Current Search: System dynamics modelling (x)
View All Items
(1 - 12 of 12)
- Title
- Modeling the innovation ecosystem and development of a dynamic innovation index.
- Creator
-
Schoen, Henriette, Karwowski, Waldemar, Hoekstra, Robert, Shumaker, Randall, Akbas, Mustafa, University of Central Florida
- Abstract / Description
-
The topic of innovation currently generates a tremendous amount of interest around the world. Innovation is considered an essential part of the solution to creating more jobs and improving the socio-economic conditions of many countries around the globe. Innovation comes about through the existence of many interrelated solutions to socio-economic problems in an extensively interconnected network, which create value for each other. Such a complex creativity and innovation value-creating...
Show moreThe topic of innovation currently generates a tremendous amount of interest around the world. Innovation is considered an essential part of the solution to creating more jobs and improving the socio-economic conditions of many countries around the globe. Innovation comes about through the existence of many interrelated solutions to socio-economic problems in an extensively interconnected network, which create value for each other. Such a complex creativity and innovation value-creating network is here called an Innovation Ecosystem (IE). The main objective of this dissertation research is to improve the current understanding of the IE by developing a simulation model that uses a broad set of relevant static and dynamic variables and incorporates the principles of system dynamics (SD). The proposed model, which is named the IECO-model is based on the relationships between 91 variables and the combined influences of the 43 parameters. Available data for 32 countries, representing a full span of GDP worldwide, was used to study the level of innovation in each of these countries. The result of the developed IECO-model is a novel ranking of the level of innovation through a dynamic innovation index, called the DII. The DII is a new tool to evaluate the innovation and entrepreneurship level of a given country in the context of the global economy. The most significant differentiator from other existing indices of innovation is that the DII is focusing more on the entrepreneurship qualities in 19 of the 43 parameters by looking at cultural values and belief systems, the social context, existing entrepreneurial culture, innovation attitudes, and mentality of each of the considered countries. According to DII-based ranking, the ten most innovative countries in the world are 1. Switzerland, 2. USA, 3. Finland, 4. Netherlands, 5. Iceland, 6. Sweden, 7. Germany, 8. Denmark, 9. The United Kingdom, and 10. Austria.
Show less - Date Issued
- 2018
- Identifier
- CFE0007586, ucf:52537
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007586
- Title
- NUTRIENT AND PATHOGEN REMOVAL IN A SUBSURFACE UPFLOW WETLAND SYSTEM USING GREEN SORPTION MEDIA.
- Creator
-
Xuan, Zhemin, Chang, Ni-Bin, University of Central Florida
- Abstract / Description
-
Due to environmental health and nutrient impact concerns, the conventional on-site sewage collection, treatment, and disposal systems are no longer able to meet the nutrient reduction requirements for wastewater effluent and may represent a large fraction of pollutant loads. The loads include not only nitrogen (N) and phosphorus (P), but also pathogens such as fecal coliform and E. coli which indicate the presence of other disease-causing bacteria flowing into aquatic system that adversely...
Show moreDue to environmental health and nutrient impact concerns, the conventional on-site sewage collection, treatment, and disposal systems are no longer able to meet the nutrient reduction requirements for wastewater effluent and may represent a large fraction of pollutant loads. The loads include not only nitrogen (N) and phosphorus (P), but also pathogens such as fecal coliform and E. coli which indicate the presence of other disease-causing bacteria flowing into aquatic system that adversely affect public health. A subsurface upflow wetland, which is an effective small-scale wastewater treatment system with low energy and maintenance requirements and operational costs, fits the current nutrient and pathogen removal situation having received wide attention throughout the world. Within this research study, a subsurface upflow wetland system (SUW), including four parallel SUW (three planted versus one unplanted), were constructed as a key component of the septic tank system receiving 454 liters per day (120 GPD) influent using the green sorption media along with selected plant species. It was proved effective in removing both nutrients and pathogens. During a one month test run, the planted wetlands achieved a removal efficiency of 84.2%, 97.3 %, 98.93 % and 99.92%, compared to the control wetland, 10.5%, 85.7 %, 99.74 % and 100.0 %, in total nitrogen (TN), total phosphorus (TP), fecal coli and E.Coli, respectively. Denitrification was proved to be the dominant pathway for removing N as evidenced by the mass balance and real-time PCR analyses. A simplified compartmental dynamics simulation model of constructed subsurface upflow wetlands was also developed to provide a dependable reference and tool for design of constructed subsurface upflow wetland.
Show less - Date Issued
- 2009
- Identifier
- CFE0002967, ucf:47964
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002967
- Title
- A Generic Framework For Multi-Method Modeling and Simulation of Complex Systems Using Discrete Event, System Dynamics and Agent Based Approaches.
- Creator
-
Mykoniatis, Konstantinos, Karwowski, Waldemar, Kincaid, John, Xanthopoulos, Petros, Akbas, Ilhan, University of Central Florida
- Abstract / Description
-
Decisions about Modeling and Simulation (M(&)S) of Complex Systems (CS) need to be evaluated prior to implementation. Discrete Event (DE), System Dynamics (SD), and Agent Based (AB) are three different M(&)S approaches widely applied to enhance decision-making of complex systems. However, single type M(&)S approaches can face serious challenges in representing the overall multidimensional nature of CS and may result in the design of oversimplified models excluding important factors....
Show moreDecisions about Modeling and Simulation (M(&)S) of Complex Systems (CS) need to be evaluated prior to implementation. Discrete Event (DE), System Dynamics (SD), and Agent Based (AB) are three different M(&)S approaches widely applied to enhance decision-making of complex systems. However, single type M(&)S approaches can face serious challenges in representing the overall multidimensional nature of CS and may result in the design of oversimplified models excluding important factors. Conceptual frameworks are necessary to offer useful guidance for combining and/or integrating different M(&)S approaches. Although several hybrid M(&)S frameworks have been described and are currently deployed, there is limited guidance on when, why and how to combine, and/or integrate DE, SD, and AB approaches. The existing hybrid frameworks focus more on how to deal with specific problems rather than to provide a generic way of applicability to various problem situations.The main aim of this research is to develop a generic framework for Multi-Method Modeling and Simulation of CS, which provides a practical guideline to integrated deployment or combination of DE, SD, and AB M(&)S methods. The key contributions of this dissertation include: (1) a meta-analysis literature review that identifies criteria and generic types of interaction relationships that are served as a basis for the development of a multi-method modeling and simulation framework; (2) a methodology and a framework that guide the user through the development of multi-method simulation models to solve CS problems; (3) an algorithm that recommends appropriate M(&)S method(s) based on the user selected criteria for user defined objective(s); (4) the implementation and evaluation of multi method simulation models based on the framework's recommendation in diverse domains; and (5) the comparison of multi-method simulation models created by following the multi-method modeling and simulation framework.It is anticipated that this research will inspire and motivate students, researchers, practitioners and decision makers engaged in M(&)S to become aware of the benefits of the cross-fertilization of the three key M(&)S methods.
Show less - Date Issued
- 2015
- Identifier
- CFE0005980, ucf:50762
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005980
- Title
- Agent-Based and System Dynamics Hybrid Modeling and Simulation Approach Using Systems Modeling Language.
- Creator
-
Soyler Akbas, Asli, Karwowski, Waldemar, Geiger, Christopher, Kincaid, John, Mikusinski, Piotr, University of Central Florida
- Abstract / Description
-
Agent-based (AB) and system dynamics (SD) modeling and simulation techniques have been studied and used by various research fields. After the new hybrid modeling field emerged, the combination of these techniques started getting attention in the late 1990's. Applications of using agent-based (AB) and system dynamics (SD) hybrid models for simulating systems have been demonstrated in the literature. However, majority of the work on the domain includes system specific approaches where the...
Show moreAgent-based (AB) and system dynamics (SD) modeling and simulation techniques have been studied and used by various research fields. After the new hybrid modeling field emerged, the combination of these techniques started getting attention in the late 1990's. Applications of using agent-based (AB) and system dynamics (SD) hybrid models for simulating systems have been demonstrated in the literature. However, majority of the work on the domain includes system specific approaches where the models from two techniques are integrated after being independently developed. Existing work on creating an implicit and universal approach is limited to conceptual modeling and structure design. This dissertation proposes an approach for generating AB-SD hybrid models of systems by using Systems Modeling Language (SysML) which can be simulated without exporting to another software platform. Although the approach is demonstrated using IBM's Rational Rhapsody(&)#174; it is applicable to all other SysML platforms. Furthermore, it does not require prior knowledge on agent-based or system dynamics modeling and simulation techniques and limits the use of any programming languages through the use of SysML diagram tools. The iterative modeling approach allows two-step validations, allows establishing a two-way dynamic communication between AB and SD variables and develops independent behavior models that can be reused in representing different systems. The proposed approach is demonstrated using a hypothetical population, movie theater and a real(-)world training management scenarios. In this setting, the work provides methods for independent behavior and system structure modeling. Finally, provides behavior models for probabilistic behavior modeling and time synchronization.
Show less - Date Issued
- 2015
- Identifier
- CFE0006399, ucf:51517
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006399
- Title
- Evaluating Floating Treatment Wetlands to Improve Nitrogen Removal in a Wet Detention Pond.
- Creator
-
Marimon, Zachary, Chang, Ni-bin, Fauth, John, Bohlen, Patrick, University of Central Florida
- Abstract / Description
-
Wet detention ponds are used for stormwater treatment across the United States and reduce most pollutants by at least 60%, but only remove 30% of total nitrogen. Floating Treatment Wetlands (FTWs) are an emerging technology that uses aquatic plants suspended in the pelagic zone to remove nitrogen through vegetative assimilation and microbial denitrification. A before-after field experiment evaluated nitrogen removal in a an existing pond in Orlando, FL, retrofitted with BioHaven(&)#174; FTWs...
Show moreWet detention ponds are used for stormwater treatment across the United States and reduce most pollutants by at least 60%, but only remove 30% of total nitrogen. Floating Treatment Wetlands (FTWs) are an emerging technology that uses aquatic plants suspended in the pelagic zone to remove nitrogen through vegetative assimilation and microbial denitrification. A before-after field experiment evaluated nitrogen removal in a an existing pond in Orlando, FL, retrofitted with BioHaven(&)#174; FTWs planted with the aquatic macrophytes Juncus effusus (Soft Rush) and Pontederia cordata (Pickerelweed). Surface water samples were used to compare the nitrogen-removal performance of the pond under both storm and non-storm conditions during a pre-analysis phase (control) to post-analysis after FTW deployment. The evaluation revealed similar TN removals in non-storm conditions during pre-analysis and post-analysis periods (-1% and -3%, respectively). During storm conditions, there was a negative TN removal of -26% in the pre-analysis compared to the positive 29% removal post-analysis. In addition, nitrogen concentrations for organic-nitrogen, ammonia/ammonium, and nitrites/nitrates were used as input for calibrating and validating a system dynamics model to predict multiple, interacting nitrogen species' transformation and translocation across the abiotic and biotic components of water, sediment, plants, and atmosphere. The validated model created in STELLA v.9.4.1 was used to simulate alternative designs to achieve maximum nitrogen removal based on the treatment efficiency in the evaluation. Simulations predicted 60% FTW coverage at the experimental planting density (22 per square meter) could achieve maximum nitrogen removal. Alternatively, similar nitrogen removal could be achieved at only 15% FTW coverage by increasing plant density. The model can be used as a low-cost tool for designing FTW technology applications and monitoring nitrogen transport.
Show less - Date Issued
- 2016
- Identifier
- CFE0006140, ucf:51168
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006140
- Title
- Total Ownership Cost Modeling of Technology Adoption Using System Dynamics: Implications for ERP Systems.
- Creator
-
Esmaeilian, Behzad, Karwowski, Waldemar, Mollaghasemi, Mansooreh, Xanthopoulos, Petros, Ahram, Tareq, Kincaid, John, University of Central Florida
- Abstract / Description
-
Investment in new technologies is considered by firms as a solution to improve their productivity, product and service quality and their competitive advantages in the global market. Unfortunately, not all technology adoption projects have met their intended objectives. The complexity of technology adoption along with little consideration of the long term cost of the technology, are among the factors that challenge companies while adopting a new technology. Companies often make new technology...
Show moreInvestment in new technologies is considered by firms as a solution to improve their productivity, product and service quality and their competitive advantages in the global market. Unfortunately, not all technology adoption projects have met their intended objectives. The complexity of technology adoption along with little consideration of the long term cost of the technology, are among the factors that challenge companies while adopting a new technology. Companies often make new technology adoption decision without enough attention to the total cost of the technology over its lifecycle. Sometimes poor decision making while adopting a new technology can result in substantial recurring loss impacts. Therefore, estimating the total cost of the technology is an important step in justifying the technology adoption. Total Ownership Cost (TOC) is a wildly-accepted financial metric which can be applied to study the costs associated with the new technology throughout its lifecycle. TOC helps companies analyze not only the acquisition and procurement cost of the technology, but also other cost components occurring over the technology usage and service stage. The point is that, technology adoption cost estimation is a complex process involving consideration of various aspects such as the maintenance cost, technology upgrade cost and the cost related to the human-resource. Assessing the association between the technology characteristics (technology upgrades over its life cycle, compatibility with other systems, technology life span, etc) and the TOC encompasses a high degree of complexity. The complexity exists because there are many factors affecting the cost over time. Sometimes decisions made today can have long lasting impact on the system costs and there is a lag between the time the decision is taken and when outcomes occur. An original contribution of this dissertation is development of a System Dynamics (SD) model to estimate the TOC associated with the new technology adoption. The SD model creates casual linkage and relationships among various aspects of the technology adoption process and allows decision makers to explore the impact of their decisions on the total cost that the technology brings into the company. The SD model presented in this dissertation composes of seven sub-models including (1) technology implementation efforts, (2) workforce training, (3) technology-related workforce hiring process, (4) preventive and corrective maintenance process, (5) technology upgrade, (6) impact of technology on system performance and (7) total ownership cost sub model. A case study of Enterprise Resource Planning (ERP) system adoption has been used to show the application of the SD model. The results of the model show that maintenance, upgrade and workforce hiring costs are among the major cost components in the ERP adoption case study presented in Chapter 4. The simulation SD model developed in this dissertation supports trade-off analysis and provides a tool for technology scenarios evaluation. The SD model presented here can be extended to provide a basis for developing a decision support system for technology evaluation.?
Show less - Date Issued
- 2013
- Identifier
- CFE0004836, ucf:49686
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004836
- Title
- MODELING SCENES AND HUMAN ACTIVITIES IN VIDEOS.
- Creator
-
Basharat, Arslan, Shah, Mubarak, University of Central Florida
- Abstract / Description
-
In this dissertation, we address the problem of understanding human activities in videos by developing a two-pronged approach: coarse level modeling of scene activities and fine level modeling of individual activities. At the coarse level, where the resolution of the video is low, we rely on person tracks. At the fine level, richer features are available to identify different parts of the human body, therefore we rely on the body joint tracks. There are three main goals of this dissertation: ...
Show moreIn this dissertation, we address the problem of understanding human activities in videos by developing a two-pronged approach: coarse level modeling of scene activities and fine level modeling of individual activities. At the coarse level, where the resolution of the video is low, we rely on person tracks. At the fine level, richer features are available to identify different parts of the human body, therefore we rely on the body joint tracks. There are three main goals of this dissertation: (1) identify unusual activities at the coarse level, (2) recognize different activities at the fine level, and (3) predict the behavior for synthesizing and tracking activities at the fine level. The first goal is addressed by modeling activities at the coarse level through two novel and complementing approaches. The first approach learns the behavior of individuals by capturing the patterns of motion and size of objects in a compact model. Probability density function (pdf) at each pixel is modeled as a multivariate Gaussian Mixture Model (GMM), which is learnt using unsupervised expectation maximization (EM). In contrast, the second approach learns the interaction of object pairs concurrently present in the scene. This can be useful in detecting more complex activities than those modeled by the first approach. We use a 14-dimensional Kernel Density Estimation (KDE) that captures motion and size of concurrently tracked objects. The proposed models have been successfully used to automatically detect activities like unusual person drop-off and pickup, jaywalking, etc. The second and third goals of modeling human activities at the fine level are addressed by employing concepts from theory of chaos and non-linear dynamical systems. We show that the proposed model is useful for recognition and prediction of the underlying dynamics of human activities. We treat the trajectories of human body joints as the observed time series generated from an underlying dynamical system. The observed data is used to reconstruct a phase (or state) space of appropriate dimension by employing the delay-embedding technique. This transformation is performed without assuming an exact model of the underlying dynamics and provides a characteristic representation that will prove to be vital for recognition and prediction tasks. For recognition, properties of phase space are captured in terms of dynamical and metric invariants, which include the Lyapunov exponent, correlation integral, and correlation dimension. A composite feature vector containing these invariants represents the action and will be used for classification. For prediction, kernel regression is used in the phase space to compute predictions with a specified initial condition. This approach has the advantage of modeling dynamics without making any assumptions about the exact form (polynomial, radial basis, etc.) of the mapping function. We demonstrate the utility of these predictions for human activity synthesis and tracking.
Show less - Date Issued
- 2009
- Identifier
- CFE0002897, ucf:48042
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002897
- Title
- A System Dynamics Model for Manpower and Technology Implementation Trade-off and Cost Estimation.
- Creator
-
Jiang, Hong, Karwowski, Waldemar, Kincaid, John, Reinerman, Lauren, Ahram, Tareq, University of Central Florida
- Abstract / Description
-
The U.S. Navy has been confronted with budget cuts and constraints during recent years. This reduction in budget compels the U.S. Navy to limit the number of manpower and personnel to control costs. Reducing the total ownership cost (TOC) has become a major topic of interest for the Navy as plans are made for current and future fleets. According to the U.S. Government Accountability Office (GAO, 2003), manpower is the most influential component of determining the life cycle cost of a ship....
Show moreThe U.S. Navy has been confronted with budget cuts and constraints during recent years. This reduction in budget compels the U.S. Navy to limit the number of manpower and personnel to control costs. Reducing the total ownership cost (TOC) has become a major topic of interest for the Navy as plans are made for current and future fleets. According to the U.S. Government Accountability Office (GAO, 2003), manpower is the most influential component of determining the life cycle cost of a ship. The vast majority of the TOC is comprised of operating and support (O(&)S) costs which account for approximately 65 percent of the TOC. Manpower and personnel costs account for approximately 50 percent of O(&)S costs. This research focused on tradeoff analysis and cost estimation between manpower and new technology implementation. Utilizing concepts from System Dynamics Modeling (SDM), System Dynamics Causal Loop diagrams (CLD) were built to identify major factors when implementing new technology, and then stocks and flows diagrams were developed to estimate manpower cost associated with new technology implementation. The SDM base model reflected an 18 months period for technology implementation, and then compared different technology implementation for different scenarios. This model had been tested by the public data from Department of the Navy (DoN) Budget estimates.The objective of this research was to develop a SDM to estimate manpower cost and technology tradeoff analysis associated with different technology implementations. This research will assist Navy decision makers and program managers when objectively considering the impacts of technology selection on manpower and associated TOC, and will provide managers with a better understanding of hidden costs associated with new technology adoption. Recommendations were made for future study in manpower cost estimation of ship systems. In future studies, one particular type of data should be located to test the model for a specific manpower configuration.
Show less - Date Issued
- 2013
- Identifier
- CFE0004869, ucf:49662
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004869
- Title
- A Simulation-Based Task Analysis using Agent-Based, Discrete Event and System Dynamics simulation.
- Creator
-
Angelopoulou, Anastasia, Karwowski, Waldemar, Kincaid, John, Xanthopoulos, Petros, Hancock, Peter, University of Central Florida
- Abstract / Description
-
Recent advances in technology have increased the need for using simulation models to analyze tasks and obtain human performance data. A variety of task analysis approaches and tools have been proposed and developed over the years. Over 100 task analysis methods have been reported in the literature. However, most of the developed methods and tools allow for representation of the static aspects of the tasks performed by expert system-driven human operators, neglecting aspects of the work...
Show moreRecent advances in technology have increased the need for using simulation models to analyze tasks and obtain human performance data. A variety of task analysis approaches and tools have been proposed and developed over the years. Over 100 task analysis methods have been reported in the literature. However, most of the developed methods and tools allow for representation of the static aspects of the tasks performed by expert system-driven human operators, neglecting aspects of the work environment, i.e. physical layout, and dynamic aspects of the task. The use of simulation can help face the new challenges in the field of task analysis as it allows for simulation of the dynamic aspects of the tasks, the humans performing them, and their locations in the environment. Modeling and/or simulation task analysis tools and techniques have been proven to be effective in task analysis, workload, and human reliability assessment. However, most of the existing task analysis simulation models and tools lack features that allow for consideration of errors, workload, level of operator's expertise and skills, among others. In addition, the current task analysis simulation tools require basic training on the tool to allow for modeling the flow of task analysis process and/or error and workload assessment. The modeling process is usually achieved using drag and drop functionality and, in some cases, programming skills.This research focuses on automating the modeling process and simulating individuals (or groups of individuals) performing tasks in a dynamic work environment in any domain. The main objective of this research is to develop a universal tool that allows for modeling and simulation of task analysis models in a short amount of time with limited need for training or knowledge of modeling and simulation theory. A Universal Task Analysis Simulation Modeling (UTASiMo) tool can be used for automatically generating simulation models that analyze the tasks performed by human operators. UTASiMo is a multi-method modeling and simulation tool developed as a combination of agent-based, discrete event, and system dynamics simulation models. A generic multi-method modeling and simulation framework, named 3M(&)S Framework, as well as the Unified Modeling Language have been used for the design of the conceptual model and the implementation of the simulation tool. UTASiMo-generated models are dynamically created during run-time based on user inputs. The simulation results include estimations of operator workload, task completion time, and probability of human errors based on human operator variability and task structure.
Show less - Date Issued
- 2015
- Identifier
- CFE0006252, ucf:51040
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006252
- Title
- A Hybrid Simulation Framework of Consumer-to-Consumer Ecommerce Space.
- Creator
-
Joledo, Oloruntomi, Rabelo, Luis, Lee, Gene, Elshennawy, Ahmad, Ajayi, Richard, University of Central Florida
- Abstract / Description
-
In the past decade, ecommerce transformed the business models of many organizations. Information Technology leveled the playing field for new participants, who were capable of causing disruptive changes in every industry. (")Web 2.0(") or (")Social Web(") further redefined ways users enlist for services. It is now easy to be influenced to make choices of services based on recommendations of friends and popularity amongst peers. This research proposes a simulation framework to investigate how...
Show moreIn the past decade, ecommerce transformed the business models of many organizations. Information Technology leveled the playing field for new participants, who were capable of causing disruptive changes in every industry. (")Web 2.0(") or (")Social Web(") further redefined ways users enlist for services. It is now easy to be influenced to make choices of services based on recommendations of friends and popularity amongst peers. This research proposes a simulation framework to investigate how actions of stakeholders at this level of complexity affect system performance as well as the dynamics that exist between different models using concepts from the fields of operations engineering, engineering management, and multi-model simulation. Viewing this complex model from a systems perspective calls for the integration of different levels of behaviors. Complex interactions exist among stakeholders, the environment and available technology. The presence of continuous and discrete behaviors coupled with stochastic and deterministic behaviors present challenges for using standalone simulation tools to simulate the business model.We propose a framework that takes into account dynamic system complexity and risk from a hybrid paradigm. The SCOR model is employed to map the business processes and it is implemented using agent based simulation and system dynamics. By combining system dynamics at the strategy level with agent based models of consumer behaviors, an accurate yet efficient representation of the business model that makes for sound basis of decision making can be achieved to maximize stakeholders' utility.
Show less - Date Issued
- 2016
- Identifier
- CFE0006122, ucf:51171
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006122
- Title
- Systems Analysis for Urban Water Infrastructure Expansion with Global Change Impact under Uncertainties.
- Creator
-
Qi, Cheng, Chang, Ni-bin, Geiger, Christopher, Xanthopoulos, Petros, Wanielista, Martin, University of Central Florida
- Abstract / Description
-
Over the past decades, cost-effectiveness principle or cost-benefit analysis has been employed oftentimes as a typical assessment tool for the expansion of drinking water utility. With changing public awareness of the inherent linkages between climate change, population growth and economic development, the addition of global change impact in the assessment regime has altered the landscape of traditional evaluation matrix. Nowadays, urban drinking water infrastructure requires careful long...
Show moreOver the past decades, cost-effectiveness principle or cost-benefit analysis has been employed oftentimes as a typical assessment tool for the expansion of drinking water utility. With changing public awareness of the inherent linkages between climate change, population growth and economic development, the addition of global change impact in the assessment regime has altered the landscape of traditional evaluation matrix. Nowadays, urban drinking water infrastructure requires careful long-term expansion planning to reduce the risk from global change impact with respect to greenhouse gas (GHG) emissions, economic boom and recession, as well as water demand variation associated with population growth and migration. Meanwhile, accurate prediction of municipal water demand is critically important to water utility in a fast growing urban region for the purpose of drinking water system planning, design and water utility asset management. A system analysis under global change impact due to the population dynamics, water resources conservation, and environmental management policies should be carried out to search for sustainable solutions temporally and spatially with different scales under uncertainties. This study is aimed to develop an innovative, interdisciplinary, and insightful modeling framework to deal with global change issues as a whole based on a real-world drinking water infrastructure system expansion program in Manatee County, Florida. Four intertwined components within the drinking water infrastructure system planning were investigated and integrated, which consists of water demand analysis, GHG emission potential, system optimization for infrastructure expansion, and nested minimax-regret (NMMR) decision analysis under uncertainties. In the water demand analysis, a new system dynamics model was developed to reflect the intrinsic relationship between water demand and changing socioeconomic environment. This system dynamics model is based on a coupled modeling structure that takes the interactions among economic and social dimensions into account offering a satisfactory platform. In the evaluation of GHG emission potential, a life cycle assessment (LCA) is conducted to estimate the carbon footprint for all expansion alternatives for water supply. The result of this LCA study provides an extra dimension for decision makers to extract more effective adaptation strategies. Both water demand forecasting and GHG emission potential were deemed as the input information for system optimization when all alternatives are taken into account simultaneously. In the system optimization for infrastructure expansion, a multiobjective optimization model was formulated for providing the multitemporal optimal facility expansion strategies. With the aid of a multi-stage planning methodology over the partitioned time horizon, such a systems analysis has resulted in a full-scale screening and sequencing with respect to multiple competing objectives across a suite of management strategies. In the decision analysis under uncertainty, such a system optimization model was further developed as a unique NMMR programming model due to the uncertainties imposed by the real-world problem. The proposed NMMR algorithm was successfully applied for solving the real-world problem with a limited scale for the purpose of demonstration.
Show less - Date Issued
- 2012
- Identifier
- CFE0004425, ucf:49354
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004425
- Title
- A Holistic Analysis of the Long-Term Challenges (&) Potential Benefits of the Green Roof, Solar PV Roofing, and GRIPV Roofing Markets in Orlando, Florida.
- Creator
-
Kelly, Carolina, Tatari, Omer, Oloufa, Amr, Mayo, Talea, Zheng, Qipeng, University of Central Florida
- Abstract / Description
-
Green roofs and roof-mounted solar PV arrays have a wide range of environmental and economic benefits, including significantly longer roof lifetimes, reductions in urban runoff, mitigation of the urban heat island (UHI) effect, reduced electricity demand and energy dependence, and/or reduced emissions of greenhouse gases (GHGs) and other harmful pollutants from the electricity generation sector. Consequently, green roofs and solar panels have both become increasingly popular worldwide, and...
Show moreGreen roofs and roof-mounted solar PV arrays have a wide range of environmental and economic benefits, including significantly longer roof lifetimes, reductions in urban runoff, mitigation of the urban heat island (UHI) effect, reduced electricity demand and energy dependence, and/or reduced emissions of greenhouse gases (GHGs) and other harmful pollutants from the electricity generation sector. Consequently, green roofs and solar panels have both become increasingly popular worldwide, and promising new research has emerged for their potential combination in Green Roof Integrated Photovoltaic (GRIPV) roofing applications. However, due to policy resistance, these alternatives still have marginal market shares in the U.S., while GRIPV research and development is still severely limited today. As a result, these options are not yet sufficiently widespread in the United States as to realize their full potential, particularly due to a variety of policy resistance effects with respect to each specific alternative. The steps in the System Dynamics (SD) methodology to be used in this study are summarized as follows. First, based on a comprehensive review of relevant literature, a causal loop diagram (CLD) will be drawn to provide a conceptual illustration of the modeled system. Second, based on the feedback relationships observed in this CLD, a stock-flow diagram (SFD) will be developed to form a quantitative model. Third, the modeled SFD will be tested thoroughly to ensure its structural and behavioral validity with respect to the modeled system in reality using whatever real world data is available. Fourth, different policy scenarios will be simulated within the model to evaluate their long-term effectiveness. Fifth, uncertainty analyses will be performed to evaluate the inherent uncertainties associated with the analyses in this study. Finally, the results observed for the analyses in this study and possible future research steps will be discussed and compared as appropriate.
Show less - Date Issued
- 2018
- Identifier
- CFE0007406, ucf:52741
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007406
