• 제목/요약/키워드: high order

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High-Order Surface Gradient Coil Design Using Target Field Approach

  • Lee, J.K.;Yang, Y.J.;Jeong, S.T.;Choi, H.J.;Cho, Z.H.;Oh, C.H.
    • 대한의용생체공학회:의공학회지
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    • 제17권1호
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    • pp.19-24
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    • 1996
  • 이 논문의 목적은 Target field approach방법을 사용하여 2차원적인 공간선택을 할 수 있는 고차 평면 경사 자계코일(High-Order SGC: High-Order Surface Gradient Coil)을 설계하는 것이다. 지금까지 쓰이던 원통형의 고차경사자제코일을 이용한 2차원적 원형 선택방법은 한 개의 RF Pulse로 2차원적인 공간 선택을 할 수 있는 장점이 있었으나 선택되어지는 체적의 지름이 6 ~ 8cm로 너무 크다는 단점이 있었다. 이 논문에서는 이와 같은 단점을 극복하기 위해 영상을 얻고자하는 부분에 코일을 좀 더 가까이 붙일 수 있어서 적은 전력으로 선택되어지는 체적의 지름을 1 ~ 4cm까지 줄일 수 있는 표면 고차자계코일을 Target field approach방법을 이용하여 설계하였으며 Phantom과 인체영상을 통해 제작된 코일의 성능을 확인해 보았다. 이전의 Field component 방법을 이용하여 설계한 코일에 의해서 선택되어지는 체적은 타원에 가까운 모양이 되었으나, Target field approach 방법을 이용하여 설계한 코일에 의해서 선택되어지는 체적은 이상적인 원에 가까운 모양이 되었다.

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추천시스템에 활용되는 Matrix Factorization 중 FM과 HOFM의 비교 (Compare to Factorization Machines Learning and High-order Factorization Machines Learning for Recommend system)

  • 조성은
    • 디지털콘텐츠학회 논문지
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    • 제19권4호
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    • pp.731-737
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    • 2018
  • 추천 시스템은 컨텐츠, 온라인 커머스, 소셜 네트워크, 광고 시스템 등 많은 분야에서 사용자가 관심 있을 만한 정보를 선별 제안함을 목적으로 활발하게 연구되고 있다. 그러나 과거 선호도 데이터를 기반으로 제안하는 추천시스템이 많고 과거 데이터가 적거나 없는 사용자를 대상으로는 제공하기 어려우므로 낮은 성능을 보인다는 부문에서 문제점이 있다. 따라서 더욱 고차원적인 데이터 분석에 관한 관심이 증가하고 있고 Matrix Factorization이 주목받고 있다. 이 논문은 그 중 추천시스템에서 주목받는 Factorization Machines Learning(FM)모델과 고차원 데이터 분석인 High-order Factorization Machines Learning(HOFM)의 비교와 재연을 연구하고 제안 한다.

수산기업의 부채수용력이 자본조달순서이론에 미치는 영향 (The Effect of Debt Capacity on the Pecking Order Theory of Fisheries Firms' Capital Structure)

  • 남수현;김성태
    • 수산경영론집
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    • 제45권3호
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    • pp.55-69
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    • 2014
  • We try to test the pecking order theory of Korean fisheries firm's capital structure using debt capacity. At first, we estimate the debt capacity as the probability of assigning corporate bond rating from credit-rating agencies. We use logit regression model to estimate this probability as a proxy of debt capacity. The major results of this study are as follows. Firstly, we can confirm the fisheries firm's financing behaviour which issues new debt securities for financial deficit. Empirical test of SSM model indicates that the higher probability of assigning corporate bond rating, the higher the coefficient of financial deficit. Especially, high probability group follows this result exactly. Therefore, the pecking order theory of fisheries firm's capital structure applies well for high probability group which means high debt capacity. It also applies for medium and low probability group, but their significances are not good. Secondly, the most of fisheries firms in high probability group issue new debt securities for their financial deficit. Low probability group's fisheries firms also issue new debt securities for their financial deficit within the limit of their debt capacity, but beyond debt capacity they use equity financing for financial deficit. Therefore, the pecking order theory on debt capacity come into existence well in high probability group.

고차표면 경사자계코일을 이용한 새로운 공간 선택 방법 (A New Spatial Localization Technique Using High-Order Surface Gradient Coils (SGC))

  • 이종권;양윤정;정성택;이윤;조장희;오창현
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1994년도 추계학술대회
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    • pp.43-46
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    • 1994
  • A new spatial localization technique using high-order surface gradient coil (SGC) is proposed. Although the Spatial Selection with High-Order gradient (SHOT) can provide a 2-D selection with only one selective RF pulse, the high-order gradient produced by cylindrical-shape coils has not been clinically useful for clinical systems due to the large minimum selection size caused by the limited radial gradient intensity. However, by using the proposed high-order SGCs located near the imaging region, the size of volume selection can be reduced to a clinically useful 1-4 cm in diameter by applying stronger radial gradient with much less gradient driving power. A 40 cm-by-40 cm $r^{2}$ SGC has been designed and constructed, and phantom and volunteer studies have been performed. Experimental results using spatially localized MRI show good agreement to the theoretically predicted behavior.

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Color Filter Array에 대한 고품질 영상보간기법 (High Quality Image Interpolation for Color Filter Arrays)

  • 이봉준;이철희
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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    • pp.171-173
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    • 2000
  • In this paper, we present a new interpolation method for the color filter away(CFA). In order to capture color images. typical input devices use a single chip CCD imaging sensor with color filter array. As a result, the single chip CCD does not provide sufficient color resolutions since it arranges different color filters sequentially on a single CCD, resulting in aliasing noise and loss of resolution. In order to reconstruct high quality color images, we propose to use the interpolation algorithm using high order B-splines. Experiments show promising results.

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GLOBAL EXPONENTIAL STABILITY OF ALMOST PERIODIC SOLUTIONS OF HIGH-ORDER HOPFIELD NEURAL NETWORKS WITH DISTRIBUTED DELAYS OF NEUTRAL TYPE

  • Zhao, Lili;Li, Yongkun
    • Journal of applied mathematics & informatics
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    • 제31권3_4호
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    • pp.577-594
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    • 2013
  • In this paper, we study the global stability and the existence of almost periodic solution of high-order Hopfield neural networks with distributed delays of neutral type. Some sufficient conditions are obtained for the existence, uniqueness and global exponential stability of almost periodic solution by employing fixed point theorem and differential inequality techniques. An example is given to show the effectiveness of the proposed method and results.

고차 내삽기법을 사용한 중첩 격자기법 (NOTES FOR AUTHORS OF THE KOREAN SOCIETY OF COMPUTATIONAL FLUIDS ENGINEERING)

  • 이경록;김규홍
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2007년도 추계 학술대회논문집
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    • pp.209-213
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    • 2007
  • This paper presents the high order conservative interpolation methods. This method has been successfully implemented into a cell-centered finite volume methods code. Results using high order and maintaining conservation interpolation method are more accurate compared to bilinear interpolation.

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ASYMPTOTIC SOLUTIONS OF HYDRODYNAMIC INTERFACIAL INSTABILITIES IN CYLINDRICAL FLOW

  • Sohn, Sung-Ik
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제20권4호
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    • pp.259-267
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    • 2013
  • We present a high-order potential flow model for the motion of hydrodynamic unstable interfaces in cylindrical geometry. The asymptotic solutions of the bubbles in the gravity-induced instability and the shock-induced instability are obtained from the high-order model. We show that the model gives significant high-order corrections for the solution of the bubble.

MEDICAL IMAGE ANALYSIS USING HIGH ANGULAR RESOLUTION DIFFUSION IMAGING OF SIXTH ORDER TENSOR

  • K.S. DEEPAK;S.T. AVEESH
    • Journal of applied mathematics & informatics
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    • 제41권3호
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    • pp.603-613
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    • 2023
  • In this paper, the concept of geodesic centered tractography is explored for diffusion tensor imaging (DTI). In DTI, where geodesics has been tracked and the inverse of the fourth-order diffusion tensor is inured to determine the diversity. Specifically, we investigated geodesic tractography technique for High Angular Resolution Diffusion Imaging (HARDI). Riemannian geometry can be extended to a direction-dependent metric using Finsler geometry. Euler Lagrange geodesic calculations have been derived by Finsler geometry, which is expressed as HARDI in sixth order tensor.

작업치료과 학생들이 지각한 작업치료사의 이미지의 대한 연구 (Occupational Therapy Students Perceive Research on Image)

  • 송민옥;장아람;정명진;홍미애;장철
    • 대한통합의학회지
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    • 제1권3호
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    • pp.97-109
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    • 2013
  • Purpose : The purpose of this study work for the therapy and how students perceive the occupational therapist was to find out how. Method : The subjects in Busan and Kyungnam located in three two-year colleges and four-year clinical experience of two college students completed work therapeutics were expressed any research to understand the purpose of those who agreed to participate in the survey responded to the 175 people working Therapeutics two, three, four grades were included in the study. Result : 1. Education according to the image of the occupational therapist in grades four-year professional, the value and worth, the patient understand the position was higher in order. 3-year sophomore highly skilled in, the patient understand the position, sincerity was higher in order. 2. Gender occupational therapist who specializes in images for men, the value and worth, high practician was higher in women who were professional, the value and worth, helfer as high. 3. Theory of motivation based on the value of occupational therapists and rewarding images aptitude and interest, high practician, attractive, intellectual was in order. Entrance examination scores as a professional party, value & worth, abuse of authority ceremony was in order. 4. Image by Place of Practice Rehabilitation Hospital occupational therapist who specializes in, high practician, intellectual was in order. Care in the hospital and rewarding value, the professional character, high practician was in order. Hospital and rewarding the value, who specializes in, hepfer was in order. University Hospital who specializes in, the value and worth, Attractive was in order. Conclusion : It had revealed that occupational image perception of occupational therapy student was positive.