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61.
This paper presents a nonlinear dynamic model for simulation and analysis of a kind of parametrically excited vibration of
stay cable caused by support motion in cable-stayed bridges. The sag, inclination angle of the stay cable are considered in
the model, based on which, the oscillation mechanism and dynamic response characteristics of this kind of vibration are analyzed
through numerical, calculation. It is noted that parametrically excited oscillation of a stay cable with certain, sag, inclination
angle and initial static tension force may occur in cable-stayed bridges due to deck vibration under the condition that the
natural frequency of a cable approaches to about half of the, first model frequency of the bridge deck system. A new vibration
control system installed on the cable anchorage is proposed as a possible damping system to suppress, the cable parametric
oscillation. The numerical calculation results showed that with the use of this damping system, the cable oscillation due
to the vibration of the deck and/or towers will be considerably reduced.
Project supported by National Natural Science Foundation of China (No. 59978044) 相似文献
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Teachers in China are regarded as vulnerable to sociopolitical changes. This paper, however, focuses on the resilience and innovativeness of state‐selected expert teachers – the recipients of the Special Rank Teacher (SRT) award. This award was the product of a transitional period in the aftermath of the Cultural Revolution, and was an act of rehabilitation for the teaching profession. Using a biographical approach, this paper analyses how the intentions of the award were reflected in the choice of recipients. It contributes to a deeper understanding of teachers in China and the notion of teaching excellence that the state‐recognised teachers exemplify. 相似文献
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The education for sustainable development movement in Japan: a political perspective 总被引:2,自引:2,他引:0
The Japanese government provided various political opportunities for non‐governmental groups and individuals in Japan to ‘jointly propose’ policy on education and sustainable development at the World Summit on Sustainable Development, Johannesburg, 2002. These opportunities resulted in the emergence of the Japanese education for sustainable development (ESD) movement, and the crystallisation of a broader proposal that led to the initiation of the UN Decade of ESD (2005–2014). In this paper, we trace the history of these two outcomes, arguing that the opportunities, developed through the coordination of non‐governmental groups by government, took place within, rather than broadened or confronted, the government’s scope of interests. While the paper illustrates how the government’s continued support was crucial to the development of the ESD movement and the UN Decade, and the movement has met with considerable achievements thus far (via its collective challenges to conventional education in a sustainability context in Japan), we argue that recognition of the political opportunity structures that affect the movement’s further development remains crucial. In particular, we argue for close attention to the significance of a corporatist framing of this emerging civil society movement in Japan by the national government, and call for further political and historical analysis of ESD movements and their relations with government, around the world. 相似文献
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A group recommendation system for online communities 总被引:1,自引:0,他引:1
Jae Kyeong Kim Hyea Kyeong Kim Hee Young Oh Young U. Ryu 《International Journal of Information Management》2010
Online communities are virtual spaces over the Internet in which a group of people with similar interests or purposes interact with others and share information. To support group activities in online communities, a group recommendation procedure is needed. Though there have been attempts to establish group recommendation, they focus on off-line environments. Further, aggregating individuals’ preferences into a group preference or merging individual recommendations into group recommendations—an essential component of group recommendation—often results in dissatisfaction of a small number of group members while satisfying the majority. To support group activities in online communities, this paper proposes an improved group recommendation procedure that improves not only the group recommendation effectiveness but also the satisfaction of individual group members. It consists of two phases. The first phase was to generate a recommendation set for a group using the typical collaborative filtering method that most existing group recommendation systems utilize. The second phase was to remove irrelevant items from the recommendation set in order to improve satisfaction of individual members’ preferences. We built a prototype system and performed experiments. Our experiment results showed that the proposed system has consistently higher precision and individual members are more satisfied. 相似文献
68.
Question answering (QA) aims at finding exact answers to a user’s question from a large collection of documents. Most QA systems combine information retrieval with extraction techniques to identify a set of likely candidates and then utilize some ranking strategy to generate the final answers. This ranking process can be challenging, as it entails identifying the relevant answers amongst many irrelevant ones. This is more challenging in multi-strategy QA, in which multiple answering agents are used to extract answer candidates. As answer candidates come from different agents with different score distributions, how to merge answer candidates plays an important role in answer ranking. In this paper, we propose a unified probabilistic framework which combines multiple evidence to address challenges in answer ranking and answer merging. The hypotheses of the paper are that: (1) the framework effectively combines multiple evidence for identifying answer relevance and their correlation in answer ranking, (2) the framework supports answer merging on answer candidates returned by multiple extraction techniques, (3) the framework can support list questions as well as factoid questions, (4) the framework can be easily applied to a different QA system, and (5) the framework significantly improves performance of a QA system. An extensive set of experiments was done to support our hypotheses and demonstrate the effectiveness of the framework. All of the work substantially extends the preliminary research in Ko et al. (2007a). A probabilistic framework for answer selection in question answering. In: Proceedings of NAACL/HLT. 相似文献
69.
There are many contingent valuation (CV) studies to estimate the economic benefits of cultural heritage, but few provided advice on the design of financial products for cultural heritage assets. This paper conducted conjoint and willingness-to-pay (WTP) analyses for providing the design implication of these financial products. We calculated WTP for each attribute. The result of conjoint analysis shows that people prefer a short period of investment, high-expected rate of return and small amount of money invested. Only the amount invested and the rate of return on investment are significant to estimate WTP for these financial products. 相似文献
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