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增强谐波辐射的一种新途径
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作者 丁武 束小建 杜祥琬 《强激光与粒子束》 EI CAS CSCD 1996年第2期286-290,共5页
提出用MOPA构型来增强谐波辐射。通过这个构型,人们可以用低能量电子束获得多种短波长和高功率相干光源。
关键词 谐波辐射 MOPA构型 自群聚 自由电子激光
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The impact of geomorphology of marsh creeks on fish assemblage in Changjiang River estuary 被引量:1
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作者 金斌松 许旺 +2 位作者 郭立 陈家宽 傅萃长 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第2期469-479,共11页
Tidal marshes are an important habitat and nursery area for fi sh.In the past few decades,rapid economic development in the coastal areas of China has led to the interruption and destruction of an increasing number of... Tidal marshes are an important habitat and nursery area for fi sh.In the past few decades,rapid economic development in the coastal areas of China has led to the interruption and destruction of an increasing number of tidal marshes.The growing interest in tidal marsh restoration has increased the need to understand the relationship between geomorphological features and fi sh assemblages in the design of marsh restoration projects.We studied temporal variations in,and the effects of creek geomorphological features on,the estuarine tidal creek fi sh community.Using modifi ed channel nets,we sampled fi sh monthly from March 2007 to February 2008 from seven tidal creeks along an intertidal channel system in Chongming Dongtan National Nature Reserve.Fourteen creek geomorphological variables were measured or derived to characterize intertidal creek geomorphological features.The Gobiidae,with 10 species,was the most speciesrich family.The most abundant fi sh species were Liza affi nis,Chelon haematocheilus,and Lateolabrax maculatus.The fi sh community was dominated by juvenile marine transients,which comprised about 80% of the total catch.The highest abundance of fi sh occurred in June and July,and the highest biomass occurred in December.Canonical redundancy analyses demonstrated that depth,steepness,cross-sectional area,and volume signifi cantly affected the fi sh species assemblage.L.affi nis favored small creeks with high elevations.Synechogobius ommaturus,Acanthogobius luridus,and Carassius auratus preferred deep,steep creeks with a large cross-sectional area and volume.These fi ndings indicate that the geomorphological features of tidal creeks should be considered in the conservation and sustainable management of fi sh species and in the restoration of salt marshes. 展开更多
关键词 intertidal environment habitat selection GEOMORPHOLOGY RESTORATION salt marshes Changjiang (Yangtze) River estuary
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Single Image Super-Resolution by Clustered Sparse Representation and Adaptive Patch Aggregation
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作者 黄伟 肖亮 +2 位作者 韦志辉 费选 王凯 《China Communications》 SCIE CSCD 2013年第5期50-61,共12页
A Single Image Super-Resolution (SISR) reconstruction method that uses clustered sparse representation and adaptive patch aggregation is proposed. First, we randomly extract image patch pairs from the training images,... A Single Image Super-Resolution (SISR) reconstruction method that uses clustered sparse representation and adaptive patch aggregation is proposed. First, we randomly extract image patch pairs from the training images, and divide these patch pairs into different groups by K-means clustering. Then, we learn an over-complete sub-dictionary pair offline from corresponding group patch pairs. For a given low-resolution patch, we adaptively select one sub-dictionary to reconstruct the high resolution patch online. In addition, non-local self-similarity and steering kernel regression constraints are integrated into patch aggregation to improve the quality of the recovered images. Experiments show that the proposed method is able to realize state-of-the-art performance in terms of both objective evaluation and visual perception. 展开更多
关键词 super-resolution sparse representation non-local means steering kernel regression patch aggregation
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Adaptive Clustering Algorithm by Ants' Optimization
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作者 Li Tu Ling Chen Jie Shen 《Journal of Systems Science and Information》 2007年第4期375-388,共14页
Inspired by the swarm intelligence in self-organizing behavior of real ant colonies, various ant-based algorithms were proposed recently for many research fields in data mining such as clustering. Compared with the pr... Inspired by the swarm intelligence in self-organizing behavior of real ant colonies, various ant-based algorithms were proposed recently for many research fields in data mining such as clustering. Compared with the previous clustering approaches such as K-means, the main advantage of ant-based clustering algorithms is that no additional information is needed, such as the initial partitioning of the data or the number of clusters. In this paper, we present an adaptive ant clustering algorithm ACAD. The algorithm uses a digraph where the vertexes represent the data to be clustered. The weighted edges represent the acceptance rate between the two data it connected. The pheromone on the edges is adaptively updated by the ants passing it. Some edges with less pheromone are progressively removed under a threshold in the process. Strong connected components of the final digraph are extracted as clusters. Experimental results on several real datasets and benchmarks indicate that ACAD is conceptually simpler, more efficient and more robust than previous research such as the classical K-means clustering algorithm and LF algorithm which.is also based on ACO 展开更多
关键词 CLUSTERING DIGRAPH ant-based K-MEANS
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