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什么样的实践活动应该记录并且成为档案的内容,是由客观实践活动决定的。首先是客观实践活动的存在,然后才是我们对客观存在的实践活动的认识。所以,档案是人的主观对客观认识的产物,档案的内容归根结底是由产生档案的一定时代的物质生活条件所决定的。一定时代的物质生活条件的发展变化,是人们实践活动的结果。客观的一定时代的物质生活条件的发展变化,使人们的实践活动有特定的内容,实践活动特定内容的发展变化,要求档案的内容也发展变化。否则, 相似文献
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《中国水运》2017,(4)
随着科学技术和社会技术的发展,机器人技术都得到了很大的发展,适用的领域越来越多,以前的传统控制理论已经不能够满足当前生产加工的复杂系统对控制系统的要求,从认识论和方法论的角度、交叉学科、控制对象、系统设计方面分析智能控制和传统的控制方法在机器人方面的区别,并从各个方面说明智能控制的开放的、分级的、分布式的结构。智能机器人有较强的综合处理信息的能力,本文设计的自适应神经控制器对闭环控制系统有界的一致可以实现,而且在稳定的控制过程中,沿着周期或回归跟踪轨迹对部分神经网络的权值的收敛性能够完成和未知闭环系统的部分的精确确逼近,学过的知识以时不变且空间分布的方式表达、以常值神经网络权值的方式存储,能够拿来改善系统的控制性能,在以后类似的任务在中也可以应用,有节省时间和减少能量的消耗的好处。仿真验证了所设计控制算法的正确性和有效性。 相似文献
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提出改进的关于软件产品的软件可靠性增长模型.分析了关于软件产品的可靠性增长原模型的特性,指出了原模型的假设与实际情况不相符的方面;在充分考虑补丁对销售后的软件产品的作用下,将Littlewood对软件模型的思想-即在测试初期出现的错误对软件失效的影响大于后期出现的错误对软件失效率的影响-引入到原模型,并提出了改进的关于软件产品的软件可靠性增长模型.针对所提出的模型,利用测量的数据进行了实际仿真. 相似文献
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<正> 集装箱运输方式的变革导致港口地位的分化,而地位的分化促使各大港口都努力确立自己的枢纽港地位,避免沦为支线港失去大量的经济利益,进而使得现代港口竞争的焦点成为枢纽港地位的竞争。 一、枢纽港地位的利益与枢纽港地位的影响因素 1.枢纽港地位的利益 最明显的好处是来自中转运作中因为双倍的装卸产生的收入,枢纽港的吞吐量会大幅度的增加;更重要的是枢纽港为当地进口商和出口商提供直接的服务,减少往返于海外市场的运输时间与运费。减少运输时间直接影响出口上的竞争力和进口商 相似文献
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孟庆林 《中国远洋航务公告》2004,(11):26-27
党的执政能力问题,是我国政权建设中的一个重大理论与实践问题。不断提高党的执政能力,是时代发展的根本要求.是我们党所处的地位、所肩负的使命的根本要求。党的执政能力建设包含着多方面的内容.党的十六大概括了最基本的五个方面.即科学判断形势的能力、驾驭市场经济的能力,应对复杂局面的能力、依法执政的能力、总揽全局的能力。党的十六届四中全会通过的《决定》在此基础上,进一步提出全党要不断提高五个方面 相似文献
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承运原木的多用途杂货船,近年来连续发生沉船事故,事故的发生已不是孤立的一件事故,而是有着内在联系的一类事故。事故的发生有外在的恶劣气象海况原因,更有船舶本身的原因。有货物的原因,更有装载的原因。有装卸的原因,更有船舶结构的原因。总之,事故的发生不是偶然的,而是长期生产营运中船舶疲劳过度的必然结果。 相似文献
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Mohammad Reza Shekari 《船舶与海洋工程学报》2014,(3)
In thispaper, the effects of a rigid baffle on the seismic response of liquid in a rigid cylindrical tank are evaluated. A baffle is an annular plate which supplies a kind of passive control on the effects of ground excitation. The contained liquid is assumed incompressible, inviscid and has irrotational motion. To estimate the seismic response, the method of superposition of modes has been applied. To analyze the rigid tank response, Laplace's equation is considered as the governing equation of the fluid domain, in both time and frequency domains. The boundary element method(BEM) is employed to evaluate the natural modes of liquid in a cylindrical tank. To gain this goal, the fluid domain is divided into two upper and lower parts partitioned by the baffle. Linearized kinematic and dynamic boundary conditions of the free surface of the contained liquid have been considered. 相似文献
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为了提高造波软件的开发效率,界面和图形部分采用VC开发,波浪计算部分由Fortran编程,并成功地开发了实验室水槽造波软件的不规则波模块,为了验证该模块的准确性,对其主要的两个过程:即谱到时序列和时序列到谱进行了验证,结果令人满意。 相似文献
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Mohammad Reza Shekari 《船舶与海洋工程学报》2014,13(3):299-304
In thispaper, the effects of a rigid baffle on the seismic response of liquid in a rigid cylindrical tank are evaluated. A baffle is an annular plate which supplies a kind of passive control on the effects of ground excitation. The contained liquid is assumed incompressible, inviscid and has irrotational motion. To estimate the seismic response, the method of superposition of modes has been applied. To analyze the rigid tank response, Laplace&#39;s equation is considered as the governing equation of the fluid domain, in both time and frequency domains. The boundary element method (BEM) is employed to evaluate the natural modes of liquid in a cylindrical tank. To gain this goal, the fluid domain is divided into two upper and lower parts partitioned by the baffle. Linearized kinematic and dynamic boundary conditions of the free surface of the contained liquid have been considered. 相似文献
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为实现船舶直线航行的轨迹控制,基于船舶航行基本原理,建立了船舶航行运动的非线性模型。针对模型强非线性的特点,依据输入-状态反馈线性化原理,将非线性模型转化为具有下三角结构的线性模型,并基于反推技术和状态反馈,设计了船舶直线航行控制器。根据Lyapunov方法证明了闭环航迹系统是可镇定的。仿真结果验证了所提控制算法的正确性和有效性。 相似文献
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The rapidly changing complexity of the Global War on Terrorism has changed the approach to equipping forward-deployed military forces. Combatant Commanders conducting operations now require timely materiel solutions to enhance mission capabilities and reduce the risk for individual soldiers. To address this challenge, the US Army established the Rapid Equipping Force to assess emerging requirements, to propose solutions to those requirements, and to implement those solutions in an expedient time frame. Unfortunately, the REF lacks a consistent analytical methodology for assessing alternative materiel solutions. To address the need for a human systems integration (HSI) analysis method, the authors developed an Assessment-Based Rapid Acquisition HSI Analysis Method (ABRAHAM) capable of generating tailored surveys and evaluating these surveys for unacceptable risks to soldiers. To validate ABRAHAM's concept and content, ABRAHAM was showcased in three Department of Defense settings: the Human Factors Engineering Technical Advisory Group, the REF, and the US Marine Corps' Operational Test and Evaluation Activity. The ABRAHAM appears to fill a gap in the current library of HSI tools. Based on the feedback provided during the product showcases, there is sufficient interest and technological maturity to further develop ABRAHAM to serve both the traditional and rapid acquisition processes. 相似文献
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三百门港泥沙淤积研究 总被引:1,自引:1,他引:0
为开发利用柘林湾水域,拟在湾内兴建深水码头,但湾内水深浅,且有三条水道与外海相通,为搞清建港后港域的泥沙回淤情况和堵塞其中一条水道造成的影响,本文通过实测水文资料分析、数学模型计算等手段,对上述问题进行了分析论证,为该工程项目提供决策依据。 相似文献
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With the rapid growth of seaborne commodity trades, port development and management has become a challenging issue to the government, enterprise and academia. To alleviate pressures on spatial demand and the environment, sustainable development and scientific management of a port is of crucial importance for its investment, construction and operation. In this article, a research path based on throughput estimation is proposed. The container port of Tianjin could expect to face immense, increasing pressure in the future several years. To meet future increasing capacity requirement, constructing new waterway and berths in a bigger contiguous area or new locations becomes a crucial strategy. Moreover, the strategy of accommodating peak seasonal traffic means existing container terminals have to attain higher output by redesigning their high-precision schedule, reconfiguring terminal topology, improving worker efficiency and employing more modern container-handling facilities. 相似文献