Digital Commons Network^™

Digitally Controlled Zvs Quasi-Resonant Boost Converter With M-Type Switch, Taufik, Patrick Luther, Makbul Anwari

Electrical Engineering

This paper presents the analysis, modeling and design of zero-voltage-switching (ZVS) quasi resonant boost converter. The use of M-type switch in the topology will be described, including circuitpsilas mode of operation along with the derivations of critical voltage and current equations in each mode. Computer simulation using OrCAD Pspice and hardware development for the resonant converter with digital control will be presented. Results from both simulation and laboratory measurements to compare with theoretical analysis will be discussed.

Comparative Study Of Sinusoidal Pulse-Width And Hysteresis Modulations In Current Source Inverter, Taufik, Yat Tam, Makbul Anwari

Electrical Engineering

In this paper, modeling and comparative analysis of current source inverter (CSI) using sinusoidal pulse-width-modulation (SPWM) and hysteresis modulation (HM) will be presented. The modeling of both CSI-SPWM and CSI-HM are implemented using OrCAD Pspice. Results from the simulations will be presented along with the performance analysis of both inverters. More specifically, comparative analysis pertaining to output current regulation, harmonic contents, and transient response will be discussed. Moreover, further investigation about the effect of current THD, power factor and efficiency for balanced and unbalanced three-phase input sources with ±1%, ±3%, ±5% rms variation at the converter stage to various output …

Susceptibility Magnetic And High Magnetic Field Esr Measurement Of Srcu2 (Po4 )2, Aripin Aripin, Mitsudo Mitsudo, T. Idehara, M Mekata

Makara Journal of Science

The magnetic susceptibility and high magnetic ESR measurement of SrCu2 (PO4 )2 has been performed at temperatures ranging from 4.2 K to 300 K and 4.2 K to 77 K, respectively. The magnetic susceptibility shows a broad maximum around T = 40 K. The magnetic susceptibility has been interpreted in terms of one-dimensional magnetic systems. The temperature dependence of the magnetic susceptibility indicated a good agreement with 4-spin alternating configuration model. In the ESR measurement, clear electron spin resonance (ESR) was observed. The integrated intensity for 120 and 301 GHz has a broad maximum at around 40 K, which is …

X-Ray Diffraction Phase Analyses For Granulated And Sintered Ceramic Materials, Suminar Pratapa

Makara Journal of Science

One basic problematic aspect in x-ray diffraction phase analysis is microabsorption effect which may arise from the size of the crystallite phases. Complication of the problem may intensify in sintered ceramic materials where milling of the samples is not simple. We report the Rietveld x-ray diffraction phase analysis of MgO-a-Al2O3 powder mixtures with phase content ratio of 1:1 by weight and MgO-Y2O3 sintered ceramic composites with Y2O3 contents of 10%, 20% and 30% by weight. The mixtures were pre-sintered at 1000°C for 2 hours and then milled while the composites were sintered at 1550°C for 3 hours. The phase composition …

Inconsistencies Between Pangean Reconstructions And Basic Climate Controls, Clinton Rowe, David B. Loope, Robert J. Oglesby, Rob Van Der Voo, Charles E. Broadwater

Department of Earth and Atmospheric Sciences: Faculty Publications

The supercontinent Pangea dominated our planet from the Permian into the Jurassic. Paleomagnetic reconstructions have been used to estimate the latitudinal position of Pangea during this 100-million-year period. Atmospheric circulation, recorded by eolian sandstones in the southwestern United States, shows a broad sweep of northeasterly winds over their northernmost extent, curving to become northwesterly in the south. This evidence is consistent with paleomagnetic reconstructions of the region straddling the equator in the Early Permian but is at odds with its northward movement to about 20°N by the Early Jurassic. At least one of the following scenarios must be true: the …

Persistent Near-Bottom Aggregations Of Mesopelagic Animals Along The North Carolina And Virginia Continental Slopes, John V. Gartner Jr., Kenneth J. Sulak, Steve W. Ross, Ann Marie Necaise

United States Geological Survey: Staff Publications

Submersible observations during four missions over the North Carolina and Virginia continental slopes (184–900 m) documented the occurrence of large aggregations of mesopelagic Wshes and macronektonic invertebrates near or on the bottom. Aggregated mesopelagics formed a layer up to tens of meters deep positioned from a few centimeters to 20 m, usually <10 >m, above the substrate. Aggregations were numerically dominated by microvores, notably the myctophid Wsh Ceratoscopelus maderensis and the penaeid shrimp Sergestes arcticus. Consistently present but in relatively lower numbers, were mesopelagic predators, including the paralepidids Notolepis rissoi and Lestidium atlanticum, the eel Nemichthys scolopaceus, the …

Index Theorems For Quantum Graphs, S. A. Fulling, P. Kuchment, J. H. Wilson

Faculty Publications

In geometric analysis, an index theorem relates the difference of the numbers of solutions of two differential equations to the topological structure of the manifold or bundle concerned, sometimes using the heat kernels of two higher order differential operators as an intermediary. In this paper, the case of quantum graphs is addressed. A quantum graph is a graph considered as a (singular) one-dimensional variety and equipped with a second-order differential Hamiltonian H (a 'Laplacian') with suitable conditions at vertices. For the case of scale-invariant vertex conditions (i.e. conditions that do not mix the values of functions and of their derivatives), …

Quantum Interferometric Sensors, Kishore T. Kapale, Leo D. Didomenico, Hwang Lee, Pieter Kok, Jonathan P. Dowling

Faculty Publications

Quantum entanglement has the potential to revolutionize the entire field of interferometric sensing by providing many orders of magnitude improvement in interferometer sensitivity. The quantum-entangled particle interferometer approach is very general and applies to many types of interferometers. In particular, without nonlocal entanglement, a generic classical interferometer has a statistical-sampling shot-noise limited sensitivity that scales like 1/√N, where N is the number of particles passing through the interferometer per unit time. However, if carefully prepared quantum correlations are engineered between the particles, then the interferometer sensitivity improves by a factor of √ to scale like I/N, which is the limit …

Modular Invariants For Lattice Polarized K3 Surfaces, Adrian Clingher, Charles F. Doran

Mathematics and Statistics Faculty Works

No abstract provided.

[Accepted Article Manuscript Version (Postprint)] The Social Implications Of Enjoyment Of Different Types Of Music, Movies, And Television Programming, Alice Hall

Communication and Media Faculty Works

This study investigated how information about an individual’s enjoyment of various genres of music, film, and TV programming could influence an observer’s expectations of that individual. An online survey of young adults found that the influence of information about another person’s genre preferences varied across genres. Enjoyment of some genres, including jazz music, film comedies, and television comedies, tended to raise expectations of the individual, whereas enjoyment of others, including heavy metal music, anime films, and television soap operas, tended to lower them. The implications of the findings are discussed in relation to uses and gratifications perspectives as well as …

Bioluminescence In A Complex Coastal Environment: 1. Temporal Dynamics Of Nighttime Water-Leaving Radiance, Mark A. Moline, Matthew J. Oliver, Curtis D. Mobley, Lydia Sundman, Thomas J. Bensky, Trisha Bergmann, W. Paul Bissett, James Case, Erika H. Raymond, Oscar M.E. Schofield

Physics

Nighttime water-leaving radiance is a function of the depth-dependent distribution of both the in situ bioluminescence emissions and the absorption and scattering properties of the water. The vertical distributions of these parameters were used as inputs for a modified one-dimensional radiative transfer model to solve for spectral bioluminescence water-leaving radiance from prescribed depths of the water column. Variation in the water-leaving radiance was consistent with local episodic physical forcing events, with tidal forcing, terrestrial runoff, particulate accumulation, and biological responses influencing the shorter timescale dynamics. There was a >90 nm shift in the peak water-leaving radiance from blue (~474 nm) …

Harnessing Online Communities For Educational Practice, Randall S. Dunn

Faculty Publications and Presentations

The rise of the use of the Internet and the subsequent connections among peoples located near and far from each other necessitates an examination of its use as a means for teachers to grow professionally, connect socially and develop pedagogical skills for teaching children to prepare for the current state of the world.

A Bayesian Model For Cross-Study Differential Gene Expression, Robert B. Scharpf, Hakon Tjelemeland, Giovanni Parmigiani, Andrew B. Nobel

Johns Hopkins University, Dept. of Biostatistics Working Papers

In this paper we define a hierarchical Bayesian model for microarray expression data collected from several studies and use it to identify genes that show differential expression between two conditions. Key features include shrinkage across both genes and studies; flexible modeling that allows for interactions between platforms and the estimated effect, and for both concordant and discordant differential expression across studies. We evaluated the performance of our model in a comprehensive fashion, using both artificial data, and a "split-sample" validation approach that provides an agnostic assessment of the model's behavior not only under the null hypothesis but also under a …

Decomposition Of Regression Estimators To Explore The Influence Of "Unmeasured" Time-Varying Confounders, Yun Lu, Scott L. Zeger

Johns Hopkins University, Dept. of Biostatistics Working Papers

In environmental epidemiology, exposure X and health outcome Y vary in space and time. We present a method to diagnose the possible influence of unmeasured confounders U on the estimated effect of X on Y and to propose several approaches to robust estimation. The idea is to use space and time as proxy measures for the unmeasured factors U. We start with the time series case where X and Y are continuous variables at equally-spaced times and assume a linear model. We define matching estimator b(u)s that correspond to pairs of observations with specific lag u. Controlling for a smooth …

Microchip Liquid Chromatography And Capillary Electrophoresis Separations In Multilayer Microdevices, Hernan Vicente Fuentes

Theses and Dissertations

In this dissertation, several microfabricated devices are introduced to develop new applications in the area of chemical analysis. Electrochemical micropumps, chip-based liquid chromatography systems and multilayer capillary electrophoresis microdevices with crossover channels were fabricated using various substrates such as poly(dimethylsiloxane) (PDMS), glass, and poly(methyl methacrylate) (PMMA). I have demonstrated pressure-driven pumping of liquids in microfabricated channels using electrochemical actuation. PDMS-based micropumps were integrated easily with channel-containing PMMA substrates. Flow rates on the order of ~10 µL/min were achieved using low voltages (10 V). The potential of electrolysis-based pumping in microchannels was further evaluated for pressure driven microchip liquid chromatography (LC). …

Ke Alakai, Vol. 80, No. 07 (2007-11-21), Brigham Young University Hawaii

Ke Alaka'i

No abstract provided.

Matching Kasteleyn Cities For Spin Glass Ground States, Alan Middleton, Creighton K. Thomas

Physics - All Scholarship

As spin glass materials have extremely slow dynamics, devious numerical methods are needed to study low-temperature states. A simple and fast optimization version of the classical Kasteleyn treatment of the Ising model is described and applied to two-dimensional Ising spin glasses. The algorithm combines the Pfaffian and matching approaches to directly strip droplet excitations from an excited state. Extended ground states in Ising spin glasses on a torus, which are optimized over all boundary conditions, are used to compute precise values for ground state energy densities.

Stony Brook Press, V. 29, N. 05, Stony Brook University. Stony Brook Press.

Stony Brook Press

v. 26, n. 04, v.:ill. ; 38 cm (original analog pub.)

Scalable And Adaptive Metadata Management In Ultra Large-Scale File Systems, Yu Hua, Yifeng Zhu, Hong Jiang

School of Computing: Technical Reports

This paper presents a scalable and adaptive decentralized metadata lookup scheme for ultra large-scale file systems (≥ Petabytes or even Exabytes). Our scheme logically organizes metadata servers (MDS) into a multi-layered query hierarchy and exploits grouped Bloom filters to efficiently route metadata requests to desired MDSs through the hierarchy. This metadata lookup scheme can be executed at the network or memory speed, without being bounded by the performance of slow disks. An effective workload balance algorithm is also developed in this paper for server reconfigurations. This scheme is evaluated through extensive trace-driven simulations and prototype implementation in Linux. Experimental results …

The Music And Literacy Connection, Emily H. Park

Honors Capstone Projects and Theses

No abstract provided.

The New Hampshire, Vol. 97 [98], No. 16 [22] (Nov. 20, 2007), The New Hampshire

The New Hampshire Print Edition

An independent student produced newspaper from the University of New Hampshire. This volume was printed as 97, but it is the 98th volume in the series. This was corrected in pencil.

This issue was printed as 16, but it is the 22nd issue in this volume. This was corrected in pencil.

Retreating To Advance Women Geoscience Faculty, Suzanne O'Connell, Mary Anne Holmes

Department of Earth and Atmospheric Sciences: Faculty Publications

Seventeen women geoscientists from New England, New York, and New Jersey assembled for a writing retreat at Boston College's Connors Family Retreat and Conference Center, set on 80 pastoral acres on the outskirts of Boston. Funded through the National Science Foundation ADVANCE program, the retreat had two objectives: to facilitate writing and to develop a supportive community. It succeeded on both accounts. Although new to science, retreats of this sort have long been a highly sought after experience for writers in other disciplines. The potential benefits for scientists, in particular, women scientists, are great. Writing is a cornerstone of our …

A Delayed Option Pricing Formula (Mittag-Leffler Institute Workshop), Salah-Eldin A. Mohammed

Miscellaneous (presentations, translations, interviews, etc)

No abstract provided.

Supporting Annotated Relations, M. Y. Eltabakh, M. Ouzzani, Walid G. Aref, Ahmed K. Elmagarmid, Y. Laura-Silva

Department of Computer Science Technical Reports

No abstract provided.

Measurement Of The Tt̅ Production Cross Section In Pp̅ Collisions At √S = 1.96 Tev Using Kinematic Characteristics Of Lepton + Jets Events, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration

Kenneth Bloom Publications

We present a measurement of the top quark pair production cross section in pp̅ collisions at √s = 1.96 TeV utilizing 425 pb^-1 of data collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair containing one high-p_T electron or muon and at least four jets. We exploit specific kinematic features of tt̅ events to extract the cross section. For a top quark mass of 175 GeV, we measure σ _tt̅ = 6.4_-1.2^+1.3(stat) ± 0.7(syst) ± 0.4(lum) pb, in good agreement with the …

Spartan Daily, November 20, 2007, San Jose State University, School Of Journalism And Mass Communications

Spartan Daily (School of Journalism and Mass Communications)

Volume 129, Issue 46

Grand Valley Forum, Volume 032, Number 17, November 19, 2007, Grand Valley State University

2007-2008, Volume 32

Grand Valley Forum is Grand Valley State's faculty and staff newsletter, published from 1976 to the present.

Not Every Risk Manager Needs To Become An Erm, Zachary S. Finn

Scholarship and Professional Work - Business

The author reflects on the responsibilities of risk managers in fulfilling their important role in insurance companies. He asserts that traditional risk managers needs to be part adjuster, part attorney, part underwriter, part risk-finance professional and part loss-control engineer. With such profound task, he contends that risk managers can perform their vital role in the organization without the need of becoming an enterprise risk manager.

Effects Of Dependency Injection On Maintainability, Ekaterina Razina, David S. Janzen

Computer Science and Software Engineering

Software maintenance consumes around 70% of the software life cycle. Improving software maintainability could save software developers significant time and money. This paper examines whether the pattern of dependency injection significantly reduces dependencies of modules in a piece of software, therefore making the software more maintainable. This hypothesis is tested with 20 sets of open source projects from sourceforge.net, where each set contains one project that uses the pattern of dependency injection and one similar project that does not use the pattern. The extent of the dependency injection use in each project is measured by a new Number of DIs …

A Set Of Phosphatase-Inert “Molecular Rulers” To Probe For Bivalent Mannose 6-Phosphate Ligand-Receptor Interactions, Xiang Fei, Christopher M. Connelly, Richard G. Macdonald, David B. Berkowitz

David Berkowitz Publications

A set of bivalent mannose 6-phosphonate “molecular rulers” has been synthesized to examine ligand binding to the M6P/IGF2R. The set is estimated to span a P-P distance range of 16-26 Å (MMFF energy minimization on the hydrated phosphonates). Key synthetic transformations include sugar triflate displacement for phosphonate installation and Grubbs I cross-metathesis to achieve bivalency. Relative binding affinities were tested by radioligand displacement assays versus PMP-BSA (pentamannose phosphate-bovine serum albumin). These compounds exhibit slightly higher binding affinities for the receptor (IC₅₀’s = 3.7-5 &#;M) than the parent, monomeric mannose 6-phosphonate ligand and M6P itself (IC₅₀ = 11.5 …