전슬관절치환술을 위한 3차원 영역기반 영상정합 기술

기재홍,서덕찬,박흥석,윤인찬,이문규,유선국,최귀원,Key, J.H.,Seo, D.C.,Park, H.S.,Youn, I.C.,Lee, M.K.,Yoo, S.K.,Choi, K.W. 대한의용생체공학회 2006 의공학회지 Vol.27 No.6

Image Guided Surgery (IGS) system which has variously tried in medical engineering fields is able to give a surgeon objective information of operation process like decision making and surgical planning. This information is displayed through 3D images which are acquired from image modalities like CT and MRI for pre-operation. The technique of image registration is necessary to construct IGS system. Image registration means that 3D model and the object operated by a surgeon are matched on the common frame. Major techniques of registration in IGS system have been used by recognizing fiducial markers placed on the object. However, this method has been criticized due to additional trauma, its invasive protocol inserting fiducial markers in patient's bone and generating noise data when 2D slice images are acquired by image modality because many markers are made of metal. Therefore, this paper developed shape-based registration technique to improve the limitation of fiducial marker based IGS system. Iterative Closest Points (ICP) algorithm was used to match corresponding points and quaternion based rotation and translation transformation using closed form solution applied to find the optimized cost function of transformation. we assumed that this algorithm were used in Total Knee replacement (TKR) operation. Accordingly, we have developed region-based 3D registration technique based on anatomical landmarks and this registration algorithm was evaluated in a femur model. It was found that region-based algorithm can improve the accuracy in 3D registration.

이미지 스트리밍 기술을 이용한 웹 기반 3차원 의료영상 시스템의 구현과 성능평가

기재홍,유선국,김용욱,최귀원 대한의료정보학회 2005 Healthcare Informatics Research Vol.11 No.4

Objective: It is still the important subject that 3D visualizing of medical images to help patient diagnose. There were many challenges for fast 3D visualization but it has some limitations that volume rendering without high price's hardware and software. Some techniques through the web were suggested to construct high quality's 3D visualization even though it was an only poor personal computer. This technique could share the volume rendering board and diagnose 3D images together. However there are some problems to construct web based 3D visualization. These are network delay, optimized visualization and security etc. The purpose of this paper was to visualize and control the 3D medical image having a high quality on the web. Methods: To construct this system, we used mainly three tools which were VolumePro1000 board, WMV9(Windows Media Video 9 Codec) and socket functions based on TCP(Transmission Control Protocol). VolumePro1000 board could calculate quickly heavy matrixes of 3D images using phong's shading and shear-warp factorization. WMV9 was able to compress efficiently live images and to apply image streaming technique. Socket functions based on TCP transmitted messages to control the 3D images. Results: We developed 3D visualization system and evaluated about image qualities and transmission conditions of different compression rates on unfixed network condition. Conclusion: It was big advantages that WMV9 encoder could decode automatically in many platforms(desk top, PDA, notebook, cellular phone, etc) without installing specific decoding programs if they only have Windows Media player. We expect 3D visualization system to be utilized various biomedical fields such as IIGS(Interactive Image Guided Surgery), CAD(Computer Aided Diagnosis) and Tele-medicine technologies.

국내 사업용 태양광발전의 지역 수용성과 동료효과 분석

기재홍 서울대학교 환경대학원 2021 環境論叢 Vol.67 No.-

서울대학교 구성원들의 에너지 절약행동에 영향을 끼치는 심리적 요인 분석 - 계획된 행동이론을 바탕으로 -

기재홍,김우창,송해,최종민,윤순진 에너지기후변화교육학회 2017 에너지기후변화교육 Vol.7 No.2

대학교는 에너지 다소비 기관이다. 특히 2013년 서울시 최다 에너지 소비기관인 서울대학교는 국립 교육기관이자 배출권거래제 이행기관으로서 에너지 소비를 줄여야 할 도덕적, 경제적 필요성이 있다. 건물 사용자의 에너지 사용 행동 변화를 유도하는 것은 에너지 소비 저감에 효과적인데, 행동 변화 유도를 위한 효과적인 개입방법 설계에는 건물 사용자들의 에너지 절약 행동에 영향을 미치는 요인에 대한 정보가 중요하다. 이에 이 연구는 서울대학교 구성원의 에너지 절약 행동에 영향을 미치는 심리적 요인을 분석하는 것을 목적으로 수행되었다. 계획된 행동이론 모형의 구성개념들과 개인적 규범(Personal Norm)을 설명변수로, 에너지 절약행동을 종속변수로 하여 설문조사를 실시하였고, 각 변수가 행동과 가지는 관계의 유의성 검정을 위해 선형회귀분석을 활용하였다. 분석결과, 계획된 행동이론의 구성변수들과 주관적 규범은 서울대학교 구성원들의 에너지 절약행동을 이해하는데 대체로 유효하게 활용될 수 있는 것으로 나타났고, 행동에 유의미한 영향을 미치는 변수는 주관적 규범과 개인적 규범인 것으로 확인되었다. 또한, 기존의 계획된 행동이론을 구성하는 설명변수(adj. R2=0.289)에 개인적 규범이 추가(adj. R2=0.325)되었을 경우, 에너지 절약 행동의 분산에 대한 설명력이 높아지는 것을 확인하였다. 대학교의 구성원은 겉으로 드러나는 사회적 특성의 편차가 크지 않은 집단이다. 따라서 이들의 에너지 절약행동을 더 잘 이해하기 위해서는 사회/경제적 변수를 이용하는 전통적인 접근보다는 심리적 요인을 변수로 이용하는 방식의 접근이 더 유용할 수 있다.

양식장 배출수 수질관리를 위한 용존공기부상 공법의 운전 인자 영향 분석

기재홍,김형준,이주영,한무영,강희웅 대한상하수도학회 2012 상하수도학회지 Vol.26 No.1

Pollutants in aquaculture system effluent mostly originated from solid wastes including uneaten feed and excreta of cultured species. In this research, DAF(Dissolved Air Flotation) unit is suggested as an integrated solid control unit especially as a form of IIBG(Inline Injection Bubble Generation) process in aquaculture system. Solid removal performance of DAF unit was examined under various operation and salinity conditions with turbidity and suspended solid. Solid waste removal efficiencies were found to be affected by operation conditions including saturator pressure, recycle ratio, coagulant concentration. Solid removal efficiency was higher under higher saturator pressure and recycle ratio under which condition larger number of bubbles is generated. Coagulant is thought to have important role in creating bubble-particle aggregate by showing better removal efficiency with higher concentration. However higher saline water showed less effectiveness in removing solids by DAF(IIBG). Application of DAF(IIBG) process also showed additional effect in phosphate removal and DO(Dissolved Oxygen) supply. Phosphate existed in polluted water was removed up to 46% after treatment, which is thought to attribute to aluminium phosphate precipitation. And DO concentration was found to increase over 50% of initial saturation concentration after the injection of micro-bubbles. Through experiments on solid removal from aquaculture effluent, DAF(IIBG) process is estimated to be effective solid control method. This property can help aquaculture system being installed and operated simply and effectively. Pollutants in aquaculture system effluent mostly originated from solid wastes including uneaten feed and excreta of cultured species. In this research, DAF(Dissolved Air Flotation) unit is suggested as an integrated solid control unit especially as a form of IIBG(Inline Injection Bubble Generation) process in aquaculture system. Solid removal performance of DAF unit was examined under various operation and salinity conditions with turbidity and suspended solid. Solid waste removal efficiencies were found to be affected by operation conditions including saturator pressure, recycle ratio, coagulant concentration. Solid removal efficiency was higher under higher saturator pressure and recycle ratio under which condition larger number of bubbles is generated. Coagulant is thought to have important role in creating bubble-particle aggregate by showing better removal efficiency with higher concentration. However higher saline water showed less effectiveness in removing solids by DAF(IIBG). Application of DAF(IIBG) process also showed additional effect in phosphate removal and DO(Dissolved Oxygen) supply. Phosphate existed in polluted water was removed up to 46% after treatment, which is thought to attribute to aluminium phosphate precipitation. And DO concentration was found to increase over 50% of initial saturation concentration after the injection of micro-bubbles. Through experiments on solid removal from aquaculture effluent, DAF(IIBG) process is estimated to be effective solid control method. This property can help aquaculture system being installed and operated simply and effectively.

원전 사고에 대한 재난 대비 수준 및 위험 인식에 영향을 미치는 요인

기재홍,윤동근 (사)위기관리이론과실천 2022 Crisisonomy Vol.18 No.11

원자력발전소에서 방사능이 누출되는 사고가 발생하는 경우, 주변 지역에 거주하는 다수의 주민에대한 주민보호조치가 시행되어야 한다. 이러한 조치가 효과적으로 이행되기 위해서는 지역 주민들이 대응 기관에 의해 권고 받는 행위를 원활하게 수행하는 것이 필요하다. 이 연구는 원전 사고발생 시 지역 주민들의 행동에 영향을 줄 수 있는 다양한 요인 중 두 가지, 대비 수준과 위험 인식에관심을 가지고, 이에 영향을 주는 요인들에 대한 분석을 수행했다. 부산광역시 거주 주민을 대상으로한 설문조사를 토대로 부분최소제곱 구조방정식모형을 활용한 분석 결과 응답자들은 사고 대응 기관에 대한 신뢰가 높을수록, 관련 교육 경험이 있을수록 원전 사고에 대해 높은 대비 수준을 보였다. 또한 대비 수준이 높은 사람은 원전 사고에 대한 위험 인식 수준이 상대적으로 낮은 것으로 나타났다. 분석 결과를 바탕으로 지역 주민들의 원전 사고에 대한 대비 수준을 향상시킬 수 있는 정책적대안을 제시했다.

감성분석과 토픽모델링을 활용한 농촌태양광 관련 이슈 연구 : 언론 기사와 블로그 포스트 비교

기재홍,안승혁,Ki, Jaehong,Ahn, Seunghyeok 한국디지털정책학회 2020 디지털융복합연구 Vol.18 No.9

사회적 의제 설정 영향력을 지닌 미디어인 언론 기사와 블로그 포스트에서 농촌태양광이 어떻게 다루어지고 있는지 분석하기 위해 텍스트 마이닝 방법을 활용하였다. 농촌태양광을 키워드로 웹스크래핑을 통해 기사와 블로그 포스트의 텍스트 자료를 수집하고, 이에 대해 감성분석과 토픽모델 기법을 적용하여 연구를 수행했다. 감성분석 결과 농촌태양광에 대한 텍스트에서 두 매체 모두 긍정적인 입장을 가지는 비율이 높았는데, 블로그의 경우 기사에 비해 부정적인 내용을 담은 텍스트의 비중이 훨씬 낮은 것을 확인할 수 있었다. 그리고 토픽모델링 결과로 긍정 기사는 정부의 보급계획 관련 토픽들의 비중이 컸고, 부정 기사는 다양한 토픽들의 비중이 고르게 분포하였다. 블로그는 긍정 포스트의 경우 농촌 지역 설치 관련 토픽들이, 부정 포스트는 환경 피해 관련 토픽들이 가장 큰 부분을 차지했다. 기존에 별개로 이루어지던 감성분석과 토픽모델링을 결합하는 연구 방식을 제시함으로써 농촌태양광에 대한 이슈를 효과적으로 파악할 수 있었다. News articles and blog posts have influence on social agenda setting and this study applied text mining on the subject of solar PV in rural area appeared in those media. Texts are gained from online news articles and blog posts with rural solar PV as a keyword by web scrapping, and these are analysed by sentiment analysis and topic modeling technique. Sentiment analysis shows that the proportion of negative texts are significantly lower in blog posts compared to news articles. Result of topic modeling shows that topics related to government policy have the largest loading in positive articles whereas various topics are relatively evenly distributed in negative articles. For blog posts, topics related to rural area installation and environmental damage are have the largest loading in positive and negative texts, respectively. This research reveals issues related to rural solar PV by combining sentiment analysis and topic modeling that were separately applied in previous studies.

도시특성이 가정용 전력 사용량에 미치는 영향

기재홍(Jaehong Ki),윤동근(Dong Keun Yoon) 한국환경정책학회 2021 한국환경정책학회 학술대회논문집 Vol.2021 No.10

인공무릎관절 수술에서의 영역기반 ICP 알고리즘

기재홍(Jaehong Key),이문규(Moonkyu Lee),이창양(Changyang Lee),김동민(Dong M. Kim),유선국(Sun K. Yoo),최귀원(Kuiwon Choi) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월

Image Guided Surgery(IGS) system has been developed to provide exquisite and objective information to surgeons for surgical operation process. It is necessary that registration technique is important to match between 3D image model reconstructed from image modalities and the object operated by surgeon. Majority techniques of registration in IGS system have been used by recognizing fiducial markers placed on the object. However, this method has been criticized due to its invasive protocol inserting fiducial markers in patient"s bone. Therefore, shape-based registration technique using geometric characteristics of the object has been invested to improve the limitation of IGS system. During Total Knee Replacement(TKR) operation, it is challenge to register with high accuracy by using shape-based registration because the area to acquire sample data from knee is limited. We have developed region-based 3D registration technique based on anatomical landmarks on the object and this registration algorithm was evaluated in femur model. It was found that region-based algorithm can improve the accuracy in 3D registration. We expect that this technique can efficiently improve the IGS system.

불포화 토양에서 공기의 배출/제한이 침투속도에 미치는 영향

기재홍 ( Jae Hong Ki ),김상래 ( Sang Rae Kim ),김영진 ( Young Jin Kim ),한무영 ( Moo Young Han ) 한국물환경학회 ( 구 한국수질보전학회 ) 2008 공동 추계학술발표회 Vol.2008 No.-