Computer Sciences Commons^™

Wildfire Emissions In The Context Of Global Change And The Implications For Mercury Pollution, Aditya Kumar

Dissertations, Master's Theses and Master's Reports

Wildfires are episodic disturbances that exert a significant influence on the Earth system. They emit substantial amounts of atmospheric pollutants, which can impact atmospheric chemistry/composition and the Earth’s climate at the global and regional scales. This work presents a collection of studies aimed at better estimating wildfire emissions of atmospheric pollutants, quantifying their impacts on remote ecosystems and determining the implications of 2000s-2050s global environmental change (land use/land cover, climate) for wildfire emissions following the Intergovernmental Panel on Climate Change (IPCC) A1B socioeconomic scenario.

A global fire emissions model is developed to compile global wildfire emission inventories for major atmospheric …

Tinyvisor: An Extensible Secure Framework On Android Platforms, Dong Shen, Zhoujun Li, Xiaojing Su, Jinxin Ma, Deng, Robert H.

Research Collection School Of Computing and Information Systems

As the utilization of mobile platform keeps growing, the security issue of mobile platform becomes a serious threat to user privacy. The current security measures mainly focus on the application level and the framework level, with little protection on the kernel. Virtualization technologies have been used in x86 platforms to protect the security of the kernel. With a higher privilege than the guest operating system, the hypervisor can effectively detect and defend against the malicious activity inside the guest kernel. In this paper, we build a hypervisor framework called TinyVisor leveraging the ARM virtualization extensions to protect the guest system …

Dictionary Learning With Structured Noise, Pan Zhou, Cong Fang, Zhouchen Lin, Chao Zhang, Y. Edward Chang

Research Collection School Of Computing and Information Systems

Recently, lots of dictionary learning methods have been proposed and successfully applied. However, many of them assume that the noise in data is drawn from Gaussian or Laplacian distribution and therefore they typically adopt the 2 or 1 norm to characterize these two kinds of noise, respectively. Since this assumption is inconsistent with the real cases, the performance of these methods is limited. In this paper, we propose a novel dictionary learning with structured noise (DLSN) method for handling noisy data. We decompose the original data into three parts: clean data, structured noise, and Gaussian noise, and then characterize them …

Modeling Engagement Of Programming Students Using Unsupervised Machine Learning Technique, Hua Leong Fwa, Lindsay Marshall

Research Collection School Of Computing and Information Systems

Engagement is instrumental to students’ learning and academic achievements. In this study, we model the engagement states of students who are working on programming exercises in an intelligent tutoring system. Head pose, keystrokes and action logs of students automatically captured within the tutoring system are fed into a Hidden Markov Model for inferring the engagement states of students. With the modeling of students’ engagement on a moment by moment basis, intervention measures can be initiated automatically by the system when necessary to optimize the students’ learning. This study is also one of the few studies that bypass the need for …

Improved Construction For Inner Product Functional Encryption, Qingsong Zhao, Qingkai Zeng, Ximeng Liu

Research Collection School Of Computing and Information Systems

Functional encryption (FE) is a vast new paradigm for encryption scheme which allows tremendous flexibility in accessing encrypted data. In a FE scheme, a user can learn specific function of encrypted messages by restricted functional key and reveals nothing else about the messages. Besides the standard notion of data privacy in FE, it should protect the privacy of the function itself which is also crucial for practical applications. In this paper, we construct a secret key FE scheme for the inner product functionality using asymmetric bilinear pairing groups of prime order. Compared with the existing similar schemes, our construction reduces …

Strong Identity-Based Proxy Signature Schemes, Revisited, Weiwei Liu, Yi Mu, Guomin Yang, Yangguang Tian

Research Collection School Of Computing and Information Systems

Proxy signature is a useful cryptographic primitive that has been widely used in many applications. It has attracted a lot of attention since it was introduced. There have been lots of works in constructing efficient and secure proxy signature schemes. In this paper, we identify a new attack that has been neglected by many existing proven secure proxy signature schemes. We demonstrate this attack by launching it against an identity-based proxy signature scheme which is proven secure. We then propose one method that can effectively prevent this attack. The weakness in some other proxy signature schemes can also be fixed …

Multi-Robot Complete Coverage Using Directional Constraints, Stefanus Malan

CCAC Theses and Dissertations

Complete coverage relies on a path planning algorithm that will move one or more robots, including the actuator, sensor, or body of the robot, over the entire environment. Complete coverage of an unknown environment is used in applications like automated vacuum cleaning, carpet cleaning, lawn mowing, chemical or radioactive spill detection and cleanup, and humanitarian de-mining.

The environment is typically decomposed into smaller areas and then assigned to individual robots to cover. The robots typically use the Boustrophedon motion to cover the cells. The location and size of obstacles in the environment are unknown beforehand. An online algorithm using sensor-based …

The Measurement Of Shielding Effectiveness For Small-In-Size Ferrite-Based Flat Materials, İsa Araz

Turkish Journal of Electrical Engineering and Computer Sciences

This work presents the results of our studies on the electromagnetic interference shielding effectiveness of small-in-size samples of ferrite composition microwave absorber prepared by using the ceramic method. The shielding effectiveness measurement was performed using the complex intrinsic parameters of the material. The coaxial holder method with the well-known test technique based on transmission/reflection measurements was used in the experimental setup. Complex intrinsic parameters were measured in the frequency range of 2-18 GHz by using the Nicholson - Ross - Weir (NRW) method with an automated test setup. First, the shielding effectiveness was measured by conventional test method and then …

Emi Filter Design Based On The Separated Electromagnetic Interference In Switched Mode Power Supplies, Samet Yalçin, Şükrü Özen, Selçuk Helhel

Turkish Journal of Electrical Engineering and Computer Sciences

Usage of switch mode power supplies (SMPS) has been increased tremendously in recent years due to their advantages compared to conventional ones. In spite of their advantages, SMPSs cause conducted and radiated emissions due to the fact that they switch on and off at specific frequencies. Electromagnetic interference (EMI) filters are mostly preferred equipment for the reduction of conducted emission for coupled circuits. Improved EMI filter in the literature to suppress both common and differential mode noises sourced by ATX (a sample of SMPS) power supply has been proposed. A proposed filter was designed by use of AWR Microwave Office …

Classification And Regression Analysis Using Support Vector Machine For Classifying And Locating Faults In A Distribution System, Sophi Shilpa Gururajapathy, Hazlie Mokhlis, Hazlee Azil Bin Illias

Turkish Journal of Electrical Engineering and Computer Sciences

Various fault location methods have been developed in the past to identify the faulty phase, fault type, faulty section, and distance. However, this identification is commonly conducted in a separate manner. An effective fault location should be able to identify all of these at the same time. Therefore, in this work, a method using a support vector machine (SVM) to identify the fault type, faulty section, and distance considering the faulty phase is proposed. The proposed method uses voltage sag magnitude of the distribution system as the main feature for the SVM to identify faults. The fault type is classified …

The Impact Of Transmission Power Levels Set Size On Lifetime Of Wireless Sensor Networks In Smart Grids, Hüseyi̇n Uğur Yildiz

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless sensor networks (WSNs) have been confirmed as one of the most promising technologies for many smart grid (SG) applications due to their low complexity and inexpensive costs. A typical WSN is formed with numerous battery limited sensor nodes mounted on critical components of a SG system for monitoring applications. Acquired monitoring data by sensor nodes are conveyed to the base station generally by using multihop communication techniques. WSN-based SG applications encounter severe propagation losses due to extreme channel conditions of the SG environment. In order to reduce possible packet errors caused by channel variations, transmission power control approaches can …

Management Of A Hybrid Renewable Power Plant Supplying An Isolated Rural Load Within A Changing Environment, Hichem Azli, Mohamed Mostefai

Turkish Journal of Electrical Engineering and Computer Sciences

Often, authors deal with the sizing issue of hybrid power plants on horizons of several years. Proposed approaches are certainly essential to optimize energy costs. However, these solutions cannot remain optimal throughout the life cycle of the plant due to the inevitable evolution of the number of households, their consumption profiles, and possible degradation of a part of the plant. In this paper, an efficient management strategy of a sized hybrid renewable system is developed. It is based on the scheduling of the different resources of the plant. The main aim is to minimize the generated energy cost while ensuring …

Improved Design Of Axial Flux Permanent Magnet Generator For Small-Scale Wind Turbine, Mojtaba Eldoromi, Sajjad Tohidi, Mohammad Reza Feyzi, Naghi Rostami, Reza Emadifar

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, much attention has been given to axial flux permanent magnet generators due to some advantages such as high efficiency, high power density, and higher torque compared to radial flux generators. In addition, increased number of poles makes them appropriate for low-speed applications such as wind power generators. In this study, an axial flux permanent magnet synchronous generator with unique features such as high power density is designed for small-scale wind turbines. The structure of generator includes a rotor and a stator. The generator is designed and then analyzed by Flux 11.2 software. The analysis includes the effects of air …

Average Modeling And Evaluation Of 18-Pulse Autotransformer Rectifier Unit Without Interphase Transformers, Shahbaz Khan, Xiaobin Zhang, Husan Ali, Haider Zaman, Muhammad Saad, Bakht Muhammad Khan

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an improved average model and evaluation of an 18-pulse autotransformer rectifier unit (ATRU) in differential delta configuration. Average models remove the switching behavior of diode rectifiers and high bandwidth transients, which not only facilitates simulation of power systems by reducing computational cost but also enables impedance-based stability analysis for large complex power systems. To experimentally validate the proposed average model, a 2-kW, 18-pulse ATRU has been tested and the results of the derived model are compared with those of the switching model and experimental prototype. Computed transfer function of load impedance from the proposed average model closely …

Application Of Acf-Wavelet Feature Extraction For Classification Of Some Artificial Pd Models Of Power Transformer, Vahid Parvin Darabad

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, 7 different artificial partial discharge (PD) models of power transformer defect types are built in a high voltage laboratory, and then PD signals are recorded in the whole power frequency cycle to develop a preliminary PD knowledge base. A specific technique is used to extract single PD events from the recorded knowledge base. By application of wavelet transform, different decomposition levels of extracted PD signals are investigated. Feature extraction is performed by application of statistic moments on the autocorrelation function of PD signal decompositions. "Best" features are selected based on the F-test. To evaluate the performance of …

Proceedings Of The Cuny Games Conference 4.0: The Interactive Course, Robert O. Duncan, Joe Bisz, Julie Cassidy, Kathleen Offenholley, Maura A. Smale, Carolyn Stallard, Deborah Sturm, Anders A. Wallace, Cuny Games Network

Publications and Research

Proceedings of the CUNY Games Conference, held from January 22-23, 2018, at the CUNY Graduate Center and Borough of Manhattan Community College.

Critical Play with History (Panel) - Composition & Storytelling - Health & Cognitive Sciences - Gaming Anthropology: Teaching Culture and Power Through Games and Design (Panel) - Twine & Writing Games - Easy Ideas II - STEM Games - Global Games for Change Catalog (Panel) - Comics & Active Learning - Fact Checking & Research - Computer Science & Game Design - SimGlobal: Building a Serious Roleplay Course for the Social Sciences (Panel) - Role Playing Games, Narrative, …

Efficient And Privacy-Preserving Outsourced Calculation Of Rational Numbers, Ximeng Liu, Kim-Kwang Raymond Choo, Robert H. Deng, Rongxing Lu, Jian Weng

Research Collection School Of Computing and Information Systems

In this paper, we propose a framework for efficient and privacy-preserving outsourced calculation of rational numbers, which we refer to as POCR. Using POCR, a user can securely outsource the storing and processing of rational numbers to a cloud server without compromising the security of the (original) data and the computed results. We present the system architecture of POCR and the associated toolkits required in the privacy preserving calculation of integers and rational numbers to ensure that commonly used outsourced operations can be handled on-the-fly. We then prove that the proposed POCR achieves the goal of secure integer and rational …

Real-World Large-Scale Iot Systems For Community Eldercare: A Comparative Study On System Dependability, Hwee-Pink Tan, Austin Zhang

Research Collection School Of Computing and Information Systems

The paradigm of aging-in-place — where the elderly live and age in their own homes, independently and safely, with care provided by the community — is compelling, especially in societies that face both shortages in institutionalized eldercare resources, and rapidly-aging populations. Internet-of-Things (IoT) technologies, particularly in-home monitoring solutions, are commercially available, and can be a fundamental enabler of smart community eldercare, if they are dependable. In this paper, we present our findings on system performance of solutions from two vendors, which we have deployed at scale for technology-enabled community care. In particular, we highlight the importance of quantifying actual system …

Improvement Of Heart Attack Prediction By The Feature Selection Methods, Hi̇dayet Takci

Turkish Journal of Electrical Engineering and Computer Sciences

Prediction of a heart attack is very important since it is one of the leading causes of sudden death, especially in low-income countries. Although cardiologists use traditional clinical methods such as electrocardiography and blood tests for heart attack prediction, computer aided diagnosis systems that use machine learning methods are also in use for this task. In this study, we used machine learning and feature selection algorithms together. Our aim is to determine the best machine learning method and the best feature selection algorithm to predict heart attacks. For this purpose, many machine learning methods with optimum parameters and several feature …

Estimating Left Ventricular Volume With Roi-Based Convolutional Neural Network, Feng Zhu

Turkish Journal of Electrical Engineering and Computer Sciences

The volume of the human left ventricular (LV) chamber is an important indicator for diagnosing heart disease. Although LV volume can be measured manually with cardiac magnetic resonance imaging (MRI), the process is difficult and time-consuming for experienced cardiologists. This paper presents an end-to-end segmentation-free method that estimates LV volume from MRI images directly. The method initially uses Fourier transform and a regression filter to calculate the region of interest that contains the LV chambers. Then convolutional neural networks are trained to estimate the end-diastolic volume (EDV) and end-systolic volume (ESV). The resulting models accurately estimate the EDV and ESV …

Automatic Detection Of The Respiratory Cycle From Recorded, Single-Channel Sounds From Lungs, Seli̇m Aras, Mehmet Öztürk, Ali̇ Gangal

Turkish Journal of Electrical Engineering and Computer Sciences

Listening to the sounds made by the lungs is a long-standing method that is still used to diagnose lung diseases. Many studies have been conducted on the automatic recognition of recorded sounds from the lungs. However, in these studies, respiratory cycles, i.e. inhalations followed by exhalations, were either monitored manually or by using multichannel signals of the sounds made by the lungs. In order to recognize sounds made by the lungs automatically, one must first use these sounds to determine the respiratory cycles. Our previous study was the first study presented in the literature in which the boundaries of respiratory …

A Novel Multistage System For The Detection And Removal Of Pectoral Muscles Inmammograms, İdi̇l Işikli Esener, Semi̇h Ergi̇n, Tolga Yüksel

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel multistage scheme for pectoral muscle removal from mammography images is proposed, and the performance of this system is verified using the publicly available Mammographic Image Analysis Society digital mammogram database. This database is composed of mediolateral oblique mammography images including three different tissue types (fatty, fatty-glandular, and dense-glandular) with three health status types (normal, benign cancer, and malignant cancer). In the implementation of the proposed system, a mammography image is first preprocessed by performing noise reduction background removal followed by artifact suppression processes. Then a presegmentation procedure is applied using region growing and line fitting …

Multimodal Medical Imaging Repository And Information System In Epilepsysurgery, Gülsüm Akdeni̇z, İbrahi̇m Atli, Fati̇h Vehbi̇ Çelebi̇

Turkish Journal of Electrical Engineering and Computer Sciences

Surgery is an option for patients with drug-resistant epilepsy, but it requires a comprehensive assessment. Electroencephalography (EEG), magnetic resonance imaging (MRI), and functional MRI (fMRI) are used to localize the epileptogenic zone, which directly affects the surgery outcome. Accessing EEG, MRI, and fMRI results and patient information simultaneously using traditional methods might result in misinformation and increase the workload of clinicians. In this study, we developed a modern web-based repository system for the preoperative evaluation of epilepsy disorder, including multimodal medical images and patient information. Our dedicated system is enriched with clinical metadata that are not currently available and is …

Gnss Augmentation Through Ku-Band Communication Satellites With Rtkrealization, Şenol Gülgönül

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a method to broadcast real-time kinematics (RTK) corrections over a communication satellite is proposed. RTK corrections generated by the reference station are uplinked to the communication satellite within a multiplexed DVB-S carrier. Corrections are received by a satellite dish and the DVB-S satellite receiver. Better than 18 cm of accuracy is achieved for rover distances of up to 500 km in Turkey. The proposed method can be used as an alternative satellite-based augmentation system for Turkey and other countries.

Ultra Low-Power Dc Voltage Limiter For Rfid Application In 0.18-Μm Cmostechnology, Rezvan Dastanian, Sajad Nejadhasan

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a low-power DC voltage limiter is designed for radio frequency identification tags. In this design, the low-power bandgap reference (BGR) circuit, which is insensitive to temperature, and also the comparator are used for the voltage limiter circuit. To make the I-V curve approach the ideal one, four inverter stages are employed to the output of the comparator. The structure of the BGR and comparator use only MOSFET transistors that work in subthreshold region when the limiter is inactive. These two blocks have power consumption of 220 pW and 1300 pW, respectively. The limited output voltage is 1.5 …

A Strategy For Improving Netclust Server Placement For Multicloud Environments, Yuting Zhao, Jinhong Liu, Qing Fang, Lifang Xu, Changlai Du, Yuan Xiaoqun

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose a fast server placement algorithm to improve the NetClust framework and make it more efficient and exible. To this end, we introduce hierarchical clustering technologies to the NetClust framework and propose a exible server placement algorithm, which integrates the agglomerative and divisive clustering technologies to reduce the time complexity and avoid the performance uctuation affected by the initial node selection. The experiment results show that our server placement algorithm may reduce the time complexity of server selection of NetClust significantly and improve the exibility and applicability of the NetClust.

Performance Analysis Of Hamming Code For Wsn-Based Smart Grid Applications, Meli̇ke Yi̇ği̇t, Vehbi̇ Çağri Güngör, Pinar Bölük

Turkish Journal of Electrical Engineering and Computer Sciences

Many methods have been employed to detect, compare, and correct errors to increase communication reliability and efficiency in wireless sensor networks (WSNs). However, to the best of our knowledge, no existing study has compared the performance of error control codes by using different modulation techniques in a smart grid communication environment when multichannel scheduling is used. This paper presents a detailed performance evaluation and makes a comparison of different modulation techniques, such as frequency shift keying (FSK), differential phase shift keying (DPSK), binary phase shift keying (BPSK), and offset quadrature phase-shift keying (OQPSK), using Hamming codes in a 500-kV line-of-sight …

Energy-Efficient And Reliable Data Collection In Wireless Sensor Networks, Deepa Puneeth, Nishanth Joshi, Pradeep Kumar Atrey, Muralidhar Kulkarni

Turkish Journal of Electrical Engineering and Computer Sciences

Ensuring energy efficiency, data reliability, and security is important in wireless sensor networks (WSNs). A combination of variants from the cryptographic secret sharing technique and the disjoint multipath routing scheme is an effective strategy to address these requirements. Although Shamir's secret sharing (SSS) provides the desired reliability and information-theoretic security, it is not energy efficient. Alternatively, Shamir's ramp secret sharing (SRSS) provides energy efficiency and data reliability, but is only computationally secure. We argue that both these approaches may suffer from a compromised node (CN) attack when a minimum number of nodes is compromised. Hence, we propose a new scheme …

An Efficient Algorithm To Decompose A Compound Rectilinear Shape Into Simplerectilinear Shapes, Imran Sharif, Debasis Chaudhuri, Naveen Kushwaha, Ashok Samal, Brij Mohan Singh

Turkish Journal of Electrical Engineering and Computer Sciences

Detection of a compound object is a critical problem in target recognition. For example, buildings form an important class of shapes whose recognition is important in many remote sensing based applications. Due to the coarse resolution of imaging sensors, adjacent buildings in the scenes appear as a single compound shape object. These compound objects can be represented as the union of a set of disjoint rectilinear shaped objects. Separating the individual buildings from the resulting compound objects in a segmented image is often difficult but important nevertheless. In this paper we propose a new and efficient technique to decompose a …

Improved Discrete Sliding Mode Control Strategy For Pulse-Width Modulationrectifier, Jing Cao, Chaonan Tong

Turkish Journal of Electrical Engineering and Computer Sciences

An improved sliding mode control utilizing repetitive control (ISMRC) is proposed for a three-phase pulse- width modulation (PWM) rectifier. The proposed controller integrates the advantages of both sliding mode control (SMC) and repetitive control (RC) by implementing a structure that embeds an RC controller into the equivalent control branch of an SMC controller. Both a simulation and an experiment are conducted to compare the proposed ISMRC controller with a conventional SMC controller. It is demonstrated that the fifth harmonic distortion of the current of the PWM rectifier system is controlled at 3.3%, the power factor is close to the unit, …