Digital Commons Network^™

Open Educational Resources: Policy, Costs And Transformation, Fengchun Miao, Sanjaya Mishra, Rory Mcgreal

Copyright, Fair Use, Scholarly Communication, etc.

Open Educational Resources (OER) — teaching, learning and research materials that their owners make free for others to use, revise and share — offer a powerful means of expanding the reach and effectiveness of worldwide education.

The Commonwealth of Learning (COL) and UNESCO co-organised the World OER Congress in 2012 in Paris. That Congress resulted in the OER Paris Declaration: a statement that urged governments around the world to release, as OER, all teaching, learning and research materials developed with public funds.

This book, drawing on 15 case studies contributed by 29 OER researchers and policy-makers from 15 countries across …

Twenty-Five Year Response Of The Herbaceous Layer Of A Temperate Hardwood Forest To Elevated Nitrogen Deposition, Frank S. Gilliam, Nicole Turrill Welch, Anne Hockenberry Phillips, Jake H. Billmyer, William T. Peterjohn, Zachariah K. Fowler, Christopher A. Walter, Mark B. Burnham, Jeffrey D. May, Mary Beth Adams

Biological Sciences Faculty Research

Increasing rates of atmospheric deposition of nitrogen (N) present a novel threat to the biodiversity of terrestrial ecosystems. Many forests are particularly susceptible to excess N given their proximity to sources of anthropogenic N emissions. This study summarizes results of a 25-yr treatment of an entire central Appalachian hardwood forest watershed via aerial applications of N with a focus on effects of added N on the cover, species richness, and composition of the herbaceous layer. Research was carried out on two watersheds of the Fernow Experimental Forest (FEF), West Virginia. The long-term reference watershed at FEF (WS4) was used as …

Investigating Predictors Of Academic Success In A Foundational Business Mathematics Course, Brooke Elise D'Aloisio

Open Access Dissertations

Research reveals that the majority of students are unprepared in making the transition from high school to college mathematics. Many students choose majors outside of STEM and business fields to pursue degrees with less rigorous mathematics requirements. According to recent findings, it is likely that over 25% of all freshmen will fail their first mathematics course. Few studies examine student success in business mathematics courses, and business is currently the most popular major in the United States. Thus, the purpose of this research was to examine what factors predict success in a foundational business mathematics course (BUS 111) at a …

Degree-Limited Defective Three Colorings Of Planar Graphs Containing No 4-Cycles Or 5-Cycles, Addie Armstrong

Open Access Dissertations

This dissertation explores and advances results for several variants on a long-open problem in graph coloring. Steinberg's conjecture states that any planar graph containing no 4-cycles or 5-cycles is 3-colorable. The conjecture has remained open for more than forty years and brought a great deal of interest to coloring planar graphs with certain structural restrictions. In this dissertation, we present a new type of defective graph coloring that allows us to prove two main results advancing the state of Steinberg's conjecture.

Bounds And Algorithms For Subspace Estimation On Riemannian Quotient Submanifolds, Thomas A. Palka

Open Access Dissertations

Subspace estimation appears in a wide variety of signal processing applications such as radar, communications, and underwater acoustics, often as a prelude to high resolution parameter estimation. As with any estimation problem the availability of statistical benchmarks on estimator accuracy is key to developing and understanding algorithm performance. The parameter space in general subspace/basis estimation problems is naturally described as a Riemannian quotient manifold. The concept of a manifold is central to many parts of geometry and modern mathematical physics because it allows more complicated structures to be described and understood in terms of the properties of Euclidean spaces. This …

A Study Of The Effect Of Harvesting On A Discrete System With Two Competing Species, Rebecca G. Clark

Theses and Dissertations

This is a study of the effect of harvesting on a system with two competing species. The system is a Ricker-type model that extends the work done by Luis, Elaydi, and Oliveira to include the effect of harvesting on the system. We look at the uniform bound of the system as well as the isoclines and perform a stability analysis of the equilibrium points. We also look at the effects of harvesting on the stability of the system by looking at the bifurcation of the system with respect to harvesting.

Fabricating Superhydrophobic And Superoleophobic Surfaces With Multiscale Roughness Using Airbrush And Electrospray, Karam N. Almilaji

Theses and Dissertations

Examples of superhydrophobic surfaces found in nature such as self-cleaning property of lotus leaf and walking on water ability of water strider have led to an extensive investigation in this area over the past few decades. When a water droplet rests on a textured surface, it may either form a liquid-solid-vapor composite interface by which the liquid droplet partially sits on air pockets or it may wet the surface in which the water replaces the trapped air depending on the surface roughness and the surface chemistry. Super water repellent surfaces have numerous applications in our daily life such as drag …

Autonomous Navigation With Obstacle Avoidance For Unmanned Aircraft Systems Using Milp, James A. Devens

Theses and Dissertations

Autonomous coordination among multiple aerial vehicles to ensure a collision free airspace is a critical aspect of today’s airspace. With the rise of Unmanned Aerial Vehicles (UAVs) in the military and commercial sectors, obstacle avoidance in a densely populated airspace is necessary. This thesis investigates finding optimal or near-optimal trajectories in real-time for aircraft in complex airspaces containing a large number of obstacles. The solution for the trajectories is described as a linear program subject to mixed integer constraints, known as a Mixed Integer Linear Program (MILP). The resulting MILP problem is solved in real time using a well-known, public …

Pattern Recognition In Class Imbalanced Datasets, Nahian A. Siddique

Theses and Dissertations

Class imbalanced datasets constitute a significant portion of the machine learning problems of interest, where recog­nizing the ‘rare class’ is the primary objective for most applications. Traditional linear machine learning algorithms are often not effective in recognizing the rare class. In this research work, a specifically optimized feed-forward artificial neural network (ANN) is proposed and developed to train from moderate to highly imbalanced datasets.

The proposed methodology deals with the difficulty in classification task in multiple stages—by optimizing the training dataset, modifying kernel function to generate the gram matrix and optimizing the NN structure. First, the training dataset is extracted …

Altmetrics Definitions And Use Cases, National Information Standards Organization (Niso)

Copyright, Fair Use, Scholarly Communication, etc.

The NISO Alternative Assessment Metrics Initiative was begun in July 2013 with funding from the Alfred P. Sloan Foundation, and divided into two phases. Phase II of the Project, which began in late 2014, set out to develop standards covering particular action items identified in Phase I through the creation of three NISO working groups. This document represents the output of the working group tasked with the following action items:

1. To come up with specific definitions for the terms commonly used in alternative assessment metrics, enabling different stakeholders to talk about the same thing; and

2. To identify the …

Meta-Mindfulness: A New Hope, Peter H. Huang

Publications

This Essay starts by tracing its humble origins to an earlier, related and unique law review article, namely, Tiger Cub Strikes Back: Memoirs of an Ex-Child Prodigy About Legal Education and Parenting. This Essay describes various professional responses to Tiger Cub Strikes Back, provides an update of some developments in research about parenting and legal education since Tiger Cub Strikes Back, and recounts a few personal stories about mindfulness and related to being an ex-child prodigy. This Essay then analyzes meta-mindfulness, defined as mindfulness about mindfulness. This Essay discusses how mindfulness about mindfulness can help facilitate the …

The Phononic Crystal Interface Layer Determines Slow-Wave And Pulse Broadening Effects, Li Sun, Aiming Ji, Jialing Hu, Canyan Zhu, Lijun Zhang, Jianfeng Yang, Lingfeng Mao

Turkish Journal of Electrical Engineering and Computer Sciences

The relationship among the slow-wave and echo pulse broadening effects in reflected acoustic waves and the width of the interface layer of phononic crystal has been theoretically investigated. It has been observed that not only the slow time for the reflected acoustic wave but also the echo pulse broadening reaches a saturation point as the size of the phononic crystal increases. From the viewpoint of the acoustic wave, there is an interface layer in the crystal that determines the slow-wave and the echo pulse broadening effects. The longest slow time, which is the time needed for transmitting 0.08 periods of …

A Hybrid Search Method Of Wrapper Feature Selection By Chaos Particle Swarm Optimization And Local Search, Mohammad Masoud Javidi, Nasibeh Emami

Turkish Journal of Electrical Engineering and Computer Sciences

Finding a subset of features from a large dataset is a problem that arises in many fields of study. Since the increasing number of features has extended the computational cost of a system, it is necessary to design and implement a system with the least number of features. The purpose of feature selection is to find the best subset of features from the original ones. The result of the best selection is improving the computational cost and the accuracy of the prediction. A large number of algorithms have been proposed for feature subset selection. In this paper, we propose a …

A Ring Crossover Genetic Algorithm For The Unit Commitment Problem, Syed Basit Ali Bukhari, Aftab Ahmad, Syed Auon Raza, Muhammad Noman Siddique

Turkish Journal of Electrical Engineering and Computer Sciences

The unit commitment problem (UCP) is a nonlinear, mixed-integer, constraint optimization problem and is considered a complex problem in electrical power systems. It is the combination of two interlinked subproblems, namely the generator scheduling problem and the generation allocation problem. In large systems, the UCP turns out to be increasingly complicated due to the large number of possible ON and OFF combinations of units in the power system over a scheduling time horizon. Due to the insufficiency of conventional approaches in handling large systems, numerous metaheuristic techniques are being developed for solving this problem. The genetic algorithm (GA) is one …

Electric Arc Furnace Power Quality Improvement By Applying A New Digital And Predicted-Based Tsc Control, Mehdi Torabian Esfahani, Behrooz Vahidi

Turkish Journal of Electrical Engineering and Computer Sciences

Static VAR compensators (SVC) can improve some of the power quality (PQ) indices such as voltage flicker, unbalances, and power factors in power systems if properly controlled. Different nonlinear and time-varying loads generate these parameters. One of the great nonlinear loads is the electric arc furnace (EAF), which causes waveform distortions, voltage unbalances, and fluctuations. In this paper, a new digital and prediction-based control for thyristor switched capacitors (TSCs) was proposed to compensate an actual steel industrial plant. The digital control was based on generating adequate synchronous pulses, calculating required suitable susceptance, and measuring correct reactive power. The proposed TSC …

Fuzzy Speed Estimation In The Case Of Sensorless Induction Machine Vector Control, Mohamed Bahloul, Mansour Souissi, Mohamed Chaabane, Larbi Chrifi Alaoui, Said Drid

Turkish Journal of Electrical Engineering and Computer Sciences

This paper deals with the problem of sensorless indirect field oriented control of an induction machine. Based on the fourth-order nonlinear model, we propose a novel structure of a full-order Takagi-Sugeno (TS) adaptive observer, through which we ensure the estimation of IM states and the rotor speed, which is considered as an immeasurable premise variable. This approach satisfies global stability for all operating conditions and operates under unknown applied load torque. In this work, a TS fuzzy model is presented to approximate a nonlinear IM model in the stationary rotating reference frame. A TS adaptive observer is then described. We …

Using Magnetic Field Analysis To Evaluate The Suitability Of A Magnetic Suspension System For Lightweight Vehicles, Hazril Md Isa, Noor Hafizah Amer, Wan Nor Liza Wan Mahadi, Rahizar Ramli

Turkish Journal of Electrical Engineering and Computer Sciences

A suspension system in a vehicle acts as an isolator that isolates vibrations between the wheel tires and the vehicle body due to road irregularities. Additionally, a suspension system serves as a vehicle stabilizer that stabilizes the vehicle body during unusual driving patterns such as cornering, braking, or accelerating. A controllable suspension system has received significant attention in the automotive world in previous years since it can perform both of the aforementioned tasks without the presence of fluid damper. The study presented in this paper focuses on using magnetic flux density analysis to evaluate a number of parameters of an …

Energy-Aware Stochastic Scheduling Model With Precedence Constraints On Dvfs-Enabled Processors, Mohammad Sajid, Zahid Raza

Turkish Journal of Electrical Engineering and Computer Sciences

The stochastic scheduling of precedence-constrained jobs on a heterogeneous processor is a challenging problem that requires solutions with one or more optimized QoS parameters. In this work, an energy-aware stochastic algorithm is proposed to schedule the batch of precedence-constrained jobs on heterogeneous DVFS-enabled processors with the objective of optimizing turnaround time and energy consumption. The processing time of tasks in all jobs and their precedence-constraint times are governed by independent probability distributions. The performance of the proposed stochastic algorithm is compared with SHEFT and ECS based on randomly generated batches of different sizes. The experimental study reveals that the proposed …

A Switching Inverse Dynamics Controller For Parallel Manipulators Around Drive Singular Configurations, Mustafa Özdemi̇r, Sitki Kemal İder

Turkish Journal of Electrical Engineering and Computer Sciences

Despite many advantages, parallel manipulators are known to possess drive singularities where the control of one or more degrees of freedom is lost. Around these singular configurations, the required actuator forces grow unbounded. Previous efforts in the literature put forward singularity-consistent trajectory planning and singularity-robust modification of the dynamic equations as a solution to this problem. However, this previous method is applicable only for the open-loop operation of the manipulator, whereas initial configuration errors, external disturbances, and modeling errors should necessarily be taken into account in a closed-loop sense in real-life applications. With this aim, a switching inverse dynamics controller …

Exploring Feature Sets For Turkish Word Sense Disambiguation, Bahar İlgen, Eşref Adali, Ahmet Cüneyd Tantuğ

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an exploration and evaluation of a diverse set of features that influence word-sense disambiguation (WSD) performance. WSD has the potential to improve many natural language processing (NLP) tasks as being one of the most crucial steps in the area. It is known that exploiting effective features and removing redundant ones help improving the results. There are two groups of feature sets to disambiguate senses and select the most appropriate ones among a set of candidates: collocational and bag-of-words (BoW) features. We introduce the effects of using these two feature sets on the Turkish Lexical Sample Dataset (TLSD), …

Digital Implementation Of A Constant Frequency Hysteresis Controller For Dual Mode Operation Of An Inverter Acting As A Pv-Grid Interface And Statcom, Lenin Prakash, Arutchelvi Meenakshi Sundaram, Kalyanraj Durairaj

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new constant frequency hysteresis current controller for the grid interface of a PV-fed three-phase voltage source inverter (VSI) for a dual mode operation, feeding real power during the daytime and reactive power alone during nights, thereby acting as a STATCOM. The constant frequency is inherently achieved by means of digital implementation in a simplified manner without any complex manipulations to choose a variable band width; rather the hysteresis band varies as a natural consequence of selecting appropriate constant sampling frequency. Analytical proof is presented for the switching frequency to remain constant, without compromising on the performance …

The Simulation Of Sound Signal Masking With Different Chaotic Oscillations And Its Circuit Application, Mehmet Nuri̇ Almali, Zi̇nnur Di̇ki̇ci̇

Turkish Journal of Electrical Engineering and Computer Sciences

The chaotic masking process on sound signals using the systems of Lorenz, Rössler, Sprott, Chen, and Arneodo chaotic oscillations are simulated with MATLAB/Simulink. The PID control method providing synchronization in the system is defined and the mean square errors between the times to reach synchronization and the input-output sound signals are compared for the system performance. The Sprott chaotic system is found to be the best synchronized system. Therefore, the application circuits are designed with respect to the Sprott chaotic system and its results are investigated in this study. It is seen that the system marked with the Sprott chaotic …

Improving Response Time Of Database Systems By Semantification Of Relational Data, Mustafa Yeni̇ad, Yakup Kutlu

Turkish Journal of Electrical Engineering and Computer Sciences

New generation web technologies present the new problem of intelligent representation of data in semantically structured systems. In this study, data hosted in a relational database system were converted to a new generation of web technologies (i.e. Web 3.0) with the semantic mapping method and semantification of the data was accomplished. The success of the transformation procedure was verified by a cross-comparison of the data between the relational database and the semantic data repository. By comparing the response time for performing SQL queries and equivalent SPARQL queries such as select, insert, update, and delete, operations hold in the semantic data …

A Comprehensive Control Strategy Of Railway Power Quality Compensator For Ac Traction Power Supply Systems, Hamed Jafari Kaleybar, Siamak Farshad

Turkish Journal of Electrical Engineering and Computer Sciences

The development of electrical railway systems leads to critical power quality problems in the power grid. This paper discusses a kind of half-bridge-based railway power quality compensator system (HBRPQC) that can compensate negative sequence currents, harmonics, and reactive power simultaneously. In order to keep the HBRPQC performance efficient for the different kinds of transformers used in traction power supply substations, a new multifunctional control strategy that performs better than previous methods is proposed. Due to the fast dynamicity of traction loads, a recessive self-tuning PI controller based on fuzzy logic is adopted in the current control system. The output control …

Computer-Assisted Cobb Angle Measurement From Posteroanterior Radiographs By A Curve Fitting Method, İbrahi̇m Yildiz

Turkish Journal of Electrical Engineering and Computer Sciences

Incorrect determination of the top or end vertebrae of a scoliotic curve causes measurement errors when using the Cobb method. Such problems are due to subjectivity. This study was performed to minimize subjectivity by using a curve fitting method. A digitally scanned posteroanterior radiographic image was used for each patient. User-defined midpoints of the curvature, which indicate the midpoints of the vertebrae, were used to fit the polynomial equation. The locations of the top and end vertebrae were calculated using the first derivative of the fitted polynomial equation to obtain the analytical Cobb angle. The interobserver technical error of measurements …

Certain Investigations On Power Generation Using Repulsive Magnets And New Stepped Dc Coupled Quasi Z-Inverter, Meenakshi Thillainayagam, Suthanthira Vanitha Narayanan, Sujith Kumar Sivaraman

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a novel approach for power generation from rotating machines in textile mills using externally coupled repulsive magnets and a new stepped DC coupled Quasi Z-inverter. Power is obtained as a byproduct of the effective harnessing of rotational energy with the use of repulsive magnets. This derived power is stored in a battery arrangement and is retrieved, buck/boosted, and converted to multilevel AC voltage with the new stepped DC coupled quasi Z-inverter. The proposed inverter is powered by isolated voltage sources, uses fewer switches, and produces less distortion in the resulting multilevel voltage compared to its counterpart, and …

An Interval-Based Contingency Selection Approach Considering Uncertainty, Chao Xu, Wei Gu, Lizi Luo, Jianguo Yao, Shengchun Yang, Ke Wang, Dan Zeng, Miao Fan

Turkish Journal of Electrical Engineering and Computer Sciences

Static security assessment is affected by uncertainties of load flow distributions introduced by renewable sources. A fast contingency selection approach based on interval theory is proposed in this paper. Firstly, an interval line active flow calculation algorithm is developed to reduce conservation in application of interval mathematics in line flow calculation. Then a novel interval comparison method based on Bayesian probability theory is applied in interval index comparison to give the relative severity information of contingencies. Finally, an approximately consistent ranking method is utilized in contingency ranking to rank screened contingencies. Numerical studies on several IEEE standard test systems and …

Validation Of Trnsys Modelling For A Fixed Slope Photovoltaic Panel, Kant Kanyarusoke, Jasson Gryzagoridis, Graeme Oliver

Turkish Journal of Electrical Engineering and Computer Sciences

TRNSYS stands for transient system simulation software. This paper describes a procedure that was used to validate a TRNSYS model for estimating electricity yields from a fixed slope photovoltaic (PV) panel. The objective was to find how close to reality predicted energy yield for a specified panel can be, at a location near one of the weather stations listed in the software's database. The software was used to predict daily total incident radiation on a horizontal plane and electrical energy yields from a 90 Wp panel when sloped at 34$^{\circ}$ facing north at a test site in Cape Town, South …

Integration Of Spectral And Spatial Information Via Local Covariance Matrices For Segmentation And Classification Of Hyperspectral Images, Uğur Ergül, Gökhan Bi̇lgi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, a novel approach is presented for the feature extraction step in hyperspectral image processing to form more discriminative features between different pixel regions. The proposed method combines both spatial and spectral information, which is very important for segmentation and classification of hyperspectral images. For comparison, five different feature sets are formed using eigen decomposition of local covariance matrices of subcubes located around a pixel of interest in the scene. Subcubes of neighbor pixels are obtained by a windowed structure to expose pattern similarities. As a novel approach, local covariance matrices are computed in eigenspace and proposed feature …

Assessment Of Energy Performance Certificate Systems: A Case Study For Residential Buildings In Turkey, Kenan Yi̇ği̇t, Bora Acarkan

Turkish Journal of Electrical Engineering and Computer Sciences

The importance of sustainable development and energy efficiency efforts has increased in the construction sector. Energy-saving efforts for buildings have become more important due to the global energy crisis, and energy rating systems have been developed globally for assessment of energy performance. In this study, international green building certificate and energy performance certificate (EPC) systems are presented. The official EPC system for buildings in Turkey is illustrated with case studies. Energy consumption and greenhouse gas emissions from residential buildings are calculated using the official national software, which is called BEP-TR. The impact of lighting on the total energy performance of …