• 한국농림기상학회지
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• 제12권1호
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• pp.23-35
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• 2010

울릉도의 성인봉을 중심으로 나리분지와 주변 산림에 대한 지속가능한 보전을 위한 생태적 기초 자료를 제공하고자 나리분지 내 산림과 외륜의 동, 서, 북사면의 산림에 대하여 군락생태학적 방법으로 임분 구조 및 종 조성 특성을 조사 분석 하였다. 조사 대상 산림 내 임분의 층위 별 중요치를 산출하여 비교 분석한 결과, 나리분지 외륜산림 방위 및 고저 별 대부분의 임분에서는 너도밤나무와 고로쇠나무가 대체로 우점하는 경향이었으며, 임분간 식물 종의 조성에서도 큰 차이를 보이지 않았다. 그러나 나리분지내의 산림에서는 너도밤나무림, 두메오리나무림, 소나무림, 낙엽활엽수림의 다양한 임분이 형성되어 있었고, 임분에 따라 종 조성도 큰 차이를 보였다. 그리고 임분의 성숙도와 안정도 등 간접적인 군락의 속성을 파악하기 위하여 종 다양도를 비교 분석한 결과 임분의 각 층위에서 모두 나리분지 내 산림이 외륜의 산림에 비해 높은 종 다양도를 보였으며, 나리분지 내 산림에서는 소나무림과 낙엽활엽수림이 너도밤나무와 두메오리나무림에 비해 각 층위에서 대체로 높은 종 다양도를 보였다. 또한 산림의 방위 및 고저 별 임분에 대한 유사성을 추정하기 위해서 S$\O$rensen의 유사도계수(Cs)를 비교 분석한 결과 동, 서 북사면과 나리분지 내 산림간 유사도 지수는 0.68~0.69의 범위로서 차이가 거의 없었고, 능선부와 산복부, 산록부, 평탄지간 유사도 지수는 0.85~0.95의 범위로서 거의 동일한 임분형을 보였으며, 나리분지 내 네 임분 간 유사도 지수도 0.66~0.88의 범위로 높은 유사도를 보였다. 나리분지 외륜의 능선부와 산복부, 산록부, 평탄지에 대한 산림의 천이의 진행에 따라 임분구조 및 개체군의 동태를 예측하기 위하여 주요 구성종의 직경급 분포도를 작성한 결과 다소의 형태적 차이는 있었지만 대체로 정규분포형에 가까운 종형(Bell-shape)을 이루고 있었으며, 이들 산림 내 임분은 대체로 안정적으로 유지될 것으로 판단되었다. 따라서 성인봉을 포함한 나리분지와 외륜 산림의 임분들은 지형적 특성에도 불구하고 대체로 구조와 종조성에 있어서 높은 유사도를 보였으며, 기후변화에 의한 임분의 단순화가 지속될 것으로 판단되어, 산림 내 생물 종 및 생태계 다양성에 대한 보전과 관리 대책이 필요하다.

• 자원환경지질
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• 제41권2호
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• pp.211-217
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• 2008

육상 및 해상에서 측정된 중력자료와 GRACE 인공위성으로부터 계산된 중력자료를 구면캡 조화분석(Spherical Cap Harmonic Analysis; SCHA)을 이용하여 통합하였다. 중력자료는 한국지질자원연구원에서 측정된 육상중력과 한국해양연구원과 국립해양조사원에서 측정된 해상자료를 이용하였으며, GRACE 인공위성 자료로는 구면조화함수의 계수형태로 되어있는 L-2 level 자료를 이용하여 중력이상값을 계산하였다 0.05도 간격으로 격자화 된 중력자료의 해상도와 구면캡 조화계수의 해상도를 일치시키기 위하여 조화계수를 order 80까지 설정하였으며 Generalized Minimal Residual (GMRES) 역산방법을 이용하여 구면캡 조화계수를 계산하였다. 이 계수로부터 다시 중력이상을 구한 결과 육상 및 해상자료와 0.950,그리고 GRACE 인공위성 자료와 0.995의 매우 높은 상관관계를 보여주어 본 연구의 방법이 매우 잘 적용 되었음을 알 수 있었다. 구면캡 조화분석의 적용으로 중자력 자료의 특성인 라플라스 방정식을 만족함으로써, 측정된 고도 이외에 다른 고도에서도 중력값을 계산할 수 있으며, 본 연구에서는 10 km에서 60 km 고도까지 중력이상을 계산하였다. 각 고도에서 매우 안정적인 결과를 얻을 수 있었으며, 인공위성 자료의 특성인 우수한 저주파성분과 육상 및 해상에서 측정된 자료의 상세한 고주파 성분이 매우 잘 융합되어 있는 것을 볼 수 있었다. 본 연구의 방법을 이용하여 여러가지 고도의 자료를 한꺼번에 통합할 수 있으므로 항공중력 둥의 자료가 추가될 경우, 더욱더 상세하고 안정적인 중력이상값을 계산 할 수 있을 것으로 기대된다.

• 한국지형학회지
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• 제24권1호
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• pp.63-76
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• 2017

This research was classified mountain areas with high ecological, environmental and resource value among the macro scaled terrain that can be checked at the space scale of less than 1:1,000,000 and analyzed the topographical characteristics. It has been confirmed that the mountains of the Korean peninsula belong to the groups IV, V, VI(classification by Kapos et al.(2000)) as a result of applying the quantitative standards for designation of mountain areas to the global mountain system. The area of mountains calculated using high resolution DEM is equivalent to 48% of the area of the Korean peninsula, and the result is quite different from the general idea of which 70% is the mountain area of the Korean peninsula. The mountain areas show the distribution of geomorphons, that is different from the plains and the hills and also, it shows the differences between the mountains of the groups IV~ VI classified according to the altitude. As a result of analyzing the relations among type pattern, slope, and relief, specific geomorphons are concentrated at $10^{\circ}$ and $20^{\circ}$ and it shows the possibility to classify the mountainous areas into two groups based on the result that the distribution of landform patterns are bimodal in the relation to the amount of relief.

• 한국조경학회지
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• 제17권3호
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• pp.1-8
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• 1990

The digital terrain model (DTM) or digital elevation model (DEM) is commonly used in representing the continuous variation of relief over space. One of the most frequent applications is to display the three dimensional view of the landform concerned. In this paper, the altitude matrices-regular grid cell format of the elevation in Mt. Kyeryong National Park were used in developing the three dimensional view software for the first time in Korea. It required the removal of hidden lines or surfaces. To do this, it was necessary to identify those surfaces and line segments that are visible and those that are invisible. Then, only the visible portions of the landform were displayed. The assumption that line segments are used to approximate contour surfaces by polygons was used in developing the three dimensional orthographic view. In order to remove hidden lines, the visibility test and masking algorithms were used. The software was developed in the engineering workstation, SUN 3/280 at the Institute of Space Science and Astronomy using 'C' in UNIX operating system. The software developed in this paper can be used in various fields. Some of them are as follows : (1) Landscape design and planning for identifying viewshed area(line of sight maps) (2) For planning the route selection and the facility location (3) Flight simulation for pilot training (4) Other landscape planning or civil engineering purposes

• Journal of the Optical Society of Korea
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• 제14권3호
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• pp.199-203
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• 2010

A mobile direct detection Doppler LIDAR based on molecular backscattering for measurement of wind in the stratosphere has been developed in Hefei, China. First, the principle of wind measurement with direct detection Doppler LIDAR is presented. Then the configuration of the LIDAR system is described. Finally, the primary experimental results are provided and analyzed. The results indicate that the detection range of the designed Doppler LIDAR reached 50 km altitude, and there is good consistency between the molecular Doppler wind LIDAR(DWL) and the wind profile radar(WPR) in the low troposphere.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.411-414
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• 2008

In this paper a novel tracking system is described, regarding the influence of shadow between array, aimed at improving the efficiency of PV tracking system. The loss by influence of those shadow can be compensated for by means of control algorithm of the tracking device. The paper suggests a method controlling an altitude for length which is received the shadow influence of PV array. By using an azimuth of current solar position and the length between arrays, the controller of tracking device is able to calculate the length between actual arrays and make a comparison of the shadow length at a specific time with the length between arrays. In the paper, we develop the control algorithm able to minimize the loss caused by the influence of shadow on the PV tracking system, and compared this with conventional output system. The controller has been tested in the laboratory with proposed algorithm and shows excellent performance

• International Journal of Aeronautical and Space Sciences
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• 제14권2호
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• pp.193-199
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• 2013

This work investigates the orbital perturbations of the cubesats that lie on LEO due to Earth albedo. The motivation for this paper originated in the investigation of the orbital perturbations for closed- Earth pico-satellites due to the sunlight reflected by the Earth (the albedo). Having assumed that the Sun lies on the equator, the albedo irradiance is calculated using a numerical model in which irradiance depends on the geographical latitude, longitude and altitude of the satellite. However, in the present work the longitude dependency is disregarded. Albedo force and acceleration components are formulated using a detailed model in a geocentric equatorial system in which the Earth is an oblate spheroid. Lagrange planetary equations in its Gaussian form are used to analyze the orbital changes when $e{\neq}0$ and $i{\neq}0$. Based on the Earth's reflectivity data measured by NASA Total Ozone Mapping Spectrometer (TOMS project), the orbital perturbations are calculated for some cubesats. The outcome of the numerical test shows that the albedo force has a significant contribution on the orbital perturbations of the pico-satellite which can affect the satellite life time.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.440-443
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• 2008

Plume radiation has been measured during ground tests of KSLV-I kick motor in order to predict the thermal load on the equipment around the kick motor at flight. The measuring positions are the kick motor base, and the measured heats were about 2${\sim}$5 w/cm$^2$. The measured heat showed a lot of shot fluctuation in their values, and the radiative heats at the latter half of time are higher than those of the first half. A plausible explanation for these phenomena was given as the variation of alumina particles with time. The radiative heats along the plume axis were also measured recently at 8 positions with 1.5m radius from plume axis, but only the initial parts of the results could be acceptable because the sensor were damaged by the accumulated heat. The strongest heat occurred at the middle of the plume, which can be explained with different view factors. Despite of the plausible explanation, it seems to need more analysis because the plume structure such as temperature, alumina particle, after burning has not been revealed until yet. The measure heat flux has been reflected in the prediction of the plume radiation at high altitude where the kick motor operates.

• Journal of Preventive Medicine and Public Health
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• 제36권2호
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• pp.108-116
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• 2003

Objective : To determine the relationships between customer's attitude, the subjective norm and the intention to use hospital-based health promotion services. Methods : This study was based on the theory of reasoned action, suggested by Fishbein and Ajzen. The subjects of this study were 501 residents of Seoul, Bun-dang, Il-san and Pyung-chon city, under 65 years, who were stratified by sex and age. A covariance structural analysis was used to identify the structural relationships between attitude towards health promotion programs or services, their subjective norm and their intention to use the aforementioned services. Results : The subjective norm for using the health promotion programs or services provided by hospitals was a significant predictor of the intention to use, but the attitude towards the services was not significant Conclusions : Our results suggest that a customer's reference group affects their use of the hospital-based health promotion services. Because the subjects of this study were restricted to specific urban areas, there are limitations to generalizing the study results. Despite the limitations of these results, they can serve as baseline information for the understanding of consumers behavior toward hospital-based health promotion services.

• 한국지형학회지
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• 제28권2호
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• pp.15-30
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• 2021

This study tried to reveal distribution of incision rate and the factors from fluvial terrace deposits on the western and eastern slopes in the Middle Sobaek Mountain Range, using OSL age dating and topographical analysis. An average incision rate of 0.220 m/ka was estimated in the western slope streams, while the streams on the eastern slope showed a lower average incision rate of 0.121 m/ka. These results seem to indicate that the study area experienced an asymmetric uplift. Patterns of incision rate in the study area were different from those in the Northern Sobaek Mountain Range, probably suggesting that the Sobaek Mountain Range experienced spatially different uplift patterns. Among the factors, which were considered to influence on distribution of incision rate in the study area (e.g., altitude of sampling point, distance from divide, distance from axis, channel width, and bedrock type), distance from axis showed the strongest relationship with incision rate. Therefore, uplift is thought to be the most significant factor in distribution of incision rate in the Middle Sobaek Mountain Range.