We describe a constrained shortest path first (CSPF) routing algorithm for lambda-switched optical networks with logical overlay OCh/SP rings. Speed is definitely a requirement if the algorithm is to be used for lambd...
详细信息
ISBN:
(纸本)0780367111
We describe a constrained shortest path first (CSPF) routing algorithm for lambda-switched optical networks with logical overlay OCh/SP rings. Speed is definitely a requirement if the algorithm is to be used for lambda-switching, but several features of the network architecture complicate the routing problem. The algorithm we present in this paper meets the requirement of being fast. Moreover, the routing of a lightpath is based on a limited amount of link state information, which can be disseminated by a lightweight routing protocol. Our numerical results show that the performance of the algorithm does not improve significantly if the routing decisions are based on more detailed information about the configuration of the network.
In a trench-first-via-last (TFVL) dual-inlaid metal process, the thickness of resist coated in the via definition step after trench formation varies according to underlying trench topography. Variation in resist thick...
详细信息
ISBN:
(纸本)0780366786
In a trench-first-via-last (TFVL) dual-inlaid metal process, the thickness of resist coated in the via definition step after trench formation varies according to underlying trench topography. Variation in resist thickness reduces via size uniformity and thus process window. Based on the modeling of resist thickness at a via location as a weighted sum of nearby trench densities, layout modifications of proximity dummy feature placement and selective via sizing are introduced to increase via size uniformity. Experimental results show significantly enlarged process window after proximity dummy features are inserted.
In this paper we propose variable voltage task scheduling algorithms (periodic as well as aperiodic) that minimize energy. We first apply the existing task scheduling algorithms to obtain a feasible schedule and then ...
详细信息
In this paper we propose variable voltage task scheduling algorithms (periodic as well as aperiodic) that minimize energy. We first apply the existing task scheduling algorithms to obtain a feasible schedule and then distribute the available slack using an iterative algorithm that satisfies the theoretically obtained relation for minimum energy. We show experimentally that the voltage assignment obtained by our algorithm is very close (0.1% error) to that of the optimal assignment.
This paper presents a new multi-criteria decision model for the material handling device (MHD) selection problem in cellular manufacturing systems. Given a set of manufacturing cells based on several automatic work-ce...
详细信息
This paper presents a physically based model and formulation for industrial load management. The formulation utilizes integer linear programming techniques for minimizing electricity costs by scheduling the loads sati...
详细信息
This paper presents a physically based model and formulation for industrial load management. The formulation utilizes integer linear programming techniques for minimizing electricity costs by scheduling the loads satisfying the process, storage, and production constraints. The proposed strategy is evaluated by a case study for a typical flour mill with different load management options. The results show that significant reductions in peak electricity consumption are possible under time of use tariffs.
A novel technique, CLIP, is presented for the automatic generation of optimal layouts of CMOS cells in the two-dimensional (2D) style. CLIP is based on integer-linearprogramming (ILP) and solves both the width and he...
详细信息
A novel technique, CLIP, is presented for the automatic generation of optimal layouts of CMOS cells in the two-dimensional (2D) style. CLIP is based on integer-linearprogramming (ILP) and solves both the width and height minimization problems for 2D cells. Width minimization is formulated in a precise form that combines all factors influencing the 2D cell width-transistor placement, diffusion sharing, and vertical interrow connections-in a common problem space;this space is then searched in a systematic manner by the branch-and-bound algorithms used by ILP solvers. For height minimization, cell height is modeled accurately in terms of the horizontal wire routing density, and a minimum-height layout is found from among all layouts of minimum width. For exact width minimization alone, CLIP's run times are in seconds for large circuits with 30 or more transistors. For both height and width optimization, CLIP is practical for circuits with up to 20 transistors. To extend CLIP to larger circuits, hierarchical methods are necessary. Since CLIP is optimum under the modeling assumptions, its layouts are significantly better than those generated by other, heuristic, layout tools.
Finding maximum a posteriori (MAP) solutions from noisy images based on a prior Markov random field (MRF) model is a huge computational task. In this paper, we transform the computational problem into an integer linea...
详细信息
Finding maximum a posteriori (MAP) solutions from noisy images based on a prior Markov random field (MRF) model is a huge computational task. In this paper, we transform the computational problem into an integer linear programming (ILP) problem. We explore the use of Lagrange relaxation (LR) methods for solving the MAP problem. In particular, three different algorithms based on LR are presented. All the methods are competitive alternatives to the commonly used simulation-based algorithms based on Markov Chain Monte Carlo techniques. In all the examples (including bothsimulated and real images) that have been tested, the best method essentially finds a MAP solution in a small number of iterations. In addition, LR methods provide lower and upper bounds for the posterior, which makes it possible to evaluate the quality of solutions and to construct a stopping criterion for the algorithm. Although additive Gaussian noise models have been applied, any additive noise model fit into the framework.
In this paper an optimal maintenance scheduling of generating units in a pouter system has been developed with transmission network representation. Here a DC load flow has been embedded in the maintenance model to inc...
详细信息
In this paper an optimal maintenance scheduling of generating units in a pouter system has been developed with transmission network representation. Here a DC load flow has been embedded in the maintenance model to include network constraints resulting in a more practical maintenance schedule. The model developed here uses the minimization of system cost (production cost plus the unserved energy cost) as the objective criterion, whereas the reliability objective function used is the minimization of unserved energy. The optimization is achieved by integer linear programming. The incorporation of transmission network adds significant complexity to maintenance scheduling. The proposed model enables almost all practical maintenance scheduling constraints to be handled easily. The optimization has been carried out to minimize the cost function considering different cases (i.e., with and without incorporation of the transmission network). The effectiveness of the proposed method has been. demonstrated by obtaining numerical results on sample and real scale test systems. A comparison of the cost objective function clearly indicates that the maintenance schedule obtained from the simple generation model alone is more expensive than the one with transmission, and that there is a considerable degree of suboptimality in the former case.
Fighter aircraft protect specific facilities on alert in the air by patrolling expectation zones. These zones are located in the direction from which enemy aircraft attacks are expected;fighter formations are sent fro...
详细信息
Fighter aircraft protect specific facilities on alert in the air by patrolling expectation zones. These zones are located in the direction from which enemy aircraft attacks are expected;fighter formations are sent from them to intercept enemy aircraft. The problem considered in this paper is to determine the optimum assignment of fighter plane formations to enemy formations. The proposed solution is based on fuzzy logic and integer linear programming. A numerical example is given to illustrate the application possibilities of the proposed solution.
The paper deals with the problem of DNA (deoxyribonucleic acid) sequencing by hybridization. A computational phase of this approach, i.e. a construction of a DNA sequence from oligonucleotides, is NP-hard in the stron...
详细信息
The paper deals with the problem of DNA (deoxyribonucleic acid) sequencing by hybridization. A computational phase of this approach, i.e. a construction of a DNA sequence from oligonucleotides, is NP-hard in the strong sense in case of errors. Thus, since the last problem does not admit a polynomial time solution, a need arises to construct efficient heuristics solving the problem. In the paper, such a heuristic algorithm based on tabu search is proposed. Computational tests have proved its low complexity and high accuracy for both types of errors: false negatives and false positives. (C) 2000 Elsevier Science B.V. All rights reserved.
暂无评论