• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.634-637
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• 2005

Multichannel seismic data acquired in Ulleung Basin of East Sea for gas hydrate exploration. The seismic sections of this area show strong BSR(bottom simulating reflections) associated with methane hydrate occurrence in deep marine sediments. Very limited information is available from deep sea drilling as the risk of heating and destabilizing the initial hydrate conditions during the processing of drilling is considerably high. Not so many advanced status of gas hydrate exploration in Korea, the most of information of gas hydrate characteristics and properties are inferred from seismic reflection data. In this study, The AVO analysis using the long offset seismic data acquired in Ulleung Basin used to explain the characteristics and structure of gas hydrate. It is used primarily P-wave velocity accessible from seismic data. To make a good quality of AVO analysis input data, seismic preprocessing including 'true gain correction', 'source signature deconvolution', twice velocity analysis and some kinds of multiple rejection and enhancing the signal to noise ratio processes is carried out very carefully. The results of AVO analysis, the eight kinds of AVO attributes are estimated basically and some others of AVO attributes are evaluated for interpretation of AVO analysis additionally. The impedance variation at the boundary of gas hydrate and free gas is estimated for investing the BSR characteristics and properties. The complex analysis is performed also to verifying the amplitude variation and phase shift occurrence at BSR. Type III AVO anomaly appearance at saturated free gas area is detected on BSR. It can be an important evidence of gas hydrate deposition upper the BSR.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.2
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• pp.142-148
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• 2012

This study presents the assessment results of adhesive properties on the interface between a silicon wafer and nano-scale polymer thin film pattern through UAFM images by using the contact resonance frequency of the cantilever. For the experiment, we varied surface treatment processes for the silicon wafer and fabricated a 300nm polymer thin film pattern through lithography. Images from the optical microscope were used to compare the produced test specimens for adhesive condition and the critical load value from the nano scratch test was used to verify the adhesive condition of the nano pattern. Each test specimen resulted in a $1{\mu}m{\times}1{\mu}m$ surface image and subsurface adhesive image. Adhesive condition was evaluated by image contrast differences on the interface according to the changing amplitudes and phases of contact resonance frequency.

• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.303-308
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• 2007

Three types dyeing wastewater (dark, medium, light color) discharged from cotton textile dyeing with reactive dye was collected at each step of process. Each process dying wastewater was analyzed and treated by ionized gas. The analysis focused on $COD_{Cr}$, SS and color. Bleaching & scouring process wastewater has the highest $COD_{Cr}$ value in the three type dyeing wastewater. SS shows the highest value at dyeing process wastewater in dark and medium color but light color has at finishing process wastewater. The result of process wastewater treatment by ionized gas was that the ionized gas was effective in $COD_{Cr}$ removing of bleaching & scouring process and finishing process wastewater but was not good at dyeing process wastewater. From that result it is estimated that the ionized gas could not work in opening the aromatic ring and react only in aliphatic component of the molecule. Because the surfactants contained in bleaching & scouring process and finishing process wastewater have only one aromatic ring in its molecular structure, in contrast with the reactive dye compounds consist of aromatic rings great part of its molecular structure. The color almost removed in 1.5 hrs reaction time but $COD_{Cr}$ removal effiency was only 30.7% through 3hrs in 1500 mL of total dyeing wastewater treated by 10 L/min ionized gas.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.683-687
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• 2006

본 연구의 목적은 경기도 파주시 적성면 설마리에 위치한 설마천 시험유역을 대상으로 신뢰성 있는 수문자료를 지속적으로 수집하여 정확한 물순환 과정을 파악하는데 있다. 따라서 강우량, 수위, 유속, 유량, 수질, 부유사량, 기상 등의 기본적인 수문관측 자료를 축적하는 것이 일차적인 목적이고 최종적으로 수집된 자료를 이용하여 산지 소하천 유역의 수문특성을 규명하는데 있다. 2005년 설마천 시험유역 수문관측은 더욱 향상된 결과를 보였다. 노후화된 관측기기의 교체 및 추가 설치, 실시간 전송장비의 보완 및 운영, 각 관측소당 2기 이상의 동시 관측자료 확보 등을 통해 자료의 결측을 최소화하였고, 정확도를 개선하여 양질의 자료를 생성할 수 있었다. 관측된 우량과 수위 자료에 대해 일상적인 자료 검토 및 처리 과정을 보다 구체적으로 체계화하여 자료의 질이 향상될 수 있도록 하였다. 특히 유량측정 및 산정 방법을 국제 기준에 준하여 수행하고, 현장에서 실시간으로 측정 자료의 분석 및 검증이 가능한 유량측정용 PDA 시스템을 사용함으로써 보다 정도 높은 유량측정성과를 확보할 수 있었다. 이렇게 다각적인 방법으로 안정적인 관측 자료를 확보한 결과, 동절기를 제외한다면 전적비교와 사방교 지점에서 무결측의 유역평균우량과 유량자료를 구축할 수 있었다. 그리고, 본 연구에서는 실시간 전송장비와 설마천 시험유역 홈페이지(http://kict.datapcs.co.kr)를 통해 실시간으로 우량과 수위 자료를 인터넷과 PCS로 확인할 수 있도록 시스템을 운영하였으며, 이로 인해 언제 어디서나 설마천 시험유역의 현장상황을 신속하게 파악할 수 있도록 하여 자료의 질을 향상시킬 수 있는 기반을 구축하여 운영 중에 있다.본 시험유역의 주요연구 내용으로는 관측시설물의 유지관리, 수문기상관측, 수문기상자료 정리 검토, 기본수문특성 분석, 수문관측방법의 비교 검토, 유량측정 정확도 제고를 위한 현장적용평가, 동절기 수위-유량자료 고찰 등을 수행하였으며, 기본 수문특성 분석 내용으로는 호우사상 현황 분석, 지속기간별 최대 강우량분석, 두 우량계간의 강우량 비교, 6개 지점간 강우량 비교, 주요 호우사상의 시 공간적 분포 특성, 연간, 월별, 주요 호우사상별 유출률 분석과 부유사량 및 수질분석 등을 수행하였으며, 이로써 산지 소하천 유역의 물순환 과정을 보다 명확히 규명하고자 노력하였다.

• Journal of the Korean Wood Science and Technology
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• v.19 no.3
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• pp.7-18
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• 1991

목재(木材)의 액체침투성(液體浸透性)을 연구(硏究)하기 위하여 국내(國內)에 있는 침엽수재(針葉樹材)와 활엽수재(闊葉樹材)의 주요수종(主要樹種)을 대상으로 축방향(軸方向), 방사방향(放射方向), 접선방향(接線方向)의 침투(浸透)를 각각 조사(調査)하였다. 또한 방사(放射) 및 접선방향(接線方向)의 주요(主要) 침투경로(浸透經路)를 광학현미경(光學顯微鏡)으로 관찰(觀察)하였다. 실험결과(實驗結果)는 다음과 같다. 1. 종침투(縱浸透)는 침(針) 활엽수재(闊葉樹材)모두 1% $NH_4OH$ 처리(處理)시 침투성(浸透性)이 가장 컸으며 수종(樹種)에 따른 침투성(浸透性)의 차이(差異)는 침엽수재(針葉樹材)인 잣나무가 활엽수재(闊葉樹材)인 물푸레나무와 현사시나무 보다는 더 컸으며 관엽수재내(關葉樹材內)에서는 물푸레나무가 현사시나무보다 침투성(浸透性)이 더 큰 것으로 나타났다. 2. 횡침투(橫浸透)는 침엽수재(針葉樹材)에 있어서 침투면별(浸透面別) 침투량(浸透量)은 접선단면(接線斷面)이 방사단면(放射斷面)보다 훨씬 컸으며, 활엽수재(闊葉樹材)의 경우는 환공재(環孔材)에서는 접선단면(接線斷面)이 방사단면(放射斷面)보다 침투량(浸透量)이 컸으나, 산공재(散孔材)에서는 수종간(樹種間)의 변이(變異)가 컸다. 활엽수재(闊葉樹材)의 환공재(環孔材) 모두 방사조직(放射組織)이 횡침투(橫浸透)에 미치는 영향(影響)은 침엽수재(針葉樹材)만큼 크지 않았다. 침투(浸透)깊이도 침엽수재(針葉樹材)가 활엽수재(闊葉樹材)보다 컸으며, 활엽수재(闊葉樹材)는 수종간(樹種間)의 차이(差異)가 심했다. 3. 침투경로(浸透經路)를 보면 침엽수재(針葉樹材)는 방사유세포(放射柔細胞), 만재부(晩材部)의 소가도관(小假導管)이 주도적(主導的)인 역할을 하였으며, 활엽수재(闊葉葉材)도 역시 방사조직(放射組織)을 통해서 침투(浸透)가 이루어지지만 수종간(樹種間)에 방사조직(放射組織)의 침투양식(浸透樣式)과 침투속도(浸透速度)가 달랐다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.3
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• pp.213-224
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• 1992

An encoding technique based on region splitting and vector quantization is proposed for the lower level Laplacian pyramid images. The lower level Laplacian pyramid images have lower variance than higher levels but a great influence on compression ration due to large spatial area. And so from data compression viewpoint, we subdivide them with variance thresholding into two regions such as one called : flat region” and the other “edge region”, and encode the flat region with its mean value and the edge region as vector quantization method. The edge region can be reproduced faithfully and significant improvement on compression ratio can be accomplished with a little degradation of PSNR in spite of the effect of large flat region since the codebook used is generated from the edge region only on from the entire image including the flat region. It can be verified by computer simulation results that proposed method is more efficient in compression ratio and processing time than the conventional encoding technique of vector quantization.

• Journal of the Korea Computer Graphics Society
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• v.20 no.1
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• pp.13-19
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• 2014

In this paper, we introduce a real-time method to render a 3D scene using image-based lighting. Previous approaches for image-based lighting focused on diffuse reflection and mirror-like specular reflection. In this paper, we provide a simple preprocessing approach to efficiently approximate Phong reflection model, which has been used for computer graphics applications for several decades. For diffuse reflection, we generate a texture map for diffuse reflection by integrating the source image in preprocessing step, similarly to the previous approaches. We adopt the similar idea to produce a set of specular reflection maps for various material shininess. By doing this, we can render a dynamic scene without high computational complexity or numerous texture map access.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.2
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• pp.83-90
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• 2010

As a reinforced fabric, asbestos has been utilized as a fire-resistant material as it has a superior flexural stiffness and heat resistance up to $1500^{\circ}C$. However, due to its harmfulness, its use has been prohibited recently and the even the installed asbestos materials are being repaired or supplemented if there is a concern about flying. Asbestos is mainly used for construction panels as a reinforced fabric and coating materials to ensure the fire-resistance of steel frames. Asbestos was used as fire-resistant materials for steel frames until 1991 and then prohibited as Act on Industrial Safety and Health limits the concentration of asbestos in the air. Classified as a designated waste according to Act on Waste Control, asbestos must be buried if there is no possibility of flying (panel-type materials) or cement-solidified and then buried if there is a possibility of flying (spray coating material) In general, it is required that a new waste landfill include a certain landfill facility for designated waste, but in reality there is an absolute storage of landfill facilities for designated waste as they only install facilities of the size required by the regulations. This could result in the 2nd environmental pollution as they cannot process asbestos wastes which will be generated in large volume in the future. This study explores a method that melts asbestos wastes at $700^{\circ}C$ rather than cement-solidifying the waste asbestos from construction sites, especially asbestos-containing spray coating. The study results showed that there was no change in the composition and shape even though asbestos wastes was melted at $1300^{\circ}C$, but there was a change for the specimen which was process in advance for low temperature melting and then melt at $900^{\circ}C$.

• Journal of Korea Multimedia Society
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• v.12 no.11
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• pp.1692-1700
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• 2009

This paper proposes the direction distribution of surface normal vectors as a feature descriptor of three-dimensional models. Proposed the feature descriptor handles rotation invariance using a principal component analysis(PCA) method, and performs mesh simplification to make it robust and nonsensitive against noise addition. Our method picks samples for the distribution of normal vectors to be proportional to the area of each polygon, applies weight to the normal vectors, and applies interpolation to enhance discrimination so that the information on the surface with less area may be less reflected on composing a feature descriptor. This research measures similarity between models with a L1-norm in the probability density histogram where the distances of feature descriptors are normalized. Experimental results have shown that the proposed method has improved the retrieval performance described in an average normalized modified retrieval rank(ANMRR) by about 17.2% and the retrieval performance described in a quantitative discrimination scale by 9.6%~17.5% as compared to the existing method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.26-34
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• 2008

This study focus on segmentation process that classifies road surfaces into 5 different categories, dry, wet water, icy, and snowy surfaces by analyzing asphalt-paved road images taken in daylight. By using the polarization coefficients, the proportions of horizontally polarized components to vertically polarized components, regions with over 1.3 polarization coefficients are classified as wet surfaces. Except for wet surfaces, the decision process a lies time-frequency analysis to other parts by using the third order wavelet packet transform. In addition, by using the average frequency characteristics of dry and icy surfaces from image templates, decide which is closer to a test image, and finally identify dry and icy surfaces. It is confirmed that the reposed estimation and segmentation of recognition on various images. This can be interpreted as an indication that image-only mad surface condition supervision is probable.