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The 24th Annual Research Conference Abstract Booklet, University Of Gondar, Ethiopia

University of Gondar Research Conferences

The 25th Annual Staff-Student Research Conference of the University of Gondar will be held on June 19 and 20, 2015 at the Science Amba Auditorium. This year's conference is special in that the year marks the Silver Jubilee of the Annual Staff and Student Research Conference. Drawing on the experiences we have accumulated for the past 25 years, we vow to strive to realize the development and transformation of the country through research and community services.

Staff, postgraduate and senior undergraduate students of the University, invited guests, and speakers will participate in the conference. The annual conference of the University …

An Examination Of Service Level Agreement Attributes That Influence Cloud Computing Adoption, Howard Gregory Hamilton

CCE Theses and Dissertations

Cloud computing is perceived as the technological innovation that will transform future investments in information technology. As cloud services become more ubiquitous, public and private enterprises still grapple with concerns about cloud computing. One such concern is about service level agreements (SLAs) and their appropriateness.

While the benefits of using cloud services are well defined, the debate about the challenges that may inhibit the seamless adoption of these services still continues. SLAs are seen as an instrument to help foster adoption. However, cloud computing SLAs are alleged to be ineffective, meaningless, and costly to administer. This could impact widespread acceptance …

Crystal Structure Of Catena-Poly[[Chlorido(4,4'-Dimethyl-2,2'-Bipyridine-Κ2n,N')Copper(Ii)]-Μ-Chlorido], Rafaela Nita, Jeffrey R. Deschamps, Scott A. Trammell, D. Andrew Knight

Chemistry and Chemical Engineering Faculty Publications

The title compound, [CuCl2(C12H12N2)]n, was obtained via a DMSO-mediated dehydration of Cu(4,4'-dimethyl-2,2'-bipyridine)copper(II)·0.25H2O. The central CuII atom is coordinated in a distorted trigonal-bipyramidal geometry by two N atoms of a chelating 4,4'-dimethyl-2,2'-bipyridine ligand [average Cu-N = 2.03 (3) Å] and three Cl atoms, one terminal with a short Cu-Cl bond of 2.2506 (10) Å, and two symmetry-equivalent and bridging bonds. The bridging Cl atom links the CuII ions into chains parallel to [001] via one medium and one long Cu-Cl bond [2.3320 (10) and 2.5623 (9) Å]. The structure displays both inter- and intramolecular C-H⋯Cl hydrogen bonding.

Ruling Out Ic/Cmb X-Rays In Pks 0637-752 And The Implications For Tev Emission From Large-Scale Quasar Jets, Eileen T. Meyer, Markos Georganopoulos, William B. Sparks, Leith E.H. Godfrey, James E.J. Lovell, Eric S. Perlman

Aerospace, Physics, and Space Science Faculty Publications

The Chandra X-ray observatory has discovered dozens of resolved, kiloparsec-scale jets associated with powerful quasars in which the X-ray fluxes are observed to be much higher than the expected level based on the radio-optical synchrotron spectrum. The most popular explanation for the anomalously high and hard X-ray fluxes is that these jets do not decelerate significantly by the kiloparsec scale, but rather remain highly relativistic (Lorentz factors ). By adopting a small angle to the line of sight, the X-rays can thus be explained by inverse Compton upscattering of cosmic microwave background (CMB) photons (IC/CMB), where the observed emission is …

Search For Vector-Like T Quarks Decaying To Top Quarks And Higgs Bosons In The All-Hadronic Channel Using Jet Substructure, Cms Collaboration, V. Khachatryan, A. M. Sirunyan, Marc M. Baarmand, Marcus Hohlmann, Himali Kalakhety, Francisco X. Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

A search is performed for a vector-like heavy T quark that is produced in pairs and that decays to a top quark and a Higgs boson. The data analysed correspond to an integrated luminosity of 19.7 fb⁻¹ collected with the CMS detector in proton-proton collisions at s=8" role="presentation" style="box-sizing: inherit; display: inline-block; line-height: normal; word-spacing: normal; overflow-wrap: normal; text-wrap: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">�=8 TeV. For T quarks with large mass values the top quarks and Higgs bosons can have significant Lorentz …

Brain Effective Connectivity During Motor-Imagery And Execution Following Stroke And Rehabilitation, Sahil Bajaj, Andrew Butler, Daniel Drake, Mukesh Dhamala

Physics and Astronomy Faculty Publications

Brain areas within the motor system interact directly or indirectly during motor-imagery and motor-execution tasks. These interactions and their functionality can change following stroke and recovery. How brain network interactions reorganize and recover their functionality during recovery and treatment following stroke are not well understood. To contribute to answering these questions, we recorded blood oxygenation-level dependent (BOLD) functional magnetic resonance imaging (fMRI) signals from10 stroke survivors and evaluated dynamical causal modeling (DCM)-based effective connectivity among three motor areas: primary motor cortex (M1), premotor cortex (PMC) and supplementary motor area (SMA), during motor-imagery and motor-execution tasks. We compared the connectivity between …

Rechecking The Centrality-Lethality Rule In The Scope Of Protein Subcellular Localization Interaction Networks, Xiaoqing Peng, Jianxin Wang, Jun Wang, Fangxiang Wu, Yi Pan

Computer Science Faculty Publications

Essential proteins are indispensable for living organisms to maintain life activities and play important roles in the studies of pathology, synthetic biology, and drug design. Therefore, besides experiment methods, many computational methods are proposed to identify essential proteins. Based on the centrality-lethality rule, various centrality methods are employed to predict essential proteins in a Protein-protein Interaction Network (PIN). However, neglecting the temporal and spatial features of protein-protein interactions, the centrality scores calculated by centrality methods are not effective enough for measuring the essentiality of proteins in a PIN. Moreover, many methods, which overfit with the features of essential proteins for …

The Biological Consequences Of Kaolin Geophagia, Deloris Alexander, Desire Richardson, Lakisha Odom, Kara Cromwell, Dejuana Grant, Micoya Myers, Eddy Cadet, Hamid Mahama, Vijaya Rangari, Ralphenia Pace, Ramble Ankumah, Kokoasse Kpomblekou-A, Curtis Fluker

Professional Agricultural Workers Journal

Abstract

Kaolin geophagia is associated with the relief of gastrointestinal distress, but it may also cause adverse health effects on the body. This study was designed to: assess kaolin composition; test if 129SvEv mice would consume kaolin and determine the consequences of consumption; and assess rotational stress modulation of consumption. Thirteen kaolin samples were purchased from Alabama and Georgia stores. Chemical and physical properties were characterized for each sample using a Munsell chart, pH meter, Energy Dispersive Spectroscopy, Transmission Electron Microscopy, Visible Near-InfraRed Spectra, and Inductively Coupled Plasma-Optical Emission Spectrometry. Kaolin was then given to mice as food supplements and …

Math Department Newsletter, 2014-2015, Mathematics Department

Mathematics Newsletter

No abstract provided.

Generating Random Vectors Using Transformation With Multiple Roots And Its Applications, Qidi Peng, Henry Schellhorn, Lu Zhu

Applications and Applied Mathematics: An International Journal (AAM)

An approach is proposed to generate random vectors using transformation with multiple roots. This approach generalizes the one-dimensional inverse transformation with multiple roots method to higher dimensions, i.e., to random vectors with or without densities. In this approach, multiple roots of the transformation and probabilities of selecting each of the roots are derived. The strategies for constructing such a transformation are discussed and several examples are presented to motivate this simulation approach.

A Note On An M/M/S Queueing System With Two Reconnect And Two Redial Orbits, Amina A. Bouchentouf, Hanane Sakhi

Applications and Applied Mathematics: An International Journal (AAM)

A queueing system with two reconnect orbits, two redial (retrial) orbits, s servers and two independent Poisson streams of customers is considered. An arriving customer of type i, i = 1, 2 is handled by an available server, if there is any; otherwise, he waits in an infinite buffer queue. A waiting customer of type i who did not get connected to a server will lose his patience and abandon after an exponentially distributed amount of time, the abandoned one may leave the system (lost customer) or move into one of the redial orbits, from which he makes a new …

Strong Uniform Consistency Of Hazard Function With Functional Explicatory Variable In Single Functional Index Model Under Censored Data, Omar Belabbaci, Abbes Rabhi, Sara Soltani

Applications and Applied Mathematics: An International Journal (AAM)

In this paper we deal with nonparametric estimate of the conditional hazard function, when the covariate is functional. Kernel type estimators for the conditional hazard function of a scalar response variable Y given a Hilbertian random variable X are introduced, where the observations are linked with a single-index structure. We establish the pointwise almost complete convergence and the uniform almost complete convergence (with the rate) of the kernel estimate of this model in various situations, including censored and non-censored data. The rates of convergence emphasize the crucial role played by the small ball probabilities with respect to the distribution of …

Estimation Of The Parameters Of Exponential Distribution Using Top-K-Lists, M. Ahsanullah, Mohamed Habibullah

Applications and Applied Mathematics: An International Journal (AAM)

This paper deals with the estimation of location and scale parameters of the exponential distribution based on top-k-list of a sequence of observations from a two parameter exponential distribution. The minimum variance unbiased estimates of the location and scale parameters are given. Some comparisons of the variances of these estimates with respect to that of the kth record values are given.

New Exact Solutions Of The Perturbed Nonlinear Fractional Schr¨Odinger Equation Using Two Reliable Methods, Nasir Taghizadeh, Mona N. Foumani, Vahid S. Mohammadi

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, the fractional derivatives in the sense of the modified Riemann-Liouville derivative and the first integral method and the Bernoulli sub-ODE method are employed for constructing the exact complex solutions of the perturbed nonlinear fractional Schr ¨odinger equation and comparing the solutions.

Gaussian Copula Mixed Models With Non-Ignorable Missing Outcomes, N. Jafari, E. Tabrizi, E. B. Samani

Applications and Applied Mathematics: An International Journal (AAM)

This paper is concerned with the analysis of mixed data with ordinal and continuous outcomes with the possibility of non - ignorable missing outcomes . A copula-based regression model is proposed that accounts for associations between ordinal and continuous outcomes . Our approach entails specifying underlying latent variables for the mixed outcomes to indicate the latent mechanisms which generate the ordinal and continuous variables . Maximum likelihood estimation of our model parameters is implemented using standard software such as function nlminb in R . Results of simulations concern the relative biases of parameter estimates of joint and marginal models using …

Analysis Of Repairable M[X]/(G1,G2)/1 - Feedback Retrial G-Queue With Balking And Starting Failures Under At Most J Vacations, P. Rajadurai, M. C. Saravanarajan, V. M. Chandrasekaran

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we discuss the steady state analysis of a batch arrival feedback retrial queue with two types of services and negative customers. Any arriving batch of positive customers finds the server is free, one of the customers from the batch enters into the service area and the rest of them get into the orbit. The negative customer, is arriving during the service time of a positive customer, will remove the positive customer in-service and the interrupted positive customer either enters the orbit or leaves the system. If the orbit is empty at the service completion of each type …

A Hybrid Variational Iteration Method For Blasius Equation, M. Sajid, N. Ali, T. Javed

Applications and Applied Mathematics: An International Journal (AAM)

The objective of this paper is to present the hybrid variational iteration method. The proposed algorithm is based on the combination of variational iteration and shooting methods. In the proposed algorithm the entire domain is divided into subintervals to establish the accuracy and convergence of the approximate solution. It is found that in each subinterval a three term approximate solution using variational iteration method is sufficient. The proposed hybrid variational iteration method offers not only numerical values, but also closed form analytic solutions in each subinterval. The method is implemented using an example of the Blasius equation. The results show …

Implicit-Explicit Higher-Order Time Integration Schemes For Computations Of Structural Dynamics With Fluid-Structure Interaction, José C. Pedro, Mapundi K. Banda, Precious Sibanda

Applications and Applied Mathematics: An International Journal (AAM)

In this paper higher order implicit Runge-Kutta schemes are applied to fluid-structure interaction (FSI) simulations. A staggered approach with a structural predictor is applied to an FSI problem. The equations governing the dynamics of the structure are integrated in time by the Explicit Single Diagonal Implicit Runge-Kutta (ESDIRK) schemes and the arbitrary high order finite volume scheme is taken as the fluid solver. The performance of the ESDIRK scheme of order of convergence three to five is tested. Comparative studies with other time integration schemes which have been successfully applied to FSI problems are undertaken. Comparisons to test the performance …

On The Analytic Solution For The Steady Drainage Of Magnetohydrodynamic (Mhd) Sisko Fluid Film Down A Vertical Belt, A. M. Siddiqui, Hameed Ashraf, T. Haroon, A. Walait

Applications and Applied Mathematics: An International Journal (AAM)

This paper presents an analytic study for the steady drainage of magnetohydrodynamic (MHD) Sisko fluid film down a vertical belt. The fluid film is assumed to be electrically conducting in the presence of a uniform transverse magnetic field. An analytic solution for the resulting non linear ordinary differential equation is obtained using the Adomian decomposition method. The effects of various available parameters especially the Hartmann number are observed on the velocity profile, shear stress and vorticity vector to get a physical insight of the problem. Furthermore, the shear thinning and shear thickening characteristics of the Sisko fluid are discussed. The …

Testing Equality Of Locally Stationary Covariances With Application To Mortality Rate Modeling, Zahra Teimouri, Ali R. Taheriyoun

Applications and Applied Mathematics: An International Journal (AAM)

No abstract provided.

Free Convective Chemically Absorption Fluid Past An Impulsively Accelerated Plate With Thermal Radiation Variable Wall Temperature And Concentrations, Sanjib Sengupta

Applications and Applied Mathematics: An International Journal (AAM)

The present paper deals with the theoretical study of thermal radiation and chemical reaction on free convective heat and mass transfer flow of a Newtonian viscous incompressible fluid past a suddenly accelerated semi–infinite vertical permeable plate immersed in Darcian absorption media. The fluid media is considered as optically thick and the Rosselend radiative heat flux model is incorporated in the energy equation. The governing equation of motions are first non-dimensionalised and then transformed into a set of ordinary differential equations by employing a suitable periodic transformation. The closed form of the expression for velocity, temperature and concentration fields as well …

Controllability Of An Eco-Epidemiological System With Disease Transmission Delay: A Theoretical Study, Samadyuti Haldar, Kunal Chakraborty, T. K. Kar

Applications and Applied Mathematics: An International Journal (AAM)

This paper deals with the qualitative analysis of a disease transmission delay induced prey preda-tor system in which disease spreads among the predator species only. The growth of the preda-tors’ susceptible and infected subpopulations is assumed as modified Leslie–Gower type. Suffi-cient conditions for the persistence, permanence, existence and stability of equilibrium points are obtained. Global asymptotic stability of the system is investigated around the coexisting equilib-rium using a geometric approach. The existence of Hopf bifurcation phenomenon is also exam-ined with respect to some important parameters of the system. The criterion for disease a trans-mission delay the induced Hopf bifurcation phenomenon …

Suspension Model For Blood Flow Through A Tapering Catheterized Inclined Artery With Asymmetric Stenosis, Devajyoti Biswas, Moumita Paul

Applications and Applied Mathematics: An International Journal (AAM)

We intend to study a particle fluid suspension model for blood flow through an axially asymmetric but radially symmetric mild stenosis in the annular region of an inclined tapered artery and a co-axial catheter in a suitable flow geometry has been considered to investigate the influence of velocity slip at the stenotic wall as well as hematocrit, shape parameter. The model also includes the tapering effect and inclination of the artery. Expressions for the flow variables have been derived analytically and their variations with various flow parameters are represented graphically. The results for the different values of the parameters involved …

Optimal Solution Of A Fully Fuzzy Linear Fractional Programming Problem By Using Graded Mean Integration Representation Method, Moumita Deb, P. K. De

Applications and Applied Mathematics: An International Journal (AAM)

In the present paper, the study of fully fuzzy linear fractional programming problem (FFLFPP) using graded mean integration representation method is discussed where all the parameters and variables are characterized by trapezoidal fuzzy numbers. A computational algorithm has been presented to obtain an optimal solution by applying simplex method. To demonstrate the applicability of the proposed approach, one numerical example is solved. Also to check the efficiency and feasibility of the proposed approach, we compare the results of examples by applying crisp numbers, triangular fuzzy numbers and trapezoidal fuzzy numbers.

Sensitivity Analysis In Correlated Bivariate Continuous And Binary Responses, Zh. Thmasebinejad, E. Tabrizi

Applications and Applied Mathematics: An International Journal (AAM)

Factorization models for correlated binary and continuous responses are proposed. Full likelihood-based approach that yields maximum likelihood estimates of the model parameters is used. A common way to investigate if perturbations of model components influence key results of the analysis is to compare the results derived from the original and perturbed models using an influence graph. So small perturbation influence of the correlation parameters of the models on likelihood displacement and a general index of sensitivity (ISNI) are also studied. The model is illustrated using data from arthritis and body mass index data. The effect of systolic blood pressure, gender …

Outlier Detection And A Method Of Adjustment For The Iranian Manufacturing Establishment Survey Data, Zahra R. Ghahroodi, Taban Baghfalaki, Mojtaba Ganjali

Applications and Applied Mathematics: An International Journal (AAM)

The role and importance of the industrial sector in the economic development necessitate the need to collect and to analyze accurate and timely data for exact planning. As the occurrence of outliers in establishment surveys are common due to the structure of the economy, the evaluation of survey data by identifying and investigating outliers, prior to the release of data, is necessary. In this paper, different robust multivariate outlier detection methods based on the Mahalanobis distance with blocked adaptive computationally efficient outlier nominators algorithm, minimum volume ellipsoid estimator, minimum covariance determinant estimator and Stahel-Donoho estimator are used in the context …

Precise Mass And Radius Measurements For The Components Of The Bright Solar-Type Eclipsing Binary Star V1094 Tauri, P. F.L. Maxted, R. J. Hutcheon, G. Torres, C. H.S. Lacy, J. Southworth, B. Smalley, K. Pavlovski, Laurence A. Marschall, J. V. Clausen

Physics and Astronomy Faculty Publications

Context. V1094 Tau is a bright eclipsing binary star with an orbital period close to nine days that contains two stars similar to the Sun.

Aims. Our aim is to test models of Sun-like stars using precise and accurate mass and radius measurements for both stars in V1094 Tau.

Methods. We present new spectroscopy of V1094 Tau, which we use to estimate the effective temperatures of both stars and to refine their spectroscopic orbits. We also present new, high-quality photometry covering both eclipses of V1094 Tau in the Strömgren uvby system and in the Johnson V-band.

Results. The masses, …

Emergence Of Negative Index In A Lossy Chiral Metamaterial Under First-Order Material Dispersion, Monish Ranjan Chatterjee, Tarig A. Algadey

Electrical and Computer Engineering Faculty Publications

For a lossless dispersive chiral material, negative index (NIM) occurred only by use of parametric analysis (and not via practical models) to first-order. These findings are re-visited for the lossy problem and the results are compared.

An International Assessment Of Mangrove Management: Incorporation In Integrated Coastal Zone Management, Haille N. Carter, Steffen W. Schmidt, Amy Hirons

Marine & Environmental Sciences Faculty Articles

Due to increasing recognition of the benefits provided by mangrove ecosystems, protection policies have emerged under both wetland and forestry programs. However, little consistency remains among these programs and inadequate coordination exists among sectors of government. With approximately 123 countries containing mangroves, the need for global management of these ecosystems is crucial to sustain the industries (i.e., fisheries, timber, and tourism) and coastal communities that mangroves support and protect. To determine the most effective form of mangrove management, this review examines management guidelines, particularly those associated with Integrated Coastal Zone Management (ICZM). Five case studies were reviewed to further explore …

A Sluggs And Gemini/Gmos Combined Study Of The Elliptical Galaxy M60: Wide-Field Photometry And Kinematics Of The Globular Cluster System, Vincenzo Pota, Jean Brodie, Terry Bridges, Jay Strader, Aaron Romanowsky, Alexa Villaume, Zach Jennings, Favio Faifer, Nicola Pastorello, Duncan Forbes, Ainsley Campbell, Christopher Usher, Caroline Foster, Lee Spitler, Nelson Caldwell, Juan Forte, Mark Norris, Stephen Zepf, Michael Beasley, Karl Gebhardt, David Hanes, Ray Sharples, Jacob Arnold

Faculty Publications

We present new wide-field photometry and spectroscopy of the globular clusters (GCs) around NGC 4649 (M60), the third brightest galaxy in the Virgo cluster. Imaging of NGC 4649 was assembled from a recently obtained Hubble Space Telescope/Advanced Camera for Surveys mosaic, and new Subaru/Suprime-Cam and archival Canada–France–Hawaii Telescope/MegaCam data. About 1200 sources were followed up spectroscopically using combined observations from three multi-object spectrographs: Keck/Deep Imaging Multi-Object Spectrograph, Gemini/Gemini Multi-Object Spectrograph and Multiple Mirror Telescope/Hectospec. We confirm 431 unique GCs belonging to NGC 4649, a factor of 3.5 larger than previous data sets and with a factor of 3 improvement in …