排序方式: 共有1866条查询结果,搜索用时 0 毫秒
321.
As an army main battle equipment, it is required that the tank should have high firing accuracy and high first round hit probability during marching. The initial disturbance of the projectile is the premier factor that takes effect on the marching fire accuracy of the tank. And the marching fire accuracy of the tank depends on the launch dynamics behaviors of the tank. In this paper, the launch dynamics theory of a tank marching fire is studied, and its launch dynamics model is established. Based on the transfer matrix method for multibody system(MSTMM) and the automatic deduction theorem of overall transfer equations, the overall transfer equation and the overall transfer matrix of a tank multibody system are deduced; the launch dynamics equations of the tank marching fire are deduced, and the dynamic response of the tank system, the motion of projectile in barrel, the initial disturbance of the projectile and the vertical target dispersion are exactly simulated; meanwhile, the results of simulation are verified by tests. This work provides both theoretical foundation and simulation approaches for improving the marching fire accuracy of the tank. 相似文献
322.
Human reliability analysis method on armored vehicle system considering error correction 总被引:1,自引:0,他引:1
Human reliability analysis(HRA) is an expansion of man-machine engineering. It is also a new multidisciplinary based on behavioral science, cognitive science, information processing, system analysis and probability statistics in order to analyze, predict, reduce and prevent human errors. Firstly, the quantitative analysis model of HRA is proposed based on Markov process theory by using human error probability(HEP) and error correction cycle(ECC) as parameters. And human reliability evaluation criterion is built. Then, the HRA process considering error correction is proposed based on cognitive reliability and error analysis method(CREAM). Finally, according to the characteristics of armored vehicle system, common performance condition(CPC) in CREAM is improved.A reliability impact index is characterized by the overall contexts of tasks. Human reliability evaluation criterion of armored vehicle system is formulated. And the result of HRA is obtained based on the method presented in this paper. In addition, the relative weights are estimated by combining scale of 10/10—18/2 and analytical hierarchy process(AHP), and the triangular fuzzy number considering confidence factor and optimism index is adopted in order to reduce the subjectivity. The analysis results show that the method presented in this paper is reasonable and feasible. Meantime, the method can provide guidance for human reliability analysis of other weapon systems. 相似文献
323.
324.
张传勇 《上海交通大学学报(英文版)》2016,21(1):33-43
As more and more Chinese and foreign-funded banks settle in the China (Shanghai) Pilot Free Trade Zone (CSPFTZ), it has become an imperative to enhance risk management of offshore banking. At the international level, the regulatory effort for offshore banking mainly focuses on tax evasion and money laundering. Existing regulatory frameworks have established standards to identify countries providing facilities for money laundering and developed punitive measures. In terms of strategy, it is suggested that, firstly, relevant regulatory measures should be improved in the short term, and it is necessary to define the scope of offshore banking and regulatory measures for Chinese banks and foreign-funded banks under a suitable legal framework. Secondly, it is necessary to establish risk exposure mechanism and risk evaluation system for the offshore banking in the CSPFTZ, while risk management measures are implemented based on on-site supervision. Thirdly, in the medium and long term, it is necessary to enhance management of potential risks which can be created by offshore banking due to deregulation. Fourthly, on the one hand, specific regulations should be formulated to provide a regulatory basis for taxation; on the other hand, tax informational exchange agreements (TIEAs) may be used as a reference for achieving effective tax regulation. 相似文献
325.
Dynamic modeling and active control of a strap-on launch vehicle are studied in this paper. In the dynamic modeling, the double-compatible free-interface modal synthesis method is used to establish dynamic model of the system, and its model precision is compared with those of finite element method(FEM), fixedinterface modal synthesis method and free-interface modal synthesis method. In the active control, the swing angle of rocket motor is used as design variable, and the control law design based on the model of mass center motion is adopted to validate the system. Simulation results indicate that the double-compatible model synthesis method can properly approximate the FEM which is used as the benchmark solution, and the model precision of the double-compatible modal synthesis method is obviously higher than those of the fixed-interface and freeinterface modal synthesis methods. Based on the control law design, the deflection of mass center of the launch vehicle is very small. 相似文献
326.
This paper proposes a new method to diagnose the system fault of the process industry based on the monitor data set of distributed control system (DCS). Firstly, it defines a homeomorphism product space named color phase space which is a Cartesian product of two-dimensional Euclidean space and three-dimensional color phase space. Secondly, it maps the DCS data to the color phase space in order to get a system color-spectrum which displays the inherent relationship of the whole system. Then, it diagnoses the system fault by observing the color change on the color-spectrum depending on the physiological characteristics that human’s eyes are more sensitive for the color change than data change. 相似文献
327.
Catherine Morency 《Transportation》2007,34(2):239-253
Ridesharing is quite a popular topic of discussion among transport authority personnel. It is perceived to be a viable alternative
to classical modes of transportation, and receives a great deal of political support from transport planners. However, not
much objective information is available on ridesharing behaviors. We use travel survey data to study the evolution of the
ridesharing market in an urban area. Our study is based on data from four large-scale OD surveys conducted in the Greater
Montreal Area (1987, 1993, 1998 and 2003).
In the latest survey conducted in Montreal, car passengers were asked to identify the driver who gave them the opportunity
to travel in this way. Their answers were classified according to the type of driver; for instance, a member of their household,
a neighbor or a co-worker. We use this information to calibrate a model matching car passengers and car drivers belonging
to the same household. This will be referred to as IHHR (intra-household ridesharing).
Preliminary results reveal that approximately 70% of all trips made by car passengers are the result of IHHR. Furthermore,
around 15% of those trips are questionable, in that they were exclusively generated for another individual’s purposes, consequently
generating an additional trip for the journey back home. Moreover, this percentage increased over time. Objective data regarding
ridesharing and its evolution in an urban area will undoubtedly help decision makers gain a clearer profile of this means
of travel and help to realign attitudes on the issue.
相似文献
Catherine MorencyEmail: |
328.
Becky P. Y. Loo 《Transportation》2007,34(4):471-486
Paratransit refers to urban transport services “somewhere between private passenger transport and conventional public transport in terms of cost and quality of service” [Rimmer (1980), Paratransit: A commentary. Environ. Plan. A 12, 937–944]. Since the 1980s, a new form of paratransit—residents’ coach, which provides exclusive transport services to residents living in private housing estates—has emerged in Hong Kong. What was the background underlying the emergence and subsequent growth of residents’ coach services? Also, what was the role of residents’ coach in the public transport system of Hong Kong? With the completion of more railway extensions, should residents’ coach services be replaced? If so, what are the potential impacts on people’s life? This paper addresses the above research questions through a large-scale questionnaire survey that examined not only people’s modal choice but also their residential choice, socio-economic background and attitudes. The findings suggest that transport policy makers should pay more attention to examine new forms of paratransit and the ways of integrating them into the overall public transport system, both spatially and temporally. It is only through the development of an efficient and multi-modal transport system can the maximum potential of paratransit in filling the transport gap between conventional mass transit and private cars be realized. 相似文献
329.
We developed a new structural lightweight concrete by totally or partially replacing coarse and fine aggregates in high performance concrete by expanded polystyrene (EPS) beads. In this work,the sizes of EPS bead were 1.0,2.5 and 6.3 mm. Lightweight EPS concretes with a wide range of concrete densities and compressive strengths were successfully developed. Compressive strength,splitting tensile strength,shrinkage,and water absorption were examined. Additionally,fine silica fume (SF) and polypropylene (PP) f... 相似文献
330.
Method for workspace calculation of 6R serial manipulator based on surface enveloping and overlaying
Aiming at the workspace calculation problem of multi-joint serial manipulators, a surface enveloping and overlaying (SEO)
method is presented to identify and visualize the manipulator workspace. The SEO method is composed of two stages: the first
stage is to choose reference points of the manipulator and calculate their boundary surfaces using the nth enveloping method; the second stage is to overlay these boundary surfaces to identify the final workspace. The SEO method
is basically a combination of the analytic method and the numerical method. By delineating the graphic representation of the
workspace step by step, the SEO method is easy to analyze the existence and the shape of voids and holes. The basic theory
of the SEO method and formulas for workspace calculation are presented based on a 6R serial manipulator. By showing the workspace
calculation results, the SEO method is proved working correctly. 相似文献