영점검출을 이용한 광섬유형 전자 스페클 패턴 간섭계의 위상이동

박형준,송민호,이준호,Park, Hyoung-Jun,Song, Min-Ho,Lee, Jun-Ho 한국광학회 2005 한국광학회지 Vol.16 No.6

We proposed an efficient phase stepping method for the use in fiber-optic ESPI. To improve phase-stepping accuracy and efficiency, a fiber-optic Michelson interferometer was phase-modulated by a ramp-driven fiber stretcher, resulting in 4$\pi$ phase excursion in the PD interference signal. The zero-crossing points of the signal, which have consecutive $\pi$ phase difference, were carefully detected and used to generate trigger signals for the CCD camera. From the experimental results by using this algorithm, $\pi$/2 phase-stepping errors between the speckle patterns were measured to be less than 0.6 mrad with 100 Hz image capture speed. Also it has been shown that the error from the nonlinear phase modulation and environmental perturbations could be minimized without any feedback algorithm. 본 논문에서는 광섬유형 전자 스페클 패턴 간섭계에 적용할 효과적인 위상이동 방법을 제안한다. 광섬유 마이켈슨 간섭계에 4$\pi$ 위상변조를 주기적으로 가하면서 각각 $\pi$의 위상차이를 갖는 4개의 영점위치를 검출하여 CCD 카메라의 이미지 취득신호를 생성한다. 이 신호에 따라 얻어지는 스페클 패턴은 위상추출 과정에 필요한 $\pi$/2 위상차이를 갖게 되며 후처리를 통하여 측정 대상체의 3차원적인 표면 위상정보를 얻게 된다. 환경적인 외란에 비하여 충분히 빠른 위상변조를 가할 경우 귀환제어 없이 빠르고 정확하게 $\pi$/2 위상 이동에 따른 CCD 동작신호를 생성할 수 있었으며, 위상변조기의 비선형적인 동작특성에 영향 받지 않는 실험결과를 얻을 수 있었다. 실험을 통하여 100 Hz의 영상 취득 속도를 얻었고, 25 Hz의 위상변조를 가할 때 출력 위상계단 신호의 오차는 0.6 mrad이었다.

한의사 전문의 인력수급에 관한 한방의료계의 인식조사

박형준,윤채현,김진희,문옥륜,Park, Hyoung-Jun,Yoon, Chai-Hyun,Kim, Jin-Hee,Moon, Ok-Ryun 대한예방한의학회 2005 대한예방한의학회지 Vol.9 No.1

The purpose of this study was to find out the various opinions of Oriental Medical Doctors to give the recommendations for making the proper policy of the supply and demand of Oriental Medical specialist. This study was desinged of 480 doctors who answered about questions that is composed of 105 Oriental medical specialist, 227 Apprentice doctor and 148 Oriental Medical doctors. On the assumption that there are many different situations and visions about the Oriental medical specialty system, we wanted to know about the each situations and visions about oriental specialty system. Generally, as one grows older, they adapted high proportion about the propriate number of specialist. About this difference from each generations, we can explain that young doctors more worry about the supply of specialist. As well each achievement, the more higher achievement, the more higher proportions of specialist is adapted. Answers about the number of present specialist, the more aging the more negative response about the number of present, number of specialist, this is because of the proprotions who wanted to be a specialist in open doctors. About the property of the number of specialist, there are many different views in each other groups. Anyway it is important that hearing the opinion of each Oriental Medical Doctors for the better Oriental Medical System.

전력설비 보호를 위한 분배형 광섬유 온도센서

박형준,이준호,송민호,Park, Hyoung-Jun,Lee, June-Ho,Song, Min-Ho 한국조명전기설비학회 2006 조명·전기설비학회논문지 Vol.20 No.5

We developed a fiber-optic temperature sensor system, with 10 fiber Bragg gratings, for abnormal high-temperature monitoring in power systems. We used Gaussian line-fitting algorithm to compensate the spectrum distortion in the wavelength-scanned Farby-Perot filter demodulation scheme. Compared with highest-peak-detection method, the proposed algorithm substantially reduced measurement errors. The overall measurement error was less than 1[%] compared with the reference thermocouple and the linearity error was 0.37[%]. 전력설비의 비정상적인 온도변화를 감시할 목적으로 10개의 광섬유격자를 이용하여 $1[^{\circ}C]$ 이내의 온도분해능을 가지는 준분배형 광섬유 온도센서를 제작하였다. 파장가변 FP 필터를 스캔하여 얻어지는 PD 출력파형의 피크위치를 검색하여 광섬유격자 센서의 출력변화를 읽어내었고, 가우시안 line-fitting 알고리즘으로 광섬유격자의 반사스펙트럼 왜곡에 의한 영향을 보상하고 정밀도를 향상시켰다. 제작한 센서시스템과 기준 온도계로 사용한 thermocouple 간의 측정값 오차는 1[%] 이내이며, 선형화 오차는 약 0.37[%]으로 측정되었다.

Fabry-Perot ITU 필터의 기준파장을 이용한 분배형 광섬유 격자 온도센서의 선형복조

박형준,손민호,Park, Hyoung-Jun,Song, Min-Ho 한국조명전기설비학회 2007 조명·전기설비학회논문지 Vol.21 No.7

We constructed a fiber-optic temperature sensor system using a sensor array with 15 fiber Bragg gratings for distributed temperature monitoring in electrical power systems. A polynomial fitting algorithm was used to compensate the nonlinear action of the MEMS tuneable wavelength filter used for Bragg wavelength demodulation Fixed passband wavelengths from a Fabry-Perot ITU filter were used as reference wavelengths for the fitting algorithm which obtained constant accuracy regardless of the wavelength scanning range and frequency. About 0.18[%] of linearity error compared to reference thermocouple thermometer has been obtained in the preliminary experimental results. 15개의 광섬유 격자를 이용하여 전력설비의 온도변화를 상시 감시하는 분배형 광섬유 온도센서 시스템을 제작하였다. MEMS 파장가변 필터를 사용하는 복조시스템의 비선형 동작특성에 의한 측정오차를 보상하기 위하여 Fabry-Perot ITU 필터의 투과파장을 기준으로 하는 다항식 피팅 알고리즘을 사용하였다. 실험을 통하여 보상알고리즘이 구동주파수와 무관하게 센서시스템의 정밀도를 유지하는 것을 확인하였으며 기준 온도계로 사용한 써모커플과의 선형화 오차는 약 0.18[%]로 측정되었다.

SOA를 광원으로 사용하는 광섬유 센서 어레이의 출력 안정화

박형준(Hyoung-Jun Park),김현진(Hyun-Jin Kim),송민호(Minho Song) 한국조명·전기설비학회 2008 한국조명·전기설비학회 학술대회논문집 Vol.2008 No.5월

We developed a fiber-optic Bragg grating sensor system using a SOA fiber laser for over heat detection in power systems. To compensate the nonlinear wavelength tuning of the fiber laser, we used fixed passband wavelengths from Fabry-Perot ITU filter as reference wavelengths. Gaussian line-fitting algorithm was also used to reduce the FBG peak detection error. Compared with a highest-peak-detection and a polynomial-fitting method, the proposed Gaussian fitting algorithm could drastically reduce the measurement errors. Also the SOA fiber laser made it possible to enhance the signal-to-noise-ratio even with several kilometers of lead fiber.

전력설비 보호를 위한 온도계전기용 광섬유 분배센서

박형준(Hyoung-Jun Park),이준호(June-Ho Lee),송민호(Minho Song) 한국조명·전기설비학회 2006 한국조명·전기설비학회 학술대회논문집 Vol.2006 No.5월

We proposed a distributed fiber-optic sensor system, with 10 fiber Bragg gratings, for over temperature protection relay in power systems. We applied Gaussian line-fitting algorithm to compensate the distortion effects in the wavelength-scanned Farby-Perot filter demodulation scheme. Compared with the highest-peak-detection method, the proposed algorithm was proved to minimize the random errors of distorted PD profiles. From experimental results, the overall measurement error was within 1 % compared with the reference thermocouple and the linearity error was less than 0.37 %.

퍼지 PI제어를 이용한 광섬유형 ESPI의 위상 안정화

박형준(Hyoung-jun Park),송민호(Min-ho Song) 한국조명·전기설비학회 2004 한국조명·전기설비학회 학술대회논문집 Vol.2004 No.5월

We propose a phase stabilization and control system for the use in fiber-optic ESPI. The fast phase stabilization against environmental perturbations has been achieved by using Fuzzy PI control. Combined with closed-loop switching, the system showed accurate and fast π/2 phase stepping capability.

HVDC-MMC 시스템의 환경모니터링 모듈을 위한 5W급 PoF 디바이스 개발

박형준(Hyoung Jun Park),김대길(Dae-gil Kim),김량수(Ryangsoo Kim),손병희(Byung-Hee Son),유학(Yoo Hark) 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.7

완충지역을 활용한 타부두 환적 컨테이너 운송 개선 방안

박형준(Hyoung-Jun Park),신재영(Jae-Young Shin),최양호(Yang-Ho Choi) 한국항해항만학회 2021 한국항해항만학회지 Vol.45 No.6

환적화물 유치를 위해 전 세계 항만 간의 경쟁이 심화되고 있다. 하지만, 최근 중국의 해운부문 카보타지 정책 해제, 안전운임제 시행 등 국내 항만의 환적화물 물동량 이탈이 우려되는 상황들이 발생하고 있다. 운영적 측면에서도 터미널별 환적 물동량의 불균형, 특정 시간대에 집중된 차량 등으로 인해 터미널 혼잡 및 차량 대기시간 문제가 심각하게 나타나고 있다. 본 논문에서는 타부두 환적운송 시스템으로 인해 발생하는 차량 대기시간 문제를 해결하기 위해 완충지역을 활용한 타부두 환적 컨테이너 운송 방식을 제안하고 문제에 대한 혼합정수계획모형을 제시하였다. 부산 신항 데이터에 기반한 터미널 혼잡 패턴과 터미널간 운송 차량 반출입 패턴을 적용하여 다양한 작업량, 가용량 변동폭에 대해 완충지역 활용에 따른 효과를 분석하였다. Competition between ports around the world is intensifying to attract transshipment cargo. However, recently, there have been concerns about the departure of transshipment cargo volume at Busan Port, such as the lifting of the cabotage policy in China’s shipping sector and the implementation of a safe fare system. In terms of operation, terminal congestion and vehicle waiting time are seriously occurring due to imbalance in the transshipment volume of each terminal and vehicles concentrated in a specific time period. In this paper, we propose a method of inter-terminal transportation (ITT) using buffer space to solve the problem caused by inefficient ITT systems and presented a mixed integer programming (MIP) for the problem. The effect of using the buffer space was analyzed for various work volumes and capacity fluctuation ranges by applying the terminal congestion pattern and ITT vehicle in/out pattern based on the Busan New Port data.

광CT 센서코일 끝단의 반사율이 전류측정에 미치는 영향

박형준(Hyoung-Jun Park),김현진(Hyun-Jin Kim),송민호(Minho Song) 한국조명·전기설비학회 2008 한국조명·전기설비학회 학술대회논문집 Vol.2008 No.5월

We improved an efficiency of fiber-optic current transformer by using a metal-coated sensor coil. To reduce the linear birefringence, we used a length of span fiber as sensor coil, and then used a flint glass fiber coil for comparison. To make the sensor coil in the reflection type, we used different reflection mirrors at the end of the sensor coil, such as a Faraday rotator mirror, a simple mirror, a metal-coated fiber end and a simple fiber end. From the experimental results, the linear error of current measurements were less than ~ 0.2 % regardless of the mirror types. The metal-coated sensor was the most cost-effective considering the fabrication cost and the simple structure.