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2005

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Articles 2551 - 2580 of 3074

Full-Text Articles in Engineering

Fuzzifying [Sic] Markov Decision Process, Ahmed Syed Irshad Jan 2005

Fuzzifying [Sic] Markov Decision Process, Ahmed Syed Irshad

LSU Master's Theses

Markov decision processes have become an indispensable tool in applications as diverse as equipment maintenance, manufacturing systems, inventory control, queuing networks and investment analysis. Typically we have a controlled Markov chain on a suitable state space in which transitional probabilities depend on the policy (or decision maker) which comes from a set of possible actions. The main problem of interest would be to find an optimal policy that minimizes the associated cost. Linear Programming has been widely used to find the optimal Markov decision policy. It requires solutions of large systems of simultaneous linear equations. By the fact that the …

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Purification And Structural Characterization Of Caged Dna Oligonucleotides, Brendan Michael Mcadams Jan 2005

Purification And Structural Characterization Of Caged Dna Oligonucleotides, Brendan Michael Mcadams

LSU Master's Theses

“Cage” molecules reversibly block the bioactivity of a target substrate molecule by a photolyzable covalent bond formed at a functional site of the target molecule. The attachment of cage molecules to DNA oligodeoxynucleotides (ODNs) to transiently block bioactivity, and site-specific restoration of bioactivity using targeted light exposure, would enable a new method of control for use in gene therapy, molecular/DNA computing, molecular biology, and drug delivery. The reaction of the cage molecule 1-(4,5-dimethoxy-2-nitrophenyl)diazoethane (DMNPE) with DNA ODNs in an batch reaction yields a mixture of products with varying degrees of caging. Purification and verification of the hypothesized site of DMNPE …

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Improved Watermarking Scheme Using Decimal Sequences, Naveed Shaik Ashfaq Jan 2005

Improved Watermarking Scheme Using Decimal Sequences, Naveed Shaik Ashfaq

LSU Master's Theses

This thesis improves upon the work carried out by Mandhani on decimal sequence watermarking showing that the embedding and decoding algorithms used by Mandhani are not robust. We next specify improvements to these algorithms so that the peak signal to noise ratio (PSNR) is maximized and the distortion introduced in the image due to the embedding is minimized. By exploiting the cross correlation property of decimal sequences, the concept of embedding more than one watermark in the same cover image has been investigated. A comparison between the PSNRs for decimal sequence watermarking and other pseudorandom sequences has been made.

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Photobiological And Thermal Effects Of Uva Light On Cell Culture, Julianne Forman Jan 2005

Photobiological And Thermal Effects Of Uva Light On Cell Culture, Julianne Forman

LSU Master's Theses

The objective of this study is to characterize the photobiological and thermal effects of UVA light on cell cultures. While near-ultraviolet light has been widely used to photoactivate fluorophores and caged compounds in cells, little is known of the long-term biological effects of this light. UVA (320-400nm) photoactivating light has been used for studying fast kinetic processes and is now being employed in higher doses to target longer duration phenomena (e.g. gene expression and silencing). Photoexposure experiments using 365nm light will examine how longer duration and increased UV doses affect photoactivation cell studies. Apoptotic and cellular injury assays have been …

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Heuristics For Offset Assignment In Embedded Processors, Satya Swaroop Mahapatra Jan 2005

Heuristics For Offset Assignment In Embedded Processors, Satya Swaroop Mahapatra

LSU Master's Theses

This thesis deals with the optimization of program size and performance in current generation embedded digital signal processors (DSPs) by the design of optimal memory layouts for data. Given the tight constraints on the size, power consumption, cost and performance of these processors, the minimization of code size in terms of the number of instructions required and the associated reduction in execution time are important. Several DSPs provide limited addressing modes and the layout of data, known as offset assignment, plays a critical role in determining the code size and performance. Even the simplest variant of the offset assignment problem …

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Sediment Tmdl Calculations For Amite River, Pradeep Kumar Mishra Jan 2005

Sediment Tmdl Calculations For Amite River, Pradeep Kumar Mishra

LSU Master's Theses

The Amite River is recognized as one of the 15 water bodies impaired by sediments in Louisiana. A sediment TMDL calculation for the Amite River is required by the EPA. Based on EPA’s Protocol sediment TMDL calculations for the Upper Amite River are conducted in this thesis. The sediment TMDL calculations are composed of four parts: (1) Development of a new sediment transport and dispersion model for the Amite River, (2) Estimation of sediment loads (sources) produced by watershed erosion, (3) Flow computation, and (4) Determination of sediment TMDL for the Amite River. Using the mass conservation principle and Reynolds …

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Contact Effects In Thermally Evaporated Pentacene Thin Films And Aspects Of Microsystem Hybrid Integration, Jagadish Yernagula Jan 2005

Contact Effects In Thermally Evaporated Pentacene Thin Films And Aspects Of Microsystem Hybrid Integration, Jagadish Yernagula

LSU Master's Theses

Organic thin film transistors have the potential to replace silicon based transistors in applications such as smart cards and RF-ID due to their low cost and low processing temperatures. Thermally evaporated pentacene is studied as an organic thin film material. Thin film transistors were fabricated in bottom contact structure using thermal evaporation of pentacene at a rate of 0.5 to 1 nm/s. Heavily doped Si was used as a gate material and 100 nm thick silicon dioxide was used as a dielectric. Ni was used as contact metal for source and drain contacts. Threshold voltage of 16 V and mobility …

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Performance Based Switching Control For Single Input Linear Time Invariant Systems, Lalitha Srigouri Devarakonda Jan 2005

Performance Based Switching Control For Single Input Linear Time Invariant Systems, Lalitha Srigouri Devarakonda

LSU Master's Theses

In the present research, we propose a new control strategy to improve the performance of a linear time invariant single input system. We consider a performance index that is dependent only on the controlled variable and try to improve it over that obtained when using a stable state feedback control. Since the control law depends on the performance of the controlled variable, we call it Performance Based Switching Control (PBSC). Switching between two state feedbacks is used to achieve this improvement in performance. The switching strategy combines the best features of both strategies. The switching surface is actually composed of …

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Effects Of Mental Rotation, Visual Aids And Training On Inspection Performance During Airport Baggage Inspection, Sunil Addepalli Jan 2005

Effects Of Mental Rotation, Visual Aids And Training On Inspection Performance During Airport Baggage Inspection, Sunil Addepalli

LSU Master's Theses

Since 9/11, airport security has become an area of critical national security. The current study investigates the effect of mental rotation training and the presence of visual decision aids on inspection performance. Forty-eight participants were divided into two groups (Group A and Group B) of twenty-four each. Each group was provided with training on visual inspection, baggage screening and on using the software simulation of airport baggage inspection. Participants had to identify from images any object that cannot be allowed on a passenger plane and register a response by clicking one of the buttons, “Threat” or “No Threat”. Participants in …

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Wafer Level Chip Scale Packaging Using Wafer Bonder, Kailash Upadhyaya Jan 2005

Wafer Level Chip Scale Packaging Using Wafer Bonder, Kailash Upadhyaya

LSU Master's Theses

An in-house processing capability is developed in this research for silicon-glass bonding for microfabrication and wafer level chip scale packaging (WLCSP) using a wafer bonder. New masking technology for wet etching of glass to a depth of more than 430 µm is reported in this research work along with development of an anodic bonding process that permits electrical feedthroughs for connections to outside world. Three novel masks were developed in this work for deep wet etching of glass. They were multilayers of metals Mo/Cr/Au (mask 1) and Cr/Au/electroplated Ni (mask 2) both in combination with 20 µm thick AZ® P4620 …

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Use Of Orthogonal Arrays, Quasi-Monte Carlo Sampling And Kriging Response Models For Reservoir Simulation With Many Varying Factors, Subhash Kalla Jan 2005

Use Of Orthogonal Arrays, Quasi-Monte Carlo Sampling And Kriging Response Models For Reservoir Simulation With Many Varying Factors, Subhash Kalla

LSU Master's Theses

Asset development teams may adjust simulation model parameters using experimental design to reveal which factors have the greatest impact on the reservoir performance. Response surfaces and experimental design make sensitivity analysis less expensive and more accurate, helping to optimize recovery under geological and economical uncertainties. In this thesis, experimental designs including orthogonal arrays, factorial designs, Latin hypercubes and Hammersley sequences are compared and analyzed. These methods are demonstrated for a gas well with water coning problem to illustrate the efficiency of orthogonal arrays. Eleven geologic factors are varied while optimizing three engineering factors (total of fourteen factors). The objective is …

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Effect Of Multiuser Interference On Subscriber Location In Cdma Networks, Rohit Sharma Jan 2005

Effect Of Multiuser Interference On Subscriber Location In Cdma Networks, Rohit Sharma

LSU Master's Theses

The last few years have witnessed an ever growing interest in the field of mobile location systems for cellular systems. The motivation is the series of regulations passed by Federal Communications Commission, requiring that wireless service providers support a mobile telephone callback feature and cell site location mechanism. A further application of the location technology is in the rapidly emerging field of intelligent transportation systems, which are intended to enhance highway safety, location based billing etc. Many of the existing location technologies use GPS and its derivatives which require a specialized subscriber equipment. This is not feasible for popular use, …

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Experimental And Numerical Study Of Feeding Channel In Proton Exchange Membrane Fuel Cell, Abul Bashar Mahmud Hasan Jan 2005

Experimental And Numerical Study Of Feeding Channel In Proton Exchange Membrane Fuel Cell, Abul Bashar Mahmud Hasan

LSU Master's Theses

The performance of a Proton Exchange Membrane Fuel Cell (PEMFC) using different feeding configurations has been studied, with a focus on the water flooding due to electrochemical reaction. Feeding channel or Bipolar plate in Proton Exchange Fuel Cell is a dominating part. As feeding channel keeps direct contact with the gas diffusion layer, it helps efficiently supplying fuel and air into the gas diffusion layer for efficient production of electricity. Experimental data have been taken at hydrogen flow rates of 20,40,60,80,100 sccm for various bipolar plate arrangements. Three bipolar plates, namely serpentine, straight channel and interdigitated designs, were arranged in …

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Augmented Watermarking, Kiranmayi Penumarthi Jan 2005

Augmented Watermarking, Kiranmayi Penumarthi

LSU Master's Theses

This thesis provides an augmented watermarking technique wherein noise is based on the watermark added to the watermarked image so that only the end user who has the key for embedding the watermark can both remove the noise and watermark to get a final clear image. The recovery for different values of noise is observed. This system may be implemented as a basic digital rights management system by defining a regime of partial rights using overlaid watermarks, together with respectively added layers of noise, in which the rights of the users define the precision with which the signals may be …

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A Slope-Dependent Disjoining Pressure For Lennard-Jones Liquid Films, Taeil Yi Jan 2005

A Slope-Dependent Disjoining Pressure For Lennard-Jones Liquid Films, Taeil Yi

LSU Master's Theses

A molecule in a bulk liquid is subject to intermolecular forces. A molecule in a thin liquid film may experience additional intermolecular forces, if the thin film thickness h is less than roughly 100 nm. The additional forces arise from the molecule's proximity to different materials or phases sandwiching the thin film. The effect of these intermolecular forces at the continuum level is captured by disjoining pressure &Pi. Since dominates at small film thickness, it determines the stability and wettability of thin films. To leading order, Π = Π (h) because thin films are generally uniform. This form, however, can …

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Scalable Schemes Against Distributed Denial Of Service Attacks, Kishori Nanduri Jan 2005

Scalable Schemes Against Distributed Denial Of Service Attacks, Kishori Nanduri

LSU Master's Theses

Defense against Distributed Denial of Service (DDoS) attacks is one of the primary concerns on the Internet today. DDoS attacks are difficult to prevent because of the open, interconnected nature of the Internet and its underlying protocols, which can be used in several ways to deny service. Attackers hide their identity by using third parties such as private chat channels on IRC (Internet Relay Chat). They also insert false return IP address, spoofing, in a packet which makes it difficult for the victim to determine the packet's origin. We propose three novel and realistic traceback mechanisms which offer many advantages …

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Electrodeposited Nanoscale Multilayers Of Invar With Copper, Diwakar Suryanarayana Iyer Jan 2005

Electrodeposited Nanoscale Multilayers Of Invar With Copper, Diwakar Suryanarayana Iyer

LSU Master's Theses

Materials with low thermal expansion coefficients (CTEs) that will survive temperature cycling are of interest in a variety of applications on the microscale, including actuation, precision assembly, and injection mold fabrication. Invar alloys exhibit a low positive coefficient of thermal expansion ranging between 0.2 – 1.2 µm/m-°C at room temperature. The electrodeposition process for fabricating nanoscale multilayers of Invar and copper in micro-patterns was characterized to assess their value in various MEMS applications. In an ongoing effort to maintain a stable CTE and effectively control the grain growth of Invar, nano-multilayers of near Invar-like FeNiCu and copper were electrodeposited into …

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Synthesis And Characterization Of Cobalt-Platinum Thin Films, Priya David Jan 2005

Synthesis And Characterization Of Cobalt-Platinum Thin Films, Priya David

LSU Master's Theses

Co-based alloy thin films have attracted a lot of interest, due to their excellent magnetic properties, that is essential in the field of magnetic recording media. Alloying Co with metals like Pt changes some of its intrinsic magnetic properties such as increasing the magnetocrystalline anisotropy constants of the alloy. Co-Pt thin films and multilayers are more suitable for ultra high-density magnetic recording media because they have high-magnetic anisotropy, chemical stability, excellent coercivity and resistance to corrosion. In the present study, Co-Pt alloy and Pt/Co multilayered films were deposited on Si substrate using dual electron beam co-evaporation. The Co-Pt alloy thin …

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Comparative Study Of The Physical And Mechanistic Properties Of Hma Mixture: Field Vs Laboratory, Chenggang Zhang Jan 2005

Comparative Study Of The Physical And Mechanistic Properties Of Hma Mixture: Field Vs Laboratory, Chenggang Zhang

LSU Master's Theses

The objectives of this study were to investigate the variability in the physical and mechanistic properties of HMA due to production, characterize and compare the mechanistic properties of roadway cores and laboratory compacted samples, develop the relationship between modulus from in situ NDT and those obtained from laboratory tests on roadway cores, and compare air voids measurements between laboratory and field test methods. Six ongoing rehabilitation projects in Louisiana were selected, in each of which several test sections were tested. Comparative analyses were conducted on density measurements between two laboratory (AASHTO T-166 and ASTM D6752-02, or Vacuum sealing) and one …

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Thermal Management Of The Lsu Micro Gas Chromatograph, Praveen K. Pasupuleti Jan 2005

Thermal Management Of The Lsu Micro Gas Chromatograph, Praveen K. Pasupuleti

LSU Master's Theses

Gas chromatography is a technique widely used for the separation and analysis of gas samples. Gas chromatographs are used for environmental maintenance, monitoring sophisticated biological analyses, and to separate components from a mixture of gases for mass spectrometer analysis. There has been a tremendous interest in miniaturization of gas chromatograph systems because of the potential for portability, faster response time, lower dead volume, lower power consumption, and lower cost of operation. Conventional gas chromatography keeps the column at a constant temperature during separation, which is called isothermal analysis. Temperature programming is a mode of gas chromatography in which the column …

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Simulation And Economic Evaluation Of Coal Gasification With Sets Reforming Process For Power Production, Zachary Hoffman Jan 2005

Simulation And Economic Evaluation Of Coal Gasification With Sets Reforming Process For Power Production, Zachary Hoffman

LSU Master's Theses

Increasing natural gas prices have raised interest in alternate energy resources. Popular belief in the connection between carbon dioxide emissions and global warming has motivated the search for a technique to isolate carbon dioxide from combustion stack gases. Coal gasification with SETS reforming has been proposed as a solution to both of these issues in that it provides an alternate energy source and 100% carbon dioxide sequestration. The purpose of this research is to simulate this process using AspenPlus to perform the rigorous material and energy balances. The results of this simulation are used to carry out a complete economic …

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Heuristics For Memory Access Optimization In Embedded Processors, Saravanan Subramanian Jan 2005

Heuristics For Memory Access Optimization In Embedded Processors, Saravanan Subramanian

LSU Master's Theses

Digital signal processors (DSPs) such as the Motorola 56k are equipped with two memory banks that are accessible in parallel in order to offer high memory bandwidth, which is required for high-performance applications. In order to make efficient use of the memory bandwidth offered by two or more memory banks, compilers for such DSPs should be capable of appropriately partitioning the program variables between the two memory banks and scheduling accesses. If two variables can be accessed simultaneously, then it is essential to have these two variables assigned to two different memory banks. Also if these two variables are in …

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Cryopreservation Of Reproductive Cells And Tissues, Guanglei Li Jan 2005

Cryopreservation Of Reproductive Cells And Tissues, Guanglei Li

LSU Master's Theses

Cryopreservation of reproductive cells and tissues is a useful technique to deliver intact genomes, maximize the distribution of favorable genes, control disease spread. It is widely applied to many fields such as biology, medicine, ecology and agriculture. To optimize the cryopreservation procedure, the biophysical responses of reproductive tissues at different cooling conditions and in different mediums must be clearly understood. Here we studied the biophysical response during freezing of: 1) bovine sperm frozen at a cooling rate of 20 ˚C/min in three media: without cryopreservation agents(CPAs), with 0.7 M glycerol, and with 0.7 M glycerol along with 1.5 mg/ml of …

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Usability Of Home Cholesterol Test Kits And Their Impact On Patients' Decision, Deepti Surabattula Jan 2005

Usability Of Home Cholesterol Test Kits And Their Impact On Patients' Decision, Deepti Surabattula

LSU Master's Theses

Release of home health testing kits into the market has enabled people to take care of their own health. Misinterpretation of results and delays in treatments are the major concerns of the doctors. In the present study, two cholesterol test kits, AccuchekÒ Instant plusÒ and Home Access® Instant Cholesterol Test, were compared on the basis of user performance, accuracy, and the patient’s future medical decisions based on the test results. The study was conducted with 30 participants, 15 men and 15 women. Participants tested their overall cholesterol level with both kits. In addition, a clinical cholesterol evaluation, the medical gold …

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Study Of The Effects Of Magnetic Field On The Properties Of Combustion Synthesized Iron Oxide Nanoparticles, Nagaraju Komuravelli Jan 2005

Study Of The Effects Of Magnetic Field On The Properties Of Combustion Synthesized Iron Oxide Nanoparticles, Nagaraju Komuravelli

LSU Master's Theses

Nanosized chain-like aggregates were developed in an iron pentacarbonyl-carbon monoxide (Fe(CO) 5 ¨C CO) air diffusion flame system. Magnetic field was applied around the diffusion flame using an electromagnet with an intensity of 0.4 Tesla. Transmission Electron Microscopy (TEM) analysis was performed to observe the behavior of the chains formed and to study the effect of magnetic field on these chains. These chain aggregates consist mainly of Fe2O3, which play a vital role in magnetic storage devices. Diffraction pattern analysis and X-ray Photon Spectroscopy (XPS) were carried out to confirm that the chain aggregates consist of mainly ¦Ã-Fe2O3. The effect …

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Functionalization Of Gold And Glass Surfaces With Magnetic Nanoparticles Using Biomolecular Interactions, Bala Sesha Giri Rao Nidumolu Jan 2005

Functionalization Of Gold And Glass Surfaces With Magnetic Nanoparticles Using Biomolecular Interactions, Bala Sesha Giri Rao Nidumolu

LSU Master's Theses

Advances in nanotechnology have enabled the production and characterization of magnetic particles with nanometer-sized features that can be functionalized with biological recognition elements for clinical and biosensing applications. In the present study the synthesis and interactions between self assembled monolayers (SAMs) and functionalized nanoparticles have been characterized. Size and shape of magnetic nanoparticles synthesized wet chemically starting from ferrous and ferric salts were verified by transmission electron microscopy (TEM). These nanoparticles were then conjugated with FITC-labeled streptavidin through carbodiimide (EDC) chemistry. SAMs of thiol-capped biotins were synthesized on gold surfaces for capture of the conjugated nanoparticles. Characterization of nanoparticle functionalization …

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Assessing The Needs For Intermediate Diaphragms In Prestressed Concrete Girder Bridges, Anand Kumar Chandolu Jan 2005

Assessing The Needs For Intermediate Diaphragms In Prestressed Concrete Girder Bridges, Anand Kumar Chandolu

LSU Master's Theses

Reinforced concrete Intermediate Diaphragms (IDs) are still being used in prestressed concrete (PC) girder bridges in Louisiana. Some of the advantages of providing IDs are disputed and also use of IDs increases the cost and time of construction. There is no consistency in the practice of providing IDs among various states and codes of practice and overall there is a lack of clarity on the effectiveness of IDs and their needs in prestressed concrete bridges. The objectives of this research are to assess the need of reinforced concrete (RC) IDs in PC girder bridges and to determine their effectiveness and …

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Factors Effecting Field Emission From Multiwalled Carbon Nanotubes, Abhilash Krishna Jan 2005

Factors Effecting Field Emission From Multiwalled Carbon Nanotubes, Abhilash Krishna

LSU Master's Theses

Carbon nanotubes (CNT) have emerged to be one of the most versatile of materials ever discovered. The small dimensions, high electrical conductivity and strength along with other physical and electrical properties make them a unique material with a wide range of promising applications. One such use is that of CNTs as electron beam sources. A typical CNT has a diameter of only a few nanometers but can be hundreds of microns long. Applying a voltage across the length of such an object results in field emission of electrons from one end of the tube. This effect is due to intense …

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Blind Multiridge Detection And Reconstruction Using Ultrasonic Signals, Rekha Katragadda Jan 2005

Blind Multiridge Detection And Reconstruction Using Ultrasonic Signals, Rekha Katragadda

LSU Master's Theses

Time-frequency signal analysis has been widely applied in the modern radar, acoustic, sonar and ultrasonic signal processing techniques. Recently, the nondestructive testing (NDT) techniques via the ultrasonic instrumentation have shown the striking capability of the quality control for the material fabrication industry. In this thesis, we first provide a general mathematical model for the ultrasonic signals collected by pulse-echo sensors and then design a totally blind, novel, signal processing NDT technique relying on neither a priori signal information nor any manual effort. The signature signal can be blindly extracted by using the automatic optimal frame size selection for further modeling …

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Damage Mechanics Of Composite Materials Using Fabric Tensors, Ziad N. Taqieddin Jan 2005

Damage Mechanics Of Composite Materials Using Fabric Tensors, Ziad N. Taqieddin

LSU Master's Theses

The major objective of this work is to relate continuum damage mechanics introduced through the concept of fabric tensors to composite materials within the framework of classical elasticity theory. A model of directional data-damage mechanics for composite materials is formulated using fabric tensors. In addition, a general hypothesis for damage mechanics is postulated. It is seen that the two available hypotheses of elastic strain equivalence and elastic energy equivalence may be obtained as special cases of the postulated general hypothesis. This general hypothesis is then used to derive the sought relationship between the damage tensor for composite materials and the …

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