基于不规则三角网的等值线填充算法

现有基于不规则三角网的等值线填充算法较少,且不能精确判断区域颜色。对此给出一种通过不规则三角网快速填充等值线图的算法,搜索出所有开区域轮廓,通过围成区域等值线属性值与不同颜色的对应关系确定区域颜色,采用深度优先的方法对开区域及其内部的多级封闭区域进行矢量填充。对不同数据源运行该算法,并与其他算法进行比较,根据对比结果可知该算法比现有算法更适合于基于三角网生成的等值线图精确填充。     

一种基于不规则三角网TIN的等值线计算方法

提出一种基于不规则三角网(TIN)的等值线生成算法,降低对TIN拓扑关系的要求,具有更广的适用范围.算法简单清晰,避免以往算法起始点选取困难、等值线走向判断复杂的问题.对封闭和非封闭等值线统一处理.     

等值线自动建立拓扑关系算法与快速填充应用

通过构建“拓扑包含二叉树”,找到了一种自动建立等值线拓扑关系的新方法,并且提出了一种基于拓扑关系的等值线图快速填充算法,从而很好地解决了在任意比例尺、任意高程间隔、任意边界情况下,实现等值线矢量快速填充应用效果的难题。该方法已在海底地形可视化与自动在图技术研究中实现了成功地应用,并取得了良好的效果。     

基于三角网的等值线填充算法研究

通过对现有等值线填充算法的深入研究,提出了一种覆盖填充等值线的算法。该算法把等值线分类为凸包边封闭等值线(CHCL)和自封闭等值线(SCL),充分利用等值线的特点,使对等值线拓扑关系及填充颜色的判定达到最简化。对于CHCL采用对凸包边等值点及凸包点追踪来确定填充区域,对于SCL则根据拓扑关系以最外层的SCL为根节点构建一棵多叉树以确定填充顺序.通过对等值区域依次反复覆盖填充,最终完成所有等值线的填充。采用了一种穿过原始离散点平滑等值线的算法,减小了等值线平滑造成的精度损失。并运用客户端语言AS3.0(ActionScript3.0)实现了算法模型。实验结果表明,该算法简单易于实现,而且运算速度能满足业务需要。     

视电阻率等值线图水体区域自动识别系统

为了实现对视电阻率等值线图中的疑似水体区域进行识别,开发了一种基于不规则三角网(TIN)等值线填充与OpenCV轮廓提取对各个水体区域进行涂色与识别的系统,改进了等值线填色过程,并根据提取的水体区域轮廓拓扑关系树,计算各个区域面积,给出区域在图像中的具体位置.通过对自动识别结果与人工识别结果的对比,验证系统的实用性,说明系统能够快速准确地识别出视电阻率等值线图的水体区域.     

一种堆栈式快速等值线图填充算法

等值线图在科学研究、石油地质勘探等应用中具有较重要的应用。对于生成填充的等值线图,提出了一种基于堆栈式边界扫描方法,该方法通过将填充边界特征点和等值线特征点进行统一排序,利用堆栈的先进后出的特性,得到等值线之间的拓扑关系,进而追踪出闭合连通区域;对于颜色充填,提出了一种双深度值填充方法。与其他方法相比,该方法较容易理解与实现,对矢量化图件能快速填充。     

散乱数据点的增量快速曲面重建算法

给出了一个新的散乱数据的曲面重建算法.算法充分利用邻近点集反映出的局部拓扑和几何信息,基于二维Delaunay 三角剖分技术快速地实现每个数据点的局部拓扑重建,然后通过自动矫正局部数据点的非法连接关系,以增量扩张的方式把局部三角网拼接成一张标准的整体二维流形网格.该算法在重建过程中能自动进行洞的检测,判断出散乱数据所蕴涵的开或闭的拓扑结构.实验结果表明,该算法高效、稳定,可以快速地直接重构出任意拓扑结构的二维流形三角形网格.     

Delaunay三角网通用合并算子及分治算法的简化

Delaunay三角网在未来地学数值模拟中将发挥重要作用。分治算法是一种著名的经典构网算法,但其子网合并过程十分复杂,限制了其应用。提出使用通用算子的概念,并用从以往算法中独立出来的算子和3个新算子来简化分治算法的子网合并。扩展三角形算子用于构造每个新三角形并维护三角网的拓扑关系和边界链表。凹边界填充算子对边界链表用递归来自动完成凹边界的智能三角形填充。子网合并算子先用一个新三角形连接两个子三角网,再合并边界链表,调用凹边界填充算子填充子网间的缝隙区域。所有算子都基于有向边的数据结构和用链表管理的三角网外边界,借助链表操作,使算法的构建简洁而又高效。除分治法外,这些算子还被成功用于构建其他算法。由随机点集以及LiDAR点云的测试表明,所有算法的构网均准确无误且分治算法的执行效率较高。     

一种基于不规则三角网的地层等值线绘制方法

等值线图是地图学中最常用的地理要素,是地质资源信息系统中最基础和常见的数据表示形式。针对地质模型其地层可视化的特点,研究和分析传统等值线追踪方法的不足,提出一种基于不规则三角网的等值线分类追踪算法。该方法对数据存储模式进行了简化处理,并结合实际应用要求在VC++与Open Scene Graph的开发环境下,实现了等值线的绘制。通过建立地层属性的映射规则,对等值线图进行了填充,达到了地层三维可视化的真实效果,以某采油厂地层离散数据为例,验证了等值线追踪算法的可行性和正确性。     

基于Delaunay三角网的等值线绘制算法*

提出了一种快速构建Delaunay三角网算法（QGDTN）。在每次迭代中,该算法从点集P最左边的两点中,选取离凸边中点距离最近的一点与凸边构成Delaunay三角形,并加入三角网中,算法实现简单,且时间复杂度为O(n)。基于Delaunay三角网,根据三角形的各边上是否有等值点,用内插值法求出等值点坐标,跟踪、连接等值点生成等值线;最后,采用三次方Bezier曲线平滑等值线。实验证明,基于Delaunay三角网的等值线绘制算法是高效的,并且具有一定的实用价值。     

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