• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2007.04a
• /
• pp.739-744
• /
• 2007

Wind loads for cladding can be estimated using the maximum wind pressure including gust effects from wind-tunnel tests. However, when estimating the maximum wind pressure with gust effects, wind pressure coefficients for cladding would be different according to the averaging time of wind pressures, In the paper, for wind pressures obtained from wind-tunnel tests for apartment buildings, whose window panes were damaged by actual strong wind, it was investigated how pressure coefficients varied according to the size of cladding and averaging time using TVL method of Lawson. In result, it was found that the lesser the size of cladding and averaging time were, the larger pressure coefficients became. Accordingly, to estimate wind loads for cladding of apartment buildings and design it, the averaging time of wind pressures should be considered properly.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2014.01a
• /
• pp.23-24
• /
• 2014

본 논문에서는 최근 모바일 기기에서 많이 사용되고 있는 마름모 패턴의 터치스크린패널(TSP; Touch Screen Pannel)에서 정확한 터치 위치를 획득하는 방법을 제안한다. 가로와 세로로 배치된 ITO 투명전극필름은 사용자의 터치로 인하여 변화된 정전용량(mutual capacitance)을 측정하여 터치위치를 파악한다. 그러나 터치패턴의 모양과 손가락의 크기에 따라서 측정되는 상호정전용량의 값에 차이가 발생하며 이 차이는 터치위치 계산에 영향을 미쳐서 정확한 터치위치를 획득하기 어렵게 한다. 이러한 결과로 TSP 상에서 직선을 그어도 측정된 터치 값은 S자 형태로 나타난다. 본 논문에서는 이러한 문제를 완화하기 위하여 Matlab 상에서 터치상황을 시뮬레이션하고 이를 이용하여 터치위치를 보상하여 보다 더 정확한 터치위치를 구하는 방법을 제안한다.

• Information and Communications Magazine
• /
• v.32 no.3
• /
• pp.44-51
• /
• 2015

디지털 홀로그램 디스플레이는 SLM을 이용하여 홀로그램 영상을 구현하므로, 홀로그램 영상의 품질은 SLM에 의하여 제한되게 된다. 따라서, 대면적 광시야각의 홀로그램 단말을 개발하기 위해서는 대면적 초고해상도의 SLM이 필수적이다. 그런데, 지금까지의 홀로그램은 주로 상용 SLM인 LCoS나 DMD를 기반으로 구현되었다. 이러한 상용 SLM의 경우에는 패널의 크기가 작고 픽셀 피치가 커서, 대면적으로 홀로그램 영상을 구현하는 것과 광시야각을 구현하는 데 있어서는 아직까지 한계를 보이고 있으며, 이에 따라 대면적 초고해상도의 SLM 개발이 요구되고 있다. 본고에서는 지금까지 홀로그램 디스플레이를 구현하는데 이용되어온 주요한 SLM인 LCoS, DMD, LCD등에 대하여 살펴보고, 이러한 SLM이 가진 한계를 극복할수 있는 기술로 대면적 디스플레이 기술을 기반으로 LCoS 기술을 구현하고자하는 SLMoG 기술에 대하여 소개고자 한다.

• Journal of Korea Multimedia Society
• /
• v.22 no.2
• /
• pp.117-127
• /
• 2019

Simultaneous pattern measurement system is new research subject for OLED panel inspection. It is defect inspection of OLED panel after deposition. This research suggests the system that calculates the size and center point of each patterns after obtaining standard and deposition pattern as one image. This system could be applied to OLED manufacturing process. The research result shows that the size and center point of each patterns could be obtained by displaying the standard pattern and deposition pattern in one image.

• The Journal of the Korea Contents Association
• /
• v.7 no.1
• /
• pp.116-123
• /
• 2007

This paper proposed a new amplitude width modulation for OLED data driver IC. The data driver controls brightness of OLED by adjusting amplitude and width of the data drive current pulse. There were two conventional methods; pulse amplitude modulation(PAM) and pulse width modulation(PWM). The PWM method suffered from lower light emitting time efficiency at low luminance signal. The PAM method suffered from large chip area using DACs for each column. The proposed method was aiming at accurately controlling of the current level by MSB data and light emitting efficiency by LSB data to improve the inefficiencies of the PAM and a PWM. The proposed AWM driver circuit implemented using $0.35-{\mu}m$ 3-poly 4-metal CMOS high voltage process. The simulation result shows the improvement in the accuracy of the gray level control even though the driver circuit is smaller than the PAM.

• The Korean Journal of Applied Statistics
• /
• v.22 no.6
• /
• pp.1315-1329
• /
• 2009

The panel survey is need to have a more concern about a response due to a secession and non-response of a sample. And generally a population is not fixed and continuously changed. Thus, the rotation sample design can be used by the method replacing the panel research. This paper is the study of comparison to equal weight method, Duncan weight, Design weight method, weight share method in rotation sample design. More specifically, this paper compared variance estimators about the existing each method for the efficiency comparison, and to compare the precision using the relative efficiency gain by the Coefficient Variance(CV) after getting the design weight from the actual data.

• Journal of Environmental Policy
• /
• v.11 no.2
• /
• pp.55-71
• /
• 2012

This paper attempts to estimate the energy price elasticity of per capita $CO_2$ emissions, which helps to understand the influence of recent energy price increase on the natural reduction of $CO_2$ emissions. For this purpose, this study researched panel data of twenty-nine OECD countries from 1978 to 2009 and adopted estimation models for testing the environmental Kuznets hypothesis. Estimation results show that the 1% increase of energy price index will cause a statistically significant decrease of per capita $CO_2$ emissions by 0.26 ~ 0.31%, which is substantial enough for policy consideration. Also Kuznet curves in estimation models were identifed, the turning points of income lie between 22.2~48.5 thousand US dollars, depending on model specifications.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.45 no.7
• /
• pp.1-8
• /
• 2008

We fabricated flexible electrophoretic display(EPD) driven by organic thin film transistors(OTFTs) on plastic substrate. We designed the W/L of OTFT to be 15, considering EPD's transient characteristics. The OTFTs employed bottom contact structure and used Al for gate electrode, the cross-linked polyvinylphenol for gate insulator, pentacene for active layer. The plastic substrate was coated by PVP barrier layer in order to remove the islands which were formed after pre-shrinkage process and caused the electrical short between bottom scan and top data metal lines. Pentacene active layer was confined within the gate electrodes so that the off current was controlled and reduced by gate electrodes. Especially, PVA/Acryl double layers were inserted between EPD panel and OTFT-backplane in order to protect OTFT-backplane from the damages created by lamination process of EPD panel on the backplane and also accommodate pixel electrodes through via holes. From the OTFT-backplane the mobility was $0.21cm^2/V.s$, Ion/Ioff current ratio $10^5$. The OTFT-EPD panel worked successfully and demonstrated to display some patterns.

• Journal of the Korean Wood Science and Technology
• /
• v.33 no.6 s.134
• /
• pp.46-54
• /
• 2005

To make the composite panels of wood particles and recycled plastics, the recycled polypropylene was used. In the composite panels the sizes of wood particles were 1/32", 1/4" and 1/2" mesh, and the composition ratios of the recycled plastics were 10%, 30%, 50% and 70%. The physical and mechanical properties of the composite panels were investigated. As the composition ratio of wood particle increases, the density increases, while it decreases at the same composition ratio because the size of wood particle increases. As the composition ratio of recycled polypropylene increases from 10% to 30%, both thickness swelling and water adsorption significantly decrease. As the composition ratio of recycled polypropylene increases, the modulus of rupture in bending strength increases, but the modulus of elasticity in bending strength decreases. SEM shows that the dissolved recycled polypropylene penetrates into tracheid and pit, and bonds mechanically to other wood particle and matrix to increase the bonding strength and improve the physical and mechanical properties of composite panel.

• The Journal of the Korea Contents Association
• /
• v.15 no.6
• /
• pp.445-454
• /
• 2015

The purpose of this study is to analyze the influence of the financial structure of pharmaceutical companies on R&D investment. 358 pharmaceutical firms listed in the KOSDAQ market from 2000 to 2012. Financial statements and comments in general and internal transactions were extracted from TS-2000 of the Korea Listed Company Association (KLCA), and data related to stock price was extracted from KISVALUE-III of NICE Information Service Co., Ltd. STATA 12.0 was used as the statistical package for panel analysis. The summary of the findings and the interpretation of the significance of this are as follows: First, the shareholding ratio of major shareholders and foreigners had a positive influence on R&D investment. Second, the ratio of outside directors had a negative influence on R&D investment. Third, the shareholding ratio of institutional investors did not have a significant influence on R&D investment.