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2015

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Articles 7351 - 7380 of 7510

Full-Text Articles in Engineering

Decode-And-Forward Relaying Based On Orthogonal Complementary Codes, Refi̇k Çağlar Kizilirmak Jan 2015

Decode-And-Forward Relaying Based On Orthogonal Complementary Codes, Refi̇k Çağlar Kizilirmak

Turkish Journal of Electrical Engineering and Computer Sciences

In this note, we propose a full-duplex decode-and-forward cooperative diversity scheme based on code division with orthogonal complementary codes. We consider a simple case in which a single user is assisted by a single relay to achieve cooperative diversity. When the cooperation is full-duplex, the operational delay of the relay makes the channel asynchronous and this may cause multiple-access interference (MAI) between the user and relay. The orthogonal complementary codes have perfect autocorrelation and cross-correlation properties that provide MAI-free operation in asynchronous channels. In the proposed scheme, the user and relay terminals spread their messages with complementary codes and the …

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Solution Of Tio$_{2}$ Memristor-Capacitor Series Circuit Excited By A Constant Voltage Source And Its Application To Calculate Operation Frequency Of A Programmable Tio$_{2}$ Memristor-Capacitor Relaxation Oscillator, Reşat Mutlu Jan 2015

Solution Of Tio$_{2}$ Memristor-Capacitor Series Circuit Excited By A Constant Voltage Source And Its Application To Calculate Operation Frequency Of A Programmable Tio$_{2}$ Memristor-Capacitor Relaxation Oscillator, Reşat Mutlu

Turkish Journal of Electrical Engineering and Computer Sciences

The memristor is a new-found circuit element and its applications in programmable circuits are also under study. Analysis of most of its combinations with other circuit elements such as resistors, capacitors, and inductors does not exist. In this work, a TiO$_{2}$ memristor model with linear dopant drift speed is used and the solution of a TiO$_{2}$ memristor and capacitor series circuit driven by a constant voltage source is given. It is then used to analyze a novel M-C oscillator circuit. In previous programmable oscillator studies, the memristance of the oscillator was assumed to be constant. However, in this study, the …

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Regulation Of Methane Gas Output From An Anaerobic Reactor System Using Moving Horizon $H_{\Infty }$ Control, Fatma Yildiz Taşcikaraoğlu, Şeref Naci̇ Engi̇n Jan 2015

Regulation Of Methane Gas Output From An Anaerobic Reactor System Using Moving Horizon $H_{\Infty }$ Control, Fatma Yildiz Taşcikaraoğlu, Şeref Naci̇ Engi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the moving horizon $\mathcal{H}_{\infty }$\textbf{ }control used for tracking a desired methane gas output from an anaerobic wastewater treatment reactor is compared with classical $\mathcal{H}_{\infty }$ control and a proportional-integral-derivative controller. The nonlinear system is first linearized around the set of equilibrium and operating points selected, and then the linear matrix inequalities required to comply with the constraints and guarantee the stability are constructed. Finally, the experimental results are obtained by implementing the control method in a MATLAB environment. It is concluded that moving horizon $\mathcal{H}_{\infty }$ control yields satisfactory results.

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3d Imaging For Ground-Penetrating Radars Via Dictionarydimension Reduction, Muhammed Duman, Ali̇ Cafer Gürbüz Jan 2015

3d Imaging For Ground-Penetrating Radars Via Dictionarydimension Reduction, Muhammed Duman, Ali̇ Cafer Gürbüz

Turkish Journal of Electrical Engineering and Computer Sciences

Ground-penetrating radar (GPR) has been widely used in detecting or imaging subsurface targets. In many applications such as archaeology, utility imaging, or landmine detection, three-dimensional (3D) images of the subsurface region is required for better understanding of the sensed medium. However, a high-resolution 3D image requires wideband data collection both in spatial and time/frequency domains. Match filtering is the main tool for generating subsurface images. Applying match filtering with the data acquisition impulse response for each possible voxel in the 3D region with the collected data requires both a tremendous amount of computer memory and computational complexity. Hence, it is …

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Semiconductor Laser Beam Bending, Remzi̇ Yildirim, Fati̇h Vehbi̇ Çelebi̇ Jan 2015

Semiconductor Laser Beam Bending, Remzi̇ Yildirim, Fati̇h Vehbi̇ Çelebi̇

Turkish Journal of Electrical Engineering and Computer Sciences

This study is about a single-component cylindrical structured lens with a gradient curve that was used for bending laser beams. It operates under atmospheric conditions and bends the laser beam independently of temperature, pressure, polarity, polarization, magnetic field, electric field, radioactivity, and gravity. A single-piece cylindrical lens that can bend laser beams was developed. Lenses are made of transparent, tinted, or colored glass and are used to undermine or absorb the energy of laser beams. This study is not a work of a plasma filamentation, nor is related to a self-accelerating wave packet. Rather, it focuses on bending the laser …

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Detection Of Stator Winding Fault In Induction Motor Using Instantaneous Power Signature Analysis, Ahmet Küçüker, Mehmet Bayrak Jan 2015

Detection Of Stator Winding Fault In Induction Motor Using Instantaneous Power Signature Analysis, Ahmet Küçüker, Mehmet Bayrak

Turkish Journal of Electrical Engineering and Computer Sciences

Stator interturn faults are one of the most common faults occurring in induction motors. Early detection of interturn short circuit is important to reduce repair costs. Axial leakage monitoring, zero-sequence components, negative sequence current, and motor current signature analysis have been used for fault detection in early states. In the paper, the instantaneous power signature analysis technique is used to detect these faults, and experimental results for healthy and faulty motors are shown and discussed.

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A New Approach To The Development Of A Nonlinear Model For Micro-Pelton Turbines, Mahmut Temel Özdemi̇r, Ahmet Orhan Jan 2015

A New Approach To The Development Of A Nonlinear Model For Micro-Pelton Turbines, Mahmut Temel Özdemi̇r, Ahmet Orhan

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a new approach that is closer to the real turbine without abandoning the advantages of nonlinear modeling simplicity compromising the simplicity of the nonlinear model is proposed. The purpose of the study is to contribute to making theoretical studies of microhydroelectric power plants (MHPPs) more realistic. Studies on their control, especially frequency control, have increased with the expansion of grid-connected power plants. However, some problems have occurred when converting simulation studies of the frequency control to practical studies. The reasons for these problems are that the systems cannot be modeled completely. In this study, first, the nonlinear …

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Automatic Classification Of Harmonic Data Using $K$-Means And Least Square Support Vector Machine, Hüseyi̇n Eri̇şti̇, Vedat Tümen, Özal Yildirim, Belkis Eri̇şti̇, Yakup Demi̇r Jan 2015

Automatic Classification Of Harmonic Data Using $K$-Means And Least Square Support Vector Machine, Hüseyi̇n Eri̇şti̇, Vedat Tümen, Özal Yildirim, Belkis Eri̇şti̇, Yakup Demi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an effective classification approach to classify harmonic data has been proposed. In the proposed classifier approach, harmonic data obtained through a 3-phase system have been classified by using $k$-means and least square support vector machine (LS-SVM) models. In order to obtain class details regarding harmonic data, a $k$-means clustering algorithm has been applied to these data first. The training of the LS-SVM model has been realized with the class details obtained through the $k$-means algorithm. To increase the efficiency of the LS-SVM model, the regularization and kernel parameters of this model have been determined with a grid …

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Determination Of Electromagnetic Properties Of Steel For Prediction Of Stray Losses In Power Transformers, Leonardo Strac, Damir Zarko Jan 2015

Determination Of Electromagnetic Properties Of Steel For Prediction Of Stray Losses In Power Transformers, Leonardo Strac, Damir Zarko

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a method for determination of equivalent linear electromagnetic parameters (constant complex permeability and electrical conductivity) of nonlinear magnetic steel, which can be used in a time-harmonic finite-element simulation to yield the same losses in the volume of that material as the measured ones. The conductivity and the static hysteresis loop of the steel have been measured, from which complex permeability as a function of flux density has been extracted. The indirect measurement of losses in various samples of nonmagnetic and magnetic steel has been carried out using a physical model of a transformer core with a coil. …

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Ofdma-Based Multicast With Multiple Base Stations, Ahmet Ci̇hat Kazez, Tolga Gi̇ri̇ci̇ Jan 2015

Ofdma-Based Multicast With Multiple Base Stations, Ahmet Ci̇hat Kazez, Tolga Gi̇ri̇ci̇

Turkish Journal of Electrical Engineering and Computer Sciences

We consider an orthogonal frequency division multiple access (OFDMA)-based multicast system where multiple base stations transmit a multicast session to a multicast group. The goal is to maximize the multicast rate (i.e. the minimum achievable user rate) subject to a total power constraint. We assume the use of an erasure code (e.g., a Reed--Solomon code) or rateless code (e.g., Luby transform code). This facilitates each user to accumulate rates from their best subchannels, so that the achievable multicast rate is not limited to the worst user. The resource allocation problem involves determining the transmitting base station at each OFDMA subchannel, …

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Effective Cooperative Dtv Detection Using The Goertzel Algorithm, Selman Kulaç, Murat Hüsnü Sazli Jan 2015

Effective Cooperative Dtv Detection Using The Goertzel Algorithm, Selman Kulaç, Murat Hüsnü Sazli

Turkish Journal of Electrical Engineering and Computer Sciences

In digital TV (DTV) detection, to monitor the DTV spectrum, only pilot tone frequency values can be observed in order to achieve calculation and energy savings. These savings can be achieved using the Goertzel algorithm. However, more than one receiver sensor is needed in order to increase the detection quality. In this technique, the Goertzel algorithm is used for energy-efficient pilot tone detection and a new effective cooperative structure is proposed. There is no extra fusion center and more than one DTV band can be monitored with this OR rule-based cooperative structure. With this new cooperative structure, reaching the desired …

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Study Of Mac Routing In The Bplc P1901 Access Network: Fixed Vs. Adaptive Approach, Asmir Gogic, Aljo Mujcic, İsmai̇l Hakki Çavdar, Matej Zajc, Nermin Suljanovic Jan 2015

Study Of Mac Routing In The Bplc P1901 Access Network: Fixed Vs. Adaptive Approach, Asmir Gogic, Aljo Mujcic, İsmai̇l Hakki Çavdar, Matej Zajc, Nermin Suljanovic

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper we propose an improved adaptive media access (MAC) layer routing algorithm for the broadband power line communication (BPLC) access network founded on the fixed basic approach routing algorithm, which is integrated within the IEEE P1901 standard. The proposed adaptive algorithm incorporates a new dynamically scaled threshold for the selection of the next hop station based on the information from the physical layer. Furthermore, the procedures for the route and the time allocation modifications during the connection setup and later adjustments are developed. Simulation of the new adaptive and existing fixed routing algorithm is performed on the model …

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Prescient: A Predictive Channel Access Schemefor Ieee 802.15.4-Compliant Devices Considering Ieee 802.11 Coexistence, Tolga Çöplü, Sema Fatma Oktuğ Jan 2015

Prescient: A Predictive Channel Access Schemefor Ieee 802.15.4-Compliant Devices Considering Ieee 802.11 Coexistence, Tolga Çöplü, Sema Fatma Oktuğ

Turkish Journal of Electrical Engineering and Computer Sciences

Coexistence is among the most significant challenges for IEEE 802.15.4-compliant devices in indoor environments. Previous works have shown that IEEE 802.11-compliant devices are the major sources of interference in the 2.4 GHz industrial, scientific, and medical band. In order to overcome the coexistence problem, IEEE 802.15.4-compliant devices should monitor the communication channel and access the channel when it is not in use. In this study, the impact of IEEE 802.11 traffic on IEEE 802.15.4 communication is analyzed and a novel predictive channel access scheme, PRESCIENT (PREdictive channel access SCheme for IEee 802.15.4-compliaNT devices), is proposed. The performance evaluation of the …

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Optimal Ipfc Damping Controller Design Based On Simplex Method And Self-Tuned Fuzzy Damping Scheme In A Two-Area Multimachine Power System, Ahmet Mete Vural, Kami̇l Çağatay Bayindir Jan 2015

Optimal Ipfc Damping Controller Design Based On Simplex Method And Self-Tuned Fuzzy Damping Scheme In A Two-Area Multimachine Power System, Ahmet Mete Vural, Kami̇l Çağatay Bayindir

Turkish Journal of Electrical Engineering and Computer Sciences

This paper develops a novel self-tuned fuzzy damping control scheme for an interline power flow controller (IPFC) to suppress the interarea mode of oscillations in a multimachine power system. The nonlinear adaptive damping controller is based on coordinated operation of two fuzzy inference systems. The first one produces the required $q$-axis voltage reference of the quasi multipulse series converter in response to generator angle oscillations, while the second one is used to tune the output of the first one online for further reducing the error signal using a given set of fuzzy rules. The simplex method is employed to search …

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Dielectric Loaded Tem Horn-Fed Ridged Horn Antenna Designfor Ultrawideband Ground-Penetrating Impulse Radar, Ahmet Serdar Türk, Ahmet Kenan Keski̇n, Mustafa Dağcan Şentürk Jan 2015

Dielectric Loaded Tem Horn-Fed Ridged Horn Antenna Designfor Ultrawideband Ground-Penetrating Impulse Radar, Ahmet Serdar Türk, Ahmet Kenan Keski̇n, Mustafa Dağcan Şentürk

Turkish Journal of Electrical Engineering and Computer Sciences

A modified double-ridged horn structure is proposed to obtain ultrawideband antenna characteristics over a bandwidth ratio of greater than 40:1 for impulse radar systems. The Vivaldi-shaped TEM horn feeder has been designed to extend the lower cut-off frequency and the partial dielectric loading technique using a small lens inward while the aperture has been implemented to enhance the gain of the standard double-ridged horn antenna without changing the physical dimensions. The starting frequency of the antenna operation band is lowered from 800 MHz to 400 MHz. Moreover, approximately 5 dB gain increment level is achieved from 4 to 10 GHz. …

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An Implementable Approach In Order To Model A Nonideal Incremental Encoder In Speed Measurement Studies, Mahdi Maaref, Alireza Rezazadeh Jan 2015

An Implementable Approach In Order To Model A Nonideal Incremental Encoder In Speed Measurement Studies, Mahdi Maaref, Alireza Rezazadeh

Turkish Journal of Electrical Engineering and Computer Sciences

Incremental encoders have attracted significant attention to measure motor speed worldwide. Due to the advantages of incremental encoders a noticeable percentage of Servo system drives have been built based on these sensors. The nonideality of encoders, especially mechanical misalignments, is one of their most important problems, affecting the precision of calculations. In the current paper we present an analytical formula to model the nonideal incremental encoder and calculate both the frequency and magnitude of vibrations due to this nonideality. Moreover, a nonideality identity parameter of the encoder is defined. This parameter can be used for quality assurance purposes. Moreover, it …

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A New High-Performance Current-Mode Fuzzy Membership Function Circuit And Its Application, Turgay Temel Jan 2015

A New High-Performance Current-Mode Fuzzy Membership Function Circuit And Its Application, Turgay Temel

Turkish Journal of Electrical Engineering and Computer Sciences

A new current-mode fuzzy-membership function circuit is proposed. The circuit has a very compact and simple architecture based on the simultaneous use of winner- and loser-take-all topologies. The circuit has also the advantage of easily adjusting generated membership function characteristics such as center or mean and width with a straightforward application of respective input currents. It is shown that the new circuit outperforms previous counterparts in terms of speed, power consumption, layout area, and robustness to variations in design parameters and errors. As an application, a fuzzy-classifier is designed with a new membership circuit as a seven fuzzy level controller.

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A New Bitwise Voting Strategy For Safety-Critical Systems With Binary Decisions, Mustafa Seçki̇n Durmuş, Oytun Eri̇ş, Uğur Yildirim, Mehmet Turan Söylemez Jan 2015

A New Bitwise Voting Strategy For Safety-Critical Systems With Binary Decisions, Mustafa Seçki̇n Durmuş, Oytun Eri̇ş, Uğur Yildirim, Mehmet Turan Söylemez

Turkish Journal of Electrical Engineering and Computer Sciences

The main issue in controlling safety-critical systems such as nuclear power reactors or railway interlocking systems is to provide high safety and reliability where the risk ratio is at the highest level because small errors might result in hazardous accidents (e.g., death or injury of many people). The N-version programming technique, where N-different modules run in parallel, can be used to improve the reliability and safety of such systems at the desired safety level. Decisions of N-different modules are then evaluated by another component, usually known as the voter, using different voting strategies. In the current study a bitwise voting …

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Application And Histology-Driven Refinement Of Active Contour Models To Functional Region And Nerve Delineation: Towards A Digital Brainstem Atlas, Nimal Patel, Sharmin Sultana, Tanweer Rashid, Dean Krusienski, Michel A. Audette Jan 2015

Application And Histology-Driven Refinement Of Active Contour Models To Functional Region And Nerve Delineation: Towards A Digital Brainstem Atlas, Nimal Patel, Sharmin Sultana, Tanweer Rashid, Dean Krusienski, Michel A. Audette

Electrical & Computer Engineering Faculty Publications

This paper presents a methodology for the digital formatting of a printed atlas of the brainstem and the delineation of cranial nerves from this digital atlas. It also describes on-going work on the 3D resampling and refinement of the 2D functional regions and nerve contours. In MRI-based anatomical modeling for neurosurgery planning and simulation, the complexity of the functional anatomy entails a digital atlas approach, rather than less descriptive voxel or surface-based approaches. However, there is an insufficiency of descriptive digital atlases, in particular of the brainstem. Our approach proceeds from a series of numbered, contour-based sketches coinciding with slices …

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Qcm-D Monitoring Of Binding-Induced Conformational Change Of Calmodulin, Hyun J. Kwon, Brian Dodge Jan 2015

Qcm-D Monitoring Of Binding-Induced Conformational Change Of Calmodulin, Hyun J. Kwon, Brian Dodge

Faculty Publications

Understanding conformational changes are important when studying a protein such as calmodulin (CaM), which activates various target enzymes and regulates numerous physiological functions. CaM is a highly flexible protein that can transitorily adopt various conformations. A quartz crystal microbalance with dissipation (QCM-D) sensor was used to study binding-induced conformational changes of surface-immobilized CaM. Structural changes of CaM were evaluated using the Voigt’s viscoelastic model with frequency (ΔF) and dissipation change (ΔD). When Apo-CaM layer was incubated in 0.1 mM Ca2+ solution, the layer decreased by approximately 0.56 nm, due to the release of coupled water molecules and conformational change. The …

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Integrating Emerging Cryptographic Engineering Research And Security Education, Mehran Mozaffari Kermani, Reza Azarderakhsh Jan 2015

Integrating Emerging Cryptographic Engineering Research And Security Education, Mehran Mozaffari Kermani, Reza Azarderakhsh

Articles

Unlike traditional embedded systems such as secure smart cards, emerging secure deeply embedded systems, e.g., implantable and wearable medical devices, have larger “attack surface”. A security breach in such systems which are embedded deeply in human bodies or objects would be life-threatening, for which adopting traditional solutions might not be practical due to tight constraints of these often-battery-powered systems. Unfortunately, although emerging cryptographic engineering research mechanisms have started solving this critical problem, university education (at both graduate and undergraduate level) lags comparably. One of the pivotal reasons for such a lag is the multi-disciplinary nature of the emerging security bottlenecks …

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Framing The Question, "Who Governs The Internet?", Robert J. Domanski Jan 2015

Framing The Question, "Who Governs The Internet?", Robert J. Domanski

Publications and Research

There remains a widespread perception among both the public and elements of academia that the Internet is “ungovernable”. However, this idea, as well as the notion that the Internet has become some type of cyber-libertarian utopia, is wholly inaccurate. Governments may certainly encounter tremendous difficulty in attempting to regulate the Internet, but numerous types of authority have nevertheless become pervasive. So who, then, governs the Internet? This book will contend that the Internet is, in fact, being governed, that it is being governed by specific and identifiable networks of policy actors, and that an argument can be made as to …

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On An Effective Submodeling Procedure For Stresses Determined With Finite Element Analysis, Ajay Ashok Kardak Jan 2015

On An Effective Submodeling Procedure For Stresses Determined With Finite Element Analysis, Ajay Ashok Kardak

LSU Doctoral Dissertations

Submodeling can enable stress analysts using finite elements to focus analysis on a subregion containing the stress concentration of interest, with consequent computational savings. Such benefits are only truly realized if the boundary conditions on the edges of the subregion that were originally contained within the global region are sufficiently accurate. These boundary conditions are drawn from initial global finite element analysis (FEA), and consequently themselves have errors that in turn lead to errors in the stresses sought. When these last boundary-condition errors are controlled, and the discretization errors incurred by the FEA of ensuing submodels are also controlled, submodeling …

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Applications Of Cfd Simulations On Fractal Fluid Distributor, Gongqiang He Jan 2015

Applications Of Cfd Simulations On Fractal Fluid Distributor, Gongqiang He

LSU Master's Theses

Since its emergence in 1970s, process intensification has been attracting extensive research interests from both academic and industrial societies over the years. One good example of process intensification in chemical industry is the optimization of flow distributors. In many chemical processes, the uniformity of flow distributions plays the key role in determining the overall efficiency. Conventional distributors rely on high pressure drop to achieve acceptable flow distribution. With scaling symmetry from fractal, fractal distributors can handle fluid distribution much better than conventional distributors. With the rapid development of computation power and numerical simulation algorithms, Computer Fluid Dynamics (CFD) provides us …

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Multiscale Modeling Of Smart Materials Under Static And Dynamic Thermo-Mechanical Loading, Soodabeh Sharafi Jan 2015

Multiscale Modeling Of Smart Materials Under Static And Dynamic Thermo-Mechanical Loading, Soodabeh Sharafi

LSU Master's Theses

Engineering material systems with tailored capabilities are a topic trend in plethora of research. Polymer based Artificial Muscle, PAM, and Shape memory polymer fiber, SMPF, enable structural engineers to incorporate smartness functionality into their design through programming cycles. Smartness functionality leads to the production of artificial muscles with different load carrying capability. SMPF is another category of smart materials, which are capable of being micro-structurally engineered to isolate vibration at different temperature and frequency conditions. The smartness functionality offers the adjustment between inherent properties of these materials with their industrial applications through modeling techniques. Mixture of phenomenological, numerical, mathematical models …

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What Does It Take To Deliver An Active Hands-On Course?, Steve C. Hsiung, Feng Jao Jan 2015

What Does It Take To Deliver An Active Hands-On Course?, Steve C. Hsiung, Feng Jao

Engineering Technology Faculty Publications

Distance Education has been implemented widely in different curricula at many institutions; different means have been used to ensure the delivery. This article introduces unique combination of different mechanisms in implementing the active/synchronous distance delivery of hands-on course(s) that is compatible and similar to the face-to-face on-campus course(s).There are three major developmental stages of these online courses - curriculum design, methodologies, and assessment to ensure the effectiveness of distance delivery of technical courses in engineering technology. The processes of curriculum design for the Embedded System Designs are discussed: (a) The development of course and labs modules for hands-on technical courses. …

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Effects Of Light Quality And Light Quantity On The Growth Kinetics Of A Louisiana Native Microalgal/Cyanobacterial Co-Culture, Jonathan Zell Barnett Jan 2015

Effects Of Light Quality And Light Quantity On The Growth Kinetics Of A Louisiana Native Microalgal/Cyanobacterial Co-Culture, Jonathan Zell Barnett

LSU Master's Theses

One of the most important factors controlling the growth of microalgae is light. Light quality and light quantity have a dramatic effect on the production of biomass, lipids and pigments of microalgae. In this research, a native Louisiana co-culture containing Chlorella vulgaris (microalgae) and Leptolyngbya sp (cyanobacteria) was studied to determine the effects of various wavelength distributions and irradiance levels on growth kinetics. Growth rates, biomass levels, lipid contents and chlorophyll-a production was examined in batch cultures to determine which color light was optimum for cultivation. At 80 µmol/m^2-sec the species shifted from microalgae dominant to cyanobacteria dominant. The impact …

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An Analytic Solution Of The Thermal Boundary Layer At The Leading Edge Of A Heated Semi-Infinite Flat Plate Under Forced Uniform Flow, Robert Jessee Jan 2015

An Analytic Solution Of The Thermal Boundary Layer At The Leading Edge Of A Heated Semi-Infinite Flat Plate Under Forced Uniform Flow, Robert Jessee

LSU Master's Theses

Abstract The heated flat plate under uniform flow has been vastly studied, with the Blasius and Pohlhausen solutions developed over 100 years ago. These solutions are numerical in nature. Here, an analytic solution is found for the temperature and velocity profiles at the leading edge of a heated flat plate under forced uniform flow. By defining a similarity variable the governing equations are reduced to a dimensionless equation with an analytic solution at the leading edge. This report gives justification for the similarity variable via scaling analysis, details the process of converting to similarity form, and presents a similarity solution. …

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Study Of Active Vibration Control Using The Method Of Receptances, Amit Maha Jan 2015

Study Of Active Vibration Control Using The Method Of Receptances, Amit Maha

LSU Doctoral Dissertations

Using the Method of Receptance, it is possible in general to assign 2_x0002_ poles (i.e. n conjugate pairs) of an axially vibrating rod of variable cross section by sensing the state at _x0002_ points along the rod. Using the sensor data, closed loop feedback control gains can be calculated by solving a simple set of linear equations. The feedback gains can be applied to generate the required control force using an actuator. This partial pole assignment can be done without continuous or discrete analytical modeling. Therefore, the physical parameters such as the rigidity, the density, and the variable cross-sectional area …

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Context Aware Textual Entailment, Soha Arab-Khazaeli Jan 2015

Context Aware Textual Entailment, Soha Arab-Khazaeli

LSU Doctoral Dissertations

In conversations, stories, news reporting, and other forms of natural language, understanding requires participants to make assumptions (hypothesis) based on background knowledge, a process called entailment. These assumptions may then be supported, contradicted, or refined as a conversation or story progresses and additional facts become known and context changes. It is often the case that we do not know an aspect of the story with certainty but rather believe it to be the case; i.e., what we know is associated with uncertainty or ambiguity. In this research a method has been developed to identify different contexts of the input raw …

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