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Synthesis And Experimental Testing Of A Nonlinear Optimal Tracking Controller, Timothy Mclain, Randal W. Beard, Christopher A. Bailey Jun 1999

Synthesis And Experimental Testing Of A Nonlinear Optimal Tracking Controller, Timothy Mclain, Randal W. Beard, Christopher A. Bailey

Faculty Publications

This paper presents a novel approach for developing tracking controllers for nonlinear systems. The approach involves the numerical solution, by Galerkin approximation, of the time-varying Hamilton-Jacobi-Bellman (HJB) equation and results in a nonlinear controller approximating the optimal tracking control law for a specified desired trajectory and cost function. Experimental results are presented for a nonlinear pendulum system.

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Metallicity Calibration Of A Ddo Cn Index And Other Low-Resolution Indices For G And K Stars, B. J. Taylor May 1999

Metallicity Calibration Of A Ddo Cn Index And Other Low-Resolution Indices For G And K Stars, B. J. Taylor

Faculty Publications

Metallicity calibrations of low-resolution parameters are potentially useful for (at least) two problems: the properties of moving groups, and the supermetallicity problem in K giants. In this paper, metallicity calibrations are derived for six sets of parameters. One of these parameters is the DDO CN index deltaCN. This parameter and three others are calibrated for use with evolved G and K stars. Two additional sets of low-resolution parameters are calibrated for use with G and K dwarfs. The calibrations are derived by comparing the input data with two catalogs of homogenized high-dispersion results from diverse authors (see Taylor 1995, 1999a). …

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The Mean Spherical Approximation For A Dipolar Yukawa Fluid, Douglas Henderson, Dezso Boda, Istvan Szalai, Kwong-Yu Chan May 1999

The Mean Spherical Approximation For A Dipolar Yukawa Fluid, Douglas Henderson, Dezso Boda, Istvan Szalai, Kwong-Yu Chan

Faculty Publications

The dipolar hard sphere fluid (DHSF) is a useful model of a polar fluid. However, the DHSF lacks a vapor–liquid transition due to the formation of chain-like structures. Such chains are not characteristic of real polar fluids. A more realistic model of a polar fluid is obtained by adding a Lennard–Jones potential to the intermolecular potential. Very similar results are obtained by adding a Yukawa potential, instead of the Lennard–Jones potential. We call this fluid the dipolar Yukawa fluid (DYF). We show that an analytical solution of the mean spherical approximation (MSA) can be obtained for the DYF. Thus, the …

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Modes And Quasi-Modes For M = 1,2 In A Gyrokinetic Model For A Non-Neutral Plasma, S. Neil Rasband, Ross L. Spencer May 1999

Modes And Quasi-Modes For M = 1,2 In A Gyrokinetic Model For A Non-Neutral Plasma, S. Neil Rasband, Ross L. Spencer

Faculty Publications

Modes and quasi-modes for m = 1,2 are studied in a gyro-kinetic model for a pure-electron plasma. Only z-independent perturbations are considered. Numerical methods are used to solve the relevant differential equations for smooth, analytic density profiles. Different temperatures and representative profiles are considered and comparison is made with the familiar cold fluid model from which the results depart but little, except at higher temperatures. A continuum component to the spectrum, present in the cold-fluid model, remains in the gyro-kinetic model to the order considered.

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The Probability Density Of Spectral Estimates Based On Modified Periodogram Averages, David G. Long, Paul E. Johnson May 1999

The Probability Density Of Spectral Estimates Based On Modified Periodogram Averages, David G. Long, Paul E. Johnson

Faculty Publications

Welch's (1967) method for spectral estimation of averaging modified periodograms has been widely used for decades. Because such an estimate relies on random data, the estimate is also a random variable with some probability density function. Here, the PDF of a power estimate is derived for an estimate based on an arbitrary number of frequency bins, overlapping data segments, amount of overlap, and type of data window, given a correlated Gaussian input sequence. The PDFs of several cases are plotted and found to be distinctly non-Gaussian (the asymptotic result of averaging frequency bins and/or data segments), using the Kullback-Leibler distance …

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Cryosphere Applications Of Nscat Data, David G. Long, Mark R. Drinkwater May 1999

Cryosphere Applications Of Nscat Data, David G. Long, Mark R. Drinkwater

Faculty Publications

Though designed to measure vector winds over the ocean, new imaging techniques facilitate the use of NASA scatterometer data (NSCAT) in cryosphere studies. NSCAT provides data of unprecedented coverage, resolution, and quality which, when coupled with the scatterometer image reconstruction with filtering (SIRF) algorithm, enables images of O at resolutions approaching 8 km over stationary targets. Such images are useful in ice mapping and classification, and multidecadal studies are possible by comparison with Seasat Scatterometer (SASS) data. The utility of NSCAT data in polar ice studies is illustrated through a review of two cryosphere applications of NSCAT data: (1) sea-ice …

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Postlaunch Sensor Verification And Calibration Of The Nasa Scatterometer, David G. Long, Wu-Yang Tsai, James E. Graf, Carroll Winn, James N. Huddleston, R. Scott Dunbar, Michael H. Freilich, Frank J. Wentz, W. Linwood Jones May 1999

Postlaunch Sensor Verification And Calibration Of The Nasa Scatterometer, David G. Long, Wu-Yang Tsai, James E. Graf, Carroll Winn, James N. Huddleston, R. Scott Dunbar, Michael H. Freilich, Frank J. Wentz, W. Linwood Jones

Faculty Publications

Scatterometer instruments are active microwave sensors that transmit a series of microwave pulses and measure the returned echo power to determine the normalized radar backscattering cross section (sigma-0) of the ocean surface from which the speed and direction of near-surface ocean winds are derived. The NASA Scatterometer (NSCAT) was launched on board the ADEOS spacecraft in August 1996 and returned ten months of high-quality data before the failure of the ADEOS spacecraft terminated the data stream in June 1997. The purpose of this paper is to provide an overview of the NSCAT instrument and sigma-0 computation and to describe the …

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Stratified Volume Diffractive Optical Elements As High Efficiency Gratings, Gregory P. Nordin, D. M. Chambers May 1999

Stratified Volume Diffractive Optical Elements As High Efficiency Gratings, Gregory P. Nordin, D. M. Chambers

Faculty Publications

We propose stratified volume diffractive optical elements as a new type of diffractive optical element that is capable of functioning as a high-efficiency grating in applications with requirements not suited to traditional holographic or diffractive optical techniques. In this approach, diffractive optical fabrication methods are used to construct an optical structure that emulates volume grating behavior. We discuss the diffraction properties of stratified volume diffractive optical elements and compare them with those used previously in both volume holographic optical elements and stratified volume holographic optical elements. A systematic design process is then presented for deriving structure parameters. We illustrate this …

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The Mycobactericidal Efficacy Of Orthophthalaldehyde And The Comparative Resistances Of Mycobacterium Bovis, Mycobacterium Terrae, And Mycobacterium Chelonae, Richard A. Robison, Adam W. Gregory, G. Bruce Schaalje, Jonathan D. Smart May 1999

The Mycobactericidal Efficacy Of Orthophthalaldehyde And The Comparative Resistances Of Mycobacterium Bovis, Mycobacterium Terrae, And Mycobacterium Chelonae, Richard A. Robison, Adam W. Gregory, G. Bruce Schaalje, Jonathan D. Smart

Faculty Publications

Objectives: To assess the mycobactericidal efficacy of an agent relatively new to disinfection, ortho-phthalaldehyde (OPA) and to compare the resistances of three Mycobacterium species. Mycobacterium bovis (strain BCG) was compared with Mycobacterium chelonae and Mycobacterium terrae to investigate the feasibility of using either of the latter two species in tuberculocidal testing. M chelonae (a rapid grower) and M terrae (an intermediate grower) both grow faster and are less virulent than M bovis (a slow grower).

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The Religious Right In Court: The Decision Making Of Christian Evangelicals In State Supreme Courts, Donald R. Songer, Susan J. Tabrizi May 1999

The Religious Right In Court: The Decision Making Of Christian Evangelicals In State Supreme Courts, Donald R. Songer, Susan J. Tabrizi

Faculty Publications

Much has been written recently about the emergence of evangelicals and others often labeled the "new Religious Right" in American politics. However, little attention has been paid to whether officials who have been socialized in the denominations characterized as being part of this Religious Right actually behave differently in office from those brought up in other religious traditions. The present study begins such an inquiry by examining differences in the voting behavior of state supreme court justices in three issue areas. Evangelical justices were found to be significantly more conservative than mainline Protestant, Catholic, and Jewish justices in death penalty, …

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Annotated Bibliography Of Research In The Teaching Of English, Deborah Brown, Wayne Martino, Gert Rijlaarsdam, Anne D'Antonio Stinson, Melissa E. Whiting May 1999

Annotated Bibliography Of Research In The Teaching Of English, Deborah Brown, Wayne Martino, Gert Rijlaarsdam, Anne D'Antonio Stinson, Melissa E. Whiting

Faculty Publications

Twice a year, in the May and November issues, RTE publishes a selected bibliography of recent research in the teaching of English, Most of the studies appeared during the six-month period preceding the compilation of the bibliography (July through December; 1998, for the present bibliography), but some studies that appeared earlier are occasionally included. The listing is selective; we make no attempt to include all research and research-related studies that appeared in the period under review Comments on the bibliography and suggestions about items for inclusion may be directed to the bibliography editors. We encourage you to send your suggestions …

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Online Auctions, Michael N. Huhns, José M. Vidal May 1999

Online Auctions, Michael N. Huhns, José M. Vidal

Faculty Publications

Auctions on the Internet can involve not only consumers, but also businesses. They can form dynamically and enable the exchange of goods much as stock exchanges manage the buying and selling of securities. But because auctions have a wide scope and a short lifetime, the opportunistic behavior needed for successful interaction requires agents to both participate in and manage auctions. The article focuses on the use of software agents in such Internet based auctions

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Ultrasonic Enhancement Of Antibiotic Action On Escherichia Coli Biofilms: An In Vivo Model, Andrea M. Rediske, Beverly L. Roeder, Maren K. Brown, Jared L. Nelson, Rachel L. Robison, David O. Draper, G. Bruce Schaalje, Richard A. Robison, William G. Pitt May 1999

Ultrasonic Enhancement Of Antibiotic Action On Escherichia Coli Biofilms: An In Vivo Model, Andrea M. Rediske, Beverly L. Roeder, Maren K. Brown, Jared L. Nelson, Rachel L. Robison, David O. Draper, G. Bruce Schaalje, Richard A. Robison, William G. Pitt

Faculty Publications

Biofilm infections are a common complication of prosthetic devices in humans. Previous in vitro research has determined that low-frequency ultrasound combined with aminoglycoside antibiotics is an effective method of killing biofilms. We report the development of an in vivo model to determine if ultrasound enhances antibiotic action. Two 24-h-old Escherichia coli (ATCC 10798) biofilms grown on polyethylene disks were implanted subcutaneously on the backs of New Zealand White female rabbits, one on each side of the spine. Low-frequency (28.48-kHz) and low-power-density (100- and 300-mW/cm2) continuous ultrasound treatment was applied for 24 h with and without systemic administration of gentamicin. The …

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Daunting, Indeed! A Critical Conversation With The Promise Of Lutheran Ethics, Gary M. Simpson Apr 1999

Daunting, Indeed! A Critical Conversation With The Promise Of Lutheran Ethics, Gary M. Simpson

Faculty Publications

The seven essayists in The Promise of Lutheran Ethics provide material for a fruitful conversation with the reviewer, which in turn provides food for thought for readers of the volume and the review.

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Harming Future Persons: Obligations To The Children Of Reproductive Technology, Philip G. Peters Jr. Apr 1999

Harming Future Persons: Obligations To The Children Of Reproductive Technology, Philip G. Peters Jr.

Faculty Publications

Two paradigms dominate contemporary ethical and legal debate about the risks posed to children who owe their lives to reproductive technology. One asks whether the children have lives so tragic that life itself is harmful. The other approach asks whether children so conceived are likely to enjoy a minimally decent existence. Although the two approaches have quite different analytic foundations, they share one crucial trait. Each concludes that children who owe their lives to reproductive technology are harmed only when that technology causes genuinely catastrophic injuries.Because these conventional paradigms define harmful conduct exclusively by reference to the magnitude of the …

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Andrews University’S First Lady, Beverly Matiko Apr 1999

Andrews University’S First Lady, Beverly Matiko

Faculty Publications

No abstract provided.

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Modern Feminism, Religious Pluralism, And Scripture, Jo Ann Davidson Apr 1999

Modern Feminism, Religious Pluralism, And Scripture, Jo Ann Davidson

Faculty Publications

No abstract provided.

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Sabbath And The New Covenant, Roy Gane Apr 1999

Sabbath And The New Covenant, Roy Gane

Faculty Publications

No abstract provided.

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A Comparison Of The Use Of Tympanic, Axillary, And Rectal Thermometers In Infants, Russell Wilshaw, Renea L. Beckstrand, Dawn Waid, Bruce Schaallje Apr 1999

A Comparison Of The Use Of Tympanic, Axillary, And Rectal Thermometers In Infants, Russell Wilshaw, Renea L. Beckstrand, Dawn Waid, Bruce Schaallje

Faculty Publications

This study examined the relationship between three instruments used in measuring tympanic, axillary, and rectal temperatures in infants less than 1 year of age. Temperatures were measured by Oto-temp Pedi Q tympanic thermometers, Becton Dickinson axillary thermometer, and rectal thermometers. A convience sample of 5 infants less than 90 day and 54 greater than 90 days with fever, as well as 34 infants less than 90 days and 27 infants greater than 90 days without fever were studied. Correlations of infants less than 90 days and greater 90 days of age, as well as differences between infant temperature with and …

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The Probability Distribution Of Nscat Measurements, Paul E. Johnson, David G. Long Mar 1999

The Probability Distribution Of Nscat Measurements, Paul E. Johnson, David G. Long

Faculty Publications

NSCAT makes only indirect measurements of wind. The direct measurement is of the backscattered radar power. The signal power is contaminated by radiometric noise so a separate measurement of the noise power is subtracted from the signal-plus-noise measurement to estimate the backscattered power. Using the radar equation, sigma-0 is computed from the measured signal power. From multiple sigma-0 mesaurements made at different azimuth angles, the wind is estimated. In wind retrieval, the NSCAT sigma-0 measurements are assumed to have a Gaussian probability distribution with a variance which depends on the mean. Given this distribution model, the maximum-likelihood estimtor is formed …

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Observations Of Lattice Curvature Near The Interface Of A Deformed Aluminium Bicrystal, Brent L. Adams, W. E. King, S. Sun Mar 1999

Observations Of Lattice Curvature Near The Interface Of A Deformed Aluminium Bicrystal, Brent L. Adams, W. E. King, S. Sun

Faculty Publications

This work was partially supported by MRSEC Program of the National Science Foundation (DMR-9632556), and under the auspices of the US Department of Energy and Lawrence Livermore National Laboratory under contract W-7405- Eng-48. S. Sun gratefully acknowledges the comments of Professor E. T. Onat, Professor B. T. Chu and Professor W. Tong of the Mechanical Engineering Department at Yale University, and their valuable guidance in the process of completing this project as a doctoral dissertation. The assistance of B. El-Dasher of Carnegie-Mellon University is also gratefully acknowledged. Reported here is a study of the pattern of lattice curvature near the …

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Particle Fluxes During Austral Spring And Summer In The Southern Ross Sea, Antarctica, Vernon L. Asper, Walker O. Smith Jr. Mar 1999

Particle Fluxes During Austral Spring And Summer In The Southern Ross Sea, Antarctica, Vernon L. Asper, Walker O. Smith Jr.

Faculty Publications

The flux of particles from the euphotic zone through 200 m was investigated on the Ross Sea continental shelf during two cruises, the first in November-December 1994 and the second in December 1995 and January 1996. An assessment of surface layer phytoplankton biomass and productivity was made simultaneously. Particle flux was measured using floating sediment traps whose collection efficiency was assessed rigorously. Phytoplankton biomass and productivity increased rapidly in November-December, and biomass was maximal in mid-December. Thereafter productivity appeared to decline substantially. Biomass declined as well, but mot as rapidly as productivity. Vertical flux rates were low early in the …

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Monte Carlo Study Of The Capacitance Of The Double Layer In A Model Molten Salt, Douglas Henderson, Dezso Boda, Kwong-Yu Chan Mar 1999

Monte Carlo Study Of The Capacitance Of The Double Layer In A Model Molten Salt, Douglas Henderson, Dezso Boda, Kwong-Yu Chan

Faculty Publications

Monte Carlo simulations are reported for charged hard spheres at high density near a charged wall. This system is a simple model for a molten salt double layer. Unfortunately, the reduced temperatures that correspond to experiment are very small. This results in a large Boltzmann factor. As a result, we are unable to obtain meaningful results for such low values and report results only for moderately low values of the reduced temperature. Even so, our results should be a useful benchmark. Further, we are able to give a qualitative answer to an interesting question. We find that at low temperatures …

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The Behavior Of Inorganic Material In Biomass-Fired Power Boilers: Field And Laboratory Experiences, Larry Lin Baxter 8507091, Thomas R. Miles, Thomas R. Miles Jr, Bryan M. Jenkins, Thomas Milne, David Dayton, Richard W. Bryers, Larry L. Oden Mar 1999

The Behavior Of Inorganic Material In Biomass-Fired Power Boilers: Field And Laboratory Experiences, Larry Lin Baxter 8507091, Thomas R. Miles, Thomas R. Miles Jr, Bryan M. Jenkins, Thomas Milne, David Dayton, Richard W. Bryers, Larry L. Oden

Faculty Publications

This paper highlights some of the major findings of the Alkali Deposits Investigation, a collaborative effort to understand the causes of unmanageable ash deposits in biomass-fired electric power boilers. A group of interested industrial institutions and the US DOE Energy Efficiency and Renewable Energy Office's Biomass Power Program through the National Renewable Energy Laboratory jointly sponsored the project. The industries contributed both funding and, in most cases, use of facilities to the project and included Mendota Biomass Power and Woodland Biomass Power (both associated with Thermo Electron Energy Systems), CMS Generation Operating (formerly Hydra-Co Operations), Wheelabrator, Shasta and Hudson Energy, …

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Digital Image Managers For The New Millennium: A Museum/University Collaboration, Samantha K. Hastings, Museums And The Web 1999 Mar 1999

Digital Image Managers For The New Millennium: A Museum/University Collaboration, Samantha K. Hastings, Museums And The Web 1999

Faculty Publications

The University of North Texas and the African American Museum in Dallas are partners in a program designed to produce expert managers of digital images and information. The School of Library and Information Sciences in cooperation with the School of Visual Arts received a grant from the federal Institute of Museum and Library services to build a collaborative program that includes a digital imaging laboratory and fellowships for students in a Certificate of Advanced Study Program. The work of the digital image manager includes the production of visual images, the creation and management of databases and the ability to use …

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Combustion Properties Of Biomass, B. M. Jenkins, Larry Lin Baxter 8507091, T. R. Miles Jr, T. R. Miles Mar 1999

Combustion Properties Of Biomass, B. M. Jenkins, Larry Lin Baxter 8507091, T. R. Miles Jr, T. R. Miles

Faculty Publications

Properties of biomass relevant to combustion are briefly reviewed. The compositions of biomass among fuel types are variable, especially with respect to inorganic constituents important to the critical problems of fouling and slagging. Alkali and alkaline earth metals, in combination with other fuel elements such as silica and sulfur, and facilitated by the presence of chlorine, are responsible for many undesirable reactions in combustion furnaces and power boilers. Reductions in the concentrations of alkali metals and chlorine, created by leaching the elements from the fuel with water, yield remarkable improvements in ash fusion temperatures and confirm much of what is …

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Determination Of A Methane Intermolecular Potential Model For Use In Molecular Simulations From Ab Initio Calculations, Richard L. Rowley, Tapani A. Pakkanen Feb 1999

Determination Of A Methane Intermolecular Potential Model For Use In Molecular Simulations From Ab Initio Calculations, Richard L. Rowley, Tapani A. Pakkanen

Faculty Publications

The possibility of obtaining an accurate site-site potential model suitable for use in molecular dynamics (MD) simulations of methane from ab initio calculations has been explored. Counterpoise-corrected (CPC), supermolecule, ab initio energies at the MP2/6-311 + G(2df,2pd) level were computed for eleven relative orientations of two methane molecules as a function of C-C separation distance. C-C, C-H, and H-H interaction parameters in a pairwise-additive, site-site potential model for rigid methane molecules were regressed from the ab initio energies, and the resultant model accurately reproduced the ab initio energies. The model suggests that C-H attractions are dominant in weakly binding the …

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Law And Politics In Judicial Oversight Of Federal Administrative Agencies, Martha Anne Humphries, Donald R. Songer Feb 1999

Law And Politics In Judicial Oversight Of Federal Administrative Agencies, Martha Anne Humphries, Donald R. Songer

Faculty Publications

Administrative agencies play a substantial role in the formulation and implementation of national policy Central to this role is their exercise of discretion. A normative consensus exists that such discretion should be constrained by administrative deference to the rule of law. The courts of appeals are expected to insure that such discretion is constrained. The analysis reported below examines how effectively they fulfill that expectation The findings suggest that agency success is related to political considerations, with agencies being successful when their decisions are consistent with the policy preferences of the judges. However, variables that captured elements of the legal …

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La France Et L'Égypte De 1882 À 1914: Intérêts Économiques Et Implications Politiques, By Samir Saul, Michael S. Smith Feb 1999

La France Et L'Égypte De 1882 À 1914: Intérêts Économiques Et Implications Politiques, By Samir Saul, Michael S. Smith

Faculty Publications

A review of La France et l'Égypte de 1882 à 1914: Intérêts économiques et implications politiques, by Samir Saul

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Childhood Aggression And Gender: A New Look At An Old Problem, Nicki R. Crick, Nicole E. Werner, Juan F. Casas, Kathryn M. O'Brien, David A. Nelson, Jennifer K. Grotpeter, Kristian Markon Feb 1999

Childhood Aggression And Gender: A New Look At An Old Problem, Nicki R. Crick, Nicole E. Werner, Juan F. Casas, Kathryn M. O'Brien, David A. Nelson, Jennifer K. Grotpeter, Kristian Markon

Faculty Publications

Because of its deleterious effects on individuals and society, and the important role that it has been given in several theories of human behavior (e.g., psychoanalytic theory, social learning theory; Freud, 1930; Bandura & Walters, 1959; Bandura, 1986), aggression has been one of the most widely researched topics in the past several decades. Although many important advances have been made in our understanding of aggressive behavior, most of this knowledge has been gained through the study of aggressive males only (Crick & Dodge, 1994; Parke, 1992; Robins, 1986) and through the study of forms of aggression that are more characteristic …

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