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11.
使用扩展逻辑效力的逻辑路径尺寸优化方法 总被引:1,自引:0,他引:1
为解决集成电路物理设计中考虑互连线影响的逻辑路径延迟优化问题,提出一个计入互连线负载的扩展的逻辑效力(ELE),并针对ELE给出一个可同时优化逻辑路径中各个逻辑门尺寸及各段互连线长度的优化流程.ELE在保留原有逻辑效力参数的同时,使用互连寄生参数提取软件获得的Ⅱ型互连线参数,实现对带有互连线负载的逻辑门的传播延迟的描述和估计;逻辑路径优化流程采用效力延迟分配策略作为初始条件来表示各段互连线负载对总效力延迟的影响,将所用目标单元库和制造工艺的物理尺寸信息作为限制条件,以ELE表达式为核心展开优化计算,辅以动态规划办法,无需迭代运算,仅通过一轮计算即可求得全部结果.实验结果表明,该流程计算任务简单,资源耗费少,可以准确、快速地获得所需的逻辑门尺寸和互连线长度;结果清晰合理,与目标单元库和工艺库完全兼容. 相似文献
12.
基于单片机的在线颗粒分析仪智能控制系统设计 总被引:1,自引:0,他引:1
针对国内粉末生产过程中粒度分布检验的滞后性,提出了在线颗粒分析仪智能控制系统设计。通过控制采样速度和喂料速度实现样品的在线分析,并实现分析数据的实时采集和传输,实现在线监控。实验结果表明,该系统测试范围达到4-300μm,可持续工作8小时,延时小于1分钟,测试准确度,重复性均达到在线控制的需要。 相似文献
13.
The urgent need to meet increasingly tight environmental regulations and new fuel economy requirements has motivated system science researchers and automotive engineers to take advantage of emerging computational techniques to further advance hybrid electric vehicle and plug-in hybrid electric vehicle (PHEV) designs. In particular, research has focused on vehicle powertrain system design optimization, to reduce the fuel consumption and total energy cost while improving the vehicle's driving performance. In this work, two different natural optimization machines, namely the synchronous self-learning Pareto strategy and the elitism non-dominated sorting genetic algorithm, are implemented for component sizing of a specific power-split PHEV platform with a Toyota plug-in Prius as the baseline vehicle. To do this, a high-fidelity model of the Toyota plug-in Prius is employed for the numerical experiments using the Autonomie simulation software. Based on the simulation results, it is demonstrated that Pareto-based algorithms can successfully optimize the design parameters of the vehicle powertrain. 相似文献
14.
This paper studies a generalization of the order acceptance and scheduling problem in a single-machine environment where a pool consisting of firm planned orders as well as potential orders is available from which an over-demanded company can select. The capacity available for processing the accepted orders is limited and each order is characterized by a known processing time, delivery date, revenue and a weight representing a penalty per unit-time delay beyond the delivery date. We prove that the existence of a constant-factor approximation algorithm for this problem is unlikely. We propose two linear formulations that are solved using an IP solver and we devise two exact branch-and-bound procedures able to solve instances with up to 50 jobs within reasonable CPU times. We compare the efficiency and quality of the results obtained using the different solution approaches. 相似文献
15.
16.
Janusz Sokó? 《Computers & Mathematics with Applications》2011,62(2):611-619
This paper presents a new class of functions analytic in the open unit disc, and closely related to the class of starlike functions. Besides being an introduction to this field, it provides an interesting connections defined class with well known classes. The paper deals with several ideas and techniques used in geometric function theory. The order of starlikeness in the class of convex functions of negative order is also considered here. 相似文献
17.
Florian Sahling Lisbeth Buschkühl Horst Tempelmeier Stefan Helber 《Computers & Operations Research》2009
This paper presents a new algorithm for the dynamic multi-level capacitated lot sizing problem with setup carry-overs (MLCLSP-L). The MLCLSP-L is a big-bucket model that allows the production of any number of products within a period, but it incorporates partial sequencing of the production orders in the sense that the first and the last products produced in a period are determined by the model. We solve a model which is applicable to general bill-of-material structures and which includes minimum lead times of one period and multi-period setup carry-overs. Our algorithm solves a series of mixed-integer linear programs in an iterative so-called fix-and-optimize approach. In each instance of these mixed-integer linear programs a large number of binary setup variables is fixed whereas only a small subset of these variables is optimized, together with the complete set of the inventory and lot size variables. A numerical study shows that the algorithm provides high-quality results and that the computational effort is moderate. 相似文献
18.
An optimal algorithm based on branch-and-bound approach is presented in this paper to determine lot sizes for a single item in material requirement planning environments with deterministic time-phased demand and constant ordering cost with zero lead time, where all-units discounts are available from vendors and backlog is not permitted. On the basis of the proven properties of optimal order policy, a tree-search procedure is presented to construct the sequence of optimal orders. Some useful fathom rules have been proven, which make the algorithm very efficient. To compare the performance of this algorithm with the other existing optimal algorithms, an experimental design with various environments has been developed. Experimental results show that the performance of our optimal algorithm is much better than the performance of other existing optimal algorithms. Considering computational time as the performance measure, this algorithm is considered the best among the existing optimal algorithms for real problems with large dimensions (i.e. large number of periods and discount levels). 相似文献
19.
This paper focuses on the performance evaluation of complex man-made systems, such as assembly lines, electric power grid,
traffic systems, and various paper processing bureaucracies, etc. For such problems, applying the traditional optimization
tool of mathematical programming and gradient descent procedures of continuous variables optimization are often inappropriate
or infeasible, as the design variables are usually discrete and the accurate evaluation of the system performance via a simulation
model can take too much calculation. General search type and heuristic methods are the only two methods to tackle the problems.
However, the “goodness” of heuristic methods is generally difficult to quantify while search methods often involve extensive
evaluation of systems at many design choices in a large search space using a simulation model resulting in an infeasible computation
burden. The purpose of this paper is to address these difficulties simultaneously by extending the recently developed methodology
of Ordinal Optimization (OO). Uniform samples are taken out from the whole search space and evaluated with a crude but computationally
easy model when applying OO. And, we argue, after ordering via the crude performance estimates, that the lined-up uniform
samples can be seen as an approximate ruler. By comparing the heuristic design with such a ruler, we can quantify the heuristic
design, just as we measure the length of an object with a ruler. In a previous paper we showed how to quantify a heuristic
design for a special case but we did not have the OO ruler idea at that time. In this paper we propose the OO ruler idea and
extend the quantifying method to the general case and the multiple independent results case. Experimental results of applying
the ruler are also given to illustrate the utility of this approach.
Zhen Shen received the B.E. degree from Department of Automation, Tsinghua University, Beijing, China in 2004. Currently, he is a Ph.D. candidate of Center for Intelligent and Networked Systems (CFINS), Department of Automation, Tsinghua University. He was a Visiting Scholar from Oct. 2007 to Apr. 2008 at Department of Manufacturing Engineering and Center for Information and Systems Engineering, Boston University, MA, USA. He specializes in the area of the discrete event dynamic systems (DEDS) theory and applications, and the optimization of complex systems. He is a student member of IEEE. Yu-Chi Ho received his S.B. and S.M. degrees in Electrical Engineering from M.I.T. and his Ph.D. in Applied Mathematics from Harvard University. Except for three years of full time industrial work he has been on the Harvard faculty. Since 1969 he has been Gordon McKay Professor of Engineering and Applied Mathematics. In 1988, he was appointed to the T. Jefferson Coolidge Chair in Applied Mathematics and Gordon McKay Professor of Systems Engineering at Harvard and as visiting professor to the Cockrell Family Regent’s Chair in Engineering at the University of Texas, Austin. In 2001, he retired from teaching duties at Harvard and became a Research Professor (2001–2006) and also was appointed to be a chair professor and chief scientist (part time), at the Center for Intelligent and Networked Systems (CFINS), Department of Automation, Tsinghua University, Beijing China. Qian-Chuan Zhao received the B.E. degree in automatic control in July 1992, the B.S. degree in applied mathematics in July 1992, and the Ph.D. degree in control theory and its applications in July 1996, all from Tsinghua University, Beijing, China. He is currently a Professor and Associate Director of the Center for Intelligent and Networked Systems (CFINS), Department of Automation, Tsinghua University. He was a Visiting Scholar at Carnegie Mellon University, Pittsburgh, PA, and Harvard University, Cambridge, MA, in 2000 and 2002, respectively. He was a Visiting Professor at Cornell University, Ithaca, NY, in 2006. His research interests include discrete event dynamic systems (DEDS) theory and applications, optimization of complex systems, and wireless sensor networks. Dr. Zhao is an associate editor for the Journal of Optimization Theory and Applications. 相似文献
Zhen ShenEmail: |
Zhen Shen received the B.E. degree from Department of Automation, Tsinghua University, Beijing, China in 2004. Currently, he is a Ph.D. candidate of Center for Intelligent and Networked Systems (CFINS), Department of Automation, Tsinghua University. He was a Visiting Scholar from Oct. 2007 to Apr. 2008 at Department of Manufacturing Engineering and Center for Information and Systems Engineering, Boston University, MA, USA. He specializes in the area of the discrete event dynamic systems (DEDS) theory and applications, and the optimization of complex systems. He is a student member of IEEE. Yu-Chi Ho received his S.B. and S.M. degrees in Electrical Engineering from M.I.T. and his Ph.D. in Applied Mathematics from Harvard University. Except for three years of full time industrial work he has been on the Harvard faculty. Since 1969 he has been Gordon McKay Professor of Engineering and Applied Mathematics. In 1988, he was appointed to the T. Jefferson Coolidge Chair in Applied Mathematics and Gordon McKay Professor of Systems Engineering at Harvard and as visiting professor to the Cockrell Family Regent’s Chair in Engineering at the University of Texas, Austin. In 2001, he retired from teaching duties at Harvard and became a Research Professor (2001–2006) and also was appointed to be a chair professor and chief scientist (part time), at the Center for Intelligent and Networked Systems (CFINS), Department of Automation, Tsinghua University, Beijing China. Qian-Chuan Zhao received the B.E. degree in automatic control in July 1992, the B.S. degree in applied mathematics in July 1992, and the Ph.D. degree in control theory and its applications in July 1996, all from Tsinghua University, Beijing, China. He is currently a Professor and Associate Director of the Center for Intelligent and Networked Systems (CFINS), Department of Automation, Tsinghua University. He was a Visiting Scholar at Carnegie Mellon University, Pittsburgh, PA, and Harvard University, Cambridge, MA, in 2000 and 2002, respectively. He was a Visiting Professor at Cornell University, Ithaca, NY, in 2006. His research interests include discrete event dynamic systems (DEDS) theory and applications, optimization of complex systems, and wireless sensor networks. Dr. Zhao is an associate editor for the Journal of Optimization Theory and Applications. 相似文献
20.
Shine-Der Lee Chin-Ming Yang Shu-Chuan Lan 《International journal of systems science》2016,47(5):1142-1154
An extended economic production quantity model that copes with random demand is developed in this paper. A unique feature of the proposed study is the consideration of transient shortage during the production stage, which has not been explicitly analysed in existing literature. The considered costs include set-up cost for the batch production, inventory carrying cost during the production and depletion stages in one replenishment cycle, and shortage cost when demand cannot be satisfied from the shop floor immediately. Based on renewal reward process, a per-unit-time expected cost model is developed and analysed. Under some mild condition, it can be shown that the approximate cost function is convex. Computational experiments have demonstrated that the average reduction in total cost is significant when the proposed lot sizing policy is compared with those with deterministic demand. 相似文献