고온벽면 충돌에 의한 미립화

전인곤,전흥신 경희대학교 레이저공학연구소 2004 레이저공학 Vol.15 No.-

The breakup behaviors of impinging droplet on a hot surface are studied experimentally. The droplets are produced by the dripping method and the breakup behaviors of liquid droplet are recorded by photographs. Experimental conditions are, droplet diameter di : 2.5, 3.2 [mm], Weber number : 30∼140, surface temperature : 28℃ (room temperature) 450℃. Water is used as a liquid. As Weber number of droplet increases, a liquid sheet, which is formed after the impingement on a hot surface, is disintergrated by the dynamical effect. But at low Weber number, it has effected by thermodynamical effect. The breakup behaviors of droplet are divided into three patterns with Weber number and surface temperature, non-disintegration, transition and disintegration region. Further, these boundary values are affected by the hot surface temperature and Weber number. S11M of breakup droplets are calculated in according to surface temperature and Weber number. The minimum SMD of breakup droplets are observed at Weber number 65.49, temperature 250℃ and Weber number 99.08, temperature 350℃

고온벽면 충돌에 의한 미립화 ( Atomization of Liquid Droplet by Impingement onto the Hot Surface )

전인곤,이준백,전홍신 대한기계학회 2000 대한기계학회 춘추학술대회 Vol.- No.-

소형 가시화 시험 엔진 개발(Ⅰ)

전인곤,김용덕,전흥신 경희대학교 산학협력기술연구원 1998 산학협력기술연구논문집 Vol.4 No.-

University, college and Technical high school those have a department of mechanical engineering need a experimental practice engine form educational machinery and using this practice student in structure of engine, operation and efficiency characteristics. But, because the engine that they have purchased is for vehicles, agriculture and industry, it is not available to experimental practice, can't alter fuel and the ration of compression and also the combustion process is not visible so efficiency of education for practical machinery is very low. In this study, a fuel, ignition time, the ration of compression is alterable and we design a single cylinder 4-cycle engine of 60~100cc rate of stroke volume with a heat-proof glass that is visible.

초음파 진동판의 표면조도에 따른 분무특성에 관한 연구

이준백,전인곤,전흥신 경희대학교 레이저공학연구소 2000 레이저공학 Vol.11 No.-

The purpose of this study is to compare the SMD(Sauter mean diameter) according to surface roughness of vibrant plates. Liquid film thickness is measured for explanation how to concern ultrasonic atomization. Ultrasonic waves is used for vibration. Immersion liquid method is used for the measure of SMD and liquid film thickness is measured using of point needle method. Distilled water and gasoline fuel are used to liquids. Supplied liquid flow rates are 18∼296cc/min. Centerline average roughness of vibrant plates are 0.5, 2.0, 4.7, 9.5㎛ and diameter of vibrand plate is 60mm. The Vibrant plate with 70, 80mm diameter are used for verify practical limit of horn diameter. In result, good atomization of liquid is obtained in widen flow rates. The mean droplet size is increased in orders of 4.7, 2.0, 9.5, 0.5㎛ surface roughness. Distilled water has a big mean droplet size than gasoline fuel below 78cc/min flow rate but above 78cc/min flow rate, distilled water has a small mean droplet size than gasoline fuel. According to 0∼20.4W ultrsonic power, liquid film changes are measured. Liquid film thickness are fluctuated in 18, 196cc/min according to capillary wave and cavitation. 25mm diameter of horn has lower liquid film thickness because of big vibration of horn.

초음파 진동판의 표면조도에 따른 분무특성에 관한 연구 ( Characteristics of Sprays used Ultrasonic Vibrant Plate with the Surface roughness )

이준백,전인곤,전흥신 대한기계학회 2000 대한기계학회 춘추학술대회 Vol.- No.-

영구자석 MRI를 위한 능동형 자기 잡음 차폐시스템 기술 개발

이수열,전인곤,이항노,이정한 대한전자공학회 2003 電子工學會論文誌-SC (System and control) Vol.40 No.3

본 논문에서는 영구자석 자기공명영상시스템에 나쁜 영향을 기치는 외부 자기 잡음을 효율적으로 차폐하는 기술을 서술하였다. 유한요소법 전자계 해석을 통하여 영구자석의 주자계 방향과 일치하는 자기 잡음 성분이 자기공명영상에 주로 영향을 미치는 것을 밝혔고, 이의 해석 결과를 기반으로 자기잡음센서, 보상코일, 그리고 코일구동기로 구성되는 능동형 자기 잡음 차폐시스템을 개발하였다. 개발된 자기 잡음 차폐시스템은 수 Hz 미만의 저주파 대역의 자기 잡음에 대하여 30dB 이상의 차폐율을 보였으며, 0.3Tesla 전신형 자기 공명영상시스템에 자기 잡음 차폐시스템을 적용하여 자기 잡음에 의한 영상 잡음이 크게 개선됨을 실험적으로 밝혔다. In this paper, we introduce a magnetic noise shielding method to reduce the noise effects in permanent magnet based MRI systems. Through FEM electromagnetic analyses, we have shown that the magnetic noise component parallel to the main magnetic field is the major component that makes various artifacts in the images obtained with a permanent magnet based MRI. Based on the FEM analyses, we have developed an active magnetic noise shielding system composed of a magnetic field sensor, compensation coils, and a coil driving system. The shielding system has shown a noise rejection ratio of about 30dB at the frequency below several Hz. We have experimentally verified that the shielding system greatly improves the image quality in a 0.3 Tesla MRI system.

영구자석 MRI를 위한 능동형 자기 잡음 차폐시스템 기술 개발

李壽烈,全寅坤,李恒魯,이정한 대한전자공학회 2003 電子工學會論文誌-SC (System and control) Vol.40 No.5

In this paper, we introduce a magnetic noise shielding method to reduce the noise effects in permanent magnet based MRI systems. Through FEM electromagnetic analyses, we have shown that the magnetic noise component parallel to the main magnetic field is the major component that makes various artifacts in the images obtained with a permanent magnet based MRI. Based on the FEM analyses, we have developed an active magnetic noise shielding system composed of a magnetic field sensor, compensation coils, and a coil driving system. The shielding system has shown a noise rejection ratio of about 30dB at the frequency below several Hz. We have experimentally verified that the shielding system greatly improves the image quality in a 0.3 Tesla MRI system. 본 논문에서는 영구자석 자기공명영상시스템에 나쁜 영향을 끼치는 외부 자기 잡음을 효율적으로 차폐하는 기술을 서술하였다. 유한요소법 전자계 해석을 통하여 영구자석의 주자계 방향과 일치하는 자기 잡음 성분이 자기공명영상에 주로 영향을 미치는 것을 밝혔고, 이의 해석 결과를 기반으로 자기잡음센서, 보상코일, 그리고 코일구동기로 구성되는 능동형 자기 잡음 차폐시스템을 개발하였다. 개발된 자기 잡음 차폐시스템은 수 Hz 미만의 저주파 대역의 자기 잡음에 대하여 30dB 이상의 차폐율을 보였으며, 0.3Tesla 전신형 자기공명영상시스템에 자기 잡음 차폐시스템을 적용하여 자기 잡음에 의한 영상 잡음이 크게 개선됨을 실험적으로 밝혔다.

소 동물 촬영을 위한 Micro-CT의 개발

이상철,김호경,전인곤,조명혜,조민형,이수열 대한의용생체공학회 2004 의공학회지 Vol.25 No.2

We developed an x-ray cone-beam micro computed tomography (micro-CT) system for small-animal imaging. The micro-CT system consists of a 2-D flat-panel x-ray detector with a field-of-view (FOV) of 120120 mm2, a micro-focus x-ray source, a scan controller and a parallel image reconstruction system. Imaging performances of the micro-CT system have been evaluated in terms of contrast and spatial resolution. The minimum resolvable contrast has been found to be less than 36 CT numbers at the dose of 95 mGy and the spatial resolution about 14 lp/mm. As small animal imaging results, we present high resolution 3-D images of rat organs including a femur, a heart and vessels. We expected that the developed micro-CT system can be greatly used in biomedical studies using small animals.

우리 방언을 활용한 표현 능력 신장의 신나는 재량 활동

류성기,안정애,박찬이,전인곤,조미옥 晋州敎育大學校 初等敎育硏究所 2004 初等敎育硏究 Vol.14 No.-

디지털 수술용 가이드의 지지타입에 따른 정확도 평가

이준연,윤민호,박태석,전인곤,윤귀덕,Lee, Junyoun,Yoon, Minho,Park, Taeseok,Chun, Inkon,Yun, Kwidug 대한치과보철학회 2018 대한치과보철학회지 Vol.56 No.1

Purpose: The purpose of this study is to evaluate the accuracy of surgical stent according to the supported type. Materials and methods: 5 sets of dental models which have tooth supported edentulous area and tooth-tissue supported edentulous area were made. Dental model were scanned with model scanner, and CBCT was taken. CT data and model scan data were overlapped using In2Guide software, implant were virtually planned in the software. Surgical stents are fabricated by 3D printing. The implant fixture were installed using the surgical stent, CBCT were retaken. CBCT before surgery and after surgery were overlapped, and the differences (angle difference, coronal difference, apical difference) were evaluated using statistical analysis. Results: In the assessment of the accuracy of surgical guides according to arch type, there are no statistically significant differences between maxilla and mandible. In the case of support type, tooth supported stents showed lower angle difference and length difference than tooth-tissue supported stents, which are statistically significant. Conclusion: Arch type does not affect the accuracy of surgical stents. But tooth support stents are more accurate than tooth-tissue support stents in the case of angle and length difference. 목적: 본 연구의 목적은 디지털 소프트웨어를 이용하여 제작된 수술용 스텐트를 이용하여 지지 형태에 따른 수술용 스텐트의 정확성을 분석하는 것이다. 재료 및 방법: 총 5세트의 치아모형에 대하여 양측에 지대치가 있는 치아지지형 무치악 모델과 근심에만 지대치가 있는 치아-조직 지지형 무치악 모델을 제작하였다. 모델을 스캐닝을 시행하고, 전산화 단층 촬영을 실시하여 In2Guide 소프트웨어를 이용하여 전산화 단층 촬영술의 정보와 모델 스캐닝 정보를 중첩하여 임플란트 고정체(USII, $4{\times}10mm$, Osstem, Seoul, Korea)에 대한 가상적인 위치배열을 실시하고 수술용 스텐트 제작하였다. DMAX 수술 키트을 사용하여 임플란트 고정체를 식립하였다. 식립후 전산화 단층 촬영을 실시하여 찍어 술전에 계획된 임플란트와 실제 식립된 임플란트 사이에 오차(angle difference, coronal difference, apical difference)를 측정하여 통계분석을 시행하였다. 결과: 악궁에 따른 정확도 결과에서 하악이 전반적으로 각도, 길이오차의 값이 작게 나타났으나 이는 통계적 유의성이 없었다. 스텐트의 지지 형태에 따른 정확도 결과에서 치아지지형 스텐트가 치아-조직지지형 스텐트보다 길이오차와 각도오차의 값이 통계적으로 유의하게 작은 값을 보였다. 결론: 악궁(상악, 하악)은 수술용 스텐트의 정확도에 영향을 미치지 않았으며, 치아 지지형 스텐트는 치아-조직지지형 스텐트보다 더 적은 오차를 보여 주었다.