• Journal of Korea Multimedia Society
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• v.10 no.10
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• pp.1271-1283
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• 2007

To detect defect of FPD(flat panel displays) is very difficult due to uneven illumination on FPD panel image. This paper presents a method to detect various types of defects using the approximated image of the uneven illumination by B-spline. To construct a approximated surface, corresponding to uneven illumination background intensity, while reducing random noises and small defect signal, only the lowest smooth subband is used by wavelet decomposition, resulting in reducing the computation time of taking B-spline approximation and enhancing detection accuracy. The approximated image in lowest LL subband is expanded as the same size as original one by wavelet reconstruction, and the difference between original image and reconstructed one becomes a flat image of compensating the uneven illumination background. A simple binary thresholding is then used to separate the defective regions from the subtracted image. Finally, blob analysis as post-processing is carried out to get rid of false defects. For applying in-line system, the wavelet transform by lifting based fast algorithm is implemented to deal with a huge size data such as film and the processing time is highly reduced.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.119-124
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• 2014

After the oil crisis in 1970s, many countries have tried to reduce oil dependency. Especially, in Korea, rapid declining oil consumption has speedily brought to electrification and a surge in electricity demand. This paper attempts to estimate the relationship between declining oil use and electrification in Korea using OECD panel data covering from 1985 to 2011. To this end, random effect model and fixed effect model are employed. The increase in the ratio of energy oil to total energy consumption by 10%p leads to reduce the electricity demand by about 15%. This result can be useful information to cope with the recent crisis of electric power. In addition, industrial sector is ranked in forth the ratio of industrial electricity use to total electricity use according to the result of comparative analysis of electricity consumption by use in OECD countries. Therefore, industrial sector should be treated as the main target of demand-side management policies for electricity.

• Communications for Statistical Applications and Methods
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• v.3 no.1
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• pp.29-37
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• 1996

계절성을 갖는 승법 계절 혼합 시계열 모형들의 동질성 검정을 위하여 Wald 검정 통계량을 구하고 그 극한 분포가 ${\chi}^2$-분포함을 보였으며 시뮬레이션 연구를 통하여 뒷받침하였다. 도시 규모가 비슷한 우리나라 지역별 평균 온도자료를 가지고 이 동질성 검정을 수행하여 시계열을 지역별로 모형화하여 예측한 것과 동질성이 있는 것을 묶고 모형화하여 예측한 것에 대한 예측 오차를 비교하였다.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.267-270
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• 2009

오늘날 전자 장비는 매우 다양한 기능의 채용으로 많은 양의 부품을 필요로 하고 그에 따른 전체 시스템의 무게와 크기를 줄이기 위해 소형화와 슬림화가 필수적이다. 따라서 다수의 부품 사용과 고성능화로 인한 열 발생 밀도도 크게 증가하여 열로 인한 온도 상승이 부품의 성능에 매우 중요한 요소로 작용하고 있다. 기기에서의 지속적인 열 발생은 기기를 탑재하고 있는 전체 시스템의 성능에도 큰 영향을 미치며, 특히 고온의 외기에 장시간 노출된 디지털전광판의 시효문제는 시급히 해결해야 할 당면 과제이기도 하다. 본 연구에서는 이와 같은 LCD 패널의 발열로 인한 기기의 성능 저하와 다운 현상을 예방할 수 있도록 열전소자를 이용한 알루미늄 압출형 히트싱크에 대한 열 저항기술을 개발하고, 냉각모듈에 대한 설계기술을 확보하여 LCD 패널용 고효율의 냉각시스템의 개발 과제를 수행했다.

• Journal of Power System Engineering
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• v.12 no.4
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• pp.46-51
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• 2008

Honeycomb panel has a constructive advantage because it is constructed with a honeycomb core, so it has relatively higher strength ratio to weight. Therefore honeycomb panel has been used as the light weight panels in the high-speed railway technology and high-speed ship like as cruise yachts. Also it has been used in the aircraft and aerospace industry as a structural panel because light weight structure is indispensible in that field of industry. Recently, the honeycomb panel is embossed in the viewpoints of high oil prices as the lightweight panel of the transport machine, however the sound insulation capacity of the honeycomb panel is poorer than those of uniform and another sandwich panels. In this paper a method to improving the sound absorption coefficient of a honeycomb panel Is studied by using the Helmholtz resonator. The sound absorption coefficients for some kinds of honeycomb cores are demonstrated by the normal incident absorption coefficient method.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2016.11a
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• pp.198-199
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• 2016

기존 콘크리트 구조물의 내력 및 처짐에 저항하기 위하여 섬유시트를 사용한 복합섬유 패널 보강재를 셋 앵커를 이용하여 콘크리트 구조물과 일체화시키는 공법을 개발하였다.. 본 연구에서 적용된 실험 결과에 의하면 엥커+에폭시 보강 I 시험체가 기준시험체에 비하여 최대하중이 3.13배 증가, 동일 앵커갯수인 앵커보강시험체에 비하여 1.14배 증가하여으며, 에폭시보강시험체는 기준시험체에 비하여 최대하중이 3.08배 증가하였으나 계면에서 섬유박리로 인한 취성 파괴가 발생하였다.

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.366-375
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• 2016

This study aims to investigate the impact of total, native-born, and foreign-born employment rates on the increases of GDP and per capita GDP for 24 OECD countries out of 34 countries depending on data availability. The panel data analysis is formed by a fixed-effects model which allows dummy variable in it to permit the intercept term to vary over time-series and cross-sectional units. Empirical evidences obtained by simple and multiple panel regressions reveal that the contribution to increasing of GDP by foreign-born employment is obviously lower than the one by native-born employment. And, native-born labor is substituted by foreign-born labor. It also has to be mentioned that the labor is playing a key role in increasing in national income. And, therefore, labor-related policy should be concerned on decreasing in labor productivity and segmentation of labor market resulted from inflow of foreign labor. It means that labor-related policy has to take care of not only the magnitude, but also the quality of foreign-born labor.

• Journal of KIBIM
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• v.12 no.4
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• pp.19-31
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• 2022

With the development of 3D-based CAD (Computer Aided Design), attempts at freeform building design have expanded to small and medium-sized buildings in Korea. However, a standardized system for continuous utilization of shape data and BIM conversion process implemented with 3D-based NURBS is still immature. Without accurate review and management throughout the Freeform building project, interference between members occurs and the cost of the project increases. This is very detrimental to the project. To solve this problem, we proposed a continuous utilization process of 3D shape information based on BIM parameters. Our process includes algorithms such as Auto Split, Panel Optimization, Excel extraction based on shape information, BIM modeling through Adaptive Component, and BIM model utilization method using ID Code. The optimal cutting reference point was calculated and the optimal material specification was derived using the Panel Optimization algorithm. With the Adaptive Component design methodology, a BIM model conforming to the standard cross-section details and specifications was uniformly established. The automatic BIM conversion algorithm of shape data through Excel extraction created a BIM model without omission of data based on the optimized panel cutting reference point and cutting line. Finally, we analyzed how to use the BIM model built for automatic conversion. As a result of the analysis, in addition to the BIM utilization plan in the general construction stage such as visualization, interference review, quantity calculation, and construction simulation, an individual management plan for the unit panel was derived through ID data input. This study suggested an improvement process by linking the existing research on atypical panel optimization and the study of parameter-based BIM information management method. And it showed that it can solve the problems of existing Freeform building project.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.5
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• pp.518-527
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• 2016

The present study considers the usage of concentrated forces to simulate real panel flutter. The concept of using concentrated forces have been validated for studying the flutter of wing structure in subsonic flow, yet its application in the supersonic region remained to be explored. Hence, a simply supported panel subjected to forces, equivalent to aerodynamic force is considered for studying supersonic panel flutter. The distributed aerodynamic forces are approximated to few concentrated forces by taking numerical integration. The aeroelastic equation is formulated using the classical small-deflection theory and the piston theory for linear panel flutter whereas for emulated panel flutter the flutter equation is derived by replacing the pressure due to aerodynamic loading with pressure from concentrated loading. Finally, flutter frequency, flutter dynamic pressure, and corresponding mode shape are found for emulated panel flutter and compared with linear panel flutter. Two important parameters, the number of concentrated forces and their location are discussed through numerical examples and optimization process respectively. So far, the flutter results acquired in this study are reasonable to suggest the feasibility of reproducing panel flutter using concentrated forces.

• Applied Chemistry for Engineering
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• v.28 no.5
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• pp.521-528
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• 2017

To find a recycling method for waste liquid crystal display (LCD) panel glasses, we investigated the synthesis process of zeolite with an ion exchange ability by hydrothermal reaction using waste LCD panel glass as a raw material. It was shown that the waste LCD panel glass can be used as a raw material for the production of zeolites having the ion exchange ability. Following conditions for the synthesis of the zeolite with an ion exchange ability were required : the molar ratio of Si to Al components of the waste LCD glass needs to be 2.0 to 2.8, and the temperature of $100^{\circ}C$ and reaction time of 12 hours are needed for the hydrothermal reaction. Based on the required conditions previously mentioned, the A type zeolite was synthesized when the molar ratio of the Si to Al component was 2.0, and the P type zeolite was produced when the molar ratio was 2.8. The type A zeolite synthesized by using the waste LCD panel glass showed a good ion exchange ability and heavy metal adsorption ability. Also, an excellent ion exchange capacity was observed as the crystal phase grows stably in a cubic phase.