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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Social interdependence's promotive interaction defined by heedful interrelating and transactive memory systems

Daniel, Sarah Rebecca 14 August 2015 (has links)
This study investigated the utility of using the constructs of transactive memory system and heedful interrelating to explain the causal mechanisms of resulting learning and attitudinal outcomes emerging from the promotive interaction which occurs under conditions of positive social interdependence. An experimental study with clarifying qualitative analyses was conducted with college students as participants. Two aspects were addressed: (a) to define the promotive interaction in quantitative and qualitative terms using heedful interrelating and transactive memory system and (b) to assess the role of the promotive interaction, defined by heedful interrelating and transactive memory system, in the relationship between social interdependence and both proximal learning-related attitudinal outcomes including task value and situational interest, as well as more distal behavioral learning-related outcomes including group and individual task performance and individual perceptions of group performance. There was no direct effect of social interdependence on any outcome of interest nor were the mediational roles of heedful interrelating and transactive memory system in the relationship between positive social interdependence and outcomes of interest (individual and group performance, situational interest, task value, and perceptions of performance) supported, further exploratory analyses revealed these constructs did have significant direct effects on various outcomes of interest. Heedful interrelating was positively predictive of participants' situational interest, task value, individual perceptions of group performance, and individual and group performance. Transactive memory system was also positively predictive of individual situational interest and task value and group performance while an unexpected negative direct effect was found for individual performance. Qualitative analyses focusing on selected groups were used to explore this unexpected impact of transactive memory system on individual learning. Ways in which future studies may build on quantitative and qualitative findings are discussed.
2

The role of transactive memory in work teams : a review

Gregory, Megan E. 01 January 2009 (has links)
Transactive memory, the transmission and use of knowledge between two or more people, is an important construct to consider when studying work teams. This thesis reviews the literature on transactive memory systems (TMS) in order to summarize what is currently known about TMS and to identify gaps in the literature in need of further investigation. Past TMS research is reviewed according to the operational definitions, antecedents, team processes, outcomes, team performance, and boundary conditions. TMS is most frequently operationalized using Lewis' (2003) TMS scale. Research has focused on three types of antecedents: Communication, Team Characteristics, and Facilitation of TMS. Two common types of team processes found were coordination and team monitoring & backup behavior. Outcomes frequently focused on were team cognition, and team effectiveness. Team performance was ubiquitous in almost all the literature. Boundary conditions, however, varied considerably
3

Multi-scale transactive control in interconnected bulk power systems under high renewable energy supply and high demand response scenarios

Chassin, David P. 06 December 2017 (has links)
This dissertation presents the design, analysis, and validation of a hierarchical transactive control system that engages demand response resources to enhance the integration of renewable electricity generation resources. This control system joins energy, capacity and regulation markets together in a unified homeostatic and economically efficient electricity operation that increases total surplus while improving reliability and decreasing carbon emissions from fossil-based generation resources. The work encompasses: (1) the derivation of a short-term demand response model suitable for transactive control systems and its validation with field demonstration data; (2) an aggregate load model that enables effective control of large populations of thermal loads using a new type of thermostat (discrete time with zero deadband); (3) a methodology for optimally controlling response to frequency deviations while tracking schedule area exports in areas that have high penetration of both intermittent renewable resources and fast-acting demand response; and (4) the development of a system-wide (continental interconnection) scale strategy for optimal power trajectory and resource dispatch based on a shift from primarily energy cost-based approach to a primarily ramping cost-based one. The results show that multi-layer transactive control systems can be constructed, will enhance renewable resource utilization, and will operate in a coordinated manner with bulk power systems that include both regions with and without organized power markets. Estimates of Western Electric Coordinating Council (WECC) system cost savings under target renewable energy generation levels resulting from the proposed system exceed US$150B annually by the year 2024, when compared to the existing control system. / Graduate
4

Developing a PV and Energy Storage Sizing Methodology for Off-Grid Communities

Vance, David M. 12 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Combining rooftop solar with energy storage for off-grid residential operation is restrictively expensive. Historically, operating off-grid requires an 'isolated self-consumption' operating strategy where any excess generation is wasted and to ensure reliability you must install costly, polluting generators or a large amount of energy storage. With the advent of Blockchain technology residents can come together and establish transactive microgrids which have two possible operating strategies: Centralized Energy Sharing (CES) and Interconnected Energy Sharing (IES). The CES strategy proposes that all systems combine their photovoltaic (PV) generation and energy storage systems (ESS) to meet their loads. IES strategy establishes an energy trading system between stand-alone systems which allows buying energy when battery capacity is empty and selling energy when battery capacity is full. Transactive microgrids have been investigated analytically by several sources, none of which consider year-round off-grid operation. A simulation tool was developed through MATLAB for comparing the three operating strategies: isolated self-consumption, CES, and IES. This simulation tool could easily be incorporated into existing software such as HOMER. The effect of several variables on total cost was tested including interconnection type, initial charge, load variability, starting month, number of stand-alone systems, geographic location, and required reliability. It was found that the CES strategy improves initial cost by 7\% to 10\% compared to the baseline (isolated self-consumption) and IES cases in every simulation. The IES case consistently saved money compared to the baseline, just by a very small amount (less than 1\%). Initial charge was investigated for March, July, and November and was only found to have an effect in November. More research should be done to show the effect of initial charge for every month of the year. Load variability had inconsistent results between the two geographic locations studied, Indianapolis and San Antonio. This result would be improved with an improved load simulation which includes peak shifting. The number of systems did not have a demonstrable effect, giving the same cost whether there were 2 systems or 50 involved in the trading strategies. It may be that only one other system is necessary to receive the benefits from a transactive microgrid. Geographic locations studied (Indianapolis, Indiana; Phoenix, Arizona; Little Rock, Arkansas; and Erie, Pennsylvania) showed a large effect on the total cost with Phoenix being considerably cheaper than any other location and Erie having the highest cost. This result was expected due to each geographic location's load and solar radiation profiles. Required reliability showed a consistent and predictable effect with cost going down as the requirement relaxed and more hours of outage were allowed. In order to accomplish off-grid operation with favorable economics it is likely that a system will need to reduce its reliability requirement, adopt energy saving consumption habits, choose a favorable geographic location, and either establish a transactive microgrid or include secondary energy generation and/or storage.
5

A Game Theoretic-based Transactive Energy Framework for Distributed Energy Resources

Bhatti, Bilal Ahmad 07 January 2021 (has links)
Power systems have evolved significantly during the last two decades with the advent of Distributed Energy Resources (DERs) like solar PV. Traditionally, large power plants were considered as the sole source of energy in the power systems. However, DERs connected to the transmission and the distribution systems are creating a paradigm shift from a centralized generation to a distributed one. Though the variable power output from these DERs poses challenges to the reliable operation of the grid, it also presents opportunities to design control and coordination approaches to improve system efficiency and operational reliability. Moreover, building new transmission lines to meet ever-increasing load demand is not always viable. Thus, the industry is leaning towards developing non-wires alternatives. Considering the existing limitations of the transmission system, line congestions, and logistic/economic constraints associated with its capacity expansion, leveraging DERs to supply distribution system loads is attractive and thus capturing the attention of researchers and the electric power industry. The primary objective of this dissertation is to develop a framework that enables DERs to supply local area load by co-simulating the power system and transactive system representations of the network. To realize this objective, a novel distributed optimization and game theory-based network representation is developed that optimally computes the power output of the Home Microgrids/DER aggregators. Moreover, the optimum operational schedules of the DERs within these Home Microgrids/DER aggregators are also computed. The novel electrical-transactive co-simulation ensures that the solution is optimum in the context of power systems i.e. power flow constraints are not violated while the payoffs are maximized for the Home Microgrids/DER aggregators. The transactive mechanism involves two-way iterative signaling. The signaling is modeled as an infinite strategy, multiplayer, non-cooperative game, and a novel theory is developed for the game model. The dissertation also introduces a novel concept of ranking the Home Microgrids/DER aggregators according to their historic performance, thus leading to fairness, higher participation, and transparency. Significant advantages offered by the framework include consumption of local generation, transmission upgrade deferral, mitigation of line congestions in peak periods, and reduced transmission systems losses. / Doctor of Philosophy / In past, electricity was primarily produced by the large fossil fuel-based and nuclear power plants, usually located farther away from the populated areas where the bulk of the electricity consumption occurs. The electricity from the power plants is carried by the transmission lines to the populated areas where it is distributed to end-users via a distribution network. However, during the last two decades, issues like global warming and depleting fossil fuels have led to the development and increased adoption of renewable energy resources like solar photovoltaics (PV), wind turbines, etc. These resources are commonly known as Distributed Energy Resources (DERs), and they are connected to both the transmission and the distribution systems. Initially, they were mainly used to supply the load within the facility in which they are installed. However, the electric load (demand) continues to grow while adding new fossil fuel-based plants and transmission lines are becoming logistically/economically challenging. Thus, researchers are working on developing techniques that can enable DERs to supply the loads in the distribution system to which they are connected. This dissertation develops a method to use DERs for load support in the distribution systems. Specifically, the buildings that house the DERs can use the energy generated by the DERs to supply the local load (building load), and once the total generation exceeds the load demand, the building can inject the power into the distribution system to support the local area load. The proposed framework considers the electric network constraints like limits of lines supplying the power and limits of the transformers. The proposed work also develops a new method to maximize the benefit (in terms of profit) for the DER owners. A ranking system is introduced for the DER owners that enhances the transparency and fairness of the process. The key benefits offered by the proposed work include reduced losses in the transmission system, more energy consumed closer to the point of generation, and avoidance of transmission line and large central generation additions.
6

Distributing the Grid: Transactive Integration of Energy Resources

Raker, David M. 11 July 2022 (has links)
No description available.
7

Transactive Control for Large-Scale Cyber-Physical Systems

Li, Sen January 2017 (has links)
No description available.
8

Analysis of Blockchain-based Smart Contracts for Peer-to-Peer Solar Electricity Transactive Markets

Lin, Jason 08 February 2019 (has links)
The emergence of blockchain technology and increasing penetration of distributed energy resources (DERs) have created a new opportunity for peer-to-peer (P2P) energy trading. However, challenges arise in such transactive markets to ensure individual rationality, incentive compatibility, budget balance, and economic efficiency during the trading process. This thesis creates an hour-ahead P2P energy trading network based on the Hyperledger Fabric blockchain and explores a comparative analysis of different auction mechanisms that form the basis of smart contracts. Considered auction mechanisms are discriminatory and uniform k-Double Auction with different k values. This thesis also investigates effects of four consumer and prosumer bidding strategies: random, preference factor, price-only game-theoretic approach, and supply-demand game-theoretic approach. A custom simulation framework that models the behavior of the transactive market is developed. Case studies of a 100-home microgrid at various photovoltaic (PV) penetration levels are presented using typical residential load and PV generation profiles in the metropolitan Washington, D.C. area. Results indicate that regardless of PV penetration levels and employed bidding strategies, discriminatory k-DA can outperform uniform k-DA. Despite so, discriminatory k-DA is more sensitive to market conditions than uniform k-DA. Additionally, results show that the price-only game-theoretic bidding strategy leads to near-ideal economic efficiencies regardless of auction mechanisms and PV penetration levels. / MS
9

Understanding the determinants of creativity at an individual and team level / Comprendre les déterminants de la créativité aux niveaux de l'individu et de l'équipe

Somsing, Autcharaporn 06 December 2016 (has links)
Beaucoup d'organisations se sont appuyées sur la créativité pour dépasser leurs concurrents et le savoir sur la façon de soutenir la créativité est devenu critique. En règle générale, la créativité aurait pour origine les individus ou un groupe de personnes travaillant ensemble. Par conséquent, dans cette thèse, notre objectif est de fournir une meilleure compréhension de la façon de faciliter la créativité à la fois au niveau individuel et de l'équipe. Pour l'équipe, nous nous concentrerons sur la créativité de l'équipe virtuelle qui a été peu étudiée malgré l’intérêt de l’analyse. Les quatre articles de cette thèse visent à fournir une meilleure compréhension de la créativité et à en identifier les déterminants tant au niveau individuel que pour l’équipe virtuelle. Nous avons analysé la littérature sur la créativité individuelle pour améliorer la compréhension de la créativité des employés. Notre analyse suggère qu'il est plus efficace de tenir compte à la fois des facteurs individuels et contextuels pour évaluer la créativité des employés. Pourtant, les interactions entre les facteurs individuels et contextuels sont multiples. Par conséquent, nous suggérons d'envisager une approche en terme de fit de la créativité entre les facteurs individuels et contextuels, ce qui nous permet également de proposer de nouvelles pratiques pour le management des ressources humaines. De plus, d’un point de vue théorique, plusieurs chercheurs suggèrent une relation étroite entre la prise de risque et la créativité des employés alors que peu d'études ont analysé cette relation. Le second article confirme qu'il existe une relation positive entre la prise de risque et la créativité des employés et aussi démontre que les facteurs individuels et contextuels issus de la littérature sur le risque et sur la créativité ont mutuellement un impact sur la prise de risque. Ensuite, sur la base de la relation étroite entre les théories du risque et de la créativité, nous abordons le comportement créatif des managers en intégrant le modèle BAM (behavioral agency model) et la théorie des capacités dynamiques. L'objectif de notre modèle théorique est d'expliquer en quoi le comportement créatif des managers devant décider d’importantes décisions stratégiques pourrait être considéré comme dynamique et évoluer avec le temps. Concernant la créativité de l'équipe virtuelle, nous avons examiné les déterminants de la créativité. Nous avons constaté que l’approche par les TMS est fructueuse pour la compréhension de la créativité de l'équipe virtuelle. Nos résultats apportent une contribution à la fois à la littérature sur la créativité et à celle concernant les équipes virtuelles et fournissent d'importantes implications managériales pour les équipes virtuelles.Dans l'ensemble, nos recherches sur la créativité individuelle sont également utiles pour les membres de l'équipe virtuelle alors considérés au niveau individuel et l’étude du comportement créatif des managers pourrait aussi s’appliquer aux managers d’équipes virtuelles. Ces quatre articles permettent (1) de fournir une vision globale de la créativité des employés en proposant l'approche par le fit; (2) d’examiner les relations précises entre la prise de risque et la créativité des employés; (3) d’étendre la théorie de la créativité en intégrant le modèle BAM et la théorie des capacités dynamiques afin de considérer la créativité comme dynamique; (4) et de révéler le rôle important du TMS pour la créativité de l'équipe virtuelle. / Many organizations have relied on creativity to outclass their competitors and the knowledge of how to support creativity has been critical. Generally, creativity could be derived from individuals or a group of individuals working together. Hence, in this thesis, we aim to provide a better understanding on how to facilitate creativity at both individual and team levels. Precisely, for the team level, we focus on virtual team creativity which has been under-researched and challenging to discover. The four articles in this dissertation aim to provide a better understanding and identify the determinants of both individual and virtual team creativity. We have reviewed individual creativity literature to extend the understanding of employee creativity. The review suggests that it is more efficient to consider both individual and contextual factors in order to assess employee creativity. Still, the interactions between individual and contextual factors are varied. Therefore, we suggest considering creativity fit approaches between individual and contextual factors derived from the review and we also provide the comprehensive practices for human resource management. In addition, theoretically, several theorists suggest the close relation between risk-taking and employee creativity whereas very few studies have investigated its relations. The second article confirms that there is a positive relation between risk-taking and employee creativity and also demonstrate that individual and contextual factors from both risk and creativity literature are mutually impacted on risk-taking. Later, based on the close relation between risk and creativity theories, we develop the creative behavior of managers by integrating the behavioral agency model and dynamic capabilities theories. The objective of this theoretical model is to explain how the creative behavior of managers in making an important strategic decision could be viewed as dynamic and evolved over time. For virtual team creativity, we aim to examine the determinants of virtual team creativity which have been recently explored. We found that Transactive Memory Systems, which have been challenging due to their importance with regard to virtual teams, have a positive impact on virtual team creativity. The findings extend both creativity and virtual team literature and provide important practical implications for virtual teams. Overall, the investigation of individual creativity is also useful for virtual team members at an individual level and managers’ creative behavior could also assess the creative behavior of virtual team managers. These four articles could in fact (1) provide the global view of employee creativity by proposing the fit approach; (2) examine the precise relations of risk-taking and employee creativity; (3) extend the creativity theory by integrating BAM and the dynamic capabilities theory to consider creativity as dynamic; (4) and reveal the critical roles of TMS in virtual team creativity.
10

Contribution à l’évaluation de la qualité de la collaboration en conception de produits. / Contribution to the assessment of the quality of collaboration in product design.

Kobenan, Kouamé Jean-Moïse 09 December 2016 (has links)
L’organisation fonctionnelle des entreprises impose un fonctionnement en mode projet. Ces projets sont menés par des experts de différentes spécialités et d’origine diverses. Ces équipes ont besoin d’outils pour être performant et proposer des solutions adaptées aux multiples besoins des marchés de plus en plus exigeants. Au cours de leurs réunions et activités, ils se créé une conscience de groupe qui s’enrichit à travers les interactions et s’appuie sur divers représentations externes. Cette thèse aborde l’étude des mécanismes permettant la performance des équipes de conception collaborative en réunion synchrone. Elle a essayé de démontrer les liens entre leur Système de Mémoire Transactive (TMS), leurs Activités de Conception Collaboratives (CDA) et leurs Objets désignés Ressources (RSC), et d’identifier les éléments favorisant ces liens. Nous avons dans un premier temps réalisé une enquête auprès des équipes de conception collaborative en environnement universitaire. Puis dans un second temps nous avons réalisé une expérimentation sur deux équipes en situation de conception collaborative synchrone autour du Serious Game Delta Design déployé sur une table interactive. Les résultats de cette recherche montrent que si la performance est favorisée par la TMS ou la CDA, leur lien statistique est établit, de même que le lien entre les activités de conception et les ressources mobilisées. Cependant, l’absence de lien statistique fort TMS CDA montre que les équipes ne semblent conscientes de l’utilisation des objets dans la construction de leur TMS, alors que les artefacts de la table interactive sont les plus sollicités et les activités de prise de décision semblent les plus importantes dans ces séances.Cette thèse contribue au corpus de connaissance sur l’étude des équipes de conception collaborative et mets à disposition des outils d’évaluation de la performance des équipes de conception collaboratives synchrone. / Today functional structure of enterprises requires teamwork and project mode organization. These projects are carried out by experts from different domains of expertise. Besides the teams need supporting tools in order to improve the efficiency of their design process and to propose adapted solutions to complex design problems. In the course of their meetings and collaborative activities they create group awareness through their interactions and creation of various artifacts. This thesis studies mechanisms that underlie performance of collaborative design team in synchronous meeting. In this thesis we demonstrate the links between Transactive Memory System (TMS), Collaborative Design Activities (CDA) and Objects called Resources (RSC), and identify the elements that drive these links. A survey has been used to study collaborative design teams in academic environment. Then, we performed direct observation of two teams during synchronous collaborative design meetings with a serious game Delta Design on interactive table. Results show that if performance is enhanced statistically by good TMS or CDA, and the link is demonstrate, so is the links between CDA RSC. However, the lack of statistical strong correlation between TMS and RSC seems to show that team members are not conscious of using artifacts during TMS building. While artifacts on interactive table are more solicited and decision making activities seems to be more important during their session. This thesis contributes to a better understanding of collaborative design teams and offers tools to evaluate collaborative design activities.

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