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Title: RELATIVE RECEIVER AUTONOMOUS INTEGRITY MONITORING FOR FUTURE GNSS-BASED AIRCRAFT NAVIGATION
Creator: Gratton, Livio Rafael
Date: 2011-05-15, 2011-05
Description: The Global Positioning System (GPS) has enabled reliable, safe, and practical aircraft positioning for en-route and non-precision phases of...
Show moreThe Global Positioning System (GPS) has enabled reliable, safe, and practical aircraft positioning for en-route and non-precision phases of flight for more than a decade. Intense research is currently devoted to extending the use of Global Navigation Satellite Systems (GNSS), including GPS, to precision approach and landing operations. In this context, this work is focused on the development, analysis, and verification of the concept of Relative Receiver Autonomous Integrity Monitoring (RRAIM) and its potential applications to precision approach navigation. RRAIM fault detection algorithms are developed, and associated mathematical bounds on position error are derived. These are investigated as possible solutions to some current key challenges in precision approach navigation, discussed below. Augmentation systems serving large areas (like the Wide Area Augmentation System (WAAS) covering the North American continent) allow certain precision approach operations within the covered region. More and better satellites, with dual frequency capabilities, are expected to be in orbit in the mid-term future, which will potentially allow WAAS-like capabilities worldwide with a sparse ground station network. Two of the main challenges in achieving this goal are (1) ensuring that navigation fault detection functions are fast enough to alert worldwide users of hazardously misleading information, and (2) minimizing situations in which navigation is unavailable because the user‟s local satellite geometry is insufficient for safe position estimation. Local augmentation systems (to be implemented at individual airports, like the Local Area Augmentation System or LAAS) have the potential to allow precision approach and landing operations by providing precise corrections to user-satellite range measurements. An exception to these capabilities arises during ionospheric storms (caused by solar activity), when hazardous situations can exist with residual range errors several orders of magnitudes higher than nominal. Until dual frequency civil GPS signals are available, the ability to provide integrity during ionospheric storms, without excessive loss of availability, will be a major challenge. For all users, with or without augmentation, some situations cause short duration losses of satellites in view. Two examples are aircraft banking during turns and ionospheric scintillation. The loss of range signals can translate into gaps in good satellite geometry, and the resulting challenge is to ensure navigation continuity by bridging these gaps, while simultaneously maintaining high integrity. It is shown that the RRAIM methods developed in this research can be applied to mitigate each of these obstacles to safe and reliable precision aircraft navigation.
Ph.D. in Aerospace Engineering, May 2011
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Title: CREDIT DERIVATIVES AND COUNTERPARTY CREDIT RISK UNDER VOLATILE MARKETS
Creator: Li, Dan
Date: 2012-11-20, 2012-12
Description: Both counterparty credit risk and credit derivatives have come under greater scrutiny under volatile markets especially after the 2007’s...
Show moreBoth counterparty credit risk and credit derivatives have come under greater scrutiny under volatile markets especially after the 2007’s credit crunch and the 2008’s global recession. This dissertation covers three essays topics that reflect different perspectives in credit derivatives and counterparty credit risk under volatile markets. In the first essay topic, we focuses on the modeling challenge after the 2007/2008 crisis in counterparty risks measurement by introducing a 4-factor model for simplicity with extensive comparison with a 2-factor model for both pre-crisis and post-crisis scenarios. Besides the correlation effects and basis risks concluded from the experimental results, those also implied the urgent needs for regulatory standardization (and transparency) for counterparty risk management (e.g. CVA, CSA, collateralization, etc.). Since CDS is one of the main hedging instruments for counterparty risks, therefore, we then tackle CDS in volatile market in our second essay topic. We will review some common practices in handling CDS since the standard bootstrapping failed using conventional JPM (2001). We will also examine the corresponding assumptions and limitations of the latest CDS standardization (ISDA (2009)). And we will compare this with the conventional CDS model. The third essay topic is a modeling survey on CDS with a special underlying – loan (LCDS) that unveils the potential usage and corresponding limitations of each prevailing modeling approach.
PH.D in Management Science, December 2012
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Title: FATIGUE AND BARKHAUSEN EFFECT
Creator: Tong, Wei
Date: 2013, 2013-05
Description: Piezomagnetism designates a change in the magnetization of materials induced by mechanical actions such as tension or compression. The type of...
Show morePiezomagnetism designates a change in the magnetization of materials induced by mechanical actions such as tension or compression. The type of Barkhausen effect that occurs in this work consists of sudden, discontinuous jumps in a material’s magnetization that appear in response to smooth (continuous) stress variations. A series of strain controlled fatigue tests with an alternating sinusoidal waveform were carried out to study the relationship between the endurance limit and the Barkhausen effect. Results of fatigue tests on steel specimens exhibiting Barkhausen pulses at various stages are reported and a threshold-crossing analysis is applied to the test results. These studies show that when the fatigue limit is approached, the Barkhausen pulses become, in general, more intense in amplitude and quantity than at other stress levels. A hypothetical mechanism is proposed that relates the intensity of the Barkhausen response to the inception of micro-cracking and rearrangements of the mechanical lattice at the microscopic level.
PH.D in Civil Engineering, May 2013
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Title: Combined Optimization Model for Sustainable Energization Strategy
Creator: Abtew, Mohammed
Date: 2011-04-01, 2011-05
Description: Access to energy is a foundation to establish a positive impact on multiple aspects of human development. Both developed and developing...
Show moreAccess to energy is a foundation to establish a positive impact on multiple aspects of human development. Both developed and developing countries have a common concern of achieving a sustainable energy supply to fuel economic growth and improve the quality of life with minimal environmental impacts. The Least Developing Countries (LDCs), however, have different economic, social, and energy systems. Prevalence of power outage, lack of access to electricity, structural dissimilarity between rural and urban regions, and traditional fuel dominance for cooking and the resultant health and environmental hazards are some of the distinguishing characteristics of these nations. Every year, 1.5 million people die due to exposure to indoor biomass stoves fumes. Rising demand for the decreasing supply of fuel wood is evident. Desertification is estimated to put 135 million people at a risk of being driven away from their land if no action is taken by 2020. Most energy planning models have been designed for developed countries' socio-economic demographics and have missed the opportunity to address special features of the poor countries. Therefore, it is critical to develop models that address the unique social-economic demographics of LCDs and are instrumental to appropriate energy policies choices. Such models must consider energization beyond electricity supply and help reduce over reliance of LCDs on limited energy sources that are fraught with high volatility and health hazard, thus providing a stable supply of energy that these countries badly need to meet their sustainable development goals. An improved mixed-integer programming energy-source optimization model is developed to address limitations associated with using current energy optimization models for LDCs, tackle development of the sustainable energization strategies, and ensure diversification and risk management provisions in the selected energy mix. The Model predicted a shift from traditional fuels reliant and weather vulnerable energy source mix to a least coast and reliable modern clean energy sources portfolio, a climb on the energy ladder, and scored multifaceted economic, social, and environmental benefits. At the same time, it represented a transition strategy that evolves to increasingly cleaner energy technologies with growth as opposed to an expensive solution that leapfrogs immediately to the cleanest possible, overreaching technologies.
Ph.D. in Management Science, May 2011
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Title: PROFESSIONAL AND TECHNICAL COMMUNICATIONS CONTRIBUTIONS TO STUDENT AFFAIRS WRITING COMPETENCIES
Creator: Schaefer, Kelly
Date: 2016, 2016-05
Description: Student affairs practitioners in mid-level positions write in the workplace daily, but in many cases they do not formally or intentionally...
Show moreStudent affairs practitioners in mid-level positions write in the workplace daily, but in many cases they do not formally or intentionally train themselves or their staff members to write. I used qualitative methods of semi-structured interviews, observations, and document analysis to investigate how and to what extent mid-level managers are competent writers. And in terms of their organizations, I investigated the value placed on writing and how and to what extent writing training happens. The investigation of writing practices of professionals working in campus centers in the field of student affairs shows that mid-level campus center professionals write extensively in their positions, including writing across many document types (letters, memos, reports, financial documents), and for multiple audiences in and outside of the university setting (students, staff, peers, supervisors, community members, alumni). Mid-level managers value writing ability and the ability of their staff members to be able to write, and could improve writing knowledge and ability through competency training and development by connecting with work in the field of professional communication. Professional associations can and should support professionals using competency language that supports writing and writing training to develop writing skill and ability competencies. Mid-level managers, as both writers and supervisors, could join associations in employing intentional strategies for writing and writing training suggested by professional communication research.
Ph.D. in Technical Communication, May 2016
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Title: SEISMIC STUDY OF HYBRID SHEAR WALL SYSTEM
Creator: Xu, Lifeng
Date: 2013, 2013-07
Description: This thesis represents the seismic behavior of new hybrid shear wall system, which consists of two exterior precast wall layers and one...
Show moreThis thesis represents the seismic behavior of new hybrid shear wall system, which consists of two exterior precast wall layers and one interior cast-in-place concrete layer. The “sandwich” shaped shear walls were already tested as a full scale specimen subjecting to vertical pressure and cyclic horizontal load in Anhui University of Architecture, China (2010). A series of 3D non-linear finite element models which include all significant details and specifications were then created in ABAQUS to simulate the experiments. The pushover analyses method was employed to reproduce the test procedures. The response of the structure was computed both at macro and micro level at the result in order to validate the correctness of the analytical model. After verifying the good agreement between the experimental observations and simulation results, an extended parametric study was conducted towards this hybrid shear wall system to explore its damage mechanism and design optimization. Based on hybrid shear wall's specific seismic resisting capacity which derived from the previous simulation, a series of 2D models were created in SAP2000 to evaluate the seismic performance of hybrid shear wall structure. What's more, in order to precisely represent the 3D model effect into 2D model in SAP2000,3D model was created in ABAQUS to account for the influence of semi-rigid connection between the concrete diaphragm and hybrid shear wall. After applying the ability of semi-rigid connection and hybrid shear wall, pushover method and time history analysis were conducted towards this 18 story structure model. The global seismic performance factor is finally evaluated according to the FEMA-P695.
PH.D in Civil Engineering, July 2013
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Title: MODELING GLUCOSE-INSULIN DYNAMICS AND AUTOMATED BLOOD GLUCOSE REGULATION IN PATIENTS WITH TYPE 1 DIABETES
Creator: Oruklu, Meriyan
Date: 2012-11-06, 2012-12
Description: Estimation of future glucose concentrations is a crucial task for diabetes management. Predicted glucose values can be used for early...
Show moreEstimation of future glucose concentrations is a crucial task for diabetes management. Predicted glucose values can be used for early hypoglycemic/hyperglycemic alarms or for adjustment of insulin amount/rate. In the first part of this thesis, reliable subject-specific glucose concentration prediction models are developed using a patient’s continuous glucose monitoring (CGM) data. CGM technologies provide glucose readings at a high frequency and consequently detailed insight into a patient’s glucose variation. Time-series analyses are utilized to develop low-order linear models from a patient’s own CGM data. Glucose prediction models are integrated with recursive identification and change detection methods, which enable dynamical adaptation of the model to inter-/intra-subject variability and glycemic disturbances. Two separate patient data sets collected under hospitalized (disturbance-free) and normal daily life conditions are used to validate the univariate glucose prediction algorithm developed. Prediction performance is evaluated in terms of prediction error metrics and Clarke error grid analysis (CG-EGA). The long-term complications of diabetes can be reduced by controlling the blood glucose concentrations within normoglycemic limits. In the second part of this thesis, the subject-specific modeling algorithm developed in part one is integrated with a control algorithm for closing the glucose regulation loop for patients with type 1 diabetes. An adaptive control algorithm is developed to keep a patient’s glucose concentrations within normoglycemic range and dynamically respond to glycemic challenges with automated subcutaneous insulin infusion. A model-based control strategy is used to calculate the required insulin infusion rate, while the model parameters are recursively identified at each sampling step. The closed-loop algorithm is designed for the subcutaneous route for both glucose sensing and insulin delivery. xii It accounts for the slow insulin absorption from the adipose tissue and the time-delay between blood and subcutaneous glucose concentrations. The performance of the control algorithm developed is demonstrated on two simulated patient populations to provide effective blood glucose regulation in response to multiple meal challenges with a simultaneous challenge on a patient’s insulin sensitivity. Physical activity and emotional stimuli such as stress are known to have a significant effect on a patient’s whole-body fuel metabolism. In the third part of this thesis, the univariate time-series models developed from recent glucose concentration history are extended to include additional information on a patient’s physical and emotional condition. Physiological measurements from a multi-sensor body monitor are used to supplement a patient’s CGM data and develop multivariate glucose prediction models. The prediction performance of the multivariate algorithm developed is evaluated on data collected from patients with type 2 diabetes, and a real life implementation of the algorithm is demonstrated for early (i.e., 30 min in advance) hypoglycemia detection. Finally, the control algorithm developed in part two is extended to utilize the glucose profiles predicted by the multivariate patient model. The multivariate closedloop algorithm is tested with two clinical experiments performed on a patient with type 1 diabetes during a high intensity exercise followed by a carbohydrate-rich meal challenge. The algorithm acquires the patient’s CGM and armband (body monitor) data every 10 min, and accordingly calculates the required basal insulin infusion rate. Insulin is administered in a fully automated manner without any food or activity announcements (e.g., no information on meal/exercise size or time). None of the algorithms developed in this thesis require any patient specific tailoring or prior experimental data before implementation. They are also designed to function in a fully automated manner and do not require any disturbance announcexiii ments or manual inputs. Therefore, they are good candidates for installation on a portable ambulatory device used in a patient’s home environment for his/her diabetes management.
PH.D in Chemical and Biological Engineering, December 2012
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Title: SIMULTANEOUS INJECTION OF STABLE AND RADIOACTIVE IONS INTO UPGRADED MULTI-USER ATLAS
Creator: Perry, Amichay
Date: 2015, 2015-12
Description: Argonne Tandem Linac Accelerator System (ATLAS) is a Department of Energy (DOE) national user research facility, located at Argonne National...
Show moreArgonne Tandem Linac Accelerator System (ATLAS) is a Department of Energy (DOE) national user research facility, located at Argonne National Laboratory (ANL). Presently, Radioactive Ion Beams (RIBs) produced in the CAlifornium Rare Isotope Breeder Upgrade (CARIBU) facility are charge bred in an Electron Cyclotron Resonance (ECR) charge breeder prior to post acceleration in ATLAS. A new state of the art Electron Beam Ion Source charge breeder, the CARIBU-EBIS charge breeder, has been developed (not in the scope of the work presented here) at ANL to replace the existing ECR for charge breeding RIBs generated in CARIBU. The CARIBU-EBIS charge breeder is now in the final stages of offline commissioning at the Accelerator Development Test Facility (ADTF). A significant part of the commissioning effort has been devoted to testing the source by breeding singlycharged cesium ions injected from a surface ionization source. Characterization of the CARIBU-EBIS performance has been accomplished through a comparison between the measured properties of extracted beams and simulation results. Following its offline commissioning, CARIBU-EBIS will be relocated to its permanent location in ATLAS. An electrostatic transport line has been designed to transport RIBs from CARIBU and inject them into CARIBU-EBIS. In addition, modifications to the existing ATLAS Low Energy Beam Transport (LEBT) were also required in order to transport the charge bred RIBs from CARIBU-EBIS to ATLAS. A proposal for upgrading ATLAS to a multi-user facility has been explored as well. In this context, beam dynamics simulations show that further modifications to the ATLAS LEBT will enable the simultaneous injection and acceleration of RIBs and stablebeams in ATLAS. Furthermore, a novel technique proposed by Ostroumov et al. will allow for the acceleration of multiple charge states from CARIBU-EBIS, thereby increasing the intensity of available RIBs by up to 60%.
Ph.D. in Physics, December 2015
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Title: SECURITY POLICY MANAGEMENT, THREAT ALLEVIATION AND TRUSTED PLATFORMS FOR EMBEDDED COMPUTING SYSTEMS
Creator: Anand, Vijay
Date: 2011-08, 2011-07
Description: Security guarantees are a measure of trust that can be placed on computing services in the safeguarding of digital assets. These security...
Show moreSecurity guarantees are a measure of trust that can be placed on computing services in the safeguarding of digital assets. These security goals and guarantees coupled with known and modeled threats to the digital assets shape the security policies for computing services. The creation, management and implementation of security policies in computing services is a challenge in defining the role of policy, the management principle for decision making when posed with threats and overall control over digital assets in a well-defined manner. In this Ph.D. thesis we establish a causal relationship of security policies with threats, provide an industry standard management framework (Six Sigma) for decision making, changes to the constructs of the trusted platform module to create a control framework and, finally show how the security framework can be used in a commercial service. The process of updating and refactoring security policy changes becomes a time consuming and tedious task, especially when threats evolve and computing service constructs change when security policy implementations are implicitly implemented. With the basis of correlation of policies over threats an explicit security policy implementation is proposed such that its adaptability, testability and risk quantification can be achieved when threats evolve. In this study we explore policy threat correlation on a Trusted Platform Module (TPM), a hardware system entrusted with security operations and guarantees. An effective TPM needs to adapt to evolving threats arising from firmware bugs or decay in the complexity of ciphering algorithms. Therefore, an adaptive TPM architecture is proposed to counter evolving threats by integrating an FPGA (Field Programmable Gate xi Arrays) block to alter and patch firmware and change ciphering systems. We present how security guarantees in an IT(Information Technology) infrastructure can be met using a TPM and thereby should be an integral part of computing services along with other security constructs like firewalls, intrusion detection systems, anti-virus, etc.. Adaptive security policy requires a management process wherein the risk management, and cost effectiveness principles can be identified. This is essential to make decisions on the trust criteria of digital assets in an industrial management framework. The security policy creation and management process presented in this thesis is based on Six Sigma model and presents a method to adapt security goals and risk management in an industrial framework. As an effective implementation of the security policy the case of application commerce workflow for developers is presented. Secure application distribution and execution guarantees lie in the transfer of trust between various processes in a computing service, also known as Chain of Trust in an embedded system. This study presents application development workflows facilitating secure commerce of digital assets thereby improving consumer trust.
Ph.D. in Computer Engineering, July 2011
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Title: MANAGING THE BIDDING PROCESS FOR THE CONSTRUCTION OWNER – DETECTION AND PREVENTION OF UNBALANCED BIDS AND COLLUSIVE BIDS
Creator: Chotibhongs, Ranon
Date: 2011-09, 2011-12
Description: There are two major problems that affect bidding efficiency: unbalanced bidding and collusive bidding. Unbalanced bidding is a serious...
Show moreThere are two major problems that affect bidding efficiency: unbalanced bidding and collusive bidding. Unbalanced bidding is a serious unethical problem in the construction industry. The owner may end up paying more money if the bid is unbalanced by the contractor. A bid can be rejected by the owner if it is unbalanced. A bidder unbalances a bid by inflating the unit price of some line items and reducing the unit price of other line items. Frontloading is the most common practice where a bidder can mathematically unbalance a bid by overstating the unit price of line items scheduled to be performed early in the project and understating the unit price of line items performed later. A bidder can also overstate the unit price of a line item whose quantity was somehow underrated by the engineer. If the owner proves that a mathematically unbalanced bid costs more to perform, the bid is said to be materially unbalanced, in which case the owner can reject the bid. A model is presented that formalizes and automates the process of detecting mathematically and materially unbalanced bids by comparing line item prices with the engineer’s estimates or the average prices offered by the bidders. This model allows owners to detect and reject unbalanced bids, and deters bidders from unbalancing their bid. Another matter that inflates bids and reduces bidding efficiency is collusion. Collusion is an insidious issue in the construction industry. Even though, it is widely acknowledged as unethical and illegal, there are not many research studies conducted to detect collusive bidding. This study proposes a two-step method to detect collusive bidding by analyzing historical bidding data provided by a construction owner. The construction owner in this study was a public agency that commissioned 108 construction projects that was worth $1.3 billion during a 10-year study period (2001-2010). The first step involves indentifying the potential cartel bidders using the residual test and the cost structure stability test developed in earlier work. The second involves comparing the behavior of the potential cartel bidders and non-cartel bidders by analyzing bid distributions, their cost dispersion, and the differences in their cost structures. After conducting the tests, it was found that the suspected cartel bidders identified in Step 1 behaved in ways to confirm collusion. Also, in an unrelated search, it was found that two of the six potential cartel bidders who were identified in this study had been audited by the public agency for bid fraud, and that another potential cartel bidder had been found guilty by the courts and forbidden from doing business with the public agency.
Ph.D. in Civil Engineering, December 2011
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Title: HOSPITAL FACILITY DESIGN: A GUIDE TO SPACE PLANNING FOR A NEW GENERAL HOSPITAL IN VIETNAM
Creator: Pham, Tuan Anh
Date: 2015, 2015-07
Description: Vietnam is a relatively small and populous developing country. Over the past several decades, the change in the country’s market economy and...
Show moreVietnam is a relatively small and populous developing country. Over the past several decades, the change in the country’s market economy and the population growth have greatly affected the lives, activities, and the demands for heath care as well as impacted the healthcare system. Since 1994, the time when the United States abolished the trade embargo against Vietnam, the economic development and the growth of the healthcare system in the country have been extraordinary. Even though substantial investment has been obtained from the Vietnamese government, limitations remain in the physical facilities in the healthcare system as well as in the facility design. Designing a new general hospital is a complicated process and requires a lot of attention and knowledge from a design team. Generally, the design process consists of two phases: a planning phase and a design phase. The planning phase is extremely important and will decide the success of the general hospital. G D Kunders, an Indian professional hospital administrator and a healthcare facility planner, has stated “Failing to plan is planning to fail” (Kunders 2004, 61). The main objective of this dissertation, “HOSPITAL FACILITY DESIGN: A GUIDE TO SPACE PLANNING FOR A NEW GENERAL HOSPITAL IN VIETNAM,” is to produce a guide that will be a reference source for the Vietnamese government to improve the current standard for hospital design. As a reference source, the proposed guide can be used as a tool to assist Vietnamese architects and other professionals in healthcare design areas in improving the quality of the hospital planning and design in Vietnam. This dissertation also aims to be a teaching reference source for architecture educators to use in their instruction at universities in Vietnam and a learning resource to help architecture students understand requirements for spaces in a general hospital as well as how a general hospital functions so they can better plan and design it. The proposed guide is set in an arrangement that can help educators and students without strong backgrounds in hospital design to easily understand how to plan a new general hospital. The research methods used in this dissertation are (i) document reviews, (ii) qualitative research based on Post-occupancy Evaluation (POE), and (iii) comparative analyses. The findings are used to create a guide to space planning for a new general hospital to use to improve the current Vietnamese standards, TCVN 4470: 2012, General Hospital - Design Standard, in hospital planning and design for Vietnam. This dissertation consists of eight chapters, which include Chapter 1 - Introduction, Chapter 2 - Literature Review, Chapter 3 - Problem Statement, Chapter 4 - Methodology, Chapter 5 - Data Analysis, Chapter 6 - Findings, Chapter 7 - A Guide to Space Planning for a New General Hospital in Vietnam, and Chapter 8 - Conclusion.
Ph.D. in Architecture, July 2015
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Title: SHORT AND ULTRASHORT-PULSED LASER-MATERIAL INTERACTIONS: MODELING AND COMPARISONS WITH EXPERIMENTS
Creator: Tao, Sha
Date: 2013, 2013-07
Description: Lasers have wide applications in numerous areas. Laser-based applications and technologies often involve certain types of laser-material...
Show moreLasers have wide applications in numerous areas. Laser-based applications and technologies often involve certain types of laser-material interactions, many of which have not been sufficiently understood. In this thesis, through the development of the corresponding physics-based models and the comparisons of modeling results with relevant experiments (when available), the laser-material interaction mechanisms during the following processes will be studied: i) laser ablation of semiconductors; ii) laser-material interactions inside microholes; and iii) laser-induced plasma evolution (more detailed conditions of the studied processes are given in the thesis). This research work is expected to improve the understanding of laser-material interaction mechanisms in the above investigated processes, which may provide information that is useful for the improvement of many related existing laser-based applications or technologies and for the development of novel ones.
PH.D in Mechanical and Aerospace Engineering, July 2013
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Title: EVALUATION OF THE EFFECTS OF VEGETATION AND GREEN WALLS ON BUILDING THERMAL PERFORMANCE AND ENERGY CONSUMPTION
Creator: Susorova, Irina
Date: 2013, 2013-05
Description: Urban development poses multiple problems, including environmental pollution, a reduction in biodiversity, and the disappearance of the...
Show moreUrban development poses multiple problems, including environmental pollution, a reduction in biodiversity, and the disappearance of the natural environment. Man-made environments and structures consume a large amount of limited natural resources through their extensive use of energy and materials. This research explored the use of vegetation in building facades as a potential solution to the problems of urban ecology and the excessive energy consumption in buildings. Vegetated facades have the ability to reduce building energy use, reduce the urban heat island effect, improve air quality, and increase the biodiversity of plants and animals in cities. The goal of this research was to evaluate the effects of plants on thermal performance and energy consumption of buildings by developing a thermal model of a building facade covered with a layer of plants. The developed mathematical model accounts for thermal physical processes in a vegetated exterior wall, including solar radiation, infrared radiative exchange between the facade and sky, the facade and ground, the facade and vegetation layer, convection to and from the facade, evapotranspiration from the plant layer, heat storage in the facade material, and heat conduction through the facade. The model calculates vegetated facade surface temperature and heat flux through the facade for multiple weather conditions, plant physiological characteristics, and facade properties. The model was validated with the results of a week-long experiment measuring the thermal properties of bare and vegetated facades on a building at the Illinois Institute of Technology campus. The experiment and subsequent sensitivity analysis demonstrated that a plant layer can effectively reduce the facade exterior surface temperature, daily temperature x viii fluctuations, exterior wall temperature gradient, and, as a result, provide as much additional thermal insulation to the facade as a 2.5 cm layer of expanded polystyrene insulation, depending on a range of plant parameters. The vegetated facade model was also used to analyze the reduction in energy consumption in generic office and residential thermal zones for multiple parameters. The simulations showed that energy reduction could be as high as 6.2% of annual total energy use and 34.6% of cooling energy use in residential thermal zones, depending on building characteristics, plant parameters, and climate zone. Overall, the vegetated wall model developed and validated herein provides a new tool for evaluating the impact of plant layers on facade thermal performance in existing buildings retrofitted with green walls and for designing green walls for optimal energy efficiency in new construction.
PH.D in Architecture, May 2013
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$THE CHARACTERIZATION FOR B2 STRUCTURE AND L2\ STRUCTURE IN THE AG-MG AND AG-MG-IN SYSTEM$

Title: THE CHARACTERIZATION FOR B2 STRUCTURE AND L2\ STRUCTURE IN THE AG-MG AND AG-MG-IN SYSTEM
Creator: Kim, Do Hyung
Date: 2013, 2013-05
Description: The concentration of point defects and the long range order for ordered B2 AgMg alloys, quenched from 973K, was investigated by statistical...
Show moreThe concentration of point defects and the long range order for ordered B2 AgMg alloys, quenched from 973K, was investigated by statistical thermodynamic modeling, powder X-Ray Diffractometery and diffraction simulation as a function of composition. The lattice parameter behavior on the Ag rich side are expectably having constitutional and thermal anti-site defects on both Ag and Mg sub-lattices, corresponding to the literature data. On the other hand, the Mg rich side has substantially thermal vacancy defects based on the lattice parameter data which shows lower, compared with previously reported data. Concentration of the equilibrium point defects at 973K was calculated from two thermodynamic models, where the Ag rich side was based on the constitutional and thermal anti-site defect formation and the Mg rich side was based on the hybrid defect formation consisting of vacancy, Mg and Ag anti-site defects The experimental long range order at 973K, determined from the integrated intensity ratio of (100) super-lattice reflection to (200) fundamental reflection, is in quite good agreement with the theoretical long range order at 973K based on the calculated integral intensities from the diffraction simulation with the equilibrium concentration of each point defect, obtained by two thermodynamic models. Furthermore, point defect hardening coefficients on both sides of stoichiometry were determined by the measurement of the Vickers hardness as a function of the equilibrium concentration of the main point defects deduced from two thermodynamic models. The hardening coefficient is G/16 for the Ag rich side with respect to Ag anti-site defects and G/3.1 for the Mg rich side with respect to vacancy defects. Also, two hardening coefficients are corresponding to the empirical correlation for the several binary B2 intermetallic compounds with anti-site defects (G/9 to G/85) xvi and vacancy defects (G/3 to G/4). This suggests that the elastic size effect on the Ag rich side is the primary hardening mechanism due to constitutional and thermal Ag anti-site defects while the Mg rich side is likely to have the elastic modulus effect due to constitutional and thermal vacancy defects. It is also indicated that the vacancy defect is more significant hardener than Ag anti-site defects for the ordered B2 AgMg intermetallic system. The partial liquidus projection in the Ag-Mg-In ternary system was established by the primary phase and liquidus temperature, using the Scanning Electron Microscopy, Energy Dispersive Spectroscopy and Differential Scanning Calorimetry. The results showed that the AgMg1-xInx phase of the Ag-Mg-In ternary system has a large primary solidification field up to 90 at.% of In, so that most ternary invariant reactions of the In rich field must be formed beyond 90 at.% of In. The liquid-solid schematic reactions in the Ag rich field were experimentally confirmed, but those of the In rich side have not been established. Furthermore, the ordering phase transition and melting temperature of the Heusler phase AgMg1-xInx alloys were investigated using Differential Scanning Calorimetry, Scanning Electron Microscopy, and powder X-Ray Diffractometery. The DSC results indicated that the melting temperature decreased with increasing the In composition, but a thermal peak for the ordering phase transition was not detected due to either a very small heat of transition or a second order transformation. The XRD results showed that the L21 structure of the Heusler phase was observed for the 15 at.% of In alloy and the degree of order of L21 structure continuously increased with the In composition, resulting from the (111) super-lattice intensity with respect to the In composition. The L21 structure ordering of the 15 at.% of In and 20 at.% of In system xvii was gradually decreased with increasing the annealing temperature, corresponding to decreasing the (111) super-lattice intensity and the long rang order parameters of the L21 structure. These XRD behaviors suggest that the L21/B2 ordering transformation phenomena is a second order transformation with respect to temperature.
PH.D in Material Science and Engineering, May 2013
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Title: POWER OPTIMIZATION FROM REGISTER TRANSFER LEVEL TO TRANSISTOR LEVEL IN DEEPLY SCALED CMOS TECHNOLOGY
Creator: Li, Li
Date: 2012-04-25, 2012-05
Description: With the progress of CMOS technology, there is a steady growth in clock frequency and chip capacity. As a result, the power dissipation of...
Show moreWith the progress of CMOS technology, there is a steady growth in clock frequency and chip capacity. As a result, the power dissipation of deeply scaled digital CMOS design has increased tremendously. On the other hand, low power VLSI designs are crucial in many areas, such as mobile phones. Furthermore, according the 2011 International Technology Roadmap for Semiconductors (ITRS), the trend towards high power consumption is far beyond the power requirement. As a result, power optimization techniques are highly appreciated in nowadays VLSI design. There are various low power methodologies from system level to layout level. In our research, we are focusing on low power techniques from register transfer level (RTL) to transistor level. Clock gating (CG) is the most widely used technique to reduce dynamic power at RTL. One of the traditional CG styles is XOR-based CG. It compares the inputs and outputs of flip-flops (FFs), and gated the FFs when they are the same. However, this CG is not effective since it does not take the signal activities into account. In this thesis, an activity-driven optimized bus specific clock gating (OBSC) is proposed. It uses finegrained RTL power models to estimate the dynamic power, and chooses only a subset of FFs to be gated selectively based on their switching activities. During the clock gated period, the gated FFs’ outputs are stable. As a result, the combinational logics which are completely dependent on these stable outputs can be power gated so as to save leakage power. Thus, CG and power gating (PG) can be integrated to reduce dynamic and leakage power simultaneously. The sleep signal of our PG is the CG enable signal which is generated during the CG implementation. It does not require an individual power management block to generate as in the case of traditional PG implementation. Moreover, in order to determine if PG leads to leakage power savings, minimum average idle time concept is proposed. Lastly, as a critical part in the integration of CG and PG, data retention logics (DRLs) are required to hold the values of the power gated logics’ outputs so that the non power gated blocks which depend on those outputs can function correctly during the power gated period. In this thesis, a low power DRL design is presented. All the above mentioned techniques have been applied to ISCAS’89 benchmark circuits, and their correctness has been verified successfully. Moreover, the whole experimental process is accomplished automatically by software program, so it is easy to be integrated into current EDA tools.
Ph.D. in Computer Engineering, May 2012
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Title: GALLIUM NITRIDE NANOSTRUCTURED POWER SEMICONDUCTOR DEVICES
Creator: Sabui, Gourab
Date: 2017, 2017-05
Description: Gallium nitride (GaN) has emerged as a promising material for development of power semiconductor devices owing to its superior material...
Show moreGallium nitride (GaN) has emerged as a promising material for development of power semiconductor devices owing to its superior material characteristics. Fabricated GaN power devices have started to outperform its silicon (Si) counterpart with low conduction and switching losses and holds the key to extremely low-loss and high efficiency power delivery circuits of the future. However, GaN power devices have been plagued with several inherent drawbacks preventing an ubiquitous adoption of GaN as the material of choice for power switches. The most critical trade-o↵ has been the choice of substrate for the growth of GaN epitaxy: a high performance, high-cost native substrate or a low-cost, non-native substrate with reliability issues. In order for GaN to thrive as a superior successor to Si, a low cost, high performance epitaxy with improved reliability is expected moving forward. A novel nanostructured approach to GaN power devices is proposed in this dissertation. The nano-GaN power devices theoretically has the potential to bypass the reliability concerns associated with a non-native substrate but still deliver comparable performance. A comprehensive model is proposed for TCAD modeling of bulk GaN power devices to accurately model the nano-GaN devices. Through extensive modeling and simulations, design guidelines for Schottky barrier diodes and field effect transistors based on the nano-GaN concept is laid out to extract the best performance out of this architecture. Dielectric and semiconductor interaction is also exploited to push these devices to perform beyond the unipolar material limit of GaN. The simulated and fabricated nano-GaN power devices show the potential to deliver equivalent or superior performance to present state of the art GaN devices but with improved reliability, ruggedness and low cost.
Ph.D. in Electrical Engineering, May 2017
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Title: HYBRID ELECTROSTATIC AND MICRO-STRUCTURED ADHESIVES FOR ROBOTIC APPLICATIONS
Creator: Ruffatto, Donald F., Iii
Date: 2015, 2015-07
Description: Current adhesives and gripping mechanisms used in many robotics applica- tions function on very speci c surface types or at de ned attachment...
Show moreCurrent adhesives and gripping mechanisms used in many robotics applica- tions function on very speci c surface types or at de ned attachment locations. A controllable, i.e. ON-OFF, adhesive mechanism that can operate on a wide range of surfaces would be very advantageous. Such a device would have applications ranging from robotic gripping and climbing to satellite docking and inspection/service mis- sions. The main goal of the research presented here was to create such an attachment mechanism through the use of a new hybrid adhesive technology. The newly devel- oped adhesive technology is a hybridization of electrostatic and micro-structured dry adhesion. The result provides enhanced robustness and utility, particularly on rough surfaces. There were challenges not only in the integration of these two adhesive elements but also with its application in a complete gripping mechanism. Electrostatic and directional dry adhesives were both individually investigated. The electrode geometry for an electrostatic adhesive was optimized for maximum ad- hesion force using nite element analysis software. Optimization results were then veri ed through experimental testing. New manufacturing techniques were also de- veloped for electrostatic adhesives that utilized a metalized mesh embedded in a sili- cone polymer and Kapton lm based construction, greatly improving adhesion. The micro-structured dry adhesive used was provided by Dr. Parness, from the NASA Jet Propulsion Lab (JPL), and consists of an array of vertical stalks with an angled front face, referred to as micro-wedges. The hybrid electrostatic dry adhesive (EDA) was created by fabricating the electrostatic adhesive directly on top of a dry adhesive mold. This process created an array of dry adhesive micro-wedges directly on the surface of the electrostatic adhesive. In operation the electrostatic adhesive provides a normal force which serves to pull the dry adhesive into the surface substrate. With greater surface contact more of the dry adhesive is able to engage, bring the electro-static adhesive even closer to the surface and increasing its e ectiveness. Therefore, the combination of these two technologies creates a positive feedback cycle whose whole is often greater than the sum of its parts. An interface mechanism is needed to transmit applied loads from a rigid struc- ture to the exiable adhesive while still maintaining its conformability. This is es- pecially important for strong adhesion on rough surfaces, such as tile and drywall. Di erent concepts such as a structured brillar hierarchy and a uid- lled backing pouch have been explored. Additionally, nite element analysis was used to evaluate di erent fribrillar shapes and geometry for the structured hierarchy. The goal was to equalize the load distribution across the adhesive while still maintaining surface compliance. A gripper mechanism was also created which used a servo for actuation and three rigid tiles with a directional dry adhesive. It was tested on a perching Micro Air Vehicle (MAV) as well as in the RoboDome facility at NASA's Jet Propulsion lab to simulate a satellite docking/capture maneuver.
Ph.D. in Mechanical and Aerospace Engineering, July 2015
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Title: METHODOLOGY FOR URBAN AREA SNOW REMOVAL USING NEW MACHINE AND PERFORMANCE-BASED ANALYSIS
Creator: Neishapouri, Mohammad
Date: 2015, 2015-12
Description: The need for alternative methods that facilitate removal of snow on urban streets with minimal pavement and bridge damages, vehicles...
Show moreThe need for alternative methods that facilitate removal of snow on urban streets with minimal pavement and bridge damages, vehicles corrosions, and environmental impacts due to use of chemicals and salts has been growing over time. Conversely, this issue has not been thoroughly investigated. This is particularly true for large urban areas where the snow removal machine and background traffic share already congested streets. In this research, a new methodology is introduced for effectively managing snow removal that involves new machine and performance-based analysis. The new machine aims to melt snow and ice using technically adequate mechanical system including special engine, heat pumps and very fast ventilation pumps in order to suck and discharge water from pavement surface to road sides. The performance-based analysis employs a life cycle cost analysis approach to estimate reductions in expenditures to pavements and bridges, and vehicle corrosions of background traffic as a result of using new machine for snow melting instead of using chemicals and salts; and an optimization model for effective dispatching of new machine across a large area, leading to a significant level of travel timing savings to the background traffic owning to shorter duration oftravel way closures. The proposed methodology is implemented in a computational study to examine the current snow removal programs in the city of Chicago for a typical winter day involving moderate and severe snowfalls that correspond to its 50 percent and 100 percent programs for filed dispatching one-half and all snow plow trucks. Compared with the use of snow removal trucks coupled with chemicals and salts, the use of new machine could result in better equivalent annualized savings as benefits component and less amount of cost components which cause the project implementation has benefit to cost ratio Xl11The need for alternative methods that facilitate removal of snow on urban streets with minimal pavement and bridge damages, vehicles corrosions, and environmental impacts due to use of chemicals and salts has been growing over time. Conversely, this issue has not been thoroughly investigated. This is particularly true for large urban areas where the snow removal machine and background traffic share already congested streets. In this research, a new methodology is introduced for effectively managing snow removal that involves new machine and performance-based analysis. The new machine aims to melt snow and ice using technically adequate mechanical system including special engine, heat pumps and very fast ventilation pumps in order to suck and discharge water from pavement surface to road sides. The performance-based analysis employs a life cycle cost analysis approach to estimate reductions in expenditures to pavements and bridges, and vehicle corrosions of background traffic as a result of using new machine for snow melting instead of using chemicals and salts; and an optimization model for effective dispatching of new machine across a large area, leading to a significant level of travel timing savings to the background traffic owning to shorter duration oftravel way closures. The proposed methodology is implemented in a computational study to examine the current snow removal programs in the city of Chicago for a typical winter day involving moderate and severe snowfalls that correspond to its 50 percent and 100 percent programs for filed dispatching one-half and all snow plow trucks. Compared with the use of snow removal trucks coupled with chemicals and salts, the use of new machine could result in better equivalent annualized savings as benefits component and less amount of cost components which cause the project implementation has benefit to cost ratio respectively 2.15 and 2 by CPI analysis and 3 and 3.04 by CCI analysis. Compared with the current practice of filed dispatching of snow plow trucks or new machine for snow removal, the optimization model for vehicle dispatching could further improve the snow removal productivity by 2-4 percent for the 100 percent program and 3-8 percent for the 50 percent program, respectively.
Ph.D. in Civil Engineering, December 2015
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Title: DEVELOPMENT OF A CREATIVE WORK ANALYSIS
Creator: Neuman, Brendan George
Date: 2014, 2014-05
Description: Creativity researchers continue to debate whether the phenomenon of creativity is a uniform construct regardless of context, or if creativity...
Show moreCreativity researchers continue to debate whether the phenomenon of creativity is a uniform construct regardless of context, or if creativity differs characteristically across domains. The present research contributes to this debate by way of an analysis of creative work. It was hypothesized that a comprehensive analysis of creative work would reflect a four-factor structure that is often used to organize the creativity research literature. Additionally, differences in both the level and nature of creativity were expected to emerge from incumbent data across occupational domains. An eight-factor, rather than four-factor structure of creative work was observed. Incumbent ratings from seven distinct job families were different in nature but not level of creative work.
PH.D in Psychology, May 2014
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Title: PHYSIOLOGICAL AND BEHAVIORAL EVIDENCE THAT CHEMICALS IN THE ENVIRONMENT INFLUENCE DEVELOPMENT OF THE ZEBRAFISH OLFACTORY SYSTEM
Creator: Valesio, Eric
Date: 2013, 2013-12
Description: Olfactory imprinting is the process of producing life-long changes through neural modification that is independent of associative learning....
Show moreOlfactory imprinting is the process of producing life-long changes through neural modification that is independent of associative learning. Here, I provide data to demonstrate that olfactory imprinting in zebrafish leads to neurobiological and behavioral changes. I treated zebrafish with an amino acid (AA) or a bile acid (BA) mixture from 4 days post-fertilization (dpf) to 40 dpf. Behavior studies showed that fish treated with odorants for 40 days exhibited preferential responses to treated odorants, which was different from the controls. These behavioral changes were retained 3 months after the odor treatment was ceased. Whole-mount immunohistochemistry was conducted using antibodies for parvalbumin (PV) and OTX. We discovered that treated fish had increased PV and OTX expression in the olfactory epithelium (OE) at 7 dpf and increased PV expression in the olfactory bulb (OB) at 12 dpf. Detailed analysis indicated that increased PV expression was observed in the OE apical region of treated groups while OTX was increased in both the apical and basal regions of the OE. In three regions of the OB analyzed, BA treated fish showed a doubling in PV expression in all regions while doubling was in two regions in AA treated fish. Increased OTX expression was in the three regions of AA treated fish but not in BA treated fish. These data demonstrate that exposure to AA or BA during zebrafish development leads to long-lasting physiological and behavioral changes. The report also includes a study of embryonic zebrafish treated with SP600125 (anthrapyrazolone), an inhibitor of the c-Jun N-terminal kinase (JNK) signaling pathway. Zebrafish embryos were treated with 1.25 μM, 5 μM, or 12.5 μM of SP600125 from 18 to 48 hours post-fertilization (hpf) followed by evaluation at 120 hpf. Zebrafish treated at 1.25 μM were not affected developmentally while embryos treated at xv 5 μM and higher displayed numerous morphological defects including edemas, eye malformations and reduction in olfactory organ size. Overall, it was observed that treatment at 5 μM, SP600125 caused severe developmental defects and that these defects worsened with increasing concentrations. Taken together, these data indicate that the environment has a profound influence on zebrafish development.
PH.D in Biology, December 2013
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