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伪复空型的一般CR-积 被引量:1
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作者 贺群 屈登兰 《西北师范大学学报(自然科学版)》 CAS 1997年第1期6-8,共3页
主要研究伪复空型的一般子流形的分解问题。
关键词 复空型 复空型 子流形 CR-积
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双相复空型及其几何特征 被引量:1
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作者 贺群 《西北师范大学学报(自然科学版)》 CAS 1993年第3期11-15,共5页
定义了一类特殊的Bochner-Kachler流形——双相复空型,讨论它的曲率张量表达式和一些几何特征,并给出了具体例子.
关键词 双相复空型 Ricci主曲率 B-K流形
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拟复空型的子流形
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作者 贺群 《西北师范大学学报(自然科学版)》 CAS 1992年第2期86-87,共2页
文献[1]中曾引进了拟复空型的概念,本文将分别讨论其上的实超曲面、不变子流形及正常CR子流形的性质。1 实超曲面设M为拟复空型M(a,b)的以母向量q为法向量的实超曲面。当M满足(?)X∈T_z(M),有A_qX=aX+βp(X)p时,称其为p拟脐超曲面。显然... 文献[1]中曾引进了拟复空型的概念,本文将分别讨论其上的实超曲面、不变子流形及正常CR子流形的性质。1 实超曲面设M为拟复空型M(a,b)的以母向量q为法向量的实超曲面。当M满足(?)X∈T_z(M),有A_qX=aX+βp(X)p时,称其为p拟脐超曲面。显然β=0时,M为全脐超曲面。 展开更多
关键词 复空型 子流形 实超曲面
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拟复空型的超曲面
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作者 黄城超 《汕头大学学报(自然科学版)》 1989年第2期1-7,共7页
本文研究了拟复空型中的两类特殊超曲面,即以母向量为法向量的实超曲面及以母向量和复母向量组成法空间的复超曲面、在第一类情况中,找到了它是Sasaki空型的条件,并且证明了在a+b≠0时它不可能是全脐超曲面,在第二类情况中,找到了在切... 本文研究了拟复空型中的两类特殊超曲面,即以母向量为法向量的实超曲面及以母向量和复母向量组成法空间的复超曲面、在第一类情况中,找到了它是Sasaki空型的条件,并且证明了在a+b≠0时它不可能是全脐超曲面,在第二类情况中,找到了在切向量是第二基本形的特征方向时一些几何性质,并且证明了当它的法连络是平坦时它是Einstein复超曲面. 展开更多
关键词 复空型 超曲面 SASAKI流形
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拟复空型的几何性质
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作者 黄城超 《复旦学报(自然科学版)》 CAS CSCD 北大核心 1992年第4期387-392,共6页
提供了与流形上的全纯截面曲率相关的拟复空型的几何特征,从几何上说明拟复空型是复空型的一种推广.
关键词 黎曼几何 复空型 复空型
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拟复空型中反不变子流形的一些结果
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作者 黄城超 《复旦学报(自然科学版)》 CAS CSCD 北大核心 1991年第4期429-436,共8页
运用经典张量分析方法,讨论拟复空型中反不变子流形结果如下:设拟复空型Q(a,b)的母向量和复母向量分别为p,q,M是Q(a,b)中余二维反不变子流形。且M的法空间(?)有平坦的法连络。若M关于p是脐点的,则M关于q是拟脐及是共形平坦的,且M中存在... 运用经典张量分析方法,讨论拟复空型中反不变子流形结果如下:设拟复空型Q(a,b)的母向量和复母向量分别为p,q,M是Q(a,b)中余二维反不变子流形。且M的法空间(?)有平坦的法连络。若M关于p是脐点的,则M关于q是拟脐及是共形平坦的,且M中存在一个以它的第二基本量的特征向量为法向量的常曲率全脐超曲面M_1。 展开更多
关键词 黎曼几何 复空型 反不变子流形
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APPLICATION OF HYBRID AERO-ENGINE MODEL FOR INTEGRATED FLIGHT/PROPULSION OPTIMAL CONTROL 被引量:4
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作者 王健康 张海波 +1 位作者 孙健国 李永进 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第1期16-24,共9页
The real-time capability of integrated flight/propulsion optimal control (IFPOC) is studied. An appli- cation is proposed for IFPOC by combining the onboard hybrid aero-engine model with sequential quadratic pro- gr... The real-time capability of integrated flight/propulsion optimal control (IFPOC) is studied. An appli- cation is proposed for IFPOC by combining the onboard hybrid aero-engine model with sequential quadratic pro- gramming (SQP). Firstly, a steady-state hybrid aero-engine model is designed in the whole flight envelope with a dramatic enhancement of real-time capability. Secondly, the aero-engine performance seeking control including the maximum thrust mode and the minimum fuel-consumption mode is performed by SQP. Finally, digital simu- lations for cruise and accelerating flight are carried out. Results show that the proposed method improves real- time capability considerably with satisfactory effectiveness of optimization. 展开更多
关键词 integrated flight/propulsion optimal control AERO-ENGINE hybrid model performance seeking con- trol sequential quadratic programming
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Boundedness of Weighted Composition Operators on Bloch Type Spaces 被引量:1
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作者 GUO Ji-dong LIU Pin +1 位作者 GAO Wen-hua NUERDANBIEKE Baitakazi 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2008年第3期356-359,共4页
In this paper, we give a necessary and sufficient condition for weighted composition operators Cu,φ to be boundedness on Bloch type spaces B^α. The theorem generalizes some previous results.
关键词 weighted composition operator Bloch type space BOUNDEDNESS
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Short-term traffic flow prediction with PSR-XGBoostconsidering chaotic characteristics 被引量:2
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作者 Li Shubin Kong Xiangke +2 位作者 Li Qingtong Lin Zhaofeng Zhao Zihao 《Journal of Southeast University(English Edition)》 EI CAS 2022年第1期92-96,共5页
To improve the level of active traffic management,a short-term traffic flow prediction model is proposed by combining phase space reconstruction(PSR)and extreme gradient boosting(XGBoost)algorithms.Firstly,the traditi... To improve the level of active traffic management,a short-term traffic flow prediction model is proposed by combining phase space reconstruction(PSR)and extreme gradient boosting(XGBoost)algorithms.Firstly,the traditional data preprocessing method is improved.The new method uses hierarchical clustering to determine the traffic flow state and fills in missing and abnormal data according to different traffic flow states.Secondly,one-dimensional data are mapped into a multidimensional data matrix through PSR,and the time series complex network is used to verify the data reconstruction effect.Finally,the multidimensional data matrix is inputted into the XGBoost model to predict future traffic flow parameters.The experimental results show that the mean square error,average absolute error,and average absolute percentage error of the prediction results of the PSR-XGBoost model are 5.399%,1.632%,and 6.278%,respectively,and the required running time is 17.35 s.Compared with mathematical-statistical models and other machine learning models,the PSR-XGBoost model has clear advantages in multiple predictive indicators,proving its feasibility and superiority in short-term traffic flow prediction. 展开更多
关键词 traffic prediction phase space reconstruct complex networks model optimization
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Designing an optimal stope layout for underground mining based on a heuristic algorithm 被引量:2
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作者 Sandanayake Don Suneth Sameera Topal Erkan Asad Mohammad Waqar Ali 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第5期767-772,共6页
An optimal layout or three-dimensional spatial distribution of stopes guarantees the maximum profitability over life span of an underground mining operation.Thus,stope optimization is one of the key areas in undergrou... An optimal layout or three-dimensional spatial distribution of stopes guarantees the maximum profitability over life span of an underground mining operation.Thus,stope optimization is one of the key areas in underground mine planning practice.However,the computational complexity in developing an optimal stope layout has been a reason for limited availability of the algorithms offering solution to this problem.This article shares a new and efficient heuristic algorithm that considers a three-dimensional ore body model as an input,maximizes the economic value,and satisfies the physical mining and geotechnical constraints for generating an optimal stope layout.An implementation at a copper deposit demonstrates the applicability and robustness of the algorithm.A parallel processing based modification improving the performance of the original algorithm in terms of enormous computational time saving is also presented. 展开更多
关键词 Stope optimization Underground mining Underground mine planning Heuristic algorithm
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Tourist Route Model Formulation Method Considering Spatial Reproducibility
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作者 Hiroyuki Kawai Kayoko Yamamoto 《Journal of Civil Engineering and Architecture》 2012年第9期1093-1108,共16页
This study aims to gradually reflect information concerning tourists and to propose tourist route model formulation techniques that take spatial reproducibility into account using GIS (geographic information systems... This study aims to gradually reflect information concerning tourists and to propose tourist route model formulation techniques that take spatial reproducibility into account using GIS (geographic information systems). The conclusions can be summarized into the following three points: (1) Kawagoe city in Saitama Prefecture was selected as the area targeted by this study. All types of data about Kawagoe city and tourists was collected and processed, and a tourist route model formulation method that considered spatial reproducibility using GIS was proposed, (2) 3-stage scenarios were created with the presence or absence of Kawagoe city tourist policies set as standards and this was used to develop tourist route models. It is POSsible to expect synergy in the encouragement of the use of sightseeing buses and the same traffic regulations as the traffic pilot program, and (3) It is considered that it is possible to apply the tourist route model formulation method proposed by this study to other tourist destinations without being limited by spatiotemporal differences or the particular issues of each tourist destinations as spatial reproducibility was confirmed. 展开更多
关键词 Tourist route model sightseeing spot spatial reproducibility GIS (geographic information systems) Kawagoe city.
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A traffic model of optical networks based on time-space complexity and traffic grooming
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作者 赵永利 《High Technology Letters》 EI CAS 2009年第2期198-202,共5页
This paper researched the traffic of optical networks in time-space complexity,proposed a novel traf-fic model for complex optical networks based on traffic grooming,designed a traffic generator GTS(gener-ator based o... This paper researched the traffic of optical networks in time-space complexity,proposed a novel traf-fic model for complex optical networks based on traffic grooming,designed a traffic generator GTS(gener-ator based on time and space)with 'centralized+distributed' idea,and then made a simulation in Clanguage.Experiments results show that GTS can produce the virtual network topology which can changedynamically with the characteristic of scaling-free network.GTS can also groom the different traffic andtrigger them under real-time or scheduling mechanisms,generating different optical connections.Thistraffic model is convenient for the simulation of optical networks considering the traffic complexity. 展开更多
关键词 optical networks traffic model time-space complexity scaling-free SELF-SIMILARITY traffic grooming
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Effects of Compound Danshen tablets(复方丹参片) on spatial cognition and expression of brain β-amyloid precursor protein in a rat model of alzheimer's disease 被引量:9
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作者 覃仁安 姚晓璇 黄竹英 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2012年第1期63-66,共4页
OBJECTIVE:To observe the effects of Compound Danshen Tablets(CDST) on spatial cognition and expression of brain b-amyloid precursor protein(β-APP) in a rat model of Alzheimer's disease.METHODS:The rat model of Al... OBJECTIVE:To observe the effects of Compound Danshen Tablets(CDST) on spatial cognition and expression of brain b-amyloid precursor protein(β-APP) in a rat model of Alzheimer's disease.METHODS:The rat model of Alzheimer's disease(AD) was established using D-galactose to cause subacute aging combined with Meynert nucleus damage.Rat behavior was monitored using the Morris water maze,and the expression of β-APP in rat brain tissue was detected via immunohistochemistry.RESULTS:CDST significantly improved spatial cognition and decreased β-APP expression in the cortex and hippocampus(P<0.05,P<0.01).CONCLUSIONS:CDST can significantly improve spatial cognition in a rat model of AD.This observation is possibly related to a reduction in β-APP ex-pression in the rat brain. 展开更多
关键词 Compound DanshenTablets(CDST) Alzheimer's disease B-amyloid precursor protein
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Order Bounded Weighted Composition Operators Mapping into the Dirichlet Type Spaces 被引量:4
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作者 Yongxin GAO Sanjay KUMAR Zehua ZHOU 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2016年第4期585-594,共10页
The authors characterize the order boundedness of weighted composition operators acting between Dirichlet type spaces.
关键词 Weighted composition operator Order boundedness Dirichlet typespaces Positive Borel measure
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