多线程在VB.NET下的实现

为了在 VB.NET 中处理并发问题和多任务管理的问题,使用多线程编程技术这一程序设计最为广泛应用的技术是最方便的解决方法,应用需要多个任务时可以使用多线程技术。在键盘输入数据的同时另一个线程在计算井传输数据,其它的线程可以同时完成屏幕的更新显示、或从端口读入数据等。研究了在 VB.NET 中线程的创建、运行和终止的方法,及如何确定和更改线程的状态和线程的同步问题。通过对 VB.NET 编译环境中线程对象的分析,深入剖析了多线程技术在 VB.NET 编译环境中的实现过程,说明了 VB.NET 中基于多线程技术的程序开发过程。     

多线程技术在工控软件中的应用

本文概述了工控软件中应用多线程技术的原因,并进而论述了线程与进程的区别、线程的创建、终止、优先级及MFC类库对多线程技术的支持 最后;本文提出了用MFC类库开发工控软件时采用多线程技术所遇到的问题,并给出解决方案.     

基于多线程的计算机硬件虚拟实验室的设计与实现

研究了计算机硬件虚拟实验室的设计与实现方法.系统采用多线程技术实现虚拟计算机的仿真运行、信号检测、信号图形化编码及信号输出4个功能模块的并行操作功能,采用加锁技术实现多线程运行的同步控制;根据系统运行时间的特点、模块的交互性、线程间优先关系,设定各线程的优先级别,按优先级别与给定时间片进行线程调度;模块间传送数据的同步控制通过多数据缓冲区机制实现,利用事件驱动方式完成各缓冲区数据的传递.系统采用多线程与多缓冲区技术相结合的方式,实现了计算机硬件虚拟实验系统模块的并行操作与数据的并行处理,提高了系统的交互性和运行效率,为计算机硬件实验教学提供了一个高度交互与仿真的虚拟实验环境.     

一种嵌入式硬件多线程处理器的研究

提出了一种基于同时多线程技术的硬件多线程处理器设计.通过处理器内部的硬件机制来完成对多线程的调度管理,实现基于硬件的时间片轮询多线程调度机制.最大程度地减少操作系统中关于线程调度的开销,提高处理器执行多用户线程时的整体效率,简化了用户在多线程条件下的编程复杂度,增强了多线程运行环境下处理器对线程的保护.     

浅谈JSP的多线程技术

JSP的多线程技术为其抹上了一道亮丽的光彩,使其得到了广泛地关注。本文对于JSP的多线程技术进行了介绍,阐述了多线程的优势,并对多线程的操作和线程调度进行了分析,并对线程池技术分析。     

基于VB的多线程实时测控系统的设计与实现

介绍在VB环境下基于多线程的压力机床测控系统的设计与实现过程，对该测控系统的技术特点，软件设计方法进行了具体论述，并给出了在VB中用ActiveX技术实现多线程实时测控的系统框架。该系统已成功地应用于一大型汽车制造企业的生产过程。     

THDS-100调度自动化系统中多线程技术的应用

为提高调度自动化系统的性能 ,以中、小型地调和县调为主要应用对象 ,结合 Windows NT操作系统多线程处理能力 ,利用多线程的特点及其优势 ,讨论了如何利用线程的优先级设置 ,使系统重要运行状况得到快速响应。同时比较了实现线程同步的几种方法 ,避免了数据的不一致。该技术已成功地应用于 THDS- 10 0调度自动化系统中 ,显示出明显的优越性。避免了常规定时器方式下时间的浪费。利用操作系统的线程调度功能管理调度自动化系统中不同功能的线程 ,使系统性能达到最高 ,并在故障处理时仍可以实现系统其他功能     

基于Windows的DSM系统中线程迁移的实现

随着多线程DSM系统的发展,线程迁移已经成为DSM系统中一个非常重要的研究课题。在分析Windows操作系统的存储和控制结构的基础上,讨论了基于Windows操作系统的多线程DSM系统的基本框架,提出了一种对线程进行动态迁移的方法。并且在一个基于Windows操作系统工作站机群的Smonn系统中成功实现,表明了该方法的有效性。     

Java语言多线程技术应用研究

多线程编程是Java语言的一个很重要的特点,它是面向对象程序设计的关键技术之一.本文简要的探讨了Java语言多线程的基本技术,就线程的创建、线程控制和调度及线程同步等处理技术做了相关探讨.     

Windows 98 下多线程编程方法研究

在新型的操作系统中，引入了多线程的概念，在支持多线程的操作系统中提供了相应的系统词用函数，研究了Windows操作系统中资源分配和调度的基本单位以及线程的特点，核心论述了在Windows操作系统下多线程编程方法的实现。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to