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2002

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Articles 31 - 60 of 98

Full-Text Articles in Engineering

On Localized Control In Qos Routing, Srihari Nelakuditi, Srivatsan Varadarajan, Zhi-Li Zhang Jun 2002

On Localized Control In Qos Routing, Srihari Nelakuditi, Srivatsan Varadarajan, Zhi-Li Zhang

Faculty Publications

In this note, we study several issues in the design of localized quality-of-service (QoS) routing schemes that make routing decisions based on locally collected QoS state information (i.e., there is no network-wide information exchange among routers). In particular, we investigate the granularity of local QoS state information and its impact on the design of localized QoS routing schemes from a theoretical perspective. We develop two theoretical models for studying localized proportional routing: one using the link-level information and the other using path-level information. We compare the performance of these localized proportional routing models with that of a global optimal proportional …

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A Localized Adaptive Proportioning Approach To Qos Routing, Srihari Nelakuditi, Zhi-Li Zhang Jun 2002

A Localized Adaptive Proportioning Approach To Qos Routing, Srihari Nelakuditi, Zhi-Li Zhang

Faculty Publications

In QoS routing, paths for flows are selected based on knowledge of resource availability at network nodes and the QoS requirements of flows. Several QoS routing schemes have been proposed that differ in the way they gather information about the network state and select paths based on this information. We broadly categorize these schemes into best path routing and proportional routing. The best path routing schemes gather global network state information and always select the best path for an incoming I-low,based on this global view. It has been shown that best path routing schemes require frequent exchange of network state, …

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Fuzzy Measures And Integrals As Aggregation Operators: Solving The Commensurability Problem, Francois Modave, Vladik Kreinovich May 2002

Fuzzy Measures And Integrals As Aggregation Operators: Solving The Commensurability Problem, Francois Modave, Vladik Kreinovich

Departmental Technical Reports (CS)

The aim of this paper is to shed some light on the use of fuzzy measures and integrals as aggregation operators in multicriteria decision making. These techniques have been widely used on an ad hoc basis, but with no axiomatization. It is possible to obtain preference representation theorems in multicriteria decision making problems, relying on a formal parallelism between decision under uncertainty and multicriteria decision making. Though, it raises some commensurability problems. In this paper, we show how to obtain an axiomatization of multicriteria decision making problems, in a very natural way, and we show how to solve the commensurability …

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Main Ideas Behind Owa Lead To A Universal And Optimal Approximation Scheme, Ronald R. Yager, Vladik Kreinovich May 2002

Main Ideas Behind Owa Lead To A Universal And Optimal Approximation Scheme, Ronald R. Yager, Vladik Kreinovich

Departmental Technical Reports (CS)

Ordered Weighted Averaging (OWA) operators have been successfully applied in many practical problems. We explain this empirical success by showing that these operators are indeed guaranteed to work (i.e., are universal), and that these operators are the best to use (in some reasonable sense).

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Selecting A Fuzzy Logic Operation From The Dnf-Cnf Interval: How Practical Are The Resulting Operations?, I. B. Turksen, A. Esper, K. Patel, Scott A. Starks, Vladik Kreinovich May 2002

Selecting A Fuzzy Logic Operation From The Dnf-Cnf Interval: How Practical Are The Resulting Operations?, I. B. Turksen, A. Esper, K. Patel, Scott A. Starks, Vladik Kreinovich

Departmental Technical Reports (CS)

In classical (two-valued) logic, CNF and DNF forms of each propositional formula are equivalent to each other. In fuzzy logic, CNF and DNF forms are not equivalent, they form an interval that contains the fuzzy values of all classically equivalent propositional formulas. If we want to select a single value from this interval, then it is natural to select a linear combination of the interval's endpoints. In particular, we can do that for CNF and DNF forms of "and" and "or", thus designing natural fuzzy analogues of classical "and" and "or" operations. The problem with thus selected "and" and "or" …

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Why Is Selecting The Simplest Hypothesis (Consistent With Data) A Good Idea? A Simple Explanation, Vladik Kreinovich, Luc Longpre, Scott Ferson, Lev Ginzburg May 2002

Why Is Selecting The Simplest Hypothesis (Consistent With Data) A Good Idea? A Simple Explanation, Vladik Kreinovich, Luc Longpre, Scott Ferson, Lev Ginzburg

Departmental Technical Reports (CS)

No abstract provided.

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From Computation With Guaranteed Intervals To Computation With Confidence Intervals: A New Application Of Fuzzy Techniques, Vladik Kreinovich, Hung T. Nguyen, Scott Ferson, Lev Ginzburg May 2002

From Computation With Guaranteed Intervals To Computation With Confidence Intervals: A New Application Of Fuzzy Techniques, Vladik Kreinovich, Hung T. Nguyen, Scott Ferson, Lev Ginzburg

Departmental Technical Reports (CS)

Traditional interval computations provide an estimate for the result y=f(x1,...,xn) of data processing when we know intervals X1,...,Xn that are guaranteed to contain the (unknown) actual values of the quantities x1,...,xn. Often, in addition to these guaranteed intervals, we have confidence intervals for these quantities, i.e., intervals Xi that contain the corresponding values xi with a certain probability. It is desirable, based on the confidence intervals for xi, to produce the resulting confidence interval for y. It turns out that the formulas for computing such resulting confidence interval are closely related with the formulas for processing fuzzy numbers by using …

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Interval Mathematics For Analysis Of Multiresolutional Systems, Vladik Kreinovich, Richard Alo May 2002

Interval Mathematics For Analysis Of Multiresolutional Systems, Vladik Kreinovich, Richard Alo

Departmental Technical Reports (CS)

The more complex the problem, the more complex the system necessary for solving this problem. For very complex problems, it is no longer possible to design the corresponding system on a single resolution level, it becomes necessary to have multiresolutional systems. When analyzing such systems -- e.g., when estimating their performance and/or their intelligence -- it is reasonable to use the multiresolutional character of these systems: first, we analyze the system on the low-resolution level, and then we sharpen the results of the low-resolution analysis by considering higher-resolution representations of the analyzed system. The analysis of the low-resolution level provides …

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Information Security System Rating And Ranking, Rayford B. Vaughn Jr., Ambareen Sira, David A. Dampier May 2002

Information Security System Rating And Ranking, Rayford B. Vaughn Jr., Ambareen Sira, David A. Dampier

Computer Sciences and Electrical Engineering Faculty Research

The term assurance has been used for decades in trusted system development to express the notion of confidence in the strength of a specific system or system of systems. The unsolved problem that security engineers must struggle with is the adoption of measures or metrics that can reliably depict the assurance associated with a specific hardware and software architecture. This article reports on a recent attempt to focus needs in this area and suggests various categories of information assurance metrics that may be helpful to an organization that is deciding which set is useful for a specific application.

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Provisioning On-Line Games: A Traffic Analysis Of A Busy Counter-Strike Server, Wu-Chang Feng, Francis Chang, Wu-Chi Feng, Jonathan Walpole May 2002

Provisioning On-Line Games: A Traffic Analysis Of A Busy Counter-Strike Server, Wu-Chang Feng, Francis Chang, Wu-Chi Feng, Jonathan Walpole

Computer Science Faculty Publications and Presentations

This paper describes the results of a 500 million packet trace of a popular on-line, multi-player, game server. The results show that the traffic behavior of this heavily loaded game server is highly predictable and can be attributed to the fact that current game designs target the saturation of the narrowest, last-mile link. Specifically, in order to maximize the interactivity of the game itself and to provide relatively uniform experiences between players playing over different network speeds, on-line games typically fix their usage requirements in such a way as to saturate the network link of their lowest speed players. While …

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Poster: Provisioning On-Line Games: A Traffic Analysis Of A Busy Counter-Strike Server, Francis Chang, Wu-Chang Feng, Wu-Chi Feng, Jonathan Walpole May 2002

Poster: Provisioning On-Line Games: A Traffic Analysis Of A Busy Counter-Strike Server, Francis Chang, Wu-Chang Feng, Wu-Chi Feng, Jonathan Walpole

Computer Science Faculty Publications and Presentations

A poster that illustrates the client/server model employed by an multiplayer online game, focusing on bandwidth usage.

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Supporting Low-Latency Tcp-Based Media Streams, Ashvin Goel, Charles Krasic, Kang Li, Jonathan Walpole May 2002

Supporting Low-Latency Tcp-Based Media Streams, Ashvin Goel, Charles Krasic, Kang Li, Jonathan Walpole

Computer Science Faculty Publications and Presentations

The dominance of the TCP protocol on the Internet and its success in maintaining Internet stability has led to several TCP-based stored media-streaming approaches. The success of these approaches raises the question whether TCP can be used for low-latency streaming. Low latency streaming allows responsive control operations for media streaming and can make interactive applications feasible. We examined adapting the TCP send buffer size based on TCP's congestion window to reduce application perceived network latency. Our results show that this simple idea significantly improves the number of packets that can be delivered within 200 ms and 500 ms thresholds.

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Proteome Database Of Hepatocellular Carcinoma., Cynthia Liang, Jason Neo, Siaw Ling Lo, Gek San Tan, Teck Keong Seow, Maxey Chung May 2002

Proteome Database Of Hepatocellular Carcinoma., Cynthia Liang, Jason Neo, Siaw Ling Lo, Gek San Tan, Teck Keong Seow, Maxey Chung

Research Collection School Of Computing and Information Systems

Hepatocellular carcinoma (HCC or hepatoma) is the most common primary cancer of the liver. Persistent viral infection by the hepatic B or C virus is probably the most important cause of HCC worldwide. It is responsible for approximately one million deaths each year, predominantly in the underdeveloped and developing countries, but its incidence is also on the rise in the developed countries. For most patients suffering from HCC, long-term survival is rare, as they are presented late and are often unsuitable for curative treatment. Thus there is great interest to identify novel HCC diagnostic markers for early detection of the …

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Range Estimation Is Np-Hard For Epsilon-Square Accuracy And Feasible For Epsilon To The Power Of 2-Delta, Vladik Kreinovich Apr 2002

Range Estimation Is Np-Hard For Epsilon-Square Accuracy And Feasible For Epsilon To The Power Of 2-Delta, Vladik Kreinovich

Departmental Technical Reports (CS)

The basic problem of interval computations is: given a function f(x1,...,xn) and n intervals [xi-,xi+], find the (interval) range Y of the given function on the given intervals. It is known that even for quadratic polynomials f(x1,...,xn), this problem is NP-hard. In this paper, following the advice of A. Neumaier, we analyze the complexity of asymptotic range estimation, when the bound "epsilon" on the width of the input intervals tends to 0. We show that for small c>0, if we want to compute the range with an accuracy c times epsilon squared, then the problem is still NP-hard; on …

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Computing Variance For Interval Data Is Np-Hard, Scott Ferson, Lev Ginzburg, Vladik Kreinovich, Luc Longpre, Monica Aviles Apr 2002

Computing Variance For Interval Data Is Np-Hard, Scott Ferson, Lev Ginzburg, Vladik Kreinovich, Luc Longpre, Monica Aviles

Departmental Technical Reports (CS)

When we have only interval ranges [xi-,xi+] of sample values x1,...,xn, what is the interval [V-,V+] of possible values for the variance V of these values? We prove that the problem of computing the upper bound V+ is NP-hard. We provide a feasible (quadratic time) algorithm for computing the lower bound V- on the variance of interval data. We also provide a feasible algorithm that computes V+ under reasonable easily verifiable conditions.

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On Efficient Representation Of Expert Knowledge By Fuzzy Logic: Towards An Optimal Combination Of Granularity And Higher-Order Approaches, Hung T. Nguyen, Vladik Kreinovich Apr 2002

On Efficient Representation Of Expert Knowledge By Fuzzy Logic: Towards An Optimal Combination Of Granularity And Higher-Order Approaches, Hung T. Nguyen, Vladik Kreinovich

Departmental Technical Reports (CS)

A natural approach to designing an intelligent system is to incorporate expert knowledge into this system. One of the main approaches to translating this knowledge into computer-understandable terms is the approach of fuzzy logic. It has led to many successful applications, but in several aspects, the resulting computer representation is somewhat different from the original expert meaning. Two related approaches have been used to make fuzzy logic more adequate in representing expert reasoning: granularity and higher-order approaches. Each approach is successful in some applications where the other approach did not succeed so well; it is therefore desirable to combine these …

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2002 (Spring) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department Apr 2002

2002 (Spring) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department

ENSI Informer Magazine Archive

The ENSI Informer Magazine published in the spring of 2002.

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Infopipes: An Abstraction For Multimedia Streaming, Andrew P. Black, Huang Jie, Rainer Koster, Jonathan Walpole, Calton Pu Apr 2002

Infopipes: An Abstraction For Multimedia Streaming, Andrew P. Black, Huang Jie, Rainer Koster, Jonathan Walpole, Calton Pu

Computer Science Faculty Publications and Presentations

To simplify the task of building distributed streaming applications, we propose a new abstraction for information flow – Infopipes. Infopipes make information flow primary, not an auxiliary mechanism that is hidden away. Systems are built by connecting predefined component Infopipes such as sources, sinks, buffers, filters, broadcasting pipes, and multiplexing pipes. The goal of Infopipes is not to hide communication, like an RPC system, but to reify it: to represent communication explicitly as objects that the program can interrogate and manipulate. Moreover, these objects represent communication in application-level terms, not in terms of network or process implementation.

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Exact Bounds On Sample Variance Of Interval Data, Scott Ferson, Lev Ginzburg, Vladik Kreinovich, Monica Aviles Mar 2002

Exact Bounds On Sample Variance Of Interval Data, Scott Ferson, Lev Ginzburg, Vladik Kreinovich, Monica Aviles

Departmental Technical Reports (CS)

We provide a feasible (quadratic time) algorithm for computing the lower bound on the sample variance V of interval data. The problem of computing the upper bound on V is, in general, NP-hard. We provide a feasible algorithm that computes the upper bound on V for many reasonable situations.

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Diagnostics Of Bar And End-Ring Connector Breakage Faults In Polyphase Induction Motors Through A Novel Dual Track Of Time-Series Data Mining And Time-Stepping Coupled Fe-State Space Modeling, Richard J. Povinelli, John F. Bangura, Nabeel Demerdash, Ronald H. Brown Mar 2002

Diagnostics Of Bar And End-Ring Connector Breakage Faults In Polyphase Induction Motors Through A Novel Dual Track Of Time-Series Data Mining And Time-Stepping Coupled Fe-State Space Modeling, Richard J. Povinelli, John F. Bangura, Nabeel Demerdash, Ronald H. Brown

Electrical and Computer Engineering Faculty Research and Publications

This paper develops the fundamental foundations of a technique for detection of faults in induction motors that is not based on the traditional Fourier transform frequency domain approach. The technique can extensively and economically characterize and predict faults from the induction machine adjustable speed drive design data. This is done through the development of dual-track proof-of-principle studies of fault simulation and identification. These studies are performed using our proven Time Stepping Coupled Finite Element-State Space method to generate fault case data. Then, the fault cases are classified by their inherent characteristics, so-called “signatures” or “fingerprints.” These fault signatures are extracted …

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Detecting And Locating Curved Cracks In Thin Plates By Lamb Wave Reflection: Validated Geometric Approach, Roberto A. Osegueda, Vladik Kreinovich Mar 2002

Detecting And Locating Curved Cracks In Thin Plates By Lamb Wave Reflection: Validated Geometric Approach, Roberto A. Osegueda, Vladik Kreinovich

Departmental Technical Reports (CS)

Lamb waves propagate through a thin plate, and thus, provide a way of scanning this plate and detecting cracks and other faults. The equations describing these waves are rather complex, and, as a result, it is difficult to extract, from the received signal, the location of the fault. Recently, a new geometric approach has been proposed which allows, for linear cracks, to determine the presence and the location of a crack by using only the geometry of wave propagation. In this paper, we extend this approach to a more realistic case of curved cracks, and apply interval techniques to provide …

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Information Efficiency In Hyperspectral Imaging Systems, Stephen E. Reichenbach, Luyin Cao, Ram M. Narayanan Feb 2002

Information Efficiency In Hyperspectral Imaging Systems, Stephen E. Reichenbach, Luyin Cao, Ram M. Narayanan

Department of Electrical and Computer Engineering: Faculty Publications

In this work we develop a method for assessing the information density and efficiency of hyperspectral imaging systems that have spectral bands of non-uniform width. Imaging system designs with spectral bands of nonuniform width can efficiently gather information about a scene by allocating bandwidth among the bands according to their information content. The information efficiency is the ratio of information density to data density and is a function of the scene’s spectral radiance, hyperspectral system design, and signal-to-noise ratio. The assessment can be used to produce an efficient system design. For example, one approach to determining the number and width …

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Nanostructures With Small- And Large-Scale Periodic And Random Rough Surfaces And Lateral Fluctuations In The Permittivity And Permeability-Scattered Near Fields, Ezekiel Bahar Feb 2002

Nanostructures With Small- And Large-Scale Periodic And Random Rough Surfaces And Lateral Fluctuations In The Permittivity And Permeability-Scattered Near Fields, Ezekiel Bahar

Department of Electrical and Computer Engineering: Faculty Publications

The scattered electromagnetic near fields due to fluctuations in the surface height and/or lateral variations in the electromagnetic medium parameters are evaluated using a full-wave approach. Since the scales of the height and medium fluctuations considered could be significantly smaller or larger than the electromagnetic wavelengths, the familiar perturbation and physical/geometrical optics solutions cannot be used nor is it possible to investigate subwave length features based on far-field measurements. The full-wave approach employs complete field expansion that includes propagating and evanescent waves as well as lateral waves and surface waves, which are not accounted for in the perturbation and physical …

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Optimization Techniques Under Uncertain Criteria, And Their Possible Use In Computerized Education, Vladik Kreinovich, Richard Alo Feb 2002

Optimization Techniques Under Uncertain Criteria, And Their Possible Use In Computerized Education, Vladik Kreinovich, Richard Alo

Departmental Technical Reports (CS)

The existing successful automated computerized systems more or less simulate the way successful human teachers teach. However, computerized systems provide more individualized options that traditional classroom education, and it is desirable to use this additional freedom to further improve the education success rate. In this papers, we briefly overview the experience of a successful Russian training system, and explain how general techniques of optimization under uncertainty can be used to optimize the content development.

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Cxquery: A Novel Xml Query Language, Peter Revesz, Yi Chen Jan 2002

Cxquery: A Novel Xml Query Language, Peter Revesz, Yi Chen

CSE Conference and Workshop Papers

XML is becoming the data exchange standard on the Internet. Previously proposed XML query languages, such as XQuery, Quilt, YALT, Lorel, and XML-QL, lack schema definition of the query result; therefore, they are limited for defining views, integrating data, updating, and further querying, all of which are often needed in e-Business applications. We propose a novel XML query language called CXQuery, which defines the schema of the query results explicitly and can easily define views, and integrate, update, and query XML data. In addition, CXQuery can express spatial and spatio-temporal queries using a constraint-based querying approach.

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Boundary Effects On Multiplication Noise In Thin Heterostructure Avalanche Photodiodes: Theory And Experiment [Al/Sub 0.6/Ga/Sub 0.4/As/Gaas], Majeed M. Hayat, Oh-Hyun Kwon, Shuling Wang, Joe C. Campbell, Bahaa E.A. Saleh, Malvin Carl Teich Jan 2002

Boundary Effects On Multiplication Noise In Thin Heterostructure Avalanche Photodiodes: Theory And Experiment [Al/Sub 0.6/Ga/Sub 0.4/As/Gaas], Majeed M. Hayat, Oh-Hyun Kwon, Shuling Wang, Joe C. Campbell, Bahaa E.A. Saleh, Malvin Carl Teich

Electrical and Computer Engineering Faculty Research and Publications

The history-dependent recurrence theory for multiplication noise in avalanche photodiodes (APDs), developed by Hayat et al., is generalized to include inter-layer boundary effects in heterostructure APDs with multilayer multiplication regions. These boundary effects include the initial energy of injected carriers as well as bandgap-transition effects within a multilayer multiplication region. It is shown that the excess noise factor can be significantly reduced if the avalanche process is initiated with an energetic carrier, in which case the initial energy serves to reduce the initial dead space associated with the injected carrier. An excess noise factor reduction up to 40% below the …

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Femtosecond Laser Utilization Methods And Apparatus And Method For Producing Nanoparticles, Dennis R. Alexander Jan 2002

Femtosecond Laser Utilization Methods And Apparatus And Method For Producing Nanoparticles, Dennis R. Alexander

Department of Electrical and Computer Engineering: Faculty Publications

The present invention teaches various femtosecond machining and drilling apparatus and processes for fabricating tools and the like from both traditional and non-traditional materials. Also described are novel tools such as scalpels, and nozzles fabricated from the apparatus and processes of the present invention. Likewise, the present invention may be utilized in both a novel propulsion system and the production of materials formed from nanometer sized particles and the like.

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Implementation And Validation Of Range Imaging On A Uhf Radar Wind Profiler, P. B. Chilson, Tian-You Yu, Richard G. Strauch, Andreas Muschinski, Robert D. Palmer Jan 2002

Implementation And Validation Of Range Imaging On A Uhf Radar Wind Profiler, P. B. Chilson, Tian-You Yu, Richard G. Strauch, Andreas Muschinski, Robert D. Palmer

Department of Electrical and Computer Engineering: Faculty Publications

The available range resolution of pulsed radar wind profilers is usually limited by bandwidth restrictions. Range imaging (RIM) has recently been developed as a means of mitigating these limitations by operating the wind profilers over a small set of distinct transmitter frequencies. A constrained optimization method can then be used to generate high-resolution maps of the reflectivity field as a function of range. This paper presents a description of how the RIM technique has been recently implemented on the Platteville 915-MHz tropospheric profiler, the first such implementation at UHF. Examples of data collected during a two-part experiment on 10 April …

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On The Optimal Choice Of Quality Metric In Image Compression, Olga Kosheleva, Vladik Kreinovich, Yeung Yam Jan 2002

On The Optimal Choice Of Quality Metric In Image Compression, Olga Kosheleva, Vladik Kreinovich, Yeung Yam

Departmental Technical Reports (CS)

No abstract provided.

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Open-Ended Configurations Of Radio Telescopes: Towards Optimal Design, Vladik Kreinovich, Scott A. Starks, Olga Kosheleva, Andrei Finkelstein Jan 2002

Open-Ended Configurations Of Radio Telescopes: Towards Optimal Design, Vladik Kreinovich, Scott A. Starks, Olga Kosheleva, Andrei Finkelstein

Departmental Technical Reports (CS)

The quality of radio astronomical images drastically depends on where we place the radio telescopes. During the design of the Very Large Array, it was empirically shown that the power law design, in which n-th antenna is placed at a distance n^b from the center, leads to the best image quality. In this paper, we provide a theoretical justification for this empirical fact.

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