Martinec and moore discussed how d - branes on orbifolds fit naturally into the algebraic framework as described by projection operators Martinec和moore讨论了d一branes上的物理如何自然地与一些非对易orbifolds上的投影算子相联系。
We find that if the vacuum state | 0 > in their paper is replaced by any state vector their construction still works . we notice that if the state vector has some s 我们注意到，在他的构造中，如果适当要求态矢量}价>的对称性质，那么构造的投影算子就是不可对易orb而ld尸/ g投影算子。
Boca further described the projection operators on orbifold t2 / g and discussed the relation between their trace and the commutator q of the operators u and v on noncommutative torus ( uv = vt / e2 ) Boca进一步在理论上论证不可对易orbifoldtz / g投影算子的存在性，讨论了它们的迹与不可对易torus上的平移算子u和v的对易因子q的关系。
The main task of this paper is to investigate the least - squares mixed method for the elliptic boudary - value problems . by introducing the projections and duality problems , we do some analysis for the approximations and finally obtain the general superconvergence results 本文的主要工作就是研究椭圆边值问题的最小二乘混合有限元方法，通过引进投影算子和对偶问题进行收敛性分析，最后得到了超收敛结果。
According to rice ' s idea , rice condition numbers for these subspaces are defined by applying perturbation expansions of orthogonal projection operators . the expressions of the rice condition numbers and the first - order perturbation estimations for these subspaces are derived . compared with sun ' s approach , the rice condition numbers are independent of the choices of basis 在子空间基底扰动展开的基础上，基于rice的想法，运用正交投影算子与空间基底选取无关的特性，改进了前人所定义的子空间和子空间对的条件数，并得到了这些rice条件数的具体表达式。
Then the following state - ments are equivalent : ( 1 ) 0 is an isolated point in ( 2 ) a is a finite rank operator ; is the spectral projector associated with . theorem4 . 5 let a be a compact normal operator , is an isolated point in prop4 . 13 let a be a compact normal operator , ao is an isolated point in a ( a ) 定理乏止设a是紧正常算子，则下列条件等价： （ ）是o （ a ）的孤立卢、 ；仰a是有限秩算子； w 2n间a二一，其中灿1 ， …为” （用自所有的互不相同的孤立点，民： h ?马人一川为关于入的谱投影算子
Computer simulation results are presented to show the effectiveness of the algorithm . according to the estimation procedure and the simulation result , we get an additional key restriction that is not included in the original theory . this nuclear restriction is that as long as the observation matrixes of all scales ( expect the finest scale ) are full column rank , the operator ' s estimation algorithm will always be efficient 针对动态多尺度系统理论中的核心? ?投影算子的实现问题，给出了一种基于最小二乘法的投影算子估计算法及其仿真，根据算法推导过程和仿真结果，得到一些有关算法实用性和原动态多尺度建模理论本身的一些结论，得出原理论框架中一个新的约束条件，进一步完善了原系统理论； 3
For a quantized subgroup of the symmetry group of hamiltonian of a molecule , a site projection operator is defined to produce symmetry - adapted wave functions from the functions with the symmetry of the subgroup . based on site projection operator , a systematic method is proposed to factorize the single - particle 对于哈密顿的对称群的量子化子群，可以定义一个位置投影算子，来从具有该子群对称性的轨道产生完全的对称性匹配轨道。基于位置投影算子，提出了一个系统的方法，用来按照分子的最大对称群，彻底地分解
All of above presents the data to study the algorithm which will be used to detect the targets against the broadened bragg lines . eigenstucture - based algorithms are used to realize bearing resolution on the basis of synthetically comparing several classical algorithms . first sea echo ’ s bearing prior knowledge is utilized to constitute project operator to constraint the noise subspace estimation with the use of constrained music algorithms , which largely increases the resolution and doa estimated accuracy 为检测海上目标的方位信息,在综合分析比较各类算法的基础上,本文采用特征结构类算法来实现空间方位分辨中的constrainedmusic算法,此方法充分利用了海浪的方位先验信息来构造投影算子约束噪声子空间的估计,大大提高了目标分辨率和估计精度。
