• 제목/요약/키워드: $\180^{\circ}$

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등가구면 시력으로부터 난시량의 예측 (Expectation of Astigmatism by Spherical Equivalent Visual Acuity)

  • 김상엽;문병연;조현국
    • 한국안광학회지
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    • 제16권2호
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    • pp.167-170
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    • 2011
  • 목적: 등가구면 시력을 통한 피검자의 난시량 예측이 가능한지를 알아보고자 하였다. 방법: 평균연령 23.3세의 남녀 54명(108안)을 대상으로 굴절이상 완전교정 후 크로스실린더의 도수를 ${\pm}$0.25D씩 증가시키면서 크로스실린더의 (-)축이 $180^{\circ}$ 일 때, $90^{\circ}$ 일 때, 그리고 $45^{\circ}$ 일 때의 원거리(5m) 시력변화를 각각 측정하였다. 결과: 크로스실린더의 도수가 증가될수록 시력은 반비례하여 감소되었다. 크로스실린더 ${\pm}$2.50D ($180^{\circ}$$90^{\circ}$)과 ${\pm}$2.25D ($45^{\circ}$)에서 측정 최소값인 시력 0.05로 나타났다. 결론: 각각의 등가구면 시력에 대응하는 난시량에 대한 관계를 추정할 수 있었다.

편파면 회전을 위한 도파관 아이리스 편파기 설계 분석 (Analysis and Design of Waveguide Iris Polarizer for Rotation of Polarization Plane)

  • 양두영;이민수
    • 한국산학기술학회논문지
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    • 제13권7호
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    • pp.3201-3206
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    • 2012
  • 본 논문은 정방형 도파관을 이용하여 편파면을 회전시키는 편파기의 단순화된 설계법을 제안하였다. Ku 밴드 주파수인 14.3GHz~14.8GHz에서 동작하는 $180^{\circ}$ 편파기의 특성을 최적화하기 위하여, 개선된 모드정합법과 구분적 멱보간법을 편파기 설계에 적용하였다. 최적화 결과는 VSWR<2 인 범위의 Ku 밴드 주파수 대역에서 500MHz의 대역폭을 나타내었고, 직교모드 $TE_{10}$$TE_{01}$ 간에 위상차는 14.2GHz~14.8GHz 주파수 대역에서 $180^{\circ}{\pm}1^{\circ}$ 를 갖는다. 그리고 교차편파 손실은 40dB 이하이고, 통과대역의 삽입손실은 0.1dB 이다. 따라서 제안한 편파기는 낮은 VSWR과 소형의 크기가 요구되는 실질적인 Ku 밴드 시스템에 적용이 가능하다.

The Effects of Isokinetic Exercise on Knee Joint Combined Russian Current Stimulation

  • Kim, Dong-Hoon;Jung, Ho-Bal
    • The Journal of Korean Physical Therapy
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    • 제27권5호
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    • pp.351-355
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    • 2015
  • Purpose: This study was conducted to determine how stimulation using Russian current changes isokinetic exercise performance of quadriceps muscle and its antagonist muscles. Methods: Subjects were 20 20-year-old healthy adults who were instructed in the flexion to extension of knees in angular velocity $60^{\circ}/sec$ and $180^{\circ}/sec$ using a Biodex (Biodex system 3). We measured the difference in muscle performance between the Russian current stimulated at the same time during the flexion to extension of knees and not stimulated. Results: The results showed that when Russian current stimulation was applied at the angular velocity $60^{\circ}/sec$, the flexed and extended muscles and the angular velocity $180^{\circ}/sec$ increased significantly, but the peak torque of flexing muscles at the angular velocity $180^{\circ}/sec$ did not increase. Conclusion: These findings suggest that Russian current stimulation with isokinetic exercise of the knee joint could affect the quadriceps muscle and its antagonist muscle performance of muscle strength and endurance.

Lange 커플러를 이용한 MMIC 위상변위기 특성 (The Characteristics of MMIC Phase Shifter with Lange Coupler)

  • 정명득;박동철
    • 한국전자파학회논문지
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    • 제14권2호
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    • pp.104-110
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    • 2003
  • 광대역에서 동작되는 간단한 180$^{\circ}$ MMIC 위상변위기를 제안하였다. 제안된 회로는 1개의 Lange 커플러와 2개의 PIN 다이오드만으로 구성되어 있다. 2-6 GHz 대역에서 측정된 위상변위기는 최대 위상오차가 13$^{\circ}$이며 3.2 dB의 최대 삽입손실과 6.3 dB의 최소 반사손실을 보였다.

정사각단면 $180^{\circ}$ 곡관덕트의 입구영역에서 비정상층류유동의 유동특성에 관한 연구 (A Study on Characteristics of Unsteady Laminar Flows in Squaresectional $180^{\circ}$ Curved Duct)

  • 박길문;모양우;조병기
    • 대한의용생체공학회:의공학회지
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    • 제17권4호
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    • pp.515-524
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    • 1996
  • The flow characteristics of developing unsteady laminar flow in a square-sectional $180^{\circ}$ curved duct are experimentally investigated by using laser doppler velocimerty (LDV) system with data acquisition and processing system of rotating machinery resolver(RMR) and PHASE software. The major flow characteristics of developing laminar pulsating flows are presented by mean velocity profilel velocity distribution of secondary flow, wall shear stress distributions, entrance lengths according to dimensionless angular frequency($\omega^+$), velocity amplitude ratio($A^1$), and time-averaged Dean number($De_ta$). The velocity profiles and wall shear stress distribution of laminar pulsating flow with dimensionlessangular frequency show the flow characteristics of the quasi-steady laminar flow in a curved duct. The developing region of laminar pulsatile flows in a square-sectional $180^{\circ}$ curved duct is extended to the curved duct angle of approximately $120^{\circ}$ under the present experimental condition.

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자세에 따른 어깨관절 굽힘 각도가 악력에 미치는 영향 (The Effects of Flexion Angle of Shoulder Joints in Various Postures on Grip Strength)

  • 이삼철;김봉환;정재우
    • 대한물리치료과학회지
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    • 제20권1호
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    • pp.43-49
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    • 2013
  • Background and purpose : The shoulder joints permit the greatest mobility of any joint area carries out the important function of stabilization for hand use. Research has now shown that grip strength has proven to be a reliable indicator for quality of life at an older age. The purpose of this study was to investigate the effects of testing posture and shoulder position on grip strength for repetitive gripping task. Methods : Forty(20male, 20female) college adult volunteers with no known shoulder dysfunction participated subject in two testing posture(sitting and standing) and three positions with shoulder flexion: (1) shoulder $0^{\circ}$ flexion (2) shoulder $90^{\circ}$ flexion (3) shoulder $180^{\circ}$ flexion. The paired t-test was used to determine any significant difference in grip strength between the testing posture and shoulder position. Results : The higher grip strength gained in the sitting with the shoulder $180^{\circ}$ flexion and the higher grip strength gained in the standing with the shoulder $180^{\circ}$ flexion. The second experiment showed that the grip strength was significant for sitting, standing position of shoulder $0^{\circ}$ flexion( p<0.05). Grip strength goes up as increase height and weight. Conclusion : These findings demonstrate that the theory does not fit with, because of the influence of gravity, a measure from the shoulder joint is the most high, $0^{\circ}$. And sitting posture and stance in the grip of a difference when compared SIT $0^{\circ}$ and standing position $0^{\circ}$ significant difference in indicated but, $90^{\circ}$ and $180^{\circ}$ in the sitting position and stance in the grip of the difference was not significant difference. To demonstrate the universality of this study's results, future studies should have a larger and more subject as well as a more even distribution of male and female subject. Therefore future research is needed to refine the definition and identify optimal methods of measuring this grip strength.

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Flare Skirt 디자인의 밑단 둘레 계산방법(計算方法) 연구(硏究) (The Calculating Method Study of the Hem Circumference in Designing Flare Skirt)

  • 정형도;박정애;유태순
    • 패션비즈니스
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    • 제1권4호
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    • pp.49-54
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    • 1997
  • Methods of the flare skirt pattern making are presented variously among foreign and domestic test books. Three of them are : First the method is using the basic skirt pattern, secondly the method is quartering rectangle of skirt length $\times\frac{W}4$, finally the method is substituting waist size for formula. But, these books don't include the calculating method of the hem circumference. This calculating method express the shape of flare skirt and the using length of trimming -race and frill-. This study aims at proposing the calculating formula of the hem circumference and the standardization of pattern making technical skill. The result were as follows. 1. The calculating formula of hem circumference had regular ratio in $180^{\circ}$, $270^{\circ}$ and $360^{\circ}C$ flare. That was (HEM) = $(\frac{(5\;{\times}\;(W\;+\;1)}{4\;{\times}\;A}+(SK.L))\;{\times}\;A\;{\times}\;0.785$. A was 4 in $180^{\circ}$, 6 in $270^{\circ}$, 8 in $360^{\circ}$. 2. The error of hem circumference from 46 to 86 centimeter of waist size was between 0.11875 and -0.63125 centimeter in $180^{\circ}$, $270^{\circ}$ and $360^{\circ}$ flare skirt. This formula was less in the error.

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가스크로마토그라피에 의한 l-에페드린과 dl-메칠에페드린의 정량 (Gas chromatographic determination of l-ephedrine and dl-methylephedrine)

  • 윤용균
    • 약학회지
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    • 제16권1호
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    • pp.55-64
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    • 1972
  • The determination method of l-ephedrine and dl-methylephedrine by gas chromatography was developed, using reactive alkaline precolumn packed with celite 545 containing KOH. Symmetrical peaks were achieved under the condition, inlet temperature, $180^{\circ}C$-$230^{\circ}C$; column temperature, $180^{\circ}C$- $160^{\circ}C$; carrier gas flow rate, 30ml/minute. The peaks of the salts coincided with those of bases. When this method was applied to preparations, using d-dimethylaminobenzaldehyde as inner standard, good results were obtained. The relative retention times of l-ephedrine and dl-methylephedrine to p-dimethyl aminobenzaldehyde were 0.50 and 0.65 respectively.

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곡관덕트에서 난류진동유동의 전단응력분포와 압력분포 (Wall shear stress and Pressure Distributions of Developing Turbulent Oscillatory Flows in a Square sectional Curved Duct)

  • 이홍구;손현철;이행남;박길문
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집E
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    • pp.380-385
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    • 2001
  • In the present study, flow characteristics of turbulent oscillatory flow in a square-sectional $180^{\circ}$ curved duct are investigated experimentally. In order to measure wall shear stress and pressure distributions, experimental studies for air flow are conducted in a square-sectional $180^{\circ}$ curved duct by using the LDV system with the data acquisition and the processing system. The wall shear stress measuring point bend angle of the $150^{\circ}$ and pressure distribution of the inlet (${\phi}=0^{\circ}$) to the outlet (${\phi}=180^{\circ}$) at $10^{\circ}$ intervals of the duct. The results obtained from the experimentation are summarized as follows: A wall shear stress value in an inner wall is larger than that in an outer wall, except for the phase angle (${\omega}t/{\pi}/6$) of 3, because of the intensity of secondary flow. The pressure distributions are the largest in accelerating and decelerating regions at the bend angle(${\phi}$) of $90^{\circ}$ and pressure difference of inner and outer walls is the largest before and after the ${\phi}=90^{\circ}$.

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