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1997

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Articles 2311 - 2340 of 2472

Full-Text Articles in Physical Sciences and Mathematics

Report To The Roger L. Kresge Foundation, December 27, 1997 : Understanding Refugee Communities In Broome County, Mi̇Hri̇ İNal. ÇAkir, Michael M. Horowitz, Institute For Development Anthropology (Binghamton, N.Y.) Jan 1997

Report To The Roger L. Kresge Foundation, December 27, 1997 : Understanding Refugee Communities In Broome County, Mi̇Hri̇ İNal. ÇAkir, Michael M. Horowitz, Institute For Development Anthropology (Binghamton, N.Y.)

Institute for Development Anthropology Papers

No abstract provided.

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Microlanguages For Operating System Specialization, Calton Pu, Andrew P. Black, Crispin Cowan, Jonathan Walpole, Charles Consel Jan 1997

Microlanguages For Operating System Specialization, Calton Pu, Andrew P. Black, Crispin Cowan, Jonathan Walpole, Charles Consel

Computer Science Faculty Publications and Presentations

Specialization is a technique that has the potential to provide operating system clients with the performance and functionality that they need, while still retaining the advantages of a simple generic code base for the operating system maintainer. However, at present the specialization process is labor-intensive and requires the knowledge of an expert in the domain of application behavior. In order to realize the full advantages of specialization, we believe that the process must be automated. This means building tools for specialization, and also making the domain knowledge explicit in some form or other. A specialization toolkit has been developed jointly …

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Contemporaneous Iue, Euve, And High-Energy Observations Of 3c 273, E. Ramos, Menas Kafatos, A. Fruscione, F. C. Bruhweiler, I. M. Mchardy, R. C. Hartman, L. G. Titarchuk, C. Von Montigny Jan 1997

Contemporaneous Iue, Euve, And High-Energy Observations Of 3c 273, E. Ramos, Menas Kafatos, A. Fruscione, F. C. Bruhweiler, I. M. Mchardy, R. C. Hartman, L. G. Titarchuk, C. Von Montigny

Mathematics, Physics, and Computer Science Faculty Articles and Research

We present the results of our 1994 January and 1995 January observations of the quasar 3C 273 obtained with the International Ultraviolet Explorer (IUE) and the Extreme-Ultraviolet Explorer (EUV E). These observations were part of a large multiwavelength campaign to observe 3C 273 from radio through γ-rays. Our 1995 January photometric observations with the EUV E Lexan/B Deep Survey (DS) instrument indicate strong evidence for variability, at a 99% confidence level, during the 12 day observing period. We have utilized ROSAT PSPC soft X-ray power-law models to correlate with EUV E count rates. Besides variations in the normalization level between …

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Lateral Shock Of The R Aquarii Jet, J. M. Hollis, J. A. Pedelty, Menas Kafatos Jan 1997

Lateral Shock Of The R Aquarii Jet, J. M. Hollis, J. A. Pedelty, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The R Aqr jet was observed with the VLA B-configuration at two epochs separated by ~13.2 yr. Comparison of the resulting 6 cm continuum images show that the radio jet has undergone a lateral counterclockwise rotation of ~6-12 on the plane of the sky. The model of jet parcels on independent trajectories is difficult to reconcile with these observations and leads us to consider a path-oriented jet (i.e., younger parcels follow the same path as older parcels). Comparison of the most recent radio image with a nearly contemporaneous HST /FOC ultraviolet image at ~2330 A suggests that the ultraviolet emission …

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Multiwavelength Blazar Studies, Menas Kafatos Jan 1997

Multiwavelength Blazar Studies, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The present report concerns the following projects 'High energy emission from hot accretion disks from active galactic nuclei'; 'OSSE spectral timing and monitoring observations of Cygnus X- 1'; 'OSSE observations of blazars'; and 'Search for correlated time variations of bright EGRET blazars'. The most favored model for the central engine inAGNs is the supermassive black hole hypothesis (Rees 1978). The observed luminosities range from approx. 10 logical and 44-45 erg /s for objects such as Mk 421 and Seyferts to as much as approx. 10logical and 47 for powerful QSOs such as 3C 273 and 3C 279, a large fraction …

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On-Road Co, Hc, No And Opacity Measurements (Presentation), Donald H. Stedman, Gary A. Bishop, Phillip Aldrete Jan 1997

On-Road Co, Hc, No And Opacity Measurements (Presentation), Donald H. Stedman, Gary A. Bishop, Phillip Aldrete

Fuel Efficiency Automobile Test Publications

No abstract provided.

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Eigenvalue And Eigenvector Determination For Damped Gyroscopic Systems, D. P. Malone, Don L. Cronin, Timothy W. Randolph Jan 1997

Eigenvalue And Eigenvector Determination For Damped Gyroscopic Systems, D. P. Malone, Don L. Cronin, Timothy W. Randolph

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

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Habitat Area Requirements Of Prairie Wetland Birds In Eastern South Dakota, David E. Naugle Jan 1997

Habitat Area Requirements Of Prairie Wetland Birds In Eastern South Dakota, David E. Naugle

Electronic Theses and Dissertations

The influence of area and vegetation structure on bird use of 830 semipermanent and seasonal wetlands (0.2-217.5 ha) was studied to evaluate vegetative needs and habitat area requirements of 20 breeding wetland bird species in eastern South Dakota in 1995-1996. Vegetative preferences of species varied, but most waterfowl and nongame species occur e4i more frequently in wetlands with intermediate cover-to-water ratios whereas five over-water nesting or secretive nongame species were found in wetlands with greater coverage of emergent vegetation. The occurrence of four nongame species that depend on vegetative structure to support the weight of their over-water nests also was …

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Symmetrically Continuous Function Which Is Not Countably Continuous, Krzysztof Ciesielski Jan 1997

Symmetrically Continuous Function Which Is Not Countably Continuous, Krzysztof Ciesielski

Faculty & Staff Scholarship

We construct a symmetrically continuous function f : R → R such that for some X ⊂ R of cardinality continuum f|X is of Sierpi´nskiZygmund type. In particular such an f is not countably continuous. This gives an answer to a question of Lee Larson.

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Darboux Like Functions That Are Characterizable By Images, Preimages And Associated Sets, Krzysztof Ciesielski Jan 1997

Darboux Like Functions That Are Characterizable By Images, Preimages And Associated Sets, Krzysztof Ciesielski

Faculty & Staff Scholarship

For arbitrary families A and B of subsets of R let C(A,B)= {f| f: R-->R and the image f[A] is in B for every A in A} and C-1 (A,B)= {f| f: R-->R and the inverse image f-1(B) is in A for every B in B}. A family F of real functions is characterizable by images (preimages) of sets if F=C(A,B) (F=C-1(A,B), respectively) for some families A and B. …

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Collected Papers, Vol. 2, Florentin Smarandache Jan 1997

Collected Papers, Vol. 2, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

No abstract provided.

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Resolution Of Local Inconsistency In Identification, Douglas Ray Anderson, Martin Zwick Jan 1997

Resolution Of Local Inconsistency In Identification, Douglas Ray Anderson, Martin Zwick

Systems Science Faculty Publications and Presentations

This paper reports an algorithm for the resolution of local inconsistency in information-theoretic identification. This problem was first pointed out by Klir as an important research area in reconstructability analysis. Local inconsistency commonly arises when an attempt is made to integrate multiple data sources, i.e., contingency tables, which have differing common margins. For example, if one ha)s an AB table and a BC table, the B margins obtained from the two tables may disagree. If the disagreement can be assigned to sampling error, then one can arrive at a compromise B margin, adjust the original AB and BC tables to …

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The Synthesis Of 6a,6b-Dideoxy-6 A,6b-(9,10-Dicyanoanthracenyl-2,3-Dimethylene)-Beta-Cyclodextrin, Jonathan D. Tan Jan 1997

The Synthesis Of 6a,6b-Dideoxy-6 A,6b-(9,10-Dicyanoanthracenyl-2,3-Dimethylene)-Beta-Cyclodextrin, Jonathan D. Tan

Dissertations, Theses, and Masters Projects

No abstract provided.

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The Synthesis Of Benzophenone-3,5-Diacid Chloride For The Double Capping Of Beta-Cyclodextrin, Clyde Wesley Eargle Jan 1997

The Synthesis Of Benzophenone-3,5-Diacid Chloride For The Double Capping Of Beta-Cyclodextrin, Clyde Wesley Eargle

Dissertations, Theses, and Masters Projects

No abstract provided.

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Merritt Lyndon Fernald, John A. Drobnicki Jan 1997

Merritt Lyndon Fernald, John A. Drobnicki

Publications and Research

Merritt Lyndon Fernald trained the future leaders in taxonomy and descriptive botany and helped maintain a high level in botanical writing through his work as editor of Rhodora.

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Diffraction From Polarization Holographic Gratings With Surface Relief In Side-Chain Azobenzene Polyesters, Izabela Naydenova, Ludmila Nikolova, Todor Todorov, N.C.R. Holme, P.S. Ramanujam, S. Hvilsted Jan 1997

Diffraction From Polarization Holographic Gratings With Surface Relief In Side-Chain Azobenzene Polyesters, Izabela Naydenova, Ludmila Nikolova, Todor Todorov, N.C.R. Holme, P.S. Ramanujam, S. Hvilsted

Articles

We investigate the polarization properties of holographic gratings in side-chain azobenzene polyesters in which an anisotropic grating that is due to photoinduced linear and circular birefringence is recorded in the volume of the material and a relief grating appears on the surface. A theoretical model is proposed to explain the experimental results, making it possible to understand the influence of the different photoinduced effects. It is shown that at low intensity the polarization properties of the diffraction at these gratings are determined by the interaction of the linear and circular photobirefringences, and at larger intensity the influence of the surface …

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Targeting Wetland Preservation Areas For Compensatory Mitigation Utilizing A Gis Protocol, Lynn M. Dancy Jan 1997

Targeting Wetland Preservation Areas For Compensatory Mitigation Utilizing A Gis Protocol, Lynn M. Dancy

Dissertations, Theses, and Masters Projects

No abstract provided.

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Correlation Of Dynamic Dielectric Properties To Reaction Kinetics And Changing Mechanical Properties Of Epoxy Resins During Cure, Yunfei Wang Jan 1997

Correlation Of Dynamic Dielectric Properties To Reaction Kinetics And Changing Mechanical Properties Of Epoxy Resins During Cure, Yunfei Wang

Dissertations, Theses, and Masters Projects

The principal objective of this paper is to describe how complex impedance, obtained from frequency dependent dielectric sensing technique, can be used as an effective diagnostic tool for in situ real-time investigation in the fabrication of thermoset structures.;Two epoxy systems (Pr500 from 3M and My720 from Ciba Geigy) with different functionality are characterized in terms of their dielectric, thermal, and rheological behavior. It is observed that there is a one to one relationship between Tg and conversion which is independent of cure temperature. The chemical kinetics of the reaction is satisfactorily described by an autocatalyzed reaction mechanism. The chemical rate …

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Solar Infrared Relative Intensity Data From The Halogen Occultation Experiment, Philip Todd Spickler Jan 1997

Solar Infrared Relative Intensity Data From The Halogen Occultation Experiment, Philip Todd Spickler

Dissertations, Theses, and Masters Projects

Solar data from the Halogen Occultation Experiment (HALOE) were analyzed to determine the center-to-limb relative intensity and the vertical temperature profile for the quiet and active Sun over wavelengths from 2.4 to 10 {dollar}\mu{dollar}m. An algorithm that incorporated a nonlinear least squares procedure was developed that modeled the HALOE instrument during data acquisition. Data obtained from limb-to-limb scans along the solar equator on days of very low activity in May 1994 were analyzed to obtain coefficients of a function describing the relative intensity from center to limb. The relative intensities produced were precise to 0.1% (2{dollar}\sigma{dollar}) from the center to …

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The Synthesis Of Reflective And Electrically Conductive Polyimide Films Via An In Situ Self-Metallization Procedure Using Silver(I) Complexes, Robin Elaine Southward Jan 1997

The Synthesis Of Reflective And Electrically Conductive Polyimide Films Via An In Situ Self-Metallization Procedure Using Silver(I) Complexes, Robin Elaine Southward

Dissertations, Theses, and Masters Projects

Optically reflective polyimide films have been prepared by the incorporation of silver(I) acetate and a {dollar}\beta{dollar}-diketone solubilizing agent, hexafluoroacetylacetone (HFAH), into a dimethylacetamide solution of the poly(amic acid) formed from {dollar}3,3\sp\prime,4,4\sp\prime{dollar}-benzophenonetetracarboxylic acid dianhydride (BTDA) and {dollar}4,4\sp\prime{dollar}-oxydianiline {dollar}(4,4\sp\prime{dollar}-ODA). Optically reflective and conductive polyimide films have been prepared by replacing the {dollar}\beta{dollar}-diketone (HFAH), with the less substituted {dollar}\beta{dollar}-diketone, trifluoroacetylacetone (TFAH). The former system has been both cast directly from the poly(amic acid) resin and cast from the poly(amic acid) resin onto a fully imidized {dollar}\rm BTDA/4,4\sp\prime{dollar}-ODA base (forming a metallized topcoat). Thermal curing of the silver(I)-containing poly(amic acid) leads to imidization with …

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Global State Predicates In Rough Real-Time, Jean Ann Mayo Jan 1997

Global State Predicates In Rough Real-Time, Jean Ann Mayo

Dissertations, Theses, and Masters Projects

Distributed systems are characterized by the fact that the constituent processes have neither common memory nor a common system clock. These processes communicate solely via message passing. While providing a number of benefits such as increased reliability, increased computational power, and geographic dispersion, this architecture significantly complicates many of the tasks of software development and verification, including evaluation of the program state. In the case of distributed systems, the program state is comprised of the local states of the constituent processes, as well as the state of the channels between processes, and is called the global state.;With no common system …

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Collision-Induced Secondary Electron And Negative Ion Emission From Metallic Surfaces, John Christopher Tucek Jan 1997

Collision-Induced Secondary Electron And Negative Ion Emission From Metallic Surfaces, John Christopher Tucek

Dissertations, Theses, and Masters Projects

Absolute yields of negative ions and secondary electrons resulting from collisions of positive sodium ions (Na{dollar}\sp{lcub}+{rcub}){dollar} with polycrystalline aluminum (Al) and molybdenum (Mo) surfaces and the Mo (100) surface have been measured as a function of the oxygen (O) coverage, from none up to several monolayers, for impact energies, E {dollar}<{dollar} 500 eV. Negative oxygen ions (O{dollar}\sp{lcub}-{rcub}){dollar} are found to be the dominant sputtered negative ions and for the three surfaces at all O coverages and Na{dollar}\sp{lcub}+{rcub}{dollar} impact energies. The O{dollar}\sp{lcub}-{rcub}{dollar} and secondary electron yields share a common impact energy threshold at {dollar}\rm E\sb{lcub}th{rcub}\approx 50{dollar} eV, and both have a strong dependence on the oxygen coverage of the surface.;The kinetic energy distributions of the secondary electrons and sputtered O{dollar}\sp{lcub}-{rcub}{dollar} were determined as functions of O coverages and impact energies. The O{dollar}\sp{lcub}-{rcub}{dollar} distributions are characterized by a narrow, low energy peak (at {dollar}\sim{dollar}1-2 eV) followed by a low level, high energy tail. The secondary electrons have a narrow (FWHM {dollar}\sim{dollar} 1-2 eV) kinetic energy distribution, centered essentially at the same most probable kinetic energy as the ions. The shapes of the respective distributions and the most probable kinetic energies are essentially invariant with the impact energy, O coverage and the metal surface.;The results were analyzed in terms of conventional collision cascade model, but the calculation could not be fitted to the experimental results. An electronic excitation mechanism is proposed to augment the collision cascade and to provide a mechanism for secondary electron emission. In the model, adsorbed O, which resides on the surface essentially as O{dollar}\sp{lcub}-{rcub},{dollar} is collisionally excited into an (MO{dollar}\sp{lcub}-{rcub})\sp*{dollar} repulsive state, and as the O{dollar}\sp{lcub}-{rcub}{dollar} exits the surface along the surface potential energy curve, it can decay by emission of an electron to the metal or to the vacuum, or it can survive as an ion. The parameters of this model can be adjusted such that the calculated kinetic energy distribution, together with that of the collision cascade, can reasonably reproduce the experimental observations for the ions and provide a reasonable fit to the corresponding electron kinetic energy distributions as well.

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Microstructures Of Poly(Vinyl Acetate) Studied By Nuclear Magnetic Resonance Spectroscopy, Hongyang Yao Jan 1997

Microstructures Of Poly(Vinyl Acetate) Studied By Nuclear Magnetic Resonance Spectroscopy, Hongyang Yao

Dissertations, Theses, and Masters Projects

Carbon-13 NMR spectroscopy was used to investigate the microstructures of poly(vinyl acetate) prepared by solution polymerization in benzene. A series of aromatic compounds was synthesized in order to model the structures formed via chain transfer to solvent. The peaks near 126.5 and 128.5 ppm in the spectra of the polymer samples were assigned to a 1-phenyl-(2n + 1)-multi-acetoxyalkane (where n = 1, 2, 3, etc.) microstructure. The concentration of that structure obtained from NMR spectra was correlated with the concentration calculated from reported kinetic data.;Chain transfer to benzene was shown to occur by addition of the macroradical to benzene, followed …

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A Study Of Poly(Vinyl Chloride) Microstructure, Vadim Guennadievich Zaikov Jan 1997

A Study Of Poly(Vinyl Chloride) Microstructure, Vadim Guennadievich Zaikov

Dissertations, Theses, and Masters Projects

High-field {dollar}\sp{lcub}13{rcub}{dollar}C and {dollar}\sp1{dollar}H NMR spectroscopies were used to investigate some unusual features of the molecular microstructure of poly(vinyl chloride) (PVC).;Several model monochloroalkenes were synthesized in order to determine {dollar}\sp{lcub}13{rcub}{dollar}C shift increments for the replacement of H by Cl at positions that are near an isolated internal double bond. These increments then were used to predict the {dollar}\sp{lcub}13{rcub}{dollar}C shifts of the internal allylic chloride structure in PVC. The predictions were not satisfactory, because, as expected, the increments were not additive.;It was shown that during conventional VC polymerization, the chloroallylic chain end (-CH{dollar}\sb2{dollar}CH=CHCH{dollar}\sb2{dollar}Cl) does not copolymerize with the monomer and is …

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Discrete-Time Linear And Nonlinear Aerodynamic Impulse Responses For Efficient Cfd Analyses, Walter A. Silva Jan 1997

Discrete-Time Linear And Nonlinear Aerodynamic Impulse Responses For Efficient Cfd Analyses, Walter A. Silva

Dissertations, Theses, and Masters Projects

This dissertation discusses the mathematical existence and the numerical identification of linear and nonlinear aerodynamic impulse response functions. Differences between continuous-time and discrete-time system theories, which permit the identification and efficient use of these functions, will be detailed. Important input/output definitions and the concept of linear and nonlinear systems with memory will also be discussed. It will be shown that indicial (step or steady) responses (such as Wagner's function), forced harmonic responses (such as Theodorsen's function or those from doublet lattice theory), and responses to random inputs (such as gusts) can all be obtained from an aerodynamic impulse response function. …

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Structural Contour Map On Top Of The Lansing Group (Pennsylvanian) In Dundy County, Nebraska, R. R. Burchett Jan 1997

Structural Contour Map On Top Of The Lansing Group (Pennsylvanian) In Dundy County, Nebraska, R. R. Burchett

Conservation and Survey Division

No abstract provided.

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Low-Degree Graph Partitioning Via Local Search With Applications To Constraint Satisfaction, Max Cut, And Coloring, Magnus M. Halldorsson, Hoong Chuin Lau Jan 1997

Low-Degree Graph Partitioning Via Local Search With Applications To Constraint Satisfaction, Max Cut, And Coloring, Magnus M. Halldorsson, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

We present practical algorithms for constructing partitions of graphs into a fixed number of vertex-disjoint subgraphs that satisfy particular degree constraints. We use this in particular to find k-cuts of graphs of maximum degree ∆ that cut at least a k - 1/k (1 + 1/2∆+k-1 ) fraction of the edges, improving previous bounds known. The partitions also apply to constraint networks, for which we give a tight analysis of natural local search heuristics for the maximum constraint satisfaction problem. These partitions also imply efficient approximations for several problems on weighted bounded-degree graphs. In particular, we improve the best performance …

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Integrated Queries To Existing Bibliographic And Structured Databases, Ee Peng Lim, Ying Lu Jan 1997

Integrated Queries To Existing Bibliographic And Structured Databases, Ee Peng Lim, Ying Lu

Research Collection School Of Computing and Information Systems

It is widely accepted that future digital library applications have to be built upon different kinds of database servers to draw upon different forms of data, including bibliographic, text, multimedia, and structured data. In this paper, the problem of integrating existing public bibliographic databases and structured databases which reside at different locations in the network is addressed. Although bibliographic data is semistructured, its attribute set is often determined by an international standard known as MARC. To unify bibliographic and structured data, the well-known SQL was extended to model bibliographic related attributes and queries. In particular, a new data type was …

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Some Applications Of Generalized Ffts, Daniel N. Rockmore Jan 1997

Some Applications Of Generalized Ffts, Daniel N. Rockmore

Dartmouth Scholarship

Generalized FFTs are efficient algorithms for computing a Fourier transform of a function defined on finite group, or a bandlimited function defined on a compact group. The development of such algorithms has been accompanied and motivated by a growing number of both potential and realized applications. This paper will attempt to survey some of these applications. Appendices include some more detailed examples.

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An Invariance Property Of Common Statistical Tests, N. Rao Chaganty, A. K. Vaish Jan 1997

An Invariance Property Of Common Statistical Tests, N. Rao Chaganty, A. K. Vaish

Mathematics & Statistics Faculty Publications

Let A be a symmetric matrix and B be a nonnegative definite (nnd) matrix. We obtain a characterization of the class of nnd solutions Σ for the matrix equation AΣA = B. We then use the characterization to obtain all possible covariance structures under which the distributions of many common test statistics remain invariant, that is, the distributions remain the same except for a scale factor. Applications include a complete characterization of covariance structures such that the chisquaredness and independence of quadratic forms in ANOVA problems is preserved. The basic matrix theoretic theorem itself is useful in other characterizing …

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