper points out that the construction of IND-CCA2 secure schemes is essentially to bridge these gaps. These gaps are categorized, analyzed and measured. Finally the methods to bridge these gaps are described. This explains the existing design approaches and gives an intuition about the difficulty of designing IND-CCA2 secure public key encryption schemes based on different types of assumptions.