The necessary continuity of the second order derivative or curvature of the cam profile has been analyzed. In order to guarantee the smoothness of the cam radius data, a proper method with which it could be possible t...The necessary continuity of the second order derivative or curvature of the cam profile has been analyzed. In order to guarantee the smoothness of the cam radius data, a proper method with which it could be possible to revise directly the first and the second order difference coefficients as well as the slope has been proposed. This method, applicable to different cam mechanisms by using a unified formula of correction, possesses the characteristics of simplicity, intuition and precision. Meanwhile, a cubic spline function for fitting the cam profile has also been described.展开更多
The online customer reviews provide important information for product improvement and redesign.However,many reviews are redundant with only several short sentences,which may even conflict with each other on the same a...The online customer reviews provide important information for product improvement and redesign.However,many reviews are redundant with only several short sentences,which may even conflict with each other on the same aspect of a product.Thus it is usually a very challenging task to extract useful design information from the reviews and provide a clear description on the product’s various aspects amongst its competitors.In order to resolve this issue,we propose an approach to build hierarchical product profiles to describe a product’s kernel design aspects quantitatively.It is achieved via three main strategies:a double propagation strategy to achieve the associated features and customers’descriptions;a deep text processing network to build the aspect hierarchy;an aspect ranking approach to quantify each kernel design aspect.Experimental results validate the effectiveness of the proposed approach on online reviews.展开更多
Starting from our definition of apodization profile functions,we discover the optimal profiles and the characteristics of defined apodization functions in sidelobe suppression.It is shown by numerical analysis that th...Starting from our definition of apodization profile functions,we discover the optimal profiles and the characteristics of defined apodization functions in sidelobe suppression.It is shown by numerical analysis that the optimal grating length is 45 mm to compensate for dispersion induced by 100 km fibres and the smoothness of the ripples in time-delay characteristics is related to the defined parameters.展开更多
The basic idea behind a personalized web search is to deliver search results that are tailored to meet user needs, which is one of the growing concepts in web technologies. The personalized web search presented in thi...The basic idea behind a personalized web search is to deliver search results that are tailored to meet user needs, which is one of the growing concepts in web technologies. The personalized web search presented in this paper is based on exploiting the implicit feedbacks of user satisfaction during her web browsing history to construct a user profile storing the web pages the user is highly interested in. A weight is assigned to each page stored in the user’s profile;this weight reflects the user’s interest in this page. We name this weight the relative rank of the page, since it depends on the user issuing the query. Therefore, the ranking algorithm provided in this paper is based on the principle that;the rank assigned to a page is the addition of two rank values R_rank and A_rank. A_rank is an absolute rank, since it is fixed for all users issuing the same query, it only depends on the link structures of the web and on the keywords of the query. Thus, it could be calculated by the PageRank algorithm suggested by Brin and Page in 1998 and used by the google search engine. While, R_rank is the relative rank, it is calculated by the methods given in this paper which depends mainly on recording implicit measures of user satisfaction during her previous browsing history.展开更多
Given two Banach spaces E, F, let B（E, F） be the set of all bounded linear operators from E into F, ∑r the set of all operators of finite rank r in B（E, F）, and ∑r^# the number of path connected components of ∑...Given two Banach spaces E, F, let B（E, F） be the set of all bounded linear operators from E into F, ∑r the set of all operators of finite rank r in B（E, F）, and ∑r^# the number of path connected components of ∑r. It is known that ∑r is a smooth Banach submanifold in B（E,F） with given expression of its tangent space at each A ∈ ∑r. In this paper, the equality ∑r^# = 1 is proved. Consequently, the following theorem is obtained： for any nonnegative integer r,∑r is a smooth and path connected Banach submanifold in B（E, F） with the tangent space TA∑r = {B E B（E,F） ： BN（A） belong to R（A）} at each A ∈ ∑r if dim F = ∞. Note that the routine method can hardly be applied here. So in addition to the nice topological and geometric property of ∑r the method presented in this paper is also interesting. As an application of this result, it is proved that if E = R^n and F = R^m, then ∑r is a smooth and path connected submanifold of B（R^n,R^m） and its dimension is dim ∑r = （m ＋ n）r- r^2 for each r, 0≤r 〈 min{n,m}.展开更多
层析是电离层三维结构反演的重要技术.增加约束可缓解层析模型的病态问题.然而,迭代层析中,大量无射线穿过的网格易对施加的约束产生与真实意图相违背的约束结果(称负面约束).针对该问题,提出了一种参数平滑的迭代层析方法(iterative to...层析是电离层三维结构反演的重要技术.增加约束可缓解层析模型的病态问题.然而,迭代层析中,大量无射线穿过的网格易对施加的约束产生与真实意图相违背的约束结果(称负面约束).针对该问题,提出了一种参数平滑的迭代层析方法(iterative tomography method via parameters smoothing, ITPS).每次迭代中,先用Chapman函数及最小二乘法拟合及改正每一垂直剖面,获取关于Chapman函数参数的二维图像,然后用移动窗口法平滑各参数图像并以此改正各网格的电子密度.实验表明:ITPS方法可一定程度上减少负面约束并抑制层像的扰动.相对于MART和CMART算法,ITPS方法在垂直剖面、F2层临界频率(f_(o)F_(2))、F_(2)层峰值高度(h_(m)F_(2))、斜电子总含量(Slant Total Electron Content, STEC)及h_(m)F_(2)以上电子密度等方面均具有更佳的表现.相对于精度较高的CMART算法,ITPS方法在f_(o)F_(2)与h_(m)F_(2)的平均优化率分别为7.49%及6.60%,STEC的平均优化率为5.19%,h_(m)F_(2)以上电子密度的平均优化率为11.41%.展开更多
文摘The necessary continuity of the second order derivative or curvature of the cam profile has been analyzed. In order to guarantee the smoothness of the cam radius data, a proper method with which it could be possible to revise directly the first and the second order difference coefficients as well as the slope has been proposed. This method, applicable to different cam mechanisms by using a unified formula of correction, possesses the characteristics of simplicity, intuition and precision. Meanwhile, a cubic spline function for fitting the cam profile has also been described.
基金Supported by National Natural Science Foundation of China(61872320,61772164,61502129)the Key Research&Development Program of Zhejiang Province(2019C03127)
文摘The online customer reviews provide important information for product improvement and redesign.However,many reviews are redundant with only several short sentences,which may even conflict with each other on the same aspect of a product.Thus it is usually a very challenging task to extract useful design information from the reviews and provide a clear description on the product’s various aspects amongst its competitors.In order to resolve this issue,we propose an approach to build hierarchical product profiles to describe a product’s kernel design aspects quantitatively.It is achieved via three main strategies:a double propagation strategy to achieve the associated features and customers’descriptions;a deep text processing network to build the aspect hierarchy;an aspect ranking approach to quantify each kernel design aspect.Experimental results validate the effectiveness of the proposed approach on online reviews.
基金Supported by 863 National High Technology Research Plan(863-307-15)Tianjin Natural Science Foundation(003600811)China Postdoctoral Science Foundation and Huawei Scientific Research Foundation.
文摘Starting from our definition of apodization profile functions,we discover the optimal profiles and the characteristics of defined apodization functions in sidelobe suppression.It is shown by numerical analysis that the optimal grating length is 45 mm to compensate for dispersion induced by 100 km fibres and the smoothness of the ripples in time-delay characteristics is related to the defined parameters.
文摘The basic idea behind a personalized web search is to deliver search results that are tailored to meet user needs, which is one of the growing concepts in web technologies. The personalized web search presented in this paper is based on exploiting the implicit feedbacks of user satisfaction during her web browsing history to construct a user profile storing the web pages the user is highly interested in. A weight is assigned to each page stored in the user’s profile;this weight reflects the user’s interest in this page. We name this weight the relative rank of the page, since it depends on the user issuing the query. Therefore, the ranking algorithm provided in this paper is based on the principle that;the rank assigned to a page is the addition of two rank values R_rank and A_rank. A_rank is an absolute rank, since it is fixed for all users issuing the same query, it only depends on the link structures of the web and on the keywords of the query. Thus, it could be calculated by the PageRank algorithm suggested by Brin and Page in 1998 and used by the google search engine. While, R_rank is the relative rank, it is calculated by the methods given in this paper which depends mainly on recording implicit measures of user satisfaction during her previous browsing history.
基金Supported by the National Science Foundation of China (Grant No.10671049 and 10771101).
文摘Given two Banach spaces E, F, let B（E, F） be the set of all bounded linear operators from E into F, ∑r the set of all operators of finite rank r in B（E, F）, and ∑r^# the number of path connected components of ∑r. It is known that ∑r is a smooth Banach submanifold in B（E,F） with given expression of its tangent space at each A ∈ ∑r. In this paper, the equality ∑r^# = 1 is proved. Consequently, the following theorem is obtained： for any nonnegative integer r,∑r is a smooth and path connected Banach submanifold in B（E, F） with the tangent space TA∑r = {B E B（E,F） ： BN（A） belong to R（A）} at each A ∈ ∑r if dim F = ∞. Note that the routine method can hardly be applied here. So in addition to the nice topological and geometric property of ∑r the method presented in this paper is also interesting. As an application of this result, it is proved that if E = R^n and F = R^m, then ∑r is a smooth and path connected submanifold of B（R^n,R^m） and its dimension is dim ∑r = （m ＋ n）r- r^2 for each r, 0≤r 〈 min{n,m}.
文摘层析是电离层三维结构反演的重要技术.增加约束可缓解层析模型的病态问题.然而,迭代层析中,大量无射线穿过的网格易对施加的约束产生与真实意图相违背的约束结果(称负面约束).针对该问题,提出了一种参数平滑的迭代层析方法(iterative tomography method via parameters smoothing, ITPS).每次迭代中,先用Chapman函数及最小二乘法拟合及改正每一垂直剖面,获取关于Chapman函数参数的二维图像,然后用移动窗口法平滑各参数图像并以此改正各网格的电子密度.实验表明:ITPS方法可一定程度上减少负面约束并抑制层像的扰动.相对于MART和CMART算法,ITPS方法在垂直剖面、F2层临界频率(f_(o)F_(2))、F_(2)层峰值高度(h_(m)F_(2))、斜电子总含量(Slant Total Electron Content, STEC)及h_(m)F_(2)以上电子密度等方面均具有更佳的表现.相对于精度较高的CMART算法,ITPS方法在f_(o)F_(2)与h_(m)F_(2)的平均优化率分别为7.49%及6.60%,STEC的平均优化率为5.19%,h_(m)F_(2)以上电子密度的平均优化率为11.41%.
