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排序方式: 共有109条查询结果,搜索用时 171 毫秒
1.
Financial stress index (FSI) is considered to be an important risk management tool to quantify financial vulnerabilities. This paper proposes a new framework based on a hybrid classifier model that integrates rough set theory (RST), FSI, support vector regression (SVR) and a control chart to identify stressed periods. First, the RST method is applied to select variables. The outputs are used as input data for FSI–SVR computation. Empirical analysis is conducted based on monthly FSI of the Federal Reserve Bank of Saint Louis from January 1992 to June 2011. A comparison study is performed between FSI based on the principal component analysis and FSI–SVR. A control chart based on FSI–SVR and extreme value theory is proposed to identify the extremely stressed periods. Our approach identified different stressed periods including internet bubble, subprime crisis and actual financial stress episodes, along with the calmest periods, agreeing with those given by Federal Reserve System reports.  相似文献   
2.
A comparative study conducted in the Sudan illustrated both the potential of a nutrition education program for pregnant women and the many obstacles to creating more optimal maternal nutrition. Included in the study were 1200 women 18-34 years of age attending the Khartoum Province Model Clinic for a minimum of 5 prenatal visits. 83.3% were Muslims and 48.2% were illiterate. The 60 women who comprised the experimental group were exposed to individual nutrition counseling and home visits. Overall, 70% of subjects were anemic, 27% had malaria, and 18% were hookworm. The average weight gain during pregnancy was 4.5 kgs; 25.0% of controls and 20.0% of those in the experimental group gained 3.5-4.0 kgs, 18.3% of controls and 33.3% of experimental subjects gained 4.5-5.0 kgs, and 23.3% of controls and 30.0% of those in the experimental groups gained 5.5 kgs or more. 53.0% of controls and 61.7% of women exposed to nutrition education breastfed for at least 6 months, and 70% of women in the former group and 95% of those in the latter had enrolled their infants in an immunization program. A baseline nutrition questionnaire revealed widespread misinformation, especially a belief that pregnant women should reduce their food intake from 3 to 1-2 meals per day to prevent the fetus from growing too large and making labor difficult. Foods such as fermented sorghum products, fresh fish, and water melon were regarded as abortifacients and avoided, while hot pepper, sour milk, and cola sodas were considered nutritious. Consumption was self-reported to be poor for milk products by 25% of mothers, for meat by 16%, and for fruits and vegetables by 40% Although the educational intervention increased women's knowledge of basic nutrition, it had only a minimal effect on actual practice. This finding is assumed to reflect the widespread belief that men and their guests should be given preference in food allocation, poverty, and avoidance, on the basis of tradition, of many healthy foods. Since 72% of women reported ownership of a television, use if this medium is recommended for nutrition education.  相似文献   
3.
This paper is concerned with the Bayesian estimation parameters of the stochastic SIR (Susceptible-Infective-Removed) epidemic model from the trajectory data. Specifically, the data from the count of both infectives and susceptibles is assumed to be available on some time grid as the epidemic progresses. The diffusion approximation of the appropriate jump process is then used to estimate missing data between every pair of observation times. If the time step of imputations is small enough, we derive the posterior distributions of the infection and recovery rates using the Milstein scheme. The paper also presents Markov-chain Monte Carlo (MCMC) simulation that demonstrates that the method provides accurate estimates, as illustrated by the synthetic data from SIR epidemic model and the real data.  相似文献   
4.
Augmented Reality focuses on the enrichment of the user's natural field of view by consistent integration of text, symbols and interactive three-dimensional objects in real time. Placing virtual objects directly into the user's view in a natural context empowers highly dynamic applications. On the other hand, this necessitates deliberate choice of information design and density, in particular for deployment in hazardous environments like military combat scenarios. As the amount of information needed is not foreseeable and strongly depends on the individual mission, an appropriate system must offer adequate adaptation capabilities. The paper presents a prototypical, vehicle-mountable Augmented Reality vision system, designed for enhancing situation awareness in stressful urban warfare scenarios. Tracking, as one of the most crucial challenges for outdoor Augmented Reality, is accomplished by means of a Differential-GPS approach while the type of display to attach can be modified, ranging from ocular displays to standard LCD mini-screens. The overall concept also includes envisioning of own troops (blue forces), for which a multi-sensor tracking approach has been chosen. As a main feature, the system allows switching between different information categories, focusing on friendly, hostile, unidentified or neutral data. Results of an empirical study on the superiority of an in-view navigation cue approach conclude the paper.  相似文献   
5.
Objective: Colleges should aim to cultivate healthy behaviors among students by addressing alterations in wellness students view as important. The purpose of this study was to determine the self-perceived wellness-related concerns and behaviors of college students. Participants: Thirty-seven undergraduate students participated in this study between January and March 2017. Methods: Focus groups served as a data collection method. Groups were recorded and transcribed verbatim. Directed and conventional approaches to data analyses were employed. Results: Participants expressed concern regarding four campus wellness topics: nutrition, economics, mental health, and campus safety. Participants offered solutions for improving campus wellness, representing a fifth theme. Conclusions: Health concerns for college students and realistic solutions to address concerns were identified across focus groups. Overall, students cared about their own health, as well as the well-being of other students. Future directions include conducting a Web-based survey among students to assess prevalence and impact of select health and wellness topics.  相似文献   
6.
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   
7.
This paper studies the role of emotions in creating spectacular revolt situations. We underline the travelling competence of sentiments and their power in crafting trans-local moments of embodied resistance. In contemporary Moroccan society, the adaptation of the Bouazizian style of protest has been a reaction to the prevailing feelings of worthlessness gripping the common citizen. The images of wasted beings in the post-2011 atmosphere have been associated with instances of social insurgence, by individuals who attempt self-immolation, or citizens treated by figures from the centre (e.g. police, public figures) in a way that inculcate in them powerful feelings of abjection, after which they feel irreparably delinked from their sense of humanity. This paper seeks to demonstrate how practices of al-hogra (humiliation) have produced cultural forms of abjection that could also be traced in the way common people inferiorize one another in everyday life through the use of a terminology of trash. By disclosing people’s non-subtle armaments of protest (i.e. self-immolation), we contend that resistance and its various trances, as well as the emotions that prompt them, have their origin in the reality of the body, realistic visions of the body owner and his/her awareness of the potential for realization (through it). Hence we will examine how vulnerable people manipulate the three conditions of corporeality, corporealism and corporealization, to subvert the humiliation and symptoms of social death imposed on them by the regime.  相似文献   
8.
This article is an attempt at developing a lens through which political culture in Mozambique can be analysed, described and interpreted. It is based on the notion of a political teleology that emerged out of the conditions within which the country fought for its independence. The paper argues that violence in a symbolic and physical form played a central role in the constitution of this political teleology by, on the one hand, allowing the liberation movement to produce an account of Mozambican history which both gave legitimacy to its own struggle while at the same time undermining alternative accounts and, on the other, set the scene for the implementation of a national project that came to be primarily concerned with the reproduction of the claim to power of the liberation movement. Forty years of independence in Mozambique offer an ideal time frame to attempt the construction of such a lens.  相似文献   
9.
Abstract

This paper examines sites of informal trade in Morocco, what the locals call joutiat (sing. joutia). It departs from the semantic and real-world politics of disposability (of objects and people), to unravel the underlying meanings of the joutia as a contested space. The joutia is a place where not only objects of value wait to be rediscovered, but also where invisible and socially underprivileged beings perpetually ransack heaps of trade articles to unmask a hidden gem. I provide an account of the social dynamics of abjection inside/outside the joutia, arresting the ambivalence of objects, which – as they keep vacillating between value and lack of it – turn into “treashure”. I use this neologism, which combines two antithetical terms (trash and treasure), to (a) put into question issues of visibility and invisibility in informal Moroccan enterprises, (b) crystallise the paradoxes of being and becoming inside and outside the market arena, (c) offer a profound reflection on the absurd nature of value in the informal landscapes of (non)random economy and (d) demonstrate that the forms of abjection inside the market have their origin elsewhere.  相似文献   
10.
In this paper, we propose a new methodology for solving stochastic inversion problems through computer experiments, the stochasticity being driven by a functional random variables. This study is motivated by an automotive application. In this context, the simulator code takes a double set of simulation inputs: deterministic control variables and functional uncertain variables. This framework is characterized by two features. The first one is the high computational cost of simulations. The second is that the probability distribution of the functional input is only known through a finite set of realizations. In our context, the inversion problem is formulated by considering the expectation over the functional random variable. We aim at solving this problem by evaluating the model on a design, whose adaptive construction combines the so-called stepwise uncertainty reduction methodology with a strategy for an efficient expectation estimation. Two greedy strategies are introduced to sequentially estimate the expectation over the functional uncertain variable by adaptively selecting curves from the initial set of realizations. Both of these strategies consider functional principal component analysis as a dimensionality reduction technique assuming that the realizations of the functional input are independent realizations of the same continuous stochastic process. The first strategy is based on a greedy approach for functional data-driven quantization, while the second one is linked to the notion of space-filling design. Functional PCA is used as an intermediate step. For each point of the design built in the reduced space, we select the corresponding curve from the sample of available curves, thus guaranteeing the robustness of the procedure to dimension reduction. The whole methodology is illustrated and calibrated on an analytical example. It is then applied on the automotive industrial test case where we aim at identifying the set of control parameters leading to meet the pollutant emission standards of a vehicle.  相似文献   
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