Two new covering problems are introduced. The partial covering P-center problem minimizes a coverage distance in such a way that a given fraction of the population is covered. The partial set covering problem seeks the minimum number of facilities needed to cover an exogenously specified fraction of the population within a given coverage distance. The problems are formulated as integer linear programming problems. Bisection search algorithms are outlined for the two problems. The search algorithm repeatedly solves a Lagrangian relaxation of the maximal covering problem. Computational results for the Lagrangian relaxation of the maximal covering problem and for the bisection search algorithms are presented on problems with up to 150 nodes. 相似文献
Two new covering problems are introduced. The partial covering P-center problem minimizes a coverage distance in such a way that a given fraction of the population is covered. The partial set covering problem seeks the minimum number of facilities needed to cover an exogenously specified fraction of the population within a given coverage distance. The problems are formulated as integer linear programming problems. Bisection search algorithms are outlined for the two problems. The search algorithm repeatedly solves a Lagrangian relaxation of the maximal covering problem. Computational results for the Lagrangian relaxation of the maximal covering problem and for the bisection search algorithms are presented on problems with up to 150 nodes. 相似文献
During the last two decades, in Canada and the United States, provincial and state governments have responded to the issue of farmland preservation with a variety of measures. These are examined within the context of political and social acceptability, cost of implementation, and impact. A typology of generic farmland protection strategies is developed to classify the state and provincial responses, with consideration given to the relative effectiveness of each. Of the four distinct policy approaches that emerge, the comprehensive-mandatory programmes are considered to promise the greatest success. Au cows des deux dernières décennies, au Canada et dans les États-Unis, les gouvernements des provinces et des états ont adopté des politiques tres variées afin de preserver le territoire agricole. Ces politiques sont analysees dans le lut de determiner si leur mise en oeuvre est acceptable au point de vue politique et social et d'Cvaluer leur coût aussi que leur efficacité. Une typologie des strategies de conservation bade sur leurs caracteristiques génériques sert à classifier les diverses politiques, notamment eu égard à leur efficacité relative. Des quatre approches de politique qui ressortent de cette étude, celle basée sur des programmes obligatoires et globaux semble la plus prometteuse. 相似文献
M. Philips Price: “A HISTORY OF TURKEY: FROM EMPIRE TO REPUBLIC” (Allen and Unwin. 1956. 20/‐.)
“THE ECONOMICS OF EMPLOYMENT AND UNEMPLOYMENT.” By Paul H. Casselman. (Public Affairs Press, Washington, D.C., 1955, pp. vi plus 183. Price $3.25.)
“THE HISTORY OF A SOVIET COLLECTIVE FARM.” Fedor Belov. Routledge. London. International Library of Sociology and Social Reconstruction. 1956. xiii plus 234, including appendices and index. 21/‐.
“RED, BLACK, BLOND AND OLIVE.” by Edmund Wilson. (W. H. Allen, London. 25/‐.)
“THE PATTERN OF WORLD CONFLICT.” by G. L. Arnold. London. (The Dial Press, New York. 1955, pp. 250.)
“FLIGHT AND RESETTLEMENT.” by H. B. Murphy and Others. (Paris: United Nations Educational, Scientific and Cultural Organization), 1955, pp.231. 相似文献
Bonnafous, A., Plassard, F., and Vulin, B., eds., Circuler Demain (DATAR/Éditions de l'Aube, 1993), 191pp., 95R, ISBN 2 87678 126 3 Dioudonnat, P.‐M., Les 700 rédacteurs de ‘Je suis partout’ 1930–1944 (Sedopolis, 1993), 107pp., 240F., ISBN 2 904177 16 7 Furet, F., Revolutionary France 1770–1880 (Blackwell, 1992), 630pp., £40.00, ISBN 0 631 17029 4 Hainsworth, P., ed., The Extreme Right in Europe and the USA (Pinter, 1992), 320pp., £45.00, ISBN 0 86187 790 X Macchia, G., L'Ange de la nuit. Sur Proust, trans, from the Italian by Marie‐France Merger, Paul Bédarida and Mario Fusco (Gallimard, 1993), 269pp., 130F., ISBN 2 07 072885 4 McPhee, P., A Social History of France 1780–1880 (Routledge, 1993), 347pp., £12.99 pbk, ISBN 0 415 01616 9 Prost, A., ’Les Anciens Combattants’ and French Society 1914–1939 (Berg, 1992), 152pp., £29.95, ISBN 0 85496 672 2 (hbk), £9.95, ISBN 0 85496 337 5 (pbk) Service d'Information et de Diffusion du Premier Ministre, La politique de la France, aoÛt 1991‐juillet 1992 (La Documentation française, 1993), 165pp., 70F., ISBN 2 11 002915 3 Teich, M., and Porter, R., eds., The National Question in Europe in Historical Context (CUP, 1993), 343pp., £40.00, ISBN 0 521 36441 8 (hbk), £13.95, ISBN 0 521 36713 1 (pbk) 相似文献
A number of critics have drawn attention to the increased number of violent women in film, media and literature and to the apparent collusion between women and violence in women's own fiction. This article examines three autofictional works by Duras, Hyvrard and Cixous to see to what extent, and in what ways, these ‘textes de sang’ rewrite and rework incidents of violence in the individual and the family, of self-mutilation and imperialism, and of illness, grief and mourning. In each case, a variety of narrative techniques is employed which enable the writer to engage with, and emerge from, identities affected by violence. In all three cases, the violent fracturing of identity into ‘je/s' and ‘elles' is co-opted into a strengthened authorial voice and a new, uncollusive persona. 相似文献