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Electrical and Computer Engineering

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Articles 4891 - 4920 of 7215

Full-Text Articles in Computer Engineering

An Interconnection And Damping Assignment Passivity-Based Controller For A Dc–Dc Boost Converter With A Constant Power Load, Jianwu Zeng, Zhe Zhang, Wei Qiao Jan 2014

An Interconnection And Damping Assignment Passivity-Based Controller For A Dc–Dc Boost Converter With A Constant Power Load, Jianwu Zeng, Zhe Zhang, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes an adaptive interconnection and damping assignment (IDA) passivity-based controller (PBC) with a complementary proportional integral (PI) controller for dc–dc boost converters with constant power loads (CPLs). The plant is modeled as a port-controlled Hamiltonian system (PCHS). A virtual circuit that interprets the parameters of the PCHS is then derived to determine the parameters of the IDA-PBC for the system to work in the underdamping, critical-damping, and overdamping modes. Moreover, a complementary PI controller is designed to eliminate the steady-state output voltage error of the IDA-PBC caused by the load variation. Simulation studies are carried out inMATLAB/Simulink to …

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An Effective Heat Propagation Path-Based Online Adaptive Thermal Model For Igbt Modules, Ze Wang, Wei Qiao, Bo Tian, Liyan Qu Jan 2014

An Effective Heat Propagation Path-Based Online Adaptive Thermal Model For Igbt Modules, Ze Wang, Wei Qiao, Bo Tian, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

The information of junction temperature is crucial for operation management of IGBT modules. In practice, junction temperature is typically estimated by using an electrothermal model. IGBT modules are subject to various aging processes during operation, some of which, e.g. substrate solder crack, changes the thermal impedance of an IGBT module. However, in the literature little work has included the aging effects into online thermal behavior modeling of IGBT modules. This paper proposes an Effective Heat Propagation Path (EHPP)-based online adaptive thermal model for IGBT modules, where the EHPP is proposed to quantify the impact of substrate solder cracks on the …

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An Isolated Multiport Dc–Dc Converter For Simultaneous Power Management Of Multiple Different Renewable Energy Sources, Jianwu Zeng, Wei Qiao, Liyan Qu, Yanping Jiao Jan 2014

An Isolated Multiport Dc–Dc Converter For Simultaneous Power Management Of Multiple Different Renewable Energy Sources, Jianwu Zeng, Wei Qiao, Liyan Qu, Yanping Jiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a new isolated multiport dc–dc converter for simultaneous power management of multiple renewable energy sources, which can be of different types and capacities. The proposed dc–dc converter only uses one controllable switch in each port to which a source is connected. Therefore, it has the advantages of simple topology and minimum number of power switches. A general topology of the proposed converter is first introduced. Its principle and operation are then analyzed. The proposed converter is applied for simultaneous maximum power point tracking (MPPT) control of a wind/solar hybrid generation system consisting of one wind turbine generator …

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Evaluation Of Ann Estimation-Based Mppt Control For A Dfig Wind Turbine, Chun Wei, Liyan Qu, Wei Qiao Jan 2014

Evaluation Of Ann Estimation-Based Mppt Control For A Dfig Wind Turbine, Chun Wei, Liyan Qu, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes an artificial neuronal network (ANN) estimation-based wind speed sensolress MPPT algorithm for wind turbines equipped with doubly-fed induction generators (DFIG). The ANN is designed to produce the optimal control signal for the DFIG power or speed controller. The optimal parameters of the ANN are determined by using a particle swarm optimization (PSO) algorithm. A 3.6 MW DFIG wind turbine is simulated in PSCAD to evaluate and compare the proposed MPPT method with the traditional tip speed ratio (TSR) and turbine power profile-based MPPT methods in both the speed control and power control modes in variable wind speed …

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A Flux Vector-Based Discrete-Time Direct Torque Control For Salient-Pole Permanent-Magnet Synchronous Generators, Zhe Zhang, Yue Zhao, Jianwu Zeng, Wei Qiao Jan 2014

A Flux Vector-Based Discrete-Time Direct Torque Control For Salient-Pole Permanent-Magnet Synchronous Generators, Zhe Zhang, Yue Zhao, Jianwu Zeng, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a flux vector-based discretetime direct torque control (DTC) scheme for salient-pole permanent-magnet synchronous generators (PMSGs) used in the variable-speed, direct-drive wind energy conversion systems (WECSs). The discrete-time control law is derived from the perspective of flux space vectors and load angle with the torque and stator flux information only. The saliency of the PMSG is eliminated by the active flux concept. Compared with the existing space vector modulation (SVM)-based DTCs, the proposed scheme removes the use of PI regulators and is less dependent on the machine parameters, e.g., stator inductances and permanent-magnet flux linkage, while maintaining the …

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Improved Rotor Position And Speed Estimators For Sensorless Control Of Interior Permanent-Magnet Synchronous Machines, Yue Zhao, Wei Qiao, Long Wu Jan 2014

Improved Rotor Position And Speed Estimators For Sensorless Control Of Interior Permanent-Magnet Synchronous Machines, Yue Zhao, Wei Qiao, Long Wu

Department of Electrical and Computer Engineering: Faculty Publications

Model-based rotor position/speed estimators are commonly used for sensorless control of interior permanentmagnet synchronous machines (IPMSMs) operating in the medium- and high-speed regions. A rotor position/speed estimation scheme usually contains three major parts: 1) a state observer; 2) a position estimator; and 3) a speed estimator. This paper proposes a sliding-mode observer (SMO) as the state observer to estimate the position-related system states, which are the extended electromotive force components in this paper. Then, two major contributions are made to achieve improved position and speed estimation. First, the rotor speed is estimated independently using a model reference adaptive system (MRAS)-based …

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Thyristor-Controlled Switch Capacitor Placement In Large-Scale Power Systems Via Mixed Integer Linear Programming And Taylor Series Expansion, Omid Ziaee, F. Fred Choobineh Jan 2014

Thyristor-Controlled Switch Capacitor Placement In Large-Scale Power Systems Via Mixed Integer Linear Programming And Taylor Series Expansion, Omid Ziaee, F. Fred Choobineh

Department of Electrical and Computer Engineering: Faculty Publications

Allocation of flexible alternating current transmission system (FACTS) devices to an electric power transmission network may be formulated as a nonlinear mathematical program. Solving such a nonlinear program for a large transmission network is computationally very expensive, and obtaining the optimal solution may be impossible. We present a Taylor series expansion approximation of the nonlinearities of the problem and propose a mixed integer linear program (MILP) for finding the optimum location and proper settings of a Thyristor-Controlled Series Capacitor (TCSC) in an electric power network. The objective of this problem is to minimize total generation cost based on the DC …

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Tunable Plasmonic And Hyperbolic Metamaterials Based On Enhanced Nonlinear Response, Christos Argyropoulos, Francesco Monticone, Nasim Mohammadi Estakhri, Andrea Alu Jan 2014

Tunable Plasmonic And Hyperbolic Metamaterials Based On Enhanced Nonlinear Response, Christos Argyropoulos, Francesco Monticone, Nasim Mohammadi Estakhri, Andrea Alu

Department of Electrical and Computer Engineering: Faculty Publications

We present here tunable and reconfigurable designs of linear and nonlinear plasmonic and hyperbolic metamaterials. Rich scattering features of multilayered composite nanoparticles are demonstrated, which include complex and exotic scattering signatures combining multiple dipolar Fano resonances and electromagnetic induced transparency (EIT) features. These dipoledipole multi-Fano scattering responses can be further tuned through altering the plasmonic properties of the concentric layers or the permittivity of the core, for instance, by the presence of nonlinearities. Strong third-order nonlinear effects, such as optical bistability, may also be induced in the scattering response of nonlinear nanoparticles due to the highly enhanced and confined fields …

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Bayesian Network Prior: Network Analysis Of Biological Data Using External Knowledge, Senol Isci, Haluk Dogan, Cengizhan Ozturk, Hasan H. Otu Jan 2014

Bayesian Network Prior: Network Analysis Of Biological Data Using External Knowledge, Senol Isci, Haluk Dogan, Cengizhan Ozturk, Hasan H. Otu

Department of Electrical and Computer Engineering: Faculty Publications

Motivation: Reverse engineering GI networks from experimental data is a challenging task due to the complex nature of the networks and the noise inherent in the data. One way to overcome these hurdles would be incorporating the vast amounts of external biological knowledge when building interaction networks. We propose a framework where GI networks are learned from experimental data using Bayesian networks (BNs) and the incorporation of external knowledge is also done via a BN that we call Bayesian Network Prior (BNP). BNP depicts the relation between various evidence types that contribute to the event ‘gene interaction’ and is used …

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Element Dependence Of Enhancement In Optics Emission From Laser-Induced Plasma Under Spatial Confinement, Changmao Li, Lianbo Guo, Xiangnan He, Zhongqi Hao, Xiangyou Li, Meng Shen, Xiaoyan Zeng, Yongfeng Lu Jan 2014

Element Dependence Of Enhancement In Optics Emission From Laser-Induced Plasma Under Spatial Confinement, Changmao Li, Lianbo Guo, Xiangnan He, Zhongqi Hao, Xiangyou Li, Meng Shen, Xiaoyan Zeng, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

In this study, the element dependence of spatial confinement effects in LIBS has been studied. Hemispheric cavities were used to confine laser-induced plasmas from aluminum samples with other trace elements. The enhancement factors were found to be dependent on the elements. Equations describing the element dependent enhancement factors were successfully deduced from the local thermodynamic equilibrium conditions, which have also been verified by the experimental results. Research results show that enhancement factors in LIBS with spatial confinement depend on the temperature, electron density, and compression ratio of plasmas, and vary with elements and atomic/ionic emission lines selected. Generally, emission lines …

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A Low-Power Compact Nqr Based Explosive Detection System, Xinwang Zhang, Nathan Schemm, Sina Balkır, Michael W. Hoffman Jan 2014

A Low-Power Compact Nqr Based Explosive Detection System, Xinwang Zhang, Nathan Schemm, Sina Balkır, Michael W. Hoffman

Department of Electrical and Computer Engineering: Faculty Publications

Nuclear quadruple resonance (NQR) has been studied for explosive detection for years. Some prototype NQR-based detection systems have been reported, but were all designed from the laboratory perspective, with bulky sizes and high power consumption. To achieve a portable NQR-based detection system for field applications, a low-power compact system utilizing state-of-the-art semiconductor technologies is presented in this paper. Several novel circuits for the key modules are proposed, including a Class-D type power amplifier, a power multiplexing and matching network, a customized IC with integrated analog signal processing chain, and a microcontroller-based logic control unit. An advanced digital signal processor platform …

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Workplace Monitoring Of Employee Health Using The Workstation Pc As A Platform, Priyankar Bhattacharjee Jan 2014

Workplace Monitoring Of Employee Health Using The Workstation Pc As A Platform, Priyankar Bhattacharjee

Department of Electrical and Computer Engineering: Faculty Publications

A country’s biggest asset is its workforce, given the fact that a healthy workforce can contribute to rapid growth of the economy. Chronic illnesses reduce productivity, are responsible for rising healthcare costs, and should be managed by the employer to reduce healthcare expenditures. This can be done through employee health and wellness programs, and well-designed health management initiatives. In addition, new information and communication technologies make it possible to monitor employee health with wearable devices and telehealth assisted surveillance techniques. This paper introduces a unique new approach to workplace healthcare monitoring, using the office workstation PC itself to monitor worker …

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Clu: Co-Optimizing Locality And Utility In Thread-Aware Capacity Management For Shared Last Level Caches, Dongyuan Zhan, Hong Jiang, Sharad C. Seth Jan 2014

Clu: Co-Optimizing Locality And Utility In Thread-Aware Capacity Management For Shared Last Level Caches, Dongyuan Zhan, Hong Jiang, Sharad C. Seth

Department of Electrical and Computer Engineering: Faculty Publications

Most chip-multiprocessors nowadays adopt a large shared last-level cache (SLLC). This paper is motivated by our analysis and evaluation of state-of-the-art cache management proposals which reveal a common weakness. That is, the existing alternative replacement policies and cache partitioning schemes, targeted at optimizing either locality or utility of co-scheduled threads, cannot deliver consistently the best performance under a variety of workloads. Therefore, we propose a novel adaptive scheme, called CLU, to interactively co-optimize the locality and utility of co-scheduled threads in thread-aware SLLC capacity management. CLU employs lightweight monitors to dynamically profile the LRU (least recently used) and BIP (bimodal …

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Intelligent Maximum Power Extraction Control For Wind Energy Conversion Systems Based On Online Q-Learning With Function Approximation, Chun Wei, Zhe Zhang, Wei Qiao, Liyan Qu Jan 2014

Intelligent Maximum Power Extraction Control For Wind Energy Conversion Systems Based On Online Q-Learning With Function Approximation, Chun Wei, Zhe Zhang, Wei Qiao, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes an intelligent maximum power point tracking (MPPT) algorithm for variable-speed wind energy conversion systems (WECSs) based on an online Q-learning algorithm. Instead of using the conventional Qlearning that uses a lookup table to store the action values for the discretized states, artificial neural networks (ANNs) are used as function approximators to output the action values by using the electrical power and rotor speed of the generator as inputs. This eliminates the need for a large storage memory. The proposed method learns the optimal speed control strategy of the WECS by updating the connecting weights of the ANNs, …

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Effects Of Droplet Diameter On The Leidenfrost Temperature Of Laser Processed Multiscale Structured Surfaces, Anton Hassebrook, Corey Kruse, Chris Wilson, Troy P. Anderson, Craig Zuhlke, Dennis R. Alexander, George Gogos, Sidy Ndao Jan 2014

Effects Of Droplet Diameter On The Leidenfrost Temperature Of Laser Processed Multiscale Structured Surfaces, Anton Hassebrook, Corey Kruse, Chris Wilson, Troy P. Anderson, Craig Zuhlke, Dennis R. Alexander, George Gogos, Sidy Ndao

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, an experimental investigation of the effects of droplet diameters on the Leidenfrost temperature and its shifts has been carried out. Tests were conducted on a 304 stainless steel polished surface and a stainless steel surface which was processed by a femtosecond laser to form Above Surface Growth (ASG) nano/microstructures. To determine the Leidenfrost temperatures, the droplet lifetime method was employed for both the polished and processed surfaces. A precision dropper was used to vary the size of droplets from 1.5 to 4 millimeters. The Leidenfrost temperature was shown to display shifts as high as 85 ˚C on …

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Optimum Renewable Generation Capacities In A Microgrid Using Generation Adequacy Study, Salman Kahrobaee, Sohrab Asgarpoor, Milad Kahrobaee Jan 2014

Optimum Renewable Generation Capacities In A Microgrid Using Generation Adequacy Study, Salman Kahrobaee, Sohrab Asgarpoor, Milad Kahrobaee

Department of Electrical and Computer Engineering: Faculty Publications

Microgrids, as small power systems, may be comprised of different types of loads and distributed generation. As the integration of renewable power generation increases, the total available generation capacity of the system will be more derated due to the effect of equipment failures and the intermittent nature of these resources. Therefore, it is critical to determine optimum renewable generation capacities and provide enough reserve margin to meet the target reliability of the microgrid. In this paper, we first model a microgrid, including conventional and renewable distributed generation and the loads. Second, we determine the renewable generation capacity required to meet …

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State Of Charge Estimation Based On A Realtime Battery Model And Iterative Smooth Variable Structure Filter, Taesic Kim, Yebin Wang, Zafer Sahinoglu, Toshihiro Wada, Satoshi Hara, Wei Qiao Jan 2014

State Of Charge Estimation Based On A Realtime Battery Model And Iterative Smooth Variable Structure Filter, Taesic Kim, Yebin Wang, Zafer Sahinoglu, Toshihiro Wada, Satoshi Hara, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a novel real-time model-based state of charge (SOC) estimation method for lithium-ion batteries. The proposed method includes: 1) an electrical circuit battery model incorporating the hysteresis effect, 2) a fast upper-triangular and D-diagonal recursive least square (FUDRLS)-based online parameter identification algorithm for the electrical battery model, and 3) an iterated smooth variable structure filter (ISVSF) for SOC estimation. The proposed method enables an accurate and robust condition monitoring for lithium-ion batteries. Due to its low complexity, the proposed method is suitable for the real-time embedded battery management system (BMS) application. Simulation and experiment are performed to validate …

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Design And Implementation Of A Low-Cost Embedded Linux Gateway For Smart Home Health Monitoring, Mateusz Mittek, Jay D. Carlson, Lance C. Pérez Jan 2014

Design And Implementation Of A Low-Cost Embedded Linux Gateway For Smart Home Health Monitoring, Mateusz Mittek, Jay D. Carlson, Lance C. Pérez

Department of Electrical and Computer Engineering: Faculty Publications

Many wireless sensor network applications require a gateway device to interface with services running on the Internet. Because of the software complexity involved in this device, it is often realized using a real-time operating system running on an application processor. Most systems burden the user with developing the protocol handling and device configuration and management inside the application. In this paper, we present the Angelos Gateway – a turnkey, low-cost, Linux-powered WSN gateway that provides a socket-based environment for rapid network-enabled application development. Experimental results demonstrate that the proposed device is capable of high-throughput packet I/O, confirming the efficacy of …

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Automated Indoor Rfid Inventorying Using A Self-Guided Micro-Aerial Vehicle, Steven A. Parkison, Eric T. Psota, Lance C. Pérez Jan 2014

Automated Indoor Rfid Inventorying Using A Self-Guided Micro-Aerial Vehicle, Steven A. Parkison, Eric T. Psota, Lance C. Pérez

Department of Electrical and Computer Engineering: Faculty Publications

A Micro-Aerial Vehicle (MAV) system is presented for automated indoor inventorying using passive radio frequency identification (RFID). This system utilizes a combination of onboard sensing and processing in order to achieve flight stabilization, generate floor maps, and perform path planning. The proposed state estimation method along with a control feedback strategy are demonstrated to be sufficiently accurate for operation in the indoor environment and the proposed path planning technique is shown to be effective for guiding the MAV while it performs automated RFID scanning.

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Achieving Robustness And Capacity Gains In Covert Timing Channels, Fahimeh Rezaei, Michael Hempel, Pradhumna Lal Shrestha, Hamid Sharif Jan 2014

Achieving Robustness And Capacity Gains In Covert Timing Channels, Fahimeh Rezaei, Michael Hempel, Pradhumna Lal Shrestha, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, we introduce a covert timing channel (CTC) algorithm and compare it to one of the most prevailing CTC algorithms, originally proposed by Cabuk et al. CTC is a form of covert channels – methods that exploit network activities to transmit secret data over packet-based networks – by modifying packet timing. This algorithm is a seminal work, one of the most widely cited CTCs, and the foundation for many CTC research activities. In order to overcome some of the disadvantages of this algorithm we introduce a covert timing channel technique that leverages timeout thresholds. The proposed algorithm is …

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Monitoring Igbt’S Health Condition Via Junction Temperature Variations, Bo Tian, Wei Qiao, Ze Wang, Tanya Gachovska, Jerry L. Hudgins Jan 2014

Monitoring Igbt’S Health Condition Via Junction Temperature Variations, Bo Tian, Wei Qiao, Ze Wang, Tanya Gachovska, Jerry L. Hudgins

Department of Electrical and Computer Engineering: Faculty Publications

Insulated gate bipolar transistor (IGBT) failures are a major issue in modern power electronics applications. Two most dominated failure mechanisms of IGBTs are solder fatigue and bond wire wear-out. This paper proposes a new method to online monitor an IGBT’s health condition by using the instantaneous junction temperature variation between present and the first operating cycles of the IGBT with the same operating current. In this work, the instantaneous junction temperature of an IGBT is estimated from a thermal network model. The proposed method is validated by experimental results obtained from accelerated aging tests for IGBTs.

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An Efficient Similarity Digests Database Lookup -- A Logarithmic Divide And Conquer Approach, Frank Breitinger, Christian Rathgeb, Harald Baier Jan 2014

An Efficient Similarity Digests Database Lookup -- A Logarithmic Divide And Conquer Approach, Frank Breitinger, Christian Rathgeb, Harald Baier

Electrical & Computer Engineering and Computer Science Faculty Publications

Investigating seized devices within digital forensics represents a challenging task due to the increasing amount of data. Common procedures utilize automated file identification, which reduces the amount of data an investigator has to examine manually. In the past years the research field of approximate matching arises to detect similar data. However, if n denotes the number of similarity digests in a database, then the lookup for a single similarity digest is of complexity of O(n). This paper presents a concept to extend existing approximate matching algorithms, which reduces the lookup complexity from O(n) to O(log(n)). Our proposed approach is based …

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A Comparative Study Of Reservoir Computing For Temporal Signal Processing, Alireza Goudarzi, Peter Banda, Matthew R. Lakin, Christof Teuscher, Darko Stefanovic Jan 2014

A Comparative Study Of Reservoir Computing For Temporal Signal Processing, Alireza Goudarzi, Peter Banda, Matthew R. Lakin, Christof Teuscher, Darko Stefanovic

Computer Science Faculty Publications and Presentations

Reservoir computing (RC) is a novel approach to time series prediction using recurrent neural networks. In RC, an input signal perturbs the intrinsic dynamics of a medium called a reservoir. A readout layer is then trained to reconstruct a target output from the reservoir's state. The multitude of RC architectures and evaluation metrics poses a challenge to both practitioners and theorists who study the task-solving performance and computational power of RC. In addition, in contrast to traditional computation models, the reservoir is a dynamical system in which computation and memory are inseparable, and therefore hard to analyze. Here, we compare …

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Efficient Anonymous Biometric Matching In Privacy-Aware Environments, Ying Luo Jan 2014

Efficient Anonymous Biometric Matching In Privacy-Aware Environments, Ying Luo

Theses and Dissertations--Electrical and Computer Engineering

Video surveillance is an important tool used in security and environmental monitoring, however, the widespread deployment of surveillance cameras has raised serious privacy concerns. Many privacy-enhancing schemes have been recently proposed to automatically redact images of selected individuals in the surveillance video for protection. To identify these individuals for protection, the most reliable approach is to use biometric signals as they are immutable and highly discriminative. If misused, these characteristics of biometrics can seriously defeat the goal of privacy protection. In this dissertation, an Anonymous Biometric Access Control (ABAC) procedure is proposed based on biometric signals for privacy-aware video surveillance. …

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Service And Communication Management In Cooperative Vehicular Networks, Olivia Brickley Jan 2014

Service And Communication Management In Cooperative Vehicular Networks, Olivia Brickley

Theses

The concept of Intelligent Transportation Systems (ITS) presents new R&D challenges for the transportation and ICT sectors and is currently receiving considerable interest from the research community. The primary objective of ITS is the creation of advanced road traffic systems for improved traffic safety, efficiency, and travelling comfort. Basic vehicle and roadside infrastructure collaboration allows for an increase in efficiency and safety and acts as the foundation for an extensive service set to achieve these ITS goals. Applications such as journey planning, automatic tolling and emergency warnings, among others, are envisaged in a system which can potentially reform modern transportation. …

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File Detection On Network Traffic Using Approximate Matching, Frank Breitinger, Ibrahim Baggili Jan 2014

File Detection On Network Traffic Using Approximate Matching, Frank Breitinger, Ibrahim Baggili

Electrical & Computer Engineering and Computer Science Faculty Publications

In recent years, Internet technologies changed enormously and allow faster Internet connections, higher data rates and mobile usage. Hence, it is possible to send huge amounts of data / files easily which is often used by insiders or attackers to steal intellectual property. As a consequence, data leakage prevention systems (DLPS) have been developed which analyze network traffic and alert in case of a data leak. Although the overall concepts of the detection techniques are known, the systems are mostly closed and commercial. Within this paper we present a new technique for network traffic analysis based on approximate matching (a.k.a …

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Quantifying Relevance Of Mobile Digital Evidence As They Relate To Case Types: A Survey And A Guide For Best Practices, Shahzad Saleem, Ibrahim Baggili, Oliver Popov Jan 2014

Quantifying Relevance Of Mobile Digital Evidence As They Relate To Case Types: A Survey And A Guide For Best Practices, Shahzad Saleem, Ibrahim Baggili, Oliver Popov

Electrical & Computer Engineering and Computer Science Faculty Publications

In this work, a survey was conducted to help quantify the relevance of nineteen types of evidence (such as SMS) to seven types of digital investigations associated with mobile devices (MD) (such as child pornography). 97 % of the respondents agreed that every type of digital evidence has a different level of relevance to further or solve a particular investigation. From 55 serious participants, a data set of 5,772 responses regarding the relevance of nineteen types of digital evidence for all the seven types of digital investigations was obtained. The results showed that (i) SMS belongs to the most relevant …

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Optimal Fuzzy Load Frequency Controller With Simultaneous Auto-Tuned Membership Functions And Fuzzy Control Rules, Abas Ali Zamani, Ehsan Bijami, Farid Sheikholeslam, Bahram Jafrasteh Jan 2014

Optimal Fuzzy Load Frequency Controller With Simultaneous Auto-Tuned Membership Functions And Fuzzy Control Rules, Abas Ali Zamani, Ehsan Bijami, Farid Sheikholeslam, Bahram Jafrasteh

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an auto-tuned fuzzy load frequency controller (FLFC)-based artificial bee colony (ABC) algorithm is developed to quench the deviations in the frequency and tie-line power due to load disturbances in an interconnected power system. Optimal tuning of membership functions (MFs) and fuzzy control rules is very important to improve the design performance and achieve a satisfactory level of robustness for a particular operation. In this work, to reduce the fuzzy system design effort and take large parametric uncertainties into account, a new systematic and simultaneous tuning method is developed for designing MFs and fuzzy rules. For this, the …

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Btsql: Nested Bitemporal Relational Database Query Language, Canan Atay, Abdullah Uz Tansel Jan 2014

Btsql: Nested Bitemporal Relational Database Query Language, Canan Atay, Abdullah Uz Tansel

Turkish Journal of Electrical Engineering and Computer Sciences

A nested bitemporal relational data model and its query language are implemented. The bitemporal atom (BTA) is the fundamental construct to represent temporal data and it contains 5 components: a value, the lower and upper bounds of valid time, and the lower and upper bounds of the recoding time. We consider 2 types of data structures for storing BTAs: 1) string representation and 2) abstract data-type representation. We also develop a preprocessor for translating a bitemporal structured query language (BtSQL) statement into standard SQL statements. The BtSQL includes the select, insert, delete, and update statements of the SQL, extended for …

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Wireless Sensor Localization Using Enhanced Dv-Aoa Algorithm, Peter Brida, Juraj Machaj, Jozef Benikovsky Jan 2014

Wireless Sensor Localization Using Enhanced Dv-Aoa Algorithm, Peter Brida, Juraj Machaj, Jozef Benikovsky

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we deal with the improvement of the positioning accuracy of distance vector (DV)-based positioning algorithms, which use angular information DV- angle of arrival (AoA). This algorithm belongs to an ad-hoc positioning system. We focus on the improvement of the algorithm and its enhanced version is presented. The angular information of particular nodes is obtained and processed by the original algorithm; however, the final position estimation is determined by the proposed novel algorithm using only a subset of all intersections. We assign weights to the individual intersections according to their positions and the positions of the RNs. For …

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