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121.
T.-P. Hong T.-T. Wang S.-L. Wang 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2001,5(6):426-433
Flexible flow shops can be thought of as generalizations of simple flow shops. In the past, the processing time for each
job was usually assumed to be known exactly, but in many real-world applications, processing times may vary dynamically due
to human factors or operating faults. In the past, we demonstrated how discrete fuzzy concepts could easily be used in the
Palmer algorithm for managing uncertain flexible-flow-shop scheduling. In this paper, we generalize it to continuous fuzzy
domains. We use triangular membership functions for flexible flow shops with more than two machine centers to examine processing-time
uncertainties and to make scheduling more suitable for real applications. We first use the triangular fuzzy LPT algorithm
to allocate jobs, and then use the triangular fuzzy Palmer algorithm to deal with sequencing the tasks. The proposed method
thus provides a more flexible way of scheduling jobs than conventional scheduling methods. 相似文献
122.
123.
Liu Jinyi 《计算机辅助绘图.设计与制造(英文版)》2000,(1)
Given two disjoint 3-dimensional convex polytopes P and Q and a straight direction along Which P moves in translation, this paper presents a linear algorithm for determining Whether P collides with Q, and the possible collision positions on P and Q. This result is achieved by using the hierarchicat representation of polytopes, of which the preprocessing time is linear with space. 相似文献
124.
虚拟驾驶是智能交通的重要组成部分。本文主要研究虚拟驾驶的行驶速度模型、行驶方向控制模型、碰撞检测算法的关键技术,分别从OpenGL和VRML两种方案实现的驾驶模型,从实现后的系统发现,应用OpenGL实现的虚拟驾驶系统使用更灵活,画面更逼真。最后对虚拟驾驶系统进行了展望,推广是可行的。 相似文献
125.
A comparison of finite elements for nonlinear beams: the absolute nodal coordinate and geometrically exact formulations 总被引:2,自引:2,他引:0
Ignacio Romero 《Multibody System Dynamics》2008,20(1):51-68
Two of the most popular finite element formulations for solving nonlinear beams are the absolute nodal coordinate and the
geometrically exact approaches. Both can be applied to problems with very large deformations and strains, but they differ
substantially at the continuous and the discrete levels. In addition, implementation and run-time computational costs also
vary significantly. In the current work, we summarize the main features of the two formulations, highlighting their differences
and similarities, and perform numerical benchmarks to assess their accuracy and robustness. The article concludes with recommendations
for the choice of one formulation over the other. 相似文献
126.
127.
This paper presents a flexible thin-film (FTF) composed by a photovoltaic (PV) cell, a flexible solid-state rechargeable battery and power management electronics. A flexible printed circuit board (fPCB) was used for providing physical support to the electronics and to the battery, whereas a PDMS (polydimethylsiloxane) layer was used for providing mechanical adhesion between the PV cell and the fPCB. The high elasticity of the PDMS makes this material an excellent candidate for adapting two materials with different thermal expansions (fPCB and PV). The physical measurements showed a prototype with a thickness in the range 1.52 ± 0.10 mm, 10 g of weight and 37 × 114 mm of size. The electrical measurements showed ability to provide an output voltage of 3.8 V in a continuously form under these conditions: the PV providing DC power for solar irradiations higher than 6 W m−2, and the battery providing DC power for solar irradiations above bellow 6 W m−2 (value that has emerged during the twilight between sunset and dusk). 相似文献
128.
为解决国内桥梁检测车全局监控设备以及碰撞警报设备缺乏的问题,设计并实现了基于Android平台的一套智能监控系统。该系统通过倾角传感器采集的数据,用3D模型实时模拟机械臂的姿态,以达到全局监控的目的。同时可以根据实际情况构建虚拟障碍物,实现机械臂与障碍物碰撞的逼真模拟与警报。结果表明,该系统性能可靠、实用性强,不但解决了传统视频监控无法达到全局监控的问题,还对人工规避障碍物提供了可靠的参考。 相似文献
129.
行人交通微观仿真中碰撞检测模型研究 总被引:1,自引:0,他引:1
结合行人交通的特征和计算机仿真的实际需要,构建出一个新的适用于行人交通微观仿真的碰撞检测模型,该模型以经典的包围盒法为基本思路,分解出"交叉"和"同道"2类行人碰撞类型,并构建出了相应的阈值算法。该模型在实际应用中能较好地解决行人微观仿真中行人交叠的问题,使仿真效果更加贴近实际。 相似文献
130.
Machine loading problem in a flexible manufacturing system (FMS) encompasses various types of flexibility aspects pertaining to part selection and operation assignments. The evolution of flexible manufacturing systems offers great potential for increasing flexibility by ensuring both cost-effectiveness and customized manufacturing at the same time. This paper proposes a linear mathematical programming model with both continuous and zero-one variables for job selection and operation allocation problems in an FMS to maximize profitability and utilization of system. The proposed model assigns operations to different machines considering capacity of machines, batch-sizes, processing time of operations, machine costs, tool requirements, and capacity of tool magazine. A genetic algorithm (GA) is then proposed to solve the formulated problem. Performance of the proposed GA is evaluated based on some benchmark problems adopted from the literature. A statistical test is conducted which implies that the proposed algorithm is robust in finding near-optimal solutions. Comparison of the results with those published in the literature indicates supremacy of the solutions obtained by the proposed algorithm for attempted model. 相似文献