• 대한소아치과학회지
• /
• 제26권1호
• /
• pp.172-184
• /
• 1999

The present study was performed to identify morphologic sub-groupings in Korean children with Class I malocclusions, and to find out anatomic differences between the sub-groups. Standardized lateral cephalometric radiographs of 152 Korean children, aged between 6 and 12 years, with Class I malocclusions were analyzed by the Counterpart Analysis. A statistical method, Ward's Minimum Variance Cluster Analysis, was employed to divide the sample into sub-groups those with similar morphologic characteristics. The results were as follows; 1. There appeared two facial types, Type I and Type II, in Korean children with Class I malocclusions, 48.7% and 51.3%, respectively. 2. In both sub-groups, there existed strong Class III skeletal patterns due to a counterclockwise rotation of the Middle Cranial Fossa alignment, and strong Class II skeletal patterns due to the long Posterior Maxillary vertical dimension and a clockwise rotation of the Ramus alignment. 3. There were no significant differences in Upper Anterior Facial Height between Type I and Type II, $52.6{\pm}2.92mm\;and\;52.8{\pm}3.23mm$, respectively. 4. The Lower Anterior Facial Height in Type II was longer ($66.0{\pm}4.03mm$) due to the long Posterior Maxillary vertical dimension, the clockwise rotation of the Ramus alignment, and a clockwise rotation of the Mandibular plane alignment than that of Type I ($64.2{\pm}4.15mm$).

• 패션비즈니스
• /
• 제16권1호
• /
• pp.69-82
• /
• 2012

This thesis aimed to reduce the differences of hair color when hair coloring, so it researched the differences & changes in hair color before shampoo v.s. after shampoo and dry on different heat processes when acid hair color dyeing. Five hair color dyes (Y, R, B, G, Br) manufactured by two different corporations were used. The acid hair color dyes were tinted on black and bleached hair pieces subjected to 3 different heat process; 1. Normal Temperature($25^{\circ}C$, 30min.) / 2. Heating($40^{\circ}C$, 15min.)+Normal Temperature($25^{\circ}C$, 15min.) / 3. Heating($40^{\circ}C$, 30min.). Color numbers were divided by NCS value, chroma, and hue. Statistical averages were derived and t-test was conducted using SPSS V12. Hair color differences and changes were drawn on an NCS chart using Photo Shop PS. The conclu is; If acid hair colorings are separated by a heating process, hair value & chroma change before shampoo vs. after shampoo & dry regardless of the color of hair and the heat process. Hue is not changed or shifted counter clockwise NCS color circle, but some exceptions, and it's the same when the total heat process results are combined. Black hair's value shifted downward and chroma left, and hue stayed either neutral or one color or it shifted counter clockwise on NCS color circle. Bleached hair's value shifted upward and chroma right, and hue stayed one color or shifted counter clockwise, but some exceptions. And it can be shown on NCS chart.

• Restorative Dentistry and Endodontics
• /
• 제48권1호
• /
• pp.10.1-10.9
• /
• 2023

Objectives: This study compared the buckling resistance of 3 nickel-titanium (NiTi) retreatment file systems and the torque/force generated during retreatment. Materials and Methods: The buckling resistance was compared among the D-RaCe (DR2), HyFlex Remover, and Mtwo R25/05 retreatment systems. J-shaped canals within resin blocks were prepared with ProTaper NEXT X3 and obturated by the single-cone technique with AH Plus. After 4 weeks, 4 mm of gutta-percha in the coronal aspect was removed with Gates-Glidden drills. Retreatment was then performed using DR1 (size 30, 10% taper) followed by DR2 (size 25, 4% taper), HyFlex Remover (size 30, 7% taper), or Mtrwo R25/05 (size 25, 5% taper) (15 specimens in each group). Further apical preparation was performed with WaveOne Gold Primary. The clockwise torque and upward force generated during retreatment were recorded. After retreatment, resin blocks were examined using stereomicroscopy, and the percentage of residual filling material in the canal area was calculated. Data were analyzed using 1-way analysis of variance with the Tukey test. Results: The HyFlex Remover files exhibited the greatest buckling resistance (p < 0.05), followed by the Mtwo R25/05. The HyFlex Remover and Mtwo R25/05 files generated the highest maximum clockwise torque and upward force, respectively (p < 0.05). The DR1 and DR2 files generated the least upward force and torque (p < 0.05). The percentage of residual filling material after retreatment was not significantly different between file systems (p > 0.05). Conclusions: NiTi retreatment instruments with higher buckling resistance generated greater clockwise torque and upward force.

• 한국안광학회지
• /
• 제12권2호
• /
• pp.47-59
• /
• 2007

이 연구는 원 근거리 상태에서의 난시 성분별, 연령별, 난시축의 분포와 원거리에서 근거리로 주시선이 이동 할 때 난시축의 변화를 비교 분석하기 위하여 안질환이 없고 눈 수술의 경험이 없는 1,598안(남 698안, 여 900안)을 대상으로 양안개방형 자동굴절검사를 실시하였다. 그 결과 원거리에서 근거리 주시 시 난시 성분들의 변화는 전체난시에서 무변화안 1,020안 (63.8%), 변화안은 578안 (36.1%)을 나타냈으며, 직난시는 사난시로, 사난시는 직난시로, 도난시는 사난시로의 변화가 각각 가장 많았다. 각막난시에서는 무변화안 1,164안(72.8%), 변화안은 434안(27.1%)을 나타냈으며, 직난시는 사난시로, 사난시는 직난시로, 도난시는 직난시로의 변화가 각각 가장 많았다. 잔여난시에서는 무변화안 935안(58.5%) 변화안은 663안(41.4%)을 나타냈으며, 직난시는 사난시로, 사난시는 도난시로, 도난시는 사난시로의 변화가 각각 가장 많았다. 원거리에서 근거리 주시 시 난시축의 회전은 전체난시의 경우 무회전이 761안 (48.5%), $10^{\circ}$ 이상 회전이 837안(52.3%)으로 나타났으며, 각막난시의 경우는 무회전이 846안(52.9%), $10^{\circ}$ 이상 회전이 752안(47%)으로, 잔여난시의 경우는 무회전이 614안(38.4%), $10^{\circ}$ 이상 회전이 984안(62.5%)으로 나타났다. 전체난시의 평균 회전 정도는 반시계방향으로 $31^{\circ}$, 시계 방향으로 $20^{\circ}$로 나타났으며, 각막난시의 평균 회전 정도는 반시계 방향으로 $25^{\circ}$, 시계 방향으로 $27^{\circ}$로 나타났다. 잔여난시에서의 평균 회전 정도는 반시계 방향으로 $33^{\circ}$, 시계방향으로 $35^{\circ}$를 나타냈다.

• 대한치과교정학회지
• /
• 제30권4호
• /
• pp.491-507
• /
• 2000

이 연구는 측두하악장애 증상을 나타내는 부정교합자를 대상으로 교합안정장치 사용 전, 후의 측모 두부방사선 사진 상의 하악골의 위치변화를 구명하는데 그 목적이 있다. 연구의 대상자는 측두하악장애증상을 나타내는 부정교합자 60명이며 남자 19명, 여자 41명으로 각각의 평균연령은 19.5세와 21.5세 이었다. 전체 대상자를 전, 후방적으로는 Angle 분류법에 따른 교합관계에 의하여 Class I, II, III로 분류하였고, 수직적으로는 Jarabak의 후안면고경과 전안면고경의 비율에 따라서 clockwise, straight downward, counterclockwise의 3군으로 구분하여 부정교합군 별로 측정했으며 하악골의 위치변화를 중심교합시의 측모 두부방사선 사진 계측치들로부터 예측할 수 있는지 알아보기 위한 분석을 시행한 것으로 다음과 같은 결과를 얻었다. 1. 전체 대상자 비교시 측두하악장애를 갖는 부정교합환자에서 교합안정장치 사용 이후 하악골은 후하방 회전을 나타내었고 overjet은 1.3mm의 증가, overbite은 1.9mm감소되어 수평변화보다 수직적인 변화의 양이 컸다. 2. 전후방 3군 분류시 하악골의 후하방 변위를 나타내는 항목의 유의성 있는 변화는 Class II군에서 가장 현저하였으며 3군중 후방변위량이 가장 컸다. 3.수직 3군 분류시 Clockwise와 counterclockwise군에서 하악골의 후하방 변위를 나타내는 항목의 유의성 있는 변화가 뚜렷하였으며, 3군 모두에서 수직적인 변화량이 수평변화량 보다 컸다. 4. 중심교합위시의 부정교합 양태 및 골격유형, 그리고 중심교합위 계측치를 통하여 중심위 계측치를 설명할 수 있는 항목은 발견되지 않았다. 이상의 결과는 기존에 시행되어 오던 중심위 전환에 의한 방법이 아니고 측두하악장애를 갖는 부정교합자에서 교합안정 장치 를 장착하여 중심위를 획득한 상태에서 하악골의 위치 변화를 계측한 것으로 측두하악장애를 동반한 부정교합환자에서 중심교합위 상태의 측모 두부방사선 사진에 의존한 진단은 부정교합의 실체를 파악할 수 없음을 확인하였으며, 통상적으로 이용되어 온 중심위 전환방법 역시 중심위 유도후 발생되는 수직적인 부조화의 양상을 나타낼 수 없음을 입증하였다. 또한 전, 후방적으로는 Class II 부정교합군, 수직적으로는 Clockwise군과 Counterclockwise군에서 교합안정장치를 사용한 중심위 회복시에 하악골의 후하방 회전과 이에 동반된 구치부의 교합간섭으로 전후방 부조화뿐 아니라 수직적부조화를 더욱 심화시키므로 이에 대한 진단 및 치료시의 고려가 요구됨을 보여주었다.

• Journal of Korean Biological Nursing Science
• /
• 제2권2호
• /
• pp.81-89
• /
• 2000

To determine the optimal rotational shift system, the effect of the direction of the rotational work shifting on the nocturnal rhythm of plasma melatonin were investigated in nursing students. Two groups of nine volunteers participated as experimental subjects, and two nursing students participated as a control group. The directions of the rotational work shift were as follows: CW(clockwise)-shift were rotated in the direction of day shift(3 days), evening shift(3 days), off duty(1 day) and night shift(5 days), and CCW(conuterclockwise)-shift were done in the reverse direction. Plasma melatonin concentrations was measured by radioimmunoassay. The results were as follows : The plasma melatonin levels were kept low at night and in the following morning in the CW night shift workers, whereas the level started to increase at 05 : 00 hr in two workers of four CCW shift workers. These result suggests that the shift rotation in the CW direction is more acceptable in terms of the adaptation of hormonal rhythms. These results indicate that the CCW rotation of shift work is somewhat better than CCW rotation for the adaptation to shift work on hormonal aspects in nurses.

• 자원환경지질
• /
• 제28권6호
• /
• pp.559-569
• /
• 1995

Paleomagnetic data have been obtained from the Upper Carboniferous-Permian Komok and Cheolam Groups which are exposed in the E-W trending Baekunsan syncline comprising the Pyongan Supergroup in eastern Korea. Two ancient components of magnetization are recovered in these groups by detailed thermal demagnetization: a post-folding component and a pre-folding component. The post-folding component $(D/I=54.0/54.6^{\circ},\;{\alpha}_{95}=14.6^{\circ})$ is a magnetic signature of the Oaebo Orogeny and appears to have been confined mainly to Cretaceous Normal Superchron. It has been rotated clockwise since this magnetization has been acquired. The pre-folding components ($D/I=341/-9.2^{\circ},\;{\alpha}_{95}=7.2^{\circ})$, paleopole at $335.7^{\circ}E$, $44.6^{\circ}N$ for Upper Carboniferous; $D/I=358.3/11.5^{\circ},\;{\alpha}_{95}=6.3^{\circ})$, paleopole at $311.9^{\circ}E$, $58.7^{\circ}N$ for Permian) pass fold and reversal tests. These paleopoles correspond only with the contemporaneous poles from the North China Block: they are removed from the poles from the South China Block. If the results of this study are corrected for the clockwise rotation deduced from the prefolding component, the enhanced agreement with North China Block can be achieved. Therefore, a first-order correlation between the Korean Peninsula and North China at least since Upper Paleozoic times is identified in this study.

• 동력기계공학회지
• /
• 제21권5호
• /
• pp.20-28
• /
• 2017

The steady-state, incompressible and three-dimensional numerical analysis was performed to investigate the flow fields around the seabed tiller used for soil improvement in coastal fisheries and the pulling force and buoyancy generated by tiller operation. The turbulence model used in this study is a realizable $k-{\varepsilon}$. As a results, at a stationary current or a current speed of 1.2 knots, where rotor rotates in a clockwise direction, a typical vortex pair appears near the tip of the rotor except for the edge, and the strength of the vortex pair increases with the number of revolutions of the rotor. The pulling force of the tiller rotating in the counterclockwise direction increases with the number of revolutions. Also, when the current flows at 1.2 knots and the rotor rotates clockwise, the pulling force of the tiller acts on the upstream side irrespective of the number of rotations of the rotor, so that no force is applied. The buoyancy of the tiller acts on the seawater surface if the flow direction inside the rotor is the same as the direction of rotation of the rotor, regardless of the current velocity, otherwise it acts on the seabed.

• 에너지공학
• /
• 제11권4호
• /
• pp.350-358
• /
• 2002

The present work determined the flame structure characteristics of coal syngas combusted inside swirl burners with various nozzle types. Fuel nozzle types are largely classified into two groups of axial and tangential. Experiments were carried out for investigating the effects of fuel nozzle geometry, fuel composition ratio, heating rate, excess air, and degree of swirl on the turbulent diffusion flame structure. To determine the characteristics of the flame structure, axial type fuel nozzle diameter of laboratory-scale combustor is varied to 1.23, 1.96, and 2.95 ㎜ and the direction of tangential type nozzles are varied to radial, clockwise, and counter-clockwise. The comparison of the experimental results was performed to understand functional parameters relating the flame structure. Data analysis showed that the vertical straight flame height generally decreased with increasing swirl number and decreasing axial type nozzle diameter. Flame height established with tangential type nozzle is 3 times shorter than that with vertical type. The flame structures among the 3 different tangential fuel nozzles relatively showed no particular difference. By increasing the heating rate, the width of flame increased generally in both vertical and tangential flame. Within the present experimental parameters of the investigation, flame structure is mainly depends on the nozzle type of the combustor. The visually investigated flame lengths are confirmed through the analysis of temperature profile of each flame.

• 자원환경지질
• /
• 제26권3호
• /
• pp.383-393
• /
• 1993

Paleomagnetic data have been obtained from the Lower Triassic Tonggo formation which is exposed in the E-W trending Baekunsan syncline comprising the Pyongan Supergroup in eastern Korea. Two ancient components of magnetization are recovered in this formation by detailed thermal demagnetization: a post-folding component and a pre-folding component The post-folding component ($D/I=58.8/55.5^{\circ}$) is normally magnetized and appears to acquire in the Cretaceous Normal Superchron. It is a magnetic signature of the Daebo Orogeny and has been rotated clockwise since this magnetization has been acquired, in common with the main synclinal axis. The pre-folding component ($D/I=1.1/19.4^{\circ}$, Paleopole at $306.1^{\circ}E$, $63.2^{\circ}N$) passes fold and reversal tests and is inferred to be a post-depositional or early chemical diagenetic remanence of Lower-Middle Triassic age. This paleopole corresponds only with the Lower Triassic poles from the North China Block: it is removed from the contemporary poles from the South China Block. If the result of this study is corrected for the clockwise rotation deduced from the Cretaceous overprint, the enhanced agreement with the Lower Triassic poles from the North China block can be achieved. Therefore, a first order correlation between the Korean Peninsula and North China at least since Lower Triassic times is identified in this study.