Future space exploration will likely include teams of autonomous robots that perform various tasks in order to minimize human risk and maximize mission efficiency. In this paper we explore cooperative manipulation of ...
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In the paper the authors present a messy geneticalgorithm-based optimization scheme for voltage stability enhancement of power systems under critical operation conditions. The placement of SVCs in a power system has b...
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Port management is a strategic issue for the developing economies. Its activities directly influence the trade volume of the region where the port is located, increase the investment in the region, and contribute to t...
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The optimal design of multidisciplinary systems under uncertainty involves three types of iterative analyses- multidisciplinary analyses, reliability analyses, and optimization. If these processes are carried out in a...
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The demand for wireless networks continues to grow as the need for portable, low-cost telecommunications systems increases around the world. Wireless networks are particularly complex because their topologies can chan...
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The demand for wireless networks continues to grow as the need for portable, low-cost telecommunications systems increases around the world. Wireless networks are particularly complex because their topologies can change in response to operational requirements or environmental conditions and also because wireless networks are susceptible to electromagnetic interference. In this thesis, we consider the challenges associated with the operation and jamming of so-called "wireless mesh networks." In a wireless mesh network, the communication devices (denoted here as a nodes) are uniform in their ability to send and receive transmissions. We formulate and solve two related optimization problems for wireless mesh networks. First, we solve the problem of the network operator, namely: In order to maximize the utility of delivered network traffic, how should one set the power transmission levels for each node, and along what sequence of transmission links should the traffic flow? The second problem we consider involves an intelligent adversary, the attacker, who wants to place jamming devices among a finite number of locations to disrupt the operator's traffic in the worst possible way. We formulate and solve mathematical programs to obtain the optimal operation and jamming of these networks. We develop a computational decision-support tool that affords the rapid reconfiguration and analysis of various deployment scenarios.
Technology scaling has not only magnified the effects of device process variations, but it has also precipitated the need for simultaneous optimization of several performance metrics. In this paper, we propose a novel...
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ISBN:
(纸本)9781595939999
Technology scaling has not only magnified the effects of device process variations, but it has also precipitated the need for simultaneous optimization of several performance metrics. In this paper, we propose a novel gate sizing approach for multi-metric optimization of delay, power, and crosstalk noise. The algorithm is based on the concepts of mathematical programming, and models the process variation uncertainty considering spatial correlations. The approach identifies leakage power, dynamic power, and crosstalk noise as the objectives, and the optimized gate delays are kept as constraints. Initially, the deterministic upper and lower bounds of the objectives are identified, and during the final step, a crisp non-linear programming problem is formulated using these boundary values. The problem is solved using KNITRO, an interior-point based optimization solver. The proposed model maximizes the variation resistance, thus providing higher yield. ITC'99 benchmarks were used to test the proposed approach, and the results indicate that our algorithm identifies the solution points that are closest to the nominal bounds, while maintaining high timing yield. Copyright 2008 ACM.
In this paper we describe a trajectory optimization algorithm that generates a second order control update. This algorithm differs from previous trajectory optimization al-gorithms in that the control update is nonlin...
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ISBN:
(纸本)9780877035442
In this paper we describe a trajectory optimization algorithm that generates a second order control update. This algorithm differs from previous trajectory optimization al-gorithms in that the control update is nonlinear and that each constraint is modeled and met to the second order. The algorithm was designed around the idea of main-taining candidate solutions within the feasible defined problem set. We describe and test various implementations and also describe the limitations of the algorithm.
In this paper we present a strategy for tuning the crystal morphology of pharmaceutical compounds by the appropriate choice of solvent via an optimization model. A three-stage approach involving a pre-design stage, a ...
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In this paper we present a strategy for tuning the crystal morphology of pharmaceutical compounds by the appropriate choice of solvent via an optimization model. A three-stage approach involving a pre-design stage, a product design stage and a post-design experimental verification stage is presented. The pre-design stage addresses the tormulation of the property constraint tor crystal morphology. This involves crystallization experiments aria development of property models and constraints for morphology. In the design stage various property requirements for the solvent along with crystal morphology are considered and the product design problem is formulated as a mixed integer nonlinear programming *** design stage provides an optimal solvent/list of candidate solvents. Similar to the pre-design stage, in the post design experimental verification stage, the morphology of the crystals （precipitated from the designed solvent） is verified through crystallization experiments followed by product characterization via scanni＇ng electron microscopy, powder X-ray diffraction imaging and Fourier transform spectra analysis.
A one-dimensional pseudo-homogeneous model is used for simulation and subsequent optimization of a MPBR. The reactive system chosen for the present study is Finlayson extended o-xylene oxidation to phthalic anhydride ...
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ISBN:
(纸本)9780816910502
A one-dimensional pseudo-homogeneous model is used for simulation and subsequent optimization of a MPBR. The reactive system chosen for the present study is Finlayson extended o-xylene oxidation to phthalic anhydride production in the presence of undesired side reactions. The case study is actually taken from Froment and Bischoff and in the present article the optimal design and operation of the reactor is searched upon. All programmed simulations and optimizations were achieved by means of Wolfram Mathematica 6.0®. As is usual for the present case, sensitivity analyses are done for o-xylene inlet concentration (molar fraction) and reactor inlet temperature. The problem for optimization with differential equation constraints is also discussed and several objective functions, technical and economical ones, are maximized.
Optimization of the firm-level asset-liability model (ALM) is an important part of enterprise risk management. In the context of the property-liability insurer we increase the credibility of the ALM by explicitly unif...
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Optimization of the firm-level asset-liability model (ALM) is an important part of enterprise risk management. In the context of the property-liability insurer we increase the credibility of the ALM by explicitly unifying the efficient management of financial risk factors across both sides of the economic balance sheet. The ALM presented in this research produces a simultaneous solution to the Markowitz mean-variance (MV) allocation of asset- and liability-side resources within a complex hierarchical goal environment. The nonlinear optimization method applied to the dual MV problem that is defined within the overall ALM is a separable program that encapsulates a vector optimized goal-program (NLGP). In addition to the identification of efficient combinations of traded assets and not-traded liabilities within a complex goal environment, the NLGP ALM also proves suitable for the extant characterization of credit, liquidity, and profit margin objectives.
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