Computer Sciences Commons^™

Plea: Parametric Loop Bound Estimation In Wcet Analysis, Saeed Parsa, Mehdi Sakhaei-Nia

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Automatic Detection Of Coronary Artery Disease Using Registration Of Ultrasound Images Of The Heart (Echocardiography), Pedram Masaeli, Seyyed Mohammad Alavi

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Reducedcbt And Supercbt: Two New And Improved Complete Binary Tree Structures, Mevlüt Bulut

Turkish Journal of Electrical Engineering and Computer Sciences

tree, a separate parent-child-sister hierarchy is employed independent of the parent-child-sister hierarchy used for the rest of the tree. Two different versions of such a local hierarchy are introduced. The result of the first proposed hierarchy is a faster and smaller footprint, while the second one provides size variation functionality without a significant computational overhead. Complexity comparison between the algorithms based on the introduced local hierarchies and ones based on previous complete binary tree structures reveals that the novel approach brings considerable memory gains and performance boosts to the complete binary tree based algorithms.

Name Spell-Check Framework For Social Networks, Burak Yildiz, Fati̇h Emekci̇

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Three-Phase Multilevel Inverter With High Value Of Resolution Per Switch Employing A Space Vector Modulation Control Scheme, Md Mubashwar Hasan, Saad Mekhilef, Mahrous Ahmed, Tarek Messikh

Turkish Journal of Electrical Engineering and Computer Sciences

inverter is presented in this paper. This configuration cancels the redundancy of output voltage steps and maximizes the number of levels in the output voltage. This structure is built by using series connected stages, which minimize the number of semiconductor switches, gate drive arrangements, occupying area, and cost. It is a modular type inverter model and the number of voltage levels can be increased by adding new stages without changing the previous connection. Space vector modulation has been applied as the control strategy. A prototype of the proposed inverter topology has been built in the laboratory. The attached hardware results …

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.

The Effect Of Using Wlans On Data Breaches: The Examination Of The Moderating Role Of Meaningful-Use Attestation, Dheyaaldin Alsalman, Insu Park

Research & Publications

Organizations have increasingly deployed wireless local area networks (WLANs) due to the benefits they can have such as mobility and flexibility. Unfortunately, the usage of wireless networks has raised many security concerns due to its capability of mobility. For instance, wireless networks are susceptible to many attacks such as eavesdropping, traffic analysis, data tampering and denial of service (DoS). Our study aims to identify a variable that moderates the effect of the usage of wireless local area networks (WLANs) on the occurrence of data breaches. Therefore, we propose a model that provides a basis for identifying the impact of meaningful-use …

Users Acceptance Of Health Behavioral Change Support Systems, Mohammad Al-Ramahi, Insu Park, Jun Liu

Research & Publications

Behavioral Change Support Systems (BCSSs) is a socio-technical information systems with psychological and behavioral outcomes aim to change users’ behavior and lifestyle. The promising outcomes of BCSSs make them especially useful in certain areas such as healthcare, where these systems could be leveraged to motivate people toward healthy behavior and then help them to achieve their goals better. However, health BCSSs cannot help facilitate self-monitoring and self-management or even improve patients’ health outcomes when patients do not accept the technology first. In this article, we extend the existing literature of users’ acceptance of health BCSSs by introducing new variables that …

Regulatory Approaches For Cyber Security Of Critical Infrastructures: The Case Of Turkey, Bilge Karabacak, Sevgi Ozkan Yildirim, Nazife Baykal

All Faculty and Staff Scholarship

Critical infrastructures are vital assets for public safety, economic welfare and/or national security of countries. Today, cyber systems are extensively used to control and monitor critical infrastructures. A considerable amount of the infrastructures are connected to the Internet over corporate networks. Therefore, cyber security is an important item for the national security agendas of several countries. The enforcement of security principles on the critical infrastructure operators through the regulations is a still-debated topic. There are several academic and governmental studies that analyze the possible regulatory approaches for the security of the critical infrastructures. Although most of them favor the market-oriented …

A Vulnerability-Driven Cyber Security Maturity Model For Measuring National Critical Infrastructure Protection Preparedness, Bilge Karabacak, Sevgi Ozkan Yildirim, Nazife Baykal

All Faculty and Staff Scholarship

Critical infrastructures are vital assets for the public safety, economic welfare and national security of countries. Cyber systems are used extensively to monitor and control critical infrastructures. A number of infrastructures are connected to the Internet via corporate networks. Cyber security is, therefore, an important item of the national security agenda of a country. The intense interest in cyber security has initiated research focusing on national cyber security maturity assessments. However, little, if any, research is dedicated to maturity assessments of national critical infrastructure protection efforts. Instead, the vast majority of studies merely examine diverse national-level security best practices ranging …

An Assessment Model To Improve National Cyber Security Governance, Bilge Karabacak, Unal Tatar, Adrian Gheorghe

All Faculty and Staff Scholarship

Today, cyber space has been embraced by individuals, organizations and nations as an indispensable instrument of daily life. Accordingly, impact of cyber threats has continuously been increasing. Critical infrastructure protection and fighting against cyber threats are crucial elements of national security agendas of governments. In this regard, governments need to assess the roles and responsibilities of public and private organizations to address the problems of current cyber protection postures and to respond with reorganization and reauthorization of these postures. A risk management approach is critical in placing these efforts in an ongoing lifecycle process. In this paper, a model is …

Understanding The Everyday Designer In Organisations, Ciaran O'Leary, Fredrick Mtenzi, Claire Mcavinia

Conference papers

This paper builds upon the existing concept of an everyday designer as a non-expert designer who carries out design activities using available resources in a given environment. It does so by examining the design activities undertaken by non-expert, informal, designers in organisations who make use of the formal and informal technology already in use in organisations while designing to direct, influence, change or transform the practices of people in the organisation. These people represent a cohort of designers who are given little attention in the literature on information systems, despite their central role in the formation of practice and enactment …

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 …

Rcd+: Fast Loop Modeling Server, José R. López-Blanco, Alejandro J. Canosa-Valis, Yaohang Li, Pablo Chacón

Computer Science Faculty Publications

Modeling loops is a critical and challenging step in protein modeling and prediction. We have developed a quick online service (http://rcd.chaconlab.org) for ab initio loop modeling combining a coarse-grained conformational search with a full-atom refinement. Our original Random Coordinate Descent (RCD) loop closure algorithm has been greatly improved to enrich the sampling distribution towards near-native conformations. These improvements include a new workflow optimization, MPI-parallelization and fast backbone angle sampling based on neighbor-dependent Ramachandran probability distributions. The server starts by efficiently searching the vast conformational space from only the loop sequence information and the environment atomic coordinates. The generated closed loop …

A Hybrid Algorithm Based On Optimal Quadratic Spline Collocation And Parareal Deferred Correction For Parabolic Pdes, Jun Liu, Yan Wang, Rongjian Li

Computer Science Faculty Publications

Parareal is a kind of time parallel numerical methods for time-dependent systems. In this paper, we consider a general linear parabolic PDE, use optimal quadratic spline collocation (QSC) method for the space discretization, and proceed with the parareal technique on the time domain. Meanwhile, deferred correction technique is also used to improve the accuracy during the iterations. In fact, the optimal QSC method is a correction of general QSC method. Along the temporal direction we embed the iterations of deferred correction into parareal to construct a hybrid method, parareal deferred correction (PDC) method. The error estimation is presented and the …

A Hybrid Parallel Delaunay Image-To-Mesh Conversion Algorithm Scalable On Distributed-Memory Clusters, Daming Feng, Andrey N. Chernikov, Nikos Chrisochoides

Computer Science Faculty Publications

In this paper, we present a scalable three dimensional hybrid MPI+Threads parallel Delaunay image-to-mesh conversion algorithm. A nested master-worker communication model for parallel mesh generation is implemented which simultaneously explores process-level parallelization and thread-level parallelization: inter-node communication using MPI and inter-core communication inside one node using threads. In order to overlap the communication (task request and data movement) and computation (parallel mesh refinement), the inter-node MPI communication and intra-node local mesh refinement is separated. The master thread that initializes the MPI environment is in charge of the inter-node MPI communication while the worker threads of each process are only responsible …

Big Data-Enabled Multiscale Serviceability Analysis For Aging Bridges, Yu Liang, Dalei Wu, Guirong Liu, Yaohang Li, Cuilan Gao, Zhongguo John Ma, Weidong Wu

Computer Science Faculty Publications

This work is dedicated to constructing a multi-scale structural health monitoring system to monitor and evaluate the serviceability of bridges based on the Hadoop Ecosystem (MS-SHM-Hadoop). By taking the advantages of the fault-tolerant distributed file system called the Hadoop Distributed File System (HDFS) and high-performance parallel data processing engine called MapReduce programming paradigm, MS-SHM-Hadoop features include high scalability and robustness in data ingestion, fusion, processing, retrieval, and analytics. MS-SHM-Hadoop is a multi-scale reliability analysis framework, which ranges from nationwide bridge-surveys, global structural integrity analysis, and structural component reliability analysis. This Nationwide bridge survey uses deep-learning techniques to evaluate the bridge …

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.

Deep Models For Brain Em Image Segmentation: Novel Insights And Improved Performance, Ahmed Fakhry, Hanchuan Peng, Shuiwang Ji

Computer Science Faculty Publications

Motivation: Accurate segmentation of brain electron microscopy (EM) images is a critical step in dense circuit reconstruction. Although deep neural networks (DNNs) have been widely used in a number of applications in computer vision, most of these models that proved to be effective on image classification tasks cannot be applied directly to EM image segmentation, due to the different objectives of these tasks. As a result, it is desirable to develop an optimized architecture that uses the full power of DNNs and tailored specifically for EM image segmentation.

Results: In this work, we proposed a novel design of DNNs for …

Results And Challenges In Visualizing Analytic Provenance Of Text Analysis Tasks Using Interaction Logs, Rhema Linder, Alyssa M. Peña, Sampath Jayarathna, Eric D. Ragan

Computer Science Faculty Publications

After data analysis, recalling and communicating the steps and rationale followed during the analysis can be difficult. This paper explores the use of interaction logs to generate summaries of an analyst's interest based on interactions with specific data items in a text analysis scenario. Our approach uses data-interaction events as a proxy for user interest in and experience of information. Logging can produce verbose logs that detail all available readable content, so the discussed approach uses topic modeling (LDA) over different time segments to summarize the verbose information and generate visualizations of the history of user interest. Our preliminary results …

Controlled Access To Cloud Resources For Mitigating Economic Denial Of Sustainability (Edos) Attacks, Zubair A. Baig, Sadiq M. Sait, Farid Binbeshr

Research outputs 2014 to 2021

Cloud computing is a paradigm that provides scalable IT resources as a service over the Internet. Vulnerabilities in the cloud infrastructure have been readily exploited by the adversary class. Therefore, providing the desired level of assurance to all stakeholders through safeguarding data (sensitive or otherwise) which is stored in the cloud, is of utmost importance. In addition, protecting the cloud from adversarial attacks of diverse types and intents, cannot be understated. Economic Denial of Sustainability (EDoS) attack is considered as one of the concerns that has stalled many organizations from migrating their operations and/or data to the cloud. This is …

Interactively Cutting And Constraining Vertices In Meshes Using Augmented Matrices, Yu-Hong Yeung, Jessica Crouch, Alex Pothen

Computer Science Faculty Publications

We present a finite-element solution method that is well suited for interactive simulations of cutting meshes in the regime of linear elastic models. Our approach features fast updates to the solution of the stiffness system of equations to account for real-time changes in mesh connectivity and boundary conditions. Updates are accomplished by augmenting the stiffness matrix to keep it consistent with changes to the underlying model, without refactoring the matrix at each step of cutting. The initial stiffness matrix and its Cholesky factors are used to implicitly form and solve a Schur complement system using an iterative solver. As changes …