• 제목/요약/키워드: correlation length

검색결과 2,175건 처리시간 0.029초

Study of Ocular Components in Determining the Refractive State of the Eye (굴절이상을 결정하는 안광학 요소에 관한 연구)

  • Seo, Y.W.;Choe, Y.J.
    • Journal of Korean Ophthalmic Optics Society
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    • 제4권1호
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    • pp.7-14
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    • 1999
  • The purpose of this study is to evaluate the relationship between ocular components and refractive error for human eye. Ocular components were measured by keratometry, phakometry, and ultrasonography. Refractive error was measured by subjective refraction on 38 subjects aged from 17 to 30. The results were as follows; 1) Refractive error and axial length, vitreous chamber depth, axial length/corneal radius were highly correlated that the correlation coefficients were 0.95, 0.96, 0.95, respectively. 2) Refractive error and corneal radius, corneal power, lens thickness were correlated with the correlation coefficients for 0.60, 0.66, 0.67 respectively. 3) There were no significant correlation between refractive error and corneal thickness.

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Air-Water Countercurrent Flow Limitation in a Horizontal Pipe Connected to an Inclined Riser

  • Kang, Seong-Kwon;Chu, In-Cheol;No, Hee-Cheon;Chun, Moon-Hyun;Sung, Chang-Kyung
    • Nuclear Engineering and Technology
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    • 제31권6호
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    • pp.548-560
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    • 1999
  • An experimental investigation has been peformed to examine the effects of various geometrical parameters and an initial operating condition on the air-water countercurrent How limitation (CCFL) in a simulated PWR hot leg. A total of 118 experimental data for the onset of CCFL and zero liquid penetration were obtained for various combinations of test parameters. It was observe that the CCFL can be classified into three different categories: (the onset of CCFL, (the partial liquid delivery, and (r) the zero liquid penetration. The observed mechanisms of the onset of CCFL were different depending on the inlet water flow rate. The parametric effects of pipe diameter, horizontal pipe length, horizontal pipe length-to-diameter (L/D) ratio, and initial water level in the horizontal pipe of the test section on the onset of air-water CCFL were also examined. An empirical correlation for the onset of CCFL in a horizontal pipe connected to an inclined riser was developed in terms of Wallis flooding parameters for the low inlet water flow rate region. Comparisons of the present empirical correlation with the air-water CCFL data of large pipe diameters show that the present correlation agrees more closely with the experimental data than the existing CCFL correlations.

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A Clinical Study on the Correlation between Spine Deformity and Foot Abnormality (척추변형과 족부병변의 임상적 상관관계)

  • Choi, Hyun-Im;Park, Hung-Ki;Ju, Mu-Yeol
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • 제10권1호
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    • pp.117-128
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    • 2004
  • I have processed all the data by using SPSS PC+. And my research process was investigated for 34 students on the Forward Bending Test, Foot Printer Test, Feedoscope Test, X-ray Test and so on. The object of this thesis is to study the correlation between spine deformity and foot abnormality in a theoretical and empirical method. The main results of this study were as follows: 1. There was statistical significance on the correlation between foot length and spine length. 2. Spinal curve is the smallest on the pes plannus group and the biggest on the pes cavus group without statistical significance. 3. Left lumbar curve is the smallest, and right thoracic spine curve is the biggest on the left foot pattern group with statistical significance. 4. On the foot weight bearing groups, there was statistical significance both of between left and right foot groups. 5. There was no statistical significance on the t-test analysis between left and right foot area according to spinal curve typology. But there was tendency that thoracic spine curve is bigger in the same side of the foot area and lumbar spine curve is bigger in the opposite side of foot area.

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The Relation between asymmetric weight-supporting and gait symmetry in patients with stroke (뇌졸중 환자의 체중지지 비대칭과 보행 대칭성의 관련성)

  • Lee, Yong-Woo;Shin, Doo-Chul;Lee, Kyoung-Jin;Lee, Seung-Won
    • Journal of the Korean Society of Physical Medicine
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    • 제7권2호
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    • pp.205-212
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    • 2012
  • Purpose : The aim of this study was to investigate the relationship between weight-supporting asymmetry and gait symmetry in patients with stroke. Methods : Sixty two stroke patients with hemiplegia stood quietly with eye opens on a force platform to calculate weight-supporting asymmetry from vertical reaction force. The GAITRite was used to evaluate their gait parameters. The data were analyzed using Pearson correlation. Results : The results of this study was showed that the medio-lateral index (ML) was correlated with symmetry rate (SR), symmetry index (SI), and Gait asymmetry (GA) of step time and length but stronger correlation with spatial gait symmetry than temporal symmetry. In gait symmetry, step length has stronger correlation with weight-supporting asymmetry than step time. Conclusions : The results of this study shows weight-supporting asymmetry was correlated with more spatial gait symmetry than temporal symmetry.

Performance of Evaporation Heat Transfer Enhancement and Pressure Drop for Liquid Nitrogen (액체질소에 대한 증발 열전달 촉진 및 압력강하 성능)

  • Nam, Sang-Chul;Lee, Sang-Chun;Park, Byung-Duck
    • Transactions of the Korean Society of Mechanical Engineers B
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    • 제24권3호
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    • pp.363-372
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    • 2000
  • An experiment was carried out to evaluate the heat transfer enhancement and the pressure drop characteristics for liquid nitrogen using wire-coil-insert technique under horizontal two-phase conditions. The tube inner diameters were 8 mm and 15 mm, respectively and the tube length was 4.7 m. The helix angle of the wire coil insert was $50^{\circ}$ and its length was 4.7 m. Heat transfer coefficients for both the plain and the enhanced test tubes were calculated from the measurements of temperatures, flow rates and pressure drops. A correlation in a power-law relationship of the Nusselt number, Reynolds number and Prandtl number for the heat transfer was proposed which can be available for design of cryogenic heat exchangers. The correlation showed that heat transfer coefficients for the wire-coil inserts were much higher than those for plain tubes, increased by more than $1.8{\sim}2.0$ times depending upon the range of the equivalent Reynolds number. The correlation was compared with other various correlations in the turbulent flow conditions.

A Study on the Subjective Textures, Sensibilities and the Objective Handle of Knit Fabrics (니트 소재의 주관적 질감 및 감성과 객관적 태에 관한 연구)

  • Ju, Jeong-Ah;Ryu, Hyo-Seon
    • Journal of the Korean Society of Clothing and Textiles
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    • 제30권1호
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    • pp.83-93
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    • 2006
  • The purpose of this study is to analyze the relationship among subjective textures, sensibilities and objective handle of knit fabrics and to provide useful information in planning and designing knit fabrics. We made 20 plain knit fabrics, as specimens, with a combination of 5 kinds of wool/rayon fiber contents and 4 kinds of stitch loop length. For the subjective evaluation, we used 29 questions of subjective textures and sensibilities and employed statistical analysis tools such as factor, Pearson's correlation analysis. An objective handle was measured by Kawabata evaluation system and HV and THV was calculated by KN-402-KT and KN-301-winter. The analysis of a Pearson's correlation with objective properties and handles and structural properties of knit fabrics demonstrated a highly linear relationship. Especially, wool/rayon contents and WT of tensile properties and loop stitch length and G of shear properties showed a correlation coefficient over 0.9. But a relationship of objective properties and subjective textures and sensibilities was non-linear and a linear multi-regression analysis showed that a objective handle had a lower prediction power in the area of subjective textures and sensibilities.

The Correlation Parameters and the Optimization of a PN Sequence Phase for Variable Spreading Gain (VSG) Multi-Rate DS/CDMA System (멀티레이트 서비스를 지원하는 VSG-DS/C음 시스템에서의 PN 시퀀스 상관 파라미터 특성과 최적화)

  • 이연우;김응배;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • 제25권1A호
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    • pp.10-17
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    • 2000
  • In this paper, we evaluate the correlation properties and the optimization of PN sequence phase for multi-media DS/CDMA system with variable spreading gain (VSG) scheme. In multi-media multi-rate DS/CDMA systems, the optimization of PN sequence phase is not a tractable problem, since the sequences should be optimized against both sequences of the same length and other sequences with different length. Hence, we verify the correlation properties of PN sequence phase in multi-rate system environment and furthermore, we propose the new phase criterion, MIN-AIP (minimum-average interference parameter), to minimize the bit error rate (BER). As the results of performance evaluations, it is shown that the performance of MIN-AIP criteria gives the best results.

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Relationship between Meteorological Elements and Yield of Potato in Goheung Area (고흥지방 기상요인과 감자의 생육 및 수량과의 관계)

  • 권병선;박희진;신종섭
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 한국자원식물학회 2000년도 춘계임시총회 및 학술발표대회
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    • pp.26-33
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    • 2000
  • This study was conducted to investigate the relationships between yearly variations of elimatic elements and yearly variations of productivity in potato. In addition, correlation coefficients among yield and yield components were estimated. The data of yield and yield components were investigated for 9 years from 1987 to 1995. The meteorological data what gathered at the Goheung Weather Station for the same period of crop growing season were used to find out the relationships between climatic elements and crop productivity. Yearly variation of the daily minimum temperature in March and April were large with coefficients of variation (C.V.) of 126.0%, 368%, respectively, but the variation of the daily mean and maximum temperature in May and June were relative small. Stem length and number of stem show more C.V. of 9.3%, 14.3%, respectively, but the variation of the yield was relative small with 3.7%. Correlation coefficients between the amount of precipitation in April and yield, yield and daily mean temperature in June were negatively significant at the level of 5, 1 %, respectively. Correlation coefficients between the growth habits and yield are positively significant at the level of 5, 1 %, respectively. Simple linear regression equations by the least square method are estimated for stem length (Yl) and the precipitation in April(X) as Y,=82.47-0.11x (R2=0.3959), and for yield(Y2) and the precipitation in April(X) as Y,=2003.61-0.94X (R2=0.5418).

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Precise Positioning from GPS Carrier Phase Measurement Applying Stochastic Models for Ionospheric Delay (전리층 지연 효과의 통계적 모델을 이용한 반송파 정밀측위)

  • Yang, Hyo-Jin;Kwon, Jay-Hyoun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • 제25권4호
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    • pp.319-325
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    • 2007
  • In case of more than 50km baseline length, the correlation between receivers is reduced. Therefore, there are still some rooms for improvement of its positional accuracy. In this paper, the stochastic modeling of the ionospheric delay is applied and its effects are analyzed. The data processing has been performed by constructing a Kalman filter with states of positions, ambiguities, and the ionospheric delays in the double differenced mode. Considering the medium or long baseline length, both double differenced GPS phase and code observations are used as observables and LAMBDA has been applied to fix the ambiguities. The ionospheric delay is stochastically modeled by well-known 1st order Gauss-Markov process. And the correlation time and variation of 1st order Gauss-Markov process are calculated. This paper gives analyzed results of developed algorithm compared with commercial software and Bernese.

Correlation between motor function and gait pattern of stroke patients (뇌졸중 환자의 운동기능과 보행 양상의 상관 관계)

  • Choi, Sanho;Lee, Ilsuk;Hong, Haejin;Oh, Jaegun;Sung, Kang-keyng;Lee, Sangkwan
    • The Journal of the Society of Stroke on Korean Medicine
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    • 제14권1호
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    • pp.8-14
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    • 2013
  • ■ Objectives The goal of this study is to find the correlation between the motor function and gait pattern of stroke patients. ■ Methods We measured Manual muscle test(MMT), Motricity index(MI) and Spatiotemporal gait parameters of admitted hemiplegic patients with stroke. The gait parameters were measured using a Treadmill gait system. ■ Results There is a significant correlation between motor function and spatiotemporal parameters such as step length, stride length, step time, stride time, total double support or cadence, in stroke patients. ■ Conclusion The better motor function of stroke was, the more gait improved.

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