Physical Sciences and Mathematics Commons^™

Study Of Vickers´ Micro Hardness On Inbi_0.85sb_0.15 Single Crystals, Dimple Shah, G. R. Pandya, S. M. Vyas, M. P. Jani

Turkish Journal of Physics

InBi_0.85Sb_0.15 single crystals have been grown by zone-melting method. The growth velocity was 0.8 cm/h and the freezing interface temperature was 35 °C/cm. A Vickers' projection microscope was used for the study of micro hardness of the crystals. Hardness tests were carried out on the as-cleaved, cold-worked and annealed surfaces of the crystals. The effect of perfection of crystals on micro hardness with respect to the cold-worked, as-cleaved and annealed crystals have been studied and the results are reported.

Longitudinal Form Factor Of Isoscalar Particle-Hole States In ^{16}O, ^{12}C And ^{40}Ca With M3y Interaction, Ali H. Taqi, Raad A. Radhi

Turkish Journal of Physics

Longitudinal form factors of the low-lying, T = 0, particle-hole states of ^{16}O, ^{12}C and ^{40}Ca are studied in the framework of Random Phase Approximation RPA. The basis of single particle states is considered to include 0s, 0p, 1s-0d and 0f-1p. The Hamiltonion is diagonalized in the presence of Michigan three-rang Yakawa (M3Y) interaction and compared with our previous results depend on Modified Surface Delta Interaction MSDI interaction. Admixture of higher configuration up to 2p-1f is considered for the ground state. Effective charges are used to account for the core polarization effect. Comparisons are made to experimental data where available …

Magnetic Levitation Of A Small Magnetic Ring Above Cylindrical Superconductor Sample In The Meissner State, H. M. Al-Khateeb, F. Y. Alzoubi, M. K. Alqadi, N. Y. Ayoub

Turkish Journal of Physics

The levitation force between a cylindrical superconductor in the Meissner state and a small magnetic ring was calculated using the dipole-dipole interaction model under the assumption that the magnetic ring is small compared with the physical dimensions of the system. We obtained analytical expressions for the levitation forces as a function of the geometrical parameters of the ring and the superconductor sample as well as the height of magnetic ring. We analyzed the levitation force in two configurations of the magnetic moment of the small ring with respect to the surface of the superconductor: one horizontal in which the magnetic …

Thickness Dependent Structural, Electrical And Optical Properties Of Chemically Deposited Nanopartical Pbs Thin Films, A. U. Ubale, A. R. Junghare, N. A. Wadibhasme, A. S. Daryapurkar, R. B. Mankar, V. S. Sangawar

Turkish Journal of Physics

Nanostructured thin films have attracted the attention of an increasing number of researchers from several disciplines during the last ten years, due to their outstanding electronic and optical properties and extensively useful applications in various optoelectronic devices. PbS thin films were deposited onto glass substrate by the method of chemical bath deposition (CBD) at 330 K temperature. The structure and surface morphology of the films were characterized by X-ray diffraction and scanning electron microscopy. The optical investigation showed that, depending on thickness films have direct allowed transitions in the range 1.88-2.28 eV. The decrease in dc dark resistivity with increase …

Preparation And Study Of The Structural, Optical And Electrical Properties Of Cu(In,Ga)Se_2 Thin Films, Athar Javed

Turkish Journal of Physics

Thin film samples of Cu(In,Ga)Se_2 (CIGS) were prepared at room temperature by physical vapor deposition (PVD) technique using resistive heating method onto soda lime glass substrates. Deposition conditions were same for all the samples. The prepared samples were annealed in vacuum at temperature of 200 °C for 5, 10, 15, 30 and 60 minutes and were characterized structurally, optically and electrically. The structural analysis indicate the partial formation of quaternary CIGS compounds for the samples which were annealed in vacuum at 200 °C for 30 and 60 minutes. XRD analysis indicate that there is a continuous growth and improvement in …

Silver Mode For Heavy Higgs Search In The Presence Of A Fourth Sm Family, Saleh Sultansoy, Gökhan Ünel

Turkish Journal of Physics

We investigate the possible enhancement to the discovery of the heavy Higgs boson through the possible fourth standard model family heavy neutrino. Using the channel h\to\nu_4\bar{\nu}_4 \to \mu W\mu W \to \mu j j\mu j j it is found that for certain ranges of the Higgs boson and \nu_4 masses, LHC could discover both of them simultaneously with 1fb^{-1} integrated luminosity.

Five Dimensional Anisotropic Homogeneous Cosmological Models In Second Self Creation Theory Of Gravitation, Ganeshwar Mohanty, Kamal Lochan Mahanta

Turkish Journal of Physics

Five dimensional homogeneous anisotropic cosmological models in Barber's second self creation theory are constructed when the gravitational field is generated by a perfect fluid. Under the power law dependence of the scale factors, the perfect fluid models degenerate Zeldovich fluid models. The physical and geometrical features of these models are discussed.

On The Eigensolutions Of The One-Dimensional Kemmer Oscillator, A. Boumali

Turkish Journal of Physics

In the present paper, we solve the one-dimensional Kemmer equation in the presence of the Dirac oscillator potential. Following Greiner in [23], we have shown that the eigensolutions are decoupled in two sets.

An Investigation Of The Effects Of Hydrogen On Local Strain Fields And Structural Disorder-To-Order Transition In Hydrogenated Amorphous Silicon, Aniekan Magnus Ukpong

Turkish Journal of Physics

This study utilizes the fluctuations in the mean silicon-silicon near neighbour distances and local atomic-level stresses to study the chemically-induced disorder-to-order transition in hydrogenated amorphous silicon as a function of hydrogen concentration C_H. The correlation between a suitable stress and structure parameter shows a three-stage structure transition that culminates in the formation of a crystalline phase at high C_H. In the low C_H limit, the structural changes are characterized by a linear response to stress giving a rigidity modulus of 73.43+-15 GPa. In the intermediate and high C_H limits, the stress-structure correlation shows a volume-dependence. At very high hydrogen concentrations, …

Optical Properties And Determination Of Thermal Transformation Parameters For Se_{0.65}Te_{0.35} High Reflectance Thin Films, Ayman Ahmed El-Amin, Aly Mohammed Badr, Foaud Abdel-Wahaab

Turkish Journal of Physics

Chalcogenide glasses Se-Te have been prepared from the high purity constituent elements. Thin films of these materials have been deposited by vacuum evaporation. The thickness effects on the optical properties have been performed for the as-deposited films. The impact of varying thickness on the value of the optical gap is also reported and discussed. The resultant films were in amorphous nature. The reflectance and transmittance spectra were measured for the mentioned films and analyzed in the incident photon energy range from 1.16 to 2.47 eV. The refractive indices were determined as a function of wavelength via the transmittance analysis in …

Electrical Resistivity Of Liquid Alkali Na-Based Binary Alloys, Aditya M. Vora

Turkish Journal of Physics

The study of the electrical resistivity \rho_L of alkali Na-based binary alloys Na_{1-x}Li_x, Na_{1-x}K_x, Na_{1-x}Rb_x and Na_{1-x}Cs_x have been made by well-recognized model potential of Gajjar et al. The most recent exchange and correlation functions due to Farid et al (F) and Sarkar et al (S) are used for the first time in the study of electrical resistivity of liquid binary mixtures and found suitable for such study. The results, due to the inclusion of Sarkar et al's local field correction function, are found superior to those obtained due to Farid et al's local field correction function. Electrical resistivity of …

Automatic Detection And Segmentation Of Robot-Assisted Surgical Motions, Henry C. Lin

Link Foundation Modeling, Simulation and Training Fellowship Reports

Robotic surgical systems such as Intuitive Surgical's da Vinci system provide a rich source of motion and video data from surgical procedures. In principle, this data can be used to evaluate surgical skill, provide surgical training feedback, or document essential aspects of a procedure. If processed online, the data can be used to provide context-specific information or motion enhancements to the surgeon. However, in every case, the key step is to relate recorded motion data to a model of the procedure being performed. This paper examines our progress at developing techniques for "parsing" raw motion data from a surgical task …

Businessfinder: Harnessing Presence To Enable Live Yellow Pages For Small, Medium And Micro Mobile Businesses, D. Chakraborty, K. Dasgupta, S. Mittal, Archan Misra, C. Oberle, A. Gupta, E. Newmark

Research Collection School Of Computing and Information Systems

Applications leveraging network presence in next-generation cellular networks have so far focused on subscription queries, where "presence" information is extracted from specific devices and sent to entities who have subscribed to such presence information. In this article we present BusinessFinder, a service that leverages the underlying cellular presence substrate to provide efficient, on-demand, context-aware matching of customer requests to nomadic micro businesses as well as small and medium businesses having a mobile workforce. Presence, in the context of BusinessFinder, is not simply limited to phone location and device status, but also encompasses dynamic attributes of vendors (both "mobile" and "static"), …

Searching And Tagging: Two Sides Of The Same Coin?, Qiaozhu Mei, Jing Jiang, Hang Su, Chengxiang Zhai

Research Collection School Of Computing and Information Systems

This paper presents the duality hypothesis of search and tagging, two important behaviors of web users. The hypothesis states that if a user views a document D in the search results for query Q, the user would tend to assign document $D$ a tag identical to or similar to Q; similarly, if a user tags a document D with a tag T, the user would tend to view document D if it is in the search results obtained using T as a query. We formalize this hypothesis with a unified probabilistic model for search and tagging, and show that empirical …

Two Neural Network Based Decentralized Controller Designs For Large Scale Power Systems, Wenxin Liu, Jagannathan Sarangapani, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Mariesa Crow, David A. Cartes

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents two neural network (NN) based decentralized controller designs for large scale power systems' generators, one is for the excitation control and the other is for the steam valve control. Though the control signals are calculated using local signals only, the transient and overall system stabilities can be guaranteed. NNs are used to approximate the unknown and/or imprecise dynamics of the local power system and the interconnection terms, thus the requirements for exact system parameters are released. Simulation studies with a three machine power system demonstrate the effectiveness of the proposed controller designs.

Multiphoton Response Of Retinal Rod Photoreceptors, Vasilios Alexiades, Harihar Khanal

Publications

Phototransduction is the process by which light is converted into an electrical response in retinal photoreceptors. Rod photoreceptors contain a stack of (about 1000) disc membranes packed with photopigment rhodopsin molecules, which absorb the photons. We present computational experiments which show the profound effect on the response of the distances (how many discs apart) photons happen to be absorbed at. This photon-distribution effect alone can account for much of the observed variability in response.

A Comparison Of Techniques To Forecast Consumer Satisfaction For Vehicle Ride, Elizabeth A. Cudney, David Drain, Kenneth M. Ragsdell, Kioumars Paryani

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper presents a comparison of methods for the identification of a reduced set of useful variables using a multidimensional system. the Mahalanobis-Taguchi System and a standard statistical technique are used reduce the dimensionality of vehicle ride based on consumer satisfaction ratings. the Mahalanobis-Taguchi System and cluster analysis are applied to vehicle ride. the research considers 67 vehicle data sets for the 6 vehicle ride parameters. This paper applies the Mahalanobis-Taguchi System to forecast consumer satisfaction and provides a comparison of results with those obtained from a standard statistical approach to the problem. Copyright © 2007 SAE International.

Hyphenated Hplc-Ms Technique For Analysis Of Compositional Monosaccharides Of Transgenic Corn Glycoprotein And Characterization Of Degradation Products Of Diazinon, Fonofos And Aldicarb In Various Oxidation Systems, Tongwen Wang

Doctoral Dissertations

"The studies of this dissertation are composed of two sections. The first one deals with the analysis of compositional monosaccharides of transgenic corn glycoproteins. The method used in this study involved derivatization of monosaccharides with two fluorophores followed by HPLC/fluorescence detection for quantitative studies, and by HPLC/SSI/MS for identification confirmation of individual monosaccharide...The second section investigates the degradation processes of several pesticides including diazinon, fonofos and aldicarb in various oxidation systems"--Abstract, page iv.

Neural Network Control Of Robot Formations Using Rise Feedback, Jagannathan Sarangapani, Travis Alan Dierks

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a combined kinematic/torque control law is developed for leader-follower based formation control using backstepping in order to accommodate the dynamics of the robots and the formation in contrast with kinematic-based formation controllers that are widely reported in the literature. A neural network (NN) is introduced along with robust integral of the sign of the error (RISE) feedback to approximate the dynamics of the follower as well as its leader using online weight tuning. It is shown using Lyapunov theory that the errors for the entire formation are asymptotically stable and the NN weights are bounded as opposed …

Adaptive Neural Network Based Stabilizing Controller Design For Single Machine Infinite Bus Power Systems, Wenxin Liu, Ganesh K. Venayagamoorthy, Donald C. Wunsch, David A. Cartes, Jagannathan Sarangapani, Mariesa Crow

Engineering Management and Systems Engineering Faculty Research & Creative Works

Power system stabilizers are widely used to generate supplementary control signals for the excitation system in order to damp out the low frequency oscillations. In power system control literature, the performances of the proposed controllers were mostly demonstrated using simulation results without any rigorous stability analysis. This paper proposes a stabilizing neural network (NN) controller based on a sixth order single machine infinite bus power system model. The NN is used to approximate the complex nonlinear dynamics of power system. Unlike the other indirect adaptive NN control schemes, there is no offline training process and the NN can be directly …

Effective Use Of Process Capability Indices For Supplier Management, Elizabeth A. Cudney, David Drain

Engineering Management and Systems Engineering Faculty Research & Creative Works

Process capability indices were originally invented to enable an organization to make economically sound decisions for process management. Process capability is a comparison of the voice of the process with the voice of the customer. Current practice is to use Cp and Cpk regardless of the validity of the underlying assumptions necessary for their use. Even if all necessary assumptions are satisfied, important problems can be missed if these indices are the sole process evaluation examined. Customer-supplier axioms are introduced to motivate more useful process evaluations and foster long-term harmonious relationships. This paper explores the alternative capability indices Cpm, Cpmk, …

Lsuhsc Facilities Biweekly Update: January 2007, Lsuhsc Property And Facilities Management

LSUHSC Facilities Biweekly Updates: 2007

LSUHSC Facilities Biweekly Updates from January 5 and 22, 2007.

These updates describe damage and a timeline of repairs at the LSU Health Sciences Center - New Orleans campus due to Hurricane Katrina which made landfall August 29, 2005.

Lsuhsc Facilities Daily Update: January 2007, Lsuhsc Property And Facilities Management

LSUHSC Facilities Daily Updates: 2007

LSUHSC Facilities Daily Updates from January 2007.

These updates describe damage and a timeline of repairs at the LSU Health Sciences Center - New Orleans campus due to Hurricane Katrina which made landfall August 29, 2005.

Graded Sparse Graphs And Matroids, Audrey Lee, Ileana Streinu, Louis Theran

Computer Science: Faculty Publications

Sparse graphs and their associated matroids play an important role in rigidity theory, where they capture the combinatorics of some families of generic minimally rigid structures. We define a new family called graded sparse graphs, arising from generically pinned bar-and-joint frameworks, and prove that they also form matroids. We also address several algorithmic problems on graded sparse graphs: Decision, Spanning, Extraction, Components, Optimization, and Extension. We sketch variations on pebble game algorithms to solve them.

A New Lower Bound On Guard Placement For Wireless Localization, Mirela Damian, Robin Flatland, Joseph O'Rourke, Suneeta Ramswami

Computer Science: Faculty Publications

The problem of wireless localization asks to place and orient stations in the plane, each of which broadcasts a unique key within a fixed angular range, so that each point in the plane can determine whether it is inside or outside a given polygonal region. The primary goal is to minimize the number of stations. In this paper we establish a lower bound of ⌊2n/3⌋−1 stations for polygons in general position, for the case in which the placement of stations is restricted to polygon vertices, improving upon the existing ⌈n/2⌉ lower bound.

In-Between Theory And Practice: Dialogues In Design Research, Arianna Bassoli, Johanna Brewer, Karen Martin

Computer Science: Faculty Publications

Why Wait? and Betwixt are two of the workshops we have recently run on the theme of in-between-ness. The approach of social computing, where researchers work to understand how the socio-cultural aspects of human life relate to the design of new technologies, was the starting point for our investigation. By observing actual instances of in-between-ness in context we explored how design activities can be used as an opportunity to discuss and take positions on a specific theme, and as a space for narrowing the gap in design research between theoretical and practical thinking.

Why De Minimis?, Matthew D. Adler

Faculty Scholarship

De minimis cutoffs are a familiar feature of risk regulation. This includes the quantitative individual risk thresholds for fatality risks employed in many contexts by EPA, FDA, and other agencies, such as the 1-in-1 million lifetime cancer risk cutoff; extreme event cutoffs for addressing natural hazards, such as the 100 - year - flood or 475 - year - earthquake; de minimis failure probabilities for built structures; the exclusion of low - probability causal models; and other policymaking criteria. All these tests have a common structure, as I show in the Article. A de minimis test, broadly defined, tells the …

A Handle On What's Going On: Combining Tangible Interfaces And Ambient Displays For Collaborative Groups, Johanna Brewer, Amanda Williams, Paul Dourish

Computer Science: Faculty Publications

While tangible interfaces open up new possibilities for in- put and interaction, they are also interesting because of the ways in which they occupy the physical world just as we do. We have been working at the intersection of three research areas – tangible interfaces, ambient displays, and collaboration awareness. Our system, Nimio, uses engaging physical objects as both input devices (capturing aspects of individual activity) and output devices (expressing aspects of group activity). We present our design and experiences, focusing in particular on the tension between legibility and ambiguity and its relevance in collaborative settings.

Cache Coherence Protocol Verification Using Ωmega, Ki Yung Ahn

Computer Science Faculty Publications and Presentations

We verify some correctness properties of the DASH cache coherence protocol using Ωmega. Ωmega is a language with a rich type system featuring GADTs, type functions, and user-guided type checking rules. Cache coherence protocols have both safety properties and liveness properties. We show how to describe some of the safety properties of DASH cache coherence protocol in mega. Since liveness properties are not easily expressed by types, we investigate invariants sufficient to imply some of the liveness properties of concern, and assert those invariants as well in the type system of Ωmega. Using Ωmega, we can have both a working …

Protecting The Internet With Public Work, Ed Kaiser, Wu-Chang Feng

Computer Science Faculty Publications and Presentations

Distributed denial-of-service attacks represent a growing problem for networked systems. To tackle this problem, this paper explores the addition of a public work function to the service advertisement mechanisms used by such systems. When under attack, services advertise this function along with their location information and clients must attach a solution to the function with subsequent requests. The function, which can be made specific to the source of traffic, is publicly verifiable, allowing arbitrary network devices at the edges of the network to quickly verify that subsequent communication from the source will be accepted by the destination. We describe a …