• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.74-75
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• 2007

We report on the characteristics of organic light-emitting diodes with Al cathode deposited by specially designed twin target sputter(TTS) system. It was found that the Al cathode films grown by TTS system were amorphous structure with nanocrystallines due to low substrate temperature during sputtering process. Effective confinement of high-density plasma between two Al targets lead to low temperature sputtering process on organic layer. Moreover, organic light-emitting diodes with Al cathode deposited by TTS system exhibited low leakage current density of $4{\times}10^{-6}\;mA/cm2$ at -6 V indicating plasma damage due to bombardment of energetic particles such as ions and $\gamma$-electrons was effectively restricted in the ITS system. Sputtering method using ITS system is expected to be applied in organic electronics and flexible displays due to its low temperature and plasma damage free deposition process.

• 열처리공학회지
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• 제36권6호
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• pp.367-373
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• 2023

600 MPa-grade deformed bar samples were manufactured by conventional hot rolling and subsequent Tempcore heat treatment processes. Considering the short-time water quenching step of the Tempcore process for hot-rolled steel, it is inevitable that the temperature profile of the deformed bar depends strongly on its position throughout the sample thickness. As a result, its microstructure can be easily divided into two regions, the surface and the core regions. The former is expected to have a fresh martensite microstructure under rapid cooling conditions, but self-tempering occurs due to the intense heat flow from the hot core region after the process. The latter is generally known to exhibit a mixed microstructure of ferrite and pearlite due to its slow cooling rate. In this study, detailed microstructural evolutions were examined through the thickness direction. The large variation of the microstructure through the thickness direction in the deformed bar samples is partly due to the easy carbon diffusion from the limited additions of alloying elements.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권3호
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• pp.363-369
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• 2017

Phase-change random access memory (PRAM) has been emerged as a potential memory due to its excellent scalability, non-volatility, and random accessibility. But, as the cell current is reducing due to cell size scaling, the read-sensing window margin is also decreasing due to increased variation of cell performance distribution, resulting in a substantial loss of yield. To cope with this problem, a novel adaptive read-sensing reference current generation scheme is proposed, whose trimming range and resolution are adaptively controlled depending on process conditions. Performance evaluation in a 58-nm CMOS process indicated that the proposed read-sensing reference current scheme allowed the integral nonlinearity (INL) to be improved from 10.3 LSB to 2.14 LSB (79% reduction), and the differential nonlinearity (DNL) from 2.29 LSB to 0.94 LSB (59% reduction).

• Journal of applied mathematics & informatics
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• 제26권5_6호
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• pp.889-900
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• 2008

The problem of scheduling n jobs on a single machine is considered when the machine is subject to stochastic breakdowns. The objective is to minimize the weighted squared deviation of job completion times from a common due date. Two versions of the problem are addressed. In the first one the common due date is a given constant, whereas in the second one the common due date is a decision variable. In each case, a general form of deterministic equivalent of the stochastic scheduling problem is obtained when the counting process N(t) related to the machine uptimes is a Poisson process. It is proved that an optimal schedule must be V-shaped in terms of weighted processing time when the agreeable weight condition is satisfied. Based on the V-shape property, two dynamic programming algorithms are proposed to solve both versions of the problem.

• 한국공작기계학회논문집
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• 제16권5호
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• pp.55-62
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• 2007

With the developments in knitting, manufacturing, and polymers, coated gloves have been evolved in a way to maximize occupational safety and functionality. In this paper, we have considered the PU-coating process for the glove knitted by Dyneema to reduce the occurrence of the defects due to air bubble. This paper classifies the types of defect due to air bubble and traces their forming mechanisms. The air between coating layer of glove and mold's surface forms the defects if it is not evacuated fully in the process of submerging into water. The defects can be suppressed or avoided by forming air-evacuating path on the surface of the molds.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.603-608
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• 2001

Recently, cold expansion of fastener holes is commonly used in the aerospace industry to increase the fatigue endurance of airframes. Cold expansion process is used as the retardation of crack initiation in the hole. This treatment leads to an improvement of fatigue behavior due to the compressive residual stresses developed on the hole surface. The residual stress profile depends on the cold expansion ratio. In the present paper, it is shown that residual stress is redistributed due to the application of cold expansion process for CT specimen. It is further shown that residual stress increases in proportion to cold expansion ratio. It is thought that crack growth rate increases as cold expansion ratio.

• 한국기계가공학회지
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• 제16권6호
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• pp.35-40
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• 2017

The aerodynamic performance of airplane is different according to the configuration of landing gear. As the drag becomes different according to this configuration, the flow stream of air must be smooth at taking off and landing. In this study, the configuration of landing gear was designed each in order to enhance the energy efficiency of airplane. Five models were compared in total at analysis. The magnitudes of drag and pressure became different and the air pressure of wake were changed due to the configuration. So, the air pressure due to the flow velocity and the air resistance happening at the rear can be estimated according to the configuration of landing gear. It is thought to improve the performance of airplane through the result of this study.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.166-167
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• 2013

Bottom ash, which is discharged through a wet process in a thermal power plant, contains much unburned coal due to quenching and much salt due to seawater. However, dry bottom ash discharged through a dry process contains low unburned coal and salt, and has light -weight due to many pores. Therefore, it is expected that it can be used as lightweight aggregate. This study deals with the basic properties of concrete used dry bottom ash as coarse aggregate. As a results, the concrete having high content of dry bottom ash aggregate showed high slump by using water reducing agent and its air content was within 5±1.5% as designed value, similarly to normal weight concrete. It also showed a lower compressive strength than 100% of crushed stone.

• International Journal of Advanced Culture Technology
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• 제12권1호
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• pp.220-226
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• 2024

Accounting is one of the fields greatly affected by the Industrial Revolution 4.0 in general and the digital transformation trend in particular. However, the digital transformation process will also be a weakness if domestic accounting and auditing training activities do not adapt promptly and keep up with the practical requirements of social needs. Job opportunities in the accounting industry will shrink due to increased labor productivity and increasing support technologies, leading to a decrease in the need for traditional accountants. This paper focuses on clarifying the shortcomings and difficulties in accounting training activities by surveying 120 accounting lecturers teaching at domestic universities. Research results show that there are six existing factors and difficulties in accounting training activities due to the digital transformation process, including: facilities, lecturer capacity, training programs, teaching methods. teaching, assessment methods and practice and practice activities. Based on the survey results, we propose recommendations for training activities due to the impact of digital transformation at universities in Vietnam.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.68-71
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• 2000

In this paper, we have measured the oxygen contents by FTIR in silicon wafer various process technology(slicing, lapping, polishing). The measured data are also compared with the data of etching process(KOH, Bright etching). Also we have measured the surface morpology in backside silicon wafer after etching treatment and etch pit density due to OISF after 4 step high temperature annealing process with optical microscope.