以寻呼区分析为基础的PHS网络优化方法

通过分析PHS网络中各寻呼区的统计指标,剖析指标劣化的根本原因,采取修改相应的参数配置、移站、调整天线等措施进行网络优化,优化实施后再次收集统计指标做对比分析,总结经验。     

On-Line File Caching

Abstract. Consider the following file caching problem: in response to a sequence of requests for files, where each file has a specified size and retrieval cost , maintain a cache of files of total size at most some specified k so as to minimize the total retrieval cost. Specifically, when a requested file is not in the cache, bring it into the cache and pay the retrieval cost, and remove other files from the cache so that the total size of files remaining in the cache is at most k . This problem generalizes previous paging and caching problems by allowing objects of arbitrary size and cost, both important attributes when caching files for world-wide-web browsers, servers, and proxies. We give a simple deterministic on-line algorithm that generalizes many well-known paging and weighted-caching strategies, including least-recently-used, first-in-first-out, flush-when-full, and the balance algorithm. On any request sequence, the total cost incurred by the algorithm is at most k/(k-h+1) times the minimum possible using a cache of size h ≤ k . For any algorithm satisfying the latter bound, we show it is also the case that for most choices of k , the retrieval cost is either insignificant or at most a constant (independent of k ) times the optimum. This helps explain why competitive ratios of many on-line paging algorithms have been typically observed to be constant in practice.     

通用自定义分页的实现

Web系统在应用过程中经常会遇到大量数据的查询,设计时如何在数据服务控件中进行分页显示,这是常碰到的问题,介绍通用自定义分页的设计思路,并对代码的设计进行了详细的分析。     

PHP分栏类及其应用

分析了分栏显示流程,指出了构造分栏类需要定义一个方法和5个属性：每页显示记录数、分页记录集、栏目数、各列显示名称及显示宽度,给出了分栏类的PHP语言代码及其在Web考试系统中的应用。     

On-Line Multi-Threaded Paging

Abstract. In this paper we introduce a generalization of Paging to the case where there are many threads of requests. This models situations in which the requests come from more than one independent source. Hence, apart from deciding how to serve a request, at each stage it is necessary to decide which request to serve among several possibilities. Four different on-line problems arise depending on whether we consider fairness restrictions or not, with finite or infinite input sequences. We study all of them, proving lower and upper bounds for the competitiveness of on-line algorithms. The main competitiveness results presented in this paper state that when no fairness restrictions are imposed it is possible to obtain competitive algorithms for finite and infinite inputs. On the other hand, for the fair case in general there exist no competitive algorithms. In addition, we consider three definitions of competitiveness for infinite inputs. One of them forces algorithms to behave efficiently at every finite stage, while the other two aim at comparing the algorithms' steady-state performances. A priori, the three definitions seem different. We study them and find, however, that they are essentially equivalent. This suggests that the competitiveness results that we obtain reflect the intrinsic difficulty of the problem and are not a consequence of a too strict definition of competitiveness.     

利用ASP实现数据库内容分页显示

利用ASP内置组件AD0的两个对象Connection和Recordset及该两个对象的属性和方法实现数据库内容在Web网页上的分页显示。     

呼叫中心市场的演进对寻呼企业的影响

呼叫中心技术的演进、Internet的屈起使得近年来呼叫中心产业在全球迅速走红，在我国的业务发展和市场潜力也非常巨大。目前国内各大寻呼企业正在积极寻求转型，如能将其原有设备稍加改造，并利用多年来积累的电信增值服务的经验，经营呼叫服务中心业务将是一个明智之举。     

基于Fluid-Flow和Gauss-Markov混合模型的位置管理性能评估

针对现有的Fluid-Flow移动模型难以拟合PCS网络中随机游走行为的问题。设计一种基于Fluid-Flow和Gauss-Markov的混合模型。该模型应用Gauss-Markov随机过程理论,将速度离散化,确定前后速度关联度参数,从而能模拟不同运动特征的移动终端。通过Matlab数值仿真,模拟PCS网络应用场景,较单纯基于Fluid-Flow模型的位置管理方法能大幅度减小系统开销,证明该模型更适于复杂位置管理性能评估。     

Exploiting the least recently used page replacement algorithm

Many implementations of paged virtual memory systems employ demand fetching with least recently used (LRU) replacement. The stack characteristic of LRU replacement implies that a reference string which repeatedly accesses a number of pages in sequence will cause a page fault for each successive page referenced when the number of pages is greater than the number of page frames allocated to the program's LRU stack. In certain circumstances when the individual operations being performed on the referenced string are independent, or more precisely are commutative, the order of alternate page reference sequences can be reversed. This paper considers sequences which cannot be reversed and shows how placement of information on pages can achieve a similar effect if at least half the pages can be held in the LRU stack.     

个人移动信息系统简介

本文介绍美国通用无线公司的ＰＬＡＮＥＴ个人移动信息系统的体制、技术特点、应用以及局限性。并对我国发展个人移动信息系统提出若干建议。