Ionic polymer metal composites (IPMC) are a new class of smart materials that have attractive characteristics such as muscle like softness, low voltage and power consumption, and good performance in aqueous environments. Therefore, there is a significant motivation for research on design and development of IPMC based biomimetic propulsion systems for underwater vehicles. In aerospace, underwater vehicles finds application for forensic studies of spaceship wrecks, missile fragments and any airplane accidents in sea and ocean terrains. Such vehicles can also survey moons and planets that house water oceans. Among biomimetic swimming systems, fish inspired swimming has gained interest since fish like swimming provides high maneuverability, high cruising speed, noiseless propulsion and efficient stabilization compared to conventional propulsion systems. In this work, the paired pectoral fin based oscillatory propulsion using IPMC for aquatic propulsor applications is studied. Dynamic characteristics of IPMC fin are analyzed using numerical simulations and optimization is used to improve the fin design. A complex hydrodynamic function is used to describe the behavior of an active IPMC fin actuator in water. The structural model of the IPMC fin is obtained by modifying the classical dynamic equation for a slender beam to account for the electromechanical dynamics of the IPMC beam in water. A quasi-steady blade element model that accounts for unsteady phenomena such as added mass effects, dynamic stall, and the cumulative Wagner effect is used to estimate the hydrodynamic performance of the flapping fin. It is shown that the use of optimization methods can lead to significant improvement in performance of the IPMC fin. Further, three fish species with high performance flapping pectoral fin locomotion are chosen and performance analysis of each fin design is conducted to discover the better configurations for engineering applications. Dynamic characteristics of IPMC actuated flapping fins having the same size as the actual fins of three different fish species, Gomphosus varius, Scarus frenatus and Sthethojulis trilineata, are also analyzed. Finally, a comparative study is performed to analyze the performance of the three different biomimetic IPMC flapping pectoral fins.

The United States Military is currently organized along the lines of regional combatant commands (COCOMs). Each COCOM is responsible for all U.S. military activity in their designated area of responsibility (AOR). They also deal with diplomatic issues of a wide variety with the countries within their respective AORs. Among these COCOMs, Southern Command (SOUTHCOM), whose AOR encompasses all of Central and South America (less Mexico) and the Caribbean, is one of the smallest in terms of size and budget, but has the longest history of activity among the COCOMs as it is the successor to the first joint command, the United States Caribbean Defense Command (CDC 1941-1947). Existing from 1941 to 1947, the CDC was tasked with protecting the Panama Canal, the Canal Zone, and all its access points as well as defending the region from Axis aggression and setting up a series of U.S. bases throughout the Caribbean from which to project U.S. military power after World War II. Throughout its short history, however, the CDC was plagued with the same types of resource scarcity that its successor commands would later experience. Early successes, as well as the progress of the war saw to it that the original mission of the Command was quickly rendered moot. Ironically, it was partially the success of the U.S. war effort that kept the CDC from ever reaching its full potential. Nevertheless, the CDC evolved into something different than had originally been envisioned. In the end, it became the model that other COCOMs would follow after November 1947 when the system of regional combatant commands was formally established. Although some research has been conducted into the history of these commands, this dissertation is the first academic attempt to chronicle the history of the United States Caribbean Defense Command. Research into this topic involved combing through the Archives of the United States Southern Command in its offices in Miami, Florida (SOUTHCOM Archives), as well as the CDC archives in Record Group 548 in the U.S. National Archives II in Suitland, Maryland. Secondary sources as well as references regarding treaties and international agreements were also consulted as necessary.

L’internationalisation des chaînes de valeur fait l’objet de nombreuses recherches macroéconomiques ou ciblées sur des secteurs majoritairement civils. En se concentrant sur l’industrie de défense, cette thèse évalue comment ce processus de fragmentation fonctionnelle et géographique peut s’appliquer à un secteur hautement régulé par les Etats et dont les échanges internationaux sont très strictement encadrés.Cette recherche apporte plusieurs estimations du niveau d’internationalisation de l’industrie navale de défense française, à partir de données originales de Naval Group. Si les programmes relatifs à la dissuasion nucléaire sont très peu internationalisés, de nombreux facteurs concourent à l’internationalisation de la filière : exigences de contenu local et transferts de technologie des clients étrangers, intégration de technologies civiles ou duales, stratégies d’internationalisation. Enfin, le recours au concept de modularité permet de montrer que l’évolution du processus productif s’accompagne souvent d’une évolution de l’architecture des produits. / Many research works have already been dedicated to the internationalization of value chains. Whereas this research is often performed through macroeconomics or focused on civilian sectors, this thesis examines how the process of functional and geographic unbundling can apply to such a regulated sector as the defense industry, where exports are strictly controlled by states.Based on original data provided by Naval Group, this dissertation set out several estimates of the internationalization level of French navy programs. Although programs related to nuclear deterrence remain almost exclusively « made in France », many factors contribute to the internationalization of value chains in the naval industry: transfer of technology, local content requirements, integration of commercial or dual-use technologies, internationalization corporate strategies. Referring to the concept of modularity, this thesis reveals that changes in production process can foster innovation in product architecture.