面向3D虚拟展示的软件定制化系统研究

针对传统三维虚拟展示软件中存在的编程过程复杂、开发周期长等缺陷,提出一个具有可定制性和扩展性面向虚拟展示的定制方法。该方法基于虚拟现实技术和软件大规模定制技术,设计面向虚拟展示的定制化系统架构;基于软件功能树对系统功能解耦,抽取可复用的公共模块实现参数定制化,封装为功能接口供系统调用;同时定义了系统的定制模板,以描述和配置应用系统的基本信息和个性化定制,从而满足不同企业产品虚拟展示功能定制需求。最后通过具体实例展示验证了该系统的有效性和实用性。     

特定风险控制水平下可配置化乳制品追溯平台

为了提高追溯系统的效率、用户体验和利用率等, 提出设计特定风险控制水平下可配置化乳制品追溯平台的方法. 该方法选择与食品风险相关的参数, 包括HACCP(危害分析关键控制点)、风险等级、风险发生可能性、追溯环节和成本选择, 应用二进制相关的数学推导生成这些参数的编码结果, 把该编码结果进行低、中、高三种区间组合进行分析, 并且详细设计追溯系统的可配置功能. 以乳制品为例, 按照企业需求系统提供定制化服务, 追溯系统可根据企业个性化需求进行定制, 解决追溯系统效率、用户体验和利用率等问题. 对不同食品类型追溯平台实施改造与设计, 可以提高企业应用追溯系统的积极性、政府监管效率以及便于消费者查询.     

基于MBSE的PHM开发平台设计

故障预测与健康管理(PHM)开发平台具有结构功能复杂的特点,传统的设计方法难以保证其结构合理性与功能可靠性。针对传统的基于文本的系统设计中存在的需求追溯性弱、问题描述模糊的问题,提出了应用基广模型的系统工程(MBSE)方法论指导平台设计过程,使用模型驱动的OOSEM建模方法对PHM开发平台进行模型搭建。通过利益相关者需求导出系统需求与系统功能,在对系统内部结构进行逻辑分析后定义了平台系统架构,实现了系统架构综合,搭建了完备的PHM开发平台MBSE模型。基于MBSE的设计过程使该模型具有结构清晰、集成性高、追溯性强的特点,模型化的设计方法保证了其通用性与可重用性。该模型的建立为PHM开发平台搭建提供了设计流程与解决方案。     

通过网管远程更新板卡软件的设计与实现

光网络设备的功能由各种板卡来完成,在网络运行中,为解决板卡设计的缺陷,满足市场的需求,需要对板卡的软件进行升级更新。文章设计一种通过网管远程更新板卡软件的方案,避免逐站点更换板卡软件,减小了设备维护的代价。     

面向在线需求的程序设计研究

软件升级需进行软件的二次开发 ,面对用户不断变更的需求 ,我们设计了面向在线需求的 L B(L ineBasic)控制平台。以“Treeview功能索引树”和“LB语言解释器”为核心 ,研究了在线需求的程序设计     

WIDS:一个基于CMM模型的软件缺陷管理系统

缺陷管理是中大型软件开发过程中的重要部分,通过对现有缺陷管理工具的分析,依据CMM模型和软件中心管理流程的特殊需求,设计和实现了一个软件缺陷管理系统WIDS.WIDS系统采用了浏览器的B/S架构,实现了缺陷跟踪的流程,对缺陷状态的变化进行控制,提供及时的问题报告,通知并定位到相应的人员,并具有统计分析、查询、权限管理等功能.实际应用表明WIDS系统有效地提高了软件的质量和管理效率.     

基于上下文的飞控软件老化缺陷定位方法研究

随着航空工业的发展和飞控软件复杂度的提高,对飞控软件可靠性和实时性的要求也越来越高。软件老化缺陷中存在一类缺陷,会使系统响应逐渐变慢,最终出现失效,严重影响飞控软件的可靠性和实时性,但目前没有定位这类缺陷的有效方法。针对这类缺陷的定位,提出了一种基于上下文的飞控软件老化缺陷定位方法。该方法将飞控软件的主循环建模成一棵任务树,飞控软件反复运行的主循环抽象成一个任务树序列。通过Mann-Kendall Test对任务树中心节点的时间属性进行趋势检测,找到可疑任务,并根据任务树之间的关系对可疑任务进行筛选,定位出含有缺陷的任务,则该任务所对应的函数即为缺陷所在的位置。实验表明,该方法不仅能够给出缺陷的具体位置,还能给出发生失效时的调用上下文。     

基于模型的飞机电滑行系统设计与研究

详细介绍了基于模型的飞机电滑行系统的开发流程与方法,并对其进行了集成仿真分析。利用Matlab/Simulink建立了电滑行系统需求的行为模型,利用Simscape建立了电机物理模型,根据电滑行系统架构进行多专业的联合仿真,验证系统的功能、性能和接口信息等。通过模型的方式实现了对系统设计的分析和确认,实现系统的图形化设计与传递,以及系统需求、系统架构、仿真模型的可追踪与追溯性,在系统开发早期验证设计,能发现潜在问题,从而避免设计的迭代。应用集成仿真验证了模型在电滑行系统设计中的指导作用。     

一种软件需求描述语言的设计与实现

提出了一种面向软件行为的需求建模方法和需求描述语言BDL,介绍了需求描述语言的设计和实现方法。利用此需求建模可以根据用户的需求信息寻找出目标系统的有效行为,建立目标系统的行为模型。该行为模型可以帮助用户和开发人员正确认识和理解目标系统的行为,而且能为以后自动检测系统的各种特性提供良好的基础。     

HLA仿真系统因果追溯性设计

随着仿真系统变得日益复杂，基于仿真数据人为的进行因果追溯已经变得越来越凼难，所以必须对原有的仿真系统进行因果追溯性设计，使自动或半自动追溯凶果成为可能。为此，首先确定了因果关系追溯的整体思路，然后面对普遍使用的高层体系结构HLA分印仿直系统，深入分析对象类和交互类两类交互数据以及交互特点，井详细划分行为事件及因果关系类型；对HLA仿真系统中关键的联邦对象模型FOM以及仿真器进行扩展设计，从而实现系统的因果追溯性，为仿真因果追溯分析提供必要的数据。最后提出保证因果追溯需要注意的几项设计原则，并对设计所能够支持的应用做出展望。     

基于决策树的软件项目估算方法

软件工程领域的一个重要问题是预测软件开发项目的规模、工作量和成本,即软件项目估算问题。基于机器学习的方法在软件项目估算领域具有优势地位,本文提出了基于决策树的聚类分析预测方法,通过对目标项目的目标属性进行正确分类,预测目标属性的取值范围。通过对502个ISBSG v9项目数据集中的项目进行基于C4.5算法的分类预测,正确率达到82.4701%,满足了软件项目估算的指标要求。     

基于检索决策树的螨种分类鉴定专家系统

应用传统的分类检索方法进行粉螨亚目螨种的分类鉴定是一个复杂、繁琐的过程。随着人工智能技术的发展,采用专家系统技术编制螨种分类鉴定软件将改变传统的分类鉴定方式。通过学习粉螨亚目的分类学和专家系统的相关知识,将螨种的分类鉴定与专家系统有机地结合起来,采用面向对象方法,设计并实现了基于决策树的螨种分类鉴定专家系统。通过构建基于面向对象的决策树知识表示模型,提炼出螨种知识库的记录结构,根据节点对象的逻辑关系,设计了基于决策树的推理机制,并按照一定的推理控制策略实现了螨种的分类鉴定。结果证明,满足了用户的需要,具有重要的实践价值。     

Detecting safety‐related components in statecharts through traceability and model slicing

With rapid development in software technology, more and more safety‐critical systems are software intensive. Safety issues become important when software is used to control such systems. However, there are 2 important problems in software safety analysis: (1) there is often a significant traceability gap between safety requirements and software design, resulting in safety analysis and software design are often conducted separately; and (2) the growing complexity of safety‐critical software makes it difficult to determine whether software design fulfills safety requirements. In this paper, we propose a technique to address the above 2 important problems on the model level. The technique is based on statecharts, which are used to model the behavior of software, and fault tree safety analysis. This technique contains the following 2 parts, which are corresponding to the 2 problems, respectively. The first part is to build a metamodel of traceability between fault trees and statecharts, which is to bridge their traceability gap. A collection of rules for the creation and maintenance of traceability links is provided. The second part is a model slicing technique to reduce the complexity of statecharts with respect to the traceability information. The slicing technique can deal with the characteristics of hierarchy, concurrency, and synchronization of statecharts. The reduced statecharts are much smaller than their original statecharts, which are helpful to successive safety analysis. Finally, we illustrate the effectiveness and the importance of the method by a case study of slats and flaps control units in flight control systems.     

Incremental Induction of Decision Trees

This article presents an incremental algorithm for inducing decision trees equivalent to those formed by Quinlan's nonincremental ID3 algorithm, given the same training instances. The new algorithm, named ID5R, lets one apply the ID3 induction process to learning tasks in which training instances are presented serially. Although the basic tree-building algorithms differ only in how the decision trees are constructed, experiments show that incremental training makes it possible to select training instances more carefully, which can result in smaller decision trees. The ID3 algorithm and its variants are compared in terms of theoretical complexity and empirical behavior.     

The Self-Organizing Map of Trees

In the standard version of the Self-Organizing Map, each neuron is associated with a vector. An extension using trees instead of vectors is presented. Compared to vectors, trees provide remarkably more degrees of freedom. The essential points of self-organization, the distance function and the learning rule, are adapted to trees by means of graph matching. In order to avoid exhaustive searching in tree matching an efficient heuristic is introduced. The results of the experiments are promising: the proposed methods apply elegantly in the process of self-organization.     

LS文法绘制分形树的参数化设计

在分析了随机LS文法生成分形树的基本原理,各分形元的实现过程和随机选择的原则之后。提出了参数化设计的思想,然后研究了如何在生成分形树时,利用生长角度参数a和概率控制参数U、V来控制树形,绘制了分形树在多种参数值下的形态,并对该参数化设计的应用做了一些拓展。     

后缀树的并行构造算法

后缀树是一种非常重要的数据结构，它在与字符串处理相关的各种领域里有着非常广泛的应用。构造后缀树是应用后缀树解决问题的前提和关键。虽然很多现有的后缀树构造算法都是线性时间和空间的，但是，当被索引的字符串的长度很长时，构造其后缀树所消耗的时间和空间仍将非常巨大，这极大地限制了后缀树的实际应用。而并行技术是解决这一问题的很好途径，因此人们提出了后缀树的并行构造算法。本文对后缀树的三种并行构造算法进行了综述，通过系统的比较和分析，总结出当前存在的问题，并指明了下一步的研究方向。     

Linear Bidirectional On-Line Construction of Affix Trees

Affix trees are a generalization of suffix trees that are based on the inherent duality of suffix trees induced by the suffix links. An algorithm is presented that constructs affix trees on-line by expanding the underlying string in both directions and that is the first known algorithm to do this with linear time complexity.     

Reactive Diffracting Trees

A shared counter is a concurrent object that provides a fetch-and-increment operation in a distributed system. Recently, diffracting trees have been introduced as an efficient way of implementing shared counters in heavily loaded distributed systems. Diffracting trees dynamically partition processors into small groups that can access a collection of disjoint local counters quickly in a globally coordinated way. Their empirical performance under heavy load surpasses all other shared counter implementations. However, diffracting trees of any particular depth are optimal for only a limited load range. Thus, there would be great benefit in designing a diffracting tree algorithm that would effectively scale up from a simple centralized queue-lock-based counter at low loads to the optimal size diffracting tree counter as the load increases and scale back down to a queue-lock as the load decreases. This paper presents the reactive diffracting tree data structure and an implementation of it in a shared memory multiprocessor system. The reactive diffracting tree is a shared structure similar to a diffracting tree, with the added property that it can grow and shrink to better handle changing access patterns and the memory layouts, providing true scalability and locality. The tree mimics the behavior of an optimal size diffracting tree for each concurrency range. Empirical evidence, collected on the Alewife cache-coherent multiprocessor and the Proteus simulator, shows that the reactive diffracting tree provides throughput within a constant factor of optimal diffracting trees at all load levels. It also proves to be an effective competitor with randomized load balancing algorithms in several producer/consumer applications.