Computer Engineering Commons^™

Development Of A Compact Vertical-Cavity Surface-Emitting Laser End-Pumped Actively Q-Switched Laser For Laser-Induced Breakdown Spectroscopy, Shuo Li, L. Liu, Rongzhang Chen, Bryan Nelsen, Xi Huang, Yongfeng Lu, Kevin Chen

Department of Electrical and Computer Engineering: Faculty Publications

This paper reports the development of a compact and portable actively Q-switched Nd:YAG laser and its applications in laser-induced breakdown spectroscopy (LIBS). The laser was end-pumped by a vertical-cavity surface-emitting laser (VCSEL). The cavity lases at a wavelength of 1064 nm and produced pulses of 16 ns with a maximum pulse energy of 12.9 mJ. The laser exhibits a reliable performance in terms of pulse-to-pulse stability and timing jitter. The LIBS experiments were carried out using this laser on NIST standard alloy samples. Shot-to-shot LIBS signal stability, crater profile, time evolution of emission spectra, plasma electron density and temperature, and …

Alloy Oxidation As A Route To Chemically Active Nanocomposites Of Gold Atoms In A Reducible Oxide Matrix, Peter Sutter, S. A. Tenney, F. Ivars- Barcelo, L. Wu, Y. Zhu, Eli Sutter

Department of Electrical and Computer Engineering: Faculty Publications

While nanoparticles are being pursued actively for a number of applications, dispersed atomic species have been explored far less in functional materials architectures, primarily because composites comprising dispersed atoms are challenging to synthesize and difficult to stabilize against sintering or coarsening. Here we show that room temperature oxidation of Au–Sn alloys produces nanostructures whose surface is terminated by a reducible amorphous oxide that contains atomically dispersed Au. Analysis of the oxidation process shows that the dispersal of Au in the oxide can be explained by predominant oxygen anion diffusion and kinetically limitedmetalmass transport, which restrict phase separation due to a …

Enhanced Four-Wave Mixing With Nonlinear Plasmonic Metasurfaces, Boyuan Jin, Christos Argyropoulos

Department of Electrical and Computer Engineering: Faculty Publications

Plasmonic metasurfaces provide an effective way to increase the efficiency of several nonlinear processes while maintaining nanoscale dimensions. In this work, nonlinear metasurfaces based on film-coupled silver nanostripes loaded with Kerr nonlinear material are proposed to achieve efficient four-wave mixing (FWM). Highly localized plasmon resonances are formed in the nanogap between the metallic film and nanostripes. The local electric field is dramatically enhanced in this subwavelength nanoregion. These properties combined with the relaxed phase matching condition due to the ultrathin area lead to a giant FWM efficiency, which is enhanced by nineteen orders of magnitude compared to a bare silver …

Anisotropy, Band-To-Band Transitions, Phonon Modes, And Oxidation Properties Of Cobalt-Oxide Core-Shell Slanted Columnar Thin Films, Alyssa Mock, Rafał Korlacki, Chad Briley, Derek Sekora, Tino Hofmann, Peter M. Wilson, Alexander Sinitskii, Eva Schubert, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

Highly ordered and spatially coherent cobalt slanted columnar thin films (SCTFs) were deposited by glancing angle deposition onto silicon substrates, and subsequently oxidized by annealing at 475°C. Scanning electron microscopy, Raman scattering, generalized ellipsometry, and density functional theory investigations reveal shape-invariant transformation of the slanted nanocolumns from metallic to transparent metal-oxide core-shell structures with properties characteristic of spinel cobalt oxide. We find passivation of Co-SCTFs yielding Co-Al₂O₃core-shell structures produced by conformal deposition of a few nanometers of alumina using atomic layer deposition fully prevents cobalt oxidation in ambient and from annealing up to 475°C.

Anisotropy, Phonon Modes, And Free Charge Carrier Parameters In Monoclinic Β-Gallium Oxide Single Crystals, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

We derive a dielectric function tensor model approach to render the optical response of monoclinic and triclinic symmetrymaterials with multiple uncoupled infrared and far-infrared active modes.We apply our model approach to monoclinic β-Ga₂O₃ single-crystal samples. Surfaces cut under different angles from a bulk crystal, (010) and (201), are investigated by generalized spectroscopic ellipsometry within infrared and far-infrared spectral regions. We determine the frequency dependence of 4 independent β-Ga₂O₃ Cartesian dielectric function tensor elements by matching large sets of experimental data using a point-by-point data inversion approach. From matching our monoclinic model to …

Saros: A Social-Aware Opportunistic Forwarding Simulator, Soumaia Al Ayyat

Papers, Posters, and Presentations

Many applications are being developed to leverage the popularity of mobile opportunistic networks. However, building adaptive testbeds can be costly and challenging. This challenge motivates the need for effective opportunistic network simulators to provide a variety of opportunistic environment setups, and evaluate proposed applications and protocols with a comprehensive set of metrics. This paper presents SAROS, a simulator of opportunistic networking environments with a variety of interest distributions, power consumption distributions, imported real traces, and social network integration. The simulator provides a wide variety of evaluation metrics that are not offered by comparable simulators. Finally, SAROS also implements several opportunistic …

Bytewise Approximate Matching: The Good, The Bad, And The Unknown, Vikram S. Harichandran, Frank Breitinger, Ibrahim Baggili

Electrical & Computer Engineering and Computer Science Faculty Publications

Hash functions are established and well-known in digital forensics, where they are commonly used for proving integrity and file identification (i.e., hash all files on a seized device and compare the fingerprints against a reference database). However, with respect to the latter operation, an active adversary can easily overcome this approach because traditional hashes are designed to be sensitive to altering an input; output will significantly change if a single bit is flipped. Therefore, researchers developed approximate matching, which is a rather new, less prominent area but was conceived as a more robust counterpart to traditional hashing. Since the conception …

A Verified Information-Flow Architecture, Arthur Azevedo De Amorim, Nathan Collins, André Dehon, Delphine Demange, Cătălin Hriţcu, David Pichardie, Benjamin C. Pierce, Randy Pollack, Andrew Tolmach

Computer Science Faculty Publications and Presentations

SAFE is a clean-slate design for a highly secure computer system, with pervasive mechanisms for tracking and limiting information flows. At the lowest level, the SAFE hardware supports fine-grained programmable tags, with efficient and flexible propagation and combination of tags as instructions are executed. The operating system virtualizes these generic facilities to present an information-flow abstract machine that allows user programs to label sensitive data with rich confidentiality policies. We present a formal, machine-checked model of the key hardware and software mechanisms used to dynamically control information flow in SAFE and an end-to-end proof of noninterference for this model. We …

Distinct And Shared Determinants Of Cardiomyocyte Contractility In Multi-Lineage Competent Ethnically Diverse Human Ipscs, Martin L. Tomov, Zachary T. Olmsted, Haluk Dogan, Eda Gongorurler, Maria Tsompana, Hasan H. Otu, Michael Buck, Eun-Ah Chang, Jose Cibelli, Janet L. Paluh

Department of Electrical and Computer Engineering: Faculty Publications

The realization of personalized medicine through human induced pluripotent stem cell (iPSC) technology can be advanced by transcriptomics, epigenomics, and bioinformatics that inform on genetic pathways directing tissue development and function. When possible, population diversity should be included in new studies as resources become available. Previously we derived replicate iPSC lines of African American, Hispanic-Latino and Asian self-designated ethnically diverse (ED) origins with normal karyotype, verified teratoma formation, pluripotency biomarkers, and tri-lineage in vitro commitment. Here we perform bioinformatics of RNA-Seq and ChIP-seq pluripotency data sets for two replicate Asian and Hispanic-Latino ED-iPSC lines that reveal differences in generation of …

Fast And De-Noise Support Vector Machine Training Method Based On Fuzzy Clustering Method For Large Real World Datasets, Omid Naghash Almasi, Modjtaba Rouhani

Turkish Journal of Electrical Engineering and Computer Sciences

Classifying large and real-world datasets is a challenging problem in machine learning algorithms. Among the machine learning methods, the support vector machine (SVM) is a well-known approach with high generalization ability. Unfortunately, while the number of training data increases and the data contain noise, the performance of SVM significantly decreases. In this paper, a fast and de-noise two-stage method for training SVMs to deal with large, real-world datasets is proposed. In the first stage, data that contain noises or are suspected to be noisy are identified and eliminated from the genuine training dataset. The process of elimination and identification is …

A New Cmos Zc-Cdta Realization And Its Filter Applications, Ersi̇n Alaybeyoğlu, Hulusi̇ Hakan Kuntman

Turkish Journal of Electrical Engineering and Computer Sciences

The Z copy current differencing transconductance amplifier (ZC-CDTA) is a new current-mode active element that was introduced recently. ZC-CDTA is improved from the current differencing transconductance amplifier (CDTA) and has increased its universality. In the current study, a CMOS implementation of ZC-CDTA is proposed. The first stage of ZC-CDTA consists of a current differencing unit. The output stage consists of a dual output transconductance amplifier. Furthermore, a third-generation current conveyor is used to copy the Z terminal current instead of a classical current mirror. A fourth-order filter application employing ZC-CDTAs is given and simulation results are added. The ZC-CDTA-based filter …

Design And Implementation Of A Man-Overboard Emergency Discovery System Based On Wireless Sensor Networks, Abdullah Sevi̇n, Cüneyt Bayilmiş, İsmai̇l Ertürk, Hüseyi̇n Eki̇z, Ahmet Karaca

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, wireless sensor networks (WSNs) have been widely employed in many different fields such as military, surveillance, health, agricultural, automation, and environmental monitoring. This paper presents a designed and implemented WSN-based man-overboard emergency discovery system, abbreviated as W-MEDS, that discovers the location of a person in emergency circumstances and runs an alarm system on a ship. The developed W-MEDS carries out a fast man-overboard (MOB) discovery and initiates the vital rescue procedure. It mainly consists of a WSN and a control and discovery system. When a MOB accident occurs, this situation is easily detected through the WSN nodes capable of …

Residential Electricity Pricing Using Time-Varying And Non-Time-Varying Scenarios: An Application Of Game Theory, Najme Khaleghifar, Hamid Amadeh, Mohammad Hosein Rezaeian Koochi

Turkish Journal of Electrical Engineering and Computer Sciences

residential consumer and the power network. With the growth of power systems and the advent of new energy sources, such as solar energy, it seems to be more essential to investigate how the network and the consumer can interact with each other to achieve more financial benefits. To do that, a static game is defined considering the fact that there is a direct relationship between the amount of load shifted by the consumer and the incentive offered by the network. It is concluded that the Nash equilibrium of this game is when the consumer decides to cooperate with the network …

A Robust Undervoltage Load Shedding Scheme Against Voltage Instability, Iman Kaffashan, Seyed Mohammad Taghi Mirali Mortezaee, Turaj Amraee

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Predicting Acute Hypotensive Episode By Using Hybrid Features And A Neuro-Fuzzy Network, Marzieh Abbasinia, Fardad Farokhi, Shahram Javadi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an approach for acute hypotensive episode (AHE) time series forecasting based on hybrid feature space and a neuro-fuzzy network. Prediction was accomplished through a combination of time domain and wavelet features by using six vital time series of each patient, obtained from MIMIC-II and available in the context of the Physionet-Computers in Cardiology 2009 Challenge. At first, statistical time domain features were used and then the wavelet coefficient was utilized for extracting time scale features. Further UTA feature selection was applied and 30 effective features were determined and achieved to predict AHE with 96.30 accuracy 1.5 h …

Energy Efficient Multiconstrained Optimization Using Hybrid Aco And Ga In Manet Routing, Nivetha Senthil Kumaran, Asokan Ramasamy

Turkish Journal of Electrical Engineering and Computer Sciences

Nodes in mobile ad hoc networks (MANET) suffer from limited battery power and bandwidth. Particularly for real time multimedia communications through MANET, metrics like residual node energy, bandwidth, and end-to-end delay have major impacts. In MANET, designing a dynamic routing algorithm to satisfy quality of service (QoS) requirements is a challenging task. Additionally, multiconstrained QoS routing aims to optimize multiple QoS metrics while providing required network resources and is an admittedly complex problem. It has been proved to be NP-complete when a combination of additive, concave, and multiplicative metrics are considered. Hence, this problem can be solved using metaheuristic methods …

A Centralized Self-Adaptive Fault Tolerance Approach Based On Feedback Control For Multiagent Systems, Şebnem Bora, Oğuz Di̇kenelli̇

Turkish Journal of Electrical Engineering and Computer Sciences

Our research introduces a self-adaptive fault tolerance approach for multiagent systems that enables the system to avoid crash failures. It is a replication-based approach that exploits a feedback control loop and a proportional (P) controller within a replication infrastructure. Thus, we are able to both observe the agents' behaviors to estimate criticalities and determine the number of replicas in replica groups with respect to the agents' criticalities and the number of available resources. Thus, agents that are to be replicated and the numbers of replicas in replica groups are automatically and adaptively identified in dynamic environments. We implement this approach …

Exploring Deviant Hacker Networks (Dhm) On Social Media Platforms, Samer Al-Khateeb, Kevin J. Conlan, Nitin Agarwal, Ibrahim Baggili, Frank Breitinger

Journal of Digital Forensics, Security and Law

Online Social Networks (OSNs) have grown exponentially over the past decade. The initial use of social media for benign purposes (e.g., to socialize with friends, browse pictures and photographs, and communicate with family members overseas) has now transitioned to include malicious activities (e.g., cybercrime, cyberterrorism, and cyberwarfare). These nefarious uses of OSNs poses a significant threat to society, and thus requires research attention. In this exploratory work, we study activities of one deviant groups: hacker groups on social media, which we term Deviant Hacker Networks (DHN). We investigated the connection between different DHNs on Twitter: how they are connected, identified …

Log Analysis Using Temporal Logic And Reconstruction Approach: Web Server Case, Murat Gunestas, Zeki Bilgin

Journal of Digital Forensics, Security and Law

We present a post-mortem log analysis method based on Temporal Logic (TL), Event Processing Language (EPL), and reconstruction approach. After showing that the proposed method could be adapted to any misuse event or attack, we specifically investigate the case of web server misuses. To this end, we examine 5 different misuses on Wordpress web servers, and generate corresponding log files of these attacks for forensic analysis. Then we establish attack patterns and formalize them by means of a special case of temporal logic, i.e. many sorted first order metric temporal logic (MSFOMTL). Later on, we implement these attack patterns in …

Personalized And Adaptive Semantic Information Filtering For Social Media, Pavan Kapanipathi

Browse all Theses and Dissertations

Social media has experienced immense growth in recent times. These platforms are becoming increasingly common for information seeking and consumption, and as part of its growing popularity, information overload pose a significant challenge to users. For instance, Twitter alone generates around 500 million tweets per day and it is impractical for users to have to parse through such an enormous stream to find information that are interesting to them. This situation necessitates efficient personalized filtering mechanisms for users to consume relevant, interesting information from social media. Building a personalized filtering system involves understanding users' interests and utilizing these interests to …

Detecting Php-Based Cross-Site Scripting Vulnerabilities Using Static Program Analysis, Steven M. Kelbley

Browse all Theses and Dissertations

With the widespread adoption of dynamic web applications in recent years, a number of threats to the security of these applications have emerged as significant challenges for application developers. The security of developed applications has become a higher priority for both developers and their employers as cyber attacks become increasingly more prevalent and damaging. Some of the most used web application frameworks are written in PHP and have become major targets due to the large number of servers running these applications worldwide. A number of tools exist to evaluate PHP code for issues, however most of these applications are not …

Miniatured Inertial Motion And Position Tracking And Visualization Systems Using Android Wear Platform, Dhruvkumar Navinchandra Patel

Browse all Theses and Dissertations

In this thesis, we have designed and developed a motion tracking and visualization system using the latest motion tracking sensory technologies. It is one of the enabling technologies for our novel visual-inertial odometer and human anatomy based 3D Locating, Mapping and Navigation system for endoscopy and drug delivery capsules used inside GI tract. In particular, we have: i) designed and completed a cloud-based sensory data collecting, processing and storage system to provide the reliable computing and storage platform; ii) explored different data processing methods to obtain improved-quality motion results from extremely noisy raw data, e.g., by using a low pass …

Computational Methods For Comparative Non-Coding Rna Analysis: From Secondary Structures To Tertiary Structures, Ping Ge

Electronic Theses and Dissertations

Unlike message RNAs (mRNAs) whose information is encoded in the primary sequences, the cellular roles of non-coding RNAs (ncRNAs) originate from the structures. Therefore studying the structural conservation in ncRNAs is important to yield an in-depth understanding of their functionalities. In the past years, many computational methods have been proposed to analyze the common structural patterns in ncRNAs using comparative methods. However, the RNA structural comparison is not a trivial task, and the existing approaches still have numerous issues in efficiency and accuracy. In this dissertation, we will introduce a suite of novel computational tools that extend the classic models …

Detecting And Tracing Slow Attacks On Mobile Phone User Service, Brian Cusack, Zhuang Tian

Australian Digital Forensics Conference

The lower bandwidth of mobile devices has until recently filtered the range of attacks on the Internet. However, recent research shows that DOS and DDOS attacks, worms and viruses, and a whole range of social engineering attacks are impacting on broadband smartphone users. In our research we have developed a metric-based system to detect the traditional slow attacks that can be effective using limited resources, and then employed combinations of Internet trace back techniques to identify sources of attacks. Our research question asked: What defence mechanisms are effective? We critically evaluate the available literature to appraise the current state of …

The Proceedings Of 14th Australian Digital Forensics Conference, 5-6 December 2016, Edith Cowan University, Perth, Australia, Craig Valli

Australian Digital Forensics Conference

Conference Foreword

This is the fifth year that the Australian Digital Forensics Conference has been held under the banner of the Security Research Institute, which is in part due to the success of the security conference program at ECU. As with previous years, the conference continues to see a quality papers with a number from local and international authors. 11 papers were submitted and following a double blind peer review process, 8 were accepted for final presentation and publication. Conferences such as these are simply not possible without willing volunteers who follow through with the commitment they have initially made, …

We Can Hear You With Wi-Fi!, Guanhua Wang, Yongpan Zou, Zimu Zhou, Kaishun Wu, Lionel M. Ni

Research Collection School Of Computing and Information Systems

Recent literature advances Wi-Fi signals to “see” people’s motions and locations. This paper asks the following question: Can Wi-Fi “hear” our talks? We present WiHear, which enables Wi-Fi signals to “hear” our talks without deploying any devices. To achieve this, WiHear needs to detect and analyze fine-grained radio reflections from mouth movements. WiHear solves this micro-movement detection problem by introducing Mouth Motion Profile that leverages partial multipath effects and wavelet packet transformation. Since Wi-Fi signals do not require line-of-sight, WiHear can “hear” people talks within the radio range. Further, WiHear can simultaneously “hear” multiple people’s talks leveraging MIMO technology. We …

Sickle Blood Cell Detection Based On Image Segmentation, Kholoud Alotaibi

Electronic Theses and Dissertations

Red blood cells have a vital role in human health. Red blood cells have a circular shape and a concave surface and exchange the gasses between the inside and outside of the body. However, at times, these normally round cells become sickle shaped, which is an indication of sickle cell disease. This paper introduces a unique approach to detect sickle blood cells in blood samples using image segmentation and shape detection. This method is based on calculating the max axis and min axis of the cell. The form factor is computed using these properties to determine whether the cell is …

Game Theoretical Approach For Joint Relay Selection And Resource Allocation In Mobile Device Networks, Runan Yao

Electronic Theses and Dissertations

With the improvement of hardware, more and more multimedia applications are allowed to run in the mobile device. However, due to the limited radio bandwidth, wireless network performance becomes a critical issue. Common mobile solutions are based on the centralized structure, which require an access point to handle all the communication requirement in the work area. The transmission performance of centralized framework relies on the density of access points. But increasing the number of access points will cost lot of money and the interference between access point will reduce the transmission quality. Thanks to the wireless sensor network implementations, the …

Breast Cancer Classification Of Mammographic Masses Using Circularity Max Metric, A New Method, Tae Keun Heo

Electronic Theses and Dissertations

Breast cancer classification can be divided into two categories. The first category is a benign tumor, and the other is a malignant tumor. The main purpose of breast cancer classification is to classify abnormalities into benign or malignant classes and thus help physicians with further analysis by minimizing potential errors that can be made by fatigued or inexperienced physicians. This paper proposes a new shape metric based on the area ratio of a circle to classify mammographic images into benign and malignant class. Support Vector Machine is used as a machine learning tool for training and classification purposes. The improved …

Data Center Load Forecast Using Dependent Mixture Model, Md Riaz Ahmed Khan

Electronic Theses and Dissertations

The dependency on cloud computing is increasing day by day. With the boom of data centers, the cost is also increasing, which forces industries to come up with techniques and methodologies to reduce the data center energy use. Load forecasting plays a vital role in both efficient scheduling and operating a data center as a virtual power plant. In this thesis work a stochastic method, based on dependent mixtures is developed to model the data center load and is used for day-ahead forecast. The method is validated using three data sets from National Renewable Energy Laboratory (NREL) and one other …