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Optimization

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Articles 571 - 600 of 656

Full-Text Articles in Physical Sciences and Mathematics

Optimization Of Control Source And Error Sensor Locations In Free Field Active Noise Control, Connor Raymond Duke Aug 2007

Optimization Of Control Source And Error Sensor Locations In Free Field Active Noise Control, Connor Raymond Duke

Theses and Dissertations

Previous work has shown that active noise control (ANC) can be applied to axial cooling fans. Optimization of the control source and error sensor placement is desired to maximize the attenuation using ANC. A genetic algorithm was developed to find the optimal placement of control sources for a given primary source. The optimal configuration of control sources around a single primary source was shown to be a linear arrangement of the sources. This holds true for both two-dimensional as well as three-dimensional configurations. The higher-order radiation of the linear arrangement has also been verified experimentally, but the improvement in the …


Discrete Algorithms For Analysis Of Genotype Data, Dumitru Brinza Jun 2007

Discrete Algorithms For Analysis Of Genotype Data, Dumitru Brinza

Computer Science Dissertations

Accessibility of high-throughput genotyping technology makes possible genome-wide association studies for common complex diseases. When dealing with common diseases, it is necessary to search and analyze multiple independent causes resulted from interactions of multiple genes scattered over the entire genome. The optimization formulations for searching disease-associated risk/resistant factors and predicting disease susceptibility for given case-control study have been introduced. Several discrete methods for disease association search exploiting greedy strategy and topological properties of case-control studies have been developed. New disease susceptibility prediction methods based on the developed search methods have been validated on datasets from case-control studies for several common …


The Relationship Between Discrete Vector Quantization And The P-Median Problem, Allen G. Holder, G Lim, J Reese Feb 2007

The Relationship Between Discrete Vector Quantization And The P-Median Problem, Allen G. Holder, G Lim, J Reese

Mathematics Faculty Research

We show that a well studied problem in the engineering community is the same as a problem studied by mathematical combinatorialists. Specifically, we show that the question of optimally designing a vector quantizer, which is an important problem in coding theory, is the same as the p-median problem, which is a classic graph theory problem with important applications in operations research. The importance of the relationship lies in the fact that both communities have spent years developing solution methodologies, and this connection permits each community to glean new ideas from the other. We show that two of the most popular …


Some Geometrical Aspects Of The Cone Linear Complementarity Problem., Madhur Malik Dr. Jan 2007

Some Geometrical Aspects Of The Cone Linear Complementarity Problem., Madhur Malik Dr.

Doctoral Theses

Cone Linear Complementarity ProblemLet V be a finite dimensional real inner product space and K be a closed convex cone in V. Given a linear transformation L : V → V and a vector q ∈ V the cone linear complementarity problem or linear complementarity problem over K, denoted as LCP(K, L, q), is to find a vector x ∈ K such thatL(x) + q ∈ K+ and hx, L(x) + qi = 0,where h., .i denotes an inner product on V and K is the dual cone of K defined as:K∗ := {y ∈ V : hx, yi ≥ …


Synthesis And Optimization Of Fluorine-Free Y And Cu Precursor Solution For Mod Processing Of Ybco Coated Conductor, Jaimoo Yoo, Young-Kuk Kim, Kookchae Chung, Jaewoong Ko, Xiaolin Wang, S X. Dou Jan 2007

Synthesis And Optimization Of Fluorine-Free Y And Cu Precursor Solution For Mod Processing Of Ybco Coated Conductor, Jaimoo Yoo, Young-Kuk Kim, Kookchae Chung, Jaewoong Ko, Xiaolin Wang, S X. Dou

Australian Institute for Innovative Materials - Papers

MOD solutions for YBCO coated conductors were synthesized with fluorine-free Y & Cu precursor. The fluorine content in the precursor solution was significantly reduced and a fast calcination profile was realized. A crack-free & thick precursor film was successfully obtained just after less than 2 hours of calcination in wet O2 atmosphere. Optimization of the precursor solution with Sm addition enables further improvement of thickness and uniformity of precursor films. The calcinated precursor film was successfully converted to dense and uniform YBCO film after annealing in wet Ar/O2 atmosphere. The measured critical current value was about 273 A/cm-w …


Validating Pareto Optimal Operation Parameters Of Polyp Detection Algorithms For Ct Colonography, Jiang Li, Adam Huang, Nicholas Petrick, Jianhua Yao, Ronald M. Summers, Maryellen L. Giger (Ed.), Nico Karssemeijer (Ed.) Jan 2007

Validating Pareto Optimal Operation Parameters Of Polyp Detection Algorithms For Ct Colonography, Jiang Li, Adam Huang, Nicholas Petrick, Jianhua Yao, Ronald M. Summers, Maryellen L. Giger (Ed.), Nico Karssemeijer (Ed.)

Electrical & Computer Engineering Faculty Publications

We evaluated a Pareto front-based multi-objective evolutionary algorithm for optimizing our CT colonography (CTC) computer-aided detection (CAD) system. The system identifies colonic polyps based on curvature and volumetric based features, where a set of thresholds for these features was optimized by the evolutionary algorithm. We utilized a two-fold cross-validation (CV) method to test if the optimized thresholds can be generalized to new data sets. We performed the CV method on 133 patients; each patient had a prone and a supine scan. There were 103 colonoscopically confirmed polyps resulting in 188 positive detections in CTC reading from either the prone or …


Cad Tools For Dna Micro-Array Design, Manufacture And Application, Nisar Hundewale Dec 2006

Cad Tools For Dna Micro-Array Design, Manufacture And Application, Nisar Hundewale

Computer Science Dissertations

Motivation: As the human genome project progresses and some microbial and eukaryotic genomes are recognized, numerous biotechnological processes have attracted increasing number of biologists, bioengineers and computer scientists recently. Biotechnological processes profoundly involve production and analysis of highthroughput experimental data. Numerous sequence libraries of DNA and protein structures of a large number of micro-organisms and a variety of other databases related to biology and chemistry are available. For example, microarray technology, a novel biotechnology, promises to monitor the whole genome at once, so that researchers can study the whole genome on the global level and have a better picture of …


No Free Lunch, Bayesian Inference, And Utility: A Decision-Theoretic Approach To Optimization, Christopher Kenneth Monson Apr 2006

No Free Lunch, Bayesian Inference, And Utility: A Decision-Theoretic Approach To Optimization, Christopher Kenneth Monson

Theses and Dissertations

Existing approaches to continuous optimization are essentially mechanisms for deciding which locations should be sampled in order to obtain information about a target function's global optimum. These methods, while often effective in particular domains, generally base their decisions on heuristics developed in consideration of ill-defined desiderata rather than on explicitly defined goals or models of the available information that may be used to achieve them. The problem of numerical optimization is essentially one of deciding what information to gather, then using that information to infer the location of the global optimum. That being the case, it makes sense to model …


Post Register Allocation Spill Code Optimization, Christopher Lupo, Kent Wilken Mar 2006

Post Register Allocation Spill Code Optimization, Christopher Lupo, Kent Wilken

Computer Science and Software Engineering

A highly optimized register allocator should provide an efficient placement of save/restore code for procedures that contain calls. This paper presents a new approach to placing callee-saved save and restore instructions that generalizes Chow's shrink-wrapping technique (Chow 1988). An efficient, profile-guided, hierarchical spill code placement algorithm is used to analyze the structure of a procedure to calculate the minimum dynamic execution count locations to place callee-saved save and restore code. The algorithm is implemented in the Gnu Compiler Collection and has been tested on the SPEC CPU2000 Integer Benchmark suite. Results show that the technique reduces the number of dynamic …


The Structure Of Flux Transfer Events Recovered From Cluster Data, H Hasegawa, B U. Ö Sonnerup, C J. Owen, B Klecker, G Paschmann, A Balogh, H Re`Me Mar 2006

The Structure Of Flux Transfer Events Recovered From Cluster Data, H Hasegawa, B U. Ö Sonnerup, C J. Owen, B Klecker, G Paschmann, A Balogh, H Re`Me

Dartmouth Scholarship

The structure and formation mechanism of a to- tal of five Flux Transfer Events (FTEs), encountered on the equatorward side of the northern cusp by the Cluster space- craft, with separation of ∼5000 km, are studied by apply- ing the Grad-Shafranov (GS) reconstruction technique to the events. The technique generates a magnetic field/plasma map of the FTE cross section, using combined magnetic field and plasma data from all four spacecraft, under the assump- tion that the structure is two-dimensional (2-D) and time- independent. The reconstructed FTEs consist of one or more magnetic flux ropes embedded in the magnetopause, suggest- ing …


Doppler-Only Multistatic Radar, Dustin G. Mixon Mar 2006

Doppler-Only Multistatic Radar, Dustin G. Mixon

Theses and Dissertations

In order to estimate the position and velocity of a target, most multistatic radar systems require multiple independent target measurements, such as angle-of-arrival, time-of-arrival, and Doppler information. Though inexpensive and reliable, Doppler-only systems have not been widely implemented due to the inherent nonlinear problem of determining a target’s position and velocity from their measurements. We solve this problem. In particular, we first establish the lack of observability in the Doppler-only bistatic system, thereby demonstrating the need for multiple transmitters and/or receivers. Next, for a multistatic system with a sufficient number of transmitter-receiver pairs, we invoke classical optimization techniques, such as …


Optimization Of Query Processing Through Constrained Vertical Partitioning Of Relational Tables, Zhenjie Liu, Janusz R. Getta Jan 2006

Optimization Of Query Processing Through Constrained Vertical Partitioning Of Relational Tables, Zhenjie Liu, Janusz R. Getta

Faculty of Informatics - Papers (Archive)

Vertical partitioning is an effective way of improving performance in the database systems where a significant percentage of query processing time is spent on the full scans of relational tables. Vertical partitioning provides even more compelling performance gains when it is combined with the controlled replication of data in the environments where the processing of queries dominates the data manipulations. This paper proposes a new algorithm that finds a suboptimal vertical partitioning of relational tables under a constraint that certain level of redundancies is acceptable in a database. TIle algorithm is based on a new cost model, which precisely estimates …


Solution Of A Certain Class Of Network Flow Problems With Cascaded Demand Aggregation And Capacity Allocation, Farzad Safaei, I. Ouveysi Jan 2006

Solution Of A Certain Class Of Network Flow Problems With Cascaded Demand Aggregation And Capacity Allocation, Farzad Safaei, I. Ouveysi

Faculty of Informatics - Papers (Archive)

This article develops analytical models for a class of networking problems that includes two cascaded stages of demand aggregation and capacity allocation. The solutions to these problems are required in real time as the demand fluctuates rapidly. The capacity allocation problem makes a large-scale integer programming problem too complex for practical applications. Using the Lagrangian relaxation technique and a suitably developed heuristic for multiplier adjustment, the computational complexity is reduced to such a degree that a real-time implementation of the algorithm is feasible. This article also develops efficient heuristics to aggregate demand. The proposed algorithm produces a near-optimal solution in …


An Efficient And Robust Computational Framework For Studying Lifetime And Information Capacity In Sensor Networks, Enrique J. Duarte-Melo, Mingyan Liu, Archan Misra Dec 2005

An Efficient And Robust Computational Framework For Studying Lifetime And Information Capacity In Sensor Networks, Enrique J. Duarte-Melo, Mingyan Liu, Archan Misra

Research Collection School Of Computing and Information Systems

In this paper we investigate the expected lifetime and information capacity, defined as the maximum amount of data (bits) transferred before the first sensor node death due to energy depletion, of a data-gathering wireless sensor network. We develop a fluid-flow based computational framework that extends the existing approach, which requires precise knowledge of the layout/deployment of the network, i.e., exact sensor positions. Our method, on the other hand, views a specific network deployment as a particular instance (sample path) from an underlying distribution of sensor node layouts and sensor data rates. To compute the expected information capacity under this distribution-based …


Spatial Sampling Design For Parameter Estimation Of The Covariance Function, Zhengyuan Zhu, Michael L. Stein Sep 2005

Spatial Sampling Design For Parameter Estimation Of The Covariance Function, Zhengyuan Zhu, Michael L. Stein

Zhengyuan Zhu

We study the spatial optimal sampling design for covariance parameter estimation. The spatial process is modeled as a Gaussian random field and maximum likelihood (ML) is used to estimate the covariance parameters. We use the log determinant of the inverse Fisher information matrix as the design criterion and run simulations to investigate the relationship between the inverse Fisher information matrix and the covariance matrix of the ML estimates. A simulated annealing algorithm is developed to search for an optimal design among all possible designs on a fine grid. Since the design criterion depends on the unknown parameters, we define relative …


Phase-Matching Optimization Of Laser High-Order Harmonics Generated In A Gas Cell, Julia Robin Miller Sutherland Jul 2005

Phase-Matching Optimization Of Laser High-Order Harmonics Generated In A Gas Cell, Julia Robin Miller Sutherland

Theses and Dissertations

Ten-millijoule, thirty-five femtosecond, 800 nm (~40 nm bandwidth) laser pulses are used to study high-order harmonic generation in helium- and neon-filled gas cells of various lengths. Harmonic orders in the range of 50 to 100 are investigated. A semi-infinite cell geometry produces brighter harmonics than cells of sub-centimeter length. In the semi-infinite geometry, the gas occupies the region from the focusing lens to a thin exit foil near the laser focus. Counter-propagating light is used to directly probe where the high harmonics are generated within the laser focus and to investigate phase matching. The phase matching under optimized harmonic generation …


Order Scheduling In Dedicated And Flexible Machine Environments, Haibing Li May 2005

Order Scheduling In Dedicated And Flexible Machine Environments, Haibing Li

Dissertations

Order scheduling models are relatively new in the field of scheduling. Consider a facility with m parallel machines that can process k different products (job types). Each machine can process a given subset of different product types. There are n orders from n different clients. Each order requests specific quantities of the various different products that can be produced concurrently on their given subsets of machines; it may have a release date, a weight and a due date. Preemptions may be allowed. An order can not be shipped until the processing of all the products for the order has been …


Optimizing Allocation Of Monitoring Effort Under Economic And Observational Constraints, Scott A. Field, Andrew J. Tyre, Hugh P. Possingham Jan 2005

Optimizing Allocation Of Monitoring Effort Under Economic And Observational Constraints, Scott A. Field, Andrew J. Tyre, Hugh P. Possingham

School of Natural Resources: Faculty Publications

Efforts to design monitoring regimes capable of detecting population trends can be thwarted by observational and economic constraints inherent to most biological surveys. Ensuring that limited resources are allocated efficiently requires evaluation of statistical power for alternative survey designs. We simulated the process of data collection on a landscape, where we initiated declines over 3 sample periods in species of varying prevalence and detectability. Changing occupancy levels were estimated using a technique that accounted for effects of false-negative errors on survey data. Declines were identified within a frequentist statistical framework, but the significance level was set at an optimal level …


On Optimizing Multi-Level Designs: Power Under Budget Constraints, Todd C. Headrick, Bruno D. Zumbo Jan 2005

On Optimizing Multi-Level Designs: Power Under Budget Constraints, Todd C. Headrick, Bruno D. Zumbo

Todd Christopher Headrick

This paper derives a procedure for efficiently allocating the number of units in multi-level designs given prespecified power levels. The derivation of the procedure is based on a constrained optimization problem that maximizes a general form of a ratio of expected mean squares subject to a budget constraint. The procedure makes use of variance component estimates to optimize designs during the budget formulating stages. The method provides more general closed form solutions than other currently available formulae. As such, the proposed procedure allows for the determination of the optimal numbers of units for studies that involve more complex designs. A …


A Tutorial On Radiation Oncology And Optimization, Allen G. Holder, Bill Salter Jan 2005

A Tutorial On Radiation Oncology And Optimization, Allen G. Holder, Bill Salter

Mathematics Faculty Research

Designing radiotherapy treatments is a complicated and important task that affects patient care, and modern delivery systems enable a physician more flexibility than can be considered. Consequently, treatment design is increasingly automated by techniques of optimization, and many of the advances in the design process are accomplished by a collaboration among medical physicists, radiation oncologists, and experts in optimization. This tutorial is meant to aid those with a background in optimization in learning about treatment design. Besides discussing several optimization models, we include a clinical perspective so that readers understand the clinical issues that are often ignored in the optimization …


Modeling Basketball Free Throws, Andrew Lang, Joerg M. Gablonsky Jan 2005

Modeling Basketball Free Throws, Andrew Lang, Joerg M. Gablonsky

College of Science and Engineering Faculty Research and Scholarship

This paper presents a mathematical model for basketball free throws. It is intended to be a supplement to an existing calculus course and could easily be used as a basis for a calculus project. Students will learn how to apply calculus to model an interesting real-world problem, from problem identification all the way through to interpretation and verification. Along the way we will introduce topics such as optimization (univariate and multiobjective), numerical methods, and differential equations.


Tournament Versus Fitness Uniform Selection, Shane Legg, Marcus Hutter, Akshat Kumar Jun 2004

Tournament Versus Fitness Uniform Selection, Shane Legg, Marcus Hutter, Akshat Kumar

Research Collection School Of Computing and Information Systems

In evolutionary algorithms a critical parameter that must be tuned is that of selection pressure. If it is set too low then the rate of convergence towards the optimum is likely to be slow. Alternatively if the selection pressure is set too high the system is likely to become stuck in a local optimum due to a loss of diversity in the population. The recent Fitness Uniform Selection Scheme (FUSS) is a conceptually simple but somewhat radical approach to addressing this problem - rather than biasing the selection towards higher fitness, FUSS biases selection towards sparsely populated fitness levels. In …


A Modeling Framework For Computing Lifetime And Information Capacity In Wireless Sensor Networks, Enrique Duarte-Melo, Mingyan Liu, Archan Misra Mar 2004

A Modeling Framework For Computing Lifetime And Information Capacity In Wireless Sensor Networks, Enrique Duarte-Melo, Mingyan Liu, Archan Misra

Research Collection School Of Computing and Information Systems

In this paper we investigate the expected lifetime and information capacity, defined as the maximum amount of data (bits) transferred before the first sensor node death due to energy depletion, of a data-gathering wireless sensor network. We develop a fluidflow based computational framework that extends the existing approach, which requires precise knowledge of the layout/deployment of the network, i.e., exact sensor positions. Our method, on the other hand, views a specific network deployment as a particular instance (sample path) from an underlying distribution of sensor node layouts and sensor data rates.


A Simple And Global Optimization Algorithm For Engineering Problems: Differential Evolution Algorithm, Dervi̇ş Karaboğa, Selçuk Ökdem Jan 2004

A Simple And Global Optimization Algorithm For Engineering Problems: Differential Evolution Algorithm, Dervi̇ş Karaboğa, Selçuk Ökdem

Turkish Journal of Electrical Engineering and Computer Sciences

Differential Evolution (DE) algorithm is a new heuristic approach mainly having three advantages; finding the true global minimum regardless of the initial parameter values, fast convergence, and using few control parameters. DE algorithm is a population based algorithm like genetic algorithms using similar operators; crossover, mutation and selection. In this work, we have compared the performance of DE algorithm to that of some other well known versions of genetic algorithms: PGA, Grefensstette, Eshelman. In simulation studies, De Jong's test functions have been used. From the simulation results, it was observed that the convergence speed of DE is significantly better than …


Haplotyping And Minimum Diversity Graphs, C Davis, Allen G. Holder Jul 2003

Haplotyping And Minimum Diversity Graphs, C Davis, Allen G. Holder

Mathematics Faculty Research

Haplotyping is the process of reconstructing the genetic information donated by a prior generation to form a current population. Haplotyping is important because it allows us to study how traits are passed from one generation to another, which in turn allows us to find genetic markers that describe a current population's susceptibility to diseases. Our goal is to study the underlying graph theory problem, and we study the bipartite graphs, called diversity graphs, that describe haplotyping. In particular, we investigate the problem of finding the minimum number of haplotypes that can reconstruct a population, called the Pure Parsimony problem. The …


Test Suite For Multiobjective Optimization And Results Using Normal Boundary Intersection (Nbi) In Design Explorer, Siva Kumar Natarajan May 2003

Test Suite For Multiobjective Optimization And Results Using Normal Boundary Intersection (Nbi) In Design Explorer, Siva Kumar Natarajan

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Several methods have been developed to solve multiobjective optimization problems (MOP's). One of these, Normal Boundary Intersection (NBI), is a method developed by John Dennis and Indraneel Das. NBI is used at The Boeing Company as a tool to solve MOP's. This report presents a test suite of MOP's that I developed for Boeing during me internship in summer 2003.

The problems in the test suite were chosen to represent the different types of multiobjective optimization problems that could arise in practice and the complexities involved in solving them. These problems range from those that have nice convex Pareto surfaces …


Computer Simulation And Homogenization In Heating Design Optimization, Daniel K. Balls May 2003

Computer Simulation And Homogenization In Heating Design Optimization, Daniel K. Balls

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The ability to ensure uniformity of temperature within a given finite physical region is an essential element in the success of many scientific processes, especially those that involve extreme fluctuation in temperature. Such a process is performed in an instrument called the LightTyper developed by Idaho Technology, Inc. of Salt Lake City Utah. This paper details the development and results of a scheme intended to obtain a heating design that ensures a high degree of temperature uniformity within the Idaho Technology instrument. Due to the experiments performed during this project, we were able to answer many questions that concerned finding …


On The Approximability Of Linear Ordering And Related Np-Optimization Problems., Sounaka Mishra Dr. Feb 2003

On The Approximability Of Linear Ordering And Related Np-Optimization Problems., Sounaka Mishra Dr.

Doctoral Theses

We investigate approximability of both maximum and minimum linear ordering problems (MAX-LOP and MIN-LOP) and several related problems such as the well known feedback set problems, acyclie subdigraph problem and several others and their variants.We show that both MAX-LOP and MIN-LOP are strongly NP-complete, and MIN- LOP, MIN-QAP(S) (a special case of minimum quadratic assignment problem) and MIN-W-FAS are equivalent with respect to strict-reduction. The strict-equivalence is also established among these problems as well as MIN-W-FVS, with weights on arcs/vertices bounded by a polynomial, and the unweighted versions of the feedback set. problems. We also show that MAX-LOP is strict-equivalent …


A Statistical Model Using Reference Evapotranspiration And Weather Data To Predict The Economic Optimal Irrigation Level For Corn Production In The Texas Panhandle, W. Arden Colette, Clay Robinson, Lal Khan Almas Apr 2001

A Statistical Model Using Reference Evapotranspiration And Weather Data To Predict The Economic Optimal Irrigation Level For Corn Production In The Texas Panhandle, W. Arden Colette, Clay Robinson, Lal Khan Almas

Conference on Applied Statistics in Agriculture

Corn yield and evapotranspiration (ET) data obtained from weighing lysimeters is accumulated from nine experiments over six years and used to estimate a response function. The quadratic response function of corn yield as a function of water use by the plants indicates that yield increases at a decreasing rate as ET increases. Extending the analysis to water application data by commercial producers in a thirteen county area in the Texas Panhandle provides a response function of yield as a function of water application to meet ET needs. The best estimate of the relationship is a quadratic function. The response function …


Engineering Production Function And Choice Of Technique., N. S. S. Narayana Dr. Apr 2001

Engineering Production Function And Choice Of Technique., N. S. S. Narayana Dr.

Doctoral Theses

This study deala wi th the selection of technological al ternaid ves of production, a problom referred to as choice of techninues" in ecommie theory. Selection of an appropriate technique (or a technolo gical al ternative) haa to be Bede with ro spe et to speci fied objectives and avail phle reDurces. Selection of proper techniques from smong many avall ablo el ternatives ha boen one of the min tasks whilu planni ng for econonio development. Generally develooping co untries like India are handi capped by problema of BCerci ty of on-lebour reaources, abundant labour force, lini ted foreign-aid, 1inited …