| Fatigue Variability of a Single Crystal Superalloy at Elevated Temperature (Preprint) |
Mar-2009 |
18 pages |
| Authors:
Reji John; JOHN PORTER; Ryan Morrissey; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
 | In order to develop more accurate life prediction tools, an improved understanding of the variability within the fatigue behavior of a material is required. Recent work has shown multiple failure mechanisms that drive the variability in fatigue life of polycrystalline titanium and nickel materials. In addition, the bimodal behavior in the fatigue response is not readily apparent when only a very small number of specimens are tested at each loading ... |
|
| Cost and Time Model of a Simulated Painting Facility for Tactical Vehicles |
AUG 2007 |
30 pages |
| Authors:
Jr. Kidd James A.; Sandra K. Young; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| This report provides a reference framework for economic and manufacturing process models. It illustrates the effect several input variables have on the cost of and time required for repainting two widely deployed U.S. Army tactical vehicles. This evaluation quantifies the required time and expense of each processing segment for refurbishing two different vehicles and provides the respective totals. This evaluation was performed with calculations using deterministic (fixed or averaged) input. ... |
|
| The Theory of Canonical Perturbations Applied to Attitude Dynamics and to the Earth Rotation. Osculating and Nonosculating Andoyer Variables |
21 JUN 2007 |
34 pages |
| Authors:
Michael Efroimsky; Alberto Escapa; NAVAL OBSERVATORY WASHINGTON DC
|
| In the method of variation of parameters we express the Cartesian coordinates or the Euler angles as functions of the time and six constants. If, under disturbance, we endow the "constants" with time dependence, the perturbed orbital angular velocity will consist of a partial time derivative and convective term that includes time derivatives of the "constants". The Lagrange constraint, often imposed for convenience, nullifies the convective term and thereby guarantees ... |
|
| A Correction for Land Contamination of Atmospheric Variables near Land-Sea Boundaries |
APR 2007 |
17 pages |
| Authors:
A. B. Kara; Alan J. Wallcraft; Harley E. Hurlburt; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| Ocean models need over-ocean atmospheric forcing. However, such forcing is not necessarily provided near the land-sea boundary because (1) the atmospheric model grid used for forcing is frequently much coarser than the ocean model grid, and (2) some of the atmospheric model grid over the ocean includes land values near coastal regions. This paper presents a creeping sea-fill methodology to reduce the improper representation of scalar atmospheric forcing variables near ... |
|
| Predictors of Attrition in the Finnish Conscript Service |
NOV 2006 |
|
| Authors:
Mikael Salo; Guy L. Siebold; NATIONAL DEFENCE COLL HELSINKI (FINLAND)
|
 | This report describes attrition in the Finnish conscript service and identifies variables that predict attrition and their relative strength as determined by various statistical models. Subjects were 2,003 conscripts, 211 of whom were separated before completing their 6-month military obligation. The categories of predictors considered were conscript demographic and background variables, aptitude, mental and physical health, and pertinent attitudes and perceptions. The research extended previous research by considering a wider ... |
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| A New Paradigm of Fatigue Variability Behavior and Implications for Life Prediction (Preprint) |
JUN 2006 |
23 pages |
| Authors:
S. K. Jha; M. J. Caton; J. M. Larsen; UNIVERSAL TECHNOLOGY CORP DAYTON OH
|
| The treatment of the fatigue variability behavior has traditionally been based on the understanding of the mean-lifetime behavior. With reference to two turbine engine materials, an alpha + Beta titanium alloy and a nickel-based superalloy, it is shown that the traditional approach may not accurately describe the fatigue variability behavior of these materials. Decreases in stress level, or microstructural change directed at increasing the mean lifetime, were found to affect ... |
|
| Hazards of U.S. Navy Enlisted Occupations: A General Model |
02 MAY 2006 |
30 pages |
| Authors:
Jr. Vickers Ross R.; Vickers Tyler C.; Linda K. Hervig; NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA
|
| The hospitalization rate for injuries varies widely across U.S. Navy enlisted occupations. Logic suggests that this variation is related to occupational demands. Previous research shows that higher accident rates occur in occupations that demand physical exertion and fast reaction times. However, the estimated effects of those demands may have been biased by the omission of other important contributors to accidents. The goal of this study was to construct a complete ... |
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| An Interactionalist Analysis of Soldier Retention across Career Stages and Time |
APR 2006 |
48 pages |
| Authors:
Gilad Chen; Robert E. Ployhart; TEXAS A AND M UNIV COLLEGE STATION
|
| Ever since the Army became an All-Volunteer force, it has become critical to understand the factors influencing Soldiers' retention decisions. While the Army can implement short-term solutions to problems resulting from turnover (e.g., increasing recruitment efforts), a long-term solution requires an understanding of the dynamics driving the current levels of attrition. The authors propose an integrative, interactional model of retention, with links among general cognitive ability, situational variables (i.e., work ... |
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| Cost as an Independent Variable: A Study of Its Continued Use by Aeronautical Systems Center's Programs and Their Contractors to Set and Maintain Cost Objectives |
MAR 2006 |
81 pages |
| Authors:
Kevin W. Codrington; AIR FORCE INST OF TECHNOLOGY WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The purpose of this research was to assess whether Aeronautical System Center's (ASC's) acquisition professionals believe CAIV has enabled their programs and contractors to set and maintain cost objectives. The three major objectives of this thesis are to answer the following questions: First, Do ASC's acquisition professionals believe their programs are setting and maintaining cost objectives? Second, Do ASC's acquisition professionals believe their contractors are setting and maintaining cost objectives? ... |
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| Static Sector Characteristics and Operational Errors |
MAR 2006 |
16 pages |
| Authors:
Scott Goldman; Carol Manning; Elaine Pfleiderer; FEDERAL AVIATION ADMINISTRATION OKLAHOMA CITY OK CIVIL AEROMEDICAL INST
|
| This study was conducted to determine if static sector characteristics are related to the occurrence of operational errors (OEs) at the Indianapolis Air Route Traffic Control Center (ZID). The authors sought to determine whether factors that predicted OEs at the Atlanta Air Route Traffic Control Center (ZTL) in a study conducted by Rodgers et al. (1998) would also predict OE occurrence at other facilities. The data consisted of a 3-year ... |
|
| A Longitudinal Examination of First Term Attrition and Reenlistment among FY1999 Enlisted Accessions |
NOV 2005 |
449 pages |
| Authors:
William J. Strickland; HUMAN RESOURCES RESEARCH ORGANIZATION ALEXANDRIA VA
|
| The U.S. Army Research Institute for the Behavioral and Social Sciences (ARI) developed Project First Term as a multi-year, longitudinal investigation of Soldier attrition and reenlistment among the cohort of recruits who joined the Army in Fiscal Year 1999. This effort allowed the evaluation of models of attrition and reenlistment intentions based on information contained in personnel records and collected from Soldiers who were surveyed as they entered the service, ... |
|
| On Quantifer Elimination by Virtual Term Substitution |
24 AUG 2005 |
20 pages |
| Authors:
Christopher W. Brown; NAVAL ACADEMY ANNAPOLIS MD DEPT OF COMPUTER SCIENCE
|
| This paper presents a new look at Weispfenning's method of quantifier elimination by virtual term substitution and provides two important improvements. Virtual term substitution eliminates a quantified variable by substituting formulas in the remaining variables for each atomic formula in which the quantified variable appears. This paper investigates the polynomials that arise in substitution formulas Weispfenning proposed and, based on this examination, provides a simpler substitution for the general case, ... |
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| Response Surface Methodology |
OCT 2004 |
32 pages |
| Authors:
Kathleen M. Carley; Natalia Y. Kamneva; Jeff Reminga; CARNEGIE-MELLON UNIV PITTSBURGH PA SCHOOL OF COMPUTER SCIENCE
|
| There is a problem faced by experimenters in many technical fields, where, in general, the response variable of interest is y, and there is a set of predictor variables x1, x2,...xk. For example, in Dynamic Network Analysis (DNA) Response Surface Methodology (RSM) might be useful for sensitivity analysis of various DNA measures for different kinds of random groups and errors. |
|
| Pattern Search Algorithms for Mixed Variable General Constrained Optimization Problems |
09 SEP 2002 |
193 pages |
| Authors:
Mark A. Abramson; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH
|
| A new class of algorithms for solving nonlinearly constrained mixed variable optimization problems is presented The Audet-Dennis Generalized Pattern Search (GPS) algorithm for bound constrained mixed variable optimization problems is extended to problems with general nonlinear constraints by incorporating a filter in which new iterates are accepted whenever they decrease the incumbent objective function value or constraint violation function value Additionally, the algorithm can exploit any available derivative information (or ... |
|
| An Investigation of Variable Time Interval "K-like" Geomagnetic Indices |
16 DEC 1999 |
134 pages |
| Authors:
Devin J. Della-Rose; UTAH STATE UNIV LOGAN
|
| The 3-hour planetary K index derivative, Kp, is designed to measure irregular fluctuations in the Earth's magnetic field due to currents in the magnetosphere-ionosphere system. The index is widely used to drive empirical models of auroral particle precipitation, high-latitude convection patterns, thermospheric composition, and neutral winds. The 3-hour time interval of Kp makes it suitable for use as a parameter in thermospheric models, since the ... |
|
| Bond Variability of Glass-Fiber-Reinforcing-Plastic Reinforcement in Concrete |
DEC 1998 |
414 pages |
| Authors:
Joseph P. Hanus; MINNESOTA UNIV MINNEAPOLIS
|
| This report summarizes an experimental program that investigated the bond variability of glass-fiber-reinforced-polymer (GFRP) reinforcement in concrete. The variables in the study were manufacturer (Marshall Industries Composites, Inc. M1 and Corrosion Proof Products/Hughes Brothers M2), bar size (No. 5 and 6), cover (2 and 3 bar diameters), and embedment length (10 through 47 in.). Tensile tests were also performed on the GFRP rebar for comparison to bond tests that exhibited ... |
|
| Variable Angle Reflectometer Employing an Integrating Sphere and a Light Concentrator |
28 APR 1998 |
|
| Authors:
Keith A. Snail; Leonard Hanssen; David Chenault; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A reflectometer and a method for measuring the reflectance and transmittance of material using an integrating sphere and a light concentrator. The reflectance and transmittance measurements are performed as a function of the angle of incidence of a beam of light onto a sample and reference material. In a preferred embodiment, a CHC-lens concentrator having a high f/# and a low index of refraction is used. |
|
| Identification of Potential Combat Effectiveness Variables |
NOV 1997 |
23 pages |
| Authors:
Richard A. White; Joseph Olmstead; CONTINENTAL SYSTEMS TECHNOLOGY CORP MARIETTA GA
|
| This report describes a project whose purpose was to identity and, where possible, develop potential individual combat effectiveness variables (CEV). The project has its origin in the need for valid combat effectiveness criteria, to be used in validation of predictors of combat effectiveness. The problem was to identity and operationalize attributes, behaviors, and performances that will serve as potential CEVs. After identification and operationalization, potential CEVs can be validated and ... |
|
| A Statistical Analysis of Variables Related to Officer Retention |
SEP 96 |
72 pages |
| Authors:
Gerald A. Scheuchner; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| The overall objective of this research effort was to statistically analyze survey responses which indicate the extent to which exiting officers say different variables affected their decision to separate. Two surveys were utilized for this analysis. These surveys were administered by the Air Force Personnel and Survey Branch in 1991 and 1993. The first analysis tested whether significant differences existed between rated and non-rated officers with regard to how strongly ... |
|
| Polymorphic Typing of Variables and References |
Jan-1996 |
15 pages |
| Authors:
GEOFFREY SMITH; Dennis Volpano; FLORIDA INTERNATIONAL UNIV MIAMI
|
| In this article we consider the polymorphic type checking of an imperative language. Our language contains variables, first-class references (pointers), and first-class functions. Variables, as in traditional imperative languages, are implicitly dereferenced, and their addresses (L-values) are not fist-class values. Variables are easier to type check than references and, in many cases, lead to more general polymorphic types. We present a polymorphic type system for our language and prove that ... |
|
| Implementation of the Majorization Program for Computing Optimum Combined Kinematic Variables on the HP9OOO/835. Software Documentation |
MAY 95 |
52 pages |
| Authors:
Marjorie R. Seemann; NAVAL BIODYNAMICS LAB NEW ORLEANS LA
|
| Use of kinematic data in mathematical modeling often requires a consistent set of kinematic variables from the acceleration to the displacement level. A method termed Marjorization was previously developed to combine photographic and sensor- derived variables in an optimal way to produce a consistent set of kinematic variables, which are called Marjorized variables. The computer program that implemented this method was developed in the 1980s on the UNIVAC computer. To ... |
|
| Some New Saturated Two-Level Designs |
JAN 95 |
19 pages |
| Authors:
Ronald B. Crosier; EDGEWOOD RESEARCH DEVELOPMENT AND ENGINEERING CENTER ABERDEEN PROVING GROUND MD
|
| First-order saturated designs can have the two desirable properties of being an orthogonal design and having two levels only if n=O mod 4, where n is the number of design points. For other cases, researchers have developed D- optimal two level designs. Recently, two-level saturated designs that are efficient for submodels containing only a few of the factors were developed. These p-efficient designs (p is the number of parameters in ... |
|
| Sensitivity Analysis for Pearson-Lawley Corrections in the Context of Nonignorable Missingness |
29 AUG 94 |
32 pages |
| Authors:
Guanghan Liu; Bengt Muthen; JOHNS HOPKINS UNIV BALTIMORE MD
|
| We consider a model sensitivity problem of a dependent variable on several exogenous variables while the dependent variable has some missing data. Under certain assumptions on the model of selected sample and on the selection mechanism, a mixture model is derived and some statistical properties are discussed. This model gives a way to derive Pearson Lawley (PL) correction formula for the covariance matrix and leads to a modification when the ... |
|
| A Variable Rate Voice Coder using LPC-10E |
12 JUL 1994 |
3 pages |
| Authors:
J. P. Macker; R. B. Adamson; NAVAL RESEARCH LAB WASHINGTON DC COMMUNICATION SYSTEMS BRANCH
|
| This paper describes the current status of an ongoing research and development effort whose objective is a variable rate voice coder with a high degree of speech intelligibility and natural voice quality with an average throughput rate near 1200 b/s. The voice coder described here is based on the DoD FS 1015 LPC-10 2400 b/s vocoder. A method of silence detection and the use of variable size data frame formats ... |
|
| Dielectric Viscometer Including Fixed and Variable Cells. |
18 JAN 1994 |
|
| Authors:
John G. Williams; Thomas M. Donnellan; Ronald E. Trabocco; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A parallel plate dielectric viscometer is provided for measuring the viscosity of a substance having differing substance dielectric properties at differing substance viscosities. Two electrodes are disposed in opposition to each other forming a variable dielectric cell having a dielectric distance between the electrodes. The viscosity of the substance is varied and force is applied to the substance to vary the dielectric distance according to the varying viscosity. The rate ... |
|
| Benchmark Production Scheduling Problems for Job Shops with Interactive Constraints |
SEP 93 |
143 pages |
| Authors:
Stewart W. James; Bruno A. Mediate Jr; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF LOGISTICS AND ACQUIS ITION MANAGEMENT
|
| United States Air Force (USAF) depots have expressed interest in utilizing DISASTER production scheduling software to schedule their maintenance operations. DISASTER attempts to increase system throughput by building effective schedules for system, constraint resources. However, when a system contains multiple, interactive constraints, DISASTER builds the constraint schedules one at a time. Since each successive schedule must adhere to timing restrictions imposed by previous constraint schedules, the quality of the schedules ... |
|
| A Comparison of Non-Performance Characteristics with United States Air Force Officer Promotions |
SEP 93 |
42 pages |
| Authors:
James W. Bruns; Lawrence A. Eichhorn; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF LOGISTICS AND ACQUIS ITION MANAGEMENT
|
| The question of which non-performance factors influence the promotion of officers to major, lieutenant colonel, and colonel within the Air Force for Promotion Boards held in 1992 is the focus of this thesis. The thesis statistically examines the impact of the variables commissioning source, prior enlistment, age, aeronautical rating, graduate education level obtained and source of education, Professional Military Education courses taken and method of completion, distinguished graduate status from ... |
|
| Closed Form Characteristic Function for General Complex Second-Order Form in Correlated Complex Gaussian Random Variables |
12 JUL 93 |
64 pages |
| Authors:
Albert H. Nuttall; NAVAL UNDERSEA WARFARE CENTER NEWPORT DIV RI
|
| The properties of the left and right eigenvectors of generalized characteristic value problems with non-Hermitian complex matrices are reviewed, and diagonal expansions of various matrix combinations and inverses are derived. The interrelationships of the solutions of two related non-Hermitian characteristic value problems are determined and found to be simply related to the earlier eigenvectors and their properties. These results are then applied to the evaluation of the characteristic function of ... |
|
| Set Based Analysis of ML Programs |
JUL 93 |
21 pages |
| Authors:
Nevin Heintze; CARNEGIE-MELLON UNIV PITTSBURGH PA SCHOOL OF COMPUTER SCIENCE
|
| Reasoning about a program by treating program variables as sets of values leads to a simple, accurate and intuitively appealing notion of program approximation. This paper presents such an approach for the compile-time analysis of ML programs. To develop the core ideas of the analysis, we consider a simple untyped call-by-value functional language. Starting with an operational semantics for the language, we develop an approximate set based operational semantics which ... |
|
| Diffusion of Polyphenylene Oxide and Polystyrene Using Variable Angle ATR |
FEB 93 |
34 pages |
| Authors:
Robert A. Shick; Jack L. Koenig; Hatsuo Ishida; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF MACROMOLECULAR SCIENCE
|
| Migration in the polyphenylene oxide - polystyrene system has been investigated using a variable angle internal reflection spectroscopic technique. Particular attention has been devoted to the condition where the PPO is glassy and the PS is in the molten state. For this case, the overall diffusion has been observed to be Fickian, however there are also some non-Fickian characteristics. |
|
| Use of AVHRR Data to Verify a System for Forecasting Diurnal Sea Surface Temperature Variability |
1993 |
13 pages |
| Authors:
J. D. Hawkins; R. M. Clancy; J. F. Price; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
|
| Forecasts from an operational system for predicting global diurnal sea surface temperature (SST) variability are compared against multichannel sea surface temperatures calculated from advanced very high resolution radiometer data from the NOAA-9 satellite. The forecast system consists of an upper-ocean model driven by heat fluxes and wind stresses from an operational global weather prediction model. Visual pattern correlations between observed and forecast diurnal changes in SST are generally favorable, indicating ... |
|
| Evicted Variables and the Interaction of Global Register Allocation and Symbolic Debugging |
OCT 92 |
|
| Authors:
Ali-Reza Adl-Tabatabai; Thomas Gross; CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF COMPUTER SCIENCE
|
| A symbolic debugger allows a user to display the values of program variables at a breakpoint. However, problems arise if the program is translated by an optimizing compiler. This paper addresses the effects of global register allocation and assignment: a register assigned to a variable V may not be holding V's value at a breakpoint since the register can also be assigned to other variables. We define the problem of ... |
|
| Variable Control System Limits On Black Hawk And Seahawk Helicopters |
OCT 92 |
39 pages |
| Authors:
J. Blackwell; S. Dutton; R. Toffoletto; J. F. Harvey; AERONAUTICAL RESEARCH LABS MELBOURNE (AUSTRALIA)
|
| Black Hawk and Seahawk helicopters have various fixed physical control limits situated throughout the control system. The range of each pilot control is variable and depends on which limit is reached first. This is a function of the pilot control inputs applied, together with any additional control inputs provided by the automatic flight control system. A procedure has been developed to monitor controls in the vicinity of each limit, and ... |
|
| Behavioral Variability, Learning Processes, and Creativity |
SEP 90 |
138 pages |
| Authors:
Marc N. Richelle; LIEGE UNIV (BELGIUM)
|
| This research investigated properties of behavioral variability in humans. Two categories of independent variables were considered: environmental and cognitive. The investigation suggested that the capacity to vary behavior is limited by the subject's general developmental level, which cannot be confounded with her/his cognitive capacities. The research concluded that variability is an inherent characteristic of behavior. Keywords: Learning behavior, Cognition variables; Visual signals. (Author) (emk) |
|
| In Search of a Combat Theory: the Tactical Utility of TMCI's Military Combat Theory |
27 NOV 89 |
47 pages |
| Authors:
James A. Muhl Jr; ARMY COMMAND AND GENERAL STAFF COLL FORT LEAVENWORTH KS SCHOOL OF ADVANCED MIL ITARY STUDIES
|
| What is the relevance of the Military Conflict Institute's (TMCI's) new military combat theory for the tactical commander? The answer to this question highlights the long debate over the role of science and art in the commander's estimate, a debate which the Soviets have answered with 'all science' and the U.S. with 'all art'. If the end objective of theory and doctrine is to generate combat power then TMCI's integrated ... |
|
| Approximations to Joint Distributions of Definite Quadratic Forms |
21 NOV 89 |
20 pages |
| Authors:
D. R. Jensen; Herbert Solomon; STANFORD UNIV CA DEPT OF STATISTICS
|
| Multidimensional Wilson-Hilferty transformations support Gaussian approximations to certain joint distributions of quadratic forms in Gaussian variables. Central and noncentral distributions are studied and applications are noted. Parameters of the approximating distributions are given up to terms of order omicron(v to the minus 3rd power) in the degrees of freedom (nu). Numerical studies validate using these approximations over a range of parameters for an essential subclass of the distributions. (KR) ... |
|
| On Detecting Influential Data and Selecting Regression Variables |
OCT 89 |
19 pages |
| Authors:
Shanti S. Gupta; Deng-Yuan Huang; PURDUE UNIV LAFAYETTE IN DEPT OF STATISTICS
|
| We consider a linear regression model. We attempt to measure the influence on the residual for the full model and the reduced model. A criterion to select important independent regression variables is also derived using the influence diagnostics. This criterion turns out to be the same as the one proposed by Gupta and Huang (1988). (kr) |
|
| Isolation of Important Input Factors in the Performance of Operational Propulsion Plant Exams (OPPE) and Light Off Exams (LOE) for Atlantic Fleet Ships |
SEP 89 |
53 pages |
| Authors:
Thomas D. Nolen; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis examines the relationships between independent variables such as underway time, material conditions, and personnel manning and dependent variables in the form of engineering exam scores. Multinomial linear regression models are used to examine these relationships. These efforts met with limited success. The percent of time that a ship spends underway prior to an OPPE was the most significant of any independent variable considered, yet efforts to model the ... |
|
| A Compound Scaling Algorithm for Mathematical Optimization |
FEB 89 |
53 pages |
| Authors:
Vipperla B. Venkayya; Victoria A. Tischler; WRIGHT RESEARCH AND DEVELOPMENT CENTER WRIGHT-PATTERSON AFB OH
|
| This paper derives a compound scaling algorithm from a single scaling algorithm for use with general mathematical optimization problems. Compound scaling is necessary when the constraints are nonlinear and the variables do not all belong to the active set. Compound scaling in conjunction with the optimality criteria method has practical applications in large scaled multidisciplinary design. It will extend the scope of the optimality criteria method to handle problems with ... |
|
| A View of Unconstrained Optimization |
02 OCT 87 |
|
| Authors:
J. E. Dennis Jr.; Robert B. Schnabel; COLORADO UNIV AT BOULDER DEPT OF COMPUTER SCIENCE
|
| Finding the unconstrained minimizer of a function of more than one variable is an important problem with many practical applications, including data fitting, engineering design, and process control. In addition, techniques for solving unconstrained optimization problems form the basis for most methods for solving constrained optimization problems. This paper surveys the state of the art for solving unconstrained optimization problems and the closely related problem of solving systems of nonlinear ... |
|
| Variable Selection in Logistic Regression |
JUN 87 |
|
| Authors:
Z. D. Bai; P. R. Krishnaiah; L. C. Zhao; PITTSBURGH UNIV PA CENTER FOR MULTIVARIATE ANALYSIS
|
| In many situations, we are interested in selection of important variables which are adequate for prediction under a logistic regression model. In this paper, some selection procedures based on the information theoretic criteria are proposed, and these procedures are proved to be strongly consistent. Keywords: Maximum likelihood estimation; Multivariate analysis; Asymptotic expansion. |
|
| Strong Consistency of Estimation of Number of Regression Variables when the Errors are Independent and Their Expectations are not Equal to Each Other |
JUN 87 |
|
| Authors:
Yuehua Wu; PITTSBURGH UNIV PA CENTER FOR MULTIVARIATE ANALYSIS
|
| This document considers the linear regression model y sub i = x sub i B + e sub i, i = 1, 2, ..., where (x sub i) - is a sequence of known p-vectors, Beta = (Beta Sub 1, ..., Beta Sub p) is an unknown p-vector, known as regression coefficients, (e Sub i) is a sequence of random errors. It is of interest to test the hypothesis H ... |
|
| Stable, Robust Tracking by Sliding Mode Control |
MAY 87 |
|
| Authors:
George C. Verghese; Benito Fernandez; J. K. Hedrick; MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR INFORMATION AND DECISION SYSTEMS
|
| Sliding mode control is examined from the perspective of obtaining stable and robust tracking of an arbitrary time-varying reference by a multi- input-output, linear, time-invariant system driven by a certain class of bounded errors, nonlinearities and disturbances. Most exciting schemes for such systems are subsumed by the one presented here. The results are developed via the use of inverse models, and make clear the constraints imposed by the finite and ... |
|
| Using Data Envelopment Analysis to Measure the Efficiency of Not-for- Profit Organizations: A Critical Evaluation Comment |
JAN 87 |
|
| Authors:
T. Ahn; A. Charnes; W. W. Cooper; TEXAS UNIV AT AUSTIN CENTER FOR CYBERNETIC STUDIES
|
| This note responds to Nunamaker (1985) who supposedly deals with deficiencies in Data Envelopment Analysis (DEA) as an approach for measuring efficiencies of not-for-profit entities identified as Decision Making Units (DMUs) and locating sources and amounts of inefficiencies in each of the input used and in each of the outputs produced by each DMU. Corrections and comments are offered with reference supplied for interested readers who wish to examine more ... |
|
| Statistical Inferences in Cross-Lagged Panel Studies |
NOV 85 |
51 pages |
| Authors:
Lawrence S. Mayer; STANFORD UNIV CA DEPT OF STATISTICS
|
| Cross-lagged panel studies are statistical studies in which two or more variables are measured for a large number of subjects at each of several waves or points in time. The variable divide naturally into two sets and the primary purpose of the analysis is to estimate and test the cross-effects between the two sets. Such studies are found in the main-streams of social behavioral and business research. One approach to ... |
|
| Effect of Additional Variables in Principal Component Analysis, Discriminant Analysis and Canonical Correlation Analysis |
AUG 85 |
|
| Authors:
Y. Fujikoshi; P. R. Krishnaiah; J. Schmidhammer; PITTSBURGH UNIV PA CENTER FOR MULTIVARIATE ANALYSIS
|
| In this paper, the authors derived asmptotic distributions of changes in certain functions of the eigenvalues of the sample covariance matrix, MANOVA matrix and canonical correlation matrix when some variables are added to the original sets of variables. The above results are useful in finding out as to whether the new variables give additional information for statistical inference; multivariate analysis; Wishart distribution. (Author) |
|
| Internal Variables in the Lattice for Cholesky Factorization. Kalman Filtering, and Model Identification |
DEC 1984 |
|
| Authors:
L. L. Scharf; C. Demeure; RHODE ISLAND UNIV KINGSTON DEPT OF ELECTRICAL ENGINEERING
|
| The Levinson recursions provide an efficient algorithm for factoring the inverse of a Toeplitz correlation matrix R into its upper and lower triangular Cholesky factors. These factors produce a Gram-Schmidt orthogonalization of the underlying time series. The recursions are routinely used to compute reflection coefficients for implementing whitening and predicting filters in lattice form. These are also used to go back and forth between reflection coefficients, order-increasing whiteners, and correlations. ... |
|
| Boundary Conditions and Operationalizations of Expectancy Theory Variables |
FEB 1984 |
27 pages |
| Authors:
D. R. Ilgen; L. H. Peters; PURDUE RESEARCH FOUNDATION LAFAYETTE IN
|
| Expectancy Theory measures were applied in a classroom setting for predicting test performance in order to compare amplitude and highest probability measures of expectancies and instrumentalities. In addition, an individual difference boundary condition reflecting the degree to which subjects realistically estimated their effort-performance expectancies was investigated. The results showed some support for the expanded expectancy model. In addition, the model was most predictive for subjects who underestimated their effort- performance ... |
|
| Selection Procedures for Optimal Subsets of Regression Variables |
1984 |
|
| Authors:
S. S. Gupta; D. Y. Huang; C. L. Chang; PURDUE UNIV LAFAYETTE IN DEPT OF STATISTICS
|
|
| Modelling with Integer Variables |
1984 |
|
| Authors:
J. K. Lowe; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| Representing nonlinear optimization problems as mixed-integer programs has largely been considered as; (1) an art with few unresolved theoretical issues, and (2) a fairly standard preprocessing routine when combined with several ad hoc modelling improvements which have evolved through computational experience. The more common avenue of research in mixed-integer programming has focused upon finding improved algorithms and heuristics to solve the problems, assuming a standard mixed-integer representation exists. This thesis, ... |
|
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