Computer Engineering Commons^™

Design Of A Frequency Control System In A Microgrid Containing Hvac, Mohammad Koochakian Jazi, Seyed Masoud Moghaddas-Tafreshi, Mehdi Jafari

Turkish Journal of Electrical Engineering and Computer Sciences

controllable loads and tending to the demand response (DR) in small power systems have helped with new ideas, which can be used in the frequency stability of a microgrid. This paper presents a novel model for frequency control of a microgrid containing controllable load and renewable resources. The controllable loads used in this paper are such as heating, ventilation, and air conditioning, which change temperature based on frequency change. The microgrid is hybrid (AC/DC) and able to connect to and energy exchange with the utility grid. The design of PID controller parameters is considered an optimization problem according to the …

A Novel Compact Defected Ground Structure And Its Application In Mutual Coupling Reduction Of A Microstrip Antenna, Soroush Veisee, Mahsa Keshavarz Hedayati, Shahrooz Asadi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel compact T-shape defected ground structure (DGS) is proposed in order to reduce the mutual coupling between elements in a microstrip antenna array structure. The proposed DGS has considerable advantages compared to an H-shaped DGS. As is known, DGS insertion is a common problem in microstrip antenna array structures. However, the proposed T-shaped structure is more compact so it could be suitable for a compact microstrip array antenna. The T-shaped DGS is about 24% more compact than the H-shaped one. However, the most important novelty of our work is reducing mutual coupling both in the E-plane …

A Current Feedback Control Strategy For Parallel-Connected Single-Phase Inverters Using A Third-Order General-Integrator Crossover Cancellation Method, Yuan Huang, An Luo

Turkish Journal of Electrical Engineering and Computer Sciences

Virtual impedance is usually introduced to the control system of parallel inverters in order to change the inverter equivalent output impedance and to enhance control accuracy and power sharing. In this paper, a current feedback control strategy using a third-order general-integrator crossover-cancellation method that can be implemented in a virtual impedance loop is proposed. This method consists of 2 parts: a crossover-cancellation feedback network, which achieves the band-pass effect, and a multilevel TOGI-OSG link, which acts as a filter. Compared with the conventional virtual impedance method, the proposed method can avoid derivation of output current, reduce system calculating burden, and …

The Use Of Cross-Company Fault Data For The Software Fault Prediction Problem, Çağatay Çatal

Turkish Journal of Electrical Engineering and Computer Sciences

We investigated how to use cross-company (CC) data in software fault prediction and in predicting the fault labels of software modules when there are not enough fault data. This paper involves case studies of NASA projects that can be accessed from the PROMISE repository. Case studies show that CC data help build high-performance fault predictors in the absence of fault labels and remarkable results are achieved. We suggest that companies use CC data if they do not have any historical fault data when they decide to build their fault prediction models.

A New Market-Based Approach For Daily Volt/Var Control Of Distribution Systems In The Presence Of Distributed Energy Resources Using Benders Decomposition Algorithm, Abouzar Samimi, Ahad Kazemi

Turkish Journal of Electrical Engineering and Computer Sciences

Distributed energy resources (DERs), if properly coordinated with other Volt/Var control (VVC) devices, could be incorporated in daily VVC problem. In this paper, a new 2-stage model is presented for daily VVC of distribution systems including DERs, taking into account environmental and economic aspects. First, in the day-ahead market, an initial environmental-economic dispatch is performed to minimize both the electrical energy costs and the gas emissions pertaining to generation units. The initial scheduling results determined by the market operator are delivered to the second stage, namely the daily optimal dispatches of VVC devices, to examine them from operational viewpoints and …

Gravitational Search Algorithm-Based Dynamic Economic Dispatch By Estimating Transmission System Losses Using A-Loss Coefficients, Ram Jethmalani Chinasamy Hemparuva, Sishaj Pulikottil Simon, Sundareswaran Kinattingal, Srinivasa Rao Nayak Panugothu

Turkish Journal of Electrical Engineering and Computer Sciences

Dynamic economic dispatch (DED) is an important problem in power system generation, operation, planning, and control. The objective of the DED problem is to schedule power generation for the online units over a time horizon, satisfying the unit and ramp rate constraints. Here, valve point loading effects that cause nonsmoothness of the objective function is also considered while solving the DED. The accuracy of the solution not only depends on the optimal scheduling of generating units, but it also lies in accuracy while estimating transmission system losses. Generally, B-loss coefficients are used in estimating transmission losses. However, in the literature, …

A Conceptual Implementation Of A Buck Converter For An Off-Grid Hybrid System Consisting Of Solar And Wind Turbine Sources, Ahmad Shukri Fazil Rahman, Abdul Rahim Abdul Razak, Syed Idris Syed Hassan

Turkish Journal of Electrical Engineering and Computer Sciences

A hybrid renewable power generation system is proposed through parallel connection between two potential energy resources: photovoltaic (PV) and wind turbines. The method consists of incorporating a buck converter connected by a wind turbine to provide adjustment according to PV potential. Unlike the conventional buck-boost converter topology that is normally used, this research tries to emphasize the use of a buck converter as part of the system configuration. Design schemes were carefully performed and the postdesign system was tested through system simulation with MATLAB/Simulink software. The simulated system offers promising and significant results, thus making it suitable for hardware implementation.

On The Analytical Formulation Of Excess Noise In Avalanche Photodiodes With Dead Space, Erum Jamil, Jeng Shiuh Cheong, J.P.R. David, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

Simple, approximate formulas are developed to calculate the mean gain and excess noise factor for avalanche photodiodes using the dead-space multiplication theory in the regime of small multiplication width and high applied electric field. The accuracy of the approximation is investigated by comparing it to the exact numerical method using recursive coupled integral equations and it is found that it works for dead spaces up to 15% of the multiplication width, which is substantial. The approximation is also tested for real materials such as GaAs, InP and Si for various multiplication widths, and the results found are accurate within ∼ …

Robust Multi-Criteria Optimal Fuzzy Control Of Discrete-Time Nonlinear Systems, Xin Wang, Edwin E. Yaz

Electrical and Computer Engineering Faculty Research and Publications

This paper presents a novel fuzzy control design of discrete-time nonlinear systems with multiple performance criteria. The purpose behind this work is to improve the traditional fuzzy controller performance to satisfy several performance criteria simultaneously to secure quadratic optimality with an inherent stability property together with a dissipativity type of disturbance reduction. The Takagi–Sugeno-type fuzzy model is used in our control system design. By solving a linear matrix inequality at each time step, the optimal control solution can be found to satisfy mixed performance criteria. The effectiveness of the proposed technique is demonstrated by simulation of the control of the …

A Computationally Efficient Method For Calculation Of Strand Eddy Current Losses In Electric Machines, Alireza Fatemi, Dan M. Ionel, Nabeel Demerdash, Dave A. Staton, Rafal Wrobel, Yew Chuan Chong

Electrical and Computer Engineering Faculty Research and Publications

In this paper, a fast finite element (FE)-based method for the calculation of eddy current losses in the stator windings of randomly wound electric machines with a focus on fractional slot concentrated winding (FSCW) permanent magnet (PM) machines will be presented. The method is particularly suitable for implementation in large-scale design optimization algorithms where a qualitative characterization of such losses at higher speeds is most beneficial for identification of the design solutions which exhibit the lowest overall losses including the ac losses in the stator windings. Unlike the common practice of assuming a constant slot fill factor, sf, for all …

Detection And Quantification Of Aromatic Hydrocarbon Compounds In Water Using Sh-Saw Sensors And Estimation-Theory-Based Signal Processing, Karthick Sothivelr, Florian Bender, Fabien Josse, Antonio J. Ricco, Edwin E. Yaz, Rachel E. Mohler, Ravi Kolhatkar

Electrical and Computer Engineering Faculty Research and Publications

This work investigates a sensor system for direct groundwater monitoring, capable of aqueous-phase measurement of aromatic hydrocarbons at low concentrations (about 100 parts per billion (ppb)). The system is designed to speciate and quantify benzene, toluene, and ethylbenzene/xylenes (BTEX) in the presence of potential interferents. The system makes use of polymer-coated shear-horizontal surface acoustic wave devices and a signal processing method based on estimation theory, specifically a bank of extended Kalman filters (EKFs). This approach permits estimation of BTEX concentrations even from noisy data, well before the sensor response reaches equilibrium. To utilize estimation theory, an analytical model for the …

Sensor-Based Estimation Of Btex Concentrations In Water Samples Using Recursive Least Squares And Kalman Filter Techniques, Karthick Sothivelr, Florian Bender, Fabien Josse, Edwin E. Yaz, Antonio J. Ricco

Electrical and Computer Engineering Faculty Research and Publications

This work investigates sensor signal processing approaches that can be used with a sensor system for direct on-site monitoring of groundwater, enabling detection and quantification of BTEX (benzene, toluene, ethylbenzene and xylene) compounds at μg/L (ppb) concentrations in the presence of interferents commonly found in groundwater. A model for the sensor response to water samples containing multiple analytes was first formulated based on experimental results. The first signal processing approach utilizes only RLSE (recursive least squares estimation) whereas the second, a two-step processing technique, utilizes both RLSE and bank of Kalman filters for the estimation process. The estimation techniques were …

Robust Multi-Criteria Optimal Fuzzy Control Of Continuous-Time Nonlinear Systems, Xin Wang, Edwin E. Yaz

Electrical and Computer Engineering Faculty Research and Publications

This paper presents a novel fuzzy control design of continuous-time nonlinear systems with multiple performance criteria. The purpose behind this work is to improve the traditional fuzzy controller performance to satisfy several performance criteria simultaneously to secure quadratic optimality with inherent stability property together with dissipativity type of disturbance reduction. The Takagi– Sugeno fuzzy model is used in our control system design. By solving the linear matrix inequality at each time step, the control solution can be found to satisfy the mixed performance criteria. The effectiveness of the proposed technique is demonstrated by simulation of the control of the inverted …

Leveraging Heritrix And The Wayback Machine On A Corporate Intranet: A Case Study On Improving Corporate Archives, Justin F. Brunelle, Krista Ferrante, Eliot Wilczek, Michele C. Weigle, Michael L. Nelson

Computer Science Faculty Publications

In this work, we present a case study in which we investigate using open-source, web-scale web archiving tools (i.e., Heritrix and the Wayback Machine installed on the MITRE Intranet) to automatically archive a corporate Intranet. We use this case study to outline the challenges of Intranet web archiving, identify situations in which the open source tools are not well suited for the needs of the corporate archivists, and make recommendations for future corporate archivists wishing to use such tools. We performed a crawl of 143,268 URIs (125 GB and 25 hours) to demonstrate that the crawlers are easy to set …

Flexc: Protein Flexibility Prediction Using Context-Based Statistics, Predicted Structural Features, And Sequence Information, Ashraf Yaseen, Mais Nijim, Brandon Williams, Lei Qian, Min Li, Jianxin Wang, Yaohang Li

Computer Science Faculty Publications

The fluctuation of atoms around their average positions in protein structures provides important information regarding protein dynamics. This flexibility of protein structures is associated with various biological processes. Predicting flexibility of residues from protein sequences is significant for analyzing the dynamic properties of proteins which will be helpful in predicting their functions.

Proactive Biometric-Enabled Forensic Imprinting, Abdulrahman Alruban, Nathan L. Clarke, Fudong Li, Steven M. Furnell

Research outputs 2014 to 2021

Threats to enterprises have become widespread in the last decade. A major source of such threats originates from insiders who have legitimate access to the organization's internal systems and databases. Therefore, preventing or responding to such incidents has become a challenging task. Digital forensics has grown into a de-facto standard in the examination of electronic evidence; however, a key barrier is often being able to associate an individual to the stolen data. Stolen credentials and the Trojan defense are two commonly cited arguments used. This paper proposes a model that can more inextricably links the use of information (e.g. images, …

Towards A Generic Ontology For Solar Irradiance Forecasting, Abhilash Kantamneni

Dissertations, Master's Theses and Master's Reports

The growth of solar energy resources in recent years has led to increased calls for accurate forecasts of solar irradiance for the reliable and sustainable integration of solar into the national grid. A growing body of academic research has developed models for forecasting solar irradiance, identified metrics for comparing solar forecasts, and described applications and end users of solar forecasts.

In recent years, many disciplines are developing ontologies to facilitate better communication, improve inter-operabiity and refine knowledge reuse by experts and users of the domain. Ontologies are explicit and formal vocabulary of terms and their relationships. This report describes a …