• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.411-411
• /
• 2010

Cavity mode Whistler wave를 사용하는 자화유도결합플라즈마 (Magnetized Inductively Coupled Plasma, MICP)의 제반 특성을 비등방성 수송계수를 가지는 Drift-Diffusion 근사, 에너지 보존 방정식 및 유도전자계를 self-consistent 하게 고려하여 계산하였다. 이러한 접근법은 비충돌성 전자가열현상을 고려하지 못하는 단점에도 불구하고, 반도체 장비설계에 필수적인 전자온도, 밀도, 플라즈마 전위, 시스템의 임피던스 특성에 대한 경향성 파악에 매우 유용하다. 뿐만 아니라 전자밀도분포가 공간내에 형성되는 R-wave mode에 미치는 영향을 분석할 수 있다. 직경 320 mm를 가지는 작은 반응기에서 시뮬레이션과 실험결과를 비교하여 본 모델링 방법의 타당성을 검증한 후, 450 mm wafer가공에 적합한 대면적 플라즈마 반응기에서 플라즈마 특성을 연구하였다. 수 mTorr의 공정압력에서 약 10 Gauss전후의 약한 자장이 인가됨으로서 반경방향의 전자밀도 균일성이 대폭 향상되었다. 플라즈마 및 안테나의 대면적화에 수반되는 높은 Q값이 자장의 인가로 큰 폭으로 감소함으로서 임피던스메칭의 안정성이 비약적으로 개선되었고 전력전달 효율 또한 크게 증가함을 알 수 있었다. 본 연구 결과는 차세대 450 mm 반도체 공정장비의 개발에 있어 자화유도결합플라즈마가 매우 유용하게 사용될 수 있음을 보여준다.

• Bulletin of the Korean Chemical Society
• /
• v.18 no.5
• /
• pp.478-484
• /
• 1997

In a recent paper[Bull. Kor. Chem. Soc. 17, 735 (1996)] we reported results of molecular dynamic (MD) simulations for the thermodynamic and structural properties of liquid n-alkanes, from n-butane to n-heptadecane, using three different models. Two of the three classes of models are collapsed atomic models while the third class is an atomistically detailed model. In the present paper we present results of MD simulations for the dynamic properties of liquid n-alkanes using the same models. The agreement of two self-diffusion coefficients of liquid n-alkanes calculated from the mean square displacements (MSD) via the Einstein equation and the velocity auto-correlation (VAC) functions via the Green-Kubo relation is excellent. The viscosities of n-butane to n-nonane calculated from the stress auto-correlation (SAC) functions and the thermal conductivities of n-pentane to n-decane calculated from the heat-flux auto-correlation (HFAC) functions via the Green-Kubo relations are smaller than the experimental values by approximately a factor of 2 and 4, respectively.

• Bulletin of the Korean Chemical Society
• /
• v.18 no.5
• /
• pp.501-509
• /
• 1997

In recent papers[Bull. Kor. Chem. Soc. 1996, 17, 735; ibid 1997, 18, 478] we reported results of molecular dynamics (MD) simulations for the thermodynamic, structural, and dynamic properties of liquid normal alkanes, from n-butane to n-heptadecane, using three different models. Two of the three classes of models are collapsed atomic models while the third class is an atomistically detailed model. In the present paper we present results of MD simulations for the corresponding properties of liquid branched-chain alkanes using the same models. The thermodynamic property reflects that the intermolecular interactions become weaker as the shape of the molecule tends to approach that of a sphere and the surface area decreases with branching. Not like observed in the straight-chain alkanes, the structural properties of model Ⅲ from the site-site radial distribution function, the distribution functions of the average end-to-end distance and the root-mean-squared radii of gyration are not much different from those of models Ⅰ and Ⅱ. The branching effect on the self diffusion of liquid alkanes is well predicted from our MD simulation results but not on the viscosity and thermal conductivity.

• Bulletin of the Korean Chemical Society
• /
• v.12 no.3
• /
• pp.315-322
• /
• 1991

In a recent $paper^1$ we reported equilibrium (EMD) and non-equilibrium (NEMD) molecular dynamics simulations of liquid argon using the Green-Kubo relations and NEMD algorithms to calculate the thermal transport coefficients-the self-diffusion coefficient, shear viscosity, and thermal conductivity. The overall agreement with experimental data is quite good. In this paper the same technique is applied to calculate the thermal transport coefficients of liquid water at 298.15 K and 1 atm using TIP4P model for the interaction between water molecules. The EMD results show difficulty to apply the Green-Kubo relations since the time-correlation functions of liquid water are oscillating and not decaying rapidly enough except the velocity auto-correlation function. The NEMD results are found to be within approximately ${\pm}$30-40% error bars, which makes it possible to apply the NEMD technique to other molecular liquids.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.23 no.6
• /
• pp.773-779
• /
• 1986

In this paper, we discuss fabrication and characteristics of the Vertical Double diffused MOS(VDMOS) transistor. The epi layers of starting wafers are 18~22\ulcorner in thickness and 8~12\ulcornercm in resistivity. The channel regions are defined through the self-aligned double diffusion process. The characteristics of the fabricated VDMOS are breakdown voltage of 240V, threshold voltage of 2V, on-resistance of 226\ulcornerand transconductance of 3x10**-3 mho.

• East Asian Economic Review
• /
• v.27 no.1
• /
• pp.61-85
• /
• 2023

The study aims to investigate the factors pursuing the women entrepreneurs to accept Islamic microfinance (IMF) in urban and rural areas of Malaysia. For this purpose, the study applies the Theory of Planned Behavior (TPB) and Innovation and Diffusion Theory to explain Islamic microfinance adoption. Using the structural equation model (SEM) with primary data collected from 384-woman entrepreneurs in Malaysia, the current study uses a 5-point Likert scale. On the basis of theory and collected data, the seven hypotheses are developed. All hypotheses are validated by both directly and indirectly, as well as through a mediating factor. Among the factors, knowledge about IMF and subjective norms significantly influence the acceptance of IMF. On the other hand, the perceived complexity does not show any substantial relationship to the acceptance of IMF. This outcome will be helpful in supporting policymakers, academics, and future studies and must take into account the supported factors. Therefore, the study contributes to develop an innovative framework, to create self-employment for women entrepreneurs.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2023.11a
• /
• pp.465-468
• /
• 2023

디퓨전 모델에서 생성한 이미지를 조작하는 기존 프롬프트 기반 방법과 포인트 기반 방법에는 각각의 단점이 있다. 프롬프트 기반은 프롬프트로만 조작이 가능하고 세세하지 못하다. 포인트 기반은 입력 이미지의 스타일을 보존하려면 파인튜닝이 필요하다. 본 논문은 디퓨전 생성 모델에 셀프 어텐션 제어와 드래그 조작을 통해, 파라미터 학습 없이, 이미지의 스타일을 보존하며 다양한 범위의 이미지 조작이 가능한 방법을 제안한다.

• Journal of the Korean Ceramic Society
• /
• v.36 no.2
• /
• pp.203-209
• /
• 1999

LaAlO3d single phase used as the butter layer on Si wafer for YBa2Cu3O7-$\delta$ superconductor application were prepared by solid state reaction method and by self-sustaining combustion process. The microstructure and crystallity of synthesiszed LaAlO3 powder studied using scanning electron microscope (SEM) and X-ray diffractometer(XRD), specific surface area and sintering characteristics fo powder were investigated by Brunauer-Emmett-Teller (BET) method and dilatometer respectively. In solid state reaction method, it is difficult to obtain LaAlO3 single phase up to 150$0^{\circ}C$ period. However, in self-sustaining combustion process, it is to easy to do it only $650^{\circ}C$. Based on the results of analysis of dilatometer it is easier to obtain high sintering density (98.87%) in self-sustaining combustion process than in the solid state reaction method. This reason is that the average particle size prepared by self-sustaining combustion process is nano crystal size and has high specific surface are value(56.54 $m^2$/g) compared with that by solid state reaction method. Also, LaAlO3 layer on the Si wafer has been achieved by screen printing and sintering method. Even though the sintering temperature is 130$0^{\circ}C$, the phenomena of silicon out diffusion in LaAlO3/Si interphase are not observed.

• Fire Science and Engineering
• /
• v.34 no.3
• /
• pp.141-149
• /
• 2020

The Korea Industrial Standards (KS) stipulates methods and test procedures for measuring the horizontal combustibility of cellular plastics exposed to small flames (KS M ISO 9772:2018) and recommendations regarding the magnetic digestion of extruded polystyrene insulation (XPS) for measurement results (KS M 3808:2020). Although products that are certified to conform to KS standards must have burning characteristics (self-extinguishing), they are incinerated and spread by welds at construction sites, causing significant human and property damages. In this study, XPS produced by five companies, certified by KS, and sold in the market were purchased and tested for ignition and diffusion caused by a weld bullion at a construction site. The results showed that the five products had differences in performance. Three out of the five products were found to be self-saturated, but the other two were easily ignited and diffused, making it difficult for them to be self-extinguishing. Based on the result of this experimental investigation in line with the KS regulations, all the three types of products, including two types of products that were incinerated through weld defects, were found to be non-self-extinguishing, as specified in KS M 3808.

• Women's Health Nursing
• /
• v.29 no.2
• /
• pp.137-145
• /
• 2023

Purpose: This non-randomized study was performed to evaluate the effects of music therapy on labor pain, the childbirth experience, and self-esteem in women during vaginal delivery. Methods: In total, 136 primiparous women over 37 weeks of gestation receiving epidural analgesia during vaginal delivery were recruited via convenience sampling. To minimize diffusion effects, data from the control group (n=71) were collected first (April 2020 to March 2021), followed by data from the music group (n=65; April 2021 to May 2022). Participants in the music group listened to classical music during labor, while the control group was offered usual care (no music). Labor pain was measured using a numeric rating scale (NRS), and self-esteem and childbirth experience were collected using self-report questionnaires. Data were analyzed using the independent t-test, chi-square test and Cronbach's α coefficients. Results: The overall pain level (NRS) at baseline was 0 in both groups. Mothers in the music therapy group had lower levels of latent pain (t=1.95, p=.005), active pain (t=3.69, p<.001) and transition-phase pain (t=7.07, p<.001) than the control group. A significant difference was observed between the two groups, and the music therapy group expressed more positive perceptions of the childbirth experience (t=-1.36, p=.018). For self-esteem, the experimental group's score was slightly higher, but without a statistically significant difference from the control group. Conclusion: Using music therapy during labor decreased labor pain and improved the childbirth experience. Music therapy can be clinically recommended as a non-pharmacological, safe, and easy method for nursing care in labor.