Information schema constructs for instantiation and composition of system manifestation features

Complementing our previous publications, this paper presents the information schema constructs (ISCs) that underpin the programming of specific system manifestation feature (SMF) orientated information management and composing system models. First, we briefly present (1) the general process of pre-embodiment design with SMFs, (2) the procedures of creating genotypes and phenotypes of SMFs, (3) the specific procedure of instantiation of phenotypes of SMFs, and (4) the procedure of system model management and processing. Then, the chunks of information needed for instantiation of phenotypes of SMFs are discussed, and the ISCs designed for instantiation presented. Afterwards, the information management aspects of system modeling are addressed. Methodologically, system modeling involves (1) placement of phenotypes of SMF in the modeling space, (2) combining them towards the desired architecture and operation, (3) assigning values to the parameters and checking the satisfaction of constraints, and (4) storing the system model in the SMFs-based warehouse database. The final objective of the reported research is to develop an SMFs-based toolbox to support modeling of cyber-physical systems (CPSs).     

光纤多模干涉应变传感器的数值模拟及实验研究

介绍了一种基于多模干涉理论的光纤应变传感器,它由两段单模光纤中间夹一段多模光纤组成。我们利用光束传播法(BPM)对这种结构进行了数值模拟,获得了多模光纤中被激励的所有高阶模式的耦合效率的解析解,通过计算得到其应变灵敏度是FBG型应变传感器的2.14倍。随后,对这种新型传感器进行了应变传感实验,实验结果为1.92倍,计算值与实验值基本一致,证明了此种数值模拟方法适于研究此类光纤多模干涉问题,并体现出这种单模-多模-单模结构的传感器在灵敏度方面的优势。     

基于MATLAB GUI图像处理系统的设计与实现

MATLAB作为算法开发及数据可视化的交互式工具,在数字图像处理方面应用广泛,并集成了具有多种算法的图像处理工具箱。本文基于MATLAB图像用户界面(GUI)和图像处理工具箱设计实现了一款图像处理系统,该系统可实现图像的运算、变换、分割、改善、形态学处理、压缩编码等内容,并通过综合实例阐述了本系统在图像识别中的应用,使图像处理可视化更加直观,便捷。多次实践表明,本系统具有良好的实用性、交互性、移植性,易于后期模式识别和机器视觉相关应用的扩展研究。     

面向SysML的系统安全性分析工具与实例研究

基于模型的安全性分析方法能够提高对目前复杂安全关键系统的建模与分析能力。系统建模语言(System Modeling Language,SysML)是一类在工业领域被广泛应用的非形式化系统功能建模语言,AltaRica是面向系统安全性分析的形式化建模语言。针对国内目前缺乏面向SysML的系统安全性分析工具的现状,设计实现了一个面向SysML的系统安全性分析工具并进行了实例研究。首先建立了SysML设计模型到AltaRica分析模型的映射规则;同时根据映射规则设计算法实现两种模型的自动转换,并集成了Altarica的分析引擎对系统模型进行自动化安全性分析;最后以SAE-AIR6110标准中的一个复杂的机轮刹车系统(Wheel Brake System,WBS)为实例,验证了所提工具的可行性和有效性。实验结果表明,对于包含25个组件类型、34个组件实例的复杂系统,该工具可有效地完成SysML模型到AltaRica模型的转换并进行正确的安全性分析。     

The Failure Trace Archive: Enabling the comparison of failure measurements and models of distributed systems

With the increasing presence, scale, and complexity of distributed systems, resource failures are becoming an important and practical topic of computer science research. While numerous failure models and failure-aware algorithms exist, their comparison has been hampered by the lack of public failure data sets and data processing tools. To facilitate the design, validation, and comparison of fault-tolerant models and algorithms, we have created the Failure Trace Archive (FTA)—an online, public repository of failure traces collected from diverse parallel and distributed systems. In this work, we first describe the design of the archive, in particular of the standard FTA data format, and the design of a toolbox that facilitates automated analysis of trace data sets. We also discuss the use of the FTA for various current and future purposes. Second, after applying the toolbox to nine failure traces collected from distributed systems used in various application domains (e.g., HPC, Internet operation, and various online applications), we present a comparative analysis of failures in various distributed systems. Our analysis presents various statistical insights and typical statistical modeling results for the availability of individual resources in various distributed systems. The analysis results underline the need for public availability of trace data from different distributed systems. Last, we show how different interpretations of the meaning of failure data can result in different conclusions for failure modeling and job scheduling in distributed systems. Our results for different interpretations show evidence that there may be a need for further revisiting existing failure-aware algorithms, when applied for general rather than for domain-specific distributed systems.     

基于状态空间模型的无线网络控制仿真研究

针对采用状态空间模型描述的几类无线网络控制系统,介绍了基于TrueTime的无线网络控制系统仿真程序的设计与实现问题。首先介绍了TrueTime工具箱的组成,然后给出了如何利用无线仿真模块实现基于状态空间模型描述的控制系统仿真方法。分别考虑当系统具有单输入多输出、网络诱导时延、数据丢包、时滞脉冲等特性时,利用TrueTime仿真工具箱,如何建立上述系统的无线网络控制仿真模型以及如何编写相应的程序代码。根据上述不同模型的仿真可以看出,对于不同的系统,他们的初始化设置基本相同,而任务代码却有很大的差别。仿真曲线符合理论结果,说明了仿真模型和程序代码的正确性与有效性。     

MOBMAS: A methodology for ontology-based multi-agent systems development

Ontologies offer significant benefits to multi-agent systems: interoperability, reusability, support for multi-agent system (MAS) development activities (such as system analysis and agent knowledge modeling) and support for MAS operation (such as agent communication and reasoning). This paper presents an ontology-based methodology, MOBMAS, for the analysis and design of multi-agent systems. MOBMAS is the first methodology that explicitly identifies and implements the various ways in which ontologies can be used in the MAS development process and integrated into the MAS model definitions. In this paper, we present comprehensive documentation and validation of MOBMAS.     

一种构件化工作流管理系统

工作流管理系统是实现各种信息管理系统工作过程自动化的核心模块。本文提出一种工作流元模型和基于该元模型进行工作流建模的方法,并实现一个构件化的工作流管理系统。该系统支持基于元模型的工作流建模,提供工作流运行的环境,并可以构件的方式集成到外部系统中。     

Advanced system‐level simulation paradigm for ultra‐wideband systems using SCERNE platform

In this article, a progressive system‐level simulation framework is developed based on Simulation de Chaînes d'Emission/Réception Nouvelle gEnération (SCERNE) platform to simulate an ultra‐wideband (UWB) impulse radar transmitter and accurately predict its performance. With the purpose of demonstrating the usefulness of the SCERNE ability in system‐level modeling, we present and simulate a simplified structure of UWB impulse radar transmitter. First, after simulation each component in different circuit‐level tools such as ADS, CST, and HFSS, each part has been modeled by using different modeling methods to transfer their data into MATLAB environment. Then, we duplicate the transmitter structure in SCERNE toolbox to validate the results. The advantage conferred by the proposed SCERNE toolbox is that fast and accurate bilateral modeling method is available at multi‐medium structures in contrast with conventional unilateral modeling, and so a lower memory and higher accuracy of the behavioral model is achieved. It can also be beneficial when the user is looking for system‐level, as the increased components amounts can help as a surrogate model. The system model can be easily extended to other UWB radar systems by simply changing the input pulse shape, UWB channel environment, transceiver topology, etc. Various effects such as signal quality, and pulse shape that can easily investigate and re‐optimize for high performance are using the developed model. To validate the practicality of the proposed paradigm, the simulations and predictions through model results are being outlined.     

基于Matlab环境的网络控制系统仿真平台

网络控制系统NCS(NetworkedControlSystem)是一种分布式实时控制系统,网络控制系统的设计与研究涉及系统控制与网络调度两个方面,目前集成的控制与调度仿真工具很少。该文对网络控制系统的仿真平台进行了分析,给出了Matlab构建的网络控制系统框架,分析了网络控制系统仿真模型,介绍了一种基于Matlab的网络控制系统的理想仿真工具TrueTime。     

Solving the problem of incomplete data in medical diagnosis via interval modeling

This paper presents an approach to making accurate and high-quality decisions under incomplete information. Our comprehensive approach includes interval modeling of incomplete data, uncertaintification of classical models and aggregation of incomplete results. We conducted a thorough evaluation of our approach using medical data for ovarian tumor diagnosis, where the problem of missing data is commonly encountered. The results confirmed that methods based on interval modeling and aggregation make it possible to reduce the negative impact of lack of data and lead to meaningful and accurate decisions. A diagnostic model developed in this way proved better than classical diagnostic models for ovarian tumor. Additionally, a framework in R that implements our method was created and is available for reproduction of our results. The proposed approach has been incorporated into a real-life diagnosis support system – OvaExpert.     

FlowVR的Scilab ToolBox的设计与实现

FlowVR是为VR提供的支持数据流的分布式框架^[1],对于构建功能强大的分布式科学数据分析系统也有很大的优势,但是FlowVR本身没有数学建模功能。Scilab具有强大的数学建模和仿真功能。结合FlowVR和Scilab的优点,可以构建高性能的科学数据分析系统,以应用于各种领域。文章介绍了FlowVR的Scilab Toolbox的设计与实现。该系统通过开发Scilab的函数编程接口,实现了FlowVR框架下各个模块与Scilab的数据交互,利用后者的科学计算功能,能够为FlowVR开发数据分析系统提供强大的建模工具。     

ADOME: an advanced object modeling environment

ADOME, which stands for ADvanced Object Modeling Environment, is an approach to integrating data and knowledge management based on object oriented technology. Next generation information systems will require more flexible data modeling capabilities than those provided by current object oriented DBMSs. In particular, integration of data and knowledge management capabilities will become increasingly important. In this context, ADOME provides versatile role facilities that serve as “dynamic binders” between data objects and production rules, thereby facilitating flexible data and knowledge management integration. A prototype that implements this mechanism and the associated operators has been constructed on top of a commercial object oriented DBMS and a rule base system     

基于Web的UML建模系统

针对目前异构网络环境下的异地开发和信息查询需求,结合MVC模式,设计并实现基于Web的UML建模系统。为了便于表示UML建模过程中的结构化数据和半结构化数据,将建模信息保存为XML文件,使系统具有更好的可扩展性、开放性、灵活性、自我描述性、可操作性及规范的层次结构。通过建立基于XML的信息查询提高了查询效率。     

模糊控制在风力水力互补发电中的应用

设计了基于模糊控制器的风力水力互补发电系统,并利用MATLAB软件中的Simulink工具箱对该系统进行了建模仿真,取得了良好的效果。仿真结果表明,基于模糊控制器的风力水力互补发电系统可以很好地解决风力发电波动性大的问题,为风电的大规模应用提供了可行的解决方案。     

一类多输入多输出网络控制系统的稳定性分析

研究了具有分布时延、有界输入的多输入多输出网络控制系统的建模和稳定性问题.基于线性时不变对象,建立了系统的数学模型.利用李雅普诺夫第2方法和线性矩阵不等式描述,分析了系统的渐近稳定性,导出了与时延相关的系统渐近稳定判据,同时得到了系统稳定运行的最大允许时延.系统渐近稳定的最大允许时延可用MatlabLMI工具箱从稳定判据获得.仿真算例表明稳定判据是可行的.     

基于RBAC模型的安全访问机制建模研究

基于角色访问控制（RBAC）是一种方便、安全、高效的访问控制机制。介绍了软件系统安全控制策略,分析了RBAC的基本思想和用户角色分配的基本方法,提出了基于面向对象的RBAC建模思想,并用标准建模语言UML的交互图描述RBAC的授权流程,从而使系统开发人员有效理解RBAC模型并建立基于角色的系统。文中还给出了在数据备份系统中运用RBAC实现用户权限管理应用模型的实例。     

Accelerating SPARQL queries by exploiting hash-based locality and adaptive partitioning

State-of-the-art distributed RDF systems partition data across multiple computer nodes (workers). Some systems perform cheap hash partitioning, which may result in expensive query evaluation. Others try to minimize inter-node communication, which requires an expensive data preprocessing phase, leading to a high startup cost. Apriori knowledge of the query workload has also been used to create partitions, which, however, are static and do not adapt to workload changes. In this paper, we propose AdPart, a distributed RDF system, which addresses the shortcomings of previous work. First, AdPart applies lightweight partitioning on the initial data, which distributes triples by hashing on their subjects; this renders its startup overhead low. At the same time, the locality-aware query optimizer of AdPart takes full advantage of the partitioning to (1) support the fully parallel processing of join patterns on subjects and (2) minimize data communication for general queries by applying hash distribution of intermediate results instead of broadcasting, wherever possible. Second, AdPart monitors the data access patterns and dynamically redistributes and replicates the instances of the most frequent ones among workers. As a result, the communication cost for future queries is drastically reduced or even eliminated. To control replication, AdPart implements an eviction policy for the redistributed patterns. Our experiments with synthetic and real data verify that AdPart: (1) starts faster than all existing systems; (2) processes thousands of queries before other systems become online; and (3) gracefully adapts to the query load, being able to evaluate queries on billion-scale RDF data in subseconds.     

空管系统中内存数据库的设计与实现

空中交通管制(ATC)系统对数据高速同步的要求越来越高,而目前所使用的传统式集中数据库存取数据的速度已远远不能满足ATC系统的需求。为此,结合ATC系统的特殊需求,设计并实现了一种基于type-index-value的内存数据库,该数据库具有良好的可移植性,可有效提高系统性能以及对数据的存取能力。