• 구강회복응용과학지
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• 제30권3호
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• pp.223-230
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• 2014

목적: 하악 절치 발치 치료를 받은 환자들의 치료로 인한 향상과 유지기간 후의 안정성을 평가하는 것이다. 연구 재료 및 방법: 하악 절치를 발치한 환자 총 20명을 대상으로 치료 전, 치료 직후, 2년의 유지기간 후의 모형 및 파노라마 방사선 사진을 분석하였다. Irregularity index, overjet, overbite, 치아 크기와 악궁 길이의 차이, 견치간 폭경, 제1 대구치간 폭경 및 미국교정학회에서 제시한 방법(ABO-CRE)을 평가하였다. 통계분석은 Wilcoxon signed-rank test를 이용하였다. 결과: 치료 전후 irregularity index가 유의하게 감소되었고(P = 0.000), 치아 크기와 악궁 길이의 차이는 유의하게 증가 하였다(P = 0.028). 유지기간 동안에 irregularity index는 유의하게 악화 되었다(P = 0.001). ABO-CRE 전체값의 변화는 치료 전후에 유의한 감소를 보이고(P = 0.000), 유지 전후에는 유의한 차이를 보이지 않았다(P = 0.053). 결론: 모형과 파노라마 방사선 사진을 이용하여 치료의 안정성 평가 결과, 하악 절치 발치 치료는 2년간의 유지기간 동안 치료 결과가 안정적으로 유지되었다고 할 수 있다.

• 대한치과의사협회지
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• 제52권10호
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• pp.623-632
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• 2014

안면비대칭의 주원인은 하악골이며, 하악골의 비대칭 성장에 대한 상악골의 보상성장에 따라 교합면 경사 등이 초래된다. 디지털 사진과 삼차원 CT 등 다양한 방법으로 정확한 진단을 하고 수술을 포함한 치료계획을 세운다. 술전 교정 치료는 상악골과 하악골 치열의 치성 보상(dental compensation)을 제거하면서 상악 치열의 중심은 상악골의 정중선에, 하악 치열의 중심은 하악골 정중선에 맞게 이동하여 술후 상하악 치열궁이 일치하면서 동시에 안모 정중선에 일치하게 맞추어야 한다. 악교정 수술은 일반적으로 상하악 동시 수술을 하게 되며 우각부 풍융도 교정과 이부 성형술(genioplasty) 등을 부가적으로 할 수 있으며, 교합면 경사 교정과 수평 회전 등의 이동이 상하악 위치에 서로 영향을 주면서 수술 후 안모 변화에 대한 예측을 어렵게 만들기 때문에, 다양한 분석을 통해 정확한 예측으로 최선의 결과를 얻는 것이 가장 중요하다.

• 구강회복응용과학지
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• 제22권1호
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• pp.11-21
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• 2006

The adjustable dental impression trays were made for being adjusted their width automatically along the width of patient's dental arch. The purpose of this study was to investigate the retentive force of adjustable dental impression trays made of different synthetic resin materials. Three pairs of adjustable trays were made of ABS(acrylonitrile butadiene styrene) synthetic resin, polyurethane synthetic resin and polycarbonate synthetic resin with a hole and without a rim on the border area of them. The experiment was done with the horse-shoe shaped metal plate to pull out the set impression body from the tray jig which was made for holding the tray on the lower part of Universal Testing Machine(UTM, Zwick Z020, Zwick Co., Germany). After the alginate impression in the tray was allowed to set four minutes, a tensile force was applied at right angles to the tray which had been previously seated on the jig. The force was applied to measure a maximum force by use of UTM at a constant strain rate 100mm per minute. The results obtained in this study were as follows : 1. The upper trays were showed higher retentive force than lower trays in three tray materials. 2. There was no significant difference in the retentive force of the tray materials(p>0.05).

• 대한소아치과학회지
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• 제33권2호
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• pp.311-316
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• 2006

중심교합위 상태에서 편측이나 양측으로 구치부의 상악치아가 하악치아의 협측으로 위치한 경우를 scissors bite라고 한다. 이런 부정교합은 상악의 폭이 크거나 하악의 폭이 좁은 경우 발생한다. 이로 인해 턱의 성장이 방해를 받고 악궁간 부조화를 유발하며 적절한 저작을 할 수 없게 된다. 따라서 scissors bite는 즉시 차단교정을 해야하며 일반적으로 scissors bite의 치료는 고정성 또는 가철성 장치를 이용하여 하악을 확장한다. 이에 저자는 scissors bite를 보이는 환아의 4세의 두 명의 남아에게 Schwarz장치를 이용하여 양호한 결과를 얻어 scissors bite의 치료법 제시에 도움이 되고자 보고하는 바이다.

• Journal of Welding and Joining
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• 제34권1호
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• pp.68-74
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• 2016

Adoption of narrow gap welding shall be increased for the butt joint of thick plate, because the deformation and welding cost is reduced by decrease of cross-sectional area. However, sometimes narrow gap causes defects such as lack of fusion since it has small groove angle and narrow groove width. Therefore, GMAW, GTAW and SAW process shall be adopted to narrow gap welding with small bead hight and low deposition rate. In this study, Super-TIG welding using C-type strip was applied to semi-narrow gap butt joint in order to increase the welding productivity. High deposition rate 10kg/hr was obtained by high current 600A without undercut, humping bead and other welding defects. Measuring the mean and standard deviation of the melting depth to evaluate the developed processes, the fusion line type was determined by measuring the difference between maximum and minium melting depth. Furthermore, a model on arch fusion line and linear fusion line was suggested in order to prevent LF on groove wall in narrow gap butt welding.

• 대한소아치과학회지
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• 제21권2호
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• pp.547-554
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• 1994

Posterior crossbites are abnormal buccal, or lingual relationship of a tooth or teeth of the maxilla, the mandible, or both when the teeth of the two arches are in occlusion and involve the molars and premolars. Posterior crossbites are classified as dental, muscular(functional), or skeletal. In an effort to avoid occlusal interferences caused by the inadequate arch width, the patient deviates the mandible laterally upon closure to achieve maximum intercuspation. This is described as functional posterior crossbite. Correction of functional posterior crossbites in the primary & early mixed dentition as early as possible after diagnosis has been recommended, because crossbites do not automatically improve with the eruption of the permanent teeth. Functional posterior crossbites, if left untreated, may have deleterious effects on the development and function of the TMJ. The diagnosis and management of three cases is presented. Each patient with functional posterior crossbites is treated using the bilateral maxillary expansion appliance.

• Architectural research
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• 제2권1호
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• pp.1-6
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• 2000

Ever since Viollet-le-Due began to examine Gothic structural elements using his method of geometrical analysis in the nineteenth century, art and architectural historians and a few engineers have periodically attempted to ascertain the structural advantages of the various characteristic features of Gothic architecture. In none of these studies, however, has the way forces work within the lightweight and spacious masonry Gothic buildings been precisely interpreted. The approach taken by art and architectural historians has therefore tended to be primarily descriptive and to be based on intuitive assumptions. This study intend to analyze the Gothic non-vaulted nef unique(aisleless) structures of Lower Languedoc which has never been scientifically tested, and to provide as comprehensive an explanation as possible of the way in which these non-vaulted buildings work. In order to achieve this goal, this paper Is to examine, by means of finite element analysis. the links between the width of non-vaulted aisleless structures, the configuration of the arches, diaphragm arch, and the buttress. Finite element analysis with a computer provides a more accurate analysis than the methods of analysis that have been heretofore applied to Gothic structures, as well as permits us to visualize the global stress behavior of the structure. Combined with traditional methods of studying historical buildings, therefore, finite element analysis inevitably give us a broader understanding of the processes involved in the design and construction of medieval buildings.

• 복식
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• 제34권
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• pp.67-78
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• 1997

We executed the wearing test in order to revise the basic Beosun pattern for five kinds of foot type. And we took sensory test to evaluated that revisions. The result were as follows: 1. The characteristics of slender foot is that the foot circumference III is short as compared with foot length. So Kou of basic Beosun is sharp-pointed Hoimok and beosunmok are broad. For slender foot we took down ou of Beosun and use foot cir-cumference III/2-1.5cm as Hoimok like the part shown in dotted line of Fin 6. 2. The characteristics of broad foot is that the foot circumference III is long as comparison with foot length. So Kou of ba-sic Beosun is stubby Hoimok and Beosunmok are narrow. For broad foot we took up Kou of Beosun put foot circum-ferenceI /2-1.5cm for the width of Apbol and circumfernce III 2/-1.5cm for Hoimok like the part shown in dotted line of Fig. 8. 3. because the arch of flat foot is flat the sole of basic Beosun is not suitable to the flat foot. It developes on wrinkles of Duichuk and sole. For flat foot we took down Hom of the basic Beousun like the part shown in dotted line of Fig. 10. 4 We evaluated the revisions of basic Beousun for foot types were useful in senso-ry test.

• 한국정밀공학회지
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• 제22권10호
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• pp.195-201
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• 2005

A laterally driven electromagnetic microactuator (LaDEM) is presented, and a micro-optical switch is designed and fabricated as a possible application. LaDEM provides parallel actuation of the microactuator to the silicon substrate surface (in-plane mode) by the Lorentz force. Poly-silicon-on-insulator (Poly-SOI) wafers and a reactive ion etching (RIE) process were used to fabricate high-aspect-ratio vertical microstructures, which allowed the equipment of a vertical micro mirror. A fabricated arch-shaped leaf spring has a thickness of $1.8{\mu}m$, width of $16{\mu}m$, and length of $800{\mu}m$. The resistance of the fabricated structure fer the optical switch was approximately 5$\Omega$. The deflection of the leaf springs increases linearly up to about 400 mA and then it demonstrates a buckling behavior around the current value. Owing to this nonlinear phenomenon, a large displacement of $60{\mu}m$ could be measured at 566 mA. The displacement-load relation and some dynamic characteristics are analyzed using the finite element simulations.

• 한국농공학회지
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• 제44권4호
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• pp.107-113
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• 2002

The pipe framed and arch shape plastic greenhouse, which is the most popular greenhouse in Korea, is relatively weak in snowdrift. Reinforcement of rigid frame or column is required to reduce the damage from heavy snow in this type. But additional rigid frames or columns decrease light transmissivity or workability, and increase construction cost. So it is desirable to prepare some temporary poles and to install them when the warning of heavy snow is announced. This study was carried out to develop the temporary pole supporting system using galvanized steel pipes for plastic housing and to evaluate the safe snow load on a temporary pole. A pipe connector, which is inserted in the top of pipe used in the temporary pole and supports the center purline, was designed and manufactured to be able to carry the upper loads safely. And a bearing plate was safely designed and manufactured in order to carry the loads acting on it to the ground. When temporary poles of ${\phi}$ 25 pipe are installed at 2.4m interval, it shows that the single span plastic greenhouses with 5~7 m width are able to support the additional snow depth of 13.9~25.3 cm beyond the snow load supported by main frame.