<p>A microprocessor based system to convert the Walsh spectrum of a frequency limited signal to its Fourier spectrum has been designed and built. The entire processing hardware is implemented on a single PLS-401 card, which consists of an Intel 4004 microprocessor, read only memories to store the conversion program and matrices of constants, random access memories to store results, and input/output ports. The converter can process up to 32 coefficients, and utilizes an 8-bit word length. For test purposes, the Walsh spectra are programmed into a read only memory, and the Fourier spectra are displayed in binary form on an LED matrix. The maximum conversion time is 1.81 seconds, and the maximum absolute error is 2.03% of the largest possible coefficient.</p> / Master of Science (MS)

<p> The energy and power used at various areas like households and industries is increasing gradually due to many reasons and there is a need to sustain it. This project introduces a method to reduce the energy used in a household by considering the energy sources and the amount of energy used by the appliances concurrently. Modules are used to measure and check the energy utilized by the appliances using ZigBee. Energy is generated on a conventional basis using three sources: solar panel, wind mill and conventional power. An inverter and a battery are used to connect these sources to a grid. When a device is connected, the units of power consumed are computed and shown on the LCD using LPC2148 microcontroller. The output of the battery is connected to the controller, which shows the voltage of the battery and also selects the best source to be used. Modules use a 5V supply and the controller uses 3.3V power supply. Voltage is controlled with the help of a 7805 voltage regulator and the output of transformer is revised by a rectifier.</p>

<p> As a functionalized pentacene, 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) is a p-type organic semiconductor with remarkable intrinsic charge carrier transport and stability in ambient conditions. TIPS pentacene is soluble in most organic solvents, making it solution processable. TIPS pentacene, nonetheless, inherently forms acutely anisotropic crystals with large gaps in between the crystals, limiting charge transport and leading to vast variations in organic thin film transistor (OTFT) performance. Described in this dissertation are crystal growth techniques implemented to overcome these challenges. The presented temperature gradient technique, achieves highly aligned crystal arrays with excellent areal coverage which essentially results in an enhanced OTFT performance. The technique is firstly utilized to guide the TIPS pentacene crystal growth. An application of a temperature gradient to a TIPS pentacene solution controls the crystallization process to alleviate the intrinsic crystal misorientation and considerably improve film morphology. Employing this method resulted in TIPS pentacene films with uniform crystal orientations and extensive areal coverage. The favorable crystal morphology gave rise to a significant enhancement in OTFT average mobility compared to OTFTs without the temperature gradient. Employing the temperature gradient technique, however, simultaneously introduced thermal cracks in the films due to the occurrence of thermally induced stress during crystallization, which reduced the device performance of the TIPS pentacene OTFTs. To further improve the performance of TIPS pentacene based OTFTs, TIPS pentacene was blended with polymers to relieve the thermal stress and effectively prevent the generation of thermal cracks. Structural examination of, specifically, TIPS pentacene/Poly(?-methyl styrene) (P?MS) blend films at an optimal weight ratio, revealed a vertical phase segregation with elevated concentrations of TIPS pentacene molecules at the active layer/gate dielectric interface, facilitating charge transport. Thus, OTFTs based on TIPS pentacene/P?MS blends exhibited a dramatic increase in average hole mobility compared to those of pristine TIPS pentacene. In addition, an improved thin film uniformity directly enhanced the device performance consistency. Following the success of employing the temperature gradient technique concurrently with the insulating polymer, P?MS, studies were extended to build OTFTs on flexible substrates, indium tin oxide (ITO) coated polyethylene terephthalate (PET), to dramatically improve TIPS pentacene/P?MS system. Ultimately, TIPS pentacene/P?MS OTFTs on ITO/PET substrates demonstrated the highest achieved mobility from utilizing the temperature gradient system.</p>

<p> The SIUe solar car team lacks a competitive communication system. To enable the competitive edge a major upgrade to the electronics and wiring was required. A new maximum power point tracker and driver support system was developed to give them the competitive edge.</p>

<p> The goal of this project is to develop, implement and test experimentally a state-feedback controller for the vibration control of a flexible structure, using an Active Mass Damper (AMD). Based on a previously developed model of the structure, a state-feedback controller with full observer has been implemented in the LabView (Laboratory Virtual Instrument Engineering Workshop) computational environment using the myRIO FPGA board (Field Programmable Gate Array). Experimental results show that the controller improves the structural response significantly by reducing the amplitude and duration of the response when the structure is subject to random earthquake-like excitations. </p>

<p> Gray-cast iron is an iron carbon alloy which is regularly used in manufacturing processes. Carbon is distributed in the iron material in the form of graphite. The distribution of the graphite flakes in the alloy contributes greatly towards the chemical and physical properties of the metal alloy. Thus it is important to identify and classify the Gray-cast iron based on the morphological parameters of the graphite flakes. Gray-Cast iron is classified into five types in ISO-945 represented with the letters A through E. These five classes possess different structures or distributions of the graphite flakes. The current project presents an automated classification method using image processing and machine learning algorithms. The method presented here obtains the required parameters from the microstructure through image morphological operations. The image information is subsequently fed through a supervised machine learning algorithm which is trained using parameters such as area of the flakes, perimeter, minimum inter-particle distance and chord length from over twenty samples. The algorithm calculates the percentage of the type of the flakes present in the given image. The simulation is done in MATLAB and was tested for six images in each class. Class C and D were classified with 100 percent accuracy, Class A and B were classified with accuracy of 82 percent and Class E was identified with accuracy of 68 percent.</p>

<p> The Internet of Things (IoT) is the network of physical objects embedded with sensors and connectivity. The ubiquitous nature of IoT nodes will allow the deployment of embedded sensors, actuators, cameras, mobile phones, and Radio Frequency Identification Devices (RFID) in buildings for monitoring the condition of the building and the well being of the occupants. The current project presents the design and implementation of a sensor network within the IoT framework, using infrared (IR) sensors to monitor the number of visitors in the building and their distribution across predetermined zones. Using IR sensor data the Demand-Controlled Ventilation (DCV) units on each floor are controlled based on zone occupancies. The occupancy data are displayed on a mobile phone or PC using a Wireless Fidelity (WiFi) module. The devices in the experimental implementation of this network include IR, temperature, and CO2 sensors, interfaced to a microcontroller. Experimental testing shows that the network performs flawlessly and reliably.</p>

Industrial robots are the key role in modern manufacture. In order to allow different robots to perform the same task, they must be programmed manually which is time-consuming and cumbersome. The ability to transfer robotic skills between heterogeneous robots would provide significances to industry. This paper presents a prototype control architecture for industrial robots which allows multiple heterogeneous robots of different morphologies to perform the same task without manually programming each robot separately. We selected three articulated industrial manipulators with different degree of freedoms (Yaskawa Motoman HP3JC, Universal Robot UR5 and Rethink Robotics Baxter) to test our approach. Two simple assembly tasks were chosen for analysis and implementation. Results indicate that our approach works well with some errors. Maximum and average position mismatch errors for UR5 are 4.938 cm and 4.431 cm. For Baxter, maximum and average position mismatch errors are 8.8797 cm and 3.785 cm. Baxter has a different range of motion therefore some places could not be reached with it.

Ultrathin films including two-dimensional materials and transparent conductive oxide nano-films are excellent candidates for future optoelectronic devices. However, external quantum efficiencies of the ultrathin film-based devices are typically limited due to their small physical thickness. The practical application of these ultrathin films therefore requires integration with optical nanostructures to enhance light-matter interaction in the thin films. In this work, I will present my efforts to modify the interaction between light and ultrathin films using different approaches, including hot electron injection, integration with Fano-resonant photonic crystals, and use a hybrid mode combining an epsilon-near-zero mode with a Huygensâ dielectric metasurface. The optoelectronic devices demonstrated based on these integrations result in significant increases in absorption, photoresponsivity, and modulation depth.

Lower-limb weakness or paralysis is a common impairment following stroke. In recent years numerous robotic-assisted systems have been developed to aid in post-stroke gait rehabilitation. The controllers developed for these systems have nearly all consisted of traditional or modified trajectory-based control systems which guide a patientâs limbs through a kinematically improved gait cycle. Controllers which do not operate on a trajectory basis may offer numerous advantages, especially when implemented on an overground (as opposed to treadmill-based) robotic system. This thesis describes the development and evaluation of a non-trajectory-based controller for use in post-stroke gait training. The controller has been implemented on a lower-limb robotic exoskeleton and tested with several subjects recovering from stroke. Subjects were able to improve gait speed and stride length after practicing overground gait in the exoskeleton.