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Articles 10171 - 10200 of 13564

Full-Text Articles in Computer Engineering

Optimization Of Pilot Tones Using Differential Evolution Algorithm In Mimo-Ofdm Systems, Muhammet Nuri̇ Seyman, Necmi̇ Taşpinar Jan 2012

Optimization Of Pilot Tones Using Differential Evolution Algorithm In Mimo-Ofdm Systems, Muhammet Nuri̇ Seyman, Necmi̇ Taşpinar

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose a differential evolution (DE) algorithm for optimizing the placement and power of the pilot tones that are utilized by a least square (LS) algorithm for channel estimation in multiple-input and multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems. Computer simulations demonstrated that the performance of the LS algorithm was increased by optimizing the pilot tones with the DE algorithm instead of locating them orthogonally. We used the upper bound of the mean square error (MSE) as a fitness function of the DE algorithm for optimization tasks. With the use of an upper bound, it is not necessary …


A Modified Particle Swarm Optimization Algorithm And Its Application To The Multiobjective Fet Modeling Problem, Ufuk Özkaya, Fi̇li̇z Güneş Jan 2012

A Modified Particle Swarm Optimization Algorithm And Its Application To The Multiobjective Fet Modeling Problem, Ufuk Özkaya, Fi̇li̇z Güneş

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a modified particle swarm algorithm to handle multiobjective optimization problems. In multiobjective PSO algorithms, the determination of Pareto optimal solutions depends directly on the strategy of assigning a best local guide to each particle. In this work, the PSO algorithm is modified to assign a best local guide to each particle by using minimum angular distance information. This algorithm is implemented to determine field-effect transistor (FET) model elements subject to the Pareto domination between the scattering parameters and operation bandwidth. Furthermore, the results are compared with those obtained by the nondominated sorting genetic algorithm-II. FET models are …


Healthface: A Web-Based Remote Monitoring Interface For Medical Healthcare Systems Based On A Wireless Body Area Sensor Network, İsmai̇l Kirbaş, Cüneyt Bayilmiş Jan 2012

Healthface: A Web-Based Remote Monitoring Interface For Medical Healthcare Systems Based On A Wireless Body Area Sensor Network, İsmai̇l Kirbaş, Cüneyt Bayilmiş

Turkish Journal of Electrical Engineering and Computer Sciences

The wireless body area sensor network (WBASN) is a type of wireless sensor network. The wireless sensor nodes in a WBASN are placed on, near, or within a human body. In a medical healthcare system, WBASNs continuously provide healthcare monitoring, especially of elderly or ill people, wherever the patient goes. Wireless nodes sense and process human vital signs such as heart rate, blood pressure, body temperature, and respiration. They then send collected data to a medical center via a base station in order for medical professionals to monitor the patient's health. In the medical center, doctors and caregivers need monitoring …


Analysis, Nonlinear Control, And Chaos Generator Circuit Of Another Strange Chaotic System, İhsan Pehli̇van, Zhouchao Wei Jan 2012

Analysis, Nonlinear Control, And Chaos Generator Circuit Of Another Strange Chaotic System, İhsan Pehli̇van, Zhouchao Wei

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we introduce a new 3-dimensional quadratic continuous autonomous chaotic system. This system can generate strange and interesting attractors. Some basic dynamical properties, such as bifurcations, and chaotic behaviors of the new chaotic system are investigated analytically and numerically. We propose a nonlinear control scheme to discuss codimension 1 and 2 Hopf bifurcations. In addition, a new circuit implementation of the chaotic attractor is reported and examined in PSpice. The new system is suitable for purposefully generating chaos in chaos-based engineering applications.


Considering Transmission Loss For An Economic Dispatch Problem Without Valve-Point Loading Using An Ep-Epso Algorithm, Sevugarathinam Muthu Vijaya Pandian, Keppanagowder Thanushkodi Jan 2012

Considering Transmission Loss For An Economic Dispatch Problem Without Valve-Point Loading Using An Ep-Epso Algorithm, Sevugarathinam Muthu Vijaya Pandian, Keppanagowder Thanushkodi

Turkish Journal of Electrical Engineering and Computer Sciences

Economic dispatch (ED) is one of the most important optimization problems in a power system. The objective of ED is sharing the power demand among the online generators while keeping the minimum cost of generation as a constraint. The aim of this paper is to operate an electric power system as economically as possible within its security limits. This paper proposes the following 2 new particle swarm optimization (PSO) algorithms to solve a nonconvex economic dispatch problem: an efficient PSO is termed as efficient particle swarm optimization (EPSO), and a hybrid of evolutionary programming (EP) and EPSO is termed as …


Symbolic Regression Of Crop Pest Forecasting Using Genetic Programming, Basim Alhadidi, Alaa Alafeef, Heba Al-Hiari Jan 2012

Symbolic Regression Of Crop Pest Forecasting Using Genetic Programming, Basim Alhadidi, Alaa Alafeef, Heba Al-Hiari

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose and evaluate a mathematical model that describes the reported data on crop pests to get an accurate prediction of production costs, food safety, and the protection of the environment. Meteorological factors are not the only things that affect a bumper harvest; it is also affected by crop plant diseases and insect pests. Studies show that relying solely on the naked-eye observations of experts to forecast well-planned agriculture is not always sufficient to achieve effective control. Providing fast, automatic, cheap, and accurate artificial intelligence-based solutions for that task can be of great realistic significance. The proposed …


Three-Dimensional Numerical Simulation Of Crystal And Crucible Rotations During Czochralski Growth Of Ge_Xsi_{1-X} Single Crystals, Serkan Abbasoğlu Jan 2012

Three-Dimensional Numerical Simulation Of Crystal And Crucible Rotations During Czochralski Growth Of Ge_Xsi_{1-X} Single Crystals, Serkan Abbasoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

The influence of crystal and crucible rotations on the flow field and the radial segregation of silicon are predicted during the growth of Ge_xSi_{1-x} crystals by the Czochralski method under microgravity conditions. Time-dependent 3-dimensional numerical simulations are carried out to present the influence of several rotation rates on the radial segregation and flow fields during the growth of Ge_xSi_{1-x}. Thermal and solutal Marangoni convection are also considered during this study. Different crystal rotation rates varying between 0 and 30 rpm and stationary or -2 rpm crucible rotation rates are considered. The results show that the crystal and crucible rotation rates …


Basal Graph Structures For Geometry Based Organization Of Wide-Baseline Image Collections, Aveek Shankar Brahmachari Jan 2012

Basal Graph Structures For Geometry Based Organization Of Wide-Baseline Image Collections, Aveek Shankar Brahmachari

USF Tampa Graduate Theses and Dissertations

We propose algorithms for organization of images in wide-area sparse-view datasets. In such datasets, if the images overlap in scene content, they are related by wide-baseline geometric transformations. The challenge is to identify these relations even if the images sparingly overlap in their content. The images in a dataset are then grouped into sets of related images with the relations captured in each set as a basal (minimal and foundational) graph structures. Images form the vertices in the graph structure and the edges define the geometric relations between the images. We use these basal graphs for geometric walkthroughs and detection …


Column: The Physics Of Digital Information-Part 2, Fred Cohen Jan 2012

Column: The Physics Of Digital Information-Part 2, Fred Cohen

Journal of Digital Forensics, Security and Law

In part 1 of this series (Cohen, 2011a), we discussed some of the basics of building a physics of digital information. Assuming, as we have, that science is about causality and that a scientific theory should require that cause(C) produces effect (E) via mechanism M (written C→ME), we explore that general theory of digital systems from the perspective of attributing effects (i.e., traces of activities in digital systems) to their causes. Full details of the current version of this physics are available online2 , and in this article, we explore a few more of them.


Technology Corner: Dating Of Electronic Hardware For Prior Art Investigations, Sellam Ismail Jan 2012

Technology Corner: Dating Of Electronic Hardware For Prior Art Investigations, Sellam Ismail

Journal of Digital Forensics, Security and Law

In many legal matters, specifically patent litigation, determining and authenticating the date of computer hardware or other electronic products or components is often key to establishing the item as legitimate evidence of prior art. Such evidence can be used to buttress claims of technologies available or of events transpiring by or at a particular date.


Applying The Acpo Principles In Public Cloud Forensic Investigations, Harjinder S. Lallie, Lee Pimlott Jan 2012

Applying The Acpo Principles In Public Cloud Forensic Investigations, Harjinder S. Lallie, Lee Pimlott

Journal of Digital Forensics, Security and Law

The numerous advantages offered by cloud computing has fuelled its growth and has made it one of the most significant of current computing trends. The same advantages have created complex issues for those conducting digital forensic investigations. Digital forensic investigators rely on the ACPO (Association of Chief Police Officers) or similar guidelines when conducting an investigation, however the guidelines make no reference to some of the issues presented by cloud investigations. This study investigates the impact of cloud computing on ACPO’s core principles and asks whether these principles can still be applied in a cloud investigation and the challenges presented …


An Overview Of The Jumplist Configuration File In Windows 7, Harjinder S. Lallie, Parmjit S. Bains Jan 2012

An Overview Of The Jumplist Configuration File In Windows 7, Harjinder S. Lallie, Parmjit S. Bains

Journal of Digital Forensics, Security and Law

The introduction of Jumplists in Windows 7 was an important feature from a forensic examiners viewpoint. Jumplist configuration files can provide the examiner with a wealth of information relating to file access and in particular: dates/times, Volume GUIDs and unique file object IDs relating to those files. Some of the information in the Jumplist could be used to build a more precise timeline relating to system and file usage. In this article, we analyse the structure of a Jumplist configuration file and in particular a record from a Jumplist configuration file and highlight some of the important entries therein.


Pandora’S Email Box? An Exploratory Study Of Web-Based Email Forgery Detection And Validation., Richard Boddington, Grant Boxall, Jeremy Ardley Jan 2012

Pandora’S Email Box? An Exploratory Study Of Web-Based Email Forgery Detection And Validation., Richard Boddington, Grant Boxall, Jeremy Ardley

Journal of Digital Forensics, Security and Law

Web based email systems may be a source of pristine digital evidence because of the perceived difficulty of client tampering with messages stored inside the email account. We demonstrate that such assumption is wrong in the case of Windows Live Hotmail®1 . Windows Live Mail®1 synchronises message on client-side computers with the Hotmail® server, benefiting users wishing to synchronise their email accounts and personal devices. However, this synchronisation opens an exploit for wrongdoers to tamper with existing email messages and attachments as well as facilitating the insertion of fabricated messages. The exploit process enables persistent storage of tampered and fabricated …


Toward Alignment Between Communities Of Practice And Knowledge-Based Decision Support, Jason Nichols, David Biros, Mark Weiser Jan 2012

Toward Alignment Between Communities Of Practice And Knowledge-Based Decision Support, Jason Nichols, David Biros, Mark Weiser

Journal of Digital Forensics, Security and Law

The National Repository of Digital Forensics Information (NRDFI) is a knowledge repository for law enforcement digital forensics investigators (LEDFI). Over six years, the NRDFI has undertaken significant design revisions in order to more closely align the architecture of the system with theory addressing motivation to share knowledge and communication within ego-centric groups and communities of practice. These revisions have been met with minimal change in usage patterns by LEDFI community members, calling into question the applicability of relevant theory when the domain for knowledge sharing activities expands beyond the confines of an individual organization to a community of practice. When …


Implementing The Automated Phases Of The Partially-Automated Digital Triage Process Model, Gary Cantrell, David A. Dampier Jan 2012

Implementing The Automated Phases Of The Partially-Automated Digital Triage Process Model, Gary Cantrell, David A. Dampier

Journal of Digital Forensics, Security and Law

Digital triage is a pre-digital-forensic phase that sometimes takes place as a way of gathering quick intelligence. Although effort has been undertaken to model the digital forensics process, little has been done to-date to model digital triage. This work discusses the further development of a model that attempts to address digital triage, the Partially-automated Crime Specific Digital Triage Process model. The model itself will be presented along with a description of how its automated functionality was implemented to facilitate model testing.


Table Of Contents Jan 2012

Table Of Contents

Journal of Digital Forensics, Security and Law

No abstract provided.


Digital Evidence Education In Schools Of Law, Aaron Alva, Barbara Endicott-Popovsky Jan 2012

Digital Evidence Education In Schools Of Law, Aaron Alva, Barbara Endicott-Popovsky

Journal of Digital Forensics, Security and Law

An examination of State of Connecticut v. Julie Amero provides insight into how a general lack of understanding of digital evidence can cause an innocent defendant to be wrongfully convicted. By contrast, the 101-page opinion in Lorraine v. Markel American Insurance Co. provides legal precedence and a detailed consideration for the admission of digital evidence. An analysis of both cases leads the authors to recommend additions to Law School curricula designed to raise the awareness of the legal community to ensure such travesties of justice, as in the Amero case, don’t occur in the future. Work underway at the University …


Human Action Recognition By Principal Component Analysis Of Motion Curves, Daniel Stephen Chivers Jan 2012

Human Action Recognition By Principal Component Analysis Of Motion Curves, Daniel Stephen Chivers

Browse all Theses and Dissertations

Human action recognition is used to automatically detect and recognize actions per- formed by humans in a video. Applications include visual surveillance, human-computer interaction, and robot intelligence, to name a few. An example of a surveillance application is a system that monitors a large public area, such as an airport, for suspicious activity. In human-machine interaction, computers may be controlled by simple human actions. For example, the motion of an arm may instruct the computer to rotate a 3-D model that is being displayed. Human action recognition is also an important capability of intelligent robots that interact with humans.

General …


Querying And Managing Opm-Compliant Scientific Workflow Provenance, Chunhyeok Lim Jan 2012

Querying And Managing Opm-Compliant Scientific Workflow Provenance, Chunhyeok Lim

Wayne State University Dissertations

Provenance, the metadata that records the derivation history of scientific results, is important in scientific workflows to interpret, validate, and analyze the result of scientific computing. Recently,

to promote and facilitate interoperability among heterogeneous provenance systems, the Open Provenance Model (OPM) has been proposed and has played an important role in the community.

In this dissertation, to efficiently query and manage OPM-compliant provenance, we first propose a provenance collection framework that collects both prospective provenance, which captures

an abstract workflow specification as a recipe for future data derivation and retrospective provenance, which captures past workflow execution and data derivation information. …


Rethinking The Design And Implementation Of The I/O Software Stack For High-Performance Computing, Xuechen Zhang Jan 2012

Rethinking The Design And Implementation Of The I/O Software Stack For High-Performance Computing, Xuechen Zhang

Wayne State University Dissertations

Current I/O stack for high-performance computing is composed of multiple software layers in order to hide users from complexity of I/O performance optimization. However, the design and implementation of a specific layer is usually carried out separately with limited consideration of its impact on other layers, which could result in suboptimal I/O performance because data access locality is weakened, if not lost, on hard disk, a widely used storage medium in high-end storage systems.

In this dissertation, we experimentally demonstrated such issues in four different layers, including operating system process management layer and MPI-IO middleware layer on compute server side, …


Techniques For Sensor-Integrated Robotic Systems: Raman Spectra Analysis, Image Guidance, And Kinematic Calibration, Luke Anthony Reisner Jan 2012

Techniques For Sensor-Integrated Robotic Systems: Raman Spectra Analysis, Image Guidance, And Kinematic Calibration, Luke Anthony Reisner

Wayne State University Dissertations

Robotics and sensor technology have made impressive advancements over the years. There are now robotic systems that help perform surgeries or explore the surface of Mars, and there are sensors that detect trace amounts of explosives or identify diseased human tissue. The most powerful systems integrate robots and sensors, which are natural complements to each other. Sensors can provide information that might otherwise be unavailable due to indirect robotic manipulation (e.g., images of the target environment), and robots can provide suitably precise positioning of an analytical sensor.

To have an effective sensor-integrated robotic system, multiple capabilities are needed in the …


Behavioral Signature-Based Framework For Identifying Unsatisfiable Variable Mappings Between Digital Designs, Vaibhav Uday Tendulkar Jan 2012

Behavioral Signature-Based Framework For Identifying Unsatisfiable Variable Mappings Between Digital Designs, Vaibhav Uday Tendulkar

Browse all Theses and Dissertations

Throughout its design process (from specification to implementation) a digital circuit goes through a variety of structural changes. These changes are introduced primarily due to the use of automated tools in the design process. Checking whether the Boolean functions representing the two designs are equivalent is thus necessary to verify if a design implementation adheres to its specification. Combinational Equivalence Checking (CEC) - a process of determining whether two combinational design functions are equiv-alent, has been one of the most researched Boolean matching problems. The well-known CEC techniques that have been proposed adopt some kind of a formal approach such …


Linked Open Data Alignment & Querying, Prateek Jain Jan 2012

Linked Open Data Alignment & Querying, Prateek Jain

Browse all Theses and Dissertations

The recent emergence of the "Linked Data" approach for publishing data represents a major step forward in realizing the original vision of a web that can "understand and satisfy the requests of people and machines to use the web content" i.e. the Semantic Web. This new approach has resulted in the Linked Open Data (LOD) Cloud, which includes more than 295 large datasets contributed by experts belonging to diverse communities such as geography, entertainment, and life sciences. However, the current interlinks between datasets in the LOD Cloud, as we will illustrate,are too shallow to realize much of the benefits promised. …


Knowledge Acquisition In A System, Christopher J. Thomas Jan 2012

Knowledge Acquisition In A System, Christopher J. Thomas

Browse all Theses and Dissertations

I present a method for growing the amount of knowledge available on the Web using a hermeneutic method that involves background knowledge, Information Extraction techniques and validation through discourse and use of the extracted information.

I present the metaphor of the "Circle of Knowledge on the Web". In this context, knowledge acquisition on the web is seen as analogous to the way scientific disciplines gradually increase the knowledge available in their field.

Here, formal models of interest domains are created automatically or manually and then validated by implicit and explicit validation methods before the statements in the created models can …


Abstraction Driven Application And Data Portability In Cloud Computing, Ajith Harshana Ranabahu Jan 2012

Abstraction Driven Application And Data Portability In Cloud Computing, Ajith Harshana Ranabahu

Browse all Theses and Dissertations

Cloud computing has changed the way organizations create, manage, and evolve their applications. While many organizations are eager to use the cloud, tempted by substantial cost savings and convenience, the implications of using clouds are still not well understood. One of the major concerns in cloud adoption is the vendor lock-in of applications, caused by the heterogeneity of the numerous cloud service offerings. Vendor locked applications are difficult, if not impossible to port from one cloud system to another, forcing cloud service consumers to use undesired or suboptimal solutions. This dissertation investigates a complete and comprehensive solution to address the …


Winding Resistance And Winding Power Loss Of High-Frequency Power Inductors, Rafal P. Wojda Jan 2012

Winding Resistance And Winding Power Loss Of High-Frequency Power Inductors, Rafal P. Wojda

Browse all Theses and Dissertations

The scope of this research is concentrated on analytical winding size optimization (thickness or diameter) of high-frequency power inductors wound with foil, solid-round wire, multi-strand wire, and litz-wire conductors.

The first part of this research concerns analytical optimization of the winding size (thickness or diameter) for the inductors conducting a sinusoidal current. Estimation of winding resistance in individual inductor layers made of foil, taking into account the skin and proximity effects is performed. Approximated equations for the winding power loss in each layer are given and the optimal values of foil thickness for each layer are derived.

A low- and …


Optimization Of Spectrum Allocation In Cognitive Radio And Dynamic Spectrum Access Networks, Tao Zhang Jan 2012

Optimization Of Spectrum Allocation In Cognitive Radio And Dynamic Spectrum Access Networks, Tao Zhang

Browse all Theses and Dissertations

Spectrum has become a treasured commodity. However, many licensed frequency bands exclusively assigned to the primary license holders (also called primary users) remain relatively unused or under-utilized for most of the time. Allowing other users (also called secondary users) without a license to operate in these bands with no interference becomes a promising way to satisfy the fast growing needs for frequency spectrum resources. A cognitive radio adapts to the environment it operates in by sensing the spectrum and quickly decides on appropriate frequency bands and transmission parameters to use in order to achieve certain performance goals. One of the …


Sensing Through The Continent: Towards Monitoring Migratory Birds Using Cellular Sensor Networks, David Anthony, William P. Bennett, Mehmet C. Vuran, Matthew B. Dwyer, Sebastian Elbaum, Anne Lacy, Mike Engels, Walter Wehtje Jan 2012

Sensing Through The Continent: Towards Monitoring Migratory Birds Using Cellular Sensor Networks, David Anthony, William P. Bennett, Mehmet C. Vuran, Matthew B. Dwyer, Sebastian Elbaum, Anne Lacy, Mike Engels, Walter Wehtje

School of Computing: Conference and Workshop Papers

This paper presents CraneTracker, a novel sensor platform for monitoring migratory birds. The platform is designed to monitor Whooping Cranes, an endangered species that conducts an annual migration of 4, 000 km between southern Texas and north-central Canada. CraneTracker includes a rich set of sensors, a multi-modal radio, and power control circuitry for sustainable, continental-scale information delivery during migration. The need for large-scale connectivity motivates the use of cellular technology in low-cost sensor platforms augmented by a low-power transceiver for ad-hoc connectivity. This platform leads to a new class of cellular sensor networks (CSNs) for time-critical and mobile sensing applications. …


Ttradeoff Tables For Compression Functions: How To Invert Hash Values Radeoff Tables For Compression Functions: How To Invert Hash Values, Orhun Kara, Adem Atalay Jan 2012

Ttradeoff Tables For Compression Functions: How To Invert Hash Values Radeoff Tables For Compression Functions: How To Invert Hash Values, Orhun Kara, Adem Atalay

Turkish Journal of Electrical Engineering and Computer Sciences

Hash functions are one of the ubiquitous cryptographic functions used widely for various applications such as digital signatures, data integrity, authentication protocols, MAC algorithms, RNGs, etc. Hash functions are supposed to be one-way, i.e., preimage resistant. One interesting property of hash functions is that they process arbitrary-length messages into fixed-length outputs. In general, this can be achieved mostly by applying compression functions onto the message blocks of fixed length, recursively. The length of the message is incorporated as padding in the last block prior to the hash, a procedure called the Merkle-Damgard strengthening. In this paper, we introduce a new …


A Robust Adaptive Fuzzy Control Of A Unified Power Flow Controller, Sebaa Morsli, Allaoui Tayeb, Denai Mouloud, Chaker Abdelkader Jan 2012

A Robust Adaptive Fuzzy Control Of A Unified Power Flow Controller, Sebaa Morsli, Allaoui Tayeb, Denai Mouloud, Chaker Abdelkader

Turkish Journal of Electrical Engineering and Computer Sciences

This paper investigates the control of a unified power flow controller (UPFC) to improve the stability of a power system, hence providing security under increased power flow conditions. The proposed control methods include a direct proportional and integral (PI) controller and an adaptive fuzzy logic controller (AFLC). The performances of these controllers were evaluated under different operating conditions of the power system and the results demonstrated that PI and AFLC are very effective in improving the transient power system stability and very robust against variable transmission line parameters.