Disfluent speech has typically been regarded as noise in spoken language processing: aspects of speech that should be ignored in order to automatically detect and understand the intended meaning of spoken language. However, it has also been suggested that disfluencies provide information about a speaker's cognitive processes and efforts to manage the discussion. Most work on disfluencies has investigated very controlled scenarios or conversational speech. In our work, we are studying high-stakes debates, including Supreme Court oral arguments and congressional hearings on the financial crisis, in addition to informal conversations among strangers and family members. By studying disfluent speech in both high and low stress situations, we can better understand the impact of stress on disfluency rates. We use text alignment techniques to understand the relationship between the perceived mistakes and correction. We subdivide and partition disfluencies into categories by classifying inserted, deleted, and substituted words according to their semantic similarity; thus, making correlations between social context and disfluency rate more evident in addition to providing a better interpretation of speaker opinions. Preliminary results show that lawyers have a tendency to model their speech patterns off of the justices they are speaking to, but not vice versa. That is, lawyers tend to be more disfluent when the justices are speaking disfluently, which indicates that disfluent speech reflects social context. Thus, we hope to develop ways to automatically detect and understand deeper meaning in spoken language, such as defensiveness and strength of opinions, through our study of disfluent speech.

Microbial growth can be monitored by changes in the optical density of a culture. In the past, these measurements were generally made by hand, one at a time at regular intervals, in order to produce a growth curve. Currently no such device is suitable for monitoring the growth of fastidious anaerobes. This presented problems for both efficiency and resolution of experiments requiring analysis of multiple cell lines and different growth conditions. For growth periods greater than a work day, researchers needed to take alternating shifts in order to capture data. This is a very tedious process which is draining on the tester. The result of such a worker demand was infrequent measurements to make the minimal curve, resulting in inherent tester bias. Naturally, the desire to automate the process arose. I began development on the ROGR system began in order to implement a microcontroller operated test setup using LEDs and phototransistors to replace the manual measurements made with a spectrophotometer. Previous work has shown that LEDs of these wavelengths do not interfere with cell growth. As this is an ongoing experiment, it is imperative that the method used to measure growth does not change the testing environment. For example, the anaerobic cultures have long been incubated with constant shaking with the culture tubes oriented in a horizontal plane, but measurements were made in the upright position in order to create an accurate reading. The ROGR is a multi-disciplinary project that addresses these project needs. The electronic design ensures system isolation and achieves high precision and dynamic range. Design also ensures mechanical stability, reducing error in LED phototransistor pairs readout originating from changes in their physical orientation. Presently the system is undergoing the physical implementation phase with its circuitry at a working state. This reproducable system will allow for data colection across multiple teams to be connected with confidence of small error.

Current medical diagnostic gold standard, the Enzyme-Linked Immune-Sorbent Assay (ELISA), requires additional labels and amplification to determine the existence of interested molecules. Such process is extremely time consuming and expensive, and thus a fast and low-cost alternative is in demand. Our project aims to develop a rapid and affordable diagnostic biosensor platform that can be administered in the Point-Of-Care (POC) setting. In our silicon photonic sensor chip, we exploit a unique aspect of light when it is confined into a waveguide much smaller than its own wavelength. Since different molecules have different refraction index, the portion of light travels outside the waveguide, called evanescent field, is capable of sensing molecules binding on the sensor surface. While the design and fabrication of these biosensing devices can be done quickly and affordably, characterizing and experimenting the devices remains challenging because of the complexity of testing submicron-scale components. Chips require careful alignment of the optical I/O fibers with micron-tolerances. Microfluidics must be integrated to deliver reagents to specific regions of the chip. Real-time processing of optical spectra is needed to facilitate user operation. Hence we have customized a low-cost test bench to perform experiments and characterizations on the silicon photonic biosensors. I have designed the software, which employs industrial standard Model-View-Controller (MVC) architecture, for instruments integration, experiments orchestration as well as data acquisition and analysis. This software has greatly enhanced the efficiency of the biosensor platform development and future improvement is foreseeable because of the ongoing progress of full automation of experiment preparation. I have characterized multiple sensor devices through optical data acquisition, analysis, model fitting and key parameters’ estimation this software provides. Characterization results show great promise on the sensing capability of the platform and we will soon proceed to biomolecules (e.g. protein), and even cell (e.g. cancer cell) sensing.

In order to increase the accuracy of particle detectors, new sensors and digital acquisition systems must be developed. With the power of reconfigurable digital logic, an acquisition system has been created using a simple and fast architecture in order to test T3MAPS, a prototype sensor for the ATLAS detector. The firmware design of the system is modular to allow for iterative improvements over time and future changes to the sensor. Currently the systems first iteration is being tested using oscilloscopes, and then the system will be connected to T3MAPS for more advanced function tests. In the future the firmware will be ported to multiple platforms with additional functions to allow time over threshold test to be conducted on T3MAPS. T3MAPS is new sensor designed to detect high-energy particles generated by particle accelerators. The ATLAS detector is one of many particle detectors at the Large Hadron Collider, a particle accelerator run by CERN. The firmware for this system is written in a hardware description language, Verilog. This language is used to describe digital designs as a programming language, enabling reconfigurable digital circuits. This offers a vast level of flexibility. As nobody has tried to implement an acquisition system for T3MAPS, great care must be taken to insure that the signal to the sensor is correct and electrically clean. This is verified using a logic analyzer and an oscilloscope to insure the signal meets the specifications required. After signal verification, testing will be conducted on T3MAPS itself using the verified design. Tests will progress from simple configuration of the sensor to full pixel by pixel scans of the chip. Results from these tests will be analyzed to compare the speed and accuracy of this system vs. the existing manual methods.

It is often forgotten students are learning to build a better future. As a group of students, we are looking to create a form of innovative technology that provides a learning experience through two of the most important learning methods: visual and kinesthetic. To provide hands on learning experience, we have created the Dynamic Mathematical Display (DMD). The DMD is a device with pins placed within a three by three grid. The pins are 10 cm long, 3.5 cm wide, and each controlled by individual motors and slide potentiometers. The dynamic movement of each pin is measured by the potentiometer's linear resistance, which is monitored electronically by a computer program. That program will engage the pin to move to a given point projected from 3D graph. The main purpose of the DMD project is to create a morphing table that will allow a user to visualize complicated 3D graphs with all their components such as depths and peaks. These components will be represented by red, green, and blue light emitting diodes (RGB LEDs), which are attached to each pin. The LED's are programmed to provide color based on the physical location of the pin at the time according to the projected graph. Both instructors and students will have the option to manipulate the brightness and color of the LEDs. While the pins provide kinesthetic information to a graph, the LEDs provide additional visual information similar to a topographic map, enhancing the learning experience of a student by presenting more realistic and information-rich representations of physical models. 

As renewable energy constitutes a greater portion of the generation fleet, so does the importance of modeling uncertainty as part of integration studies. In pursuit of optimal system operations, it is important to capture not only the definitive behavior of power plants but also the risks associated with system wide interactions. Load forecasting is an area of renewable energy integration studies that is often neglected, chiefly because of a lack of available data. In this research, the dependence of load forecast errors on external predictor variables such as temperature, day type, and time of day was examined. The analysis was utilized to create statistically relevant instances of sequential load forecasts with only a time series of historic, measured load available. The creation of such load forecasts relies on Bayesian techniques for informing and updating the model, thus providing a basis for networked and adaptive load forecast models in future operational applications.

The Advanced Propulsion Lab from the Earth & Space Sciences Department has developed a Pulsed Plasma Thruster (PPT) which utilizes a propulsion system ideal for operating in a low pressure and high altitude environment. In order to test the PPT, a high-altitude flight will be carried out at the end of May 2014. The structure housing the thruster is a zeppelin-type aircraft composed of two lifting balloons, a primary zeppelin balloon, and a supporting frame. There are several constraints that need to be fulfilled by the aircraft. The zeppelin frame needs to be strong and durable enough to support the thruster, while still light enough to fulfill the weight compliance from the FAA. In addition, the zeppelin needs to be able to raise the payload above the jet stream to an altitude of approximately 70,000 feet and maintain that height once reached. To achieve this, the structure uses two 800-g high altitude latex balloons with 150 cubic feet of helium providing the lifting force. Once the optimal height is reached, the two balloons will be separated from the main structure through the uses of NiChrome wire and the primary balloon will take over, providing neutral buoyancy at the desired location in order to accurately measure the thrust of the PPT. The main core of zeppelin is currently being fabricated in house using mylar as the primary material for the balloon and carbon fiber rod for the supporting frame by our team. Current calculations estimate the size of the zeppelin to be 45 feet horizontally with a 4.5 feet radius. There are several issues the zeppelin is currently facing such as the fragility of the material used, the expansion of the helium at high altitude, the weight of the payload, and the sheer size of the aircraft. We are currently testing various materials and structural designs that will house the payload in order to develop a lightweight and aerodynamic aircraft that will address these issues. 

Magnetohydrodynamic (MHD) propulsion uses water, electricity and magnets to create thrust.  The importance of MHD drives is that they require no moving parts, allowing for less energy loss due to friction as well as silent propulsion.  The MHD engine works by creating thrust when an electric current is run through a liquid or plasma in the presence of a magnetic field.  The interaction between the electrons in the medium and the electric field draws water in one end and expels it out the other, creating thrust.  Our project seeks to optimize the thrust of a MHD system in a saltwater solution so it is a viable replacement engine for a water craft.  We present here our design of a novel closed-circuit MHD-engine testing apparatus that allows for real-time varying of magnetic field strength and engine geometry in order to achieve optimal thrust configurations for a given MHD engine design.

Sleep apnea is a common syndrome where a person has an irregular breath rate only during sleep, making it difficult to be detected and diagnosed. Yet, in the U.S. about two percent of children are affected by this syndrome and thus at risk of some health issues. There are some prevalent breath detection products on the market but they remain inaccessible due to the undesired prices and limited range of detection. In the breath detection project I was participating in, we intended to detect the breath rate by wireless technology, e.g. home-based WiFi. Our design would ease the cost of production by zero assembly and installation of the hardware components and would achieve the detection for anywhere inside a house (whole-home detection) by wireless signal transmissions in line-of-sight, none-line-of-sight, and through-the-wall scenarios. The detection system broadcasts the wireless signals in a home environment, receives the reflected signals from the targeted person, and then computes the frequency of the target’s breathing over a period of detection. We expected that frequency plots would be uniform for a normal person but irregular for a patient with sleep apnea. One practical implication of performing such frequency analysis in the whole-home environment is that children’s health monitoring can still happen without parental interference.

The development of drug-resistant HIV variants is an important cause of virologic failure. In order to choose effective regimens, assays for diagnosing resistance are essential. Pol gene mutations within the HIV retrovirus, which are associated with drug failure and phenotypic resistance, can be used as the assay targets. Current diagnostic assays include various genotypic and phenotypic assays, recombinant virus assays and other commercial assays. However, these assays are time consuming. To address this issue, we are applying engineering principles to convert the oligonucleotide ligation assay (OLA), developed by Frenkel et al., for point-of-care (POC) diagnostics, to significantly reduce the timeframe for diagnosing drug resistance, leading to regimen decisions. In order to detect the HIV pol gene using OLA, nucleic acid (NA) from bodily fluids need to be extracted and purified. Current extraction methods are time consuming, and require complex procedures, instrumentation, and expensive reagents unavailable in low-resource settings. We are developing novel approaches to capture NA without instrumentation through the use of stimuli-responsive polymers. These polymers are capable of responding to specific changes in their environments, such as temperature variations, resulting in a change of their physical properties; our polymer becomes cationic and aggregating. Magnetic nanoparticles (mNPs) can be utilized in conjunction with these polymers for biomolecule separation by applying a stimulus and a magnetic field. The new NA extraction strategy starts from complexing cationic stimuli-responsive polymers with NA, and then magnetically separating NA from solution via the co-aggregation with mNPs and heating (characterized using standard agarose gel protocol). This extraction method utilizes 2 reagents and takes about 20 minutes, which will reduce cost and enable POC diagnostics in low-resource settings. The extracted NA can then be amplified, tested for the presence of the mutant pol gene, and used to better diagnose HIV drug-resistance and determine patient regimens.

According to the World Health Organization, cardiovascular diseases are the leading cause of mortality worldwide. The low regenerative capacity of the heart renders it ineffective in healing itself after heart failure. Our lab has developed efficient methods to derive cardiomyocytes (cardiac muscle cells) from human embryonic stem cells (hESCs). However, it has become apparent that the cardiomyocytes derived using current differentiation methods exhibit immature morphological and functional properties. An important characteristic of mature cardiomyocytes is the presence of T-tubules, which are invaginations of the plasma membrane into the cell interior. These subcellular structures are critical for synchronized calcium release and contraction of mature cardiomyocytes. The protein caveolin-3 is a critical component of T-tubules, and thus its visualization can be used to assess the development of these important subcellular structures. I am currently evaluating the expression of caveolin-3 in hESC-derived cardiomyocytes using immunostaining techniques. For these studies, I expose the sample to anti-caveolin-3 as the primary antibody followed by a complementary secondary antibody conjugated to a fluorescent marker for visualizing the protein. Titration of several parameters, such as time of incubation and dilution of the antibodies allows for staining optimization. I have obtained detailed images of T-tubules aligning with striations in control heart tissue, but the staining is diffuse for the hESC-derived cardiomyocytes grown in standard 2D cultures. I am currently exploring whether this is a technical issue or the result of developmental immaturity. To assess the latter, I will stain hESC-derived cardiomyocytes that are more mature due to mechanical conditioning in 3D constructs. Optimization of this technique will facilitate our efforts to find novel agents that can accelerate the maturation of hESC cardiomyocytes. Finding ways to mature these cells will then provide a better platform for therapeutic applications such as drug screening, disease modeling and cardiac repair.