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Full-Text Articles in Computer Sciences

Wireless Sensor Network Modeling Using Modified Recurrent Neural Network: Application To Fault Detection, Azzam Issam Moustapha Apr 2008

Wireless Sensor Network Modeling Using Modified Recurrent Neural Network: Application To Fault Detection, Azzam Issam Moustapha

Doctoral Dissertations

Wireless Sensor Networks (WSNs) consist of a large number of sensors, which in turn have their own dynamics. They interact with each other and the base station, which controls the network. In multi-hop wireless sensor networks, information hops from one node to another and finally to the network gateway or base station. Dynamic Recurrent Neural Networks (RNNs) consist of a set of dynamic nodes that provide internal feedback to their own inputs. They can be used to simulate and model dynamic systems such as a network of sensors.

In this dissertation, a dynamic model of wireless sensor networks and its …


Missouri S&T Mote-Based Demonstration Of Energy Monitoring Solution For Network Enabled Manufacturing Using Wireless Sensor Networks (Wsn), James W. Fonda, Maciej Jan Zawodniok, Al Salour, Jagannathan Sarangapani, Donald Miller Apr 2008

Missouri S&T Mote-Based Demonstration Of Energy Monitoring Solution For Network Enabled Manufacturing Using Wireless Sensor Networks (Wsn), James W. Fonda, Maciej Jan Zawodniok, Al Salour, Jagannathan Sarangapani, Donald Miller

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, an inexpensive electric utilities monitoring solution using wireless sensor networks is demonstrated that can easily be installed, deployed, maintained and eliminate unnecessary energy costs and effort. The monitoring solution is designed to support network enabled manufacturing (NEM) program using Missouri University of Science and Technology (MST), formerly the University of Missouri-Rolla (UMR), motes.


Numerical Simulations Of A Nonlinear Transmission Line, Stuart Rogers Apr 2008

Numerical Simulations Of A Nonlinear Transmission Line, Stuart Rogers

Electrical & Computer Engineering Theses & Dissertations

This thesis investigates wave propagation along a nonlinear transmission line having a voltage-dependent capacitance. The telegrapher's equations that model wave propagation along such a transmission line are derived and shown to represent a nonlinear hyperbolic system of balance laws. The Lax-Friedrichs, Lax-Wendroff, and hybrid numerical schemes for obtaining approximate solutions to nonlinear hyperbolic systems of balance laws are presented, analyzed, and applied to the nonlinear telegrapher's equations. The Lax-Wendroff and hybrid schemes are invoked to numerically simulate wave propagation along a nonlinear transmission line. Simulations obtained via the hybrid scheme are used to briefly study the potential application of a …


Improving Query Efficiency Of Multiresolution Data Aggregation For Analytical Exploration Of Large Relational Dataset, Yu-Ting Huang Apr 2008

Improving Query Efficiency Of Multiresolution Data Aggregation For Analytical Exploration Of Large Relational Dataset, Yu-Ting Huang

Masters Theses

Tree structures are developed to organize the data more efficiently by using fewer resources for searching records. This thesis investigates the tree's actual structure on the hard disk to see the influence of different kinds of structures on the tree building time and query execution time. In order to improve efficiency, one multi-file structure and two reorganization structures, BFS and DFS, are examined to achieve this goal. The results indicate that two reorganization structures on KDB-tree structure can significantly improve the query execution time in large data sets and multi-file structure can slightly improve the TPIE lover level building time.


Output Feedback Controller For Operation Of Spark Ignition Engines At Lean Conditions Using Neural Networks, Jonathan B. Vance, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier Mar 2008

Output Feedback Controller For Operation Of Spark Ignition Engines At Lean Conditions Using Neural Networks, Jonathan B. Vance, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier

Electrical and Computer Engineering Faculty Research & Creative Works

Spark ignition (SI) engines operating at very lean conditions demonstrate significant nonlinear behavior by exhibiting cycle-to-cycle bifurcation of heat release. Past literature suggests that operating an engine under such lean conditions can significantly reduce NO emissions by as much as 30% and improve fuel efficiency by as much as 5%-10%. At lean conditions, the heat release per engine cycle is not close to constant, as it is when these engines operate under stoichiometric conditions where the equivalence ratio is 1.0. A neural network controller employing output feedback has shown ability in simulation to reduce the nonlinear cyclic dispersion observed under …


Digital Signal Processing Leveraged For Intrusion Detection, Theodore J. Erickson Mar 2008

Digital Signal Processing Leveraged For Intrusion Detection, Theodore J. Erickson

Theses and Dissertations

This thesis describes the development and evaluation of a novel system called the Network Attack Characterization Tool (NACT). The NACT employs digital signal processing to detect network intrusions, by exploiting the Lomb-Scargle periodogram method to obtain a spectrum for sampled network traffic. The Lomb-Scargle method for generating a periodogram allows for the processing of unevenly sampled network data. This method for determining a periodogram has not yet been used for intrusion detection. The spectrum is examined to determine if features exist above a significance level chosen by the user. These features are considered an attack, triggering an alarm. Two traffic …


Automatic Drift Compensation Using Phase Correlation Method For Nanomanipulation, Qinmin Yang, Jagannathan Sarangapani, Eric W. Bohannan Mar 2008

Automatic Drift Compensation Using Phase Correlation Method For Nanomanipulation, Qinmin Yang, Jagannathan Sarangapani, Eric W. Bohannan

Electrical and Computer Engineering Faculty Research & Creative Works

Nanomanipulation and nanofabrication with an atomic force microscope (AFM) or other scanning probe microscope (SPM) are a precursor for nanomanufacturing. It is still a challenging task to accomplish nanomanipulation automatically. In ambient conditions without stringent environmental controls, the task of nanomanipulation requires extensive human intervention to compensate for the spatial uncertainties of the SPM. Among these uncertainties, the thermal drift, which affects spatial resolution, is especially hard to solve because it tends to increase with time, and cannot be compensated simultaneously by feedback from the instrument. In this paper, a novel automatic compensation scheme is introduced to measure and estimate …


Signal Processing Design Of Low Probability Of Intercept Waveforms, Nathaniel C. Liefer Mar 2008

Signal Processing Design Of Low Probability Of Intercept Waveforms, Nathaniel C. Liefer

Theses and Dissertations

This thesis investigates a modification to Differential Phase Shift Keyed (DPSK) modulation to create a Low Probability of Interception/Exploitation (LPI/LPE) communications signal. A pseudorandom timing offset is applied to each symbol in the communications stream to intentionally create intersymbol interference (ISI) that hinders accurate symbol estimation and bit sequence recovery by a non-cooperative receiver. Two cooperative receiver strategies are proposed to mitigate the ISI due to symbol timing offset: a modified minimum Mean Square Error (MMSE) equalization algorithm and a multiplexed bank of equalizer filters determined by an adaptive Least Mean Square (LMS) algorithm. Both cooperative receivers require some knowledge …


Multi-Class Classification Fusion Using Boosting For Identifying Steganography Methods, Benjamin M. Rodriguez, Gilbert L. Peterson Mar 2008

Multi-Class Classification Fusion Using Boosting For Identifying Steganography Methods, Benjamin M. Rodriguez, Gilbert L. Peterson

Faculty Publications

No abstract provided.


A Suite Of Robust Controllers For The Manipulation Of Microscale Objects, Qinmin Yang, Jagannathan Sarangapani Feb 2008

A Suite Of Robust Controllers For The Manipulation Of Microscale Objects, Qinmin Yang, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A suite of novel robust controllers is introduced for the pickup operation of microscale objects in a microelectromechanical system (MEMS). In MEMS, adhesive, surface tension, friction, and van der Waals forces are dominant. Moreover, these forces are typically unknown. The proposed robust controller overcomes the unknown contact dynamics and ensures its performance in the presence of actuator constraints by assuming that the upper bounds on these forces are known. On the other hand, for the robust adaptive critic-based neural network (NN) controller, the unknown dynamic forces are estimated online. It consists of an action NN for compensating the unknown system …


Use Of Characteristic Basis Function Method For Scattering From Terrain Profiles, Atacan Yağbasan, Celal Alp Tunç, Vakur B. Ertürk, Ayhan Altintas, Raj Mittra Jan 2008

Use Of Characteristic Basis Function Method For Scattering From Terrain Profiles, Atacan Yağbasan, Celal Alp Tunç, Vakur B. Ertürk, Ayhan Altintas, Raj Mittra

Turkish Journal of Electrical Engineering and Computer Sciences

An integral equation (IE) based solution procedure is presented for the rigorous analysis of scattering from terrain profiles. The procedure uses characteristic basis function method (CBFM), which is hybridized with the forward-backward method (FBM), to reduce the storage requirements of the resultant Method of Moments (MoM) impedance matrix, as well as to accelerate the solution procedure. Numerical results in the form of induced current and scattered field are presented to assess the accuracy and efficiency of the solution procedure.


Lightweight Objective Quality Of Voice Estimation Through Machine Learning, Daniel Riordan Jan 2008

Lightweight Objective Quality Of Voice Estimation Through Machine Learning, Daniel Riordan

Theses

Communication systems are undergoing constant and rapid innovation, both at the design stage and in the field. This in turn has led to an inereasing need for fast, efficient, portable and economic methods for the testing of these systems. For voice carrying communication systems the quality of the transmitted voice that the system produces is a large factor in the overall performance rating of the system. This measure is known as the ‘Quality of Voice’ (QoV) and can be evaluated either subjectively or objectively.

Speech quality is a complex subjective phenomenon that can be best quantified by subjective testing. A …


Analysis Of Information Remaining On Hand Held Devices Offered For Sale On The Second Hand, Andy Jones, Craig Valli, Iain Sutherland Jan 2008

Analysis Of Information Remaining On Hand Held Devices Offered For Sale On The Second Hand, Andy Jones, Craig Valli, Iain Sutherland

Journal of Digital Forensics, Security and Law

The ownership and use of mobile phones, Personal Digital Assistants and other hand held devices is now ubiquitous both for home and business use. The majority of these devices have a high initial cost, a relatively short period before they become obsolescent and a relatively low second hand value. As a result of this, when the devices are replaced, there are indications that they tend to be discarded. As technology has continued to develop, it has led to an increasing diversity in the number and type of devices that are available, and the processing power and the storage capacity of …


Management Framework For Hybrid Wireless Networks, Chong Shen Jan 2008

Management Framework For Hybrid Wireless Networks, Chong Shen

Theses

The objective of the Hybrid Wireless Network with dedicated Relay Nodes (HWN*) architecture is to interface the Base Station (BS) Oriented Mobile Network (BSON) and the 802.fix based Mobile Ad hoc Wireless Network (MANET) so that one system can be utilised as an alternative radio access network for data transmissions, while the incorporation of Relay Nodes (RN) is to extend the communication coverage, optimise medium resource sharing, increase spatial reuse opportunity, stabilise MANET link and create more micro-cells. The HWN* keeps the existing cellular infrastructure and a Mobile Terminal (MT) can borrow radio resources from other cells via secure multi-hop …


Rapid Prototyping For Virtual Environments, Emre Baydogan Jan 2008

Rapid Prototyping For Virtual Environments, Emre Baydogan

Electrical & Computer Engineering Theses & Dissertations

Development of Virtual Environment (VE) applications is challenging where application developers are required to have expertise in the target VE technologies along with the problem domain expertise. New VE technologies impose a significant learning curve to even the most experienced VE developer. The proposed solution relies on synthesis to automate the migration of a VE application to a new unfamiliar VE platform/technology. To solve the problem, the Common Scene Definition Framework (CSDF) is developed, that serves as a superset/model representation of the target virtual world. Input modules are developed to populate the framework with the capabilities of the virtual world …


Comparison Of Rectangular And Cylindrical Fdtd Representations On A Ring Resonator Problem, Funda Akleman, Levent Sevgi̇ Jan 2008

Comparison Of Rectangular And Cylindrical Fdtd Representations On A Ring Resonator Problem, Funda Akleman, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this paper is to discuss rectangular and cylindrical representations of finite-difference time-domain (FDTD) method over characteristic tests and comparisons. A ring resonator is chosen as a canonical structure and modeled with both rectangular- and cylindrical-FDTD packages. Calibration against analytical exact solution derived in terms of cylindrical Bessel functions is also performed. It is shown that rectangular-FDTD with periodic boundary condition, where the computation domain is reduced, can also be applied in modeling circular structures.


Generation Of High-Repetition-Rate Pulses Utilizing Cascaded Single Mode Fiber And Semiconductor Optical Amplifier, Jianwei Wu, Hai-Bo Bao Jan 2008

Generation Of High-Repetition-Rate Pulses Utilizing Cascaded Single Mode Fiber And Semiconductor Optical Amplifier, Jianwei Wu, Hai-Bo Bao

Turkish Journal of Electrical Engineering and Computer Sciences

To generate high-repetition-rate optical pulses, a novel and simple device is demonstrated, in which the cascaded single mode fiber (SMF) with negative third order dispersion and semiconductor optical amplifier (SOA) are adopted. Numerical research results show that let an optical pulse with center wavelength in zero dispersion wavelength of optical fiber transit in SMF for generating an oscillation pulse. Subsequently, the followed SOA is provided for amplification. As a consequence, the high-repetition-rate optical pulses can be obtained.


A Study On The Reliability Of Polyester Insulators Blended With Borax, Aysel Ersoy, Yasi̇n Özcelep, Ayten Kuntman Jan 2008

A Study On The Reliability Of Polyester Insulators Blended With Borax, Aysel Ersoy, Yasi̇n Özcelep, Ayten Kuntman

Turkish Journal of Electrical Engineering and Computer Sciences

Tracking is the main factor which limits the safe working electric stress of insulation in power system applications. Polymer samples have been tested in laboratory conditions according to ASTM D2303 on accelerated inclined plane tracking test. In this paper, a model based on improved Weibull statistics is proposed for estimating the breakdown time of polymeric insulating materials with borax. The confidence intervals of the Weibull shape parameter and the Weibull scale parameter are determined for the borax concentration values using the Weibull 7++ program.


A Novel Theoretical Procedure To Determine Absorption And Gain Coefficients In A Symmetric Single Step-Index Quantum Well Laser, Mustafa Temi̇z, Özgür Önder Karakilinç, Mehmet Ünal Jan 2008

A Novel Theoretical Procedure To Determine Absorption And Gain Coefficients In A Symmetric Single Step-Index Quantum Well Laser, Mustafa Temi̇z, Özgür Önder Karakilinç, Mehmet Ünal

Turkish Journal of Electrical Engineering and Computer Sciences

If the indices n_{II}, n_{I,III} of the regions, the thickness 2a of the active region (AR) and the wavelength \lambda for a single symmetric step-index quantum well laser (SSSIQWL) are given, the normalized propagation constant (NPC) \alpha is obtained. In this novel method, absorption and gain coefficients for the SSSIQWL have been obtained in terms of the NPCs \alpha in the even and odd fields, directly.


Online Tuning Of Set-Point Regulator With A Blending Mechanism Using Pi Controller, Engi̇n Yeşi̇l, Müjde Güzelkaya, İbrahi̇m Eksi̇n, Ö. Aydin Teki̇n Jan 2008

Online Tuning Of Set-Point Regulator With A Blending Mechanism Using Pi Controller, Engi̇n Yeşi̇l, Müjde Güzelkaya, İbrahi̇m Eksi̇n, Ö. Aydin Teki̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new control structure that exploits the advantages of one degree of freedom (1-DOF) and two degree of freedom (2-DOF) control structures with an online tuned set-point regulator with blending mechanism (SPR-BM) is proposed. In this structure, the filtered output of the reference and the pure reference signals are blended so that the overall performance of the system is ameliorated with respect to load disturbance rejection and set-point following. Internal Model Control (IMC) based PI controller is used as the primary controller and the blending dynamics are determined with the aim of producing a system output that …


A New Approach Using Temporal Radial Basis Function In Chronological Series, Mustapha Guezouri Jan 2008

A New Approach Using Temporal Radial Basis Function In Chronological Series, Mustapha Guezouri

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present an extended form of Radial Basis Function network called Temporal-RBF (T-RBF) network. This extended network can be used in decision rules and classification in Spatio-Temporal domain applications, like speech recognition, economic fluctuations, seismic measurements and robotics applications. We found that such a network complies with relative ease to constraints such as capacity of universal approximation, sensibility of node, local generalisation in receptive field, etc. For an optimal solution based on a probabilistic approach with a minimum of complexity, we propose two TRBF models (1 and 2). Application to the problem of Mackey-Glass time series has …


Recent Advances In Perfectly Matched Layers In Finite Element Applications, Özlem Özgün, Mustafa Kuzuoğlu Jan 2008

Recent Advances In Perfectly Matched Layers In Finite Element Applications, Özlem Özgün, Mustafa Kuzuoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

We present a comparative evaluation of two novel and practical perfectly matched layer (PML) implementations to the problem of mesh truncation in the finite element method (FEM): locally-conformal PML, and multi-center PML techniques. The most distinguished feature of these methods is the simplicity and flexibility to design conformal PMLs over challenging geometries, especially those with curvature discontinuities, in a straightforward way without using artificial absorbers. These methods are based on specially- and locally-defined complex coordinate transformations inside the PML region. They can easily be implemented in a conventional FEM by just replacing the nodal coordinates inside the PML region by …


The Characteristic Basis Function Method (Cbfm): A Numerically Efficient Strategy For Solving Large Electromagnetic Scattering Problems, Eugenio Lucente, Gianluigi Tiberi, Agostino Monorchio, Giuliano Manara, Raj Mittra Jan 2008

The Characteristic Basis Function Method (Cbfm): A Numerically Efficient Strategy For Solving Large Electromagnetic Scattering Problems, Eugenio Lucente, Gianluigi Tiberi, Agostino Monorchio, Giuliano Manara, Raj Mittra

Turkish Journal of Electrical Engineering and Computer Sciences

The objective of this paper is to describe a numerically efficient strategy for solving large electromagnetic scattering problems. This novel approach, termed as the Characteristic Basis Function Method (CBFM), is based on utilizing Characteristic Basic Functions (CBFs)-special functions defined on macro domains (blocks)-that include a relatively large number of conventional sub-domains discretized by using triangular or rectangular patches. The CBFs can be derived either analytically (from PO solutions), or by applying the conventional MoM. Use of these basis functions leads to a significant reduction in the number of unknowns, and results in a substantial size reduction of the MoM matrix. …


Generalized Hamilton-Jacobi-Bellman Formulation-Based Neural Network Control Of Affine Nonlinear Discrete-Time Systems, Zheng Chen, Jagannathan Sarangapani Jan 2008

Generalized Hamilton-Jacobi-Bellman Formulation-Based Neural Network Control Of Affine Nonlinear Discrete-Time Systems, Zheng Chen, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we consider the use of nonlinear networks towards obtaining nearly optimal solutions to the control of nonlinear discrete-time (DT) systems. The method is based on least squares successive approximation solution of the generalized Hamilton-Jacobi-Bellman (GHJB) equation which appears in optimization problems. Successive approximation using the GHJB has not been applied for nonlinear DT systems. The proposed recursive method solves the GHJB equation in DT on a well-defined region of attraction. The definition of GHJB, pre-Hamiltonian function, HJB equation, and method of updating the control function for the affine nonlinear DT systems under small perturbation assumption are proposed. …


Table Of Contents Jan 2008

Table Of Contents

Journal of Digital Forensics, Security and Law

No abstract provided.


Who Is Reading The Data On Your Old Computer?, Vivienne Mee Jan 2008

Who Is Reading The Data On Your Old Computer?, Vivienne Mee

Journal of Digital Forensics, Security and Law

Researchers at Rits Information Security performed a study in how the Irish population disposes of their old computers. How would you dispose of your old computer, or how would the company you work for dispose of their old computers?

The majority of Irish homeowners, would bring their old computers to local civic amenity centres, give it away to a relative or sell it on to another party.

Some organisations would give their old equipment to a staff member, as a gift gesture, others may simply discard in the local civic amenity site.

What is wrong with the methods currently being …


Trends In Virtualized User Environments, Diane Barrett Jan 2008

Trends In Virtualized User Environments, Diane Barrett

Journal of Digital Forensics, Security and Law

Virtualized environments can make forensics investigation more difficult. Technological advances in virtualization tools essentially make removable media a PC that can be carried around in a pocket or around a neck. Running operating systems and applications this way leaves very little trace on the host system. This paper will explore all the newest methods for virtualized environments and the implications they have on the world of forensics. It will begin by describing and differentiating between software and hardware virtualization. It will then move on to explain the various methods used for server and desktop virtualization. Next, it will explain how …


Data Recovery From Palmmsgv001, Satheesaan Pasupatheeswaran Jan 2008

Data Recovery From Palmmsgv001, Satheesaan Pasupatheeswaran

Journal of Digital Forensics, Security and Law

Both SMS and MMS data analysis is an important factor in mobile forensic analysis. Author did not find any mobile forensic tool that is capable of extracting short messages (SMS) and multimedia messages (MMS) from Palm Treo 750. SMS file of Palm Treo 750 is called PalmMgeV001 and it is a proprietary file system. A research work done to find a method to recover SMS data from PalmMsgV001 file. This paper is going to describe the research work and its findings. This paper also discusses a methodology that will help recover SMS data from PalmMsgV001. The PalmMsgV001 file is analysed …


Extraction And Categorisation Of User Activity From Windows Restore Points, Damir Kahvedžić, Tahar Kechadi Jan 2008

Extraction And Categorisation Of User Activity From Windows Restore Points, Damir Kahvedžić, Tahar Kechadi

Journal of Digital Forensics, Security and Law

The extraction of the user activity is one of the main goals in the analysis of digital evidence. In this paper we present a methodology for extracting this activity by comparing multiple Restore Points found in the Windows XP operating system. The registry copies represent a snapshot of the state of the system at a certain point in time. Differences between them can reveal user activity from one instant to another. The algorithms for comparing the hives and interpreting the results are of high complexity. We develop an approach that takes into account the nature of the investigation and the …


Steganography: Forensic, Security, And Legal Issues, Merrill Warkentin, Ernst Bekkering, Mark B. Schmidt Jan 2008

Steganography: Forensic, Security, And Legal Issues, Merrill Warkentin, Ernst Bekkering, Mark B. Schmidt

Journal of Digital Forensics, Security and Law

Steganography has long been regarded as a tool used for illicit and destructive purposes such as crime and warfare. Currently, digital tools are widely available to ordinary computer users also. Steganography software allows both illicit and legitimate users to hide messages so that they will not be detected in transit. This article provides a brief history of steganography, discusses the current status in the computer age, and relates this to forensic, security, and legal issues. The paper concludes with recommendations for digital forensics investigators, IT staff, individual users, and other stakeholders.