近年来,以微博、微信、Facebook为代表的社交网络不断发展,网络表示学习引起了学术界和工业界的广泛关注.传统的网络表示学习模型利用图矩阵表示的谱特性,由于其效率低下、效果不佳,难以应用到真实网络中.近几年,基于神经网络的表示学...近年来,以微博、微信、Facebook为代表的社交网络不断发展,网络表示学习引起了学术界和工业界的广泛关注.传统的网络表示学习模型利用图矩阵表示的谱特性,由于其效率低下、效果不佳,难以应用到真实网络中.近几年,基于神经网络的表示学习方法因算法效率高、较好地保存了网络结构信息,逐渐成为网络表示学习的主流算法.网络中的节点因为不同类型的关系而相互连接,这些关系里隐藏了非常丰富的信息(如兴趣、家人),但所有现存方法都没有区分节点之间边的关系类型.提出一种能够编码这种关系信息的无监督网络表示学习模型NEES(network embedding via edge sampling).首先,通过边采样得到能够反映边关系类型信息的边向量;其次,利用边向量为图中每个节点学习到一个低维表示.分别在几个真实网络数据上进行了多标签分类、边预测等任务,实验结果表明:在绝大多数情况下,该方法都表现最优.展开更多
In this paper, a sampling adaptive for block compressed sensing with smooth projected Landweber based on edge detection （SA-BCS-SPL-ED） image reconstruction algorithm is presented. This algorithm takes full advantag...In this paper, a sampling adaptive for block compressed sensing with smooth projected Landweber based on edge detection （SA-BCS-SPL-ED） image reconstruction algorithm is presented. This algorithm takes full advantage of the characteristics of the block compressed sensing, which assigns a sampling rate depending on its texture complexity of each block. The block complexity is measured by the variance of its texture gradient, big variance with high sampling rates and small variance with low sampling rates. Meanwhile, in order to avoid over-sampling and sub-sampling, we set up the maximum sampling rate and the minimum sampling rate for each block. Through iterative algorithm, the actual sampling rate of the whole image approximately equals to the set up value. In aspects of the directional transforms, discrete cosine transform （DCT）, dual-tree discrete wavelet transform （DDWT）, discrete wavelet transform （DWT） and Contourlet （CT） are used in experiments. Experimental results show that compared to block compressed sensing with smooth projected Landweber （BCS-SPL）, the proposed algorithm is much better with simple texture images and even complicated texture images at the same sampling rate. Besides, SA-BCS-SPL-ED-DDWT is quite good for the most of images while the SA-BCS-SPL-ED-CT is likely better only for more-complicated texture images.展开更多
文摘近年来,以微博、微信、Facebook为代表的社交网络不断发展,网络表示学习引起了学术界和工业界的广泛关注.传统的网络表示学习模型利用图矩阵表示的谱特性,由于其效率低下、效果不佳,难以应用到真实网络中.近几年,基于神经网络的表示学习方法因算法效率高、较好地保存了网络结构信息,逐渐成为网络表示学习的主流算法.网络中的节点因为不同类型的关系而相互连接,这些关系里隐藏了非常丰富的信息(如兴趣、家人),但所有现存方法都没有区分节点之间边的关系类型.提出一种能够编码这种关系信息的无监督网络表示学习模型NEES(network embedding via edge sampling).首先,通过边采样得到能够反映边关系类型信息的边向量;其次,利用边向量为图中每个节点学习到一个低维表示.分别在几个真实网络数据上进行了多标签分类、边预测等任务,实验结果表明:在绝大多数情况下,该方法都表现最优.
基金supported by the National Natural Science Foundation of China (61071091, 61071166)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institution-Information and Communication Engineering
文摘In this paper, a sampling adaptive for block compressed sensing with smooth projected Landweber based on edge detection （SA-BCS-SPL-ED） image reconstruction algorithm is presented. This algorithm takes full advantage of the characteristics of the block compressed sensing, which assigns a sampling rate depending on its texture complexity of each block. The block complexity is measured by the variance of its texture gradient, big variance with high sampling rates and small variance with low sampling rates. Meanwhile, in order to avoid over-sampling and sub-sampling, we set up the maximum sampling rate and the minimum sampling rate for each block. Through iterative algorithm, the actual sampling rate of the whole image approximately equals to the set up value. In aspects of the directional transforms, discrete cosine transform （DCT）, dual-tree discrete wavelet transform （DDWT）, discrete wavelet transform （DWT） and Contourlet （CT） are used in experiments. Experimental results show that compared to block compressed sensing with smooth projected Landweber （BCS-SPL）, the proposed algorithm is much better with simple texture images and even complicated texture images at the same sampling rate. Besides, SA-BCS-SPL-ED-DDWT is quite good for the most of images while the SA-BCS-SPL-ED-CT is likely better only for more-complicated texture images.
