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An investigation of genetic operators for continuous parameter space (open access)

An investigation of genetic operators for continuous parameter space

The success of a genetic optimization algorithm in continuous parameter space depends on the recombination (crossover) operators that it uses. In this paper we consider a wide spectrum of such operators within a unified framework and study their relative importance in the search process. We consider four basic types recombination operators which cover the relevant exploration potential of a continuous space: Interpolation, Extrapolation, Exchange and Mutation. Each of these basic types may have several variants. We characterize the various operators and their variants by their spatial sampling properties and examine their contributions to the search by applying different mixtures of the operators in several benchmark problems. The results suggest that the optimal mixture of operators may depend on the problem. But, in general, all basic types are needed for efficient optimization.
Date: March 9, 1994
Creator: Grossman, T. & Davidor, Y.
Object Type: Article
System: The UNT Digital Library
Improving the Search on the Internet by Using WordNet and Lexical Operators (open access)

Improving the Search on the Internet by Using WordNet and Lexical Operators

This article discusses improving the search on the internet by using WordNet and lexical operators.
Date: July 21, 1999
Creator: Moldovan, Dan I. & Mihalcea, Rada, 1974-
Object Type: Article
System: The UNT Digital Library
Improved Evolutionary Hybrids for Flexible Ligand Docking in Autodock (open access)

Improved Evolutionary Hybrids for Flexible Ligand Docking in Autodock

In this paper we evaluate the design of the hybrid evolutionary algorithms (EAs) that are currently used to perform flexible ligand binding in the Autodock docking software. Hybrid EAs incorporate specialized operators that exploit domain-specific features to accelerate an EA's search. We consider hybrid EAs that use an integrated local search operator to reline individuals within each iteration of the search. We evaluate several factors that impact the efficacy of a hybrid EA, and we propose new hybrid EAs that provide more robust convergence to low-energy docking configurations than the methods currently available in Autodock.
Date: January 27, 1999
Creator: Belew, Richard K.; Hart, William E.; Morris, Garrett M. & Rosin, Chris
Object Type: Article
System: The UNT Digital Library
41. DISCOVERY, SEARCH, AND COMMUNICATION OF TEXTUAL KNOWLEDGE RESOURCES IN DISTRIBUTED SYSTEMS a. Discovering and Utilizing Knowledge Sources for Metasearch Knowledge Systems (open access)

41. DISCOVERY, SEARCH, AND COMMUNICATION OF TEXTUAL KNOWLEDGE RESOURCES IN DISTRIBUTED SYSTEMS a. Discovering and Utilizing Knowledge Sources for Metasearch Knowledge Systems

Advanced Natural Language Processing Tools for Web Information Retrieval, Content Analysis, and Synthesis. The goal of this SBIR was to implement and evaluate several advanced Natural Language Processing (NLP) tools and techniques to enhance the precision and relevance of search results by analyzing and augmenting search queries and by helping to organize the search output obtained from heterogeneous databases and web pages containing textual information of interest to DOE and the scientific-technical user communities in general. The SBIR investigated 1) the incorporation of spelling checkers in search applications, 2) identification of significant phrases and concepts using a combination of linguistic and statistical techniques, and 3) enhancement of the query interface and search retrieval results through the use of semantic resources, such as thesauri. A search program with a flexible query interface was developed to search reference databases with the objective of enhancing search results from web queries or queries of specialized search systems such as DOE's Information Bridge. The DOE ETDE/INIS Joint Thesaurus was processed to create a searchable database. Term frequencies and term co-occurrences were used to enhance the web information retrieval by providing algorithmically-derived objective criteria to organize relevant documents into clusters containing significant terms. A thesaurus provides …
Date: March 18, 2008
Creator: Zamora, Antonio
Object Type: Report
System: The UNT Digital Library
Venture Capital Investment and Protocol Analysis (open access)

Venture Capital Investment and Protocol Analysis

This study used protocol analysis to identify key variables in the venture capital investment decision-making process. The study used a fictional business plan which was based on six actual business plans. This fictional business plan was presented to ten venture capitalists who were asked to review it to decide whether to interview the investee. The protocols obtained from these subjects were analyzed to determine patterns within the subjects' review. The sections of the business plan which were commonly reviewed first were the deal structure, the executive summary, and the management section. The management section was used by the greatest number of subjects. The market section was used the greatest number of times. The data were also organized by type of operators used in each subject's protocols. Information Search/Retrieval operators were most common, followed by Task Structuring/Set Goal operators. When classified into the four major categories of Task Structuring/Set Goal, Information Acquisition, Analytical/ Inferential, and Choice operators, Analytical/Inferential operators were used most frequently. Choice operators were least used. The phrases were analyzed by the relevant section in the business plan. The market received the greatest number of references, followed by references to the product and to management. However, when references to …
Date: December 1987
Creator: Pfeffer, Mary Graves
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Dynamic Foundation of Fractal Operators. (open access)

The Dynamic Foundation of Fractal Operators.

The fractal operators discussed in this dissertation are introduced in the form originally proposed in an earlier book of the candidate, which proves to be very convenient for physicists, due to its heuristic and intuitive nature. This dissertation proves that these fractal operators are the most convenient tools to address a number of problems in condensed matter, in accordance with the point of view of many other authors, and with the earlier book of the candidate. The microscopic foundation of the fractal calculus on the basis of either classical or quantum mechanics is still unknown, and the second part of this dissertation aims at this important task. This dissertation proves that the adoption of a master equation approach, and so of probabilistic as well as dynamical argument yields a satisfactory solution of the problem, as shown in a work by the candidate already published. At the same time, this dissertation shows that the foundation of Levy statistics is compatible with ordinary statistical mechanics and thermodynamics. The problem of the connection with the Kolmogorov-Sinai entropy is a delicate problem that, however, can be successfully solved. The derivation from a microscopic Liouville-like approach based on densities, however, is shown to be impossible. …
Date: May 2003
Creator: Bologna, Mauro
Object Type: Thesis or Dissertation
System: The UNT Digital Library
[News Clip: Gun search] captions transcript

[News Clip: Gun search]

Video footage from the WBAP-TV station in Fort Worth, Texas to accompany a news story about a sought after murder weapon in Fort Worth.
Date: January 6, 1959
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
Intervals in evolutionary algorithms for global optimization (open access)

Intervals in evolutionary algorithms for global optimization

Optimization is of central concern to a number of disciplines. Interval Arithmetic methods for global optimization provide us with (guaranteed) verified results. These methods are mainly restricted to the classes of objective functions that are twice differentiable and use a simple strategy of eliminating a splitting larger regions of search space in the global optimization process. An efficient approach that combines the efficient strategy from Interval Global Optimization Methods and robustness of the Evolutionary Algorithms is proposed. In the proposed approach, search begins with randomly created interval vectors with interval widths equal to the whole domain. Before the beginning of the evolutionary process, fitness of these interval parameter vectors is defined by evaluating the objective function at the center of the initial interval vectors. In the subsequent evolutionary process the local optimization process returns an estimate of the bounds of the objective function over the interval vectors. Though these bounds may not be correct at the beginning due to large interval widths and complicated function properties, the process of reducing interval widths over time and a selection approach similar to simulated annealing helps in estimating reasonably correct bounds as the population evolves. The interval parameter vectors at these estimated bounds …
Date: May 1, 1995
Creator: Patil, R. B.
Object Type: Article
System: The UNT Digital Library
A generalized stationary point convergence theory for evolutionary algorithms (open access)

A generalized stationary point convergence theory for evolutionary algorithms

This paper presents a convergence theory for evolutionary pattern search algorithms (EPSAs). EPSAs are self-adapting evolutionary algorithms that modify the step size of the mutation operator in response to the success of previous optimization steps. Previously, the authors have proven a stationary point convergence theory for EPSAs for which the step size is not allowed to increase. The present analysis generalizes this analysis to prove a convergence theory for EPSAs that are allowed to both increase and decrease the step size. This convergence theory is based on an extension of the convergence theory for generalized pattern search methods.
Date: February 1, 1997
Creator: Hart, W.E.
Object Type: Article
System: The UNT Digital Library
Phase Reconstruction from FROG Using Genetic Algorithms[Frequency-Resolved Optical Gating] (open access)

Phase Reconstruction from FROG Using Genetic Algorithms[Frequency-Resolved Optical Gating]

The authors describe a new technique for obtaining the phase and electric field from FROG measurements using genetic algorithms. Frequency-Resolved Optical Gating (FROG) has gained prominence as a technique for characterizing ultrashort pulses. FROG consists of a spectrally resolved autocorrelation of the pulse to be measured. Typically a combination of iterative algorithms is used, applying constraints from experimental data, and alternating between the time and frequency domain, in order to retrieve an optical pulse. The authors have developed a new approach to retrieving the intensity and phase from FROG data using a genetic algorithm (GA). A GA is a general parallel search technique that operates on a population of potential solutions simultaneously. Operators in a genetic algorithm, such as crossover, selection, and mutation are based on ideas taken from evolution.
Date: April 12, 1999
Creator: Omenetto, F. G.; Nicholson, J. W.; Funk, D. J. & Taylor, A. J.
Object Type: Article
System: The UNT Digital Library
[News Clip: Strip search] captions transcript

[News Clip: Strip search]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story. This story aired at 10 P.M.
Date: November 16, 1980
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
Neutrino-electron scattering and the search for new physics (open access)

Neutrino-electron scattering and the search for new physics

I want to discuss the role of neutrino-electron scattering in the search for physics beyond the standard model. The standard model makes specific predictions about the nature of the neutrinos which participate in such processes and about the interactions responsible for them. The process upon which I shall concentrate is elastic scattering, but I shall pay some attention to inelastic processes in which the target electron is itself transformed into a heavier charged lepton, in other words the inverse of the decay of the heavier lepton. In the case of elastic scattering we are mainly looking at neutral-currents and we can ask a series of simple questions: Does the interaction conserve lepton flavor. Does it fit the prescriptions of the standard model. Are the neutrinos Majorana or Dirac particles. In the case of inverse muon and tau decays we are looking at charge-currents, and we want to pin down the identity of the neutrinos emitted in the decay of these charged leptons as well as to set bounds on non-(V-A) components of the interaction. In order to discuss these topics, it is useful to review the general properties of the scattering process, especially the kinematics and the general form of …
Date: January 1, 1988
Creator: Rosen, S. P.
Object Type: Article
System: The UNT Digital Library
Competing electron-electron/electron-phonon interactions and polyacetylene (open access)

Competing electron-electron/electron-phonon interactions and polyacetylene

Using Lanczos exact diagonalization, we investigate the effects of the competition between the electro-electron and electron-phonon interactions in the context of the 1-D tight-binding Peierls-Hubbard Hamiltonian, studying various structural, optical, and vibrational properties of strongly correlated systems. We use polyacetylene as our experimental guide, and perform a parameter space search to determine the level at which a unique set of parameters can model this prototypical conducting polymer and, more generally, the applicability of the simple'' 1-D Peierls-Hubbard Hamiltonian to these highly interesting materials. 9 refs., 3 tabs.
Date: April 8, 1991
Creator: Gammel, J.T. (Los Alamos National Lab., NM (USA) Bayreuth Univ. (Germany, F.R.). Physics Inst.); Campbell, D.K. (Los Alamos National Lab., NM (USA)) & Loh, E.Y. Jr. (Thinking Machines Corp., Cambridge, MA (USA))
Object Type: Article
System: The UNT Digital Library
A Diagnostic Hierarchy Approach to Root Cause Analysis for Heavy Water Reactor Malfunction Management (open access)

A Diagnostic Hierarchy Approach to Root Cause Analysis for Heavy Water Reactor Malfunction Management

The Nuclear Engineering and Chemical Engineering Artificial Intelligence Groups at The Ohio State University have developed a diagnostic system for the heavy water production reactors at the Savannah River Site. The diagnostic module of the system uses hybrid hierarchical decomposition methodology to decompose the search space. The knowledge is arranged so that the search space is traversed similarly to how an expert would solve the problem. The system was tested on the SRS development simulator and the results show that the system can properly diagnose all the process water and cooling water malfunctions that are programmed into the simulator. The system was not validated by operators due to hardware unavailability. Since the New Production Reactor development efforts have been halted, the probability for future work on this project is unlikely. The development used a standardized Verification and Validation program to assist in the design and construction of the system. The use of this standardized procedure is referred to as a text book example of designing an expert system in the expectation that its use would provide guidance in future projects. Of the eight phases of the software development lifecycle, five of the phases were completed and documented.
Date: October 30, 1993
Creator: Miller, D. W.; Hajek, B. K. & Hines, J. W.
Object Type: Report
System: The UNT Digital Library
Implications of D^0-\overline D^0 Mixing for New Physics (open access)

Implications of D^0-\overline D^0 Mixing for New Physics

We provide a comprehensive, up-to-date analysis of possible New Physics contributions to the mass difference {Delta}M{sub D} in D{sup 0}-{bar D}{sup 0} mixing. We consider the most general low energy effective Hamiltonian and include leading order QCD running of effective operators. We then explore an extensive list of possible New Physics models that can generate these operators, which we organize as including Extra Fermions, Extra Gauge Bosons, Extra Scalars, Extra Space Dimensions and Extra Symmetries. For each model we place restrictions on the allowed parameter space using the recent evidence for observation of D meson mixing. In many scenarios, we find strong constraints that surpass those from other search techniques and provide an important test of flavor changing neutral currents in the up-quark sector. We also review the recent BaBar and Belle findings, and describe the current status of the Standard Model predictions of D{sup 0}-{bar D}{sup 0} mixing.
Date: June 8, 2007
Creator: Golowich, Eugene; Hewett, JoAnne; Pakvasa, Sandip & Petrov, Alexey A.
Object Type: Article
System: The UNT Digital Library
Constructing a resilience index for the enhanced critical in Frastructure Protection Program. (open access)

Constructing a resilience index for the enhanced critical in Frastructure Protection Program.

Following recommendations made in Homeland Security Presidential Directive 7, which established a national policy for the identification and increased protection of critical infrastructure and key resources (CIKR) by Federal departments and agencies, the U.S. Department of Homeland Security (DHS) in 2006 developed the Enhanced Critical Infrastructure Protection (ECIP) program. The ECIP program aimed to provide a closer partnership with state, regional, territorial, local, and tribal authorities in fulfilling the national objective to improve CIKR protection. The program was specifically designed to identify protective measures currently in place in CIKR and to inform facility owners/operators of the benefits of new protective measures. The ECIP program also sought to enhance existing relationships between DHS and owners/operators of CIKR and to build relationships where none existed (DHS 2008; DHS 2009). In 2009, DHS and its protective security advisors (PSAs) began assessing CIKR assets using the ECIP program and ultimately produced individual protective measure and vulnerability values through the protective measure and vulnerability indices (PMI/VI). The PMI/VI assess the protective measures posture of individual facilities at their 'weakest link,' allowing for a detailed analysis of the most vulnerable aspects of the facilities (Schneier 2003), while maintaining the ability to produce an overall protective measures …
Date: October 14, 2010
Creator: Fisher, R. E.; Bassett, G. W.; Buehring, W. A.; Collins, M. J.; Dickinson, D. C.; Eaton, L. K. et al.
Object Type: Report
System: The UNT Digital Library
Geothermal Reservoir Well Stimulation Program: technology transfer (open access)

Geothermal Reservoir Well Stimulation Program: technology transfer

To assess the stimulation technology developed in the oil and gas industry as to its applicability to the problems of geothermal well stimulation, a literature search was performed through on-line computer systems. Also, field records of well stimulation programs that have worked successfully were obtained from oil and gas operators and service companies. The results of these surveys are presented. (MHR)
Date: May 1, 1980
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Exploitation and Optimization of Reservoir Performance in Hunton Formation, Oklahoma (open access)

Exploitation and Optimization of Reservoir Performance in Hunton Formation, Oklahoma

Hunton formation in Oklahoma has been the subject of attention for the last ten years. The new interest started with the drilling of the West Carney field in 1995 in Lincoln County. Subsequently, many other operators have expanded the search for oil and gas in Hunton formation in other parts of Oklahoma. These fields exhibit many unique production characteristics, including: (1) decreasing water-oil or water-gas ratio over time; (2) decreasing gas-oil ratio followed by an increase; (3) poor prediction capability of the reserves based on the log data; and (4) low geological connectivity but high hydrodynamic connectivity. The purpose of this investigation is to understand the principal mechanisms affecting the production, and propose methods by which we can optimize the production from fields with similar characteristics.
Date: June 30, 2007
Creator: Kelkar, Mohan
Object Type: Report
System: The UNT Digital Library
Search for Charged Lepton Violation in Narrow Upsilon Decays (open access)

Search for Charged Lepton Violation in Narrow Upsilon Decays

Charged lepton flavor violating processes are unobservable in the standard model, but they are predicted to be enhanced in several extensions to the standard model, including supersymmetry and models with leptoquarks or compositeness. We present a search for such processes in a sample of 99 x 10{sup 6} {Upsilon}(2S) decays and 117 x 10{sup 6} {Upsilon}(3S) decays collected with the BABAR detector. We place upper limits on the branching fractions {Beta}({Upsilon}(nS) {yields} e{sup {+-}}{tau}{sup {-+}}) and {Beta}({Upsilon}(nS) {yields} {mu}{sup {+-}}{tau}{sup {-+}}) (n = 2, 3) at the 10{sup -6} level and use these results to place lower limits of order 1 TeV on the mass scale of charged lepton flavor violating effective operators.
Date: August 19, 2011
Creator: Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E. et al.
Object Type: Article
System: The UNT Digital Library
Ground state searches in fcc intermetallics (open access)

Ground state searches in fcc intermetallics

A cluster expansion is used to predict the fcc ground states, i.e., the stable phases at zero Kelvin as a function of composition, for alloy systems. The intermetallic structures are not assumed, but derived regorously by minimizing the configurational energy subject to linear constraints. This ground state search includes pair and multiplet interactions which spatially extend to fourth nearest neighbor. A large number of these concentration-independent interactions are computed by the method of direct configurational averaging using a linearized-muffin-tin orbital Hamiltonian cast into tight binding form (TB-LMTO). The interactions, derived without the use of any adjustable or experimentally obtained parameters, are compared to those calculated via the generalized perturbation method extention of the coherent potential approximation within the context of a KKR Hamiltonian (KKR-CPA-GPM). Agreement with the KKR-CPA-GPM results is quite excellent, as is the comparison of the ground state results with the fcc-based portions of the experimentally-determined phase diagrams under consideration.
Date: December 1, 1991
Creator: Wolverton, C.; de Fontaine, D. (Lawrence Berkeley Lab., CA (United States)); Ceder, G. (Massachusetts Inst. of Tech., Cambridge, MA (United States)) & Dreysse, H. (Nancy-1 Univ., 54 (France). Lab. de Physique du Solide)
Object Type: Article
System: The UNT Digital Library
Reliable motion detection of small targets in video with low signal-to-clutter ratios (open access)

Reliable motion detection of small targets in video with low signal-to-clutter ratios

Studies show that vigilance decreases rapidly after several minutes when human operators are required to search live video for infrequent intrusion detections. Therefore, there is a need for systems which can automatically detect targets in live video and reserve the operator`s attention for assessment only. Thus far, automated systems have not simultaneously provided adequate detection sensitivity, false alarm suppression, and ease of setup when used in external, unconstrained environments. This unsatisfactory performance can be exacerbated by poor video imagery with low contrast, high noise, dynamic clutter, image misregistration, and/or the presence of small, slow, or erratically moving targets. This paper describes a highly adaptive video motion detection and tracking algorithm which has been developed as part of Sandia`s Advanced Exterior Sensor (AES) program. The AES is a wide-area detection and assessment system for use in unconstrained exterior security applications. The AES detection and tracking algorithm provides good performance under stressing data and environmental conditions. Features of the algorithm include: reliable detection with negligible false alarm rate of variable velocity targets having low signal-to-clutter ratios; reliable tracking of targets that exhibit motion that is non-inertial, i.e., varies in direction and velocity; automatic adaptation to both infrared and visible imagery with variable …
Date: July 1, 1995
Creator: Nichols, S. A. & Naylor, R. B.
Object Type: Article
System: The UNT Digital Library
Demonstration of safeguards technology at the Russian Institute of Experimental Physics (VNIIEF), Arzamas-16 (open access)

Demonstration of safeguards technology at the Russian Institute of Experimental Physics (VNIIEF), Arzamas-16

As part of the US-Russian Lab-to-Lab program for strengthening nuclear material protection, control, and accounting (MPC&A), a testbed facility has been established in a laboratory of the VNIIEF to demonstrate safeguards technology to nuclear facility operators. The design of the testbed MPC&A system provides the functions of nondestructive measurements for plutonium and highly enriched uranium, item control, personnel access control, radiation portal monitoring, search equipment, and computerized on-line accounting. The system controls, monitors, and accounts for nuclear material and people as the material moves through three MBAs. It also assists with physical inventory taking. A total of 39 instruments and control systems are being demonstrated in the present version of the testbed. Of these, about half are of Russian design and fabrication, including the software for the item monitoring and the accounting systems. These two computer systems are on an ethernet network and connected in a client-server local area architecture. The item monitoring system is integrated with the accounting system, providing alarm and status information to a central dispatcher terminal. The operation of the MPC&A testbed has been demonstrated under routine and alarm conditions in collaboration with safeguards staff from the six participating US national labs. Workshops and training for …
Date: September 1, 1995
Creator: Yuferev, V.; Skripka, G. & Augustson, R.H.
Object Type: Article
System: The UNT Digital Library
Feasibility of a continuous surface mining machine using impact breakers. First quarterly report, October 1-December 31, 1979 (open access)

Feasibility of a continuous surface mining machine using impact breakers. First quarterly report, October 1-December 31, 1979

This is the first quarterly report on the efforts to evaluate the feasibility of excavating coal and overburden from surface mines using impact breakers. The initial stages of the project are devoted to a literature search, equipment selection, test site selection, and conceptual test system design. Hence, this report details the progress made in these areas; the next quarter will see the finalization of Phase I. Included as appendices to this report are FMA internal reports on the individual mines visited. These reports are the basis of the test site selection, and have been censored here to remove data the mine operators deemed as confidential.
Date: January 1, 1980
Creator: Fisk, A. T.
Object Type: Report
System: The UNT Digital Library
Treating paraffin deposits in producing oil wells (open access)

Treating paraffin deposits in producing oil wells

Paraffin deposition has been a problem for operators in many areas since the beginning of petroleum production from wells. An extensive literature search on paraffin problems and methods of control has been carried out, and contact was made with companies which provide chemicals to aid in the treatment of paraffin problems. A discussion of the nature of paraffins and the mechanisms of this deposition is presented. The methods of prevention and treatment of paraffin problems are summarized. Suggested procedures for handling paraffin problems are provided. Suggestions for areas of further research testing are given.
Date: January 1, 1992
Creator: Noll, L.
Object Type: Report
System: The UNT Digital Library