43 resultados para pacs: distributed system software


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Respiration-induced target motion is a major problem in intensity-modulated radiation therapy. Beam segments are delivered serially to form the total dose distribution. In the presence of motion, the spatial relation between dose deposition from different segments will be lost. Usually, this results in over-and underdosage. Besides such interplay effects between target motion and dynamic beam delivery as known from photon therapy, changes in internal density have an impact on delivered dose for intensity-modulated charged particle therapy. In this study, we have analysed interplay effects between raster scanned carbon ion beams and target motion. Furthermore, the potential of an online motion strategy was assessed in several simulations. An extended version of the clinical treatment planning software was used to calculate dose distributions to moving targets with and without motion compensation. For motion compensation, each individual ion pencil beam tracked the planned target position in the lateral aswell as longitudinal direction. Target translations and rotations, including changes in internal density, were simulated. Target motion simulating breathing resulted in severe degradation of delivered dose distributions. For example, for motion amplitudes of +/- 15 mm, only 47% of the target volume received 80% of the planned dose. Unpredictability of resulting dose distributions was demonstrated by varying motion parameters. On the other hand, motion compensation allowed for dose distributions for moving targets comparable to those for static targets. Even limited compensation precision (standard deviation similar to 2 mm), introduced to simulate possible limitations of real-time target tracking, resulted in less than 3% loss in dose homogeneity.

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A dynamic measurement system was developed by the Institute of Modern Physics (IMP) for the dipole prototype of Rapid Cycle Synchrotron (RCS) of China Spallation Neutron Source (CSNS). The repetition frequency of RCS is 25 Hz. The probe is a moving arc searching-coil, and the data acquisition system is based on the dynamic analysis modular of National Instrument. To get the error of high order harmonics of the field at basic frequency, the hardware integrator is replaced by a high speed ADC with software filter and integrator. A series of harmonic coefficients of field are used to express the varieties of dynamic fields in space and time simultaneously. The measurement system has been tested in Institute of High Energy Physics (IHEP), and the property of the dipole prototype of RCS has been measured. Some measurement results and the repeatability of system are illustrated in this paper.

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Software Engineering Society of Korean; Institute for Information Scientists and Engineers; IEEE Reliability Society; KAIST (Korea Advanced Institute of Science and Technology); Korea Information Promotion Agency; Samsung SDS

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Among the functional nucleic acids studied, adenine-rich nucleic acids have attracted attention due to their critical roles in many biological processes and self-assembly-based nanomaterials, especially deoxyribonucleic acids (abbreviated as poly(dA)). Therefore the ligands binding to poly(dA) might serve as potential therapeutic agents. Coralyne, a kind of planar alkaloid, has been firstly found that it could bind strongly to poly(dA). This work herein reports an approach for visual sensing of the coralyne-poly(dA) interaction. This method was based on the coralyne inducing poly(dA) into the homo-adenine DNA duplex and the difference in electrostatic affinity between single-stranded DNA and double-stranded DNA with gold nanoparticles (GNPs). Furthermore, we applied the recognition process of the interaction between coralyne and poly(dA) into specific coralyne detection with the assistance of certain software (such as Photoshop). A linear response from 0 to 728 nM was obtained for coralyne, and a detection limit of 91 nM was achieved.

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本文设计了研磨抛光机器人分布式控制系统中的一种运动控制器,并对运动控制器基于AT91M40800微控制器的硬件结构、基于μC/OS-Ⅱ实时操作系统的软件模块和采用的参数模糊自整定PID机器人关节位置控制策略进行了详细介绍。实验表明该控制器可以大大降低研磨抛光机器人的位置跟踪误差。提高了关节控制的计算及处理能力,易于扩展和维护。

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为了实现可重构装配系统的快速重构能力,在分析了传统控制结构的基础上,结合分层递阶和分布式控制的优点,提出了基于多智能体系统的混合控制体系结构。这种结构具有低复杂性、强鲁棒性、易维护性、可扩展性以及可重用性等特点,能够适应重构系统的要求。在遵守智能物理代理基金会规范的前提下,以Java智能体开发平台进行了装配系统中各层智能体的实例开发。

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多水下机器人仿真系统是一个能够对多水下机器人系统的体系结构、协调控制、路径规划、学习算法等进行演示验证的分布式实时数字仿真系统,是开展多水下机器人技术研究的基础和有效手段.讨论了应用基于局域网的分布式仿真技术来解决多水下机器人系统仿真的问题,并详细说明了仿真系统的硬件组成和软件总体设计.

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本文给出了一种基于 CAN总线的分布式数据采集与控制系统的设计与应用,介绍了 CAN总线的硬件接口电路设计,并对系统的整体结构、硬件配置、软件功能及各节点功能分别作了详细说明。实验表明,该系统具有结构简单、可靠性高、性能价格比高等特点,有广阔的应用前景。

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本文介绍了我们建立的基于Agnet的分布协作式多机器人装配系统-DAMAS,在此基础上研究了多机器人合作的协商协议,采用了改进的合同网协议方法,针对多机器人协商协议的软件实现了,采用了应用前景广阔的分布式对象技术,介绍了机器人合作装配的协商协议的具体实现方法。

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介绍了一个热网分布式计算机监控系统。包括系统设计目标、系统构成、控制策略、系统通讯、软件实现及系统运行环境。该系统在铁煤集团热电厂运行 ,取得了较好的效果

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随着电子技术和计算机技术的不断发展,工业生产过程的控制系统正在向着智能化、数字化和网络化的方向发展。传统的集散控制方式和计算机分层控制方式已经开始让位于智能终端与网络结合的总线网络控制方式。当今,在工厂中过程控制环境下的分布式自动化系统变得越来越复杂,尤其系统内部的各设备之间需要快速交换大量的信息,以便实现对被控系统更为精确的控制和提供一些辅助的评价函数。这就意味着要不断增加带宽和提高通信速率以满足网络通信的需要。在现有的多种可利用网络设备中,CAN总线以其清晰的定义、极高的可靠性及其独特的设计,被认为是最能有效地解决这一问题的途径之一。而且市场上基于通信技术的产品中,就实时性考虑,由于CAN总线采用的非表意性的通信方式,因此其结构更为简单,实时性更好。基于此背景,我们以CAN总线作为通信媒介,将分布于各控制现场的传感器、执行器和控制器有序地连接起来,构成了一个基于CAN总线的分布式局域网络控制系统。本文首先介绍了基于CAN总线的分布式数据采集与控制系统的总体结构。然后从硬件方面描述了基于CAN总线的通信协议转换单元、数据采集单元和输出控制单元的功能、硬件配置及各单元功能的具体实现过程,给出了各单元的性能指标。软件方面,以C语言作为平台,开发了基于CAN总线的上位计算机管理与监控软件,实现了对整个网络设备的系统管理和系统控制功能。对于该总线系统,作者运用了PID控制和模糊控制算法实现了对水箱液位的控制,达到了理想的效果。基于CAN总线的控制系统很好地解决了集散控制系统难以解决的难题,模糊控制的应用能很好地把总线控制系统应用到具有非线性、大时滞和难于获得精确模型的控制系统中。

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Numerical modeling of groundwater is very important for understanding groundwater flow and solving hydrogeological problem. Today, groundwater studies require massive model cells and high calculation accuracy, which are beyond single-CPU computer’s capabilities. With the development of high performance parallel computing technologies, application of parallel computing method on numerical modeling of groundwater flow becomes necessary and important. Using parallel computing can improve the ability to resolve various hydro-geological and environmental problems. In this study, parallel computing method on two main types of modern parallel computer architecture, shared memory parallel systems and distributed shared memory parallel systems, are discussed. OpenMP and MPI (PETSc) are both used to parallelize the most widely used groundwater simulator, MODFLOW. Two parallel solvers, P-PCG and P-MODFLOW, were developed for MODFLOW. The parallelized MODFLOW was used to simulate regional groundwater flow in Beishan, Gansu Province, which is a potential high-level radioactive waste geological disposal area in China. 1. The OpenMP programming paradigm was used to parallelize the PCG (preconditioned conjugate-gradient method) solver, which is one of the main solver for MODFLOW. The parallel PCG solver, P-PCG, is verified using an 8-processor computer. Both the impact of compilers and different model domain sizes were considered in the numerical experiments. The largest test model has 1000 columns, 1000 rows and 1000 layers. Based on the timing results, execution times using the P-PCG solver are typically about 1.40 to 5.31 times faster than those using the serial one. In addition, the simulation results are the exact same as the original PCG solver, because the majority of serial codes were not changed. It is worth noting that this parallelizing approach reduces cost in terms of software maintenance because only a single source PCG solver code needs to be maintained in the MODFLOW source tree. 2. P-MODFLOW, a domain decomposition–based model implemented in a parallel computing environment is developed, which allows efficient simulation of a regional-scale groundwater flow. The basic approach partitions a large model domain into any number of sub-domains. Parallel processors are used to solve the model equations within each sub-domain. The use of domain decomposition method to achieve the MODFLOW program distributed shared memory parallel computing system will process the application of MODFLOW be extended to the fleet of the most popular systems, so that a large-scale simulation could take full advantage of hundreds or even thousands parallel processors. P-MODFLOW has a good parallel performance, with the maximum speedup of 18.32 (14 processors). Super linear speedups have been achieved in the parallel tests, indicating the efficiency and scalability of the code. Parallel program design, load balancing and full use of the PETSc were considered to achieve a highly efficient parallel program. 3. The characterization of regional ground water flow system is very important for high-level radioactive waste geological disposal. The Beishan area, located in northwestern Gansu Province, China, is selected as a potential site for disposal repository. The area includes about 80000 km2 and has complicated hydrogeological conditions, which greatly increase the computational effort of regional ground water flow models. In order to reduce computing time, parallel computing scheme was applied to regional ground water flow modeling. Models with over 10 million cells were used to simulate how the faults and different recharge conditions impact regional ground water flow pattern. The results of this study provide regional ground water flow information for the site characterization of the potential high-level radioactive waste disposal.

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The engineering geological properties of Neogene hard clays and related engineering problems are frontiers in the fields of Engineering Geology, Soil Mechanics and Rock Mechanics. Recently, it has been recognized that Neogene hard clay is the intermediate type of material between the soil and the rock. Many aspects of them, such as sampling, testing, calculating and engineering process, are special, which could not be researched by means of theories and methods of traditional Soil Mechanics of Rock Mechanics. In order to get real knowledge and instruct the engineering practice, intersect studying of multiple disciplines, including Engineering Geology, Soil Mechanics and Rock Mechanics, etc., is necessary. Neogene hard clay is one of the important study objects of regional problem rocks & soils in our country, which extensively distributed in China, especially in Eastern China. Taking the related areas along the middle line of the Project of Transferring Water from the South to the North (e.g. Nanyang basin, Fangcheng-Baofeng area and Handan-Yongnian area), South-west of Shandong, Xu-Huai area and Beijing area, etc. as main study areas, the paper divided Neogene hard clays into reduction environment dominated origin and oxidation environment dominated origin, which distributed on areas western and eastern to Mount Taihangshan respectively. Intermediate types are also existed in some areas, which mainly distribute near the edges of depositional basins; they are usually of transitions between diluvial and lacustrine deposits. As to Neogene hard clays from Eastern China, the clay particle content is high, and montmorillonite or illite/montmorillonite turbostratic mineral is the dominating clay mineral. The content of effective montmorillonite is very high in each area, which is the basis for the undesirable engineering properties of Neogene hard clays. For hard clays from the same area, the content of effective montmorillonite in gray-greenish hard clay is much higher than that in purple-brownish or brown-yellowish hard clay, which is the reason why the gray-greenish hard clay usually has outstanding expansive property. On the other hand, purple-brownish or brown-yellowish hard clay has relatively less montmorillonite, so its property is better. All of these prove that the composition (clay mineral) of Neogene hard clay is the control factor for the engineering properties. Neogene hard clays have obvious properties such as fissured, overconsolidated and expansive, which are the main reasons that many engineering problems and geological harzards usually occur in Neogene hard clays. The paper systematically elaborates the engineering properties of Neogene hard clays from Eastern China, analyses the relationships between engineering properties and basic indexes. The author introduces the ANN method into the prediction of engineering property indexes of hard clays, which provides a new way for quantitatively assessment and prediction of engineering property indexes. During investigation in the field, the author found that there exists obvious seam-sheared zone between different hard clays in Miocene Xiacaowan formation in Xu-Huai area. Similar phenomenon also exists near the borderline between Neogene hard clays and underlying coal measures in the Southwest of Shandong province, which could be observed in the cores. The discovery of seam-sheard zone has important theoretical and practical significance for engineering stability analysis and revealing the origin of fissures in Neogene hard clays. The macrostructure, medium structure and microstructure together control the engineering properties of hard clays. The author analyses and summarizes the structural effects on hard clays in detail. The complex of the strength property of hard clays is mostly related to the characteristics of fissures, which is one of the main factors that affect the choice of shear strength parameters. So structure-control theory must be inseparably combined with composition-control theory during the engineering geological and rock/soil mechanics research of hard clays. The engineering properties, such as fissured, overconsolidated and expansive, control the instability of engineering behaviors of Neogene hard clays under the condition of excavation, i.e. very sensitive to the change of existence environment. Based on test data analysis, the author elaborates the effects of engineering environment change on the engineering properties. Taking Nanyang basin as example, the author utilizes FEM to study the effects of various factors on stability of cutting canal slopes, than sets forth the characteristics, development laws and formation mechanism of the deformation and failure of hard clay canal slopes, summarizes the protection and reinforcement principles, as well as the protection and remedy steps. On the basis of comparison of engineering properties of domestic and foreign Neogene muddy deposits, in the view of whole globe and associated with the geological characteristics of China, the paper demonstrates that the intermediate type of the material between the soil and the rock, named "hard clay/soft rock", which can not be separated abruptly, really exists in China. The author has given a preliminary classification based on its geological origin and distribution law, which is very significant for promoting the mixture of Engineering Geology, Soil Mechanics and Rock Mechanics. In the course of large scales engineering construction in China, many engineering experiences and testing data are gained, summarizing these testing results and automatically managing them with computer technology are very necessary. The author develops a software named "Hard Clay-Soft Rock Engineering Geological Information Management and Analysis System (HRGIMS)", realizes the automatic and visual management of geo-engineering information, on the basis of information management, the functions of test data analysis and engineering property prediction are strengthened. This system has well merits for practice and popularization.