Physical Sciences and Mathematics Commons^™

Applications Of Underground Structures For The Protection Of Critical Infrastructure, George H. Baker, Richard G. Little, Don A. Linger

George H Baker

The U.S. President’s Commission on Critical Infrastructure Protection (PCCIP), convened in the wake of the bombing of the Murrah Federal Building in Oklahoma City, concluded that the nation’s physical security and economic security depend on our critical energy, communications, and computer infrastructures. While a primary motivating event for the establishment of the commission was the catastrophic physical attack of the Murrah Building, it is ironic that the commission focused its attention primarily on cyber threats. Their rationale was that cyber vulnerabilities posed a new, unaddressed challenge to infrastructure security. This approach was further questioned by the events of September 11, …

Supervisory Control And Data Acquisition (Scada) Systems, George H. Baker, Allan Berg

George H Baker

Our critical national infrastructure systems have become almost universally dependent upon computer-based control systems technically referred to as supervisory control and data acquisition (SCADA) systems. SCADA systems evolved from the telemetry and event-alarm systems developed in the early days of utilities. With the widespread use of SCADA systems, computers have become the "basis element" for much of our critical infrastructure. Thus, the disruption of controlling computer terminals and networks due to natural disasters, electric power failure, accidents or malicious activity can have catastrophic consequences.

Oral History Interview With Laszlo A. Belady, Philip L. Frana

Philip L Frana

Belady discusses his early life and education in Hungary, escape to West Germany during the 1956 revolution, and work as a draftsman at Ford Motor Company in Cologne and as an aerodynamics engineer at Dassault in Paris. Belady covers his 1961 immigration into the United States, where he joined International Business Machines and did early work in operating systems, virtual machine architectures, program behavior modeling, memory management, computer graphics, Asian character sets, and data security. He also ...

Polarization From Microlensing Of Spherical Circumstellar Envelopes By A Point Lens., J. F. L. Simmons, J. E. Bjorkman, R. Ignace, I. J. Coleman

Richard Ignace

We discuss the flux and polarization signals obtained from the microlensing of stars with extended circumstellar envelopes by a single point-mass lens. A previous paper considered the case of main-sequence stars, and showed that microlensing of the stellar photosphere could produce a small net polarization (up to 0.1 per cent). In this paper, we show that stars with extensive envelopes will show a much higher level of variable polarization (up to 10 per cent), even if they are spherically symmetric. Since the stellar envelopes most likely to be lensed are produced by red giant winds, we also investigate the effects …

A Mathematical Model Of Bacterial Aerotaxis, Borbala Mazzag, Alex Mogilner

Borbala Mazzag

No abstract provided.

On Porosity Prediction From Seismic Data In Ghawar Field, Saudi Arabia, Thomas M. Loretto

Thomas M Loretto

No abstract provided.

Expressing Logistic Regression Coefficients As Changes In Initial Probability Values: Useful Information For Practitioners, John Fraas, J Michael Drushal, Jef Graham

John W. Fraas

No abstract provided.

Heat Transport In Sb2àXvxte3 Single Crystals, Jeffrey Dyck, W. Chen, C. Uher, Č. DrašAr, P. LošŤÁK

Jeffrey Dyck

Antimony telluride doped with small concentrations of vanadium was recently identified as a diluted magnetic semiconductor. We present a study of the heat transport in single crystals of [formula] with [formula] 0.01, 0.02, and 0.03. Thermopower and thermal conductivity were measured from 1.5 K to 300 K. The thermopower is positive for all samples investigated and has a modest dependence on vanadium content. At low temperatures, the lattice thermal conductivity has an approximate [formula] dependence and the data up to 100 K can be fitted well assuming that phonons scatter on boundaries, point defects, charge carriers, and other phonons. Theoretical …

Calorimetric Study Of Nematic Prewetting, Xuewu Liu, David W. Allender, D. Finotello

David W Allender

We report specific-heat measurements for a series of liquid crystals imbedded in a porous cylindrical geometry. Above the nematic-to-isotropic transition and dependent on nematic width (or chain length), the specific heat shows a small peak. In analogy to known ellipsometry results, the peak is believed to be the signature of a nematic prewetting transition.

Researching The History Of Software: Mining Internet Resources In The “Old World,”“New World,” And The “Wild West”, Juliet Burba, Philip L. Frana

Philip L Frana

So wrote the great philosopher and poet Jorge Augustín Nicolás Ruiz de Santayana in his essay" The Elements and Function of Poetry."[1] Without doubt, the advent of the early Web unleashed a mania, an unreasonable recklessness that to this day resists being swept back under the rug. How can we tease" sanity" out of the Web? Can the historian put this madness to good use?

Predictable Assembly Of Substation Automation Systems: An Experiment Report, Scott A. Hissam, John Hudak, James Ivers, Mark H. Klein, Magnus Larsson, Gabriel A. Moreno, Linda M. Northrop, Daniel Plakosh, Judith Stafford, Kurt C. Wallnau, William G. Wood

Gabriel A. Moreno

Maximization Of The Open Circuit Voltage For Hydrogenated Amorphous Silicon N–I–P Solar Cells By Incorporation Of Protocrystalline Silicon P-Type Layers, R. J. Koval, Chi Chen, G. M. Ferreira, A. S. Ferlauto, Joshua M. Pearce, P. I. Rovira, C. R. Wronski, R. W. Collins

Joshua M. Pearce

The Enthalpy Of Vaporization And Sublimation Of Corannulene, Coronene, And Perylene At T = 298.15 K, James S. Chickos, Paul Webb, Gary Nichols, Tetsu Kiyobayashi, Pei-Chao Cheng, Lawrence Scott

James Chickos

No abstract provided.

Oral History Interview With Peter Watson, Philip L. Frana

Philip L Frana

Peter Watson is founder of Berkeley Computer Services Limited (BCS), one of the oldest continuously operating software houses in Scotland. The company was established in 1978, and is based in Glasgow. BCS's first customer was Kangolwear. The company moved into healthcare solutions in the 1980s. In 1991 the company launched the integrated software package Masterlab, first implemented at Neville Hall Hospital in Abergavenny, Wales. In 2002 BCS was one of the largest providers of laboratory information systems in the United ...

Oral History Interview With Charles Antony Richard Hoare, Philip L. Frana

Philip L Frana

Sir Antony Hoare is Senior Researcher at Microsoft Research in Cambridge, England, and Research/Professor Emeritus at the University of Oxford. Hoare is the recipient of the AM Turing Award for fundamental contributions to the definition and design of programming languages. He has also been awarded the Kyoto Prize in Advanced Technology for pioneering and fundamental contributions to software science. In this oral history Hoare recounts his personal involvement in the development of academic computing science ...

Core Services In The Architecture Of The National Digital Library For Science Education (Nsdl), Carl Lagoze, Walter Hoehn, David Millman, William Arms, Stoney Gan, Diane Hillmann, Christopher Ingram, Dean Krafft, Richard Marisa, Jon Phipps, John Saylor, Carol Terrizzi, James Allan, Sergio Guzman-Lara, Tom Kalt

James Allan

We describe the core components of the architecture for the (NSDL) National Science, Mathematics, Engineering, and Technology Education Digital Library. Over time the NSDL will include heterogeneous users, content, and services. To accommodate this, a design for a technical and organization infrastructure has been formulated based on the notion of a spectrum of interoperability. This paper describes the first phase of the interoperability infrastructure including the metadata repository, search and discovery services, rights management services, and user interface portal facilities.

Highly Anisotropic Crystal Growth And Thermoelectric Properties Of K2bi8_Xsbxse13 Solid Solutions: Band Gap Anomaly At Low X, Jeffrey S. Dyck, Theodora Kyratsi, Wei Chan, Duck-Young Chung, Ctirad Uher, Konstantinos Paraskevopoulos, Mercouri Kanatzidis

Jeffrey Dyck

The thermoelectric properties of solid solutions of the type B -K2Bi8_xSbxSe13 (0

Why Lawyers Should Care, John C. Dernbach

John C. Dernbach

No abstract provided.

Oral History Interview With Carl Machover, Philip L. Frana

Philip L Frana

Carl Machover is computer graphics pioneer and president of Machover Associates Corporation (MAC), a computer graphics consultancy founded in 1976. MAC provides a broad range of management, engineering, marketing, and financial services to computer graphics users, suppliers, and investors worldwide. In this oral history Machover describes his upbringing in Iowa and training in the Eddy radar and radio program and other Navy service schools in Mississippi and Texas. He also provides details of his education under ...

Packaging And Deploying Predictable Assembly, Scott A. Hissam, Gabriel A. Moreno, Judith Stafford, Kurt C. Wallnau

Gabriel A. Moreno

Significant economic and technical benefits accrue from the use of pre-existing and commercially available software components to develop new systems. However, challenges remain that, if not adequately addressed, will slow the adoption of software component technology. Chief among these are a lack of consumer trust in the quality of components, and a lack of trust in the quality of assemblies of components without extensive and expensive testing. This paper describes predictionenabled component technology (PECT). A PECT results from integrating component technology with analysis models. An analysis model permits analysis and prediction of assembly-level properties prior to component composition, and, perhaps, …

Thermal-Lens Model Compared With The Sheik-Bahae Formalism In Interpreting Z-Scan Experiments On Lyotropic Liquid Crystals, Fabio Luiz Sant'anna Cuppo, Antonio Martins Figueiredo Neto, Sergio Leonardo Gomez, Peter Palffy-Muhoray

Peter Palffy-Muhoray

We carried out Z-scan measurements on lyotropic liquid crystals and on lyotropic liquid crystals doped with ferrofluid. In these experiments, the sample is translated through the focal region of a focused Gaussian laser beam. The dependence of the far-field intensity on sample position due to intensity-dependent optical nonlinearities has been analyzed on the basis of the thermal-lens model of Gordon et al. and the Gaussian decomposition analysis of Sheik-Bahae et al. The thermal-lens model is nonlocal in space and time, whereas the Gaussian decomposition is predicated on a strictly local response. We compare the goodness of fit of the predictions …

The Blups Are Not “Best” When It Comes To Bootstrapping, Jeffrey S. Morris

Jeffrey S. Morris

In the setting of mixed models, some researchers may construct a semiparametric bootstrap by sampling from the best linear unbiased predictor residuals. This paper demonstrates both mathematically and by simulation that such a bootstrap will consistently underestimate the variation in the data in finite samples.

Oral History Interview With Lee Keet, Philip L. Frana

Philip L Frana

In this oral history software entrepreneur Ernest E.(Lee) Keet chronicles his education in programming and engineering at Cornell University, his early work as a salesperson and systems engineer for IBM in White Plains, NY, and his success as founder and CEO of Turnkey Systems, Inc.(TSI). Keet characterizes the heavy" craft" versus the" art" components of computer programming; he discusses the introduction of TSI's Task/Master, the first commercial telecommunications monitor; and his entrepreneurial efforts in Europe. Keet ...

Statistical Models For Empirical Component Properties And Assembly-Level Property Predictions: Toward Standard Labeling, Gabriel A. Moreno, Scott A. Hissam, Kurt C. Wallnau

Gabriel A. Moreno

One risk inherent in the use of software components has been that the behavior of assemblies of components is discovered only after their integration. The objective of our work is to enable designers to use known (and certified) component properties as parameters to models that can be used to predict assembly-level properties. Our concern in this paper is with empirical component properties and compositional reasoning, rather than formal properties and reasoning. Empirical component properties must be measured; assessing the effectiveness of predictions based on these properties also involves measurement. This, in turn, introduces systematic and random measurement error. As a …

Photovoltaics — A Path To Sustainable Futures, Joshua M. Pearce

Joshua M. Pearce

Transport Properties Of Polycrystalline Type-I Sn Clathrates, G. S. Nolas, J. L. Cohn, Jeffrey Dyck, C. Uher, J. Lang

Jeffrey Dyck

Thermal conductivity, resistivity, Seebeck coefficient, and Hall measurements on polycrystalline Sn-clathrate compounds with the type-I hydrate crystal structure are reported. Interstitial alkali-metal atoms in these compounds reside inside polyhedral cavities formed by the tetrahedrally bonded Sn network atoms. Localized disorder associated with “rattling” motion of these interstitial atoms contributes to the low thermal conductivity of these semiconducting compounds. The Hall coefficient and resistivity for some compounds exhibit nonmonotonic temperature dependences consistent with a crossover with decreasing temperature from conduction-band to impurity-band conduction. The carrier mobility is found to be low even in the absence of interstitial atoms within the Sn …

Three-Dimensional Dye Distribution In Photo-Oriented Liquid-Crystal Alignment Layers, S. Bardon, D. Coleman, N. A. Clark, T. Kosa, H. Yuan, Peter Palffy-Muhoray

Peter Palffy-Muhoray

The three-dimensional optical anisotropy of photo-buffed dye-doped polymer films and the resulting orientation imparted to a liquid crystal in contact are probed using total internal reflection. Although the linearly polarized writing light generates a uniaxial distribution of dye molecules, the polymer films are biaxial, a result of symmetry breaking by the film surface.

Smaller Solutions For The Firing Squad, Amber Settle, Janos Simon

Amber Settle

Profile Shapes For Optically Thick X-Ray Emission Lines From Stellar Winds., R. Ignace, K. G. Gayley

Richard Ignace

We consider the consequences of appreciable line optical depth for the profile shape of X-ray emission lines formed in stellar winds. The hot gas is thought to arise in distributed wind shocks, and the line formation is predominantly via collisional excitation followed by radiative decay. Such lines are often modelled as optically thin, but the theory has difficulty matching resolved X-ray line profiles. We suggest that for strong lines of abundant metals, newly created photons may undergo resonance scattering, modifying the emergent profile. Using Sobolev theory in a spherically symmetric wind, we show that thick-line resonance scattering leads to emission …

Thermoelectric Properties Of The N-Type Filled Skutterudite Ba0.3co4sb12 Doped With Ni, Jeffrey Dyck, Wei Chen, Ctirad Uher, Lidong Chen, Xinfeng Tang, Toshio Hirai

Jeffrey Dyck

Synthesis and electrical and thermal transport properties are reported for several filled skutterudite compounds doped with Ni: Ba0.3NixCo4_xSb12 with 0