• 한국전기전자재료학회논문지
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• 제19권1호
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• pp.75-80
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• 2006

We have fabricated a carbon nanotube field emission display(CNT-FED) panel with a 2 inch diagonal size using a screen printing method and in-situ vacuum sealing technology. The field emission properties of CNT FED panel with square-type CNT emitters. As results, the square-characterized and compared with those of the line-type CNT emitters. As results, the square-type CNT emitters showed much larger emission current and more stable I-V characteristics. Light emission started to be occurred at an electric field of 3.5 V/${\mu}m$ corresponding to the anode-cathode voltage of 700 V. The vacuum level inside of the in-situ vacuum sealed panel was obtained with $1.4 {\times} 10^{-5}$ torr. The sealed panel showed the similar I-V characteristics with the unsealed one and the uniform light emission with very high brightness at a current density of $243 {\mu}A/ cm^2$ obtained by the electric field of 10 V/${\mu}m$.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 제5회 박판성형 SYMPOSIUM
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• pp.81-85
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• 2006

The characteristic of sheet metal process is the few loss of material during process, the short processing time and the excellent price and strength. The sheet metal process with above characteristic is common used in industrial field, but in order to analysis irregular field problems the reliable and economical analysis method is demanded. Finite element method is very effective method to simulate the forming processes with good prediction of the deformation behaviour. Among Finite element method, The static-implicit finite element method is applied effectively to analyze real-size auto-body panel stamping processes, which include the forming stage. In this paper, it was focussed on the drawability factors on auto-body panel stamping by AUTOFORM with using tool planing alloy to reduce law price as well as high precision from Design Optimization of die. According to this study, the results of simulation will give engineers good information to access the Design Optimization of die.

• 한국정밀공학회지
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• 제27권12호
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• pp.84-91
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• 2010

The bonding process of LCD panel is attaching an inner lead to an outer lead in the production line of LCD panel module. It is composed of an OLB process and a PCB bonding process. Since bonding tool assembly is one of the core parts of the bonding equipment that determines the durability and performance of the final product, much design efforts to enhance uniformity and efficiency of the process have been made. In this paper, FE analyses have been employed to determine the bonding tool size. Bonding tool of long bar shape has been simplified as a piece with same heater pitch, and appropriate boundary conditions such as convection and radiation are considered. Thermal analysis results by the FEM have been validated by the experiments. With the use of FE analysis varies design parameters and the corresponding effects have been evaluated. It was observed that the approach presented in this paper could be employed for the design of LCD module bonding tool.

• 한국주거학회논문집
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• 제19권6호
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• pp.127-135
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• 2008

Due to the increasing social participation of women and the decrease in the size of the typical family, childre's environments have become increasingly more important. In fact, children are one of the main groups who use the community environments. However, children as a group have not been considered in the planning of residential neighborhood environments. A child's spiritual, psychological and physical health develops upon their interaction with the surrounding environment. Residential community should therefore be planned in a child-friendly way. The aim of this study is to introduce possible criteria for developing design guidelines for Children-friendly residential environments. The principal objective is to investigate the actual conditions of children's lifestyles in residential environments and the exploration of design guidelines for children. In this study, a small group workshop panel method was used. The subjects were 4 panel groups which was consisted of households with children. Each of the panel included 2 consecutive workshops. In this study, a list of valuable criteria for design guidelines was identified. In addition, the current residential community environment was found to be inadequate to accommodate for children's lifestyles and children had different housing needs according to their ages. In conclusion, the design guidelines should be developed to provide children with developmentally appropriate community environments.

• 한국지진공학회논문집
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• 제17권4호
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• pp.151-157
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• 2013

In this study, an externally reinforced structural system for SMC(Sheet Molding Compound) panel water tank, designed according to the Japanese design code, is experimented to evaluate its seismic performance. The test tank is 3m long, 2m wide and 3m high, considering the capacity and size of the shaking table. The measured hydrodynamic pressures are found to be approximately 70% of the Japanese design code values. It may be partially due to the convex shape effect of the unit panels. The analytical results of externally reinforced system based on the measured dynamic water pressures are found in good agreement with the test results. If the design hydrodynamic pressures are estimated properly, the proposed analytical model for the externally reinforced water tank becomes a useful design tool and the Japanese design code is found to provide a safe design for the external frames of SMC panel water tank.

• 한국정보통신학회논문지
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• 제25권12호
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• pp.1777-1783
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• 2021

대단위 신재생 에너지 발전단지의 효율적인 유지관리를 위해 드론의 활용이 점차 증가하고 있다. 오래전부터 태양광 패널을 드론으로 촬영하여 패널의 유실 및 오염 등을 관리하고 있다. 본 논문에서는 열화상카메라를 장착한 드론을 이용하여 획득된 태양광패널 이미지에서 아크, 단선, 크랙 등의 고장 유무를 판별하기 위해 시멘틱세그멘테이션 기법을 이용한 분류모델을 제안한다. 또한 적은 데이터셋으로도 강인한 분류 성능을 보이는 U-Net의 튜닝을 통해 효율적인 분류모델을 구현하였다.

• 아태비즈니스연구
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• 제15권3호
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• pp.417-430
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• 2024

Purpose - This paper investigates the asymmetric capital structure adjustment toward target leverage. Our study consistently estimates heterogeneous speeds of adjustment in different regimes reflecting heterogeneity in firm characteristics. Design/methodology/approach - We collect balanced panel data on Korean listed firms over the period 2005 - 2023. In order to capture non-linearities in the speed of capital structure adjustments, this paper employs the dynamic panel threshold model that allows endogeneity in regressors and threshold variables. Findings - Using firm characteristics as proxies for adjustment costs of deviation from and adjustment to target leverage, we find asymmetric effects on the speed of capital structure adjustments. Firms of large size, with high profitability, with large cash flow and with large investment adjust capital structure faster than those with the opposite characteristics. On the other hand, firms with high growth opportunities and with high risk move slowly toward the target leverage. Research implications or Originality - This paper provides new evidence of cross-sectional asymmetries in capital structure adjustments, which calls for cautions in sample-splitting in an arbitrary manner.

• 한국산학기술학회논문지
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• 제9권4호
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• pp.878-885
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• 2008

최근에 많은 수요와 각광을 받고 있는 디스플레이 장치에서 CRT는 곡면이며 무겁고 큰 부피 때문에 LCD, PDP, OLED와 같은 평판디스플레이(FPD)로 대체되고 있다. FPD는 $0.6\sim0.8mm$ 두께의 대면적 글래스에 여러 공정을 거친 후에 최종 제품 규격으로 절단하여 제작하기 때문에 글래스의 면적이 크면 클수록 FPD의 생산성이 높다는 밀접한 관계를 갖는다. 따라서 FPD 제조 업계에서는 글래스 면적을 증가시키기 위하여 노력하고 있으며, 예를 들면, 현재 8세대 LCD인 경우 약 $2,200mm\times2,600mm$의 면적을 가진다. 이러한 글래스를 이송하는 대표적인 장치로서 공기부상 컨베어시스템은 압축공기를 이용해서 FPD용 대면적 글래스 등을 약 $0.3\sim0.5mm$ 정도 부상시켜 비접촉으로 이송할 수 있는 장치이다. 이 때 글래스와 다공질판 표면 사이의 공기 유동이 모델링되고 해석되며, 이것으로부터 글래스의 공기부양 조건이 예측될 수 있다. 글래스를 이송시 전기공급 중단에 의하여 압축공기가 공급되지 않아 부상판과 접촉이 발생하였을 때, 자기윤활 특성을 가진 다공질판 위의 글래스는 1mm 홀을 많이 가진 사각덕트 부상판 위의 글래스와 조사, 비교된다.

• 통상정보연구
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• 제17권1호
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• pp.217-240
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• 2015

본 논문은 28개 국가에 제공한 공적개발원조(ODA)와 원조 수원국의 무역개방이 우리나라 수출에 미친 영향에 중점을 두고 분석하였다. 본 연구는 2005~2012년 기간의 패널자료를 가지고 원조 수원국의 경제규모(1인당 GDP), 무역개방(trade openness), 인구수, 원조 공여국의 공적개발원조(ODA) 규모, 원조 공여국과 수원국간의 거리(distance) 등의 변수를 포함하여 모형을 구축하였다. 또한 원조 수원국을 아시아, 아프리카, 아메리카 등 3개 지역으로 구분하여 이들 지역에 제공한 원조가 우리나라 수출에 미친 영향도 분석하였다. 모형의 적합성을 판단하기 위해 패널 단위근과 패널 공적분 검정을 실시하였으며, 이를 토대로 panel OLS, panel GLM, panel EGLS 등의 추정방법을 이용하였다. 분석결과에 따르면, 원조 수원국의 경제규모, 인구수, 무역개방과 우리나라의 공적개발원조(ODA)는 우리나라 수출 증가에 긍정적이며 통계적으로도 유의한 영향을 준 것으로 나타났다. 반면에 거리변수는 수출증가에 부정적이며 통계적으로도 유의한 영향을 준 것으로 나타났다. 더미변수를 이용한 경우, 아프리카와 아메리카 지역에 대한 원조는 각각 5%와 10% 유의수준에서 우리나라 수출증가에 부정적인 영향을 준 것으로 나타났다. 따라서 아프리카에 대한 원조 규모가 최근에 증가하는 추세를 고려할 때 이 지역에 대한 원조가 우리나라 수출을 증진시킬 수 있는 방안들을 우선적으로 모색해야 한다. 또한 아프리카와 아메리카 지역에 대한 원조가 우리나라 수출시장의 확대보다는 자원의 확보와 개발에 중점을 두었는지에 대한 향후 연구도 필요하다.

• 한국의류학회지
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• 제25권4호
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• pp.719-730
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• 2001

The purpose of this study is to develop the basic patterns of adult womens brassiere therewith, provide for some basic data useful to the brassiere manufacturing which are both functional and fitting. For this purpose, 220 adults women(aged between 20 and 59) were sampled to be measured for their body sizes and tested for their brassiere wearing. The collected data were statistically processed using the SAS 6.12 for Means, Standard Deviation, etc. The results of this study can be summarized as follows; 1. In order to develop the basic patterns of adult womens brassieres, 75A size was selected out of 12 size combination(3 women per 75A size) and then, their brassiere fitting was tested. As a result, the fronts of the basic patterns were found to have such problems as undone front center, poor levelling of upper cups bottom line or lower cups top line, poor shape of upper cups outside top line and shoulder strip position. On the other hand, n the rear side of the basic patterns, the central part of the wing was slightly lifted, while the wing width and straps interval did not befit the full-cup brassiere. The result of this first brassiere fitting test showed that the functionality and aesthetics of the basic pattern brassieres were more or less satisfactory, and thus, the problems were address for the second test. In the second test, the aesthetics, breast-shaping effect and functionality of the basic pattern brassieres were much improved. 2. The basic patterns of adult womens brassieres were characterized by a round cup wired as well as a full cup embracing the entire breasts. Each basic pattern which consisted of upper and lower cups was shaped \"straight(-)\". The basic sizes adopted at the first design stage (see fig. 1-2) was 75A of which was designed as upper foundation basic pattern. At the second stage, the upper body foundation pattern were used to design lower cup, upper cup, front panel and wing in their order.(see fig. 3-5, fig. 8)5, fig. 8)