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61.
This paper discusses a new algebraic model of electrical networks by which a deeper understanding is achieved of the interrelation existing between a system of independent cut sets and the corresponding system of independent “contours”, in the sense of orthogonal network theory (1).The new model allows, by a redefinition of f-cut sets, to give an interpretation in terms of linear graph theory to the inverse connection matrix A.sb, i.e. to the transformation matrix between voltages in the orthogonal and the primitive reference frames, for a general choice of independent contours.Furthermore, a directly algebraic derivation of the voltage transformation is presented, recalling the properties of dual vector spaces and without invoking the principle of invariance of the instantaneous power.  相似文献   
62.
This paper proposes a novel query expansion method to improve accuracy of text retrieval systems. Our method makes use of a minimal relevance feedback to expand the initial query with a structured representation composed of weighted pairs of words. Such a structure is obtained from the relevance feedback through a method for pairs of words selection based on the Probabilistic Topic Model. We compared our method with other baseline query expansion schemes and methods. Evaluations performed on TREC-8 demonstrated the effectiveness of the proposed method with respect to the baseline.  相似文献   
63.
Education and Information Technologies - Integrating computer science (CS) into school curricula has become a worldwide preoccupation. Therefore, we present a CS and Robotics integration model and...  相似文献   
64.
This paper elaborates a view on knowledge as a result of a combinatorial search activity, so as to investigate its effects on economic growth at the regional level. Empirical estimations corroborate the hypothesis that knowledge coherence and variety, besides the traditional measure of knowledge stock, matter in shaping regional economic performances. The check for spatial dependence suggests that cross-regional externalities exert additional triggering effects on growth, without debasing the effects of knowledge properties. Important policy implications stem from the analysis, in that regional innovation strategies should be carefully coordinated so as to reach a higher degree of internal coherence and trigger economic performances.  相似文献   
65.
This work studies verbal conflict between parents and preadolescents through analysis of family dinnertime conversations. We move from the assumption that verbal conflict is an educational instrument of interaction and a tool of socialization. The aim of the research is to analyze the participants' strategies in situations of conflict and to highlight the relations between parents and preadolescents in these specific situations. The data collection methodology is mainly ethnographical: videotape recordings of Italian middle class family dinners (the families were selected as being dual career ones with two children) were fully transcribed and codified following the approach of Conversation Analysis. The results of the quantitative (by the use of the log-linear models) and qualitative analyses confirm the importance of verbal conflict in family context as a particular cultural strategy of relationships between parents and preadolescents. The analytical data underline the relations between different aspects of conflict and the pragmatic implications for all family members at dinnertime conversations.  相似文献   
66.
The bulk of today's (“preorder-,” “reward-,” “gift-,” and “donation-based”) crowdfunding raises funds for small, private entrepreneurial ventures without granting funders private claims to the projects’ income or the ability to guarantee the realization and delivery of project outcomes. We theorize and show empirically – via a mixed-method approach applied to a representative and remarkably informative case – that the payoff structure for crowdfunders, akin to a public good contribution problem, leads to the tangible value of main project outputs exerting little influence on contributions to crowdfunding. This then raises the question of which funder motivations fund seekers may have to address to crowdfund their projects. We demonstrate the especially large role of non-pecuniary motivations and pinpoint three particular motivations that profit-seeking entrepreneurs may stimulate to be financed through crowdfunding. The findings hold important implications for entrepreneurs’ crowdfunding strategies, platform design, and our understanding of how this funding institution works in general. The study also adds to emerging research on the implications of the public good nature of crowdfunding.  相似文献   
67.
Croplands are the single largest anthropogenic source of nitrous oxide (N2O) globally, yet their estimates remain difficult to verify when using Tier 1 and 3 methods of the Intergovernmental Panel on Climate Change (IPCC). Here, we re-evaluate global cropland-N2O emissions in 1961–2014, using N-rate-dependent emission factors (EFs) upscaled from 1206 field observations in 180 global distributed sites and high-resolution N inputs disaggregated from sub-national surveys covering 15593 administrative units. Our results confirm IPCC Tier 1 default EFs for upland crops in 1990–2014, but give a ∼15% lower EF in 1961–1989 and a ∼67% larger EF for paddy rice over the full period. Associated emissions (0.82 ± 0.34 Tg N yr–1) are probably one-quarter lower than IPCC Tier 1 global inventories but close to Tier 3 estimates. The use of survey-based gridded N-input data contributes 58% of this emission reduction, the rest being explained by the use of observation-based non-linear EFs. We conclude that upscaling N2O emissions from site-level observations to global croplands provides a new benchmark for constraining IPCC Tier 1 and 3 methods. The detailed spatial distribution of emission data is expected to inform advancement towards more realistic and effective mitigation pathways.  相似文献   
68.

In this paper, we examine the attitudes toward integrating work and family in a sample of 247 teachers in Switzerland and Israel. More particularly, we focus on the national context’s role in mediating the relations between professional and private spheres. The data were collected by a questionnaire implemented and administered in the two countries. The analysis reveals differences between Israeli and Swiss teachers regarding the importance of attribution to life roles and their attitudes toward conflict and facilitation. Findings suggest new insights into the consideration of cultural elements in shaping the teachers’ attitudes toward the integration of family and work.

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69.
At the end of 2019, the Covid-19 pandemic spread caused restrictions in business and social spheres. Higher education was also severely affected: universities and medical schools moved online to distance learning and laboratory facilities closed. Questions arise about the long-term effects of this pandemic on anatomical education. In this systematic review, the authors investigated whether or not anatomical educators were able to deliver anatomical knowledge during this pandemic. They also discuss the challenges that anatomical education has faced over the last year. The search strategy was conducted between July 2020 and July 2021. Two hundred and one records were identified, and a total of 79 studies were finally included. How best to deliver anatomy to students remains a moot point. In the last years, the advent of new technologies has raised the question of the possible overcoming of dissection as the main instrument in anatomical education. The Covid-19 pandemic further sharpened the debate. Remote learning enhanced the use of technologies other than cadaveric dissection to teach anatomy. Moreover, from the analyzed records it appears that both from students' perspective as well as teachers' there is a clear tear between those who endorse dissection and those who believe it could be easily overcome or at least integrated by virtual reality and online learning. The authors strongly believe that the best anatomy teaching practice requires the careful adaptation of resources and methods. Nevertheless, they support cadaveric dissection and hope that it will not be replaced entirely as a result of this pandemic.  相似文献   
70.
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