面向生物信息的网格工作流开发与运行环境

网格工作流系统通过组合网格计算结点上的资源为生物计算等领域的复杂计算任务提供了支持。为了解决已有系统中用户需要对流程语言细节有较深入了解以及操作和配置较为复杂等问题,设计和实现了面向生物信息领域的网格工作流开发与运行环境。生物信息领域的用户使用该系统,可以通过web的方式实现对生物计算模型较高抽象层次的在线流程设计、流程作业的提交、作业状态的管理以及计算结果的查看等操作。最后通过生物计算领域的基因计算任务说明了系统对生物信息学应用的支撑功能。     

大规模空气动力学数值模拟中的并行重叠网格装配技术

重叠网格方法因为其网格生成简单、局部网格质量高等优点,是模拟有相对运动的非定常问题的一种常用方法。重叠网格首先需要装配过程,即通过建立网格间的重叠关系、确定宿主及待插值单元,实现网格间的流场信息交换。本文针对大规模数值模拟中,网格分散存储在多个处理器上的情况,研究了分布式重叠网格装配方法。本文先提出分布式网格装配问题,再详细阐述适用于三维结构网格的分布式装配技术,最后利用标准的机翼挂载模型对算法进行了测试,结果表明该算法可以在保证较高并行性的同时,为非定常计算提供准确的流场插值信息。     

User Interaction and Data Management for Large Scale Grid Applications

In this paper we present a model that combines the X3DMMS application with the G3CPie execution framework, that enables the user to perform large scale computations on distributed computing environments. Such an approach facilitates the management and the preparation of the data required to define the input files for DL_POLY, a popular Molecular Dynamics (MD) package used for the study of molecular systems. The researcher can define in a intuitive way the initial configuration of the molecular system, making use of the X3DMMS virtual reality environment, and prepares the related MD package oriented input files. After having defined the initial conditions of the system, the researcher can carry out the required computations by using the G3CPie workflow environment, which controls the execution of the calculation on a distributed computing infrastructure. To test the validity of the developed model, implemented in the EGI infrastructure, we present the results carried out for a propane bulk system, where the solvation process of propane inside the bulk has been investigated. The presented approach provides a reusable example for other laboratories or groups interested both in acting through virtual representation of the molecular systems and porting their applications to distributed computing infrastructures.     

推进DSLAM规模商用

1.DSLAM进入规模建设,主流机型得到规模应用在整个电信行业普遍不景气的今天,DSLAM市场却如早春一样欣欣向荣、蓬勃发展。截止2002年底,中国ADSL的市场容量已经超过500万线,2003年的第一季度仍然表现出强劲的发展势头。华为、阿尔卡特、中兴等成为主流设备供应商。在DSLAM市场的激烈竞争中,华为公司持续关注客户需求,以理性、务实的态度,按照DSLAM规模建设和持续发展的客观需求,兼顾对网络投资的保护,提供了系列化的产品、丰富的业务接口和灵活的组网能力,通过合理的BAS组网模式和宽带网络增值业务平台,构建完善、成熟、可持续发…     

从万维网到信息网格

信息网格追求的最终目标是能够做到服务点播(Service On Demand)和一步到位的服务(One Click Is Enough)。本文基于因特网的最新发展趋势,主要从信息网格的定义、特点和应用三个方面讲述了因特网从万维网(Web)到信息网格(Grid)的发展之路。     

From Centralized Workflow Specification to Distributed Workflow Execution

Current workflow management systems fall short of supporting large-scale distributed, enterprise-wide applications. We present a scalable, rigorously founded approach to enterprise-wide workflow management, based on the distributed execution of state and activity charts. By exploiting the formal semantics of state and activity charts, we develop an algorithm for transforming a centralized state and activity chart into a provably equivalent partitioned one, suitable for distributed execution. A synchronization scheme is developed that guarantees an execution equivalent to a non-distributed one. This basic solution is further refined in order to reduce communication overhead and exploit parallelism between partitions whenever possible. The developed synchronization schemes are compared in terms of the number and size of synchronization messages.     

基于网格计算的大规模数据集SVM分类方法研究

针对SVM分类过程中,处理大规模训练样本集遇到的因样本维度高、消耗大量内存导致分类效率低下的问题,提出基于网格环境的计算策略。该策略针对密集型计算问题分别提出按步骤、按功能、按数据进行任务分解的三种解决方案。用户根据SVM样本训练和分类的实际来选择使用哪一种方案。对遥感数据分别在单机环境和网格环境的对比实验表明,能够提高训练和分类速度,在计算环境的层面弥补处理大规模数据对计算性能的高要求。     

Petri网在生物信息学中的应用

生物信息学是一门正在快速发展的使用数学和计算机技术来构造和分析生物学模型的学科.Petri网是近来被用于生物信息学的有效工具,但是应用的深度和广度还有待深入研究.文中综述了Petri网在生物信息学领域应用的最新研究进展,主要包括三个方面:应用位置/变迁网定性分析生物学对象的结构性质;应用随机Petri网将随机性加入到生物学建模和分析中;应用混合Petri网描述和分析同时具有离散特性和连续特性的生物系统.最后对Petri网在生物信息学领域的应用情况进行总结并展望了未来的研究方向.     

VOLMAP: a Large Scale Benchmark for Volume Mappings to Simple Base Domains

Correspondences between geometric domains (mappings) are ubiquitous in computer graphics and engineering, both for a variety of downstream applications and as core building blocks for higher level algorithms. In particular, mapping a shape to a convex or star-shaped domain with simple geometry is a fundamental module in existing pipelines for mesh generation, solid texturing, generation of shape correspondences, advanced manufacturing etc. For the case of surfaces, computing such a mapping with guarantees of injectivity is a solved problem. Conversely, robust algorithms for the generation of injective volume mappings to simple polytopes are yet to be found, making this a fundamental open problem in volume mesh processing. VOLMAP is a large scale benchmark aimed to support ongoing research in volume mapping algorithms. The dataset contains 4.7K tetrahedral meshes, whose boundary vertices are mapped to a variety of simple domains, either convex or star-shaped. This data constitutes the input for candidate algorithms, which are then required to position interior vertices in the domain to obtain a volume map. Overall, this yields more than 22K alternative test cases. VOLMAP also comprises tools to process this data, analyze the resulting maps, and extend the dataset with new meshes, boundary maps and base domains. This article provides a brief overview of the field, discussing its importance and the lack of effective techniques. We then introduce both the dataset and its major features. An example of comparative analysis between two existing methods is also present.     

Adaptive Execution of Jobs in Computational Grid Environment

In a computational grid, jobs must adapt to the dynamically changing heterogeneous environment with an objective of maintaining the quality of service. In order to enable adaptive execution of multiple jobs running concurrently in a computational grid, we propose an integrated performance-based resource management framework that is supported by a multi-agent system (MAS). The multi-agent system initially allocates the jobs onto different resource providers based on a resource selection algorithm. Later, during runtime, if performance of any job degrades or quality of service cannot be maintained for some reason (resource failure or overloading), the multi-agent system assists the job to adapt to the system. This paper focuses on a part of our framework in which adaptive execution facility is supported. Adaptive execution facility is availed by reallocation and local tuning of jobs. Mobile, as well as static agents are employed for this purpose. The paper provides a summary of the design and implementation and demonstrates the efficiency of the framework by conducting experiments on a local grid test bed.     

大比例尺土壤数据库的组织与设计研究--以安徽宣城样区为例

以安徽宣城样区为例,就大比例尺土壤数据库的组织与设计进行了系统地研究。分析了大比例尺土壤数据库的特点及组织原则,在此基础上,进一步就大比例尺土壤数据库空间制图单元构建及其属性数据的采集、组织、管理等问题作了详细地探讨,并在GIS软件支持下完成了样区土壤数据库设计。     

From Semantic Grid to Knowledge Service Cloud

1 Introduction The World Wide Web is a major breakthrough in the history of human communication and information sharing (Berners-Lee et al.,2006).     

高分三号卫星在极地冰区导航中的应用评价

针对面向极地冰区船舶航行导航的需求,利用我国第一颗民用合成孔径雷达卫星高分三号(GF-3)数据,通过定量化统计分析,开展了GF-3号标准条带模式数据在极地冰区应用潜力的评估。结果表明,GF-3号标准条带数据能较好地反映冰面的纹理,HH极化在图像层次和信息量上要优于HV极化;在图像的层次表达方面,GF-3/HV极化数据优于Radarsat-2/HV数据,GF-3/HH极化数据不如Radarsat-2/HH极化数据;GF-3数据能较好地反映南极冰区的纹理和类型特征,对于冰山、冰裂隙等冰上障碍具有较好的识别能力,对极地冰区导航和冰上卸货具备较好的应用效果。     

电子调速器在大型透平离心式压缩机中的应用

以大型乙烯装置裂解气压缩机为例，结合WW505E的功能特点，着重介绍了电子调速器在抽气式透平中对转速，抽气压力(或流量)的控制。     

中小型PLC在大型自来水厂的应用

南海市第二水厂设计总规模为日供水100万m^3。首期工程为日供水25万m^3，于1997年4月建成投产，二期日供水25万m^3工程即将建成投产。自控项目主要包括一期的工程改造和二期的工程建设，并为后续扩建预留接口。     

一种实用高效的文本分类算法

在模式识别研究领域已有的分类算法中,大多数都是基于向量空间模型的算法,其中使用范围最广的是kNN算法.但是,其中的大多数算法都因为计算复杂度太高而不适用于大规模的场合.而且,当训练样本集增大时都需要重新生成分类器,可扩展性差.为此,提出了互依赖和等效半径的概念,并将两者相结合,提出新的分类算法——基于互依赖和等效半径、易更新的分类算法SECTILE. SECTILE计算复杂度较低,而且扩展性能较好,适用于大规模场合.将SECTILE算法应用于中文文本分类,并与kNN算法和类中心向量法进行比较,结果表明,在提高分类精度的同时,SECTILE还可以大幅度提高分类速度,有利于对大规模信息样本进行实时在线的自动分类.     

大规模数字高程模型的可视化研究

根据细节层次模型（LOD）的设计思想,提出了大规模数字高程模型的数据组织和可视化方法。该方法在数据分页算法和细节层次模型相结合的基础上,采用视区计算和边界融合算法,实现了地形的快速绘制。实验证明该方法实现了高性能绘制大规模数字高程模型。