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161.
国内外医学期刊网站现状及分析 总被引:3,自引:0,他引:3
通过互联网了解国内外不同医学期刊网站建设的现状,对比发现国内与国外医学期刊的网站建设差距明显.对差距产生的原因做一分析并提出改进建议. 相似文献
162.
《Research Policy》2019,48(10):103582
In the light of pressing societal challenges such as climate change and resource scarcity, scholars are increasingly interested in studying policy mixes in the context of sustainability transitions. However, despite numerous conceptual advances and empirical insights, researchers still lack universal criteria or accepted heuristics for delineating policy mixes in these complex policy spaces. We address this gap by conducting an extensive review of the literature, synthesizing best practices, and developing an analytical framework that provides researchers with two archetypical methodological approaches. The top-down approach builds on the idea that the elements of a policy mix originate from an overarching strategic intent. By contrast, the bottom-up approach starts from the definition of a focal impact domain that is affected by a range of policy instruments. For each approach, we outline a systematic analytical procedure, then implement it to scrutinize how policy affects the emerging technological domain of energy storage in California. We find that each approach has particular advantages that render it useful for certain policy mix analyses. Discussing how researchers may choose between the two approaches or leverage their complementarities, we seek to provide the basis for a consistent research program building on the policy mix framework. 相似文献
163.
Gamification is here to stay, and tourism and hospitality online review platforms are taking advantage of it to attract travelers and motivate them to contribute to their websites. Yet, literature in tourism is scarce in studying how effectively is users’ behavior changing through gamification features. This research aims at filling such gap through a data-driven approach based on a large volume of online reviews (a total of 67,685) collected from TripAdvisor between 2016 and 2017. Four artificial neural networks were trained to model title and review’s word length, and title and review’s sentiment score, using as input 12 gamification features used in TripAdvisor including points and badges. After validating the accuracy of the model for extracting knowledge, the data-based sensitivity analysis was applied to understand how each of the 12 features contributed to explaining review length and its sentiment score. Three badge features were considered the most relevant ones, including the total number of badges, the passport badges, and the explorer badges, providing evidence of a relation between gamification features and traveler’s behavior when writing reviews. 相似文献
164.
The diffusion of knowledge within organizations provides opportunities for interpersonal co-operation, improves creative ability and therefore leads to competitive advantage. Focus of prior literature on knowledge diffusion has been on identifying factors that influence individuals' behavioral intentions to seek and share knowledge. However, knowledge diffusion as an enigmatic, emergent and organizational-level process is more than the simple aggregation of individual attributes and needs to be further investigated. Accordingly, this study focuses on three distinct system-level factors, i.e., architectures of connections among individuals, distributions of knowledge roles and designs of selection mechanisms and analyses their effects on knowledge diffusion. To be more specific, we examine three distinct knowledge roles: seekers, contributors and brokers. We also distinguish between three types of selection mechanisms: objective selection mechanisms, feedback-based selection mechanisms and random selection mechanisms. By conducting agent-based simulations on four representative networks, i.e., regular networks, random networks, small-world networks and scale-free networks, our results show that the optimal knowledge diffusion performance can be achieved on scale-free networks where all agents implement objective mechanisms and show characteristics of brokers. Moreover, our results (a) highlight the significance of brokers, (b) illustrate the superiority of objective selection rules and (c) demonstrate that scale-free networks provide an optimal framework for knowledge diffusion. Furthermore, we also find the interdependent relevance of these three factors to knowledge diffusion and propose a qualitative explanation of these findings. 相似文献
165.
166.
基于时序LAI的地块尺度玉米长势监测方法 总被引:1,自引:0,他引:1
农作物长势监测可为田间管理措施调整和农作物产量预测提供及时、准确的信息。针对中国地块面积小的情况,本文采用中高分辨率的多源遥感影像Landsat-7 ETM+影像、Landsat-8 OLI影像、高分一号(GF-1)影像、HJ-1 A/B卫星影像为数据源;针对目前过多依赖NDVI等易饱和植被指数的问题,研究中选择LAI为长势监测指标,并利用PROSAIL辐射传输模型反演LAI,以保证该指标的准确性;长势实时监测采用RPLAI、LVCI、MLVCI指标,从多个角度表征长势的实时监测结果。研究结果表明:①同时相GF-1影像和Landsat-8 OLI影像具有较高的相关性,2种影像在近红外波段、绿波段、红波段的相关性决定系数R2分别为0.9320、0.7339、0.7153。②基于PROSAIL模型可以反演得到高精度的LAI,基于时序LAI的玉米生长过程监测结果表明:2015年,黑龙江农垦总局八五二农场6月下旬玉米冠层LAI快速增加,7月底、8月初LAI达到最大,并持续一段时间,进入8月下旬后,LAI开始下降。③利用RPLAI、LVCI、MLVCI指标对研究区玉米长势实时监测的结果表明,与2011—2014年相比,2015年八五二农场玉米长势一般,研究区北部长势较好,南部区域长势较差。从研究结果我们得出如下结论:①同时相的Landsat-8 OLI影像与GF-1遥感影像,经过相对辐射定标后可以结合使用于农作物长势监测中;②利用PROSAIL模型反演时序LA,可用于地块尺度的农作物长势精细监测。 相似文献
167.
[目的/意义]在非结构化语料集中抽取知识要素,是实现知识图谱的重要环节,本文探索了应用深度学习中的卷积神经网络(CNN)模型进行旅游领域知识关系抽取方法。[方法/过程]抓取专业旅游网站的相关数据建立语料库,对部分语料进行人工标注作为训练集和测试集,通过Python语言编程实现分词、向量化及CNN模型,进行关系抽取实验。[结果/结论]实验结果表明,应用卷积神经网络对非结构化的旅游文本进行关系抽取时能够取得满意的效果(Precision 0.77,Recall 0.76,F1-measure 0.76)。抽取结果通过人工校对进行优化后,可以为旅游知识图谱构建、领域本体构建等工作奠定基础。 相似文献
168.
Alejandra Mizala 《教育政策杂志》2020,35(4):529-555
ABSTRACT Reformers in developing countries increasingly seek to raise education quality. Yet we know little about the politics of improving education. One significant and instructive case of reforms designed to boost education quality comes from Chile, where in 2016 the government enacted a sweeping reform of teaching careers. This paper first uses a quantitative analysis of appearances in the news to identify key stakeholders and then turns to process tracing to analyze how and when these stakeholders influenced reform dynamics. Comparatively, the Chilean case differs from similar reforms elsewhere in Latin America due to the absence of business, the strong role of policy networks, and the final negotiated settlement with the teacher union. Theoretically, the analysis confirms general theories that emphasize the roles of distributive politics and policy networks. 相似文献
169.
Political polarization remains perhaps the “greatest barrier” to effective COVID-19 pandemic mitigation measures in the United States. Social media has been implicated in fueling this polarization. In this paper, we uncover the network of COVID-19 related news sources shared to 30 politically biased and 2 neutral subcommunities on Reddit. We find, using exponential random graph modeling, that news sources associated with highly toxic – “rude, disrespectful” – content are more likely to be shared across political subreddits. We also find homophily according to toxicity levels in the network of online news sources. Our findings suggest that news sources associated with high toxicity are rewarded with prominent positions in the resultant network. The toxicity in COVID-19 discussions may fuel political polarization by denigrating ideological opponents and politicizing responses to the COVID-19 pandemic, all to the detriment of mitigation measures. Public health practitioners should monitor toxicity in public online discussions to familiarize themselves with emerging political arguments that threaten adherence to public health crises management. We also recommend, based on our findings, that social media platforms algorithmically promote neutral and scientific news sources to reduce toxic discussion in subcommunities and encourage compliance with public health recommendations in the fight against COVID-19. 相似文献
170.
Within policy discourses, teachers are positioned as objects of reform who enact policies under rational systems of observation and accountability and are, therefore, situated as de-professionalized actors lacking expert knowledge. This research project asks relatively straight-forward questions: If practicing teachers were given a voice in political debates over urban education policy and reform, what would they say? What macro-level policy problems would they identify as being important? Findings indicate the primary policy problems include Systemic Inequity and Bad Policy. The primary policy solutions include, Schools as a Community Resource; Shared Decision-Making; Contextual Goals; and Time, Space and Resources. 相似文献