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Greenland Snow Accumulation Estimates From Satellite Radar Scatterometer Data, Mark R. Drinkwater, David G. Long, Andrew W. Bingham Dec 2001

Greenland Snow Accumulation Estimates From Satellite Radar Scatterometer Data, Mark R. Drinkwater, David G. Long, Andrew W. Bingham

Faculty Publications

Data collected by the C band ERS-2 wind scatterometer (EScat), the Ku band ADEOS-1 NASA scatterometer (NSCAT), and the Ku band SeaWinds on QuikScat (QSCAT) satellite instruments are used to illustrate spatiotemporal variability in snow accumulation on the Greenland ice sheet. Microwave radar backscatter images of Greenland are derived using the scatterometer image reconstruction (SIR) method at 3-day intervals over the periods 1991–1998 and 1996–1997 for EScat and NSCAT, respectively. The backscatter coefficient σ° normalized to 40° incidence, A, and gradient in backscatter, B, in the range 20°–60° are compared with historical snow accumulation data and recent measurements …

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The Flexible Firm: Capability Management In Network Organizations, C. Annique Un Dec 2001

The Flexible Firm: Capability Management In Network Organizations, C. Annique Un

Faculty Publications

The article reviews the book "The Flexible Firm: Capability Management in Network Organizations," edited by Julian Birkinshaw and Peter Hagström.

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Annotated Bibliography Of Research In The Teaching Of English, Deborah Brown, Judith Kalman, Macrina Gómez, Gert Rijlaarsdam, Anne D'Antonio Stinson, Melissa E. Whiting Nov 2001

Annotated Bibliography Of Research In The Teaching Of English, Deborah Brown, Judith Kalman, Macrina Gómez, Gert Rijlaarsdam, Anne D'Antonio Stinson, Melissa E. Whiting

Faculty Publications

Twice a year, in the May and November issues, RTE publishes a selected bibliography of recent research in literacy education, Most of the studies appeared during the six-month period preceding the compilation of the bibliography (January through June, 2001 for the present bibliography), but studies that appeared earlier are occasionally included. The listing is selective;; we make no attempt to include all research and research-related articles that appeared in the period tinder review Comments on the bibliography and suggestions about items for inclusion may be directed to the bibliography editors. We encourage you to send your suggestions to [email protected], [email protected], …

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Stacked Subwavelength Gratings As Circular Polarization Filters, Gregory P. Nordin, P. C. Deguzman Nov 2001

Stacked Subwavelength Gratings As Circular Polarization Filters, Gregory P. Nordin, P. C. Deguzman

Faculty Publications

We have stacked subwavelength gratings (SWGs) on a single substrate to create a compact, integrated circular polarization filter. The SWGs consist of a wire grid polarizer and a broadband form-birefringent quarter-wave plate (QWP). Rigorous coupled-wave analysis was used to design the QWP for operation over the 3.5-5.0 m wavelength range. The fabricated silicon broadband QWP exhibited a phase retardance of 82-97° across this wavelength range. Two stacked structures are presented, each with a different wire grid polarizer fabricated on an organic planarization layer (SU-8) that is deposited on a QWP grating. Transmittance measurements of the first structure when illuminated with …

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Economic Hardship As Coercion Under The Protocol On International Trafficking In Persons By Organized Crime Elements, Linda A. Malone Nov 2001

Economic Hardship As Coercion Under The Protocol On International Trafficking In Persons By Organized Crime Elements, Linda A. Malone

Faculty Publications

No abstract provided.

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A Dipolar Coupling Based Strategy For Simultaneous Resonance Assignment And Structure Determination Of Protein Backbones, Fang Tian, Homayoun Valafar, James H. Prestegard Nov 2001

A Dipolar Coupling Based Strategy For Simultaneous Resonance Assignment And Structure Determination Of Protein Backbones, Fang Tian, Homayoun Valafar, James H. Prestegard

Faculty Publications

A new approach for simultaneous protein backbone resonance assignment and structure determination by NMR is introduced. This approach relies on recent advances in high-resolution NMR spectroscopy that allow observation of anisotropic interactions, such as dipolar couplings, from proteins partially aligned in field ordered media. Residual dipolar couplings are used for both geometric information and a filter in the assembly of residues in a sequential manner. Experimental data were collected in less than one week on a small redox protein, rubredoxin, that was 15N enriched but not enriched above 1% natural abundance in 13C. Given the acceleration possible with partial 13C …

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Using Ssm Proxies To Provide Efficient Multiple-Source Multicast Delivery, Daniel Zappala, Aaron Fabbri Nov 2001

Using Ssm Proxies To Provide Efficient Multiple-Source Multicast Delivery, Daniel Zappala, Aaron Fabbri

Faculty Publications

We consider the possibility that single-source multicast (SSM) will become a universal multicast service, enabling large-scale distribution of content from a few well-known sources to a general audience. Operating under this assumption, we explore the problem of building the traditional IP model of any-source multicast on top of SSM. Toward this end, we design an SSM proxy service that allows any sender to efficiently deliver content to a multicast group. We demonstrate the performance improvements this service offers over standard SSM and describe extensions for access control, dynamic proxy discovery, and multicast proxy distribution.

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Ortho-Planar Linear-Motion Springs, John J. Parise, Larry L. Howell, Spencer P. Magleby Nov 2001

Ortho-Planar Linear-Motion Springs, John J. Parise, Larry L. Howell, Spencer P. Magleby

Faculty Publications

This paper presents an ortho-planar spring design that operates by raising or lowering its platform relative to the base with no rotation. The compact nature of the design, and its non-rotating motion, eliminates the problem of rotation against adjoining surfaces and is less sensitive to variation in assemblies than many current compact springs. Nomenclature is presented to identify different configurations, mathematical equations are provided that accurately model the force-defection relationships, and a pneumatic valve positioner application is demonstrated.

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Si3N4/Algan/Gan-Metal-Insulator-Semiconductor Heterostructure Field-Effect Transistors, X. Hu, A. Koudymov, Grigory Simin, J. Yang, M. Asif Khan, A. Tarakji, M. S. Shur, R. Gaska Oct 2001

Si3N4/Algan/Gan-Metal-Insulator-Semiconductor Heterostructure Field-Effect Transistors, X. Hu, A. Koudymov, Grigory Simin, J. Yang, M. Asif Khan, A. Tarakji, M. S. Shur, R. Gaska

Faculty Publications

We report on a metal–insulator–semiconductor heterostructurefield-effect transistor (MISHFET) using Si3N4 film simultaneously for channel passivation and as a gate insulator. This design results in increased radio-frequency (rf) powers by reduction of the current collapse and it reduces the gate leakage currents by four orders of magnitude. A MISHFET room temperature gate current of about 90 pA/mm increases to only 1000 pA/mm at ambient temperature as high as 300 °C. Pulsed measurements show that unlike metal–oxide–semiconductor HFETs and regular HFETs, in a Si3N4 MISHFET, the gate voltage amplitude required for current collapse is much higher …

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Modeling The Effects Of Transforming Growth Factor-Beta On Extracellular Matrix Alignment In Dermal Wound Repair, J. C. Dallon, J. A. Sherratt, P. K. Maini Oct 2001

Modeling The Effects Of Transforming Growth Factor-Beta On Extracellular Matrix Alignment In Dermal Wound Repair, J. C. Dallon, J. A. Sherratt, P. K. Maini

Faculty Publications

We present a novel mathematical model for collagen deposition and alignment during dermal wound healing, focusing on the regulatory effects of TGF. Our work extends a previously developed model which considers the interactions between fibroblasts and extracellular matrix, composed of collagen and a fibrin based blood clot, by allowing fibroblasts to orient the collagen matrix, and produce and degrade the extracellular matrix, while the matrix can direct the fibroblasts and control their speed. Here we extend the model by allowing a time varying concentration of TGF to alter the properties of the fibroblasts. Thus we are able to simulate experiments …

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Induced Strain Mechanism Of Current Collapse In Algan/Gan Heterostructure Field-Effect Transistors, Grigory Simin, A. Koudymov, A. Tarakji, X. Hu, J. Yang, M. Asif Khan, M. S. Shur, R. Gaska Oct 2001

Induced Strain Mechanism Of Current Collapse In Algan/Gan Heterostructure Field-Effect Transistors, Grigory Simin, A. Koudymov, A. Tarakji, X. Hu, J. Yang, M. Asif Khan, M. S. Shur, R. Gaska

Faculty Publications

Gated transmission line model pattern measurements of the transient current–voltage characteristics of AlGaN/GaN heterostructurefield-effect transistors(HFETs) and metal–oxide–semiconductor HFETs were made to develop a phenomenological model for current collapse. Our measurements show that, under pulsed gate bias, the current collapse results from increased source–gate and gate–drain resistances but not from the channel resistance under the gate. We propose a model linking this increase in series resistances (and, therefore, the current collapse) to a decrease in piezoelectriccharge resulting from the gate bias-induced nonuniform strain in the AlGaN barrier layer.

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Statistics And Supermetallicity: The Metallicity Of Mu Leonis, B. J. Taylor Oct 2001

Statistics And Supermetallicity: The Metallicity Of Mu Leonis, B. J. Taylor

Faculty Publications

For the often-studied "SMR" giant µ Leo, Smith & Ruck (2000) have recently found that [Fe/H] approximately + 0.3 dex. Their conclusion is tested here in a "statistical" paradigm, in which statistical principles are used to select published high-dispersion µ Leo data and assign error bars to them. When data from Smith & Ruck and from Takeda et al. (1998) are added to a data base compiled in 1999, it is found that conclusions from an earlier analysis (Taylor 1999c) are essentially unchanged: the mean value of [Fe/H] approximately + 0.23 ± 0.025 dex, and values ≤ + 0.2 dex …

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Jesus The Way, The Cross, And The World According To The Gospel Of John, Craig R. Koester Oct 2001

Jesus The Way, The Cross, And The World According To The Gospel Of John, Craig R. Koester

Faculty Publications

According to the internal logic of John's Gospel, Jesus' claim to be "the way, the truth, and the life" is a remarkably inclusive statement, with none of the exclusive character sometimes attributed to it.

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The American Militia And The Origin Of Conscription: A Reassessment, Jeffrey Rogers Hummel Oct 2001

The American Militia And The Origin Of Conscription: A Reassessment, Jeffrey Rogers Hummel

Faculty Publications

No abstract provided.

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"Even If Noah, Daniel, And Job" (Ezekiel 14:14, 20)—Why These Three?, Jo Ann Davidson Oct 2001

"Even If Noah, Daniel, And Job" (Ezekiel 14:14, 20)—Why These Three?, Jo Ann Davidson

Faculty Publications

No abstract provided.

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Modeling Irda Performance: The Effect Of Irlap Negotiation Parameters On Throughput, Scott V. Hansen, Charles D. Knutson, Michael G. Robertson, Franklin E. Sorenson Oct 2001

Modeling Irda Performance: The Effect Of Irlap Negotiation Parameters On Throughput, Scott V. Hansen, Charles D. Knutson, Michael G. Robertson, Franklin E. Sorenson

Faculty Publications

The Infrared Data Association's (IrDA) infrared data transmission protocol is a widely used mechanism for short-range wireless data communications. In order to provide flexibility for connections between devices of potentially disparate capabilities, IrDA devices negotiate the values of several transmission parameters based on the capabilities of the devices establishing the connection. This paper describes the design and implementation of a software tool, Irdaperf, to model IrDA performance based on negotiated transmission parameters. Using Irdaperf, we demonstrate that for fast data rates, maximizing window size and data size are key factors for overcoming the negative effects of a relatively long link …

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Tort Recovery For Loss Of A Chance, David A. Fischer Oct 2001

Tort Recovery For Loss Of A Chance, David A. Fischer

Faculty Publications

Tort lawyers in the United States often think of “loss of a chance” as a theory of “probabilistic causation” that only applies to medical malpractice misdiagnosis cases. The theory is that if a physician negligently fails to diagnose a curable disease, and the patient is harmed by the disease, the physician should be liable for causing the “loss of a chance” of a cure. We shall see that if the chance of a cure is less than 50 percent, the plaintiff cannot prove by a preponderance of evidence that the negligence caused the harm, and would recover no damages under …

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Chicago Newspaper Theater Critics Of The Early 20th Century, Scott B. Fosdick Oct 2001

Chicago Newspaper Theater Critics Of The Early 20th Century, Scott B. Fosdick

Faculty Publications

In the early years of the twentieth century, when live theater dominated the entertainment world and print media led public discourse, each without competition from electronic forms, the daily newspaper theater critic mediated ideas and values quite differently than today’s critics, whose main function has been reduced to that of a consumer guide. This article examines the corps of theater critics who served ten Chicago newspapers about 100 years ago. At a time when news editors were reluctant to cover new ideas and social movements, such as the push for women’s suffrage, theater critics were encountering radical new social ideas …

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Ambiguous Commitments And Uncertain Policies: The Truman Doctrine In Greece, 1947-1952, By Judith S. Jeffrey, Gerasimos Augustinos Oct 2001

Ambiguous Commitments And Uncertain Policies: The Truman Doctrine In Greece, 1947-1952, By Judith S. Jeffrey, Gerasimos Augustinos

Faculty Publications

Reviews the book Ambiguous Commitments and Uncertain Policies: The Truman Doctrine in Greece, 1947-1952, by Judith S. Jeffrey.

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Assessing Observation Focus And Conference Targets Of Cooperating Teachers, Margaret M. Coleman, Murrary F. Mitchell Oct 2001

Assessing Observation Focus And Conference Targets Of Cooperating Teachers, Margaret M. Coleman, Murrary F. Mitchell

Faculty Publications

The purpose of this study was to develop a strategy to assess two facets of the supervisory responsibilities of Cooperating Teachers (CTs): (a) what CTs choose to observe during a lesson when preparing to offer comments to a student teacher and (b) what CTs choose to bring to the attention of student teachers after observing a lesson. The purpose also was to determine the usefulness of the strategy in discriminating among CTs that may have different preparation backgrounds for supervisory duties. Eighteen elementary level CTs participated by individually watching a videotaped lesson, preparing a written critique, and responding to interviews …

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The Constitution In Exile: Is It Time To Bring It In From The Cold?, William W. Van Alstyne Oct 2001

The Constitution In Exile: Is It Time To Bring It In From The Cold?, William W. Van Alstyne

Faculty Publications

No abstract provided.

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The Biographer’S Tale By A. S. Byatt. New York: Alfred A. Knopf, 2001. 305 Pp. $24.00. Isbn 0-375- 41114-3., Jennifer A. Marshall Oct 2001

The Biographer’S Tale By A. S. Byatt. New York: Alfred A. Knopf, 2001. 305 Pp. $24.00. Isbn 0-375- 41114-3., Jennifer A. Marshall

Faculty Publications

No abstract provided.

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Caleb’S Finest Hour, Roy E. Gane Oct 2001

Caleb’S Finest Hour, Roy E. Gane

Faculty Publications

No abstract provided.

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Chemical Bonding, Elasticity, And Valence Force Field Models: A Case Study For Α-Pt2si And Ptsi, Gus L. W. Hart, J. E. Klepeis, O. Beckstein, O. Pankratov Sep 2001

Chemical Bonding, Elasticity, And Valence Force Field Models: A Case Study For Α-Pt2si And Ptsi, Gus L. W. Hart, J. E. Klepeis, O. Beckstein, O. Pankratov

Faculty Publications

We have carried out a detailed study of the chemical bonding for two room-temperature stable platinum silicide phases, tetragonal α-Pt2Si. These elements of the bonding are further analyzed by constructing valence force field models using the results from recent first principles calculations of the six (nine) independent, nonzero elastic constants of α-Pt2Si (PtSi). The resulting volume-, radial-, and angular-dependent force constants provide insight into the relative strength of various bonding elements as well as the trends observed in the elastic constants themselves. The valence force field analysis yields quantitative information about the nature of the chemical bonding that is not …

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Poynting's Theorem And Luminal Total Energy Transport In Passive Dielectric Media, Scott Glasgow, Michael Ware, Justin Peatross Sep 2001

Poynting's Theorem And Luminal Total Energy Transport In Passive Dielectric Media, Scott Glasgow, Michael Ware, Justin Peatross

Faculty Publications

Without approximation the energy density in Poynting's theorem for the generally dispersive and passive dielectric medium is demonstrated to be a system total dynamical energy density. Thus the density in Poynting's theorem is a conserved form that by virtue of its positive definiteness prescribes important qualitative and quantitative features of the medium-field dynamics by rendering the system dynamically closed. This fully three-dimensional result, applicable to anisotropic and inhomogeneous media, is model independent, relying solely on the complex-analytic consequences of causality and passivity. As direct applications of this result, we show 1 that a causal medium responds to a virtual, instantaneous …

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Aha/Acc Guidelines For Preventing Heart Attack And Death In Patients With Atherosclerotic Cardiovascular Disease: 2001 Update - A Statement For Healthcare Professionals From The American Heart Association And The American College Of Cardiology, Sidney C. Smith Jr., Steven N. Blair, Robert O. Bonow, Lawrence M. Brass, Manuel D. Cerqueira, Kathleen Dracup, Valentin Fuster, Antonio M. Gotto, Scott M. Grundy, Nancy Houston-Miller, Alice Jacobs, Daniel Jones, Ronald M. Krauss, Lori Mosca, Ira S. Ockene, Richard C. Pasternak, Thomas A. Pearson, Marc A. Pfeffer, Rodman K. Starke, Kathryn A. Taubert Sep 2001

Aha/Acc Guidelines For Preventing Heart Attack And Death In Patients With Atherosclerotic Cardiovascular Disease: 2001 Update - A Statement For Healthcare Professionals From The American Heart Association And The American College Of Cardiology, Sidney C. Smith Jr., Steven N. Blair, Robert O. Bonow, Lawrence M. Brass, Manuel D. Cerqueira, Kathleen Dracup, Valentin Fuster, Antonio M. Gotto, Scott M. Grundy, Nancy Houston-Miller, Alice Jacobs, Daniel Jones, Ronald M. Krauss, Lori Mosca, Ira S. Ockene, Richard C. Pasternak, Thomas A. Pearson, Marc A. Pfeffer, Rodman K. Starke, Kathryn A. Taubert

Faculty Publications

No abstract provided.

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Indium-Silicon Co-Doping Of High-Aluminum-Content Algan For Solar Blind Photodetectors, V. Adivarahan, Grigory Simin, G. Tamulaitis, R. Srinivasan, J. Yang, M. Asif Khan, M. S. Shur, R. Gaska Sep 2001

Indium-Silicon Co-Doping Of High-Aluminum-Content Algan For Solar Blind Photodetectors, V. Adivarahan, Grigory Simin, G. Tamulaitis, R. Srinivasan, J. Yang, M. Asif Khan, M. S. Shur, R. Gaska

Faculty Publications

We report on an indium–silicon co-doping approach for high-Al-content AlGaN layers. Using this approach, very smooth crack-free n-type AlGaN films as thick as 0.5 μm with Al mole fraction up to 40% were grown over sapphire substrates. The maximum electron concentration in the layers, as determined by Hall measurements, was as high as 8×1017 cm−3 and the Hall mobility was up to 40 cm2/Vs. We used this doping technique to demonstrate solar-blind transparent Schottky barrierphotodetectors with the cut-off wavelength of 278 nm.

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Characterization Of Two-Dimensional Finite-Aperture Wire Grid Polarizers By A Spectral-Domain Technique, Michael A. Jensen, Gregory P. Nordin Sep 2001

Characterization Of Two-Dimensional Finite-Aperture Wire Grid Polarizers By A Spectral-Domain Technique, Michael A. Jensen, Gregory P. Nordin

Faculty Publications

We investigate the transmission characteristics of perfectly conducting two-dimensional wire grid polarizers fabricated in finite and infinite apertures using a rigorous spectral-domain mode-matching method. Specifically, the transmission coefficient for both transverse-electric and transverse-magnetic polarizations, extinction ratio, and diffraction pattern are characterized for a wide variety of geometric and material parameters including aperture dimension, conducting wire fill factor, wire spacing, polarizer thickness, material dielectric constants, and incident wave arrival angle. The results indicate that the transmission behavior is largely insensitive to aperture dimension.

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Improving Cluster Utilization Through Set Based Allocation Policies, Quinn O. Snell, Julio C. Facelli, Brian D. Haymore, David B. Jackson Sep 2001

Improving Cluster Utilization Through Set Based Allocation Policies, Quinn O. Snell, Julio C. Facelli, Brian D. Haymore, David B. Jackson

Faculty Publications

While clusters have already proven themselves in the world of high performance computing, some clusters are beginning to exhibit resource inefficiencies due to increasing hardware diversity. Much of the success of clusters lies in the use of commodity components built to meet various hardware standards. These standards have allowed a great level of hardware backwards compatibility that is now resulting in a condition referred to as hardware 'drift' or heterogeneity. The hardware heterogeneity introduces problems when diverse compute nodes are allocated to a parallel job, as most parallel jobs are not self-balancing. This paper presents a new method that allows …

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Photon Decay At The Schwarzschild Horizon, Brett Altschul, R. Jackiw Aug 2001

Photon Decay At The Schwarzschild Horizon, Brett Altschul, R. Jackiw

Faculty Publications

A recent proposal that gravity theory is an emergent phenomenon also entails the possibility of photon decay near the Schwarzschild event horizon. We present a possible mechanism for such decay, which utilizes a dimensional reduction near the horizon. © 2001 Elsevier Science B.V.

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