• 에너지공학
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• 제19권2호
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• pp.128-135
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• 2010

본 연구에서는 LabVIEW를 활용한 임베디드 태양추적장치가 개발되었다. 이 시스템은 LabVIEW로 작성된 소프트웨어, CompactRIO, C-계열의 모션 인터페이스 모듈, 아날로그 수집 모듈(DAQ:Data Acquisition), 스텝 드라이브, 스텝 모터, 피드백디바이스 그리고 기타 부품들로 구성되어져 있다. CompactRIO는 내부에 리얼타임 프로세서를 내장하고 있으며 이는 태양추적장치가 외부 제어없이도 자동으로 작동이 가능하게 한다. 태양 추적장치의 정확도를 높이기 위하여 천문학적인 방법과 광학적인 방법을 통합하여 개발하였다. 광학적인 방법에서는 피드백디바이스가 사용되었는데 4개의 CdS를 사용하여 지속적으로 피드백 신호를 컨트롤러로 공급하여 문제 발생시에도 태양을 지속적으로 추적한다. 태양의 고도 및 방위각의 데이터베이스는 미국의 Naval Observatory의 데이터와 비교하였다.

• Journal of Astronomy and Space Sciences
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• 제28권3호
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• pp.173-181
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• 2011

Korea Astronomy and Space Science Institute researchers have installed and operated magnetometers at Mt. Bohyun Observatory to measure the Earth's magnetic field variations in South Korea. We, in 2007, installed a fluxgate magnetometer (RFP-523C) to measure H, D, and Z components of the geomagnetic field. In addition, in 2009, we installed a Overhauser proton sensor to measure the absolute total magnetic field F and a three-axis magneto-impedance sensor for spectrum analysis. Currently three types of magnetometer data have been accumulated. In this paper, we provide the preliminary and the first statistical analysis using the BOH magnetometer installed at Mt. Bohyun Observatory. By superposed analysis, we find that daily variations of H, D, and Z shows similar tendency, that is, about 30 minutes before the meridian (11:28) a minimum appears and the time after about 3 hours and 30 minutes (15:28) a maximum appears. Also, a quiet interval start time (19:06) is near the sunset time, and a quiet interval end time (06:40) is near the sunrise time. From the sunset to the sunrise, the value of H has a nearly constant interval, that is, the sun affects the changes in H values. Seasonal variations show similar dependences to the sun. Local time variations show that noon region has the biggest variations and midnight region has the smallest variations. We compare the correlations between geomagnetic variations and activity indices as we expect the geomagnetic variation would contain the effects of geomagnetic activity variations. As a result, the correlation coefficient between H and Dst is the highest (r = 0.947), and other AL, AE, AU index and showed a high correlation. Therefore, the effects of geomagnetic storms and geomagnetic substorms might contribute to the geomagnetic changes significantly.

• Journal of Astronomy and Space Sciences
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• 제26권3호
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• pp.329-344
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• 2009

일광절약시간제는 하절기에 낮 시간을 효율적으로 활용하기 위한 것이다. 한국은 해방이후부터 1988년까지 12번의 일광절약시간제를 시행하였다. 지난 20여년간 이 제도가 실시되지 않았으나, 최근에 일광절약시간제의 시행에 관한 문제가 다시 제기되고 있다. 이 논문에서는 세계 여러 국가의 일광절약시간제 시행경향, 한국의 일광절약시간제 실시의 역사를 살펴보고, 일출 몰시각 변화에 따른 낮의 길이 변화를 계산해 한국에 적합한 일광절약시간제 시행시기를 연구하였다. 한국은 동경 $135^{\circ}$ 표준자오선을 사용하고 있는데, 일출시각과 표준자오선의 지역적 치우침을 고려해 계산한 결과, 5월 두번째 일요일이나 4월 두번째 일요일이 적절한 일광절약시간제의 시작시기임을 알아내었다. 또한 일광절약시간제를 시행할 경우 발생하는 한국표준시에 대한 시간마찰과 이에 파생되는 문제들을 논하였다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.31-36
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• 2009

There have been many solar tracking systems developed for the high accuracy in solar tracking. One of the key components of any motion control system is software. LabVIEW offers an ideal combination of flexibility, ease-of-use and well-integration with other I/O pieces for developing solar tracking system. Real-time solar positions which vary with GPS's data are used simultaneously to control the solar tracker by a chain of operating modes between the open and closed loops. This paper introduces a step by step procedure for the fabrication and performance assessment of a precision solar tracking system. The system developed in this study consists of motion controllers, motor drives, step-motors, feedback devices and application. CRD sensors are applied for the solar tracking system which play a primary role in poor conditions for tracking due to a gear backlash and a strong wind. Mini-dish was used as a concentrator for collecting sun light. The solar position data, in terms of azimuth and elevation, sunrise and sunset times was compared with those of KASI(Korea Astronomy & Space Science Institute). The results presented in this paper demonstrate the accuracy of the present system in solar tracking and utilization.

• 한국수산과학회지
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• 제36권3호
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• pp.263-269
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• 2003

Morphological development of eggs, larvae and juvenile of the sunrise sculpin, Pseudoblennius cottoides were studed in the field and laboratory at the coastal Dolsan-do, Yeosu-shi from October, 2000 to April, 2001 Egg mass of Pseudoblennius cottoides in peribranchial cavity of Halocynthia hilgendorfi, were observed during late fall to winter in the study area. Fertiliged eggs were spherical in shape, demersal, adhesive, transparent and greenwish yellow color, measuring 1.84 mm (1.83-1.87 mm) in diameter. There were numerous and 17 (15-20) various-sized oil globules accounted in the yolk. Granular materials formed a mass in the yolk. Fertiliged eggs hatched at 301 hr 20 min after morula stage. Newly hatched larvae 6.31 mm (6.24-6.37 mm) in total length (TL), had a large yolk. At 3 days after hatching, the larvae, 6.77 mm (6.69-7.14 mm) in TL came out through the excurrent siphon of Halocynthia hilgendorfi. At 13 days after hatching, the larvae 12.59 mm (12.42-12.63 mm) in TL transformed to postlarval stage. At 32 days after hatching, postlarvae of TL 19.18 mm (19.01-19.46 mm) have reached the juvenile stage.

• 수산해양기술연구
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• 제52권2호
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• pp.96-102
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• 2016

In order to establish the basic data for the active use of the LED light source in the aquaculture industry, the experiment about the behavior of rockfish (Sebastes inermis) corresponding to the LED light was conducted by image analysis. LED lights for the experiment were one red light (wave length: 622 nm; light power: 811 mW) and two green lights (wave length: 518 nm; light power: 648 mW, wave length: 518 nm; light power: 810 mW). Behavior of the rockfish was analyzed using a moving distance (MD5) for 5 minutes where MD5s during the period of feeding were 20.0 m, 19.6 m, 16.3 m and 20.5 m in the ch1, ch2, ch3 and ch4. At the sunrise, mean MD5 of the entire channel about right before and right after were 6.3 m and 8.2 m. At the sunrise, mean MD5s of the entire channel about right before and right after were 13.6 m and 12.0 m. In the ch1, ch2 and ch3, mean MD5s during the period of 24 hours were 13.2 m, 9.6 m and 6.8 m at experiment 1and 5.2 m, 3.8 m and 2.9 m in the experiment 2.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.276-292
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• 1996

The purpose of this study was to evaluate whether removal of gingival epithelium with pulsed Nd :YAG laser could inhibit the downgrowth of junctional epithelium after alloplastic material grafting in periodontal bone defect. The periodontal bone defects were created surgically on the palatal aspect of the upper right and left molar teeth in 30 rats and filled with resorbable calcium carbonate($Biocoral\;450^{(R)}$: Inoteb, France). The control sites(right molar area) was sutured. The test side (left molar area) received controlled deepithelization of the oral and sulcular epithelium with pulsed Nd:YAG laser($Sunrise\;Maste^{(R)}$: Sunrise Technologies, U.S.A.) under the mode of 1.75W, 15Hz, 116mJ/pulse and was sutured. The control and test sites were evaluated clinically and histologically, at 1, 3, 7, 14, and 28 days postoperation. Clinically, the gingiva showed normal color and shape at the 5th day in the control site and at the 10th day in the test sites. Histologically, the junctional epithelium was formed at the 7th day in the control sites and at the 14th day in the test sites, and the long JE attachment were observed at the 28th day in both sites. The attachment of connective tissue to root surface was observed initially at the 7th day in the control sites and at the 14th day in the test sites, and completed at the 28th day in both sites. In summary, these results showed that the removal of oral epithelium using pulsed Nd:YAG Laser could not prevent epithelial downgrowth after alloplastic material implantation in rat periodontal bone defect.

• 대기
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• 제23권3호
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• pp.275-282
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• 2013

In this study, the numerical model was developed to evaluate the observational environment of sunshine duration and, for evaluating the accuracy and utility of the model, it was verified against the observational data measured at Dae-gu Automated Synoptic Observing System (ASOS) located in an urban area. Three-dimensional topography and building configuration as the surface input data of the model were constructed using a Geographic Information System (GIS) data. First, the accuracy of the computing planetary positions suggested by Paul Schlyter was verified against the data provided by Korea Astronomy and Space Science Institute (KASI) and the results showed that the numerical model predicted the Sun's position (the solar azimuth and altitude angles) quite precisely. Then, this model was applied to reproduce the sunshine duration at the Dae-gu ASOS. The observed and calculated sunshine durations were similar to each other. However, the observed and calculated sunrise (sunset) times were delayed (curtailed), compared to those provided by KASI that considered just the ASOS's position information such as latitude, longitude, and elevation height but did not consider the building and topography information. Further investigation showed that this was caused by not only the topographic characteristic (higher in the east and lower in the west) but also the buildings located in the southeast near the sunrise and the southwest near the sunset. It was found that higher building resolution increased the accuracy of the model. It was concluded that, for the accurate evaluation of the sunshine duration, detailed building and topography information around the observing sites was required and the numerical model developed in this study was successful to predict and/or the sunshine duration of the ASOS located in an urban area.

• 에너지공학
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• 제20권4호
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• pp.353-357
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• 2011

본 연구에서는 AVR 마이크로 컨트롤러를 사용하여 임베디드 태양추적장치를 개발하였다. 본 시스템은 Atmega128 마이크로 컨트롤러, 스텝 모터, 스텝 드라이브 모듈, CdS 센서 그리고 GPS 모듈 및 기타 부품들로 구성되어 있다. 태양추적장치는 광학적 방법과 천문학적인 방법에 의해 작동된다. 최초 태양추적은 천문학적인 계산방법에 의해 얻어진 결과에 따라 이루어지고 CdS에 의해 미세 조정이 이루어진다. 태양추적장치가 설치된 지점에서 GPS는 UTC(Universal Time Coordinated)와 위도 및 경도 데이터를 마이크로 컨트롤러에 전송한다. 전송되어진 데이터에 의해 실시간으로 태양위치, 일출 및 일몰시간이 계산되어 진다. 태양 추적에 필요한 데이터들은 범용 비동기화 송수신기(UART)를 통하여 컴퓨터로 전송 받을 수 있다.

• Korean Journal of Acupuncture
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• 제36권4호
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• pp.252-263
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• 2019

Objectives : This research aimed to 1) analyze the true meanings of the chapter, 'Wigi Haeng (Wei Qi Xing), the movement of guard qi' in Youngchu (Ling Shu) from the point of view of ancient Chinese Astronomy, 2) calculate the speed of Wigi over 24 Chinese seasons, 3) analyze the true meaning of daytime and nighttime in the chapter. Methods : 1) The chapter 'Wigi Haeng' was analyzed using concepts of ancient Chinese astronomy, 2) the records of angular distances of 28 constellations in the Book of Han (Han Shu) were used to analyze the meanings, and 3) the records of lengths of daytime and nighttime in the Book of Hou Han (Hou Han Shu) were used to calculate the speed of Wigi. Results : 1) The author of the chapter 'Wigi Haeng' did not consider the irregularity in the angular distances of the 28 Chinese constellations (Su). 2) The commentary in the Huangjenaegyong Taeso (Huang Di Nei Jing Tai Su) about the constellations in the chapter is correct. 3) The speed of Wigi changes in daytime and nighttime depending on the seasons. 4) When the speed of Wigi increases in daytime, the speed in nighttime decreases, and vice versa. 5) The beginning of daytime in 'Wigi Haeng' is not the time of sunrise but the time of dawn (2.5 Gak before sunrise). The nighttime ends 2.5 Gak after sunset. Conclusions : 1) The chapter 'Wigi Haeng' demonstrates the ancient astronomical point of view on the universe and the movement of Wigi. The speed of Wigi is variable. 2) This chapter does not address the irregularity in the angular distances of the 28 Su. 3) More research is needed on the meaning of daytime and nighttime in 'Wigi Haeng'.