MERIT 2004 Student Participants

The MERIT Fair is held at the end of the summer to showcase the research conducted by the undergraduate students during the summer. This forum provides them with the opportunity to present their work to the wider public. Their efforts are subjected to scrutiny from a panel of judges selected from academia, industry, and government laboratories. Winners are selected in the two main areas of technical focus: INSPIRE/PEER and RITE. The prize winning projects are listed just below with a complete listing of all MERIT 2004 projects after that.

INSPIRE/PEER - Winner:
Electro-Mechanical Analysis of AIN Micro-Mechanical Beam Resonators: Christopher Lombardo
RITE - Winners:
Multi-Echo Integration for Sonar-Based Vehicle Navigation: Marshall Miller and Guarav Singal
RITE - Runners-Up:
Adjustable Time Delays for Optical Clock Recovery Systems: Amir Ali Ahmadi and Elric Von Eden

• Fabrication and Characterization of Visible Blind UV Photodectors and Device Protection Using Radiation Hard Windows: Richard Graham III and Sathyaprasad Ramaseshan

• Characterization of Interface Traps in SiC Semiconductor Devices: Michael Bolen
• High Temperature Dielectrics for Wide Band Gap Power Devices: Joseph Hernandez
• Electro-Mechanical Analysis of AlN Micro-Mechanical Beam Resonators: Christopher Lombardo
• High Temperature Capping Layers for SIC Based Devices: Pamela Lee and Eri Nishiyama

• Testing and Refinement of a Low-Power, Lightweight Neural Amplifier and Spike Sorter: Kevin Boyle and Dorielle Tucker
• Packaging Bio-amplifiers to Monitor Extra-cellular Activity: Tony Li
• Wavelet Analysis of Magnetoencephalographic Auditory Activity: Chris Rodgers
• Cell Clinics: Design of an Integrated Potentiostat and Testing of Capacitance Sensors: Joel Van Sickel
• Human Movement Categorization Through MOCAP Data and Body Angles Analysis: John Chaparro
• Normalization of Facial Expressions: Divya Jhalani
• Automatic Speech Recognition: Identifying Nasalization in Vowels: Shuo Chen
• Investigation of Acoustic Features in Text-Independent Speaker Verification: Thomas Plummer
• Acoustic Parameter Based Speech Recognition in Noisy Environment: Qin Zou
• Multi-Echo Integration for Sonar-based Vehicle Naviagation: Marshall Miller and Gaurav Singal
• GPS-Based Location Determination: Kun Lin
• Ad Hoc Network Security: Wui Cheong Wong
• Adjustable Time Delays for Optical Clock Recovery Systems: Amir Ali Ahmadi and Elric Von Eden
• Evaluation of Polarization Dependence in Nonlinear Optical Detectors: Audrey Strunc
• An Examination of Security Algorithm Flaws in Wireless Networks: Hirsh Goldberg and Erica Simcoe
• Improving the Robustness and Imperceptibility of Curve Fingerprinting: Daniel Cardy

Fabrication and Characterization of Visible Blind UV Photodectors and Device Protection Using Radiation Hard Windows
Richard Graham III (Rose-Hulman Institute of Technology)
Sathyaprasad Ramaseshan (University of Maryland at College Park)
Faculty Mentor: Prof. R.D. Vispute (University of Maryland at College Park)

The goal of our project is to fabricate MgZnO film based fully functional UV detector. MgZnO thin films have been grown on sapphire substrate using pulse laser deposition. The UV spectroscopy and X Ray diffraction have been performed on the resultant film. The bandgap of the film has been calculated from UV absorption measurements. Metal-semiconductor-metal (MSM) interdigital contacts have been fabricated by standard photolithography process and the thermal evaporator will be used to deposit Chrome and Gold. The devices have been characterized for I-V and UV-optical response. We also propose to develop an efficient way to package the material with radiation hard windows, after which reliability of the device shall be determined.
Poster Presentation

Characterization of Interface Traps in SiC Semiconductor Devices
Michael Bolen (Michigan Technological University)
Faculty Mentor: Dr. Aivars Lelis (Army Reasearch Laboratory) and Dan Habersat (Army Research Laboratory)

Silicon carbide (SiC) semiconductor devices have the potential to revolutionize high power and high temperature electronics because of material advantages vis-à-vis silicon. These advantages include a much wider bandgap for high-temperature operation, a greater critical electric-field value for high-voltage operation, and a greater thermal conductivity for high-power operation. However, SiC metal oxide semiconductor field effect transistors (MOSFETs) have much greater charge trapping at the silicon dioxide (SiO2) insulating gate/SiC interface than there is in the Si/SiO2 system. These charges cause variations in the threshold voltage, lower the effective inversion-channel mobility, and create concerns regarding the integrity of the insulating film. To quantify these effects, we characterized MOS test structures for interface-trap density versus energy in the band gap and leakage current through the insulating gate-oxide film. Interface-trap characterization techniques included C-V and conductance measurements on MOS capacitors, and charge pumping on fully processed MOSFETs.
Poster Presentation

High Temperature Dielectrics for Wide Band Gap Power Devices
Joseph Hernandez (Virginia Tech)
Faculty Mentors: Prof. R. D. Vispute (UMCP), Dr. Shiva Hullavard (UMCP), and Aivars Lelis (Army Research Laboratory)

The goal of our project is to develop dielectrics for wide band gap SiC devices. The dielectric yttrium oxide (Y2O3) was deposited on sapphire, silicone, and silicone carbide substrates. The UV spectroscopy and X-Ray diffraction have been performed on the films on the substrates for different sputtering conditions in order to optimize the dielectric films being sputtered. A Metal-Insulator-Semiconductor (MIS) structure has been fabricated by standard photolithography and metallization process in order to study the dielectric properties. Finally, electrical characterization will be done to measure leakage current as a function of temperature to demonstrate usefulness of newly grown dielectric layers for high-temperature semiconductor devices.

Electro-Mechanical Analysis of AlN Micro-Mechanical Beam Resonators
Christopher Lombardo(University of Maryland, College Park)
Faculty Mentors: Prof. R. D. Vispute (UMCP), Dr. Alma Wickenden (Army Research Laboratory), Jennifer Grim (Army Research Laboratory), and Dr. Shiva Hullavarad (UMCP)

AlN-based piezoelectric microelectromechanical (MEMS) resonators have been observed to exhibit an extremely high mechanical quality factor, but have shown poor electrical performance, indicating significant insertion loss. The electrical and mechanical loss mechanisms were researched, and found to include beam motional resistance, parasitic losses due to device design, and losses present within the component materials. An electromechanical model was used to determine the extent of these losses and recommend improvements in resonator design as well as future loss analysis approaches. MEMS resonators and test devices were fabricated using sputtered AlN layers, to compare material losses relative to devices previously fabricated using pulsed laser deposited AlN.
Poster Presentation

High Temperature Capping Layers for SIC Based Devices
Pamela Lee (Columbia University) and Eri Nishiyama (University of San Diego)
Faculty Mentors: Dr. Ken Jones (ARL), Prof. R. D. Vispute(UMCP), Dr. Matthew Ervin (ARL), Dr. Pankaj Shah (ARL), Michael Derenge (ARL), Dr. Shiva Hullavarad(UMCP), and Samantha Lei (ARL)

Silicon Carbide (SiC) is a wide band-gap semiconductor appropriate for high power and high temperature devices. Annealing the devices to high temperatures enable implanted atoms to diffuse to their equilibrium sites. This requires the use of a cap to limit the surface damage due to silicon evaporation, which damages the device structure. Experiments in the past have revealed the prevention of the preferential evaporation through the use of BN/AlN annealing caps, but sometimes particulates form on the BN film that lead to reduction of its effectiveness. In addition, stacking faults sometimes arise in the implanted SiC during the activation anneal. Tantalum Carbide (TaC) and Tungsten Carbide (WC) deposited using pulsed laser deposition (PLD) have drawn interest as caps because they are stable at high temperatures and do not react with the SiC. In addition, they offer the future possibility of providing a mask for selective area growth that could result in replacing the more defective ion implanted material with material that is grown epitaxially. The morphology of the TaC, WC, and SiC surfaces were studied using the scanning electron microscope (SEM); The crystalline structure of the TaC and WC films and the implanted SiC were examined using x-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS), and transmission electron microscopy (TEM); and the electrical properties of the SiC diodes were studied using electron beam induced current (EBIC) measurements.
Poster Presentation

Testing and Refinement of a Low-Power, Lightweight Neural Amplifier and Spike Sorter
Kevin Boyle (University of Notre Dame)
Dorielle Tucker (Clark Atlanta University)
Faculty Mentors: Pamela Abshire (UMCP) and Timothy Horiuchi (UMCP)

To understand the complex dynamics of a brain, it is necessary to retrieve and analyze neural data from animals exhibiting natural behaviors. There are many technical barriers in obtaining neural signals from a freely-moving animal, including the need to restrain the subject. The purpose of our project is to simplify data acquisition by testing and refining a lightweight, low-power integrated circuit containing a neural amplifier and spike sorter. This summer we analyzed the circuit and adjusted the biasing to obtain proper functionality. In addition, we refined methods for obtaining neural signals from live blowflies and tested the chip with live signals. Developing this integrated circuit is an important step towards enabling the wireless retrieval of data simultaneously from large populations of spiking neurons.
Poster Presentation

Packaging Bio-amplifiers to Monitor Extra-cellular Activity
Tony Li (University of Maryland at College Park)
Faculty Mentor: Prof. Pamela Abshire (UMCP)

Integrated bio-amplifiers are able to directly measure extra-cellular voltage signals from biological cells and amplify those weak signals. A major technical barrier to obtaining signals directly from cells is the contact between electrodes on the chip surface and biological samples, including cells and aqueous growth medium. The technical challenge is to ensure that cells are not harmed by non-biocompatible materials in the chip package, and that the chip package is isolated from corrosive materials in the cellular environment. A packaging assembly was designed, built, and tested for making injected silicone molds to act as an isolation barrier. In addition, a biocompatibility study was performed to determine the biocompatibility of various silicone materials with bovine aortic smooth muscle cells in order to find a suitable mold material. Further, a graphical user interface and data acquisition program was designed and coded in Matlab for the acquisition of the voltage signals from the cells through the bio-amplifier.
Poster Presentation

Wavelet Analysis of Magnetoencephalographic Auditory Activity
Chris Rodgers (Purdue University)
Faculty Mentors: Prof Jonathan Z. Simon (UMCP) and Dr. Yadong Wang (UMCP)

The technique of magnetoencephalography (MEG) holds exciting promise for the study of electrical impulses in the brain. Based on the detection of minute magnetic fields caused by those impulses, MEG measurements offer high temporal resolution, well-suited for understanding how the brain processes stimuli. Tones evoke neural responses in the gamma band (around 35 Hz) which are phase-locked to the stimulus and are therefore easy to detect by averaging. Previous work has shown that an `induced' gamma response, which is not phase-locked to the stimulus, may also occur. Because of the inconsistent phase and because of the high noise associated with MEG data, the induced response can be hard to detect, but it is important because it may be an indication of higher-level brain activity. In this project we will use wavelets to analyze MEG data, which was collected using modulated short tones as stimuli, and attempt to detect an induced gamma response.
Poster Presentation

Cell Clinics: Design of an Integrated Potentiostat and Testing of Capacitance Sensors
Joel Van Sickel (Grove City College)
Faculty Mentor: Prof. Pamela Abshire (University of Maryland, College Park)

Cell clinics are biolabs-on-a-chip for studying individual cells comprising lidded microvials in which the cells are directly interfaced with bio-amplifiers and other sensors. Isolation of cells requires the integration of CMOS electronics with MEMS actuators to control lids on microvials. CMOS potentiostats will be designed to enable control of the MEMS actuators and allow them to be integrated directly into the substrate on which they are fabricated. Lids will be opened and closed on individual cells by controlling the electrochemical potential with the potentiostats. Previously fabricated capacitance sensors will also be tested. Anticipated challenges include positioning an electrode with nanometer accuracy and using an electrode that is electrically floating instead of grounded.
Poster Presentation

Human Movement Categorization Through MOCAP Data and Body Angles Analysis
John Chaparro (Texas Tech University)
Faculty Mentor: Prof. Rama Chellappa (University of Maryland, College Park

Though the use of MOCAP data, we will be investigating the detection and categorization of human movement to eventually classify abnormalities in human gait. Periodic movement detection is achieved though the use of similarity matrices. Through this detection and from parameters extracted from the MOCAP data, movement will be classified into four different categories: 1. Walking, jogging: 2. sitting: 3. sweeping: 4. crawling. Once preliminary classification is complete, more categories will be added to allow movement abnormalities to be detected and categorized.
Poster Presentation

Normalization of Facial Expressions
Divya Jhalani (University of Maryland at College Park)
Faculty Mentor: Prof. Rama Chellappa (University of Maryland at College Park)

Robust face recognition involves many issues such as pose, illumination, aging and expressions. To improve the performance of the existing recognition algorithms, and make them invariant towards the issues mentioned above, the effects of all these factors need to be compensated for as much as possible. In this work, the focus is on making the face recognition algorithms insensitive to the facial expressions of a person, particularly the expressions where the mouth is involved as the mouth moves the most in the face. Therefore, to make a face expression-free, or in other words neutral, we change the mouth area to get a face which is closer to being a neutral one. This is achieved by using a triangular mesh that initially represents a generic face. This mesh is modified to make it as accurate a representation as possible of a face with expression by changing its various parameters. Once the mesh is created, it can be easily used to go back to the neutral face. This neutral face can then be used instead of the original face in the face recognition algorithms to yield better results.

Automatic Speech Recognition: Identifying Nasalization in Vowels
Shuo Chen (Virginia Tech)
Faculty Mentor: Prof. Carol Espy-Wilson (University of Maryland at College Park)

The Speech Communication Lab (SCL) is pursuing a radically new approach to automatic speech recognition that centers on the study of acoustic-phonetics and its usage in capturing phonetic features from speech waveforms. In this project, the SCL is investigating acoustic parameters for the phonetic feature nasal, particularly when nasals are co-articulated with preceding vowels. This co-articulation is called "nasalization". The goal of this project is to develop acoustic parameters, specific to nasalization, that can be automatically and effectively extracted from a continuous speech signal.
Poster Presentation

Investigation of Acoustic Features in Text-Independent Speaker Verification
Thomas Plummer (University of Miami)
Faculty Mentor: Prof. Carol Espy-Wilson, (University of Maryland at College Park)

Text-independent Speaker Verification has received considerable attention due to its extensive application in security. However, the current front-end of the speaker verification system is affected by the acoustical channel and various environments. This sensitivity motivates the present research on the processing of the speech derived acoustical features. In particular, the proposed research explores the application of source information in speaker verification and the processing of source information with conventional Mel- Frequency Cepstral Coefficients (MFCC). Principal Component Analysis (PCA) will also be implemented to reduce data dimensions by extracting the top few principal component feature sets from the MFCC processed source information, which will in-turn reduce data and calculation overhead while improving system accuracy.
Poster Presentation

Acoustic Parameter Based Speech Recognition in Noisy Environment
Qin Zou (University of Maryland at College Park
Faculty Mentor: Prof. Carol Espy-Wilson (University of Maryland at College Park)

One of the main reasons current automatic speech recognizers perform poorly in practical applications is the mismatch in the training and the testing environments. We have developed a set of Acoustic Parameters (APs) that capture the salient features of various broad classes of speech. The aim of this project is to study the effect of different types of background noise on these APs and to develop compensation algorithms that minimize the distortion of these APs in order to improve the accuracy of the recognition system.
Poster Presentation

Multi-Echo Integration for Sonar-based Vehicle Naviagation
Marshall Miller (University of Maryland at College Park)
Gaurav Singal (Columbia University)
Faculty Mentor: Prof. Timothy Horiuchi (University of Maryland at College Park)

Based on principles of bat echolocation, we have designed a robotic vehicle capable of navigating through a field of obstacles using sonar. The robot, equipped with a speaker and two microphones, emulates the bat's mouth and ears. We developed an algorithm to convert sonar echoes into positional information about the obstacles in the field and implemented it on a PIC microcontroller. We used a second PIC to implement a motion-control algorithm, "Openspace", which combines obstacle information with target direction to choose the best heading. This heading is converted into motor commands and sent to the robot, which executes the command.
Poster Presentation

GPS-Based Location Determination
Kun Lin (University of Maryland at College Park)
Faculty Mentor: Dr. P. S. Krishnaprasad (University of Maryland at College Park)

Systems that utilize feedback are called closed-loop control systems. Such systems continuously adjust their control signals according to the received feedback signals (e.g. cruise control). Currently, we are constructing a closed-loop control system modeled after the classical pursuit problem. The system uses two robots, programmed using Motion Description Language Extended, named Fox and Rabbit. Fox will attempt to intercept course with Rabbit using both its GPS (Global Positioning System) location data and that of the Rabbit's. Challenges encountered are robot hardware configuration and GPS data accuracy. Although, technical difficulties still persist, we remain optimistic.
Poster Presentation

Ad Hoc Network Security
Wui Cheong Wong (Binghampton University)
Faculty Mentor: Prof. Ray Liu (UMCP)

A mobile ad hoc network is a group of mobile nodes that do not require centralized administration, in which nodes can communicate with each other even when they are not in direct communication ranges. However, before ad hoc network can be successfully deployed, the security issues must be resolved first. In this project, we investigate the secure routing protocols for mobile ad hoc networks, and implement a testbed using C++.
Poster Presentation

Adjustable Time Delays for Optical Clock Recovery Systems
Amir Ali Ahmadi (University of Maryland at College Park)
Elric Von Eden (University of Maryland at College Park)
Faculty Mentor: Prof. Tom Murphy (University of Maryland at College Park)

We built an all-optical clock recovery system based on two-photon absorption (TPA) in a silicon avalanche photodiode. The system is polarization insensitive, compact, broadband, and capable of supporting future high-speed optical networks. One key element in this new system is an adjustable time delay that allows the clock timing to be modulated. This was accomplished by using a phase modulator and polarization maintaining fiber (PMF) to periodically dither the timing of the clock signal. Finally, a phase detector circuit followed by a phase-locked loop (PLL) was implemented to synchronize the clock and data signals.
Poster Presentation

Evaluation of Polarization Dependence in Nonlinear Optical Detectors
Audrey Strunc (Washington University)
Faculty Mentor: Prof. Tom Murphy (University of Maryland, College Park)

This project investigates the nonlinear process of two-photon absorption in the photomultiplier tube, a nonlinear optical detector. We theoretically predict and experimentally measure the polarization dependence in the photomultiplier tube. In addition to this, we examine the photomultiplier's sensitivity to the input continuous wavelength light. We also measure how the output signal changes as a function of the detector position.
Poster Presentation

An Examination of Security Algorithm Flaws in Wireless Networks
Hirsh Goldberg (University of Maryland at College Park)
Erica Simcoe (Pennsylvania State University)
Faculty Mentor: Prof. Sennur Ulukus (University of Maryland at College Park)

The area of interest in this research is Wireless Local Area Networks (WLANs) specifically based on the IEEE 802.11 protocol. Although there are numerous measures in place that have been designed specifically to protect sensitive user information, research has shown that there are significant flaws in current security mechanisms implemented in this standard. Emphasis is placed on examining these security flaws and understanding what measures have been taken to eliminate them. Finally, several simulations of an attack on a WLAN using the IEEE 802.11 standard are studied in order to prove the overall insecurity of this standard.
Poster Presentation

Improving the Robustness and Imperceptibility of Curve Fingerprinting
Daniel Cardy (Washington University)
Faculty Mentor: Prof. Min Wu (University of Maryland, College Park)

Due to the proliferation of scanning and pen-based devices, images consisting primarily of curves, such as maps, drawings and signatures, are becoming increasingly common in the digital domain. These digital documents can be easily stored and stolen, used and misused. Consequently, it is important to be able to trace the unauthorized distribution and malicious tampering of such documents. This can be accomplished by hiding information in them, where the hidden data provides tell-tale signs, for example, from whom a classified document is leaked. B-splines, which are piecewise polynomial functions, can be used to approximate a curve from a small set of characterizing data called control points. Information can be embedded in the curve by making slight modifications to these control points. My algorithm optimizes the placement of control points to facilitate robust and invisible data embedding. Instead of simple uniform placement, fewer control points are placed in linear areas and more in areas with large curvature and drastic changes. With my algorithm, the overall changes introduced by the embedding step can be substantially reduced. It allows more information to be embedded in the curve, or the same amount of information be embedded in a more robust way.
Poster Presentation