Physical Sciences and Mathematics Commons^™

General Rotational Surfaces In The 4-Dimensional Minkowski Space, Georgi Ganchev, Velichka Milousheva

Turkish Journal of Mathematics

General rotational surfaces as a source of examples of surfaces in the 4-dimensional Euclidean space were introduced by C. Moore. In this paper we consider the analogue of these surfaces in the Minkowski 4-space. On the basis of our invariant theory of spacelike surfaces we study general rotational surfaces with special invariants. We describe analytically the flat general rotational surfaces and the general rotational surfaces with flat normal connection. We classify completely the minimal general rotational surfaces and the general rotational surfaces consisting of parabolic points.

A Characterization Of The Projective Transformation In Minkowski 3-Space, Yasemi̇n Alagöz

Turkish Journal of Mathematics

We consider transformations preserving asymptotic directions of surfaces in Minkowski 3-space and show that a transformation preserves the asymptotic directions of a surface if only if it is the projective one. Therefore, we obtain a characterization of the projective transformation.

The Property Of Real Hypersurfaces In 2-Dimensional Complex Space Form With Ricci Operator, Dong Ho Lim, Woon Ha Sohn, Seong Soo Ahn

Turkish Journal of Mathematics

Let M be a real hypersurface in a complex space form M_2(c), c \neq 0. In this paper, we prove that S \phi=\phi S on M if and only if M is pseudo-Einstein.

Population Dynamical Behaviors Of Stochastic Logistic System With Jumps, Ruihua Wu, Ke Wang

Turkish Journal of Mathematics

This paper is concerned with a stochastic logistic model driven by martingales with jumps. In the model, generalized noise and jump noise are taken into account. This model is new and more feasible. The explicit global positive solution of the system is presented, and then sufficient conditions for extinction and persistence are established. The critical value of extinction, nonpersistence in the mean, and weak persistence in the mean are obtained. The path-wise and moment properties are also investigated. Finally, some simulation figures are introduced to illustrate the main results.

On A Generalization Of Kelly's Combinatorial Lemma, Aymen Ben Amira, Jamel Dammak, Hamza Si Kaddour

Turkish Journal of Mathematics

Kelly's combinatorial lemma is a basic tool in the study of Ulam's reconstruction conjecture. A generalization in terms of a family of t -elements subsets of a v -element set was given by Pouzet. We consider a version of this generalization modulo a prime p. We give illustrations to graphs and tournaments.

Frobenius-Like Groups As Groups Of Automorphisms, Güli̇n Ercan, İsmai̇l Şuayi̇p Güloğlu, Evgeny Khukhro

Turkish Journal of Mathematics

A finite group FH is said to be Frobenius-like if it has a nontrivial nilpotent normal subgroup F with a nontrivial complement H such that FH/[F,F] is a Frobenius group with Frobenius kernel F/[F,F]. Such subgroups and sections are abundant in any nonnilpotent finite group. We discuss several recent results about the properties of a finite group G admitting a Frobenius-like group of automorphisms FH aiming at restrictions on G in terms of C_G(H) and focusing mainly on bounds for the Fitting height and related parameters. Earlier such results were obtained for Frobenius groups of automorphisms; new theorems for Frobenius-like …

Hilbert Series Of The Braid Monoid Mb_4 In Band Generators, Zaffar Iqbal, Shamaila Yousaf

Turkish Journal of Mathematics

L. A. Bokut gave a Gröbner--Shirshov basis of the braid group B_n in band generators. Using this presentation and solving all the ambiguities we construct a linear system for irreducible words and compute the Hilbert series of the braid monoid MB_4.

A Cohen Type Inequality For Laguerre--Sobolev Expansions With A Mass Point Outside Their Oscillatory Regime, Edmundo José Huertas Cejudo, Francisco Marcellán Espanol, María Francisca Pérez Valero, Yamilet Quintana

Turkish Journal of Mathematics

Let consider the Sobolev type inner product \langle f, g\rangle_S = \int_0^{\infty} f(x)g(x)d \mu (x) + Mf(c)g(c) + Nf^{\prime}(c) g^{\prime}(c), where d\mu (x) = x^{\alpha} e^{-x}dx, \alpha > -1, is the Laguerre measure, c < 0, and M, N \geq 0. In this paper we get a Cohen-type inequality for Fourier expansions in terms of the orthonormal polynomials associated with the above Sobolev inner product. Then, as an immediate consequence, we deduce the divergence of Fourier expansions and Cesàro means of order \delta in terms of this kind of Laguerre--Sobolev polynomials.

Pseudosymmetric Lightlike Hypersurfaces, Sema Kazan, Bayram Şahi̇n

Turkish Journal of Mathematics

We study lightlike hypersurfaces of a semi-Riemannian manifold satisfying pseudosymmetry conditions. We give sufficient conditions for a lightlike hypersurface to be pseudosymmetric and show that there is a close relationship of the pseudosymmetry condition of a lightlike hypersurface and its integrable screen distribution. We obtain that a pseudosymmetric lightlike hypersurface is a semisymmetric lightlike hypersurface or totally geodesic under certain conditions. Moreover, we give an example of pseudosymmetric lightlike hypersurfaces and investigate pseudoparallel lightlike hypersurfaces. Furthermore, we introduce Ricci-pseudosymmetric lightlike hypersurfaces, obtain characterizations, and give an example for such hypersurfaces.

On The Equivariant Cohomology Algebra For Solenoidal Actions, Ali̇ Arslan Özkurt

Turkish Journal of Mathematics

We prove, under certain conditions, that if a solenoidal group (i.e. 1-dimensional compact connected abelian group) acts effectively on a compact space then the fixed point set is nonempty and H_G^*(X,Q) has a presentation similar to the presentation of H^*(X,Q) as proven by Chang in the case of a circle group.

Functionals Of Gasser--Muller Estimators, Petre Babilua, Elizbar Nadaraya, Grigol Sokhadze

Turkish Journal of Mathematics

The asymptotic properties of a general functional of the Gasser--Muller estimator are investigated in the Sobolev space. The convergence rate, consistency, and central limit theorem are established.

Shear-Wave Splitting And Mantle Deformation Beneath The Western Tibetan Plateau, Melissa Ann Ray

Masters Theses

"The Tibetan Plateau has been an enigma to the scientific community since scientists first began to focus their attention on the area. Numerous studies over the decades were conducted to address how the plateau formed, mostly in the central and eastern portions of the Tibetan Plateau. Many questions still remain regarding the western Tibetan Plateau, and this study will add constraints to the mechanisms which regulated the formation of the plateau.

Data was acquired from over 13,000 measurements from 172 stations covering the western region of the plateau encompassing the Qiangtang Terrane, the Lhasa Terrane, and the Himalayan Orogenic Zone. …

Greendss Tool For Data Center Management, Michael Pawlish, Aparna Varde, Stefan Robila, Cynthia Alvarez, Christopher Fleischl, Genesis Serviano

Department of Computer Science Faculty Scholarship and Creative Works

As society shifts towards the Internet to conduct a greater share of communications and commerce, the demand for storage and processing of information is increasing. This is represented by the growth in data centers and energy usage. Traditionally, energy usage with respect to the greening of data centers has been a secondary concern. However, with the escalating total cost of ownership, and the ability to use smart meters this has become more important to monitor for increased savings. This paper describes the research conducted leading to the development of a software tool called GreenDSS (Decision Support System for Green Data …

Elemental Chemostratigraphy Of The Three Forks Formation, Williston Basin, North Dakota, Brian R. Murphy

Theses and Dissertations

The Three Forks Formation of the Williston Basin in northwestern North Dakota is an Upper Devonian stratigraphic unit unconformably overlain by the Bakken Formation. It consists principally of dolostone, shale and anhydrite. The Three Forks is a productive tight oil resource play, which in recent years has been increasingly targeted and developed as part of the unconventional Bakken Petroleum System. Core analysis via energy dispersive x-ray fluorescence (ED-XRF) is a non-destructive, high-resolution chemostratigraphic data collection method that has been used here to produce concentration logs which reflect both lithologic heterogeneity and paleoredox conditions for the Three Forks Formation. These geochemical …

Complexity Of The Soundness Problem Of Workflow Nets, Guan Jun Liu, Jun Sun, Yang Liu, Jin Song Dong

Research Collection School Of Computing and Information Systems

Classical workflow nets (WF-nets for short) are an important subclass of Petri nets that are widely used to model and analyze workflow systems. Soundness is a crucial property of workflow systems and guarantees that these systems are deadlock-free and bounded. Aalst et al. proved that the soundness problem is decidable for WF-nets and can be polynomially solvable for free-choice WF-nets. This paper proves that the soundness problem is PSPACE-hard for WF-nets. Furthermore, it is proven that the soundness problem is PSPACE-complete for bounded WF-nets. Based on the above conclusion, it is derived that the soundness problem is also PSPACE-complete for …

Mining Weakly Labeled Web Facial Images For Search-Based Face Annotation, Dayong Wang, Steven C. H. Hoi, Ying He, Jianke Zhu

Research Collection School Of Computing and Information Systems

This paper investigates a framework of search-based face annotation (SBFA) by mining weakly labeled facial images that are freely available on the World Wide Web (WWW). One challenging problem for search-based face annotation scheme is how to effectively perform annotation by exploiting the list of most similar facial images and their weak labels that are often noisy and incomplete. To tackle this problem, we propose an effective unsupervised label refinement (ULR) approach for refining the labels of web facial images using machine learning techniques. We formulate the learning problem as a convex optimization and develop effective optimization algorithms to solve …

Further Characterization Of A Secreted Lipase From The Human Pathogen Leishmania Donovani By Determining The Effect Of Various Metal Ions On Its Enzymatic Activity., Lana Hoertz

Pell Scholars and Senior Theses

Leishmania donovani, a protozoan parasite, is the causative agent of the often fatal disease visceral leishmaniasis. The current treatments available are minimal and toxic to the patient. It has been shown that these organisms exhibit lipolytic activity during their growth in vitro. Lipases are enzymes that are known to aid in the development and virulence of several pathogenic organisms such as Candida albicans and Staphylococcus warneri. Little information is known, however, about the role of lipases in Leishmania species. We hypothesize that lipase may play a part in Leishmania's ability to survive within the human host as well as its …

Loki: A Privacy-Conscious Platform For Crowdsourced Surveys, Thivya Kandappu, Vijay Sivaraman, Arik Friedman, Roksana Boreli

Research Collection School Of Computing and Information Systems

Emerging platforms such as Amazon Mechanical Turk and Google Consumer Surveys are increasingly being used by researchers and market analysts to crowdsource large-scale survey data from on-line populations at extremely low-cost. However, by participating in successive surveys, users risk being profiled and targeted, both by surveyors and by the platform itself. In this paper we propose, develop, and evaluate the design of a crowdsourcing platform, called Loki, that is privacy conscious. Our contributions are three-fold: (a) We propose Loki, a system that allows users to obfuscate their (ratings-based or multiple-choice) responses at-source based on their chosen privacy level, and gives …

Sea-Ice Melt Co2-Carbonate Chemistry In The Western Arctic Ocean: Meltwater Contributions To Air-Sea Co2 Gas Exchange, Mixed-Layer Properties And Rates Of Net Community Production Under Sea Ice, N. R. Bates, R. Garley, K. E. Frey, K. L. Shake, J. T. Mathis

Geography

The carbon dioxide (CO2)-carbonate chemistry of sea-ice melt and co-located, contemporaneous seawater has rarely been studied in sea-ice-covered oceans. Here, we describe the CO2-carbonate chemistry of sea-ice melt (both above sea-ice as "melt ponds" and below sea-ice as "interface waters") and mixed-layer properties in the western Arctic Ocean in the early summer of 2010 and 2011. At 19 stations, the salinity (∼0.5 to <6.5), dissolved inorganic carbon (DIC; ∼20 to <550 μmol kg-1) and total alkalinity (TA; ∼30 to <500 μmol kg-1) of above-ice melt pond water was low compared to the co-located underlying mixed layer. The partial pressure of CO2 (pCO2) in these melt ponds was highly variable (∼<10 to >1500 μatm) with the majority of melt ponds acting as potentially strong sources of CO2 to the atmosphere. The pH of melt pond waters was also highly variable ranging from mildly acidic (6.1 to 7) to slightly …

Random Forests Based Rule Learning And Feature Elimination, Sheng Liu

Electronic Theses and Dissertations

Much research combines data from multiple sources in an effort to understand the underlying problems. It is important to find and interpret the most important information from these sources. Thus it will be beneficial to have an effective algorithm that can simultaneously extract decision rules and select critical features for good interpretation while preserving the prediction performance. We propose an efficient approach, combining rule extraction and feature elimination, based on 1-norm regularized random forests. This approach simultaneously extracts a small number of rules generated by random forests and selects important features. To evaluate this approach, we have applied it to …

Using User Saliency For Effective Oled Display Power Management, Kiat Wee Tan

Dissertations and Theses Collection (Open Access)

The display component on mobile device has always been a main power drain compared to networking and processing components. Even with advancement in display technology such as Organic Light Emitting Diodes (OLED) displays to help reduce this cost, the increasing display size and new mobile usage paradigm (App stores and Social networking), the display still remains as the largest power drain component. In this thesis, we describe an approach to reduce power consumption on OLED display by dimming areas of the screen that the user might not be interested in. We determine these uninteresting areas by reviewing large number applications …

On The Maximum Leaf Number Of A Family Of Circulant Graphs, Felix P. Muga Ii

Mathematics Faculty Publications

This paper determines the maximum leaf number and the connected domination number of some undirected and connected circulant networks which are optimal among all the maximum leaf numbers and connected domination numbers of circulant networks of the same order n and the same degree 2k. We shall tackle this problem by working on the largest possible number of vertices between two consecutive jump sizes.

The Impact Of Multiple Nursery Areas On The Population Structure Of Atlantic Menhaden, Brevooria Tyrannus, Kristen A. Anstead

OES Theses and Dissertations

Understanding the population structure and patterns of connectivity in marine fishes is essential when making predictions about a species' resiliency and persistence in an increasingly changing environment. The Atlantic Menhaden Brevoortia tyrannus is a clupeid that plays a critical role in the marine food web and supports one of the largest fisheries on the US East Coast. In addition to a decrease in overall numbers and spawning stock biomass, recruitment levels have remained low since the 1990s. Menhaden use numerous estuaries along the Atlantic coast for juvenile development before recruiting to the adult population and the contribution of each of …

Assessing Resilience In Stressed Watersheds, Kristine T. Nemec, Joana Chan, Christina Hoffman, Trisha L. Spanbauer, Joseph A. Hamm, Craig R. Allen, Trevor Hefley, Donald Pan, Prabhakar Shrestha

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Although several frameworks for assessing the resilience of social-ecological systems (SESs) have been developed, some practitioners may not have sufficient time and information to conduct extensive resilience assessments. We have presented a simplified approach to resilience assessment that reviews the scientific, historical, and social literature to rate the resilience of an SES with respect to nine resilience properties: ecological variability, diversity, modularity, acknowledgement of slow variables, tight feedbacks, social capital, innovation, overlap in governance, and ecosystem services. We evaluated the effects of two large-scale projects, the construction of a major dam and the implementation of an ecosystem recovery program, on …

Bright Microwave Pulses From Psr B0531+21 Observed With A Prototype Transient Survey Receiver, J. A. O'Dea, F. A. Jenet, Tsan Huei Cheng, Chau M. Buu, Martin Beroiz, Sami W. Asmar, J. W. Armstrong

Physics and Astronomy Faculty Publications and Presentations

Recent discoveries of transient radio events have renewed interest in time-variable astrophysical phenomena. Many radio transient events are rare, requiring long observing times for reliable statistical study. The National Aeronautics and Space Administration/Jet Propulsion Laboratory's Deep Space Network (DSN) tracks spacecraft nearly continuously with 13 large-aperture, low system temperature radio antennas. During normal spacecraft operations, the DSN processes only a small fraction of the pre-detection bandwidth available from these antennas; any information in the remaining bandwidth, e.g., from an astronomical source in the same antenna beam as the spacecraft, is currently ignored. As a firmware modification to the standard DSN …

Search For Gravitational Radiation From Intermediate Mass Black Hole Binaries In Data From The Second Ligo-Virgo Joint Science Run, J. Aasi, B. P. Abbott, H. Daveloza, S. R. Morriss, Soma Mukherjee, M. E. Normandin, O. Puncken, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, Robert Stone, Cristina V. Torres, G. Valdes

Physics and Astronomy Faculty Publications and Presentations

This paper reports on an unmodeled, all-sky search for gravitational waves from merging intermediate mass black hole binaries (IMBHB). The search was performed on data from the second joint science run of the LIGO and Virgo detectors (July 2009–October 2010) and was sensitive to IMBHBs with a range up to ∼200 Mpc, averaged over the possible sky positions and inclinations of the binaries with respect to the line of sight. No significant candidate was found. Upper limits on the coalescence-rate density of nonspinning IMBHBs with total masses between 100 and 450 M⊙ and mass ratios between 0.25 and 1 were …

Unidirectional Lasing Emerging From Frozen Light In Nonreciprocal Cavities, Hamidreza Ramezani, S. Kalish, I. Vitebskiy, T. Kottos

Physics and Astronomy Faculty Publications and Presentations

We introduce a class of unidirectional lasing modes associated with the frozen mode regime of nonreciprocal slow-wave structures. Such asymmetric modes can only exist in cavities with broken timereversal and space inversion symmetries. Their lasing frequency coincides with a spectral stationary inflection point of the underlying passive structure and is virtually independent of its size. These unidirectional lasers can be indispensable components of photonic integrated circuitry.

Dynamical Models Of Elliptical Galaxies – Ii. M87 And Its Globular Clusters, A. Angello, N. Evans, Aaron Romanowsky, J. Brodie

Faculty Research, Scholarly, and Creative Activity

We study the Globular Cluster (GC) system of the nearby elliptical galaxy M87 using the newly available dataset with accurate kinematics (Strader et al.2011). We find evidence for three distinct sub-populations of GCs in terms of colours, kinematics and radial profiles. We show that a decomposition into three populations (blue, intermediate and red GCs) is statistically preferred to one with two or four populations, and relate them to the stellar profile. We exploit the sub-populations to derive dynamical constraints on the mass and Dark Matter (DM) content of M87 out to ∼100 kpc. We use a class of global mass-estimators …

Enhancing Understanding Of Discrete Event Simulation Models Through Analysis, Kara Ann Olson

Computer Science Theses & Dissertations

Simulation is used increasingly throughout research, development, and planning for many purposes. While model output is often the primary interest, insights gained through the simulation process can also be valuable. Insights can come from building and validating the model as well as analyzing its behaviors and output; however, much that could be informative may not be easily discernible through these existing traditional approaches, particularly as models continue to increase in complexity.

This research extends current work in model analysis and program understanding to assist modelers in obtaining more insight into their models and the systems they represent. A primary technique …

Biosensors And Nanobiosensors: Design And Applications, Ahmed Touhami

Physics and Astronomy Faculty Publications and Presentations

The goal of this chapter is to cover the full scope of biosensors. It offers a survey of the principles, design, operation, and biomedical applications of the most popular types of biosensing devices in use today. By discussing recent research and future trends based on many excellent books and reviews, it is hoped to give the readers a comprehensive view on this fast growing field.