用PowerBuilder实现实时多点循控

ＰｏｗｅｒＢｕｉｌｄｅｒ是目前公认的较好的数据库开发环境，但与其他数据库开发环境类似ＰｏｗｅｒＢｕｉｌｄｅｒ存在对硬件控制力差，实时性差的问题，本文介绍一种用Ｄｅｌｐｈｉ编写动态连接库，与ＰｏｗｅｒＢｕｉｌｄｅｒ相结合实现中口进行多点循控的方法，用该方法我们在齐鲁电视台设备管理系统中实现了一对三十点的循回控制。     

基于PowerBuilder开发网上购票系统

分布式数据库系统是数据库领域的新技术,是数据库技术、计算机网络技术和分布式处理相结合的产物。介绍了利用PowerBuilder环境开发分布式数据库系统应用的方法及其原理,并给出运用PowerBuilder开发网上数据库应用系统的实例(网上购票系统)。利用分布式数据库系统和网络功能实现网上购票,对民航、铁路和公路交通运输部门有着重要的意义。     

Power Builder中使用FoxPro数据库的方法

PowerBuilder是十分优秀的用于客户／服务器环境的信自管称系统开考了具．其优秀之处不仅是因为可以开发基于客户／服务器模式的系统，而且简单、易学。PowerBuilder自身是没有数据库管理系统（DBMS）的，它是首先通过不同的驱动程序联接不同的数据库，再通过这种联接，实现对数据的管理。Po、ernuild，r随盘附带有一个小型的数据库管理系统：SQLAnywhere，所以用户也可以直接开发用于单机的完整的信息管理系统。笔者以前曾开发过基于FoxPro环境下的数据库系统，但F。XI40的编程太麻烦，不但要处理数据的管理，而且还要花大量的精力…     

PowerBuilder开发卡号打印系统

PowerBuilder是目前最流行的数据库开发工具之一.PowerBuilder以其简洁高效的集成开发环境、强大的数据窗口技术、(几乎)无所不能的数据库访问能力,越来越受到编程人员的青睐.数据窗口(DataWindow)是PowerBuilder的专利,也是PowerBuilder应用程序的核心和精华所在.     

出版管理信息系统的研究与设计

通过对出版计算机综合管理信息系统的分析与研究，采用客户/服务器模式的信息系统结构，建立了以网络为中心的计算机环境，利用构建数据库应用系统的最新技术即客户端的数据库应用开发工具PowerBuilder等，开发出功能强、运行可靠的出版管理信息系统。     

基于PB技术的地方民办学校教学管理系统研究

在系统设计上采用PowerBuilder开发环境与SQL Server数据库的设计,并在硬件上采用VPN路由器技术实现远程数据共享等功能,使民办学校走出作坊式管理混乱的经营瓶颈,真正享受到人性化、信息化、科学化管理所带来的便利。     

OLE技术在PowerBuilder中的实现

论述OLE技术在PowerBuilder中的实现。提出了PowerBuilder对OLE的支持及在数据库中如何使用OLE对象的方法，并针对PowerBuilder的打印报表功能相对较弱的缺点，阐述了使用OLE技术解决的方法，并给出了具体实例。     

利用PB开发一个数据库比较软件

针对数据库开发项目中遭到的数据库比较问题，编制了数据库自动比较程序。介绍了在PowerBuilder中多事务对象、动态游标、动态数据窗口等的开发技巧和常用方法。     

窗口集成测试的研究与实践

目前应用最多的是信息管理系统，PowerBuilder作为MIS系统最有效的开发工具，提供了基于面向对象技术的数据库开发环境。面向对象技术的发展使得软件测试的具体采取的策略要相应变化，尤其要根据开发工具的特点进行新的尝试。本文介绍了在PowerBuilder环境下进行窗口测试的特殊性以及可行性的一种测试方案，并加以具体实践。     

系统开发及开发工具

0306156数据库应用的需求分析研究[刊]/张峰岭//计算机工程与应用.—2002,38(18).—210～211,217(L)文章分析了数据库应用需求的特点,结合作者工作实践分析了传统需求分析方法在开发数据库应用中遇到的问题,提出相应的解决方法,并介绍了中山大学软件研究所在这方面的研究成果。参40306157PowerBuilder 中动态 SQL 语句的实现[刊]/任少云//微型机与应用.—2002,21(10).—53～54,60(D)介绍了 PowerBuilder 开发工具中的动态 SOL 语句,并通过具体实例说明了如何在 PowerBuilder 中使用4种格式的动态 SQL 语句。参2     

Engineering Functional Collagen Scaffolds: Cyclical Loading Increases Material Strength and Fibril Aggregation

Variation in collagen fibril diameter in nature is a major factor determining biological material properties. However, the mechanism resulting in this fibril diameter difference is not clear and generally assumed to be cell‐dependent. It is certainly not possible so far to engineer this into implantable scaffold materials. This gap in our knowledge is crucial for the fabrication of truly biomimetic tissue‐like materials. We have tested the idea that fibril diameter can be regulated directly without cell involvement, using cyclical mechanical loading to promote fibril fusion. Specific loading regimes increased collagen fibril diameter (> 2 fold) in direct relation to cycle number, whilst thin fibrils disappeared. Tensile properties increased, producing a 4.5 fold rise in break strength. This represents the first demonstration of direct cyclical load‐promoted fibril fusion and provides a direct relation with material properties. The ability to control material properties in this way makes it possible to fabricate truly biomimetic collagen materials without cells.     

Verification system robust to occlusion using low-order Zernike moments of palmprint sub-images

This paper proposes a palmprint based verification system which uses low-order Zernike moments of palmprint sub-images. Euclidean distance is used to match the Zernike moments of corresponding sub-images of query and enrolled palmprints. These matching scores of sub-images are fused using a weighted fusion strategy. The proposed system can also classify the sub-image of palmprint into non-occluded or occluded region and verify user with the help of non-occluded regions. So it is robust to occlusion. The palmprint is extracted from the acquired hand image using a low cost flat bed scanner. A palmprint extraction procedure which is robust to hand translation and rotation on the scanner has been proposed. The system is tested on IITK, PolyU and CASIA databases of size 549, 5239 and 7752 hand images respectively. It performs with accuracy of more than 98%, and FAR, FRR less than 2% for all the databases.     

LAN interconnect using X.25 network services

The use of X.25 for medium-speed applications (<56 kb/s) in personal computer local area networks (LANs) is considered, focusing on a number of popular LAN-based applications that are appropriately matched for X.25 services. For architectural reasons, they are broadly classified into two categories: PC-to-host access (terminal emulation), as in token ring, to synchronous data link control (SDLC) hosts using host gateways; and client-server applications, such as distributed databases that are bridged or routed. For each class of applications, the traffic characteristics are discussed, it is explained how an efficient interconnection can be accomplished, and some insight is provided into how LAN internetworking devices (routers and gateways) function in an X.25 environment     

Synchronous CDMA based on the cyclical translations of a CAZAC sequence

A new scheme of synchronous CDMA is introduced in the paper. The new scheme is based on a code made by all the cyclical translations of a basic sequence having constant amplitude and white discrete spectrum. Such a code is proposed here for the first time as a code for CDMA. According to the proposed scheme, a cyclic prefix is appended to the multiplexed signal. The proposed scheme has a property that none of the known CDMA schemes has: in a multipath environment, it allows multiuser interference to become cyclic intersymbol interference. Noticeably, the memory of the finite state machine that describes the ISI model is equal to memory of the multipath channel. The main advantage of our proposed scheme is that optimal and suboptimal detectors can be obtained from detectors proposed in the past for the ISI channel, which are much easier to implement than conventional multiuser detectors of classical CDMA schemes. Another advantage of our scheme is that it leads naturally to a signal processing architecture similar to that of OFDM systems, hence based on the efficient FFT/IFFT algorithm.     

Hierarchical browsing and search of large image databases

The advent of large image databases (>10000) has created a need for tools which can search and organize images automatically by their content. This paper focuses on the use of hierarchical tree-structures to both speed-up search-by-query and organize databases for effective browsing. The first part of this paper develops a fast search algorithm based on best-first branch and bound search. This algorithm is designed so that speed and accuracy may be continuously traded-off through the selection of a parameter lambda. We find that the algorithm is most effective when used to perform an approximate search, where it can typically reduce computation by a factor of 20-40 for accuracies ranging from 80% to 90%. We then present a method for designing a hierarchical browsing environment which we call a similarity pyramid. The similarity pyramid groups similar images together while allowing users to view the database at varying levels of resolution. We show that the similarity pyramid is best constructed using agglomerative (bottom up) clustering methods, and present a fast sparse clustering method which dramatically reduces both memory and computation over conventional methods.     

A measurement-based methodology for the determination of validitydomains of prediction models in urban environment

The choice of a given propagation model has a major impact on the accuracy and effectiveness of cellular planning, especially in an urban environment, where a higher degree of detail is required. Rigorous models, such as those based on ray optics, are generally heavily time-consuming; furthermore, they are accurate only if high-resolution databases (of buildings, land usage, etc.) are available, and the cost of these databases is increasingly affecting the operators' budget. Therefore, one should use them only in their “validity domain,” i.e., the area where they are both reliable and necessary: using complex tools where it's not needed implies an overhead in terms of computation time and, above all, database cost. For this reason, increasing interest and effort are being devoted by operators, manufacturers, and system planners in general to determine the validity domains of propagation models in an urban environment. We introduce a new methodology, based on objective indicators related to field strength statistics, to determine these domains     

翻译Snort规则到Statl规则

各种入侵检测系统越来越多,其中大多是基于信号检测(signaturebased)的。它们的信号库各不相同,不能共享。这导致每个产品都要开发自己的信号库,因此不同厂家的入侵检测系统根本无法互相配合,共同防范攻击。提出了一种将一个网络入侵检测系统的Snort的规则转换为STATL(NetSTAT)规则的方法,初步实现了两者之间的规则共享。     

PLC在发射机监控电路中的应用

发射机监控电路已经从传统的继电器联锁电路发展到采用计算机和微控制器为核心进行控制,监控电路能否可靠工作对整机可靠性有着重要影响。大功率发射机由于存在很多大功率器件工作在开关状态,是一个强大的干扰源,单片机系统很难在强电磁干扰环境中可靠工作。PLC(可编程逻辑控制器)具有很高的可靠性,在工业控制中得到了广泛应用,但在发射机中的应用不多。文中介绍了采用PLC控制的发射机监控电路的组成,以及利用PLC内置通信协议进行远程控制的方法。     

一种嵌入式数据库安全增强方案的设计与实现

由于嵌入式平台的开放性和智能化,嵌入式数据库面临的安全威胁日益增长。在此提出一种嵌入式数据库安全增强方案,融合多种安全技术,如指纹识别、访问控制、数据加密等,设计了一种基于嵌入式数据库的安全中间件,构造访问嵌入式数据库的安全通道,对嵌入式数据库系统进行安全增强。该安全方案在嵌入式数据库Berkeley DB系统上得到了应用,验证了嵌入式数据库安全方案的可行性,能够有效地增强嵌入式数据库的安全性。