Dissertations / Theses on the topic 'Marine communications'
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Monaghan, Joseph Francis. "Evaluation of digital communications using the Marine Corps Communications Architecture Analysis Model." Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/23661.
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Approved for public release; distribution is unlimitedThe United States Marine Corps (USMC) is currently evolving to digital communications. This change has created a need for an analysis tool capable of analyzing digital architectures. Traditional communications are being supplemented, and in some cases, replaced by automated systems like the Marine Tactical Command and Control System (MTACCS) Older equipment, the PRC-77 and AN/VRC-12 family of radios, is being replaced by lighter, more efficient equipment like SINCGARS and the Digital Communications Terminal (DCT). Protocols like the Marine Tactical System (MTS) Broadcast Protocol are being implemented to orchestrate this new way of communicating. To assist in the transition, this thesis modified the Marine Corps Communications Architecture Analysis Model (MCCAAM) so it could measure the impact of changing from voice to digital communications. The Fidelity Enhancement Process (FEP) , a comprehensive methodology for model upgrades, was used to systematically modify the model. The model's usefulness is demonstrated in an analysis example by comparing three separate partially digital communications architectures.
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Amin, Kruna, Jeffrey Dixon, Kathryn Hunt, Peter Manternach, Brenda Roach, Larry Bochenek, Richard Elgart, Yancy Jeleniewski, Jonathan Reap, and Brian Song. "United States Marine Corps Expeditionary Rifle Squad Communications." Thesis, Monterey, California. Naval Postgraduate School, 2009. http://hdl.handle.net/10945/6942.
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This CAPSTONE Report documents the Systems Engineering (SE) efforts of "Team Marine," from JAN 2009 to SEP 2009, in developing a recommendation to the US Marine Corps Systems Command (MCSC), on the best course of action to 'Enhance the USMC Expeditionary Rifle Squad Communications System.' The squad leader is the cornerstone for USMC tactical operations. Clear, concise, accurate and reliable communications to and from the squad leader is the key to squad operations, performance and tactical effectiveness. Today's fielded communications system for the squad leader requires the use of two separate radios, each with different encryption algorithms, different user interfaces, and different data processing capabilities. This primitive design has thrust the squad leader into a complex Human Factors environment with disparate components that have not been well engineered or integrated. Team Marine applied and tailored the systems engineering (SE) process based on NPS course work and professional experience. This SE process enabled the team to completely understand and model the current system in terms of architecture, capabilities and functions. The process led the team and stakeholders to conclude that an evolutionary approach of system integration was preferred over the traditional Manufacturer A vs. Manufacturer B run off. The team's recommendation is to pursue an integrated communications system, based on existing and emerging components, as the best course of action. The first incremental step of the recommendation is to upgrade the existing elements by adding an automated communications processor with enhanced human to system interfaces.
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Eynard, Goulven. "Techniques de synchronisation pour les communications acoustiques sous-marine." Télécom Bretagne, 2009. http://www.theses.fr/2008TELB0094.
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Le but de cette thèse est de construire des algorithmes de synchronisation robustes permettant de fiabiliser une transmission par lien acoustique entre un AUV et un bateau. Les algorithmes de type aveugle ou piloté par décisions ont été privilégiés. On se place dans un contexte de modulations mono-porteuses, pour des transmissions à flot continu et sur un canal acoustique sous marin petits fonds. Dans un premier temps, le travail s'est focalisé sur les boucles à verrouillage de phase et leurs applications en synchronisation porteuse. On cherche en particulier à déterminer un jeu de paramètres qui garantisse la robustesse des algorithmes de synchronisation sur la durée de la transmission, en prenant en compte les caractéristiques de transmission connues au récepteur (débit utilisé, distance et vitesse relative maximale, rapport signal à bruit). Une structure innovante de boucle à verrouillage de phase, capable de compenser de forts décalages en fréquence dans un contexte de faible rapport signal sur bruit est proposée. Les algorithmes de synchronisation utilisés classiquement en radiocommunication ne sont pas toujours capables de suivre l'évolution rapide des paramètres du canal. C'est d'autant plus le cas dans un contexte de transmission acoustique sous-marine, lorsque la vitesse relative entre l'émetteur et le récepteur est élevée. Il en résulte un effet Doppler déformant en temps et en fréquence le signal reçu. Des algorithmes robustes, exploitant les spécificités du canal acoustique sous-marin ont donc été développés pour une synchronisation conjointe rythme et porteuse. Enfin, on propose un algorithme de synchronisation rythme bouclé, capable d'exploiter la diversité spatiale pour estimer le Doppler, tout en assurant un échantillonnage différent sur chaque antenne. Cette thèse s'est déroulée en collaboration avec le GESMA dans le cadre d'un contrat de recherche. Les algorithmes ont été testés et validés sur des enregistrements effectués lors d'essais en mer.
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Allen, Bernal B. "Meteor burst communications for the U.S. Marine Corps Expeditionary Force." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/27131.
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Approved for public release; distribution is unlimitedMeteor Burst Communications (MBC) is explored in relation to its usefulness to Marine Expeditionary Force Communications. A description of the physics and geometry of meteor trail propagation is presented. Communication techniques used to exploit the phenomenon are discussed. Current MBC circuits have operational ranges of 1200 miles without relay and maintain average data rates of 60 to 150 Bits per Second(BPS). MBC is primarily limited by the physics and geometry of the propagation medium and its usefulness is bounded by its slow data rate. Within these boundaries however, several significant use of MBC are identified. Keywords: Theses. (fr)
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Long, John M. "Junior officer oral communications in the Navy and Marine Corps." access online version, LEAD access online version, NPS access online version, DTIC, 2004. http://handle.dtic.mil/100.2/ADA424715.
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Labat, Joël. "Apport de l'égalisation auto-adaptative en communications acoustiques sous-marines." Brest, 1994. http://www.theses.fr/1994BRES2004.
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Cette these traite de l'optimisation conjointe des fonctions d'egalisation et de synchronisation dans un recepteur coherent. Le domaine d'application vise est celui des communications acoustiques sous-marines pour lequel on distingue schematiquement deux types de canaux, le canal vertical et le canal horizontal. Le premier type de canal autorise des efficacites spectrales pouvant raisonnablement atteindre 2 voire 3 bit/s/hz. En revanche le canal horizontal se montre tres hostile. L'interference entre symboles, liee a la presence de trajets de plusieurs trajets de propagation, couvre en general plusieurs durees symboles. De plus, a ce probleme particulierement delicat qui interdit pour l'heure la mise en oeuvre de detecteurs optimaux (au sens du critere de vraisemblance maximale) viennent en general s'ajouter des effets tout aussi genants tels que l'effet doppler (non-stationnarite du canal de transmission). Dans ce contexte, une solution attrayante consiste a retenir une structure de recepteur coherent, lineaire ou non, dans laquelle les fonctions d'egalisation et de synchronisation sont conjointement optimisees selon un critere d'optimalite donne (lms, godard). Divers resultats concernant des signaux reels sont presentes a la fois dans le cas des canaux verticaux et horizontaux. On y etudie notamment un certain nombre d'algorithmes (sglms, rls, godard) ainsi que diverses structures d'egaliseurs (egaliseur lineaire transverse synchrone ou fractionne, egaliseur a retour de decision, annuleur d'interferences)
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West, Michael Brooks. "Object-oriented modelling and analysis of a Marine Corps communications architecture." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/27176.
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Approved for public release; distribution is unlimitedThe United States Marine Corps (USMC) will be fielding the SINCGARS frequency-hopping radio system during the next 5 years. There will be units within the Corps during the transition period in which both the conventional fixed-frequency radio and the SINCGARS radio will be employed in the same area at the same time. The Marine Corps Communications Architecture Analysis Model (MCCAAM) presented in this thesis will give Marine Corps decision makers, analysts, and communications officers the ability to quantify the effectiveness of alternative tactical radio system configurations within a given Marine Air-Ground Task Force (MAGTF) environment. Using a unique traffic workload paradigm to generate realistic message traffic, this object-oriented simulation model assesses the overall performance of a given architecture with a specified mix of fixed-frequency and frequency-hopping radios through a penalty accrual process or through aggregating traditional communications MOEs. USMC decision makers and communications officers can use the results of the system performance rankings and associated sensitivity trade-off analysis to determine where best to allocate the new frequency hopping radios, as they become available, in order to maximize the overall FM communications performance of a given MAGTF.
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Bonnifay, Sandrine. "Séparation de sources appliquée aux communications sous-marines." Brest, 2001. http://www.theses.fr/2001BRES2020.
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La séparation de sources consiste à retrouver n signaux sources à partir des signaux observés sur un réseau de p capteurs. L'application de la séparation de sources dans un contexte expérimental est un problème délicat, particulièrement dans le domaine des communications sous-marines. Dans la configuration deux sources et deux capteurs, le système de mélange est modélisé par une matrice (2, 2) de filtres RIF à coefficients complexes. La séparation est réalisée en inversant le système de mélange. Sous l'hypothèse d'indépendance statistique des signaux sources, le critère à satisfaire est l'indépendance des signaux obtenus en sortie du système de séparation. L'hypothèse de système à phase minimale étant difficilement vérifiable expérimentalement, nous n'avons retenu que les méthodes faisant abstraction de cette hypothèse. Le système de séparation est estimé sous la forme d'une matrice (2,2) de filtres RIF. Le canal sous-marin est caractérisé par un filtre RIF composé d'une série de coefficients nuls suivie d'une série de pics associés à chaque arrivée de l'onde sur le capteur. La modélisation du mélange dans ce canal nous a permis de mettre en évidence deux types de transmission : la propagation horizontale/verticale et la propagation horizontale/horizontale. Dans le premier cas, les ordres des filtres diagonaux du système de mélange sont très différents de ceux des filtres anti-diagonaux. En raison de la non stationnarité du canal sous-marin, le nombre d'échantillons disponibles des observations est faible, par conséquent le nombre de paramètres à adapter doit être minimisé. On propose dans ce cas d'adopter un modèle de mélange simplifié dont les éléments diagonaux sont des scalaires. Les performances des algorithmes de séparation de sources sont liées au choix des ordres des filtres de séparation. Ces derniers étant similaires aux filtres de mélange, nous proposons d'estimer les ordres, ainsi que le nombre de paramètres à adapter, par une mesure des maxima de la fonction d'intercorrélation des observations. En revanche, pour une transmission horizontale/horizontale, on considère l'approche par déconvolution multicanaux du modèle de mélange constitué de quatre filtres RIF. Les filtres solutions sont alors des filtres RII qui sont estimés par des filtres RIF. Les ordres des filtres sont estimés à partir de la mesure des maxima des fonctions d'autocorrélation des signaux observés. Ces méthodes sont validées sur des mélanges synthétiques de signaux de communication. Dans le cadre d'une application en aveugle, les fonctions d'intercorrélation des observations permettent de distinguer ces deux types de transmission, et par conséquent de définir l'approche à utiliser. Les mélanges de signaux filtrés expérimentalement nous ont permis d'identifier différents problèmes liés à la non stationnarité du canal sous-marin, pour lesquels nous proposons quelques solutions à venir.
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King, Zaffrenarda L. "An analysis of Marine Corps beyond line of sight wideband satellite communications requirements." Thesis, Monterey, California. Naval Postgraduate School, 2010. http://hdl.handle.net/10945/5152.
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Approved for public release; distribution is unlimitedSatellite communications are critical to Marine Corps command and control. Capabilities in the domain of beyond line of sight systems, such as wideband SATCOM, must periodically be assessed for alignment with relevant strategy, policy, and doctrinal publications. The National Security Strategy and other documents are periodically updated to provide direction to the U.S. Armed Forces. This thesis provides an analysis of a broad range of publications that extend from national level strategy documents down to service level doctrinal publications that specifically address how the Marine Corps conducts military operations. The focus is to identify how beyond LOS SATCOM systems can support the key tenets of the NSS and USMC doctrine. The analysis forms the basis for an assessment of current USMC SATCOM systems and capabilities, followed by considerations for future USMC SATCOM systems and capabilities. SATCOM provides capacity, range, and coverage that allow expeditionary forces such as the Marine Corps to operate anywhere, anytime. Beyond LOS capabilities allow us to mass effects from fewer, more widely dispersed forces. This thesis provides an analytical foundation to help shape future USMC SATCOM operational concepts. It may then help shape USMC SATCOM requirements that must be satisfied by new systems.
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Schneider, Toby Edwin. "Advances in integrating autonomy with acoustic communications for intelligent networks of marine robots." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/79162.
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Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and the Woods Hole Oceanographic Institution), 2013.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (p. 151-161).
Autonomous marine vehicles are increasingly used in clusters for an array of oceanographic tasks. The effectiveness of this collaboration is often limited by communications: throughput, latency, and ease of reconfiguration. This thesis argues that improved communication on intelligent marine robotic agents can be gained from acting on knowledge gained by improved awareness of the physical acoustic link and higher network layers by the AUV's decision making software. This thesis presents a modular acoustic networking framework, realized through a C++ library called goby-acomms, to provide collaborating underwater vehicles with an efficient short-range single-hop network. goby-acomms is comprised of four components that provide: 1) losslessly compressed encoding of short messages; 2) a set of message queues that dynamically prioritize messages based both on overall importance and time sensitivity; 3) Time Division Multiple Access (TDMA) Medium Access Control (MAC) with automatic discovery; and 4) an abstract acoustic modem driver. Building on this networking framework, two approaches that use the vehicle's "intelligence" to improve communications are presented. The first is a "non-disruptive" approach which is a novel technique for using state observers in conjunction with an entropy source encoder to enable highly compressed telemetry of autonomous underwater vehicle (AUV) position vectors. This system was analyzed on experimental data and implemented on a fielded vehicle. Using an adaptive probability distribution in combination with either of two state observer models, greater than 90% compression, relative to a 32-bit integer baseline, was achieved. The second approach is "disruptive," as it changes the vehicle's course to effect an improvement in the communications channel. A hybrid data- and model-based autonomous environmental adaptation framework is presented which allows autonomous underwater vehicles (AUVs) with acoustic sensors to follow a path which optimizes their ability to maintain connectivity with an acoustic contact for optimal sensing or communication.
by Toby Edwin Schneider.
Ph.D.
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Mariotte, Hubert. "Caractérisation d'un canal non stationnaire et sélectif : Application aux communications numériques acoustiques sous-marines." Brest, 1995. http://www.theses.fr/1995BRES2018.
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Cette these traite de la caracterisation d'un canal non stationnaire et selectif. La propagation dans un tel canal est caracterisee par la presence conjointe de trajets multiples et d'effet doppler. Ce type de canal se rencontre notamment dans le cas des communications radiomobiles ou des communications acoustiques sous-marines. Nous nous sommes interesses au deuxieme type de canal. Le signal emis est un signal a modulation de phase a deux etats, le signal modulant etant une sequence binaire a longueur maximale. Compte-tenu des contraintes apportees par le canal de propagation, le signal recu peut etre considere comme une suite d'echos du signal emis. Ces echos sont retardes, attenues et decales en frequence. Nous avons mis au point, en nous basant sur les idees de l'algorithme em (expectation maximization), un algorithme original qui permet d'estimer les differents parametres intervenant dans une propagation de type non stationnaire et selectif. Ces parametres sont: l'attenuation, l'instant d'arrivee et le decalage doppler de chaque echo detecte en reception. Nous avons appele cet algorithme: algorithme de syntonisation des pics interferants. Des simulations informatiques ont ete effectuees afin de valider notre approche et d'etudier le comportement et la robustesse de l'algorithme. Enfin, l'acquisition et le traitement de signaux acoustiques reels nous ont permis de caracteriser le canal acoustique sous-marin horizontal par petits fonds. Cette caracterisation a ete faite dans differentes configurations: profondeur d'immersion, distance emetteur-recepteur, type de fond
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Parker, Michael A. Arp Lance T. "Scalability study of wireless tactical communications in support of a Marine Corps Expeditionary Brigade." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2000. http://handle.dtic.mil/100.2/ADA379706.
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Thesis (M.S. in Information Technology Management and M.S. in Systems Technology) Naval Postgraduate School, June 2000.Thesis advisors: Osmundson, John ; Kemple, William. "June 2000." Includes bibliographical references (p. 213). Also available online.
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Foster, Joseph D. "Swarming unmanned aerial vehicles (UAVs): extending Marine aviation ground task force communications using UAVs." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/44564.
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Reissued 2 Mar 2015 to correct degree earnedApproved for public release; distribution is unlimited
Reissued 2 Mar 2015 to correct degree earned
Technological advances and research are pushing the application of unmanned vehicles in exciting directions. This thesis emphasis is on cost estimation for a new unmanned aerial vehicle (UAV) with swarm applications. The new swarm UAV theoretical can be designed to emulate the current unmanned aerial system (UAS) mission, and expand upon the communication relay mission. Small UASs have a line-of-sight capability limitation that leaves room for improvement. The UAVs organic to the U.S. Marine Corps (USMC) are the primary focus for this analysis because organic USMC UAVs are habitually small UAVs. The analysis will determine a rough cost estimation range for a future AV with new technology. Based on the adaptation of networking topologies and research, the communication relay mission is a feasible capability to Peruse in future swarm UAVs. The analysis suggests that a swarm UAV is comparable in cost to legacy UAVs currently in service in the USMC.
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Parker, Michael A., and Lance T. Arp. "Scalability study of wireless tactical communications in support of a Marine Corps Expeditionary Brigade." Thesis, Monterey, California. Naval Postgraduate School, 2000. http://hdl.handle.net/10945/7784.
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Approved for public release; distribution is unlimitedThis thesis reports the findings of a simulation modeling the communications architecture used during Major System Demonstrations 1 (MSD-1) of the Extended Liftoral Battlespace (ELB) Advanced Concept Technology Demonstration (ACTD) and a suitable architecture for a large-scale battlespace. The simulation was accomplished with the use of a leading edge simulation tool, EXTENDTM, and the specifications inherent to wireless communications. Specifically, EXTEND was used to replicate the protocols that are inherent within the WaveLAN and VRC-99A systems. A feasible sized architecture was modeled utilizing scaling techniques, which simulated the operation of a Marine Expeditionary Brigade (MEB), covering a 2OOX2OO mile wireless tactical battlespace. This thesis further investigates the validity of a completely wireless tactical network versus the additional use of ground relays. This thesis demonstrates that the wireless tactical battlespace is scalable to satisfy the requirements of a Marine Expeditionary Brigade. Lastly, this thesis demonstrates the effects of an all WaveLAN architecture
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Youcef, Abdelhakim. "Amélioration des performances du traitement des interférences dans le domaine fréquentiel pour les communications acoustiques sous marines." Télécom Bretagne, 2013. http://www.telecom-bretagne.eu/publications/publication.php?idpublication=14141.
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Les communications acoustiques sous-marines permettent la transmission sans fils de l'information entre la surface et le fond via l'onde acoustique. Le lien acoustique sans fils réduit l'infrastructure matérielle nécessaire par rapport aux communications sous-marines câblées, permettant ainsi un déploiement à coût limité. Néanmoins, le canal acoustique sous-marin impose de sévères limitations de par ses caractéristiques de propagation qui diffèrent largement de celles du canal hertzien. La propagation multitrajets provoquée par les réflexions multiples sur le fond et la surface, engendre de l'interférence entre symboles qui doit être compensée à la réception. De plus, le mouvement des plateformes d'émission et de réception engendre un effet Doppler qui agit sur le signal comme un phénomène de compression/dilatation temporel de la durée symbole associé à un décalage fréquentiel du spectre. L'objectif de cette thèse est de proposer des techniques d'émission/réception de faible complexité calculatoire permettant de supprimer les interférences et de réduire le taux d'erreurs binaires sous la contrainte d'une efficacité énergétique de la transmission acoustique sous-marine. La réduction en complexité est assurée par le traitement d'interférences dans le domaine fréquentiel lequel permet de minimiser la consommation énergétique du système de transmission. Dans un premier temps, nous proposons des techniques d'égalisation fréquentielle adaptative en mode piloté par décision afin de compenser et de suivre la variation temporelle du canal acoustique sous-marin. Dans un second temps, nous proposons un schéma de transmission SC-FDMA mono-utilisateur en mode distribué uniforme en insérant des intervalles de garde fréquentiels afin d'améliorer la robustesse du lien de transmission contre l'effet Doppler du canal acoustique sous-marin. Enfin, nous proposons un turbo-égaliseur fréquentiel adaptatif basé sur un traitement itératif en réception et permettant de réduire le taux d'erreurs binaires au fil des itérations. Notons qu'un traitement multi-voies est considéré à la réception afin d'améliorer le rapport signal sur bruit et que l'égalisation est optimisée conjointement avec la synchronisation de phase pour compenser d'éventuels décalages fréquentiels résiduels. Les solutions proposées dans cette thèse sont validées expérimentalement sur des signaux réels issus d'enregistrements de transmission en milieu marinUnderwater acoustic (UWA) communications allow wireless transmission between the surface and the bottom of a subsea environment based on acoustic waves. The wireless acoustic link reduces the physical infrastructure cost compared to the cable-based underwater communications. However, underwater acoustic channel imposes severe degradations on the transmitted signal. Its propagation characteristics are widely different from those of the radio channel. The multipath propagation caused by multiple reflections on the bottom and the surface, causes intersymbol interference (ISI) which must be compensated at the receiver. Furthermore, by the movement of the transmitting and receiving platforms, the UWA channel is time-variant yielding Doppler spread which induces a compression/expansion phenomenon of the symbol duration, associated to a frequency shift of the signal spectrum. The objective of this thesis is to propose low-complexity communication techniques in the UWA channel, in order to remove interferences while ensuring energy-efficient transmission link. The reduction in complexity is achieved by treating interferences in the frequency-domain which minimizes the energy consumption of the transmission system. We first propose adaptive frequency-domain equalization techniques in a decision directed mode, in order to remove ISI and track the time-variation in the UWA channel. Then, we propose a single-user SC-FDMA transmission scheme with a uniform distributed subcarrier allocation and using frequency-domain interval guards, in order to improve the robustness of the receiver against the Doppler effect in the UWA channel. Finally, we propose an adaptive frequency-domain turbo equalizer using iterative receiver, which allows to significantly reduce the bit error rate over iterations. Note that multiple-input receiver is considered in order to benefit from the diversity combining gain to achieve a higher signal to noise ratio (SNR). Furthermore, equalization is optimized jointly with phase synchronization to compensate residual frequency offsets at the equalizer output. The performance of the proposed solutions are measured over real time-variant underwater acoustic channel in the Atlantic Ocean
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Mokhtari, Kambiz. "Advanced risk management in offshore terminals and marine ports." Thesis, Liverpool John Moores University, 2011. http://researchonline.ljmu.ac.uk/6094/.
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This research aims to propose a Risk Management (RM) framework and develop a generic risk-based model for dealing with potential hazards and risk factors associated with offshore terminals' and marine ports' operations and management. Hazard identification was conducted through an appropriate literature review of major risk factors of these logistic infrastructures. As a result in the first phase of this research a Fuzzy Analytical Hierarchal Process (FAHP) method was used for determining the relative weights of the risk factors identified via the literature review. This has led to the development of a generic risk -based model which can help related industrial professionals and risk managers assess the risk factors and develop appropriate strategies to take preventive/corrective actions for mitigation purposes, with a view of maintaining efficient offshore terminals' and marine ports' operations and management. In the second phase of the research the developed risk-based model incorporating Fuzzy Set Theory (FST), an Evidential Reasoning (ER) approach and the IDS software were used to evaluate the risk levels of different ports in real situations using a case study. The IDS software based on an ER approach was used to aggregate the previously determined relative weights of the risk factors with the new evaluation results of risk levels for the real ports. The third phase of the research made use of the Cause and Consequence Analysis (CCA) including the Fault Tree Analysis (FTA) and Event Tree Analysis (ETA) under a fuzzy environment, to analyse in detail the most significant risk factors determined from the first phase of the research, using appropriate case-studies. In the fourth phase of the research an individual RM strategy was tailored and implemented on the most significant risk factor identified previously. In the last phase of the research and in order to complete the RM cycle, the best mitigation strategies were introduced and evaluated in the form of ideal solutions for mitigating the identified risk factors. All methods used in this research have quantitative and qualitative nature. Expert judgements carried out for gathering the required information accounted for the majority of data collected. The proposed RM framework can be a useful method for managers and auditors when conducting their RM programmes in the offshore and marine industries. The novelty of this research can help the Quality, Health, Safety, Environment and Security (QHSES) managers, insurers and risk managers in the offshore and marine industries investigate the potential hazards more appropriately if there is uncertainty of data sources. In this research with considering strategic management approaches to RM development the proposed RM framework and risk based model contribute to knowledge by developing and evaluating an effective methodology for future use of the RM professionals.
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Pottier, Antony. "Méthodes décentralisées d'allocation des ressources dans le canal d'interférence acoustique sous-marin." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2018. http://www.theses.fr/2018IMTA0095/document.
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L’onde acoustique est utilisée par de nombreux systèmes et organismes marins pour communiquer, naviguer ou inférer de l’information sur l’environnement. Le développement des activités humaines liées au monde de la mer induit une augmentation du nombre de sources acoustiques en activité simultanée dans l’océan. L’environnement acoustique sous-marin (ASM) est donc partagé par de nombreuses sources hétérogènes (sonars, modems, mammifères marins, ...) entrant involontairement en compétition pour l’utilisation d’une ressource offerte par le canal de transmission. L’objectif de ce travail de thèse est de proposer des solutions permettant aux systèmes de communications ASM d’adapter leurs paramètres de transmission de manière intelligente, autonome et décentralisée selon l’environnement acoustique dans lequel ils évoluent. A plusieurs égards, les problématiques de ce sujet de thèse sont proches de celles ayant motivé le développement des recherches sur la radio cognitive. Cependant, les spécificités du milieu acoustique, les sources d’interférencesde diverses natures, et l’absence de standards de communications posent de nouvelles difficultésUnderwater acoustic waves are used by many systems and biologic organisms to communicate, navigate or infer information about the environment. Future developments of human maritime activities imply an increase of the number of active acoustic sources in the oceans. The underwater environment is therefore shared by many heterogeneous sources (sonars, modems, marine mammals, ...) competing involuntarily for using the physical resources offered by the communication channel.The goal of this thesis is to provide solutions allowing autonomous and decentralized adaptation of the transmission strategies of underwater acoustic communication systems, according to the environment. To some extent, this work deals with topics that are closely related to what has motivated the first researches on cognitive radio systems. However, the specific properties of the underwater environment, the heterogeneity of interfering acoustic sources, and the absence of communication standards rise new difficulties
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YE, Zi. "Traitement statistique de l'information et du signal pour l'internet des objets sous-marins." Thesis, Institut polytechnique de Paris, 2021. https://tel.archives-ouvertes.fr/tel-03179373.
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On assiste au développement des activités humaines liées au monde océanique, mais aucune norme n'a encore émergé pour l'Internet des objets appliqué aux objets autonomes marins. Bien qu'elle possède une bande passante limitée, l'onde acoustique est le seul moyen de communiquer sur des distances importantes et elle est donc utilisée par de nombreux systèmes sous-marins pour communiquer, naviguer ou déduire des informations sur l'environnement. Cela a conduit à une forte demande de réseaux sans fil qui nécessitent à la fois une bonne efficacité spectrale et énergétique avec la faible complexité des algorithmes associés. Par conséquent, au cours de ce doctorat, nous avons proposé plusieurs solutions originales pour relever le défi de développer des techniques numériques, capables de faire face au canal acoustique.En raison d’une diversité inhérente d'espace du signal (SSD), les constellations tournées permettent de meilleures performances théoriques que les constellations conventionnelles et ce, sans détérioration spectrale. Nous passons en revue les propriétés structurelles des constellations tournées M-QAM uniformément projetées, afin de proposer une technique de demapping souple à faible complexité pour les canaux à fading. Puis, nous proposons une technique originale de réduction du PAPR pour les systèmes OFDM utilisant les constellations tournées. Afin de réduire la complexité du décodage aveugle, nous nous appuyons sur les propriétés des constellations tournées M-QAM uniformément projetées, pour concevoir un estimateur de faible complexité. De plus, pour faire face à la sélectivité du canal acoustique, nous avons proposé un turbo-détecteur parcimonieux adaptatif avec seulement quelques coefficients à mettre à jour afin de réduire la complexité. Enfin, nous avons proposé un algorithme original auto-optimisé pour lequel les tailles de pas de l'égaliseur sont mises à jour de manière adaptative et assistées par des informations souples de manière itérative, afin de répondre à l'exigence de convergence rapide et de faible erreur quadratique sur des canaux variant rapidement dans le tempsThere has been recently a large development of human activities associated to the ocean world, where no standard has emerged for the Internet of Things (IoT) linked to marine autonomous objects. Though it has a limited bandwidth, the acoustic wave is the only way to communicate over average to large distances and it is thus used by many underwater systems to communicate, navigate, or infer information about the environment. This led to a high demand for wireless networks that require both spectral efficiency and energy efficiency with the associated low-complexity algorithms. Therefore, in this Ph.D. thesis, we proposed several original solutions to face this challenge.Indeed, due to the inherent Signal Space Diversity (SSD), rotated constellations allow better theoretical performance than conventional constellations with no spectral spoilage. We review the structural properties of uniformly projected rotated M-QAM constellations, so as to propose a low complexity soft demapping technique for fading channels. Then, we present an original blind technique for the reduction of the PAPR for OFDM systems using the rotated constellations with SSD. In order to reduce the complexity of blind decoding for this technique, we again rely on the properties of uniformly projected M-QAM rotated constellations to design a low-complexity estimator. Moreover, to face the selectivity of the acoustic channel, we suggest a sparse adaptive turbo detector with only a few taps to be updated in order to lower down the complexity burden. Finally, we have proposed an original self-optimized algorithm for which the step-sizes of both the equalizer and the phase estimator are updated adaptively and assisted by soft-information in an iterative manner, so as to meet the requirement of fast convergence and low MSE over time-varying channels
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Thome, Geoffrey D. "U.S. Marine specific software interoperability requirements of the AFATDS and IOS software suites." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FThome.pdf.
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Thesis (M.S. in Information Technology Management and M.S. in Software Engineering)--Naval Postgraduate School, September 2002.Thesis advisor(s): John Osmundson, Richard Riehle. Includes bibliographical references (p. 119-123). Also available online.
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Rautio, Leonard J. "Study of standards used to screen recruits for assignment to the communications field in the U.S. Marine Corps." Thesis, Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/5791.
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Approved for public release; distribution is unlimited.This thesis examines the relationship between ASVAB composite scores and success at the 06 Occupational Field Schools. The author analyzes Marine Corps personnel data obtained from the Total Force Data Warehouse. The range of the data studied covers a period from fiscal year 2006 through fiscal year 2009, including 9,921 Marines. Several multivariate regression models are estimated to determine the effects of ASVAB composites and other measures of performance on success at the Communications Schools. Results indicate that the Electronics aptitude test composite has a significant positive effect on success at the Communications Schools. Additional variables that have a positive effect on the probability of success are being married, Hispanic, American Indian, the Clerical aptitude test composite score, enlisting in fiscal year 2007 (compared to 2009), and attending 0612 or 0651 MOS schools (when compared to 0621). Factors that had a negative effect on success include being female, having fewer than 12 years of education, and attending 0613, 0614, 0622, 0623, 0628, or 0656 MOS schools (when compared to 0621). Further research is recommended to examine additional factors and to refine the variable for years of education.
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Travis, William L. "The economic and risk constraints in the feasibility analysis of wireless communications in Marine Corps Combat Operation Centers." Thesis, Monterey, California: Naval Postgraduate School, 2013. http://hdl.handle.net/10945/37735.
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Approved for public release; distribution is unlimitedThis thesis will provide Marine Corps acquisitions and communications personnel a general understanding of wireless communications capabilities, financial feasibility, benefits and the risks of implementing a wireless solution into the current existing communications infrastructure in particular, the Combat Operations Center (COC) CapSet models already employed and deployed throughout the Marine Corps Air Ground Task Force. The content of this thesis is of an unclassified nature. This thesis is intended to serve as a reference for acquisitions or communications personnel dealing with the acquisition, procurement, planning, and implementation of wireless technologies in the Marine Corps, so that they will be able to intelligently articulate the financial feasibility, benefits, and risks of adopting or implementing a wireless solution to the Marine Corps Enterprise Network and COC infrastructure, and make informed decisions on the subject.
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Simmons, Randall J. Curran Christopher C. "Mesh networks within a distributed operations framework utilizing IP based radios." Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion-image.exe/07Sep%5FSimmons.pdf.
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Thesis (M.S. in Information Technology Management)--Naval Postgraduate School, September 2007.Thesis Advisor(s): Bordetsky, Alex. "September 2007." Description based on title screen as viewed on Oct. 22, 2007. Includes bibliographical references (p. 93-95). Also available in print.
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Saintier, David. "Caractérisation numérique d’antennes VLF-LF en environnement réel." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4081/document.
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Les très basses fréquences (VLF) sont aujourd’hui principalement utilisées pour les communications sous-marines. Ces fréquences ont en effet l’avantage de pénétrer dans l’eau de mer jusqu’à quelques dizaines de mètre de profondeur, ainsi que de permettre des communications à très longue distance, au-delà de l’horizon. Les antennes nécessaires à l’établissement de ces communications sont nécessairement de très petite taille par rapport aux longueurs d’onde mises en jeu. Ces antennes sont des structures composées de centaines de mètre de câbles métalliques, situées à un emplacement étudié pour les qualités diélectriques du sol ou les avantages structurels du relief. Pour étudier de telles antennes, nous proposons l’utilisation d’un code basé sur une méthode temporelle, la TLM. Cette méthode peut se révéler être très efficace pour des études sur de larges bandes de fréquence et en présence d’un environnement diélectrique complexe. Pour cela, nous avons amélioré le modèle du Fil Mince permettant de modéliser une structure métallique en une dimension et avons cherché à valider son fonctionnement en présence d’un environnement réaliste. Dans ce document, nous présentons ainsi les différentes étapes ayant abouties aux améliorations apportées au modèle de Fil Mince. Notre code a été validé en comparant nos résultats à ceux de FEKO, un logiciel commercial basé sur la MoM considéré comme la méthode la plus adaptée à ce type de problème. Nous avons proposé, en particulier, une solution permettant de garantir une bonne précision du modèle quel que soit l’orientation du fil dans le maillage cartésien 3D. Nous avons ensuite précisé le domaine de validité des fils coudés ainsi que des jonctions de plusieurs fils. Nous avons étudié également l’interaction entre le fil et des milieux inhomogènes. Il s’agit là d’une problématique ambitieuse pour laquelle nous avons apporté quelques éléments de réponse mais qui reste à ce jour un verrou technologique à lever. Enfin, nous avons étudié des structures antennaires réalistes. Les simulations d’un système composé d’antennes en T déployé dans une vallée ont permis d’appréhender le fonctionnement d’une telle structure et ont montré l’intérêt de notre méthode. En effet, les temps de calcul nécessaires à la résolution du problème sont significativement plus faibles avec le code TLM qu’avec le logiciel FEKO sur ce type de sol complexe. Les simulations d’une antenne Trideco avec un plan de masse radial aérien ou enterré ont quant à elles montré les limites actuelles du code TLM qui reste handicapé par une modélisation imprécise des nœuds de connexion entre plusieurs fils et de leur interaction avec les milieux inhomogènesSubmarine communications are the main usage of the very low frequency (VLF). This frequency band allows to radiate up to a few tens meter of depth and to a very long distance. Antennas for such telecommunications are necessarily small in regard to the wavelength. However, these structures are composed of hundred meters of thin metallic cables and their locations are often chosen for their dielectric characteristics or the structural advantage provided by the relief. To evaluate such antennas, we propose to use a home-made software, based on the TLM method. Such technique can be efficient for studying wide band electromagnetic problems in complex dielectric environment. Then we have improved the TLM Thin Wire model and we have evaluated its performances in realistic environment. In this document, we present our work and its validation by comparing our results to those obtained with the commercial software FEKO, based on the MoM, considered as the most suitable technique for this kind of problem. A solution assuring a good accuracy of the model for an arbitrary orientation of the Thine Wire in the 3D cartesian grid was proposed. We have also specified the limitations of the bent wire and the wires junction. In addition, we have studied the interaction between the wire and inhomogeneous media. This is an ambitious problem for which we brought some elements of answer but which remains a challenge. Finally, we have tested our software on some realistic antenna systems. The simulations of a valley span T antennas system allow to understand the functioning of such radiating structure and to show the interest of our method. The computation times are significantly lower with the TLM method than with FEKO to deal with antennas above such complex ground. However, the simulations of a Trideco antenna with aerial or buried radial ground plane showed the actual limitations of the TLM software which remains handicapped by an insufficient accuracy of the wires junction model and the inhomogeneous media interactions
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Wappelhorst, Annika. "In the Net : The Visual and Verbal Rhetoric of the Campaign “Operation Dolphin Bycatch” by Sea Shepherd France." Thesis, Jönköping University, HLK, Medie- och kommunikationsvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-54617.
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The marine conservation organization Sea Shepherd is most known for its radical direct action, e. g., against whale poaching. This thesis examines the campaign “Operation Dolphin Bycatch,” coordinated by the French branch of the NGO, through discourse analysis and interviews with Sea Shepherd France (SSF) members. Dolphins serve as the flagship species of the campaign. They allow SSF to criticize non-selective fishing methods that cause the accidental killing of dolphins in the Bay of Biscay. With expressions from war and religion, SSF portrays the French government and most fishermen as enemies of the dolphins’ wellbeing that pursue self-interested profit values. It is found that SSF positions itself as radical more in its worldview than its approaches. The ecological philosophy of biocentrism contradicts the anthropocentrism that dominates society. In this campaign, the NGO uses “outsider” tactics: It exerts pressure on French policy-makers with footage of dolphin bycatch and takes great care to maintain international legitimacy by staying within legal boundaries.L’organisation de conservation du milieu marin Sea Shepherd est surtout connue pour ses méthodes d’action directe radicale, par exemple contre le braconnage des baleines. Ce mémoire de master examine la campagne « Opération Dolphin Bycatch », qui est coordonnée par la branche française de l’ONG, à travers une analyse multimodale du discours et des entretiens avec des bénévoles de Sea Shepherd France (SSF). Les dauphins sont l’espèce porte-drapeau de la campagne. Ils permettent ainsi à SSF de critiquer les méthodes de pêche non sélectives qui provoquent la mort accidentelle de dauphins dans le Golfe de Gascogne. Avec des expressions provenant des champs lexicaux de la guerre et de la religion, SSF dépeint le gouvernement français et la plupart des pêcheurs comme poursuivant des valeurs lucratives égoïstes à l’encontre du bien-être des dauphins. Il s’avère que SSF se positionne comme radicale dans sa vision du monde plus que dans ses approches. Sa philosophie biocentrée de l’environnement contredit l’anthropocentrisme qui domine la société. Dans cette campagne, l’ONG utilise des tactiques « extérieures », c’est-à-dire qu’elle exerce une pression sur les décideurs politiques français avec des images de prises accessoires de dauphins et prend soin de maintenir une légitimité internationale en restant dans un cadre légal.
Die Meeresschutzorganisation Sea Shepherd ist vor allem für ihre radikalen „Direct Action“-Methoden bekannt, beispielsweise gegen Wal-Wilderei. Diese Arbeit untersucht die Kampagne „Operation Dolphin Bycatch“, die vom französischen Zweig der NGO koordiniert wird, durch multimodale Diskursanalyse und Interviews mit Mitgliedern von Sea Shepherd Frankreich (SSF). Delfine dienen als Flaggschiff-Art der Kampagne. Sie ermöglichen es SSF, die nicht-selektiven Fischereimethoden zu kritisieren, die das versehentliche Töten von Delfinen im Golf von Biskaya verursachen. Mit Begriffen aus Krieg und Religion schreibt SSF der französischen Regierung und den meisten Fischerleuten eigennützige Profitinteressen zu und stellt sie als Feinde des Wohlergehens der Delfine dar. Es zeigt sich, dass SSF eher in ihrer Weltanschauung als in ihren Ansätzen eine radikale Position beansprucht. Ihre biozentrische Umwelt-Philosophie steht im Widerspruch zum Anthropozentrismus, der in der Gesellschaft vorherrscht. Bei dieser Kampagne bedient sich die NGO „Außenseiter“-Taktiken: Sie übt Druck auf französische Politiker*innen aus, indem sie Filmaufnahmen von Delfin-Beifang zeigt, und achtet durch das Einhalten gesetzlicher Vorgaben darauf, internationale Legitimität zu wahren.
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Sauvadet, Anne-Laure. "Interactions entre ciliés et métazoaires dans deux environnements marins contrastés : les sources hydrothermales et les sédiments anoxiques." Paris 6, 2010. http://www.sb-roscoff.fr/images/stories/sbr/Edition-communication/theses/these_sauvadet.pdf.
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Les communautés d’eucaryotes unicellulaires associées à des métazoaires endémiques de deux environnements marins, les sources hydrothermales et les sédiments marins côtiers, ont été caractérisées par des études moléculaires et microscopiques. Ce travail de recherche a permis i) de caractériser et de comparer la distribution des communautés d’eucaryotes unicellulaires associées à différents environnements marins profonds, ii) de mettre en évidence de nouveaux clades, notamment chez les ciliés détectés dans les bivalves hydrothermaux, iii) de redéfinir et de comparer la distribution d’un groupe particulier de ciliés, les astomes, retrouvé uniquement en interaction avec des polychètes, iv) de mettre en évidence dans ces astomes endocommensaux, un troisième degré d’interaction représenté par des bactéries endocytoplasmiques. Ainsi, cette étude montre qu’une majorité d’eucaryotes unicellulaires détectés au niveau des sources hydrothermales sont des organismes cosmopolites des océans. Cependant, des niches écologiques distinctes et stables, représentées par les bivalves endémiques, abritent des communautés de ciliés plus spécifiques. De plus, les polychètes Cirratulidae retrouvés dans les sédiments côtiers réduits abritent un modèle d’interaction tripartite composé d’astomes endocommensaux associés à des bactéries endocytoplasmiques. Ces endosymbiontes sont phylogénétiquement très éloignés des organismes déjà décrits, et pourraient être ainsi les témoins d’une histoire évolutive commune. Ces nouveaux modèles d’étude ouvrent le champ des interactions entre eucaryotes et bactéries
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Phillips, Bradley W. "Beyond the space cadre." Quantico, VA : Marine Corps Command and Staff College, 2008. http://handle.dtic.mil/100.2/ADA490929.
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Long, John M. "Junior Officer oral communication in the Navy and Marine Corps." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Jun%5FLong.pdf.
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Thesis (M.S. in Leadership and Human Resource Development)--Naval Postgraduate School, June 2004.Thesis advisor(s): Gail Fann Thomas, Anne-Marie Drew. Includes bibliographical references (p. 95-99). Also available online.
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Justice, Barry D. "A scheduling model for the U.S. Marine Corps Communication-Electronics School." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from the National Technical Information Service, 1993. http://handle.dtic.mil/100.2/ADA274958.
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Thesis (M.S. in Operations Research) Naval Postgraduate School, September 1993.Thesis advisor(s): Brown, Gerald Gerard ; Wood, R. Kevin. "September 1993." Includes bibliographical references. Also available online.
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Campbell, Maria Shauna. "Fisheries, marine conservation, marine renewable energy and displacement : a fresh approach." Thesis, University of Plymouth, 2017. http://hdl.handle.net/10026.1/8336.
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Fishers are among the biggest commercial resource users in the marine environment. In order to meet international, national and local policies, the UK has to designate a suite of marine protected areas (MPAs) and reach marine renewable energy (MRE) targets. Inevitably, there will be conflict between these two industries and marine conservation. This study uses a multi-disciplinary approach to examine evaluate the suitability of various sources of data, which could be used to detect, assess, and ultimately predict, fishing effort displacement within the different sectors of the > 15 m fleet in the South West of the UK. Gear-specific Vessel Monitoring System (VMS) data from 2005-2008 was used to assess potential effort displacement due to Haig Fras, a proposed MPA and Wave Hub, a marine renewable energy installation (MREI). The spatial distribution of fishing activity was highly heterogeneous and distinct areas of intense fishing could be identified for all gear-types. A closure of Haig Fras would have the greatest impact on gillnetters. Scallop dredgers also occasionally use the area. The current closure at Wave Hub has the greatest impact on potters and whelkers whose geographic specialisation is most pronounced and who use the area extensively. Longliners also use the area disproportionately would be affected. A simple index of variability was developed in order to determine baselines and two other sources of data were used. High resolution seabed data and low resolution catch data. A semi structured interview was conducted with forty fishers to elicit further information on the challenges, barriers to progress and priority issues in relation to MRE those fishers face. The theme of discontent with the consultation process scored highly throughout. Fishers’ Knowledge (FK) another source of data also scored highly, although further work must be carried out to identify what aspects of this data are useful in assessment of fishing effort displacement.
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Jefferson, Rebecca Louise. "Communicating marine environmental health : connecting science, social and policy values." Thesis, University of Plymouth, 2010. http://hdl.handle.net/10026.1/2666.
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Human activities are degrading marine ecosystems and undermining the ecological functions and processes which provide valued goods and services. European and UK marine policy developments aim to implement the Ecosystem Approach to support better management of activities and maintain the health of regional seas. Current public perceptions of the UK marine environment are overwhelmingly negative, creating a barrier to engaging society with marine environmental issues and policy. This thesis conducts a study of the attributes of a suite of 72 UK marine species to identify those which contribute most to marine ecological health. The findings show that structurally complex species are most important and are recommended as species to assess and monitor Good Environmental Status as defined by the EU Marine Strategy Framework Directive. Existing conservation policies are biased towards large vertebrate species, with ecologically important species being underprotected. A survey of public perceptions of the marine environment. revealed conflicting perceptions of charismatic megafauna. Charismatic species were the most interesting species but least important as measures of marine health. Ecologically important species were the least interesting, but ecological health concepts were considered important measures of marine health. Perceptions of the marine environment varied with socio-demographic and social value factors. By integrating these studies, barriers and opportunities to engaging society with the marine environment were identified. Communication strategies which address these are proposed, including a suite of Spokes Species, potential high profile species to champion the marine environment. These include puffin, cod, basking shark and seagrass. A series of themes are proposed which implement other key findings such as the importance of personal experience in building connections with marine species. Communication strategies are supported by ecologically defined assessments of marine environmental health, are relevant to current policy developments and will resonate with social values of the marine environment.
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Johansson, Björn G. "Chemical Communication and Mate Choice : Investigations into the Meaning of a Fruit Fly Pheromone." Doctoral thesis, Uppsala University, Department of Ecology and Evolution, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4840.
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Chemical signals are the most widely used form of sexual communication throughout the living world. However, there is in general little knowledge about what these signals actually communicate. The role of chemical signals, i.e. pheromones, in sexual behaviour has traditionally been seen as restricted to mate attraction and species recognition. This thesis reviews the evidence for pheromones as indicators of mate quality, and then investigates three important factors for mate quality signals – individual variation, heritability and cost – by using the male pheromone of the lekking fruit fly Drosophila grimshawi as a model.
The experiments presented indicate that the pheromone of D. grimshawi has multiple functions, and that these functions vary with social context. Thus, with regard to females, the pheromone seems to act mainly as a species/mate recognition signal, since females show little preference for the amount of pheromone deposited by a male. Moreover, males invest less in pheromone production when subjected to females as compared to when subjected to rival males. However, the pheromone seems to be costly in production since males that invest much in pheromone deposition has a shorter lifespan. This suggests a function for the pheromone in male-male interactions. Males can distinguish their own pheromone depositions from those of a strange male, and also discriminate between pheromone depositions from one and two strange males. This might give them the ability to assess the size of a lek and the competitive capacities of rivals, information that should be useful when optimizing sexual behaviour.
In conclusion, the pheromone seems to act as an honest mate/competitor quality signal in some social contexts, and as a non-costly species/mate recognition signal in other. In addition, I show for the first time that a chemical signal has differential fitness costs, and that an insect is able to distinguish between individual odour signatures.
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Noel, Allen L. "Performance study of a Marine Expeditionary Force radio system." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA238486.
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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, September 1990.Thesis Advisor(s): Ha, Tri T. Second Reader: Myers, Glen A. "September 1990." Description based on title screen as viewed on March 22, 2010. DTIC Identifier(s): Marine Corps Equipment, Theses. Author(s) subject terms: VHF radio, HF radio, Single channel radio, Circuit switching, Voice Communication, Engset distribution. Includes bibliographical references (p. 63). Also available in print.
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Wierucka, Kaja. "Multimodal mother-offspring recognition in the Australian sea lion, Neophoca cinerea." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS432.
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La reconnaissance joue un rôle important dans les systèmes de communication animale et plusieurs modalités sensorielles sont impliquées à cette fin. Bien que la reconnaissance mère-jeune ait été largement étudiée, il y a un manque d'information sur la reconnaissance multimodale et l'importance relative des différentes modalités dans ce processus. Dans cette thèse, j'ai exploré la communication multimodale chez un mammifère colonial - le lion de mer Australien (Neophoca cinerea). La reconnaissance mère-jeune est connue pour être multimodale chez cette espèce, mais les processus sous-jacents de la reconnaissance olfactive et visuelle, ainsi que les interactions entre les indices acoustiques, visuels et olfactifs, et leurs contributions relatives restent inconnues. Des analyses chimiques ont permis de déterminer si les profils chimiques diffèrent selon le sexe et l'âge, les colonies et les régions corporelles des animaux. La présence de similarités chimiques entre la mère et son petit suggèrent que l'appariement des phénotypes pourrait être utilisé pour la reconnaissance olfactive. J'ai examiné le rôle des indices visuels lors de la reconnaissance mère-jeune et j'ai constaté que les indices visuels spécifiques à l'âge sont utilisés par les femelles pour affiner la recherche de leur petit dans la colonie. Les jeunes ont également la capacité de distinguer divers indices visuels, qui peuvent être utilisés pour identifier les différentes classes de congénères. Enfin, j’ai pu aussi déterminer comment les indices acoustiques, olfactifs et visuels sont utilisés de manière synergique dans le processus d’identification individuel, et les résultats sont interprété dans une perspective coûts-avantages pour démêler les pressions évolutives sur chaque composante de ce système de communication. Si les différents indices sensoriels ont la capacité de transmettre des informations en isolation, leur rôle peut être différent lorsque d'autres indices sensoriels sont présents. Les résultats de cette recherche fournissent des résultats sans précédent, contribuant à une meilleure compréhension de la reconnaissance mère-jeune chez les mammifères, ainsi que des règles générales de communication chez les vertébrésRecognition plays an important role in animal communication systems and individuals often employ different sensory modalities to enact this activity. Although recognition has been widely investigated, especially for mother-offspring interactions, there is a dearth of information about multimodal recognition and the relative importance and interactions of various sensory cues. In this thesis, I explored multimodal communication in a colonial mammal – the Australian sea lion (Neophoca cinerea). Communication during mother-pup reunions is known to be multimodal in this species, yet the underlying processes of olfactory and visual recognition, as well as the interactions between acoustic, visual and olfactory cues remain unclear. Through chemical analyses, I determined whether chemical profiles differ among sex and age classes, colonies, and body regions of animals. Chemical similarities between mothers and pups indicate that phenotype matching may be used by Australian sea lions for olfactory recognition. I examined the role of visual cues in mother-pup recognition and found that age-specific visual cues assist mothers to refine their search for their offspring in the colony. Pups are capable of distinguishing various visual cues that can be used in the assessment of conspecifics. Having provided baseline information about the role of sensory cues in isolation, I determined how acoustic, olfactory, and visual cues are used in a synergistic way to ensure accurate mutual recognition and then interpreted the results using a cost-benefit perspective to disentangle the evolutionary pressures on each component of this communication system. I showed that although cues have the ability to convey given information in isolation, their role may be different when other sensory cues are present. Furthermore, there is a mutual dependency in the communication system, where the limitations imposed on one participant of the dyad affect cue use by the other. These findings contribute to a better understanding of mammal mother-offspring recognition and communication mechanisms in vertebrates
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Moshiri, Hesam. "Implementation of a Generic Gateway as a Multipurpose Communication Node." Thesis, Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-24840.
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Steering and navigation systems play an essential role in governing today’s leisure boats. CPAC Systems AB, a subsidiary of Volvo AB, satisfies a large part of the global market needs for this kind of products. CPAC Systems, among others, manufactures a well-known “steer-by-wire” (SBW) control system, the “Electronic Vessel Control” (a.k.a. EVC). The need to connect the EVC to systems and devices designed by other companies resulted in the development of “gateway” devices, which have a primary role in preserving the integrity of the overall system architecture. Whenever the SBW communicates with external products, gateways are used as electric isolators and protocol translators, in order to protect the integrity of the SBW function. Today, a number of different gateway devices are required to match the different interfaces to which the CPAC’s EVC system has to be connected. This thesis aims to tackle the huge diversification of the requirements and evaluates the possibility of designing a “single” product that satisfies most of the requirements. In addition to that, the work aims to design a flexible device that could be easily updated to comply with the potential needs of the incoming applications. This isbeneficial in terms of both technology and cost-efficiency. Existing gateway products are designed to fulfill the assigned tasks or just to do a specific protocol conversion and apart from this significant difference with a generic gateway, they have some limitations concerning environmental conditions and prospective upgrades. Therefore designing, testing and implementation of one multifunctional gateway to be applicable as a multipurpose communication node to cover several functionalities, would be beneficial. Several challenges arose in designing the generic gateway device, such as: hardware design with a limited number of connection I/Os (solution is limited to 20 I/Os, whereas current gateway products require as many as 35 I/Os), robustness, final cost and power consumption. The contribution of the thesis was to analyse current gateway products, to design the hardware (Schematic and PCB), to implement the software, to debug the operation, to verify of the designed hardware to ensure the operation of each part. For gathering test results and investigation of communication or instruction signals, industrial equipment like digital oscilloscope and CAN analyser have been used to prove the operation of the device which are demonstrated in the “design tests” part. In addition, robustness of the gateway has been tested against several industrial test parameters, such as temperature variations, isolation, power supply robustness and typical power consumption. The results of these tests are iscussed in the “robustness tests” part. By fulfilling all of these steps and collaboration with the company team, satisfactory results have been achieved.
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Brossier, Jean-Marc. "Egalisation adaptative et estimation de phase : application aux communications sous-marines." Grenoble INPG, 1992. http://www.theses.fr/1992INPG0124.
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Ce travail concerne deux problemes d'estimation adaptative lies aux systemes numeriques de communication: le probleme de l'estimation de phase et celui de l'egalisation. L'estimation de phase est abordee de facon academique. Cette approche permet d'introduire simplement deux outils d'analyse du comportement d'un algorithme adaptatif. Nous utilisons ensuite ces outils pour determiner l'influence de la distribution du bruit sur la capacite de poursuite des estimateurs de phase adaptatifs. Cette etude conduit a definir et a etudier un nouvel algorithme d'estimation de phase theoriquement bien adapte a la poursuite de non-stationnarites lentes en contexte non gaussien. Nous abordons ensuite le probleme de la recuperation de porteuse et celui de l'egalisation. Des algorithmes de recuperation de porteuse et/ou d'egalisation asymptotiquement optimaux en poursuite de non-stationnarites lentes sont presentes. L'efficacite et la robustesse de ces algorithmes sont mises en evidence a l'aide de simulations. Parmi ces algorithmes, l'algorithme d'estimation conjointe de porteuse et d'egaliseur est tout particulierement interessant en pratique. Le domaine d'application vise est celui des communications acoustiques sous-marines. L'utilisation de donnees reelles permet de valider les algorithmes obtenus dans des situations realistes (transmissions acoustiques sous-marines horizontales ou verticales)
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Bird, Corey D. "Investigation and suppression of multipath communication signals with applications to a marine environment." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23119.pdf.
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Neu, Charles R. Davenport Jon Smith William R. "U.S. Marine communication-electronics school training process discrete event simulation and lean options /." Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion-image.exe/07Dec%5FNeu%5FMBA.pdf.
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"Submitted in partial fulfillment of the requirements for the degree of Master of Business Administration from the Naval Postgraduate School, December 2007."Advisor(s): Heath, Susan ; Simon, Cary ; Summers, Don. "December 2007." "MBA professional report"--Cover. Description based on title screen as viewed on January 10, 2008. Includes bibliographical references (p. 91-94). Also available in print.
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Neu, Charles R., William R. Smith, and Jon Davenport. "U.S. Marine communication-electronics school training process: discrete event simulation and lean options." Thesis, Monterey, California. Naval Postgraduate School, 2007. http://hdl.handle.net/10945/10217.
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MBA Professional ReportApproved for public release; distribution is unlimited
This paper uses discrete-event simulation modeling, inventory-reduction, and process improvement concepts to identify and analyze possibilities for improving the training continuum at the Marine Corps Communication-Electronics School (MCCES), specifically in terms of reducing adverse effects of lost-time spent in the Marines Awaiting Training (MAT) Platoon queue. Every possible improvement that the local commander could make without spending any capital was tested using the Process Analyzer Function (PAN) in Arena. The researchers also tested increasing the number of instructors up to the quantity authorized. Potential effects on the MCCES operating budget are offered, i.e., a cost-benefit analysis based on average salaries was conducted with recommendations for making the training system more efficient while examining potential changes to reduce costs. The premise of the study is that Marines Awaiting Training (MAT) are potential warfighters not gaining value-added training nor benefiting the Marine Corps when waiting in a queue to begin Military Occupational Specialty (MOS) training, i.e., adversely affecting Fleet Marine Forces operational readiness. The study coincides with current emphasis on reducing the Training, Transients, Patients, and Prisoners (T2P2) account. The researchers determined that changing from the present MCCES process of scheduling classes to an on-demand scheduling method, and, in some MOSs, changes to the minimum and maximum class sizes and the number of instructors, would result in a reduction in the average days spent in MAT and the average number of Marines in MAT. By utilizing all recommendations, the researchers identified a potential value savings in terms of salary of $1 1.6 million and a potential cost savings to the barracks and base support costs of $1 .9 million.
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Lyonnet, Bastien. "Diversité spatiale et compensation Doppler en communication sous-marine sur signaux large-bandes." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00664710.
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Le milieu sous-marin est doublement dispersif, en temps et en fréquence. L'utilisation récente de signaux de communication multi-porteuses offre une solution pour lutter contre la sélectivité fréquentielle. Mais ce type de signaux reste très sensible à la dispersivité fréquentielle. Cette thèse se concentre sur le problème de la dispersivité fréquentielle qu'est l'effet Doppler. Des méthodes d'estimation du paramètre Doppler sont développées pour des signaux multi-porteuses DMT. Est également abordé le problème de la compensation Doppler dans les cas mono et multitrajets. Une méthode générale et une méthode spéci que au signaux multiporteuses sont présentées et testées sur simulation. Cette thèse se distingue par son modèle du canal sous-marin qui considère un paramètre Doppler différent sur chaque trajet. Ceci résulte de la géométrie du problème et des vitesses émetteur/récepteur considérées. Nous présentons nalement des méthodes pour séparer les différents trajets arrivant sur une antenne a n de pouvoir considérer un paramètre Doppler unique sur chacun.
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OGOR, MARIELLE. "Communications electromagnetiques sous-marines par ondes laterales dans la gamme elf/vlf." Nice, 1998. http://www.theses.fr/1998NICE5236.
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Cette etude porte sur la faisabilite de radiocommunications numeriques sous-marines en zones cotieres dans la gamme de frequence 30 hz-30 khz. Elle est plus particulierement consacree a la mise en evidence de l'interet potentiel des ondes laterales dans l'accroissement de la portee des systemes de communications electromagnetiques en milieu marin. Elle s'articule en quatre parties. La premiere fait un tour d'horizon de l'ensemble des connaissances sur les emetteurs et recepteurs radios (seul le champ magnetique est aborde), les proprietes du canal de transmission sous-marin, les techniques des telecommunications a proprement parler ainsi que les differentes sources de bruit rencontrees sous l'eau. La seconde presente la determination des principales proprietes du canal en regime harmonique. La caracterisation du canal, schematise par un milieu stratifie, est realisee via le developpement de simulations informatiques. Nous conduisons une estimation de la portee atteignable. Une experience en bassin a echelle reduite vient appuyer ces outils. La partie suivante s'attache a etudier les bruits identifies auparavant. Nous illustrons la construction d'un logiciel qui permet de simuler des tranches de bruit atmospherique, a partir des renseignements extraits des references bibliographiques. Les schemas retenus pour ce logiciel sont ensuite confrontes a des enregistrements de bruit magnetique. Enfin, la derniere partie detaille le developpement d'un simulateur complet de communications numeriques electromagnetiques sous-marines, associant les deux elements logiciels concus precedemment. Les releves issus d'un prototype grandeur reelle teste en mer sont traites et compares aux predictions du simulateur.
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Bishop, John. "Application of radio-navigation systems to the remote tracking of marine animals." Thesis, Bangor University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360999.
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Parameshwara, Vinayak Kota. "ENHANCEMENT OF NORTH CAROLINA AGRICULTURAL AUTOMATED WEATHER NETWORK AND DEVELOPMENT OF ADVANCED COMMUNICATION, DATA ACQUISITION, AND DISSEMINATION SYSTEMS." NCSU, 2000. http://www.lib.ncsu.edu/theses/available/etd-20000606-114101.
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AgNET is a weather network, which collects surface and subsurface meteorological data in North Carolina. Each AgNet weather station measures a variety of weather parameters such as air temperature, relative humidity, wind speed and direction, barometric pressure, solar radiation, photosynthetically active radiation, soil temperature, soil moisture and precipitation. The station summarizes the above parameters for every hour and stores them in its local memory. Currently the data collected over the entire day are then transferred to a central server through phone lines. The data collected at the central server are published on the Internet and disseminated by other means as well. The purpose of this thesis is to describe the modernization of the AgNet weather network by making the network conform to standards, implement a uniform sensor configuration and improve the methods of data acquisition, dissemination and display of weather data.Since phone-based communication is not economical for real time data transfers other techniques such as Radio Frequency (RF) communication and satellite based communication were evaluated. RF communication was the most promising communication technique. Since RF is limited by distance, a combination of RF and Internet was designed. In this type of communication, data are transmitted from the weather station and received by a base station that is on the Internet. The received data are then forwarded to a central server at the State Climate Office where they are archived and disseminated. A successful test was conducted as proof of concept between Lake Wheeler road Field laboratory site, Raleigh and Varsity Laboratory, NC State University.Since every system has inherent noise, data collected at each station have to go through different quality control algorithms to insure data quality. Different Quality Control (QC) algorithms were implemented which are discussed in the thesis.
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Hamza, Tasnim. "Communications optiques sous-marines : transmission longue-portée haut débit et analyse des performances." Thesis, Ecole centrale de Marseille, 2017. http://www.theses.fr/2017ECDM0002.
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Aujourd'hui, un large éventail d'activités d'exploration et d'exploitation du milieu sous-marin requière l'établissement de transmissions de données à haut débit. Dans ce contexte, les solutions de communications traditionnelles par câble ou par fibre optique impliquent des déploiements coûteux et une flexibilité très limitée. D'autre part, les communications acoustiques offrent des performances opérationnelles très faibles. Récemment, avec le développement de composants optoélectroniques compacts et peu coûteux, il est devenu possible de réaliser des modems optique pour les communications sans-fil, qui soient compacts et offrent des vitesses de transmission et une efficacité énergétique sans précédentes. Cependant, cette technologie souffre encore de plusieurs limitations, notamment quand il s'agit d'établir des liens de communication sur des distance relativement longues et à des débits de transmission élevés. Pour faire face à certaines de ces faiblesses, cette thèse considère l'utilisation de nouveaux composants optoélectroniques et des techniques de traitement du signal adaptées afin d'améliorer les performances des liaisons de communication optique sans fil sous-marine.En effet, après l'étude de l'effet du bruit solaire sur la performance de ces liaisons, nous étudions l'utilisation d'une nouvelle technologie de photo détection, basée sur les photomultiplicateurs en silicium (SiPM). Nous étudions les performances de ces composants dans différentes conditions de turbidité de l'eau. Par ailleurs, nous proposons des techniques de transmission efficaces basées principalement sur la modulation d'amplitude et l'égalisation dans le domaine fréquentiel. Cette dernière est employée afin de dépasser la limitation imposée sur les débits de transmission par les composants d'émissions et de réception, notamment les LEDs et les SiPMs, et ainsi permettre une transmettre les données à des débits plus élevés. L'efficacité des solutions proposées est ensuite validée par une étude expérimentaleToday we are witnessing a growing need to high-rate data transmission in underwater missions in a wide range of application areas. Within this context, traditional cable- or fiber-based communications imply costly deployments with very limited flexibility, and the conventional acoustic communications offer very low operational performance. Recently, with the development of small and low-cost optoelectronic components and devices, it has become feasible to realize small and compact wireless optical communication transceivers providing unprecedentedly high transmission rates and energy efficiency. However, there still remain several shortcomings of this technology, in particular to attain high data rates over relatively long communication ranges. In order to overcome some of these limitations, this PhD thesis considers the use of advanced optoelectronic components and signal processing techniques in order to improve the performance of underwater wireless optical communication (UWOC) links. In this view, after studying the effect of solar background noise on the performance of these links, we investigate the use of the recent promising Silicon photo-multipliers (SiPMs) in UWOC receivers and study the corresponding system performance in different conditions of water turbidity. We also propose efficient transmission solutions, mainly based on pulse amplitude modulation and frequency domain equalization in order to surpass the bandwidth limitation of the emitters and SiPMs to allow high rate data transmission. The benefits of the proposed solutions are further validated through experimental measurements
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Woodward, John A. "A proposed architecture for communication planning in support of Marine Air Ground Task Force operations." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/26184.
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The author uses a systems approach methodology to address the requirements for a Marine Air Ground Task Force communication planner. An architecture is developed in which line of sight and beyond line of sight computer programs are used to assist the planner. Particular needs are stated for line of sight information requirements. There is special emphasis on high frequency (HF) communication planning due to the vulnerability of satellite communications in a wartime environment. In particular, an algorithm for HF communications is designed for HF frequency requests and for HF frequency to net assignments. That algorithm was coded by personnel at the Naval Ocean Systems Center (NOSC) and included as a test module in the latest release of the Advanced Prophet program. A menu driven program is designed and incorporates the features required for a Marine communication planner to enhance the command and control process for the commander. Theses. (RH)
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Psillas, Christopher F. "A preliminary economic evaluation of Marine Corps acquisition practices: UHF satellite communication ground terminal acquisitions." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/27220.
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Economic theories and concepts are used to discuss allocating scarce fiscal resources for acquiring UHF satellite communication ground terminals. This thesis provides and overview of current acquisition practices and suggests how applied economics can explicitly aid in better decision making. Keywords: Command control and communications, Telecommunications, Demand, Supply, Acquisitions, Demand management. (KR)
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Ben, Rhouma Ons. "Diversité en émission dans un contexte de communication autodidacte." Télécom Bretagne, 2007. http://www.theses.fr/2007TELB0037.
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Alayrangues, Pierre. "Madame du deffand epistoliere ou l'impossible communication." Paris 4, 1986. http://www.theses.fr/1986PA040042.
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Pour madame du deffand, la correspondance est le lieu et l'instrument d'une interminable quete de soi, d'un continuel questionnement de son existence qui fait penser a un journal intime, a des "essais" a la facon de montaigne. S'eprouvant tout au long de sa vie comme etrangere a ses origines, a son monde, a son siecle et a elle-meme, degoutee de tout (et d'abord d'elle-meme), elle cherche a faire de ses correspondants les auxiliaires de cette aventure d'etre par des tentatives decevantes d'identification (avec les figures parentales fortement idealisees et donc inaccessibles de voltaire et de madame de choiseul), d'"adoption" (en realite tentatives pour modeler des etres qui repondent a son attente avec les figures filiales de julie de lespinasse et de d'alembert), et enfin d'abandon de soi dans une relation crispee (qui voudrait etre une relation amoureuse) avec l'autre represente de facon exemplaire par walpole. En realite, muree dans un narcissisme inexpugnable de caractere nettement pathologique (melancolie chronique), elle ne peut s'accommoder de l'exteriorite qui oppose a la libre expansion du moi son opacite (sa resistance) ou son insipidite (son insignifiance : henault) on peut lire dans cette espece de biographie spirituelle une frustration affective profonde qui conduit a une crise des valeurs, a une metamorphose de la sensibilite, au vertige devant une existence dont il faut assumer solitairement le risque au sein d'un monde qui se derobe dans une absence radicale et d'une duree vide offerte a l'invention du moiFor madame du deffand, letter-writing is the thorough means of an endless selfinvestigation (or quest), of an exerlasting wondering about one's existence which reminds of a personal diary, of "essays" such as montaigne wrote them. She felt alien to her background, her world, her age and even to her own self all through her life ; she was disgusted with everything (first and foremost with her own self) she tried to turn her pen friends into the auxiliaries of this quest for living through disappointing attempts at identification (such as highly idealistic parents'images, voltaire's and madame de choiseul's out of reach gifts), at adoption (as a matter of fact, attempts at shaping up beings that reflect her expectation, with julie de lespinasse's and d'alembert's filial relation-ships), at last at self-surrender in a thwarted relationship (which meant to be a loving one) with the other one perfectly embodied in walpole. As a matter of fact, blocked up by an ineradicable narcissism, a definitely pathological, chronical melancholy mania, she couldn't adjust herself to the outside world that set in action against the free expansion of her ego, its standing value or its lack of meaning. This kind of spiritual biography can be read as a deep, emotional frustration which leads to a "value" crisis (or upheaval), to a thorough change of the sensitivity, to a giddy feeling when living has to be faced, the risk of which must be run, alone, in a world doesn't provide any support because it keeps vanishing and because self growth can only be achieved from an empty span of time
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Fangbemi, Kossivi Agbessi. "Collaborative control of wave glider platforms - Local Communication and Sea State Estimation." Master's thesis, Faculty of Engineering and the Built Environment, 2019. http://hdl.handle.net/11427/31411.
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Climate change is the focus of many oceanography and marine engineering researchers, with possible links between climate change and the carbon cycle in the Southern Ocean being considered. This type of investigation requires modern and cost-effective tools to conduct surveys and collect data from the ocean. The self-propelled unmanned surface vessel, the Liquid Robotics Wave Glider, was designed primarily as a marine research tool and offers several advantages over existing research vessels and other tools employed for data acquisition in the ocean. The main advantages are its robustness at sea, i.e. its ability to withstand extreme weather conditions, its propulsion energy source, which is the wave energy, and its customisable electronics payload. The inter-platform communication strategy of the Wave Glider inspired a few engineering questions, one of which is the focal point of this research: whether Low Power Wide Area Network (LPWAN) technology can be used to set up a local communication system enabling the collaboration of two or more Wave Gliders and reduce the cost, in terms of power and communication channels, involved in the communication with the Wave Glider platforms during missions. This research considers various LPWAN technologies available on the market and proposes LoRaWAN technology for the local communication system. LoRaWAN was selected as it presented a robust radio modulation and had growing support in the industry. In this research, a LoRa-based network of two nodes was developed, implemented and tested over the surface of the ocean. It was found that the system performs well over a distance of 1 km with both antennas having one end at the mean surface level of the sea. With the intention to increase the range of the platform and achieve a reliable and robust system, the research continued with the study of the influence of the surface waves on the proposed local communication system by exploring, firstly, the impact of seawater and, secondly, the wave height on signal transmission. The first study investigated the influence that the electromagnetic properties of seawater may have on the transmission of signals from one node to the second through simulations using the computational electromagnetic package FEKO. It revealed that, at the frequency of operation, which was 868 MHz, seawater reacted as a lossy conductor and reflected the signal upward, with negligible power penetrating the surface of the ocean. The subsequent study reviewed the statistical properties of the ocean surface waves in a sea of deep waters and proposed a relationship between the wind speed (or surface wave elevation), the antenna height, the distance separation between the two nodes and the probability of the presence of a line of sight (LoS) between the two nodes. This relationship quantifies the expected result that the probability of the LoS diminishes as the wind speed or the distance between the two nodes increases, whereas it improves with an increase in the antenna height. The last part of the research focused on initial works on sea state estimation using the lossless wave equation and Kalman Filter to provide 3D sea surface elevations that would be used to change to the probability of the LoS calculated previously in the research. Indeed, using the local communication to share the point-wise sea state data can be exploited to estimate the sea state over a rectangular region delimited to include these points. Sea state estimation is expected to enhance the joint navigation and coordination of the platforms and consequently, boost the probability of the LoS through the transmission at the crest of the waves. During the development of the Kalman Filter model, it was discovered that the sample time and the sample space significantly affect the performance and the stability of the discretised models. However, a carefully selected sampling time and sample space exhibited a stable system model. The results of the Kalman filtering were a realistic sea state estimate with a minimum error at the locations in the surrounding of the measurements.
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Stoffle, Richard W., and Jessica Minnis. "Resilience at Risk: Epistemological and Social Construction Barriers to Risk Communication." Journal of Risk Research, 2008. http://hdl.handle.net/10150/292434.
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This paper is about the persistent failure of social scientists to bring into the Environmental Impact Assessment (EIA) process socially constructed environmental concerns held by potentially impacted communities. The failure to communicate perceived risks results from a two-communities divide based on both epistemological differences and obfuscation due to vernacular communication. The analysis provides robust modeling variables that can bridge this social-environmental divide. The case involves data collected from members of traditional communities regarding their perceptions of the potential impacts of proposed Marine Protected Areas (MPAs). The study is situated in the Bahamas where the government has approved setting aside 30 No-take MPAs to protect
their sea. This analysis is based on 572 interviews conducted during eight field
trips with members of six traditional settlements in the Exuma Islands and Cays
in the central Bahamas. Confidence in the findings is high because the sample
involves 34% of the census population of these settlements and the findings have repeatedly been returned for review and approval by the members of these settlements.
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Nachabe, Yasmine. "Marie al-Khazen's photographs of the 1920s and 1930s." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=107742.
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Marie al-Khazen was a Lebanese photographer who lived between 1899 and 1983. Her photographs were mostly taken between the 1920s and 1930s in the North of Lebanon. They were compiled by Mohsen Yammine, a Lebanese collector who later donated the photographs to the Arab Image Foundation. Her work includes a collection of intriguing photographs portraying her family and friends living their everyday life in Zgharta. Al-Khazen seized every opportunity to use her camera to capture stories of her surroundings. She not only documented her travels around tourist sites in Lebanon but also sought creative experimentation with her device by staging scenes, manipulating shadows and superimposing negatives to produce different effects in her prints. Within the borders of her photographs, bedouins and European friends, peasants and landlords, men and women, comfortably share the same space. Most of Marie al-Khazen's photographs, which are circulated online through the Arab Image Foundation's website, suggest a narrative of independent and determined Lebanese women. These photographs are charged with symbols that can be understood, today, as representative of women's emancipation through their presence as individuals, separate from family restrictions of that time. Images in which women are depicted smoking a cigarette, driving a car, riding horses and accompanying men on their hunting trips counter the usual way in which women were portrayed in 1920s Lebanon. The photographs can be read as a space for al-Khazen to articulate her vision of the New Woman or the Modern Girl as described by Tani Barlow in The Modern Girl Around the World. In this anthology, authors like Barlow point to the ways in which the modern girl "disregards the roles of dutiful daughter, wife and mother," in seeking sexual, economic and political emancipation. Al-Khazen's photographs lead me to pose a series of questions pertaining to the representation of femininity and masculinity through the poses, reasoning, and activities adopted by women and men in the photographs. The questions which frame this study have to do with the ways in which notions of gender, class and race are inscribed within Marie al-Khazen's photographs.Marie al-Khazen est une photographe libanaise qui vécut entre 1899 et 1983. La plupart de ses photos furent prises dans les années vingt et trente dans la région de Zgharta au Nord du Liban. Ces photos font partie de la collection de Mohsen Yammine, un collectionneur libanais. Elles sont actuellement conservées dans les archives de la Fondation de l'image Arabe à Beyrouth et sont disponibles en ligne sur le site internet de la Fondation. Le corpus d'al-Khazen est constitué d'un ensemble de photographies captivantes qui représentent le quotidien de sa famille et de ses amis à Zgharta. Al-Khazen saisissait son milieu social grâce à son appareil photo. Néanmoins, elle ne se contentait pas de documenter ses excursions touristiques au Liban; elle explorait également les capacités techniques de son appareil photo en inventant des scènes photographiques et en manipulant les ombres dans l'espace photographique. Au travers de ses photos on retrouve les effets surréalistes qu'elle créait – peut-être intentionnellement – en faisant des tirages de deux négatifs superposés. Dans le cadre de ces images, on retrouve des bédouins et des Européens, des paysans et des bourgeois, des femmes et des hommes se partageant le même espace. La plupart des photos de Marie al-Khazen évoquent les destins de femmes indépendantes et engagées. Ces photos sont chargées de symboles qui suggèrent une représentation de la femme émancipée. A travers le corpus d'al-Khazen, des femmes apparaissent en train de fumer des cigarettes et de conduire des automobiles. On retrouve également des femmes qui accompagnaient les hommes dans leurs excursions de chasse. Ces photos semblent incompatibles avec la façon dont les femmes étaient représentées dans la presse des années vingt au Moyen Orient où les femmes, en général, évitaient de se montrer dans des endroits publiques. Je propose une lecture qui articule la façon dont al-Khazen a utilisé l'espace photographique pour manifester sa vision de la nouvelle femme: la femme moderne comme celle décrite par Tani Barlow et ses collègues dans The Modern Girl Around the World. Cette anthologie représente la "modern girl" qui, selon Barlow et ses collègues, "disregards the roles of dutiful daughter, wife and mother," en recherchant une émancipation sexuelle, économique et politique.Les photos d'al-Khazen m'incitent à interroger de façons multiples la représentation de la femininité et la masculinité à travers le comportement, le raisonnement, et les activités des femmes et des hommes dans ces photographies. Ces questions s'adressent à la sociologie de l'identité sexuelle et se proposent d'analyser la façon dont cette identité est évoquée dans les photos de Marie al-Khazen.