• 한국지구과학회지
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• 제31권6호
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• pp.555-562
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• 2010

응력을 받고 있는 사면의 변형 여부를 분석하기 위해 3차원 레이저 스캐너를 이용하여 일정 기간의 차이를 두고 정밀 측량을 수행하였다. 3차원 레이저 스캐너는 비접촉식으로 레이저 빔의 주행시간을 이용하여 대상점의 3차원 좌표를 결정할 수 있는 장비로써, 사면이나 대형 구조물의 변위를 분석하는데 매우 유용한 장비이다. 스캐닝은 약 7개월의 시간차이를 두고 이루어졌으며, 측정간의 비교를 위해 사면의 외부에 기준점을 유지하여 사용하였다. 변형 여부를 판단하기 위해, 평면각 변화, 곡면도 변화, 격자 틀의 각도 변화, 공통 병합점의 편차 등을 분석하였다. 분석 결과, 사면의 변형이 특히 많이 발생한 지점을 결정할 수 있었고 이를 보수·보강 방안의 마련에 활용할 수 있었다.

• 대한화학회지
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• 제27권2호
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• pp.127-132
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• 1983

톨루엔의 동종간 주고 받기 반응에 대한 ZSM-5 촉매의 활성은 양이온의 종류, 이온교환을 그리고 반응온도에 좌우된다. 활성은 알카리금속, 알카리토금속, 수소, 희토류 금속 이온이 교환되는 순서로 증가하며 이온 교환도가 증가함에 따라 감소한다. 이온 교환된 ZSM-5 촉매중에서 Cs-ZSM-5만이 p-크실렌에 대해 우세한 선택성을 나타내는데 p-크실렌에 대한 선택성은 세슘이온 교환율이 증가할 수록 반응온도가 감소 할수록 증가한다. 이러한 현상은 ZSM-5의 세공 교차점에 있는 세슘이온이 부분적으로 세공을 막아주는 형상 선택성으로 해석된다.

• 천문학회보
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• 제39권2호
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• pp.110.1-110.1
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• 2014

The optics of Space telescope is one of the major parts of space mission used for imaging observation of astronomical targets and the Earth. These kinds of space mission have a bulky and complex opto-mechanics with a long optical tube, but there are attempts have been made to observe a target with a small satellite in many ways. In this paper, we describe an optical design of a reflecting telescope for use in a CubeSat mission. For this design, we adopt the off-axis segmented method of astronomical observation techniques based on the Ritchey-Chr$\acute{e}$tien type telescope. The primary mirror shape is a rectangle with dimensions of $8cm{\times}8cm$, and a secondary mirror has dimensions of $2.4cm{\times}4.1cm$. The focal ratio is 3 which can obtain a $0.3{\times}0.2$ degree diagonal angle in a $1280{\times}800$ CMOS color image sensor with a pixel size of $3{\mu}m{\times}3{\mu}m$. This optical design can capture a ${\sim}4km{\times}{\sim}2.3km$ area of the earth's surface at 700 km altitude operation. Based on this conceptual design, we will keep trying to study more for astronomical observation with Attitude control system.

• 수산해양교육연구
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• 제29권2호
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• pp.396-408
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• 2017

This study aims to analyze pre-service elementary teachers' oceanographic literacy, understanding of ocean environmental problems and opinions on teaching strategies for ocean topics. As survey participants, this study selected 126 pre-service elementary teachers. Firstly, as a result of testing their oceanographic literacy, this study found out that out of all the basic principles, 'Oceans Largely Unexplored' was highest in the mean score, followed by 'Human Connections', 'Ocean & Its Life Shape Earth', 'Habitability', 'Biodiversity', 'Weather & Climate' and 'Size of Ocean'. Besides, regarding environmental problems affecting all the aspects of ocean, they mentioned oil spills caused by vessel accidents, so called 'Oil Pollution', as the most serious marine environmental problem. Regarding environmental problems affecting coral reefs, they considered over-fishing as the most serious problem. Secondly, as a result of analyzing their opinions on effective teaching strategies for ocean-related topics in elementary science textbooks, this study found out that regarding topics about understanding the undersea topography in the chapter of the earth and moon, they proposed 'Making an Undersea Topographic Model with Sand' most as an effective teaching strategy. As an effective teaching strategy for the chapter of animals' lives, they proposed 'Classifying Animals with Marine Animal Cards' most. As an effective teaching strategy for the chapter of ground surface changes, they proposed 'Making and Simulating Seashore Topography' most.

• 대한원격탐사학회지
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• 제21권5호
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• pp.405-415
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• 2005

It is difficult to classify tidal flat surface that is composed of a mixture of mud, sand, water and microphytobenthos. We used a Linear Spectral Unmixing (LSU) method for effectively classifying the tidal flat surface characteristics within a pixel. This study aims at 1) detecting algal mat using LSU in the Saemangeum tidal flats, 2) determining a suitable end-member selection method in tidal flats, and 3) find out a habitual characteristics of algal mat. Two types of end-member were built; one is a reference end-member derived from field spectrometer measurements and the other image end-member. A field spectrometer was used to measure spectral reflectance, and a spectral library was accomplished by shape difference of spectra, r.m.s. difference of spectra, continuum removal and Mann-Whitney U-test. Reference end-members were extracted from the spectral library. Image end-members were obtained by applying Principle Component Analysis (PCA) to an image. The LSU method was effective to detect microphytobenthos, and successfully classified the intertidal zone into algal mat, sediment, and water body components. The reference end-member was slightly more effective than the image end-member for the classification. Fine grained upper tidal flat is generally considered as a rich habitat for algal mat. We also identified unusual microphytobenthos that inhabited coarse grained lower tidal flats.

• 동의생리학회지
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• 제14권2호통권20호
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• pp.11-21
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• 1999

In this paper the nine orifices were analyzed horizontally and vertically and the relationship between the upper seven orifices and lower two orifices was looked into specifically. The following results were obtained : l. Horizontal is the shenji (神機) which comes in and out, and it symbolizes animality based on heaven. so it is dynamic. Vertical is the qiji (氣機) which goes up and down. and it symbolizes vegetability based on earth. so it is static. 2. The shape of the eyes and lips is horizontal, so the shape of the liver and spleen which are related to the eyes and lips respectively is also horizontal. Thus the eyes and lips can move and the action of these are mainly concerned with the coming in and out of energy. 3. The shape of the nose and ears is vertical. so the shape of the lungs and kidneys which are related to the nose and ears respectively is also vertical. Thus the nose and ears remain still and the action of these are mainly concerned with going up and down of energy. 4. One means yang(陽) and two means yin(陰). so the nose and mouth which have one are yang. the eyes and ears which have two are yin. 5. The urethra consists of yangming(陽明) and taiyin(太陰) which control the front so it draws out urine which is yang(陽). The anus controls the back. so it draws out feces which is yin(陰). 6. The upper seven orifices are related to the five viscera which control immaterial spirit. The lower two orifices are related to the six bowels which control material movement.

• Journal of the Optical Society of Korea
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• 제17권6호
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• pp.533-537
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• 2013

Space telescope optics is one of the major parts of any space mission used to observe astronomical targets or the Earth. This kind of space mission typically involves bulky and complex opto-mechanics with a long optical tube, but attempts have been made to observe a target with a small satellite. In this paper, we describe the optical design of a reflecting telescope for use in a CubeSat mission. For this design we adopt the off-axis segmented method for astronomical observation techniques based on a Ritchey-Chr$\acute{e}$tien type telescope. The primary mirror shape is a rectangle with dimensions of $8cm{\times}8cm$, and the secondary mirror has dimensions of $2.4cm{\times}4.1cm$. The focal ratio is 3 which can yield a 0.383 degree diagonal angle in a $1280{\times}800$ CMOS color image sensor with a pixel size of $3{\mu}m{\times}3{\mu}m$. This optical design can capture a ${\sim}4km{\times}{\sim}2.3km$ area of the earth's surface at 700 km altitude operation.

• 천문학회보
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• 제44권1호
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• pp.80.1-80.1
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• 2019

Photometric investigations of asteroids allow us to determine their rotation states and shape models (Apostolovska et al. 2014). Our main target, asteroid (2078) Nanking's perihelion distance (q) is 1.480 AU, which belongs to the Mars-crossing asteroid (1.3 < q < 1.66 AU). Mars-crossing asteroids are objects that cross the orbit of Mars and regarded as one of the primary sources of near-Earth asteroids due to the unstable nature of their orbits. We present the analysis of the spin parameters and 3D shape model of (2078) Nanking. We conducted Cousins_R-band time-series photometry of this asteroid from November 26, 2014 to January 17, 2015 at the Sobaeksan Optical Astronomy Observatory (SOAO) and for 25 nights from March to April 2016 using the Korea Microlensing Telescope Network (KMTNet) to reconstruct its physical model with our dense photometric datasets. Using the lightcurve inversion method (Kaasalainen & Torppa 2001; Kaasalainen et al. 2001), we determine the pole orientation and shape model of this object based on our lightcurves along with the archival data obtained from the literatures. We derived rotational period of 6.461 h, the preliminary ecliptic longitude (${\lambda}_p$) and latitude (${\beta}_p$) of its pole as ${\lambda}_p{\sim}8^{\circ}$ and ${\beta}_p{\sim}-52^{\circ}$ which indicates a retrograde rotation of the body. From the apparent W UMa-shaped lightcurve and its location in the rotation frequency-amplitude plot of Sheppard and Jewitt (2004), we suspect the contact binary nature of the body (Choi 2016).

• 한국정보통신학회논문지
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• 제16권6호
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• pp.1279-1284
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• 2012

본 연구는 ASTER영상을 이용한 해안선 변화에 관한 연구이다. ASTER영상은 1999년 12월에 일본에서 발사된 지구탐사위성에 탑재된 센서이다. ASTER 영상은 15m, 30m, 90m의 해상도와 VNIR, TIR, WIR의 3개의 센서를 가지고 있으나 비교적 영상이 저렴하다. 특히 다양한 파장대를 분포하고 있어 기존의 위성영상보다 지구상의 많은 정보의 획득이 가능하다. 해안선은 국지성이 강하므로 지형 형상에 따라서 변화하게 된다. 그리고 해양지리정보구축에서 가장 중요한 요소 중의 하나다. 따라서 본 연구에서는 ASTER 위성영상으로부터 해안선을 Vector Line으로 자동추출 후 변화량을 분석하였다. 연구결과는 향후 해안선 변화를 분석하는데 중요한 기초자료로 활용될 것이다.

• 한국산학기술학회논문지
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• 제8권4호
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• pp.713-720
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• 2007

그레이팅은 아스팔트 도로에 설치하여 배수를 할 수 있는 구조물이다. 본 논문에서는 그레이팅의 구조를 개선하여 토사의 쌓임을 방지 할 수 있는 개선품을 제안한다. 기존 제품은 프레임에 오물이 쌓여 있어 평상시 해충이나 악취가 발생하며 우천 시 배수가 원활하지 못해 물이 고이는 현상도 빈번할 뿐만 아니라 역류하는 현상이 발생한다. 또한 기존 그레이팅이 프레임과 본체를 일체형으로 설치하여 파손 시 전체를 교체하여야 하는 단점이 있다. 본 연구는 그레이팅 본체와 프레임을 분리시킨 구조로 프레임을 멘 홀에 시멘트와 함께 기초공사 하여 고정한 후 그레이팅 본체는 장착탈이 가능하도록 한 구조로 개발하였다.