It is difficult point of the design of the new system that directly generated statistic data from the data sources . because that the ability of monitoring of each enterprise of petrochina is different . especially they lack of some monitoring point , and the monitoring frequency is inconformity 从数据源直接生成统计汇总数据是新系统的设计难点和突破口由于股份公司各企业监测能力和具体情况悬殊很大，存在监测频率不一致、监测点位不足等问题，使得监测点类别划分上很困难。
Among the design of the truss system , it is deeply analyzed that the thought of choosing truss system type , the difficulties in designing truss system and their solutions , the constrain of column to truss chord deformation and the chord modified coefficients used in this case 在桁架体系设计中，笔者主要分析了桁架体系的选型思路；提出了桁架体系的设计难点，并给出了解决方案；分析了柱子约束对桁架弦杆受力的影响，并给出了在手算桁架体系杆件受力时所需要的弦杆内力修正系数。
The difficulty of common processing platform lies in in stage two : the design of ip core - - pci - local bus bridge , . this thesis analyses the structure and operation principle of this bridge at first , then according to the structure of the bridging module , fmishes the design of fpga with four modules which fulfill the bridging function of ip core - pci - local bus , and succeeds in matching at spartanll series device x2s50 - fq256 - 5 , company of xilinx , finally simulates emulation of bridge of pci - local bus in terms of system level , and detaily analyses the output waveform 通用处理平台的设计难点在于阶段二中ip核? ? pci - localbus桥的设计与实现，本文首先分析该桥的组成结构与工作原理，然后参照桥接模块结构分四个模块完成该ip核的fpga设计与实现，并在xilinx公司spartan系列器件上成功匹配。最后从系统级的角度完成对pci - localbus桥的模拟仿真，并对输出波形进行了详细分析。
Based on the researching conclusion of the s econd and third parts , the farmers " grain supply response and rational behavior decision , the grain theory of different kinds of grain market , the integration of the market and the policy are provided in the last part of the thesis . chapter 12 puts forward the ideal proposals and the difficulty of design grain policy . in the end , author presents the conclusion of this thesis and puts forward some theoretical reference and policy recommendation for the grain market - oriented reform in china 在《上篇》和《中篇》结论的基础上，对政府干预粮食市场的行为进行经济学分析，探讨中国粮食政策与粮食市场运行机制不协调的深层次原因，同时论证了中国粮农的理性生产决策行为，并对中国目前的收购市场、供给市场、需求市场以及运行状况进行了博弈分析，提出市场与政策冲突的矛盾所在，进而提出了中国粮食市场与政策耦合的理想方案、目标导向、设计难点以及对策。
In this paper , based on a typical plan arrangement of two - user - on - one - storey and leap storey type multi - story house , the mechanical behaviours of the truss system , the difficulties in designing the truss system and the design of composite floor system is deeply analysed ; the connection design , fire proofing and corrosion protection used in this structure system are briefly introduced 本论文以一梯两户跃层式多层住宅的一种典型平面布置为依托，以构思该住宅结构体系设计的方式，对这种桁架体系的受力性能、设计难点和应用于该结构体系的压型钢板?混凝土组合楼盖的设计进行了深入分析，对结构采用的连接、墙体和防火防腐措施进行了简单讨论。
Further investigated and analyzed composition structure and flow data that dsa ' s formation of image is systematic at first in this paper , carried on intact summing up to the data in the system , having given out the plan of design of high speed and large capacity data channel of digital formation of image system of x - ray ; deeper discussion of control way on sdram , give solution that many pieces of sdram works togetherses of realizing heavy capacity , designing of heavy capacity deposit board realize storing at a high speed to vision data by frame on the basis of this ; through further investigations of interface of pci bus , optimize back end state machine design and urge procedure making with lower , giving intact pci interface scheme that realize high speed dma data transmission and satisfy request of video transmitting ; further investigate the figure systematic design method of programmable logic devices , due to the difficult point of drifting about of enabled signal in fifo in common use and setting up and keeping of output signal , method has been proposed of improving stability of system making use of signal utilizing the phase locking ring in fpga to offer a lot of clocks to move thus realize coordinating the data between every module of system to transmit at a high speed by making use of fifo 本文首先对数字减影血管造影( dsa )成像系统的组成结构和数据流向进行了深入研究和分析，并对系统中的数据流向进行了完整的归纳和总结，给出了x线数字成像系统中的高速大容量数据通道的设计方案；在对sdram的控制方式做了深入探讨后，给出了实现大容量多条sdram共同工作的解决方案，在此基础上设计了大容量帧存板实现对图象数据进行高速存储；通过对pci总线接口的深入研究，优化后端状态机设计和低层驱动程序开发，给出了完整的pci接口方案实现高速dma数据传输，完全可以满足视频传输要求；深入研究了基于大规模可编程器件的数字系统设计方法，针对通用fifo使能信号漂移、输出数据难于建立和保持等设计难点，提出了利用fpga中的锁相环提供多个时钟相移的信号来提高系统稳定性的解决方案，从而实现利用fifo来协调系统各模块之间的数据高速传输。
4 . the design flow of the distributed simulation system of airborne sar is dicussed . analyse the development of two important federates , echo producer and signal processor , point out the difficulties in design , such as disassemble of calculation , communication of federates , time management , and explain the solutions in details 4 .按照软件设计开发的流程,阐述了基于hla的机载sar系统分布式仿真软件的设计思路,重点分析了回波产生、成像处理联邦成员的开发过程,并详细的说明了对于其中的设计难点,如计算量的分化、联邦成员间的通信、时间管理、同步等的考虑和解决方案。
