• 천문학회지
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• 제8권1호
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• pp.15-23
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• 1975

A new technique of photographic observations is developed for the determination of time of minimum light of eclipsing binary. An instrumental system to accomplish the observation is described. With this instrument the atmospheric extinction coefficients in Seoul are observed, and four times of minimum light for Algol and W UMa are determined.

• 한국지구과학회지
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• 제25권7호
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• pp.507-518
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• 2004

이 연구의 목적은 중등학교에서의 실험수업을 평가하기 위한 도구를 개발하고 이를 적용하는 것이다. Dana(2001)가 개발한 상황적 실험활동도구를 수정, 보완하여 ‘실험수업의 탐구수준을 평가하기 위한 도구’를 만들었다. 타당도를 확보하기 위하여 전문가들과 여러 차례의 협의를 거쳤으며, 15명의 과학교육 전공 대학원생들에게 의뢰하여 타당도를 검증하였다. 신뢰도를 높이기 위하여 연구자와 평가자 2인이 3개의 전사된 수업을 읽고 난 후, 함께 녹화된 실험 수업을 보여 수준을 달리 하였을 때 도구의 내용을 수정하는 방법으로 신뢰도를 확보하였다. 이렇게 만들어진 평가도구를 4명의 중학교 초임과학교사의 수업에 적용하였다. 그 결과 개발된 평가도구는 중등학교의 실험수업 탐구수준을 결정하는데 좋은 도구라는 것을 확인하였다. 본 연구에 참여한 중학교 초임과학교사의 탐구수준은 확인수준과 구조화된 탐구주준인 것으로 나타났다.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 춘계학술발표회논문집
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• pp.83-89
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• 2004

The electronic distance measurement instrument, first introduced in the 1950s has, since those early days, undergone continual refinement. Rapid advances in related technologies have provided lighter, smaller and more precise equipment. Understanding for the principle, the standardized observation technique and the precision of EDM instrument is mostly important to improve the quality and the reliability of by-product in the field of engineering and industrial surveying. Simple and accurate calibration is regularly and periodically necessary to maintenance the precision of EDM instrument. This paper describes the calculated example of zero error and scale error as a correction of EDM by applying the least square method to baseline observations. Here we deals also with the testing criteria for precision instrument testing according to different types of EDM instruments.

• 대한인간공학회지
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• 제18권3호
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• pp.13-26
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• 1999

126 male and 95 female Korean college students were examined for Scoliosis by using Moire type body observation apparatus. Scoliotic hump measuring instrument, and spinal cord side curvature condition measuring instrument. The prevalence rate of Scoliosis along with identifying its possible causal factors and characteristics were investigated. The results revealed that 5.56% of male and 8.42% of female students(male to female ratio 1:1.47) were suspected as having Scoliosis. There was a significant correlation between the students who have symptoms of Scoliosis and their physiological measurements(e.g., lower breathing capacity of the lungs). There were also close relationships between the suspected cases and their habits(e.g., poor sitting and sleeping posture). It is concluded that the Scoliosis in Korean college students should not be ignored.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.113-115
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• 2005

To explore the seafloor, an observation instrument should be laid there for a long time and it should be again withdrawn. This system must be designed low power consumption model because it operates for a long period, but because power control don't execute or simply control algorithm executes, power efficiency is low. Hereupon, a power control algorithm for retrieval system using the ultrasonic communication that was improved its controllability and movability was presented in this paper. Likewise, the logicality of control algorithm and remote control system were ascertained by experiments.

• 한국환경과학회지
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• 제11권10호
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• pp.1055-1060
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• 2002

A new method of automatic recording raingauge is developed to measure rainfall 1200mm full scale with high accuracy and resolution. The principle of new instrument is to detect a weight change of a buoyant weight according to a change in water level of raingauge measured by the use of a strain gauge load cell. This method has the advantage of increasing measurement accuracy, since no moving equipment is used. Laboratory test of the instrument was recorded 0.4% error of 190mm rainfall amount. The validity of new instrument was examined by comparing its measured values with values recorded by automatic weather station on June 24 to 25 2001 at Daegu Meteorological Station, when there is 148.3mm rainfall amount. In spite of much rainfall there is only 0.77mm difference of total rainfall amount. This instrument was accomplished high accuracy and resolution at field test in much rainy day.

• 한국환경과학회지
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• 제31권9호
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• pp.803-813
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• 2022

In this study, we improved the water-based condensation particle counter in Atmospheric Research Aircraft NARA and investigated the condensation particle number concentration over the Korean peninsula. Pump and set point information were changed to improve the instrument used by aircraft for observation. Ground-based observational result showed that the error between two instruments, which are water-based condensation particle counter and butanol-based condensation particle counter, was 4.7%. Aerial observational result revealed that the number concentration before improvement indicate large variation with unstable condition, whereas the number concentration after improvement indicate a reasonable variation. After improvement, the number concentration was 706±499 particle/cm³ in the West Sea and 257±80 particle/cm³ in Gangwon-do, and these are similar to the concentration range reported in previous studies. Notably, this is the first attempt to use aerial observation with water-based condensation particle counter to investigate condensation particle number concentration.

• 한국과학교육학회지
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• 제13권1호
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• pp.80-91
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• 1993

The purpose of this study is to develop an reliable instrument for evaluating science inquiry skills through an R&D procedure. A total of ten seience inquiry skills were selected for the development of the instrument, ie, observation, classifying, recognizing problems, measuring, inferring, formulating hypothesis, controlling variables, experimenting, interpreting and drowing a conclusion. And three items were developed for each sceince inquiry skill, totaling up to thirty items. The content areas of developed items are divided into three categories, material and energy, life and environment, and the earth and the space. There are 10 items for each category. The content validity and the objectivity of developed items were checked, verified in the two field trials and revised according to the analysis of items by seven experienced specialists with the degree of doctors in science education and five teachers who were studying for their master's degree in science education. According to the results of the second field trial. the content validity of the instrument was 91.1%, reliablity(K-R 20) 0.78, defficulty index 49.13%, discrimination index 0.42, mean achivement 61.85%, standard deviation 5.11, and standard error 2.40. Considering the above results, the developed instrument in this study is regarded as a appropriate instrument for evaluating science inquiry skills of elementary school students.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.334-334
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• 2022

Improvement of old-fashioned rain gauge systems for automatic, timely, continuous, and accurate precipitation observation is highly essential for weather/climate prediction and natural hazards early warning, since the occurrence frequency and intensity of heavy and extreme precipitation events (especially floods) are recently getting more increase and severe worldwide due to climate change. Although rain gauge accuracy of 0.1 mm is recommended by the World Meteorological Organization (WMO), the traditional rain gauges in both weighting and tipping bucket types are often unable to meet that demand due to several existing technical limitations together with higher production and maintenance costs. Therefore, we aim to introduce a newly developed and cost-effective hybrid rain gauge system at 0.1 mm accuracy that combines advantages of weighting and tipping bucket types for continuous, automatic, and accurate precipitation observation, where the errors from long-term load cells and external environmental sources (e.g., winds) can be removed via an automatic drainage system and artificial intelligence-based data quality control procedure. Our rain gauge system consists of an instrument unit for measuring precipitation, a communication unit for transmitting and receiving measured precipitation signals, and a database unit for storing, processing, and analyzing precipitation data. This newly developed rain gauge was designed according to the weather instrument criteria, where precipitation amounts filled into the tipping bucket are measured considering the receiver's diameter, the maximum measurement of precipitation, drainage time, and the conductivity marking. Moreover, it is also designed to transmit the measured precipitation data stored in the PCB through RS232, RS485, and TCP/IP, together with connecting to the data logger to enable data collection and analysis based on user needs. Preliminary results from a comparison with an existing 1.0-mm tipping bucket rain gauge indicated that our developed rain gauge has an excellent performance in continuous precipitation observation with higher measurement accuracy, more correct precipitation days observed (120 days), and a lower error of roughly 27 mm occurred during the measurement period.

• 한국환경과학회지
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• 제23권3호
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• pp.399-407
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• 2014

In this study, before and after sunset carbon dioxide concentration and air temperature were observed in two points of atmosphere (lower observation point of the GL + 0.1 m, the upper observation point of GL + 1.0 m) on the foreshore at located in Suncheon Bay and their variations were analyzed. Observation was performed on the foreshore on 2~4 August 2010. Instrument (VAISALA, GMP343) was set two hours before sunset and then observation was made continuously for six hours. In three days, observed carbon dioxide concentration was 375~419 ppm, and the air temperature was in the range of $28.7{\sim}32.5^{\circ}C$. The average concentration of carbon dioxide was 388~399 ppm in the upper observation point and 386~396 ppm in the lower observation point. It was higher in the upper observation point and its fluctuations were similar in two observation points. Correlation coefficients between carbon dioxide concentration and air temperature in the upper observation point were in the range of -0.64~-0.88, and were calculated -0.65 to -0.90 in the lower observation point. For the carbon dioxide concentration, correlation coefficients between the upper part and the lower part were very high as 0.98 in three times. For the air temperature, correlation coefficients between the upper part and the lower part were very high as 0.97 and 0.99. In the same observation time, the slope of the linear regression function as carbon dioxide concentration in the lower observation point for the upper observation point was in the range of 0.97~1.01. Carbon dioxide concentration was slightly higher in the upper observation point. Because carbon dioxide in the lower observation point was closer on the surface of the foreshore and absorbed from atmosphere to the foreshore. In this study, it was showed that the vertical variation of carbon dioxide concentration was insignificant in the several meter scale of atmosphere on the surface of the foreshore.