Concurrent Undo Operations in Collaborative Environments using Operational Transformation Auteur(s) : Ferrié, Jean Vidot, Nicolas Cart, Michelle Auteurs secondaires : Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier (LIRMM) ; Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Laboratoire de Mathématiques Informatique et Applications (LAMIA) ; Université des Antilles et de la Guyane (UAG) Robert Meersman Zahir Tari Éditeur(s) : HAL CCSD Springer Berlin / Heidelberg Résumé : International audience In distributed collaborative systems, replicated objects, shared by users, are subject to concurrency constraints. All methods [4, 13, 18, 15, 16, 19, 22] proposed to serialize concurrent operations and achieve copies convergence of replicated objects are based on the use of Operational Transformations. In this context, giving the user the ability to undo an operation has been recognized as a difficult problem [1, 2, 3, 12, 14, 20, 21]. The few general propositions to solve the problem sometimes compromise copies convergence and/or users' intention, insofar as the Operational Transformations used are unsuitable for undo. This paper has a twofold objective. Firstly, it aims to highlight two general conditions (named C3 and C4) that need to be satisfied by any transformation adapted to undo. Secondly, it presents a general undo algorithm based on the definition of a generic undo-fitted transformation, which automatically verifies these conditions. The interest of the proposed method is that the undoing of an operation obeys to the same processing as the one used for regular operations in collaborative systems such as [15,19]. 12th International Conference on Cooperative Informations Systems Agia Napa, Cyprus hal-00684656 https://hal.archives-ouvertes.fr/hal-00684656 DOI : 10.1007/978-3-540-30468-5_12 | Partager |
Assessment of tropical shrimp aquaculture impact on the environment in tropical countries, using hydrobiology, ecology and remote sensing as helping tools for diagnosis Auteur(s) : Fuchs, Jacques Martin, Jean-louis M. Populus, Jacques Résumé : After a period of rapid development of the sites (an increase in both reared surface area and production), tropical shrimp aquaculture is currently being faced with critical problems due to economical and ecological constraints. In many countries with favourable conditions for shrimp aquaculture such as indonesia or Vietnam, sites are often badly selected and/or over-exploited. This conducts to sorne extent to decreases or collapses in the production due to the difficulty in predicting the maximum production capacity of the sites. Furthermore, it appears that production sustainability depends on many factors among which socio-economy and ecolo gy are of prime importance.
The STD3 project titled « Assessment of tropical shrimp aquaculture impact on the environment in tropical countries using hydrobiology, ecology and remote sensing as helping tools for diagnosis )) was initiated in 1994, with the aim to study the sustainability of marine shrimp aquaculture in tropical areas, main! y Indonesia and Vietnam, through the following tasks: (i) improve site selection and study the impact of aquaculture on marine environments presenting a variable sensitivity to organic sewage, (ii) analyse the socio-economical aspects and profitability of the aquaculture industry and of common resources (iii) use remote sensing and geographical data bases for diagnosis and monitoring of site degradation (iv) reinforce the capacity of Asian
scientists through training.
Severa! aquaculture sites have been investigated in the Lampung region (South Sumatra, Indonesia), the Mekong delta (Vietnam) and on the West coast of New-Caledonia, providing a large range of typical ecosystems encountered in Asia and in the Pacifie, from coralline sites to coastal plains with mangrove and deltaic areas. The study concerned the spatial structure and seasonal influence of these ecosystems, the temporal variation during the course of the project (3 years) and the relation between the ecological structure and farm productions.
Remote sensing provides a synoptic vision over large land expanses. Severa! scenes were processed for landuse mapping using conventional classification techniques. Concerning water quality assessment, a general relation for the Java sea was found between image and field data in terms of total suspended matter. Applying this relation to a new site in Sumatra has provided an initial approach to water type and, together with land use mapping, a preliminary assessment of the suitability of the area to shrimp aquaculture development.
Socio-economic research has been focused on the identification ofneeds for collective action, including public policy, in the perspective of shrimp farming sustainability. The main concern is in the regulation of shrimp farming intensification and extensification at the scale of coastal ecosystemic entities in a common property resource management perspective. The common considered here is coastal water quality. Comparing the local development profiles and the institutional grounds for the design and implementation of collective management rules shows that variables such as land tenure system, farm owner socio-economic profile, social homogeneity or heterogeneity of the farmers are key factors to analyse the potential for sustainability. The defmition of
water quality and the possible means to ensure its collective management are discussed. The main conclusion is that the economie incentives to farming development are strong but there is no significant difference among traditional, semi-intensive and intensive systems in terms of economie efficiency or wealth distribution.
The description of the functioning of the different kinds of ecosystems make it possible to give an advice concerning the positioning of the activity inside the ecosystem, and furthermore to have a reference state in order to determine the impact of the activity on the coastal environnement. This impact can be summarized as an increase in the concentration of total suspended matt€?r, of particulate organic matter and of sulfate reducing bacterias. This organic ma~.er is either issued from rearing activities or from telluric origine, due to mangrove eradication when building the ponds.
An evaluation of the relationship existing between productivity and characteristics of each ecosystem bas been conducted by correlating ecological indicators data (concentration of total suspended matter, particulate organic matter, chlorophyll, percentage of pheopigments in total pigments and cyanobacteria and sulfatereducing bacteria in water and sediments) with the average production of the farms. This comparison lead to the compilation of a scale of observed production integrating the range of these environmental parameters with shrimp production levels, bound to facilitate the positioning of shrimp farming in relation with the confmement leve! of each ecosystem.
Lastly, ali geographie data originated from the various compartments of the study have been geo-referenced and loaded into a geographical information system. This allows to display any query made on spatial variables and their related statistical data, including the ir variations over the last few years and to reveal patterns and phenomena otherwise not obvious. Le programme mis en oeuvre par la DRV (Paris, CREMA-L'Houmeau, DELIAO Brest, COP Tahiti, GIE/RA Nouvelle Calédonie), dans le cadre d'un projet européen STD3 «(Sciences et Technique au Service du Développement», en collaboration avec l'Université de Montpellier II, l'Ecole Nationale d'Agronomie de Rennes, l'ITC (Hollande), l'Institut Océanographique de Nha Trang (Vietnam), le BADC de Jepara et le BPPT de Jakarta (Indonésie), avait pour but la mise au point de méthodes permettant d'améliorer la sélection des sites ainsi que le suivi du développement et de l'impact de l'aquaculture des crevettes Péneides en milieu tropical pour éviter la surexploitation. Quatre axes de recherche ont été défmis : a) identifier la nature et quantifier les rejets de déchets issus de ce type d'aquaculture, b) définir les caractéristiques écologiques des écosystèmes susceptibles d'accueillir l'activité aquacole et suivre leur évolution sous l'influence des rejets, c) déterminer l'influence de la gestion des fermes et des ressources (aspects économiques) sur les performances de productivité, d) déterminer la capacité de la télédétection comme outil de diagnostic d'impact à l'échelle de la région, e) mener un programme de formation d'étudiants et jeunes chercheurs Vietnamiens et Indonésiens. Droits : 1998 Ifremer http://archimer.ifremer.fr/doc/00132/24357/22357.pdf http://archimer.ifremer.fr/doc/00132/24357/ | Partager |
The Fisheries Information System of Ifremer: a multidisciplinary monitoring network and an integrated approach for the assessment of French fisheries, including small-scale fisheries Auteur(s) : Leblond, Emilie Daures, Fabienne Berthou, Patrick Dintheer, Christian Éditeur(s) : ICES 2008 Annual Science Conference, 22-26 september 2008, HALIFAX, CANADA Résumé : Since 2000, Ifremer has been implemented a Fisheries Information System (FIS), in strong collaboration with the DPMA (Direction of fisheries and aquaculture of the French Ministry of Agriculture and Fisheries). The FIS aims at building an operational and multidisciplinary monitoring network for scientific purposes, allowing a comprehensive view of fishery systems including their biological, technical, environmental and economical components. The objectives of the FIS are (i) to provide the specifications and methodologies for the collection, storage and processing of fisheries data, with the constant concern to harmonise all these procedures on a national scale, (ii) to improve data management system and access to data for a wide-spread public, and (iii) to produce and distribute relevant datasets, indicators and synthesis, for understanding and evaluation, including bio-economic diagnostics of the fisheries, and assessment of the short and long-term impacts of fisheries management scenario and measures. The FIS covers all the French fisheries, including overseas territories and small-scale fisheries, for which data are often hardly available or missing, whereas two thirds of the French vessels are less than 12 meters long. The challenge was to establish a statistical and an integrated approach supporting bio-ecological and economic issues. To further an integrated analysis of the fishery systems, the wide range kinds of data - including acoustic surveys, biological in-situ observations, environmental observations, as well as fishing statistics (landings and efforts) or economic data - are managed in a single data management system, based on an integrated relational data base with geographical facilities. Droits : 2008 ICES http://archimer.ifremer.fr/doc/00059/17002/14504.pdf http://archimer.ifremer.fr/doc/00059/17002/ | Partager |
La bibliométrie : un nouveau cap pour une archive institutionnelle ; Bibliometrics: a new feature for institutional repositories Auteur(s) : Merceur, Frederic Le Gall, Morgane Salaun, Annick Éditeur(s) : Caught in the "fishing net" of information 14th Biennal EURASLIC Meeting 17-20 May, 2011, Lyon, France Résumé : In addition to its promotion and conservation objectives, Archimer, Ifremer’s institutional repository, offers a wide range of bibliometric tools described in this document. As early as the recording stage, numerous automatic operations homogenize the information (author’s name, research body, department…), thus proving the quality of the bibliometric analyses. Now, Archimer enables, among others, the automatic calculation of several indicators defined by Ifremer and the different ministries in charge in the framework of its four-year contract. It also offers various criteria aimed at analysing its document production (eg. distribution of the value of the journals’ impact factors, evolution of the number of quotations in other publications, presentation of international collaborations…). As a consequence, the centralisation of Ifremer’s document production in Archimer will replace a number of different systems currently used by its research units to carry out such tasks. This should therefore result in an increase in Ifremer’s productivity as well as in a greater reliability of the archived documents. En complément de ses objectifs de diffusion et de conservation, Archimer, l’archive institutionnelle de l’Ifremer, offre un ensemble d’outils bibliométriques. Dès l'enregistrement, de nombreux automatismes homogénéisent les informations (noms d'auteurs, organismes, affiliation interne...), gage de qualité des analyses bibliométriques. Archimer permet le calcul automatique de plusieurs indicateurs définis entre l'Ifremer et ses Ministères de Tutelles dans le cadre de son contrat quadriennal. Il offre également des éléments d’analyses de sa production documentaire (ex : répartition de la valeur des facteurs d’impacts des revues, évolution du nombre de citations des publications, présentation des collaborations internationales…). La centralisation de cette production documentaire dans Archimer permettra ainsi l’abandon d’une multitude de systèmes actuellement utilisés par les différentes unités de recherche pour assurer ces fonctions. C’est donc un gain de productivité autant que de fiabilité qui est attendu. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/00031/14253/11537.pdf http://archimer.ifremer.fr/doc/00031/14253/11886.pdf http://archimer.ifremer.fr/doc/00031/14253/ | Partager |