CBCT 및 3D CT를 활용한 상악 유구치 치근과 근관 형태

김준희,김현태,신터전,현홍근,김영재,김정욱,장기택,송지수,Kim, Joon Hee,Kim, Hyuntae,Shin, Teo Jeon,Hyun, Hong-Keun,Kim, Young-Jae,Kim, Jung-Wook,Jang, Ki-Taeg,Song, Ji-Soo 대한소아치과학회 2021 大韓小兒齒科學會誌 Vol.48 No.4

이 연구의 목적은 상악 유구치의 치근 및 근관의 형태학적 특성을 분석하는 것이다. 2006년 1월부터 2020년 4월까지 서울대학교 치과병원에서 CBCT 및 3D CT를 촬영한 3 - 7세 환자 총 268명(남자 175명, 여자 93명)이 연구에 포함되었으며, 치근 흡수와 치수병변이 없는 총 1002개의 상악 유구치의 치근과 근관 수를 분석하였다. 218개의 치아에 대해 치근과 근관의 형태, 이개각도, 치근과 근관의 길이 및 근관의 단면 형태를 분석하였다. 48개의 치아에 대해서는 Mimics 및 3-Matics software를 사용하여 치근 치수의 부피와 표면적, 치근-치수 비를 측정하였다. 절반 이상이 3개의 치근과 3개의 근관을 가지고 있었다. 좌우측 치아의 대칭성(Cohen's kappa coefficient)은 약 0.63이었다. 치근과 근관의 형태는 상악 제1유구치에서는 직선형이, 제2유구치에서는 곡선형이 많이 관찰되었다. 치근의 이개 정도, 치근과 근관의 길이는 상악 제1, 2유구치 모두 구개측 치근에서 가장 크게 나타났다. 근단부에서 근관의 단면 형태는 주로 ovoid 혹은 round형이었다. 치근 치수의 부피와 표면적, 치근-치수 비는 상악 제1,2유구치 모두 구개측 치근 치수에서 가장 크게 나타났다. The purpose of this study is to analyze morphological characteristics of maxillary primary molar's root and root canal. 268 children aged 3 - 7 years (175 boys, 93 girls) who had CBCT (152 children) and 3D CT (116 children) taken in Seoul National University Dental Hospital from January 2006 to April 2020 were included. The number of roots and root canals were analyzed in 1002 teeth without any root resorption or periapical pathologies. Curvature, angulation, length of root and root canal, as well as cross-sectional shapes of the root canal were analyzed in 218 teeth. By using Mimics and 3-Matics software, volume, surface area, and volume ratio of root canal was analyzed in 48 teeth. More than half of maxillary primary molars have 3 roots and 3 root canals. The degree of symmetry of root canal type was about 0.63 (Cohen's kappa coefficient). The most frequent shape of roots and canals was linear in 1^st primary molars and curved in 2^nd primary molars. Angulation, length of root and root canals was the largest on palatal roots. Most teeth showed ovoid or round shapes at apex. The largest root canal volume, surface area, volume ratio was found in the palatal roots.

다중비중선별기를 이용한 광물찌꺼기로부터 비소제거 연구

김준희,김민규,김우람,한오형,Kim, Jun-Hee,Kim, Min-Gyu,Kim, Woo-Ram,Han, Oh-Hyung 한국자원리싸이클링학회 2014 資源 리싸이클링 Vol.23 No.5

광물찌꺼기에는 다양한 종류의 중금속이 함유되어 있어, 국내외에서 광물찌꺼기로부터 중금속을 제거하기 위해 많은 연구가 이루어졌으나, 중금속을 제거하기에는 여러 가지 문제점과 제약이 따르기 때문에 한계가 있었다. 따라서 이를 해결하고자 본 연구에서는 미립자의 선별까지도 가능한 다중비중선별기(Multi-gravity separator, MGS)를 사용하여 광물찌꺼기에 함유된 비소를 제거하기 위한 비중선별실험을 수행하였다. MGS를 이용하여 비중선별에 의해 비중이 높은 비소를 함유한 광물을 제거하고자 경사각, 세척수량, 광액농도, 드럼의 회전속도, 급광량에 따른 영향을 확인하였다. 실험결과 최적실험 조건인 MGS의 경사각 $3^{\circ}$, 세척수량 5 l/min., 광액농도 30%, 드럼 회전속도 208 rpm, 그리고 급광량 265.24 g/min. 에서 As 제거율과 산출율이 각각 88.21%와 92.25%인 결과를 얻었다. It comtained various kinds of heavy metal in beneficiatian tailing and in order to eliminate the heavy metals, various technologies have been researched, But there are a limits because many problems and restrictions are accompanied. Therefore, in this study, in order to solve this problem, It was performed gravity separation using melti-gravity seperator (MGS) to remove As contained in tailing, which can sort out even the fine particle. It was attempted a study to remove As, which is a kind of heavy metals, by MGS gravity separation and verified the impact by slope, wash water, pulp density, rotational speed and feed rate. In the results of performing gravity concentration under the condition with the MGS slope of $3^{\circ}$, wash water of 5 l/mm, pulp density of 30%, rotational speed of 208 rpm, and the feed rate of 265.24 g/mm, the As removal rate of 88.21% and yield of 92.25% were obtained.

연구논문 - 촉매분과 : 수성가스 전환반응용 CoMo 촉매의 활성에 미치는 알칼리 금속염의 영향

김준희,이호인 ( Joon Hee Kim,Ho In Lee ) 한국공업화학회 1997 한국공업화학회 연구논문 초록집 Vol.1990 No.3

N/A Effects of alkali metals and anions on CoMo catalysts for water gas shift reaction were studied. For CoMo/γ-Al₂O₃ catalysts made by impregnation, the doping of alkali metals like lithium enhanced the activity. For K-doped catalysts made with the potassium salts having different anions, the activity increased with increasing BET surface area. Among the catalysts prepared by nitrates as precursor, Li-doped catalyst showed the best activity, and the others did not make significant differences giving a relatively low activity. Both BET surface area and TPR did not show significant differences in the catalysts doped with alkali metals in the form of nitrates. However, the activity of the Li-doped catalyst was remained relatively constant with the amount of Li doped, whereas those of other catalysts changed with the amount of Li doped.

황에 저항성을 가지는 수성가스 전환반응 촉매의 연구 II. CoMo 촉매의 활성에 미치는 알칼리 금속염의 영향

김준희,이호인,Kim, Joon Hee,Lee, Ho In 대한화학회 1998 대한화학회지 Vol.42 No.6

황피독에 저항성을 가지는 수성가스 전환반응용 CoMo 계열 촉매에 알칼리금속염 첨가가 반응활성에 미치는 영향에 대하여 연구하였다. 알칼리금속염의 음이온과 양이온의 각각에 대한 영향을 알아보기 위하여 크게 두 경우로 나누어 촉매를 제조하였다. 그 하나는, 양이온을 K로 고정시키고 음이온을 변형시킨 경우로서, 반응활성의 변화는 BET 표면적의 변화로 설명되었다. 다른 한 경우는, 음이온을 $NO_3^-$로 고정시키고 알칼리금속 이온을 변형시킨 경우로서, Li가 첨가된 촉매의 활성이 가장 뛰어났으며 다른 양이온의 경우에는 서로 비슷한 낮은 활성을 보였다. 알칼리금속의 첨가량의 변화에 따른 BET 표면적의 변화와 반응활성의 변화가 같은 경향을 보였다. 알칼리금속염의 양이온을 변화시킨 경우에는 BET 표면적과 정8면체 배위구조 속의 $Mo^{6+}$에 대한 정4면체 배위구조 속의 $Mo^{6+}$의 비, 즉 $Mo^6+[T]/Mo^{6+}[O]$ 값의 복합적인 관계를 통해 반응활성의 변화를 설명할 수 있었다. The effect of alkali metal salt on the activity of Co-Mo catalyst which has high resistance to sulfur poisoning for water gas shift reaction(WGSR) was studied. Two groups of catalysts were prepared to investigate the effects of anion and cation in alkali metal salts. For K-doped catalysts made with various potassium salts having different anion, the catalytic activity was explained to depend mainly on the BET surface area. Among the catalysts prepared by various nitrates of alkali metal as precursor, the Li-doped catalyst showed the best activity, and the others did not make significant differences giving relatively low activities. And the change of BET surface area by varying the loading of alkali metal showed a similar trend to that of activity. In this case, the activity was dependent on both BET surface area and the ratio of $Mo^{6+}$ with a tetrahedral coordination symmetry to $Mo^{6+}$ with an octahedral one, $Mo^6+[T]/Mo^{6+}[O]$ value.

Alcoholism의 문제점(間題點) 및 underwriting 제고(提高) 방안(方案)

김준희,조신자,Kim, Jun-Hee,Cho, Shin-Ja 한국생명보험의학회 2004 保險醫學會誌 Vol.23 No.-

열이력에 따른 Poly(ethylene 2,6-naphthalene dicarboxylate) 섬유의 미세구조와 물성

김준희,조현혹,Kim Joon Hee,Cho Hyun Hok 한국섬유공학회 2005 한국섬유공학회지 Vol.42 No.1

PEN fibers spun at 4 km/min by melt-spinning were treated by high tension annealing (HTA) at $220^{\circ}C$. The as-spun PEN fibers and fibers treated by HTA at $220^{\circ}C$ were given various thermal history. The fine structure and physical properties of the PEN fibers were investigated with various techniques such as wide-angle X-ray diffraction, DSC thermograms, density, birefringence, dynamic viscroelasticity, tensile testing, etc$\ldots$ In case of the PEN fibers treated by HTA at $220^{\circ}C$, change with thermal history could not be detected from WAXD diagrams and DSC thermograms. In the case of dynamic viscoelasticity of PEN fibers treated by HTA, storage modulus decreased with thermal history. Also, birefringence and initial modulus of the PEN fibers treated by HTA decreased rapidly. Therefore, orientation of non-crystalline region is lowered. From tilting WAXD diagrams, in case of $6^{\circ}$ tilting, peaks became bigger with thormal history. Thus, thermal history affect not only the non-crystalline region but also the crystalline region. WAXD diagrams of PEN fibers at different temperatures from $23^{\circ}C\;to\;220^{\circ}C$ suggested that only d-spacing of $\beta$ form crystal increased. But the d-spacing of transformed $\alpha$ form crystal did not change. Also d-spacing returned to the original value on cooling.

직접 메탄올 연료전지용 산화극 제조 변수가 성능에 미치는 영향

김준희,하흥용,오인환,홍성안,이호인,Kim, Joon-Hee,Ha, Heung-Yong,Oh, In-Hwan,Hong, Seong-Ahn,Lee, Ho-In 한국전기화학회 2003 한국전기화학회지 Vol.6 No.1

Single cell performance has been investigated and characterized with variables in the fabrication of DMFC anode. The performance was checked as a function of ionomer content which affects ion conductivity in the catalyst layer, and catalyst slurry solvent which determines structure of agglomerates consisting of an ionomer and a catalyst. Anode with total ionomer to catalyst ratio of 0.6 showed the best performance and the lowest polarization resistance. Also, electrochemically effective surface area increased with ionomer content. As solubility of the ionomer decreases with decreasing solvent polarity, the size of agglomerates consisting of a catalyst and an ionomer became larger in the less polar solvent. The anode using DPK $(\varepsilon=12.60)$ as a solvent, which is less polar than generally-used water or alcohol species, showed the maximum performance and the lowest polarization resistance. 직접 메탄을 연료전지(DMFC)의 산화극 제조 변수들에 따른 단위전지의 성능변화 관찰 및 특성분석을 수행하였다. 촉매층에서의 이온 전도도에 영향을 주는 이오노머의 양과, 이오노머와 촉매의 결합구조를 결정하는 촉매 슬러리의 용매를 변수로 하였다 전체 이오노머의 비가 0.6일 때 최고 성능을 보였으며 분극 저항도 가장 작게 나타났다. 전기화학적 활성면적도 이오노머가 늘어날수록 증가하였다. 극성이 작은 용매일수록 이오노머가 잘 용해되지 않아 촉매 응집체의 크기가 커졌다 기존의 물이나 알코올 종류의 용매들에 비해 극성이 낮은 DPK $(\varepsilon=12.60)$를 사용하여 제조한 전극이 가장 높은 성능을 보였으며 낮은 분극 저항 값을 가졌다.

서울·경기지역 외식·조리전공 대학생의 중요 대학서비스에 대한 만족도(IPA) 분석

김준희,구본길,오왕규,Kim, Jun-Hee,Gu, Bon-Gil,Oh, Wang-Kyu 한국식품영양학회 2013 韓國食品營養學會誌 Vol.26 No.4

The purpose of this study is to measure the priority items according to attributes and analyze the differences between the importance and satisfaction rates through the IPA for the university service. The results in the study are as follow: First, from the result of the factorial analysis, 5 factors are included First, the possibilities for development of universities, universities' physical environment, Universities' administrative (employee) services, majors' educational services, and majors' laboratory environment. Second, as the total average value for important attributes of the universities is 3.50 and the average value of satisfaction is 2.91, there were significant differences (p<0.001). Third, in the analytical result of IPA, the 1st quadrant includes faster developments than other universities, departments' characterization, etc. The 2nd quadrant includes the convenience to issue all kinds of certificates, kindness of administrative staffs, etc. The 3rd quadrant includes convenience of the procedure to improve unsatisfactory services, development efforts to benchmark advanced universities, etc. Finally, the 4th quadrant includes heavy investments in education and environment, efforts to reflect students' demands, and needs, etc. Even though the importance of research subjects related to university services for these attributes is high, they are not fully satisfied, and there are plenty of dissatisfied students. Therefore, urgent supplementations to increase students' satisfaction rates are important. Form the results of the study, it has been found that urgent efforts to improve satisfaction rates of university students who major in catering cooking in the university services are essential and special plans to build competitive systems which can provide high-quality services are also necessary.

단국대학교 LINC+ 4차산업혁명 혁신선도대학 사업단 소개

김준희,Kim, Jun-Hui 한국전산구조공학회 2019 전산구조공학 Vol.32 No.2

친환경 포장관리제도-친환경 포장 인증 제도

김준희,Kim, Jun-Hui 한국포장협회 2015 包裝界 Vol. No.