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1.
SONET (Synchronous Optical NETworks) add-drop multiplexers (ADMs) are the dominant cost factor in the WDM(Wavelength Division Multiplexing)/SONET rings. The number of SONET ADMs required by a set of traffic streams is determined by the routing and wavelength assignment of the traffic streams. Previous works took as input the traffic streams with routings given a priori and developed various heuristics for wavelength assignment to minimize the SONET ADM costs. However, little was known about the performance guarantees of these heuristics. This paper contributes mainly in two aspects. First, in addition to the traffic streams with pre-specified routing, this paper also studies minimizing the ADM requirement by traffic streams without given routings, a problem which is shown to be NP-hard. Several heuristics for integrated routing and wavelength assignment are proposed to minimize the SONET ADM costs. Second, the approximation ratios of those heuristics for wavelength assignment only and those heuristics for integrated routing and wavelength assignment are analyzed. The new Preprocessed Iterative Matching heuristic has the best approximation ratio: at most 3/2.  相似文献   
2.
Financial capability—financial knowledge, skills, and access to financial services—may help smooth transitions to adulthood for youth and is affected by socialization experiences with parents and other family members. Among a sample of youth and their parents enrolled in the YouthSave experiment in Ghana (n?=?4,065), this study examined whether physical access to financial services and/or visiting banks with parents or other family members was associated with youth’s perceptions and understanding of financial institutions. We found a statistically significant association between visiting the bank with a parent or other family member and youth’s attitudes (β?=?1.45, p?<?0.001) and understanding of financial services (β?=?2.96, p?<?0.001), controlling for other factors like household income and assets. Conversely, physical access (distance, travel time) was not associated with financial services attitudes or understanding. Parents may play an important role in introducing their children to financial services. Practitioners and policy makers should consider ways to include parents in efforts to promote financial capability among youth.  相似文献   
3.
This article examines individual variability in sexual desire and sexual satisfaction by exploring the relation between these sexual aspects and sexual attitudes (implicit and explicit) and by taking gender into account, as this has been shown to be an influential factor. A total of 28 men and 33 women living in heterosexual relationships completed questionnaires assessing sexual desire (dyadic, solitary), sexual satisfaction, and explicit sexual attitudes. An adapted version of the Affect Misattribution Procedure was used to assess implicit sexual attitudes. Results showed higher levels of dyadic and solitary sexual desire in men than in women. No gender differences were found regarding sexual satisfaction or sexual attitudes. High dyadic sexual desire was associated with positive implicit and explicit sexual attitudes, regardless of gender. However, solitary sexual desire was significantly higher in men than women and was associated, in women only, with positive implicit sexual attitudes, suggesting that solitary sexual desire may fulfill different functions in men and women. Finally, sexual satisfaction depended on the combination of explicit and implicit sexual attitudes in both men and women. This study highlights the importance of considering both implicit and explicit sexual attitudes to better understand the mechanisms underlying individual variability in sexual desire and satisfaction.  相似文献   
4.
Previous studies suggest significant differences between navigating virtual environments in a life-like walking manner (i.e., using treadmills or walk-in-place techniques) and virtual navigation (i.e., flying while really standing). The latter option, which usually involves hand-centric devices (e.g., joysticks), is the most common in Virtual Reality-based studies, mostly due to low costs, less space and technology demands. However, recently, new interaction devices, originally conceived for videogames have become available offering interesting potentialities for research. This study aimed to explore the potentialities of the Nintendo Wii Balance Board as a navigation interface in a Virtual Environment presented in an immersive Virtual Reality system. Comparing participants' performance while engaged in a simulated emergency egress allows determining the adequacy of such alternative navigation interface on the basis of empirical results. Forty university students participated in this study. Results show that participants were more efficient when performing navigation tasks using the Joystick than with the Balance Board. However there were no significantly differences in the behavioral compliance with exit signs. Therefore, this study suggests that, at least for tasks similar to the studied, the Balance Board have good potentiality to be used as a navigation interface for Virtual Reality systems.  相似文献   
5.
This paper offers a theory of respectable business femininity. Respectable business femininity is theorized as a discursive and relational process that explains tensions women elite leaders experience at the nexus of being both One and Other and sometimes privileged, embedded notions of leadership as masculine and wider expectations of acceptable embodied femininity. Such tensions manifest through a disciplining of women leaders’ bodies and appearance by self‐and‐others, as a means of appraising women as credible elite leaders and respectable women. Through a qualitative study we show how, within sites of ambiguity, embodied leadership and subjectivities are both enabled and constrained. Accounts highlight how privilege is fluid and (de)stabilized in that it is conferred, contested and defended through women's bodies and appearance. We advance understandings of contemporary respectable femininity, privilege at work, and body work, and consider practical implications for women leaders and management education.  相似文献   
6.
Seasonal fractional ARIMA (ARFISMA) model with infinite variance innovations is used in the analysis of seasonal long-memory time series with large fluctuations (heavy-tailed distributions). Two methods, which are the empirical characteristic function (ECF) procedure developed by Knight and Yu [The empirical characteristic function in time series estimation. Econometric Theory. 2002;18:691–721] and the Two-Step method (TSM) are proposed to estimate the parameters of stable ARFISMA model. The ECF method estimates simultaneously all the parameters, while the TSM considers in the first step the Markov Chains Monte Carlo–Whittle approach introduced by Ndongo et al. [Estimation of long-memory parameters for seasonal fractional ARIMA with stable innovations. Stat Methodol. 2010;7:141–151], combined with the maximum likelihood estimation method developed by Alvarez and Olivares [Méthodes d'estimation pour des lois stables avec des applications en finance. Journal de la Société Française de Statistique. 2005;1(4):23–54] in the second step. Monte Carlo simulations are also used to evaluate the finite sample performance of these estimation techniques.  相似文献   
7.
Urbanization causes species loss around the world, but its effects on phylogenetic diversity are poorly known in tropical forests. Using a patch-landscape approach in an urbanizing region of the Brazilian Atlantic Forest, we tested whether the increase in landscape urbanization reduces plant species density, phylogenetic richness and divergence, and increases the relatedness among co-occurring individuals and species. We assessed plant responses to urbanization in adult (diameter at breast height?>?10 cm) and sapling communities (2.5–10 cm diameter) separately, as saplings are proxies of the future flora. We sampled 2860 woody plants belonging to 155 species in nine circular landscapes with urbanization level varying from 0% to 45%, and estimated the relatedness among the species that have increased and decreased in relative abundance in more urbanized landscapes (winner and losers, respectively). As expected, species density and phylogenetic richness decreased with the increase in urbanization. These responses were consistent for adult and sapling communities, suggesting a persistent loss of species and lineages in more urbanized landscapes. Contrary to our expectations, phylogenetic divergence and structure did not respond to urbanization, indicating that the more urbanized landscapes still retain much evolutionary history. However, because the relatedness among winners was greater than among losers, it is likely that the phylogenetic divergence gradually reduces and the relatedness increases, resulting in impoverished forests with uncertain ability to provide ecosystem services such as carbon storage and pest control. This environmental cost should be taken into account to align urban sprawl with biodiversity conservation.  相似文献   
8.
The purpose of this study was to assess the benefits of an exercise program associated to the educational phase of the "Back School Program" in the quality of life of workers from a cigar factory. This is a case study conducted over four months with three activities a week, two times a day, with the third day devoted to educational activities, focusing on healthy lifestyle, correct posture, postural orientations, daily living and work activities, work motivation, and other issues.  相似文献   
9.
This paper approaches the challenge of considering the principles of sustainable development in the conception of products, services or systems in a specific territory, though inserted in a globalized world. The reflection takes place by crosschecking the information gathered through bibliographical research on the following themes: wellbeing, design, and the local versus global relation. Thus, the strategy of analysis adopted comprehends the triangulation of information for further comparison of the survey and discussion of the data obtained. This paper results in a set of reflections on the interactions between human beings and their territories, towards new conceptions oriented to a more sustainable future.  相似文献   
10.
A company making women's clothing, located in Belo Horizonte, Minas Gerais was studied in its ergonomic aspects with regard to the layout. With this study it was possible to establish the best positioning of machines and jobs of employees. The analysis criteria used were: frequency of use, functional grouping, sequence of use, flow and intensity of preferred connections. An ideal arrangement in the workplace provides improved manufacturing quality and employee performance and consequently higher production yields.  相似文献   
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