나노 입자 적층 시스템(NPDS)을 이용한 염료 감응 태양전지 - 전기 변색 통합 소자 및 에너지 하베스팅 시스템에 대한 연구

김광민,김형섭,최다현,이민지,박윤찬,추원식,천두만,이선영,Kim, Kwangmin,Kim, Hyungsub,Choi, Dahyun,Lee, Minji,Park, Yunchan,Chu, Wonshik,Chun, Dooman,Lee, Caroline Sunyong 한국마이크로전자및패키징학회 2016 마이크로전자 및 패키징학회지 Vol.23 No.2

본 연구에서는 나노 입자 적층 시스템(Nano Particle Deposition System, NPDS)을 이용하여 전기변색소자의 작동 전극을 적층하고 또한 염료 감응 태양전지의 반도체 층으로 사용되는 $TiO_2$층 및 전기변색소자의 이온 저장 층으로 사용되는 Antimony Tin Oxide(ATO) 층을 제작하였다. NPDS는 상온 건식 분말 적층법으로 노즐을 통하여 초음속으로 가속된 분말의 높은 에너지를 이용하여 기판에 적층하는 새로운 개념의 건식 적층 방법이다. 본 연구에서 코팅된 물질의 두께는 전기변색소자의 투과율에 영향을 끼치는데, 이는 표면 프로파일 측정법(surface profiling method)으로 측정하였으며, 적층된 $TiO_2$와 ATO 및 복합 층의 미세 구조를 확인하기 위해 SEM을 이용한 분석을 진행하였다. 한편 염료 감응 태양전지의 광 변환 효율은 솔라 시뮬레이터로 분석하였다. 또한 UV-visible spectrometer와 power source를 이용하여 630 nm 대역에서 전기 변색 소자가 갖는 투과도 변화와 낮은 전압에서의 작동 및 변색 횟수를 측정하였으며, 결과적으로 상기 과정을 거쳐 제작되고, 측정된 염료 감응 태양전지 - 전기 변색 통합 구조 소자를 자체 제작한 에너지 하베스팅 시스템과 연결하여 통합 구조 소자 내 태양전지의 전압 발생을 통해 자체 구동이 가능한 전기 변색 소자 시스템 제작에 성공하였다. NPDS를 통해 제작된 변색 소자의 경우, 최대 49%의 투과도 변화와 500회 작동에서 C-V curve를 유지함을 측정하여 성능과 내구성을 입증하였고, 통합 소자 내 태양 전지의 광 변환 효율은 최대 2.55%로 측정되었으며, 통합 소자 내 변색 소자의 경우 최대 26%의 투과도 변화를 보였다. In this study, Antimony Tin Oxide (ATO) ion storage layer and $TiO_2$ working electrode were fabricated using Nano Particle Deposition System. NPDS is the cutting-edge technology among the dry deposition methods. Accelerated particles are deposited on the substrate through the nozzle using NPDS. The thicknesses for coated layers were measured and layer's morphology was acquired using SEM. The fabricated electrochromic cell's transmittance was measured using UV-Visible spectrometer and power source at 630 nm. As a result, the integrated electrochromic/DSSC hybrid system was successfully fabricated as an energy harvesting system. The fabricated electrochromic cell was self-operated using DSSC as a power source. In conclusion, the electrochromic cell was operated for 500 cycles, with 49% of maximum transmittance change. Also the photovoltaic efficiency for DSSC was measured to be 2.55% while the electrochromic cell on the integrated system had resulted in 26% of maximum transmittance change.

인슐레이션을 제거한 소형 초전도 회전자 디자인

김광민(Kwangmin Kim),정성준(Sung-Jun Jung),김경훈(Gyeong-Hun Kim),김남원(Nam-Won Kim),박민원(Minwon Park),유인근(In-Keun Yu),박태준(Tae-Joon Park),김태원(Tae-Won Kim) 대한전기학회 2011 대한전기학회 학술대회 논문집 Vol.2011 No.7

수치해석을 이용한 소형 승용 차량의 항력 저감장치 개발

김광민(Kwangmin Kim),하성준(Sungjun Ha),김재민(Jaemin Kim),김문상(Moonsang Kim),김용석(Yongsuk Kim),김용년(Yongnyun Kim) 한국자동차공학회 2014 한국자동차공학회 학술대회 및 전시회 Vol.2014 No.11

효과적인 지식확장을 위한 LOD 클라우드에서의 변화수용적 심층검색

김광민(Kwangmin Kim),손용락(Yonglak Sohn) 한국지능정보시스템학회 2018 지능정보연구 Vol.24 No.2

LOD(Linked Open Data) cloud is a practical implementation of semantic web. We suggested a new method that provides identity links conveniently in LOD cloud. It also allows changes in LOD to be reflected to searching results without any omissions. LOD provides detail descriptions of entities to public in RDF triple form. RDF triple is composed of subject, predicates, and objects and presents detail description for an entity. Links in LOD cloud, named identity links, are realized by asserting entities of different RDF triples to be identical. Currently, the identity link is provided with creating a link triple explicitly in which <owl:sameAs> associates its subject and object with source and target entities. Link triples are appended to LOD. With identity links, a knowledge achieves from an LOD can be expanded with different knowledge from different LODs. The goal of LOD cloud is providing opportunity of knowledge expansion to users. Appending link triples to LOD, however, has serious difficulties in discovering identity links between entities one by one notwithstanding the enormous scale of LOD. Newly added entities cannot be reflected to searching results until identity links heading for them are serialized and published to LOD cloud. Instead of creating enormous identity links, we propose LOD to prepare its own link policy. The link policy specifies a set of target LODs to link and constraints necessary to discover identity links to entities on target LODs. On searching, it becomes possible to access newly added entities and reflect them to searching results without any omissions by referencing the link policies. Link policy specifies a set of predicate pairs for discovering identity between associated entities in source and target LODs. For the link policy specification, we have suggested a set of vocabularies that conform to RDFS and OWL. Identity between entities is evaluated in accordance with a similarity of the source and the target entities’ objects which have been associated with the predicates’ pair in the link policy. We implemented a system “Change Acceptable In-Depth Searching System(CAIDS)”. With CAIDS, user’s searching request starts from depth_0 LOD, i.e. surface searching. Referencing the link policies of LODs, CAIDS proceeds in-depth searching, next LODs of next depths. To supplement identity links derived from the link policies, CAIDS uses explicit link triples as well. Following the identity links, CAIDS’s in-depth searching progresses. Content of an entity obtained from depth_0 LOD expands with the contents of entities of other LODs which have been discovered to be identical to depth_0 LOD entity. Expanding content of depth_0 LOD entity without user’s cognition of such other LODs is the implementation of knowledge expansion. It is the goal of LOD cloud. The more identity links in LOD cloud, the wider content expansions in LOD cloud. We have suggested a new way to create identity links abundantly and supply them to LOD cloud. Experiments on CAIDS performed against DBpedia LODs of Korea, France, Italy, Spain, and Portugal. They present that CAIDS provides appropriate expansion ratio and inclusion ratio as long as degree of similarity between source and target objects is 0.8 ~ 0.9. Expansion ratio, for each depth, depicts the ratio of the entities discovered at the depth to the entities of depth_0 LOD. For each depth, inclusion ratio illustrates the ratio of the entities discovered only with explicit links to the entities discovered only with link policies. In cases of similarity degrees with under 0.8, expansion becomes excessive and thus contents become distorted. Similarity degree of 0.8 ~ 0.9 provides appropriate amount of RDF triples searched as well. Experiments have evaluated confidence degree of contents which have been expanded in accordance with in-depth searching. Confidence degree of content is directly coupled with identity ratio of an entity, which means the degree of identit

MCV 수동화를 기반으로 한 굴삭기 자동정지 제어

김광민(Kwangmin Kim),김민지(Minji Kim),김동목(Dongmok Kim),이동준(Dongjun Lee) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12

We propose a passivity-based control framework for the excavator with main control valve (MCV). We first derive mathematical model of a 4-way valve, then develop a passivity-based control rule using spool actuation forces as control inputs. The passivity-based control is done in two steps: 1) MCV passifying control and 2) spool actuation control. First, the flow rate of each valve in MCV is decomposed into active flow source and a passive dissipation, and valve passifying control is presented based on this structure. Second, we present a spool actuation input to control the spool position to the desired value. In addition, we compensate the self-weight in order to make the passivity of the excavator less conservative. Finally, we propose a passivity-based auto-stop function of excavator when it collides with an underground obstacle.

풍력발전용 피치 드라이브 시스템의 복합 유성기어류에 대한 피로 강도해석

김광민(KwangMin Kim),배명호(MyungHo Bae),조연상(YonSang Cho) 한국트라이볼로지학회 2021 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.37 No.2

Wind energy is considered as the most competitive energy source in terms of power generation cost and efficiency. The power train of the pitch drive for a wind turbine uses a 3-stage complex planetary gear system in being developed locally. A gear train of the pitch drive consists of an electric or hydraulic motor and a planetary decelerator, which optimizes the pitch angle of the blade for wind generators in response to the change in wind speed. However, it is prone to many problems, such as excessive repair costs in case of failure. Complex planetary gears are very important parts of a pitch drive system because of strength problem. When gears are designed for the power train of a pitch drive, it is necessary to analyze the fatigue strength of gears. While calculating the specifications of the complex planetary gears along with the bending and compressive stresses of the gears, it is necessary to analyze the fatigue strength of gears to obtain an optimal design of the complex planetary gears in terms of cost and reliability. In this study, the specifications of planetary gears are calculated using a self-developed gear design program. The actual gear bending and compressive stresses of the planetary gear system were analyzed using the Lewes and Hertz equation. Additionally, the calculated specifications of the complex planetary gears were verified by evaluating the results from the Stress - No. of cycles curves of gears.

확장칼만필터를 이용한 LP-EGR 가솔린엔진 에어패스의 상태추정

김광민(Kwangmin Kim),김민지(Minji Kim),김진성(Jinsung Kim),박천교(Cheongyo Bahk),이동준(Dongjun Lee) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.5

4MW급 풍력발전기의 복합유성기어 강도 평가

김광민(KwangMin Kim),배명호(MyungHo Bae),조연상(YonSang Cho) 한국트라이볼로지학회 2021 한국트라이볼로지학회 학술대회 Vol.2021 No.4

시민참여가 개인 심리와 삶의 만족도에 미치는 영향

김광민(Kim, Kwangmin),이대웅(Lee, Daewoong),권기헌(Kwon, Gi-heon) 서울행정학회 2018 한국사회와 행정연구 Vol.29 No.3

현대사회에서 시민참여는 정부 행정의 참여성과 투명성 그리고 합의성을 증진시키는 중요한 역할을 수행하고 있다. 그렇다면 “정부의 관점에서 긍정적인 영향을 가지는 온라인 시민참여가 시민들 개개인에게는 어떠한 영향을 미칠까?” 본 연구는 상기한 질문에 답하고자 한다. 온라인 시민참여를 통해 개인들의 긍정적 심리자본이 증가하고 삶의 만족도가 증가되어야만, 시민들은 지속적으로 참여할 것이고 우리사회 전반에 시민참여문화가 확산될 수 있기 때문이다. 따라서 본 연구는 특히 현대사회에서 증가하는 온라인 시민참여가 개인의 심리 나아가 삶의 만족도 에 미치는 영향을 분석했다. 분석은『2016 디지털정보격차실태조사』자료를 토대로 AMOS를 활용한 구조방정식 모델링 분석(SEM: structural equation model)과 매개효과 분석(Mediated Effect Analysis)을 실시하였다. 중요한 분석결과를 살펴보면, 모바일 온라인 시민참여와 삶의 만족도 간의 관계, 모바일 온라인 시민참여와 자존감 간의 관계가 통계적으로 유의미하게 나타났다. 또한 모바일 온라인 시민참여와 삶의 만족도 간의 관계에 자존감이 유의미한 매개효과를 가지는 것으로 나타났다. 본 연구는 온라인 시민참여를 통한 개인의 삶의 만족도 제고와 심리적 요인의 영향을 규명하고, 이상의 분석결과를 근거로 정책적 시사점을 제시하였다. Citizen participation plays an important role in promoting public participation, transparency, and consensus in modern society. If so, “How does online citizen participation with a positive impact from the government`s perspective affect individual citizens?” This study will answer this question. If the positive psychological capital and the satisfaction of life are increased through online citizen participation, the citizen will continuously participate in the citizen participation, and the citizen participation culture can spread through the whole society through this. Therefore, this study analyzed the effect of increasing online citizen participation on personal psychology and life satisfaction, especially in modern society. The structural equation model (SEM) and the mediated effect analysis (ANOVA) were conducted using AMOS based on the “2016 Digital Divide Survey” data. The results of the analysis show that the relationship between mobile online citizen participation and life satisfaction and mobile online citizen participation and self-esteem are statistically significant. Also, self - esteem has a significant mediating effect on the relationship between mobile online citizen participation and life satisfaction. The purpose of this study is to investigate the effects of psychological factors on the satisfaction of life through online citizen participation and suggest policy implications based on the above analysis.

부유형 해양 광생물반응기의 선택적 투과막의 술폰화 반응을 통한 Biofouling 억제 및 미세조류 생산성 향상

김광민(Kwangmin Kim),이윤우(Yunwoo Lee),김지훈(Z-Hun Kim),박한울(Hanwool Park),정인재(Injae Jung),박재훈(Jaehoon Park),임상민(Sang-Min Lim),이철균(Choul-Gyun Lee) 한국해양바이오학회 2017 한국해양바이오학회지 Vol.9 No.1

The purpose of this study was to inhibit biofouling on a selectively permeable membrane (SPM) and increase biomass productivity in marine photobioreactors (PBRs) for microalgal cultivation by chemical treatment. Surfaces of a SPM, composed of polyethylene terephthalate (PET), was sulfonated to decrease hydrophobicity through attaching negatively charged sulfonic groups. Reaction time of sulfonation was varied from 0 min to 60 min. As the reaction time increased, the water contact angle value of SPM surface was decreased from 75.5o to 44.5o, indicating decrease of surface hydrophobicity. Furthermore, the water permeability of sulfonated SPM was increased from 5.42 mL/㎡/s to 10.58 mL/㎡/s, which reflects higher nutrients transfer rates through the membranes, due to decreased hydrophobicity. When cultivating Tetraselmis sp. using 100-mL floating PBRs with sulfonated SPMs, biomass productivity was improved by 34% compared with the control group (non-reacted SPMs). In addition, scanning electron microscopic observation of SPMs used for cultivation clearly revealed lower degree of cell attachment on the sulfonated SPMs. These results suggest that sulfornation of a PET SPM could improve microalgal biomass productivity by increasing nutrients transfer rates and inhibiting biofouling by algal cells.