Thesis (S.M.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and the Woods Hole Oceanographic Institution), 2006. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Includes bibliographical references (p. 89-96). / Blainville's beaked whales (Mesoplodon densirostris) use broadband, ultrasonic echolocation signals (27 to 57 kHz) to search for, localize, and approach prey that generally consist of mid-water and deep-water fishes and squid. Although it is well known that the spectral characteristics of broadband echoes from marine organisms are a strong function of size, shape, orientation and anatomical group, little is known as to whether or not these or other toothed whales use spectral cues in discriminating between prey and non-prey. In order to study the prey-classification process, a stereo acoustic tag was mounted on a Blainville's beaked whale so that emitted clicks and corresponding echoes from prey could be recorded. A comparison of echoes from prey selected by the whale and those from randomly chosen scatterers suggests that the whale may have, indeed, discriminated between echoes using spectral features and target strengths. Specifically, the whale appears to have favored prey with one or more deep nulls in the echo spectra as well as ones with higher target strength. A three-dimensional, acoustic scattering model is also developed to simulate broadband scattering from squid, a likely prey of the beaked whale. / (cont.) This model applies the distorted wave Born approximation (DWBA) to a weakly-scattering, inhomogeneous body using a combined ray trace and volume integration approach. Scatterer features are represented with volume elements that are small (less than 1=12th of the wavelength) for the frequency range of interest (0 to 120 kHz). Ranges of validity with respect to material properties and numerical considerations are explored using benchmark computations with simpler geometries such as fluid-filled spherical and cylindrical fluid shells. Modeling predictions are compared with published data from live, freely swimming squid. These results, as well as previously published studies, are used in the analysis of the echo spectra of the whale's ensonified targets. / by Benjamin A. Jones. / S.M.

Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2008. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Includes bibliographical references. / Ecological processes at deep-sea hydrothermal vents on fast-spreading mid-ocean ridges are punctuated by frequent physical disturbance. Larval dispersal among disjunct vent sites facilitates the persistence of sessile invertebrate species in these geologically and chemically dynamic habitats despite local extinction events. Regional population extension and rapid recolonization by the siboglinid tubeworm Riftia pachyptila have been well documented along the East Pacific Rise and the Galápagos Rift. To analyze spatial and temporal population genetic patterns and the processes governing them at ephemeral and disjunct habitats, a suite of 12 highly variable microsatellite DNA markers were developed for this species. Eight of these loci were used to assess the regional and within-ridge genetic structure of recent colonists and resident adults collected from nine sites in the eastern Pacific Ocean over period of three to seven years. A significant seafloor eruption during the seven-year sampling period allowed investigation into the role of local extinction in population genetic diversity at the Tica vent site at 9°N EPR, while collections within two and five years of an eruption that created the Rosebud vent field at 86°W GAR provided insights into genetic diversity input over population establishment. For the first time, this thesis demonstrated significant genetic differences between Riftia populations on the East Pacific Rise and Galápagos Rift. Moreover, the separate treatment of colonist and resident subpopulations revealed a high potential for local larval retention at vent sites. This mechanism for recruitment likely sustains disjunct populations and supports the recolonization of locally extinct areas after disturbance events, while episodic long-distance dispersal maintains genetic coherence of the species. / (cont.) Temporal population genetic consideration at the Tica site on the East Pacific Rise suggests that the 2005-2006 seafloor eruption had little to no discernable effect on local population genetic composition. Yet local populations appear to exhibit a small degree of genetic patchiness, with a high degree of relatedness (half-sibs) among subsets of individuals within both colonist and resident cohorts. This thesis broadens the application of recently developed molecular techniques to study the effect of ridge-crest processes and offers new perspectives into marine dispersal, gene flow, and population differentiation. / by Abigail Jean Fusaro. / Ph.D.

Thesis (S.M.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and the Woods Hole Oceanographic Institution), 2008. / Includes bibliographical references (p. 54-56). / Landmines and mine-like traps are effective weapons that are difficult to detect and discriminate from a safe distance. The ability to detect landmines in their host environment at a distance and to discriminate them from other objects would be valuable for countering the landmine threat. This paper explores a standoff acoustic/laser technique to discriminate landmines from other forms of man-made objects (clutter) in an urban environment. A novel approach currently under investigation by MIT Lincoln Labs, University of Mississippi, and other groups employs a non-contact acoustic/laser technique to detect landmines from a safe standoff range. This technique uses a sound source to excite vibrations in targets with an acoustic wave. These vibrations are in turn measured remotely with a Laser Doppler Vibrometer (LDV). In this thesis, the vibration responses of landmine variants are measured, analyzed, and compared to those of common urban objects likely to be found on a landmine field or roadside. The Fourier Transform of the vibration of the target as measured by the LDV is used to generate a target vibration spectrum. Target vibration spectra in response to a sound source were experimentally measured for 59 trials, 28 of which were of simulated landmine variants and the remaining trials were of urban clutter objects. Using an algorithm adapted from a methodology for mass spectral analysis, parameters of the target signatures are estimated; then individual target signatures are classified using a Support Vector Machine (SVM) with a training set composed of parameters from the remaining members of the total population. The best results obtained from this methodology had a 71% probability of detection and a 3% false alarm rate corresponding to 20 of 28 of the simulated landmine variants correctly identified and a single clutter object misidentified as a landmine variant. / by John Houston Doherty. / S.M.

Thesis (S.M.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and the Woods Hole Oceanographic Institution), 2008. / Includes bibliographical references (p. 159-170). / This thesis formulates an estimation framework for Simultaneous Localization and Mapping (SLAM) that addresses the problem of scalability in large environments. We describe an estimation-theoretic algorithm that achieves significant gains in computational efficiency while maintaining consistent estimates for the vehicle pose and the map of the environment.We specifically address the feature-based SLAM problem in which the robot represents the environment as a collection of landmarks. The thesis takes a Bayesian approach whereby we maintain a joint posterior over the vehicle pose and feature states, conditioned upon measurement data. We model the distribution as Gaussian and parametrize the posterior in the canonical form, in terms of the information (inverse covariance) matrix. When sparse, this representation is amenable to computationally efficient Bayesian SLAM filtering. However, while a large majority of the elements within the normalized information matrix are very small in magnitude, it is fully populated nonetheless. Recent feature-based SLAM filters achieve the scalability benefits of a sparse parametrization by explicitly pruning these weak links in an effort to enforce sparsity. We analyze one such algorithm, the Sparse Extended Information Filter (SEIF), which has laid much of the groundwork concerning the computational benefits of the sparse canonical form. The thesis performs a detailed analysis of the process by which the SEIF approximates the sparsity of the information matrix and reveals key insights into the consequences of different sparsification strategies. We demonstrate that the SEIF yields a sparse approximation to the posterior that is inconsistent, suffering from exaggerated confidence estimates. / (cont) This overconfidence has detrimental effects on important aspects of the SLAM process and affects the higher level goal of producing accurate maps for subsequent localization and path planning. This thesis proposes an alternative scalable filter that maintains sparsity while preserving the consistency of the distribution. We leverage insights into the natural structure of the feature-based canonical parametrization and derive a method that actively maintains an exactly sparse posterior. Our algorithm exploits the structure of the parametrization to achieve gains in efficiency, with a computational cost that scales linearly with the size of the map. Unlike similar techniques that sacrifice consistency for improved scalability, our algorithm performs inference over a posterior that is conservative relative to the nominal Gaussian distribution. Consequently, we preserve the consistency of the pose and map estimates and avoid the effects of an overconfident posterior. We demonstrate our filter alongside the SEIF and the standard EKEF both in simulation as well as on two real-world datasets. While we maintain the computational advantages of an exactly sparse representation, the results show convincingly that our method yields conservative estimates for the robot pose and map that are nearly identical to those of the original Gaussian distribution as produced by the EKF, but at much less computational expense. The thesis concludes with an extension of our SLAM filter to a complex underwater environment. We describe a systems-level framework for localization and mapping relative to a ship hull with an Autonomous Underwater Vehicle (AUV) equipped with a forward-looking sonar. The approach utilizes our filter to fuse measurements of vehicle attitude and motion from onboard sensors with data from sonar images of the hull. We employ the system to perform three-dimensional, 6-DOF SLAM on a ship hull. / by Matthew R. Walter. / S.M.

Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2008. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Includes bibliographical references. / The benthic habitat is the terminal destination for marine animals in terms of their reproductive lifecycle. Recruitment dynamics relating to seasonal changes in the benthic habitat may be the best source of information for predicting recruit abundance and for marine resources management. The transition from the pelagic to the benthic phases is the last stage in the connectivity between benthic populations. The transition to the benthos may be a process that dominates recruitment dynamics to the exclusion of other characteristics of larvae such as their quality and their density. Recruitment of benthic marine animals is influenced by two seasonally varying factors of the benthic habitat. First, the availability of suitable habitat for recruitment can in large part determine the survival probability for settlers, a trend that is most pronounced for low or no survival when the settlement substrate is saturated by conspecifics from a recruitment cohort. Preemption is caused by the presence of current occupants from a recruit cohort, and it influences the settlement rate or the survival probability of conspecifics. Descriptive statistics (Chapter 2) and a field experiment (Chapter 4) highlight the role of preemption on barnacle recruitment. The second factor results from seasonal changes in environmental conditions that settlers experience in the benthic habitat, which could affect the physiology and survival probability of barnacle settlers. Highly unpredictable features of recruitment dynamics also play a role, such as wind that enhances wave action in the rocky intertidal that has been linked to the rate of settlement. Day to day variability in wind may cause patterns of settlement to be highly unpredictable. Predator induced mortality is spatially aggregated, and the random pattern of mortality in space is highly unpredictable. In contrast to these high frequency sources of recruitment variability, seasonal factors that vary at lower frequencies and that often change monotonically lend great predictive ability for recruitment dynamics. It appears that barnacles have evolved to compete for suitable habitat and have mechanisms to cope with seasonally varying environmental conditions in the benthic habitat, which may be the basis for why these features dominate the barnacle recruitment dynamic. / by Jonathan N. Blythe. / Ph.D.

L’idée qui traverse l’ensemble de la thèse est la possibilité de la rencontre de deux mouvements : Psichiatria democratica et la psychothérapie institutionnelle, de deux psychiatres Basaglia et Tosquelles, rencontre entre médecin et patient ; rencontre entre patient psychotique et le monde, monde étant compris comme la société mais aussi le groupe de soin.La réflexion est basée sur des points « d’accrochage » entre différents discours : psychanalytique, historique, sociologique, philosophique ou phénoménologique à travers un axe central : celui de la relation possible entre médecin et patient au-delà d’une logique institutionnelle close. La pratique de la rencontre, à travers leurs protagonistes : opérateurs, usagers, patients etc… Ne peut, de fait, être comprise qu’à travers les concepts qui la fondent : l’inconscient, le transfert, la pulsion, etc. Elle est, comme on l’entendra ici, un rencontre transférentielle lieu de relations interpersonnelles qui doivent savoir s’adapter à la singularité de chacun. / The main theory of the thesis is the possibility of two psychiatrical movements meeting at a crossroad: Italian "psichiatria democratica" and French "psychothérapie institutionnelle". In the study their two founders, the psychiatrists Basaglia and Tosquelles are compared as well as the relation between psychiatrist and patient and patient and world (as society but also as group of care). The observation is focused on common grounds among different disciplines, psychoanalytic, historical, sociological, philosophical and phenomenological, over a central axis: the relationship between physician and patient outside the logic of closed institutional clinics. The setting of this intellectual encounter of operators, users and patients can only be understood through the concepts that underlie it: the unconscious, the transfer, the impulse. Lastly our “encounter” is, as we'll understand it here, a transferential encounter. It is a network of interpersonal relations that must adapt to each other actor’s singularity and individuality.

Résumé.La CGV, Confédération reliant cinq syndicats viticoles languedociens a été créée en 1907 pour agir en tant qu’institution de l’interaction en réponse à la crise méridionale par la défense du vin naturel en utilisant le moyen de la poursuite et de la répression des fraudes. Cette création en tension, dans le corps et dans le processus d’interaction, a été suivie de plusieurs séquences, réussite-résistance-déclin-extinction s’articulant chacune à partir de singularités dont l’étude n’avait à ce jour, jamais été exhaustivement menée. Il s’agissait d’observer comment cette histoire s’est écrite en termes d’unité, de puissance et de cohérence pour l’organisation, puis en termes d’interactions entretenues avec d’autres centres de pouvoir et particulièrement les pouvoirs publics nationaux, puis européens.Cette observation a pu s’appuyer à titre principal sur l’exploitation des archives de l’organisation déposées à Narbonne ainsi que sur d’autres fonds régionaux, nationaux et européens, sur celle de la presse régionale et nationale, généraliste et spécialisée et sur quelques entretiens avec des acteurs encore actifs durant la période d’observation.Les choix fondateurs de la CGV lui ont permis à la fois d’accéder à une hégémonie nationale institutionnellement reconnue et à l’intégration partielle de ses services par l’administration d’Etat. Cette reconnaissance, fondée sur des valeurs d’intérêt public unanimement partagées, est entrée en résonnance avec une puissance viticole régionale affirmée par le lien confédéral créé, devenue dominante dans la nation. Cette construction a atteint son apogée en 1922 avant d’amorcer une phase de déclin liée à la mise en œuvre de nouvelles priorités, à un affaiblissement interne de l’organisation et à l’évolution de la position de l’Etat souhaitant reprendre en main sa mission de service public. Ce retournement a été aggravé dès la fin du premier conflit mondial par des difficultés liées à la montée en puissance de nouvelles priorités concernant la régulation du marché (prix du vin, distillation et alcools, importations, fiscalité) puis son aménagement (solution à apporter au problème algérien). Ces difficultés, d’abord surmontées ont ensuite donné lieu à des situations de rupture qui ont finalement emporté la CGV. Restaurée entre 1930 et 1940 par la réussite du statut viticole, sa reconnaissance par les pouvoirs publics a d’abord été fortement altérée entre 1953 et 1956 par des orientations nationales qui se différenciaient des siennes et qui ont mis à mal son unité fondatrice et la solidité du lien confédéral. Après 1970, l’extension géographique du marché du vin à l’Europe et l’aggravation des tensions de la période précédente, transposées à une relation aux pouvoirs publics européens ont accéléré ce déclin. La CGVM, puissance viticole hégémonique en France, nationalement reconnue a progressivement reculé vers une situation de dépendance, aggravée après 1970 jusqu’à l’effacement. Cette histoire syndicale singulière s’est donc inscrite dans celle des rapports entretenus entre corps intermédiaires représentatifs et pouvoirs publics nationaux, puis européens. La CGV a d’abord bénéficié de l’intérêt qu’elle présentait en tant que puissance régionale et nationale représentative pour renforcer leur action, mais a ensuite été confrontée à un mouvement inverse d’affirmation autonome de leur mission de service public et de prise de décision guidées par une orientation capitaliste libérale en relation avec le poids de centres d’intérêts concurrents et antagonistes alors que sa représentativité s’affaiblissait jusqu’à l’extinction. / AbstractThe CGV, General Confederation for wine, is an organisation linking five Languedoc wine unions that was created in 1907 in order to act as an institution for interaction to answer the southern crisis with defending natural wine using prosecution and fraud repression. This creation being tense both in the interaction content and process, was followed by several sequences, success-resistance-decline-extinction, each articulated on the basis of singularities never comprehensively studied so far.It was about observing how this story was written in terms of unity, of power and consistency for the organisation, then in terms of interactions with other powerful centres and organisations and particularly national authorities, then European ones.This observation was primarily based on the exploitation of the archives of the organisation filed in Narbonne as well as on other regional, national and European funds, also based on the regional and national press, either general or specialised, and based finally on some interviews with still active players during the observation period.The founding choices of the CGV enabled this organisation both to reach an institutionally recognised national hegemony and a partial integration of its services by the state administration. This recognition, based on universally shared values of public interest, echoed with a regional wine-making power - a nationwide dominating organisation - stated by the creation of a confederate link. This construction reached its peak in 1922 before initiating a phase of decline linked to the implementation of new priorities, to an internal weakening of the organisation and to the evolution of the position of the State wishing to control back its public service mission.This reverse was aggravated by the end of the first world conflict by difficulties related to the rise of new priorities concerning market regulation (wine price, distillation and alcohol, imports, taxation) then its development (solution to be given to the Algerian problem). These difficulties, first overcome, and then gave rise to situations of break that finally ended the CGV.Restored between 1930 and 1940 by the success of the viticultural status, its recognition by the public authorities was first strongly altered between 1953 and 1956 by national orientations that differed from its own ones and that undermined the confederal bond founding unity and strength. After 1970, the geographical extension of the wine market to Europe and the worsening of the tensions of the previous period, transposed to a relation with the European public authorities accelerated that decline. The CGVM, hegemonic viticultural power in France, nationally recognised, gradually retreated into a situation of dependence, aggravated after 1970 and finally disappeared.This singular union history was therefore inscribed in the relationship maintained between representative intermediate bodies and national and European public authorities. The CGV first benefited from its interest as a representative regional and national power to strengthen their action, but was then confronted with a reverse movement of independent assertion of their public service mission and decision-making processes guided by a liberal capitalist orientation in relation to the weight of competing and antagonistic centres of interest while its representativity weakened to eventually end.

Notre thèse explore la communication numérique des institutions culturelles via les réseaux sociaux, se penche en particulier sur la médiation de la mémoire sociale des musées d'ethnologie via facebook. L'objectif est de questionner la façon de médiation culturelle sur les réseaux sociaux : comprendre le processus de co-construction de la mémoire sociale issu de la dynamique des interactions numériques entre producteurs et récepteurs. Nous nous penchons sur la médiation et l’intermédiation de la mémoire sociale dans le cas de trois musées d’ethnologie. À partir d'une approche pluridisciplinaire en SIC, le musée d’ethnologie est envisagé comme institution culturelle, un média et un espace de médiation sociale et culturelle. En passant de la communication de masse à une communication numérique, créant une dynamique de coproduction de sens et de mémoire, les musées passent de la médiation à l'intermédiation culturelle. Notre démarche compréhensive et herméneutique, s'intéresse aux acteurs produisant les discours sur facebook, musées et internautes. Corpus constitué par une triangulation méthodologique. Nos analyses thématique, sémantique et cognitivo-discursive montrent que le musée d'ethnologie comme lieu ouvert de savoirs et d'idée, où les internautes sont des publics et acteurs. Les réseaux sociaux, outils de médiation et d'intermédiation de la mémoire sociale permettent une dynamique de coproduction de connaissances. L'originalité de la thèse est l'étude de la dynamique de médiation numérique dans des contextes sociohistoriques et sociopolitiques variés. Permet l'élargissement de la problématique de la médiation et la communication à l'intermédiation et la coproduction. / Our thesis explores the digital communication of cultural institutions via social networks, and focuses in particular, on the mediation of the social memory in museums of ethnology via facebook. The objective is to question the way of cultural mediation on social networks : to understand the process of co-construction of social memory resulting from the dynamics of digital interactions between producers and receivers as Internet users. We focus on the mediation and intermediation of social memory in the case of three ethnology museums. Based on a multidisciplinary approach in SIC, the ethnology museum is considered as a cultural institution, a media and a social and cultural mediation area. By moving from mass communication to digital communication, creating a dynamic of co-production of meaning and memory, museums are moving from mediation to cultural intermediation. Our comprehensive and hermeneutic approach, is interested in the actors producing the speeches on facebook, museums and Internet users. Corpus constituted by a methodological triangulation. Our thematic, semantic and cognitive-discursive analyzes show that the ethnology museum is an open place of knowledge and ideas, where Internet users are public and actors. Social networks, as tools of mediation and intermediation of the social memory allow a dynamic of co-production of knowledge. The originality of the thesis is the study of the dynamics of digital mediation in various sociohistorical and socio-political contexts. That is allows the expansion of the problematic of the mediation and communication to the intermediation and co-production.

<p>The purpose of this thesis is to examine whether institutional ownership has an influence on CEO compensation in companies where the institutions have invested. In order to fulfil the purpose of the thesis a quantitative study was carried out within the Swedish corporate context where we have studied Swedish institutional investors and companies quoted on the Stockholm Stock Exchange. Our period of study was the financial year of 2007.</p><p>The empirical questions at issue is; Was there a connection between Swedish institutional ownership and the size of the CEO compensation, and, does Swedish institutional ownership lead to a certain type of CEO compensation in terms of structure?</p><p>Our results did not suggest that an increased institutional ownership neither leads to a certain type of salary level nor a certain kind of salary structure. These results contradict earlier American research, which has been done within this area and has previously shown a secured connection.</p><p>The reasons for our results may be many and it is difficult to state any concrete conclusions to why we received differing results. Based on our results we can only state that institutional ownership is not decisive for the formation of CEO compensation. It remains for future research to disprove the results of this study.</p> / <p>Syftet med denna uppsats är att undersöka hur institutionellt ägande påverkar VD-lönerna i de företag i vilka de har investerat. För att uppfylla vårt syfte har vi genomfört en kvantitativ studie inom den svenska företagskontexten där vi studerat bolag som var noterade på Stockholmsbörsens Large Cap-lista samt svenska institutionella investerare. Den tidsperiod som studerades var räkenskapsåret 2007.</p><p>De frågeställningar som vi ämnar besvara är dels om det finns ett samband mellan svenskt institutionellt ägande och storlek på VD-lön i svenska börsbolag, dels om svenskt institutionellt ägande leder till en viss typ av VD-lönestruktur i svenska börsbolag.</p><p>Våra resultat visar på intet sätt att ökade ägarandelar för institutioner leder till vare sig en viss typ av lönenivå eller en viss typ av lönestruktur. Detta går emot tidigare amerikansk forskning på området som har funnit just dessa samband.</p><p>Förklaringarna till våra resultat kan vara flera och det är svårt att lägga fram några konkreta slutsatser om vad våra resultat beror på. Utifrån våra resultat så kan vi endast konstatera att institutionellt ägande inte är avgörande för VD-löner utformning. Det återstår för vidare forskning att motbevisa det vi kommit fram till.<em></em></p>

Sweden has had laws protecting nature for about a hundred years. In this paper the views of nature and the values that serve as a rationale for protective measures are analyzed as results of a social process characterized by the dialectic relationship between institutions and discourse. Critical discourse analysis (CDA) is used to study this relationship and the discursive practices used by institutions, which reproduce or reshape views of nature that define the relationship between society and nature. Institutional design contributes to shaping discourse in the field of nature protection, while being originally shaped by discourse. In Sweden, the national park is an institution that reproduces a view of nature as the wild and untamed opposite of society, and the natural reserves reproduce a view of nature as holder of a multi-faceted set of values intertwined with society. However, the most recently formed national park, the marine national park of the Koster sea includes resource values that threaten the hegemony of arcadian discourse within the institution and indicates social change.