The study is an interpretative analysis of Virginia Cooperative Extension that examined the mission of the agency, as defined through its history and enabling acts of legislation. The study investigated how the mission has evolved during the eighty-four years of its existence. The study used the intent and context of the federal Smith-Lever legislation of 1914 as its benchmark to discover what the desired and anticipated outcomes were for Cooperative Extension by the original patrons of the legislation. Subsequent legislative acts at both the state and federal levels, as well as actions by the executive branch of government, were studied to discover if and when the mission of cooperative extension has changed and to identify the political, economic, and social factors that influenced the changes. The study incorporated accepted methods of historical research and included the review and analysis of both primary and secondary sources of information. Interviews of key leaders who have influenced the policy position of Virginia Cooperative Extension over the past thirty years were conducted. The data gathered by the study were analyzed and presented to highlight major themes that could have influenced critical policy issues that have confronted Virginia Cooperative Extension. The conclusion is that the mission of extension is two fold: (1) to provide education that could lead to increased economic opportunity and, (2) to enhance the quality of life enjoyed by Virginia’s citizens. Three critical attributes are identified that relate to the ability of Virginia Cooperative Extension to fulfill its mission: (1) access to research-based information, (2) a strong presence in local communities, and (3) a capacity to provide timely responses to emerging issues. / Ph. D.

Thesis advisor: Masayuki Wasa / This dissertation describes the development of cooperative catalyst systems for the functionalization of monocarbonyl compounds and stereoselective transformations of alpha-C–H bonds of N-alkylamines, inspired by the concepts of frustrated Lewis pairs (FLPs). Prior to this dissertation research, practical and broadly applicable C–C and C–heteroatom bond forming reactions involving the FLP complexes that provide synthetically desirable products with high enantioselectivity remained to be developed. Chapter 1 of this dissertation describes the recent advances in the transformations involving FLPs and B(C₆F₅)₃-catalyzed reactions. Inspired by the unique capability of FLP catalysts to activate otherwise unreactive molecules, and circumvent undesirable acid–base complexation, we have developed potent cooperative acid/base catalysts for C–C bond forming reactions of various monocarbonyl compounds and an appropriate electrophile, which will be discussed in Chapter 2. Another reactivity of FLPs to be explored has to do with the catalytic and enantioselective reactions of N-alkylamines, where two Lewis acid catalysts with potentially overlapping functions, work cooperatively to activate alpha-amino C–H bonds and promote the enantioselective C–C bond forming reaction between N-alkylamines and a nucleophilic species. In Chapter 3, B(C₆F₅)₃-catalyzed union of N-alkylamines and silicon enolates followed by the enantioselective B(C₆F₅)₃/Mg–PyBOX-catalyzed alpha-alkylation of N-alkylamines and alpha,beta-unsaturated compounds to form beta-amino carbonyl compounds will be described. In Chapter 4, B(C₆F₅)₃/Cu–PyBOX-catalyzed alpha-C–H alkynylation of N-alkylamines and the applications in late-stage functionalization and stereoselective synthesis will be discussed. / Thesis (PhD) — Boston College, 2020. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Safety concerns have been keeping autonomous vehicles off the roads for decades, although the main drivers for introducing some autonomy are to increase safety, reduce congestion, and greenhouse gas emissions. Safety is a vast topic that includes the safety of the system alone, known as string stability, and the safety of the system on public roads. This thesis provides experimental validation of the string stability of the Assume-Guarantee approach. This approach suggests that each agent models the interactions with neighbors as bounded disturbances while simultaneously self-imposing symmetric magnitude bounds. Two main controllers were tested in an indoor lab set-up: decentralized platooning and decentralized cooperative adaptive cruise controllers. First, we tested three versions of the platooning controller whose objective is to maintain a constant spacing. They differ in the assumptions and guarantees. We observed a robust performance with relaxed bounds and some violations as the bounds become tighter and tighter. Second, we modified and transformed the platoon model into cooperative adaptive cruise control (CACC). Unlike the platoon controller, the cooperative adaptive cruise controller keeps the time gap constant. Two experiments were conducted at different velocities to evaluate the limitation of the controller. The results show a stable and smooth performance.

Au cours de cette dernière dizaine d’années, l’intérêt pour la diffusion en temps réel de séquences vidéo sur réseaux sans fil ad-hoc a grandi sans cesse, en raison de l'attrayante propriété d’être capable de déployer un système de communication visuelle à tout moment et en tout lieu, sans la nécessité d'une infrastructure préexistante. Une large gamme d'applications des opérations militaires et de sauvetage, jusqu'aux applications commerciales, éducatives, récréatives, a été envisagée, ce qui a crée un grand intérêt pour toutes les technologies concernées. L'objectif de cette thèse est de fournir un service efficace et robuste de diffusion vidéo en temps réel sur réseaux mobiles ad-hoc, avec un aperçu des solutions disponibles à ce moment, et de proposer de nouvelles solutions qui permettraient de surmonter les limites de celles actuelles. Nos contributions touchent à plusieurs aspects du paradigme mobile vidéo streaming : une nouvelle technique de codage vidéo par descriptions multiples, qui fournit une qualité vidéo acceptable, même en présence d'un taux élevé de pertes ; un protocole cross-layer pour la création et le maintien d'un réseau de overlay, qui, avec un échange de messages limité, géré de façon repartie un ensemble d'arbres de multicast, un pour chaque description du flux ; un cadre original de fonctions distribuées pour l'optimisation congestion-distorsion, qui, grâce à une représentation compacte des informations de topologie, permet aux nœuds d'apprendre la structure du overlay et d'optimiser leur comportement en conséquence ; et enfin, une intégration avec le paradigme émergent du codage réseau. / During the last decade, real-time video streaming over ad-hoc networks has gathered an increasing interest, because of the attractive property of being able to deploy a visual communication system anytime and anywhere, without the need for a pre-existing infrastructure. A wide range of target applications, from military and rescue operations, to business, educational, and recreational scenarios, has been envisaged, which has created great expectations with respect to the involved technologies. The goal of this thesis is to provide an efficient and robust real-time video streaming system over mobile ad-hoc networks, proposing cross-layer solutions that overcome the limitations of both the application and network solutions available at this time. Our contributions cover several aspects of the mobile video streaming paradigm: a new multiple description video coding technique, which provides an acceptable video quality even in presence of high loss rates; a novel cross-layer design for an overlay creation and maintenance protocol, which, with a low overhead, distributedly manages a set of multicast trees, one for each description of the stream; an original distributed congestion-distortion optimisation framework, which, through a compact representation of the topology information, enables the nodes to learn the structure of the overlay and optimise their behaviour accordingly; and, finally, an integration with the emerging network coding paradigm.

The Bear River Valley Co-op Association was described in terms of certain changes that have occurred in its history, and analysis was made of how these changes relate to changes in the degree of local control by officers and members of the organization. The method used in this study was content analysis of records of the organization. The main sources of data were: The Articles of Incorporation and By-Laws of the organization for 1947 and 1964, and the minutes of meetings from 1968 to 1977. The study shows that the Bear River Valley Co-op Association today, as compared to the early period of its formation, has grown and changed from small-scale to a larger scale organizational pattern. This change is evidenced by a greater degree of formality and bureaucracy in its present organization than existed in the early period. Additional evidence is reflected in the greater concern for business matters today that formerly. Correlated with this change has been a decrease in local control which previously appeared as a predominant characteristic of the organization. This decrease is evidenced in some reduction of concern for membership relations and in a reduction in efforts to encourage local neighborhood and community discussion and planning in regard to common problems and needs of members

Commercial egg production in Utah has developed gradually since 1920. Production of eggs increased from 142 million in 1924 to 433 million eggs in 1946. The percentage of total farm income of the state derived from the poultry industry increased from 5.3 percent in 1924 to 23.1 percent in 1946 and at the present time constitutes the largest income of any farm enterprise in this area. Factors influencing this development are: 1. High prices resulting from the war period of 1917 to 1920 followed by the depression period when prices were low. 2. The organization of cooperative egg-marketing associations. 3. Shipments of eggs to the eastern markets. 4. The lack of marketing facilities for the high-quality eggs produced in the state.

Mobile ad hoc networks (MANETs) have experienced rapid growth in their use for various military, medical, and commercial scenarios. This is due to their dynamic nature that enables the deployment of such networks, in any target environment, without the need for a pre-existing infrastructure. On the other hand, the unique characteristics of MANETs, such as the lack of central networking points, limited wireless range, and constrained resources, have made the quest for securing such networks a challenging task. A large number of studies have focused on intrusion detection systems (IDSs) as a solid line of defense against various attacks targeting the vulnerable nature of MANETs. Since cooperation between nodes is mandatory to detect complex attacks in real time, various solutions have been proposed to provide cooperative IDSs (CIDSs) in efforts to improve detection efficiency. However, all of these solutions suffer from high rates of false alarms, and they violate the constrained-bandwidth nature of MANETs. To overcome these two problems, this research presented a novel CIDS utilizing the concept of social communities and the Dempster-Shafer theory (DST) of evidence. The concept of social communities was intended to establish reliable cooperative detection reporting while consuming minimal bandwidth. On the other hand, DST targeted decreasing false accusations through honoring partial/lack of evidence obtained solely from reliable sources. Experimental evaluation of the proposed CIDS resulted in consistently high detection rates, low false alarms rates, and low bandwidth consumption. The results of this research demonstrated the viability of applying the social communities concept combined with DST in achieving high detection accuracy and minimized bandwidth consumption throughout the detection process.

This study investigated the effects of Cooperative Learning on seventh graders’ vocabulary learning in China. This study was conducted because in China, students usually learn vocabulary via traditional learning method-rote memorization. However, this method has a lot of issues. For example, students only know how to write the words but they cannot use them in contexts. Students tend to forget new words they have newly learned. The purpose of this study was to find out whether Chinese secondary school students can benefit from Cooperative Learning in vocabulary; whether Cooperative Learning can help students in applying new words and whether students can retain new words longer using Cooperative Learning. This research followed a quasi-experimental design, with an experimental group and a control group. Data were collected in a secondary school in Beijing, China. The participants took three tests: a pretest, post-test and a delayed post-test. A one-way repeated ANOVA was used to analyze the data in SPSS (25.0). The findings showed that there was a significant difference across three time points in the two groups (p < .001). There was no significant difference in the students’ vocabulary scores between the two groups (p > .05). However, it was found that there was a significant interaction between time and group on students’ vocabulary learning. An ANCOVA analysis showed that there was a significant difference between the two groups in the delayed post-test (p = .01). These findings can be beneficial to the professionals who work as English teachers in secondary schools in China. My results suggest that Cooperative Learning may be helpful in improving students’ vocabulary learning outcomes.

This dissertation proposes autonomous robotic strategies for urban search and rescue (USAR) which are map-based semi-autonomous robot navigation and fully-autonomous robotic search, tracking, localization and mapping (STLAM) using a team of robots. Since the prerequisite for these solutions is accurate robot localization in the environment, this dissertation first presents a novel grid-based scan-to-map matching technique for accurate simultaneous localization and mapping (SLAM). At every acquisition of a new scan and estimation of the robot pose, the proposed technique corrects the estimation error by matching the new scan to the globally defined grid map. To improve the accuracy of the correction, each grid cell of the map is represented by multiple normal distributions (NDs). The new scan to be matched to the map is also represented by NDs, which achieves the scan-to-map matching by the ND-to-ND matching. In the map-based semi-autonomous robot navigation strategy, a robot placed in an environment creates the map of the environment and sends it to the human operator at a distant location. The human operator then makes decisions based on the map and controls the robot via tele-operation. In case of communication loss, the robot semi-autonomously returns to the home position by inversely tracking its trajectory with additional optimal path planning. In the fully-autonomous robotic solution to USAR, multiple robots communicate one another while operating together as a team. The base station collects information from each robot and assigns tasks to the robots. Unlike the semi-autonomous strategy there is no control from the human operator. To further enhance the efficiency of their cooperation each member of the team specifically works on its own task. A series of numerical and experimental studies were conducted to demonstrate the applicability of the proposed solutions to USAR scenarios. The effectiveness of the scan-to-map matching with the multi-ND representation was confirmed by analyzing the error accumulation and by comparing with the single-ND representation. The applicability of the scan-to-map matching to the real SLAM problem was also verified in three different real environments. The results of the map-based semi-autonomous robot navigation showed the effectiveness of the approach as an immediately usable solution to USAR. The effectiveness of the proposed fully- autonomous solution was first confirmed by two real robots in a real environment. The cooperative performance of the strategy was further investigated using the developed platform- and hardware-in-the-loop simulator. The results showed significant potential as the future solution to USAR. / Ph. D.

Syftet med denna kunskapsöversikt är att skapa en överblick över aktuell forskning angående metoden kooperativt lärande med fokus på elevernas resonemangsförmåga inom ämnet matematik. Kooperativt lärande är ett arbetssätt att strukturera samarbete mellan eleverna när de lär sig. För att jag ska kunna svara på undersökningsfrågan harjag genomfört systematiska undersökningar i olika databaser, exempelvis Ebsco, Swepub och även sekundära sökningar. Texten är uppbyggt med en inledningsdel som redogör vad kooperativt lärandet och resonemangsförmåga innebär. Sedan har jag sammanställt de funna artiklarna i en tabell och vidare har artiklarna studerats och analyserats. Resultatet visar hur kooperativt lärande kan påverka elevernas resonemangsförmåga positivt, dock krävs det en välstrukturerad undervisning där lärarens kompetens och engagemang är en viktig faktor. Avslutningsvis diskuteras resultaten utifrån framtida yrkesverksamhet och förslag på fortsatt forskning.