전기 임피던스 단층촬영법에서 빠른 반복적 가우스-뉴턴 방법을 이용한 온라인 영상 복원

김창일(Chang Il Kim),김봉석(Bong Seok Kim),김경연(Kyung Youn Kim) 대한전자공학회 2017 전자공학회논문지 Vol.54 No.4

전기 임피던스 단층촬영법은 전극을 통해 주입된 전류와 측정된 전압을 기반으로, 내부 도전율 분포를 복원하는 기술로, 비교적 새로운 비파괴 영상 복원 기법이다. 본 논문에서는 이원 혼합물 유동 응용분야에서 온라인으로 적용시킬 수 있도록, 역문제의 계산시간을 줄일 뿐만 아니라 공간 해상도도 함께 향상시킬 수 있는 역문제 해법인 빠른 반복적 가우스-뉴턴 방법을 제안하였다. 제안한 방법의 영상 복원성능을 평가하기 위해 모의실험을 수행하고 그 결과를 비교분석하였다. Electrical impedance tomography is a relatively new nondestructive imaging modality in which the internal conductivity distribution is reconstructed based on the injected currents and measured voltages through electrodes placed on the surface of a domain. In this paper, a fast iterative Gauss-Newton method is proposed to increase the spatial resolution as well as reduce the inverse computational time in the inverse problem, which could be applied to online binary mixture flow applications. To evaluate the reconstruction performance of the proposed method, numerical experiments have been carried out and the results are analyzed.

압전 캔틸레버 구조를 이용한 도로용 에너지 하베스터의 개발 및 평가

김창일,김경범,전종학,정영훈,조정호,백종후,강인석,이무용,최범진,조영봉,박신서,남산,이영진,Kim, Chang-Il,Kim, Kyung-Bum,Jeon, Jong-Hac,Jeong, Young-Hun,Cho, Jeong-Ho,Paik, Jong-Hoo,Kang, In-Seok,Lee, Moo-Yong,Choi, Beom-Jin,Cho, Young-Bong 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.7

A road energy harvester was designed and fabricated to convert mechanical energy from the vehicle load to electrical energy. The road energy harvester is composed of 24 piezoelectric cantilevers and a vehicle load transfer mechanism. Applying a vehicle load transfer mechanism rather than directly installing energy harvesters under roads decreases the area of road construction and allows more energy harvesters to be installed on the side of the road. The power generation amount with respect to the vehicular velocity change was assessed by installing the vehicle load transfer mechanism and the energy harvester in the form of speed bumps and underground. The energy harvester installed in a speed bump form generated power of 7.61 mW at the vehicular velocity of 20 km/h. Also, power generation of the energy harvester installed in the underground form was 63.9 mW at the vehicular velocity of 28 km/h. Although the number of piezoelectric cantilevers was reduced by 1/3 to 24 in comparison to the previous research results with 72 piezoelectric cantilevers, similar power generation characteristic value was obtained within the vehicular velocity of 20 km/h by altering the vehicle load transfer mechanism and cantilever vibration method.

MEICP 식각에 의한 SBT 박막의 표면 반응 연구

김동표,김창일,Kim, Dong-Pyo,Kim, Chang-Il 대한전자공학회 2000 電子工學會論文誌-SD (Semiconductor and devices) Vol.37 No.4

최근에 빠른 쓰기/읽기 속도, 적은 소비 전력과 비휘발성을 가지는 메모리 캐패시터의 유전 재료로서 SrBi/sub 2/Ta/sub 2/O/sub 9/(SBT)에 대한 관심이 집중되고 있다. 강유전체 물질을 이용한 고밀도 FeRAM을 생산하기 위하여서는 식각에 의한 패턴이 형성되어야 한다. 강유전체 물질의 성장과 그 전기적 특성에 관한 연구와 발표는 많이 발표 되고 있다. 그러나, 강유전체 물질의 식각의 어려움 때문에 SBT 박막 식각에 관한 연구는 거의 전무하다고 할 수 있다. 그러므로, SBT 박막의 식각의 특성을 알아보기 위하여, SBT 박막은 CF/sub 4/Ar 가스 플라즈마를 이용하여 MEICP로 식각 되어졌다. XPS를 이용하여 식각 된 SBT 박막의 표면에서의 화학 반응을 분석하였고, XPS 분석을 검증하기 위하여 SIMS 분석을 하여 비교하였다. Recently, SrBi$_{2}$Ta$_{2}$ $O_{9}$(SBT) and Pb(Zr,Ti) $O_{3}$(PZT) were much attracted as materials of capacitor for ferroelectric random access memory(FRAM) with higher read/ write speed, lower power consumption and nonvolartility. SBT thin film has appeared as the most prominent fatigue free and low operation voltage. To highly integrate FRAM, SBT thin film has to be etched. A lot of papers have been reported over growth of SBT thin film and its characteristics. However, there are few reports about etching SBT thin film owing to difficult of etching ferroelectric materials. SBT thin film was etched in CF$_{4}$Ar plasma using magnetically enhanced inductively coupled plasma (MEICP) system. In order to investigate the chemical reaction on the etched surface of SBT thin films, X-ray Photoelecton spectrosocpy (XPS) and Secondary ion mass spectroscopy(SIMS) was performed.

수치파동수로를 이용한 유수실 내장 경사식 해수교환방파제의 유입유속 특성에 관한 연구

김창일(Chang Il Kim),이달수(Dal Soo Lee),전인식(In Sik Chun) 대한토목학회 2004 대한토목학회 학술대회 Vol.2004 No.10

배양된 인간 골막기원세포의 조골활성에 대한 덱사메타손 농도의 효과

김종렬,박봉욱,이창일,하영술,김덕룡,조영철,성일용,변준호,Kim, Jong-Ryoul,Park, Bong-Wook,Lee, Chang-Il,Hah, Young-Sool,Kim, Deok-Ryong,Cho, Yeong-Cheol,Sung, Iel-Yong,Byun, June-Ho 대한악안면성형재건외과학회 2009 Maxillofacial Plastic Reconstructive Surgery Vol.31 No.4

Long-term treatment with glucocorticoid leads to the development of osteoporosis and osteonecrosis. In contrast to the marked inhibitory effect of pharmacological doses of glucocorticoids on bone formation, the relationship between physiological concentrations of glucocorticoids and osteoprogenitor cell proliferation and phenotypes has not been elucidated yet. In addition, the effects of dexamethasone treatment on the proliferation and osteoblastic differentiation of osteoprogenitor cells are also controversial. The purpose of this study was to examine the effects of dexamethasone on the proliferation and osteoblastic differentiation of periosteal-derived cells. Periosteal-derived cells were obtained from mandibular periosteums and introduced into the cell culture. After passage 3, the cells were further cultured for 21 days in the osteogenic induction medium with different dexamethasone concentrations of 0, 10, and 100 nM. The proliferation and osteoblastic phenotypes of periosteal-derived cells were promoted in dexamethasone-treated cells than in untreated cells. Among the dexamethasone-treated cells, cell proliferation was slightly greater in 10 nM dexamethasone-treated cells than in 100 nM dexamethasone-treated cells. Histochemical staining and the bioactivity of alkaline phosphatase (ALP) were higher in 100 nM dexamethasone-treated cells than in 10 nM dexamethasone-treated cells. Similarly, von Kossa-positive mineralization nodules and calcium content were also more evident in 100 nM dexamethasone-treated cells than in 10 nM dexamethasone-treated cells. These results suggest that dexamethasone enhances the in vitro osteoblastic differentiation of periosteal-derived cells. The present study also demonstrates that higher dexamethasone concentrations reduce the in vitro proliferation of periosteal-derived cells.

손가락에 발생한 신경초종의 1예

김창일 ( Chang Il Kim ),조선영 ( Sun Young Jo ),정한힘 ( Han Him Jeong ),정홍필 ( Hong Pil Jeong ),허은필 ( Eun Phil Heo ),고재완 ( Jae Wan Go ) 대한피부과학회 2020 大韓皮膚科學會誌 Vol.58 No.10

바이몰프형 압전세라믹 캔틸레버를 이용한 수력에너지 하베스터 모듈 제작 및 발전 특성

김경범,김창일,윤지선,정영훈,남중희,조정호,백종후,남산,성태현,Kim, Kyoung-Bum,Kim, Chang-Il,Yun, Ji-Sun,Jeong, Young Hun,Nahm, Jung Hee,Cho, Jeong-Ho,Paik, Jong-Hoo,Nahm, Sahn,Seong, Tae-Hyeon 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.12

A new water energy harvester module, which is composed of piezoelectric bimorph cantilevers, harvesting circuit and a shaft with 16 impellers at a center axis, was fabricated for energy harvesting application. High energy density $Pb(Zr_{0.54}Ti_{0.46})O_3$ + 0.2 wt% $Cr_2O_3$ + 1.0 wt% $Nb_2O_5$ (PZT-CN) thick film obtained by tape casting method was used for the bimorph cantilever. The PZT-CN bimorph cantilever with a proof mass of 49 g exhibited extremely high output power of 22.5 mW (24 $mW//cm^3$) at resonance frequency of 11 Hz. In addition, the fabricated water energy harvester has a cylindrical structure with 48 bimorph cantilevers clamped at inner surface. A significantly high output power of 433 mW was obtained at a rotation speed of 120 rpm with a resistive load of $500{\Omega}$ for the water energy harvester.

이공본풀이계 서사체의 전개와 공간 의미 고찰

김창일(Kim Chang-Il) 한국무속학회 2003 한국무속학 Vol.0 No.6

이 글은 이공본풀이계 서사체의 서사전개 양상과 공간 의미에 대해 살펴보았다. 우선 이공본풀이계 서사체는 3명의 주인공이 순차적으로 부각되면서 이야기를 형성하고 있음을 밝혔다. 사라도령이 천상의 부름을 받고 떠나는 제1노정기, 원강암이 장자로부터 고통받는 수난기, 할락궁이 아버지를 찾아 탈출하여 길을 떠나는 제2노정기 그리고 세 주인공이 함께 신으로 상승되는 좌정기로 나누었다. 다음으로 이공본풀이계 서사체의 공간 의미에 대해 세 가지로 나누어 살펴보았다. 첫째, 선ㆍ악의 공간인데 장자의 집은 악의 공간으로, 서천꽃밭은 선의 공간으로, 사라수대왕의 궁은 현실계의 가치중립적 공간으로 설정하였다. 둘째, 공간이동 경로에 따라 두 계열로 나누었는데 이를 통해 비현실계로서의 서천꽃밭은 신의 공간이면서 동시에 현실계의 인간이 도달할 수 있는 공간임을 알 수가 있었다. 셋째, 서천은 생명의 공간이기도 하다. 이렇게 꽃과 인간의 생명을 관련지어 생각한 것은 우리의 오랜 사유체계 속에 잠재되어 있었던 것으로 보았다. This study focuses on the spatial and narrative style of the Egongonpuri type. First of all the narrative consists of 3 main characters to make up the story. SaraDoryung receives his calling from heaven and starts the first journey period. WonKangAm during the ordeal period being persecuted by JangJa. HalRakGung who starts out to look for his father makes up the second journey period. And finally all three of the main characters make up the ascension into heaven period(to become a divine being). All of these sections are combined to make up the story. This is called linking through episodes. Not only do SarasuDaewang, WonangBuyin, AhnrakGuk divide the unfolding of the story, but also, depending on whom the focus is on, the theme of the story differs. Focusing on the life of SarasuDaewang, the theme becomes the previous life of Buddha. Focusing on WonangBuyin, the theme becomes the hardship and sacrifices of women. Focusing on AhnrakGuk the theme becomes the life of a hero. Next this study looks at the spatial meaning of the Egongonpuri narrative style by dividing it into three parts. The first of good versus evil, with the house of JangJa being the setting for evil, the Seocheon flower garden being the setting for good, and the SaraSuDaeWang( SaraSu the great king)s palace set as the neutral ground of the real world. The second division can be made by examining the spatial movement. Here the Seocheon flower garden becomes both the setting for divine beings while at the same time it becomes a setting where mortals also can arrive at. The third division can be made by thinking of Seocheon as the setting for Life. How the lives of humans are linked in the subconscious with flowers is shown here through many examples.

Gd₂O₃ 첨가에 따른 AC PDP 보호막용 MgO 박막의 광학적.전기적 특성

김창일,임은경,박용준,이영진,백종후,최은하,정석,김정석,Kim, Chang-Il,Lim, Eun-Kyeong,Park, Young-Jun,Lee, Young-Jin,Paik, Jong-Hoo,Choi, Eun-Ha,Juang, Seok,Kim, Jeong-Seok 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.7

The effects of $Gd_2O_3$ addition and sintering condition on optical and electrical properties of MgO films as a protective layer for AC plasma display panels were investigated. Doped MgO films prepared by the e-beam evaporation have a higher ${\Upsilon}$ (secondary electron emission coefficient) than pure MgO protective layer. Relative density and grain size increased with amount of $Gd_2O_3$ up to 100 ppm and then decreased further addition. These results showed that discharge properties and optical properties of MgO protective layers seemed to be closely related with microstructure factors such as relative density and grain size. Good optical and electrical properties of ${\Upsilon}$ of 0.138, surface roughness of 5.77 nm and optical transmittance of 95.76 % were obtained for the MgO+100 ppm $Gd_2O_3$ protective layer sintered at $1700^{\circ}C$ for 5 hrs.

특징창과 특징링크를 이용한 스테레오 특징점의 정합 성능 향상

김창일,박순용,Kim, Chang-Il,Park, Soon-Yong 한국정보처리학회 2012 정보처리학회논문지B Vol.19 No.2

스테레오 정합(stereo matching) 기술은 주어진 두 영상에서 동일한 물체의 영상점이 어떤 위치 관계를 가지고 있는지를 결정하는 기술이다. 본 논문에서는 영상 특징점에 대해 스테레오 위치관계를 결정하는 새로운 스테레오 특징점 정합(stereo feature matching) 방법을 제시한다. 제안하는 방법은 주어진 스테레오 영상에서 FAST 추출기를 이용하여 특징점을 추출하고, 특징점 벡터들의 정보들을 내부에 포함하는 특징창(feature window)이라는 공간을 정의하여 스테레오 정합의 성능을 향상한다. 제안하는 방법은 표준 영상에 추출된 특징점들에 대해 특징창을 생성하고, 참조 영상에서 표준 영상의 특징창과 가장 유사한 특징창을 탐색 및 결정한 다음, 결정된 두 개의 특징창 내부의 특징점들의 시차관계는 특징링크(feature link)를 생성하여 시차를 결정한다. 만약, 이 과정에서 시차가 결정되지 않은 특징점들이 있다면, 특징창 내의 결정된 시차 정보를 이용하여 시차 값을 보간한다. 마지막으로, 제안하는 방법의 성능을 검증하기 위해 결과 영상과 정답 영상의 시차를 비교하여 정합 정확성과 수행시간을 비교하였다. 또한, 기존의 특징점 기반 스테레오 정합 방법들과 제안하는 방법의 성능을 비교 및 분석하였다. This paper presents a new stereo matching technique which is based on the matching of feature windows and feature links. The proposed method uses the FAST feature detector to find image features in stereo images and determines the correspondences of the detected features in the stereo images. We define a feature window which is an image region containing several image features. The proposed technique consists of two matching steps. First, a feature window is defined in a standard image and its correspondence is found in a reference image. Second, the corresponding features between the matched windows are determined by using the feature link technique. If there is no correspondence for an image feature in the standard image, it's disparity is interpolated by neighboring feature sets. We evaluate the accuracy of the proposed technique by comparing our results with the ground truth of in a stereo image database. We also compare the matching accuracy and computation time with two conventional feature-based stereo matching techniques.