• Title/Summary/Keyword: radial

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Estimation of Old Climate and the Radial Growth of Trees since 1782 in South Korea (1782 年 以來 韓國의 古氣候와 수種의 肥大成長推定)

  • Lee, Myung Soon;Kwang Soo Paik;Yang-Jai Yim
    • The Korean Journal of Ecology
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    • v.8 no.4
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    • pp.215-223
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    • 1985
  • The fluctuation of old climate was studied by the analysis of radial growth in trees, since 1782. For the effects of environmental factors on the radial growth, the authors proposed the relative radial growth(Rg) concept modified the emperical equation of Fritts (1969) as follow: Yt=aebt Yt: theoretical annual ring width time t a and b: constants in different tree species Rg=Yt/Yt Rg: ratio of real radial growth to theoretical growth with age Yt: real annual radial growth Used the Rg value, the relationship between climatic conditions and the radial growth during 70 years was investigated, and the fluctuations in climate during the last 200 years with the historical records was detected.

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The characteristics of radial consolidation & permeability on the inflow & outflow condition (내.외향류 방사형 압밀/투수 특성에 관한 연구)

  • 천홍래;김지용;김수삼
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.109-116
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    • 1999
  • This study is to make clear for the characteristics of radial drainage consolidation/permeability At the result of the radial drainage consolidation / permeability test, the permeability of outflow drainage condition is higher than Inflow drainage condition and the time for the end of consolidation, outflow drainage condition is shorter than inflow drainage condition. So drainage area ratio test and control of hydraulic gradient test are carry out to analysis this result. Finally, compared with the characteristics on the condition of inflow and outflow permeability and consolidation.

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ON ENERGY ESTIMATES FOR A LANDAU-LIFSCHITZ TYPE FUNCTIONAL IN HIGHER DIMENSIONS

  • Qi, Longxing;Lei, Yutian
    • Journal of the Korean Mathematical Society
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    • v.46 no.6
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    • pp.1207-1218
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    • 2009
  • The authors study the asymptotic behavior of radial minimizers of an energy functional associated with ferromagnets and antiferromagnets in higher dimensions. The location of the zeros of the radial minimizer is discussed. Moreover, several uniform estimates for the radial minimizer are presented. Based on these estimates, the authors establish global convergence of radial minimizers.

THE RADIAL DERIVATIVES ON WEIGHTED BERGMAN SPACES

  • Kang, Si-Ho;Kim, Ja-Young
    • Communications of the Korean Mathematical Society
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    • v.18 no.2
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    • pp.243-249
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    • 2003
  • We consider weighted Bergman spaces and radial derivatives on the spaces. We also prove that for each element f in B$\^$p, r/ there is a unique f in B$\^$p, r/ such that f is the radial derivative of f and for each f$\in$B$\^$r/(i), f is the radial derivative of some element of B$\^$r/(i) if and only if, lim f(tz)= 0 for all z$\in$H.

Performance Improvement of Radial Basis Function Neural Networks Using Adaptive Principal Component Analysis (적응적 성분분석 기법에 의한 RBF 신경망의 성능개선)

  • 조용현;윤중환
    • Proceedings of the Korean Information Science Society Conference
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    • 2000.04b
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    • pp.475-477
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    • 2000
  • 본 논문에서는 적응적 성분분석 기법을 이용하여 radial basis 함수 신경망의 학습시간과 분류성능을 개선한 새로운 기법을 제안하였다. 제안된 기법에서 적응적 성분분석 기법은 radial basis 함수 신경망의 은닉층 뉴런 개수와 중심값 설정을 위해 이용하였다. 제안된 기법의 radial basis 함수 신경망을 200명의 암환자를 2부류(초기와 악성)로 분류하는 문제에 적용하여 시뮬레이션한 결고, k-평균 군집화 알고리즘을 이용한 radial basis 함수 신경망과 비교할 때 학습시간과 시험 데이터의 분류에서 더욱 우수한 성능이 있음을 확인할 수 있었다.

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Radial Vibration of Cylindrical Piezoelectric Transducers (원통형 압전 변환기의 반경방향 진동 특성)

  • 김진오;정형곤
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.1138-1143
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    • 2001
  • The paper deals with a theoretical study on the radial vibration of cylindrical piezoelectric transducers. The differential equations of piezoelectric radial motion have been derived in terms of the radial displacement and electrical potential. Applying mechanical and electrical boundary conditions has yielded the characteristic equations of natural vibration. Numerical results of the fundamental natural frequency have been compared with experimental observations for the transducers of several sizes, and have shown a good agreement.

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Detection of Radial Pulse Wave by Photoplethysmogram (광전용적맥파를 이용한 요골동맥 맥파 검출)

  • 정동근;김광년;연규선;최병철;서덕준
    • Journal of Life Science
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    • v.13 no.1
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    • pp.42-46
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    • 2003
  • Photoplethysmogram is widely used to measure heart rate and arterial blood oxygen saturation in human. This paper describes radial pulse waves recorded by photoplethysmogram with 940 nm wavelength infra red light. Radial pulse waves were varied according to the recording site. When recorded on the skin over radial artery, the radial pulse wave was inverted, comparing to the photoplethysmogram at fingertip. The mechanism of inverted pulse wave seemed to be caused by the change of the blood volume in the subcutaneous tissue between radial artery and the skin, which was reduced during systolic period and increased during diastolic period of the cardiac cycle. These results suggest that radial arterial wall may reflect infra red ray.

Development of Radial Turbine for Air Cycle Refriger (공기 사이클 냉동기에 적응되는 반경 터빈의 개발)

  • Kwon, Gi-Hun;Lee, Ki-Ho;Kim, Jong-Seon
    • 유체기계공업학회:학술대회논문집
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    • 2001.11a
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    • pp.281-286
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    • 2001
  • The radial turbine has been successfully applied to the systems which request relatively small output compared with the axial turbine, and has low manufacturing cost due to it's small size and simple structure. Recently, the researches on the development and the efficiency maximization of the radial turbine are in progress corresponding with the trend toward miniaturization in turbo machinery and the development of small dispersed power generation systems. The radial turbine is to be applied to our turbo refrigerator of which engine speed is 26,000 rpm and turbine efficiency is $88\%$. Also, as a heat exchanger is accepted instead of a combustor in our turbo refrigerator, the design of radial turbine has been performed to be appropriate to the circumstance of low temperature air, not high temperature combustor gas, into the turbine inlet . This radial turbine is being developed in consideration with not only the aero-dynamic performance but also the simplification of manufacturing and integration, and the durability at operating condition. This paper refer to the performance evaluation about the radial turbine design by comparison with consulting from Russia and the our evaluation about various design factors which are considered in aero-dynamic design process.

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Vibration Characteristics of Tires for Light-duty Truck under Free Suspension (자유상태에서 경상용차용 타이어의 진동특성)

  • 김용우;최동수
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.6
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    • pp.49-56
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    • 2000
  • Due to the rapid increase of long-distance transportation, particular attentions have been paid to truck tires, especially to their dynamic characteristics. In this research, experimental modal analysis on two kinds of light-duty truck tires, i.e., radial tire and bias tire, are performed by using GRFP(global rational fraction polynomial) method to investigate differences of the dynamic behavior of the two tires. The test results have shown that the modal frequencies of bias tire are much higher than the corresponding values of radial tire with a similar mode shape, which is in accordance with the fact that the radial rigidity of bias tire is higher than that of radial tire. And most of the modal decay rates of bias tire are larger than those of radial tire within the scope of this experiment. In the frequency domain range of test, the bias tire has extra modes, which do not occur in the radial tire. This difference is based on the fact that the circumferential rigidity of the bias tire is quire low whereas that of radial tire is so high that the frequencies of the corresponding modes are out of the frequency range of test.

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