Physical Sciences and Mathematics Commons^™

Case-Control Current Status Data, Nicholas P. Jewell, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

Current status observation on survival times has recently been widely studied. An extreme form of interval censoring, this data structure refers to situations where the only available information on a survival random variable, T, is whether or not T exceeds a random independent monitoring time C, a binary random variable, Y. To date, nonparametric analyses of current status data have assumed the availability of i.i.d. random samples of the random variable (Y, C), or a similar random sample at each of a set of fixed monitoring times. In many situations, it is useful to consider a case-control sampling scheme. Here, …

Domain Wall Relaxation, Creep, Sliding, And Switching In Superferromagnetic Discontinuous Co80Fe20/Al2O3 Multilayers, X. Chen, O. Sichelschmidt, Wolfgang Kleemann, Christian Binek, J.B. Sousa, Susana Cardoso De Freitas, P.P. Freitas

Christian Binek Publications

The ac susceptibility of a superferromagnetic discontinuous multilayer [Co₈₀Fe₂₀(1.4   nm)/ Al₂O₃(3   nm)]10 is measured as a function of temperature, frequency, and field amplitude and compared to static and dynamic hysteresis loops. Its properties are successfully mapped onto the predicted [T. Nattermann, V. Pokrovsky, and V. M. Vinokur, Phys. Rev. Lett. 87, 197005 (2001).] dynamical phase transitions, which link the relaxation, creep, sliding, and switching regimes of pinned domain walls.

Electronic Publication Of Legal Scholarship: New Issues And New Models, Richard A. Danner

Journal of Legal Education

No abstract provided.

Liberal Arts - Fall 2002, University Of Mississippi. College Of Liberal Arts

Liberal Arts Newsletters

First fellowship recipients represent psychology, chemistry, English

The Tide Is High For The Boston Beaches, Marissa Glowac

New England Journal of Public Policy

In 1993, Massachusetts Governor William Weld and Boston Mayor Thomas Menino approved the “Back to the Beaches” project, a seven-year, $30.5 million public project to restore nineteen Boston Harbor beaches. Today, these sites have new, cleaner sand, improved access, and new amenities and facilities now ready to offer additional opportunities for recreation. People are coming back to the Boston Harbor beaches in numbers significantly higher than a decade ago. This study concludes that the implementation and success of the “Back to the Beaches” project can be attributed to several factors — an increased public awareness of the value of open …

Experimental Observation Of Energetic Ions Accelerated By Three-Dimensional Magnetic Reconnection In A Laboratory Plasma, Michael R. Brown, C. D. Cothran, Matthew Joseph Landreman , '03, David J. Schlossberg , '01, W. H. Matthaeus

Physics & Astronomy Faculty Works

Magnetic reconnection is widely believed responsible for heating the solar corona as well as for generating X-rays and energetic particles in solar flares. On astrophysical scales, reconnection in the intergalactic plasma is a prime candidate for a local source (Mpc) of cosmic rays exceeding the Greisen-Zatsepin-Kuzmin cutoff (∼10(19) eV). In a laboratory astrophysics experiment, we have made the first observation of particles accelerated by magnetic reconnection events to energies significantly above both the thermal and the characteristic magnetohydrodynamic energies. These particles are correlated temporally and spatially with the formation of three-dimensional magnetic structures in the reconnection region.

Development Of A Hybrid Photo-Diode And Its Front-End Electronics For The Btev Experiment, Raymond Mountain

Physics - All Scholarship

This paper describes the development of a 163-channel Hybrid Photo-Diode (HPD) to be used in the RICH Detector for the BTEV Experiment. This is a joint development project with DEP, Netherlands. It also reports on the development of associated front-end readout electronics based on the va_btev ASIC, undertaken with IDEAS, Norway. Results from bench tests of the first prototypes are presented.

Trends. War On Personality And Personality And War: Comments On Nass And Lee (2002), Ibpp Editor

International Bulletin of Political Psychology

This Trends article discusses another article – Identity and deconstruction, by Clifford Nass and Kwan Min Yee – published in volume 3 (2002) of Archives of Psychiatry & Psychotherapy in which the authors demonstrate that people reliably attribute personality characteristics to computer-synthesized speech, exploring the ramifications in a political psychological context.

Field Trip Guide (For The Nebraska Well Drillers Association) Central Nebraska Geology, James W. Goeke, Robert F. Diffendal Jr., Duane A. Eversoll

Conservation and Survey Division: Faculty and Staff Publications

Field trip guide, for the Nebraska Well Drillers Association, covering Central Nebraska Geology from September 2002.

The Tegrid Semantic Web Application, Steven Gollery, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Over the past several years there has been an increasing recognition of the shortcomings of message-passing data-processing systems that compute data without understanding, and the vastly superior potential capabilities of information-centric systems that incorporate an internal information model with sufficient context to support a useful level of automatic reasoning.

The key difference between a data-processing and an information-centric environment is the ability to embed in the information-centric software some understanding of the information being processed. The term information-centric refers to the representation of information in the computer, not to the way it is actually stored in a digital machine. This …

The Role Of Discovery In Context-Building Decision-Support Systems, Steven J. Gollery, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

There are many sources of on-line information available to those responsible for making decisions in complex situations. However, most of that information is either intended for human use or is available only in custom or proprietary formats. Both of these conditions reduce the ability of computer software to perform automatic reasoning about this information. As a result, the usefulness of on-line information in intelligent decision-support systems is currently limited to the few sources that are implemented specifically for those systems. The vast mass of sources that do not fit that description are virtually invisible.

Current practices for integrating multiple information …

Data, Information, And Knowledge In The Context Of Sils, Michael A. Zang, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Data, information, and knowledge are becoming increasingly common terms in the literature of the software industry. This terminology originated some time ago in the disciplines of cognitive science and artificial intelligence to reference three closely related but distinct concepts. Traditionally, mainstream software engineering has lumped all three concepts together as data and has only recently begun to distinguish between them. Unfortunately, the popular desire to distinguish between data, information, and knowledge within the mainstream has blurred the individual meanings of the words to the point where there is no longer a clear-cut distinction between them for most people. This problem …

Proceedings Of The 2002 Onr Decision-Support Workshop Series: Transformation..., Collaborative Agent Design Research Center

Collaborative Agent Design (CAD) Research Center

In August of 1998 the Collaborative Agent Design Research Center (CADRC) of the California Polytechnic State University in San Luis Obispo (Cal Poly), approached Dr. Phillip Abraham of the Office of Naval Research (ONR) with the proposal for an annual workshop focusing on emerging concepts in decision-support systems for military applications. The proposal was considered timely by the ONR Logistics Program Office for at least two reasons. First, rapid advances in information systems technology over the past decade had produced distributed, collaborative computer-assistance capabilities with profound potential for providing meaningful support to military decision makers. Indeed, some systems based on …

Monte Carlo Simulation On The Indirect Exchange Interactions Of Co-Doped Zno Film, Abraham F. Jalbout, Hanning Chen, Scott L. Whittenburg

Chemistry and Biochemistry Faculty Publications

Monte Carlo simulations using a three-dimensional lattice model studied the Ruderman–Kittel–Kasuya–Yosida (RKKY) indirect exchange interaction of doped magnetic Co ions in ZnOfilms. The results of the calculations show that the RKKY interaction in Co-doped ZnO is long ranged and its magnitude is proportional to (inverse of the distance from a central ion). The sign oscillates with a frequency that depends on the concentration of the carrier. The long-distance sum of the RKKY indirect exchange energies is positive indicating that these materials are ferromagnetic, in direct correlation with previously reported results.

Performance Evaluation Of Linear Hash Structure Model In A Nested Transaction Environment, Malik Ayed Tubaishat, Sanjay Kumar Madria, Bharat Bhargava

Computer Science Faculty Research & Creative Works

We design and implement a linear hash algorithm in nested transaction environment to handle large amount of data with increased concurrency. Nested transactions allow parallel execution of transactions, and handle transaction aborts, thus provides more concurrency and efficient recovery. We use object-oriented methodology in the implementation which helped in designing the programming components independently. In our model, buckets are modeled as objects and linear hash operations are modeled as methods. The papers contribution is novel in the sense that the system, to our knowledge, is the first to implement linear hashing in a nested transactions environment. We have built a …

Identification Of Cool White Dwarfs In The Noao Deep Wide-Field Survey, M. Kilic, Don E. Winget, T. Von Hippel, C.F. Claver

Publications

The chronology of star formation is recorded in the white dwarf luminosity function (WDLF). White dwarf (WD) structure implies a relatively simple connection between WD luminosity and age. First attempts to exploit WDs as chronometers [3,4,6] showed that the WDLF was a map of the history of star formation in the disk, and a significant shortfall of low-luminosity degenerates–the inevitable consequence of the finite age of the disk. The shortfall near log(L/L⊙)≈−4.5 implies a disk age of 6.5–9.5 Gyr [2]. The WDLF from wide common proper motion binaries [5] does not show the shortfall seen by Liebert et al. (1988). …

Search For Oxygen In Cool Dq White Dwarf Atmospheres, M. Kilic, Ted Von Hippel, D. E. Winget, D. F. Lester, D. Saumon

Publications

The existence of carbon in cool He white dwarf (WD) atmospheres has been known for a relatively long time[5]. The presence of carbon in these atmospheres is explained by convective dredge up of interior carbon [6]. Pelletier et al. (1986) presented the first detailed calculations of this process and showed that carbon diffuses upwards from the core into the base of the He-rich envelope where it can be dredged up by a surface convection zone. As the temperature of the star decreases, more carbon diffuses upward, and the base of convection zone moves deeper into the star, further enriching the …

Construction, Pattern Recognition And Performance Of The Cleo Iii Lif-Tea Rich Detector, Raymond Mountain, R. Ayad, Konstantin Vladimirovich Bukin, A. Efimov

Physics - All Scholarship

We briefly describe the design, construction and performance of the LiF-Tea RICH detector built to identify charged particles in the CLEO III experiment. Excellent pion/kaon separation is demonstrated.

Density And Conformation With Relaxed Substrate, Bulk, And Interface In Electrophoretic Deposition Of Polymer Chains, F.W. Bentrem, J. Xie, Ras B. Pandey

Faculty Publications

Characteristics of relaxed density profile and conformation of polymer chains are studied by a Monte Carlo simulation on a discrete lattice in three dimensions using different segmental (kink-jump (K), crank-shaft (C), reptation (R)) dynamics. Three distinct density regimes, substrate, bulk, and interface, are identified. With the KC segmental dynamics, we find that the substrate coverage grows with a power law, d_s∝t^γ with a field (E) dependent non-universal exponent γ=0.23+0.7E. The bulk volume fraction d_b and the substrate polymer density (d_s) increases with the field with power-laws (d_{b …}

Heterogeneous Self-Reconfiguring Robotics: Ph.D. Thesis Proposal, Robert C. Fitch

Computer Science Technical Reports

Self-reconfiguring robots are modular systems that can change shape, or "reconfigure," to match structure to task. They comprise many small, discrete, often identical modules that connect together and that are minimally actuated. Global shape transformation is achieved by composing local motions. Systems with a single module type, known as "homogeneous" systems, gain fault tolerance, robustness and low production cost from module interchangeability. However, we are interested in "heterogeneous" systems, which include multiple types of modules such as those with sensors, batteries or wheels. We believe that heterogeneous systems offer the same benefits as homogeneous systems with the added ability to …

An Ab Initio Excursion On The Lowest 18 Electronic Surfaces Of The Ncl + Ncl System: Some Insight Into The Long-Range Self-Quenching Pathways Of The First Excited State Of Ncl, Gregory S. Tschumper, Michael C. Heaven, Keiji Morokuma

Chemistry Faculty Research & Creative Works

A series of state-averaged complete active space self-consistent field (SA-CASSCF) computations were carried out in search of low-energy self-annihilation pathways for two NCl molecules in their first excited state (a1Δ). Numerous scans of the lowest 18 electronic surfaces that correlate with the interaction of two NCl molecules in the X3Σ-, a1Δ, and b1Σ+ states are reported. Eight long-range, low-energy pathways were located (four in C2v and eight in C2h symmetry) that connect NCl(a1Δ) + NCl(a1Δ) to NCl(X3Σ-) + NCl(b1Σ+) and NCl(X3Σ-) + NCl(a1Δ). It was possible to rigorously characterize the minima on four of these seams of crossings (MSXs). The …

Spatially Resolved Spectroscopy Of Coma Cluster Early-Type Galaxies - Ii. The Minor Axis Dataset, G. Wegner, E. M. Corsini, R. P. Saglia, R. Bender

Dartmouth Scholarship

We present minor axis, offset major axis and one diagonal long slit spectra for 10 E and S0 galaxies of the Coma cluster drawn from a magnitude-limited sample studied before. We derive rotation curves, velocity dispersion profiles and the H3 and H4 coefficients of the Hermite decomposition of the line of sight velocity distribution. Moreover, we derive the line index profiles of Mg, Fe and Hβ line indices and assess their errors. The data will be used to construct dynamical models of the galaxies and study their stellar populations.

Imaging And Engineering The Nanoscale-Domain Structure Of A Sr0.61Ba0.39Nb2O6 Crystal Using A Scanning Force Microscope, K. Terabe, S. Takekawa, M. Nakamura, K. Kitamura, Alexei Gruverman

Alexei Gruverman Publications

We have investigated the ferroelectric domain structure formed in a Sr_0.61Ba_0.39Nb₂O₆ single crystal by cooling the crystal through the Curie point. Imaging the etched surface structure using a scanning force microscope (SFM) in both the topographic mode and the piezoresponse mode revealed that a multidomain structure of nanoscale island-like domains was formed. The island-like domains could be inverted by applying an appropriate voltage using a conductive SFM tip. Furthermore, a nanoscale periodically inverted-domain structure was artificially fabricated using the crystal which underwent poling treatment.

Oxidation Of Metals At The Chromium Oxide Interface, Ruihua Cheng, C.N. Borca, N. Pilet, Bo Xu, Lu Yuan, Bernard Doudin, Sy_Hwang Liou, Peter A. Dowben

Peter Dowben Publications

Metal thin-film deposition, over the Cr₂O₃ surface of CrO₂ thin-film substrates, exhibits a redox reaction at the interface. The transition metal forms an oxide in combination with the reduction of the near-surface chromium oxide to Cr₂O₃ . The insulating barrier layer Cr₂O₃ increases with the formation of Pb₃ O₄ in Pb/Cr₂O₃ /CrO₂ and CoO in Co/Cr₂O₃ /CrO₂ junctions, respectively.

Prairie Dogs And The Prairie Ecosystem, Scott E. Hygnstrom, Dallas R. Virchow

School of Natural Resources: Faculty Publications

Prairie dogs play an important role in the prairie ecosystem by creating unique patches of habitat in the expansive prairies of the American West. Their daily activities change the physical characteristics of the community, which leads to increased plant and animal diversity. Prairie dogs are a source of food for several predators, and their burrows provide homes for a variety of species, including the burrowing owl and endangered black-footed ferret. They also provide recreational opportunities for nature observers, photographers, and the sporting public. The presence of large, healthy prairie dog towns, however, is not always compatible with agriculture and other …

Why Prefer Double Robust Estimates? Illustration With Causal Point Treatment Studies, Romain Neugebauer, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

In point treatment marginal structural models with treatment A, outcome Y and covariates W, causal parameters can be estimated under the assumption of no unobserved confounders. Three estimates can be used: the G-computation, Inverse Probability of Treatment Weighted (IPTW) or Double Robust (DR) estimates. The properties of the IPTW and DR estimates are known under an assumption on the treatment mechanism that we name "Experimental Treatment Assignment" (ETA) assumption. We show that the DR estimating function is unbiased when the ETA assumption is violated if the model used to regress Y on A and W is correctly specified. The practical …

An Extension Of Elton's L(1)(N) Theorem To Complex Banach Spaces, S J. Dilworth, Joseph P. Patterson

Faculty Publications

No abstract provided.

Bivariate Current Status Data, Mark J. Van Der Laan, Nicholas P. Jewell

U.C. Berkeley Division of Biostatistics Working Paper Series

In many applications, it is often of interest to estimate a bivariate distribution of two survival random variables. Complete observation of such random variables is often incomplete. If one only observes whether or not each of the individual survival times exceeds a common observed monitoring time C, then the data structure is referred to as bivariate current status data (Wang and Ding, 2000). For such data, we show that the identifiable part of the joint distribution is represented by three univariate cumulative distribution functions, namely the two marginal cumulative distribution functions, and the bivariate cumulative distribution function evaluated on the …

Current Status Data: Review, Recent Developments And Open Problems, Nicholas P. Jewell, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

Researchers working with survival data are by now adept at handling issues associated with incomplete data, particular those associated with various forms of censoring. An extreme form of interval censoring, known as current status observation, refers to situations where the only available information on a survival random variable T is whether or not T exceeds a random independent monitoring time C. This article contains a brief review of the extensive literature on the analysis of current status data, discussing the implications of response-based sampling on these methods. The majority of the paper introduces some recent extensions of these ideas to …

Creating Nanocavities Of Tunable Sizes: Hollow Helices, Bing Gong, Huaqiang Zeng, Jin Zhu, Lihua Yuan, Yaohua Han, Shizhi Cheng, Mako Furukawa, Ruben D. Parra, Audrey Y. Kovalevsky, Jeffrey L. Mills, Ewa Skrzypczak-Jankun, Suzana Martinovic, Richard D. Smith, Chong Zheng, Thomas Szyperski, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

A general strategy for creating nanocavities with tunable sizes based on the folding of unnatural oligomers is presented. The backbones of these oligomers are rigidified by localized, threecenter intramolecular hydrogen bonds, which lead to well-defined hollow helical conformations. Changing the curvature of the oligomer backbone leads to the adjustment of the interior cavity size. Helices with interior cavities of 10 Å to >30 Å across, the largest thus far formed by the folding of unnatural foldamers, are generated. Cavities of these sizes are usually seen at the tertiary and quaternary structural levels of proteins. The ability to tune molecular dimensions …