Physical Sciences and Mathematics Commons^™

Poly[(Nitrato-KO)Tris((Μ3-1h-1,2,4-Triazolato)Dizinc(Ii)]: A Three-Dimensional Coordination Polymer, Josephy M. Ellsworth, Mark D. Smith, Hans-Conrad Zur Loye

Faculty Publications

In the title compound, [Zn₂(C₂H₂N₃)₃(NO₃)], there are two unique Zn atoms, both with site symmetry m. One forms a ZnN₃O tetrahedron and the other a ZnN₆ octahedron. One and a half 1H-1,2,4-triazolate ligands, with the half-ligand located on a mirror plane, and a disordered nitrate anion complete the asymmetric unit of the structure. The polymeric connectivity is three-dimensional.

Structural Characterization Using The Multiple Scattering Effects In Grazing-Incidence Small-Angle X-Ray Scattering, Byeongdu Lee, Chieh-Tsung Lo, P. Thiyagarajan, Dong R. Lee, Zhongwei Niu, Qian Wang

Faculty Publications

The multiple scattering effects present in grazing-incidence small-angle X-ray scattering (GISAXS) data and interference between them are addressed theoretically as well as experimentally with measurement of a series of patterns at different incident angles, referred to as `incident-angle-resolved GISAXS' (IAR-GISAXS). X-ray reflectivity (XR), GISAXS and IAR-GISAXS of virus particles on Si-substrate supported-polystyrene films have been measured and all the data have been analyzed with appropriate formalisms. It was found that under certain conditions it is possible to extract the correct structural features of the materials from the GISAXS/IAR-GISAXS data using the kinematic SAXS formalisms, without the need to use the …

Analysis And Suppression Of Chatter In Robotic Machining Process, Zengxi Pan, H. Zhang

Faculty of Informatics - Papers (Archive)

One of the most challenging issues in robotic machining process is to know the vibration/chatter characteristics. To reduce the trial and error frustration, this paper presents the underline mechanism and theoretical analysis to provide physical understanding for the onset of chatter problem and principles to prevent that. First, the cutting force model and robot structure model are established for a systematic analysis of chatter mechanism. Completely different from common woes of regenerative chatter in conventional CNC machine paradigm, another type of chatter, namely, mode-coupling chatter was identified as the dominant source of vibrations in robotic machining, largely due to the …

Displacement Estimation Based On Model Calibration In Weak Feedback Optical Self-Mixing System, L. Wei, Jiangtao Xi, J. Chicharo

Faculty of Informatics - Papers (Archive)

This paper presents a novel method to estimate displacement of a moving object based on model calibration in a weak feedback laser diode self-mixing system. A hybrid genetic algorithm is employed to locate the global minimum for the cost function which is constructed as the discrepancy between theoretically calculated system output and the experimental data. In turn, displacement measurement is achieved by identifying the optimal parameters for the system model. The proposed method is tested by both simulation and experimental setup with measuring accuracy better than 25nm.

Mac Design And Analysis For Wireless Sensor Networks With Co-Operative Localisation, M. Rengasamy, E. Dutkiewicz, M. Hedley

Faculty of Informatics - Papers (Archive)

Abstract—Co-operative localisation in wireless sensor networks (WSNs) is a method in which wireless sensor nodes interact with each other as peers to determine their physical position. In such networks it is crucial for communication between nodes to be contention free to meet the strict timing requirements. Medium Access Control (MAC) protocols provide the strongest influence over contention control in WSNs. The focus of this work is the design and analysis of a WSN MAC protocol suitable for supporting co-operative localisation. This paper presents a design overview of the MAC protocol and details its control structure. Preliminary simulation results are also …

Location-Based Drm Using Wifi Access Points, Martin Jan Surminen, Nicholas Paul Sheppard, Reihaneh Safavi-Naini

Faculty of Informatics - Papers (Archive)

Location-based Digital Rights Management (DRM) refers to a system allowing the owner of an electronic file to specify not only the actions a user is allowed to perform regarding the content, but also restrict the actions to a specified geographical area. A method for retrieving location information is required. One such method is to place wireless accesspoints in areas of interest, requiring a device to be in the vicinity of the correct accesspoint(s) in order to access a file.

The Bullwhip Effect In Complex Supply Chains, I. Alony, Albert Munoz Aneiros

Faculty of Informatics - Papers (Archive)

This paper reviews the various methods of modelling the dynamics of supply chains. We then present recently documented causes of the Bullwhip effect in production supply chains, and the methodologies used to describe and measure the importance of these causes. We examine the limitations of these methodologies and suggest a combined approach discrete event-continuous simulation modelling approach to further study this phenomenon in complex production supply chains.

Alternative Splicing: Associating Frequency With Isoforms, Anuradha Roy, Jennifer Leopold, Anne M. Maglia

Computer Science Faculty Research & Creative Works

In the simplest model of protein production, a gene gives rise to a single protein; DNA is transcribed to form pre-mRNA, which is converted to mRNA by splicing or removing introns. The result is a chain of exons that is translated to form a protein. Alternative splicing of exons may result in the formation of multiple proteins from the same gene sequence. However, not all of these proteins may be functional. Thus, we ask whether we can predict and rank (in order of frequency of occurrence and functional importance) the set of possible proteins for a gene. Herein we describe …

Rigidity Of Gradient Ricci Solitons, Peter Petersen, William Wylie

Mathematics - All Scholarship

We define a gradient Ricci soliton to be rigid if it is a flat bundle N*_GammaR^k where N is Einstein. It is known that not all gradient solitons are rigid. Here we offer several natural conditions on the curvature that characterize rigid gradient solitons. Other related results on rigidity of Ricci solitons are also explained in the last section.

Chromospherically Active Stars. Xxvi. The Double-Lined Late-Type Binary Hd 19485 = Wz Arietis, Francis C. Fekel, Charles Thomas Bolton

Information Systems and Engineering Management Research Publications

We have used spectroscopic observations to determine the orbital elements and some basic properties of the double-lined spectroscopic binary HD 19485 = WZ Ari. The orbital period is 6.247854 days, and the orbit is circular. The G5 V primary and K0 V secondary are chromospherically active. One star or possibly both are synchronously rotating. Based on the Hipparcos parallax and the magnitude differences derived in this work, we find that both components are approximately 1 mag above the zero-age main sequence, a result that is inconsistent with the assumption that the components are coeval. We discuss some possible solutions to …

Diversity Performance Of Precoded Ofdm With Mmse Equalization, Xiaojing Huang

Faculty of Informatics - Papers (Archive)

Two sets of bit error rate (BER) lower bounds for precoded orthogonal frequency division multiplexing (OFDM) systems using minimum mean square error (MMSE) equalization over frequency-selective multipath fading channels are evaluated by Monte Carlo method in this paper. The first set represents the best performance under different data group sizes used for precoding, whereas the second set represents the best performance under different channel multipath diversity orders. These performance bounds can serve as the guidelines for system designers to decide proper data group sizes for precoded OFDM systems in order to achieve better trade-off between system performance and complexity. Numerical …

Measurement Of The Pp̅→ Tt̅ + X Production Cross Section At √S = 1.96 Tev In The Fully Hadronic Decay Channel, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

A measurement of the top quark pair production cross section in proton antiproton collisions at an interaction energy of √s= 1.96 TeV is presented. This analysis uses 405 ± 25 pb^-1 of data collected with the D0 detector at the Fermilab Tevatron Collider. Fully hadronic tt̅ decays with final states of six or more jets are separated from the multijet background using secondary vertex tagging and a neural network. The tt̅ cross section is measured as σ _tt̅= 4.5_-1.9^+2.0(stat)_-1.1^+1.4(syst) ± 0.3(lumi) pb for a top quark mass of m_{t …}

Detailed Version: Analyzing Direct Effects In Randomized Trials With Secondary Interventions: An Application To Hiv Prevention Trials, Michael A. Rosenblum, Nicholas P. Jewell, Mark J. Van Der Laan, Stephen Shiboski, Ariane Van Der Straten, Nancy Padian

U.C. Berkeley Division of Biostatistics Working Paper Series

This is the detailed technical report that accompanies the paper “Analyzing Direct Effects in Randomized Trials with Secondary Interventions: An Application to HIV Prevention Trials” (an unpublished, technical report version of which is available online at http://www.bepress.com/ucbbiostat/paper223).

The version here gives full details of the models for the time-dependent analysis, and presents further results in the data analysis section. The Methods for Improving Reproductive Health in Africa (MIRA) trial is a recently completed randomized trial that investigated the effect of diaphragm and lubricant gel use in reducing HIV infection among susceptible women. 5,045 women were randomly assigned to either the …

Growth-Temperature Optimization For Low Carrier-Density In0.75Ga0.25As-Based High Electron Mobility Transistors On Inp, Paul J. Simmonds, H. E. Beere, D. A. Ritchie, S. N. Holmes

Paul J. Simmonds

Two-dimensional electron gases (2DEGs) were formed in undoped In_0.75Al_0.25As / In_0.75Ga_0.25As / In_0.75Al_0.25As quantum wells. The optimal growth temperature for this structure is 410°C, with peak 2DEG electron mobility and density values of μ = 221000 cm²/V s and n = 1.36 × 10¹¹ cm⁻² at 1.5 K. This electron mobility is equal to the highest previously published for these undoped structures but with a factor of 2 reduction in n. This has been achieved through the use of a significantly thinner InAlAs …

Collision Broadening Using Alkali-Filled, Hollow Core Fibers, Luke P. Rodgers

Theses and Dissertations

The goal of this research was to demonstrate the possibility of collision broadening in a cesium-filled, hollow-core fiber as an alternative to the proven technique of pressure broadening. Theoretically, alkali electrons should relax from the ²P_3/2 to the ²P_1/2 level and the absorption spectrum should collisionally broaden due to the presence of fiber walls, as opposed to the more common pressure broadening method. An absorption dip located at 852.34nm was recorded in a pressure broadened comparison leg. This data was used as a baseline during analysis of the fiber leg's data. While the fiber was successfully …

Nanoindentation Of The A And C Domains In A Tetragonal Batio3 Single Crystal, Young-Bae Park, Matthew J. Dicken, Zhi-Hui Xu, Xiaodong Li

Faculty Publications

Nanoindentation in conjunction with piezoresponse force microscopy was used to study domain switching and to measure the mechanical properties of individual ferroelectric domains in a tetragonal BaTiO₃ single crystal. It was found that nanoindentation has induced local domain switching; the a and c domains of BaTiO₃ have different elastic moduli but similar hardness.Nanoindentationmodulus mapping on the a and c domains further confirmed such difference in elasticity. Finite element modeling was used to simulate the von Mises stress and plastic strain profiles of the indentations on both a and c domains, which introduces a much higher stress level than …

Ubiquitous Low-Velocity Layer Atop The 410-Km Discontinuity In The Northern Rocky Mountains, John Jasbinsek, Kenneth Dueker

Physics

Receiver functions from three 30-station IRIS-PASSCAL small-aperture arrays (2–15 km station spacing) operated for 10 months each in the northern Rocky Mountains show a ubiquitous negative polarity P to S conversion just preceding the 410-km discontinuity arrival. Data from the three arrays were sorted into NW, SE, and SW back-azimuth quadrants and stacked to form nine quadrant stacks. Remarkably, the negative polarity arrival (NPA) is apparent in 8 of the 9 quadrant stacks, with 7 of the 8 having well-correlated waveforms. Each quadrant stack also contains clear P to S conversions from the 410- and 660-km discontinuities. Moveout analysis shows …

Topic And Role Discovery In Social Networks With Experiments On Enron And Academic Email, Andrew Mccallum, Xuerui Wang, Andrés Corrada-Emmanuel

Andrés Corrada-Emmanuel

Previous work in social network analysis (SNA) has modeled the existence of links from one entity to another, but not the attributes such as language content or topics on those links. We present the Author-Recipient-Topic (ART) model for social network analysis, which learns topic distributions based on the direction-sensitive messages sent between entities. The model builds on Latent Dirichlet Allocation (LDA) and the Author-Topic (AT) model, adding the key attribute that distribution over topics is conditioned distinctly on both the sender and recipient---steering the discovery of topics according to the relationships between people. We give results on both the Enron …

On The Variability Of Mesospheric Oh Emission Profiles, Romina Nikoukar, Gary R. Swenson, Alan Z. Liu, Farzad Kamalabadi

Physical Sciences - Daytona Beach

Mesospheric OH radiance limb profiles measured by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument aboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) spacecraft were inverted to yield altitude profiles of OH volume emission rates. The Abel inversion results of two months of data (from 1 June to 31 July 2004) were analyzed for the layer mean and standard deviation as a function of latitude and local time. Statistical analysis of SABER data shows that the global difference between the mean and standard deviation profiles for the OH(vu = 7, 8, 9; ∆v …

Optimization Of Non-Natural Nucleotides For Selective Incorporation Opposite Damaged Dna, Diana Vineyard, Xuemei Zhang, Alison Donnelley, Irene Lee, Anthony J. Berdis

Chemistry Faculty Publications

The promutagenic process known as translesion DNA synthesis reflects the ability of a DNA polymerase to misinsert a nucleotide opposite a damaged DNA template. To study the underlying mechanism of nucleotide selection during this process, we quantified the incorporation of various non-natural nucleotide analogs opposite an abasic site, a non-templating DNA lesion. Our kinetic studies using the bacteriophage T4 DNA polymerase reveal that the π-electron surface area of the incoming nucleotide substantially contributes to the efficiency of incorporation opposite an abasic site. A remaining question is whether the selective insertion of these non-hydrogen-bonding analogs can be achieved through optimization of …

A Smoothing Approach To Data Masking, Yijie Zhous, Francesca Dominici, Thomas A. Louis

Johns Hopkins University, Dept. of Biostatistics Working Papers

Individual-level data are often not publicly available due to confidentiality. Instead, masked data are released for public use. However, analyses performed using masked data may produce invalid statistical results such as biased parameter estimates or incorrect standard errors. In this paper, we propose a data masking method using spatial smoothing, and we investigate the bias of parameter estimates resulting from analyses using the masked data for Generalized Linear Models (GLM). The method allows for varying both the form and the degree of masking by utilizing a smoothing weight function and a smoothness parameter. We show that data masking by using …

Time Resolution Of Collapse Events During The Progation Of Ultraviolet Filaaments, Teresa J. Fondren

Theses and Dissertations

Long distance propagation, or filamentation, of short, intense laser pulses is suggested to be possible through the balance of two effects: self-focusing, when a nonlinear index of refraction of air is induced by high intensities, and de-focusing, due to the plasma created by the pulse. Applications for filamentation include areas such as remote sensing and directed energy. A split-step spectral propagation simulation is used to model the behavior of a high intensity ultraviolet laser pulse propagating through air. Convergence of femtosecond duration collapses that form on the leading edge of the pulse in the time domain is achieved with an …

Analysis, Selection, And Implementation Of A Case Management System For Local City Government Attorney's Office, Patricia D. Hughes

Regis University Student Publications (comprehensive collection)

This paper focuses on the business analysis, selection, and implementation of a case management system for a local government City Attorney's Office which is a document management system in addition to calendaring, notes, tasks, and billing. Their current system relies on paper document organization and as well as some electronic documentation in a simple file folder structure on a windows network file server. A business analysis review demonstrated the need for a cost effective automated business system to support and manage daily business processes, automate document creation and filing, track deadlines and tasks, and comply with new document retention and …

"Conversational" Dialogues In Direct-Manipulation Interfaces, David G. Novick

David G. Novick

This paper reports ongoing research in extending direct-manipulation interfaces by incorporating, via the direct-manipulation modality itself, interaction techniques that add kinds of language features associated with spoken conversation. The paper proposes means of implementing ways for a user of a direct-manipulation system to define new kinds of relations among objects in the interface.

Users And Uses Of Synchronous Business Communications Software, David G. Novick, Eleanor Wynn

David G. Novick

To help designers and authors understand users' intentions and work practices for synchronous business communications in a systematic way, we used ethnographic and task-analytic techniques to collect, analyze and classify evidence of the activities of potential users as they conducted their work lives. The interactions we observed among our users took place through a variety of modalities. We found eight categories of tasks for the collaborative or interactive work in which our subjects engaged. Based on these data, we were able to classify roles of potential users of synchronous business communications software into a set of "archetypes" that characterize their …

Hands-Free Documentation, Karen Ward, David G. Novick

David G. Novick

In this paper, we introduce an analysis of the requirements and design choices for hands-free documentation. Hands-busy tasks such as cooking or car repair may require substantial interruption of the task: moving the pan off the burner and wiping hands, or crawling out from underneath the car. We review the need for hands-free documentation and explore the role of task in the use of documentation. Our central analysis examines the roles and characteristics of input and output modalities of hands-free documentation. In particular, we review the use of speech as an input modality, and then visual means and speech as …

An Interaction Initiative Model For Documentation, David G. Novick, Karen Ward

David G. Novick

In this paper we propose a model of creation and use of documentation based on the concept of mixed-initiative interaction. In our model, successful single-initiative interaction is characterized by grounding of contributions, and successful mixed-initiative interaction is characterized by both grounding and agreement. Just as in spoken conversation, achievement of actual agreement depends on the intentions of both parties; agreement is achieved when the reader follows the documentation’s instructions. In fact, readers are not obligated to—and often do not—act according to the author’s intentions. By making these dynamics explicit, the model can aid authors in developing effective documentation. The paper …

Assessing Effectiveness Of Personality Style In Documentation, Kenneth Sayles, David G. Novick

David G. Novick

This paper extends previous work by other researchers that indicated that users of computers preferred a computer with a personality that was similar to theirs. We conducted a similar experiment, but looking beyond preference to see if the personality of documentation would make a difference in the user’s performance. Our data suggest did not indicate that personality match affects performance; and if such a relationship exists it is likely to be weak. We discuss the related research, describe our methodology, present our results, and describe their implications and limitations.

Asymmetric Weak-Pinning Superconducting Channels: Vortex Ratchets, Britton Plourde, T. W. Heitmann, C. Song, M. P. Defeo, Kang Yu

Physics - All Scholarship

The controlled motion of objects through narrow channels is important in many fields. We have fabricated asymmetric weak-pinning channels in a superconducting thin-film strip for controlling the dynamics of vortices. The lack of pinning allows the vortices to move through the channels with the dominant interaction determined by the shape of the channel walls. We present measurements of vortex dynamics in the channels and compare these with similar measurements on a set of uniform-width channels. While the uniform-width channels exhibit a symmetric response for both directions through the channel, the vortex motion through the asymmetric channels is quite different, with …

Cpd -20 1123 (Albus 1) Is A Bright He-B Subdwarf, Stéphane Vennes, Adéla Kawka, Jonathan Allyn Smith

Aerospace, Physics, and Space Science Faculty Publications

Based on photometric and astrometric data it has been proposed that Albus 1 (also known as CPD -20 1123) might be a hot white dwarf similar to G191-B2B or, alternatively, a hot subdwarf. We obtained a series of optical spectra showing that CPD -20 1123 is a bright He-B subdwarf. We analyzed the H i Balmer and He i line spectra and measured Tcff = 19,800 ± 400 K, and. Thislogg p 4.55 ± 0.10 and log N(He)/N(H) p 0.15 ± 0.15 This peculiar object belongs to a family of evolved helium-rich stars that may be the products of double-degenerate …