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Informe de la Comision de la Verdad Para El Salvador: Anexos, Tomo 2

Description: Second annex published as part of the United Nations (UN) report from The Commission on the Truth for El Salvador (La Comision de la Verdad para El Salvador). This section includes supplementary documentation of the Commission's work: statistical analysis of testimony received, lists of victims, lists of disappeared persons, a list of members of the armed forces who were killed, and a list of members of the Frente Farabundo Martí para la Liberación Nacional (FMLN) who were killed.
Date: 1993
Creator: La Comision de la Verdad para El Salvador
Partner: UNT Libraries

Mathematical Programming Approaches to the Three-Group Classification Problem

Description: In the last twelve years there has been considerable research interest in mathematical programming approaches to the statistical classification problem, primarily because they are not based on the assumptions of the parametric methods (Fisher's linear discriminant function, Smith's quadratic discriminant function) for optimality. This dissertation focuses on the development of mathematical programming models for the three-group classification problem and examines the computational efficiency and classificatory performance of proposed and existing models. The classificatory performance of these models is compared with that of Fisher's linear discriminant function and Smith's quadratic discriminant function. Additionally, this dissertation investigates theoretical characteristics of mathematical programming models for the classification problem with three or more groups. A computationally efficient model for the three-group classification problem is developed. This model minimizes directly the number of misclassifications in the training sample. Furthermore, the classificatory performance of the proposed model is enhanced by the introduction of a two-phase algorithm. The same algorithm can be used to improve the classificatory performance of any interval-based mathematical programming model for the classification problem with three or more groups. A modification to improve the computational efficiency of an existing model is also proposed. In addition, a multiple-group extension of a mathematical programming model for the two-group classification problem is introduced. A simulation study on classificatory performance reveals that the proposed models yield lower misclassification rates than Fisher's linear discriminant function and Smith's quadratic discriminant function under certain data configurations. Data configurations, where the parametric methods outperform the proposed models, are also identified. A number of theoretical characteristics of mathematical programming models for the classification problem are identified. These include conditions for the existence of feasible solutions, as well as conditions for the avoidance of degenerate solutions. Additionally, conditions are identified that guarantee the classificatory non-inferiority of one model over another in the training ...
Date: August 1993
Creator: Loucopoulos, Constantine
Partner: UNT Libraries

An Empirical Comparison of Random Number Generators: Period, Structure, Correlation, Density, and Efficiency

Description: Random number generators (RNGs) are widely used in conducting Monte Carlo simulation studies, which are important in the field of statistics for comparing power, mean differences, or distribution shapes between statistical approaches. Statistical results, however, may differ when different random number generators are used. Often older methods have been blindly used with no understanding of their limitations. Many random functions supplied with computers today have been found to be comparatively unsatisfactory. In this study, five multiplicative linear congruential generators (MLCGs) were chosen which are provided in the following statistical packages: RANDU (IBM), RNUN (IMSL), RANUNI (SAS), UNIFORM(SPSS), and RANDOM (BMDP). Using a personal computer (PC), an empirical investigation was performed using five criteria: period length before repeating random numbers, distribution shape, correlation between adjacent numbers, density of distributions and normal approach of random number generator (RNG) in a normal function. All RNG FORTRAN programs were rewritten into Pascal which is more efficient language for the PC. Sets of random numbers were generated using different starting values. A good RNG should have the following properties: a long enough period; a well-structured pattern in distribution; independence between random number sequences; random and uniform distribution; and a good normal approach in the normal distribution. Findings in this study suggested that the above five criteria need to be examined when conducting a simulation study with large enough sample sizes and various starting values because the RNG selected can affect the statistical results. Furthermore, a study for purposes of indicating reproducibility and validity should indicate the source of the RNG, the type of RNG used, evaluation results of the RNG, and any pertinent information related to the computer used in the study. Recommendations for future research are suggested in the area of other RNGs and methods not used in this study, such as additive, combined, ...
Date: August 1995
Creator: Bang, Jung Woong
Partner: UNT Libraries

Characterizing Spontaneous Neurophysiological Activity with Measures of Statistical Serial Dependence: a Summary Statistic and an Extension of the Joint Interval Histogram

Description: Two measures which indicate statistical serial dependence were evaluated. The n-dimensional Average Stored Information index (ndASI) is a measure of conditional information, which compares the entropies of higher order conditional distributions to estimate average statistical serial dependence. The generalized ranked joint interval histogram (RJIH-o) is a new nonparametric graphical analysis method. It extends the joint interval histogram by depicting longer interval sequences and can be interpereted precisely analagously to the joint interval histogram. The generalized ranked joint interval histogram correctly represents independence in a Poisson process model and statistical serial dependence in a directionally reinforced Markov model. The generalized ranked joint interval histogram correctly depicts the underlying periodic and strange attractors in a standard map model. Both measures can be used to effectively analyze interspike interval sequences from spontaneous neurophsyiological activity effectively.
Date: August 1994
Creator: Weil, Jon C. (Jon Christopher)
Partner: UNT Libraries

Structural Causes of Transnational Terrorism: a Cross-National Longitudinal Analysis

Description: This study provides a first attempt at building a multivariate model to explain terrorist activity by including six national factors proposed to have a relationship to the number of terrorist events occurring in a given nation and the number of terrorist incidents attributed to groups primarily identified with a given nation. These factors include rate of population growth, level of economic development, economic growth rate, level of democracy, presence of leftist regime type, and level of repression. After applying Ordinary Least Squares to these national factors in both a cross-sectional and a pooled cross-sectional time series analysis, only the level of democracy, the level of repression, and the lagged endogenous variables representing previous terrorist activity demonstrated strong and statistically significant relationships to the two dependent variables tested in both designs.
Date: August 1994
Creator: Wendel, Dierdre L. (Dierdre Lynelle)
Partner: UNT Libraries

Robustness of the One-Sample Kolmogorov Test to Sampling from a Finite Discrete Population

Description: One of the most useful and best known goodness of fit test is the Kolmogorov one-sample test. The assumptions for the Kolmogorov (one-sample test) test are: 1. A random sample; 2. A continuous random variable; 3. F(x) is a completely specified hypothesized cumulative distribution function. The Kolmogorov one-sample test has a wide range of applications. Knowing the effect fromusing the test when an assumption is not met is of practical importance. The purpose of this research is to analyze the robustness of the Kolmogorov one-sample test to sampling from a finite discrete distribution. The standard tables for the Kolmogorov test are derived based on sampling from a theoretical continuous distribution. As such, the theoretical distribution is infinite. The standard tables do not include a method or adjustment factor to estimate the effect on table values for statistical experiments where the sample stems from a finite discrete distribution without replacement. This research provides an extension of the Kolmogorov test when the hypothesized distribution function is finite and discrete, and the sampling distribution is based on sampling without replacement. An investigative study has been conducted to explore possible tendencies and relationships in the distribution of Dn when sampling with and without replacement for various parameter settings. In all, 96 sampling distributions were derived. Results show the standard Kolmogorov table values are conservative, particularly when the sample sizes are small or the sample represents 10% or more of the population.
Date: December 1996
Creator: Tucker, Joanne M. (Joanne Morris)
Partner: UNT Libraries

The Dynamic Foundation of Fractal Operators.

Description: 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. This dissertation, in fact, establishes the existence of a striking conflict between densities and trajectories. The third part of this dissertation is devoted to establishing the consequences of the conflict between trajectories and densities in quantum mechanics, and triggers a search for the experimental assessment of spontaneous wave-function collapses. The research work of this dissertation has been the object of several papers and two books.
Date: May 2003
Creator: Bologna, Mauro
Partner: UNT Libraries

A Monte Carlo Study of the Robustness and Power Associated with Selected Tests of Variance Equality when Distributions are Non-Normal and Dissimilar in Form

Description: When selecting a method for testing variance equality, a researcher should select a method which is robust to distribution non-normality and dissimilarity. The method should also possess sufficient power to ascertain departures from the equal variance hypothesis. This Monte Carlo study examined the robustness and power of five tests of variance equality under specific conditions. The tests examined included one procedure proposed by O'Brien (1978), two by O'Brien (1979), and two by Conover, Johnson, and Johnson (1981). Specific conditions included assorted combinations of the following factors: k=2 and k=3 groups, normal and non-normal distributional forms, similar and dissimilar distributional forms, and equal and unequal sample sizes. Under the k=2 group condition, a total of 180 combinations were examined. A total of 54 combinations were examined under the k=3 group condition. The Type I error rates and statistical power estimates were based upon 1000 replications in each combination examined. Results of this study suggest that when sample sizes are relatively large, all five procedures are robust to distribution non-normality and dissimilarity, as well as being sufficiently powerful.
Date: August 1990
Creator: Hardy, James C. (James Clifford)
Partner: UNT Libraries

A Computer Assisted Drill and Practice System for Introductory Statistics Instruction

Description: To supplement college introductory statistics instruction, an interactive drill system was developed and implemented on a Hewlett- Packard 2000 timesharing computer. Unlimited practice in basic procedures and algorithms was provided over 38 topics including Chi-square, correlational methods, and one-way analysis of variance. Validation of intermediate computational steps was provided, and more difficult or remedial problems sets were made available. Optional files recorded performance data. Four support programs initialized performance files and generated summary reports. Extensive documentation and a library of reusable subroutines were designed to assist future authors to expand the system. The drill and practice system was made generally available to all university departments and students.
Date: May 1979
Creator: Ellis, Richard George
Partner: UNT Libraries

Fiscal years of state and local governments.

Description: Discusses variations in the fiscal reporting periods used by state and local governments. Contains tables describing the fiscal year endings of various types of governments in the United States.
Date: June 1945
Creator: United States. Bureau of the Census.
Partner: UNT Libraries Government Documents Department

The War with Germany: A Statistical Summary

Description: Book containing statistical figures regarding the United States of America's conflict with Germany during World War I, including statistics for casualties, expenditures, and ordnance. Index starts on page 151.
Date: 1919
Creator: Ayres, Leonard Porter, 1879-1946
Partner: UNT Libraries Government Documents Department

Clean Cities Fact Sheet, August 2007

Description: Fact sheet for the Clean Cities Program, describing the purpose and scope of the DOE program, with current statistics. Clean Cities facilitates the use of alternative and advanced fuels and vehicles to displace petroleum in the transportation sector.
Date: August 2007
Creator: United States. Department of Energy. Office of Energy Efficiency and Renewable Energy.
Partner: UNT Libraries Government Documents Department

[News Clip: Krueger]

Description: Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story. This story aired at 10:00 P.M.
Date: February 23, 1978
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections

Petroleum Refinery Statistics: 1930

Description: From Summary: "The year 1930 marked a turning point in record-breaking performances for refining industry. From the time of the first refinery statistics of the Bureau of Mines in 1916 through 1929 the utilization of crude at refineries and the production of the principal product (motor fuel) has increased steadily. In 1930, however, the depressed conditions had a noticeable effect on motor-fuel consumption, which only increased 5 per cent over that in 1929, compared with an average annual increase for the preceding decade of 16 per cent.
Date: 1932
Creator: Hopkins, G. R.
Partner: UNT Libraries Government Documents Department

[News Script: Labor dept. statistics]

Description: Script from the WBAP-TV/NBC station in Fort Worth, Texas, covering a news story about Brunswick Bagdon, the director of the Labor Department's Bureau of Statistics in the south, arriving at Dallas to speak of the statistics in the area.
Date: May 22, 1963
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections