Engineering Commons^™

Performance Study Of Ofdm Over Fading Channels For Wireless Communications, Ahmed Alshammari

Electronic Theses and Dissertations

Orthogonal Frequency Division Multiplexing (OFDM) is a very efficient multicarrier technique. OFDM is used more and more in recent wideband digital communications. It has numerous advantages such as the ability to handle severe channel conditions, efficient spectral usage, reduced inter symbol interference (ISI), and high data rate. Therefore, it has been utilized in many wired and wireless communication systems like DSL, wireless networks and 4G mobile communications.

Studying the performance of OFDM over different channels is the main focus of this research. Channels' environments simulated in Matlab are additive white Gaussian noise (AWGN) and fading channels. Each channel affects the …

The Bit Error Rate (Ber) Performance In Multi-Carrier (Ofdm) And Single-Carrier, Saleh M. Albdran

Electronic Theses and Dissertations

The spectacular growth of wireless communication tools has escalated the number of mobile subscribers from almost 700 million in 2000 to more than 4 billion in 2009. The huge number of subscribers has led to several issues with how service is provided. The high user demand has forced developers to overcome the problems of the old analog systems and to introduce OFDM as a promising technique that can fulfill users' high demands. This technique matches well with high data rate connection and provides a higher capacity for the subscribers' usage.

The OFDM, as a multi-carrier, is more complex than the …

Development Of Wearable Sensors For Body Joint Angle Measurement, Saba Bakhshi Khayani

Electronic Theses and Dissertations

This thesis presents the development of three different methods for body joint angle measurement using wearable sensors. Continuous monitoring of patients' movements and activities has recently become one of the active research areas in the field of body sensor network and telehealth monitoring. For many medical and rehabilitation applications, a continuous monitor of the patients' daily activities at home without visiting the hospital is desirable. This type of monitoring is beneficial for the therapists and physicians as it does not require patients' physical presence. Traditionally, measuring the range of motion (ROM) is performed in hospitals by utilizing standard tools such …

Hybrid Sensing And Adaptive Control For Direct Brain Actuation Of Artificial Limbs, Christopher Aasted

Electronic Theses and Dissertations

Developing a non-invasive direct brain control of artificial limbs is both challenging and desirable. Such a sensory and control system, if successful, will have a profound impact on the disabled. In this dissertation, we present the design and development of a non-invasive, hybrid sensory system, which uses near-infrared spectroscopy (NIRS) and electroencephalography (EEG) to measure brain activity with simultaneous electromyography (EMG) to provide feedback data in a healthy limb. Through the combination of these sensory techniques, we have successfully trained a control system capable of mapping brain activity onto muscle actuation. The design of a control algorithm capable of automatic …

Simulation, Application, And Resilience Of An Organic Neuromorphic Architecture, Made With Organic Bistable Devices And Organic Field Effect Transistors, Robert A. Nawrocki

Electronic Theses and Dissertations

This thesis presents work done simulating a type of organic neuromorphic architecture, modeled after Artificial Neural Network, and termed Synthetic Neural Network, or SNN. The first major contribution of this thesis is development of a single-transistor-single-organic-bistable-device-per-input circuit that approximates behavior of an artificial neuron. The efficacy of this design is validated by comparing the behavior of a single synthetic neuron to that of an artificial neuron as well as two examples involving a network of synthetic neurons. The analysis utilizes electrical characteristics of polymer electronic elements, namely Organic Bistable Device and Organic Field Effect Transistor, created in the laboratory at …

Solar Power System Modeling And Performance Analysis, Jiaqi Wang

Electronic Theses and Dissertations

At present the main source of our power and energy needs are from fossil fuel; almost all transportation tools and nearly 70% of electrical power are produced by fossil fuel. But unfortunately these materials are limited in our planet, with obvious drawback such as pollution. So looking for new kinds of energy supply is an urgent matter. Solar-powered photovoltaic system provides a clean energy solution to this problem. It is developing fast all over the world in terms of both research work and actual applications. It is estimated that the power supplied by solar energy can provide 10 percent of …

Sift-Me: A New Feature For Human Activity Recognition, Guosheng Wu

Electronic Theses and Dissertations

Action representation for robust human activity recognition is still a challenging problem. This thesis proposed a new feature for human activity recognition named SIFT-Motion Estimation (SIFT-ME). SIFT-ME is derived from SIFT correspondences in a sequence of video frames and adds tracking information to describe human body motion. This feature is an extension of SIFT and is used to represent both translation and rotation in plane rotation for the key features. Compare with other features, SIFT-ME is new as it uses rotation of key features to describe action and it robust to the environment changes. Because SIFT-ME is derived from SIFT …

Toward A Distributed Actuation And Cognition Means For A Miniature Soft Robot, Xiaoting Yang

Electronic Theses and Dissertations

This thesis presents components of an on-going research project aimed towards developing a miniature soft robot for urban search and rescue (USAR). The three significant contributions of the thesis are verifying the water hammer actuation previous work, developing an estimator of water hammer impulse direction from hose shape, and creating the infrastructure for distributed cognitive networks. There are many technical issues in designing soft robots, in terms of perception, actuation, cognition, power, physical structure and so on. We are focusing on actuation and cognition issues in this thesis. We investigated water hammer actuation as an alternative system which provides a …

Analysis And Design Of A Feedback Controlled Adaptive Pneumatic Cast, Susan Renee Mueller

Electronic Theses and Dissertations

A pneumatic system with PID control for an actively controlled cast is designed. The cast is intended to aid healing of diabetic foot ulcers by relieving pressure from the sole of a patient's foot and distributing it to the calf. This is accomplished by a pneumatic system which maintains set pressure in multiple air bladders. The research began by defining an electrical circuit analogous to a single supply subsystem. Tests are performed to determine the coefficients for each component. These coefficients are used in a mathematical model to better understand the response of the system to pressure input. A controller …

Parametric Model Of Head Related Transfer Functions Based On Systematic Movements Of Poles And Zeros With Sound Location For Pole/Zero Models, Bahaa W. Al-Sheikh Hussein

Electronic Theses and Dissertations

Directional transfer functions (DTFs), the directional components of the Head Related Transfer Functions (HRTFs), are generally measured at finite locations in azimuth and elevation. Thus models are needed to synthesize DTFs at finer spatial resolution than the measured data to create complete virtual auditory displays. In this research, minimum-phase all-pole and all-zero models were used for modeling both human and cat DTFs. Real cepstrum analysis has been used to represent minimum phase HRTFs in the time domain. For the human DTFs, model orders were chosen to achieve specific objective error criteria published in previous studies that were based on subjective …

Lifetime Estimation Of Wireless Body Area Sensor Network For Patient Health Monitoring, Frank Agyei-Ntim

Electronic Theses and Dissertations

Wireless Body Area Sensor Networks (WBASN) is an emerging technology which utilizes wireless sensors to implement real-time wearable health monitoring of patients to enhance independent living. These sensors can be worn externally to monitor multiple bio-parameters (such as blood oxygen saturation (SpO2), blood pressure and heart activity) of multiple patients at a central location in the hospital.

In health monitoring, the loss of critical or emergency information is a serious issue so there is a concern for quality of service which needs to be addressed. It is important to have an estimate of the time the first node will fail …

Fabrication Of Silicon Photovoltaic Micro-Particles For Low-Cost Solar Energy Generation, Siddhartha Kala

Electronic Theses and Dissertations

The relatively high cost of the high quality semiconductor materials (typically silicon) and complex conventional techniques for the fabrication of solar cells result in the overall high cost of the commercially available solar cells. Although, research in the field of solar technologies has been going on for a long time, but, utilization of solar energy still remains limited to a very few applications, owing to the high manufacturing costs and lower efficiency. In this work we present a new solar technology based on silicon photovoltaic micro-particles and demonstrate a fabrication technique for such particles. The photovoltaic micro-particles can be manufactured …

Photonics Based Techniques For Millimeter-Wave Generation, Transmission, And Multiplexing, Daw Asderah

Electronic Theses and Dissertations

Millimeter-waves have found wide application in various fields. In this research, MMW generation, transmitting and receiving, multiplexing techniques are investigated. Three ways of MMW generation based on photonics are discussed. By modeling these three techniques and applying different situations of transmission links up to 100 km and fixed bit rate of 2.5 Gb/s, different results were found and compared to each other. Also, the effect of chromatic dispersion is discussed in addition to the phase conjugation way of dispersion compensation. Dispersion compensation based on phase conjugation was also simulated and applied to OSSB millimeter-wave generator in order to transmit the …

Mems Transducer For Hearing Aid Device, Houwen Tang

Electronic Theses and Dissertations

A study of implantable middle ear MEMS piezoelectric transducer for hearing aids was developed. The physical vibration deflection at the tip of the transducer is simulated using finite element method. Further, a study of thermoelastic damping effect of four designed MEMS mirrors used as resonators is presented. An optical measurement system based on Mach-Zehnder interferometer is