基于统一结构的并行混合放疗计划优化策略

为了满足适形调强放疗对治疗计划逆向优化计算的需要,针对靶区定义的复杂情况构造了新的目标函数.以模拟退火算法和遗传算法优势组合为例,研究了逆向放射治疗计划并行混合优化策略,给出了基于统一结构的并行广义邻域搜索混合优化算法,并在多CPU、多核计算机上实现了这一算法.描述了用该并行混合优化算法计算的数字体模和5个临床病例的例子,获得了满意的结果.结果表明,这种优化算法有效、实用,为开发新型并行混合优化算法建立了平台,为把商业化的三维适形放疗计划系统进一步发展为生物导向的放疗计划打下了基础.     

一种简化的调强强度图谱计算方法及实现

优化算法是适形调强放射治疗（IMRT）软件系统的核心。模糊权重算法是一种优化算法,但该算法存在一个缺陷——剂量强度图谱分布上有锯齿现象。在原有模糊权重优化算法基础上提出一种简化方法。采用线性主射束替代三维锥形射束的方法消除了锯齿现象。实验结果表明,该算法在优化速度和优化结果上有很大的改进。     

一种调强放射治疗逆向计划多目标混合优化方法研究

针对调强放射治疗(IMRT)逆向计划的优化问题,提出了基于L-BFGS和Pareto最优解的多目标遗传算法———NSGA-Ⅱ算法的调强放射治疗计划多目标混合优化方法。根据IMRT对多个目标的剂量约束条件,建立了多目标优化的简化及精确的数学模型。为了加快优化速度,首先采用L-BFGS算法求解简化模型,并将其作为精确模型的初始解;然后采用NSGA-Ⅱ算法对精确模型求解来获得分散性良好的Pareto最优解集,使临床医生能根据各个目标的剂量体积直方图等加以决策,以便从中选择合适的治疗方案。实验结果表明,采用上述方法得到的非劣解在目标空间中分布均匀,计算速度快,鲁棒性好。与常用的将该多目标优化问题通过加权求和转化为单目标优化问题加以求解相比较,由于该方法提供了Pareto最优解集合提供给决策者选择,因此具有更强的灵活性,能更好地满足临床的实际需要。     

角色访问控制技术在放射治疗中的应用

放射治疗计划系统(RTPS)是放射治疗解决方案的重要组成部分,其安全性直接影响整个治疗方案的执行效果。该文介绍基于角色访问控制(RBAC)模型的基本原理,结合RTPS的开发实践和放射治疗临床实际情况,说明RBAC模型在RTPS中的应用合理性和有效性,分析基于该模型的访问控制模块与治疗计划系统的关系,给出访问控制模块的系统结构、数据库表结构设计及其在VC6.0 下的实现方式。     

调强放疗中强度矩阵分解算法的研究

强度矩阵分解作为调强放疗(IMRT)中的一个核心技术,是一个NP-hard问题。调强一般分为两种：静态模式和动态模式。本文中,我们针对静态调强放疗,对总治疗时间所主要依赖的四个参数：总机器跳数（TNMU）、子野个数（NS）、多叶准直器叶片移动速率和验证记录（V     

三维放射治疗计划系统的研究

论述三维放射治疗计划系统(RTPS-2000)的设计方案和实现技术.阐释系统的总体结构和系统的功能模块,给出各个功能模块实现的技术和采取的方案.RTPS-2000采用面向对象设计的思想,使用VC++作为开发工具,实现了基于CT图像的三维放射治疗计划系统.RTPS-2000系统采用模块化的设计方法,在设计上应用设计模式的思想,使各个模块之间的耦合度达到最小,从而最大限度地实现了分块设计,分块实现,降低了软件设计开发的风险.RTPS-2000系统包括图像数据的获取,患者信息的管理,患者的解剖建模,治疗计划的制定,剂量学数据的管理,可视化,质量保证和控制,治疗计划方案的输出等功能.     

多通道智能化剂量仪在成都剂量体模上的测试及应用

介绍了可测定10个点辐射剂量的智能化仪器在成都剂量体模上的测试及应用.该仪器采用微型半导体探头作为辐射探测器,用于ICRU命名的"成都剂量体模"及仿真材料的150 kV～15 MV X线及137Cs,192Ir,60Co γ射线的辐射试验,放射治疗中配合剂量体模在中、高能谱范围能进行三维适形放疗的剂量体积分布测量,以及对三维治疗计划系统剂量分布进行检验.     

三维放射治疗计划系统

治疗计划系统是一种计算机辅助治疗系统。该文介绍了 ＴＰＳ－Ⅲ的设计方案与实现技术。系统通过应用最新的计算机图像处理和图形学技术,实现了图象输入、图象配准、图象融合、三维重建、剂量计算、计划评估等功能,从而为放射治疗提供有力的保障。     

自适应调强技术(A-IMRT)的仿真算法研究

在仿真人体模上,通过增加照射野方向,利用自适应调强技术(A-IMRT)优化各方向上照射野强度,初步实现并验证了这种综合传统IMRT和VMAT技术优点,规避其缺点的自适应IMRT新技术(A-IMRT):为模拟临床,我们选取仿真体模中相对简单的腹部病兆,给予7个野照射45Gy为参照,算法中m被分别限定为1,2,3且最多30个子野(相对简单的腹部肿瘤30个子野通常可以达到较理想的结果)。根据软件给出的计划难以指数显示plan20/20最容易达到,plan10/10最难达到。Plan10/20与Plan10/30处于中位值附近,但与标准计划plan7/30相比,在难易程度上差距不大。且plan10/20和plan20/20在剂量断层分布和各感兴趣组织DVH图上都有较理想表现,在保证肿瘤处方剂量的基础上给予正常组织较小的剂量,有较好的保护作用。因此,利用计算机仿真技术,从传统IMRT技术着手,可实现介于IMRT与VMAT之间的自适应A-IMRT技术,并得到更优化的方案。这一技术通过验证具有可行性和高效性,这一点在仿真人腹部模型上得到较理想的结果。     

放射治疗靶区勾画软件MIM在应用中常见问题的分析及处理

放射治疗是恶性肿瘤的重要组成治疗手段。随着放疗IMRT的广泛应用,其要求放疗科医生需更好、更详细地理解靶区结构^[1]。靶区勾画作为放射治疗中的重要环节,需要有稳定高效的勾画工具做保障,MIM Maestro Unlimited(以下简称MIM)作为靶区勾画系统的代表软件,其拥有MR/CT形变配准、ART Assist、GTV勾画、自动勾画、4D CT、自适应放疗、剂量评估、计划查看、肿瘤会诊、MIM Cloud等功能。MIM在临床上应用广泛,已成为临床图像处理不可或缺的一部分。为保障放疗科医生在使用MIM进行靶区勾画工作时的高效与稳定,本文总结了我院MIM.6(6.7.4)在临床使用中遇到的常见问题的分析及处理方法,供使用者参考。     

基于多Agent的定时事件序列控制技术研究

0 引言定时事件序列是MIS中一种以时间为过程控制基础的处理对象,它不仅具有以管理信息处理为主体的一般事务处理工作流的特点,而且具有基于定时标准的并发控制处理过程。随着AI领域Agent理论及其应用技术的深入研究,这种类人化控制技术在MIS系统的设计过程中越来越广泛地被采用,以适应生产工具自动化程度不断提高的生产过程管理要求。     

基于功能接口的网络化ATS软件平台研究

介绍了一种网络化自动测试系统软件测试平台构成及设计思想;该软件测试平台以组件技术为核心,采用基于功能接口模型的软件设计思想;通过对功能接口模型的模型设计思想,功能接口描述,TPS的可移植性和仪器互换性的实现机制,数据采集、分析处理、数据管理和故障诊断分离,网络通信功能的实现等关键技术进行研究,提出网络化测试系统软件平台应采用"层次结构 功能接口"的设计方案,建立了网络化自动测试系统软件平台,有效地提高了系统的可靠性,灵活性;试用结果表明基于功能接口模型的软件平台实现了仪器可互换性,较好地解决了TPS的可移植性和可重用性.     

ATS中TPS的软件测试技术研究

自动测试系统(ATS)的软件是整个系统的核心,而软件测试是保证TPS质量的关键要素.在总结TPS的软件测试经验的基础上,给出了TPS的软件测试模型,分析了TPS软件测试中遇到的相关技术,并且在ATE8000等项目开发中取得了良好的效果.     

ViMediaNet: an emulation system for interactive multimedia based telepresence services

The telepresence service (TPS) leverages advanced communication, virtual reality, and cooperative web technologies to provide remote engaged users an immersive experience of being fully present, which are widely used in teleconferencing, remote surgery, and hazardous environment exploration. The common feature of TPS-based applications lies in that the users’ experiences heavily depend on the quality of interactive multimedia services, that is, most deliveries of multimedia contents are mission-critical, as well as time-critical, to ensure the control and operation accuracy for telerobots. Therefore, the delivery performance of multimedia contents over heterogeneous networks becomes the primary concern in the TPS system design, especially for those delay sensitive applications, like remote surgery and environment exploration. In this paper, we incorporate video processing tools with the network simulator to design and implement a joint emulation system, named as the virtual media network (ViMediaNet), through which, the TPS designer can readily deploy the TPS system over a heterogeneous network virtualized by the network emulator, investigate the critical network performance metrics in the multimedia content delivery, such as transmission delay and packet jitter, and observe control results in real time. To verify the capability of ViMediaNet in emulating the real-setting TPS system, we take a mobile device based vision navigation system as an example to evaluate performance impacts of the rate adaptation technology in the telerobot control. The experimental results reveal that the adaptive video streaming is a promising solution to significantly enhance the control accuracy of telerobots in TPS systems.     

基于多Agent的定时事件序列控制技术研究

定时事件序列是MIS中基于时间的处理流程,它不仅具有MIS工作流的全部特性,而且具有基于定时系统的并发过程。本文首先分析MIS中定时事件序列的特性,并就定时和控制特征对定时事件序列中信息流的影响进行阐述。本文在分析多Agent系统性能的基础上,对Agent之间的数据共享、通信和同步等问题进行分析,并给出基于多A-gent的定时事件序列控制模型和机场航班生产调度系统的应用实例及其性能评估。     

Model theory approach to transaction processing system development

This paper presents a new approach, model theory approach, to small and medium scale transaction processing system (TPS) development. A TPS of this paper is an information system designed to process day-to-day business event data at operational level of an organization. The paper is not concerned with data base construction but with transaction processing.

The model theory approach is not a software engineering approach but a systems theory approach. In the approach a model of the target system, which is called a user model, is constructed in set theory using a formal system structure of a TPS. The user model is, then, compiled into an extended Prolog (extProlog) model. The extProlog is an extension of Prolog to meet requirements for management information system development. On compilation a standardized user interface (UI) called internal UI is attached. The extProlog model with the internal UI is, then, executed under control of another standardized UI called an external UI. Implementation is an integral part of the approach. Because the UIs are designed for the formalized (abstract) structure of a TPS, they can be standardized and are provided as black box components to system development. Because a systems developer is required to only build a user model in set theory based on a model theoretic structure in the approach, it is called a model theory approach. Advantages of this approach are that it provides a theoretical structure to information systems development so that systems development can be made an engineering discipline, and facilitates rapid systems development.     

The Double Edge Sword Based Distributed Executor Service

Scalability is one of the most important quality attribute of software-intensive systems, because it maintains an effective performance parallel to the large fluctuating and sometimes unpredictable workload. In order to achieve scalability, thread pool system (TPS) (which is also known as executor service) has been used extensively as a middleware service in software-intensive systems. TPS optimization is a challenging problem that determines the optimal size of thread pool dynamically on runtime. In case of distributed-TPS (DTPS), another issue is the load balancing b/w available set of TPSs running at backend servers. Existing DTPSs are overloaded either due to an inappropriate TPS optimization strategy at backend servers or improper load balancing scheme that cannot quickly recover an overload. Consequently, the performance of software-intensive system is suffered. Thus, in this paper, we propose a new DTPS that follows the collaborative round robin load balancing that has the effect of a double-edge sword. On the one hand, it effectively performs the load balancing (in case of overload situation) among available TPSs by a fast overload recovery procedure that decelerates the load on the overloaded TPSs up to their capacities and shifts the remaining load towards other gracefully running TPSs. And on the other hand, its robust load deceleration technique which is applied to an overloaded TPS sets an appropriate upper bound of thread pool size, because the pool size in each TPS is kept equal to the request rate on it, hence dynamically optimizes TPS. We evaluated the results of the proposed system against state of the art DTPSs by a client-server based simulator and found that our system outperformed by sustaining smaller response times.     

轮胎压力监测系统及轮胎压力传感器的现状与发展

介绍了汽车轮胎压力监测系统及轮胎压力传感器的种类、工作机制、特点和其发展现状,涉及了典型的硅压阻式、电容式轮胎压力传感器、无电池石英谐振式表面波轮胎压力传感器的研究状况,以及可直接与标准轮胎集成的声表面横波压力传感器等新型汽车轮胎压力传感器,并探讨了当前研究中需解决的问题和今后发展方向。     

基于多信号模型的电路板TPS开发方法研究

结合电路板测试程序集的开发现状和开发经验,提出了一种基于多信号模型的电路板TPS开发方法;首先给出了多信号模型方法的定义和表示,然后结合示例根据其有向图得到组成单元故障和测试之间的相关矩阵,最后通过相关矩阵的简化和测试的优选制定出被测电路板的故障诊断策略,完成电路板TPS开发;该方法通用性好,适用于不同类型的电路板和武器系统其他装备;实践证明,该方法提高了电路板TPS开发效率和质量,降低了对开发人员的要求。     

An Integrated Model of the Toyota Production System with Total Quality Management and People Factors

The Toyota production system (TPS), or lean production, has been associated with many benefits for manufacturing firms that implement the system. However, to implement the TPS successfully, it is necessary to integrate the so‐called “hard side” of the system (that is, the technical aspects of material handling) with the “soft side” of the program (that is, the aspects associated with human factors). The present study makes a contribution to such a holistic view of the TPS by proposing an integrated model that consists of the technical aspects of the TPS, together with elements associated with total quality management (TQM), human resources management (HRM), and certain identified “people factors.” The study then uses structural equation modeling (SEM) to test this holistic model using data obtained from a questionnaire survey of 153 Taiwanese manufacturing firms. The empirical study confirms the appropriateness of the causal model, which is evaluated by several goodness‐of‐fit methods. The study confirms the proposition that the inclusion of the “people factors” together with TQM and HRM significantly improves the realization of benefits associated with the TPS practices of “just‐in‐time” (JIT) and “autonomation.” The conclusion is that such an integrated model provides a much more effective “lean system” and has the potential to produce significantly enhanced benefits for firms that implement it. © 2012 Wiley Periodicals, Inc.