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1.
This paper examines young people's firsthousing acquisition in Spain. The majority ofyoung Spanish people leave home to buy aproperty and to live with a partner and/orchild. We examine the extent to which thistransition dominates first housing moves duringthe 1980s and consider the ways in which widerfamily networks facilitate leaving home to buya property. We then examine characteristicsassociated with deviation from this normativeroute. We find alternative transitions,particularly moving into rented accommodation,are more common among young people from moreadvantaged backgrounds, and those living innorthern Spain.  相似文献   
2.
A Genetic Algorithm for the Weight Setting Problem in OSPF Routing   总被引:1,自引:1,他引:1  
With the growth of the Internet, Internet Service Providers (ISPs) try to meet the increasing traffic demand with new technology and improved utilization of existing resources. Routing of data packets can affect network utilization. Packets are sent along network paths from source to destination following a protocol. Open Shortest Path First (OSPF) is the most commonly used intra-domain Internet routing protocol (IRP). Traffic flow is routed along shortest paths, splitting flow at nodes with several outgoing links on a shortest path to the destination IP address. Link weights are assigned by the network operator. A path length is the sum of the weights of the links in the path. The OSPF weight setting (OSPFWS) problem seeks a set of weights that optimizes network performance. We study the problem of optimizing OSPF weights, given a set of projected demands, with the objective of minimizing network congestion. The weight assignment problem is NP-hard. We present a genetic algorithm (GA) to solve the OSPFWS problem. We compare our results with the best known and commonly used heuristics for OSPF weight setting, as well as with a lower bound of the optimal multi-commodity flow routing, which is a linear programming relaxation of the OSPFWS problem. Computational experiments are made on the AT&T Worldnet backbone with projected demands, and on twelve instances of synthetic networks.  相似文献   
3.
This article analyzes a yearlong ethnography of the Southside Free Press, a non-school-affiliated community-based organization that served diverse adolescent staff writers who prepared articles for a monthly newspaper publication. The study employed a perspective of learning as legitimate peripheral participation with/in a newsroom community of practice. Specifically, using Rogoff’s three planes of analysis—apprenticeship, guided participation, and participatory appropriation—demonstrates that the process of becoming staff writers affected their learning and development. Thus, their ongoing participation provided opportunities to come to enact and embody the available meanings, identities, and epistemologies around becoming a staff writer and citizenship.  相似文献   
4.
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   
5.
One of the most important policy objectives in the post-apartheid South African economy is to reduce poverty. Although economic growth and job creation are the preferred sources of alleviating poverty and inequality, social grant spending has contributed significantly to reduce poverty (Van der Berg et al. in Poverty trends since the transition: what we know. Stellenbosch Economic Working Papers: 19/09. Stellenbosch: Stellenbosch University, 2009). Recently proposals were tabled by the Department of Social Development of South Africa (Fin24 in R3.3bn plan to extend child support grant to 21. http://www.fin24.com/Economy/R33bn-child-care-grant-extension-to-21-on-cards-20150316. Accessed August 7, 2015, 2015) to extend the age eligibility of the child support grant (CSG) to 21 years (at the time of writing children aged up to 18 years are eligible). This sparked an interest to investigate the impact on poverty of changes to the eligibility criteria of CSG, as well as its fiscal implications. Using person and household data from the 2010/2011 Income and Expenditure Survey, various simulations are performed to assess the impact on poverty rates and changes to social spending, given the following changes: (1) if all age-eligible children applied; (2) if all beneficiaries received the grant amount for the full 12-month duration; (3) if the age eligibility criterion is extended; and (4) if the monthly child grant income amount is revised upwards. We also examine how changes in the eligibility criteria affect the income distribution.  相似文献   
6.
This article compares the extended family integration of Euro and Mexican American women and men and assesses the importance of class and culture in explaining ethnic differences. Using National Survey of Families and Households II data (N = 7,929), we find that ethnic differences depend on the dimension of integration. Mexican Americans exhibit higher rates of kin coresidence and proximity, but lower rates of financial support than Euro Americans. Two additional differences exist only among women: Mexican American women are more likely than Euro American women to give household or child care help. As to the explanation for these differences, social class is the key factor; cultural variables have little effect. Our findings support a theoretical framework attending to intersections among ethnicity, gender, and class.  相似文献   
7.
Urbanization alters ecosystems worldwide, but little is known about its effects in the Neotropical region. In the present research we examined the relative influence of different levels of urbanization and of some urban development measures on bird species richness, abundance and composition. We surveyed 104 observation stations at which we collected data on the relative abundance of bird species, and also data on seven environmental variables as measures of urban development and human activity. We registered 57 native bird species. Bird species richness and bird abundance increased with lower urbanization levels. Both variables were positively related to vegetation cover and native vegetation, and negatively to built-up cover, abundance of Rock Pigeon (Columa livia), pedestrian rate and car rate. A canonical correspondence analysis produced a significant model that explained 37% of the total variation in species data. This analysis segregated bird species along two important gradients: urbanization and elevation. The most urbanized areas were dominated by a few synanthropic species tolerant to human disturbance, such as Rufous-Collared Sparrow (Zonotrichia capensis), Eared Dove (Zenaida auriculata) or Chiguanco Thrush (Turdus chiguanco). Areas with lower urbanization levels had more species typically associated with native vegetation, such as Plain-Mantled Tit-Spinetail (Leptasthenura aegitaloides) or D’Orbigny’s Chat-Tyrant (Ochthoeca oenanthoides), among others. Elevation had a significant influence in structuring bird communities, with some species restricted to higher elevations and some to lower elevations. Although changes in elevation had an important influence, urbanization had a stronger effect on structuring bird communities. This study provides valuable information and an important baseline for future studies.  相似文献   
8.
Social Indicators Research - This paper aims to construct a financial well-being index and analyze its determinants among adults in Mexico. It employs multiple correspondence analysis, multiple...  相似文献   
9.
In 2009 Argentina introduced a large poverty-alleviation program (AUH) that provides monthly cash transfers per child to households without workers in the formal sector. In this paper we study the potential unintended effect of this program on fertility. We apply a difference-in-difference strategy comparing the probability of having a new child among eligible and ineligible mothers both before and after the program inception. The intention to treat estimations suggest a significant positive impact on fertility in households with at least one child (around 2 percentage points), but no significant effect on childless households. Given the short time window since the implementation of the AUH, we are unable to identify whether this positive effect reflects changes in the timing of births or in the equilibrium number of children.  相似文献   
10.
Research has demonstrated that infants recognize emotional expressions of adults in the first half year of life. We extended this research to a new domain, infant perception of the expressions of other infants. In an intermodal matching procedure, 3.5‐ and 5‐month‐old infants heard a series of infant vocal expressions (positive and negative affect) along with side‐by‐side dynamic videos in which one infant conveyed positive facial affect and another infant conveyed negative facial affect. Results demonstrated that 5‐month‐olds matched the vocal expressions with the affectively congruent facial expressions, whereas 3.5‐month‐olds showed no evidence of matching. These findings indicate that by 5 months of age, infants detect, discriminate, and match the facial and vocal affective displays of other infants. Further, because the facial and vocal expressions were portrayed by different infants and shared no face–voice synchrony, temporal, or intensity patterning, matching was likely based on detection of a more general affective valence common to the face and voice.  相似文献   
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