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951.
The aim of this paper is to obtain new sharp inequalities for a large family of topological indices, including the second variable Zagreb index \(M_2^{\alpha }\), and to characterize the set of extremal graphs with respect to them. Our main results provide lower bounds on this family of topological indices involving just the minimum and the maximum degree of the graph. These inequalities are new even for the Randi?, the second Zagreb and the modified Zagreb indices. 相似文献
952.
953.
Vladimir Vanyushyn Maria Bengtsson Malin H. Näsholm Håkan Boter 《Review of Managerial Science》2018,12(2):535-557
International coopetition has rarely been studied in relation to innovation. Further exploration of effects of international coopetition, i.e. the pursuit of simultaneous cooperation and competition, on a firm’s innovation performance is especially important as such a relationship is challenging with a high propensity to fail. This observation formed the point of departure for this study, which aims to increase the understanding of the effects of international coopetition on firm innovativeness and how these effects are conditioned on the magnitude of the organizational adjustments a firm introduces. We use an unbalanced panel of 9839 firms that participated in four waves of the Swedish Community Innovation Survey between 2008 and 2014 as our empirical base. We illustrate that firms that cooperate with competitors internationally are more likely to exhibit higher propensity to introduce radical innovations, yet this effect is conditioned upon the magnitude of organizational adjustments. Overall, our study contributes to the understanding of the implications of international coopetition and what a firm needs to benefit from it. 相似文献
954.
Ricarda B. Bouncken Sven M. Laudien Viktor Fredrich Lars Görmar 《Review of Managerial Science》2018,12(2):385-410
Coopetition has the potential to improve entrepreneurship and innovation. It will be prevalent in coworking-spaces building a growing field for individual and corporate entrepreneurship. The individuals’ physical closeness in the professional and social space of the coworking-space eases multifaceted transfers of explicit and implicit knowledge, stimulating creation, transfer, overhaul, and implementation of entrepreneurial ideas. While entrepreneurs in these coworking-spaces collaborate on sharing knowledge and resources and on finding creative ideas from which can breed new venture concepts, they simultaneously compete on the appropriation of values. Thus, entrepreneurs in coworking-spaces face coopetitive tensions of creating and appropriating the values. Based on interview data and secondary sources, this paper explains four different prototype institutions of coworking-spaces: the corporate coworking-space, the open corporate coworking-space, the consultancy coworking-space, and the independent coworking-space. Study explains different tensions of value creation and appropriation that occur within the coopetition in the different forms of coworking-spaces. 相似文献
955.
We describe a regression-based approach to the modelling of age-, order-, and duration-specific period fertility, using retrospective survey data. The approach produces results that are free of selection biases and can be used to study differential fertility. It is applied to Demographic and Health Survey data for Ethiopia, Kenya, Tanzania, and Zimbabwe to investigate differential trends in fertility by education. Parity progression fell and the intervals following each birth lengthened between the 1970s and 2000s in all four countries. Fertility fell most among women with secondary education. In contrast to other world regions, postponement of successive births for extended periods accounted for much of the initial drop in fertility in these African countries. However, family size limitation by women with secondary education in Ethiopia and Kenya and longer birth spacing in Zimbabwe also played significant roles. Thus, birth control is being adopted in Eastern Africa in response to diverse changes in fertility preferences. 相似文献
956.
Harris N 《Habitat International》1988,12(3):103-120
"The paper presents a discussion of the economic justification for taking cities seriously, a section outlining the scale of urbanisation and some of the issues raised, a section that discusses the policy approaches, one that looks at the local agencies for the formulation and execution of policy, and a short final part on some of the implications for aid policy." The focus is on the importance of the urban sector for economic development in developing countries. 相似文献
957.
Economic development and urbanisation 总被引:1,自引:0,他引:1
Harris N 《Habitat International》1988,12(3):5-15
Trends in urbanization in developing countries are analyzed, with a focus on the causes of rapid urbanization and particularly on the role of the division of labor. The impact of urbanization on the process of economic development is described. The role of government and of urban planning policies is also considered. 相似文献
958.
In the last decade the Maltese population has seen an influx of overseas-born individuals. This has been largely due to Malta’s
access to the European Union and the increased intake of refugee immigrants. These immigration trends have resulted in changes
in population composition, with the overseas-born population increasing from 17,740 (4.7%) in 1995 to 24,560 (6.1%) in 2005.
There has also been an increase in the proportion of births registered in Malta to overseas citizens, including citizens of
non-EU Europe (1.1%); the African continent (1.5%); America (0.3%); and Asia (0.8%). About ten per cent of marriages in Malta
are between a Maltese spouse and a foreigner. The data suggest that the Maltese population is slowly becoming more cosmopolitan,
a trend that is gradually changing the ethnic composition of the Maltese community. 相似文献
959.
Many important questions and theories in demography focus on changes over time, and on how those changes differ over geographic
and social space. Space-time analysis has always been important in studying fertility transitions, for example. However, demographers
have seldom used formal statistical methods to describe and analyze time series of maps. One formal method, used widely in
epidemiology, criminology, and public health, is Knox’s space-time interaction test. In this article, we discuss the potential
of the Knox test in demographic research and note some possible pitfalls. We demonstrate how to use familiar proportional
hazards models to adapt the Knox test for demographic applications. These adaptations allow for nonrepeatable events and for
the incorporation of structural variables that change in space and time. We apply the modified test to data on the onset of
fertility decline in Brazil over 1960–2000 and show how the modified method can produce maps indicating where and when diffusion
effects seem strongest, net of covariate effects. 相似文献
960.
Alisson F. Barbieri Edson Domingues Bernardo L. Queiroz Ricardo M. Ruiz José I. Rigotti José A. M. Carvalho Marco F. Resende 《Population and environment》2010,31(5):344-370
This research contributes to an understanding of the relationship between climate change, economic impacts and migration.
We model the long-term relationship (up to 45 years of projection) between demographic dynamics—particularly migration—driven
by changes in the performance of the economy due to climate changes in the Northeast region of Brazil. The region is of particular
relevance to the study of climate change impacts given its large human population (28% of Brazil’s population) and high levels
of impoverishment, having an extensive semi-dry area which will be severely impacted by growing temperatures. Ultimately,
the integrated model generates state- and municipal-level migration scenarios based on climate change impacts on the primary
economic sectors and their articulations with other sectors. Results suggest that the predicted climate changes will impact
severely the agriculture sector in the region, acting as a potential migration push factor to other regions in the country.
Finally, we discuss how the increased vulnerability of some groups, particularly migrants, can be factored into Brazilian
public policy and planning. 相似文献