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.

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.

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.

고장력 열처리한 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 high speed melt-spinning were treated by two methods, constant length annealing (CLA) and high tension annealing (HTA) at 130, 160, 190, and $220^{\circ}C$. The fine structure and physical properties of the PEN fibers were investigated with various techniques such as wide-angle X-ray diffraction, DSC thermo-grams, density, birefringence, tensile test etc. As the annealing temperatures is increased, a partial transition of the crystal structure, from $\beta$ form crystal to $\alpha$ form crystal appeared in the WAXD test in case of CLA treatment. But, in case of HTA treatment, the transition of the crystal form from $\beta$ form crystal to $\alpha$ form crystal appeared dominantly. As the annealing temperature and tension increases, the melting peaks become sharper in DSC thermograms. Density of PEN fibers from HTA treatment is lower than that from CLA treatment, but birefringence and initial modulus of the PEN fibers from HTA treatment are much higher than those from CLA treatment. But, shrinkage of the PEN fibers from HTA treatment is higher than that from CLA treatment.

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.

기내 감마선 조사에 의한 팔레높시스의 생육 및 감수성

김준희 ( Joon Hee Kim ),고재철 ( Jae Chul Koh ) 대구가톨릭대학교 자연과학연구소 2010 자연과학연구논문집 Vol.8 No.1

The study was conducted to develop the method of making up new cultivars of phalaenopsis through the induction of mutation by in vitro irradiation with the gamma rays. While culturing the Phalaenopsis the material in PLB state at the stage of in vitro protocorm and seedlings in vitro about to be planted on outside place were treated with 20, 40, 60Gy of gamma rays. And, the ratio of the PLB necrosis, the degree of the sensitivities and variation for the gamma ray treatment in the M1 generation after the transplant of in vitro seedlings were measured and examined. The necrosis ratio at the in vitro protocorm stage was between 40.5% and 62.0% at the treatment with 20Gy gamma ray, 85.4% and 82.2% at the treatment with 40Gy gamma ray, and 84.0% and 94.2% at the treatment with 60Gy gamma ray, showing the optimal amount of the irradiation treatment is 20 Gy or below the level. Even though all the seedlings survived the in vitro treatment, the experiment showed the results that the higher the irradiation amount gets, the later the generation of a new leaf, and such negative phenomena as brown spots on the edge of a leaf or curling disease leafroll dialal was observed, producing new mutant forms with small flowers in size by making flower stalk suddenly out of season due to the irradiation of gamma rays. In the sensitivities of gamma rays in the flowering period of M1 generation by the irradiation quantity, the mini group with flower stalk length did not show a clear difference in comparison with the control group in terms of the amount in irradiation treatment, but in the group with long flower stalk showed that the higher the amount of the irradiation treatment, the shorter it gets. The number of the flowers is divided into KS413 group showing the increase in difference and KS4861 showing the decrease in difference, according to the amount of the irradiation treated with, depending on the group of cultivars publicly announced. The result has shown us that the higher the amount of the irradiation treated with, the smaller the length and width of a leaf, and that the length and width of a flower, a calyx, and a petal were al mostsimilar or a little bit smaller by the group of the cultivars publicly announced.

복합하중 조건하의 범퍼 최적설계 프로그램 개발에 대한 연구

김준희(Joon hee Kim),조후택(Hootaek Cho),오영섭(Youngsub Oh),강성욱(Sunguk Kang) 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11

Nowadays it is required for a car bumper system to meet the various impact safety regulations. Until now, bumper system is designed for satisfying each impact condition independently. So it is very difficult to design a bumper system tosatisfy all requirements simultaneously, and it has been done by trial and error until now. To overcome these problems, many studies on the optimization of bumper system are being performed. In this study, the bumper optimum design program is developed to optimize the bumper system satisfying the bumper barrier impact, pedestrian protection bumper impact and new IIHS(Insurance Institute for Highway Safety) bumper impact conditions. For this bumper optimum design program, equivalent beam analysis model is developed for each bumper loading condition.

Head Impact 성능 만족을 위한 Latch system 해석 기술에 대한 연구

김준희(Joon Hee Kim),조광표(Kwang Pyo Cho),나원균(Weon Kyun Na),윤석배(Seok Bae Yoon) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Head impact performance is the one of the safety regulation in FMVSS 201, Domestic safety standard 88, ECE 21. The main contents of this regulation is that deceleration shall not exceed 80g continuously for more than 3 milliseconds to pass the test and interior compartment doors shall not open. Lately, interior compartment doors are designed on the center fascia of the crash pad to satisfy customer's convenience. So there are many problems that interior compartment door is open during the test in the last stage of the car development In this study we have tried to search optimum design spec of latch system and to set up the analysis technique to satisfy Head Impact regulation by using FEM simulation and DFSS technique in the early stage of car development.

8주간의 플라이오메트릭 트레이닝과 웨이트트레이닝 시간에 따른 체육계열학과 지망생의 순발력 및 민첩성에 미치는 영향

김준희(Joon-Hee Kim),이재석(Jae suk Lee) 한국발육발달학회 2017 한국발육발달학회지 Vol.25 No.4

The purpose of this study was to investigate the influence of 8-week plyometric training and weight training time on speed and agility of college of kinesiology applicants. 10 subjects of plyometric group accomplished 60-minute plyometric training 4 times a week(Monday, Tuesday, Thursday, Friday) for 8 weeks divided into A, B stage-4 weeks each. 10 subjects of weight training group accomplished 60-minute plyometric training-mainly quadriceps, gluteus, hamstrings, core-4 times a week(Monday, Tuesday, Thursday, Friday) for 8 weeks. Groups participated in the experiment(plyometric group(10 subjects), weight training group(10 subjects), controlled group(10 subjects)) all accompanied standing long jump training and 10m shuttle run training for 180 minutes 6 times a week(Monday~Saturday). Students who are willing to apply for college of kinesiology were experimented before and after the 8-week plyometric training and weight training. Two-way ANOVA with repeated measures were used to experiment subjects. All 3 groups showed statistically similar difference between records of standing long jump before and after the training. Plyometric group showed the biggest improvement, and weight training group and controlled group followed plyometric group. Also all 3 groups showed statically similar difference between records of 10m shuttle run before and after the training. Weight training group showed the biggest improvement, and plyometric group and controlled group came next. Through this results, we found out that plyometric training had a great influence on speed exercise and that it also helps improving agility. Weight training was found out to improve agility exercise and speed exercise. Students who are willing to apply for college of kinesiology are advised to include plyometric training and weight training for better speed and agility.