Computer Engineering Commons^™

Fault Tolerant Broadcasting Analysis In Wireless Monitoring Networks, Akbar Ghaffarpour Rahbar

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless monitoring networks can be used for security applications such as the monitoring of narrow passages and operational fields. These networks can be designed based on sensor networks. In sensor networks, each node can hear a message and broadcast the message to its neighbor nodes. Nevertheless, nodes may fail, so that faulty nodes cannot hear or cannot transmit any message, where the locations of the faulty nodes are unknown and their failures are permanent. In this paper, the nodes are situated on a line or a square grid-based topology in a plane for security/monitoring applications. For each topology, 2 nonadaptive …

Digital Control System Design And Analyses Of A 3-Phase Bearingless Induction Motor, Wenshao Bu, Conglin Zu, Shaojie Wang, Shenghua Huang

Turkish Journal of Electrical Engineering and Computer Sciences

The overall configuration of a magnetic suspension decoupling control system is designed to realize the reliable digital control of a 3-phase bearingless induction motor whose rotor windings are not pole-specific. Based on a digital signal processor complementary metal-oxide semiconductor chip, the digital control hardware and software systems are analyzed and designed. In this paper, the calculation and regulation of the motor rotational speed, correction and regulation methods of the radial displacements, calculation and compensation algorithms of the unilateral magnetic pulls, induction compensation algorithm of the effective suspension control current, current regulation, and space-vector pulse width modulation algorithms, are presented in …

Class-E Gaas Hbt Power Amplifier With Passive Linearization Scheme For Mobile Wireless Communications, Uthirajoo Eswaran, Harikrishnan Ramiah, Jeevan Kanesan, Ahmed Wasif Reza

Turkish Journal of Electrical Engineering and Computer Sciences

A linearization technique for improving the class-E power amplifier (PA)'s adjacent channel power ratio (ACPR) is proposed. The design is simulated in a 2-mu m InGaP/GaAs heterojunction bipolar transistor process. The integration of a passive predistorter at the input of the PA linearizes the proposed architecture. At a 29-dBm output power, the PA's ACPR is indicated to be -51 dBc, meeting the stringent code division multiple access regulation. At this exact output power, the simulated power added efficiency is 55 % with the collector voltage headroom consumption of 3.4 V. The input return loss, S11, of the PA is simulated …

A Reconfigurable Baseband Circuit Applied For Wimax Low-If Receivers, Xin Cheng, Guangjun Xie

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a reconfigurable baseband circuit for WiMAX low-IF receivers, including a complex filter and 2 automatic gain controllers (AGCs) for I and Q channels. Only by changing the capacitor values can the center and cutoff frequencies of the complex filter be adjusted simultaneously to realize the reconfigurability. Meanwhile, a novel one-step method to obtain fast gain settling of AGCs is proposed. The chip is fabricated in 0.13-\mu m CMOS technology, occupies 0.9 \times 1.3 mm^2, and consumes 14.8 mW of power with a 1.2-V power supply. The measurement results show a reconfigurable bandwidth of 2 K to 3.5/5/10 …

Predics: A New Go-Po-Based Ray Launching Simulator For The Calculation Of Electromagnetic Scattering And Rcs From Electrically Large And Complex Structures, Caner Özdemi̇r, Betül Yilmaz, Özkan Kirik

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present a new simulator called pRediCS for the calculation of electromagnetic scattering and radar cross-section (RCS) from electrically large and complex targets. The simulator utilizes the geometric optics (GO) theory and launching of electromagnetic rays for tracing and calculating the electric field values as the electromagnetic waves bounce around the target. The physical optics (PO) theory is also exploited to calculate the final scattered electric field by calculating the far-field PO integration along the observation direction. The simulator is first tested with known objects of canonical shapes, whose analytical solutions are available in the literature. Next, …

Sliding Mode Controller Design With Fractional Order Differentiation: Applications For Unstable Time Delay Systems, Celaleddi̇n Yeroğlu, Gürkan Kavuran

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a design method for a sliding mode controller with the contribution of a fractional order differential operator. The conventional sliding mode controller has been widely studied in different control applications. This paper proposes that the fractional order differential operator enlarges the output span of the classical sliding mode controller to obtain a better-fitting control signal for enhanced control performance. The sliding surface and the equivalent control law are modified with the addition of a fractional differential operator and a conventional one. The proposed sliding mode controller with fractional order differentiation is applied to the unstable time delay …

Real-Time Control Of An Automated Guided Vehicle Using A Continuous Mode Of Sliding Mode Control, Bi̇rol Soysal

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a tracking control method for a certain type of differential-drive wheeled mobile robot, called automated guided vehicles (AGVs), using a continuous mode approach of sliding mode control (SMC). The SMC applied produces a continuous signal in between the U and -U control signals instead of discrete ones. The controller is applied to control the velocity and direction angle of the vehicle in order to keep it on a desired path. The obtained algorithm is applied to the experimental system under load and disturbance to show its robustness. The experimental results are satisfactory and verify the performance of …

A Novel Fuzzy Filter For Speckle Noise Removal, Mehmet Ali̇ Soytürk, Alper Baştürk, Mehmet Emi̇n Yüksel

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel fuzzy system-based method for speckle noise removal is proposed. The proposed method consists of a fuzzy inference system, an edge detection and dilation unit, and an image combiner. The fuzzy inference system includes 5 inputs and 1 output, and it is responsible for filtering the speckle noisy image. The inputs of the fuzzy system consist of the center pixel of the filtering window and its 2 horizontal and vertical neighbors. The edge detection and dilation unit is used for classifying the uniform areas and nonuniform image regions such as edges. The image combiner unites the …

Abrupt And Incipient Fault Detection And Compensation For A 4-Tank System Benchmark, Pedram Hajiani, Javad Poshtan

Turkish Journal of Electrical Engineering and Computer Sciences

Fault detection and compensation play a key role in enhancing the high demand for performance and security in technological systems. This paper proposes an active fault-tolerant control scheme that detects and compensates for actuator faults in a 4-tank system benchmark. The faults are modeled as a drastic gain loss in actuators (pumps), which could lead to a large loss in the nominal performance. The model-based approach uses a recursive least squares parameter estimation algorithm to form a fault detection and diagnosis subsystem and utilizes a parametric eigenstructure assignment method to reconfigure the state feedback controller. The designed controller is simulated …

Performance Of Exhaustive Search With Parallel Agents, Toni Draganov Stojanovski

Turkish Journal of Electrical Engineering and Computer Sciences

The advent of high-performance computing via many-core processors and distributed processing emphasizes the possibility for exhaustive search by multiple search agents. Despite the occurrence of elegant algorithms for solving complex problems, exhaustive search has retained its significance since many real-life problems exhibit no regular structure and exhaustive search is the only possible solution. Here we analyze the performance of exhaustive search when it is conducted by multiple search agents. Several strategies for joint search with parallel agents are evaluated. We discover that the performance of the search improves with the increase in the level of mutual help between agents. The …

Website Accessibility In Australia And The National Transition Strategy: Outcomes And Findings, Vivienne Conway

Theses: Doctorates and Masters

In the most recent statistics, published by the Australian Bureau of Statistics in 2012, it was reported that slightly under one in five people stated they had a disability. A further twenty-one percent of the population (4.7 million people) reported that they had a long-term health condition that did not restrict their everyday activities. This total group of people who suffer either a disability or a long-term health condition numbers 8.9 million people, or over thirty-nine percent of the Australian population. Of the people reporting a disability, 3.7 million or eighty-eight percent of that group experienced limitations in the activities …

On The Security Of Auditing Mechanisms For Secure Cloud Storage, Yong Yu, Lei Niu, Guomin Yang, Yi Mu, Willy Susilo

Research Collection School Of Computing and Information Systems

Cloud computing is a novel computing model that enables convenient and on-demand access to a shared pool of configurable computing resources. Auditing services are highly essential to make sure that the data is correctly hosted in the cloud. In this paper, we investigate the active adversary attacks in three auditing mechanisms for shared data in the cloud, including two identity privacy-preserving auditing mechanisms called Oruta and Knox, and a distributed storage integrity auditing mechanism.We show that these schemes become insecure when active adversaries are involved in the cloud storage. Specifically, an active adversary can arbitrarily alter the cloud data without …

A Federated Architecture For Heuristics Packet Filtering In Cloud Networks, Ibrahim M. Waziri Jr

College of Graduate Studies: Theses & Dissertations

The rapid expansion in networking has provided tremendous opportunities to access an unparalleled amount of information. Everyone connects to a network to gain access and to share this information. However when someone connects to a public network, his private network and information becomes vulnerable to hackers and all kinds of security threats. Today, all networks needs to be secured, and one of the best security policies is firewall implementation.

Firewalls can be hardware or cloud based. Hardware based firewalls offer the advantage of faster response time, whereas cloud based firewalls are more flexible. In reality the best form of firewall …

Neuromodulation Based Control Of Autonomous Robots On A Cloud Computing Platform, Cameron Muhammad

College of Graduate Studies: Theses & Dissertations

In recent years, the advancement of neurobiologically plausible models and computer networking has resulted in new ways of implementing control systems on robotic platforms. The work presents a control approach based on vertebrate neuromodulation and its implementation on autonomous robots in the open-source, open-access environment of robot operating system (ROS). A spiking neural network (SNN) is used to model the neuromodulatory function for generating context based behavioral responses of the robots to sensory input signals. The neural network incorporates three types of neurons- cholinergic and noradrenergic (ACh/NE) neurons for attention focusing and action selection, dopaminergic (DA) neurons for rewards- and …

Using Software-Based Decision Procedures To Control Instruction-Level Execution, William B. Kimball

AFIT Patents

An apparatus, method and program product are provided for securing a computer system. A digital signature of an application is checked, which is loaded into a memory of the computer system configured to contain memory pages. In response to finding a valid digital signature, memory pages containing instructions of the application are set as executable and memory pages other than those containing instructions of the application are set as non-executable. Instructions in executable memory pages are executed. Instructions in non-executable memory pages are prevented from being executed. A page fault is generated in response to an attempt to execute an …

Enhanced Optical Bistability With Film-Coupled Plasmonic Nanocubes, Christos Argyropoulos, Cristian Ciraci, David R. Smith

Department of Electrical and Computer Engineering: Faculty Publications

Colloidally synthesized nanocubes strongly coupled to conducting films hold great promise for enhancing different nonlinear optical processes. They exhibit a robust and sensitive scattering response that can be easily controlled by their geometrical and material parameters. Strong local field enhancement is generated at the gap regions between the nanocubes and the metallic film. We show that strong optical bistability and all-optical switching behavior can be obtained by loading these nanogaps with Kerr nonlinear materials. Relatively low input intensities are required to obtain these nonlinear effects. The proposed design can lead to efficient, low-power, and ultrafast all-optical memories and scattering nanoswitches.

Mobile Sensor Data Mining, Jeff Lockhart Fcrh '13

The Fordham Undergraduate Research Journal

At an ever increasing rate, the smartphones and other devices people carry with them in their everyday lives are packed with sensors and processing power. This provides an unprecedented opportunity to apply data mining techniques to people’s activities as they go about their daily lives, without changing their routine. The goal of the Wireless Sensor Data Mining (WISDM) Project is to explore the possibilities of data mining on these powerful mobile platforms.1 Data mining involves extracting knowledge from data using computer algorithms. A major sensor in these devices is the tri-axial accelerometer originally included for screen rotation and advanced gaming. …

Data Management In Cloud Environments: Nosql And Newsql Data Stores, Katarina Grolinger, Wilson A. Higashino, Abhinav Tiwari, Miriam Am Capretz

Electrical and Computer Engineering Publications

: Advances in Web technology and the proliferation of mobile devices and sensors connected to the Internet have resulted in immense processing and storage requirements. Cloud computing has emerged as a paradigm that promises to meet these requirements. This work focuses on the storage aspect of cloud computing, specifically on data management in cloud environments. Traditional relational databases were designed in a different hardware and software era and are facing challenges in meeting the performance and scale requirements of Big Data. NoSQL and NewSQL data stores present themselves as alternatives that can handle huge volume of data. Because of the …

Reduced Row Echelon Form And Non-Linear Approximation For Subspace Segmentation And High-Dimensional Data Clustering, Akram Aldroubi, Ali Sekmen

Computer Science Faculty Research

Given a set of data W={w1,…,wN}∈RD drawn from a union of subspaces, we focus on determining a nonlinear model of the form U=⋃i∈ISi, where {Si⊂RD}i∈I is a set of subspaces, that is nearest to W. The model is then used to classify W into clusters. Our approach is based on the binary reduced row echelon form of data matrix, combined with an iterative scheme based on a non-linear approximation method. We prove that, in absence of noise, our approach can find the number of subspaces, their dimensions, and an orthonormal basis for each subspace Si. We provide a comprehensive analysis …

Multiplexed Fiber-Ring Laser Sensors For Ultrasonic Detection, Tongqing Liu, Lingling Hu, Ming Han

Department of Electrical and Computer Engineering: Faculty Publications

We propose and demonstrate a multiplexing method for ultrasonic sensors based on fiber Bragg gratings (FBGs) that are included inside the laser cavity of a fiber-ring laser. The multiplexing is achieved using add-drop filters to route the light signals, according to their wavelengths, into different optical paths, each of which contains a separate span of erbium-doped fiber (EDF) as the gain medium. Because a specific span of EDF only addresses a single wavelength channel, mode completion is avoided and the FBG ultrasonic sensors can be simultaneously demodulated. The proposed method is experimentally demonstrated using a two-channel system with two sensing …

Situational Awareness/Triage Tool For Use In A Chemical, Biological, Radiological Nuclear Explosive (Cbrne) Environment, John N. Scarlett, Heather L. Gallup, David A. Smith

AFIT Patents

A method of managing patient care and emergency response following a Chemical, Biological, Radiological, or Nuclear Explosive (CBRNE) attack and maintaining compliance with the Health Insurance Portability and Accountability Act (HIPAA). The method including identifying each patient with a unique patient identifier, the identifier based upon the geospatial location of the patient, the geospatial location including at least the latitude and longitude of the patient when first treated, the unique patient identifier being part of patient data. Providing a collection point of patient data to form a patient data database where in the patient location data may be used to …

Microgrid Development Using A Grid Tie Inverter, Hartono Budi Santoso, Budiyanto Budiyanto

Makara Journal of Technology

The use of renewable energy sources (RES), especially photovoltaic (PV), to meet the demand of electrical energy has been getting a great deal of attention as an alternative solution to electrical energy deficit problems. RES are being applied in power systems in a variety of configurations including microgrid systems. One of the characteristics of a microgrid is capability to supplying power to grid when there is an excess power to supply local load. This research examines the chances of saving power consumption from grid using power converters grid tie inverter (GTI) in a microgrid configuration. The test is done by …

Surface Treatment Of Fly Ash For Improving The Tensile Strength Of Fly Ash/Unsaturated Polyester Composites, Sugiman Sugiman, Paryanto Dwi Setyawan

Makara Journal of Technology

The paper presents the surface treatment of fly ashes using acid and alkali solution on the tensile strength of the fly ash/unsaturated polyester (UP) composites. Sulfuric acid (H2SO4), hydrofluoric acid (HF) and sodium hydroxide (NaOH) solution with concentration of 0%, 5%, 10%, 15%, and 20% (by weight) were used for surface treatment of fly ashes. Generally, the tensile strength of the treated fly-ash/UP composites shows a significant increase compared to the untreated fly ash. Of all surface treatments studied, the optimum tensile strength was obtained at a concentration of 10%. At this concentration, at a fly ash content of 30% …

Recycling Roof Tile Waste Material For Wall Cover Tiles, Ambar Mulyono, Silfia Mona Aryani, Joko Lulut

Makara Journal of Technology

Prior research on roof tile waste treatment has attempted to find the appropriate technology to reuse old roof tile waste by create wall cladding materials from it. Through exploration and experimentation, a treatment method has been discovered to transform the tile fragments into artificial stone that resembles the shape of coral. This baked clay artificial stone material is then processed as a decorative element for vertical surfaces that are not load-bearing, such as on the interior and exterior walls of a building. Before applying the fragments as wall tiles, several steps must be taken: 1) Blunting, which changes the look …

Synthesis Of Tungsten Oxide Nanowires Onto Ito Glass Using T-Cvd, Tomy Abuzairi, Bohr-Ran Huang, Tzu-Ching Lin

Makara Journal of Technology

Tungsten oxide is an n-type semiconductor with interesting physical and chemical properties that make it suitable for various technological applications. Tungsten oxide nanowires were synthesized not only at low temperature but also without the use of any catalysts. The tungsten oxide nanowires were synthesized at 550 °C with tungsten layers onto the ITO glass using thermal chemical vapor deposition (T-CVD). The SEM image shows that the tungsten oxide nanowires are effectively grown with the 200 nm tungsten film. The Raman spectra shoulder at ~690 cm-1 proves the synthesized of tungsten oxide nanowires.

Semiconductor Thermal Neutron Detector, Toru Aoki, Aki Miyake, Takayuki Nakano, Akifumi Koike, Hisashi Morii, Hidenori Mimura

Makara Journal of Technology

The CdTe and GaN detector with a Gd converter have been developed and investigated as a neutron detector for neutron imaging. The fabricated Gd/CdTe detector with the 25 mm thick Gd was designed on the basis of simulation results of thermal neutron detection efficiency and spatial resolution. The Gd/CdTe detector shows the detection of neutron capture gamma ray emission in the 155Gd(n, g)156Gd, 157Gd(n, g)158Gd and 113Cd(n, g)114Cd reactions and characteristic X-ray emissions due to conversion-electrons generated inside the Gd film. The observed efficient thermal neutron detection with the Gd/CdTe detector shows its promise in neutron radiography application. Moreover, a …

Radiation Characteristics Of A Planar Strip Dipole Antenna And A Slot Dipole Antenna For Thz Applications, Catur Apriono, Eko Tjipto Rahardjo

Makara Journal of Technology

The development of a THz system often requires a device that is used to radiate or detect THz waves. One way to fulfill this requirement is to use an antenna. Therefore, we need to consider the radiation characteristics of an antenna working in the THz region. In this paper, we present simulation study of two dipole antennas, i.e. a planar strip dipole antenna and a slot dipole antenna. The simulation results show that a planar strip dipole antenna has a better radiation efficiency (more than 95%) compared to the slot dipole. It also shows that an efficiency of more than …

The Effect Of Pressing Temperature And Time On The Quality Of Particle Board Made From Jatropha Fruit Hulls Treated In Acidic Condition, Apri Heri Iswanto, Fauzi Febrianto, Yusuf Sudo Hadi, Surdiding Ruhendi, Dede Hermawan

Makara Journal of Technology

The high of pH of jatropha fruit hulls causes the negative properties of particleboard made from this material. Adjusting the particle acidity and pressing conditions (temperature and time) is among the technical modifications available to improve this particleboard’s properties. Particle acidity has been adjusted in a previous research project, and immersing the particles in acetic acid was found to be the best treatment in this preliminary research. In order to improve the particleboard’s properties, an experiment was conducted to determine the best pressing temperature and time. The objective of the research was to evaluate the influence of pressing temperature and …

Intensity-Demodulated Fiber-Ring Laser Sensor System For Acoustic Emission Detection, Ming Han, Tongqing Liu, Lingling Hu, Qi Zhang

Department of Electrical and Computer Engineering: Faculty Publications

We theoretically and experimentally demonstrate a fiber-optic ultrasonic sensor system based on a fiber-ring laser whose cavity consisting of a regular fiber Bragg grating (FBG) and a tunable optical band-pass filter (TOBPF). The FBG is the sensing element and the TOBPF is used to set the lasing wavelength at a point on the spectral slope of the FBG. The ultrasonic signal is detected by the variations of the laser output intensity in response to the cold-cavity loss modulations from the ultrasonicallyinduced FBG spectral shift. The system demonstrated here has a simple structure and low cost, making it attractive for acoustic …

A Problem Solving Approach To Enterprise Filevault 2 Management And Integration, Nicholas Cobb

Masters Theses & Specialist Projects

Consumer technology adoption into large enterprise environments is occurring at an unprecedented rate. Employees require the flexibility and efficiency of using operating systems, computers, and mobility products they are familiar with and that enable their productivity. Due to this industry phenomenon, one large shipping enterprise must work to create solutions to integrate Apple’s OS X operating system into its traditional Windows-based operating environment. This level of integration must take place carefully to enable usability and foster the continued data security of enterprise assets. This paper describes the steps and methodology taken, as well as the rationale used, to accomplish the …