2,909 research outputs found
Trends in the French commercial farm population
Knowledge and projection of farm numbers and the structure of their population is an important issue for agricultural economists and policy makers. Although Markov chain models have enjoyed decades of popularity in forecasting total farm numbers, they generally fail to provide a detailed insight of the farm populationâs structure; to overcome this caveat we estimate a parametric distribution of the utilized agricultural area of French commercial farms. Our method provides detailed information on the structure of the population and accounts for the specificity of off-land farming. We also model the influence of variables such as the farmâs legal status, type of farming and farm holderâs age. The estimation leads to a relevant description of the entire population of professional farm. When compared with the 2005 Farm Structure Survey data, our simulations based on FADN data display a close match across a number of key variables.farm structures, farm size distribution, maximum likelihood and simulation
Trends in the French commercial farm population
.Knowledge and projection of farm numbers and the structure of their population is an important issue for agricultural economists and policy makers. Although Markov chain models have enjoyed decades of popularity in forecasting total farm numbers, they generally fail to provide a detailed insight of the farm populationâs structure; to overcome this caveat we estimate a parametric distribution of the utilized agricultural area of French commercial farms. Our method provides detailed information on the structure of the population and accounts for the specificity of off-land farming. We also model the influence of variables such as the farmâs legal status, type of farming and farm holderâs age. The estimation leads to a relevant description of the entire population of professional farm. When compared with the 2005 Farm Structure Survey data, our simulations based on FADN data display a close match across a number of key variables.farm structures, farm size distribution, maximum likelihood, simulation
LâĂ©volution de la cohabitation intergĂ©nĂ©rationnelle au Maroc : les solidaritĂ©s privĂ©es mises Ă lâĂ©preuve ?
International audienceDans les pays occidentaux, les relations entre gĂ©nĂ©rations prennent aujourdâhui rarement la forme dâune cohabitation au sein du mĂȘme logement, alors que dans les pays du Sud la prĂ©sence dâau moins deux gĂ©nĂ©rations adultes est encore rĂ©pandue. Nous Ă©tudions cette situation au Maroc oĂč lâachĂšvement de la transition dĂ©mographique est proche, lequel entraĂźnera un fort vieillissement dĂ©mographique dans les prochaines dĂ©cennies (dĂ©jĂ 2,4 millions de personnes ĂągĂ©es de 60 ans et plus et 5,8 millions attendus en 2030).Au Maghreb, la famille est la clĂ© de voute de la sociĂ©tĂ©. Elle repose sur des principes qui mettent en exergue la fonction patriarcale, le respect des aĂźnĂ©s, la famille Ă©largie. En milieu rural oĂč subsiste une Ă©conomie traditionnelle, on trouve encore couramment des relations dâentraide entre les diffĂ©rents membres dâune mĂȘme famille allant jusquâau partage du logement. En revanche, cette situation est moins frĂ©quente en milieu urbain et sâattĂ©nue Ă chaque enquĂȘte ou recensement. Nous proposons de mieux apprĂ©cier les raisons de la dĂ©cohabitation intergĂ©nĂ©rationnelle. Si lâexode rural, la taille des logements en milieu urbain (âŠ) sont des arguments frĂ©quemment Ă©voquĂ©s, il convient aussi de considĂ©rer certaines Ă©volutions socio-culturelles : la plus grande recherche dâintimitĂ© du couple vis-Ă -vis des ascendants, lâĂ©volution du statut des femmes, lâinfluence des modes de vie occidentaux via les mĂ©dias (âŠ).La moindre cohabitation intergĂ©nĂ©rationnelle dont on peut penser quâelle se diffusera aussi en milieu rural est-elle associĂ©e Ă un affaiblissement des relations dâentraide entre gĂ©nĂ©rations ? A partir des donnĂ©es de lâenquĂȘte nationale sur les personnes ĂągĂ©es au Maroc (ENPA-2006), nous montrons que la solidaritĂ© entre gĂ©nĂ©rations offre une certaine « rĂ©sistance », que dâaucuns prĂ©sentent comme une possible spĂ©cificitĂ© de la sociĂ©tĂ© marocaine (voire maghrĂ©bine). Le recul de la cohabitation intergĂ©nĂ©rationnelle, qui apparaĂźt notamment Ă travers les donnĂ©es collectĂ©es par les diffĂ©rents recensements, ne semble donc pas traduire un affaiblissement des solidaritĂ©s familiales envers les aĂźnĂ©s mais plutĂŽt rĂ©vĂ©ler une modification des formes de ces solidaritĂ©s. Toutefois, dans un pays oĂč les systĂšmes de retraite sont loin dâĂȘtre arrivĂ©s Ă maturitĂ©, la nuclĂ©arisation des mĂ©nages sera problĂ©matique pour certaines personnes modestes et pauvres, peu entourĂ©es socialement : les femmes veuves, analphabĂštes, dĂ©munies Ă©conomiquement, sont Ă ce titre les plus vulnĂ©rables. Plus gĂ©nĂ©ralement, on peut redouter que lâallongement de la durĂ©e de la vie, associĂ© Ă la disparition de la cohabitation entre les gĂ©nĂ©rations provoquent de fortes inĂ©galitĂ©s entre les personnes ĂągĂ©es dĂ©tentrices de pensions retraite ou dâun patrimoine et celles qui ont peu de capital ; entre celles qui vivent en couple, bien entourĂ©es par leurs proches, et les personnes veuves isolĂ©es ; entre celles bĂ©nĂ©ficiant dâune assurance mĂ©dicale et celles ayant des difficultĂ©s dâaccĂšs aux soins⊠Au final, la gĂ©rontocroissance entraĂźnera vraisemblablement une mise Ă lâĂ©preuve des solidaritĂ©s familiales et une dĂ©gradation des conditions de vie de certaines personnes ĂągĂ©es, si ne se met pas en place une politique publique de soutien spĂ©cifiquement dĂ©diĂ©e aux aĂźnĂ©s vulnĂ©rables, concernant notamment le logement, les revenus et les soins mĂ©dicaux. Lâinstauration dâune politique publique ciblant spĂ©cifiquement la population ĂągĂ©e semble souhaitable pour agir en complĂ©mentaritĂ© avec les solidaritĂ©s familiales qui ne disparaissent pas mais se transforment. Une telle politique sera dâautant plus efficace quâelle sera articulĂ©e Ă une maturation du systĂšme de protection sociale dans son ensemble.DonnĂ©es et mĂ©thodes : Nous travaillons sur les donnĂ©es de lâenquĂȘte nationale sur les personnes ĂągĂ©es au Maroc (ENPA-2006) et sur les donnĂ©es des Recensements GĂ©nĂ©raux de la Population et de lâHabitat de 1982, 1994 et 2004 afin de pouvoir faire des comparaisons entre dates diffĂ©rentes
The Utility of Using Social Media Networks for Data Collection in Survey Research
Social media networks (SMNs) such as Facebook, LinkedIn or Twitter seem appealing tools for matters of reaching potential candidates for survey or case study research. Yet scholars remain cautious about leveraging these platforms. This research in progress paper compares and discusses the benefits of six generic strategies for reaching survey candidates on SMNs, and argues that while their use has potential pitfalls, the upside for explanatory type research may outweigh its risks. Furthermore, the paper outlines the empirical setting of a study that has been conducted to assess our propositions, and in which Linkedin was used to identify and solicit survey candidates
La lucha contra el narcotrĂĄfico en Colombia : la cooperaciĂłn de la UniĂłn Europea entre 1980 y 1995
Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias PolĂticas y SociologĂa, Departamento de Derecho Internacional PĂșblico y Relaciones Internacionales, leĂda el 20-10-1997Depto. de Relaciones Internacionales e Historia GlobalFac. de Ciencias PolĂticas y SociologĂaTRUEpu
La lucha contra el narcotrĂĄfico en Colombia : la cooperaciĂłn de la UniĂłn Europea entre 1980 y 1995
Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias PolĂticas y SociologĂa, Departamento de Derecho Internacional PĂșblico y Relaciones Internacionales, leĂda el 20-10-1997Depto. de Relaciones Internacionales e Historia GlobalFac. de Ciencias PolĂticas y SociologĂaTRUEpu
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Libro reseñado: Las fuentes en las reflexiones sobre el pasado: usos y contextos en la investigaciĂłn histĂłrica en Colombia. Ăscar Almario GarcĂa (ediciĂłn acadĂ©mica). Universidad Nacional de Colombia, MedellĂn, 2014, 240 pp. El libro, editado por el historiador Ăscar Almario, se compone de ocho capĂtulos escritos por diferentes autoÂres, antecedidos por una introducciĂłn del editor. La publicaciĂłn es el resulÂtado de un seminario organizado por la Universidad Nacional de Colombia, sede MedellĂn, en el que se encontraÂron, en noviembre de 2012, los miemÂbros de dos grupos de investigaciĂłn para discutir sobre âfuentes, problemas e investigaciĂłn histĂłricaâ. Tomado de la reseñ
Total Dose Effects on Single Event Transients in Linear Bipolar Systems
Single Event Transients (SETs) originating in linear bipolar integrated circuits are known to undermine the reliability of electronic systems operating in the radiation environment of space. Ionizing particle radiation produces a variety of SETs in linear bipolar circuits. The extent to which these SETs threaten system reliability depends on both their shapes (amplitude and width) and their threshold energies. In general, SETs with large amplitudes and widths are the most likely to propagate from a bipolar circuit's output through a subsystem. The danger these SET pose is that, if they become latched in a follow-on circuit, they could cause an erroneous system response. Long-term exposure of linear bipolar circuits to particle radiation produces total ionizing dose (TID) and/or displacement damage dose (DDD) effects that are characterized by a gradual degradation in some of the circuit's electrical parameters. For example, an operational amplifier's gain-bandwidth product is reduced by exposure to ionizing radiation, and it is this reduction that contributes to the distortion of the SET shapes. In this paper, we compare SETs produced in a pristine LM124 operational amplifier with those produced in one exposed to ionizing radiation for three different operating configurations - voltage follower (VF), inverter with gain (IWG), and non-inverter with gain (NIWG). Each configuration produces a unique set of transient shapes that change following exposure to ionizing radiation. An important finding is that the changes depend on operating configuration; some SETs decrease in amplitude, some remain relatively unchanged, some become narrower and some become broader
Total Dose Effects on Error Rates in Linear Bipolar Systems
The shapes of single event transients in linear bipolar circuits are distorted by exposure to total ionizing dose radiation. Some transients become broader and others become narrower. Such distortions may affect SET system error rates in a radiation environment. If the transients are broadened by TID, the error rate could increase during the course of a mission, a possibility that has implications for hardness assurance
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