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Despite the advancement of research and development on multi-robot teams, a key challenge still remains as to how to develop effective mechanisms that enable the robots to autonomously generate, adapt, and enhance team behaviours while improving their individual performance simultaneously. After a literature review of various multi-agent learning approaches, the two most promising learning paradigms, i.e., cooperative learning and advice sharing are adopted for future development. Although individually these methodologies may not provide a solution, their proper integration will provide a platform that allows for the incorporation of multi-agent learning with social behaviours. These methods are examined in relation to the performance characteristics of single-robot learning to ascertain if they retain viable learning characteristics despite the integration of individual learning into team behaviour. Further, various modifications to the Q-Learning algorithm were tested, and the best performing modification was implemented into the proposed multi robot learning approach.

Despite the advancement of research and development on multi-robot teams, a key challenge still remains as to how to develop effective mechanisms that enable the robots to autonomously generate, adapt, and enhance team behaviours while improving their individual performance simultaneously. After a literature review of various multi-agent learning approaches, the two most promising learning paradigms, i.e., cooperative learning and advice sharing are adopted for future development. Although individually these methodologies may not provide a solution, their proper integration will provide a platform that allows for the incorporation of multi-agent learning with social behaviours. These methods are examined in relation to the performance characteristics of single-robot learning to ascertain if they retain viable learning characteristics despite the integration of individual learning into team behaviour. Further, various modifications to the Q-Learning algorithm were tested, and the best performing modification was implemented into the proposed multi robot learning approach.

It is expected that Wireless Body Area Network (WBAN) will greatly improve the quality of our life because of its myriad applications for our human beings. However, one of the challenges is to design energy efficient communication protocols to support the reliable communication as well as to prolong the network lifetime. Cooperative communications have the advantage of spatial diversity to combat multipath fading, thus improving the link reliability and boosting energy efficiency. In this thesis, we investigate the energy efficient cooperative communications for WBAN. We first analyze the outage performance of three transmission schemes, namely direct transmission, single relay cooperation, and multi-relay cooperation. To minimize the energy consumption, we then study the problem of optimal power allocation with the constraint of targeted outage probability. Two strategies of power allocation are considered: power allocation with and without posture state information. Simulation results verify the accuracy of the analysis and demonstrate that: 1) power allocation making use of the posture information can reduce the energy consumption; 2) within a possible range of the channel quality in WBAN, cooperative communication is more energy efficient than direct transmission only when the path loss between the transmission pair is higher than a threshold; and 3) for most of the typical channel quality due to the fixed transceiver locations on human body, cooperative communication is effective in reducing energy consumption.

As diverse and data-heavy underwater applications emerge, demanding requirements are further imposed on underwater wireless communication systems. Future underwater wireless communication networks might consist of both mobile and stationary nodes which exchange data such as control, telemetry, speech, and video signals among themselves as well as a central node located at a ship or onshore. The submerged nodes, which can, for example, take the form of an autonomous underwater vehicle/robot or diver, can be equipped with various sensors, sonars, video cameras, or other types of data acquisition instruments. Innovative physical layer solutions are therefore required to develop efficient, reliable, and high-speed transmission solutions tailored for challenging and diverse requirements of underwater applications. Building on the promising combination of multi-carrier and cooperative communication techniques, this dissertation investigates the fundamental performance bounds of cooperative underwater acoustic (UWA) communication systems taking into account the inherent unique characteristics of the UWA channel. We derive outage probability and capacity expressions for cooperative multi-carrier UWA systems with amplify-and-forward and decode-and-forward relaying. Through the derived expressions, we demonstrate the effect of several system and channel parameters on the performance. Furthermore, we investigate the performance of cooperative UWA systems in the presence of non-uniform Doppler distortion and propose receiver designs to mitigate the degrading Doppler effects.

Recently, the U.S. Department of Defense placed the technological development of intelligence, surveillance, and reconnaissance (ISR) tools at the top of its priority list. Area surveillance that takes place in an urban setting is an ISR tool of special interest. Unmanned aerial vehicles (UAVs) are ideal candidates to perform area surveillance because they are inexpensive and they do not require a human pilot to be aboard. Multiple unmanned systems increase the rate of information flow from the target region and maintain up to date information. The purpose of the research described in this dissertation is to develop and test a system that coordinates multiple UAVs on a wide area coverage surveillance mission. The research presented in this document implements a waypoint generator for multiple aerial vehicles that is especially suited for large area surveillance. The system chooses initial locations for the vehicles and generates a set of balanced sub-trees which cover the region of interest (ROI) for the vehicles. The sub-trees are then optimally combined to form a single minimal tree that spans the entire region. The system transforms the tree path into a series of waypoints suitable for the aerial vehicles. The output of the system is a set of waypoints for each vehicle assigned to the coverage task. Results from computer simulation and flight testing are presented.

This thesis reports a research effort that comprises six papers and a cover paper. In essence, the thesis contributes to the understanding of collaborative settings by introducing the perspective of ‘places of collaboration’. This perspective is particularly important when designing computer-based technologies that support collaborative settings.   The starting point and overall research aim is to understand people’s efforts to configure their current context for the purposes of collaboration. The cover paper of the thesis comprises a theoretical reflection and examination of four collaborative settings. The settings have been studied in situ through ethnographic inquiry and the results are reported in the six papers enclosed in the thesis. In my theoretical reflection, the concepts of ‘place’, ‘space’ and ‘boundary objects’ are central.   The studies revealed that people’s efforts to configure the current context create and reflect a ‘place of collaboration’. In other words, the effort to configure the context results in a practice characterized by an understanding of how to cooperate; a collaborative practice that constitutes a ‘place of collaboration’. During this configuration, the space and the use of materiality in this space are important parts in the creation of a place of collaboration. In addition, people configure collaborative contexts of intersecting practices by creating boundary objects. Boundary objects serve as mediators in a place-making process for the integration of places into a ‘place of collaboration’ for several practices. What is more, the dynamics of a place of collaboration may affect changes in existing modes of working and in computer-based tools that have been introduced into the workplace. The people and practices that constitute the place will in turn re-configure the place of collaboration, including the space and objects available due to the new circumstances.   People’s configuration of their current context reveals crucial aspects about the place of collaboration that must be considered also when designing to support this setting. However, this configuration may not necessarily equal efficiency and effectiveness, as evaluated by actors external to this context. The conclusion of this thesis is that future research and design should consider how to support people in their own effort to configure their collaborative context.

The overall purpose of this study was to develop a model to inform the design of professional development programs and the implementation of cooperative learning within Thai primary school mathematics classrooms. Action research design, with interviews, surveys and observations, was used for this study. Survey questionnaires and classroom observations investigated the factors that influence the implementation of cooperative learning strategies and academic achievement in Thai primary school mathematics classrooms. The teachers’ interviews and classroom observation also examined the factors that need to be addressed in teacher professional development programs in order to facilitate cooperative learning in Thai mathematics classrooms. The outcome of this study was a model consisting of two sets of criteria to inform the successful implementation of cooperative learning in Thai primary schools. The first set of criteria was for proposers and developers of professional development programs. This set consists of macro- and micro-level criteria. The macro-level criteria focus on the overall structure of professional development programs and how and when the professional development programs should be implemented. The micro-level criteria focused on the specific topics that need to be included in professional development programs. The second set of criteria was for Thai principals and teachers to facilitate the introduction of cooperative learning in their classrooms. The research outcome also indicated that the attainment of these cooperative learning strategies and skills had a positive impact on the students’ learning of mathematics.

This study was undertaken in conjunction with the Successful Integration of Learning Technologies (SILT) project in state schools in Victoria, Australia. The thesis reports an interpretative analysis of cooperative learning in computer-supported classes as it is currently conducted in selected Victorian primary schools. The framework for the study is grounded in the belief that cooperative learning encourages learning as a group as opposed to learning in a group (Slavin, 1980). The framework emphasises the importance of teachers using cooperative learning as a structure to enable students to think together. Therefore, analysis focuses on cooperative learning in a classroom context and the teachers’ units of work guiding the tasks they create. Using a mixed-method approach involving questionnaires, interviews and videotaped observations, the study was conducted in four sites with two teachers from each school and two groups of students from each class. (For complete abstract open document)

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