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Right-and-left visual field stimulation:A frequency and space mixed coding method for SSVEP based brain-computer interface

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Science china(Information Sciences) 2011年第12期54卷 2512-2518页

作者： YAN Zheng, GAO XiaoRong & GAO ShangKai department of Biomedical Engineering, School of Medicine, Tsinghua university, Beijing 100084,{2. 1. department of Biomedical Engineering School of Medicine Tsinghua University Beijing 100084 China

On the condition of using limited frequencies, fewer targets could be presented in brain-computer interface (BCI) based on steady-state visual evoked potentials (SSVEP). This paper proposes a novel coding method for SSVEP that, through a combination of frequency and spatial information, could increase the number of targets. Each target was composed of two flickers placed in the right-and-left visual fields. Given the role of the optic chiasm in the vision pathway, the two frequency components could be projected to contralateral occipital regions. Canonical correlation analysis (CCA) was utilized to detect the frequency components from the right or left visual cortex. Asymmetric index as a supplementary feature was also computed. Linear discriminant analysis (LDA) was used for target recognition. The attractive feature of this method is that it would substantially increase the number of targets. If the number of frequency was N, the method could present N times more targets than conventional SSVEP-based BCIs.

关键词： brian-computer interface (BCI) frequency-space mixed coding steady-state visual evoked potential (SSVEP)

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乘积空间上的Z_2.Z_2.指标理论

数学学报（中文版） 1998年第3期41卷 501-506页

作者：钟承奎师恪兰州大学数学系新疆大学数学系

本文针对Ｚ２×Ｚ２群在乘积空间上的自然作用定义一种新的指标．这种指标满足通常指标的一般性质，但不满足维数性质．作为这个指标的应用，我们还给出了两个抽象的临界点定理．

关键词：等变映射临界点临界值乘积空间指标理论

Performance Analysis of Two CFAR Detectors in Clutter Edge Situation

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Journal of Systems Engineering and Electronics 2001年第2期12卷 44-51页

作者： He You department of Electronic Engineering, Naval Aeronautical Engineering Academy Yantai 2.4001, P. R. china Guan Jian department of Electronic Engineering, Tsinghua university, Beijing 100084, R R. china department of Electronic Engineering Naval Aeronautical Engineering Academy Yantai 264001 P. R. China department of Electronic Engineering Tsinghua University Beijing 100084 P. R. China

This paper studies the performance of the GOSGO and GOSSO CFAR detectors [1] in clutter edge situation. The authors derive the analytic expressions of the false alarm probabilities in that situation, analyze their performances against clutter edge, and compare them with the OS, CA, GO and SO detectors. The results show that GOSGO possesses better performance than GO for countering clutter, but the performance of GOSSO is very unideal.

关键词： Alarm systems Clutter (information theory) Gaussian noise (electronic) Signal to noise ratio White noise

Neocartilage formation from predifferentiated human adipose derived stem cells in vivo

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Acta Pharmacologica Sinica 2007年第5期28卷 663-671页

作者： Xiao-bing JIN~2.Yong-sheng SUN~2.Ke ZHANG~2.Jing WANG~3,Xiao-dong JU~2.Si-quan LOU~(2.4)~2.0} of Orthopedics,Peking university,Third Hospital,Beijing 100083,{2. ~3department of Dentistry,College of Stomatology,Fourth Military Medical university,Xi'an 710032.{2. departmentofOrthopedics PekingUniversityThirdHospitalBeijing100083China departmentofDentistry CollegeofStomatologyFourthMilitaryMedicalUniversityXi'an710032China

Aim:To examine the chondrogenic potential of human adipose derived stem cells(hASC) induced by human transforming growth factor beta2.(hTGF beta2. invitro,and to investigate if predifferentiated hASC can produce neocartilage ***:hASC were isolated from subcutaneous adipose tissue and cul-tured in pellets with the addition of hTGF *** differentiationwas assayed by RT-PCR,Western blotting,toluidine blue staining,and immuno-histochemistry staining for collagen type Ⅱ.For the in vivo study,intact inducedcell pellets or the released cells embedded in alginate gel with different concentra-tions were implanted subcutaneously in nude *** were harvested atdifferent time points and carried with histological and immunohistochemistry ex-amination to evaluate the cartilage ***:RT-PCR analysis revealedthat hASC produced aggrecan and collagen type Ⅱ after 7 d of induction andcontinued throughout the culture *** was also demonstrated by theWestern blot analysis,positive staining of toluidine blue,and immunohistochem-istry for collagen type Ⅱ.After reseeding in the monolayer,the cells isolated fromthe pellets displayed a polygonal morphology compared with the primary spindleshape,hASC were released from the induced cell pellets when embedded inalginate gel (implanted cell concentration=5×10～6/mL or higher).They producedneocartilage after 12.weeks in vivo culture;however,intact induced cell pelletsimplanted subcutaneously rapidly lost their differentiated ***:Chondrogenesis of hASC in vitro can be induced by combining pellet culture andhTGF beta2.*** hASC embedded in alginate gel have theability of producing neocartilage in vivo.

关键词： human adipose derived stem cell (hASC) human transforming growth factor beta2.(hTGF beta2. cartilage: tissue engineering alginate

The survey of touristry information system

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Journal of Geographical Sciences 1999年第1期9卷 77-82页

作者： MAO Zheng-yuan(department of Geography, Central china Normal {2., Wuhan 430079, china)

In this paper, the writer briefly introduces the concept of touristry information system (TIS), its current research situation, its necessity and urgency of development, analyses the structure, function and technical ... 详细信息

关键词： tourism Touristry Information System (TIS) touristry consumption touristry management touristry administration multi-medium network

Key parameter estimation for radar rotating object imaging with multi-aspect observations

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Science china(Information Sciences) 2010年第8期53卷 1641-1652页

作者： YE ChunMao, XU Jia , PENG YingNing & WANG XiuTan department of Electronic Engineering, Tsinghua university, Beijing 100084,{2. 1. department of Electronic Engineering Tsinghua University Beijing 100084 China

Rotating object model is commonly used for imaging analysis in high resolution radars such as the inverse synthetic aperture radar (ISAR). For a rotating object, it is known that multi-aspect observations can improve cross-range resolution with the known imaging geometry. For the non-cooperative rotating object with unknown imaging geometry, this paper proposes an integrated scheme to estimate the key parameters, e.g., the rotating velocity and the aspect angle difference between every two observations. Furthermore, convolution back-projection (CBP) method is applied to provide fused imaging result with improved resolution. Also, the accuracy of the ultimate parameter estimation is analyzed, which is strongly related with several important factors like position extraction error of scattering centers and so on. Finally, the results of numerical experiments are provided to demonstrate the effectiveness of the proposed method.

关键词： rotating objects multi-aspect observations fused imaging aspect angle difference

一元关联函数的可拓变换及其在昆虫种群生态学中的应用

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数学的实践与认识 2003年第11期33卷 119-123页

作者：陈薇彩万志中国农业大学应用数学系北京100094 中国农业大学昆虫学系北京100094

本文依据一元关联函数的基本概念和初等关联函数的可拓变换定义 ,首次将关联函数的可拓变换应用于豆田天敌蝽类的生态研究 ,为控制害虫发生 ,更好地保护维持生态平衡的重要天敌类群提供理论根据 .

关键词：一元关联函数初等关联函数可拓变换生态平衡昆虫种群生态学

INVESTIGATION OF LOW CYCLE FATIGUE BEHAVIOROF BUILDING STRUCTURAL STEELS UNDEREARTHQUAKE LOADING

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Acta Metallurgica Sinica(English Letters) 1997年第1期10卷 51-55页

作者： G.M Sheng and S.H Gong(department of Metallurgy and Materials Engineering, Chongqing university Chongqing 630044,{2.) Chongqing Univ Chongqing China

Based on the failure model of building structural steels under earthquake loading, the low cycle fatigue test at constant strain, the stochastical fatigue test under real earthquake load spectrum and the structural fatigue test are carried out. The experimental results show that microalloying of V Ti and Nb can improve the anti-seismic propersties of steel bars. In the high strain and shori life range, both the static strength and ductility of steels are very important to increasing the low cycle fatigue resistance of steels.

关键词： low cycle fatigue earthquake building structural steel microalloying

A measure of centrality based on modularity matrix

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Progress in Natural Science:Materials International 2008年第8期18卷 1043-1047页

作者： Gaoxia Wang, Yi Shen *, Enjie Luan The department of Control Science and Engineering, Huazhong university of Science and Technology, Wuhan 430074,{2. The department of Control Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

In this paper, a kind of measure of structural centrality for networks, called modularity centrality, is introduced. This centrality index is based on the eigenvector belonging to the largest magnitude eigenvalue of modularity matrix. The measure is illustrated and compared with the standard centrality measures using a classic dataset. The statistical distribution of modularity centrality is investigated by considering large computer generated graphs and two networks from the real world.

关键词： Centrality Modularity centrality Modularity matrix