Cooperative driving holds the potential to considerably improve the level of safety and efficiency on our roads. Recent advances in in-vehicle sensing and wireless communication technology have paved the way for the development of cooperative traffic safety applications based on the exchange of data between vehicles (or between vehicles and road side units) over a wireless link. The access to up-to-date status information from surrounding vehicles is vital to most cooperative driving applications. Other applications rely on the fast dissemination of warning messages in case a hazardous event or certain situation is detected. Both message types put high requirements on timeliness and reliability of the underlying communication protocols. The recently adopted European profile of IEEE 802.11p defines two message types,periodic beacons for basic status exchange and event-triggered hazard warnings, both operating at pre-defined send rates and sharing a common control channel. The IEEE 802.11p Medium Access Control (MAC) scheme is a random access protocol that doesnot offer deterministic real-time support, i.e. no guarantee that a packet is granted access to the channel before its deadline can be given. It has been shown that a high number of channel access requests, either due to a high number of communicating vehicles or highdata volumes produced by these vehicles, cannot be supported by the IEEE 802.11p MAC protocol, as it may result in dropped packets and unbounded delays. The goal of the work presented in this thesis has therefore been to enhance IEEE 802.11p without altering the standard such that it better supports the timing and reliability requirements of traffic safety applications and provides context-aware andefficient use of the available communication resources in a vehicular network. The proposed solutions are mapped to the specific demands of a set of cooperative driving scenarios (featuring infrastructure-based and infrastructure-free use cases, densely and sparsely trafficked roads, very high and more relaxed timing requirements) and evaluated either analytically, by computer simulation or by measurements and compared to the results produced by the unaltered IEEE 802.11p standard. As an alternative to the random MAC method of IEEE 802.11p, a centralized solution isproposed for application scenarios where either a road side unit or a suitable dedicated vehicle is present long enough to take the coordinating role. A random access phase forevent-driven data traffic is interleaved with a collision-free phase where timely channel access of periodic delay-sensitive data is scheduled. The ratio of the two phases isdynamically adapted to the current data traffic load and specific application requirements. This centralized MAC solution is mapped on two cooperative driving applications: merge assistance at highway entrances and platooning of trucks. Further,the effect of a context-aware choice of parameters like send rate or priority settings based on a vehicle’s position or role in the safety application is studied with the goal to reduce the overall number of packets in the network or, alternatively, use the available resources more efficiently. Examples include position-based priorities for the merge assistance use case, context-aware send rate adaptation of status updates in anovertaking warning application targeting sparsely-trafficked rural roads and an efficient dissemination strategy for warning messages within a platoon. It can be concluded that IEEE 802.11p as is does not provide sufficient support for the specific timing and reliability requirements imposed by the exchange of safety-criticalreal-time data for cooperative driving applications. While the proper, context-awarechoice of parameters, concerning send rate or priority level, within the limits of the standard, can lead to improved packet inter-arrival rates and reduced end-to-end delays,the added benefits from integrating MAC solutions with real-time support into the standard are obvious and needs to be investigated further.

Wireless Sensor Networks (WSNs) are networks of small devices, called motes, designed to monitor resources and report to a server. Motes are battery-powered and have very little memory to store data. To conserve power, the motes usually form clusters to coordinate their activities. In heterogeneous WSNs, the motes have different resources available to them. For example, some motes might have more powerful radios, or larger power supplies. By exploiting heterogeneity within a WSN can allow the network to stay active for longer periods of time. In WSNs, the communications between motes draw the most power. By choosing better clusterheads in the clusters to control and route messages, all motes in the network will have longer lifespans. By leveraging heterogeneity to select better clusterheads, I have developed Heterogeneous Clustering Control Protocol (HCCP). HCCP is designed to be highly robust to change and to fully utilize the resources that are currently available.

Interpersonal growth is one part of the definition of outdoor education. Collaboration and common purpose are key phrases in cooperation learning. Both those two teaching methods are including students’ social development. To find out the effects of teachers’ and students’ attitude toward cooperative learning in outdoor education, this study explores the benefits and limitations of group work in outdoor education theoretically. Also, this study explores the attitudes of teachers and students regarding group work in outdoor learning. Questionnaires were used to find the students’ opinion of group work in outdoor education, during the analysis of data, thematic analysis was conducted with interview data to find out teachers’ attitudes. The participates of this study mainly had a very positive attitude towards group work in outdoor education, although some limitations were identified, such as students sometimes lost focus, were absent or were less involved.

Universiẗat, Diss., 1993--Marburg.

Thesis (M.A.)--Chulalongkorn University, 1986. / In Thai; abstract also in English. Added t.p.: Cooperative measures in solving economic problems related to peasants during the reigns of King Rama VI and King Rama VII. Includes bibliographical references (leaves 116-126). Also issued in print.

Thesis (M.S. in Information Systems and Operations)--Naval Postgraduate School, March 2008. / Thesis Advisor(s): Buddenberg, Rex ; Hoivik, Tom. "March 2008." Description based on title screen as viewed on May 16, 2008. Includes bibliographical references (p. 131-132). Also available in print.

Thesis (doctoral)--Université de Genève. / Library has 2d part only: Les syndicats professionnels agricoles.

Issued also as Thesis (Ph. D.)--University of California. / Cover title. Bibliography: p. 133-137.

Thesis (M.S.)--University of California, Davis, 1973. / Typescript (photocopy). Includes bibliographical references (leaves 156-160).

Thesis (Ph. D.)--Catholic University of America, 1926. / Vita. Bibliography: p. 94-99.