• Title/Summary/Keyword: horizontal radius

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Measurement of Radius of Corneal curvature for Korean adults with Keratometer (한국인 성인 남녀의 각막곡률반경측정)

  • Kang, H.S.;Seo, Y.W.;Kang, I.S.
    • Journal of Korean Ophthalmic Optics Society
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    • v.1 no.2
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    • pp.71-76
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    • 1996
  • As the results of measurement of the radius of corneal curvature with keratometer, for the right eye of 91 male adults, horizontal radius is 7.16 mm to 8.49 mm and vertical radius is 7.03 mm to 8.34 mm, and for the left eye of male adults, horizontal radius is 7.10 mm to 8.48 mm and vertical radius is 7.01 mm to 8.24 mm. In case of 61 female adults, horizontal radius is 7.16 mm to 8.45 mm, vertical radius 7.11 mm to 8.18 mm for the right eye, and horizontal radius 7.15 mm 108.43 mm and vertical radius 7.01 mm to 8.26 mm for the left eye. The mean value of radius of corneal curvature is 7.74 mm for male and 7.69 mm for female. Also the mean value of horizontal radius is 7.79 mm and vertical radius is 7.64 mm. Overall mean value of the radius of corneal curvature is 7.71 mm that is corresponded to Gullstrand's eye. The horizontal radius is 0.15 mm bigger than vertical radius.

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A Study of Allowable Vertical Curve Radius on Horizontal Curved Section (원곡선구간에 종곡선 설치 가능한 곡선반경에 관한 연구)

  • Lee Ki-Seung
    • Proceedings of the KSR Conference
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    • 2003.05a
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    • pp.309-314
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    • 2003
  • A vertical curve should be installed in straight section. In case, it be installed on horizontal curved section, safety factor go down. In this study, it is calculated that the deficiency of cant about vertical curve radius on horizontal curved section. The result of this study will be used on planning the tack layout of railroad and design the track construction.

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Laboratory investigation of the effects of translation on the near-ground tornado flow field

  • Razavi, Alireza;Sarkar, Partha P.
    • Wind and Structures
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    • v.26 no.3
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    • pp.179-190
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    • 2018
  • Translation of tornadoes is an important feature in replicating the near-ground tornado flow field which has been simulated in previous studies based on Ward-type tornado simulators using relative motion of the ground plane. In this laboratory investigation, effects of translation on the near-ground tornado flow field were studied using the ISU Tornado Simulator that can physically translate over a ground plane. Two translation speeds, 0.15 m/s and 0.50 m/s, that scale up to those corresponding to slowly-moving tornadoes in the field were selected for this study. Compared with the flow field of a stationary tornado, the simulated tornado with translation had an influence on the spatial distribution and magnitude of the horizontal velocities, early reversal of the radial inflow, and expansion of the core radius. Maximum horizontal velocities were observed to occur behind the center of the translating tornado and on the right side of its mean path. An increase in translation speed, resulted in reduction of maximum horizontal velocities at all heights. Comparison of the results with previous studies that used relative motion of the ground plane for simulating translating tornadoes, showed that translation has similar effects on the flow field at smaller radial distances (~2 core radius), but different effects at larger radial distances (~4 core radius). Further, it showed that the effect of translation on velocity profiles is noticeable at and above an elevation of ~0.6 core radius, unlike those in studies based on the relative motion of the ground plane.

Effect of the Pin Radius on the Radiation Characteristics of a Patch Antenna with a Pin Array on a Patch (핀 반경이 패치에 핀 배열을 가지는 안테나의 방사 특성에 미치는 영향)

  • Lee, Woo-Ram;Kim, Tae-Young;Kim, Boo-Gyoun;Shin, Jong-Dug
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.355-356
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    • 2008
  • Effect of the pin radius on the radiation characteristics of a patch antenna with a pin array inserted between a patch and ground plane is investigated. As the pin radius increases, the resonant frequency increases and the radiation intensity in the horizontal plane decreases. However, the radiation intensity in the horizontal plane increases for the pin radius larger than a certain value.

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Study in Radius of Corneal Curvature of university Students with Keratometer (RGP 렌즈 착용한 대학생의 각막곡률반경 측정)

  • Kim, Chang-Sik;Ryu, Kwang-Min
    • Journal of Korean Ophthalmic Optics Society
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    • v.11 no.3
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    • pp.181-185
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    • 2006
  • The measurement of the radius of corneal curvature with keratometer was followed in 184 university students who wearing RGP contact lens and consisted of female(167), male(17) and keratoconus patients(3). Overall mean value in the radius of corneal curvature is 7.77mm, and right and left eyes is appeared the same mean value. Overall mean value in horizontal and vertical is 7.88mm and 7.65mm. Horizontal means is larger than vertical means by 0.22mm of the all female and male students. Male's mean value in the radius of corneal curvature(7.84mm) is larger than female's by 0.08mm, and right and left eyes is also the same mean value. Keratoconus patients' mean value in the radius of corneal curvature(6.86mm) is smaller than others students by 0.91mm.

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Evaluation on the Horizontal Alignment of Road Centerline using GIS Programming (GIS 프로그래밍을 이용한 도로중심선 평면선형 평가)

  • Kim, Dong-Ki;Choi, Se-Hyu
    • International Journal of Highway Engineering
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    • v.14 no.1
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    • pp.1-8
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    • 2012
  • The horizontal alignment of road is deeply related with the stability of the road and traffic capacity. It is necessary to analyze horizontal alignment of road accurately for efficient maintenance of the road and relevance judgment about the standard. Recently the study on horizontal alignment of road using Lidar data and GPS was concluded, but they were many problem analyzing horizontal alignment radius of curvature in wide area. In this study, the tool which the radius of curvature can evaluate the suitability about "Rules about the Road Structure & Facilities Standards" by using center lines of the road of the digital map tries to implement on GIS. The interface was designed and implemented which can automatically estimate the Road Centerline Horizontal Alignment by using $ESRI^{(R)}$ $ArcObject^{TM}$.

Development of Estimation of Curve Radii of Road Considering Design Consistency (설계일관성을 고려한 도로 곡선반경 산정에 관한 연구)

  • Park, Je-Jin;Lee, Sang-Ha;Park, Kwang-Won;Ha, Tae-Jun
    • International Journal of Highway Engineering
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    • v.10 no.2
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    • pp.125-133
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    • 2008
  • Achieving consistent geometric design is an important goal in highway design to ensure obtaining safe, economical and smooth traffic operation. Most evaluation of consistency is based on 'speed change' in speed profile. According to literature, the speed depends on geometric elements, speed on tangent section prior to a curve, and background around roads. Especially, the radius is the most main element mentioned in various literature. Therefore, this paper shows two ways of calculating horizontal radius on real road, that is, three-dimensional road. First of all, the radius of horizontal curve is calculated based on physical method. The calculated radius contains not only superelevation but also longitudinal grade while the current minimum radius is calculated by considering superelevation and side friction according to the point-mass equation. Secondly, the problem of composed curves with distorted appearance by overlaying sag or crest vertical alignment has been known. To quantify the extent of distortion effects, the method of calculation of real seen so called 'Perspective Radius' is developed. The paper presents the perspective radius and recommended perspective radius.

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The Study for Reduction of Stress Concentration at the Stepped Shaft According to Two Types of External Force (하중 종류에 따른 다단축의 응력 집중 완화에 대한 연구)

  • Park, I.S.;Shim, J.J.
    • Journal of Power System Engineering
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    • v.14 no.1
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    • pp.47-52
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    • 2010
  • In this study, Finite Element Analysis have been adopted to analyze reducing stress effect and used to induce the sensitivity of design parameter on various techniques which was used for reducing stress. And so it can be utilized as a data to design on similar model. The effect of reducing stress with respect to change of relief groove radius can be increased by 27.3~18.2 % more than radius of fillet. And if a shoulder fillet radius is larger, additional reducing stress by relief groove radius is not obtained. And there was only little effect on reducing stress by changing the center point of groove radius along horizontal direction. In the case that undercut radius is 1.5mm, Max. Equivalent stress is reduced by 5.71% under bending force and 11.11% under torsion. The best effect of reducing stress at undercut model was yielded when the undercut radius is a forth of difference of stepped shaft radius.

Basic Research for the Tactual User Interface Design (촉각적 사용자 인터페이스 디자인에 관한 기초 연구 -소형 원형 버튼의 크기 판별을 중심으로-)

  • Yang, Seung-Mu;Jeong, Byung-Yong
    • IE interfaces
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    • v.13 no.2
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    • pp.253-257
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    • 2000
  • This study was conducted to test the significance of differences in the tactual difference thresholds and perception time for tactual direction type and finger type and radius size based on small circular button. The results show that difference threshold of vertical tactual perception is significantly greater than horizontal perception, but there are no significant differences in difference thresholds among finger types and radius sizes. Also, there are no significant differences in tactual perception time among tactual direction types, finger types, and radius types. These findings are applicable for tactual user interface design.

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Effect of the Pin Radius on the Radiation Characteristics of a Patch Antenna with an Array of Pins Interconnecting the Patch and the Ground (패치와 접지면 사이에 삽입된 핀 배열을 가지는 안테나의 방사특성에 핀 반경이 미치는 효과)

  • Lee, Woo-Ram;Kim, Tae-Young;Kim, Boo-Gyoun;Shin, Jong-Dug
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.10
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    • pp.80-89
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    • 2008
  • Patch antennas with an array of pins interconnecting the patch and the ground (Pin array patch antennas) are fabricated and their characteristics are measured. The radiation characteristics of pin array patch antennas are compared to those of conventional patch antennas. The suppressions of the radiation in horizontal directions in E-plane and H-plane are more than 10 dB and 4 dB, respectively. The forward radiation is increased, while the backward radiation is decreased. The directivity is improved because the half-power beamwidth of radiation patterns in both E-plane and H-plane is reduced. The resonance frequency of a pin array patch antenna increases as the pin radius of a pin amy patch antenna increases. An optimum pin radius of a pin array patch antenna exists for the maximum suppression of the radiation in horizontal directions.