Water is a basic necessity for turfgrass growth and metabolic processes, with optimal levels required for the maintenance of turf quality and function. As water restrictions for irrigation of landscapes become more widespread across the United States, turfgrass managers will need to rely on management strategies to improve the performance of turfgrasses under reduced irrigation environments. Therefore, the objectives of the research were to (i) compare the performance of different Agrostis species and cultivars under reduced irrigation, (ii) evaluate the use of wetting agents for maintaining turf quality under reduced irrigation, (iii) and examine the physiological mechanisms associated with improved drought resistance traits of Agrostis species. To address our primary objectives, we conducted a two-year field study comparing cultivars of three bentgrass species, including ‘Revere’ and ‘Tiger II’ colonial bentgrasses (Agrostis capillaris), ‘Legendary’ and ‘Greenwich’ velvet bentgrasses (A. canina), and ‘13M’, ‘T-1’, ‘L-93’, and ‘Penncross’ creeping bentgrasses (A. stolonifera) in response to reduced irrigation with and without the use of a wetting agent. In general, the use of a wetting agent did not result in any significant differences in turf quality or soil moisture content among treatments. There were significant differences in turf quality among bentgrass species and cultivars under reduced irrigation. Colonial bentgrass cultivars maintained high turf quality, and were found to be well suited for fairways under reduced irrigation. Due to excessive thatch accumulation in our study, velvet bentgrass cultivars exhibited significant declines in quality regardless of irrigation level. Among creeping bentgrass cultivars, T-1 exhibited improved drought tolerance compared to the older cultivars of creeping bentgrass. Based on results from the field study, we further evaluated the drought resistance and recovery characteristics among five cultivars of colonial bentgrass (‘Barking’, 'Tiger II’, ‘Revere’, ‘Capri’, and ‘Greentime’). Under moderate drought stress, Barking, Tiger II, and Revere all exhibited lower leaf relative water content levels compared to Capri and Greentime, although no significant differences in turf quality or soil water content were observed during the drought period. Following re-watering, Barking and Tiger II exhibited the most rapid recovery from drought (as measured by percent green cover), while Capri and Greentime exhibited delayed recovery. Therefore, although significant differences in turf performance during drought stress were not observed, recovery potential seems to vary among the different cultivars of colonial bentgrass.

Macromolecular magnetic resonance imaging (MRI) contrast agents have unique localization and contrast enhancement properties. We have designed and studied a monodisperse paramagnetic β-cyclodextrin click cluster (Gd10) decorated with Gd-containing arms and unique contrast enhancing polymers. To synthesize Gd10, a novel alkyne-functionalized diethylenetriaminetetraacetic acid chelate was created and coupled to a per-azido-β-cyclodextrin core and chelated with Gd(III) to yield the precursor macromolecule. Luminescence measurements were carried out using an analogous structure Eu(III)-containing structure and indicated that each lanthanide has an average of 1.8 water exchange sites. Gd10 yields a high relaxivity profile (6.2 mM⁻¹ s⁻¹ per Gd(III) at 9.4 T). Gd10 shows toxicity higher than clinically used contrast agents such as Magnevist&trade in vitro in cardiomyoblast cells. No acute toxicity was observed in the rats (n = 9) and contrast enhanced image analysis indicates renal processes may be involved in clearance. The contrast enhancing polymers we developed are new macromolecular beacons that allow the delivery of nucleic acids to be visualized at different biological scales. They contain repeated oligoethyleneamines, for binding and compacting nucleic acids into nanoparticles, and Gd(III)/Eu(III) chelates. The chelated lanthanides allow the visualization of the delivery vehicle via microscopy and via magnetic resonance imaging (MRI). We demonstrate that these new delivery beacons effectively bind plasmid DNA(pDNA) and protect their cargo nucleic acids from nuclease damage. The lanthanide-chelate materials have been found to efficiently deliver pDNA into cultured cells and do not exhibit toxicity. Micrographs of cultured cells exposed to the nanoparticle complexes formed with fluorescein-labeled pDNA and the europium-chelated polymers reveal effective intracellular imaging of the delivery process. MRI of bulk cells exposed to the complexes formulated with pDNA and the gadolinium-chelated structures show bright image contrast, allowing visualization of effective intracellular delivery on the tissue-scale. Because of their versatility as imaging probes, these delivery beacons posses remarkable potential for tracking and understanding nucleic acid transfer in vitro and have promise for in vivo imaging applications. In later studies the Ln-chelating polymers were co-polymerized with dimethylgalacterate which definitively increases luciferase gene expression (up 50x enhancement) and cellular uptake (up to 2x enhancement). / Ph. D.

The purpose of this dissertation is to present our agent-based human tracking framework, and to evaluate the results of our work in light of the previous research in the same field. Our agent-based approach departs from a process-centric model where the agents are bound to specific processes, and introduces a novel model by which agents are bound to the objects or sub-objects being recognized or tracked. The hierarchical agent-based model allows the system to handle a variety of cases, such as single people or multiple people in front of single or stereo cameras. We employ the job-market model for agents' communication. In this dissertation, we will present several experiments in detail, which demonstrate the effectiveness of the agent-based tracking system. Per our research, the agents are designed to be autonomous, self-aware entities that are capable of communicating with other agents to perform tracking within agent coalitions. Each agent with high-level abstracted knowledge seeks evidence for its existence from the low-level features (e.g. motion vector fields, color blobs) and its peers (other agents representing body-parts with which it is compatible). The power of the agent-based approach is its flexibility by which the domain information may be encoded within each agent to produce an overall tracking solution. / Ph. D.

Agent-based models are computer simulations in which entities (agents) interact with each other and their environment according to local update rules. Local interactions give rise to global dynamics. These models can be thought of as in silico laboratories that can be used to investigate the system being modeled. Optimization problems for agent-based models are problems concerning the optimal way of steering a particular model to a desired state. Given that agent-based models have no rigorous mathematical formulation, standard analysis is difficult, and traditional mathematical approaches are often intractable. This work presents techniques for the analysis of agent-based models and for solving optimization problems with such models. Techniques include model reduction, simulation optimization, conversion to systems of discrete difference equations, and a variety of heuristic methods. The proposed strategies are novel in their application; results show that for a large class of models, these strategies are more effective than existing methods. / Ph. D.

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The purpose of this experiment was to determine the value of sulphur dioxide as a dehydrating agent for sweet potatoes.

Self-reconfigurable robotic systems are variable-morphology machines capable of changing their overall structure by rearranging the modules they are composed of. Individual modules are capable of connecting and disconnecting to and from one another, which allows the robot to adapt to changing environments. Optimally reconfiguring such systems is computationally prohibitive and thus in general self-reconfiguration approaches aim at approximating optimal solutions. Nonetheless, even for approximate solutions, centralized methods scale poorly in the number of modules. Therefore, the objective of this research is the development of decentralized self-reconfiguration methods for modular robotic systems. Building on completeness results of the centralized algorithms in this work, decentralized methods are developed that guarantee stochastic convergence to a given target shape. A game-theoretic approach lays the theoretical foundation of a novel potential game-based formulation of the self-reconfiguration problem. Furthermore, two extensions to the basic game-theoretic algorithm are proposed that enable agents to modify the algorithms' parameters during runtime and improve convergence times. The flexibility in the choice of utility functions together with runtime adaptability makes the presented approach and the underlying theory suitable for a range of problems that rely on decentralized local control to guarantee global, emerging properties. The experimental evaluation of the presented algorithms relies on a newly developed multi-robotic testbed called the "Robotarium" that is equipped with custom-designed miniature robots, the "GRITSBots". The Robotarium provides hardware validation of self-reconfiguration on robots but more importantly introduces a novel paradigm for remote accessibility of multi-agent testbeds with the goal of lowering the barrier to entrance into the field of multi-robot research and education.

This thesis investigates existing game development methodologies, through the process of researching game and system development models. The results indicate that these methodologies are engineered to solve specific problems, and most are suitable only for specific game genres. Different approaches to building games have been proposed in recent years. However, most of these methodologies focus on the design and implementation phase. This research aims to enhance game development methodologies by proposing a novel game development methodology, with the ability to function in generic game genres, thereby guiding game developers and designers from the start of the game development phase to the end of the implementation and testing phase. On a positive note, aligning development practice with universal standards makes it far easier to incorporate extra team members at short notice. This increased the confidence when working in the same environment as super developers. In the gaming industry, most game development proceeds directly from game design to the implementation phase, and the researcher observes that this is the only industry in which this occurs. It is a consequence of the game industry’s failure to integrate with modern development techniques. The ultimate aim of this research to apply a new game development methodology using most game elements to enhance success. This development model will align with different game genres, and resolve the gap between industry and research area, so that game developers can focus on the important business of creating games. The primary aim of Agent Oriented Agile Base (AOAB) game development methodology is to present game development techniques in sequential steps to facilitate game creation and close the gap in the existing game development methodologies. Agent technology is used in complex domains such as e-commerce, health, manufacturing, games, etc. In this thesis we are interested in the game domain, which comprises a unique set of characteristics such as automata, collaboration etc. Our AOAB will be based on a predictive approach after adaptation of MaSE methodology, and an adaptive approach using Agile methodology. To ensure proof of concept, AOAB game development methodology will be evaluated against industry principles, providing an industry case study to create a driving test game, which was the problem motivating this research. Furthermore, we conducted two workshops to introduce our methodology to both academic and industry participants. Finally, we prepared an academic experiment to use AOAB in the academic sector. We have analyzed the feedbacks and comments and concluded the strengths and weakness of the AOAB methodology. The research achievements are summarized and proposals for future work outlined.

Frågan som denna rapport ställer sig är hur en användares engagemang i en aktivitet påverkas av vetskapen att motparten är en datorstyrd, dels jämfört med om motparten är en människostyrd Agent jämfört med en människostyrd Avatar och dels beroende på om den datorstyrda Agenten uppvisar ett mer mänskligt beteende, till motsats till ett mer maskin-likt. I syfte att besvara denna fråga har en utförlig litteraturstudie gjorts, som dels utforskat konceptet Engagemang, men även utforskat andra koncept, såsom Social närvaro, Ethopoeia och Simulering av mänskligt beteende. Dessa teorier har sedan använts för att utveckla ett webbaserat experiment, vars mål har varit att samla empiriska data. Experimentet gick ut på att lösa en serie enklare matematiska uppgifter, vissa mot datorn och andra med en mänsklig administratör som deltog på distans, och det som mättes var s.k. Dwell time, d.v.s. hur länge användaren var engagerad nog att ha fokus på aktiviteten. Resultatet visade att det fanns klara indikationer på att engagemanget i aktiviteten är lägre om motparten styrs av en dator, jämfört med om den styrs av en människa. Den andra ”delfrågan” var svårare att definitivt svara på, men författaren anser att det går att tolka resultatet som att engagemanget blir högre. / The question that this essay posed was how the user’s engagement is affected by the fact that the other party is a computer controlled Agent, both compared to if the other party was a human-controlled Avatar, but also depending on whether the Agent displays a more human-like behavior, as opposed to a more machine-like one. To answer this question an extensive litterature study was performed, both to develop the concept of Engagement, but also to explore other concepts, such as Social presence, Ethopoeia and Simulation of human behaviour. These theories were then used to design a web based experiment, with the purpose of collecting empirical data. The experiment consisted of solving simple math tasks, some against the computer, but others involving a human administrator, who participated from a remote location. The measured metric was Dwell time, i.e. the actual time the user was engaged enough to focus on the activity. The result showed that there is a definite indication that the level of engagement in activities is lower if the other party is controlled by a computer, as opposed to it being controlled by a human. The second part of the question was not as clearly answered by the result, but the author believes the result can be interpreted as showing an increase of engagement.

This thesis proposes a holistic and hierarchical architecture to Multi-agent System design, in order to resolve the collaboration problem in diabetic healthcare system. A diabetic healthcare system is a complex and social system in the case that it involves many actors and interrelations. Collaborations among various healthcare actors are vital to the quality of diabetic healthcare. The collaboration problem is manifested by the problems of accessibility and interoperability. To support the collaboration in diabetic healthcare as such a complex and social system, the MAS must have corresponding social entities and relationships. Therefore, it is assumed that theories explaining social activity can be applied to design of MAS. Activity Theory, specifically its holistic triangle model from Engström and hierarchy thinking, provides theoretical supports to the design of individual agent architecture and MAS coordination mechanism. It is argued that the holistic and hierarchical aspects should be designed in a MAS when applied to the healthcare setting. The diabetic healthcare system is analyzed on three levels based on the hierarchy thinking. The collaboration problem is analyzed and resolved via MAS coordination. Based on the holistic activity model in Activity Theory, Müller’s Vertical Layered Architecture is re-conceptualized in the Control Unit and Knowledge Base design. It is also argued that autonomy, adaptivity and persona should be especially focused when designing the interaction between an agent system and human users. This study has firstly identified some important social aspects and the technical feasibility of embedding those identified social aspects in agent architecture design. Secondly, a MAS was developed to illustrate how to apply the proposed architecture to design a MAS to resolve the collaboration problem in diabetic healthcare system. We have designed and implemented an agent system – IMAS (Integrated Multi-agent System) to validate the research questions and contributions. IMAS system provides real time monitoring, diabetic healthcare management and decision supports to the diabetic healthcare actors. A user assessment has been conducted to validate that the quality of the current diabetic healthcare system can be improved with the introduction of IMAS.