为了更有效地进行图像去噪,提出了一种基于分块奇异值分解(Singular value decomposition,SVD)的两级图像去噪方法,该方法首先将含噪图像中具有相似结构的图像块组织成具有很强相关性的图像块组;然后,利用二维奇异值分解去除图像块组中...为了更有效地进行图像去噪,提出了一种基于分块奇异值分解(Singular value decomposition,SVD)的两级图像去噪方法,该方法首先将含噪图像中具有相似结构的图像块组织成具有很强相关性的图像块组;然后,利用二维奇异值分解去除图像块组中每个相似块的内部相关性,利用一维奇异值分解去除相似图像块组之间的冗余;最后,通过硬阈值方法收缩变换系数实现图像与噪声的有效分离.为了进一步提高去噪效果,对含噪图像再次进行上述操作.不同的是,在第二级去噪过程中,相似图像块组根据第一级估计出的图像计算获得且相似图像块间的相关性通过离散余弦变换去除.仿真实验表明,提出的两级图像去噪算法不仅可以较大程度地去除图像噪声,还能有效保留图像细节,取得了良好的去噪效果.展开更多
针对未编码的多输入多输出(MIMO,Multi-Input Multi-Output)系统,提出一种复杂度适中的分组全分集全码率(GFDFR,Group-wise Full Diversity Full Rate)空时编码方案。该方案通过在发送端进行天线分组,各组独立编码,减小全分集全码率(FDF...针对未编码的多输入多输出(MIMO,Multi-Input Multi-Output)系统,提出一种复杂度适中的分组全分集全码率(GFDFR,Group-wise Full Diversity Full Rate)空时编码方案。该方案通过在发送端进行天线分组,各组独立编码,减小全分集全码率(FDFR,Full Diversity FullRate)编码块的大小从而降低系统编解码复杂度;在频率选择性信道中,进一步对子载波分组进行独立编码,获得频率分集(或多径分集),以适中的复杂度在不降低系统分集度的情况下保证了信息的全码率传输,是一种在MIMO信道中极具实用价值的空时编码方案。展开更多
AIM:To investigate the ezrin expression in normal colorectal mucosa and colorectal cancer tissues, and study the correlation between ezrin expression in colorectal cancer tissues and tumor invasion and metastasis.METH...AIM:To investigate the ezrin expression in normal colorectal mucosa and colorectal cancer tissues, and study the correlation between ezrin expression in colorectal cancer tissues and tumor invasion and metastasis.METHODS: Eighty paraffin-embedded cancer tissue samples were selected from primary colorectal adenocarcinoma. Twenty-eight patients had well-differentiated, 22 had moderately differentiated and 30 had poorly differentiated adenocarcinoma. Forty-five patients and 35 patients had lymph node metastasis. Forty-five patients were of Dukes A to B stage, and 35 were of C to D stage. Another 22 paraffi n-embedded tissue blocks of normal colorectal epithelium (>5 cm away from the edge of the tumor) were selected as the control group. All patients with colorectal cancer were treated surgically and diagnosed histologically, without preoperative chemotherapy or radiotherapy. The immunohistochemistry was used to detect the ezrin expression in paraffin-embedded normal colorectal mucosa tissues and colorectal cancer tissue samples.RESULTS: Ezrin expression in colorectal cancer was significantly higher than in normal colorectal mucosa (75.00% vs 9.09%, P<0.01), and there was a close relationship between ezrin expression and the degree of tumor differentiation, lymph node metastasis and Dukes stage (88.46% vs 50.00%, P<0.01; 94.28% vs 51.11%, P<0.01; 94.28% vs 51.11%, P<0.01).CONCLUSION: Ezrin expression is obviously higher in colorectal cancer tissues than in normal colorectal mucosa tissues, and the high level of ezrin expression is closely related to the colorectal cancer invasion and metastasis process.展开更多
This paper reviews three main perspectives of chunk analyses： traditional phraseological, psycholinguistic, and corpus linguistic perspectives. Traditional phraseological perspective focuses on syntactic and semantic...This paper reviews three main perspectives of chunk analyses： traditional phraseological, psycholinguistic, and corpus linguistic perspectives. Traditional phraseological perspective focuses on syntactic and semantic aspects of chunks and its most important criteria of chunk identifications and classifications are compositionality and frozenness/fixedness. Psycholinguistic perspective focuses on the psychological salience of chunks and its most important criterion of identifying a chunk is whether it is processed as a whole unit. Corpus linguistic perspective focuses on frequencies of chunks and its identification of chunks is done on the basis of frequency counts. All of the three perspectives have tapped into the phenomenon of multi-word combinations and yielded fruitful findings on the use of chunks in aspects of quantitative, syntactic, semantic, functional, and psychological features; however, each has their pros and cons展开更多
A novel hybrid self-reconfigurable modular robot is designed to finish the morphing action from line shape to hexagon shape. The robot is composed of many basic modules,each of which consists of a master module and a ...A novel hybrid self-reconfigurable modular robot is designed to finish the morphing action from line shape to hexagon shape. The robot is composed of many basic modules,each of which consists of a master module and a slave module in the shape of triangular prism. There are four connection ports on each basic module. For the master module there are two holes on each connection port,and for the slave one there are two pegs on each connection. The docking process between two neighboring basic modules is analyzed with a peg-in-hole mechanical structure. A small motion's method is presented and the contact forces are derived. According to the force/moment,the pose of a motion module should be adjusted to make two neighboring modules align and finish the docking process.Finally,a simulation of 3 basic modules is shown to finish the morphing and docking process effectively. The system can finish the morphing task from the line shape to the hexagon shape.展开更多
Unified Irrpossible Differential （UID） cryptanalysis is a systeimtic method for finding impossible differentials for block ciphers. Regarding to the problem of automatically retrieving the impossible differential ch...Unified Irrpossible Differential （UID） cryptanalysis is a systeimtic method for finding impossible differentials for block ciphers. Regarding to the problem of automatically retrieving the impossible differential characteristics of block ciphers, with the use of particular intermediate difference state expression, UID gets the same or better results compared with other present cryptanalysis results. ARIA is a Korean block cipher expecting that there are no impossible differentials on four or rmre rounds. Based on a property of the Diffusion layer （DL） of ARIA, a specific selection is used before conflict searching to optimize. UID is applied to ARIA, and 6 721 impossible differential chains are found. The length of those chains is four rounds, the same as eisting results, but more varied in form Moreover, ARIA is a Substitution-Penmtation Network （SPN）, not a Feistel structure or generalized Feistel structure as UID was applied to before.展开更多
文摘为了更有效地进行图像去噪,提出了一种基于分块奇异值分解(Singular value decomposition,SVD)的两级图像去噪方法,该方法首先将含噪图像中具有相似结构的图像块组织成具有很强相关性的图像块组;然后,利用二维奇异值分解去除图像块组中每个相似块的内部相关性,利用一维奇异值分解去除相似图像块组之间的冗余;最后,通过硬阈值方法收缩变换系数实现图像与噪声的有效分离.为了进一步提高去噪效果,对含噪图像再次进行上述操作.不同的是,在第二级去噪过程中,相似图像块组根据第一级估计出的图像计算获得且相似图像块间的相关性通过离散余弦变换去除.仿真实验表明,提出的两级图像去噪算法不仅可以较大程度地去除图像噪声,还能有效保留图像细节,取得了良好的去噪效果.
文摘针对未编码的多输入多输出(MIMO,Multi-Input Multi-Output)系统,提出一种复杂度适中的分组全分集全码率(GFDFR,Group-wise Full Diversity Full Rate)空时编码方案。该方案通过在发送端进行天线分组,各组独立编码,减小全分集全码率(FDFR,Full Diversity FullRate)编码块的大小从而降低系统编解码复杂度;在频率选择性信道中,进一步对子载波分组进行独立编码,获得频率分集(或多径分集),以适中的复杂度在不降低系统分集度的情况下保证了信息的全码率传输,是一种在MIMO信道中极具实用价值的空时编码方案。
基金Supported by Natural Science Foundation of Shanghai,No.04ZB14072
文摘AIM:To investigate the ezrin expression in normal colorectal mucosa and colorectal cancer tissues, and study the correlation between ezrin expression in colorectal cancer tissues and tumor invasion and metastasis.METHODS: Eighty paraffin-embedded cancer tissue samples were selected from primary colorectal adenocarcinoma. Twenty-eight patients had well-differentiated, 22 had moderately differentiated and 30 had poorly differentiated adenocarcinoma. Forty-five patients and 35 patients had lymph node metastasis. Forty-five patients were of Dukes A to B stage, and 35 were of C to D stage. Another 22 paraffi n-embedded tissue blocks of normal colorectal epithelium (>5 cm away from the edge of the tumor) were selected as the control group. All patients with colorectal cancer were treated surgically and diagnosed histologically, without preoperative chemotherapy or radiotherapy. The immunohistochemistry was used to detect the ezrin expression in paraffin-embedded normal colorectal mucosa tissues and colorectal cancer tissue samples.RESULTS: Ezrin expression in colorectal cancer was significantly higher than in normal colorectal mucosa (75.00% vs 9.09%, P<0.01), and there was a close relationship between ezrin expression and the degree of tumor differentiation, lymph node metastasis and Dukes stage (88.46% vs 50.00%, P<0.01; 94.28% vs 51.11%, P<0.01; 94.28% vs 51.11%, P<0.01).CONCLUSION: Ezrin expression is obviously higher in colorectal cancer tissues than in normal colorectal mucosa tissues, and the high level of ezrin expression is closely related to the colorectal cancer invasion and metastasis process.
文摘This paper reviews three main perspectives of chunk analyses： traditional phraseological, psycholinguistic, and corpus linguistic perspectives. Traditional phraseological perspective focuses on syntactic and semantic aspects of chunks and its most important criteria of chunk identifications and classifications are compositionality and frozenness/fixedness. Psycholinguistic perspective focuses on the psychological salience of chunks and its most important criterion of identifying a chunk is whether it is processed as a whole unit. Corpus linguistic perspective focuses on frequencies of chunks and its identification of chunks is done on the basis of frequency counts. All of the three perspectives have tapped into the phenomenon of multi-word combinations and yielded fruitful findings on the use of chunks in aspects of quantitative, syntactic, semantic, functional, and psychological features; however, each has their pros and cons
基金Supported by the National Natural Science Foundation of China(No.61175069,51075272,51475300)
文摘A novel hybrid self-reconfigurable modular robot is designed to finish the morphing action from line shape to hexagon shape. The robot is composed of many basic modules,each of which consists of a master module and a slave module in the shape of triangular prism. There are four connection ports on each basic module. For the master module there are two holes on each connection port,and for the slave one there are two pegs on each connection. The docking process between two neighboring basic modules is analyzed with a peg-in-hole mechanical structure. A small motion's method is presented and the contact forces are derived. According to the force/moment,the pose of a motion module should be adjusted to make two neighboring modules align and finish the docking process.Finally,a simulation of 3 basic modules is shown to finish the morphing and docking process effectively. The system can finish the morphing task from the line shape to the hexagon shape.
基金Acknowledgements This paper was supported by the National Natural Science Foundation of China under Ccant No.61073149 the Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20090073110027.
文摘Unified Irrpossible Differential （UID） cryptanalysis is a systeimtic method for finding impossible differentials for block ciphers. Regarding to the problem of automatically retrieving the impossible differential characteristics of block ciphers, with the use of particular intermediate difference state expression, UID gets the same or better results compared with other present cryptanalysis results. ARIA is a Korean block cipher expecting that there are no impossible differentials on four or rmre rounds. Based on a property of the Diffusion layer （DL） of ARIA, a specific selection is used before conflict searching to optimize. UID is applied to ARIA, and 6 721 impossible differential chains are found. The length of those chains is four rounds, the same as eisting results, but more varied in form Moreover, ARIA is a Substitution-Penmtation Network （SPN）, not a Feistel structure or generalized Feistel structure as UID was applied to before.
