環狀 열파이프의 最大熱傳導率에 관한 硏究

權寧弼,方時桓 崇實大學校 1978 論文集 Vol.8 No.2

동작속도의 발달에 관한 연구

권영필 淸州敎育大學校 1998 論文集 Vol.35 No.-

The purpose of this study was to investigate the effects of age and sex on movement speed. Experiment was designed to examine the changes of movement time as a function of age(7, 10, 13, 16, 19), sex(male, female) and task complexity(1, 2, 4) from the developmental viewpoint. Subjects for the Experiment were 70 right-handed males and females and they were equally divided into five age groups: 7 years, 10 years, 13 years, 16 years, 19 years old groups. In all condition, task was simple and choice reaction and apparatus was Multipurpose Reaction Timer. Subjects were ordered to press the left button with the right hand as rapidly as possible after a few seconds of foreperiods. Experiment was performed in a 5 x 2 3-factors within subject design. The conclusions were as follows: First, movement time decreased as the increase of Age. Second, movement time increased as the increase of task complexity. Third, movement time of man is generally shorter than that of female.

跳馬 Handspring 動作의 Kinematic的 分析

權寧畢 師範大學 體育硏究所 1987 서울大學校 體育硏究所論集 Vol.8 No.2

The main purpose of this study was to clarify the Long Horse Vaulting technique of Korean athletes. In this study Hand Jump of those were investigated and their motions were filmed with 16mm high speed camera. By analyzing the film, We have reached the following conclusions. 1. At the taking off, There was a decrease in running speed which affect the horizontal velocity. 2. At the preflight, There was a tendency of rising up the location of the center of gravity. This was a factor involved in the decrease of the horizontal velocity. 3. At the hand departure, the angle of horse and body was relatively big and time of touching the horse was relatively long. These were the factors involved in the decreasing postflight duration. 4. At the postflight, Athletes didn't distribute horizontal and vertical components of velocity ideally. This was a factor that makes the postflight and landing difficult. 5. At the landing, The angle of body and land was different from person to person. This tells that the landing was unstable.

충돌면과 노즐의 형상이 원형충돌제트에 의한 충돌순음 발생에 미치는 영향

권영필,임정빈 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.6

쐐기소리에 관한 실험적 연구

권영필,장욱 崇實大學校 1999 論文集 Vol.29 No.1

Edge-tones are generated by a plane jet impinging on a wedge. Although a number of investigations with various wedges and nozzles have been performed, they are for low speed or supersonic jets with the purpose of confirming the Powell's feedback model. Thus, the objective of this paper is to measure the frequency characteristics, unstable region, unstable modes, convection velocities, directivity of edge-tones in the range of subsonic jet velocities. The experiment is performed by varying velocities and impinging distances for a slit nozzle and a sharp edged wedge in the central plane of the jet. It is found that impinging tones are generated in all subsonic velocities, but the characteristics of tones are found to be shifted around Re?14000, probably due to the transition of the shear layer from laminar to turbulent flow. The frequencies decreased with the Reynolds number and the impinging distance. The sound pressure level increases with the Reynolds numbers, but its maximum value is almost constant for Re≥ 10000. It is found that the unstable modes of plane jet are completely asymmetric. The directivity of the radiated sound is dipole-like with some shift to the downstream direction due to the jet stream. Convection velocities ratios were increased with Strouhal number and asymptotically decreased with stage number.

妊婦의 慢性 梗秘에 對한 Biotamin의 效果

權寧畢 梨花女子大學校 藥學硏究所 1964 梨花藥學硏究 Vol.- No.5

임신 2개월 - 10개월까지의 임부 21예에 대하여 활성 Vitamin 제인; Biotamin의 변비에 대한 효과를 검토하여 다음과 같은 결론을 얻었다. 1.변비기간단축효과 21예중 19예가 유효(유효률 90.4%)2예는 무효였다. 또한 3일간 변비라는 증상이 많았지만 그들은 11예중 7예까지가 2일에 있어서 배변했고 3일간 변비를 하고 있는 것 같은 증상에서는 본예는 이상적 치료제가 생각되었다. 2.배변량 증량효과 21예중 14예는 보통량 4예는 소량, 3예는 다량이고 특히 다량이 증량하는 것은 약간밖에 안보이므로 배변량 증량의 문제는 금후에 남은 연구과제이다. 3.유조산 기타 부작용은 없다. Biotamin은 이상 임부중 변비외에도 신경성질환에 있어서 신경통, 내과질환에 있어서의 피로회복, 각기 및 각기양증상, 급만성의 피부질환 안과질환 등 각 영역에서 사용되고 있다.

고속 충돌제트의 불안정 특성

권영필,임정빈,Gwon, Yeong-Pil,Im, Jeong-Bin 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.4

The characteristics of the unstable impinging circular jet is investigated based on the frequency characteristics and the sound field of the impinging-tones. Two symmetric modes S1 and S2, associated with low frequency and high frequency respectively, and one helical mode H have been observed. At low speed the S2 mode is dominant and switched by the S1 mode as the speed increases. When the jet speed is high the S1 mode is very active over the impinging distance from half the nozzle diameter to its ten times, while the S2 mode occurs at shorter distance corresponding to stage 2 and 3. The helical mode H seems unstable, likely to be influenced much by the experimental environment, and occurs at relatively high speed with almost the same frequency characteristics as the S2 mode. By estimating the convection speed of the unstable jet, it is found that the ratio of the convection speed to the jet speed decreases with both Strouhal number and Reynolds number and the speed of S2 mode is faster than the Si mode. When the present experimental results are compared with the previous investigations performed for the hole tone and the impinging tone with a small plate, the S1 mode is found to be associated with the ring vortex of large diameter with low speed, but the S2 mode with the vortex of small diameter with high speed. In addition, the frequency is found to be influenced by the nozzle configuration but the characteristics is almost the same. From the impinging distance and frequency range, it can be deduced that S1 mode is related with the jet column mode and S2 mode with the shear mode.

기류가 있는 관에서 가열에 의한 열음향력의 발생

권영필,이병호 한국음향학회 1984 韓國音響學會誌 Vol.3 No.1

Thermoacoustic oscillation induced by a heater in a tube with air current is studied theoretically. Linearized perturbation equations are derived in dimensionless form under the assumption that the system is one dimensional. The equation to predict the acoustic power generation from a heating surface is derived and calculated by solving differential equations numerically. The effect of the mean velocity of the air current is illustrated. The energy conversion mechanism is shown by pressure-volume diagram like a heat engine.

맥동류에 놓인 등온 원통의 열전달 응답

권영필,이병호 대한기계학회 1986 대한기계학회논문집 Vol.10 No.5

본 연구는 맥동류의 진동 속도가 평균 유속에 비하여 매우 작은 경우로서 Re- ynolbs수가 40 이하 층류유동에 관한 것이다. 부력은 무시하고 비압축성의 점성유체 에 관한 비정상 Navier-Stokes 방정식과 에너지방정식의 선형 섭동방정식을 구하고, 진동성분의 복소진폭을 수치적으로 풀어서 저항력과 함께 열전달 응답의 진폭과 위상 을 구하였다. The unsteay heat transfer from an isothermal circular cylinder in fluctuating cross flow is simulated numerically, for the case where the amplitude of the oscillating velocity is small compared with the mean velocity. By solving the linear perturbation equations derived from the unsteady full Navier-Stokes and the energy equations, the amplitude and the phase of heat transfer response are obtained in the range of Reynolds number R$_{3}$ < 40. The effects of the velocity, the cylinder radius and the frequency on the response are expressed graphically in terms of the normalized velocity and the cylinder radius.

쐐기소리의 되먹임 사이클의 위상조건

권영필,Gwon, Yeong-Pil 대한기계학회 1996 大韓機械學會論文集B Vol.20 No.3

The phase criterion of the feedback cycle of low-speed edgetones has been obtained using the jet-edge interaction model which is based on the substitution of an array of dipoles for the reaction of the wedge to the impinging jet. The edgetone is produced by the feedback loop between the downstream-convected sinuous disturbance and upstream-propagating waves generated by the impingement of the disturbance on the wedge. By estimation of the phase difference between the downstream and the upstream disturbances, the relationship between the edge distance and the wavelength is obtained according to the phase-locking condition at the nozzle lip. With a little variation depending on the characteristics of jet-edge interaction, the criterion can be approximated as follows: h/.LAMBDA. + h/.lambda. = n - 1/4, where h is the stand-off distance between the nozzle lip and the edge tip, .LAMBDA. is the wavelength of downstream-convected wave, .lambda. is the wavelength of the upstream-propagating acoustic wave and n is the stage number for the ladder-like characteristics of frequency. The present criterion has been confirmed by estimating wavelengths from available experimental data and investigating their appropriateness. The above criterion has been found to be effective up to 90.deg. of wedge angle corresponding to the cavitytones.