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时尚作为一种社会现象,是由个别人物的倡导和示范,先在少数人中流行,然后迅速蔓延到社会.多数人出于新奇与从众心理而仿效.对于它的研究有助于人们把握这种社会现象的产生与蔓延过程,深入认识和控制它的发展.由于它的复杂多样性,当前还缺乏对它的定量分析与研究.论文利用基于智能主体的仿真方法,分析了时尚的涌现过程.文中建立了两种模型,用于确定公众能否接受某种时尚的临界值.一种模型基于公众能获取全部信息,另一种则基于个人只能获取邻近信息. 相似文献
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Michiyuki Yagi Shigemi Kagawa Shunsuke Managi Hidemichi Fujii Dabo Guan 《Risk analysis》2020,40(9):1811-1830
Disasters often cause exogenous flow damage (i.e., the [hypothetical] difference in economic scale with and without a disaster in a certain period) to production (“supply constraint”). However, input-output (IO) analysis (IOA) cannot usually consider it, because the Leontief quantity model (LQM) assumes that production is endogenous; the Ghosh quantity model (GQM) is considered implausible; and the Leontief price model (LPM) and the Ghosh price model (GPM) assume that quantity is fixed. This study proposes to consider a supply constraint in the LPM, introducing the price elasticity of demand. This study uses the loss of social surplus (SS) as a damage estimation because production (sales) is less informative as a damage index than profit (margin); that is, production can be any amount if without considering profit, and it does not tell exactly how much profit is lost for each supplier (upstream sector) and buyer (downstream sector). As a model application, this study examines Japan's largest five earthquakes from 1995 to 2017 and the Great East Japan Earthquake (GEJE) in March 2011. The worst earthquake at the peak tends to increase price by 10–20% and decrease SS by 20–30%, when compared with the initial month's prices/production. The worst damage tends to last eight months at most, accumulating 0.5-month-production damage (i.e., the sum of [hypothetical] differences in SS with and without an earthquake [for eight months] is 50% of the initial month production). Meanwhile, the GEJE in the five prefectures had cumulatively, a 25-month-production damage until the temporal recovery at the 37th month. 相似文献
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Tomoki Fujii 《Journal of Economic Inequality》2013,11(3):373-392
Applying the small-area estimation methods to Cambodia data, we decompose the total inequality in wealth (consumption) and health (child undernutrition) indicators into within-location and between-location components. Because the knowledge of the pattern of spatial disparity in poverty and undernutrition is important for the geographic targeting of resources, we conduct a geographic decomposition of the variance of the Foster-Greere-Thorbecke index in addition to the standard decomposition exercise based on the generalized entropy measures. We find that a sizable proportion of wealth inequality is due to between-location inequality, whereas health inequality is mainly due to within-location inequality. 相似文献
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Summary We performed multiple-generation competition experiments betweenCallosobruchus analis andC. phaseoli with different bean sizes. In each system, we supplied 5 g of mung beans (Vigna radiata) every 10 days. We examined three types of bean conditions: 5 g of large beans, 5 g of small beans, and a mixture of 2.5
g of large and small beans. In small bean condition,C. analis dominatedC. phaseoli in all three replicates andC. phaseoli was extinct by the 260th day. On the contrary,C. phaseoli overcameC. analis within 250 days in large beans in all three replicates. In mixed beans condition the two bruchid species coexisted more than
500 days in two out of the three replicates. Even in the exceptional case, both species coexisted for 460 days. These results
were examined in the light of the predictions from short-term larval competition experiments and a game theoretical model
by Smith and Lessells (1985). The density and frequency dependent results during larval competition inside a bean was concluded
to be a main factor to produce the above long-term competition results. 相似文献
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This study is part of a collaborative project examining the quality of life in Confucian societies in Asia. Our major findings
suggest that, when our sixteen specific life domains are grouped into three life spheres, namely, material, post-material,
and public, the Japanese people tend to be most satisfied with the post-material sphere of life and least satisfied with the
public sphere of life such as the condition of environment and welfare system. In searching the direct, independent effects
of demographics, lifestyles, value priorities, and domain assessments on the quality of life, none of the public life domain
assessments shows a significant impact on the quality of life, while friendships and spiritual life in the post-material sphere
of life are an important determinant. Equally notable is the finding that neither educational attainment nor household income
contributes significantly to the experience of subjective well-being. Leading a global lifestyle also affects positively the
quality of life. Finally, being married and satisfaction with marital life appear to be powerful and prevalent influence on
the quality of life in Japan.
相似文献
Takashi InoguchiEmail: |
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We analyzed the butterfly communities in the newly designed city parks (area C), “newly opened habitat islands”, of Tsukuba
City, central Japan. The area constituted a natural ecological experiment on the mainland for clarifying the pattern and process
of faunal immigration. We compared butterfly communities in area C with those in two other areas in the light of the theory
of island biogeography and the concept of generalist/specialist. Our results showed the following: (1) Fewer species were
found in area C than in other areas, due largely to the absence of many specialist types, restricted and habitat specialists,
and/or low density species in the area. Generalist types, widespread and habitat generalists, and/or high density species
predominated in area C. (2) The difference in the species numbers among the three sections within area C could be explained
by the habitat structure in and around the respective sections. (3) The densities of many species were low in area C, probably
due to its man-modified habitat structure. In particular, several species occurred at extremely low densities in area C, but
at high densities in other areas. (4) The internal structure of the habitat island butterfly community in area C was almost
perfectly consistent with that of “quasi-equilibrium” communities that appear during the colonization of an island. Our results
demonstrate that the synergetic application of the generalist/specialist concept and the island biogeography theory is effective
for the understanding of the patterns and structures of habitat island communities. 相似文献
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Among many stabilizing factors for community dynamics, nonlinear biological interactions such as type III functional response
have been widely considered to be major characteristics. However, most experimental biological communities employed so far
had quite simple structures. Therefore, the possibility that the conclusions in earlier studies were dependent on simple community
structure is undeniable. In this study, using a multiple-species experimental community, we evaluated which combinations of
component species and what kinds of interspecific interactions allow communities to persist and how these contribute to community
persistence. We conducted experimental communities using two species of beans, the adzuki bean (Vigna angularis) and the red kidney bean (Phaseolus vulgaris), two species of bean weevils, the Mexican bean weevil (Zabrotes subfasciatus, Coleoptera: Bruchidae) and adzuki bean weevil (Callosobruchus chinensis, Coleoptera: Bruchidae), and two species of parasitic wasp, Heterospilus prosopidis (Hymenoptera: Braconidae) and Anisopteromalus calandrae (Hymenoptera: Pteromalidae). The outcome of multiple-generation experimental communities was explained by the characteristics
of component species obtained from short-term experiments. In our two resources–two herbivores–one carnivore system, the strong
density-dependent attack ability of one parasitic wasp species (A. calandrae) led to the extinction of C. chinensis. On the other hand, the weak density-dependent attack ability of the other parasitic wasp species (H. prosopidis) led to system persistence. Our overall results show that, in a multiple-species community, the combination of species itself
is more important for community persistence than are the characteristics of the particular species.
Received: September 29, 1997 / Accepted: October 5, 1998 相似文献
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