In-situ monitoring and control of hydrogenated amorphous silicone germanium band-gap profiling during plasma deposition process

문세연,D.J. You,S.E. Lee,Heon Min Lee 한국물리학회 2013 Current Applied Physics Vol.13 No.7

In-situ germanium content monitoring and its characteristics in SiH4/GeH4/H2 plasmas was studied during hydrogenated amorphous siliconegermanium (a-SiGe:H) film depositions. Since an appropriate band-gap profiling in a-SiGe:H deposition is very important to achieve high efficiency solar cell, the accurate monitoring and control of Ge contents are required. In this work, we found the spectral intensity ratio of silicon atom (288.2 nm) and germanium atom (303.9 nm) emission has strong relation with Ge content in plasmas. In typical, band-gap energy of films was decreased with the increasing of gas flow ratio GeH4/SiH4. However, at different total flow rate of GeH4, the band-gap was different for same gas flow ratio cases because the Ge content in plasmas was changed due to the changes of electron temperature by hydrogen dilution. On the other hand, the emission intensity ratio Ge/Si detected the band-gap variation. Using this method, therefore, we measured and control Ge/Si to make a U-shape band-gap profile which was proved by an ellipsometer and Auger electron spectroscopy depth profile analysis.

우주소재부품 개발용 플라즈마 기술 연구

문세연,김호석,강보람,유희일,오필용,최성만 한국진공학회 2019 한국진공학회 학술발표회초록집 Vol.2019 No.8

성인학습자의 학습동기와 관련 변인에 대한 국내연구 메타분석

문세연,나승일 한국산업교육학회 2008 산업교육연구 Vol.17 No.-

이 연구의 목적은 국내 성인학습자의 학습동기 관련 변인 연구를 종합하여 각 변인들이 학습동기에 미치는 효과크기를 구명하는데 있었다. 구체적으로 학습동기 관련 변인군(인구 통계학적 변인군, 학습자 심리․능력 변인군, 교수학습 변인군, 조직환경 변인군)이 학습동 기에 미치는 효과크기의 차이를 구명하였고, 학습동기 관련 개별 변인들이 학습동기에 미치 는 효과크기를 구명하였다. 이 연구에서는 성인의 학습동기 관련 변인의 효과를 통계적으로 종합하기 위하여 효과크기를 이용한 메타분석을 실시하였다. 이 연구의 주요 결과는 다음과 같다. 첫째, 성인학습자의 학습동기 관련 변인군이 학습동 기에 미치는 효과크기는 조직환경 변인군(ES=0.256), 교수학습 변인군(ES=0.245), 학습자 심 리․능력 변인군(ES=0.188), 인구통계학적 변인군(ES=0.111) 순으로 나타났다. 둘째, 인구통 계학적 변인군 내에서는 결혼유무(ES=0.359), 전공(ES=0.267), 소득(ES=0.208) 순으로 학습 동기에 가장 영향을 많이 미치는 것으로 나타났다. 셋째, 학습자 심리․능력 변인군 내에서 는 기대(ES=0.673), 자기효능감(ES=0.660), 인지전략(ES=0.597) 순으로 학습동기에 가장 영 향을 많이 미치는 것으로 나타났다. 넷째, 교수학습 관련 변인군 내에서는 교육내용 (ES=0.556), 학습환경(ES=-0.267), 웹-집합 수업유형(ES=0.326) 순으로 학습동기에 가장 영 향을 많이 미치는 것으로 나타났다. 다섯째, 조직환경 관련 변인군 내에서는 구성원 지원 (ES=0.397), 인사관리(ES=0.183), 선택자유도(ES=0.136) 순으로 성인학습자의 학습동기에 가 장 영향을 많이 미치는 것으로 나타났다. 이 연구에서 얻은 결과에 기초하여 후속 연구로서 성인학습자의 학습동기와 관련된 다양 한 변인들에 대한 연구, 성인학습자를 구성하는 집단 간 학습동기 관련 변인의 효과크기 비 교연구, 종속변인인 성인학습자의 학습동기를 유형별로 세분화한 메타연구, 메타분석 방법 면에서 다양한 방법을 통해 대상 연구물의 질을 평가하는 연구 등이 제안되었다. The purpose of this study was to identify the effect sizes on learning motivation of adult learners and its related variables through synthesizing quantitatively the master's theses, doctoral dissertations and journal papers in Korea. Specifically, the effect sizes of demographics variables, psychological variables, teaching and learning variables, and organizational variables on learning motivation of adult learners were analyzed, and effect size of each variable of them also was analyzed. This purpose was accomplished by utilizing the meta-analysis technique of research integration. The major findings of this study were as follows: First, among the effect sizes of variables on learning motivation of adult learners, organizational variables (ES=0.256) showed the highest, and teaching and learning variables (ES=0.245), psychological variables (ES=0.188), and demographics variables (ES=0.111) in order. Second, among the effect sized of demographics variables on learning motivation of adult learners, marriage (ES=0.359) showed the highest, as followed by academic major (ES=0.267) and income (ES=0.208). Third, among the effect sized of psychological variables on learning motivation of adult learners, expectancy (ES=0.673) showed the highest, as followed by self-efficacy (ES=0.660) and cognitive strategy (ES=0.597). Forth, among the effect sized of teaching and learning variables on learning motivation of adult learners, learning contents (ES=0.556) showed the highest, as followed by learning environment (ES=-0.267), and instruction style as web-based or classroom-based (ES=0.326). Fifth, among the effect sized of organizational variables on learning motivation of adult learners, support of co-workers (ES=0.397) showed the highest, as followed by human resource management (ES=0.183) and degree of choice(ES=0.136). Some recommendations for future researches were suggested: First, further research needs to investigate other variables that was not dealt in this study. Second, since adult learners could be categorized, further research needs to identify effect sizes on learning motivation and its variables by the category. Third, according to the type of learning motivation, further research needs to be performed with different type. Forth, further research need to evaluate and select qualitative papers using meta-analysis.

중소기업 근로자의 무형식학습과 관련 변인

문세연,나승일 한국성인교육학회 2011 Andragogy Today : International Journal of Adult & Vol.14 No.3

The purpose of this study was to identify a causal relationship among informal learning, learning motivation, learning strategy, interpersonal relationship, and job characteristics of workers in small and medium-sized enterprises. The population for this study was workers in small and medium-sized enterprises (SMEs). Though the Small and Medium Businesses Information System (SMINFO), 534 questionnaires were used for analysis. The covariance structure analysis was performed using AMOS 7.0 version. The findings of the study were as follows: First, the fit index of causal model among informal learning, learning motivation, learning strategy, interpersonal relationship, and job characteristics were identified suitably. Second, factor loading of learning motivation to informal learning was β=0.814, learning motivation was β=0.301 and interpersonal relationship was β=0.107. The factor loading of job characteristics was not significant. Third, in relationship between informal learning and learning motivation, learning strategy and interpersonal relationship had moderating effect. Forth, in relationship between informal learning and job characteristic, both learning motivation and interpersonal relationship had not significant moderating effect. 이 연구의 목적은 우리나라 중소기업 근로자의 무형식학습과 관련 변인의 영향관계를 구명하여 어떻게 효과적인 무형식학습이 이루어질 수 있는지를 설명하고자 하였다. 구체적으로는 근로자들의 학습동기, 학습전략, 대인관계 및 직무특성이 무형식학습에 직접적으로 정적인 영향을 미치는지, 학습동기와 무형식학습의 관계에서 학습전략과 대인관계가 매개효과를 가지는지, 직무특성과 무형식학습의 관계에서 학습동기와 대인관계가 매개효과를 가지는지를 검증하였다. 이 연구의 모집단은 우리나라 중소기업 근로자로 중소기업청에서 주관하는 중소기업현황정보시스템(http://sminfo.smba.go.kr)에 등록된 중소기업을 대상으로 조사하여 534부를 분석에 사용하였다. 자료분석은 AMOS 7.0 통계프로그램을 이용하여 공변량구조분석을 실시하였다. 이 연구의 결과는 첫째, 중소기업 근로자의 무형식학습과 학습동기, 학습전략, 대인관계 및 직무특성의 인과모형에 대한 적합도는 적합하게 나타났다. 둘째, 중소기업 근로자의 무형식학습에 대하여 학습동기는 경로계수 β=0.814, 학습전략 경로계수 β=0.301, 대인관계 경로계수 β=0.107로 유의미하게 영향을 미치는 것으로 나타났으나, 직무특성은 유의미하지 않았다. 셋째, 중소기업 근로자의 무형식학습과 학습동기 관계에서 학습전략과 대인관계는 간접효과를 가지며 매개하는 것으로 나타났다. 넷째, 중소기업 근로자의 무형식학습과 직무특성 관계에서 학습동기와 대인관계는 유의미한 매개효과를 가지지 않았다.

Capacitive discharge mode transition in moderate and atmospheric pressure

문세연,J. K. Rhee,D.B. Kim,B.M. Gweon,최원호 한국물리학회 2009 Current Applied Physics Vol.9 No.1

Current–voltage characteristics of α- and γ-modes were investigated in moderate and atmospheric pressure capacitive discharges. The α- and γ-modes, the co-existence of both modes, and the α- to γ- and γ- to α-mode transitions were observed with the changes in voltage, current, and plasma volume. Changing of gas pressure, (100–760) Torr, the α to γ and the γ to a transition occurred with respect to input power increasing and decreasing, respectively. The hysteresis in current and voltage curve was observed and became more evident at higher pressure. Using a simple electrical circuit model, the relation between the gas pressure and the α-sheath thickness before mode transition was described.

Decontamination Effects of Ozone Generated in an Atmospheric-pressure Air Plasma on Packaged Fruits

문세연,문아영 한국진공학회 2019 Applied Science and Convergence Technology Vol.28 No.2

Atmospheric-pressure plasma has recently been intensively studied for agricultural product treatment because of its strong decontamination effect and its abundant active agents such as atomic oxygen, ozone, and ultra-violet radiation. However, detailed mechanistic studies of plasma and agricultural products have yet to be conducted. In this study, a dielectric barrier air-discharge plasma was used to treat fruit in packages, and its decontamination mechanism was studied through plasma characterization, microbiological analysis, and food-quality check. By heating the gas introduced for plasma generation and filling packages, we found that the plasma-treated gases enabled better storage conditions for fruits without significant quality degradation. In addition, the control of ozone concentration was revealed to be one of the main decontamination factors.

Application of Semi-automatic Program for Gas Temperature Measurement in Atmospheric Pressure Plasmas Using a Synthetic Diatomic Molecular Spectrum Method

문세연 한국진공학회 2019 Applied Science and Convergence Technology Vol.28 No.4

Gas temperature is one of the most important parameters for atmospheric pressure plasma applications. Based on the fact that this parameter is closely related to the rotational temperature of diatomic molecules at atmospheric pressure, a spectroscopic method of measuring the rotational temperature was used by analyzing the OH, O2, N2 +, CH, and CN molecular spectra, which are frequently observed in various atmospheric pressure plasmas. In this work, a semi-automatic program for the determination of the rotational temperature was developed, allowing the use of modest resolution monochromators, generally used in industries and laboratories. Different atmospheric pressure plasma sources were used for application to the various gas temperatures in the range of 4002500 K. Different diatomic molecular spectra emitted under the same plasma condition showed almost the same gas temperature. Through a sensitivity study of the method, it was found that the diagnostic conditions, such as molecular species and optical resolution, should be carefully selected for more accurate measurements.

플라즈마 분광 진단 기술

문세연 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.2

UV 광흡수법을 이용한 C4F8/Ar 유도결합플라즈마의 CF2 절대밀도 공간분포진단 연구

문세연,한종구,조덕균 한국진공학회 2020 한국진공학회 학술발표회초록집 Vol.2020 No.2

OH 분자 방출 스펙트럼을 이용한 상압 플라즈마의 기체온도 측정

문세연,최원호 한국물리학회 2002 New Physics: Sae Mulli Vol.44 No.6

From an application point of view, the gas temperature is one of the most important parameters in atmospheric plasmas. In this article, a spectroscopic method of measuring the gas temperature by analyzing the OH molecular spectrum emitted from the atmospheric plasma is described. The OH diatomic molecular spectrum ($A^{2} \Sigma^{+}, \nu=0 \rightarrow X^{2} \Pi,~\nu'=0$,~306~-~310~nm) due to the oxygen and hydrogen existing in ambient air. In order to utilize a low--resolution spectrometer, we compared the synthetic OH molecular spectrum with the experimentally obtained spectrum. For the low gas-temperature case with an arc plasma, a thermocouple was used to verify the accuracy of the measurement method. The result from the thermocouple was shown to be in excellent agreement with that from the spectroscopic method. 상압 플라즈마의 응용 면에서 보면, 플라즈마의 기체온도는 저압 플라즈마에서와는 달리 매우 중요한 플라즈마 변수 중 하나이다. 상압에서 발생된 플라즈마는 대기 중에 수증기의 형태로 존재하는 산소와 수소로 인하여 OH 이원자 분자의 스펙트럼($A^{2} \Sigma^{+}, \nu=0 \rightarrow X^{2} \Pi,~\nu'=0$,~306~-~310~nm)을 방출한다. 상압 플라즈마로부터 방출되는 OH 분자의 스펙트럼을 분석하여 플라즈마의 기체온도를 측정하였다. 분광기의 한정된 분해능을 극복하기 위해 분자 스펙트럼의 이론적 모형을 통하여 얻은 스펙트럼과 실험으로부터 얻은 스펙트럼을 비교하여 대기압 플라즈마의 기체온도를 결정하였다. 이 기체온도 진단법의 정확도를 검정하기 위해 열전쌍(thermocouple)을 이용할 수 있을 정도의 기체온도를 가진 아크 플라즈마를 발생시키고 열전쌍으로 측정한 값과 비교해 본 결과, 잘 일치함을 알 수 있었다.