51,842 research outputs found
Aircraft turning ground maneuvers
In this project a fully parameterized mathematical model of an aircraft turning on the ground in order to get the maximum aircraft speed and minimum infrastructure taxiway radius for three different types of aircrafts (A320, A380 and B737) is developed.
The mathematical model takes the form of a system of coupled ordinary differential equations (ODEs). The airframe is considered as a rigid body with six DOF and the equations of motion are derived by balancing the respective forces and moments. Other formulas as Newton’s second law, centripetal equations, friction formulas and other equations will be used to calculate the safest velocity depending on the radius of the taxiway curvature.
The software Matlab will be used so as to make all the calculations and will enable us to change the parameters such as mass, friction or radius to find new velocities according to the aircraft. Moreover, the use of Microsoft Excel software to insert those results already found in Matlab and create new tables depending on the radius and ground weather conditions (dry or wet). The results show that each aircraft has a different safety velocity although they turn with the same taxiway radius.
There is also a bibliographic and modelling work explaining how to get all the equations and the different types of taxiway entries
Deformation and tension analysis during embryonic development
The aim of this document is to introduce the reader into the process, through microscopic threedimensional
images, of the cellular embryonic deformation of the Drosphila Melanogaster fly through
its development. It will also be exposed a program with which it will be possible to calculate the
tensions through a code of finite elements from a model of lineal material.
In order to carry this study, it will be used the Matlab program, with which a code will be created where
the experimental data will be entered and the tension and the deformation of the affected cells will be
calculated. The study will be carried through two models: one of them will be a cell-centered model
while the other one will be a vertex model.
With the pertinent procedures, it will be obtained a series of documents that, when analyzed with a
tridimensional visualization tool, will offer a representation of both models and the evolution for each
of their meshes. This project will conclude with an appreciation on the efficiency of both
two-dimensional and three-dimensional approaches
Assessing Corruption: Expert Surveys versus Household Surveys, Filling the Gap
La mesure de la gouvernance est une source d’occupation relativement nouvelle pour les économistes. Le World Bank Institute a ouvert la voie à la fin des années 90 avec la désormais célèbre suite “Governance Matters”, I, II, III, IV… Le peu d’imagination de KKZ1 dans le choix du titre de leurs publications cache, en réalité, les plus populaires des indicateurs de gouvernance. L’accent mis sur la corruption pourrait, lui aussi, revendiquer la paternité de la Banque mondiale dans la mesure où l’on doit la création de Transparency International à Peter Eigen ancien cadre de la Banque, mais également, à James Wolfensohn, premier directeur de la Banque à s’intéresser au fléau de la corruption, dans un contexte de « de-géopolitisation » de l’aide au développement. Avec les prémices de la systématisation des enquêtes ménages, une nouvelle manière de mesurer la gouvernance voit le jour. Si les enquêtes menées auprès de la population peuvent constituer un outil intéressant pour évaluer la qualité des institutions, cette prise en compte de l’opinion des populations introduit de nouveaux écueils. Cette étude vise à analyser l’écart de perception entre experts et populations, en matière de corruption. En effet, les enquêtes d’experts et les enquêtes ménages s’accordent difficilement dans leurs estimations de l’étendue de la corruption. Nous suggérons que la liberté de la presse, la culture, la tolérance et la confiance envers les dirigeants puissent venir fausser les pistes. Governance measurement is a relatively new source of entertainment for economists. The World Bank Institute paved the way in the late 90`s with the now famous suite “Governance Matters”, I, II, III, IV… The little imagination of KKZ, regarding the choice of their publications title, hides the most popular aggregated governance indicators. Corruption focus could also claim World Bank parenthood since Transparency International birth was the fruit of a former “affair” between James Wolfensohn and Peter Eigen. With the prelude to household surveys systematization, a new way to measure governance and corruption saw the day. If household surveys may stand for an interesting tool for institutional assessment, populations’ opinions also introduce new pitfalls. This study aims to investigate the gap between expert and household surveys regarding corruption measurement. Indeed, experts and populations barely agree on their estimations of corruption extent. We suggest that press freedom, culture, permissiveness and leadership approval may cover one’s track.(Full text in french)
Measuring corruption: perception surveys or victimization surveys?
While methodologies and survey techniques recorded progress over the years, corruption measurement remains a many-headed monster. Since 2003 and the first publication of Transparency International's Global Corruption Barometer, researchers have access to population's feeling about the corruption scourge across institutions. Thereby, wider room emerged for populations' perceptions in the field of corruption quantification. In this paper, we analyze the gulf separating perceived corruption from experienced bribe situations using global household surveys in a Panel dataset. We show that the gap between these two types of data can be wide and unevenly distributed across countries. Introducing further objective and subjective data we try to puzzle out perception mechanisms.Corruption, Global Corruption Barometer, Governance, CPI, Transparency International, Corruption measurement, Perception indicators, Press freedom, Econometrics, Panel Data, Household surveys.
Development stakeholders and territorial identity in Portugal
The need to reaffirm the diversity of places and regions in order to make them economically and culturally “more competitive” on the globalised market of goods and services has been widely accepted in regional and local development policies in Portugal, but much more so rhetorically than in operational terms. This largely reflects the fact that policies, as well as their instruments, do not rely on empirical evidence of the changing character of territorial identity. In particular, there are virtually no records regarding representations of territorial identity features and issues by local/regional development stakeholders, both individual and institutional ones. The problem is that appropriate conceptualisations and analytical tools for comprehensive identification and assessing of various dimensions local/regional identity have been lacking. Since it has not been clear what the identity of places and regions means in factual and verifiable terms to different development stakeholders, it is has not been possible to determine what aspects of the identity need to be strengthened, preserved, diversified, or made “more competitive” in regional and local development policy design and implementation. This paper brings forward a methodological framework for the study of the changing character of local identities and the role of local development stakeholders in this change. The region-specific evidence obtained from a nation-wide field survey of Portuguese local development agents’ knowledge, attitudes and practice in relation to the territorial identity as a regional development issue is presented and discussed.
Measuring corruption: perception surveys or victimization surveys? Towards a better comprehension of populations’ perception mechanisms: press freedom, confidence and gossip
While methodologies and survey techniques recorded progress over the years, corruption measurement remains a many-headed monster. Since 2003 and the first publication of Transparency International’s Global Corruption Barometer, researchers have access to population’s feeling about the corruption scourge across institutions. Thereby, wider room emerged for populations’ perceptions in the field of corruption quantification. In this paper, we analyze the gulf separating perceived corruption from experienced bribe situations using global household surveys in a Panel dataset. We show that the gap between these two types of data can be wide and unevenly distributed across countries. Introducing further objective and subjective data we try to puzzle out perception mechanisms. Bien que les techniques d’enquête et les méthodologies se soient améliorées au fil des années, la mesure corruption demeure problématique. Depuis 2003 et la première publication du Baromètre Mondial de la Corruption par Transparency International, les chercheurs ont dorénavant accès aux perceptions des populations pour évaluer l’étendue de la corruption au sein de différentes administrations. Dans cet article, nous analysons l’écart entre les perceptions de la corruption et l’expérience concrète de celle-ci en utilisant des données de panel issues d’enquêtes ménages menées à une échelle mondiale. Nous comparons ainsi, au sein même des populations, les écarts entre expériences et perceptions de la corruption, afin d’isoler au mieux les mécanismes à l’oeuvre dans la construction des perceptions. Nous montrons alors que les écarts entre ces deux types de donnée peuvent être importants et inégalement distribués.(Full text in english)
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