• 대한치과보철학회지
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• 제18권1호
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• pp.15-35
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• 1980

The purpose of this study was to investigate stresses in the various components of fixed partial dentures restoring the posterior teeth of the lower jaw, and to measure quantitatively the effects of certain modifications in structural design on the stresses in the restorations using two-dimensional photoelasticity. Two-dimensional photoelastic methods were used in this study. Several models of fixed partial dentures were constructed. Shoulder less margins and anatomic occlusal reduction were incorporated in Model 1. Rounded shoulders and flat occlusal reduction were incorporated in Model 2, while Model 3 was a cantilever fixed partial denture. Other similar fixed partial dentures were constructed with V and U notches deliverately included in the region of the fixed joints for comparative reasons. The birefringent materials used in this study were PSM-1 and PSM-5 in standard sheets. PSM-1 was used for constructing the substructure, and PSM-5 was used in making the components of the fixed partial dentures. The two materials were used in the construction of composite photoelastic models. Improved artificial stone was used to represent dental cement in luting the composite photoelastic models. Static loading procedures were used at preplanned sites to represent occlusal loads in the mouth. 35 mm color and B/W film were used to record isochromatics in accordance with photoelastic procedures. Data reduction was performed using the grid method, which helped in, the mathematical integration procedure (Shear difference method) to separate the principal stresses. The results were as follows. 1. Fixed partial dentures do not function in bending as a symmetrical beam. Alternate areas of tension and compression were demonstrated when multiple contact loading was used. 2. The weakest part in posterior fixed partial dentures is the fixed joint. 3. (1) Models I and modified Model I were loaded on the pontic using a 50 pound vertical static load. The shear stress near the posterior fixed joint in Model 1 (U notches) was+129.4 p.s.i., and at the same fixed joint in modified Model 1 (V notches) was+239.4 p.s.i. The concentration of stress in fixed joint was reduced by 50% when U notches replaced the V notches. (2) Modified Model 2 was loaded using a multiple contact loader at a total load of 125 pounds. The difference between the principal stresses (${\sigma}_1-{\sigma}_2$), shear stress, at the V notches was+600 p.s.i., and at the U notches was+3l7 p.s.i. The shear stress was reduced by 50% when U notches replaced the V notches. V-grooves at the fixed joints should be avoided, and should be replaced by regular shaped U-grooves. 4. Cantilever fixed partial dentures had much higher stresses at the fixed joint than fixed partial dentures that were attached at both ends.

• Geosciences Journal
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• 제22권6호
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• pp.881-889
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• 2018

The Geodo skarn deposit is located in the Taebaeksan Basin, central eastern Korean Peninsula. The geology of the deposit consists of Cambrian to Ordovician calcareous sedimentary rocks and the Cretaceous Eopyeong granitoids. The skarns at Geodo occur around the Eopyeong granitoids, which consist, from early to late, of magnetite-bearing equigranular quartz monzodiorite, granodiorite, and dykes. These dykes emanated randomly from equigranular granodiorite and some of dykes spatially accompany skarns. Skarn Fe mineralization, referred as Prospect I and II in this study, is newly discovered beyond previously known skarns adjacent to the quartz monzodiorite. These discoveries show a vertical and lateral variation of skarn facies, grading from massive reddish-brown garnet-quartz in a lower and proximal zone to banded in an upper and distal zone, reflecting changes in lithofacies of the host rocks. Skarn veins in distal locations are parallel to sedimentary laminae, suggesting that lithologic control is important although proximal skarn has totally obliterated primary structures, due to intense retrograde alteration. Skarns at Geodo are systematically zoned relative to the causative dykes. Skarn zonation comprises proximal garnet, distal pyroxene, and vesuvianite (only in Prospect I) at the contact between skarn and marble. Retrograde alteration is intensely developed adjacent to the contact with dykes and occurs as modification of the pre-existing assemblages and progressive destruction such as brecciation of the prograde assemblages. The retrograde alteration assemblages consist predominantly of epidote, K-feldspar, amphibole, chlorite, and calcite. Most of the magnetite (the main ore mineral), replaces calc-silicate minerals such as garnet in the lower proximal exoskarn, whereas it occurs massive in distal pyroxene and amphibole in the upper and distal exoskarn. The emanation of dykes from the equigranular granodiorite has provided channelways for ascent of skarn-forming fluids from a deep source, whereas the style and nature of skarns suggest that originally structurally-controlled skarn-forming fluids may migrate long distances laterally to produce skarn in calcareous sedimentary rocks.

• 대한치과교정학회지
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• 제40권5호
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• pp.304-313
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• 2010

본 연구는 한국인 정상교합자와 부정교합자 사이의 교합력의 크기와 교합 시의 접촉 면적의 차이 및 골격 형태와 교합 관계, 연령, 성별이 교합력의 크기에 영향을 미치는지 알아보기 위해 시행되었다. 정상교합자 15명, 부정교합자 636명에서 일회용 pressure sensitive sheet (Dental $Prescale^{(R)}$ 50H, typeR, Fuji Film Corp., Tokyo, Japan)를 자연 두부위에서 최대 근력으로 교합하도록 한 후, CCD camera ($Occluzer^{(R)}$ FPD 707, Fuji Film Corp., Tokyo, Japan)로 판독하여 교합력의 크기 및 접촉 면적을 측정하였다. 정상교합자군의 교합력의 크기는 $744.5{\pm}262.6N$, 접촉면적은 $24.2{\pm}8.2mm^2$으로, 부정교합자군의 $439.0{\pm}229.9N$, $12.4{\pm}10.7mm^2$에 비해 교합력의 크기와 접촉 면적이 유의하게 컸다 ($p$ < 0.05). 부정교합자군의 경우 연령에 따른 교합력의 차이는 없었으나, 남자가 여자에 비해 큰 교합력을 가지고 있었다 ($p$ < 0.05). 악안면의 전후방적인 골격 형태를 나타내는 ANB 및 골격성 1급 부정교합에서의 구치부의 Angle 분류는 교합력에 유의한 차이를 나타내지 않았으나, 수직적인 골격 형태를 구분하는 mandibular plane angle, gonial angle이 큰 경우, 교합력이 유의하게 작았다 ($p$ < 0.05). 하지만, 교합력의 크기와 접촉 면적간에는 높은 상관관계가 존재하는 점과 접촉 면적을 통제한 상태에서의 골격 형태와 교합력의 크기 사이에는 유의할 만한 상관관계가 없는 점을 고려한다면 수직적인 골격 형태가 직접적으로 교합력에 영향을 주기보다는 수직적인 골격 형태에 따른 접촉 면적의 감소가 교합력 저하에 관여한다고 판단된다.

• 한국전산구조공학회논문집
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• 제24권3호
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• pp.337-342
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• 2011

매우 큰 편심하중을 지지하면서 상하로 수직위치를 제어하는 의료용 리프트 칼럼은 수직위치의 정확도를 확보하기 위해 매우 낮은 구조적 변형과 진동은 물론 높은 피로강도가 요구된다. 리프트 칼럼은 일반적으로 3단 슬라이딩 붐구조로 유도전동기로 작동되며, 상하운동에 따라 변동응력을 나타낸다. 본 연구에서는 리프트 칼럼의 상하운동으로 야기되는 변동응력에 따른 피로강도를 수치해석적으로 예측하였다. 한 주기 상하운동에 따른 응력변동은 유한요소해석으로 구하였으며, 피로수명은 Palmgren-miner기법과 재료의 S-N선도를 적용하여 예측하였다. 수치해석의 신뢰성을 확보하기 위하여 리프트 칼럼의 상세형상과 체결부위을 반영한 3차원 FEM모델을 생성하였으며, 칼럼과 패드사이 계면은 접촉조건으로 처리하였다.

• 비파괴검사학회지
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• 제36권4호
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• pp.295-299
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• 2016

증기발생기 2차측(관판 상단 및 관 지지판)에 잔류하는 이물질은 전열관에 마모를 야기하여 누설을 발생시킬 가능성이 있으며, 마모는 전열관 재료의 부식 특성과는 별개로 이물질의 재료, 형태, 크기 등에 따라 큰 영향을 받는다. 관판 상단 및 관 지지판 부위의 이물질 여부는 원격육안검사(FOSAR) 방법과 와전류탐상검사(ECT)를 통해 확인하고 있다. 증기발생기 2차측의 잔류 이물질은 그 재질이나 전열관과의 접촉상태 등에 따라 검출하는데 제한성이 나타난다. 따라서, 본 연구에서는 다양한 형태와 재료의 이물질을 관판 상단에서 수직 및 수평한 방향으로 이동시켰을 때, 이물질에 대한 보빈신호의 검출 감도를 측정하기 위해 데이터를 수집하고 분석하였다.

• Archives of Plastic Surgery
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• 제45권2호
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• pp.135-139
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• 2018

Background Static reconstruction surgery that tightens the tension of the inferior tarsus, thereby raising the lax lower eyelid, is a common treatment for paralytic ectropion of the lower eyelid. We present one such operative procedure, in which an orbicularis oculi muscle flap was used. Methods The surgical technique involves partial resection of the tarsus and the skin, as well as a superior-based orbicularis oculi muscle flap that is sutured to the firm tissue present on the Whitnall tubercle. The muscle flap is approximately 7 mm in width and 15 mm in length, with a superior pedicle that is attached to the tarsus at the medial point of the resected tarsus. The procedure results in contact between the ocular surface and the lower eyelid. Results The procedure was performed in 11 patients with lower eyelid ectropion due to facial paralysis. Ten cases showed a favorable outcome following surgery, with stable results seen over an average follow-up period of 4.5 years. In one case, recurrence of ectropion was observed 2 months after surgery due to an insufficient correction, and the patient required repeat surgery. Conclusions The orbicularis oculi muscle flap was an effective means of suspension and was able to maintain long-term traction tension. This procedure can therefore be considered a favorable treatment option for lower eyelid ectropion due to facial paralysis.

• 한국운동역학회지
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• 제18권1호
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• pp.159-168
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• 2008

본 연구는 피겨스케이팅의 여자국가대표 선수 4명으로부터 고난도 스핀기술인 FSS과 FCS동작을 분석하였다. 이를 위하여 자세유형에 따른 스핀동작 간 족저압력변인 접지면적(CA), 최대힘(MF), 최대압력(PP) 그리고 인체무게중심(COG)에 의한 발바닥 9개 영역을 중심으로 압력변화를 고찰하였다. 본 회전구간에서 두 스핀기술 간 접지면적이 17.2%의 차이로 스핀축이 한 곳에 보다 잘 집중된 경우는 FCS인것으로 나타났다. 최대힘에서 FSS는 97%BW, FCS는 143%BW로서 20% 높았으며, 최대압력 또한 FCS가 FSS보다 20% 높은 수치를 보였다. 이러한 결과는 인체무게중심선과 압력중심점과의 상호관계로부터 FSS의 압력중심점이 인체무게중심선보다 발바닥 후면, 반대로 FCS는 발바닥 앞면에 위치하는 자세패턴에 의한 기능적 차이로 분석되었다. 위의 결과로부터 FCS가 상대적으로 FSS보다 스핀기술 시 높은 인체중심과 하지말단을 이용한 큰 회전반경으로부터 스핀속도를 보다 잘 통제하는 운동구조로 고찰되었다.

• 대한간호학회지
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• 제27권1호
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• pp.201-211
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• 1997

This study was an evaluation study of AIDS education program. The purpose of this study was to clarify the education effects on AIDS for health care workers to develop a better next education program. This study was done by self reporting with a 67 items of structured questionnaire by 431 health care workers included doctors, nurses, laboratory technicians, and health educators. Data were collected at the time of completion of each AIDS education with the help of education program manager. Both the AIDS related knowledge score and the acceptance attitudes score were significantly higher in the male group, in the medical institution employer group, in the group who have met the HIV infected person, who has known the HIV positive person, and the group of laboratory technician, but the AIDS prevention intention score was statistically higher in the group of female and laboratory technician group. The post education scores of AIDS related knowledge. acceptance attitudes, and preventive intention were statistically higher than those of the preeducation. The most increased item among AIDS prevention intention list was 'I will provide the meeting between the HIV infected persons and the public (+21.9%)'. But even the decreased item among AIDS prevention intention list was 'I will advice to female not to have extra marital sexual contact to avoid AIDS(-3.1%)'. It could be concluded that the health care workers were ignorant of vertical transmission of AIDS, they were afraid of disclosing the infection status, and have less AIDS prevention intention. Therefore it is needed to take an assessment process before each new education trategy to increase AIDS related the effect of the education on AIDS.

• 한국지반공학회논문집
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• 제17권6호
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• pp.37-46
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• 2001

무리말뚝의 하중지지능력에서 말뚝캡이 부담하는 비율을 파악하고 무리말뚝을 구성하는 개개 말뚝의 하중전이 특성을 알아보고자 재하시험을 수행하였다. 직경 92.5mm의 강관말뚝 24본(4개씩 6열)을 지표 아래 3m 깊이까지 근입 시컥 풍화암 상단에 말뚝선단이 위치하도록 하였다. 최대하중 320t을 지표면에 접촉되어 있는 $1.5\times2.3m$ 크기의 말뚝캡에 재하하였다. 최대 시험하중인 320t에서는 말뚝캡이 전체하중의 약 22%에 해당하는 하중을 분담하였다. 무리 말뚝 재하시험시 말뚝의 평균 극한지지력은 16.4t이며, 이 값은 말뚝캡을 타설하기 전에 무리말뚝의 모서리에 위치한 말뚝에 대하여 수행한 단말쪽 재하시험으로부터 구한 극한지지력보다 상당히 크게 나타났다. 변위장중첩 효과로 인하여 무리말뚝 중앙에 위치한 말뚝은 작은 하중이 작용하여도 외곽부의 말뚝과 같은 침하량을 기록한 것으로 나타났다. 무리말뚝에서는 주면마찰력의 분담율이 전 하중단계에서 약 60%로 일정하나 단말뚝 시험에서는 하중이 증가함에 따라 주면마찰력의 분담율이 82%에서 65%로 감소하였다.

• Journal of Oral Medicine and Pain
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• 제21권1호
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• pp.55-65
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• 1996

This study was performed to investigate the effects of head posture and occlusal splint on the vertical dimension in mandibular rest position and swallowing. Thirty health dental students ware selected lot this study and BioEGNⓡ(Bioresearch Inc., USA) was used for measuring interocclusal distance during rest - swallowing - rest - tapping movement. This swallowing movements were observed in both normal head posture(NHP) and forward head posture (FHP). Thickness of occlusal splint was about 2mm at posterior molar area and even tooth contact were achieved on light biting. The four mandibular positions at which interocclusal distance measured were swallowing position, after swallowing position in which interocclusal distance was maximum, rest position follows swallowing, and tapping position after rest. Changes of distance in each position were measured for three mandibular planes, that is, sagittal, frontal, and horizontal plane, respectively. The results obtained were as follows : 1. In normal head posture, the mandible was raised 1.03mm without splint, and 0.77mm with splint on swallowing, and there was no significant difference between the two. In horizontal plane, however, mandible was displaced more anteriorly in both swallowing position and tapping position with splint. 2. In forward head posture, the mandible was less raised with splint on swallowing, but features in horizontal plane were almost same as those in normal head posture. 3. In natural dentition, significant difference between NHP and FHP were observed in horizontal plane trajectory for swallowing and tapping position. But the difference for same positions were observed in frontal trajectory with splint. 4. Total amount of mandibular movement of two groups classified with sagittal interocclusal distance of swallowing position generally showed significant difference between the higher and the lower height group in head posture without splint. 5. Correlationship among total amount of mandibular movement for three mandibular planes were observed between sagittal plane and horizontal plane, and between sagittal plane and frontal plane in head posture without splint.