| Document Classification by Fuzzy Attribute Evaluation |
DEC 2000 |
26 pages |
| Authors:
Aivars Celmins; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
 | A technique for classifying objects is proposed that combines classification estimates based on the properties of object attributes. The technique was developed as an aid to classifying captured foreign documents on the battlefield. In this approach, the input information consists of linguistic assessments of the document's classification; these assessments are based on document attributes such as document age, format, and place of discovery. The assessments are modeled as fuzzy sets ... |
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| Terrain Exploration by Autonomous Robots |
SEP 2000 |
49 pages |
| Authors:
Aivars Celmins; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Terrain exploration with the help of autonomous unmanned ground vehicles can be very cost effective in several military applications, such as mine clearing, decontamination, surveillance, and similar operations. A subtask in autonomous operations is planning the traveling route so that the main goal (the exploration of the terrain) is achieved in the shortest time, the entire area of interest is covered, and the terrain features ... |
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| Multimap Procedures for Robot Route Finding in Open Terrain |
FEB 1999 |
38 pages |
| Authors:
Aivars Celmins; ARMY RESEARCH LAB ADELPHI MD
|
| An important task for scouting robots in open terrain is the planning of route to a prescribed destination with the help of digital maps. In an open environment, available terrain maps usually will be too large for a timely analysis of a whole map and may cover areas that are not relevant for route planning. One needs, therefore, route-planning procedures that use partial terrain maps. This ... |
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| Battlefield Robot Cybernation and Navigation |
DEC 97 |
36 pages |
| Authors:
Aivars Celmins; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| This report describes a paradigm of battlefield robot cybernation and presents, within that paradigm, a navigation technique for such robots. The navigation technique is an algorithm for route planning in an open terrain that contains areas with different characteristics, such as navigation speed or level of threat. Optimal routes for battlefield robots in such a terrain are task specific: for instance, the fastest route, the safest route, a hidden route, ... |
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| Fuzzy-Logic Control of Battlefield Communications |
OCT 96 |
47 pages |
| Authors:
Aivars Celmins; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| The basic communications network in a battlefield is a single low- bandwidth radio channel that is used simultaneously by a small group of stations. In a modern Army environment, the nodes that share the radio channel will be computers that compose, encode, broadcast, receive, and display messages. Because the radio channel is used simultaneously by several nodes, one can expect collisions of messages, particularly during high combat activities. To reduce ... |
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| Battlefield Communications Network Model (BATNET) |
AUG 95 |
60 pages |
| Authors:
Aivars Celmins; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Typical future battlefield communication networks may consist of a moderate number of mobile radio nodes that broadcast on a common low-bandwidth channel. One can assume that the nodes will have high computing power, while the communications channel is slow and possibly noisy. In such a network, control of access times is necessary to avoid a breakdown of communications by colliding messages during times of high network traffic. To experiment with ... |
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| Cost Effectiveness Analysis Using Fuzzy Set Theory |
DEC 93 |
17 pages |
| Authors:
Albert G. Gluckman; Aivars Celmins; ARMY RESEARCH LAB ADELPHI MD
|
| This report describes the concepts of an expert system for cost and operational effectiveness analysis (COEA) of the nuclear survivability of Army systems. We propose the modelling of empirical decision rules in the expert system with the help of fuzzy set theory. Cost and Operational Effectiveness Analysis (COEA), Fuzzy sets, Experts nuclear survivability, Nuclear hardening. |
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| Least-Squares Determination of Burst-Point Coordinates |
DEC 93 |
30 pages |
| Authors:
Aivars Celmins; Miguel Andriolo; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| This report describes the determination of burst-point coordinates from azimuth and elevation measurements by the method of least squares. The observations are made from a number of observation towers and observed are angles of azimuth and elevation. Both angles are treated as regressand variables, and the burst-point coordinates are determined by minimizing the sum of the correction squares of all observations. Two numerical solution methods are presented, both producing identical ... |
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| Nuclear-Survivability Cost Analysis Using Fuzzy-Set Theory |
NOV 93 |
113 pages |
| Authors:
Aivars Celmins; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| To conduct a cost-effectiveness analysis of the nuclear survivability of weapon systems, one needs to evaluate and compare different proposed system modifications. That task can require the evaluation of a large number of options and the processing of vague information. This report describes a pilot computer program that has been developed to assist the decision maker in such tasks. The program treats vague information using the formalism of fuzzy set ... |
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| Vulnerability of Approximate Targets |
JUN 93 |
29 pages |
| Authors:
Aivars Celmins; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| This report describes the computation of vulnerability in case of approximately specified targets and threats whereby the specifications are assumed to be vague but not stochastic. Such specifications are typical for hypothetical or generic weapon systems. Treating the inaccuracies within the framework of possibility theory we obtain two confidence measures for the occurrence of a kill, namely, the values of possibility and necessity of kill. These measures replace the usual ... |
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| Least-Squares Averaging of Burst Points |
DEC 92 |
22 pages |
| Authors:
Aivars Celmins; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| The average burst point of artillery shells is computed from individual burst-point observations. We review such calculations within the framework of general least-squares averaging of observation in an n-dimensional space and propose an iterative solution for cases where the event scatter is unknown and neither it nor the observational scatters can be neglected. The solution produces the average burst point and an estimate of the event scatter, that is of ... |
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| Feasibility of Cosmic-Ray Muon Intensity Measurements for Tunnel Detection |
JUN 90 |
40 pages |
| Authors:
Aivars Celmins; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Subsurface cosmic-ray muon intensity depends on the amount of material above the point of reference and is therefore influenced by anomalies in rock density. Because such anomalies might be caused by geological structures (e.g. ore bodies), cosmic-ray intensity measurements have been used for geophysical exploration. Recently, cosmic-ray muon intensity measurements have been also proposed as a method to detect tunnels. The feasibility of this application depends on the type of ... |
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| Accuracy of Vulnerability Integrals |
APR 90 |
44 pages |
| Authors:
Aivars Celmins; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| This report investigates the accuracy of vulnerability indicators that represent average vulnerability either over a threat dispersion area or over the silhouette of a target. Mathematically, these indicators are surface integrals of local vulnerability over a reference plane normal to the direction of the threat. In applications, the integrals are computed by discrete numerical integration. The accuracy of the resulting indicators depends on the accuracy of the local vulnerability, the ... |
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| Possibilistic Vulnerability Measures |
DEC 89 |
26 pages |
| Authors:
Aivars Celmins; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Possibility theory has been developed to handle data that are vague but not necessarily probabilistic. Because this type of information is characteristic for vulnerability problems, possibility theory is particularly well suited for applications in vulnerability analysis. This report provides a short introduction to the theory and describes how possibilistic concepts can be used to analyze vulnerabilities. The essential result is the establishment of measures for the possibility and necessity of ... |
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| Reconstruction of a Blast Field from Pressure History Observations |
SEP 1981 |
|
| Authors:
Aivars Celmins; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
 | This report describes a method for the calculation of parts of a spherical blast field from pressure history observations at stations placed at various distances from the blast center. The method consists of a determination of the pressure field by model fitting and of a subsequent numerical integration of the flow governing equations. The results provide a complete flow description (pressure, density, and particle velocity) as well as estimates of ... |
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| Variable Transformation in Nonlinear Least Squares model Fitting |
JUL 1981 |
|
| Authors:
Aivars Celmins; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| The numerical treatment of nonlinear model fitting problems often can be simplified by manipulating the model equations. Algebraic manipulations, including nonlinear transformations of model parameters, do not change the numerical result of the adjustment. Therefore, such manipulations can be a powerful method to improve the performance of solution algorithms. Nonlinear transformations of the observations, on the other hand, do change the numerical results unless the normal equations are transformed accordingly. ... |
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| Partitionability of Implicit Least Squares Model Fitting Problems |
MAY 1981 |
|
| Authors:
Aivars Celmins; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Non-linear least squares model fitting problems differ from general optimization problems due to the special structure of the least squares normal equations. In simple least squares problems, that structure algorithmic simplification can be achieved. More general least squares problems can often be made partitionable by proper parameter manipulations. In this report, sufficient partitionability conditions are derived and parameter manipulations are discussed for the achievement of partitionability. |
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| Strong Blast Wave Computer Programs. |
SEP 1980 |
|
| Authors:
Aivars Celmins; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| This report describes a computer program package for the computation of the flow field within a strong blast bubble. The programs are based on Sedov-Laporte-Chang formulas and compute any of the following: shock front location and corresponding flow values, flow profiles at fixed times, flow histories at fixed distances, particle trajectories, and Mach-lines. The input and the output are in terms of dimensional quantities expressed in SI base units. The ... |
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| Least Squares Adjustment with Finite Residuals for Non-Linear Constraints and Partially Correlated Data, |
JUL 1973 |
|
| Authors:
Aivars Celmins; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD
|
| The subject of the paper is the adjustment (curve fitting) of data by the least squares method. Based on general formulas, which are derived in the paper, a new algorithm for the least squares method is established. It can be applied to cases where more than one observable contain observational errors and where the postulated relation between the observables is non-linear. Also taken into account are accuracies of the observations ... |
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| A Computer Program for a Cartridge Expelling Gun. |
APR 1973 |
|
| Authors:
Aivars Celmins; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD
|
| The report is a users manual for a package of FORTRAN routnines. The package calculates the gas flow and the motions of the projectile and cartridge in a gun, which is designed to expel the cartridge through its muzzle. The code is based on one-dimensional Lagrangian formulation of the problem. The numerical solution employs an artificial viscosity computing scheme. (Author) |
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| MINIMIZATION OF a-th POWERS USING CONVENTIONAL LEAST SQUARES ROUTINES, |
JUL 1970 |
|
| Authors:
Aivars Celmins; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD
|
| Adjustment problems are considered where the sum of a-th powers of deviations (with 1 = or |
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| COMPUTATION OF HOLLOW CYLINDER EXPLOSIONS, |
NOV 1967 |
|
| Authors:
Aivars Celmins; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD
|
| The report treats the explosion caused by a charge which is placed between two hollow co-axial cylinders. It is assumed that at the beginning of the motion of the cylinders the explosive has been detonated completely so that the space between the cylinders is filled by a gas under high pressure. The flow of this gas during the collapse of the inner cylinder and the expansion of the outer cylinder ... |
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| DATA REDUCTION FROM PHOTOGRAPHS OF BLASTS. |
NOV 1966 |
|
| Authors:
Aivars Celmins; BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD
|
| The report gives a detailed description of a code for reduction of data from blast photographs. The code furnishes data about the orientation of the camera, computes scale factors of the frames, expresses the refractive distortion of the Sun's image in proper angles and determines the parameters of a function R sub o(f), which gives the radius of the blast bubble as a function of the frame number f (i.e., ... |
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Reports by Author
