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软件项目管理涉及软件生命周期的各个部分,对整个软件项目的成功起着非常重要的作用.合理的管理方法,可以有效地提高开发效率和成功率,降低开发成本.对开发过程的管理和开发成本的估算,是软件项目管理的重要环节.有效的软件开发过程量化方法可以提供大量的量化数据,通过对这些量化数据的分析与统计,可以确定量化指标等,以此为基础,进行软件工作量的估算和开发成本的估算,相对于传统的依据经验估算,将会取得更加准确的结果.因此,本文基于软件量化过程中的变更数据,结合工作量估算模型COCOMOⅡ,进行了相关研究,并给出了具体的估算方法. 相似文献
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所有成功的软件组织都将度量作为保证自己管理和技术质量的重要手段,软件成本估计则是软件度量的核心任务。为了提高成本估算的准确性,文章根据特定软件企业中的历史项目数据对基本COCOMO模型进行校准,在具体的参数修正方法上利用对数数据相关算法进行校正,并与其它方法进行了比较,得到了满意的结果。校准后的模型对项目开发成本的预测将会更加准确.从而切实体现COCOMO成本度量工作对于软件项目的指导价值。因此,文章所做的成本估算模型的校准工作,对软件开发企业非常具有实用价值。 相似文献
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唐俊 《信息技术与标准化》2008,(5):49-51
在软件项目成本估算中采用功能点方法,成本预算中实施工作结构分解和COCOMO方法结合的方法,软件项目结束后引入决算和审计机制,为软件企业建立起一个基于估算、预算和决算的知识库系统,来达到提高成本管理能力的目的. 相似文献
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敏捷开发是当前非常流行的一种软件开发方法,而常用的软件工作量估计方法针对敏捷开发项目效果并不好。为能准确估算出敏捷开发项目的工作量,研究一种基于神经网络工作量估算模型,以适用于敏捷开发项目的工作量估计。 相似文献
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数据库规模估算数学模型研究 总被引:1,自引:1,他引:0
数据库规模估算是软件规模估算的基础.定义了数据库规模是综合指标的概念,运用文字叙述、表格及图形等方法分析了表类型、表结构、表元组、存储过程等因素对数据库规模的影响,设计了数据库规模估算的数学模型,并对模型中的各个参数进行了详细解释,指出了在软件生命周期前、后阶段进行估算的方法. 相似文献
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We developed a low organic contamination (LOC ) electric cable as part of efforts to reduce organic contamination in semiconductor equipment. Our development strategies for LOC cables were obtained from the study of the behavior of outgassing from electric cables and the behavior of adsorption on silicon wafers. Strategy I: Reduce low boiling point organic contaminants from electric cables. Strategy II: Reduce organic contaminants with high adsorption rates on silicon wafers. Developing LOC cable under these two strategies, consequently, the amount of organic contaminants that are outgassed from the developed LOC cable was 1/10 or less of the level that is achieved by conventional cables. When compared with conventional cables, the flame-retardancy and flexibility are comparable. Then, we installed LOC cables in actual semiconductor equipment. The amount of organic contaminants adsorbed on the silicon wafer exposed in the equipment that was installed LOC cable and other low outgas parts were 1/6 lower than the conventional equipment. By using this low-outgassing cable in semiconductor equipment, we succeeded in reducing organic contamination in the equipment. 相似文献
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Optimum Cooperation of the Cooperative Coding Scheme for Frequency Division Half-Duplex Relay Channels 总被引:2,自引:0,他引:2
Kyoung-Lae Noh Serpedin E. Suter B. 《Wireless Communications, IEEE Transactions on》2007,6(5):1654-1658
This paper analyzes the effects of the level of cooperation (LOC) on the performance of a practical cooperative coding scheme for frequency division half-duplex relay links in general wireless ad-hoc networks. The end-to-end bit error probability (BEP) and the corresponding optimum LOG minimizing the end-to-end BEP are investigated for specific realizations using a family of rate compatible punctured convolutional (RCPC) codes. This paper shows that the BEP of the cooperative coding scheme depends on the LOC and there exists an optimum LOC for every specific realization. Further, it is shown that more than a certain level of cooperation is required to achieve possible cooperative gains in practical signal-to-noise ratio (SNR) regions, and increasing LOC does not effect much on the BEP performance for sufficiently large LOCs 相似文献
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针对仪表着陆系统中的双频航向信标(localizer,LOC)阵列天线最大旁瓣电平抑制和覆盖性能优化问题,改进了一种混沌量子粒子群(chaos quantum particle swarm optimization,CQPSO)算法,对既定约束的LOC阵列天线方向图进行馈电参数寻优。在分析双频LOC覆盖形成的基础上,剖析了国际民航组织对LOC信号的覆盖要求,获得LOC方向图应满足的约束条件。为提升全局寻优能力和有效避免陷入局部最优,引入混沌思想和加权平均最优位置对CQPSO算法进行改进,使用改进的CQPSO算法对20阵元等间距LOC阵列天线进行约束条件下的馈电参数寻优,并依据所获得的馈电参数仿真分析LOC阵列天线的方向性。仿真实验表明,改进CQPSO算法寻优得到的馈电参数形成的方向图,相比于目前广泛使用的24阵元等间距LOC阵列天线的方向图,在天线数量减少16.67%的情况下,航道信号辐射的最大旁瓣电平降低了3.32 dB,且覆盖性能更好;而相比于目前广泛使用的20阵元不等间距LOC阵列天线的方向图,航道信号辐射的最大旁瓣电平降低了25.55 dB,证明了改进CQPSO算法的有效性。 相似文献
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Distributed mapping management of identifiers and locators in mobile‐oriented Internet environment 下载免费PDF全文
Moneeb Gohar Heeyoung Jung Seok‐Joo Koh 《International Journal of Communication Systems》2014,27(1):95-115
Many schemes have recently been proposed for the separation of identifier (ID) and locator (LOC), which include the Host Identity Protocol, the Identifier‐Locator Network Protocol, and the Locator Identifier Separation Protocol. However, all of these schemes were originally designed in fixed network environment, rather than mobile network environment. In particular, these schemes are based on a centralized map server that is used as an anchor point for mobile nodes, and thus intrinsically subject to some limitations in a mobile environment. In this paper, we propose a distributed ID‐LOC mapping management scheme in a mobile‐oriented Internet environment. In the proposed scheme, we assume that a host has a globally unique and hierarchical Host ID (HID) that contains the information of its home network domain. Each network domain has a distributed map server for distributed management of ID‐LOC mappings. For roaming support, each distributed map server maintains its own home HID register and visiting HID register, which are used to keep the mappings of HID and LOCs for mobile nodes in the distributed manner. By performance analysis, it is shown that the proposed distributed scheme can give better performance than the existing centralized schemes in terms of ID‐LOC binding update and data delivery costs. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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针对普通双目立体摄像机在机器人立体视觉仿真中的不足,提出一种复眼立体摄像系统。通过对其原理分析,找出被摄目标的深度、方位与摄像机之间的几何关系,推出计算公式,给出其在机器人视觉仿真中的应用方案。该系统提高了机器人视觉仿真精度,应用方案简单可行。 相似文献