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- Genre: Doctoral Dissertation
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Description
The main objective of this research is to develop an integrated method to study emergent behavior and consequences of evolution and adaptation in engineered complex adaptive systems (ECASs). A multi-layer conceptual framework and modeling approach including behavioral and structural aspects is provided to describe the structure of a class of engineered complex systems and predict their future adaptive patterns. The approach allows the examination of complexity in the structure and the behavior of components as a result of their connections and in relation to their environment. This research describes and uses the major differences of natural complex adaptive systems (CASs) with artificial/engineered CASs to build a framework and platform for ECAS. While this framework focuses on the critical factors of an engineered system, it also enables one to synthetically employ engineering and mathematical models to analyze and measure complexity in such systems. In this way concepts of complex systems science are adapted to management science and system of systems engineering. In particular an integrated consumer-based optimization and agent-based modeling (ABM) platform is presented that enables managers to predict and partially control patterns of behaviors in ECASs. Demonstrated on the U.S. electricity markets, ABM is integrated with normative and subjective decision behavior recommended by the U.S. Department of Energy (DOE) and Federal Energy Regulatory Commission (FERC). The approach integrates social networks, social science, complexity theory, and diffusion theory. Furthermore, it has unique and significant contribution in exploring and representing concrete managerial insights for ECASs and offering new optimized actions and modeling paradigms in agent-based simulation.
ContributorsHaghnevis, Moeed (Author) / Askin, Ronald G. (Thesis advisor) / Armbruster, Dieter (Thesis advisor) / Mirchandani, Pitu (Committee member) / Wu, Tong (Committee member) / Hedman, Kory (Committee member) / Arizona State University (Publisher)
Created2013
Description
Consumers search before making virtually any purchase. The notion that consumers engage in costly search is well-understood to have deep implications for market performance. However to date, no theoretical model allows for the observation that consumers often purchase more than a single product in an individual shopping occasion. Clothing, food, books, and music are but four important examples of goods that are purchased many items at a time. I develop a modeling approach that accounts for multi-purchase occasions in a structural way. My model shows that as preference for variety increases, so does the size of the consideration set. Search models that ignore preference for variety are, therefore, likely to under-predict the number of products searched. It is generally thought that lower search costs increase retail competition which pushes prices and assortments down. However, I show that there is an optimal number of products to offer depending on the intensity of consumer search costs. Consumers with high search costs prefer to shop at a store with a large assortment of goods and purchase multiple products, even if the prices that firm charges is higher than competing firms' prices. On the other hand, consumers with low search costs tend to purchase fewer goods and shop at the stores that have lower prices, as long as the store has a reasonable assortment offering. The implications for market performance are dramatic and pervasive. In particular, the misspecification of demand model in which search is important and/or multiple discreteness is observed will produce biased parameter estimates leading to erroneous managerial conclusions.
ContributorsAllender, William Jacob (Author) / Richards, Timothy J. (Thesis advisor) / Park, Sungho (Committee member) / Hamilton, Stephen (Committee member) / Arizona State University (Publisher)
Created2013
Description
Traditional approaches to modeling microgrids include the behavior of each inverter operating in a particular network configuration and at a particular operating point. Such models quickly become computationally intensive for large systems. Similarly, traditional approaches to control do not use advanced methodologies and suffer from poor performance and limited operating range. In this document a linear model is derived for an inverter connected to the Thevenin equivalent of a microgrid. This model is then compared to a nonlinear simulation model and analyzed using the open and closed loop systems in both the time and frequency domains. The modeling error is quantified with emphasis on its use for controller design purposes. Control design examples are given using a Glover McFarlane controller, gain sched- uled Glover McFarlane controller, and bumpless transfer controller which are compared to the standard droop control approach. These examples serve as a guide to illustrate the use of multi-variable modeling techniques in the context of robust controller design and show that gain scheduled MIMO control techniques can extend the operating range of a microgrid. A hardware implementation is used to compare constant gain droop controllers with Glover McFarlane controllers and shows a clear advantage of the Glover McFarlane approach.
ContributorsSteenis, Joel (Author) / Ayyanar, Raja (Thesis advisor) / Mittelmann, Hans (Committee member) / Tsakalis, Konstantinos (Committee member) / Tylavsky, Daniel (Committee member) / Arizona State University (Publisher)
Created2013
Description
Transmission expansion planning (TEP) is a complex decision making process that requires comprehensive analysis to determine the time, location, and number of electric power transmission facilities that are needed in the future power grid. This dissertation investigates the topic of solving TEP problems for large power systems. The dissertation can be divided into two parts. The first part of this dissertation focuses on developing a more accurate network model for TEP study. First, a mixed-integer linear programming (MILP) based TEP model is proposed for solving multi-stage TEP problems. Compared with previous work, the proposed approach reduces the number of variables and constraints needed and improves the computational efficiency significantly. Second, the AC power flow model is applied to TEP models. Relaxations and reformulations are proposed to make the AC model based TEP problem solvable. Third, a convexified AC network model is proposed for TEP studies with reactive power and off-nominal bus voltage magnitudes included in the model. A MILP-based loss model and its relaxations are also investigated. The second part of this dissertation investigates the uncertainty modeling issues in the TEP problem. A two-stage stochastic TEP model is proposed and decomposition algorithms based on the L-shaped method and progressive hedging (PH) are developed to solve the stochastic model. Results indicate that the stochastic TEP model can give a more accurate estimation of the annual operating cost as compared to the deterministic TEP model which focuses only on the peak load.
ContributorsZhang, Hui (Author) / Vittal, Vijay (Thesis advisor) / Heydt, Gerald T (Thesis advisor) / Mittelmann, Hans D (Committee member) / Hedman, Kory W (Committee member) / Arizona State University (Publisher)
Created2013
Description
Through manipulation of adaptable opportunities available within a given environment, individuals become active participants in managing personal comfort requirements, by exercising control over their comfort without the assistance of mechanical heating and cooling systems. Similarly, continuous manipulation of a building skin's form, insulation, porosity, and transmissivity qualities exerts control over the energy exchanged between indoor and outdoor environments. This research uses four adaptive response variables in a modified software algorithm to explore an adaptive building skin's potential in reacting to environmental stimuli with the purpose of minimizing energy use without sacrificing occupant comfort. Results illustrate that significant energy savings can be realized with adaptive envelopes over static building envelopes even under extreme summer and winter climate conditions; that the magnitude of these savings are dependent on climate and orientation; and that occupant thermal comfort can be improved consistently over comfort levels achieved by optimized static building envelopes. The resulting adaptive envelope's unique climate-specific behavior could inform designers in creating an intelligent kinetic aesthetic that helps facilitate adaptability and resiliency in architecture.
ContributorsErickson, James (Author) / Bryan, Harvey (Thesis advisor) / Addison, Marlin (Committee member) / Kroelinger, Michael D. (Committee member) / Reddy, T. Agami (Committee member) / Arizona State University (Publisher)
Created2013
Description
There have been multiple calls for research on consumers' responses to social issues, regulatory changes, and corporate behavior. Thus, this dissertation proposes and tests a conceptual framework of parents' responses to government regulations and corporate social responsibility (CSR) that address juvenile obesity. This research builds on Attribution Theory to examine the impact of government regulations and CSR on consumers' attitudes and their subsequent behavior. Three pilot studies and three main experiments were conducted; a between-subjects and randomized experimental design being used to capture the effects of regulations and corporate actions on product satisfaction, company evaluations, and behavioral intentions, while examining the mediating role of attributions of responsibility for a negative product outcome. This research has implications for policy makers and marketing practitioners and scholars. This is the first study to offer a new perspective, based on attributions of blame, to explain the mechanism that drives consumers' responses to government regulations. Considering numerous calls for government actions that address childhood obesity, it is important to understand how and why consumers respond to such regulations. The results illustrated that certain policies may have unintended consequences due to unexpected attributions of blame for unhealthy products. Only recently have researchers tried to address the psychological mechanism through which CSR has an impact on consumers' attitudes and behavior. To date, few studies have investigated attributions as a mediating variable in the transfer of CSR associations on consumer responses. Nonetheless, this is the first study that concentrates on attributions of responsibility, per se, to explain the impact of CSR on company evaluations. This dissertation extends previous research, where locus, stability, and controllability mediated the relationship between CSR and attributions of blame; the degree of blame being consequential to brand evaluations. The current results suggest that attributions of responsibility, per se, mediate the impact of CSR on company evaluations. Additionally, attributions of blame are measured as the degree to which consumers take personal responsibility for a negative product outcome. This highlights a new role of the CSR construct, as a moderator of consumers' self-serving bias, a fundamental psychological response that has been neglected in the marketing literature.
ContributorsDumitrescu, Claudia (Author) / Shaw Hughner, Renée (Thesis advisor) / Schmitz, Troy G. (Committee member) / Seperich, George (Committee member) / Shultz, Ii, Clifford J. (Committee member) / Arizona State University (Publisher)
Created2013
Description
This thesis studies three different types of anhydrous proton conducting electrolytes for use in fuel cells. The proton energy level scheme is used to make the first electrolyte which is a rubbery polymer in which the conductivity reaches values typical of activated Nafion, even though it is completely anhydrous. The protons are introduced into a cross-linked polyphospazene rubber by the superacid HOTf, which is absorbed by partial protonation of the backbone nitrogens. The decoupling of conductivity from segmental relaxation times assessed by comparison with conductivity relaxation times amounts to some 10 orders of magnitude, but it cannot be concluded whether it is purely protonic or due equally to a mobile OTf- or H(OTf)2-; component. The second electrolyte is built on the success of phosphoric acid as a fuel cell electrolyte, by designing a variant of the molecular acid that has increased temperature range without sacrifice of high temperature conductivity or open circuit voltage. The success is achieved by introduction of a hybrid component, based on silicon coordination of phosphate groups, which prevents decomposition or water loss to 250ºC, while enhancing free proton motion. Conductivity studies are reported to 285ºC and full H2/O2 cell polarization curves to 226ºC. The current efficiency reported here (current density per unit of fuel supplied per sec) is the highest on record. A power density of 184 (mW.cm-2) is achieved at 226ºC with hydrogen flow rate of 4.1 ml/minute. The third electrolyte is a novel type of ionic liquids which is made by addition of a super strong Brønsted acid to a super weak Brønsted base. Here it is shown that by allowing the proton of transient HAlCl4, to relocate on a very weak base that is also stable to superacids, we can create an anhydrous ionic liquid, itself a superacid, in which the proton is so loosely bound that at least 50% of the electrical conductivity is due to the motion of free protons. The protic ionic liquids (PILs) described, pentafluoropyridinium tetrachloroaluminate and 5-chloro-2,4,6-trifluoropyrimidinium tetrachloroaluminate, might be the forerunner of a class of materials in which the proton plasma state can be approached.
ContributorsAnsari, Younes (Author) / Angell, Charles A (Thesis advisor) / Richert, Ranko (Committee member) / Chizmeshya, Andrew (Committee member) / Wolf, George (Committee member) / Arizona State University (Publisher)
Created2013
Description
Energy is a central concern of sustainability because how we produce and consume energy affects society, economy, and the environment. Sustainability scientists are interested in energy transitions away from fossil fuels because they are nonrenewable, increasingly expensive, have adverse health effects, and may be the main driver of climate change. They see an opportunity for developing countries to avoid the negative consequences fossil-fuel-based energy systems, and also to increase resilience, by leap-frogging-over the centralized energy grid systems that dominate the developed world. Energy transitions pose both challenges and opportunities. Obstacles to transitions include 1) an existing, centralized, complex energy-grid system, whose function is invisible to most users, 2) coordination and collective-action problems that are path dependent, and 3) difficulty in scaling up RE technologies. Because energy transitions rely on technological and social innovations, I am interested in how institutional factors can be leveraged to surmount these obstacles. The overarching question that underlies my research is: What constellation of institutional, biophysical, and social factors are essential for an energy transition? My objective is to derive a set of "design principles," that I term institutional drivers, for energy transitions analogous to Ostrom's institutional design principles. My dissertation research will analyze energy transitions using two approaches: applying the Institutional Analysis and Development Framework and a comparative case study analysis comprised of both primary and secondary sources. This dissertation includes: 1) an analysis of the world's energy portfolio; 2) a case study analysis of five countries; 3) a description of the institutional factors likely to promote a transition to renewable-energy use; and 4) an in-depth case study of Thailand's progress in replacing nonrenewable energy sources with renewable energy sources. My research will contribute to our understanding of how energy transitions at different scales can be accomplished in developing countries and what it takes for innovation to spread in a society.
ContributorsKoster, Auriane Magdalena (Author) / Anderies, John M (Thesis advisor) / Aggarwal, Rimjhim (Committee member) / Van Der Leeuw, Sander (Committee member) / Arizona State University (Publisher)
Created2013
Description
Zinc oxide (ZnO) has attracted much interest during last decades as a functional material. Furthermore, ZnO is a potential material for transparent conducting oxide material competing with indium tin oxide (ITO), graphene, and carbon nanotube film. It has been known as a conductive material when doped with elements such as indium, gallium and aluminum. The solubility of those dopant elements in ZnO is still debatable; but, it is necessary to find alternative conducting materials when their form is film or nanostructure for display devices. This is a consequence of the ever increasing price of indium. In addition, a new generation solar cell (nanostructured or hybrid photovoltaics) requires compatible materials which are capable of free standing on substrates without seed or buffer layers and have the ability introduce electrons or holes pathway without blocking towards electrodes. The nanostructures for solar cells using inorganic materials such as silicon (Si), titanium oxide (TiO2), and ZnO have been an interesting topic for research in solar cell community in order to overcome the limitation of efficiency for organic solar cells. This dissertation is a study of the rational solution-based synthesis of 1-dimentional ZnO nanomaterial and its solar cell applications. These results have implications in cost effective and uniform nanomanufacturing for the next generation solar cells application by controlling growth condition and by doping transition metal element in solution.
ContributorsChoi, Hyung Woo (Author) / Alford, Terry L. (Thesis advisor) / Krause, Stephen (Committee member) / Theodore, N. David (Committee member) / Arizona State University (Publisher)
Created2012
Customer participation in service conversations: an investigation of the dynamics of service context
Description
In this research, I focus on service conversations in professional services. For most Business-to-Business or Business-to-Consumer professional services, the service conversation is an important part of the service experience and is critical to solutions co-creation as well as customer satisfaction. In this research, I examine service conversation sequences at the micro-level and explore two important research questions: (1) how do I explain the dynamics of moment-by-moment Customer Participation in Service Conversations (CPSC)? and (2) how do the temporal and process dynamics of CPSC relate to customer satisfaction and solution compliance? From a dynamic context perspective, I develop a conceptual framework that explains the co-existence of stable and dynamic customer participation behavior in a service conversation. I conduct a series of lab experiments and an observation study of online conversations between 173 customers and 52 doctors to empirically validate the conceptual framework. This research demonstrates that at any given moment, customers manage their information sharing and interaction control based on their mental representation of the context complexity. Although the context-behavior relationships are stable, the service conversation context is dynamic. The service provider's behavior can constantly change and introduce new context cues. When the context changes so does the CPSC behavior. Finally, this research shows that to improve customer satisfaction, customer perceived service quality, and customer solution compliance, service providers should focus on helping customers reduce their perceived context complexity as early as possible, by providing information and educating customers. This research makes important theoretical and managerial contributions. Theoretically, it defines and develops measures of service context complexity in terms of its psychological features. It develops a conceptual framework to explain the temporal dynamics of CPSC on multi-dimensions. Empirically, this research adopts a phase-based sequence analysis approach and uses a negative bi-nominal model to examine the temporal process effect of the service conversation on service outcomes. Managerially, the research findings provide firms important and actionable guidelines to manage conversation-based professional services.
ContributorsWang, Si (Author) / Binter, Mary Jo (Thesis advisor) / Ostrom, Amy L. (Committee member) / Olsen, G. Douglas (Committee member) / Arizona State University (Publisher)
Created2013