• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.197-200
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• 2008

We propose a novel n-type a-Si:H TFT pixel circuit which is proper to AMOLED display for the large size and high resolution. Proposed pixel circuit will be suit to panel for the high resolution because of different threshold sampling method. Driving method of proposed pixel circuit is very simple like an AMLCD. Our simulation indicates that the proposed pixel circuit can compensate the Vth shift and IR rising of power line so that provide better quality image.

• 한국정보디스플레이학회:학술대회논문집
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• 2001.08a
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• pp.9-12
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• 2001

With the explosive growth of Note-PC and Desktop monitor market, TFT LCD market confronted a entire supply shortage during 1999. Forecasting a more booming stage for the next several years, many TFT-LCD panel manufacturers continue to expand the capacity of their existing plants and also make an additional investment in building new plants. The new investment is concentrated on the $4^{th}$ generation TFT LCD line in order to improve investment efficiency. The set up of the Samsung's Gen 3.5 line progressed with satisfactorily performance using $600{\times}720mm$ glass size. We have continuously reviewed several issues regarding the glass size for our next Gen. 4 line, which leads to adopt $730{\times}920mm$. Due to the continuous enlargement of a substrate size and following difficulty in transferring cassettes, the next line is expected to be the last line that employs "cassette transfer". The layout of the next line will shift from conventional "concentration-type" to "separation-type" configuration for the purpose of reducing transfer distance as well as transfer time. The details will be discussed in this paper.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.52-55
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• 2006

The driving-current degradation of a-Si:H thin-film transistor(TFT) device has been analyzed for the first time. A method to analyze the performance of TFT circuits is presented, which is different from the conventional one by threshold voltage shift method. It can be also used to evaluate the performance of gate driver on array (GOA) circuit, which is integrated in a 12.1" WXGA ($1280{\ast}3{\ast}800$) TFT-LCD panel.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.692-696
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• 2005

In an attempt to fabricate all inclusive display systems we are presenting a study on several elements that would be used as building blocks for all-on-board integrated applications on stainless steel foils. These systems would include in the same substrate all or many of the components needed to drive a flat panel OLED display. We are reporting results on both digital and analog circuits on stainless steel foils. Shift registers running at speeds greater than 1.0MHz are shown as well as oscillators operating at over 40MHz. Pixel circuits for driving organic light emitting diodes are presented. The device technology of choice is that based on poly-silicon TFT technology as it has the potential of producing circuits with good performance and considerable cost savings over the established processes on quartz or glass substrates (amorphous Silicon a-Si:H or silicon on Insulator SOI).

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.822-824
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• 2007

This paper investigated a gate driver circuit with amorphous silicon for mobile TFT-LCD. In the conventional circuit, the fluctuation of the off-state voltage causes the fluctuation of gate line voltages in the panel and then image quality becomes worse. Newly designed gate driver circuit with dynamic switching inverter and carry out signal reduce the fluctuation of the off-state voltage because dynamic switching inverter is holding the off-state voltage and the delay of carry signal is reduced. The simulation results show that the proposed a-Si:H gate driver has low noise and high stability compared with the conventional one.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.321-324
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• 1998

Pixel-Design Array Simulation Tool(PDAST) was used to profoundly the gate signal distortion and pixel changing capability, which are the most critical limiting factors for high-quality TFT-LCDs. Since PDAST can simulate the gate, data and pixel voltages of a certain pixel on TFT array at any time and at any location on an array, the effect of the resistivity of gate line material on the pixel operations can be effectively analyzed. The gate signal delay, pixel charging ratio, level-shift of the pixel voltage were simulated with varying the resis5tivity of the gate line material. The information obtained from this study could be utilized to design the larger area and finer image quality panel.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.2
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• pp.133-140
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• 2024

This study offers a comprehensive evaluation of the role and impact of advanced power semiconductors in solar module systems. Focusing on silicon carbide (SiC) and gallium nitride (GaN) materials, it highlights their superiority over traditional silicon in enhancing system efficiency and reliability. The research underscores the growing industry demand for high-performance semiconductors, driven by global sustainable energy goals. This shift is crucial for overcoming the limitations of conventional solar technology, paving the way for more efficient, economically viable, and environmentally sustainable solar energy solutions. The findings suggest significant potential for these advanced materials in shaping the future of solar power technology.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.289.2-289.2
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• 2016

In-Ga-Zn-O(IGZO) receive great attention as a channel material for thin film transistors(TFTs) as next-generation display panel backplanes due to its superior electrical and physical properties such as a high mobility, low off-current, high sub-threshold slope, flexibility, and optical transparency. For the purpose of fabricating high performance IGZO TFTs, a thermal recovery process above a temperature of $300^{\circ}C$ is required for recovery or rearrangement of the ionic bonding structure. However diffused metal atoms from source/drain(S/D) electrodes increase the channel conductivity through the oxidation of diffused atoms and reduction of $In_2O_3$ during the thermal recovery process. Threshold voltage ($V_{TH}$) shift, one of the electrical instability, restricts actual applications of IGZO TFTs. Therefore, additional investigation of the electrical stability of IGZO TFTs is required. In this paper, we demonstrate the effect of Ti diffusion and modulation of interface traps by carrying out an annealing process on IGZO. In order to investigate the effect of diffused Ti atoms from the S/D electrode, we use secondary ion mass spectroscopy (SIMS), X-ray photoelectron spectroscopy, HSC chemistry simulation, and electrical measurements. By thermal annealing process, we demonstrate VTH shift as a function of the channel length and the gate stress. Furthermore, we enhance the electrical stability of the IGZO TFTs through a second thermal annealing process performed at temperature $50^{\circ}C$ lower than the first annealing step to diffuse Ti atoms in the lateral direction with minimal effects on the channel conductivity.

• Journal of Korea Trade
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• v.26 no.4
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• pp.63-82
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• 2022

Purpose - Drawing on relational institutional theory, we explored how demographic similarity between board members of a firm and newly emerged political elites led to firms' increased financial resource acquisition such as leverage ratio and decreased export intensity amidst the Asian financial crisis. We also studied how a firm's leverage ratio and export intensity can further affect firm profitability and financial credit rating. Design/methodology - We revisited and explored a unique, unprecedented crisis that affected most Korean firms: the Asian financial crisis that coincided with a governmental shift from a conservative to a liberal party. We collected demographic information from 432 listed Korean firms' board members and 43 political elites of the Blue House from 1998-2000 to create a demographic similarity measurement. We collected firms' financial information, built panel data, and used ordinary least squares regression to test our theory. Findings - Our results showed that demographic similarity between a firm's directors and newly emerged politicians had a positive association with a firm's leverage ratio but a negative association with a firm's export intensity. A firm's leverage ratio had a negative relationship with firm performance measured by firm profitability and financial credit rating. A firm's export intensity showed a positive effect on firm performance. Originality/value - We highlighted that during an economic crisis that coincided with a governmental shift and change of leading political actors, firms exerted efforts to survey the environment and build new external stakeholder relationships to cope with the changing landscape. We proposed that in an emerging market like Korea where low levels of trust and favoritism are prevalent across society, one of the relational institutional strategies that firms can employ is the selection of directors with similar demographic characteristics to political elites based on factors including birthplace and school affiliations. We examined the efforts of firms to build political networks with newly empowered political elites during a financial crisis, and the consequences of establishing such networks. We highlighted that during a financial crisis, the demographic similarity between a firm's board members and newly emerged politicians can provide firms with access to financial resources but can also result in poor management and reduced effort to enhance its international competitiveness.

• Korean Journal of Occupational Health Nursing
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• v.25 no.4
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• pp.277-289
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• 2016

Purpose: This study aims to investigate the cross-sectional association of company size and self-rated health using representative data on Korean workers. Methods: We used the data from 2,884 wage workers collected by Korean Labor and Income Panel Study (17th). The association between company size and self-rated health was analyzed using logistic regression with covariates including demographic characteristics, work environment, job satisfaction, and health-related behaviors. Resulst: Odds ratio (OR) for better health status among workers in large-sized company was 1.351 (CI. 1.054~1.731), compared to workers in small-sized company. We performed three separate models stratified by firm size (small, medium, and large companies). Occupation variables showed different effect on health depending on firm sizes. OR for better health of white-color job (referred to blue-color job) was 1.693 in medium-sized company model but it was 0.615 in large company model. OR for better health of the workers working shift work showed 0.606 in large company model but it was not significant in small and medium company models. Conclusion: We found that small-sized company workers have significantly poor self-rated health compared to large-sized firm workers. This study revealed that there exist differences among health related factors depending on firm sizes.