Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Constraint based routing (2)
- Matlab (2)
- A priori signal-to-noise ratio (1)
- A.c. supply (1)
- Aircraft safety (1)
-
- Analog testing (1)
- Anodic bonding (1)
- Artificial neural networks (1)
- Augmented watermarking (1)
- Bio-implantable (1)
- Bio-telemetry (1)
- Bistable (1)
- Broadcast channels (1)
- Brushless dc motor (1)
- Burst drop (1)
- CDMA (1)
- CMOS (1)
- Carbon nanotubes (1)
- Charge pump (1)
- Cic filter (1)
- Clock booster circuit (1)
- Clock divider circuit (1)
- Cmos decimator (1)
- Co-operative diversity (1)
- Correlation (1)
- D.c. supply (1)
- DDoS attacks (1)
- Dc-dc converter (1)
- Dct (1)
- Decimal sequence (1)
Articles 1 - 30 of 34
Full-Text Articles in Engineering
Transform Techniques And Non-Stationarity With An Emphasis On Network Applications, Phat Piron
Transform Techniques And Non-Stationarity With An Emphasis On Network Applications, Phat Piron
LSU Master's Theses
The recent years brought a phenomenal development of Internet. It is, therefore, important to find some ways to improve the performances. The first step in this direction is the characterization and modeling of the network traffic. It has been tested that the network traffic behaves like a self-similar process, while packets interarrivals time possess the long-range dependence property. In particular, we model them by using fractional Brownian motion and fractional Gaussian noise, respectively. Note that, the former is just the cumulative sum of the latter. By using these concepts, the traffic characterization reduces to the estimation of one value: the …
Deposition Of Carbon Layers From Cyclohexane By Thermal Chemical Vapor Deposition, Bharath Thiruvengadachari
Deposition Of Carbon Layers From Cyclohexane By Thermal Chemical Vapor Deposition, Bharath Thiruvengadachari
LSU Master's Theses
The overall aim of this thesis is to deposit carbon layers by thermal Chemical Vapor Deposition (CVD) and investigate the effects of process parameters on the morphology and structure of the deposited carbon layers. Cyclohexane (C6H12) hydrocarbon is the precursor material used as the source of carbon. A 20% Cu- 80% Ni alloy, deposited by RF magnetron sputtering and annealed at the growth temperature either in an argon flow or in 10% hydrogen-90% argon flow, is used as a catalyst prior to carbon film deposition by CVD. The CVD temperature is varied between 550 0C and 800 0C. The Cu-Ni …
Heuristics For Offset Assignment In Embedded Processors, Satya Swaroop Mahapatra
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 …
Traffic Engineering And Path Protection In Mpls Virtual Private Networks, Pooja S. Aniker
Traffic Engineering And Path Protection In Mpls Virtual Private Networks, Pooja S. Aniker
LSU Master's Theses
Traffic Engineering (TE) attempts to establish paths for the flow of data in a network so as to optimize the resource utilization and maximize the network performance. One of the main goals of Traffic Engineering is to bring about efficient and reliable network operations. Constraint based routing is the key to Multiprotocol label switching TE. Constraint based routing helps to manage traffic paths within a MPLS network and allows for traffic to flow along certain desired paths. MPLS also supports explicit routing thus providing TE capabilities. MPLS TE enables resiliency and reliability to be built into networks, thus increasing the …
Remote Power Delivery For Hybrid Integrated Bio-Implantable Electrical Stimulation System, Venkat Reddy Gaddam
Remote Power Delivery For Hybrid Integrated Bio-Implantable Electrical Stimulation System, Venkat Reddy Gaddam
LSU Master's Theses
Bio-implantable devices such as heart pacers, gastric pacers and drug-delivery systems require power for carrying out their intended functions. These devices are usually powered through a battery implanted with the system or are wired to an external power source. In this work, a remote power delivery system (RPDS) is considered as a means to charge rechargeable batteries that power a Bio-implanted Electrical Stimulation System (BESS). A loosely coupled inductive power transmitter and receiver system has been designed to recharge batteries for a bio-implanted gastric pacer. The transmitter coil is periodically worn around the waist. The receiver coil, rechargeable batteries, battery-charging …
Blind Multiridge Detection And Reconstruction Using Ultrasonic Signals, Rekha Katragadda
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 …
Development Of Process Techniques For Bistable Microbeam Fabrication, Varsha Francis
Development Of Process Techniques For Bistable Microbeam Fabrication, Varsha Francis
LSU Master's Theses
A design which uses bistable beams to modulate light is suggested in this thesis and appropriate processing techniques are presented. A beam when placed under compression above the Euler limit has two stable states. The compression in an electroplated beam can be controlled by the plating current density of nickel during electrodeposition. This beam is attached to an electromechanical comb. Voltages applied to the combs cause the beam to snap from one stable state to another. Structures were designed with dimensions that gave feasible voltages, snap distances, compressions required to snap. A two mask process was used for the fabrication …
Performance Of Disc Brushless Dc Motor Applied As Gearless Drive For Wheelchair, Deepti Rao Chikkam
Performance Of Disc Brushless Dc Motor Applied As Gearless Drive For Wheelchair, Deepti Rao Chikkam
LSU Master's Theses
The currently used electric drive for a wheelchair consists of brush permanent magnet DC motor and mechanical transmission that drives the wheels. The overall efficiency of this kind of drive usually does not exceed 60%. At present there is under study much more effective drive that consists of brushless DC motor which embedded into the wheel rim directly drives the wheelchair. This type of high efficiency gearless drive is the object of this thesis project. The particular brushless DC motor is a torus - type motor with a high energy rare - earth magnets and ferromagnetic teeth that fill in …
Factors Effecting Field Emission From Multiwalled Carbon Nanotubes, Abhilash Krishna
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 …
Scalable Schemes Against Distributed Denial Of Service Attacks, Kishori Nanduri
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 …
Heuristics For Memory Access Optimization In Embedded Processors, Saravanan Subramanian
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 …
Superposition Coding Based Co-Operative Diversity Schemes, Anil Kumar Goparaju
Superposition Coding Based Co-Operative Diversity Schemes, Anil Kumar Goparaju
LSU Master's Theses
With a prefixed decoding order at receiver end, superposition coding approach intended for degraded broadcast channels was proposed to improve the average throughput in a point-to-point wireless channel. In this thesis, we first rigorously show the optimal decoding strategy when two Gaussian codebooks are superposed together to send source information to its receiver. Our results rigorously prove the optimality of performing successive interference cancellation at receiver end. Decoding failure at relays imposes a bottle neck to improving overall throughput in relay channels with decode-and-forward relaying strategy. We then extend this framework for a single link to relay channels to optimize …
Object Tracking Using Log-Polar Transformation, Saikiran Sri Thunuguntla
Object Tracking Using Log-Polar Transformation, Saikiran Sri Thunuguntla
LSU Master's Theses
In this thesis, we use log-polar transform to solve object tracking. Object tracking in video sequences is a fundamental problem in computer vision. Even though object tracking is being studied extensively, still some challenges need to be addressed, such as appearance variations, large scale and rotation variations, and occlusion. We implemented a novel tracking algorithm which works robustly in the presence of large scale changes, rotation, occlusion, illumination changes, perspective transformations and some appearance changes. Log-polar transformation is used to achieve robustness to scale and rotation. Our object tracking approach is based on template matching technique. Template matching is based …
New Contention Resolution Techniques For Optical Burst Switching, Kishore Reddy Koduru
New Contention Resolution Techniques For Optical Burst Switching, Kishore Reddy Koduru
LSU Master's Theses
Optical burst switching (OBS) is a technology positioned between wavelength routing and optical packet switching that does not require optical buffering or packet-level parsing, and it is more efficient than circuit switching when the sustained traffic volume does not consume a full wavelength. However, several critical issues still need to be solved such as contention resolution without optical buffering which is a key determinant of packet-loss with a significant impact on network performance. Deflection routing is an approach for resolving contention by routing a contending packet to an output port other than the intended output port. In OBS networks, when …
High-Freequency Cmos Vlsi Chip Testability And On-Chip Interconnect Modeling, Evan Ross Shultz
High-Freequency Cmos Vlsi Chip Testability And On-Chip Interconnect Modeling, Evan Ross Shultz
LSU Master's Theses
As high-speed digital and radio-frequency mixed-signal integrated circuits become increasingly common in product designs in industry, it is important for VLSI designers to be familiar with the challenges of chip testing and the behavior of circuit elements, including on-chip interconnect, at high frequencies. Expensive, specialized test equipment and software simulation packages for high-frequency chip testing and design are not always accessible for student research. This thesis documents the setup and characterization of a best-possible environment for high-frequency chip testing and data acquisition using existing laboratory equipment and resources. Experimental methodologies and measurement results of on-chip interconnect signal integrity and delay, …
Power Supply Current [Ips] Based Testing Of Cmos Amplifier Circuit With And Without Floating Gate Input Transistors, Vanikumari Pulendra
Power Supply Current [Ips] Based Testing Of Cmos Amplifier Circuit With And Without Floating Gate Input Transistors, Vanikumari Pulendra
LSU Master's Theses
This work presents a case study, which attempts to improve the fault diagnosis and testability of the power supply current based testing methodology applied to a typical two-stage CMOS operational amplifier and is extended to operational amplifier with floating gate input transistors*. The proposed test method takes the advantage of good fault coverage through the use of a simple power supply current measurement based test technique, which only needs an ac input stimulus at the input and no additional circuitry. The faults simulating possible manufacturing defects have been introduced using the fault injection transistors. In the present work, variations of …
Graphical Pilot Interface Simulator (Gpis), Jeffry Jorge Handal
Graphical Pilot Interface Simulator (Gpis), Jeffry Jorge Handal
LSU Master's Theses
The thesis develops a graphic interface for a dynamic system simulation implemented in the SIMULINK environment. The dynamic system is a B747-200 modeled as a rigid body with six degrees of freedom. The equations and database of aerodynamic coefficients over the complete flight envelope were provided by NASA’s Langley Research Center for the research project “Aircraft Safety: Managing Control Upsets.” The purpose of the interface is to allow the user to “fly the plane from the keyboard;” i.e., interact with the simulation by manipulating, from the keyboard, the main control surfaces and engine thrust and observing the performance of the …
Computer-Aided Diagnosis Tool For The Detection Of Cancerous Nodules In X-Ray Images, Pallavi Bomma
Computer-Aided Diagnosis Tool For The Detection Of Cancerous Nodules In X-Ray Images, Pallavi Bomma
LSU Master's Theses
This thesis involves development of a computer-aided diagnosis (CAD) tool for the detection of cancerous nodules in X-ray images. Both cancerous and non-cancerous regions appear with little distinction on an X-ray image. For accurate detection of cancerous nodules, we need to differentiate the cancerous nodules from the non-cancerous. We developed an artificial neural network to differentiate them. Artificial neural networks (ANN) find a large application in the area of medical imaging. They work in a manner rather similar to the brain and have good decision making criteria when trained appropriately. We trained the neural network by the backpropagation algorithm and …
Effect Of Multiuser Interference On Subscriber Location In Cdma Networks, Rohit Sharma
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, …
Traffic Engineering In Multiprotocol Label Switching Vpns, Vinay Kumar Desai
Traffic Engineering In Multiprotocol Label Switching Vpns, Vinay Kumar Desai
LSU Master's Theses
The changing nature of Internet-based applications is imposing stricter demands on the performance of the Internet. For many new applications requiring differentiated quality of service, the best effort model of the internet is no longer adequate. Multiprotocol label switching (MPLS) overlays a connection oriented network on the connection-less IP networks, thereby addressing several shortcomings of the IP network. MPLS improves the forwarding speed, and it provides a virtual path capability to efficiently carry differentiated services. Additionally, MPLS enables traffic engineering by explicit traffic engineering tunnels to be set up across the network to utilize all available bandwidth in an efficient …
A Programmable Cmos Decimator For Sigma-Delta Analog-To-Digital Converter And Charge Pump Circuits, Raghavendra Reddy Anantha
A Programmable Cmos Decimator For Sigma-Delta Analog-To-Digital Converter And Charge Pump Circuits, Raghavendra Reddy Anantha
LSU Master's Theses
PROGRAMMABLE DECIMATOR FOR SIGMA-DELTA ANALOG-TO-DIGITAL CONVERTER: In this work a programmable decimator design has been presented in 1.5 μm n-well CMOS process for integration with an existing modulator to form a sigma-delta analog-to-digital converter (ADC). The decimator is implemented using a second order Cascaded Integrator Comb (CIC) filter and can be programmed to work with two different oversampling ratios of 64 and 16. The input to the decimator is provided from a first order modulator. With oversampling ratios of 64 and 16, an output resolution of 10-bit and 7-bit, respectively are achieved for the ADC. The ADC can be operated …
Comparative Analysis Of Conventional And Ici-Self-Cancellation Digital Video Broadcasting Transceivers, Khaled Z. Matarneh
Comparative Analysis Of Conventional And Ici-Self-Cancellation Digital Video Broadcasting Transceivers, Khaled Z. Matarneh
LSU Master's Theses
Digital video broadcasting–terrestrial (DVB-T) is one of the important technologies in the communication area because of its capability of high data-rate multimedia transmission. Orthogonal frequency division multiplexing (OFDM) has been the backbone technique in the current DVB-T systems adopted by Europe and Japan. However, since the OFDM system is very sensitive to the frequency synchronization and phase errors, which will induce the intercarrier interference (ICI), the ongoing research has been dedicated to this ICI problem in the presence of the Doppler frequency drift and the fading channels. A means to deal with the ICI problem is called the ICI self-cancellation …
Contact Effects In Thermally Evaporated Pentacene Thin Films And Aspects Of Microsystem Hybrid Integration, Jagadish Yernagula
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 …
Mapping Weak Multidimensional Torus Communications On Optical Slab Waveguides, Karthik Sethuraman
Mapping Weak Multidimensional Torus Communications On Optical Slab Waveguides, Karthik Sethuraman
LSU Master's Theses
This thesis deals with the mapping of communication of a d-dimensional weak torus on an optical medium. Our results are derived in the setting of a sawtooth slab waveguide. The mapping aims to reduce the number and cost of optical components, by exploiting the fact that not all edges of a weak topology are used simultaneously. This approach allows for a better utilization of the huge bandwidth of an optical slab waveguide; currently the cost and size of optical components external to the optical communication medium are the primary bottleneck of an optical interconnect. We introduce the notion of adjacency …
Fuzzifying [Sic] Markov Decision Process, Ahmed Syed Irshad
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 …
Improved Watermarking Scheme Using Decimal Sequences, Naveed Shaik Ashfaq
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.
A Robust Noise Spectral Estimation Algorithm For Speech Enhancement In Voice Devices, Brett Joseph Chessher
A Robust Noise Spectral Estimation Algorithm For Speech Enhancement In Voice Devices, Brett Joseph Chessher
LSU Master's Theses
In this thesis, a new robust noise spectral estimation algorithm is proposed for the purpose of single-microphone speech enhancement. This algorithm can generate the optimal noise spectral estimates in the Minimum Mean Square Error (MMSE) sense based on the speech statistics in the noisy environments. Compared to the well-adopted conventional noise spectral estimation method using the single-pole recursion, our proposed scheme is more reliable since the recursion coefficients are adaptable and optimal in the MMSE therein. We also propose a new accurate Resulting Signal-to-Noise Ratio (R-SNR) estimator as a quality measure to benchmark the existing noise spectral estimation techniques. This …
Analysis Of Performance Of Single-Phase Reluctance Linear Motor, Subhadra Devi Ganti
Analysis Of Performance Of Single-Phase Reluctance Linear Motor, Subhadra Devi Ganti
LSU Master's Theses
The design and principle of operation, as well as the electromechanical phenomena of a single-phase linear reluctance motor are discussed. The motor with transverse magnetic flux consists of a primary part, which is moving and a secondary part which is stationary and does not have any windings. The motor can operate under AC or DC supply. When supplied from an AC source it must be equipped with a capacitor connected in series with the coil. In this case the motor operates on the basis of resonance in an RLC primary circuit. When supplied from a DC source it must be …
Wafer Level Chip Scale Packaging Using Wafer Bonder, Kailash Upadhyaya
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 …
Ternary Logic To Binary Bit Conversion Using Multiple Input Floating Gate Mosfets In 0.5 Micron N-Well Cmos Technology, Sowmya Subramanian
Ternary Logic To Binary Bit Conversion Using Multiple Input Floating Gate Mosfets In 0.5 Micron N-Well Cmos Technology, Sowmya Subramanian
LSU Master's Theses
In the present work, a CMOS ternary to binary bit conversion technique has been proposed using multiple input floating gate MOSFETs. The proposed circuit has been implemented in 0.5 µm n-well CMOS technology. The ternary input signals of {-1, 0, +1} are represented as -3 V, 0 V and +3 V, respectively. The ternary input is given as a combination of any two of the three voltage levels and the 4-bit binary output is generated in which the left most bit is sign bit (SB) followed by most significant bit (MSB), second significant bit (SSB) and the least significant bit …