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971.
972.
地铁公安通信系统已经成为地铁公安人员开展日常工作稠处理突发事件的重要工具。该系统提供一个安全、可靠、灵活的现代化通信手段,在发现治安问题时通过它能快速合理地调动警力。本文从地铁公安通信业务需求分析入手,针对各系统可采用的方案对公安通信系统网络结构进行优化,对轨道交通公安通信系统建设具有一定参考价值。 相似文献
973.
Linux has a special feature of automount in the Linux kernel. Filesystem can be mounted and unmounted automatically. Its performance is similar to MS Windows. It works well under demands of more saving resources and automatization, like memory of system. An approach to install/update software automatically on embedded platform was proposed. This approach derives from above feature based on embedded environment with Linux OS. Configurations of files related to this feature were introduced. An example in practice was given to realize this approach from universal serial bus (USB) memory disk when USB disk is available. 相似文献
974.
Trust is one of the most important security requirements in the design and implementation of peer-to-peer (P2P) systems. In an environment where peers' identity privacy is important, it may conflict with trustworthiness that is based on the knowledge related to the peer's identity, while identity privacy is usually achieved by hiding such knowledge. A trust model based on trusted computing (TC) technology was proposed to enhance the identity privacy of peers during the trustworthiness evaluation process between peers from different groups. The simulation results show that, the model can be implemented in an efficient way, and when the degree of anonymity within group (DAWG) is up to 0.6 and the percentage of malicious peers is up to 70%7 the service selection failure rate is less than 0.15. 相似文献
975.
Applications on iterative control and multiple input multiple output (MIMO) system were developed. Two new charts derived from extrinsic information transfer (EXIT) chart were employed as the designing tools, which are called as output mutual information chart with defined iterative degree (DID) chart and near optimum output mutual information (NOMI) chart respectively. Different from the EXIT chart, they can show the iterative performance on the whole signal-to-noise ratio range with one single curve, whereas computation complexity is greatly reduced compared with conventional bit error ratio (BER) performance curve. The iterative control was implemented according to a near-optimum iterative degree vector determined by NOMI chart, the reasonability of uncertain parameters was analyzed in one MIMO system. The concepts were illustrated based on bit-interleaved coded modulation with iterative decoding (BICM-ID). 相似文献
976.
An identity-based verifiably committed signature scheme (IB-VCS) was proposed, which is proved secure in the standard model (i.e., without random oracles). It enjoys the setup-free property and stand-alone property, both of which make an exchange protocol more practical. The scheme is unconditionally secure against the cheating signer, its security against the cheating verifier is reduced to the computational Diffie-Hellman (CDH) problem in the underlying group, it is secure against the cheating trusted third party if the underlying Paterson Schuldt's identity based signature (IBS) scheme is secure, which is proven true based on the CDH assumption in the standard model. 相似文献
977.
Repairing effect of fly ash (FA) on damage of recycled coarse aggregate was evaluated by characteristics of pores and cracks in the vicinity of interracial transition zone (ITZ). The interracial structure between the virgin aggregate and the attached old mortar was investigated and compared with ITZ of recycled aggregate concrete in the presence of FA or ultra-fine FA(UFA) by means of scanning electron microscope (SEM). Diam- eter and plumpness frequency distribution of pores as well as width of the old ITZ, length of contacting points and cracks density were analyzed. The SEM results reveal that the diameter of pores is decreases significantly but pores plumpness increases. A decreased ITZ width and cracks density as well as an increased bonding zone length can also been observed, which indicates that FA or UFA repairs damage of recycled coarse aggregate due to its granular effect. 相似文献
978.
目的 探讨精神分裂症受试冠状位最大垂体切面颞叶测量值与正常对照的差异 ,分析精神分裂症受试病理心理评定值与颞叶测量值的相关性。方法 2 4例精神分裂症和 2 1例匹配的正常对照进行冠状位T1加权图 1mm层厚连续扫描 ,测量两组受试两半球MRI垂体最大层面颞叶横径、颞叶高径、颞叶上、中、下回面积、颞叶横径指数和颞叶高径指数。对精神分裂症组进行SAPS、SANS评定 ,并与颞叶 14个测量值进行回归分析。结果 与正常对照相比较 ,精神分裂症右颞下回面积减少 ,妄想因子与左颞高径、左颞上回面积呈显著负相关。结论 本研究显示首发精神分裂症存在高比率的颞叶结构性缺陷 相似文献
979.
吗啡在慢性染毒大鼠体内死后再分布 总被引:1,自引:0,他引:1
目的 研究吗啡在慢性染毒大鼠体内的死后再分布特性。方法 在室温条件下 ,将对吗啡形成依赖的大鼠处死 ,分别在死亡当时和死后 2 4、48、72、96h采集心血及心肌、脑、肝、肾、肺组织 ,用固相萃取 气相色谱法 (SPE GC)检测吗啡含量。结果 除肺外 ,心血和各组织吗啡含量在大鼠死后 96h内有不同程度增加。肝增加幅度最大 ,肾在 72~ 96h呈现下降 ,心肌在 2 4h有所下降 ,以后逐渐上升。各组织与死亡当时心血中吗啡含量相比 ,在大鼠死后 96h内脑中吗啡含量与其相差最小。结论 吗啡在慢性染毒大鼠体内存在死后再分布现象 ,脑组织能较好反映死亡当时心血中的吗啡含量 相似文献
980.
陕西地区汉族群体Y染色体STR基因座多态性研究 总被引:1,自引:0,他引:1
目的 研究 14 0名陕西地区汉族男性个体Y染色体 6个STR基因座的遗传多态性 ,为法医学实践和群体学研究提供基础数据。方法 应用Y PLEXTM6荧光标记复合扩增系统 ,PCR扩增后用ABI 310 0Avant遗传分析仪进行基因扫描和基因分型。结果 6个基因座分别检测出 4、6、7、8、4、37种等位基因 ,基因多样性 (GD)从 0 .35 94~0 .95 6 5。在 14 0名个体中共检测出 135种不同的单倍型 ,其中 131个只出现 1次 ,单倍型多样性 (HD)为 0 .992 3,个体识别能力 (DP)为 0 .96 4 3。结论 这 6个Y染色体STR基因座具有较好的多态性 ,联合单倍型具有较高的个体识别能力和非父排除率 ,适用于法医学实践和群体遗传学研究 相似文献