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Title: LASER MICROMACHINING, SINTERING, AND LASER-INDUCED PLASMA DEBURRING
Creator: Gao, Yibo
Date: 2013, 2013-12
Description: Lasers can provide non-mechanical-contact, localized and concentrated energy input to materials with controlled durations and high spatial...
Show moreLasers can provide non-mechanical-contact, localized and concentrated energy input to materials with controlled durations and high spatial resolutions down to a few microns or less. Therefore, lasers have more and more applications in manufacturing and materials processing, such as laser micromachining (which is to create micro-scale features through laser-induced material removal) and laser sintering. Despite the previous research work in the literature, many laser-based manufacturing and materials processing areas still require lots of further research work. Specifically, the following topics will be investigated in the research work in this thesis: nanosecond-pulsed laser ablation of silicon carbide at an infrared wavelength, nanosecond laser-induced plasma deburring, two-step nanosecond laser surface texturing, and the fabrication of carbon nanotube (CNT)-ceramic composites through the laser sintering process.
PH.D in Mechanical and Aerospace Engineering, December 2013
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Title: BIOLOGICAL STRATEGIES FOR ENHANCEMENT OF LIQUID FUELS: SULFUR REMOVAL FROM PETROLEUM AND BIOETHANOL PRODUCTION
Creator: Wang, Jia
Date: 2013, 2013-12
Description: Rhodococcus baikonurensis CW25 was transformed with the Rhodococcus erythropolis strain IGTS8 desulfurization operon (dszABC, which encodes...
Show moreRhodococcus baikonurensis CW25 was transformed with the Rhodococcus erythropolis strain IGTS8 desulfurization operon (dszABC, which encodes the enzymes of the “4S” desulfurization pathway) or this operon modified to contain a synthetic cysteine-methionine rich “sulpeptide” gene (S1) (dszAS1BC). The two CW25 derivatives were subjected to directed evolution to select faster growing cells using the key 4S pathway substrate dibenzothiophene (DBT) as the sole source of sulfur. Data of cell doubling times verified the success of selection of cultures with increasingly rapid growth. The desulfurization activities of resting cells of early passages demonstrated improvements, and the highest activity of the dszAS1BC-bearing CW25 derivative was 115% higher than that of the CW25 derivative without S1. In addition, a trend of initial high activity was followed by a decrease in subsequent passages. Rates of DBT metabolism of growing cells demonstrated a different trend, probably because the activity of growing cells concurrently reflects the activity of DszABC enzymes and the growth rates of the recombinants. Dry cell weights fluctuated during the evolution process, probably because of variations in the efficiency of the conversion of the sulfur in DBT into sulfite, then into sulfate or biomass, or, for the S1-bearing cells, because the secretion of the S1 peptide from cells might have variable efficiency. A mixed culture of two Paenibacillus species (“W” and “Y”) was isolated that can metabolize DBT at temperatures up to 54 ºC. Strain Y is the only one of the two with desulfurization activity, while strain W enhances the desulfurization ability of Y. The W-Y culture may be a useful starting point for selection of desulfurization cultures with even greater thermal stability. xiii Ethanologenic Escherichia coli strain FBR5 was compared with Vitreoscilla hemoglobin (VHb)-expressing FBR5 (TS3) regarding the concentrations of ATP, NAD+, NADH, NAD+/NADH ratio; and growth and ethanol production at various points during growth. The significant finding was that the NAD+/NADH ratio for TS3 was lower in early growth, but higher in later growth compared to that for FBR5. This is probably because more NADH was required by TS3 for its enhanced ethanol production and VHb-related increased respiration under microaeration conditions.
PH.D in Biology, December 2013
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Title: MIN- AREA RETIMING UNDER WIRE-DELAY MODEL
Creator: Luo, Tianchen
Date: 2011-05-09, 2011-05
Description: Retiming is a powerful optimization technique for synchronize sequential circuits that relocates delay unit without changing the circuit’s...
Show moreRetiming is a powerful optimization technique for synchronize sequential circuits that relocates delay unit without changing the circuit’s input-output functionality. Wire delay is significant and can no longer be ignored in deep sub-micrometer technologies. Existing algorithms solve the problem of min-area and min-period either optimal or heuristically without taking wire delay into consideration. However, those techniques cannot be applied directly to circuit with wire delay. Recent work solved the min-period problem under wire delay model. This paper proposes an algorithm that solves the problem of min-area wire retiming under fixed clock period optimally and efficiently.
M.S. in Electrical and Computer Engineering, May 2011
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Title: Thermal Resistance of Salmonella in Desiccation and Rehydration
Creator: Ahuja, Rameet
Date: 2011-12-06, 2011-12
Description: Transfer of salmonellae from a desiccated existence in dry food ingredients or processing environments to food products having higher water...
Show moreTransfer of salmonellae from a desiccated existence in dry food ingredients or processing environments to food products having higher water activities (e.g., peanut butter used in pie, chocolate in cake) leads to partial or full re-hydration of the bacteria. This study characterized the thermal behavior of Salmonella in response to desiccation and the subsequent rehydration. The thermal resistance of the desiccated S. enterica ser Tennessee was inversely correlated to aw: for example, desiccation at 11 to 97% equilibrated relative humidity (ERH) resulted in 0.5 to 3.3 log reduction, respectively, after 60ºC treatment for 10 min. Cells stored at lower ERH showed a lower survival rate, but higher thermal resistance. Once cells established their initial physiological response to desiccation, continual storage at 11% ERH up to three weeks did not further change the thermal resistance of Salmonella. Rehydration of the desiccated cells (11% ERH) to higher ERH conditions (84 to 97%) led to greater than 5 log reduction after heating cells at 60ºC for 10 min, in contrast, the same heat treatment resulted in approximate 3 log reduction for cells stored constantly at 84-97% ERH. There was no significant difference in regard to thermal sensitivity between cells rehydrated from 11% ERH to 33-55% ERH and that stored constantly at each ERH, only about 0.3-0.5 log CFU reduction in both cases. The study showed that rehydration moderately reduced cell viability, but greatly increased thermal sensitivity when a drastic aw shift occurred.
M.S. in Food Safety and Technology, December 2011
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Title: EBSD CHARACTERIZATION OF LOW TEMPERATURE DEFORMATION MECHANISMS IN MODERN ALLOYS
Creator: Kozmel, Thomas S Ii
Date: 2015, 2015-05
Description: For structural applications, grain re nement has been shown to enhance mechanical properties such as strength, fatigue resistance, and...
Show moreFor structural applications, grain re nement has been shown to enhance mechanical properties such as strength, fatigue resistance, and fracture toughness. Through control of the thermo-mechanical processing parameters, dynamic recrystallization mechanisms were used to produce microstructures consisting of sub-micron grains in 9310 steel, 4140 steel, and Ti-6Al-4V. In both 9310 and 4140 steel, the distribution of carbides throughout the microstructure a ected the ability of the material to dynamically recrystallize and determined the size of the dynamically recrystallized grains. Processing the materials at lower temperatures and higher strain rates resulted in ner dynamically recrystallized grains. Microstructural process models that can be used to estimate the resulting microstructure based on the processing parameters were developed for both 9310 and 4140 steel. Heat treatment studies performed on 9310 steel showed that the sub-micron grain size obtained during deformation could not be retained due to the low equilibrium volume fraction of carbides. Commercially available aluminum alloys were investigated to explain their high strain rate deformation behavior. Alloys such as 2139, 2519, 5083, and 7039 exhibit strain softening after an ultimate strength is reached, followed by a rapid degradation of mechanical properties after a critical strain level has been reached. Microstructural analysis showed that the formation of shear bands typically preceded this rapid degradation in properties. Shear band boundary misorientations increased as a function of equivalent strain in all cases. Precipitation behavior was found to greatly in uence the microstructural response of the alloys. Additionally, precipitation strengthened alloys were found to exhibit similar ow stress behavior, whereas solid solution strengthened alloys exhibited lower ow stresses but higher ductility during dynamic loading. Schmid factor maps demonstrated that shear band formation behavior was in uenced by texturing in these alloys.
Ph.D. in Materials Science and Engineering, May 2015
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Title: UNDERGROUND AIRPORT
Creator: Kim, Churl Jong
Date: 2014, 2014-12
Description: The idea of this project is to investigate the possibility of an underground airport with passenger facilities below and aircrafts above with...
Show moreThe idea of this project is to investigate the possibility of an underground airport with passenger facilities below and aircrafts above with minimum over-ground space. An important advantage is the possibility of loading and unloading passengers at two or more aircraft entrances thereby shortening the turn-around time of aircrafts. This accessibility can be more easily managed when approached from below. Furthermore, an underground facility is expected to provide several additional advantages: 1) greater freedom for aircrafts to get into position to efficiently load and unload; 2) potential for aircrafts to power-in and power-out of gate areas omitting the need for towing; 3) shorter walking distances for passengers due to greater compactness; 4) potential for an effective and efficient Automated People Mover (APM) system; 5) greater potential for systematic airport expansion when needed; 6) potentially reduced operating cost for ventilation, heating, and cooling. These advantages will answer many of the difficulties that current airports are experiencing today. However, in order to achieve these advantages, there are many important practical questions such as the spatial, environmental, structural aspects that need to be most carefully addressed. This project endeavored to investigate these important aspects as thoroughly as time and resources permit.
M.S. in Architecture, December 2014
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Title: ADULTS WITH SICKLE CELL DISEASE: THE DISEASE'S IMPACT ON PAIN NEUROPSYCHOLOGICAL DYSFUNCTION AND QUALITY OF LIFE
Creator: Vernale Iii, Michael A.
Date: 2013, 2013-07
Description: The primary aim of this study is to address the neuropsychological functioning of adults with Sickle Cell Disease (SCD) by examining the...
Show moreThe primary aim of this study is to address the neuropsychological functioning of adults with Sickle Cell Disease (SCD) by examining the association of illness-related and psychosocial factors with cognition. The neuropsychological functioning of adults with SCD will be compared to that of controls matched on gender, race, and age. There is considerable evidence for neuropsychological complications associated with SCD (Anie, 2005; Schatz, 2004). Much of the cognitive deficits are thought to be the result of cerebrovascular accidents commonly suffered by this population. Studies of cognition in children with SCD suggest that cognitive complications tend to increase with age. Particularly implicated are deficits in attention, concentration, and executive functioning. Although the specific neuropsychological morbidity is not as clearly understood for adults with SCD as it is for children, global cognitive impairment within this population has been documented. In addition, pain negatively affects cognitive functioning in both children and adults (Libon et al., 2010). The pattern of impairment was suggested to be the result of additional demands on attentional capacity. However, the relationship between pain and cognitive performance in adults with sickle cell disease is less clear. As a result of frequent pain, individuals with SCD often report a low evaluation of quality of life particularly as a result of health complaints (Anie, 2005). Thus, the inter-dynamic of health -related quality of life, pain , and cognitive dysfunction is not entirely clear within the sickle cell population and therefore warrants examination.
PH.D in Psychology, July 2013
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Title: SUPPORT VECTOR MACHINE BASED CLASSIFICATION FOR TRAFFIC SIGNS AND ULTRASONIC FLAW DETECTION
Creator: Virupakshappa, Kushal
Date: 2015, 2015-12
Description: The use of machine learning techniques for the advanced signal and image processing applications is gaining importance due to performance...
Show moreThe use of machine learning techniques for the advanced signal and image processing applications is gaining importance due to performance increases in accuracy and robustness. Support Vector Machine (SVM) is a machine learning method used for classification and regression analysis of complex real-world problems that may be difficult to analyze theoretically. In this dissertation, the use of SVM for the application of ultrasonic flaw detection and traffic sign classification has been investigated and new methods are introduced. For traffic sign detection, Bag of visual Words technique has been implemented on Speeded Up Robust Feature (SURF) descriptors of the traffic signs and later the sturdy classifier SVM is used to categorize the traffic signs to its respective groups. Experimental results demonstrate that the proposed method of implementation can reach an accuracy of 95.2 % . For ultrasonic aw detection, subband decomposition filters are used to generate the necessary feature vectors for the SVM classifier. Experimental results, using A-scan data measurements from a steel block, show that a very high classification accuracy can be achieved. Robust performance of the classifier is due to proper selection of frequency-diverse feature vectors and successful training. SVM has also been used for regression analysis to locate and amplify the aw by suppressing the clutter noise. The results show that the use of SVM is reliable and achievable for both the applications.
M.S. in Electrical Engineering, December 2015
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Title: PARAMETRIC COST ESTIMATION MODEL OF INTEGRATED REACTOR VESSEL UNDER MODULAR CONSTRUCTION WITHIN A FACTORY ENVIRONMENT
Creator: Chen, Xuan
Date: 2013, 2013-12
Description: High initial cost is one of the major barriers for the nuclear power industry. Small modular reactors (SMR) may be a solution to this problem...
Show moreHigh initial cost is one of the major barriers for the nuclear power industry. Small modular reactors (SMR) may be a solution to this problem because they have a much smaller financial barrier. In this thesis, parametric cost estimation modeling studies have been performed for the SMR integrated reactor vessel (IRV) under a factory environment. Based on different prior fabrication experiences, three scenarios have been studied, and the corresponding possible manufacturing costs of the entire IRV and its subcomponents have been estimated. To explore the cost allocation, the total cost has been divided into five cost contributors: labor, material, tooling labor, tooling replacement, and other. The results have been analyzed and discussed.
M.S. in in Mechanical, Material and Aerospace Engineering, December 2013
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Title: COMPARISON BETWEEN TWO CHITIN-PURIFIED PRO-DEATH PROTEINS IN MITOCHONDRIA TARGETING ANALYSIS
Creator: Yeap, Xin Yi
Date: 2011-04-19, 2011-05
Description: Bax protein belongs to the Bcl-2 family. It is pro-apoptotic and the most common form is Bax α. When a cell receives death stimuli, Bax...
Show moreBax protein belongs to the Bcl-2 family. It is pro-apoptotic and the most common form is Bax α. When a cell receives death stimuli, Bax protein will oligomerize and target to mitochondria. Another isoform of Bax called Bax 2, which has lost exon 2 and has a frame shift mutation, is verified to be more potent in inducing apoptosis than Bax α. Here, we would like to understand more about Bax 2 mitochondria targeting ability compared to the more common Bax α form. We first set up a cell-free system which contained purified Bax protein and purified mitochondria. The mitochondrial binding protein was identified using fractionation and Western blot with Bax isoformspecific antibodies. Integration of Bax protein into the mitochondrial membrane was determined using the alkaline stripping method. The results suggest that the majority of Bax α targeted and integrated into the mitochondria membrane, while the majority of Bax 2 did not target to mitochondria in the cell-free system. This may suggest that Bax 2 might need additional help from certain cytosol components such as co-factors to target to mitochondria or that Bax 2 induces cell death through a mechanism other than mitochondrial targeting.
M.S. in Biology, May 2011
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Title: MOLECULAR AND GENETIC ENGINEERING STUDIES OF VITREOSCILLA HEMOGLOBIN
Creator: Chen, Yang
Date: 2014, 2014-05
Description: Biodesulfurization is a promising field that can be applied to the processing of crude oil for removing dibenzothiophene (DBT) and its...
Show moreBiodesulfurization is a promising field that can be applied to the processing of crude oil for removing dibenzothiophene (DBT) and its derivatives. A thermophilic bacterial strain Paenibacillus naphthalenovorans (32O-Y) was found to metabolize DBT as sole sulfur source. Another thermophilic strain Paenibacillus apiaries (32O-W) which cannot utilize DBT, however, was found to increase the desulfurization activity of 32O-Y in mixed 32O-Y+W culture in minimal-DBT medium at temperatures between 45 and 50 °C. In order to increase the desulfurization activity of these strains, we genetically engineered strain 32O-Y to express Vitreoscilla hemoglobin (VHb). VHb is the first hemoglobin found in bacteria and has been used to increase the growth and product yields various cells. The VHb gene (vgb) was successfully cloned into shuttle vector pNW33N. 32O-Y was successfully transformed with pNW33N-vgb while 32O-W was not. Compared to untransformed 32O-Y, 32O-Y[pNW33N-vgb] grew slower and reached a lower maximum OD600 when cultured in minimal-DBT medium at 45 °C. However, the Gibbs assay showed that VHb expression in 32O-Y increased its desulfurization activity by 18%. Thus, VHb can help 32O-Y metabolizing DBT while it might not promote growth. A series of high temperatures cultures need to be conducted to select an even more thermophilic strain which can fulfill the 60 °C requirement of industrial process. The VHb mutant (vgbM3) was also studied, which was previously found correlated with increased growth of E. coli DH5α, compared with the effect of wild type VHb. The effect that the mutant amino acids in VHbM3 was determined. Plasmid pUC- vgbM3 was obtained and successfully transformed to DH5α. After sequencing, two copies of vgbM3 were found in the plasmid. In order to study only one copy of vgbM3, x primers were designed for amplification. Fragment vgbM3 was successfully inserted into vector pUC18, followed by successful transformation into DH5α. Cell free extract was obtained from strains DH5α, DH5α[pUC8:16] and DH5α[pUC18-vgbM3] for CO-difference assay. As expected, DH5α expressed no hemoglobin. DH5α[pUC8:16] expressed wild type hemoglobin at 20 nmol/gm wet weight, while DH5α[pUC18-vgbM3] expressed mutant hemoglobin at 4 nmol/gm wet weight. Oxygen dissociation constant determination of VHbM3 will be the next step.
M.S. in Biology, May 2014
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Title: NETWORK CODING BASED COOPERATIVE PEER-TO-PEER REPAIR IN WIRELESS NETWORKS
Creator: Liu, Yu
Date: 2012-07-11, 2012-07
Description: Multimedia Broadcast/Multicast Service (MBMS) in cellular networks has emerged recently as a promising distribution model to provide rich...
Show moreMultimedia Broadcast/Multicast Service (MBMS) in cellular networks has emerged recently as a promising distribution model to provide rich content distribution where a batch of content is broadcast to a large number of peers simultaneously. However, ensuring efficient error-free message delivery in such a scenario is a challenge, since packet loss is inevitable due to the time-varying nature of wireless transmissions, and the server is probably overwhelmed by floods of individual retransmission requests from peers. Cooperative Peer-to-Peer (P2P) information repair has been proposed to mitigate the packet loss among peers during Base Station (BS) broadcast, by allowing peers to cooperate on information exchange among themselves, rather than asking the BS to rebroadcast the lost packets for the peers. Network Coding, a fairly recent transmission paradigm with the potential network throughput improvement and high reliability advantage, has been widely recognized as a promising information dissemination approach for wireless networks. In this research, we study the network coding based cooperative P2P information repair in wireless networks. We first propose our initial work - a connected dominating set (CDS) based P2P information repair (PPIR) protocol with network coding which utilize the clustering idea, to minimize the total repair latency as well as alleviate the congestion and burden of BS’s downlink channels. Then the decision making problem for P2P repair with densely distributed nodes is studied and two approaches are provided. Later on, the NC based P2P information repair protocol with tunable parameter (NC-PIRTP) which evolved from PPIR protocol is proposed to further reduce transmission collisions and total repair latency. At last, P2P information repair under mobile network environment with pedestrian speed is studied and three efficient protocols are illustrated which are suitable to different specific cases. Extensive simulation results are provided for performance evaluation and comparisons, and to demonstrate the effectiveness and efficiency of our proposed protocols in terms of the total repair latency. Furthermore, an analytical model is developed, based on which theoretical results are derived. These results validate our protocol models and provide useful protocol design guideline for the cooperative P2P information repair problem in wireless networks.
Ph.D. in Electrical Engineering, July 2012
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Title: SUSTAINABLE NEW CITY VAN, TURKEY
Creator: Dursun, Kevser Pinar
Date: 2013, 2013-07
Description: While the negative effects of rapid urbanization is threatening cities and the environment, being more conscientious about the current...
Show moreWhile the negative effects of rapid urbanization is threatening cities and the environment, being more conscientious about the current problems and future expansions of the cities and developing new visions and strategies for new cities is crucial. In this proposal, the aim is to develop a prototype of a sustainable new city in Turkey. Design area is called Carpanak, at the east shore of Lake Van. It is in the north of Van, the biggest city in the Eastern Anatolia district of Turkey. Eastern Anatolia is a mountainous district with a severe climate. The region is less developed than the other regions in every aspect. Severe climate and lack of job opportunities caused outmigration from this region to big cities or onshore regions with more developed industries. A city with sufficient infrastructure, efficient energy solutions, green areas, well-designed transportation, economic viability, and open social structure will help reverse the migration and rescue Eastern Anatolia from being abandoned. It is hoped that the design decisions, ideas, and the research can be applied as an outline to other underdeveloped areas in Turkey.
M.S. in Architecture, July 2013
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Title: URBAN RETROFIT OF THE HISTORICAL CITY OF AHMEDABAD, INDIA
Creator: Patel, Chanakya Dineshbhai
Date: 2012-11-26, 2012-12
Description: Most great cities of today originally started as small settlements on the banks of rivers. Ahmedabad, founded in year 1411 AD by emperor Ahmed...
Show moreMost great cities of today originally started as small settlements on the banks of rivers. Ahmedabad, founded in year 1411 AD by emperor Ahmed Shah indeed has a claim for thriving in all aspects of life for the past six centuries. Established as a small military settlement on the dry and sandy north Gujarat plains on the bank of river Sabarmati, Ahmedabad today is fifth largest city and seventh largest metropolitan of India. Geographically the Sabarmati River divides the city of Ahmedabad into two segments. Within each side of the city there are two distinct images, urban west and historic east. It could be stated that the historic district of city must now hold its position as the center both geographically and economically considering the overall metropolitan area of Ahmedabad. With rapid urbanization, the historic district is overlapped by today’s fast paced life and urbanity resulting a steady loss of its heritage and greater than that, a sense of place. This thesis proposes a conservation and reconstruction model for the historic district of Ahmedabad addressing the most fundamental issues of economic viability and sustainability. The main challenge driving this thesis is how to retrofit the historic district so that it matches the urbanity of 21st century along with keeping its historic character intact. The initial process is to assemble background observations and research that will provide an understanding of the concepts required for retrofitting the historic district of Ahmedabad. It is hopeful that the ideas and architectural process can also be a framework to be applied on other historic cores that have been neglected and suppressed by today’s urbanity and especially in Asian countries.
M.S. in Architecture, December 2012
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Title: VIDEO FEATURE DETECTION AND MATCHING FOR STRUCTURE FROM MOTION SYSTEM
Creator: Yang, Guojun
Date: 2015, 2015-05
Description: With the improvements in sensor technologies and image processing algorithms, computer vision has become a major tool for robots to recognize...
Show moreWith the improvements in sensor technologies and image processing algorithms, computer vision has become a major tool for robots to recognize and gauge their surroundings. For instance, the Kinect sensor can be used as an excellent depth camera for indoor navigation. However, there exist situations that need recognition and spatial interpretation of the environment using limited hardware resources. The Kinect is not suitable for outdoor use, while LIDAR is too large and expensive to be installed on an autonomous miniature surveillance drone. Therefore, the use of a single camera is the only feasible option for many embedded applications. To perform SfM (structure from motion) by using single camera is challenging due to the complexity of 3D mapping. Feature detection and mapping is the very fist step to perform SfM. To be more specific, matched feature points are used as anchors cross images or frames. Without such matched feature points, most SfM method will not be able to generate reliable results; moreover, instead of using frames from videos as inputs, most feature detectors and matching strategies are designed for SfM applications using images as inputs. Therefore, this thesis will discuss how to detect feature points from video and match them effectively. Image projection and SfM fundamentals will be introduced in this thesis as well.
M.S. in Electrical Engineering, May 2015
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Title: THE MOLECULAR MECHANISM OF BAXΔ2-MEDIATED CELL DEATH AND ITS TISSUE DISTRIBUTION IN COLON CANCER
Creator: Zhang, Honghong
Date: 2014, 2014-07
Description: Bax is a pro-death tumor suppressor in the Bcl-2 family, and is frequently mutated in microsatellite instable tumors, especially Hereditary...
Show moreBax is a pro-death tumor suppressor in the Bcl-2 family, and is frequently mutated in microsatellite instable tumors, especially Hereditary Non-Polyposis Colorectal Cancer (HNPCC). The loss of apoptotic Bax contributes to tumor development and chemoresistance. We recently uncovered that the combination of a Bax microsatellite mutation with a specific alternative splicing generated a unique Bax isoform (BaxΔ2) in Bax-negative cells. Similar to the prototype Baxα, BaxΔ2 is a potent pro-apoptotic molecule. However, the pro-apoptotic mechanism, therapeutic implication, and tumor tissue distribution of BaxΔ2 protein remain elusive. In this thesis research, we isolated and analyzed isogenic sub-cell lines that represent different Bax microsatellite statuses from colorectal cancer cells. We found that the colon cancer cells harboring Bax microsatellite G7/G7 alleles produced low levels of endogenous BaxΔ2 transcripts and proteins. BaxΔ2-positive cells were selectively sensitive to a subgroup of chemotherapeutics in comparison with BaxΔ2-negative cells. Different from other Bax isoforms, which mostly act through targeting mitochondria, BaxΔ2 recruited caspase-8 into the aggregates for activation, and consequently induced cell death independent of the mitochondrial pathway. Furthermore, the distribution of BaxΔ2 protein was mostly found in well-differentiated epithelial cells in primary colon tumor tissues or in primary squamous buccal cells, which contain Bax G7 mutation. However, not all cells harboring the Bax G7 mutation had a detectable level of BaxΔ2 proteins. These data suggest that, similar to Baxα, BaxΔ2 protein is pro-apoptotic, but not toxic to normal cells; expression of BaxΔ2 protein restores apoptotic program in Bax negative cells via a non-classical signaling pathway. Importantly, BaxΔ2 may provide a selective chemotherapeutic advantage for certain Bax-negative colon tumors.
Ph.D. in Biology, July 2014
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Title: ROLE OF EXTRACELLULAR MATRIX IN CELLULAR BEHAVIOR AND TISSUE FUNCTION
Creator: Sridharan, Indumathi
Date: 2012-04-22, 2012-05
Description: Matrix-dictated control of stem cell differentiation and tissue status are of considerable interest to cell biologists and tissue engineers....
Show moreMatrix-dictated control of stem cell differentiation and tissue status are of considerable interest to cell biologists and tissue engineers. To create suitable biological scaffolds for tissue engineering and cell therapeutics, it is essential to understand the matrix mediated specification of cell lineage. Our study examines the role of matrix properties on cellular behavior and tissue mechanics. To this end, we studied the effect of collagen type I on stem cell differentiation and its mechanical properties within a live tissue. We altered the properties of collagen type 1 by incorporating CNT. The collagen-carbon nanotube (collagen-CNT) composite material was stiffer with thicker fibers and longer D-period. We find that the enhanced mechanical and structural properties of collagen-CNT allow for rapid and efficient derivation of neural progenitors from human decidua parietalis placental stem cells (hdpPSC). Both structure and stiffness of the matrix are important determinants of neural differentiation rate. Strikingly, the collagen-CNT matrix, unlike collagen, imposes the neural fate by an alternate mechanism that is independent of beta-1 integrin and beta-catenin. The study demonstrates the sensitivity of stem cells to subtle changes in the matrix and the utilization of a novel biocomposite material for efficient and directed differentiation of stem cells. Investigation of connective tissue disorders has led to the understanding of the important role played by collagen. So far, native collagen fibers within an intact tissue have not been examined. In this study, we employed a unique approach- histochemical staining guided high-resolution elasticity mapping- to study collagen and smooth muscle in fresh vaginal wall connective tissue. The comparative study of tissues collected from healthy pre-menopausal (pre-M) and post-menopausal (post-M) women suggest that during menopause, collagen’s structure and elasticity are subtly altered. The systematic analysis enables detection of minute changes in collagen in non-fatal conditions such as pelvic organ prolapse and other genitor-urinary disorders, where the initial symptoms are subtle and multivariate and where early diagnosis will allow non-invasive interventions and reduce incidence of surgical correction for these common disorders.
Ph.D. in Molecular Biochemistry and Biophysics, May 2012
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Title: Sustainable New City - Johor, Malaysia
Creator: Meah, Nasser Meah Bin Mahmud
Date: 2011-12-06, 2011-12
Description: The purpose of this thesis is to develop an effective design approach necessary in building a new city. The challenge is to assemble a...
Show moreThe purpose of this thesis is to develop an effective design approach necessary in building a new city. The challenge is to assemble a background observations and research that will provide an understanding of the concepts required for developing new sustainable cities. It is hopeful that the ideas and design process can also be a framework to be applied on other undeveloped land that has the potential for new cities particularly in Malaysia. The main idea is to develop a thorough understanding of how the built environment plays an important role in shaping a community as well as identifying the technology involved. It specifically addresses the central issues involved with the art of place making, which determines the success of any particular urbanity. Environment then becomes the most important factor responsible for the physical, mental, and psychological development of an urban society.
M.S. in Architecture, December 2011
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Title: EFFICIENT AND FAIR RESOURCE ALLOCATION FOR OFDMA NETWORKS
Creator: Alavi, Seyed Mohamad
Date: 2012-11-26, 2012-12
Description: In Orthogonal Frequency Division Multiple Access (OFDMA) systems, resources, including subcarriers, bits and power, need to be adaptively...
Show moreIn Orthogonal Frequency Division Multiple Access (OFDMA) systems, resources, including subcarriers, bits and power, need to be adaptively allocated to users in order to improve spectral efficiency, increase capacity, and reduce power consumption, while satisfying the Quality of Service (QoS) requirements for users. Most of the previous works concentrate on satisfying rate and power requirements, however providing delay requirement is also necessary, especially with increasing demand on delay-sensitive applications. We first model the resource allocation problem as a cross-layer optimization problem considering the constraints on bit error rate (BER), data rate, total power, as well as delay. We first develop a nonlinear optimization model, which generally requires high computation complexity. To consider a more realistic scenario, we take into account imperfect Channel State Information (CSI) due to estimation errors or channel feedback delay, and incorporate the imperfect CSI into the optimization problem formulation. We then derive the solution through a dual decomposition method. Due to the duality gap between the original and dual optimizations, we convert the non-linear optimization to an equivalent linear formulation so that an exact solution can be obtained. To further reduce the complexity, we develop a heuristic algorithm to provide a solution close to the optimum. Then, we study the notion of fairness in the context of resource allocation. In particular, cooperative game theory can be applied to OFDMA networks for fair resource allocation. We apply two cooperative games, Non-Transferable Utility (NTU) game and Transferable Utility (TU) game, to provide fairness in OFDMA networks. In NTU game, fairness is achieved by defining appropriate objective function, while in TU game, fairness is provided by forming the appropriate network structure. For NTU game, we analyze the Nash Bargaining Solution (NBS) as a solution of NTU game taking into account CSI and Queue State Information (QSI). In a TU game, we show that coalition among subcarriers to jointly provide rate requirements leads to better performance in terms of power consumpviii tion. We show that although NTU and TU games are modeled as rate adaptive and margin adaptive problems, respectively, but both solutions provide a fair distribution of resources with minimum fairness index of 0.8. Although NBS can provide fairness, the fairness is not from user perspective. In competitive fairness, which is based on auction theory, each user is responsible for his/her own action. A distributed allocation of resources in OFDMA networks is studied through auction theory. A combinatorial auction is formulated in which the users’ utility enforce the truthful resource demands. Since the original problem is NP hard, a method based on simulated annealing applied to find near-optimum results. Then, we turn our attention toward a more complicated scenario of multicell OFDMA networks. A combinatorial auction, which takes into account the interference from adjacent cells is presented. Auction objective is to minimize the interference, while power of users is limited. Due to the complexity of original problem, we apply a heuristic approach, in which the bids are ordered based on the linear programming approximation of combinatorial auction, and then local improvements are made in the order of bids. Our iterative approach along with the proposed load control scheme provides fair distribution of resources to the users, regardless of their position in the cell. Finally, we propose a comprehensive auction in OFDMA network. We present an auction framework for allocation of subcarriers, in which winner pays monitoring and entry fees, in addition to the price which he is paying for the allocated subcarrier. We prove that in our framework users will avoid bidding for the subcarriers where they have a relatively low chance of winning. We obtain optimal bidding strategy based on Bayesian Nash Equilibrium (BNE) in which users are maximizing their net profit. In a Fractional Frequency Reuse (FFR) implementation of frequency planning, we will find a focal distance which classifies the users into cell-center and cell-edge users. It is shown that the focal distance increases as the interference decreases.
PH.D in Electrical Engineering, December 2012
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Title: ULTRASONIC RANGING AND INFRARED DEPTH PROFILING FOR 3D IMAGE RECOl'STRUCTION AND SCENE ANALYSIS
Creator: Jia, Weldi
Date: 2013, 2013-07
Description: This doctoral work cannot be done without the help, support and dedication of numerous people. First of all, I will give my great thanks to my...
Show moreThis doctoral work cannot be done without the help, support and dedication of numerous people. First of all, I will give my great thanks to my advisor Dr. Jafar Saniie, who is patient, fundamental and knowledgeable in providing advices, suggestions and guidance to all my six years' study. I would like to express my sincere thanks for his encouragement and nancial support during my study. I will never forget the days and nights he spent with me doing research work in the ECASP research lab. His spirit of carefully searching, friendly talking and knowledgeably thinking stays in my mind forever. My gratitude extends to my committee members, Dr. Anjali, Dr. Moderes and Dr. Oruklu. Also, I would like to give my thanks to my colleagues and friends, especially the people in ECASP research lab, Won-Jae, Sufeng, Thomas, Spenser and Pramod. Their kindness and powerful knowledge in di erent elds help me enhance my work so much. I will never forget the days debugging programs with them and the days we cheered for our success. I would like to dedicate this thesis to my family, especially to my grandfather who just passed away but gave me nancial support and advices from childhood till now, my father who is not able to speak after an accident during my study, my mother who is taking care of my father herself during the past six years, and my wife Wenhui Liu, who encouraged and helped me living in the United States. I promise that I will use what I learned from here to change the world and their constant support of my academic ventures from the beginning to the present would be valuable. Thank you Grandpa, rest in peace in heaven.
PH.D in Electrical Engineering, July 2013
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