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哈齐高速铁路对区域可达性及经济联系的影响研究 被引量:13
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作者 焦红 方雅淳 《铁道运输与经济》 北大核心 2018年第11期7-12,共6页
哈齐高速铁路是哈大齐工业走廊交通体系中的重要组成部分,对区域联动和空间重组产生深刻影响。选取可达性模型,测度哈齐高速铁路的开通对区域可达性水平的影响;再根据距离引力模型测量城市之间的经济联系强度,并利用经济隶属度,分析各... 哈齐高速铁路是哈大齐工业走廊交通体系中的重要组成部分,对区域联动和空间重组产生深刻影响。选取可达性模型,测度哈齐高速铁路的开通对区域可达性水平的影响;再根据距离引力模型测量城市之间的经济联系强度,并利用经济隶属度,分析各个城市经济联系方向,从而探究哈齐高速铁路背景下黑龙江经济格局的演变。研究结果表明:哈齐高速铁路的开通大幅度优化了区域沿线城市之间的可达性水平;同时,哈齐高速铁路也加大了沿线城市间的经济联系强度,区域经济格局逐渐呈现"多中心化"的趋势;高速铁路轴带极化现象明显,部分空间隶属关系模糊。 展开更多
关键词 哈齐高速铁路 可达性 经济联系强度 经济隶属度 动态演变分析
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Self-Adaptive Topic Model: A Solution to the Problem of "Rich Topics Get Richer" 被引量:1
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作者 FANG Ying 《China Communications》 SCIE CSCD 2014年第12期35-43,共9页
The problem of "rich topics get richer"(RTGR) is popular to the topic models,which will bring the wrong topic distribution if the distributing process has not been intervened.In standard LDA(Latent Dirichlet... The problem of "rich topics get richer"(RTGR) is popular to the topic models,which will bring the wrong topic distribution if the distributing process has not been intervened.In standard LDA(Latent Dirichlet Allocation) model,each word in all the documents has the same statistical ability.In fact,the words have different impact towards different topics.Under the guidance of this thought,we extend ILDA(Infinite LDA) by considering the bias role of words to divide the topics.We propose a self-adaptive topic model to overcome the RTGR problem specifically.The model proposed in this paper is adapted to three questions:(1) the topic number is changeable with the collection of the documents,which is suitable for the dynamic data;(2) the words have discriminating attributes to topic distribution;(3) a selfadaptive method is used to realize the automatic re-sampling.To verify our model,we design a topic evolution analysis system which can realize the following functions:the topic classification in each cycle,the topic correlation in the adjacent cycles and the strength calculation of the sub topics in the order.The experiment both on NIPS corpus and our self-built news collections showed that the system could meet the given demand,the result was feasible. 展开更多
关键词 topic model infinite Latent Dirichlet Allocation Dirichlet process topic evolution
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