基于生长模型的温室虚拟黄瓜构建研究*

在温室内对黄瓜植株生长进行实验观测,以生育期内累积生长度日为参数分别建立黄瓜的形态发生与生理功能模型.采用类封装技术对植株生长单元及器官类进行定义,建立植株拓扑结构与器官形态变化的规则化描述模型,通过信息融合与重构处理构建植株生长的虚拟模型.实验表明该方法在虚拟植株生长方面具有一定的可行性和有效性,为动态掌握和预测适宜...     

基于视频特征提取的虚拟植物动态仿真研究*

植物生长信息的提取与重构是在计算机上实现植物生长动态仿真的基础和关键。以树的生长为对象,将包含植物生长信息的视频图像转换为若干关键帧数据,提取反映植株拓扑结构与器官形态变化的特征信息,采用枝条拼接算法对植株拓扑变化过程进行重构。通过3DMAX开发平台对植株生长过程进行重建,结果表明该方法既能有效构建植株生长的数字化模型,又能较好地虚拟植物生长和形态演变过程。     

蠕虫智能扩散形式化分析及权策略算法实现

抽象蠕虫扩散的一般过程,采用确定的有限自动机理论,对蠕虫扩散行为进行形式化描述。建立智能扩散自动机模型,为研究蠕虫扩散过程提供了一种直观的形式化手段。提出加权树策略,基于该策略设计智能扩散模型并详细阐述权策略的核心算法,描述蠕虫智能扩散的本质特征和执行过程。形式论证结果表明,该模型能够有效地刻画智能扩散的特征,实现基于堆遍历加权策略的扩散仿真。     

一种基于环境变化的树木动态生长仿真模型

研究虚拟植物生长的仿真应用较广.针对数字娱乐领域中用于虚拟场景的植物形态-功能仿真的有限需求,为了提高真实性,提出了一种通用的基于环境变化的虚拟树木动态生长的仿真模型,来仿真各种树木的生长过程.采用L系统描述树木的拓扑结构,结合植物学相关知识,引入了环境因素对树木生长的影响,将树木的生物学特性进行抽象与加权处理,建立了树木生长与光照信息交换的简洁算法.仿真实验结果表明,该模型能较好地反映了环境因素变化对植物生长的影响,较真实地仿真再现了树木的动态生长过程.     

化工过程仿真培训系统的单元过程多模型集成

该文提出经工过程仿真训练系统的单元过程多模型集成方法，用有限状态自动机控制的集成多模型描述方法，描述了经工过程仿真系统的单元过程模型，进而讨论了对集成的多模型进行仿真的方法，提出了状态转换的监测与协调算法。把引发状态转换的事件分析为四类：数据通讯，教师台操作高等系统事件，外部操作，发生时间可预先确定的显式事件；由工艺参数和／或控制信号的变化引发的，发生时间不能预先定的隐式事件，分别讨论了多各事件在     

基于生长动力学的芦苇属植株虚拟生长模型

针对植株形态建模过程中由于缺乏生理生态特性而导致模型无法真实再现植株生长发育规律的问题,提出了一种基于生长动力学的植株形态变化模型构建方法。以芦苇属植株为例,首先研究了植株生长动力学特性,并以有效积温、生长速率变化等为驱动力构造了植株形态建成模型;其次,应用开放式L系统(Open-L)方法描述了植株冠层拓扑演变过程;最后,通过耦合植株拓扑与器官形体的几何模型及显示模型,给出了植株虚拟生长模型构建算法。实验结果表明,该方法实现了植株形态的可视化,并反映了植物生长机理,有利于动态掌握和预测植物生长发育状况。     

基于送达率约束的无线传感器网络低时延拓扑控制算法研究

基于数据紧迫采集应用场景(如地震、火灾预警),分析了其拓扑控制的目标和需求,建立了网络模型并且进行了形式化描述和数学分析,提出了一种基于送达率约束的低时延拓扑控制算法(LDBDC)。该算法可以根据给定的送达率约束计算给定区域的近似最优平均跳数,从而得到虚拟网格的边长。仿真实验表明,LDBDC能够获得近似最优的拓扑结构,在满足送达率约束的前提下使得网络的平均时延最小。     

网格调度仿真测试环境中自动机模型的研究

网格调度仿真测试环境通过模拟广域范围内的异构资源以及网格中间件的部分功能,为网格调度算法提供了测试环境.自动机模型来源于形式语言与自动机领域,在GridSim的基础上应用自动机模型,设计了仿真处理自动机实现了模拟过程的状态化,使得仿真测试环境具有了层次清晰、可配置和可扩展等优点.     

面向描述语言的蠕虫扩散过程形式化研究

建立典型的蠕虫扩散自动机模型,运用确定的有限状态自动机理论对蠕虫扩敞行为进行形式化描述,并且论证其正确性.本文提出一种扩敞描述语言,解决扩散自动机的形式描述、本质特征和执行过程问题.为研究蠕虫扩散行为提供一种更为直观的形式化手段.     

一种数据模型的范畴论建模方法

针对数据模型复杂语义建模的应用需求, 以及目前数据模型范畴论建模方法理论研究与工程实践方面存在的不足, 建立了一种素描数据模型。该模型在模型范畴的形式化框架内, 用与特定数据库建模语言无关的范畴论对数据库状态的一致性转换进行了形式化描述, 扩展了传统ER模型的表示与处理功能。基于素描对图形化建模规范的支持, 设计了ER模型向素描数据模型转换的算法, 以精确的语义联系保证模型转换的语义完整性, 并通过实验与对比分析了素描数据模型与算法的优势, 为数据模型的范畴论建模方法研究提供便利、高效的形式化理论框架。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate