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Title: THE EUML-ARC PROGRAMMING MODEL
Creator: Marth, Kevin
Date: 2014, 2014-07
Description: The EUML-ARC programming model shows that the increasing parallelism available on multi-core processors requires evolutionary (not...
Show moreThe EUML-ARC programming model shows that the increasing parallelism available on multi-core processors requires evolutionary (not revolutionary) changes in software design. The EUML-ARC programming model combines and extends software technology available even before the introduction of multi-core processors to provide software engineers with the ability to specify software systems that expose abstract platform-independent parallelism. The EUML-ARC programming model is a synthesis of Executable UML, the Actor model, role-based modeling, split objects, and aspect-based coordination. Computation in the EUML-ARC programming model is structured in terms of semantic entities composed of actor-based agents whose behaviors are expressed in hierarchical state machines. An entity is composed of a base intrinsic agent and multiple extrinsic role agents, all with dedicated conceptual threads of control. Entities interact through their role agents in the context of featureoriented collaborations orchestrated by coordinator agents. The conceptual threads of control associated with the agents in a software system expose both intra-entity and inter-entity parallelism that is mapped by the EUML-ARC model compiler to the hardware threads available on the target multi-core processor. The hardware and software e ciency achieved with representative benchmark systems show that the EUML-ARC programming model and its compiler can exploit multi-core parallelism while providing a productive model-driven approach to software development.
Ph.D. in Computer Science, July 2014
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Title: INSTANTANEOUS DETECTION OF SPATIAL GRADIENT ERRORS IN DIFFERENTIAL GNSS
Creator: Jing, Jing
Date: 2014, 2014-12
Description: Differential GNSS (Global Navigation Satellite System) is currently being ex- tended using a high integrity Ground Based Augmentation System ...
Show moreDifferential GNSS (Global Navigation Satellite System) is currently being ex- tended using a high integrity Ground Based Augmentation System (GBAS) to enable civil aircraft precision approach and landing. Differential GPS carrier phase measure- ments between ground-based GBAS reference antennas can provide the means to de- tect and isolate certain signal-in-space (SIS) failures and anomalies that are hazardous to aircraft, most notably ionospheric anomalies and ephemeris failures, which can be characterized as spatial range error gradients. In this research, we develop a monitor capable of instantaneously detecting multi-dimensional spatial gradient faults. The existence of large gradients, while rare, has prompted the development of numerous ground monitors for their detection. One drawback of previously proposed monitors is that their performance for a given ground antenna con guration is de- pendent on how antennas are paired to form measurement differences. In contrast, in this work a new monitor approach is developed to provide consistent detection performance, regardless of how the antennas are paired, by combining measurements from multiple, spatially separated ground antennas through a null space transforma- tion. It is shown that the `null space' monitor signi cantly improves the detection performance over existing fault detection algorithms and enables GBAS to support Category III precision approach and landing. The instantaneous carrier phase monitor cannot detect all gradients due to the presence of integer cycle ambiguities. These ambiguities cannot be resolved because the gradient magnitude is unknown a priori. Furthermore, it has been shown that the performance of such monitors is highly dependent on the reference antenna topol- ogy. The range of detectable gradients for all carrier phase monitors depends on two factors: the number of antennas and their con guration. One can always expand the detection range by using many antennas, but only at greatly increased operational cost. Optimizing antenna con guration has been overlooked as a means to improve performance; simple, heuristic arguments typically prevail in the associated siting decisions. For example, when given four antennas it is generally assumed that they should be sited in a square arrangement to balance performance in all directions. However, such heuristics do not provide the maximum detectable range of gradients, and exploiting the freedom to choose the antenna topology can dramatically expand the detectable range. Due to the presence of carrier phase cycle ambiguities, the re- sulting optimization problem is a constrained, mixed integer nonlinear programming problem. By solving the nonlinear program, the optimal GBAS antenna topology that maximizes the range of detectable gradients can be found for any number of antennas. For ionospheric fronts, the magnitude of the resulting gradient is bounded. However, orbit ephemeris faults can be arbitrarily large. The monitor must be able to detect all large gradients. To detect gradients beyond the capability of the car- rier phase monitor, code phase measurements are integrated into the monitor. Al- though we show this allows for the detection of all gradients, the number and spacing of ground antennas may not be suitable for all ground stations. Therefore, dual frequency carrier phase measurements are also considered to reduce the number of antennas required to achieve the desired detection performance. Finally, a search algorithm is developed to nd the antenna topology that enables the null space mon- itor to detect all hazardous gradients using code and dual frequency carrier phase measurements.
Ph.D. in Mechanical and Aerospace Engineering, December 2014
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Title: ISOGEOMETRIC ANALYSIS VIA TRIANGULATION
Creator: Jaxon, Noah
Date: 2013-05-15, 2013-05
Description: We present a method for isogeometric analysis on a triangulation of a domain bounded by NURBS curves. In this method, both the geometry and...
Show moreWe present a method for isogeometric analysis on a triangulation of a domain bounded by NURBS curves. In this method, both the geometry and the physical eld are represented by bivariate splines in Bernstein B ezier form over the triangulation. We describe a set of procedures to construct a parametric domain and its triangulation from a given physical domain, construct Cr-smooth basis functions over the domain, and establish a rational Triangular B ezier Spline (rTBS) -based geometric mapping that Cr smoothly maps the parametric domain onto the physical domain and exactly recovers NURBS boundaries. As a result, this approach can achieve automated meshing of objects with complex topologies and allows highly localized re nement. Isogeometric analysis of problems from linear elasticity and advectiondi usion analysis are demonstrated.
M.S. in in Mechanical Engineering, May 2013
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Title: RECEIVER AUTONOMOUS INTEGRITY MONITORING AGAINST ORBIT EPHEMERIS FAULTS IN CARRIER PHASE DIFFERENTIAL GPS
Creator: Stevanovic, Stefan
Date: 2013-04-18, 2013-05
Description: This work investigates the potential of the Global Positioning System (GPS) to enable a safe approach for rendezvous applications including...
Show moreThis work investigates the potential of the Global Positioning System (GPS) to enable a safe approach for rendezvous applications including shipboard landing of military aircraft. GPS has been shown to have the necessary accuracy for such an operation, and could potentially replace the existing radar or laser based systems. [Kha08][WPF08]1 However, to ensure safe operation, GPS must also be able to avoid hazardous situations. Shipboard aircraft approach navigation is an example rendezvous application requiring both high accuracy and high integrity. In this work, GPS measurement error models and orbit ephemeris fault (OEF) detection algorithms are developed for rendezvous applications, and performance is analyzed for the aircraft shipboard landing application. Both reference station and user based monitors can be used for orbit ephemeris fault detection. The available reference monitors either require a stationary reference receiver, or cannot protect against all types of orbit ephemeris faults. As an alternative, this work develops and investigates the use of receiver autonomous integrity monitoring (RAIM), which is user-based. Two contrasting algorithms, differential RAIM (DRAIM) and relative RAIM (RRAIM) are derived and analyzed for a realistic shipboard landing application. DRAIM is most effective when the aircraft first begins the approach. On the other hand, RRAIM performs best near the end of the approach. Assessing integrity risk is shown to be a major challenge for the RRAIM algorithm. Thus, a new unified RAIM (URAIM) concept is introduced. It seamlessly integrates DRAIM and RRAIM into a single detection algorithm, and also facilitates integrity risk evaluation. This is because the URAIM measurement equation can be used for both position estimation as well as fault detection. 1Corresponding to references in the Bibliography. xii Since high accuracy is desired, fixing integer cycle ambiguities is required. The Enforced Position-Domain Integrity-Risk Cycle Resolution Algorithm (EPIC) method of integrity risk bounding is used along with the URAIM fault detection algorithm in what we call the EPIC-URAIM algorithm. In general, the OEF will interfere with the cycle resolution process. In this work, the EPIC integrity risk bound formula is modified to account for the presence of an OEF. The EPIC-URAIM algorithm is simulated for 1507 sea-based locations around the globe. An average global availability of accuracy and integrity of 98.6% is achieved. This work illustrates the feasibility of detecting orbit ephemeris faults with integrity, while simultaneously meeting stringent accuracy requirements for real-time rendezvous navigation applications.
M.S. in Mechanical and Aerospace Engineering, May 2013
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Title: IMPACT OF WORK FLOW DISRUPTIONS, PROJECT CHARACTERISTICS AND FOREMEN CHARACTERISTICS ON IMPROVISATIONAL DECISIONS AND ACTIONS ON CONSTRUCTION SITES
Creator: Kleps, Stephen M.
Date: 2013, 2013-12
Description: Disruptions on construction sites are a constant issue and unfortunately can have negative impacts on the workflow and productivity of the...
Show moreDisruptions on construction sites are a constant issue and unfortunately can have negative impacts on the workflow and productivity of the impacted crews. As a result of these disruptions, foremen must quickly generate improvised solutions to the disruptions to keep the work of their crew progressing. Yet the mechanics of how exactly this improvisational decision making is occurring has not been previously studied. To address this void in the literature, this study examined the factors that may influence a foremen's ability to improvise, such as the type of disruption, the jobsite characteristics, and the personality, experience, and education of the foremen, in relation to the level of improvisation occurring. To accomplish this, this study collected data from 50 foremen within the electrical construction industry to measure to what degree they improvised and with what speed they improvised in response to their daily disruptions, resulting in 244 recorded disruption incidents. In analyzing these incidents with multilevel modeling analysis techniques, it was determined that the type of disruption did not have as large of an effect on the degree and speed of the resulting improvisation as originally hypothesized. In addition, it was found that factors such as the level of cooperation on the job site, the time pressure on the foremen, and the level of collaboration on the job site influenced the degree and speed of the improvisation. Yet the factors that explained the largest total variance in both the degree and speed of improvisation were the personality traits of the foremen. Thus, these findings emphasize the importance of foremen on job sites, while also documenting how improvisation is occurring on job sites.
PH.D in Civil Engineering, December 2013
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Title: BOUNDING ESTIMATION INTEGRITY RISK FOR LINEAR SYSTEMS WITH STRUCTURED STOCHASTIC MODELING UNCERTAINTY
Creator: Langel, Steven Edward
Date: 2014, 2014-05
Description: Safety critical estimation applications require quantification of integrity risk, which is the probability of the state estimate error...
Show moreSafety critical estimation applications require quantification of integrity risk, which is the probability of the state estimate error exceeding predefined bounds of acceptability. Integrity risk can only be evaluated when the state estimate error probability density function is precisely known, necessitating stochastic models that exactly describe measurement noise and disturbance inputs. Uncertainty in these models directly results in inaccurate assessments of integrity risk. This dissertation develops the first implementable methods to upper bound integrity risk when the autocorrelation functions of stochastic inputs reside between upper and lower bounding functions. The first part of this work considers real-valued estimation applications that use the Kalman filter or batch weighted least squares estimator. Explicit relations are developed between the estimate error variance and autocorrelation functions using a new generalized covariance matrix derived in this dissertation. From these expressions, two methods are provided to upper bound integrity risk. The first method enables fast computation of a conservative bound, and the second method produces the minimum upper bound via semi-definite optimization. Mixed real/integer estimation applications utilizing integer bootstrapping are the focus of the second part of this work. The integrity risk bound is formally defined as the global solution to a non-convex optimization problem over a polytope. Determination of the polytopic region is difficult, and two bounding approaches are initially developed for a circumscribing hyper-rectangular feasible region. Using an innovative method to define the polytope together with linear programming, a third method is derived to upper bound integrity risk over the true polytopic feasible region.
PH.D in Mechanical and Aerospace Engineering, May 2014
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Title: SIMULATIONS OF CENTERLINE DEFECT CLOSURE IN OPEN DIE FORGING
Creator: Gangatirkar, Suhasini
Date: 2014, 2014-12
Description: Open die forging is a technique widely used to achieve desired shape and sound mechanical properties. Due to large sizes, the ingots often...
Show moreOpen die forging is a technique widely used to achieve desired shape and sound mechanical properties. Due to large sizes, the ingots often have internal defects such as porosity, shrinkage cavities which damage the overall quality of the final product and affect the mechanical properties of the material. The voids developed during cooling of the ingot have to be treated in the initial forming operation known as cogging which depends on parameters such as die width ratio, die overlap, feed ratio, die shape etc. In this work, finite element method has been used to identify different aspects affecting centerline defect closure, material properties, effect of friction coefficient, relationship between effective strain and the grain size. FORGE 2011 and FORGE NxT 1.0 by Transvalor Corp were used to create numerical models. The material used in this case is H13. Material data and compression test samples were obtained from experiments in a Gleeble 3500. Physical experiments carried out on the Gleeble 3500 were used to determine the coefficient of friction for samples treated at different temperature, strain and strain rates. The effect of these parameters on coefficient of friction was studied in later part of the study. The formulae from the literature used to calculate the coefficient of friction was validated by using simulation models of the compression test samples. These samples were also used to study fraction recrystallized for a particular sample to study the relationship between effective strain and microstructure. Comparisons between validation experiments and simulations showed that there was good agreement between the two and established the effective strain criterion for void closure. From the conclusions obtained from validation experiments, optimal pass schedule was developed to ensure closure of internal voids and uniform distribution of effective strain along centerline for sound quality of the workpiece by changing die overlap percentage every two passes.
M.S. in Material Science Engineering, December 2014
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Title: SYNTHESIS, PURIFICATION AND CRYSTAL GROWTH OF INDIUM IODIDE SEMICONDUCTORS
Creator: Bertorello, Charles
Date: 2012-04-23, 2012-05
Description: The indium monoiodide (InI) semiconductor is a promising candidate for Gamma-ray and X-ray radiation detector devices. The high atomic number...
Show moreThe indium monoiodide (InI) semiconductor is a promising candidate for Gamma-ray and X-ray radiation detector devices. The high atomic number of indium (In) and iodine (I), along with high density, give the InI detector a higher photon stopping power (attenuation coe cient) compared to germanium based detectors and comparable to that of CdT e. Based on the previous research on melt synthesis and vapor synthesis by Dr. Ostrogorsky at Rensselaer Polytechnic Institute (RPI) and Dr. Burger at Fisk University from 2006 to 2009, the present work improves the purity of indium monoiodide by demonstrating the e ciency of zone re ning of this material. A segregation coe cient study is presented based on a Glow Discharge Mass Spectrometry (GDMS) and an Instrumental Gas Analysis (IGA) analyses performed by Evans Analytical Group (EAG). Two indium monoiodide crystals were grown using the Vertical Bridgman technique and analyses done on one of the crystals shown a resistivity of 3 109 .cm which is the second highest value reported. Indium monoiodide synthesized and puri ed in this current study was used to grow several Czochralski crystals.
M.S. in Mechanical, Materials, and Aerospace Engineering, May 2012
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Title: RE-POSITIONING THE CHICAGO BOULEVARD SYSTEM: TOWARDS THE DEFINITION OF AN ACTIVE URBAN INFRASTRUCTURE
Creator: Vadacca, Anna
Date: 2016, 2016-05
Description: How can urban infrastructures be reinterpreted based on their social potential? The thesis discusses the value that infrastructures can have...
Show moreHow can urban infrastructures be reinterpreted based on their social potential? The thesis discusses the value that infrastructures can have in relation to mobility and quality of life, in the context of the urban project, and proposes an example of how underutilized spaces, that pertains to an outdated model of the city, can be re-configured as adaptable and dynamic infrastructures. The Boulevard System of Chicago emerged during the process of “beautification” that the “City Beautiful” movement fostered in the 19th century. From being the “Emerald Necklace”, as it was known, the Boulevard System became today a fragmented infrastructure that mirrors the socio-economic segregation of Chicago neighborhoods. Within the archipelago of different urban realities of the city, the Boulevard System represents today an under-utilized urban space that reinforces the already existing urban thresholds between different urban communities. The goal of the research is to re-think the Boulevard System as a new transportation corridor, able to interact with other urban systems. The proposal for the boulevards is part of an Infrastructure Plan for Chicago that aims to propose ways inwhich different actions on infrastructure can revitalize the City. The idea is to re-activate the boulevard through a series of interventions, articulated around the re-connection of the fragmented system, as a new “ring” infrastructure, and the engagement with the surrounding specificities. The proposed Bus Rapid Transit system should offer an experience through the parks in Chicago and support its reactivation through the promotion of activities and events. Furthermore, the creation of a hub around the Garfield Green Line station is meant to propose a more engaging transit experience around the city of Chicago.
M.S. in Architecture, May 2016
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Title: LOW POWER METHODOLOGIES USING UNIFIED POWER FORMAT
Creator: Varsha
Date: 2012-11-14, 2012-12
Description: This thesis would be incomplete without the mention of people who made it possible and encouraged me at every step along the way. I would like...
Show moreThis thesis would be incomplete without the mention of people who made it possible and encouraged me at every step along the way. I would like to thank Spenser for helping me with the scripts, design of the architectures and always being ready to assist timely with so many issues. My immense gratitude goes to my advisor and mentor Dr. Erdal Oruklu, who pushed me at every step to achieve my best, drove me to explore new avenues, think new ideas and rethink old ones. I am truly thankful to him for his guidance, believing in me and giving me this opportunity to work under him. Thanks to my committee members Dr. Jafar Saniie and Dr. Tricha Anjali for their insights and suggestions. My heartfelt thanks goes to Hirva, Sneha, Pavan, Sagar, Mateen, Pooja and Neha for their continued support and encouragement throughout. Special thanks to Pavan and Sagar for assisting with the architectures and Mateen for helping with the documentation. Thanks to Krishna for being the go-to person for LATEX issues and always being there to help. Thanks to Santhosh and innumerous friends and acquaintances who helped unconditionally in so many ways. My family has been instrumental in the execution of my thesis. Thanks to my sister for inspiriting me, my brother-in-law for his endless encouragement and advice, their continued support along with my uncle, and my family for standing by me. Finally, this thesis is dedicated to my parents, for never giving up on me, believing in me and letting me pursue my dreams.
M.S. in Electrical Engineering, December 2012
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Title: REAL-TIME TRAFFIC SIGN RECOGNITION WITH RECONFIGURABLE HARDWARE
Creator: Waite, Sheldon
Date: 2012-07-12, 2012-07
Description: This work describes an implementation of a system that recognizes tra c signs within an image or video frame. In addition it covers a brief...
Show moreThis work describes an implementation of a system that recognizes tra c signs within an image or video frame. In addition it covers a brief history of automotive technology and the safety motivations for the technology presented here. An algo- rithm is presented that takes RGB image data, extracts relevant pixels, lters the image, labels prospective tra c signs and evaluates them against template tra c sign images. Furthermore a system is described that uses a Virtex 5 Xilinx FPGA and the EDK tool kit to create an embedded processor and a hardware IP periph- eral that together implement the algorithm. This implementation is shown to have positive results both in terms of timing performance and accuracy.
M.S. in Computer Engineering, July 2012
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Title: SCALABLE RESOURCE MANAGEMENT SYSTEM SOFTWARE FOR EXTREMESCALE DISTRIBUTED SYSTEMS
Creator: Wang, Ke
Date: 2015, 2015-07
Description: Distributed systems are growing exponentially in the computing capacity. On the high-performance computing (HPC) side, supercomputers are...
Show moreDistributed systems are growing exponentially in the computing capacity. On the high-performance computing (HPC) side, supercomputers are predicted to reach exascale with billion-way parallelism around the end of this decade. Scientific applications running on supercomputers are becoming more diverse, including traditional large-scale HPC jobs, small-scale HPC ensemble runs, and fine-grained many-task computing (MTC) workloads. Similar challenges are cropping up in cloud computing as data-centers host ever growing larger number of servers exceeding many top HPC systems in production today. The applications commonly found in the cloud are ushering in the era of big data, resulting in billions of tasks that involve processing increasingly large amount of data. However, the resource management system (RMS) software of distributed systems is still designed around the decades-old centralized paradigm, which is far from satisfying the ever-growing needs of performance and scalability towards extreme scales, due to the limited capacity of a centralized server. This huge gap between the processing capacity and the performance needs has driven us to develop next-generation RMSs that are magnitudes more scalable. In this dissertation, we first devise a general system software taxonomy to explore the design choices of system software, and propose that key-value stores could serve as a building block. We then design distributed RMS on top of key-value stores. We propose a fully distributed architecture and a data-aware work stealing technique for the MTC resource management, and develop the SimMatrix simulator to explore the distributed designs, which informs the real implementation of the MATRIX task execution framework. We also propose a partition-based architecture and resource sharing techniques for the HPC resource management, and implement them by building the Slurm++ real workload manager and the SimSlurm++ simulator. We study the distributed designs through real systems up to thousands of nodes, and through simulations up to millions of nodes. Results show that the distributed paradigm has significant advantages over centralized one. We envision that the contributions of this dissertation will be both evolutionary and revolutionary to the extreme-scale computing community, and will lead to a plethora of following research work and innovations towards tomorrow’s extremescale systems.
Ph.D. in Computer Science, July 2015
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Title: CORROSION-RESISTANT ELECTRO-CATALYSTS AND SUPPORTS FOR ELECTROCHEMICAL ENERGY CONVERSION
Creator: Wang, Guanxiong
Date: 2016, 2016-12
Description: Polymer electrolyte fuel cells (PEFCs) convert chemical energy of fuels (eg. Hydrogen) directly to electrical energy with excellent power...
Show morePolymer electrolyte fuel cells (PEFCs) convert chemical energy of fuels (eg. Hydrogen) directly to electrical energy with excellent power density, high efficiency, and zero emissions. Several challenges have delayed the commercialization of fuel cells with one being the high cost and durability of the carbon-supported-platinum-based (Pt/C) electrocatalysts. The lifetime/durability issue is critical as insufficient durability/reliability of the catalysts affects the lifetime and economical viability of these devices. Carbon support corrosion is a major durability issue since the corrosion reaction is thermodynamically favorable but kinetically sluggish under normal operating conditions. The potential transients that occur during start and stop in automotive applications can lead to electrode potential excursions of up to 1.5 V and contribute to carbon corrosion. The best way to mitigate support corrosion in PEFCs is to replace the carbon supports with alternatives having high electronic conductivity, surface area and porosity. This dissertation investigates the following carbon alternatives: (i) tin doped indium oxide (ITO) and (ii) 1:1 mixed oxides of ruthenia and silica (RSO). Microstructure characterization and electrochemical evaluations, including accelerated stress tests (start-up/shut-down and load cycling protocols) were performed to evaluate ORR activity, fuel cell performance, and electrochemical stability under PEFC operating conditions. The ITO support and 40%Pt/ITO catalysts demonstrated exceptional electrochemical stability (and reasonable ORR activity) in rotating disk electrode (RDE) experiments under accelerated potential cycling that mimicked automotive drive cycles. However, Pt/ITO exhibited poor performance and stability during MEA evaluation in a PEFC. X-ray photoelectron spectroscopy (XPS) was employed to reveal the degradation modes of Pt/ITO during PEFC operation and it was found that the increase in the surface hydroxide concentration generates a passivating In(OH)3 layer that increases electrode resistance and undermines PEFC performance. The influence of the catalyst support on PEM degradation during PEFC operation was also studied. Rotating ring-disk electrode (RRDE) experiments were employed to estimate the fraction of H2O2 generated during the ORR on the supports (C and RSO) and catalysts (benchmark Pt/C and Pt/RSO). The percentage of H2O2 generated on C and Pt/C was 50% higher than that on RSO and Pt/RSO thus explaining the observed oxidative degradation resistance of the PEM with the latter supports/catalysts.
Ph.D. in Chemical Engineering, December 2016
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Title: TOWARDS COMPREHENSIVE COUNTERMEASURES AGAINST CYBER ATTACKS TO IMPROVE SYSTEM SURVIVABILITY
Creator: Wang, Li
Date: 2012-11-20, 2012-12
Description: Survivability refers to the capability of a system to ful ll its mission, in a timely manner, in the presence of attacks, failures, or...
Show moreSurvivability refers to the capability of a system to ful ll its mission, in a timely manner, in the presence of attacks, failures, or accidents. For many distributed systems, ensuring their survivability under directed attacks is critical. Tra c analysis, conducted by the attacker, could reveal the protocol being carried out by the components. Furthermore, having inferred the protocol, the attacker can use the pattern of the messages as a guide to the most critical components. In this thesis, we rst thwart these directed attacks by using message forwarding to reduce tra c di erences, thus diverge attackers from directed attack to random attack, which probabilistically prolongs the availability of important components in the system. Then, we investigate how to improve system availability when the system is under random attack. Although the attackers cannot di erentiate the di erences between critical and non-critical components, they can intelligently decide how to invest their resources by rationally selecting the number of components to attack. Under this case, how to maintain system reliability is another challenging issue. This thesis further discusses the attacker-defender problem and analyzes how to maximize system reliability under rational attacks. When one or more system processing elements are compromised by attackers, how to select applications and deploy their tasks to the remaining processing elements so that the system availability is maximized is also investigated in this thesis. To be more speci c, we assume the applications may have di erent values towards system availability and may or may not share the same composing tasks, and we presented two di erent approaches, i.e., Genetic Algorithm (GA) based approach and Max-Min-Min based approach to solving this problem. GA-based approach produces near optimal solutions and it can be used o -line when the performance is important and timing complexity is not the primary concern. While the Max-Min-Min based approach is computationally e cient and it is used when the timing is critical.
PH.D in Computer Science, December 2012
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Title: DIRECT DIFFEOMORPHIC REPARAMETERIZATION FOR CORRESPONDENCE OPTIMIZATION IN STATISTICAL SHAPE MODELING
Creator: Li, Kang
Date: 2015, 2015-05
Description: This dissertation proposes an efficient optimization approach for obtaining shape correspondence across a group of objects for statistical...
Show moreThis dissertation proposes an efficient optimization approach for obtaining shape correspondence across a group of objects for statistical shape modeling. With each shape represented in a B-spline based parametric form, the correspondence across the shape population is cast as an issue of seeking a reparametrization for each shape so that a quality measure of the resulting shape correspondence across the group is optimized. The quality measure is the description length of covariance matrix of the shape population, with landmarks sampled on each shape. The movement of landmarks on each B-spline shape is controlled by the reparameterization of the B-spline shape. The reparameterization itself is also represented with B-splines and B-spline coefficients are used as optimization parameters. We have developed formulations for ensuring the bijectivity of the reparameterization. A gradient-based optimization approach is developed, including techniques such as constraint aggregation and adjoint senstivity for efficient, direct di↵eomorphic reparameterization of landmarks to improve the group-wise shape correspondence. Numerical experiments on both synthetic and real 2D and 3D data sets demonstrate the efficiency and e↵ectiveness of the proposed approach.This dissertation proposes an efficient optimization approach for obtaining shape correspondence across a group of objects for statistical shape modeling. With each shape represented in a B-spline based parametric form, the correspondence across the shape population is cast as an issue of seeking a reparametrization for each shape so that a quality measure of the resulting shape correspondence across the group is optimized. The quality measure is the description length of covariance matrix of the shape population, with landmarks sampled on each shape. The movement of landmarks on each B-spline shape is controlled by the reparameterization of the B-spline shape. The reparameterization itself is also represented with B-splines and B-spline coefficients are used as optimization parameters. We have developed formulations for ensuring the bijectivity of the reparameterization. A gradient-based optimization approach is developed, including techniques such as constraint aggregation and adjoint senstivity for efficient, direct di↵eomorphic reparameterization of landmarks to improve the group-wise shape correspondence. Numerical experiments on both synthetic and real 2D and 3D data sets demonstrate the efficiency and e↵ectiveness of the proposed approach.
Ph.D. in Mechanical and Aerospace Engineering, May 2015
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Title: BIOPHYSICAL AND BIOCHEMICAL STUDY OF NATIVE AND EDITED DYSTROPHIN ROD REGION
Creator: Mangat, Khushdeep
Date: 2014, 2014-12
Description: Duchenne Muscular Dystrophy (DMD) is a severe X-linked recessive disease affecting 1 in 3500 boys that is characterized by the degeneration of...
Show moreDuchenne Muscular Dystrophy (DMD) is a severe X-linked recessive disease affecting 1 in 3500 boys that is characterized by the degeneration of muscle function and strength. The cause of this disease lies in gene defects that eliminate expression of the protein dystrophin. Becker Muscular Dystrophy, BMD is a milder form of disease that has a later onset and much longer survival (up to the 7th decade of life, compared to median survival of 25 years for DMD patients) because of the presence of low levels of modified dystrophin protein. BMD is very heterogeneous, however, and many cases are nearly as severe as DMD. A major therapy for DMD involves exon skipping, which produces modified forms of dystrophin that are very similar to BMD. However, how these edits impact the function of dystrophin, and how they are linked to the severity of BMD or the BMD-like state produced in DMD exon skip therapy is unknown. We investigated this in two specific cases involving a specific panel of BMD defects linked to a major cause of death, dilated cardiomyopathy (DCM). We also investigated the contribution of various exons to interaction with a signaling partner of dystrophin, neuronal nitric oxide synthetase (nNOS).
Ph.D. in Biological and Chemical Sciences, December 2014
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Title: A PARAMETRIC STUDY OF THE THERMAL PERFORMANCE OF DIFFERENT WALL SYSTEMS AT VARIOUS CLIMATE ZONES
Creator: Lai, Se Yen
Date: 2013, 2013-12
Description: One of the most common energy conservative measures used is designing an air-tight and a well-insulated envelope. While there is an abundance...
Show moreOne of the most common energy conservative measures used is designing an air-tight and a well-insulated envelope. While there is an abundance of high-efficiency building envelope designs in the market which offer low thermal conductivity and high R-values as well as various studies on the thermal performance of various wall constructions, the results were often based on simplified study model and are not incompliance with the current building code. Most studies also focus on only one particular climate zone and one type of wall construction. This research aims to examine the thermal performance of different types of wall construction based on the traditional building envelope design materials in various climate zones based on insulation and air cavity placements on a non-simplified reference model that is used for construction. Study models developed are incompliance with the American Society of Heating, Refrigerating, and Air-Conditioning Engineers [ASHRAE] 90.1-2010 based on U.S. Department of Energy [DOE] Commercial Prototype Building Model. The thermal performance of the wall will be determined using two different methods. The first method will be using Building Energy Modeling [BEM] software where the exterior wall construction will be modified based on DOE reference models where the results for the overall annual energy consumption [AEC] will be compared. AEC results showed small differences between study models which are negligible. The second method is the Total Thermal Constant [TTC] method, where the thermal lag will be compared. The building structures that will be used are a steel-framed structure which represents a medium office and a wood-framed structure which represents a quick service restaurant. TTC results were able to determine the least favorable study model.
M.S. in Civil Engineering, December 2013
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Title: STRUCTURE AND FUNCTION OF NATIVE AND EDITED DYSTROPHIN RODS
Creator: Sahni, Neha
Date: 2011-05-10, 2011-05
Description: The purpose of this study is to examine the biophysical properties of the rod region of the dystrophin protein. This is important due to the...
Show moreThe purpose of this study is to examine the biophysical properties of the rod region of the dystrophin protein. This is important due to the severity of the disease Duchenne Muscular Dystrophy, (DMD), which is associated with the malfunction of this protein. DMD is one of the most serious single gene genetic defects of man. This rod region consists of a number of repeat motifs called spectrin type repeats or STRs. The thermodynamical and biochemical stability analysis shows, which single motifs are unstable on their own and which ones become more stable when linked to their appropriate tandem neighbors. This knowledge will impact strategies to produce modified mini dystrophins for gene therapy. Exon skipping therapy is an emerging approach to treat such genetic diseases. This is done by the administration of modified antisense oligonucleotides, AONs, which can interfere with exon splicing process and eliminate certain exons from the mature transcript. Furthermore, the rod region has a number of ancillary functions, such as providing secondary binding sites for actin, neuronal NO synthetase and phospholipids, which may be adversely perturbed by the edits.
Ph.D. in Biological, Chemical, and Physical Sciences, May 2011
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Title: APPLICABILITY OF THE INTERVAL ANALYSIS METHOD TO RELIABILITY ASSESSMENT OF STRUCTURES
Creator: Taha, Raguez A.
Date: 2012-11-26, 2012-12
Description: The scope of this study is focused on the applicability of the interval method to the reliability analysis of structures. The study includes...
Show moreThe scope of this study is focused on the applicability of the interval method to the reliability analysis of structures. The study includes using the traditional probability methods in several applications and comparing the results with the interval analysis. Accordingly, the interval arithmetic rules are applied in several examples and the results are compared with those from the traditional probability theory concepts. Specifically, the procedure for using the interval methods was applied to the development of the probability of failure for a simple structural member; and for a link in a network system. Through three simple examples, the research shows that the interval method offers comparable results with those from the traditional first-order reliability method. The procedure based on the interval method, however, may offer advantages, especially in cases where the uncertainties in various parameters describing the reliability of a system are large. In the presence of large uncertainties, the traditional methods of reliability analysis, based on the first order approximation, may lose their accuracy. In these cases, the interval method may offer a simple method yet with more accurate results.
M.S. in Civil Engineering, December 2012
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Title: DAMAGE DETECTION OF STRUCTURES USING INTERVAL FINITE ELEMENT METHOD
Creator: Venkitaraman, Shyamala
Date: 2012-04-16, 2012-05
Description: Health assessment and damage detection for existing structures is an essential procedure for their safe and reliable operation so that any...
Show moreHealth assessment and damage detection for existing structures is an essential procedure for their safe and reliable operation so that any catastrophic failure may be prevented in a timely manner. However, results obtained from a health assessment of a structure possess uncertainties in measurements, system properties and loads. Furthermore, the conventional deterministic structural analyses are incapable of considering these uncertainties, thereby resulting in error when estimating the state of health of a structure. Interval (unknown-but-bounded) representation is one method to quantify uncertainty in a physical system. Using an interval variable, the uncertain parameter is bounded between extreme values. In this work, a new method for damage assessment of structures is developed that utilizes the results from structural health assessment as uncertain input parameters in an interval finite element analysis scheme. This method, due to its capability of considering uncertainties, offers a more robust process for estimating the possible existence of damage and overall health of the structure. As an illustrative example, the method is applied for a failed sign support structure. First, the structure's response from previous health assessment procedure was used to construct uncertain interval responses. Then using these interval responses as input parameters, an interval finite element method was performed. The results of the analysis verify and correlate with the failure location of the actual structure. Moreover, the lifetime assessment of the structure obtained from this method is the lower bound of, and correlates with the actual failure time of the structure.
M.S. in Civil Engineering, May 2012
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