Development of cu-based conversion cathodes for alkali-ion batteries

Lee, Yongseok Sungkyunkwan University 2024 국내박사

전기자동차 및 에너지 저장 시스템의 대용량 전원 공급 장치의 중요성으로 인해, 고에너지밀도 특성의 에너지 저장 장치에 대한 시장 수요가 지속적으로 증가하고 있다. 그러나 현재 주류를 이루고 있는 삽입-탈리 기반 양극 소재는 에너지 밀도의 한계에 다다르고 있는 실정이다. 반면 전환형 양극 소재는 이에 비해 동일한 전이금속 몰 당 더 많은 리튬 이온을 저장할 수 있어 큰 가능성을 지니고 있다. 하지만 전환형 양극 소재는 저조한 전도성, 큰 부피 변화 및 낮은 작동 전압으로 인해 실사용에 큰 어려움을 겪고 있다. 본 학위논문에서는 전환형 양극 소재에 대하여 다중음이온 도입을 통한 작동 전압의 향상 및 카본 코팅과 나노 사이징을 통한 동역학 개선 방안을 제시하였다. 해당 전략을 바탕으로 리튬, 소듐 및 포타슘 이온전지용 고성능 전환형 양극소재를 개발하였으며, X-ray 기반 고도분석을 통한 전환 반응 메커니즘을 규명하였다. 이러한 발견을 통하여 알칼리 이온전지용 고성능 전환형 양극 소재 개발 전략의 적용 가능성을 제시하였다. The market's demand for high-energy-density energy storage solutions continues to surge, driven by their crucial role in supplying abundant power for electric vehicles and energy storage systems. While intercalation-based cathodes in lithium-ion batteries have undergone extensive research, their specific capacity still falls short of 230 mAh g−1. To enhance specific capacity, conversion-based reactions are being explored, but they encounter challenges such as poor conductivity, large volume change and voltage hysteresis. Typically, general metal oxide conversion reactions occur at low voltages, resulting in a low average operational voltage, which often makes them preferred as anode materials. Hence, we have devised two approaches for the practical utilization of conversion-based electrodes as cathodes. Firstly, to enhance the operational voltage of the conversion reaction, it is necessary to maximize the inductive effect by incorporating polyanion groups into the structure. Secondly, surface modifications such as carbon coating and nano-sizing can significantly enhance thesluggish kinetics of conversion cathodes. These effective strategies have enabled the development of novel conversion cathodes, including Cu2P2O7, Cu(PO3)2, and CuSO4, that exhibit high energy density in Li-, Na-, and K-ion batteries. These findings offer valuable insights into surpassing the energy density limitations of cathode materials for alkali-ion batteries.

서울市 産業構造變化에 따른 建築物 市場需要와 用途變更의 構造的 變化

고종옥 강원대학교 2008 국내박사

산업구조변화는 부동산시장에 많은 영향을 주고 있다. 또한, 급변하는 시장 환경과 도시지역의 토지부족 현상은 기존 건축물에 대한 재사용의 필요성을 증대시키고 있다. 특히, 대도시에 있는 건축물들은 시장 환경 변 화에 따른 다양한 수요에 탄력적으로 대응할 수 있어야 한다. 그 동안 건 축물 공급은 신축 위주였지만, 이제는 신속하고 순발력 있는 용도변경 방 식의 건축물 공급을 적극적으로 검토해야 할 시점이다. 그러기 위해서는 무엇보다 용도변경 수요를 미리 예측할 수 있는 선행 지표가 필요한데, 현재로서는 용도변경 시장규모를 미리 파악할 수 있는 방법이 없다고 해도 과언이 아니다. 따라서 본 연구가 산업구조변화와 용 도변경의 관련성 및 용도변경 간 구조적인 변화를 밝힐 수 있다면 그 의 미가 크다고 할 것이다. 본 논문의 연구목적은 빠른 산업변화에 따른 기존 건축물의 재활용에 대한 중요성이 증대되고 있는 시점에서 산업구조변화와 건축물 용도변경 의 관련성을 밝히고 용도변경 간에 나타나는 구조적 변화를 분석하는 것 이다. 이렇게 하여 밝혀진 연구 결과는 건축물의 용도변경 활성화에 기여 할 수 있기 때문이다. 연구범위는 한국표준산업분류의 대분류 변수들의 과거 10년(1996-2005) 간 변화와 서울시 20개 자치구에서 동 기간 동안에 추진된 용도변경 건수 를 전수조사 하였다. 이렇게 수집된 자료를 통계적 방법으로 상관관계를 분석하였고, 서울시를 서울지역ㆍ강남지역ㆍ강북지역으로 구분하여 용도 변경 전.후에 대한 CNA(용도변경 네트워크 분석: conversion network analysis)분석을 하였다. 본 논문은 이러한 연구목적을 달성하기 위해서 다음과 같은 1차 연구가 설과 2차 연구가설을 설정한 후 통계분석과 네트워크 분석을 통해서 검증 하고자 한다. H1: 서울지역 산업구조변화는 건축물 용도변경과 관련성이 높을 것이다. H2: 산업구조변화는 지역 간 차이가 있으므로, 건축물 용도변경도 지역 간 차이가 있을 것이다. H2-1: 강남지역은 주로 서비스관련 사업체들이 건축물 용도변경과 관 련성이 높을 것이다. H2-2: 강북지역은 주로 제조업 관련 사업체들이 건축물 용도변경과 관 련성이 높을 것이다. 산업구조변화와 건축물 용도변경의 관련성 및 건축물의 용도변경 간 네 트워크 분석결과는 다음과 같다. 첫째, 서울지역은 부동산업이 강한 상관관계를 나타냈고, 다음으로 음식 업, 교육업, 금융보험업, 보건사회업 순으로 나타났다. 각 지역별 분석결과 동대문구는 제조업, 도.소매업, 음식업, 교육업, 보건사회업 모두 강한 상 관관계가 있는 것으로 분석되었다. 양천구는 숙박업, 부동산업, 음식업, 보 건사회업이 강한 상관관계가 있는 것으로 나타났다. 네트워크 분석결과는 근생, 업무, 교육관련 용도로 집중되는 현상을 보였는데 근린생활시설군에 속하는 건축물은 약 80여 개의 다양한 용도로 사용할 수 있기 때문이고, 업무용도는 서비스업 사업체수, 교육용도는 학원관련 사업체수의 증가현 상과 관련이 있다. 둘째, 강남지역은 도.소매업, 음식업, 교육업, 부동산업, 금융보험업, 보 건사회업(6개 사업체군)이 용도변경과 상관성이 높고, 제조업과 숙박업(2 개 사업체군)은 상관성이 없는 것으로 나타났다. 네트워크 분석결과는 근 생, 업무, 교육용도에 집중되고 있는데, 근린생활건축물은 용도의 다양성, 업무용 건축물은 테헤란로 상권의 영향, 교육용 건축물은 강남지역의 학 원 집중현상과 관계가 있다. 셋째, 강북지역은 사업체수 대부분이 용도변경과는 관련성이 미약한 것 으로 나타났다. 네트워크 분석결과는 근린생활시설1), 주택용도가 1차 중 심, 업무용도가 2차 중심을 형성하고 있는 것으로 나타났다. 이상에서 건축물 용도변경과 상관관계가 있는 사업체는 서울지역은 숙 박업 외 모든 사업체(제조업, 도.소매업, 음식업, 교육업, 부동산업, 금융 보험업, 보건사회업)가, 강남지역은 제조업과 숙박업을 제외한 모든 사업 체(도.소매업, 음식업, 교육업, 부동산업, 금융보험업, 보건사회업)가, 강 북지역은 전반적으로 상관관계가 미약한 것으로 나타났다. 따라서 서울전 역과 강남지역 대부분의 용도변경은 산업구조변화와 상관관계가 높은 것 으로 나타났다. 연구결과를 바탕으로 한 시사점은 다음과 같다. 첫째, 건축물의 유지관리와 시간경과에 따른 시장경쟁력 확보 차원에서 신축 당시에 용도변경을 고려한 설계를 할 필요가 있다. 둘째, 건축법의 용도변경 분류기준을 표준산업분류와 일치시킨다면 통 계자료의 유용한 활용이 가능할 것이다. 셋째, 지역별로 상관관계가 있는 것으로 나타난 사업체 변화를 용도변 경 활성화 및 지역발전계획에 반영할 필요가 있다. 넷째, 건축물 용도분류 항목을 현실에 맞게 재조정 할 필요가 있다. 실 례로 제2종 근린생활시설군에 포함되어 있는 안마시술소나 안마장은 위락 시설 항목으로 이동을 검토해야 한다. The change of the industrial structure has a great impact on the real estate market. And the rapidly changing market environment and the phenomenon of land shortage in the urban area present a need for reuse of existing buildings. Especially, building in large cities should be able to respond flexibly to diverse demand with the change of the market environment. Building has been supplied by the newly built buildings for the years, but now it is a point in time that buildings should be supplied in a rapid and flexible method of conversion. For this purpose, the leading indicators are needed to predict the demand for conversion above all. It is not an exaggeration to say that there is no method to identify the size of the conversion market in advance. Therefore, it would be greatly significant if this study could identify the relationship between the change of the industrial structure and conversion and the structural change between conversion. The purpose of this study was to identify the relationship between the change of the industrial structure and the conversion of the building at the point in time that the importance of reuse of the existing building increases with the industrial change and analyze the structural change found between conversion. The findings of this study could contribute to the revitalization of building conversion. The scope of this study was to survey the 10-year(1996-2005) change of the variables of great classification in the Korean Standard Industrial Classification and the numbers of conversion carried out for the same period under the jurisdiction of 20 local governments in Seoul. This study attempted to analyze the data collected this way to investigate the correlation in a statistical method. CNA(conversion network analysis) was conducted on the buildings before and after conversion by dividing Seoul into the Seoul district, the Kangnam district and the Kangbuk district. To attain this goal of study, this study attempted to set and test the following primary study hypotheses and the secondary study hypotheses through statistical analysis and network analysis: H1: The change of the industrial structure in the Seoul district would have high relationship to building conversion. H2: Building conversion would have the difference between districts as the change of the industrial structure is different between districts. H2-1: Service-related businesses would have high relationship to building conversion in the Kangnam district. H2-2: Manufacturing-related businesses would largely have high relationship to building conversion in the Kangbuk district. An attempt was made to conduct conversion network analysis on the relationship between the change of the industrial structure and building conversion. As a result, the following findings were obtained: First, it was found that there was a strong correlation between real estate business and building conversion in the Seoul district, followed by restaurant, education, finance and insurance, and health and social welfare businesses. The results of conversion network analysis by district showed that in the Dongdaemun district, manufacturing, wholesaling and retailing, restaurant, education and health and social welfare businesses all had a strong correlation with building conversion. And it was found that in the Yangcheon district, lodging, real estate and health and social welfare businesses had a strong correlation with building conversion. Conversion network analysis showed that building conversion was concentrated on the uses related to neighborhood living, business and education. Seeing that the buildings belonging to the group of neighborhood living facilities can be used for 80 diverse uses or so, the business use is related to the number of service businesses and the educational use is related to the phenomenon of increase in the number of academy-related businesses. Second, it was found that in the Kangnam district, wholesaling and retailing, restaurant, education, real estate, finance and insurance and health and social welfare(group of six businesses) had a high correlation with building conversion but manufacturing and lodging business(group of two businesses) had no correlation with building conversion. Coversion network analysis showed that building conversion was concentrated on the use of neighborhood living, business and education businesses. The neighborhood living building is related to the diversity of uses, the business building related to the influence of the trade area of Teheran Street, and the education-use building related to the concentration of academies in the Kangnam district. Third, it was found that most of the businesses had a weak relationship to building conversion in the Kangbuk district. Conversion network analysis showed that building conversion into neighborhood living facilities was primary and building conversion into the business-use facility was secondary. In summary, it was found that the businesses related to building conversion were all businesses except lodging business(manufacturing, wholesaling and retailing, restaurant, education, real estate, finance and insurance, and health and social welfare businesses) in the Seoul district, all the businesses except manufacturing and lodging businesses(wholesaling and retailing, restaurant, education, real estate, finance and insurance and health and social welfare businesses) in the Kangnam district. But it was found that building conversion had a weak correlation with the change of the industrial structure. Accordingly, it was found that most of building conversion had a strong correlation with the change of the industrial structure in the Seoul district and the Kangnam district. The finding of this study present the following suggestions: First, it is necessary to design the building with due regards to its conversion at the time of new construction in terms of securing building maintenance and market competitiveness with the passage of time. Second, it would be possible to make practical use of statistical data if the standard and criterion for classification of building conversion in the Building Code is made to correspond with the Standard Industrial Classification. Third, it is necessary to reflect in the plan for conversion revitalization and local development the change in businesses found to have a correlation with building conversion in each district. Fourth, it is necessary to readjust the item of building use classification to fit the realities. For example, it is necessary to examine the movement of the massage parlor included in the 2nd-class neighborhood living facility group to the item of amusement facilities.

불균일한 플라스마 및 메타물질에서의 모드변환: 불변 끼워넣기 이론의 적용

유대중 아주대학교 2012 국내박사

In homogeneous plasmas wave modes are decoupled and distinct. On the contrary, in inhomogeneous plasmas there can be a linear coupling and associated energy transfer called linear mode conversion between two modes for some special conditions. Mode conversion is one of the most fundamental processes in space and laboratory plasmas. Since the study of mode conversion contains inhomogeneity, one faces great difficulty to understand the physics, so many researches are concentrated on the simple geometries and approximate WKBJ-type methods are often used. In other to understand more deeply about the mode conversion processes in inhomogenoeus plasmas, we use a new kind of invariant imbedding method which gives numerically exact results. This method was successfully applied to various kind of problems including mode conversion in previous researches. We first investigated the effect of periodic density modulation superimposed on linear density profile on mode conversion in a cold, unmagnetized plasma. Most of previous studies are on the linear density profile and universal behavior of mode conversion coefficient with the maximum value of 0.5 is obtained. Superimposing the periodic modulation on the linear density profile, we obtained nonmonotonic behavior of mode conversion such that there appears new mode conversion peak whose value sometimes reaches 1, which depends significantly on the wave number, modulation period, and incident angle. The unusual peak is explained by the formation of cavity near resonance point where the incident field is strongly enhanced. When plotting as a function of frequency multiple peaks are present at certain frequencies with regular pattern. This phenomenon can be useful for enhancing the heating efficiency. Secondly, we studied the effect of periodic electron plasma density variation on mode conversion. It was found that mode conversion band associated with the periodicity appears in some frequency range which is related to transmission. The mode conversion coefficient has a oscillating behavior as a function of frequency. We also found that the mode conversion coefficient has a dip at certain frequency, incident angle, and the number of modulation period, which is associated with the standing wave formation. Thirdly, we investigated the effect of random modulation superimposed on linear electron density profile on mode conversion. Since the electromagnetic waves are mostly reflected when propagating through the random medium, it is expected that the mode conversion coefficient decreases as the strength of randomness increases, which is due to Anderson localization effect. We report additional effect competing with Anderson localization effect. We observed that the mode conversion coefficient becomes reduced at first, increases up to certain maximum value, and then decreases again for strong randomness. The intermediate increase is due to enhanced tunneling between (new) resonance points or between resonance and cutoff points, and the former and the latter decreases are due to multiple scattering, the Anderson localization. In this case both local-range effect near resonance points and long-range effect have significant contributions to mode conversion behavior. All three previous results dealt with direct problems, conversion of electromagnetic wave mode into electrostatic mode, in cold, unmagnetized plasmas. Next, we considered both direct and inverse problems in warm, unmagnetized plasmas where the electromagnetic wave and Langmuir wave are coupled. As in the first case, we investigated linear electron density profile where the ion motion is neglected and found that equal amount of energy is transferred between two modes regardless of the temperature and the reciprocity principle is verified. The temperature-dependent shift of mode conversion coefficient whose maximum is near 0.5 is observed for small temperature range, which is similar to previous results, but the detailed variation is more sensitive than previous result, which means that temperature may play more crucial role in mode conversion process than expected. The mode conversion also occurs outside the atmosphere of the Earth. Outside the ionosphere, there exists magnetosphere and magnetopause in its outer edge. In these areas the plasmas can be treated as a fluid and many kinds of wave exist. The magnetohydrodynamics (MHD) deals with this situations. In cold plasmas two modes exist, compressional mode and transverse (Alfv\'{e}n) mode. The mode conversion from compressional mode into transverse mode is considered at the magnetopause which has an Alfv\'{e}n speed crest where the effect of magnetosheath flow or solar wind is imposed. We studied three cases. The first is that the MHD wave propagates from the magnetosheath into magnetosphere through the magnetopause where the flow is in the magnetosheath. The second case is the reverse of the first case such that the wave propagates from the magnetosphere to the magnetosheath across the magnetopause. Third case is that the wave propagates from a region of magnetosheath to another region of magnetosheath through the magnetosphere. For the first case, when the flow is present there appears a cutoff range in the the mode conversion band and the wave is totally reflected in this range. For the second case, there appears new mode conversion peak in the same frequency range corresponding to cutoff range of the first case. The value and frequency of the the mode conversion peak depend strongly on the flow speed. The third case is very similar to first case except that it has more oscillating behavior. All three cases have ripples in their reflectivity, transmissivity, and mode conversion coefficient curves. Recent theoretical studies provide the possibility of new mode conversion in transition metamaterials where the parameters $\epsilon$ and $\mu$ change arbitrarily from positive to negative values in space. In addition to $p$ wave, mode conversion for $s$ wave can occur when $\mu$ varies continuously from positive to negative values. The mode conversion and resonant absorption similar to $p$ wave case and the interference effect by multiply scattered waves between two mode conversion points were previously reported. Considering that $\epsilon$ and $\mu$ vary from positive to negative values with different ratios, we observed that all the electromagnetic field components can be greatly enhanced at the resonance region, which can give new synergy effect on nonlinear optical uses. In addition, we investigated the mode conversion in transition metamaterials with small gain. The situation is similar to inverse mode conversion where the energy of longitudinal oscillations transforms to that of electromagnetic waves. We observed giant amplification of electromagnetic radiation due to phase coherence when electromagnetic waves are incident on the transition metamaterial with small gain. We also found that the value of amplification and the radiation angle can be controlled by appropriate design of the $\epsilon$ and $\mu$ profiles . It turned out that the interference between two resonance points also significantly affects the radiation intensity. Finally, we applied the invariant imbedding method to a different subject, the propagation of the linear shallow water wave. This application is possible because the equation of $p$ wave has the same form with that of linear shallow water wave identifying the correspondence between the dielectric permittivity and the inverse water depth. By using this relationship we studied the influence of bottom topography on the propagation of linear shallow water wave in three cases. Considering the linear depth profile we have a perfect agreement with the analytical formula such that the field intensity at the shore is greatly enhanced, which is so-called tsunami effect. The wave function has a singular behavior at the shore since the water depth approaches zero. The Bragg scattering competing with the tsunami effect is investigated as a second case, resulting in large reflection in a wide frequency range. Finally, resonant tunneling associated with the symmetric field distribution is observed by examining the ridge-shaped bottom profile.

La Conversion de Charles Peguy : Charles Peguy의 개화

조정옥 서울대학교 대학원 1962 국내박사

Integration and conversion of semi-structured documents

고승규 Graduate School, Yonsei University 2003 국내박사

XML은 웹문서 표준으로 상호운영성, 재사용성, 확장성, 스타일과 내용의 분리 등의 장점을 지니고 있다. 이러한 장점으로 인해 최든에 제정된 웹 관련 표준들은 대부분 XML에 기반하고 있다. 이와 같이 XML이 널리 사용됨에 따라 XML문서 교환의 필요성이 대두되었으며, 이는 주로 문서의 통합이나 변환의 형태로 이루어진다. 이러한 통합이나 변환에서는 XML의 주된 특징인 문서구조가 매우 중요하다. 따라서 제안된 대부분의 기법들은 문서 구조를 이용하고 있다. 그러나 대부분의 제안 방법에서는 매칭의 효율을 높이기 위하여 구조 정보를 확대 해석하는 경향이 있으며, 이로 인해 잘못된 매칭이 다수 발생하게 되는데, 아직까지 이에 관해서는 고려되지 않고 있다. 이러한 잘못된 매칭은 탐지하기가 어려우며, 수작업으로 교정을 해야 하는 등의 높은 비용이 필요하다. 또한 매칭의 결과로부터 변환 스크립트를 생성하는 과정 많은 수작업이 필요한 부분이나 아직까지 이와 관련된 연구가 많지 않다. 이에 본 논문에서는 XML 문서 통합/변환 시 사용자 작업을 줄이기 위하여 잘못된 매칭을 최소화하는 매칭 기법과 변환 스크립트를 자동으로 생성하는 방법을 제안한다. 제안 매칭 기법은 XML 문서에서 엘리먼트의 의미는 부모 노드에 따라 결정되는 경우가 많다는 사실에 기반한다. 제안 기법에서는 이를 위하여 의미 노드를 정의하고 이를 이용한 중간 모델을 정의하였다. 문서 통합/변환 시 이용되는 제안 중간 모델은 실제 문서로부터 생성되며, 의미 노드로 재표현된다. 또하 ㄴ제안 모델은 엘리먼트로 표현된 문서 구조와 속성으로 표현된 문서 구조를 전부 표현할 수 있다. 본 논문에서는 DTD를 정의하는 과정을 상위 개념을 하위 개념으로 대치하는 과정으로 가정하였다. 그리고 이에 따라 의미 노드로 정의된 중간 모델에서 가능한 매칭 기법을 상향식, 하향식 그리고 절충식의 세가지로 구별하였다. 하향식 기법은 개념들은 상위 수준에서 공통되는 경우가 많다는 가정에 기반한 방법으로 초기 매칭 효율은 좋으나 하위로 갈수록 매칭 효율이 떨어지며, 특히 잘못된 매칭이 발생하면 그 하위의 모든 노드들이 잘못 매칭되는 단점을 지닌다. 상향식 방법은 최하위의 개념들은 전문가 사이에서 공통되는 경우가 많다는 가정에 기반한 매칭 방법이다. 이 방법은 하위의 개념들 간에 매칭 효율은 높으나 최악의 경우 단순히 두 종류의 문서들을 통합할 수 도 있다는 단점이 있다. 절충식은 상향식을 이용하여 하위의 노드들을 매칭시킨 후 하향식 기법을 적용하는 방식이다. 이 방법은 상향식의 단점과 하향식의 단점을 최소화 시키면서 장점만을 최한 기법이다. 의미 노드를 이용한 매칭을 수행하여도 잘못된 매칭은 발생하다. 이를 위해 본 논문에서는 매칭 규칙을 노드수준과 구조 수준으로 구별하였다. 잘못된 매칭은 구조 수준의 규칙 중 일부에서 발생하므로, 잘못된 미스 매치를 발생시킬 수 잇는 규칙들을 찾아내고, 이 규칙이 적용될 경우에는 노드들에 표시를 하여 사용자에게 검증을 받도록 하였다. 이를 통해 잘못된 매칭을 탐색하는 사용자의 작업을 크게 줄일 수 있다. 본 논문에서는 변환 스크립트를 자동으로 생성하기 위하여 변환 템플릿을 정의하였다. 이를 위해 먼저 XML 문서에서 발생 가능한 대응 관계를 추출한 후 이를 카디널리티(cardinality)에 따라 분류한 후 각각에 대하여 변환 템플릿을 정의하였다. 따라서 매칭 결과인 매핑 테이블을 카디널리티에 따라 분류한 후 각각에 적합한 변환 템플릿을 이용하면 변환 스크립트가 생성된다. 본 논문은 통합이나 변환 시에 발생하는 수작업을 최소화시킬 수 있는 의미 노드를 이용한 매칭 기법과 변환 템플릿을 제안하였으며, 이를 실제 전자책 문서 변환에 적용하였다. 적용 결과 제안 매칭 기법은 사용자 작업을 최대 절반 가량 줄일 수 있음을 보여주었다. 이 결과는 본 논문에서 표시한 잠재적인 잘못된 매칭 정보를 무시한 결과로 실제로는 좀 더 나은 결과를 보여줄 것으로 예측된다. 그리고 본 매칭 기법은 이용가능한 구조 정보가 많을수록 사용자 작업을 줄일 수 있는 것으로 나타났다. 또한 제안 변환 템플릿을 이용하여 생성된 변환 스크립트는 전자책 내용을 적절하게 변환시킬 수 있음을 보여주었다. XML is a web document standard and has many advantages such as interoperability, reusability, extensibility, separation of content from style, and so on. Because of these many advantages, recently published web-related standards are almost all based on XML. As XML is used widely, the need to exchange XML documents has increased. The exchange of XML has appeared as integration or conversion forms in business. In the integration or conversion of XML documents, the main characteristic of XML, document structure, is very important. So, previous integration or conversion researches used the document structure. However most researches have tended to use structure information excessively to increase the matching rate. This caused many mismatches, and most studies did not consider the mismatches seriously. But much manual work is required to detect and correct mismatches. There is also intensive manual work involved in conversion or integration. It is a generating the conversion scripts, which have not been well studied until now. Therefore, we suggest matching methods that reduce the mismatches, and conversion templates that can generate the conversion scripts from the result of the matching processes. The proposed matching methods are based on the fact that the meaning of the element depends on its parent. To express these elements, we define the semantic nodes and the intermediate model. The intermediate model is generated from document instances, and it can describe all structure-related information expressed as elements or attributes. This dissertation regards the process of definition of DTD as replacing the high level concept with lower level concepts. According to this, possible matching methods in the intermediate model are divided into three kinds, top-down, bottomup, and hybrid approaches. The assumption of the top-down approach is that concepts tend to be common at the high level. This method shows a good matching rate in the early stages, but the matching rate is decreased as it goes down. A disadvantage is that mismatch influences all the children below it. The assumption of the bottom-up approach is that the lowest level concepts are common in the experts. This method shows a good matching rate in the bottom level. However, if there is no match in the bottom level, then simply merge them. So, in the worst case, it may simply merge two document kinds. The hybrid approach is a mixture of these approaches. After the bottom-up approach is applied to the bottom level nodes, the top-down approach is applied. This method minimizes the disadvantages and takes advantage of the top-down and bottom-up approaches. Despite using the semantic nodes to reduce mismatches, mismatches still occur. So, to decrease them further we classify our matching rules into node level and structure level. And we identify which rules cause the mismatches. So, if they are used, then our methods mark the nodes to make them validated by users. These marks reduce the detection cost of mismatches greatly. We define conversion templates to generate conversion scripts automatically. To this, we extract the possible mapping relations between XML documents, classify them by cardinalities, and define conversion templates for each class. Therefore, we classify mapping instances by cardinalities in the matching result and use the appropriate conversion template of each class; then conversion scripts can be generated. To validate our proposed matching methods and conversion templates, we have applied them on the real eBook content conversion as a case study. The case study showed that our matching method can reduce the manual work by half. However, the case study ignores the marked information, so the result is pessimistic. This means our methods can show better performance if mark information is considered. In addition, the case study showed that as more structure information is available, then more mismatches can be reduced by the proposed method. In addition, defined conversion templates made it possible to generate the conversion scripts from the matching results. The generated conversion scripts converted the eBook content properly. So, our conversion templates can be regarded as valid to real XML document conversion.

Effects of REDD+ on Forest Conversion and related Issues : Effects of REDD+ on Forest Conversion and related Issues

He TIAN 서울시립대학교 2017 국내석사

세계 경제의 성장으로 인한 산림 벌채 및 거래 증가는특히 개발 도상국의 심각한 산림파괴를 유발하고 있다. 본 논문에서는 최근 산림 보존에 대한 국제 공동체의 역할에 대해 주목을 받고 있는 REDD+ 메커니즘을 소개하려 한다. 이 메커니즘은 산림 파괴 및 산림황폐화뿐 아니라산지 전용 문제에 대해서도 다룬다. 산림 파괴 및 산림 황폐화는 특히 열대 국가들에서 두드러지며 나타나는 실정이며, 사실상 점점 악화되고 있다. REDD+의 목적은 산림자원을 보호하고 공동체의 생계를 지원하는 것이므로, 산지 전용 문제에 대해 다루어야 한다. 본 연구는 산지 전용 예방에 대한 REDD+ 메커니즘의 역할을 분석하기 위해 수행되었다. 문헌 및 데이터 분석에 따르면, REDD+ 메커니즘은 산림 이용 및 전용 제한 등 산림규제 강화를 목적으로 실행되는 경우, 어느 정도는산림 보호를 위한기여 촉진에 일조할 수 있음이 파악되었다. 그러나, 산지 전용 및 관련 활동에 대한 REDD+ 영향의 측면에서 그 효과는 기대했던 만큼 대단하지는 않았다. 아마도 주로 현재 REDD+는 아직 진행 중인 단계로서 충분한 금전적 보상을 도출하지 못하고 있으며, 이 프로젝트를 통한 생계 개선 및 산지 전용 예방의 장점들이 아직은 완벽하게 반영되지 않았기 때문에 그렇게 비효율적인 듯하다. 즉, REDD+ 메커니즘은 산림 벌채 및 산지 전용 활동이 이루어지는 산림지대 및 목재자원 등 프로젝트 분야의 소규모 이해관계자들에게 상당한 영향을 미치지 않았다. 마지막으로, 본 연구에서는 향후 산림보전에 대한 REDD+ 메커니즘의 효과를 개선하기 위한 몇 가지 제안을 한다. 본 연구를 통해 연구자들은 산림보전에 대한 REDD+ 메커니즘의 역할에 대해 더욱 잘 이해하게 될 것이다. 또한, 기후 협상 및 산림 관리 메커니즘 구축을 위한 추가 연구에 대한기준값을 제공할 것이다. 주요 용어:REDD+, 산지진용,삼림지,산림 관리,산림 보호 As the world economics grows, more tree logs are being cut and traded, resulting in severe deforestation especially in developing countries. In this paper, the REDD+ mechanism is introduced, which recently attracts attention from international communities with its role in forest conservation; it is about reducing deforestation and forest degradation. At the same time, the forest conversion issue is also discussed. Deforestation or forest degradation is evident especially in tropical countries; in fact, it is getting worse. Since the purpose of the REDD+ is protecting forest resources and promoting the livelihood of the community, the forest conversion issue should be addressed by the REDD+.This study has been performed to analyze the role of the REDD+ mechanism in preventing forest conversion. Based on the literature and data analysis, it has been found that, if it is implemented to enhance forestry regulations such as restriction on forest access and conversion, the REDD+ mechanism to a certain extent can play a role in promoting the forest protection interventions. However, in terms of the impact of the REDD+ on forest conversion and related activities, its effectiveness is not very significant unlike being expected. The ineffectiveness is most probably because the current REDD+ is still in the exploration stage, sufficient financial compensation is not made, and the benefits of improving the people's livelihood and preventing forest conversion by a REDD+ project have not yet fully reflected. In other words, the REDD+ mechanism has not had significant impact on small stakeholders in project areas such as woodlands and timber resources where forest clearance and forest conversion activities are practiced. Finally, in this study, a few of recommendation are made to improve the effectiveness of the REDD+ mechanism in forest conservation in the future. This study will contribute to researchers’ better understanding of the role of REDD+ mechanism in forest conservation. Also, it will provide a reference value for future researches on climate negotiation and forest governance mechanism establishment. Keywords: REDD+, forest conversion, woodland, forest governance, forest conservation

MFI와 MTW 제올라이트에서 메탄올의 저급올레핀으로 전환 반응: 활성중간체와 활성저하

장회구 전남대학교 2015 국내박사

The shaky price and impending exhaustion of crude oil have forced the development of alternatives for producing raw materials of chemical industries from non-petroleum sources. In an effort to create a stable supply of lower olefins, methanol-to-olefin (MTO) conversion has recently been commercialized. The selectivity for the products and the lifetime of catalysts in MTO conversion strongly depend on the type and modification method of the zeolite catalysts. MFI zeolite shows a slow deactivation in hydrocarbon conversion because of its 10MR sinusoidal pores, while the slow diffusion of aromatic compounds in MTW zeolite, caused by repeated potential restrictions in its linear 12MR pores, induces a particular distribution of reaction intermediates in its pores. In this study, the active intermediates of MTO conversion generated on MFI and MTW zeolites have been investigated using various techniques including electron spin resonance (ESR) spectroscopy. The phosphorous modification of these zeolites is beneficial in preserving the hyperfine splitting of ESR signals of active intermediates by reducing the number of strong acid sites and by placing obstacles in order to induce their sparse distribution in the pores. In addition, MFI zeolite is modified with ceria and lanthana to extend its catalyst lifetime in MTO conversion by blocking its external surface. The modification of MFI zeolite with phosphorous compounds reduces the concentration of active intermediates formed in the micropores and weakens spin-spin interaction between them, facilitating the observation of their hyperfine splittings of the ESR signal. The hyperfine splitting appears in the early stages of MTO conversion, confirming the formation of tetramethylbenzenium radical cations; the positive correlation between the radical cation concentration and the conversion of methanol indicates their role as active intermediates. Repeated potential restrictions on the distribution of polymethylbenzenes (PolyMBs) in the pores of MTW zeolite with an additional limitation by phosphorous modification results in a distant distribution of PolyMBs and weakens their spin-spin interaction. The ESR signal with hyperfine splitting observed on MTW zeolite during MTO conversion has confirmed that the large MTW pores allow the predominant generation of hexamethylbenzenium radical cations as active intermediates. The positive relationship between the spin number of the radical cations and the conversion of methanol in the early stages of MTO conversion supports this deduction. These active intermediates formed on MFI and MTW zeolites during MTO conversion determine the product composition. The dispersion state of ceria and lanthana on MFI zeolite has been studied using various techniques such as SEM-mapping, TEM, XPS, N2 adsorption, and uptake of o-xylene and methanol to explain the effect of these modifications on catalyst deactivation in MTO conversion. Ceria is mainly located on the external surface, while lanthana is dispersed on the pore entrances as well as on the external surface. Therefore, the catalyst lifetime of MFI zeolite largely depends on the modifier; ceria modification effectively extends the catalyst lifetime due to the masking of acid sites on the external surface, maintaining a high conversion of methanol up to 2700 min at 450 °C and WHSV=7 h-1. However, the coke deposited on the lanthana dispersed on the pore entrances chokes the pores, resulting in rapid deactivation. Only the dispersion of ceria on the external surface of MFI zeolite greatly improves its stability in MTO conversion by suppressing coke deposits that block its pore entrances.

회심경험과 신앙발달에 관한 기독교교육학적 접근

김강인 연세대학교 연합신학대학원 2002 국내석사

본 논문은 회심경험과 신앙발달에 관한 기독교교육학적 접근을 통해 통전적 회심교육의 기독교교육 과정(curriculum)을 제안하는 것을 연구의 목적으로 한다. Ⅱ장에서는 회심경험의 이해에 관하여 회심의 정의, 유형, 요인과 효과의 측면에서 연구하였다. 지금까지 회심은 다양하게 정의되어 왔다. 또한 회심의 유형은 다양하다: 급격한 회심, 점진적 회심 등. 이 연구는 회심의 전통적 이해를 성찰하는데 중요한 시사점을 제시한다. 곧 다양한 과정과 경로를 통해 경험되는 회심현상의 다양성과 복합성에 대한 종합적 이해를 제공한다. 회심은 통전적이고 역동적이고 다차원적이다. 달리 서술하여, 통전적 회심이란 인지·정서·행동적 차원에서의 총체적인 변형을 의미한다. 본 연구는 또한 회심은 단 일회적인 종교적 경험이어야 한다거나 또는 급격한 회심이 가장 바람직한 종교적인 회심이라고 주장하는 왜곡된 해석으로부터 벗어날 수 있는 통찰력을 제공한다. Ⅲ장에서는 신앙발달의 이해에 관하여 신앙의 정의와 신앙발달의 측면에서 연구하였다. 스미스(Wilfred C. Smith), 그룸(Thomas H. Groome), 오스머(Richard R. Osmer)의 이론들은 통전적(holistic) 차원의 신앙의 특성을 보여준다. 이 연구는 또한 신앙발달의 개념에 대한 이해를 위해 골드만(Ronald Goldman)의 종교적 사고이론과 파울러(James W. Fowler)의 신앙발달이론 및 오저(Fritz K. Oser)의 종교적 판단이론을 논의하였다. 이들 연구는 기독교적 신앙(faith)의 본질과 현상에 관한 경험적 차원의 이해를 시도한 것으로, 기독교교육의 현장에서 학습자를 이해하는 데 도움을 주며, 오늘날 한국교회에서 실시되고 있는 신앙교육의 형태를 비판적으로 성찰해 보는 데 도움을 준다. Ⅳ장에서는 회심과 발달의 통합의 필요성과 가능성을 모색하기 위해 회심경험과 신앙발달의 상관성에 관하여 연구하였다. 회심과 발달은 분명히 구별되는 실체이지만, 이 둘은 밀접하게 연결되어 있다. 회심과 발달은 분리하여 이해될 수 없는 상호보완적 관계에 있다. Ⅴ장에서는 통전적 회심교육에 대해서 연구하였다. 통전적 회심의 교육과정(curriculum)은 다음과 같이 설계될 수 있다. 회심교육의 목적에서는 통전적 회심을 지향하는 교육목적과 교육목표를 수립해야 할 필요성이 있다. 교육의 내용은 성서와 전통을 포함한 신앙의 내용과 경험된 내용으로서의 일상생활이 포함되어야 한다. 교수-학습과정은 회심경험의 다양성을 인식하는 맥락에서 회심교육의 프로그램이 구성될 필요가 있다. 특히 회심을 교회의 다양한 교육적 사역 곧, 케리그마, 코이노니아, 디아코니아, 프로페테이아, 레이투르기아와 연결시킬 필요성이 있다. 회심교육의 교사는 교수-학습과정에 대한 전문적 지식과 회심의 경험과 함께 성숙한 영성을 지닌 교사로 제안한다. 교사의 역할은 변형의 촉매자, 후원자, 안내자로 비유될 수 있다. 학습자는 단순히 지식을 전수받는 자가 아니라 배움의 과정에 적극적으로 참여하는 자로 고려해야 하며, 학습 자체보다는 학습자의 삶의 변화에 초점을 맞추어야 한다. 통전적 회심교육의 환경은 교회적 환경으로만 제한되어서는 안 된다. 그러나 교육환경에 있어서, 회심경험과 직접적으로 관련된 신앙공동체가 매우 중요하고 필수적이다. 회심교육의 평가는 단기적 평가보다는 장기적 평가를 중시한다. 통전적 회심교육의 여섯 가지 차원을 다루는 데 있어, 목적, 내용, 과정, 교사-학습자, 환경과 평가의 모든 차원을 함께 고려해야 한다. 이 차원들은 실제의 교수-학습과정에서 서로 밀접하게 관련되어 있으면서, 서로에게 영향을 끼친다. 결론적으로 회심을 돕는 기독교교육의 방법론에 대한 논의는 통전적 회심 교육의 변화와 재구성을 위한 잠재적 가능성을 돌아보는 데 유익한 통찰력을 제공함을 밝힌다. The purpose of this study is to explore the Christian educational approach to Conversion Experience and Faith Development, and to design the Christian education curriculum for Holistic Conversion Education. The second chapter examined aspects of definitions, categories, factors, and effects of conversion for understanding of Conversion Experience. Conversion has been defined in numerous ways. There are many types of conversion process: sudden conversion, gradual conversion, and so on. This study has some profound implications for reflecting the traditional understanding of conversion. And it provides a comprehensive understanding of the diversity and the complexity of conversion phenomena which are experienced through various processes and courses. Conversion is holistic, dynamic, and multi-dimensional. In other words, Holistic Conversion means the whole transformation including cognitive, affective, and behavioral dimensions. And this study also provides us with a helpful insight which corrects false interpretation that conversion must be one-time religious experience and sudden conversion is the most desirable religious conversion. The third chapter studied aspects of the concept and theory of Faith Development for understanding of Faith Development. The theories of Wilfred C. Smith, Thomas H. Groome, and Richard R. Osmer offer a useful insight to understand the holistic characteristic of faith. This study is to explore the conceptions, stages and characteristics of Ronald Goldman's Religious Thinking theory, James W. Fowler's Faith Development theory and Fritz K. Oser's Religious Judgement theory. These theories which tried to study for understanding of the empirical dimension concerning the nature and phenomenon of Christian faith are commonly used for understanding the learner in the field of Christian education, and shall be helpful to critically reflect Christian education for faith in the Korean church. The fourth chapter examined the correlation between Conversion Experience and Faith Development so as to check the necessity and the possibility of integration of conversion and development. Conversion and development, though clearly distinct realities, are intimately connected. They are in the relationships which cannot be understood separately. The fifth chapter inquired into Holistic Conversion Education. It is built as follows. The purpose of conversion education needs to establish the aim and objective of education toward holistic conversion. The content contains the story of Bible and tradition, and everyday life as experienced content. The teaching-learning process must be consisted of the programs on conversion education in the context which recognizes the variety of conversion experiences. Especially, in the teaching-learning process, conversion needs to connect with various educational tasks of the church, namely kerygma, koinonia, diakonia, propheteia, and leitourgia. The teacher of Holistic Conversion Education is compared to a catalyst of transformation, a supporter, and a guide. The Student must be considered as a learner who actively participates in the process of learning. The context for Holistic Conversion Education must not be limited to church settings. However, in the context of conversion education, the faith community which is directly related with conversion experience seems to be crucial and required. The evaluation of conversion education is taking a longitudinal evaluation rather than a short-term evaluation. Dealing with the six dimensions of Holistic Conversion Education, we need to consider all of the dimensions of purpose, content, process, teacher-student, context and evaluation together. These dimensions are closely related to and influence one another in the actual teaching and learning process. In conclusion, this study is to disclose that the discussion of the methodology of Christian education for conversion provides us with a valuable insight in looking at the latent possibility for change and reconstruction of Holistic Conversion Education.

미디어 콘텐츠의 매체전환 유형에 관한 연구 : 일본의 매체전환 콘텐츠를 중심으로

박수철 韓國外國語大學校 大學院 2011 국내석사

This study examines different types of media conversion with particular focus on the Japanese media industry. Media conversion of content is when content, which was developed under a certain platform, is recreated in order to be used in different media types such as novels, TV dramas, and movies. Concepts that define the phenomena of source content’s emergence across different types of media are, for example, remediation, remake, OSMU(one source multi-use), and Transmedia Storytelling. These concepts share similarity that certain media content goes through the process of derivation; however, there are differences in their meanings in terms of their perspectives. Based on previous research that discusses derivative concepts of content, this study examines elements of media conversion in light of producer perspectives, types of conversion, and intellectual property rights. Also, this research investigates media conversion in the Japanese media content industry during the last decade and produces a set of quantitative data. This approach allows statistical identification of conversion frequency by types of source content. The findings show that media conversion of Japanese content between 2001 and 2010 accounted for 604 cases. After cross-analysis of the data, the findings were statistically significant (p<.001). Conversion from text content to visual content are observed to be the majority type of media conversion, taking up 90.1% of the total media conversion. More specified analysis shows that conversion from novels to movies was the highest in number, followed by comics to TV dramas, comics to movies and novels to TV dramas. The frequency of the conversion by year showsa gradual increase, and media conversion of source content seems to be carried out actively. Analysis of Japanese TV dramas’ source content and performance (rating) demonstrates that 60.6% of TV dramas used original drama scripts and 39.4% of them originated from novel, comics, or movies. Comprehensive analysis of the last 10 years shows that TV dramas used original drama scripts more than content converted from novels, comics or movies. Between 2000 and the mid 2000s, the proportion of TV dramas that used cross-media content appeared to increase each year. The most favored type of content was comics (21.3%), followed by novels (16.4%) and movies (1.7%). Co-relation between ratings of TV dramas and types of source content (drama scripts or other types such as novels and movies) was statistically insignificant. Different from research that focus on individual case studies or theoretical discussion, this study takes a quantitative approach to derivations of media content through analysis and categorization of cases of media conversion in the Japanese media content industry during the last 10 years. In the era of media convergence, this study suggests utilization of content and its derivative diversity, which have not been actively carried out in Korea. The introduction of media conversion concepts through investigation of Japanese cases and analysis of derivative types of content make this study distinctiveand academically significant. Value-creation through derivative utilization or media conversion of content is a natural flow in the content industry which attempts to adapt to new paradigms. The Japanese media content industry, which faces high competition, tries to generalize and structuralize derivative types of content in an attempt to penetrate the saturated market. This study identifies the significance of media conversion of content under these circumstances. Recently, the Korean media content industry began to import the mechanism of media conversion of source content. This study suggests the implications for the Korean media content industry in light of how Korean media content industry could adapt to this trend.

전기장을 이용한 생물전기화학 기반 갈탄의 메탄 전환

오경근 한국해양대학교 대학원 2023 국내박사

Coal is an energy source with an even distribution worldwide. However, when energy is produced from coal, a large amount of greenhouse gases and environmental pollutants are emitted. Therefore, there is a need for an eco-friendly such as Power-to-Gas (P2G) technology that increases the value of coal as energy production. In addition, low-grade coal has a low calorific value, a high water content, and a high ratio of organic carbon, so it is possible to biologically convert methane. However, biological methane conversion using anaerobic digestion by many researchers produces small amounts of methane. Because toxic intermediates are formed during the decomposition of coal, deterioration of microorganisms occurs and methane conversion rate is lowered. The bioelectrochemical methane conversion is an emerging technology by direct interspecies electron transfer (DIET) using the electrode pair that are polarized by an external power source. Bioelectrochemical methane conversion can overcome the intermediates of coal by DIET in electroactive microorganisms. However, the bioelectrochemical methane conversion of coal has not yet been studied at all. In this thesis, therefore, the following topics were studied to improve the methane conversion of Lignite; 1) methane conversion according to changes in substrates such as glucose and acetic acid in bioelectrochemical reactor with an electric field, 2) bioelectrochemical methane conversion of lignite by high strength of the electric field, 3) replace expensive yeast extracts as biostimulants, 4) the temperature conditions changes in bioelectrochemical reactor 5) control the frequency using the AC power supply. 1. The bioelectrochemical methane production from acetate as a non-fermentable substrate, glucose as a fermentable substrate, and their mixture were investigated in an anaerobic sequential batch reactor exposed to an electric field. The electric field enriched the bulk solution with exoelectrogenic bacteria (EEB) and electrotrophic methanogenic archaea, and promoted direct interspecies electron transfer (DIET) for methane production. However, bioelectrochemical methane production was dependent on the substrate characteristics. For acetate as the substrate, the main electron transfer pathway for methane production was DIET, which significantly improved methane yield up to 305.1 mL/g chemical oxygen demand removed (CODr), 77.3% higher than that in control without the electric field. For glucose, substrate competition between EEB and fermenting bacteria reduced the contribution of DIET to methane production, resulting in the methane yield of 288.0 mL/g CODr, slightly lower than that of acetate. In the mixture of acetate and glucose, the contribution of DIET to methane production was less than that of the single substrate, acetate or glucose, due to the increase in the electron equivalent for microbial growth. The findings provide a better understanding of electron transfer pathways, biomass growth, and electron transfer losses depending on the properties of substrates in bioelectrochemical methane production. 2. The bulk solution in bioelectrochemical reactors was exposed to the electrostatic fields ranged from 0.67 V/cm to 3.33 V/cm by polarizing the insulated electrodes with an external voltage source, and the bioelectrochemical reactors were operated at mesophilic condition (35℃). Another anaerobic batch reactor without the insulated electrode pair was also prepared at the same procedure and used as the control. After the start-up, the methane production was started from the bioelectrochemical reactors without the lag phase. The cumulative methane production was gradually saturated to 176.3 mL in the bioelectrochemical reactor with the electrostatic field of 1.67 V/cm, which was higher than the reactor with 0.67 V/cm or 3.33 V/cm as well as the control. The exoelectrogenic and electrotrophic species in the bulk solution were confirmed by the electrochemical analysis (cyclic voltammetry and electrochemical impedance spectroscopy). This suggests that the electrostatic field of 1.67 V/cm significantly enhanced the biological direct interspecies electron transfer for the methane conversion of coal. Interestingly, after the cumulative methane production was saturated, the residual organic matter, the intermediates produced from the hydrolysis and acidogenic fermentation of coal, was still high in the bioelectrochemical reactors. This suggests that the intermediates have a self-inhibitory effect on methane conversion. The residual intermediates were further converted to methane by supplementing the anaerobic medium and anaerobic sludge. The total methane conversion of coal in the bioelectrochemical reactor exposed to the electrostatic field of 1.67 V/cm reached 168.5 mL/g lignite, which is the highest reported so far. An electric field established by polarizing insulated electrode greatly improves methane conversion of coal in the bioelectrochemical reactor. 3. Bioelectrochemical methane conversion of lignite was investigated under mesophilic- (35℃) and thermophilic (55℃) conditions. An anaerobic batch bioelectrochemical reactor with a pair of electrodes was prepared and a medium containing yeast extract (1.0 g/L), anaerobic seed sludge and lignite powder (5.0 g/L) was added to the reactor. The electrodes were polarized using an external voltage source to expose the bulk solution to 1.67 V/cm. The bioelectrochemical reactor was operated under mesophilic- and thermophilic conditions by mixing the bulk solution using a blade connected to a DC motor. Under thermophilic condition, the methane production in the bioelectrochemical reactor was started without any lag time and gradually saturated to 103.3 mL, which was higher than the thermophilic control. Under mesophilic condition, the trend of methane production in the bioelectrochemical reactor was similar to that under the thermophilic condition, but the cumulative methane production less than the thermophilic condition. When the methane production was saturated at 10th days, the yeast extract and seed sludge were supplemented to the reactor. Under thermophilic condition, the bioelectrochemical methane production was abruptly increased and reached to 362.4 mL (155.6 mL/g lignite), which was much higher than 316.3 mL (133.6 mL/g lignite) under mesophilic condition. Based on the cyclic voltammogram, however, the redox peaks under thermophilic condition was not significantly different from those under mesophilic condition. From the electrochemical impedance spectroscopy data, the charge transfer resistance under mesophilic condition was slightly higher than that under thermophilic condition. The results suggest that the methane conversion of lignite was improved by direct interspecies electron transfer between the electroactive microorganisms. However, the redox condition that convert better the lignite to methane bioelectrochemically under thermophilic condition is shifted to slightly better condition, compared to the mesophilic condition. The thermophilic condition for the bioelectrochemical methane conversion of lignite require more heating energy. The thermophilic bioelectrochemical conversion of lignite to methane requires further studies to assess the economic feasibility. 4. The methane conversion of coal could be improved by bio-stimulation with yeast extract after bio-augmentation with anaerobic sludge in a bioelectrochemical system. However, yeast extract is a bio-stimulant that is too expensive for field use. In this study, it was investigated whether glucose and acetate, as well as yeast extract, could be used as the bio-stimulants to improve the methane conversion of coal in the bioelectrochemical system. The cumulative methane productions in the bioelectrochemical reactors with glucose as bio-stimulant were increased without lag time after the start-up, and gradually saturated to 89.7 mL, which was similar to 90.6 mL in the reactor with yeast extract. This indicates that glucose as bio-stimulant in the bioelectrochemical reactor was as effective as yeast extract in converting coal to methane. However, the methane production in the bioelectrochemical reactor with acetate was only 28.2 mL, which was slightly more than 13.4 mL in the control. The methane conversion of coal could be significantly improved in a bioelectrochemical reactor by the simultaneous use of bio-stimulation and bio-augmentation. As a bio-stimulant, glucose, a fermentable substrate, is as effective as yeast extract for the methane conversion of coal in a bioelectrochemical reactor. However, the bioelectrochemical methane conversion of coal cannot be sufficiently improved by acetate, which is a non-fermentable substrate. In a bioelectrochemical reactor, the anaerobic microorganisms that contribute to the improved methane conversion of coal are mainly exoelectrogens. 5. Recently, research results have been reported that the methane conversion rate of coal can be improved by promoting direct interspecies electron transfer under electrostatic field conditions. However, it was not possible to sufficiently control the substrate inhibitory effect of the intermediate even under electrostatic field conditions. In this study, a study was conducted to further improve the methane conversion rate of coal for lignite under various frequency electromagnetic field conditions. In the anaerobic batch reactor for the experiment, a titanium electrode with a surface insulation coating and an electromagnetic field of 1.67 V/cm was formed in the bulk solution between the electrodes. The methane conversion rate of coal was compared in the frequency range of 50-500K Hz. At the low frequency condition of 50 Hz, the peak current of CV, the HOMO-LUMO energy band gap, and the electron transfer resistance were not significantly different from those of the electrostatic field condition. However, as the frequency increased, the peak current of CV increased, and the energy band gap and electron transfer resistance gradually decreased. The cumulative methane production amount was maximum at 500K Hz as 185.2 mL (69.9 mL/g Lignite). Using a high-frequency electromagnetic field, it was possible to improve the methane conversion rate of coal by reducing the substrate inhibitory effect and promoting decomposition.