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Summer Research Experience for Undergraduates (REU)
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Professor Douglas Ernie |
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Professor Bethanie Stadler |
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2003 Summer Program Abstracts
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Current CMOS design is between static and dynamic logic. While both styles have their advantages they also contain major drawbacks. Static circuits, while robust, are slow to evaluate wavefronts. Dynamic circuits have high-speed but they are severely sensitive to noise and create large clock loads. Pulsed static CMOS design combines the best elements of static and dynamic logic. It allows for faster evaluation speeds than static circuits and is resistant to noise in contrast to dynamic circuits. Pulsed static CMOS design uses a clocking technique found in dynamic circuits to attain superior evaluation speed. The basic concept behind pulsed static design is to precondition the static gates between each evaluation wavefront with a reset wavefront. Each gate can then be skewed to favor the one possible switch it might have to make during the evaluate cycle. This allows for very fast evaluation speeds and an excellent receptivity to noise. Pulsed static CMOS logic is a promising advancement in circuit design that can lead to faster, more reliable, and smaller electronic devices. |
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TerminatorBot is a centimeter-scale cylindrical crawling robot. Its intended uses are military surveillance and search and rescue missions. TerminatorBot uses two, three-degree-of-freedom arms, for not only movement through terrain but also manipulation of the environment. With all that freedom in the movement of the arms, various movement gaits have been coded into the robot. TerminatorBot also has a tiny onboard camera which is used not only to locate targets, but also to identify what type of terrain the robot is on. One of my projects this summer has been collecting data of the robot traversing through different types of terrain: rocks, woodchips, foam, BBs, and carpet. As the robot moves through the terrain, the camera bounces up and down, and it is through this "bounce" that we are able to classify the terrain type. My other project involved working with tethers and trying to figure out a way to keep all the benefits of tethers-reliable communication and power, while minimizing the problems-friction force and limited movement. |
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This summer I worked with a simulated processor, the VeSPA processor. The VeSPA processor stands for Very Small Processor Architecture processor. My task was to get the VeSPA processor to support run time I/O which would allow a user to interact with the processor during simulation. In order to complete this task, there are certain steps that needed to be taken. C programs needed to be written to handle the I/O functions, and the simulator needed to be modified to recognize I/O calls. Also, an interface that would communicate between the simulator and C programs would be needed. Completing these steps would allow the user to input data while the processor is running, by having an input window open. Allowing the processor to support run time I/O would provide added functionality to the processor, and open up new uses for the processor. |
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An oscillator is a device used for the purpose of generating a signal. Oscillators are widely used in many physical systems such as mechanics, optics, and electronics. For example, all kinds of mechanical clocks and engines are oscillators. Optical lasers are also oscillators. In electronic fields, oscillators are found in computers, wireless receivers and transmitters, and audio-frequency equipment, particularly music synthesizers. The principle work for all oscillators is the same: an oscillator employs a sensitive amplifier whose output is fed back to the input in phase. Thus, the signal regenerates and sustains itself. Circuit and device noise inside an oscillator will perturb the amplitude and phase of its output. Once present on a signal, phase noise is impossible to remove and can have major impact on the whole system performance. My research this summer deals with predicting the phase noise at the oscillator's outputs using the Monte Carlo method. Monte Carlo is a statistical method which basically considers the noise of the oscillator as an additional current source inside the circuit which produces some random signals. |
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In order to make computation of regularly used forms of the Landau-Lifschitz-Gilbert equation faster and easier an analytical solution to those forms is desirable. This paper shows step-by-step how to obtain a analytical solution to the Landau-Lifschitz-Gilbert equation for the case where the initial magnetization and applied field are along the anisotropy axis. Theta is angle from the positive z axis and phi is the angle from the positive x axis. Initially it is assumed that the applied field be in the negative z direction and the magnetization be slightly off of the positive z direction. Also the case where the uniaxial anisotropy on the same axis as the initial magnetization and applied field at an angle of 3pi/2 in theta and 0 in phi and 3pi/4 is explored but not solved. |
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Overstiding can lead to or enhance various joint and bone conditions. The goals of this investigation were to create a system to simultaneously measure joint angles (hip, knee, and ankle), velocity of center of mass, and impact force experienced by the tibia bone during walking, and to quantitatively capture overstriding. Eventually the data will be used to define an overstriding threshold as a function of joint angles, velocity of center of mass, and body weight. The results show an increase in average absolute deceleration with increased step length, which correlates to an increased resistive force with increased step length. All necessary improvements to the system and be made with time and ingenuity. The results are few, and as of yet, inconclusive. The investigation as a whole, however, shows promise and makes feasible the possibility of defining overstriding threshold for both runners and walkers alike. |
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With the advent of conductive polymers such as polypyrrole, we are now able to make low-power MEMS actuators; one possible use for this would be a valve in a glaucoma drainage device such as the Ahmed Valve. This paper discusses the research and experimentation that went into developing a working actuator for such a device, from the initial stages to the first working actuator prototype. |
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The applications of commercially grown nanopores are limited by their unorganized structure. Current processes to make organized arrays, however, are too time consuming to be incorporated by the technology industry. The objective of this research was to develop a faster method for growing organized nanopore arrays through imprinting. Three successful imprint stamps were fabricated using photolithography and Reactive Ion Etching (RIE). One stamp was particularly successful and will ultimately be used to imprint a pattern in aluminum foil in order to produce aligned nanopores in aluminum oxide through anodization. The dimensions of the stamp were as follows: 1 mm2 base, a Si3N4 pillar height of 40nm;, an average pillar diameter of 1 micron, and an average pitch of 2.8 microns. This stamp is evidence that a faster, more efficient method of producing nanopores will soon be incorporated into the commercial world. |
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This research is about designing a temperature insensitive circuit that will behave essentially the same regardless of the change of temperature. This paper will focus on the current mirror configuration and its biasing voltage. To obtain a temperature insensitive voltage it is necessary to reference the voltage in sum of VBE and VT. Both VBE and VT have opposite TCF. (TCF is the change in output current per degree of temperature variation.) A constant reference voltage allows a current source to be insensitive to a change in temperature. Variation in the transistor's band gap must be tested to find its effect on VBE. Other parameters in a transistor must also be modified to obtain a more reliable temperature insensitive reference voltage. HSPICE is the simulation tool used in this research to test the behavior of different band-gap reference subcircuits. |
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This project is to investigate high-contrast waveguides coated via colloidal self-assembled silica spheres to form three-dimensional Photonic Band Gap (PBG) structures. When the silica spheres assemble, they form a natural crystalline array such as hexagonal closed packed or face centered cubic (fcc) structures. Photonic Band Gap materials are periodic structures that exhibit electromagnetic band gaps, where photon energies cannot propagate through the crystal. Photonic band gaps can be analogous to electronic band gaps found in semiconductor materials. Hence, Photonic crystals may be applied to emulate electronic components, besides its immediate application as filters, lasers, and low-loss high propagation waveguides. |
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Kristin Hanekamp |
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