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2004

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Articles 3061 - 3090 of 4447

Full-Text Articles in Physical Sciences and Mathematics

A Theorem On Divergence In The General Sense For Continued Fractions, Douglas Bowman, James Mclaughlin Jan 2004

A Theorem On Divergence In The General Sense For Continued Fractions, Douglas Bowman, James Mclaughlin

Mathematics Faculty Publications

If the odd and even parts of a continued fraction converge to different values, the continued fraction may or may not converge in the general sense. We prove a theorem which settles the question of general convergence for a wide class of such continued fractions. We apply this theorem to two general classes of q continued fraction to show, that if G(q) is one of these continued fractions and |q| > 1, then either G(q) converges or does not converge in the general sense. We also show that if the odd and even parts of the continued fraction K∞n=1an/1 converge to …

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On The Divergence Of The Rogers-Ramanujan Continued Fraction On The Unit Circle, Douglas Bowman, James Mclaughlin Jan 2004

On The Divergence Of The Rogers-Ramanujan Continued Fraction On The Unit Circle, Douglas Bowman, James Mclaughlin

Mathematics Faculty Publications

This paper is an intensive study of the convergence of the Rogers-Ramanujan continued fraction. Let the continued fraction expansion of any irrational number t ∈ (0, 1) be denoted by [0, a1(t), a2(t), · · · ] and let the i-th convergent of this continued fraction expansion be denoted by ci(t)/di(t). Let S = {t ∈ (0, 1) : ai+1(t) ≥ φ di(t) infinitely often}, where φ = (√ 5 + 1)/2. Let YS = {exp(2πit) : t ∈ S}. It is shown that if y ∈ YS then the Rogers-Ramanujan continued fraction, R(y), diverges at y. S is an …

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Relationship Between Lake-Record Weights Of Fishes And Reservoir Area And Growing Season, Gene R. Wilde, Kevin L. Pope Jan 2004

Relationship Between Lake-Record Weights Of Fishes And Reservoir Area And Growing Season, Gene R. Wilde, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

We used information from an angler recognition program to assess the relationship between lake-record weights of freshwater fishes captured by Texas anglers and two predictors of fish production and growth: reservoir surface area and growing-season length. The lake-record weights of two species, largemouth bass Micropterus salmoides and flathead catfish Pylodictis olivaris, were directly related to the logarithm of surface area. The record weights of all species studied were unrelated to growing-season length. Regardless of the statistical significance of individual correlations, there was a significant excess of positive correlations across all species between lake-record weights of fish and log surface area. …

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Effect Of Catch-And-Release Angling On Growth Of Largemouth Bass, Micropterus Salmoides, K. L. Pope, G. R. Wilde Jan 2004

Effect Of Catch-And-Release Angling On Growth Of Largemouth Bass, Micropterus Salmoides, K. L. Pope, G. R. Wilde

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Catch-and-release angling is popular in many parts of the world and plays an increasingly important role in management of recreational fisheries. Although the magnitude of catch-and-release mortality is well documented for many species, potential sublethal effects have been little studied. An experiment was conducted to assess directly the effects of catch-and-release angling on growth of largemouth bass, Micropterus salmoides Lacépède. Angling mortality was 0.00 ± 0.092% for largemouth bass caught on plastic grubs. There was no difference (P = 0.57) in weight gain between caught and uncaught fish over a 40-day angling and recovery period. Although catch-and-release angling appears to …

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Age-Specific Patterns In Density-Dependent Growth Of White Crappie, Pomoxis Annularis, K. L. Pope, G. R. Wilde, B. W. Durham Jan 2004

Age-Specific Patterns In Density-Dependent Growth Of White Crappie, Pomoxis Annularis, K. L. Pope, G. R. Wilde, B. W. Durham

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The relationship between growth in white crappie, Pomoxis annularis Rafinesque, and climate, lake morphometry and population density was studied in 103 Texas reservoirs. Growth of age-0 through age-3 white crappie was significantly (P≤ 0.05) related to latitude, growing season and surface area. Growth of age-1 through age-5 white crappie also was related to annual precipitation. Multiple linear regression models with precipitation and mean catch per unit effort (CPUE) of white crappie as independent variables explained 14–22% of the variation in growth of age-0, -1 and -2 white crappie. By contrast, growth of age-3, -4 and -5 white crappie was unrelated …

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Anglers’ Probabilities Of Catching Record-Size Fish, Gene R. Wilde, Kevin L. Pope Jan 2004

Anglers’ Probabilities Of Catching Record-Size Fish, Gene R. Wilde, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Most state fishery management agencies publish lists of the largest (e.g., 10, 25, and 50) specimens of each species captured by anglers. We fitted normal
distributions for smallmouth bass Micropterus dolomieu and striped bass Morone saxatilis and a mixture of two normal distributions of largemouth bass Micropterus salmoides to the length of time that individual fish had been present on lists of the largest 50 specimens of each species caught by Texas anglers using rod and reel. In any given year, there is only a probability (p) of 0.102 that a largemouth bass large enough to make the recordweight list …

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Spin Uncoupling In Free Nb Clusters: Support For Nascent Superconductivity, Ramiro Moro, Shuangye Yin, Xiaoshan Xu, Walt A. De Heer Jan 2004

Spin Uncoupling In Free Nb Clusters: Support For Nascent Superconductivity, Ramiro Moro, Shuangye Yin, Xiaoshan Xu, Walt A. De Heer

Xiaoshan Xu Papers

Molecular beam Stern-Gerlach deflection measurements on Nb clusters (NbN, N <100) show that at very low temperatures the odd-N clusters deflect due to a single unpaired spin that is uncoupled from the cluster. At higher temperatures the spin is coupled and no deflections are observed. Spin uncoupling occurs concurrently with the transition to the recently found ferroelectric state, which has superconductor characteristics [Science 300, 1265 (2003)]. Spin uncoupling (also seen in V, Ta, and Al clusters) is analogous to the reduction of spin-relaxation rates observed in bulk superconductors below Tc.

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Aragonite Pseudomorphs In High Pressure Marbles Of Syros, Greece, John B. Brady, Michelle J. Markley, John C. Schumacher, John T. Cheney, Grace A. Bianciardi Jan 2004

Aragonite Pseudomorphs In High Pressure Marbles Of Syros, Greece, John B. Brady, Michelle J. Markley, John C. Schumacher, John T. Cheney, Grace A. Bianciardi

Geosciences: Faculty Publications

Numerous rod-shaped calcite crystals occur in the blueschist to eclogite facies marbles of Syros, Greece. The rods show a shape-preferred orientation, and the long axes of the rods are oriented at a large angle to foliation. The crystals also have a crystallographic-preferred orientation: calcite c-axes are oriented parallel to the long axes of the rods. Based on their chemical composition, shape, and occurrence in high-pressure marbles, these calcite crystals are interpreted as topotactic pseudomorphs after aragonite that developed a crystallographic-preferred orientation during peak metamorphism. This interpretation is consistent with deformation of aragonite by dislocation creep, which has been observed …

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Art Network Discussion, Paul Thomas Jan 2004

Art Network Discussion, Paul Thomas

Creative Connections Symposium @ BEAP2004 September 4, 2004

No abstract provided.

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Dit-Call: Naturally Speaking But Slow, Dermot Campbell, Marty Meinardi, Bunny Richardson, Eugene Coyle, Olivia Donnellan, Pak Kui Leung, Ciaran Macdonaill, Elmar Jung, Charles Pritchard Jan 2004

Dit-Call: Naturally Speaking But Slow, Dermot Campbell, Marty Meinardi, Bunny Richardson, Eugene Coyle, Olivia Donnellan, Pak Kui Leung, Ciaran Macdonaill, Elmar Jung, Charles Pritchard

Articles

This paper introduces a new development in speech technology and describes its planned application in an EFL context. Special attention is paid to the pedagogical potential of the resultant language tool.

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A Survey Of Results Involving Transforms And Convolutions In Function Space, David Skough, David Storvick Jan 2004

A Survey Of Results Involving Transforms And Convolutions In Function Space, David Skough, David Storvick

Department of Mathematics: Faculty Publications

In this paper we survey various results involving Fourier-Wiener transforms, Fourier-Feynman transforms, integral transforms and convolution products of functionals over function space that have been established since Cameron and Martin first introduced Fourier-Wiener transforms in 1945.

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Mesospheric Temperature Climatology Above Utah State University, Joshua P. Herron Jan 2004

Mesospheric Temperature Climatology Above Utah State University, Joshua P. Herron

Physics

A Rayleigh-scatter lidar has been in operation at Utah State University (41.7o N, 111.8 ° W) starting in September 1993 until the present (October 2003). The return profiles from the atmosphere have been analyzed to provide temperature measurements of the middle atmosphere from 45 to 90 km. Various methods of averaging were used to construct a temperature climatology of the region based on these observations. The data analysis algorithm has been critically analyzed to find possible sources of error, and has been compared to an independently derived technique. The resulting temperatures have been compared to other mid-latitude lidars with good …

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Variation Of Chemical Potential Oscillations Of A 2deg In A Quantum Well Under A Magnetic Field For Multiple Sub-Band Occupation As Function Of Temperature And Level-Broadening, Berri̇n Özdemi̇r, Zeki̇ Yarar, Meti̇n Özdemi̇r Jan 2004

Variation Of Chemical Potential Oscillations Of A 2deg In A Quantum Well Under A Magnetic Field For Multiple Sub-Band Occupation As Function Of Temperature And Level-Broadening, Berri̇n Özdemi̇r, Zeki̇ Yarar, Meti̇n Özdemi̇r

Turkish Journal of Physics

We study the variation of chemical potential in a two dimensional electron gas in a uniform magnetic field as a function of temperature and level-broadening parameter. Schrödinger and Poisson equations are solved self-consistently for a two dimensional electron gas formed in a Ga_xAl_{1-x}As/GaAs quantum well, to numerically determine the potential profile, empty or occupied energy sub-bands, the wavefunctions and electron concentrations corresponding to each sub-band at various temperatures. Then assuming that the electron concentration is not altered, the variation of chemical potential with respect to both temperature and energy level-broadening parameter is studied under a uniform and constant magnetic field. …

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Numerical Simulation Of Soliton Pulse Propagation In Doped Optical Fibres By Finite-Difference Method, Adams Usman, Junaidah Osman, D. R. Tilley Jan 2004

Numerical Simulation Of Soliton Pulse Propagation In Doped Optical Fibres By Finite-Difference Method, Adams Usman, Junaidah Osman, D. R. Tilley

Turkish Journal of Physics

We report results of applications of explicit finite-difference schemes, viz. the combination of forward-difference and central-difference approximation schemes, to study a simulation of soliton pulse propagation in saturable optical fibres. The dynamic governing equation is the saturable nonlinear Schrödinger equation (SNLE). This equation thus far lacks analytical solution in the sense of the inverse scattering method, although an analytical solitary wave solution is available. We use the localized solution to generate data for simulations of fundamental and second order soliton pulse propagation. In addition, we check the numerical accuracy of the results by considering the physical significance of two conserved …

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Modeling Relaxation Length And Half-Thickness Of Wood By Method Of Gamma Radiation, Louis E. Akpabio, Sunday E. Etuk, Samuel David Ekpe Jan 2004

Modeling Relaxation Length And Half-Thickness Of Wood By Method Of Gamma Radiation, Louis E. Akpabio, Sunday E. Etuk, Samuel David Ekpe

Turkish Journal of Physics

Relaxation lengths and half-thickness values of different types of wood were determined using gamma radiation from ^{60}C0 source. Results show that oxystigma (Oxystima spp) has the highest relaxation length of 23.810cm, while mangrove (Rhizoohora spp) has the least relaxation length of 1.247 cm. Results also show that Oxystima (Oxystima spp) has the highest half thickness value of 16.500 cm and Mangrove (Rhizophora spp) has the least half-thickness value of 0.864 cm. Two mathematical models have been developed for the prediction or determination of density \rho, variation with relaxation length and half thickness value of wood. A good agreement (greater than …

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Dielectric Properties And Conductivity Of Khco_3, Fathy Salman, S. Aboelhssan, Eslam Sheha, Mabrouk Elmansy Jan 2004

Dielectric Properties And Conductivity Of Khco_3, Fathy Salman, S. Aboelhssan, Eslam Sheha, Mabrouk Elmansy

Turkish Journal of Physics

KHCO_{3} compound was characterized in three principle realms: for its dielectric properties as a function of temperature and frequency in the ranges 300--370 K and 50 Hz to 1 MHz, respectively; bulk conductivity as a function of temperature, via impedance technique; and relaxation time as function of temperature. Variations of the bulk conductivity and relaxation time with temperature have been found to yield two segments, with two different activation energies. The activation energy for the two segments due to bulk conductivity have been found as 1.96 eV and 1.85 eV, while the activation energy due to relaxation have been found …

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Formation And Elastic Behavior Of Lead-Magnesium Chlorophosphate Glasses, Hj. Ab. Aziz Sidek, S. P. Chow, Z. A. Talib, S. A. Halim Jan 2004

Formation And Elastic Behavior Of Lead-Magnesium Chlorophosphate Glasses, Hj. Ab. Aziz Sidek, S. P. Chow, Z. A. Talib, S. A. Halim

Turkish Journal of Physics

A series of ternary lead-magnesium chlorophosphate glasses, (PbCl_{2})_{x}(MgO)_{1 - x}(P_{2}O_{5})_{0.4}, of various compositions with 0.3 \le x \le 0.45 have been successfully prepared and their elastic properties have been characterized at room temperature. Results from the studies show that both the longitudinal and shear wave velocities decrease with increase of PbCl_{2} composition. The elastic constants C_{11}, C_{44} and Young's modulus show a decreasing trend while the elastic constant C_{12}, bulk modulus and Poisson's ratio show an increasing trend as the fraction of PbCl_{2} increases. This behavior of the elastic properties is related to the change in the structure of glasses …

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Some New Mathematical Results Obtained Using Closure, Harry A. Mavromatis Jan 2004

Some New Mathematical Results Obtained Using Closure, Harry A. Mavromatis

Turkish Journal of Physics

Several new mathematical sum rules are derived using closure. Their convergence and other properties are then discussed.

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Track Registration Characteristics Of Low-Energy Protons In Cellulose Nitrate (Cn-85), Arif Mahmood, Shazia Bashir, Attiq Us-Salam, Faizan Ul-Haq Jan 2004

Track Registration Characteristics Of Low-Energy Protons In Cellulose Nitrate (Cn-85), Arif Mahmood, Shazia Bashir, Attiq Us-Salam, Faizan Ul-Haq

Turkish Journal of Physics

We describe our efforts to determine the most important track registration parameters for the suitable use of CN-85 track detectors in the registration of low energy protons.

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Analysis Of Rgu Photometry In Selected Area 51, Selçuk Bi̇li̇r, Sali̇h Karaali̇, R. Buser Jan 2004

Analysis Of Rgu Photometry In Selected Area 51, Selçuk Bi̇li̇r, Sali̇h Karaali̇, R. Buser

Turkish Journal of Physics

A low-latitude anticenter field (l = 189°, b = +21°) is investigated by using the full calibration tools of RGU photometry. The observed RGU data are reduced to the standard system and the separation of dwarfs and evolved stars is carried out by an empirical method. Stars are categorized into three metallicity classes, i.e. -0.25

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Empirical Models For The Correlation Of Monthly Average Daily Global Solar Radiation With Hours Of Sunshine On A Horizontal Surface At Karachi, Pakistan, Firoz Ahmed, Intikhab Ulfat Jan 2004

Empirical Models For The Correlation Of Monthly Average Daily Global Solar Radiation With Hours Of Sunshine On A Horizontal Surface At Karachi, Pakistan, Firoz Ahmed, Intikhab Ulfat

Turkish Journal of Physics

A new set of constants for Angstrom-type correlation of first and second order, to estimate monthly average daily global solar radiation, has been obtained employing sunshine hours data recorded at Karachi, Pakistan (Lat. 24^° 54' N, Long. 67^° 08' E). Least square regression is performed to derive these constants. The correlation equations developed are employed to calculate the monthly average daily global solar radiation. These results are then compared with various other existing correlations and the measured data. Excellent agreement has been found between the estimated and the measured values.

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Provenance Of Sand In Periglacial Sand Wedges And Sheet Sand, Northeastern Nebraska, Usa, William J. Wayne Jan 2004

Provenance Of Sand In Periglacial Sand Wedges And Sheet Sand, Northeastern Nebraska, Usa, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

Sand-wedge polygons on upland surfaces beneath thin loess in northeastern Nebraska record the existence of permafrost around the margin of the Wisconsinan glacier at its maximum advance. Strong unidirectional wind not only kept the upland surfaces free of snow, allowing frost to penetrate deeply and thermal contraction cracks to develop, but also dessicated the surface material so that frost action and sublimation of pore ice could loosen surface material. The strong NW-SE winds deflated soils from upland surfaces, made ventifacts of the cobbles in the lag that remained and created fields of yardangs oriented NW-SE. Sand derived from the soils …

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Teaching For Change: The Leadership In Environmental Education Partnership, Paul Faulstich Jan 2004

Teaching For Change: The Leadership In Environmental Education Partnership, Paul Faulstich

Pitzer Faculty Publications and Research

Humans are transforming earth's landscape from a natural matrix with pockets of civilization to just the opposite. Most of us realize that this pattern is not sustainable. I live and work in Claremont, California, a charming college town in the midst of suburban sprawl. The town has a central village of terminally tasteful, overpriced bungalows nestled in the shade of tall, largely exotic trees. Indeed, most of the landscape of this "city of trees and Ph.D.s" has been imported; only a remnant parcel of coastal sage scrub that the Claremont Colleges have reluctantly preserved remains.

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Comparison Of Dissolved And Acid-Extractable Metal Concentrations In Groundwater, Eastern Arkansas, Burmshik Kim, Kenneth F. Steele, Todd Fugitt Jan 2004

Comparison Of Dissolved And Acid-Extractable Metal Concentrations In Groundwater, Eastern Arkansas, Burmshik Kim, Kenneth F. Steele, Todd Fugitt

Journal of the Arkansas Academy of Science

No abstract provided.

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Imagining The Performance Zone: Overcoming Ambiguity In Consumer Based Electronic Performance Support Systems, Jason Simons Jan 2004

Imagining The Performance Zone: Overcoming Ambiguity In Consumer Based Electronic Performance Support Systems, Jason Simons

Theses : Honours

The locus of performance support implementation was once the domain of large corporations where its principles offered an attractive alternative to traditional methods of training within the scope of contemporary business practices. Due to economies of scale the large corporations were able to build effective performance support through the precise identification of the PERFORMANCE ZONE. This zone is created through the defining of the three attributes of performance, 1) the nature of the worker, 2) the nature of the task, and 3) the type and amount of support needed. lncreasingly the principles of performance-centred design have been adopted within diverse …

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Prescribed Fire Impacts To Amphibians And Reptiles In Shelterwood-Harvested Oak-Dominated Forests, Patrick D. Keyser, David J. Sausville, W. Mark Ford, Donald J. Schwab, Patrick H. Brose Jan 2004

Prescribed Fire Impacts To Amphibians And Reptiles In Shelterwood-Harvested Oak-Dominated Forests, Patrick D. Keyser, David J. Sausville, W. Mark Ford, Donald J. Schwab, Patrick H. Brose

Virginia Journal of Science

As part of a larger study examining the role of prescribed fire in regenerating upland oaks (Quercus spp.), seasonal prescribed burns (winter, spring, summer, and unburned control) were applied to first-stage shelterwood-harvested stands on Horsepen Wildlife Management Area in the Virginia Piedmont in 1995. Because fire impacts are poorly documented for herpetofaunal communities, we surveyed these stands in 1996 capturing 133 individuals of ten species during over 12,720 pitfall trapnights. We found no significant differences in relative abundance of Eastern Red-backed Salamanders (Plethodon cinereus) (P = 0.26), American Toads (Bufo americanus) (P = 0.93), …

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Diffusional Interactions At Dual Disk Microelectrodes: Comparison Of Experiment With Three-Dimensional Random Walk Simulations, John E. Baur, Perry N. Motsegood Jan 2004

Diffusional Interactions At Dual Disk Microelectrodes: Comparison Of Experiment With Three-Dimensional Random Walk Simulations, John E. Baur, Perry N. Motsegood

Faculty Publications – Chemistry

Three dimensional random walk simulations were used to model the diffusional interactions between coplanar dual disk microelectrodes. Working curves for the dependence of shielding factor, collection efficiency, and amplification factor on the size of the gap between the electrodes were developed. The simulations showed that when the gap size was ≥22 radii, the electrodes could be considered as independent and diffusionally isolated. Empirical equations for determining the gap size from simple shielding and generator-collector experiments were established. The simulation was used to model the collector electrode response for square waves of various frequencies applied to the generator electrode. Simulation results …

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Metallic Single-Walled Silicon Nanotubes, Jaeil Bai, Xiao Cheng Zeng, Hideki Tanaka, J. Y. Zeng Jan 2004

Metallic Single-Walled Silicon Nanotubes, Jaeil Bai, Xiao Cheng Zeng, Hideki Tanaka, J. Y. Zeng

Xiao Cheng Zeng Publications

Atomistic computer-simulation evidences are presented for the
possible existence of one-dimensional silicon nanostructures: the
square, pentagonal, and hexagonal single-walled silicon nanotubes
(SWSNTs). The local geometric structure of the SWSNTs
differs from the local tetrahedral structure of cubic diamond
silicon, although the coordination number of atoms of the SWSNTs
is still fourfold. Ab initio calculations show that the SWSNTs
are locally stable in vacuum and have zero band gap, suggesting
that the SWSNTs are possibly metals rather than wide-gap
semiconductors.

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Multivariate Analysis Of Variance And Covariance (Manova And Mancova), Gudmund R. Iversen Jan 2004

Multivariate Analysis Of Variance And Covariance (Manova And Mancova), Gudmund R. Iversen

Mathematics & Statistics Faculty Works

No abstract provided.

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Random Error, Gudmund R. Iversen Jan 2004

Random Error, Gudmund R. Iversen

Mathematics & Statistics Faculty Works

No abstract provided.

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