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Articles 181 - 210 of 226
Full-Text Articles in Engineering
Target Tracking In Wireless Sensor Networks, Tarun Anand Malik
Target Tracking In Wireless Sensor Networks, Tarun Anand Malik
LSU Master's Theses
The problem being tackled here relates to the problem of target tracking in wireless sensor networks. It is a specific problem in localization. Localization primarily refers to the detection of spatial coordinates of a node or an object. Target tracking deals with finding spatial coordinates of a moving object and being able to track its movements. In the tracking scheme illustrated, sensors are deployed in a triangular fashion in a hexagonal mesh such that the hexagon is divided into a number of equilateral triangles. The technique used for detection is the trilateration technique in which intersection of three circles is …
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 …
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 …
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 …
Performance Based Switching Control For Single Input Linear Time Invariant Systems, Lalitha Srigouri Devarakonda
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 …
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 …
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 …
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 …
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 …
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 …
Knowledge-Based Fault Detection Using Time-Frequency Analysis, Venkata S. Vongala
Knowledge-Based Fault Detection Using Time-Frequency Analysis, Venkata S. Vongala
LSU Master's Theses
This work studies a fault detection method which analyzes sensor data for changes in their characteristics to detect the occurrence of faults in a dynamic system. The test system considered in this research is a Boeing-747 aircraft system and the faults considered are the actuator faults in the aircraft. The method is an alternative to conventional fault detection method and does not rely on analytical mathematical models but acquires knowledge about the system through experiments. In this work, we test the concept that the energy distribution of resolution than the windowed Fourier transform. Verification of the proposed methodology is carried …
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.
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, …
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 …
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 …
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 …
Testing A Cmos Operational Amplifier Circuit Using A Combination Of Oscillation And Iddq Test Methods, Pavan K. Alli
Testing A Cmos Operational Amplifier Circuit Using A Combination Of Oscillation And Iddq Test Methods, Pavan K. Alli
LSU Master's Theses
This work presents a case study, which attempts to improve the fault diagnosis and testability of the oscillation testing methodology applied to a typical two-stage CMOS operational amplifier. The proposed test method takes the advantage of good fault coverage through the use of a simple oscillation based test technique, which needs no test signal generation and combines it with quiescent supply current (IDDQ) testing to provide a fault confirmation. A built in current sensor (BICS), which introduces insignificant performance degradation of the circuit-under-test (CUT), has been utilized to monitor the power supply quiescent current changes in the CUT. The testability …
Iddq Testing Of A Cmos First Order Sigma-Delta Modulator Of An 8-Bit Oversampling Adc, Anand K. Chamakura
Iddq Testing Of A Cmos First Order Sigma-Delta Modulator Of An 8-Bit Oversampling Adc, Anand K. Chamakura
LSU Master's Theses
This work presents IDDQ testing of a CMOS first order sigma-delta modulator of an 8-bit oversampling analog-to-digital converter using a built-in current sensor [BICS]. Gate-drain, source-drain, gate-source and gate-substrate bridging faults are injected using fault injection transistors. All the four faults cause varying fault currents and are successfully detected by the BICS at a good operation speed. The BICS have a negligible impact on the performance of the modulator and an external pin is provided to completely cut-off the BICS from the modulator. The modulator was designed and fabricated in 1.5 μm n-well CMOS process. The decimator was designed on …
Watermarking Using Decimal Sequences, Navneet Kumar Mandhani
Watermarking Using Decimal Sequences, Navneet Kumar Mandhani
LSU Master's Theses
This thesis introduces the use of decimal sequences in watermarking to hide information for authentication. The underlying system is based on code division multiple access (CDMA), which is a form of spread spectrum communication. Different algorithms for the use of decimal sequences have been formulated for use in black and white images. The watermark is spread across the carrier image by using the d- sequences of optimal period and retrieval is made by the use of correlation. Matlab version 6.5 was used to implement the algorithms discussed in this thesis. The advantage of using d-sequences over PN sequences is that …
Survivable Multicasting In Wdm Optical Networks, Sateesh Chandra Shekhar
Survivable Multicasting In Wdm Optical Networks, Sateesh Chandra Shekhar
LSU Master's Theses
Opportunities abound in the global content delivery service market and it is here that multicasting is proving to be a powerful feature. In WDM networks, optical splitting is widely used to achieve multicasting. It removes the complications of optical-electronic-optical conversions [1]. Several multicasting algorithms have been proposed in the literature for building light trees. As the amount of fiber deployment increases in networks, the risk of losing large volumes of data traffic due to a fiber span cut or due to node failure also increases. In this thesis we propose heuristic schemes to make the primary multicast trees resilient to …
Zooplankton Visualization System: Design And Real-Time Lossless Image Compression, Dattatreya Reddy Tetala Satya Surya
Zooplankton Visualization System: Design And Real-Time Lossless Image Compression, Dattatreya Reddy Tetala Satya Surya
LSU Master's Theses
In this thesis, I present a design of a small, self-contained, underwater plankton imaging system. I base the imaging system’s design on an embedded PC architecture based on PC/104-Plus standards to meet the compact size and low power requirements. I developed a simple graphical user interface to run on a real-time operating system to control the imaging system. I also address how a real-time image compression scheme implemented on an FPGA chip speeds up image transfer speeds of the imaging system. Since lossless compression of the image is required in order to retain all image details, I began with an …
An Evaluation Of Multiple Branch Predictor And Trace Cache Advanced Fetch Unit Designs For Dynamically Scheduled Superscalar Processors, Slade S. Maurer
An Evaluation Of Multiple Branch Predictor And Trace Cache Advanced Fetch Unit Designs For Dynamically Scheduled Superscalar Processors, Slade S. Maurer
LSU Master's Theses
Semiconductor feature size continues to decrease permitting superscalar microprocessors to continue to increase the number of functional units available for execution. As the instruction issue width increases beyond the five instruction average basic block size of integer programs, more than one basic block must be issued per cycle to continue to increase instructions per cycle (IPC) performance. Researchers have created methods of fetching instructions beyond the first taken branch to overcome the bottleneck created by the limitations of conventional single branch predictors. We compare the performance of the multiple branch prediction (MBP) and trace cache (TC) fetch unit optimization methods. …
Design And Performance Of Electric Shock Absorber, Oly D. Paz
Design And Performance Of Electric Shock Absorber, Oly D. Paz
LSU Master's Theses
The electric shock absorber is a device that converts the kinetic energy of an oscillating object into electric energy. This kinetic energy is normally dumped in a form of thermal energy in a conventional, mechanical shock absorber. The electric shock absorber consists of a permanent magnet linear synchronous generator (PMLSG), a spring, and an electric energy accumulator. The major goal of the project is to design and analyze the operation of an electric shock absorber. In order to define the initial requirements that the electric shock absorber has to satisfy, the construction and performance of currently used shock absorbers were …
First Order Sigma-Delta Modulator Of An Oversampling Adc Design In Cmos Using Floating Gate Mosfets, Syam Prasad Sbs Kommana
First Order Sigma-Delta Modulator Of An Oversampling Adc Design In Cmos Using Floating Gate Mosfets, Syam Prasad Sbs Kommana
LSU Master's Theses
We report a new architecture for a sigma-delta oversampling analog-to-digital converter (ADC) in which the first order modulator is realized using the floating gate MOSFETs at the input stage of an integrator and the comparator. The first order modulator is designed using an 8 MHz sampling clock frequency and implemented in a standard 1.5µm n-well CMOS process. The decimator is an off-chip sinc-filter and is programmed using the VERILOG and tested with Altera Flex EPF10K70RC240 FPGA board. The ADC gives an 8-bit resolution with a 65 kHz bandwidth.
Design Of Power Efficient Multicast Algorithms For Sparse Split Wdm Networks, Kavitha Devi Buddharaju
Design Of Power Efficient Multicast Algorithms For Sparse Split Wdm Networks, Kavitha Devi Buddharaju
LSU Master's Theses
Recent years witnessed tremendous increase in data traffic as new Internet applications were launched. Optical networks employing recent technologies such as DWDM and EDFA`s emerged as the most prominent and most promising solutions in terms of their ability to keep with the demand on bandwidth. However for a class of applications bandwidth is not the only important requirement, These applications require efficient multicast operations. They include data bases, audio/video conferencing, distributed computing etc. Multicasting in the optical domain however has its own unique set of problems. First, an optical signal can be split among the outputs of a node but …
Remote Power Delivery And Signal Amplification For Mems Applications, Sunitha Kopparthi
Remote Power Delivery And Signal Amplification For Mems Applications, Sunitha Kopparthi
LSU Master's Theses
Device such as remotely located sensors and bio-implanted devices such as gastric pacer require power for operation. The most commonly used energy source for such devices is a battery cell included in the receiver capsule. Wires can also be used with an external power source but in some applications have serious limitations. This work examines a wireless power transmitter and receiver system to provide power to a remotely located microsystem. Inductive power coupling is the method of choice. For gastric pacer application, external transmitter coil can be worn around the waist as a belt and the receiver coil can be …
Blind Fault Detection Using Spectral Signatures, Pallavi Chethan
Blind Fault Detection Using Spectral Signatures, Pallavi Chethan
LSU Master's Theses
This work studies a blind fault detection method, which only analyses a system's output signal for any change in the characteristics from pre-fault to post-fault to identify the occurrence of faults. In our case the fault considered to develop the procedure is change in time constant of an aircraft's aileron-actuator system and its simplified version - a position servo system. The method is studied as an alternative to conventional fault detection and identification methods. The output signal is passed through a filter bank to enhance the effect of a fault. The Short time Fourier transform is performed on the enhanced …
Circuitry For A Remotely Powered Bio-Implantable Gastric Electrical Stimulation System, Satish Kona
Circuitry For A Remotely Powered Bio-Implantable Gastric Electrical Stimulation System, Satish Kona
LSU Master's Theses
Power to bio-implantable devices is usually supplied through a battery implanted with the system or through wires extending to an outside power source. The latter case with wires protruding out of the body can be unaesthetic in appearance and can cause infection. In this research, we consider an alternative way to power a bio-implantable microsystem. It involves using rechargeable lithium batteries. Here, power is delivered remotely to charge implanted battery or batteries. This approach avoids periodic surgery necessary for battery replacement. It also does not tie a person to an external power source at all times. This improves patient’s quality …
Traffic Engineering In Multiprotocol Label Switching Networks, Chung-Yu Wei
Traffic Engineering In Multiprotocol Label Switching Networks, Chung-Yu Wei
LSU Master's Theses
The goal of Traffic Engineering is to optimize the resource utilization and increase the network performance. Constraint-based routing has been proposed as an networks effective approach to implement traffic engineering in Multiprotocol Label Switching. In this thesis, we review several algorithms on constraint-based routing from the literature and point out their advantages and disadvantages. We then propose several algorithms to overcome some of the shortcomings of these approaches. Our algorithms are specifically suitable for large densely connected networks supporting both Quality of Service traffic and the Best Effort traffic. In large networks the size of the MPLS label space in …
Iddq Testing Of A Cmos 10-Bit Charge Scaling Digital-To-Analog Converter, Srinivas Rao Aluri
Iddq Testing Of A Cmos 10-Bit Charge Scaling Digital-To-Analog Converter, Srinivas Rao Aluri
LSU Master's Theses
This work presents an effective built-in current sensor (BICS), which has a very small impact on the performance of the circuit under test (CUT). The proposed BICS works in two-modes the normal mode and the test mode. In the normal mode the BICS is isolated from the CUT due to which there is no performance degradation of the CUT. In the testing mode, our BICS detects the abnormal current caused by permanent manufacturing defects. Further more our BICS can also distinguish the type of defect induced (Gate-source short, source-drain short and drain-gate short). Our BICS requires neither an external voltage …