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- Title
- Innovative Uses of Native CAD Files Progress Report June 2011
- Creator
- Kleps, Stephen M., Menches, Cindy
- Date
- 2013-09-18, 2011-06
- Description
-
This publication presents an literature review, progress of an environmental scan, and preliminary findings of research for the project...
Show moreThis publication presents an literature review, progress of an environmental scan, and preliminary findings of research for the project entitled Innovative Uses of Native CAD Files.
Sponsorship: Electri International
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- Title
- STATISTICAL METHODS FOR LARGE-SCALE TRANSPORTATION NETWORK TRAFFIC VOLUME FORECASTING
- Creator
- Meng, Xiao
- Date
- 2012-11-27, 2012-12
- Description
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Forecasting is the procedure of making declarations about future events whose actual outcomes have not yet been observed. A lot of decisions...
Show moreForecasting is the procedure of making declarations about future events whose actual outcomes have not yet been observed. A lot of decisions are made based on predictions of future unknown events. Knowing the essence of forecasting, it is not hard to interpret what traffic volume forecasting is. Traffic volume forecasting is the process of estimating the number of vehicles that will be on a planned highway in the future. It plays important roles in different aspects of transportation and related field, such as highway level of service analysis, measure of effectiveness, highway improvement and expansion, geometric design and air quality analysis, etc. A good forecast is needed for decision making in future land use and transportation planning. City and county planners can provide useful information about land use planning and projected developments. County engineers may provide information about future county projects that may cause detours and changes in traffic patterns along a trunk highway. Highway designers need forecasted traffic volumes to ensure proper geometric designs. Since short term forecasting has been a hot topic on research, many statistical methods have been used, such as the mean, historical moving average, exponential smoothing, and autoregressive integrated moving average. Among them, Box Jenkins method (Autoregressive Integrated Moving Average) has been found as the best model on forecasting of time series data with seasonality and trend.
M.S. in Civil Engineering, December 2012
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- Title
- BICYCLE CRASH ANALYSIS IN CHICAGO
- Creator
- Van Nortwick, Taylor Wade
- Date
- 2013, 2013-07
- Description
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The United States is making big plans for improvements in bicycle infrastructure. To best understand if the improvements will be successful in...
Show moreThe United States is making big plans for improvements in bicycle infrastructure. To best understand if the improvements will be successful in creating a safe network, a study was done to determine contributing factors in bicycle crashes. Bicycle and motor vehicle crash data from around Chicago between 2005 and 2011 was analyzed for significant factors in infrastructure, cyclist and motorist attributes. Temperature was used as a predictor of bicycle traffic due to the seasonality of bicycling in Chicago. It was found that more bicycles and vehicles result in higher crash rates. It was also found that on -street parallel parking, signalized, skewed and multiple legged intersections lead to higher crash rates.
M.S. in Civil Engineering, July 2013
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- Title
- OPTIMAL SIGNAL TIMING DESIGN FOR URBAN STREET NETWORKS UNDER USER EQUILIBRIUM BASED TRAFFIC CONDITIONS
- Creator
- Liu, Yi
- Date
- 2015, 2015-05
- Description
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In the ever-growing travel demand, traffic congestion on freeways and expressways recurs more frequently at a higher number of locations and...
Show moreIn the ever-growing travel demand, traffic congestion on freeways and expressways recurs more frequently at a higher number of locations and for longer durations with added severity. This becomes especially true in large metropolitan areas. Particular to the urban areas, excessive crowdedness caused by inefficient traffic control also results in urban street networks operating in near or over-saturated conditions, leading to unpleasant travel experience due to long delays at intersections. As a consequence, the recurrent traffic congestion on roadway segments and vehicle delays at intersections inevitably compromise energy efficiency, traffic mobility improvement, safety enhancement, and environmental impacts mitigation. All too often, neither restraining travel demand nor expanding system capacity is desirable and practical. Conversely, effectively utilizing the capacity of the existing transportation system has been increasingly thought of as the solution to congestion relief. With respect to the urban street networks, developing effective means for urban intersection signal optimization becomes essential to reduce intersection delays. Conventional signal timing optimization methods use historical traffic data and assume that traffic flows will remains unchanged after the implementation of new signal timing plans. Traffic flows are assumed to be constant, but in fact, when signal timing plans change, travel times for some travel routes will alter, which requires drivers in the network to adjust their choice of travel routes to arrive at the destinations, and result in redistribution of traffic in the network. Therefore, the effects of interactions between signal timing plans and traffic flows need to be explicitly taken into consideration. This study introduces a new methodology that jointly considers signal timing optimization and traffic assignment in an overall analytical framework that contains model formulations under assumptions consistent with real world situations. Such a framework is well suited for applications in real world cases. Specifically, the overall optimization framework is formulated as a bilevel optimization problem. In the proposed basic model, at the upper level, a traffic signal timing optimization problem for urban network is introduced to minimize system total travel time by optimizing signal green splits. At the lower level, a static user equilibrium problem is formulated for networkwide traffic assignment. In the vehicle delay estimation, the time-dependent stochastic delay model in the 2010 Highway Capacity Manual (HCM 2010) is employed and formulated as Variational Inequality constraints, what allow the state-of-the-art MPEC solver, GAMS/NLPEC, to solve the problem for a local optimal effectively and efficiently. The bi-level optimization model is first tested using a small network (the test network) and a computational experiment using a subarea network in the Chicago central district is conducted to assess the practicality of the model formulation in real world applications. In order to import more reality to the basic model and also consider the potential system benefit that comes from different signal phasing design, an enhanced model is developed based on the basic model by employing integer and binary variables. Formulating the problem with binary variables allows for the selection of proper phasing design. Heuristic solution methods are proposed and tested using the test network.
Ph.D. in Civil Engineering, May 2015
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- Title
- DEVELOPMENT AND APPLICATION OF THE KIRIE WASTEWATER TREATMENT PLANT MODEL
- Creator
- Mendez, Thomas E.
- Date
- 2012-07-15, 2012-07
- Description
-
The Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) is tasked with protecting the public’s water supply and improving the...
Show moreThe Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) is tasked with protecting the public’s water supply and improving the quality of water in their service area’s watercourses. Principal in this mission are the seven wastewater treatment plants that are operated by MWRDGC. The greater Chicago area possesses a combined sewer system (CSS) that combines sanitary sewage and stormwater runoff. Because of this CSS, water reclamation plants are burdened with not only processing sewage and sanitary waste, but also stormwater runoff. As a result there can be a large variation in water quality and quantity. MWRDGC’s newest water reclamation plant is the James C. Kirie Water Reclamation Plant, which was completed in 1980. This plant operates as a nitrification plant with no separate distinct denitrification process. It is important to note that no clearly defined unit processes such as nitrification towers are utilized at the Kirie Water Reclamation Plant. Nitrification occurs primarily in the aeration basins and is currently sufficient to meet water quality standards. However, because of the current regulatory climate, stricter standards on effluent discharge are likely in the near future especially with respect to nutrients. Stricter standards on total nitrogen in effluent instead of the current ammonia limits are one such expected water quality change. As a result of this expectation, modeling modifications and processes at a treatment plant can be a key tool in adjusting to evolving standards. Because water reclamation plants vary greatly depending on their technology, influent and processes, computer modeling provides a convenient way to assess how the plant will react to dynamic changes in influent quality and still be able to meet static effluent standards. Although computer modeling has been applied to water reclamation plants for some time now, there are no clearly defined or accepted protocols for this modeling. Combined with the variation exhibited by various types of water reclamation plants, often modeling protocols must be custom created for individual plants or types of plants. What follows is a study and simulation of the Kirie Water Reclamation Plant. Simulation was used to examine wet weather events at the Kirie Water Reclamation Plant. Wet weather phenomena were explored in step-wise manner to determine the relative effects of different perturbations in influent water quality and quantity. The results show the various effects in effluent quality depending upon the variable or combination of variables deviated. Deviations in temperature and flow dominate all other variations simulated and result in the largest effect on effluent water quality. Deviations of 50% to both temperature and flow simultaneously yielded an increase in effluent BOD and NH3 at twice and six times the steady state values, respectively.
M.S. in Environmental Engineering, July 2012
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- Title
- SAFETY TRAINING IN CONSTRUCTION
- Creator
- Demirkesen, Sevilay
- Date
- 2011-11-29, 2011-12
- Description
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The construction industry is one of the most hazardous industries. Therefore, the ways to reduce the number of risks have been a concern for...
Show moreThe construction industry is one of the most hazardous industries. Therefore, the ways to reduce the number of risks have been a concern for construction companies. Safety training is considered as one of the most efficient ways of improving safety record. Therefore, this study aimed to describe the best safety training methods and the most efficient organization in safety training. The study also aimed to show how to take best safety measures to protect construction workers. In this thesis study, a questionnaire was conducted in order to investigate the achievement of safety learning, challenges in a safety training program and the methods of improving safety record. Thus, the questionnaire was e-mailed to 400 contractors in US. The data collected also indicated the importance of safety training in companies’ success in the industry. Additionally, this study presents recommendations on how companies could improve their safety record.
M.S. in Civil Engineering, December 2011
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- Title
- Understanding Construction Workers’ Risk Decisions Using Cognitive Continuum Theory
- Creator
- Menches, Cindy L., Saxena, Jaya
- Date
- 2013-09-19, 2013-09-19
- Description
-
The goal of the research presented in this article was to construct a theory about the influence of decision cues on intuitive and...
Show moreThe goal of the research presented in this article was to construct a theory about the influence of decision cues on intuitive and deliberative decision-making in high-hazard construction environments. Drawing from Cognitive Continuum Theory, the article specifies a framework for understanding why and how construction workers make decisions that lead to taking or avoiding physical risks when they encounter daily hazards. A secondary aim of the research was to construct a set of hypotheses about how specific decision cues influence whether a worker is more likely to engage their intuitive impulses or to use careful deliberation when responding to a hazard. These hypotheses are described in this article, and the efficacy of the hypotheses was evaluated using cross-tabulations and nonparametric measures of association. While most of the associations between decision cues and decision mode (i.e., intuition or deliberation) identified in this data set were generally modest, none of the associations were statistically zero, thus indicating that further research is warranted based on theoretical grounds. A rigorous program of theory testing is the next logical step to the research, and the article thus concludes with numerous suggestions for extending the research and testing the proposed hypotheses.
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- Title
- PROPOSITION AND EVALUATION OF A NEW DAMPER, CALLED ROTATIONAL CYLINDRICAL FRICTION DAMPER (RCFD)
- Creator
- Divani, Abbass
- Date
- 2013, 2013-12
- Description
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The objective of this study is to propose and evaluate an innovative frictional damper for structural systems, called Rotational Cylindrical...
Show moreThe objective of this study is to propose and evaluate an innovative frictional damper for structural systems, called Rotational Cylindrical Friction Damper (RCFD), which does not bear limitation of previously proposed systems and yet maintains their advantages. Different kinds of energy dissipaters have been studied and used in structural systems in recent years. They perform more effectively compared to structures without any energy dissipater. Each of previously employed devices has its advantages and limitations. In this report, applicability of previous energy dissipaters will be investigated; then the proposed damper, RCFD, will be introduced, and the performance of RCFD will be evaluated under lateral load using ABAQUS software. RCFD consists of a shaft, a cylinder and proper assembly of braces so that the bracing members make the cylinder and shaft move in opposite circular directions under defined load. The assemblage of braces depends on type of bracing system that is employed. When load in bracing member exceeds the buckling load of the member, it overcomes the friction between the shaft and inner surface of the cylinder and while providing the ductility demand of the structure, it absorbs the energy of the seismic load, and it will work like a safety valve to protect main structural members from inelastic deformation. In spite of other types of frictional dampers, RCFD does not use and reduces the construction cost of high strength bolts. There is no limitation for the size and fitness of the bracing members more than that is for conventional design of braced frames. When we prove the performance of RCFD, some of the requirements of conventional design such as requirement of section F2 of Seismic Provisions for Structural Steel Buildings, AISC 341-10, will be eliminated. The pressure needed for developing friction is provided by heating the shaft and placing it into the cylinder with slightly smaller xiii diameter. It is simple to design and construct and does not have the limitation of other kinds of frictional damper systems. It can also be installed with little or no modification on any kind of Braced Frames or to retrofit Moment Frames. In this study, RCFD will be installed and evaluated on an Inverted V Concentrically Braced Frame, although installation of the RCFD on X Braced frame will be illustrated.
M.S. in Civil Engineering, December 2013
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- Title
- DEGRADATION RATE MODEL TO ESTIMATE SOIL CARBON SEQUESTRATION
- Creator
- Zhai, Wenjuan
- Date
- 2016, 2016-05
- Description
-
Concern over climate change as a consequence of carbon dioxide (CO2) emissions from human activities has resulted in efforts to better...
Show moreConcern over climate change as a consequence of carbon dioxide (CO2) emissions from human activities has resulted in efforts to better understand potential mitigation measures such as carbon sequestration in soils. Processes shaping natural carbon sequestration may be used to remove excess CO2 from combustion and other anthropogenic sources of carbon, and, alleviate concerns over climate change. Land application of biosolids is a process that increases the amount of soil carbon sequestration and may produce carbon credits in accordance with the definition of UN Climate Change Convention. A dynamic degradation rate model (DRM) has been developed based on a mass balance and first order kinetics to describe the soil organic carbon (SOC) decomposition process, which provides insights on carbon sequestration due to microbial biomass, SOC, CO2 emission rates, residence time of sequestered carbon, and biomass to biosolids ratios. A curve fitting approach was used to produce a best fit average degradation rate for biosolids degradation and microbial biomass yield. This study employed a 34-year biosolids application database from the literature to determine the amount of carbon sequestered in 41 strip-mined Illinois fields. The DRM application identifies two SOC phases in soil. Soil organic carbon gain in phase one (first 10 yrs) is primarily due to biosolids C application remaining and accumulation while in phase two, SOC gain is due to biomass or C sequestration. Carbon sequestration changes with time relate to variations in biosolids application amounts (10 and 18 Mg ha-1 yr-1), different degradation rate constants (0.04yr-1 to 0.16yr-1), and biomass yields (35 to 40%). Additionally, comparison between model simulation results and laboratory resultsdetermine the amount of carbon sequestered in 41 strip-mined Illinois fields. The DRM application identifies two SOC phases in soil. Soil organic carbon gain in phase one (first 10 yrs) is primarily due to biosolids C application remaining and accumulation while in phase two, SOC gain is due to biomass or C sequestration. Carbon sequestration changes with time relate to variations in biosolids application amounts (10 and 18 Mg ha-1 yr-1), different degradation rate constants (0.04yr-1 to 0.16yr-1), and biomass yields (35 to 40%). Additionally, comparison between model simulation results and laboratory resultsdetermine the amount of carbon sequestered in 41 strip-mined Illinois fields. The DRM application identifies two SOC phases in soil. Soil organic carbon gain in phase one (first 10 yrs) is primarily due to biosolids C application remaining and accumulation while in phase two, SOC gain is due to biomass or C sequestration. Carbon sequestration changes with time relate to variations in biosolids application amounts (10 and 18 Mg ha-1 yr-1), different degradation rate constants (0.04yr-1 to 0.16yr-1), and biomass yields (35 to 40%). Additionally, comparison between model simulation results and laboratory resultsdetermine the amount of carbon sequestered in 41 strip-mined Illinois fields. The DRM application identifies two SOC phases in soil. Soil organic carbon gain in phase one (first 10 yrs) is primarily due to biosolids C application remaining and accumulation while in phase two, SOC gain is due to biomass or C sequestration. Carbon sequestration changes with time relate to variations in biosolids application amounts (10 and 18 Mg ha-1 yr-1), different degradation rate constants (0.04yr-1 to 0.16yr-1), and biomass yields (35 to 40%). Additionally, comparison between model simulation results and laboratory results provided by a yearlong study indicates that higher temperatures and moisture content and finer soils are related to larger degradation rates. To summarize, this study has the following contributions: (1) developed a degradation rate model which simulates the biosolids degradation process in soil and identifies two SOC phases in soil, and quantifies the biosolids degradation rate constant, biomass yield, and the C sequestered amount for multiple and long term soil application; (2) assessed the effect of changes in the amount of biosolids applied, soil type, and weather conditions on the C degradation rate by comparing model results to laboratory data; and (3) provides an easy quantitative method for predicting C sequestration from biosolids added to soil.
Ph.D. in Environmental Engineering, May 2016
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- Title
- STRUCTURAL SEISMIC PERFORMANCE EVALUATION WITH CONSIDERATION OF ECONOMIC VULNERABILITY
- Creator
- Romero, Daniela Zuloaga
- Date
- 2014, 2014-05
- Description
-
Performance evaluation of structures has until now been based on evaluation of maximum displacements, interstory drifts, deformation patterns,...
Show morePerformance evaluation of structures has until now been based on evaluation of maximum displacements, interstory drifts, deformation patterns, ductility and other similar parameters; a relative economic loss estimation as a performance measure for the structure is the next step that follows, and is what has been investigated in this work. For this study a steel mid-rise structure was designed according to code provisions using modal spectral analysis, after which it was subjected to an Incremental Dynamic Analysis (IDA) procedure to evaluate the capacity curve of the building. The capacity analysis was then used to determine damage states and compute fragility curves. Finally, economic relative loss values were assigned to represent each designated damage state, for which the mean damage ratio was computed (in terms of economic loss relative to total replacement cost) as a function of spectral displacement.
M.S. in Civil Engineering, May 2014
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- Title
- EFFECT OF TEMPERATURE, MOISTURE CONTENT AND SOIL SURFACE AREA ON THE BIOLOGICAL DEGRADATION OF BIOSOLIDS ADDED TO SOIL
- Creator
- Wen, Dongqi
- Date
- 2016, 2016-05
- Description
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The objective is to develop and apply an organic matter degradation model (OMDM) that predicts changes in the biological degradation of...
Show moreThe objective is to develop and apply an organic matter degradation model (OMDM) that predicts changes in the biological degradation of organic matter added to soils as a function of soil temperature, moisture content and mineral surface area using data from field and laboratory measurements. A one year long laboratory study was conducted to determine biosolids microbial degradation rates (21 ˚C and 20% moisture content) for soils from eight different fields Biosolids microbial degradation rates were also determined for the eight soils under field condition (10 ˚C and 10% moisture content) by applying a degradation rate model (DRM). The total mineral surface areas for 27 soil samples were also determined. Regression analysis revealed that the degradation rate was positively associated with mineral soil surface area (R2=0.85) and that the biosolids application rate is not significantly associated with the biosolids degradation rate (p value =0.35>0.01). The OMDM determines a decomposition rate of 1.04 yr-1 at 30 ˚C, 20% moisture content, and 10 m2/g soil and provides correction factors for changes in soil temperature, moisture, and mineral surface area. The model predicted in changes of the biological degradation rate of biosolids added to soils with mineral surface areas that vary from 1 to 10 m2/g soil under laboratory and field conditions. A comparison of the measured and simulated degradation rates for eight different soils produced R2 = 0.87 for field data. The model was also able to predict the degradation rate of biosolids for 19 additional soils under field conditions (R2=0.89). The model was also applied to agricultural plant litter. The estimated degradation rates are 0.45 yr-1 corn stover, 0.35 yr-1 oats, 0.26 yr-1 wheat, and 0.13 yr-1 millet at 30 ˚C, 20% moisture content and 10 m2/g. This study demonstrates that the effects of environmental conditions and soil mineral surface area have a significant impact on degradation rates of organic matter and must be considered when assessing degradation rates for organic matter added to soil. Higher temperatures and moisture content and finer soils are related to larger degradation rates.
Ph.D. in Environmental Engineering, May 2016
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- Title
- AN ASSESSMENT OF HEAT PUMP APPLICATION AT WATER TREATMENT FACILITIES-THAT USE SURFACE WATER
- Creator
- Yan, Wenpeng
- Date
- 2012-07-17, 2012-07
- Description
-
Energy-efficient heat pumps have been applied in the United States and other regions of the world for decades. Geothermal heat pumps have been...
Show moreEnergy-efficient heat pumps have been applied in the United States and other regions of the world for decades. Geothermal heat pumps have been used, but their application is not wide spread due to the high cost of drilling and installing a ground loop. An alternative choice for space conditioning at municipal water utilities is a surface water source heat pump. Because treated surface water is readily available and it exists in a relatively narrow temperature range it could be useful heat transfer fluid. In this project the economic benefits and greenhouse gas emissions of a heat pump system for a building in NE Illinois are analyzed. Heating and cooling requirements for a hypothetical a 1000 m2 space at a drinking water treatment plant are considered. The analysis includes initial, operating and maintenance costs as well as greenhouse gas emissions, between a heat pump system and a conventional natural gas furnace and air-conditioner. The cost savings in this project for the heat pump system were from $39900 to $41511 over the life cycle of the system depending on the different efficiency level of the heat pump system. Surprisingly the initial cost of the standard efficiency heat pump system is lower than the conventional NGAC system. There is no need to take time to make up the additional initial cost. Surface water heat pumps operating at different efficiency level produce less greenhouse gas than the conventional NGAC system. The CO2 emission reduction could be as high as 73%.
M.S. in Environmental Engineering, July 2012
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- Title
- A study of the effects produced on Portland cement by the addition of various percentages of hydrated lime
- Creator
- Knuepfer, Claude Albert, Hook, Leonard Doolittle
- Date
- 2009, 1915
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/studyofeffectspr00knue
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaf 99
- Title
- Jobsite Characteristics that Influence Improvised Decision-making on Construction Sites
- Creator
- Kleps, Stephen M., Menches, Cindy
- Date
- 2013-10-07, 2013-10-07
- Description
-
This article examines the relationship between specific construction project characteristics and the degree and speed that the foremen are...
Show moreThis article examines the relationship between specific construction project characteristics and the degree and speed that the foremen are able to improvise in response to disruptive events on the jobsite. Specifically, characteristics such as the number of crew members working under the supervision of a foreman, the occupancy status of the project (i.e., occupied or unoccupied) during construction, the stage of completion of the project, and the levels of turbulence, time pressure, cooperation, collaboration, and organization, were examined. Using a multilevel regression modeling approach, an analysis of 244 disruptions reported by 50 foremen was conducted to determine whether the construction project characteristics could predict more or less improvisation and faster or slower improvisation by the foreman. The findings indicate that on construction projects that are rated by the foremen as more organized, the foremen can make more modest improvised decisions to resolve a disruption, but that on construction projects that were rated by the foremen as more collaborative (i.e., involved joint decision-making), a greater degree of improvisation was deployed. In addition, it was found that on sites that were rated by the foremen as more cooperative (i.e., involved greater willingness to help each other), the foremen required more time to improvise their decisions.
Sponsorship: National Science Foundation
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- Title
- OPTIMAL MATERIAL SELECTION MODEL FOR LEED CERTIFICATION USING GENETIC ALGORITHMS
- Creator
- Kim, Taehyoung
- Date
- 2012-12-16, 2012-12
- Description
-
Material selection is an important part of building design because it has great impact on the environment, as buildings during/after...
Show moreMaterial selection is an important part of building design because it has great impact on the environment, as buildings during/after construction are responsible for a large portion of carbon emissions and use many resources and considerable energy. Selecting green materials is an emergent issue in both design firms and construction companies. Green building certification such as LEED systems originated from the desire to improve environmental, economic, financial, and social benefits. The current approach to material selection for sustainability is based only on the designer’s past experiences. An arbitrary approach based on subjective opinions causes unnecessary expense, longer construction duration, and failure to meet desired environmental goals. In order to help decision-makers with the selection of the right materials, this study proposes a model that uses Genetic Algorithms in MATLAB and that optimizes the desired points in LEED Certification within budget constraints. This model can be applied to any project that is pursuing LEED Certification. If the user specifies the desired LEED points, the system recommends the least expensive combination of materials extracted from a database containing detailed information about a large member of materials. The modified model uses multi-objective genetic algorithms to establish trade-off between budget constraints and LEED points. The proposed system is expected to be a useful tool for inexperienced designers and a valuable guideline for designers with extensive experience.
M.S. in Civil Engineering, December 2012
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- Title
- DEVELOPMENT OF A NEW EMERGENCY EVACUATION SYSTEM FOR MINES
- Creator
- Qian, Qingyi
- Date
- 2011-08, 2011-07
- Description
-
Underground mining is a very high risk industry. There are many potential hazards in the underground mining these include fire, explosion,...
Show moreUnderground mining is a very high risk industry. There are many potential hazards in the underground mining these include fire, explosion, inundation, roof collapse, toxic gases, chemical pollution, etc. Over past centuries, in US alone, more than 100,000 miners lost their life in different accidents. The primary safety methods used in underground mines concentrate on the monitoring of the hazardous gases, fire detection and ventilation. Using advanced instruments and monitoring techniques have significantly reduced the accidents in the modern mines. However despite the advancement of these monitoring facilities, accidents still occur in underground mining annually around the world, and many miners were killed because they were trapped and unable to escape due to blocked of exit access. This thesis describes a new development of an emergency evacuation system in underground mines and analyzes the advantages and disadvantages of the system. It is expected that the new system will greatly improve the emergency exit methods and save more lives in the future. The new emergency evacuation system consists of vertical concrete mineshaft, high capacity mineshaft elevators, surface terminal and underground support structures. In addition, the study of numerical simulation was carried out to observe the ground response during excavation. A typical ground profiles for underground mining in south part of China was used in this analysis. The results selected from shaft excavation simulation indicate that fluid drilling method effectively prevents the soil around mineshaft from collapse hazard. Compared to soil strength, soil stiffness has a significant influence on the soil response induced by excavating shafts.
Ph.D. in Civil Engineering, July 2011
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- Title
- SEISMIC STRUCTURAL ANALYSIS USING INTERVAL GROUND MOTION
- Creator
- Venezia, Adam
- Date
- 2011-12-05, 2011-12
- Description
-
Seismic analysis is a crucial procedure for the design of a structure subjected to ground motion. In conventional seismic analysis procedures,...
Show moreSeismic analysis is a crucial procedure for the design of a structure subjected to ground motion. In conventional seismic analysis procedures, a structure is subjected to a limited number of earthquake excitations. Moreover, these procedures do not consider the presence of variations and uncertainties in those excitations. Interval analysis is one method capable of accounting for both of these limitations. In this work, a new method for seismic structural analysis, with interval uncertainty in the response spectrum, is developed, which is capable of obtaining the bounds of the dynamic response of a structure. This method is hereinafter referred to as Interval Ground Motion Analysis (IGMA). In this method, first, various response spectra are combined as an interval function, referred to as an interval response spectrum. Then, the response spectrum analysis is performed using the developed interval response spectrum, and the bounds of the dynamic response of the structure are obtained. It is shown that obtaining these bounds is computationally feasible and does not require iterative procedures such as Monte Carlo simulation. Numerical example problems, which illustrate the developed algorithm, are presented, along with a comparison of solutions obtained by another solution method.
M.S. in Civil Engineering, December 2011
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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
- 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
- A diary study of the disruption experiences of crew members on a jobsite (Working Paper)
- Creator
- Menches, Cindy L., Chen, Juan
- Date
- 2012-06-01, 2012-06-01
- Description
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This article demonstrates the use of a diary technique in a construction setting. The advantage of a diary study over other methods for...
Show moreThis article demonstrates the use of a diary technique in a construction setting. The advantage of a diary study over other methods for capturing subjective experience is its ability to capture the thoughts, decisions, actions, and emotions of individuals in situ – while they are working in their natural setting – at multiple points in time during an individual’s workweek. Hence, the diary method is uniquely designed to answer questions about group-level trends as well as individual behavior. The specific goal of the study reported in this article was to derive an understanding of the types of fast decisions and actions that are made following a workflow disruption and how the disruption impacts the worker’s state of mind. The analyses revealed that there was a group-level positive correlation between experiencing a disruption and initiating a fast improvised decision and action. However, some workers tended to improvise frequently when disrupted while others did not. The analyses also revealed that the workers’ emotions fluctuated throughout the week, and two emotions – determined and interested – tended to decline following a disruption. But, some of the workers also experienced increases in their negative emotions while others did not, suggesting that not all workers react in the same way to disruptions. Consequently, the diary technique provides a novel way to identify the impact of disruptive events on worker decision-making and performance.
Sponsorship: National Science Foundation
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