• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.658-663
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• 2011

The purpose of this study is to develop an air-passing soundproofing panel with more improved structure to reduce the $CO_2$ emission and installation cost. To reduce the emission of $CO_2$ ; it is suggested to choose low $CO_2$ emission material relative to the aluminum and to reduce the materials by developing a specially designed air-passing soundproofing panel structure. First of all, we performed the flow analysis to predict the wind pressure according to the open angle of the air-passing soundproofing panel and the noise level analysis at the receiver point. To verify the simulation, a prototype of the soundproofing panel was made. The flow test in the wind tunnel and load test were performed. The economic evaluation for the installation of the air-passing soundproofing panel was performed and specifications of the installation was prepared. As the results of this research, it was verified that the wind load was reduced about 40% to that of the conventional one at 25m/s wind speed in the wind tunnel test. By applying the 4m span soundproofing wall with air-passing soundproofing panel and under the cost of 250 thousand $won/m^2$ instead of the conventional 2m span panel, the installation cost will always be lowered than the conventional one in the combination of (60:40~50:50) conventional to air-passing soundproofing panel from the economic evaluation. The 20% reduction of $CO_2$ was found by changing the 50% of aluminum soundproof panel to air-passing soundproofing panel.

• 한국석유지질학회:학술대회논문집
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• autumn
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• pp.57-72
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• 2000

The Murzuk Basin covers an area in excess of $350,000{\cal}km^2$, and is one of several intra-cratonic sag basins located on the Saharan Platform of North Africa. Compared with some of these basins, the Murzuk Basin has a relatively simple structure and stratigraphy, probably as a result of it's location on a the East Saharan Craton. The basin contains a sedimentary fill which reaches a thickness of about $4,000{\cal}m$ in the basin centre. This fill can be divided into a predominantly marine Paleozoic section, and a continental Mesozoic section. The principal hydrocarbon play consists of a glacial-marine sandstone reservoir of Cambro-Ordovician age, sourced and sealed by overlying Silurian shales. The present day borders of the basin are defined by tectonic uplifts, each of multi-phase generation, and the present day basin geometry bears little relation to the more extensive Early Palaeozoic sedimentary basin within which the reservoir and source rocks were deposited. The key to the understanding of the Cambro-Ordovician play is the relative timing of oil generation compared to the Cretaceous and Tertiary inversion tectonics which influenced source burial depth, reactivated faults and reorganised migration pathways. At the present day only a limited area of the basin centre remains within the oil generating window. Modelling of the timing and distribution of source rock maturity uses input data from AFTA and fluid inclusion studies to define palaeo temperatures, shale velocity work to estimate maximum burial depth and source rock geochemistry to define kinetics and pseudo-Ro. Migration pathways are investigated through structural analysis. The majority of the discovered fields and identified exploration prospects in the Murzuk Basin involve traps associated with high angle reverse faults. Extensional faulting occurred in the Cambro-Ordovician and this was followed by repeated compressional movements during Late Silurian, Late Carboniferous, Mid Cretaceous and Tertiary, each associated with regional uplift and erosion.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.607-615
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• 2016

The delamination along the annual ring on the cross-section of laminae and the bonding strength according to the tangential angle between laminae were evaluated for the production of 3-ply cross-laminated timber (CLT) using domestic larch. Since there is no standard for CLT in Korea, the production and test of specimens for bonding strength followed the standard procedure of "Structural glued laminated timber" (KS F 3021). The standard specifies to exclude any measurement from the cracks of timbers resulted from drying or knots during delamination test of the glued laminated timbers. However, the failure of cross-sectional tissues along the annual rings was observed near the glue-line of all specimens during the delamination test. Because this phenomenon can generate defects in the CLT that may be exposed to various temperatures and relative humidities after the actual construction, the delamination percentage was measured by including this wood failure. As a result, the delamination percentage of the CLT which had been combined in such a way that the annual rings of outer lamina were directed inward was the lowest, which was around 13%, regardless of the annual ring direction of the middle lamina. On the other hand, the delamination percentage of the CLT which had been combined in such a way that the annual rings of outer lamina were directed outward was the highest, which was around 26%. Furthermore, end-split occurred in the outer lamina during the drying process of the boiling delamination test, which affected the delamination percentage. Therefore, the soaking delamination test was found to be more appropriate for evaluating the delamination strength of CLT. The block shear strength of larch CLT was $3.9{\pm}0.9$ MPa on average, which was 46% lower than the block shear strength requirement (7.1 MPa) of the standard, but satisfied the criteria of the block shear strength (3.5 MPa) of the European Standard (prEN 16351: 2013).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.4
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• pp.413-423
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• 2016

Worldview-3 satellite sensor provides panchromatic image with high-spatial resolution and 8-band multispectral images. Therefore, an image-sharpening technique, which sharpens the spatial resolution of multispectral images by using high-spatial resolution panchromatic images, is essential for various applications of Worldview-3 images based on image interpretation and processing. The existing pansharpening algorithms tend to tradeoff between spectral distortion and spatial enhancement. In this study, we applied six pansharpening algorithms to Worldview-3 satellite imagery and assessed the quality of pansharpened images qualitatively and quantitatively. We also analyzed the effects of time lag for each multispectral band during the pansharpening process. Quantitative assessment of pansharpened images was performed by comparing ERGAS (Erreur Relative Globale Adimensionnelle de Synthèse), SAM (Spectral Angle Mapper), Q-index and sCC (spatial Correlation Coefficient) based on real data set. In experiment, quantitative results obtained by MRA (Multi-Resolution Analysis)-based algorithm were better than those by the CS (Component Substitution)-based algorithm. Nevertheless, qualitative quality of spectral information was similar to each other. In addition, images obtained by the CS-based algorithm and by division of two multispectral sensors were shaper in terms of spatial quality than those obtained by the other pansharpening algorithm. Therefore, there is a need to determine a pansharpening method for Worldview-3 images for application to remote sensing data, such as spectral and spatial information-based applications.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.4
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• pp.453-460
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• 2009

For constructing 3D information using aerial photograph or video sequences, left and right stereo images having different viewing angle should be prepared in overlapping area. In video sequences, left and right stereo images would be generated by mosaicing left and right slice images extracted in consecutive video sequences. Therefore, this paper is focused on generating left and right stereo mosaic images that are able to construct 3D information and video sequences could be made for the best use. In the stereo mosaic generation, motion parameters between video sequences should be firstly determined. In this paper, to determine motion parameters, free mosaic method using geometric relationship, such as relative orientation parameters, between consecutive frame images without GPS/INS geo-data have applied. After determining the motion parameters, the mosaic image have generated by 4 step processes: image registration, image slicing, determining on stitching line, and 3D image mosaicking. As the result of experiment, generated stereo mosaic image and analyzed result of x, y-parallax have showed.

• Korean Journal of Remote Sensing
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• v.31 no.2
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• pp.161-170
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• 2015

This paper presents an efficient image fusion method to be appropriate for the KOMPSAT-2 and 3 satellites. The proposed method is based on the well-established component substitution (CS) approach. The proposed method is divided into two parts: 1) The first step is to create a intensity image by the weighted-averaging operation of a multi-spectral (MS) image and 2) the second step is to produce an optimal high-frequency image using the statistical properties of the original MS and panchromatic (PAN) images. The performance of the proposed method is evaluated in both quantitative and visual analysis. Quantitative assessments are performed by using the relative global dimensional synthesis error (Spatial and Spectral ERGAS), the image quality index (Q4), and the spectral angle mapper index (SAM). The qualitative and quantitative assessment results show that the fusion performance of the proposed method is improved in both the spectral and spatial qualities when it is compared with previous CS-based fusion methods.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.41-41
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• 2018

안정적이고 효율적인 전력 공급을 위해 번화가 대로변 주변에 다수의 지상 변압기 및 개폐기가 설치되고 있으며, 이로 인해 불법 부착물로 인한 도시의 미관 훼손, 변압기 및 개폐기의 오염 등의 문제가 발생하고 있다. 따라서 각 산업체 및 연구 기관에서는 부착 방지용 코팅 도료 및 시트에 대해 다양한 연구개발을 진행하고 있으며, 현장에 적용되고 있는 사례도 있다. 하지만 현재 현장에 적용된 대부분의 제품들은 약 1년 정도의 시간이 지나면 고유의 기능을 상실하며, 도료 및 시트와 기판 사이의 박리가 일어나 우수한 성능을 보이지 않아, 결과적으로 도시에 더욱더 악영향을 주고 있다. 이러한 원인으로는 도료 및 시트의 성능 평가를 위한 다양한 규격들이 존재하지만, 테이프류 탈착 시 영향을 주는 인자(Factor)들이 명확하게 설정되어 있지 않고, 이에 대해 면밀하게 분석한 자료가 없으며, 정량적이고 객관적인 시험 방법이 고려되지 않고 있기 때문에 좋은 제품을 선별하기 어려운 상황이다. 따라서 여러 가지 제품들의 비교평가 및 기술 개발에 활용할 수 있는 가이드라인을 제시하기 위해 일반적으로 사용되고 있는 면테이프(Duct tape)를 이용하여 기판(Substrate)에 대해 다양한 인자를 기준으로 탈착 특성을 측정 및 평가하였다. 현재 지상 배전함 및 개폐기는 분체도장(Powder coating)으로 구성되어져 있으며, 그 모재는 탄소강(Carbon steel)으로 이루어져 있고, 소수의 경우 스테인리스(Stainless steel)를 사용하기 있기 때문에 분체도장(Powder coating), 탄소강(Carbon steel), 스테인리스(Stainless steel)를 기판으로 선정하여 탈착 특성을 평가했다. 탈착 특성에 관여하는 요인으로는 탈착 각도(Peeling angle), 탈착 속도(Peeling speed), 표면 조도(Surface roughness) 등이 있고, 상대 습도(Relative humidity)의 경우 탈착 특성에 영향을 거의 주지 않는 것을 확인했다. 탈착 시 각도가 클수록, 속도가 빠를수록, 조도가 작을수록 부착력(Peel resistance, N/cm)과 탈착 에너지(Energy, J)가 커지며, 탈착 특성에 영향을 주는 인자를 바탕으로 95% 신뢰도 구간을 적용한 탈착특성 모델링을 제시하였다. 이 모델링을 이용하여 실제 현장에서 발생할 수 있는 다양한 각도($90^{\circ}$, $180^{\circ}$)와 속도 범위(100 ~ 1500mm/min)에서의 탈착 특성을 추정하는 것으로, 좋은 성능 및 내구성을 가진 제품을 효과적으로 선별한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.12
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• pp.865-873
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• 2019

To improve the survivability of a missile, it needs to be lowered that the detection possibility by radars on the ground. The radar exposure of the target is given as a function of relative distance from the radar to the target and RCS (Radar Cross Section). The RCS of the missile is determined by the incidence angle of the target to electromagnetic radiation emitted from the radar. Under the assumption that the missile equips appropriate attitude control system, the attitude of the missile to minimize radar exposure at a high altitude is investigated in this paper. Two different types of performance cost are considered: the total sum of RCS and the total sum of SNR during the flight. Optimal solutions against multiple ground radars are found by using a SQP (Sequential Quadratic Programming)-based optimization technique.

• Spatial Information Research
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• v.12 no.4 s.31
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• pp.351-370
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• 2004

At present, environmental monitoring of linear infrastructure is based mainly on field sampling. The 'integrated mapping' approach has received only limited attention from field scientists. The increased environmental regulation of corridor targets has required remote sensing research to develop a sensor or technique for targets ranging from 15 m to 100 m in swath width. In an attempt to identify the optimal remote sensing system for linear targets, an overview is provided of the application requirements and the technology currently available. The relative limitation of traditional remote sensing systems in such a linear application is briefly discussed. It is noted that airborne video could provide, in a cost-effective manner, information required for a very narrow and long strip target utilising the narrow view angle and dynamic stereo coverage. The value of this paper is warranted in proposing a new concept of video infrastructure monitoring as a future research direction in the recognition of sensor characteristics and limitations.

• Macromolecular Research
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• v.12 no.4
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• pp.367-373
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• 2004

We have developed a rigorous heat treatment method to improve the biocompatibility of chitosan as a tissue-engineered scaffold. The chitosan scaffold was prepared by the controlled freezing and lyophilizing method using dilute acetic acid and then it was heat-treated at 110$^{\circ}C$ in vacuo for 1-3 days. To explore changes in the physicochemical properties of the heat-treated scaffold, we analyzed the degree of deacetylation by colloid titration with poly(vinyl potassium sulfate) and the structural changes were analyzed by scanning electron microscopy, Fourier transform infrared (FT-IR) spectroscopy, wide-angle X-ray diffractometry (WAXD), and lysozyme susceptibility. The degree of deacetylation of chitosan scaffolds decreased significantly from 85 to 30% as the heat treatment time increased. FT-IR spectroscopic and WAXD data indicated the formation of amide bonds between the amino groups of chitosan and acetic acids carbonyl group, and of interchain hydrogen bonding between the carbonyl groups in the C-6 residues of chitosan and the N-acetyl groups. Our rigorous heat treatment method causes the scaffold to become more susceptible to lysozyme treatment. We performed further examinations of the changes in the biocompatibility of the chitosan scaffold after rigorous heat treatment by measuring the initial cell binding capacity and cell growth rate. Human dermal fibroblasts (HDFs) adhere and spread more effectively to the heat-treated chitosan than to the untreated sample. When the cell growth of the HDFs on the film or the scaffold was analyzed by an MTT assay, we found that rigorous heat treatment stimulated cell growth by 1.5∼1.95-fold relative to that of the untreated chitosan. We conclude that the rigorous dry heat treatment process increases the biocompatibility of the chitosan scaffold by decreasing the degree of deacetylation and by increasing cell attachment and growth.