查看更多>>摘要：In this paper,we first study some compositions/transformations,such as the scalar-multiplication,spherical addition and canonical transformation,etc.,on the unit sphere of Euclidean spaces,and in turn on spherically convex sets in the unit sphere.Then we study valuations on the families of spherically convex sets.In particular,we show that the spherical projections defined recently by Ferreira et al are valuations in some cases.
查看更多>>摘要：Lutwak,Yang and Zhang defined the (p,q)-mixed volumes very recently.In this paper,some Brunn-Minkowski type inequalities on the (p,q)-mixed volumes are established based on the general Lp-projection bodies and the general Lp-centroid bodies.
查看更多>>摘要：A general framework of polar Brunn-Minkowski theory that unifies the Orlicz Brunn-Minkowski inequality,the Lp Brunn-Minkowski inequality for p ∈ (0,1) and the log-Brunn-Minkowski inequality all for polar bodies is provided.It is shown that this general polar φ Brunn-Minkowski inequality is equivalent to a general polar φ Minkowski mixed volume inequality.
查看更多>>摘要：Three aspects which include differential equation of motion,Noether symmetry and conserved quantity,perturbation to Noether symmetry and adiabatic invariant are investigated for the nonshifted Birkhoffian system,nonshifted Hamiltonian system and nonshifted Lagrangian system,respectively.Then,some relationships among the three mechanic systems and some special cases of the main results are presented.Finally,an example is given to illustrate the application of the methods and results.
查看更多>>摘要：For positive real numbers a,b,a + b ≤ max {a + b1/2 a1/2,b+a1/2b1/2}.In this note,we generalize this fact to matrices by proving that for positive semidefinite matrices A and B of order n,for any c∈[-1,1]and j=1,2,…,n,sj(A+B)≤sj((A ⊕ B) + φc(A,B)) ≤ sj(A+ | B1/2A1/2 |) ⊕ (B+| A1/2B1/2 |),where sj(X) denotes the j-th largest singular value of X and φc(A,B):=1/2((1+c)|B1/2A1/2| (1-c)A1/2B1/2 (1-c)B1/2A1/2 (1+c)|A1/2B1/2|).This result sharpens some known result.Meanwhile,some related results are established.
查看更多>>摘要：Let R=Fpm +uFpm +vFpm +uvFpm,where u2 =v2 =0,uv =vu.Then R is a local ring,but it is not a chain ring.R contains precisely (pm-1) p 3m units,namely,α + uβ + vγ + uvδ,where α,β,γ,αδ∈Fpm,α≠0.In this paper,we investigate all constacyclic codes of length ps over R.Firstly,we classify all α-constacyclic and (α+uvβ)-constaeyclic codes of length ps over R,respectively,and obtain their structure in each of those α-constacyclic and (α + uvβ)-constacyclic codes.Secondly,we address the (α+uβ)-constacyclic codes of length ps over R,and get their classification and structure.Finally,using similar discussion of (α + uβ)-constacyclic codes,we obtain the classification and the structure of α+vβ,α+uβ+uvγ,α+vβ+uvγ,α+u β+vγ,α+uβ+vγ+uvδ-constacyclic codes of length ps over R.
查看更多>>摘要：In this paper,the boundary knot method is applied to simulate inverse problems of determining physical boundary occurring in an inaccessible interior part.This is fulfilled from measurements of the partially accessible outer boundary.The truncated singular value decomposition under parameter choice of the cross validation method is employed for noisy boundary data cases.Numerical results for two benchmark problems show that the boundary knot method is simple,accurate,stable and computationally efficient for inverse problems under domains with doubly connected domains.
查看更多>>摘要：Permutation polynomials is a hot topic in finite fields,they have many applications in different areas.Permutation binomials and trinomials over finite fields were studied recently.In this paper,by using a powerful lemma given by Zieve and some degree 5 and 6 permutation polynomials over Fq,we construct some permutation binomials over Fqm.
查看更多>>摘要：Person detection,which can locate the person regions in the image,continues to be a hot research topic in both computer vision and signal processing communities.However,detecting person at small scale remains a challenging problem due to the lack of discriminative details in the typical image at small scale.In this paper,we propose a decomposition mapping method which contains two subnets: encoder subnet and decoder subnet.Encoder subnet can exploit decomposition transformation for person regions from big scale to small scale.Decoder subnet reverses the process of the encoder subnet.We add deconvolution network to the decoder subnet to make up for the lost information and a discriminative mapping has been restructured to transform the person regions from the small scale to the big scale.Therefore,person-regions and background-regions can then be separated according to their decomposition positions in the new scale space.The proposed approach is evaluated on two challenging person datasets: Caltech dataset and the KITTI dataset.Compared with SAF R-CNN,the miss rate has been optimized by 3.96％ on Caltech person dataset and the mean average precision has been optimized by 1.76％ on KITTI person dataset.
查看更多>>摘要：Problems in power quality such as temporary drops in grid voltage and flickers have been caught attention with the increasing capacity of the new energy grid-connected systems,such as photovoltaic (PV) and photovoltaic storage.To solve these problems,a dynamic voltage restorer (DVR) for fault ride-through of photovoltaic energy storage systems is presented.We select the appropriate DVR topology and compensation strategy for PV energy storage systems which are used as energy supply equipment for DVR.It proves to be energy-saving and solves the instability of photovoltaic output effectively.The intelligent algorithm that optimized the controller parameter of dynamic voltage restorer is used and the effectiveness of the controller strategy proposed has been assessed by time-domain simulations in the MATLAB/Simulink platform.
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