Physical Sciences and Mathematics Commons^™

Patterns As Objects In Grace, Andrew P. Black, Michael Homer, James Noble, David J. Pearce, Kim B. Bruce

Computer Science Faculty Publications and Presentations

Object orientation and pattern matching are often seen as conflicting approaches to program design. Object oriented programs place type-dependent behaviour inside objects and invoke it via dynamic dispatch, while pattern matching programs place type-dependent behaviour outside data structures and invoke it via multiway conditionals (case statements). Grace is a new, dynamic, object-oriented language designed to support teaching: to this end, Grace needs to support both styles. In this paper we explain how this conflict can be resolved gracefully: by modelling patterns and cases as partial functions, reifying those functions as first-class objects, and then building up complex patterns from simpler …

Characterisation Of Glasgow/Cnm Double-Sided 3d Sensors., Aaron Mac Raighne, K. Akiba, K. Balbuena, R. Bates, M. Van Beuzekom, J. Buytaert, P. Collins, M. Crossley, R. Dumps, L. Eklund, C. Fleta, A. Gallas, M. Gersabeck, V.V. Gligorov, M. John, M. Kohler, M. Lozano, D. Maneuski, G. Stewart

Conference papers

3D detectors are proposed as an alternative to planar silicon technology to withstand the high radiation environments in planned future high energy physics experiments. Here we review the characterization of double-sided 3D detectors designed and built at CNM and the University of Glasgow. A non-irradiated sensor is characterized in a pion test-beamutilizing the Timepix telescope. The charge collection and detection efficiency across the unit pixel are shown. Area of inefficiency can be found at the columnar electrodes at perpendicular angles of beam incidence while the pixels are shown to be fully efficient at angles greater than ten degrees. A reduction …

Donor-Sigma-Acceptor (D-Sigma-A) Molecules With Perylenebisimide Acceptors Having Alkyl Or Peg Swallowtails With Sulfur Or Hydroxyl Anchors: Synthesis And Applications In Langmuir-Blodgett Films, Single Molecule Spectroscopy (Sms), G-Quadruplex Studies And Passivation Of Gold Nanoparticles, Rajesh Kota

Electronic Theses and Dissertations

Use of single molecules as electronic devices is presently considered a potential alternative to semiconductor-based nanoscale electronics. The ability to study a single molecule or a small group of molecules provides a great opportunity to build electronic devices at the molecular level. It is vital to understand the parameters that control the device properties such as molecular structure, conformation and arrangement at the surface. Ari Aviram and Mark A. Ratner proposed the construction of a single organic molecule as an organic rectifier. Donor-Sigma-Acceptor (D-?-A ) molecules, when arranged with a proper orientation as Langmuir-Blodgett (LB) films and fixed between two …

Stochastic Models For Evolutionary Genetic Problems, Wei Liao

Electronic Theses and Dissertations

Two stochastic models are designed for answering evolutionary genetic problems. The first study shows that inbreeding-environment interactions increase extinction risk. The second research demonstrates that 1) the carrying capacity and initial population growth rate is critical to determine the population persistence time; 2) increasing the advantageous mutation rate reduces the extinction risk although its effects are usually shadoby population size and fitness; 3) the new mutation correlation among environments rises during the evolution process, but it has compromised effects on population fate. Being able to accurately estimate the persistence time of populations of endangered plants and animals is central to …

Electrochemistry, Transport Properties And Electronic Spectroscopy Of Lanthanide Solutes In Bis(Trifluoromethylsulfonyl)Imide-Based Ionic Liquids, Yunfeng Pan

Electronic Theses and Dissertations

No abstract provided.

Challenging The “Man” In Mangroves: The Missing Role Of Women In Mangrove Conservation, Alyssa L. Bosold

Student Publications

Mangroves provide valuable ecosystem services including carbon sequestration, pollution filtration, and protection from tsunamis, tropical storms, and coastal erosion. They also supply coastal communities with important natural resources like firewood, medicine, timber, honey, and fodder for livestock. Unfortunately, the world’s mangroves are rapidly degrading due to rising coastal population, climate change, and destruction for coastal development, agriculture, and aquaculture. Considering their value for the environment and coastal communities, mangrove conservation should become a priority and effort must be invested to find new and successful methods for conserving mangrove ecosystems. As it has proven effective in other conservation contexts, a gendered …

Heat Equation, Wyatt Sherlock

A with Honors Projects

This document describes the process of deriving the heat equation from known thermodynamic laws followed by an analytic solution. Towards the end of the document, the heat equation is discussed in terms of practical engineering problems.

Environmentalism/Postmodernism, Toby Ogunniya

A with Honors Projects

This presentation explores the meaning of environmentalism and postmodernism in a political science context.

Shoreline Evolution: Prince William County, Virginia Potomac River, Occoquan Bay, And Occoquan River Shorelines, Donna A. Milligan, Christine Wilcox, C. Scott Hardaway Jr., Mary C. Cox

Reports

Prince William County is situated along the Potomac River (Figure 1). Through time, the County’s shoreline has evolved, and determining the rates and patterns of shore change provides the basis to know how a particular coast has changed through time and how it might proceed in the future. Along Chesapeake Bay’s estuarine shores, winds, waves, tides and currents shape and modify coastlines by eroding, transporting and depositing sediments.

The purpose of this report is to document how the shore zone of Prince William County has evolved since 1937. Aerial imagery was taken for most of the Bay region beginning that …

2012 Henrico County, Virginia Shoreline Inventory Report Methods And Guidelines, Marcia Berman, Harry Berquist, Sharon Killeen, Carl Hershner, Karinna Nunez, Karen Reay, Tamia Rudnicky, Daniel E. Schatt

Reports

The data inventory developed for the Shoreline Inventory is based on a three tiered shoreline assessment approach. In most cases this assessment characterizes conditions that can be observed from a small boat navigating along the shoreline. The three tiered shoreline assessment approach divides the shorezone into three regions:

1 ) the immediate riparian zone, evaluated for land use; 2 ) the bank, evaluated for height, stability, cover and natural protection; and 3 ) the shoreline, describing the presence of shoreline structures for shore protection and recreational purposes. GPS registered videography was used to collect data on conditions observed in the …

Preface: Trends In Natural And Machine Intelligence, Jonathan H. Chan, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Trends in natural and machine intelligence are increasingly reflecting a convergence in these two well-established fields of study. The Third International Neural Network Society Winter Conference (INNS-WC 2012) was held in Bangkok, Thailand, on October 3-5, 2012. INNS-WC2012, with an aim to bring together scientists, practitioners, and students worldwide, to discuss the past, present, and future challenges and trends in the area of natural and machine intelligence. This event has been a bi-annual conference of the International Neural Network Society (INNS) to provide a forum for international researchers to exchange latest ideas and advances on neural networks and related discipline.

New Change Impact Factor Estimation In Software Development, Murat Kahraman Güngör, Ersi̇n Elbaşi, James Walter Fawcett

Turkish Journal of Electrical Engineering and Computer Sciences

Change in software is always an essential part of software development and maintenance. Estimating a proposed change's effect on the later phases of the development helps project managers and developers with decision-making and predicting future progress. During development, on some occasions, speedy solutions are necessary to meet project schedules. Such quick changes may lead to major quality flaws in the long term, even though they solve local problems in the short term. Controlled management of change is achieved by being able to estimate the impact of changes. In this paper, we propose a new change impact factor estimation and present …

Action-Reaction Based Parameters Identification And States Estimation Of Flexible Systems, Islam Shoukry, Emrah Deni̇z Kunt, Asif Sabanovic

Turkish Journal of Electrical Engineering and Computer Sciences

This work attempts to identify and estimate flexible system's parameters and states by a simple utilization of the Action-Reaction law of dynamical systems. Attached actuator to a dynamical system or environmental interaction imposes an action that is instantaneously followed by a dynamical system reaction. The dynamical system's reaction carries full information about the dynamical system including system parameters, dynamics and externally applied forces that arise due to system interaction with the environment. This in turn implies that the dynamical system's reaction can be considered as a natural feedback as it carries full coupled information about the dynamical system. The idea …

Ttradeoff Tables For Compression Functions: How To Invert Hash Values Radeoff Tables For Compression Functions: How To Invert Hash Values, Orhun Kara, Adem Atalay

Turkish Journal of Electrical Engineering and Computer Sciences

Hash functions are one of the ubiquitous cryptographic functions used widely for various applications such as digital signatures, data integrity, authentication protocols, MAC algorithms, RNGs, etc. Hash functions are supposed to be one-way, i.e., preimage resistant. One interesting property of hash functions is that they process arbitrary-length messages into fixed-length outputs. In general, this can be achieved mostly by applying compression functions onto the message blocks of fixed length, recursively. The length of the message is incorporated as padding in the last block prior to the hash, a procedure called the Merkle-Damgard strengthening. In this paper, we introduce a new …

Reducing Electromagnetic Interferences In Flyback Ac-Dc Converters Based On The Frequency Modulation Technique, Gökhan Çabuk, Selçuk Kilinç

Turkish Journal of Electrical Engineering and Computer Sciences

One of the most preferable types of switched-mode power supplies (SMPS) is the flyback converter, due to its wide range of application areas. Properties such as low cost, provision of multiple output voltage terminals, and higher efficiencies make it important, and hence its usage in technologies including cell phone chargers, personal computers, set-top boxes, and televisions is increasing. Special attention should be paid to the design of this type of converter due to its working principles and electromagnetic interference (EMI) performance. Rapid switching of high current and high voltage during the operation of SMPS causes an EMI problem. The level …

A Robust Adaptive Fuzzy Control Of A Unified Power Flow Controller, Sebaa Morsli, Allaoui Tayeb, Denai Mouloud, Chaker Abdelkader

Turkish Journal of Electrical Engineering and Computer Sciences

This paper investigates the control of a unified power flow controller (UPFC) to improve the stability of a power system, hence providing security under increased power flow conditions. The proposed control methods include a direct proportional and integral (PI) controller and an adaptive fuzzy logic controller (AFLC). The performances of these controllers were evaluated under different operating conditions of the power system and the results demonstrated that PI and AFLC are very effective in improving the transient power system stability and very robust against variable transmission line parameters.

Lyapunov's Direct Method For Stabilization Of The Furuta Pendulum, Türker Türker, Haluk Görgün, Gali̇p Cansever

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a novel stabilization result for the Furuta pendulum for a large region of attraction including almost all of the upper half plane. The solution is obtained via constructing a Lyapunov function after set of coordinate changes. Then, a set of differential equations are solved to achieve asymptotic stability which is proved in accordance with La Salle's invariance principle. The effectiveness of the proposed stabilization method is illustrated with simulation studies.

Energy Savings In Simultaneous Multi-Threaded Processors Through Dynamic Resizing Of Datapath Resources, Gürhan Küçük, Mi̇ne Mesta

Turkish Journal of Electrical Engineering and Computer Sciences

Nowadays, all the designers of systems from high-performance servers to battery-operated handheld devices aim for reliability, high-performance and longevity. Central within these aims the issue of processor power consumption is becoming increasingly important. In this study, we aim to adapt our already-proven method for single-threaded superscalar processors to simultaneous multi-threaded (SMT) processors for energy savings. The original method focused on resizing datapath resources according to the demands of running applications. To achieve this, the targeted resources are physically divided into multiple partitions, and turned on and off according to the needs of the applications. Since, the energy consumption of the …

An Improved Distributed Power-Control Scheme For Cellular Mobile Systems, Hamid Farrokhi, Mostafa Rezayi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new distributed power-control (DPC) scheme is suggested to improve convergence speed and system robustness against carrier-to-interference-ratio (CIR) estimation errors. To expedite the CIR balancing in our DPC scheme, an instability detection rule was used. As compared with Foschini's DPC (FDPC) method, numerical results indicated that the proposed algorithm achieves performance improvements in terms of outage probability as well as in the algorithm's convergence speed. More specifically, by appropriate selection of some parameters, the algorithm speed reduces from about 90 iterations in FDPC to 9 iterations in the proposed algorithm. The system robustness against CIR estimation errors …

Tunable Srr-Based Substrate For A Microstrip Patch Antenna, Adnan Sondaş, Mustafa Hi̇kmet Bi̇lgehan Uçar, Yunus Emre Erdemli̇

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a microstrip patch antenna over an artificial substrate composed of split-ring resonator (SRR) elements is introduced. As the SRR-based substrate provides miniaturization for the patch, metallic loadings placed between the rings of the SRR elements offer frequency-tuning capability. Practical switch models are employed in lieu of those loadings to demonstrate dynamic control of the operational frequency. The full-wave analysis and design of the proposed tunable patch were carried out using CST Microwave Studio, and the cross-comparisons were provided via Ansoft HFSS. Preliminary measurements are also presented, demonstrating the prospective performance of the proposed design.

Fuzzy Logic Control For A Wind/Battery Renewable Energy Production System, Onur Özdal Mengi̇, İsmai̇l Hakki Altaş

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a designed proportional-integral (PI) controller and a fuzzy logic controller (FLC) that fix the voltage amplitude to a constant value of 380 V and 50 Hz for loads supplied from a wind/battery hybrid energy system are explained and compared. The quality of the power produced by the wind turbine is affected by the continuous and unpredictable variations of the wind speed. Therefore, voltage-stabilizing controllers must be integrated into the system in order to keep the voltage magnitude and frequency constant at the load terminals, which requires constant voltage and frequency. A fuzzy logic-based controller to be used …

Discrete Particle Swarm Optimization For The Team Orienteering Problem, Ai̇şe Zülal Şevkli̇, Fati̇h Erdoğan Sevi̇lgen

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel discrete particle swarm optimization (PSO) algorithm is proposed to solve the team orienteering problem (TOP). Discrete evaluation is achieved by redefining all operators and operands used in PSO. To obtain better results, a strengthened PSO, which improves both exploration and exploitation during the search process, is employed. Our algorithm achieves the best known solutions in a short time compared to previous heuristics for the TOP.

A Modified Particle Swarm Optimization Algorithm And Its Application To The Multiobjective Fet Modeling Problem, Ufuk Özkaya, Fi̇li̇z Güneş

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a modified particle swarm algorithm to handle multiobjective optimization problems. In multiobjective PSO algorithms, the determination of Pareto optimal solutions depends directly on the strategy of assigning a best local guide to each particle. In this work, the PSO algorithm is modified to assign a best local guide to each particle by using minimum angular distance information. This algorithm is implemented to determine field-effect transistor (FET) model elements subject to the Pareto domination between the scattering parameters and operation bandwidth. Furthermore, the results are compared with those obtained by the nondominated sorting genetic algorithm-II. FET models are …

Performance Comparison Of New Nonparametric Independent Component Analysis Algorithm For Different Entropic Indexes, Yusuf Sevi̇m, Ayten Atasoy

Turkish Journal of Electrical Engineering and Computer Sciences

Most independent component analysis (ICA) algorithms use mutual information (MI) measures based on Shannon entropy as a cost function, but Shannon entropy is not the only measure in the literature. In this paper, instead of Shannon entropy, Tsallis entropy is used and a novel ICA algorithm, which uses kernel density estimation (KDE) for estimation of source distributions, is proposed. KDE is directly evaluated from the original data samples, so it solves the important problem in ICA: how to choose nonlinear functions as the probability density function (pdf) estimation of the sources.

Performance Analysis Of Wind Turbine-Driven Permanent Magnet Generator With Matrix Converter, Ramasamy Bharanikumar, A Nirmal Kumar

Turkish Journal of Electrical Engineering and Computer Sciences

Wind energy, among all of the renewable energy sources, has made rapid developments and significant inroads in electrical power systems. With the increased use of wind energy conversion systems (WECSs), several technologies have been developed. Since WECSs are more cost competitive, the comparison of different wind generator systems is the need of the hour. Permanent magnet generators employing these technologies have some significant advantages over conventional generators, such as no need of excitation, low volume and weight, high precision, and deletion of the gearbox. A variable-speed WECS with a permanent magnet generator and a matrix converter is proposed in this …

Economic Analysis Of A Wind-Battery Hybrid System: An Application For A House In Gebze, Turkey, With Moderate Wind Energy Potential, Bahti̇yar Dursun, Ci̇han Gökçöl

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the energy demand of a house in Gebze, Turkey, is met by using wind energy as a primary energy source combined with rechargeable batteries. The wind-battery system is simulated by MATLAB while considering that energy continuity is maintained by using a sufficient number of batteries. A life-cycle cost analysis is carried out over a 20-year system lifetime because the operating time of the hybrid system is subject to the turbine life, usually assumed to be 20 years. The wind turbine generators considered are of various nominal powers, ranging from 0.6 to 450 kW. For each wind turbine, …

Short-Term Wind Speed Estimation Based On Weather Data, Okan Özgönenel, David W.P. Thomas

Turkish Journal of Electrical Engineering and Computer Sciences

For accurate and efficient use of wind power, it is important to know the statistical characteristics, availability, diurnal variation, and prediction of wind speed. Prediction of wind power permits the scheduling of the connection or the disconnection of wind turbines to achieve optimal operating costs. In this paper, a simple and accurate method for predicting wind speed based on weather-sensitive data is presented. The proposed wind speed prediction system is cost-effective and only needs wind speed data at 40 m and weather data to forecast wind speeds at 50 m and 60 m for the current and next months. Hellman …

Compact Dual-Band Split-Ring Antenna For 2.4/5.2 Ghz Wlan Applications, Siddik Cumhur Başaran

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a compact dual-band printed antenna for 2.4/5.2 GHz WLAN applications. The radiating elements of the proposed antenna are composed of rectangular split-ring elements and metallic loadings placed appropriately between the rings. The antenna size is very compact (22 \times 26 \times 1.6 mm), and it can be integrated easily with other RF front-end circuits. It is demonstrated that the proposed antenna can completely cover the required bandwidths of IEEE 802.11b (2.4-2.484 GHz) and IEEE 802.11a (5.15-5.35 GHz) with satisfactory radiation characteristics. Analysis and design of the proposed antenna was carried out with the Ansoft highfrequency structure simulator. …

Multiobjective Fet Modeling Using Particle Swarm Optimization Based On Scattering Parameters With Pareto Optimal Analysis, Fi̇li̇z Güneş, Ufuk Özkaya

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, design-oriented field effect transistor (FET) models are produced. For this purpose, FET modeling is put forward as a constrained, multiobjective optimization problem. Two novel methods for multiobjective optimization are employed: particle swarm optimization (PSO) uses the single-objective function, which gathers all of the objectives as aggregating functions; and the nondominated sorting genetic algorithm-II (NSGA-II) sorts all of the trade-off solutions on the Pareto frontiers. The PSO solution is compared with the Pareto optimum solutions in the biobjective plane and the success of the first method is verified. Furthermore, the resulting FET models are compared with similar FET …

A Procedure To Specify The Weighting Matrices For An Optimal Load-Frequency Controller, Silvio José Pinto Simões Mariano, Jose Álvaro Nunes Pombo, Maria Do Rosário Alves Calado, Luis António Fialho Marcelino Ferreira

Turkish Journal of Electrical Engineering and Computer Sciences

The linear quadratic optimal regulator is one of the most powerful techniques for designing multivariable control systems. The performance of the system is specified in terms of a cost, which is the integral of a weighted quadratic function of the system state and control inputs, that is to be minimized by the optimal controller. The components of the state cost weighting matrix, Q, and the control cost weighting matrix, R, are ours to choose in mathematically specifying the way we wish the system to perform. Changing these matrices, we can modify the transient behavior of the closed-loop system. This paper …