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2005

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Articles 361 - 390 of 5573

Full-Text Articles in Physical Sciences and Mathematics

Location Privacy In Mobile Ip, Rungrat Wiangsripanawan, R. Safavi-Naini, Willy Susilo Nov 2005

Location Privacy In Mobile Ip, Rungrat Wiangsripanawan, R. Safavi-Naini, Willy Susilo

Faculty of Informatics - Papers (Archive)

Several security issues arise, due to the design of the mobile IP and its deployment in conjunction with other network protocols. Most of the work on the security of mobile IP has focused on authentication of the control packet and the confidentiality of the content in the protocol, and there are not many proposals in the area of location privacy. In this paper, we propose a method to provide location privacy for mobile IP users. We present two protocols that use an overlay network approach, and designed particularly for mobile IP. We employ universal re-encryption and extend it to n-out-of-n …

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Secure And Anonymous Mobile Ad-Hoc Networks, Y. Mu, F. Zhang, Willy Susilo Nov 2005

Secure And Anonymous Mobile Ad-Hoc Networks, Y. Mu, F. Zhang, Willy Susilo

Faculty of Informatics - Papers (Archive)

A mobile ad-hoc network (MANET) is a wireless network made up of mobile hosts that do not require any fixed infrastructure to communicate. The major features of ad-hoc networks is self-organization and dynamics in user participation. Because of these features, the security in ad-hoc becomes a challenge. In this paper, we consider an interesting scenario, where an arbitrary number of nodes in MANET can dynamically form an anonymous group that exhibits the following features: (1) any outsider can be convinced that the node is indeed in the group; (2) any outsider can send a message back to the node in …

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Relationship Between Fault Zone Architecture And Groundwater Compartmentalization In The East Tintic Mining District, Utah, Sandra Myrtle Conrad Hamaker Nov 2005

Relationship Between Fault Zone Architecture And Groundwater Compartmentalization In The East Tintic Mining District, Utah, Sandra Myrtle Conrad Hamaker

Theses and Dissertations

The Eureka Lilly fault zone provides an impermeable barrier for groundwater flow in the East Tintic mining district. The fault zone separates two distinct groundwaters that have different temperatures, compositions, and potentiometric surfaces. The damage zone of the fault is an extensive network of interconnected open fractures and fault intersections that provide conduits for groundwater flow in otherwise impermeable units. The fault core breccia has been re-cemented and mineralized, which eliminates porosity in the rock by creating a thick impermeable zone, which has compartmentalized groundwaters across the fault zone. The compartmentalization of groundwater shows that fault zone variability (from strain …

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Casual Mediation Analyses With Structural Mean Models, Thomas R. Tenhave, Marshall Joffe, Kevin Lynch, Greg Brown, Stephen Maisto Nov 2005

Casual Mediation Analyses With Structural Mean Models, Thomas R. Tenhave, Marshall Joffe, Kevin Lynch, Greg Brown, Stephen Maisto

UPenn Biostatistics Working Papers

We represent a linear structural mean model (SMM)approach for analyzing mediation of a randomized baseline intervention's effect on a univariate follow-up outcome. Unlike standard mediation analyses, our approach does not assume that the mediating factor is randomly assigned to individuals (i.e., sequential ignorability). Hence, a comparison of the results of the proposed and standard approaches in with respect to mediation offers a sensitivity analyses of the sequential ignorability assumption. The G-estimation procedure for the proposed SMM represents an extension of the work on direct effects of randomized treatment effects for survival outcomes by Robins and Greenland (1994) (Section 5.0 and …

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Identity Configurations Of The Sandpile Group, William Chen '06 Nov 2005

Identity Configurations Of The Sandpile Group, William Chen '06

Distinguished Student Work

The abelian sandpile model on a connected graph yields a finite abelian group Q of recurrent configurations which is closely related to the combinatorial Laplacian. We consider the identity configuration of the sandpile group on graphs with large edge multiplicities, called “thick” graphs. We explicitly compute the identity configuration for all thick paths using a recursion formula. We then analyze the thick cycle and explicitly compute the identity configuration for the three-cycle, the four-cycle, and certain types of symmetric cycles. The latter is a special case of a more general symmetry theorem we prove that applies to an arbitrary graph.

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Efficient And Highly Scalable Route Discovey For On-Demand Routing Protocols In Ad Hoc Networks, Mehran Abolhasan, Justin Lipman Nov 2005

Efficient And Highly Scalable Route Discovey For On-Demand Routing Protocols In Ad Hoc Networks, Mehran Abolhasan, Justin Lipman

Faculty of Informatics - Papers (Archive)

This paper presents a number of different route discovery strategies for on-demand routing protocols, which provide more control to each intermediate node make during the route discovery phase to make intelligent forwarding decisions. This is achieved through the idea of selfselection. In self-selecting route discovery each node independently makes Route Request (RREQ) forwarding decisions based upon a selection criterion or by satisfying certain conditions. The nodes which do not satisfy the selection criterion do not rebroadcast the routing packets. We implemented our self-selecting route discovery strategies over AODV using the GloMoSim network simulation package, and compared the performance with existing …

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A Simulation Study Of Tcp Over The Ieee 802.15.3 Mac, Kwan-Wu Chin, Darryn Lowe Nov 2005

A Simulation Study Of Tcp Over The Ieee 802.15.3 Mac, Kwan-Wu Chin, Darryn Lowe

Faculty of Informatics - Papers (Archive)

This paper presents the impact of IEEE 802.15.3 MAC’s channel time allocation methods on a TCP flow’s performance. We show the importance of having super rate and appropriately sized channel time allocations (CTAs).

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Evidence Of Reduced Measurement Uncertainties From An Ftir Instrument Intercomparison At Kiruna, Sweden, A. Meier, Clare Paton-Walsh, C. Bell, T. Blumenstock, F. Hase, A. Goldman, A. Steen, R. Kift, P. Woods, Y. Kondo Nov 2005

Evidence Of Reduced Measurement Uncertainties From An Ftir Instrument Intercomparison At Kiruna, Sweden, A. Meier, Clare Paton-Walsh, C. Bell, T. Blumenstock, F. Hase, A. Goldman, A. Steen, R. Kift, P. Woods, Y. Kondo

Faculty of Science - Papers (Archive)

We report the results of an intercomparison of vertical column amounts of HCl, HF, N2O, HNO3, CH4, O3, CO2 and N2 derived from the spectra recorded by two ground-based FTIR spectrometers operated side-by-side using the sun as a source. The procedures used to record spectra and derive vertical column amounts followed the format of previous instrument intercomparisons organised by the Network for Detection of Stratospheric Change (NDSC), but the level of agreement achieved was significantly better than for previous intercomparisons. For most gases the differences were typically 1% or less, with at least one of the five datasets showing no …

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Combination Of Cdf And D0 Results On The W Boson Mass And Width, V. M. Abazov, Gregory Snow, D0 Collaboration Nov 2005

Combination Of Cdf And D0 Results On The W Boson Mass And Width, V. M. Abazov, Gregory Snow, D0 Collaboration

Gregory Snow Publications

The results based on 1992–95 data (Run 1) from the CDF and D0 experiments on the measurements of the W boson mass and width are presented, along with the combined results. We report a Tevatron collider average Mw = 80.456 ± 0.059 GeV. We also report the Tevatron collider average of the directly measured W boson width Γw = 2.115 ± 0.105 GeV. We describe a new joint analysis of the direct W mass and width measurements. Assuming the validity of the standard model, we combine the directly measured W boson width with the width extracted from the …

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Pumping Or Mixing System Using A Levitating Magnetic Element, Aexandre N. Terentiev Nov 2005

Pumping Or Mixing System Using A Levitating Magnetic Element, Aexandre N. Terentiev

Physics and Astronomy Faculty Patents

A system capable of pumping or mixing fluids using a rotating magnetic element or bearing levitated by a cold superconducting element is disclosed.

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Development Of Commercial Applications For Recycled Plastics Using Finite Element Analysis, Nanjunda Narasimhamurthy Nov 2005

Development Of Commercial Applications For Recycled Plastics Using Finite Element Analysis, Nanjunda Narasimhamurthy

Theses and Dissertations

This thesis investigates the suitability of thermo-kinetically recycled plastics for use in commercial product applications using finite element analysis and statistics. Different recycled material blends were tested and evaluated for their use in commercial product applications. There are six different blends of thermo-kinetically recycled plastics used for testing and CATIA is used for finite element analysis. The different types of thermo-kinetically recycled plastics blends are: pop bottles made of PolyethyleneTeraphthalate (PET), milk jugs made of High-Density Polyethylene (HDPE), Vinyl seats made of Poly Vinyl Chloride (PVC) and small amount of Polypropylene (PP) and Urethane, electronic scrap made of engineering resins …

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Photovoltaic Effect In Bent Quantum Wires In The Ballistic Transport Regime, Yuriy V. Pershin Dr, Carlo Piermarocchi Nov 2005

Photovoltaic Effect In Bent Quantum Wires In The Ballistic Transport Regime, Yuriy V. Pershin Dr, Carlo Piermarocchi

Faculty Publications

A scheme for the generation of a photocurrent in bent quantum wires is proposed. We calculate the current using a generalized Landauer-Büttiker approach that takes into account the electromagnetic radiation. For circularly polarized light, it is demonstrated that the curvature in the bent wire induces an asymmetry in the scattering coefficients for left and right moving electrons. This asymmetry results in a current at zero bias voltage. The effect is due to the geometry of the wire which transforms the photon angular momentum into translational motion for the electrons. Possible experimental realizations of this scheme are discussed.

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Generating Medical Logic Modules For Clinical Trial Eligibility, Craig G. Parker Nov 2005

Generating Medical Logic Modules For Clinical Trial Eligibility, Craig G. Parker

Theses and Dissertations

Clinical trials are important to the advancement of medical science. They provide the experimental and statistical basis needed to determine the benefit of diagnostic and therapeutic agents and procedures. The more patients enrolled in a clinical trial, the more confidence we can have in the trial's results. However, current practices for identifying eligible patients can be expensive and time-consuming. To assist in making identification of eligible patients more cost effective, we have developed a system for translating the eligibility criteria for clinical trials to an executable form. This system takes as input the eligibility criteria for a trial formatted as …

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1,4-Dimethyl-1,4-Diazoniabicyclo[2.2.2]Octane Diiodide Acetonitrile Solvate, Daron E. Janzen, Paul C. Ewbank, Kent R. Mann Nov 2005

1,4-Dimethyl-1,4-Diazoniabicyclo[2.2.2]Octane Diiodide Acetonitrile Solvate, Daron E. Janzen, Paul C. Ewbank, Kent R. Mann

Daron E Janzen, Ph.D.

No abstract provided.

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A General Imputation Methodology For Nonparametric Regression With Censored Data, Dan Rubin, Mark J. Van Der Laan Nov 2005

A General Imputation Methodology For Nonparametric Regression With Censored Data, Dan Rubin, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

We consider the random design nonparametric regression problem when the response variable is subject to a general mode of missingness or censoring. A traditional approach to such problems is imputation, in which the missing or censored responses are replaced by well-chosen values, and then the resulting covariate/response data are plugged into algorithms designed for the uncensored setting. We present a general methodology for imputation with the property of double robustness, in that the method works well if either a parameter of the full data distribution (covariate and response distribution) or a parameter of the censoring mechanism is well approximated. These …

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Manipulation Skills Acquisition Through State Classification And Dimension Decrease, S. Dong, F. Naghdy Nov 2005

Manipulation Skills Acquisition Through State Classification And Dimension Decrease, S. Dong, F. Naghdy

Faculty of Informatics - Papers (Archive)

The work carried out to explore the feasibility of reconstructing human constrained motion manipulation skills is reported. This is achieved by tracing and learning the manipulation performed by a human operator in a haptic rendered virtual environment. The peg-in-hole insertion problem is used as a case study. In the developed system, force and position variables generated in the haptic rendered virtual environment combined with a priori knowledge about the task are used to identify and learn the skills in the newly demonstrated task. The data obtained from the virtual environment is classified into different cluster sets using Fuzzy Gustafson-Kessel Model …

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Practical Application Of Support-Based Distributed Search, Peter Harvey, C. F. Chang, Aditya K. Ghose Nov 2005

Practical Application Of Support-Based Distributed Search, Peter Harvey, C. F. Chang, Aditya K. Ghose

Faculty of Informatics - Papers (Archive)

Algorithms for Distributed Constraint Satisfaction Problems have tended to mirror existing non-distributed global-search or local-search algorithms. Unfortunately, existing distributed global-search algorithms derive from classical backtracking search methods and require a total ordering over variables for completeness. Distributed variants of local-search algorithms (such as distributed breakout) inherit the incompleteness properties of their predecessors. A meeting scheduling problem translates to a DisCSP where a global ordering is difficult to maintain and creates undesirable behaviours. We present a practical demonstration of an algorithm in which a global ordering is not required, while avoiding the problems of local-search algorithms.

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Grid-Enabling A Vibroacoustic Analysis Application, Brian Bentow, Jon Dodge, Aaron Homer, Christopher D. Moore, Robert M. Keller, Matthew T. Presley, Robert Davis, Jorge Seidel, Craig Lee, Joseph Betser Nov 2005

Grid-Enabling A Vibroacoustic Analysis Application, Brian Bentow, Jon Dodge, Aaron Homer, Christopher D. Moore, Robert M. Keller, Matthew T. Presley, Robert Davis, Jorge Seidel, Craig Lee, Joseph Betser

All HMC Faculty Publications and Research

This paper describes the process of grid-enabling a vibroacoustic analysis application using the Globus Toolkit 3.2.1. This is the first step in a project intended to grid-enable a suite of tools being developed as a service-oriented architecture for spacecraft telemetry analysis. Many of the applications in the suite are compute intensive and would benefit from significantly improved performance. In this paper we show the advantage of using Globus to grid-enable a single tool in a vibroacoustic analysis flow, with the result that using as few as eleven nodes, that tool’s runtime improved by a factor of eight. While communication overhead …

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Structural And Chiroptical Properties Of The Two Coordination Isomers Of Ybdota-Type Complexes, Lorenzo Di Bari, Gennaro Pescitelli, A. Dean Sherry, Mark Woods Nov 2005

Structural And Chiroptical Properties Of The Two Coordination Isomers Of Ybdota-Type Complexes, Lorenzo Di Bari, Gennaro Pescitelli, A. Dean Sherry, Mark Woods

Chemistry Faculty Publications and Presentations

Studies of the structural, physical, and chemical properties of the lanthanide(III) complexes of DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and related ligands are often complicated by the presence of two coordination isomers in solution. Since these coordination isomers are in exchange and cannot be separated, many techniques offer information only on the weighted average of the two isomers. Lanthanide ion complexes formed with the ligands S(RRRR)NO2BnDOTMA and S(SSSS)NO2BnDOTMA preferentially adopt only one of the two common coordination isomers in solution, so the ytterbium complexes of these ligands offer a unique opportunity to study …

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Scaling Laws For Rotating Rayleigh-Bénard Convection, Janet Scheel, M. Cross Nov 2005

Scaling Laws For Rotating Rayleigh-Bénard Convection, Janet Scheel, M. Cross

Janet D. Scheel

Numerical simulations of large aspect ratio, three-dimensional rotating Rayleigh-Bénard convection for no-slip boundary conditions have been performed in both cylinders and periodic boxes. We have focused near the threshold for the supercritical bifurcation from the conducting state to a convecting state exhibiting domain chaos. A detailed analysis of these simulations has been carried out and is compared with experimental results, as well as predictions from multiple scale perturbation theory. We find that the time scaling law agrees with the theoretical prediction, which is in contradiction to experimental results. We also have looked at the scaling of defect lengths and defect …

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Estimating A Treatment Effect With Repeated Measurements Accounting For Varying Effectiveness Duration, Ying Qing Chen, Jingrong Yang, Su-Chun Cheng Nov 2005

Estimating A Treatment Effect With Repeated Measurements Accounting For Varying Effectiveness Duration, Ying Qing Chen, Jingrong Yang, Su-Chun Cheng

UW Biostatistics Working Paper Series

To assess treatment efficacy in clinical trials, certain clinical outcomes are repeatedly measured for same subject over time. They can be regarded as function of time. The difference in their mean functions between the treatment arms usually characterises a treatment effect. Due to the potential existence of subject-specific treatment effectiveness lag and saturation times, erosion of treatment effect in the difference may occur during the observation period of time. Instead of using ad hoc parametric or purely nonparametric time-varying coefficients in statistical modeling, we first propose to model the treatment effectiveness durations, which are the varying time intervals between the …

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Implementation Of Operational Framework In The Nlp (Based On Mof And Itil Standards), James Kapp Nov 2005

Implementation Of Operational Framework In The Nlp (Based On Mof And Itil Standards), James Kapp

Regis University Student Publications (comprehensive collection)

An operational framework, as proposed by the Microsoft Operational Framework (MOF) and the Information Technology Infrastructure Library (ITIL) provides a process model for controlling and managing Information Technology (IT) operations. With a strict focus on IT operations, it provides the processes and terminology to coordinate and integrate the functional elements of an IT department. The Systems Engineering and Applications Development (SEAD) practicum is composed of four main groups; Data Access, Network, Integrated Services and Development. This professional project will propose the beginning framework for overall operation and integration of the SEAD Practicum with an emphasis on service support and documentation. …

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Inhibition Of Cellular Respiration By Doxorubicin, Zhimin Tao, Henry G. Withers, Harvey S. Penefsky, Jerry Goodisman, Abdul Kader Souid Nov 2005

Inhibition Of Cellular Respiration By Doxorubicin, Zhimin Tao, Henry G. Withers, Harvey S. Penefsky, Jerry Goodisman, Abdul Kader Souid

Chemistry - All Scholarship

Doxorubicin executes apoptosis, a process known to produce leakage of cytochrome c and opening of the mitochondrial permeability transition pores. To define the loss of mitochondrial function by apoptosis, we monitored cellular respiration during continuous exposure to doxorubicin. A phosphorescence analyzer capable of stable measurements over at least 5 h was used to measure [O(2)]. In solutions containing glucose and cells, [O(2)] declined linearly with time, showing that the kinetics of oxygen consumption was zero order. Complete inhibition of oxygen consumption by cyanide indicated that oxidations occurred in the respiratory chain. A decline in the rate of respiration was evident …

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Modeling Differentiated Treatment Effects For Multiple Outcomes Data, Hongfei Guo, Karen Bandeen-Roche Nov 2005

Modeling Differentiated Treatment Effects For Multiple Outcomes Data, Hongfei Guo, Karen Bandeen-Roche

Johns Hopkins University, Dept. of Biostatistics Working Papers

Multiple outcomes data are commonly used to characterize treatment effects in medical research, for instance, multiple symptoms to characterize potential remission of a psychiatric disorder. Often either a global, i.e. symptom-invariant, treatment effect is evaluated. Such a treatment effect may over generalize the effect across the outcomes. On the other hand individual treatment effects, varying across all outcomes, are complicated to interpret, and their estimation may lose precision relative to a global summary. An effective compromise to summarize the treatment effect may be through patterns of the treatment effects, i.e. "differentiated effects." In this paper we propose a two-category model …

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Mathematics And The Divine (Book Review), Calvin Jongsma Nov 2005

Mathematics And The Divine (Book Review), Calvin Jongsma

Faculty Work Comprehensive List

Reviewed Title: Teun Koetsier and Luc Bergmans, editors. Mathematics and the Divine. Boston: Elsevier, 2005. 701 pages. ISBN 0-444-50328-5

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Palladium-Imidazolium Carbene Catalyzed Heck Coupling Reactions And Synthesis Of A Novel Class Of Fluoroanthracenylmethyl Ptc Catalysts, Jiuqing Zhang Nov 2005

Palladium-Imidazolium Carbene Catalyzed Heck Coupling Reactions And Synthesis Of A Novel Class Of Fluoroanthracenylmethyl Ptc Catalysts, Jiuqing Zhang

Theses and Dissertations

Palladium catalyzed Heck coupling with aryl and alkenyl halides has become a powerful means of carbon-carbon bond formation. This standard synthetic method has been developed to a high level of utility using various catalysts, conditions and substrates. Yet significant drawbacks remain, including poor reactivity, the need for high temperatures and base, limited substrate generality, and selectivity. Mixed products often suffer from olefin migration following insertion. N-Heterocyclic carbenes (NHC) have proven to be electron-rich donors which provide higher stability and reactivity than phosphines. In a previous paper reported by our research group the imidazolium-palladium carbene has proven to be highly efficient …

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Parametrizations And Dynamical Analysis Of Angle-Integrated Cross Sections For Double Photoionization Including Nondipole Effects, Andrei Y. Istomin, Anthony F. Starace, N. L. Manakov, A. V. Meremianin, A. S. Kheifets, Igor Bray Nov 2005

Parametrizations And Dynamical Analysis Of Angle-Integrated Cross Sections For Double Photoionization Including Nondipole Effects, Andrei Y. Istomin, Anthony F. Starace, N. L. Manakov, A. V. Meremianin, A. S. Kheifets, Igor Bray

Department of Physics and Astronomy: Faculty Publications

Similarly to differential cross sections for one-electron photoionization, the doubly differential cross section for double photoionization (DPI) may be conveniently described by four parameters: the singly differential (with respect to energy sharing) cross section (sigma0), the dipole asymmetry parameter (beta), and two nondipole asymmetry parameters (gamma and delta). Here we derive two model-independent representations for these parameters for DPI from a 1S0 atomic bound state: (i) in terms of one-dimensional integrals of the polarization-invariant DPI amplitudes and (ii) in terms of the exact two-electron reduced matrix elements. For DPI of He at excess energies, Eexc, of 100 eV, 450 eV, …

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Faint Blue Objects In The Hubble Deep Field–South Revealed: White Dwarfs, Subdwarfs, And Quasars, Mukremin Kilic, Ted Von Hippel, Et Al. Nov 2005

Faint Blue Objects In The Hubble Deep Field–South Revealed: White Dwarfs, Subdwarfs, And Quasars, Mukremin Kilic, Ted Von Hippel, Et Al.

Publications

We explore the nature of the faint blue objects in the Hubble Deep Field–South. We have derived proper motions for the point sources in the Hubble Deep Field–South using a 3 yr baseline. Combining our proper-motion measurements with spectral energy distribution fitting enabled us to identify four quasars and 42 stars, including three white dwarf candidates. Two of these white dwarf candidates, HDF-S 1444 and 895, are found to display significant proper motion, 21:1±7:9 and 34:9 ± 8:0 mas yr -1, and are consistent with being thick-disk or halo white dwarfs located at ̴2 kpc. The other faint …

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Nonlinear All-Optical Gan/Algan Multi-Quantum-Well Devices For 100 Gb/S Applications At Λ = 1.55 Μm, Greg Sun, Jacob B. Khurgin, Richard A. Soref Nov 2005

Nonlinear All-Optical Gan/Algan Multi-Quantum-Well Devices For 100 Gb/S Applications At Λ = 1.55 Μm, Greg Sun, Jacob B. Khurgin, Richard A. Soref

Physics Faculty Publications

Using quantum-mechanical analysis, a strain-balanced stack of coupled GaN/AlGaNquantum wells has been engineered for bandwidth-optimized all-optical switching at low switching powers. Intersubband transitions between three conduction subbands provide the basis for the large, fast, nonlinear optical response. Optimized performance for a given symbol rate is obtained by engineering the response time and nonlinear phase shift.

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Real-Time Motion Transition By Example, Cameron Quinn Egbert Nov 2005

Real-Time Motion Transition By Example, Cameron Quinn Egbert

Theses and Dissertations

Motion transitioning is a common task in real-time applications such as games. While most character motions can be created a priori using motion capture or hand animation, transitions between these motions must be created by an animation system at runtime. Because of this requirement, it is often difficult to create a transition that preserves the feel that the actor or animator has put into the motion. An additional difficulty is that transitions must be created in real-time. This paper provides a method of creating motion transitions that is both computationally feasible for interactive speeds, and preserves the feel of the …

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