• 제목/요약/키워드: Local Correlation

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Fluorine-Induced Local Magnetic Moment in Graphene: A hybrid DFT study

  • Kim, Hyeon-Jung;Jo, Jun-Hyeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.127.1-127.1
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    • 2013
  • Recent experimental evidence that fluorinated graphene creates local magnetic moments around F adatoms has not been supported by semilocal density-functional theory (DFT) calculations where the adsorption of an F adatom induces no magnetic moment in graphene. Here, we show that such an incorrect prediction of the nonmagnetic ground state is due to the self-interaction error inherent in semilocal exchange-correlation functionals. The present hybrid DFT calculation for an F adatom on graphene predicts not only a spin-polarized ground state with a spin moment of ${\sim}1{\mu}_B$, but also a long-range spin polarization caused by the bipartite nature of the graphene lattice as well as the induced spin polarization of the graphene states. The results provide support for the experimental observations of local magnetic moments in fluorinated graphene.

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How to identify fake images? : Multiscale methods vs. Sherlock Holmes

  • Park, Minsu;Park, Minjeong;Kim, Donghoh;Lee, Hajeong;Oh, Hee-Seok
    • Communications for Statistical Applications and Methods
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    • v.28 no.6
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    • pp.583-594
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    • 2021
  • In this paper, we propose wavelet-based procedures to identify the difference between images, including portraits and handwriting. The proposed methods are based on a novel combination of multiscale methods with a regularization technique. The multiscale method extracts the local characteristics of an image, and the distinct features are obtained through the regularized regression of the local characteristics. The regularized regression approach copes with the high-dimensional problem to build the relation between the local characteristics. Lytle and Yang (2006) introduced the detection method of forged handwriting via wavelets and summary statistics. We expand the scope of their method to the general image and significantly improve the results. We demonstrate the promising empirical evidence of the proposed method through various experiments.

The automatic recognition of the plate of vehicle using the correlation coefficient and hough transform (상관계수와 하프변환을 이용한 차량번호판 자동인식)

  • Kim, Kyoung-Min;Lee, Byung-Jin;Lyou, Kyoung;Park, Gwi-Tae
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.5
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    • pp.511-519
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    • 1997
  • This paper presents the automatic recognition algorithm of the license number in on vehicle image. The proposed algorithm uses the correlation coefficient and Hough transform to detect license plate. The m/n ratio reduction is performed to save time and memory. By the correlation coefficient between the standard pattern and the target pattern, licence plate area is roughly extracted. On the extracted local area, preprocessing and binarization is performed. The Hough transform is applied to find the extract outline of the plate. If the detection fails, a smaller or a larger standard pattern is used to compute the correlation coefficient. Through this process, the license plate of different size can be extracted. Two algorithms to each separate number are proposed. One segments each number with projection-histogram, and the other segments each number with the label. After each character is separated, it is recognized by the neural network. This research overlomes the problems in conventional methods, such as the time requirement or failure in extraction of outlines which are due to the processing of the entire image, and by processing in real time, the practical application is possible.

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Correlation Effects in Superconducting $Sr_2VO_3FeAs$ (초전도 $Sr_2VO_3FeAs$에서 상관효과)

  • Lee, K.W.
    • Progress in Superconductivity
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    • v.12 no.1
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    • pp.46-50
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    • 2010
  • In the superconducting $Sr_2VO_3FeAs$, containing bimetallic layers, with maximum $T_c{\approx}\;46\;K$ correlation effects on V ions have been investigated using LDA+U method. Within the local density approximation (LDA) this system has the one-third filled $t_{2g}$ manifold of V, decomposed into $d_{xy}$ of bandwidth W=2 eV and nearly degenerate $d_{zx}d_{yz}$ of W=1 eV. Consideration of correlation effects leads to a metal-insulator transition on V ions $t^{2\uparrow}_{2g}\;{\rightarrow}\;d^{1\uparrow}_{xz}\;d^{1\uparrow}_{yz}$ at the critical on-site Coulomb repulsion $U_c$= 3.5 eV. At U=4 eV, the electronic structure, in which V ions are insulating, leads to several van Hove singularities near $E_F$ and similar Fermiology with other pnictides. Applying U to V ions results in increasing Fe moment as well as V moment, indicating somewhat hybridization between Fe and V ions even though this system is strongly 2-dimesional. Our results show possible importance of correlation effects on this system.

A Correlation Study of Perception to Hospice and Knowledge and Attitude to Advanced Directives in Adults in a Local Community (일 지역 성인의 호스피스 인식과 사전의료의향서에 대한 지식과 태도의 관계)

  • Park, Kyongran;Jang, Sunhee
    • Journal of The Korean Society of Integrative Medicine
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    • v.7 no.4
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    • pp.181-191
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    • 2019
  • Purpose : This narrative research study aimed to identify the degree of correlation between hospice awareness and knowledge of and attitude toward advance directives. Methods : A survey was conducted from July 5 to July 15, 2018 with 210 adults in C city, Gyeongsangnam-do. Using the SPSS 21.0 program, the data analysis methods utilized were the independent t-test, one-way ANOVA, Scheffe, and Pearson's correlation coefficients. Results : The degree of hospice awareness was measured according to the general characteristics of the subjects, which were as follows: heard about economic level, importance of religion, heard of hospice, heard about advance directives, and intention to execute advance directives. The knowledge of advance directives had significant differences by age, hospitalization experience, religion, and being the final decision maker for a family problem. The attitude toward advance directives differed significantly by marriage status and the intention to write an advance directives. The relationship between hospice awareness and knowledge and attitude toward advance directives showed a positive significant correlation (r=.47, p<001). The relationship between knowledge of and attitude toward advance directives also indicated a positive significant correlation (r=.20, p=.005). Conclusion : This study provided basic data to inform promotion of hospice awareness and an educational intervention about advance directives.

A Method for Object Tracking Based on Background Stabilization (동적 비디오 기반 안정화 및 객체 추적 방법)

  • Jung, Hunjo;Lee, Dongeun
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.14 no.1
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    • pp.77-85
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    • 2018
  • This paper proposes a robust digital video stabilization algorithm to extract and track an object, which uses a phase correlation-based motion correction. The proposed video stabilization algorithm consists of background stabilization based on motion estimation and extraction of a moving object. The motion vectors can be estimated by calculating the phase correlation of a series of frames in the eight sub-images, which are located in the corner of the video. The global motion vector can be estimated and the image can be compensated by using the multiple local motions of sub-images. Through the calculations of the phase correlation, the motion of the background can be subtracted from the former frame and the compensated frame, which share the same background. The moving objects in the video can also be extracted. In this paper, calculating the phase correlation to track the robust motion vectors results in the compensation of vibrations, such as movement, rotation, expansion and the downsize of videos from all directions of the sub-images. Experimental results show that the proposed digital image stabilization algorithm can provide continuously stabilized videos and tracking object movements.

A Study on Characteristics of Determining Factor of Rental Price of Apartment by Sub-regions in Seoul (서울시 아파트 전세가격 결정요인의 권역별 특성에 관한 연구)

  • Lee, Seok-Ju;Lee, Joo-Hyung
    • KIEAE Journal
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    • v.11 no.4
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    • pp.19-27
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    • 2011
  • This study aims to find the determining factors for apartment rental prices by using Stepwise Multiple Regression Analysis. In the process, differences among the groups and multicollinearity and correlation between the variables are examined using analysis of variance(ANOVA), correlation analysis and factor analysis. The comprehensive analysis of reliability of the variable and comprehensivization ensure objectivity. For this analysis, the characteristics of the determining factors for apartment rental prices by sub-regions in Seoul are as follows : First, the housing supply rate appears center of the central and the southwest region is influenced by the cultural and ecological environment, convenience, the size of the complex and reputation of the developer. Second, the northeast region is generally influenced by the regional economy, housing size, the density of the complex, well-known construction companies and relevant variables of individual housing and the density of the complex, physical and social environment, reputation of the developer, local economy and housing size. Lastly, the southeast region appears to be influenced by the local economy, the density of the complex, housing size and the educational environment.

Genotypic Difference in Leaf Senescence during Grain Filling and Its Relation to Grain Yield of Rice (벼 등숙기 엽노화의 품종간 차이 및 수량과의 관계)

  • 이변우;박재홍
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.3
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    • pp.224-231
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    • 2003
  • This study was conducted to investigate the varietal differences in leaf senescence during ripening stage and its relation to grain yield of rice. During grain filling period leaf senescence was evaluated by SPAD readings (an indirect indicator of chlorophyll content) for 74 varieties including local, improved domestic, and introduced varieties in the field condition. Leaf senescence was varied greatly among 74 varieties. Jodongji and Dadajo known as local rice varieties had significantly lower SPAD value than the other varieties and became senescent rapidly. However, SPAD value of the flag leaf and 2nd leaf of SNU-SG1 were much higher than the other varieties and leaves of SNU-SG1 also showed a tendency of delayed senescence compared to the other varieties. There were significantly positive correlation between cumulated SPAD value of upper leaf(flag leaf and 2nd leaf) during 35 days after heading and grain yield divided by sunshine hour during 40 days of grain filling and compensated for temperature effect, and cumulated SPAD value of the 4th leaf showed negative correlation with the yield. That is, the delayed senescence of the upper leaves and the rapid senescence of lower leaves were positively associated with grain yield increase.

Implementation of the Ultrasonic Local Positioning System using Dual Frequencies and Codes (이중 주파수와 코드를 이용한 초음파 위치 인식 시스템 구현)

  • Cho, Bong-Su;Cho, Seck-Bin;Yang, Sung-Oh;Baek, Kwang-Ryul;Lee, Dong-Hwal
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.7
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    • pp.647-655
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    • 2008
  • This paper presents real-time algorithm for an ultrasonic Local Positioning System(LPS). An ultrasonic LPS consists of 4 transmitters and n receivers. Each transmitter transmits an sequential ultrasonic signal to avoid interference of ultrasonic signal. This method is a noneffective application for a fast object. Because receiver detects four sequential transmissive ultrasonic signal and calculates a position. This paper proposes the method which 4 transmitters transmit simultaneous ultrasonic signal and each transmitter distinguished by frequencies and codes. And Auto-Correlation Function(ACF) method separates codes from an ultrasonic echo signal which is interference of each transmitter's code. If the receiver uses only ACF method, it is difficult to implement real time application for increased computation. This paper implements LPS using dual frequencies and ACF method. Using dual frequencies reduces codes length. The reduced codes length save computation in ACF. To prove this algorithm by experiment, high performance DSP(digital signal processor) used. The result shows the performance of the designed system is good enough positioning.