A l’aide de la télédétection, de la géomatique et des enquêtes de terrain, nous avons confirmé l’existence d’un reverdissement du Sahel, durant la période 1981 à 2006, même si il est loin d’être homogène. Ces différences spatiales ne peuvent s’expliquer uniquement par des facteurs naturels. La croissance démographique ne permet pas non plus, seule, d’expliquer ces différences à l’échelle du Sahel. L’approche multiscalaire des changements du couvert végétal sur plus de cinquante ans, au sein des six ateliers appartenant à trois pays différents, montre que la présence de plus en plus importante de l’homme n’engendre pas systématiquement la disparition des arbres. L’expansion agricole observée semble avoir entraîné un « déplacement » des arbres de la savane arborée vers les zones de cultures et les villages, les sociétés rurales sahéliennes façonnant le couvert arboré en fonction de leurs besoins (agriculture, défrichement, coupe, bois énergie). L’analyse du discours des personnes rencontrées a montré que l’implication de « facilitateurs » locaux est indispensable à la réussite de projets de replantation et de sauvegarde du patrimoine forestier de chaque village. Le recours à des analyses géo-textométriques du discours a permis de mettre en évidence l’opposition « Utilisateurs-Gestionnaires » mais aussi les différences entre sites le long du gradient bioclimatique nord-sud. Néanmoins les générations futures ont une représentation de leur environnement qui pourrait aller de pair avec une préoccupation pour sa préservation. / Using remote sensing, geomatics and field surveys, we confirmed the existence of Sahelian regreening during the period 1981 to 2006, even though it is far from homogeneous. These spatial differences can not be explained solely by natural factors. Population growth alone does not explain these differences across the Sahel. The multiscale approach to changes in plant cover over more than 50 years, in the six workshops belonging to three different countries, shows that the increasing presence of man does not systematically cause the disappearance of trees. The observed agricultural expansion seems to have led to the "displacement" of trees from the savannah to the cultivated areas and villages, the rural Sahelian societies shaping tree cover according to their needs (agriculture, clearing, cutting, energy wood). The analysis of the speeches of the people we met showed that the involvement of local "facilitators" is essential to the success of replanting projects and safeguarding the forest heritage of each village. The use of geo-textometric analyzes of the discourse made it possible to highlight the opposition "Users-Managers" but also the differences between sites along the north-south bioclimatic gradient. Nevertheless, future generations have a representation of their environment that could go hand in hand with a concern for its preservation

These guidelines provide an overview of the issues to be considered when undertaking or commissioning geophysical survey in archaeology. As every project diff ers in its requirements (e.g. from fi nding sites to creating detailed maps of individual structures) and variations in geological and environmental conditions lead to diff erent geophysical responses, there is no single ‘best’ survey technique or methodology. Th is guide, in its European approach, highlights the various questions to be asked before a survey is undertaken. It does not provide recipebook advice on how to do a geophysical survey or a tick list of which technique is suitable under what conditions. Experienced archaeological geophysicists should be consulted to address the questions that are being posed. Using geophysical techniques and methods inappropriately will lead to disappointment and may, ultimately, result in archaeologists not using them at all. “If all you have is a hammer (or magnetometer), driving a screw becomes impossible”. Especially in the American literature the term ‘remote sensing’ is oft en used to describe geophysical as well as air and space based exploration of underground features (e.g. Wiseman and El-Baz 2007). By contrast, and in line with European traditions, a clear distinction is made here between ground-based geophysical techniques and remote sensing techniques. Th is is based on the imaging principles underlying the respective technologies. Ground based systems usually collect one spatially registered data sample from each sensor location (e.g. a single reading for each magnetometer, or a single trace from each GPR antenna). Remote sensing techniques, by contrast, collect spatially resolved data from a whole area of investigation from each sensor location, using either the system’s optical aperture (e.g. photography) or a scanning device (e.g. laser sampling). These guidelines are based on the experience of the authors in archaeological geophysics and infl uenced by various published sources.

A study was conducted on the North Slope of the Uinta Mountains from January, 1972 through June, 1974, to determine the effects of three simulated levels of moose utilization on the crude protein content, phosphorus content, digestibility and vigor of willow plants. A comparison was also made on the crude protein content, phosphorus content and digestibility of current year's versus past years' willow growth. Finally, the validity of direct and indirect population enumeration methods was compared for the possible development of a standardized moose survey technique. Clipping caused a highly significant increase in crude protein and phosphorus content between treatment levels. There was also a highly significant increase in digestibility between years. Plant vigor comparisons were confounded by additional sources of mortality and the effects of environmental variables. A comparison of the nutrient content and digestibility of 1 t o 5 year-old willow growth showed that crude protein content, phosphor us content and digestibility decreased with increasing twig age. Additional factors are discussed which indicate that the carrying capacity of the winter range is larger than previously described. A poor correlation was found be tween direct aerial moose observations and indirect population estimates from pellet-group counts.

This dissertation examines El Marquesillo, a settlement in an archaeologically unexplored region of the Southern Gulf Lowlands of Veracruz, Mexico. Evidence suggests the site has been consistently occupied from the Early Formative period (c. 1500 BC) to the present. Thus, this investigation presents an opportunity to re-examine the sociopolitical continuum encompassing the Olmec cultural phenomenon (c. 1150-300 BC), the emergence of which has been used repeatedly as an example of incipient social complexity. Theorists have portrayed the development of sociopolitical complexity as a mosaic process in which environmental, social, political, economic, ideological, and demographic variables act independently or in combination to bring about change. In order to examine these variables, a suite of traditional and progressive archaeological techniques -- remote sensing, geophysical survey, GIS, mapping, anthropogenic soil survey -- were employed to prospect, document, and analyze the natural and built environments along with the material record documented at El Marquesillo. I argue that the resulting data do not fit many of the traditional models that have been offered to explain the development of Olmec sociopolitical complexity. The term "traditional Olmec paradigm" is used to describe a collective array of conjectural concepts that have been proposed by theorists to explain how Formative people of the Southern Gulf Lowlands constructed and experienced their reality. Findings from El Marquesillo and other recent Heartland investigations suggest that much of this traditional Olmec paradigm may not be accurate. The Gulf Olmec were not a homogeneous and uniform entity across space and time. At El Marquesillo, idiosyncratic behaviors of the ancients relating to ancestor veneration and their connection to the landscape and worldview have been identified. These noted variations in social expression and the lack of adherence to the traditional Olmec paradigm suggest that some hypotheses regarding the Formative people of the Southern Gulf Lowlands be re-visited and possibly revised in the light of new evidence.

My dissertation focuses on the design and incentives of survey techniques. As many institutions use surveys to allocate funding or determine policy, ensuring surveys provide accurate information is essential. Though incentives certainly play a role in whether survey participants report information truthfully, economists have largely overlooked the issue while statisticians tend to focus on estimators without directly modeling incentive constraints. One of the chapters models and analyzes the incentives of a commonly used survey technique, randomized response, while the other two chapters of my dissertation design two response techniques which improve upon others found in the literature by obtaining more precise estimates and/or incentivizing participants better. In Chapter One "A Game Theoretic Analysis of the Randomized Response Technique," I explicitly model the decision of participants to truthfully respond in the randomized response survey as a game. Randomized response techniques are used to determine the proportion of a population that belongs to a stigmatized group and introduce noise so the surveyor cannot perfectly infer whether a participant belongs to a stigmatized group, regardless of how a participant responds. The interviewer wants to reduce noise as much as possible while maintaining enough noise to ensure participants respond truthfully. Unlike prior literature, I find that the incentives of a participant depend on the number of participants; therefore, the amount of noise required under randomized response decreases when the number of participants increases as adding respondents relaxes truth-telling constraints. However, adding respondents only relaxes incentive constraints to a limit, so some noise remains even when there are a large number of participants. I improve upon the original randomized response technique in two ways in Chapter 2: "Eliciting Private Information using Correlation: A Modification of Randomized Response." In standard randomized response techniques, participants receive questions independently by using a randomization device such as a die. With my technique, participants receive perfectly correlated questions which reduces the variance of the surveyor's estimator while still protecting the privacy of the subjects. Unlike with the randomized response technique, adding correlation allows the surveyor to use a dominant strategy mechanism though it provides limited information. In addition to correlation, my technique provides the surveyor with private information on the distribution of questions asked. Because of the private information, participants become more uncertain of which question is more associated with the stigmatizing characteristic giving them a stronger incentive to respond truthfully. My final chapter, Chapter 3 "A Response Technique with Dominant Strategies in Forced Responses," improves upon a randomized response technique commonly used in practice. In the forced response technique, a fraction of survey participants are directly asked whether they belong to the stigmatizing group while the remaining participants either simply state "yes" or "no" according to a privately observed command. Unlike the original randomized response technique, the surveyor must worry whether participants obey the command in addition to answering truthfully. Psychologically, participants may feel more inclined to disobey than to lie. Therefore, I design a technique where obeying the command is a dominant strategy by providing the surveyor with private information. The paper then discusses a more general response technique with private information and suggests restrictions on the mechanisms to ensure the surveyor does not have an incentive to try to "trick" respondents into believing they have more privacy protection than they actually do. The chapter concludes with a discussion on privacy measures.

Submitted by Andrea Bastian (avbastian@uol.com.br) on 2018-05-04T14:02:03Z No. of bitstreams: 1 D_Andrea Bastian.pdf: 13299305 bytes, checksum: 50cbf0a85fab39aad8d8e2306af713f7 (MD5) / Approved for entry into archive by Biblioteca de Arquitetura (bibarq@ufba.br) on 2018-05-09T14:10:25Z (GMT) No. of bitstreams: 1 D_Andrea Bastian.pdf: 13299305 bytes, checksum: 50cbf0a85fab39aad8d8e2306af713f7 (MD5) / Made available in DSpace on 2018-05-09T14:10:25Z (GMT). No. of bitstreams: 1 D_Andrea Bastian.pdf: 13299305 bytes, checksum: 50cbf0a85fab39aad8d8e2306af713f7 (MD5) / Esta pesquisa apresenta um estudo sobre métodos e técnicas de baixo custo para o levantamento métrico de sítios históricos, iniciando com os conceitos de patrimônio cultural e as primeiras recomendações internacionais para conservação e restauro de monumentos. Foram discutidos também, a crescente preocupação com a proteção de bens no Brasil e os diversos inventários já realizados. Foram apresentadas as principais tecnologias para levantamento de formas arquitetônicas baseadas em imagens com ênfase na Fotogrametria Digital, os conceitos e processos envolvidos, os requisitos e orientações para levantamentos fotogramétricos e os principais programas utilizados para restituição. A pesquisa, também, tratou do problema de extração de feições a partir de imagens digitais, discutindo os conceitos e etapas de processamento. A parte prática mostra os estudos de caso realizados com o objetivo de apreender e testar três ferramentas (PhotoModeler, Orthoware e pacote Sphera), avaliando qualidade, limites e potencialidades, gerando como produtos: ortofotos, ortofotomosaico e desenhos de restituição de fachadas, que foram utilizados como fonte de dados para geração de modelos geométricos. Ainda, foram realizados experimentos para extração automática de feições (vetorização automática) de imagens com o intuito de facilitar o processo de vetorização das ortofotos. Pode-se comprovar que a Fotogrametria Digital é uma ferramenta acessível, de custo reduzido que atende à demanda existente de documentação, de forma rápida e precisa; mas, para que isso seja possível, se deve levar em conta o conhecimento das diversas técnicas, a definição dos produtos desejados e as ferramentas existentes para que a escolha recaia sobre a técnica mais adequada. / This thesis presents a study on methods and low-cost techniques for historic sites surveys, it starts with the concepts of culture heritage and the first international recommendations for conservation and restoration of monuments, this study discussed about the evolution of the concern for the protection of property in Brazil and the various inventories already made. It presented the survey technologies for architectural documentation based on images with emphasis on Digital Photogrammetry, the concepts and processes involved the requirements and guidelines for photogrammetric surveys and the main photogrammetric software used to restitution. The survey also addressed the problem of features extraction from digital images, discussing the concepts and processing steps. The practical part presents some case studies that allowed to the apprehending and also the testing of three tools (PhotoModeler, Orthoware and Sphera package), as a way to assess quality, limits and potential to generate products as orthophotos, ortofotomosaico and facades restitution drawings, which were used as data source for generating geometric models. Still, experiments for automatic feature extraction were performed (automatic vectorization) of images in order to facilitate the process of vectorization from orthophotos. Digital Photogrammetry proved to be a handy low-cost tool, which meets the existing demand for documentation, as quickly and accurately as possible, but in order to make this possible is necessary to know the different techniques,the definition of the desired products and existing survey methods to select the most appropriate technique.

This dissertation is concerned with the foundations in volume unstable soils and objects disorders which are related to this. The thesis was focused on the study of clay and loess soils which are abundant in the geological profile of the Czech Republic. First, the formation of the two groups of soils is introduced, then their properties are examined and finally the influence of vegetation on the former type and the influence of collapsibility in the latter type are investigated. The conclusion is, in fact, a recommendation on the design of structures so that the system of clay / structure is not damaged and that structures are not subject to renovations. Several instance of problems with structures are discussed which were subject to structural repairs employing both a civil and geotechnical engineers.