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311.
数据融合中的Dempster-Shafer证据理论   总被引:15,自引:3,他引:12  
虽然 D- S方法已广泛地应用于各种数据融合系统中 ,但在实际应用中依然存在着许多困难。总结了数据融合应用中的 Dempster- Shafer证据理论研究概况 ,从四个方面阐述和对比分析了一些有代表性的研究成果 ;同时为下一步的研究提出了新的课题和思路  相似文献   
312.
将强度折减法引入强震作用下的海底隧道衬砌结构安全稳定性研究,利用FLAC3D软件建立了海底隧道-岩土体-海水相互作用的强度折减法数值模型,综合考虑海底隧道衬砌在强震作用下的位移、剪应变增量和塑性区变化,确定了海底隧道衬砌局部破坏的极限平衡状态和整体破坏的极限平衡状态,分析了海底隧道衬砌在强震作用下的破坏机理。结果表明:海底隧道衬砌在水平地震波的作用下,主要是围岩变形导致隧道衬砌破坏;隧道衬砌破坏位置发生在右侧侧墙中部,破坏形式为剪切破坏;隧道衬砌局部破坏的极限安全系数为1.47,整体破坏的极限安全系数为1.8,2种安全系数的极限状态可对应结构设计中的正常使用极限状态和承载力极限状态。研究成果可为海底隧道衬砌设计提供理论依据。  相似文献   
313.
All underwater drilling and blasting operations generate seismic waves.However,due to a lack of suitable vibration sensing instruments,most studies on the propagation of seismic waves have been limited to shorelines near construction areas or wharfs,whereas comparatively few studies have been conducted on the larger seafloor itself.To address this gap,a seafloor vibration sensor system was developed and applied in this study that consists of an autonomous acquisition storage terminal,soft-ware platform,and hole-plugging device that was designed to record the blasting vibration intensities received through submarine rocks at a given measurement point.Additionally,dimensional analyses were used to derive a predictive equation for the strength of blast vibrations that considered the in-fluence of the water depth.By combining reliable vibration data obtained using the sensor system in submarine rock and the developed predictive equation,it was determined that the water depth was an important factor influencing the measured vibration strength.The results using the newly derived equation were compared to those determined using the Sadowski equation,which is commonly used on land,and it was found that predictions using the derived equation were closer to the experimental values with an average error of less than 10%,representing a significant improvement.Based on these results,the developed sensor system and preliminary theoretical basis was deemed suitable for studying the propagation behavior of submarine seismic waves generated by underwater drilling and blasting operations.  相似文献   
314.
In this article, we study item shuffling (IS) problems arising in the logistics system of steel production. An IS problem here is to optimize shuffling operations needed in retrieving a sequence of steel items from a warehouse served by a crane. There are two types of such problems, plate shuffling problems (PSP) and coil shuffling problems (CSP), considering the item shapes. The PSP is modeled as a container storage location assignment problem. For CSP, a novel linear integer programming model is formulated considering the practical stacking and shuffling features. Several valid inequalities are constructed to accelerate the solving of the models. Some properties of optimal solutions of PSP and CSP are also derived. Because of the strong NP‐hardness of the problems, we consider some special cases of them and propose polynomial time algorithms to obtain optimal solutions for these cases. A greedy heuristic is proposed to solve the general problems and its worst‐case performances on both PSP and CSP are analyzed. A tabu search (TS) method with a tabu list of variable length is proposed to further improve the heuristic solutions. Without considering the crane traveling distance, we then construct a rolling variable horizon heuristic for the problems. Numerical experiments show that the proposed heuristic algorithms and the TS method are effective. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012  相似文献   
315.
针对舰艇防空作战中遇到的不确定性问题,在科学分析影响目标状况因素的基础上,根据专家经验,运用模糊推理的原理和方法,重点分析了目标状况知识信息的表示方法,给出了模糊推理规则,研究设计了用于舰艇防空辅助决策的模糊专家系统。最后给出了一个应用实例。  相似文献   
316.
通过词源分析和背景介绍,从军事、物理学和社会学等角度给出对Cyberspace的内涵与特征的理解,在定义了Cyberspace概念的基础上,给出"网络全域"的译名及其考量因素。  相似文献   
317.
This paper studies the four-engine liquid rocket flow field during the launching phase. Using three-dimensional compressible Navier-Stokes equations and two-equation realizable k-epsilon turbulence model, an impact model is established and flow fields of plume impinging on the two different shapes of flame deflectors, including wedge-shaped flame deflector and cone-shaped flame deflector, are calcu-lated. The finite-rate chemical kinetics is used to track chemical reactions. The simulation results show that afterburning mainly occurs in the mixed layer. And the region of peak pressure occurs directly under the rocket nozzle, which is the result of the direct impact of exhaust plume. Compared with the wedge-shaped flame deflector, the cone-shaped flame deflector has great performance on guiding exhaust gas. The wedge-shaped and cone-shaped flame deflectors guide the supersonic exhaust plume away from the impingement point with two directions and circumferential direction, respectively. The maximum pressure and temperature on the wedge-shaped flame deflector surface are 37.2% and 9.9% higher than those for the cone-shaped flame deflector. The results provide engineering guidance and theoretical significance for design in flame deflector of the launch platforms.  相似文献   
318.
给出一种基于模型故障诊断的实现方案——MCIES,着重介绍MCTES所采用的建模方法和推理策略,最后介绍该系统各组成模块的功能。  相似文献   
319.
全军在推进人才强军战略工程的实践中,相继出台了一系列新举措:一是科学确定出新世纪新阶段军队建设急需培养的新型高素质军事人才"五支队伍";二是建立依托国民教育培养军队干部的人才培养新机制;三是创立军队吸引保留高层次人才的多项新制度;四是完善激励军队优秀人才献身部队建设的奖励制度。  相似文献   
320.
科学管理和科学技术是现代军队战斗力的基本要素和新的增长点。按照新装备形成战斗力的客观规律,阐述了强化装备科学管理的重要性及其原则,提出了构建装备科学管理创新工程的基本思路。  相似文献   
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