• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.608-610
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• 2009

지열 분포에 관련된 지질구조의 특성을 파악하기 위하여 지온경사, 지열류량 자료와 인접한 선구조의 방향성에 대한 상관성 분석을 실시하였다. GIS를 이용하여 지열정보데이터베이스에서 발췌한 209개 지온경사 자료와 218개 지열류량 자료에 대하여 전국 광역단열도로부터 가장 인접한 선구조를 추출하고 10도 간격의 방향별 지온경사 및 지열류량 자료 빈도 및 평균값을 그래프에 도시하였다. 인접 선구조의 방향별 지온경사 평균은 $N30^{\circ}{\sim}40^{\circ}W$, $N10^{\circ}{\sim}20^{\circ}E$ 방향에서 $58.9^{\circ}C/km$, $54.9^{\circ}C/km$로 가장 높았고, 인접 선구조의 방향별 지열류량 평균은 $N80^{\circ}{\sim}90^{\circ}W$, $N50^{\circ}{\sim}60^{\circ}W$ 방향에서 98.71 $mW/m^2$, $98.70mW/m^2$로 가장 높았다. 각 선구조 상의 좌표들을 이용하여 지열류량 분포도에서 지열류량 값을 추출한 결과 $N10^{\circ}W{\sim}N40^{\circ}E$, $N60^{\circ}{\sim}70^{\circ}W$, $N50^{\circ}{\sim}60^{\circ}E$ 방향의 지열류량 높은 것으로 나타났다. 결과적으로 지온경사와 지열류량 자료에 대한 인접 선구조의 방향은 북북동, 북서, 서북서 방향이 우세한 것으로 나타났다. 이는 우리나라 조구조 운동과 관련한 단층, 절리 등의 단열구조의 우세 방향과 잘 일치하는 것으로 해석된다.

• Journal of the Economic Geographical Society of Korea
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• v.16 no.3
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• pp.445-457
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• 2013

This paper aims to investigate changes in the characteristics of urban spatial structure in Korea by regional groups and city size between 2000 and 2010. The characteristics of urban spatial structure is analyzed by Clark's population gradient curve in this paper. Therefore key parameters in population gradient function, such as population density gradients and population density in CBD represent the characteristics of urban spatial structure. The result shows that most of cities in Korea have experienced suburbanization rather than concentration, but small-size cities have experienced concentration during the period.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.3
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• pp.369-375
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• 2010

Since multi-view images can be utilized for 3D visualization and surveying as well, a system calibration is an essential procedure. The cameras in the system are mounted to the holder and their locations and attitudes are relatively fixed. Therefore, the locations and the attitudes of the perspective centers of the four oblique looking cameras can be calculated using the location and attitude of the nadir looking camera and the boresight values between the cameras. In this regard, this research is focusing on the analysis of the relative location and attitude between the nadir and oblique looking cameras based on the results of the exterior orientation parameters after the aerial triangulation of the real multiview images. We acquired high standard deviations of the relative locations between the nadir and oblique cameras. Standard deviations of the relative attitudes between the cameras were low when only the exterior orientations of the oblique looking cameras were allowed to be adjusted. Moreover, low standard deviations of the relative attitudes came when we considered not all the exterior orientations of the cameras but the attitudes of them only.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.1
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• pp.13-19
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• 2013

The aim of this study was to investigate difference of the muscle activation patterns of the upper body during wheelchair cycle ramps ascent of different slopes for disabled with spinal cord injury. Three subjects who is disabled with spinal cord injury participated in this study. Surface electromyography (EMG) data (reaction time [RT], onset-offset time, and peak value of muscle activation) were collected biceps, triceps, upper trapezius, anterior deltoid, latissimus dorsi, and upper rectus abdominal muscles during wheelchair cycle ramps ascent ($0^{\circ}$, $3^{\circ}$, and $6^{\circ}$). For latissimus dorsi muscle, RT and peak value of muscle activation was were increased and offset time was delayed as the slope increased (p < 0.05). These results indicate that wheelchair cycle ramps ascent might cause excessive overuse of latissimus dorsi muscle.

• Korean Journal of Materials Research
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• v.1 no.2
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• pp.105-112
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• 1991

In PLZT system, a new type of material for piezoelectric actuator was developed and its properties were investigated. This material consists of three layers : a piezoelectric ceramic layer, an interlayer which composition changes gradually, and another piezoelectric layer. This kind of materials is called functionally Gradient Materials(FGM). The composition of these layers were selected from the $(Pb,\;La)(Zr,\;TiO_3$ system through the concept of materials design. Sintered FGM at $1300^{\circ}C$, 2hr has an interlayer of about $20\mu\textrm{m}$ with no distorted damage. Dielectric and piezoelectic properties of FGM show intervalues of each side composition. The strain-voltage characteristics in FGM system was improved comparison with any single composition. Especially, the FGMs were fabricated which has high piezoelectric-low dielectric composition and low piezoelectric-high dielectric composition. The properties of both FGMs were significantly improved.

• Journal of Cadastre & Land InformatiX
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• v.46 no.2
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• pp.43-55
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• 2016

This study estimated land prices using instance-based learning. A k-nearest neighbor method was utilized among various instance-based learning methods, and the 10 distance metrics including Euclidean distance were calculated in k-nearest neighbor estimation. One distance metric prediction which shows the best predictive performance would be normally chosen as final estimate out of 10 distance metric predictions. In contrast to this practice, an ensemble technique which combines multiple predictions to obtain better performance was applied in this study. We applied the gradient boosting algorithm, a sort of residual-fitting model to our data in ensemble combining. Sales price data of farm lands in Haenam-gun, Jeolla Province were used to demonstrate advantages of instance-based learning as well as an ensemble technique. The result showed that the ensemble prediction was more accurate than previous 10 distance metric predictions.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.4
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• pp.187-192
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• 2007

Impact on cylindrical surface caused by plunging breaking waves is investigated experimentally. The breaking waves are generated in a wave flume by decreasing the wave maker frequencies linearly and focusing the generated wave components at one specific location. The breaking wave packets are based on constant wave steepness spectrum. Three inclination angles of cylinder are applied to examine the effect of contact angle between cylinder and front surface of breaking waves. Also, the effect of cylinder diameter on pressure distribution and its peak value is investigated by adopting three cylinders with different diameters. The longitudinal location of cylinder is slightly moved in eight different points to find out a probable maximum value of impact pressure. The pressures and total force on cylinder surface are measured by piezo-electric pressure sensors and 3-components load cell with 30kHz sampling rate. The variation of peak impact pressures and forces is analyzed in terms of cylinder diameter, inclination angle and location. Also, the pressure distribution on cylindrical surface is examined. The cylinder location and surface position are more important parameters that govern the magnitude and shape of peak pressures, while the cylinder diameter and inclined angle are relatively insignificant. In a certain conditions, the impact phenomenon becomes very unstable which results in a large variation of measured valves in repeated runs.

• Korean Journal of Remote Sensing
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• v.37 no.5_3
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• pp.1425-1434
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• 2021

Continuous and periodic data acquisition must be preceded to maintain and manage the river facilities effectively. Adapting the existing general facilities methods, which include river surveying methods such as terrestrial laser scanners, total stations, and Global Navigation Satellite System (GNSS), has limitation in terms of its costs, manpower, and times to acquire spatial information since the river facilities are distributed across the wide and long area. On the other hand, the Mobile Mapping System (MMS) has comparative advantage in acquiring the data of river facilities since it constructs three-dimensional spatial information while moving. By using the MMS, 184,646,009 points could be attained for Anyang stream with a length of 4 kilometers only in 20 minutes. Levee points were divided at intervals of 10 meters so that about 378 levee cross sections were generated. In addition, the waterside maximum and average slope could be automatically calculated by separating slope plane form levee point cloud, and the accuracy of RMSE was confirmed by comparing with manually calculated slope. The reference slope was calculated manually by plotting point cloud of levee slope plane and selecting two points that use location information when calculating the slope. Also, as a result of comparing the water side slope with slope standard in basic river plan for Anyang stream, it is confirmed that inspecting the river facilities with the MMS point cloud is highly recommended than the existing river survey.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.4 s.34
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• pp.27-32
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• 2005

DEM is needed for urban modeling, forecasting of floods and the analysis of slope and aspect. It has been generated using digital maps, aerial photos or satellite imageries. Recently, however, many studies on DEM generation from LiDAR data has been conducted because of its efficiency and accuracy. Filtering is said to be the process of making DEM by eliminating non-ground points from LiDAR data. In most researches, some input parameters such as the size of filter are required. The purpose of this investigation is to automatically obtain DEM by eliminating objects of various sizes without the knowledge of the objects' sizes. The experimental results show that most of objects on steep terrain are eliminated by the proposed method.

• Journal of the Mineralogical Society of Korea
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• v.17 no.2
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• pp.177-187
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• 2004

Measurements of the lattice parameters of albite and oligoclase from electron diffraction patterns with the Au internal standard resulted in errors of less than 1 %. An electron diffraction map for natural oligoclase samples was constructed and 11 stations of zone-axes diffraction patterns were obtained. This process is indispensible for reliable TEM studies of triclinic feldspars. Utilizing the [001] cleavage plane of feldspar and the double-tilting TEM holder the following information is obtainable: Si-Al ordering and chemistry of alkali feldspars could be estimated from the $\alpha$＊ - ＊ plot, where ＊ is measured from the [001] orientation, while $\alpha$＊ is measured from the [100] orientation. Si-Al ordering of Na-rich plagioclase could be estimated from ＊ [001] patterns. Structure and chemistry or Na-poor plagioclase could be estimated from existence of e-reflections, their intensity variations as well as their positional changes.