17 resultados para Quantitative process research

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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随着软件应用范围的不断扩大和复杂程度的不断提高,软件开发过程越来越难以控制,软件质量也越来越难以保障。质量管理的思想和理念,已经从单纯的以面向软件产品的检验为主要手段的质量控制,发展到更加成熟、更加主动地对软件产品生产过程进行管理的质量保障。 作为高成熟度软件过程的特征,量化过程管理逐渐被软件组织接受并实施。通过实施量化管理,能够刻画项目或过程目标的满足程度,找到造成过程或产品重大偏差的根本原因。然而,在量化过程管理实施期间,软件组织面对不同的软件开发过程、众多的过程性能度量指标、复杂的统计分析方法,既要考虑量化管理方法的合理性和复杂程度,又要权衡量化管理的实施成本,这使得实施有效的量化过程管理充满挑战。本文以缺陷数据为中心,提出了一种缺陷驱动的量化过程管理框架,以及基于该框架的两个量化管理方法,支持软件组织收集量化过程管理所需数据,建立过程性能基线和过程性能模型,量化管理软件项目。该框架适合迭代、瀑布等不同的开发方法,支持项目全生命周期的量化管理。 本文主要贡献包括: 提出了一种缺陷驱动的量化过程管理框架(Defect-driven Quantitative Process Management framework, DefQPM)。量化管理中,保障软件质量是核心。质量和缺陷密切相关,软件开发过程中各类工程活动(如:需求、设计、编码、测试等)都伴随着缺陷的注入、排除和遗留。DefQPM框架以缺陷数据作为量化管理的出发点,自底向上的通过数据层、模型层、使用层来指导软件组织分析过程性能,识别度量指标间的相关性,建立符合自身情况的过程性能基线和过程性能模型,有效的实施量化过程管理。DefQPM框架给出了实施量化管理的过程和机制。基于DefQPM框架,可以建立针对特定应用场景的量化管理方法,以及针对特定软件组织的量化管理解决方案。 提出了一种基于DefQPM的迭代项目量化管理方法(process performance Baseline based Defect-driven iteration management, BiDefect)。迭代开发方法由于其灵活性和管理需求变更的能力,得到了广泛应用。然而,如何对迭代项目实施量化管理依然充满挑战。迭代项目中,各种活动多次并行执行,难以找到合适的控制点,也缺乏针对迭代项目的度量指标及分析方法。基于DefQPM框架,本文研究了迭代开发项目典型的量化管理需要(例如:通过控制每次迭代工作产品的质量来保障最终交付软件产品的质量),提出了一种针对迭代项目的量化管理方法,解决了量化管理迭代项目的几个主要挑战。该方法关注缺陷的注入、排除、遗留情况,指导项目策划期间建立整体估算和度量,在项目执行期间评价软件过程执行情况及软件产品的质量,及时识别异常并采取纠正措施,进而为项目后续工作中成本、进度、质量等方面提供估算、控制方面的指导。 提出了一种基于DefQPM的测试过程量化管理方法(Quantitatively Managing Testing process, TestQM)。测试是重要的质量控制活动,对于高成熟度软件组织来说也是需要进行量化管理的活动。缺陷检测和缺陷修复是测试过程的两类主要活动,需要不同技能的人员执行。目前流行的软件估算方法多是将缺陷检测和缺陷修复的工作量和进度统一纳入测试活动中进行估算和管理,不够准确。基于DefQPM框架,本文提出了一种专门针对测试过程的量化管理方法。该方法关注缺陷按注入阶段分布情况,缺陷与修复工作量的相关性,以及缺陷与修复进度的相关性,指导在早期项目建立测试过程的估算,在测试过程中根据缺陷按注入阶段分布情况调整缺陷修复工作量和进度,使得测试过程受控。同时,介绍了TestQM针对Web应用开发项目的经验模型。 最后,介绍了上述量化管理方法在国内软件组织中的应用,包括BiDefect方法在迭代开发项目中的应用,以及TestQM方法在Web应用开发项目中的应用。软件组织实施量化过程管理前后的过程性能变化表明,应用本文方法能够对项目进行有效的估算、度量、重新估算和控制,进而提高产品质量,改善客户满意度。

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The petroleum migration, happening in the geologic past, is the very important and complex dynamic processes in the petroleum systems. It plays a linking role among all static factors in a system. The accumulation is in fact the result of the petroleum migration. For the petroleum geology, the dynamics research of the petroleum migration refers to the mechanism and process research, as well as the use of the quantitative methods. In this thesis, combining with the qualitative analysis and quantitative modeling, the author manages to discuss theoretically some key problems dealing with migration processes, which have not been solved yet, and to apply the studied results in petroleum system analysis in actual basins. The basin analysis offers the base of the numerical modeling for geological phenomena occurring in sedimentary basins, that consists of the sedimentary facies analysis, the section reconstructing technique, eroded thickness estimating, etc. The methods to construct the geologic model, which is needed in the research of oil and gas migration and accumulation, are discussed. The basin analysis offers also the possibility for the latter modeling works to get and select the parameters, such as stratum's thickness, age, stratigraphy etc. Modeling works were done by using two basin modeling softwares: Basin_Mod and TPC_Mod. The role of compaction during the secondary migration and the heterogeneity of migrating paths within the clastic carrier are modeled. And the conclusions were applied in the migration studies in the Jungaer Basin, lying on the Northwest part of the China. To construct a reliable migration model, the author studied the characteristics of the sedimentation, the pore fluid pressure evolution, as well as the distribution and the evolution of fluid potential, following the tectonic evolution of the Jungaer Basin. The geochemical prospecting results were used to evidence and to calibrate the migration processes: the oil-source correlation, the distribution of the properties of oil, gas and water. Finally, two important petroleum systems, Permian one and Jurassic one were studied and identified, according, principally, to the studies on the petroleum migration within the Jungaer Basin. Since the oil, as well as the gas, moves mainly in separate phase during the secondary migration, their migrating behaviors would be determined by the dynamics conditions of migration, including the driving forces and pathways. Based on such a consideration, the further understandings may be acquired: the roles played by permeable carriers and low-permeable source rock would be very different in compaction, overpressure generation, petroleum migration, and so on. With the numerical method, the effect of the compaction on the secondary migration was analyzed and the results show that the pressure gradient and the flux resulted from compaction are so small that could be neglected by comparing to the buoyancy of oil. The main secondary migration driving forces are therefore buoyancy and capillary within a hydrostatic system. Modeling with the commercial software-Basin_Mod, the migration pathways of petroleum in clastic carriers seem to be inhomogeneous, controlled by heterogeneity of the driving force, which in turn resulted from the topography of seals, the fabrics and the capillary pressure of the clastic carriers. Furthermore, the direct and indirect methods to study fault-sealing properties in the course of migration were systemically summarized. They may be characterized directly by lithological juxtaposition, clay smear and diagenesis, and indirectly the comparing the pressures and fluid properties in the walls at two apartments of a fault. In Jungaer Basin, the abnormal pressures are found in the formations beneath Badaowan or Baijantan Formation. The occurrence of the overpressure seems controlled by the stratigraphy. The rapid sedimentation, tectonic pressuring, clay sealing, chemical diagensis were considered as the principal pressuring mechanisms. The evolution of fluid pressure is influenced differently at different parts of the basin by the tectonic stresses. So the basin appears different pressure evolution cycles from each part to another during the geological history. By coupling the results of thermal evolution, pressure evolution and organic matter maturation, the area and the period of primary migration were acquired and used to determine the secondary migration time and range. The primary migration in Fengcheng Formation happened from latter Triassic to early Jurassic in the main depressions. The main period of lower-Wuerhe Formation was at latter Jurassic in Changji, Shawan and Pen-1-jing-xi Depression, and at the end of early Cretaceous in Mahu Depression. The primary migration in Badaowan and Sangonghe Formation is at the end of early-Cretaceous in Changji Depression. After then, the fluid potential of oil is calculated at the key time determined from area and time of the primary migration. Generally, fluid potential of oil is high in the depressions and low at the uplifts. Synthetically, it is recognized that the petroleum migration in the Jungaer Basin is very complex, that leads us to classify the evolution of petroleum systems in Northwestern China as a primary stage and a reformed one. The remigration of accumulated petroleum, caused by the reformation of the basin, results in the generation of multiple petroleum systems. The faults and unconformities are usually the linkers among the original petroleum systems. The Permian petroleum system in Jungaer Basin is such a multiple petroleum system. However, the Jurassic petroleum system stays still in its primary stage, thought the strong influences of the new tectonic activities.

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软件过程在软件开发中占有非常重要的地位.根据项目的需求和特点,选择一个合适的软件过程可以使项目的开发事半功倍.为了指导软件过程的选择,本文给出了一个简明的软件过程比较框架,并依据这个比较框架,对几个典型的软件过程进行了分析和比较.

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随着软件对社会各领域、各层次的渗透,软件逐渐转变为一种对社会团体、 甚至对社会公众的服务,软件的规模越来越大、用户需求越来越多、功能和性能 要求也越来越复杂。因此,对软件的可用性、可靠性、可信性等质量要求不断提 高。伴随着软件业的逐渐发展,软件过程技术逐渐被应用于软件产品的开发当中。 “质量形成于产品的生产过程”这一理念逐渐被软件组织所接受。其核心思想体 现在通过对软件过程的策划、控制和改进来保证软件产品的质量,进而提高软件 组织的经营业绩。软件过程度量作为软件过程管理和过程改进的关键活动,越来 越为软件组织所重视。 通过实施过程管理,能够刻画项目或过程目标的满足程度,找到造成过程 或产品重大偏差的根本原因,进而实施过程改进。然而,在软件过程度量实施期 间,软件组织面对不同的软件开发过程、众多的过程性能度量指标、复杂的统计 分析方法,既要考虑量化管理方法的合理性和复杂程度,又要权衡量化管理的实 施成本,这使得实施有效的过程度量充满挑战。本文基于经验软件工程方法,提 出一种多粒度多维度软件过程度量框架,以及实现该框架的关键技术:软件过程 性能基线的建立和维护方法;同时介绍了该框架下的软件项目进度量化控制模 型,支持软件组织实施有效的过程管理和改进。 本文的主要贡献包括: 提出了一种多粒度多维度软件过程度量框架(Multi-granularity Multi-dimensional software Process Measurement Framework,M2-PMF),该框架通 过综合考虑软件过程管理和改进的必要信息所属的特征维度和软件组织的过程 管理粒度,自底向上的通过实体层、度量分析层和目标层指导软件组织建立一套 可以覆盖软件全生命周期的、开放的、支持过程改进的综合指标体系和模型。支 持软件组织裁减和定制确定环境下的度量体系,清晰了解其软件过程能力和性 能,提高软件组织对软件过程的控制能力,保障软件开发过程和软件产品的质量。 提出了基于统计分析的过程性能基线的建立和改进方法(Baseline – Statistic - Refinement, BSR),该方法可以有效地建立和维护过程性能基线,支持软件 组织从定性管理提升到定量管理。该方法应用波动图,在过程尚不稳定、数据样 本不足的情况下尽可能多的获得过程改进信息,识别过程改进机会,确定过程改 进途径,帮助软件组织高效地改进其过程中明显的弱项。在过程逐步稳定之后, 利用控制图、排列图、因果图、散点图等统计工具,分析过程性能,建立过程性 多粒度多维度软件过程度量和改进方法研究 ii 能基线,并不断精化。 在M2-PMF 框架下,提出了基于统计过程控制(Statitical Process Control, SPC)和挣值管理(Earned Value Management,EVM)的项目进度量化控制模型 SEVM,该方法通过对项目进度指数的统计控制,分析其稳定性,并通过估算模 型,根据项目当前挣值数据推算项目总进度偏差,并加以控制。支持软件组织对 项目进度进行量化控制,提高了项目按期交付的可能性。 最后,介绍了本文提出的过程度量框架和量化管理方法在国内多家软件组 织中的实际应用。应用案例表明,本文的方法和模型具有广泛的适应性和高度的 可操作性。应用本文方法能够对项目进行有效的估算、度量和控制,进而提高产 品质量并改善客户满意度。

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水泥烧成过程作为水泥厂整个生产流程中的核心环节,其主要任务是对生料进行预热、分解、煅烧和冷却等一系列处理,使其发生符合工艺要求的物理化学反应,最终成为合格的熟料。由于水泥烧成过程具有多变量强耦合、强非线性、大滞后以及工况变化频繁等综合复杂特性,使得烧成过程难以实现自动控制,因而造成分解炉出口温度、篦下压力等关键工艺参数难以准确控制,使得熟料质量差、热量回收效率低。本文针对水泥烧成过程中存在的实际问题,开展了动态机理建模、系统特性分析、回路控制算法和工况状态识别等方面的研究,取得了如下成果: 1、在深入分析水泥烧成过程工艺机理的前提下,基于合理的假设条件和“三传一反”基本原理以及部分常用经验公式,以质量平衡、热量平衡和动量平衡为基础并结合反应动力学,从理论上建立了预热分解系统、高温煅烧系统和熟料冷却系统的动态机理数学模型,并应用现场测试数据验证了模型的有效性,为水泥烧成过程的动态仿真及控制方案设计提供了有力支持。 2、针对分解炉出口温度控制回路具有非线性、大滞后和大扰动的问题,在对预热分解系统进行动态模型仿真和特性分析的基础上,提出了具有前馈补偿的约束Smith广义预测控制方法来实现分解炉出口温度的稳定控制。现场工业实验结果表明,该方法有效地抑制了生料流量波动和系统滞后所带来的不利影响,提高了分解炉出口温度的控制精度,保证了生料入窑分解率的稳定。 3、针对篦下压力控制回路存在的大惯性、工况变化频繁以及检测信号的信噪比性能差、噪声严重的问题,在对熟料冷却系统进行动态模型仿真和特性分析的基础上,提出了基于Kalman滤波器的模糊自整定PID控制方案来实现篦下压力的稳定控制。现场工业实验结果表明,该方案有效地去除了篦下压力检测信号中的噪声影响,增强了控制器对工况状态变化的适应能力,提高了篦下压力的控制精度和热量回收效率。 4、针对水泥回转窑工况状态难以准确判断的问题,在证明窑电流信号具有分形特性的前提下,提出了基于简单分形的工况特征识别方法,并通过现场实际工况数据进行了仿真验证;接下来,为了能够从过程信号中提取更多的局部特征信息,进一步提出了基于多重分形谱的工况特征提取与识别方法来对窑电流信号进行更为全面细致的描述,以获取更多的信息用于回转窑工况状态的识别;最后,总结了基于分形理论进行工况识别的方法与步骤。上述尝试性研究的成功,不但为今后研制水泥烧成过程的性能监控与优化运行系统奠定了基础,也为复杂工业过程的工况特征识别研究提供了新的思路。

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激光再制造技术是在20世纪80年代末期出现的激光熔覆技术基础上结合再制造技术所发展起来的一项先进制造技术,它利用高能激光束局部熔化零件表面形成熔池,同时将金属合金粉末同步送入熔池而形成与基体金属冶金结合的熔覆层,赋予零部件耐高温、耐腐蚀、耐磨损、抗疲劳等性能。该技术融合了激光技术、材料科学、数控加工、CAD/CAM技术、光电检测技术、机构设计技术、优化设计和系统仿真等相关领域的关键技术,是一门全新的光、机、电、计算机、自动化、材料综合交叉的制造技术。它的出现给机电设备的再制造带来了全新的理念,解决了很多传统再制造技术无法解决的难题,极大的带动和促进了再制造产业的发展,具有广阔的应用前景,产生了巨大的经济、社会和环境效益。 目前,国内外激光再制造技术的研究尚处于萌芽阶段,研究还没有形成系统化,仍然有很多关键技术需要进行深入细致的研究。本文在国家863计划、中科院知识创新基金和地方科技攻关等项目的支持下,系统地研究了激光再制造的关键技术,在建立各项关键技术知识点分析和理论研究的基础上,给出了关键技术的实施路线和解决方案,为激光再制造技术的工艺试验和工业化应用提供了理论依据和技术支持。具体的研究内容如下: (1) 进行了激光再制造系统本体研究,在系统地研究了各功能模块的基础上,提出了各功能模块选择的原则,有效的避免了搭建再制造系统时各功能模块任意选择的误区。针对国产激光器不稳定和使用寿命短等缺点,借鉴固态激光器的结构原理,设计开发了新一代模块化CO2激光器;针对国产送粉系统不稳定、送粉不均匀等缺点,设计开发了一种新型内外双水冷的同轴送粉喷嘴,经过试验测试,此喷嘴可长时间连续稳定运行,满足工业化生产的需要。基于模糊数学理论的优化设计方法,自主开发了一套三维多功能激光再制造系统,该系统结构完整、功能完善、性能可靠,可以对大型设备零部件进行激光修复和激光淬火。 (2) 进行了激光再制造熔池温度场检测系统的研究,建立了一套在线、小视场、大量程、高精度红外测温系统;通过红外滤光片的选择和设计,有效解决了传统3CCD相机比色测量的准确度差和精度低的问题;提出了一种红外热像系统位置标定的方法,为其它领域红外系统的摄像机标定提供了研究基础;进行了各加工工艺参数对熔池温度场稳定性影响的研究,从而更加了解了激光熔覆凝固成型的原理。同时,进行了熔覆层厚度检测系统的研究,建立了一套单CCD应用线结构光测量熔覆层厚度的系统,并对系统的构成、系统的标定和测量原理进行了分析和研究,从而实现了熔覆层厚度由定性测量向定量测量的跨越。 (3) 进行了工业生产中常见装备及其零部件的失效分析研究,提出了一套按照增加熔覆层性能的失效原因分类原则;进行了激光熔覆粉末种类及其特点的研究,提出了一套激光熔覆粉末的选择原则,给出了各类熔覆层应该采用的熔覆粉末的具体配比方案,从而为激光再制造技术的工业应用奠定了基础。 (4) 进行了激光再制造工艺设计研究,详细分解了激光熔覆过程中涉及到的各工艺步骤,如光束选择、送粉方式、不同基材的熔覆工艺、预处理工艺、预热处理、加工路径规划和后处理等,结合大量的工艺试验,提出了各工艺的选择原则;提出了激光比能量、送粉速度、搭接率、预热温度、预置粉末厚度和保护气流量是影响激光再制造熔覆层质量的最重要工艺参数,并结合工艺实验验证了这些工艺参数对熔覆层质量的实际影响;进行了熔覆层质量的宏观判据和微观判据研究,给出了宏观判据现象产生的原因和微观判据测量的方法,从而为激光再制造技术的工业应用铺平了道路。 (5) 在解决了上述激光再制造关键技术的基础上,进行了板坯结晶器激光再制造工艺试验研究,分析了板坯结晶器的失效原因,并根据失效分析设计和选择熔覆粉末,然后对每种熔覆粉末进行了熔覆工艺设计,采用正交试验法获得了各加工工艺的最佳工艺参数,并制备了相应的样件;然后对样件熔覆层的各种宏观现象和微观性能测试的进行了分析,包括孔隙率、浸润性、微观形貌、显微硬度、成分偏析、金相研究、抗腐蚀性和抗热疲劳性能等,从而得出了大面积板坯结晶器激光熔覆的最佳熔覆粉末、最佳工艺和工艺参数等,并进行了窄板结晶器的激光再制造。

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The epoxidation of styrene catalyzed by a reaction-controlled phase transfer catalyst [(C18H37(30%)+C16H33(70%))N(CH3)(3))(3)](3)-[PW4O16] with H2O2 in a biphasic medium was investigated. Under certain conditions, the selectivity for styrene oxide was 95%, the conversion of styrene based on H2O2 was 85%, and the reaction time was less than 1 h. During the reaction, this catalyst powder formed soluble active species by the action of H2O2, was recovered as a precipitate, and was reused after H2O2 was used up. After two times recycling, the catalyst kept almost the same activity.

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By recalling mankind's path during past 50 years in the present article, we mainly highlight the significance of environmental issues today. In particular, two major factors leading to environment deterioration in China such as water resources and coal burning are stressed on. Present-day environmental issues are obviously interdisciplinary, of multiple scales and multi-composition in nature. Therefore, a process-based approach for environment research is absolutely necessarily. A series of sub-processes, either physical, chemical or biological, are subsequently analyzed in order to established reasonable parameterization scheme and credible comprehensive model. And we are now in a position to answer questions still open to us, improve existing somewhat empirical engineering approaches and enhance quantitative accuracy in prediction. To illustrate this process-based research approach, three typical examples associated with the Yangtze River Estuary, Loess Plateau and Tenggeli Desert environments have been dealt with respectively. A theoretical model of vertical flow field accounting for runoff and tide interaction has been established to delineate salinity and sediment motion which are responsible for the formation of mouth bar at the outlet and the ecological evolution there. A kinematic wave theory combined with the revised Green-Ampt infiltration formula is applied to the prediction of runoff generation and erosion in three types of erosion region on the Loess Plateau. Three approaches describing water motion in SPAC system in arid areas at different levels have been improved by introducing vegetation sub-models. However, we have found that the formation of a dry sandy layer and biological crust skin are additional primary causes leading to deterioration of water supply and succession of ecological system.

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In this paper the finite element method was used to simulate micro-scale indentation process. The several standard indenters were simulated with 3D finite element model. The emphasis of this paper was the differences between 2D axisymmetric cone model and

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Broad bandwidth group match conditions are reported for a noncollinear type I optical parametric process. The theoretical calculations corresponding to two special situations in practice were made, respectively, which are in accordance with the published experimental results. Furthermore, we provide a method to not only achieve maximal parametric bandwidth output but also match the group velocities between three waves. (c) 2006 Optical Society of America.