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1.
本文主要针对目前工程量计算过程中存在的问题,介绍了统筹法计算工程量的具体方法,并根据实际需要,给出了主要分项工程量计算顺序及计算公式.  相似文献   

2.
2003年7月开始实施的《建设工程工程量清单计价规范》具有一些新特点,使建设工程造价的编制方法发生了变化,这些变化必然会对审计工作产生影响。  相似文献   

3.
研究了某武器装备正态型和对数正态型数据的维修性评估问题,提出了评估的主要指标,并用实例计算了其主要指标。计算结果表明,这些指标能够很好地定量评估服从正态和对数正态分布的武器装备的维修性。  相似文献   

4.
主要介绍了一些与精度计算有关的基础理论知识,如误差分类、误差合成、精度计算常用方法、常用公式等,目的在于理清和说明建立制导精度计算模型的原理和方法,最后简单介绍了如何确定制导控制系统精度计算模型。  相似文献   

5.
系统阐述了数值模拟技术这一新兴手段在钻地武器研制中的主要算法及应用,比较了算法之间的优缺点,介绍了当今流行的各种主要计算程序。作为算例,运用非线性动力有限元LS-DYNA计算程序,对一个防空建筑在弹头侵彻下的动态响应及应力变化情况作了计算,图像形象显示了战斗部在侵彻过程中的形变及其速度,质量随时间的变化情况,最后阐述了数值模拟技术在武器设计等领域的应用。  相似文献   

6.
一种有效的星载可移点波束天线方案   总被引:2,自引:0,他引:2  
主要论述及计算了一种同步轨道通信卫星用可移点波束天线方案,介绍了方案的布局,采用物理光学法对扫描特性进行了计算,讨论了在采用该方案时遇到的问题并提出了解决手段。  相似文献   

7.
纤维增强陶瓷基复合材料中纤维增韧分析模型   总被引:3,自引:0,他引:3  
对于单向纤维增强陶瓷基复合材料,在考虑纤维桥联和纤维拔出两种主要增韧机理的基础上,建立了研究紧凑拉伸试样断裂行为的理论模型,并利用该模型计算了裂纹扩展的R-阻力曲线和载荷/位移曲线,计算结果表明:由于纤维桥联与拔出,使得R-曲线和载荷/位移曲线呈现明显的非线性行为,纤维桥联是主要增韧机制。体积分数50%SiC1/LAS复合材料断裂韧性的计算值与实验值吻合。  相似文献   

8.
本文主要介绍了开发变压器保护的整定计算及定值管理系统的设计思路,面向对象的编程方法,以及与数据库的连接方法,介绍该系统所能实现的主要功能。  相似文献   

9.
星载红外凝视相机信噪比计算分析   总被引:2,自引:0,他引:2  
曹移明  张伟  丛明煜 《宇航学报》2007,28(4):955-959
红外相机信噪比计算是衡量相机能否满足探测要求、评估系统总体指标是否合理的必要环节。从电子数角度出发,引入了计算空间红外凝视相机系统噪声与信噪比的方法,首先建立了完整的噪声计算模型,分析了不同噪声源对探测能力的影响,并比较了电子数法与比探测率法计算信噪比的适用情况。在此基础上分析了点目标探测与面目标探测中影响系统信噪比的主要因素。最后,利用建立的电子数计算模型,分析了美国微型传感器技术集成演示试验(MSTI-3)系统对大气背景的测量能力。  相似文献   

10.
LS-DYNA程序在战斗部仿真计算中的应用   总被引:4,自引:0,他引:4  
在简要介绍非线性动力有限元程序LS—DYNA及程序中所采用主要算法的基础上,着重叙述了它在战斗部仿真计算中的应用,并用LS—DYNA程序对某型子母弹战斗部火药燃烧驱动子弹的前期运动过程进行了仿真计算,获得了子弹的初始运动速度和初始运动姿态以及子弹弹体的初始受力情况。计算获得的子弹抛撒初速度与试验值基本一致。  相似文献   

11.
经营决策中数学及运筹学方法的应用,使决策方案在定性分析的基础上获得了可靠的定量分析信息,为科学决策提供了方法上的保障。但由于决策方案一般涉及大量的约束条件和决策变量,给定量计算工作带来沉重的负担。本文通过对利用计算机软件进行规划求解的介绍,可以力便地缓解繁杂的计算工作问题,使经营决策的规划求解问题能够变得十分方便。  相似文献   

12.
VAPS技术在载人航天器MFD软件开发中的应用   总被引:1,自引:0,他引:1  
利用虚拟原型应用系统(VAPS)及其相关配套工具提供的先进功能,实现多功能显示设备软件的开发。首先简要介绍VAPS技术及其开发流程,然后详细阐述显示界面程序和显示驱动程序的开发过程,最后论述VAPS技术在多功能显示器以太网地面仿真中的应用及实现。结果表明:该方法具有较强的通用性和可扩展性,编程工作量减少到原来的30%~40%。  相似文献   

13.
Human locomotion in simulated lunar and Martian environments is investigated. A unique human-rated underwater treadmill and an adjustable ballasting harness simulate partial gravity in order to better understand how gravity determines the biomechanics and energetics of human locomotion. This study has two research aspects, biomechanics and energetics. The fundamental biomechanics measurements are continuously recorded vertical forces as exerted by subjects of the treadmill which is instrumented with a force platform. Experimental results indicate that peak vertical force and stride frequency decrease as the gravity level is reduced. Foot contact time is independent of gravity level. Oxygen uptake measurements, VO2, constitute the energetics, or workload, data for this study. As theory predicts, locomotion energy requirements for lunar (1/6-g) and Martian (3/8-g) gravity levels are significantly less than at 1-g. The observed variation in workload with gravity level is nonmonotonic, however, in over half the subject population. The hypothesis is offered that energy expenditure increases for lunar, as compared with Martian, locomotion due to the subject "wasting energy" for stability and posture control in simulated lunar gravity. Biomechanics data could influence advanced spacesuit design and planetary habitat design, while workload data will help define oxygen requirements for planetary life support systems.  相似文献   

14.
为提高教学质量、减轻教师的工作负担,本文给出了一种基于J2EE的网上考试系统,同时对该系统功能结构进行了详细的设计与分析。  相似文献   

15.
This paper presents an experiment which examined the effects of isolation and confinement during a simulation of a short-term space mission. During the 7-day spaceflight simulation, four Canadian astronauts were tested daily on a 30-min performance task. The task, CAMS (Cabin Air Management System), represents a computer-based simulation of a generic life support system. As a multiple-task environment, it allows the measurement of a wide range of task management variables such as primary and secondary task performance, and system control activities. Measures of subjective state variables were also taken. The results did not show any evidence of serious performance decrements for any crew member. The analysis revealed different adjustment patterns with which crew members responded as a function of mission duration and variations in workload. Among the secondary tasks employed, prospective memory was found to be more sensitive than reaction time to increases in workload. The paper concludes with a discussion of the utility of spaceflight simulations and computer-based simulations of space work.  相似文献   

16.
本文主要介绍了教学任务管理系统的分析与开发过程。程序实现了教学计划的录入与存储以及教学任务书、班级课程汇总表的打印,同时还具有统计教师工作量以及教师工作总量的功能。  相似文献   

17.
提出了利用贝叶斯 (Bayes)理论对飞行器运动辨识的复杂假设进行检验的方法 ,推导了检验规则及实现算法。该研究对于大型复杂仿真系统的置信度评估和提高仿真结果的正确性及减少仿真工作量具有一定的参考价值  相似文献   

18.
ASSESS II (Airborne Science/Spacelab Experiments System Simulation) was a cooperative NASA-ESA project which consisted of a detailed simulation of Spacelab operations using the NASA Ames Research Center CV-990 aircraft laboratory. The Medical Experiment reported on in this paper was part of the complex payload consisting of 11 different experiments. Its general purpose was to develop a technology, possibly flown on board of Spacelab, and enabling the assessment of workload through evaluating changes of circadian rhythmicity, sleep disturbances and episodical or cumulative stress. As parameters the following variables were measured: Rectal temperature, ECG, sleep-EEG and -EOG, the urinary excretion of hormones and electrolytes. The results revealed evidence that a Spacelab environment, as simulated in ASSESS II, will lead to internal dissociation of circadian rhythms, to sleep disturbances and to highly stressful working conditions. Altogether these effects will impose considerable workload upon Payload Specialists. It is suggested that an intensive pre-mission system simulation will reduce these impairments to a reasonable degree. The bioinstrumentation applied in this experiment proved to be a practical and reliable tool in assessing the objectives of the study.  相似文献   

19.
Iwase S 《Acta Astronautica》2005,57(2-8):75-80
To test the effectiveness of centrifuge-induced artificial gravity with ergometric exercise, 12 healthy young men (20.7 +/- 1.9 yr) were exposed to simulated microgravity for 14 days of -6 degrees head-down bedrest. Half the subjects were randomly selected and loaded 1.2 G artificial gravity with 60 W (four out of six subjects) or 40 W (two out of six subjects) of ergometric workload on days 1, 2, 3, 5, 7, 9, 11, 12, 13, 14 (CM group). The rest of the subjects served as the control. Anti-G score, defined as the G-load x running time to the endpoint, was significantly elongated by the load of the centrifuge-ergometer. Plasma volume loss was suppressed (-5.0 +/- 2.4 vs. -16.4 +/- 1.9%), and fluid volume shift was prevented by the countermeasure load. Elevated heart rate and muscle sympathetic nerve activity after bedrest were counteracted, and exaggerated response to head-up tilt was also suppressed. Centrifuge-induced artificial gravity with exercise is effective in preventing cardiovascular deconditioning due to microgravity exposure, however, an effective and appropriate regimen (magnitude of G-load and exercise workload) should be determined in future studies.  相似文献   

20.
舱外航天服热平衡试验热流计算工作量大,有必要改进外热流模拟方法。文章提出用红外加热笼分类模拟舱外航天服包围面上外热流,并给出包围面外热流的概念,分析包围面上外热流,得出外热流模拟改进方法的关键措施,且用仿真方法验证了模拟方法的可行性。  相似文献   

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