Three-dimensional analysis of soft and hard tissue changes after mandibular setback surgery in skeletal Class III patients

Park, Jae-Woo,Kim, Nam-Kug,Kim, Myung-Jin,Chang, Young-Il The Korean Association Of Orthodontists 2005 대한치과교정학회지 Vol.35 No.4

하악 수술로 치료한 골격성 3급 부정교합 환자의 연조직 변화를 3차원적으로 분석하였다. 수술전과 수술후에 CT를 촬영하고, 연조직과 경조직을 각각의 임계값에 따라 segmentation였다. FH.평면, 정중시상면, PNS를 포함하는 전두면을 기준으로 공통 좌표계를 구성하고, 이 좌표계를 기준으로 술전, 술후 영상을 위치시켰다. 술후의 변화를 측정하기 위해 각각의 모형에 대해 전두면에 평행한 grid를 형성하였다. Grid내의 교점에서 골조직과 연조직 모형에 투사하여 만나는 점의 좌표값을 구하고, 이를 바탕으로 술후의 변화를 측정하였다. 하악골 후퇴술시 안모의 변화는 하악골 부분에서만 발생한 것이 아니라, 구각부에서도 관찰되었다. 하악골 부위의 연조직 변화는 대응되는 골조직 이동량에 따른 상대적인 값으로 계산하였다. 정중시상면에서의 변화율은 $77\~102\%$로 나타났다. (p<0.05). 정중시상면 이외의 부분의 변화양상도 이와 유사하였다. 구각부에서의 변화는 하악골의 이동을 대표할 수 있는 점의 이동량에 대한 상대적인 값으로 계산하였다. 정중시상면에서의 변화는 B점을 기준으로 $14\~29\%$이고, Pog점을 기준으로 $17\~37\%$, grid상 83번째 점을 기준으로 $11\~22\%$로 관찰되었다.(p<0.05) The three-dimensional (3D) changes of bone, soft tissue and the ratio of soft tissue to bony movement was investigated in 8 skeletal Class III patients treated by mandibular setback surgery. CT scans of each patient at pre- and post-operative states were taken. Each scan was segmented by a threshold value and registered to a universal three-dimensional coordinate system, consisting of an FH plane, a mid-sagittal plane, and a coronal plane defined by PNS. In the study, the grid parallel to the coronal plane was proposed for the comparison of the changes. The bone or soft tissue was intersected by the projected line from each point on the gird. The coordinate values of intersected point were measured and compared between the pre- and post-operative models. The facial surface changes after setback surgery occurred not only in the mandible, but also in the mouth corner region. The soft tissue changes of the mandibular area were measured relatively by the proportional ratios to the bone changes. The ratios at the mid-sagittal plane were $77\~102\%(p<0.05)$. The ratios at all other sagittal planes had similar patterns to the mid-sagittal plane, but with decreased values. And, the changes in the maxillary region were calculated as a ratio, relative to the movement of a point representing a mandibular movement. When B point was used as a representative point, the ratios were $14\~29\%$, and when Pog was used, the ratios were $17\~37\%(9<0.05)$. In case of the 83rd point of the grid, the ratios were $11\~22\%(p<0.05)$.

Formulation of a reference coordinate system of threedimensional head & neck images : Part Ⅱ. Reproducibitity Ⅱ부 수평기준면과 정중사상면의 재현성

Kim, Nam-Kug,Park, Jae-Woo,Chang, Young-Il 대한치과교정학회 발행 2005 대한치과교정학회지 Vol.35 No.6

This study was performed to investigate the reproducibility of the horizontal and midsagittal planes, and to suggest a stable coordinate system for three-dimensional (3D) cephalometric analysis. Eighteen CT scans were taken and the coordinate system was established using 7 reference points marked by a volume model, with no more than 4 points on the same plane. The 3D landmarks were selected on V works (Cybermed Inc., Seoul, Korea), then exported to V surgery (Cybermed Inc., Seoul, Korea) to calculate the coordinate values. All the landmarks were taken twice with a lapse of 2 weeks. The horizontal and midsagittal planes were constructed and its reproducibility was evaluated. There was no significant difference in the reproducibility of the horizontal reference planes. But, FH planes were more reproducible than other horizontal planes. FH planes showed no difference between the planes constructed with 3 out of 4 points. The angle of infersection made by 2 FH planes, composed of both Po and one Or showed less than 1° difference. This was identical when 2 FH planes were composed of both Or and one Po. But, the latter cases showed a significantly smaller error. The reproducibility of the midsagittal plane was reliable with an error range of 0.61 to 1.93° except for 5 establishments (FMS-Nc, Na-Rh, Na-ANS, Rh-ANS, and FR-PNS). The 3D coordinate system may be constructed with 3 planes; the horizontal plane constructed by both Po and right Or; the midsagittal plane perpendicular to the horizontal plane, including the midpoint of the Foramen Spinosum and Nc; and coronal plane perpendicular to the horizontal and midsagittal planes, including point clinodale, or sella, or PNS. 본연구는 삼차원 두부 영상을 위치시키기 위한 좌표계를 구성하는 방법에 대한 제안하기 위해, CT data에서 기존의 두부방사선 계측사진에서 쓰이는 점들을 선정하고, 이를 바탕으로 수평, 수직평면의 안정성을 조사하였다. 서울대학교 치과병원에 내원한 환자 18명의 CT자료를 채득하였으며, 모든 환자는 서울대학교 병원 진단방사선과에서 촬영하였다. (Somatom Plus 4: Siemens, Eriange, Germany). V works for surgery 4.0 (Cybermed Inc., Seoul, Korea)을 이용하여 3차원 좌측표를 선정하고, 계측점을 선택하였다. 좌표축을 동일하게 설정하기 위해 7개의 점(reference point)을 4·4·2 pixel size의 voxel로 따로 표시하였다. 계측점을 선정한 후 V surgery (Cybermed Inc., Seoul, Korea)에서 각 점의 좌표값을 추출하였다. 각각의 점들은 2회 반복 선정한 후 점들을 조합하여 수평, 수직평면의 재현성을 평가한 결과 다음과 같은 결론을 얻었다 수평 기준면의 재현도는 S-CI평면을 제외하고는 통계적으로 유의한 차이를 보이지 않았으나, 사잇각은 FH평면이 가장 작게 나타났다. FH평면은 Po과 Or중 어느 3점을 선택하더라도, 통계적으로 유사한 재현도를 보였다. FH1과 FH2의 사잇각과 FH3과 FH4의 사잇각은 1° 이하의 적은 오차를 보이며, FH3과 FH4의 사잇각이 통계적으로 더 작은 차이를 보였다. 정중시상면의 재현도는 FMS-Nc, Na-Rh, Na-ANS, Rh-ANS, FR-PNS를 기준으로 설정한 경우를 제외하면, 0.61~1.93° 의 양호한 값을 보였다. 이상의 결과에 의하면 공간에서 정의되는 평면의 재현도는 평면을 정의하는 점 자체의 식별오차뿐 아니라, 각 점의 위치관게에도 영향을 받는 것을 알 수 있었다. 따라서, 안정적인 3차원 기준좌표계를 구성하려면 양측 Po과 편측 Or으로 구성되는 평면을 수평기준면으로, 수평면에 수직이고, Foramen Spinosum의 중점과 Nc를 포함하는 평면을 수직기준면으로, 수평면과 수직면에 수직이고, clinoidale나 sella, PNS를 지나는 평면을 전두면으로 설정하는 것이 바람직할 것으로 생각된다.

Analysis of Airtightness and Air Leakage of Wooden Houses in Korea

Sejong Kim,Yoon-seong Chang,Joo-saeng Park,Kug-bo Shim 한국목재공학회 2017 목재공학 Vol.45 No.6

Airtightness of buildings is one of critical aspects of its energy performance. To build up references of air-tightness of wooden houses built in Korea, blower door tests have been carried out in 42 houses since 2006. Causes of air leakage were investigated recently. The average value of air change rate was 3.7 h^-1 for light frame house and 5.5 h^-1 for post-beam construction at ACH50 (air change per hour at 50 Pa air pressure differ-ence). Foam type insulation was more advantageous in ensuring building airtightness than glass fiber batt. Airtightness of wooden houses which were constructed after 2010 was improved to have less than 1.5 h^-1 of ACH50, threshold for application of artificial air change. The average air change rate of CLT (cross laminated timber) houses showed the lowest value, 1.1 h^-1, among the tested structures.

컴퓨터 그래픽수업에서 STAD모형을 이용한 웹 기반 협동학습의 효과

김창국 동의대학교 경제경영전략연구소 2005 經濟經營硏究 Vol.3 No.2

This study aims to identify the effect of Web‐Based STAD cooperative learning utilized in computer graphic instruction on learners’ attitudes toward instruction, their achievements and satisfaction. In order to achieve the purpose of this study, the following specific research questions were selected: Research Question 1: Is there any difference among three groups in computer graphic instruction by types of learning? Research Question 2: Do academic achievements of three groups in computer graphic instruction vary with types of learning? Research Question 3: Do levels of satisfaction with computer graphic instruction differ among three groups? The subjects of this study were 96 students of 3 classes who are attending "Photoshop(Ⅲ)", one of the courses of ‘Practical Computer’, which is currently a required cultural subjects of P University in 2005. The experimental study was carried out dividing those students into three groups: an existing learning group where its members are composed by the STAD instruction model; a project cooperative learning group where its constituents were selected by the STAD instruction model and performed a joint work; and a feedback cooperative learning group where each member performs tasks individually but feedbacks are exchanged only within the group. All three groups received face-to-face instructions from professors while learning through data, assignment, and Q & A boards. Two of three groups, which were constituted by the STAD cooperative learning teams with each team consisting of four members, performed all the cooperative learning activities through chat, discussion, and team learning rooms. Web‐based computer graphic instruction were given for 8 weeks in total except the orientation session.

전자부품 검사용 지능형 로봇 비젼 시스템 개발

한성현,김윤구,안종국,조창제 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

Developed shape awareness technology and vision technology for slant in this research, and including external form state of lens for the performance verification, developed so that can be good, achieve badness finding. And, establish to existing reflex data because inputting surface badness degree of scratch's standard specification condition directly, and error designed to distinguish from product more than schedule error to badness product by normalcy product within schedule extent after calculate the error comparing actuality measurement reflex data and standard reflex data mutually. Developed system to smallest 1 pixel unit though measuring is possible 1pixel as 3.7㎛×3.7㎛(0.1369×10^(-4)㎟) the accuracy to 10^(-4)㎜ minutely measuring is possible performance verification and trust ability through an experiment prove.

벼, 콩 및 채소류에 대한 Mn-54, Co-60, Zn-65, Cs-137의 토양-작물체간 전이계수

박찬걸,조용우,최용호,김국찬,이창우,이강석,이정호 대한방사선 방어학회 1991 방사선방어학회지 Vol.16 No.2

벼, 콩, 상치, 당근, 호박의 가식부위에 대하여 몇가지 토양에 있어서 토양-작물체간 Mn-54, Co-60, Zn-65, Cs-137의 전이계수를 포트 재배에 의한 방사성 추적자 흡수실험을 통하여 조사하였다. 핵종간 전이계수는 거의 모든 경우 Zn-65>Mn-54>Cs-137>Co-60의 순이었다. 콩이 벼보다 전반적으로 한 자리 정도 높은 값을 보였고 채소류의 경우에는 대체로 상치에서 가장 높고 호박에서 가장 낮은 값을 보였다. 강산성 토양에서는 약산성 토양에서보다 전이계수가 훨씬 높았다. 본 조사결과에 입각하여 한국인의 섭식경로 피폭선량 평가에 이용하기 위한 각 핵종의 전이계수치가 작물별로 제안되었다. Soil-to plant transfer coefficients of Mn-54, Co-60, Zn-65 and Cs-137 were estimated for the edible parts of the rice, soybean, lettuce, carrot, and squash grown in different soils by radiotracer uptake experiments using pot cultures. The transfer coefficients of radionuclides were n the order of Zn-65>Mn-54>Cs-137>Co-60 in most of the cases studied. The coefficients for soybean were roughly and order of magnitude higher than those for rice. Among vegetables, lettuce mostly showed the highest value and squash, the lowest. In the strongly acidic soils. From the data obtained, crop-specific transfer coefficients of the four nuclides were proposed for the use in Korean food-radiation dose assessment.

구내 표준 방사선사진을 이용한 구내방사선촬영기의 선질 평가

이상섭,권혁락,심우현,오승현,이지연,전국진,김기덕,박창서 대한구강악안면방사선학회 2000 Imaging Science in Dentistry Vol.30 No.3

Purpose : This study was to evaluate the beam quality of intraoral X-ray equipments used at Yonsei University Dental Hospital (YUDH) using the half value layer (HVL) and the characteristic curve of intraoral standard X-ray film. Materials and Methods : The study was done using the intraoral X-ray equipments used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. Results : Most of the HVLs of intraoral X-ray equipments were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANPAS 601 model and REX 601 model at operative dentistry department, the X-705 model of prosthodontic dentistry department, and the REX601 model at the student clinic were relatively low. Conclusion : HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X-ray equipment should be managed in the planned and organized fashion. (Korean J Oral Maxillofac Radiol 2000; 30: 183-188)

가토 외고정 모델을 이용한 치밀체형 세라믹스의 골결합능 평가

이재협,이동호,이재학,공현식,안영준,류현승,서준혁,홍국선,김환,장봉순,이춘기 대한정형외과연구학회 2003 대한정형외과연구학회지 Vol.6 No.2

비후성심근증의 임상적 관찰

전상중(Sang Joong Jeon),정진홍(Jin Hong Chung),홍경순(Kyung Soon Hong),전재은(Jae Eun Jun),박의현(Wee Hyun Park),박희명(Hi Myung Park),김윤년(Yoon Nyun Kim),김권배(Kwon Bae Kim),장성국(Sung Kug Chang),이종주(Jong Joo Lee) 대한내과학회 1987 대한내과학회지 Vol.33 No.4

N/A The clinical and laboratory features of hypertrophic cardiomyopathy were studied in 30 cases. They consisted of 21 males and 9 females, and the age ranged from 21 to 74 years with an average of 50. The cardinal presenting symptoms were dyspnea, chest pain and palpitation in the order of decreasing frequency. Physical examination revealed apical systolic murmur in 27 cjases (90%), with thrill in 10 (33%), and the routine chest films showed enlargment of cardiac silhouette in 15 cases (50%). Abnormal electrocardiographic findings are noted in 27 cases (90%). Among them repolarization abormalities and left ventricular hypertrophy were the most common, occurring in 71% and 66 % of the cases, respectively, follower1 by left atrial enlargment in 24% and the abnormal Q waves in 20% Among various echocardiographic abnormalities, the mean of septal thickness and its ratio to left ventricular posterior wall thickness were 19 mm and 2,1 respectively, and the mean of the degree of systolic anterior motion of mitral valves was 9 mm. The mean of preejection period and left ventricular ejection time as well as their ratio determined in 10 cases were within normal limits. Out of 20 eases treated with beta or calcium blockers. for a mean of 22 months, 14 (70) experienccd symptomatic improvement. □ (5%) deteriorated and in the remainder (25%) there were no noticeable changes.

연구논문 : 일본 생명공학정보센터의 데이터베이스 구축 및 웹 서비스 현황

김창국 ( Chang Kug Kim ),김진아 ( Jin A Kim ),김명식 ( Myung Sik Kim ),윤도원 ( Do Won Yun ),김용환 ( Yong Hwan Kim ) 한국국제농업개발학회 2008 韓國國際農業開發學會誌 Vol.20 No.4