전처리를 이용한 탄소 나노 섬유의 균일한 SnO₂ 코팅막 형성

김동하,류도형,최병준,Kim, Dong Ha,Riu, Doh-Hyung,Choi, Byung Joon 한국분말야금학회 2018 한국분말재료학회지 (KPMI) Vol.25 No.1

Carbon nanofibers (CNF) are widely used as active agents for electrodes in Li-ion secondary battery cells, supercapacitors, and fuel cells. Nanoscale coatings on CNF electrodes can increase the output and lifespan of battery devices. Atomic layer deposition (ALD) can control the coating thickness at the nanoscale regardless of the shape, suitable for coating CNFs. However, because the CNF surface comprises stable C-C bonds, initiating homogeneous nuclear formation is difficult because of the lack of initial nucleation sites. This study introduces uniform nucleation site formation on CNF surfaces to promote a uniform $SnO_2$ layer. We pretreat the CNF surface by introducing $H_2O$ or $Al_2O_3$ (trimethylaluminum + $H_2O$) before the $SnO_2$ ALD process to form active sites on the CNF surface. Transmission electron microscopy and energy-dispersive spectroscopy both identify the $SnO_2$ layer morphology on the CNF. The $Al_2O_3$-pretreated sample shows a uniform $SnO_2$ layer, while island-type $SnO_x$ layers grow sparsely on the $H_2O$-pretreated or untreated CNF.

원자층 증착법을 적용한 리튬 이온 전지 연구 동향

김동하,최병준,Kim, Dong Ha,Choi, Byung Joon 한국분말야금학회 2016 한국분말재료학회지 (KPMI) Vol.23 No.2

Lithium-ion batteries (LIBs) are rapidly improving in capacity and life cycle characteristics to meet the requirements of a wide range of applications, such as portable electronics, electric vehicles, and micro- or nanoelectro-mechanical systems. Recently, atomic layer deposition (ALD), one of the vapor deposition methods, has been explored to expand the capability of LIBs by producing near-atomically flat and uniform coatings on the shell of nanostructured electrodes and membranes for conventional LIBs. In this paper, we introduce various ALD coatings on the anode, cathode, and separator materials to protect them and improve their electrochemical and thermomechanical stability. In addition, we discuss the effects of ALD coatings on the three-dimensional structuring and conduction layer through activation of electrochemical reactions and facilitation of fluent charge collection.

공간가중회귀 모형을 이용한 서울시 에너지 소비에 따른 이산화탄소 배출 분석

김동하,강기연,손소영,Kim, Dong Ha,Kang, Ki Yeon,Sohn, So Young 대한산업공학회 2016 대한산업공학회지 Vol.42 No.2

Effort to reduce energy consumptions or CO2 emissions is global trend. To follow this trend, spatial studies related to characteristics affecting energy consumptions or CO2 emissions have been conducted, but only with the focus on spatial dependence, not on spatial heterogeneity. The aim of this study is to investigate spatial heterogeneity patterns of CO2 emission based on socio-economic factors, land-use characteristics and traffic infrastructure of Seoul city. Geographically Weighted Regression (GWR) analysis was performed with 423 administrative district data in Seoul. The results suggest that population and employment densities, road density and railway length in most districts are found to have positive impact on the CO2 emissions. Residential and green area densities also have the highest positive impact on CO2 emissions in most districts of Gangnam-gu. The resulting model can be used to identify the spatial patterns of CO2 emissions at district level in Seoul. Eventually it can contribute to local energy policy and planning of metropolitan area.

신개발정화조의 오염절감효과 및 경제성 분석

김동하,박흥석,박완철 ( Dong Ha Kim,Hung Suck Park,Wan Chul Park ) 한국폐기물자원순환학회 1991 한국폐기물자원순환학회지 Vol.8 No.2

초기 청소년의 인터넷 사용시간 변화에 영향을 미치는 보호요인과 위험요인에 관한 종단연구

김동하 ( Kim Dong Ha ) 한국청소년복지학회 2017 청소년복지연구 Vol.19 No.2

본 연구는 초등학생에서 중학생으로 넘어가는 전환기에 인터넷 사용시간의 변화와 관련된 다양한 위험요인과 보호요인을 확인하는 데 그 목적이 있다. 이를 위해 본 연구에서는 패널회귀분석 확률효과모형을 활용하여 주중 하루 평균 인터넷 사용시간의 변화에 영향을 미치는 요인을 개인, 정신건강, 가족, 학교차원에서 경험적으로 검증하였다. 본 연구에서는 한국아동·청소년패널조사에서 초4패널의 3차년도(초6)와 5차년도(중2) 자료를 활용하였으며, 두 시점 모두 응답한 총 2,027명을 최종 분석하였다. 분석결과, 남학생이 여학생보다 시간의 경과에 따라 인터넷 사용시간이 증가하는 것으로 나타났으며, 인터넷을 학습관련용도로 사용하는 경우는 인터넷 사용시간이 줄어든 반면, 오락 및 게임용으로 사용하는 경우는 인터넷 사용시간이 증가하였다. 또한 청소년의 연령, 공격성, 부모의 강압적 양육태도, 방임, 방과후 보호자의 부재 정도가 인터넷 사용시간을 증가시키는 위험요인으로 작용하였다. 반면에 형제자매의 유무, 학교활동 참여도, 좋은 학교성적, 방과후 교육 참여, 문화활동 참여는 인터넷 사용시간을 줄이는 보호요인으로 작용 하였다. 본 연구의 결과를 토대로 초기 청소년의 인터넷 과다사용에 대한 예방적 접근에 유용한 제언을 하였다. This study aims to explore the risk and protective factors associated with changing internet use time during the period of early adolescence. The 3rd and 5th survey waves collected from 2,037 students by the Korean Children and Youth Panel Survey (KCYPS) was used. Panel Random Effects Analysis was conducted to empirically testify factors influencing internet use time for a day of a weekday in individual, mental health, family, and school aspects. Major findings indicated that male students spent longer time accessing the internet than female students as time passed. In terms of the purpose of accessing the internet, youths accessing the internet for entertaining or playing computer games was likely to increase internet use, whereas youths accessing the internet for learning was likely to decrease internet use over time. In addition, age, aggression of adolescents, harsh parenting, neglect, and parental absence after-school had a significant effect on increasing internet use time. On the contrary, having siblings, participation in school activities, good school grades, taking part in after-school programs, and participation in cultural activities had a significant effect on decreasing internet use time. On the basis of these findings, this study suggests useful strategies to prevent young adolescents` internet overuse.

산업디자인 혁신의 실체에 관한 연구

김동하(Kim Dong-Ha) 한국디자인학회 2008 한국디자인학회 학술발표대회 논문집 Vol.- No.-

‘헌법’과 통합의 정치

김동하(Dong Ha Kim) 한국정치학회 2013 한국정치학회보 Vol.47 No.1

본 논문은 헤겔『법철학』에 나타난 헌법과 통합의 이념이 대의제에 기초한 현대사회의 규범적 통합문제를 성찰하는데 유효한 모델을 제공한다는 인식에서 출발한다. 지금까지『법철학』에 나타난 헌법학적·제도론적 시각이 배척을 받은 이유는『법철학』이 인정이론적 계기를 체계적으로 다루지 않음으로 해서 생긴 논증상의 한계 때문이었다. 이를 위해 본 논문은 인정이라는 현대 민주주의의 규범적 원리에 부합하는 방식으로 헤겔의 헌법개념과 통합의 이념을 정치제도론적으로 재구성하였다. 특히 본 논문은 기존의 단순한 제도론적 해석과는 달리『법철학』에 내재된 정치문화론적 맥락에 주목하면서 재해석하고자 하였다. 이를 통해 헤겔의 헌법개념이 단순히‘사실성’에 기초한 성문화된 기호의 체계가 아니라 정치문화 안에 구현된 자유의 이념과 가치질서를 대의하는 상징의 체계임을 해명하였다. 이상의 논의를 통해 본 논문은『법철학』의 현재성을 헌법을 통한 규범적 통합의 이념 속에 있음을 해명하고『법철학』을 규범적 통합의 이론체계로 논증하였다. 본 논문이 옹호한『법철학』의 현재적 요소들은 단순히 서구의 이론적 지형 속에서만 유효한 것이 아니라, 현대 한국의 헌정질서 안에서도 유효한 현재성이라고 할 수 있다. It has been criticized that the intense process of multipolarization in modern society could be an impediment to the continual development of democracy. As a result, political integration has been pointed out as an essential factor for the continuous development of democracy. This study argue that the unique institutional perspective in the concept of “constitution” in Hegel’s Philosophy of Right can provide insight into reflecting upon the problem of normative integration of deeply divided modern societies being based on a representative system. For this purpose, this work explains the concrete interrelationship between constitutions and political integration on the one hand and reveals the correlation between constitutional norm and patriotism on the other by reinterpreting the concept of constitution in Hegel’s Philosophy of Right from the perspective of political institution theory. It is claimed that the constitution is not merely a codified legal system but also a symbolic order representing value order of freedom embedded in political culture. Throughout this reinterpretation, this study demonstrates Hegel’s Philosophy of Right as a normative theory of integration.

한일 독도 영유권과 어업문제 연구: 샌프란시스코 강화조약 전후시기를 중심으로

김동하(Kim, Dong-Ha) 동북아시아문화학회 2020 동북아 문화연구 Vol.1 No.64

The confrontation between Korea and Japan over Dokdo Island’s sovereignty continues to this day. However, it has been over 70 years since the liberation from Japan to reclaim the stolen territory. It also raises questions about the basis for Japan to claim Dokdo Island as their territory. One of the reasons is that Dokdo Island was not contained in the territory of Korea that Japan should give up in the contents of the San Francisco Peace Treaty. And this is the basis that Japan keep claiming Dokdo Island’s sovereignty. Meanwhile, Japan’s expansion of fishing zones immediately after the signing of the San Francisco Peace Treaty was a major threat to Korean fishing workers. Naturally, the Korean government tried to come up with a countermeasure. This was directly related to Dokdo Island’s territorial sovereignty, accelerating friction with Japan. If so, there is a natural interest in how Korea and Japan’s Dokdo Island dispute and the fisheries issues are connected to each other. And also it is necessary to find out how did Korean government resist against expansion of Japanese fishing territory after the San Francisco Peace Treaty. Therefore, this research is focusing on the period before and after the San Francisco Peace Treaty, which signed in September 1951, to find out how the international recognition of Korea’s sovereignty over Dokdo Island is frustrated and what was the countermeasure of Korean government against Japan’s illegal fishing on the Korean Peninsula. In order to progress this research subject, the researcher will use related book, thesis and internet material.

협력 관점에서 ‘서울시 건강생태계 조성사업’ 돌아보기

김동하(Dong Ha Kim),유승현(Seunghyun Yoo) 한국보건교육건강증진학회 2022 보건교육건강증진학회지 Vol.39 No.3

저 레이놀즈수에서 비정상 에어포일의 흐름 가시화

김동하(Dong Ha Kim),장조원(Jo Won Chang) 한국가시화정보학회 2006 한국가시화정보학회지 Vol.4 No.2

A boundary layer visualization was carried out in order to investigate the influence of Reynolds number on an oscillating airfoil. An NACA 0012 airfoil is sinusoidally pitched at the quarter chord point with oscillation amplitude of ±6°. A smoke-wire technique was employed to visualize the boundary layer and the near-wake. The freestream velocities are 1.98, 2.83 and 4.03㎧ and corresponding chord Reynolds numbers are 2.3×10⁴, 3.3×10⁴, and 4.8×10⁴, respectively. As the reduced frequency of K=0.1 is fixed, the corresponding frequency of an airfoil was adjusted in each case. The results reveal that the point at which the shear stress in an unsteady boundary layer separation disappears does not correspond with the position of the breakdown of the boundary layer, and that the breakdown of the boundary layer occurs further downstream.