• 대한치과의사협회지
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• 제13권1호
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• pp.33-36
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• 1975

To determine the dental arch length and width in Korean yaung adults, various points (shown on Fig 1) were measured by means of Boley gauge on the 124 plaster models which obtained from 2 young men. The measurements value were as follows: A : 36.10㎜ a : 25.53㎜ B : 33.35㎜ b : 28.20㎜ C : 39.80㎜ c : 33.07㎜ D : 43.36㎜ d : 36.36㎜ E : 44.80㎜ e : 39.12㎜ F : 49.11㎜ f : 42.48㎜ G : 59.98㎜ g : 44.92㎜ H : 62.22㎜ h : 57.85㎜ I : 52.66㎜ i : 49.91㎜

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제49권6호
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• pp.332-338
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• 2023

Objectives: This study aimed to compare the effectiveness of a hybrid arch bar (hAB) with the conventional Erich arch bar (EAB) for the management of jaw fractures, focusing on their use for temporary fixation in patients undergoing open reduction and internal fixation (ORIF). Materials and Methods: Patients presenting with maxillary and mandibular fractures at our institution were included in this prospective, comparative study. Placement time and ease of occlusal reproducibility were recorded intraoperatively for Group A (hAB patients) and Group B (EAB patients). The primary outcome was comparison of the postoperative stability of the two arch bars. Postoperative measurements also included mucosal overgrowth, screw loosening or wire retightening, and replacement rates. The data were tabulated and computed with a P<0.05 considered statistically significant. Results: The study included 41 patients. A statistically significant difference was observed in postoperative stability scores (3) between Group A and Group B (85.0% vs 9.5%, P=0.001). The mean placement time in Group A (23.3 minutes) significantly differed from that in Group B (86.4 minutes) (P<0.001). The ease of intraoperative occlusion was not different between the two groups (P=0.413). Mucosal overgrowth was observed in 75.0% of patients (15 of 20) in Group A. Conclusion: The hAB was superior to EAB in clinical efficiency, maxillomandibular fixation time reduction, stability, versatility, and safety. Despite temporary mucosal overgrowth, the benefits of hAB outweigh the disadvantages. The choice between hAB and EAB should be based on specific clinical requirements.

• Computers and Concrete
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• 제22권1호
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• pp.101-116
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• 2018

As one of the most important engineering structures, arch dams are huge constructions built with human hands and have strategical importance. Because of the fact that long construction duration, water supply, financial reasons, major loss of life and material since failure etc., the design of arch dams is very important problem and should be done by expert engineers to determine the structural behavior more accurately. Finite element analyses and non-destructive experimental measurements can be used to investigate the structural response, but there are some difficulties such as spending a long time while modelling, analysis and in-situ testing. Therefore, it is more useful to conduct the research on the laboratory conditions and to transform the obtained results into real constructions. Within the scope of this study, it is aimed to determine the structural behavior of arch dams considering experimentally validated prototype laboratory model using similitude and scaling laws. Type-1 arch dam, which is one of five arch dam types suggested at the "Arch Dams" Symposium in England in 1968 is selected as reference prototype model. The dam is built considering dam-reservoir-foundation interaction and ambient vibration tests are performed to validate the finite element results such as dynamic characteristics, displacements, principal stresses and strains. These results are considered as reference parameters and used to determine the real arch dam response with different scales factors such as 335, 400, 416.67 and 450. These values are selected by considering previously examined dam projects. Arch heights are calculated as 201 m, 240 m, 250 m and 270 m, respectively. The structural response is investigated between the model and prototype by using similarity requirements, field equations, scaling laws etc. To validate these results, finite element models are enlarged in the same scales and analyses are repeated to obtain the dynamic characteristics, displacements, principal stresses and strains. At the end of the study, it is seen that there is a good agreement between all results obtained by similarity requirements with scaling laws and enlarged finite element models.

• Journal of Korean Neurosurgical Society
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• 제58권6호
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• pp.528-533
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• 2015

Objective : We sought to examine anatomic variations of the atlas and the clinical significance of these variations. Methods : We retrospectively reviewed 1029 cervical 3-dimensional (3D) CT images. Cervical 3D CT was performed between November 2011 and August 2014. Arcuate foramina were classified as partial or complete and left and/or right. Occipitalization of the atlas was classified in accordance with criteria specified by Mudaliar et al. Posterior arch defects of the atlas were classified in accordance with criteria specified by Currarino et al. Results : One hundred and eight vertebrae (108/1029, 10.5%) showed an arcuate foramen. Bilateral arcuate foramina were present in 41 of these vertebrae and the remaining 67 arcuate foramina were unilateral (right 31, left 36). Right-side arcuate foramina were partial on 18 sides and complete on 54 sides. Left-side arcuate foramina were partial on 24 sides and complete on 53 sides. One case of atlas assimilation was found. Twelve patients (12/1029, 1.17%) had a defect of the atlantal posterior arch. Nine of these patients (9/1029, 0.87%) had a type A posterior arch defect. We also identified one type B, one type D, and one type E defect. Conclusion : Preoperative diagnosis of occipitalization of the atlas and arcuate foramina using 3D CT is of paramount importance in avoiding neurovascular injury during surgery. It is important to be aware of posterior arch defects of the atlas because they may be misdiagnosed as a fracture.

• Journal of Chest Surgery
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• 제30권1호
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• pp.83-87
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• 1997

Tausslg-Bing 기형은 드물게 대동맥궁 중단과 병발되며, 이 경우 양대혈관의 크기 가 현저히 달라 대동맥 전환술을 시행함에 어려움이 있다. 생후 20일 된 환아가 상기 진단으로 내원하여, 다장기부전에 대한 3주간의 집중관리 후 수술을 받았다. 수술은 심실중격 결손의 복원, 대동맥 전환술 및 광범위한 대동맥궁형성술로 이루어졌으며, 대혈관들의 크기 차이는 상행 및 하행 대동맥의 절편을 이용하여 원위신대동맥(distal neoaorta)를 형성하므로써 극복하였다. 환아는 큰 문제 없이 회복하였으며, 수술후 시행한 심도자상의 결과도 양호한 상태로 16개월간 추적 관찰중이다.

• Steel and Composite Structures
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• 제25권2호
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• pp.231-244
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• 2017

This paper presents the structural identification of an arch dam model for the damaged, repaired and strengthened conditions under different water levels. For this aim, an arch dam-reservoir-foundation model has been constructed. Ambient vibration tests have been performed on the damaged, repaired and strengthened dam models for the empty reservoir (0 cm), 10 cm, 20 cm, 30 cm, 40 cm, 50 cm and full reservoir (60 cm) water levels to illustrate the effects of water levels on the dynamics characteristics. Enhanced Frequency Domain Decomposition Method in the frequency domain has been used to extract the dynamic characteristics. The dynamic characteristics obtained from the damaged, repaired and strengthened dam models show that the natural frequencies and damping ratios are considerably affected from the varying water level. The maximum differences between the frequencies for the empty and full reservoir are obtained as 16%, 33%, and 25% for damaged, repaired and strengthened model respectively. Mode shapes obtained from the all models are not affected by the increasing water level. Also, after the repairing and strengthening implementations, the natural frequencies of the arch dam model increase significantly. After strengthening, between 46-92% and 43-62% recovery in the frequencies are calculated for empty and full reservoir respectively. Apparently, after strengthening implementation, the mode shapes obtained are more acceptable and distinctive compared to those for the damaged model.

• 대한치과교정학회지
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• 제32권2호통권91호
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• pp.117-127
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• 2002

본 연구는 전후방적인 부조화가 폭경에 영향을 미치는지 알기 위해 I급 정상교합군과 III급 부정교합군을 비교하였고, III급 부정교합군내에서 수직적인 부조화가 폭경에 영향을 미치는지 알기 위해 Hyperdivergent군과 Neutral군으로 나누어 폭경의 차이를 비교하였다. 부산대학교병원 치과교정과에 내원한 골격성 III급(ANB< 0$^{\circ}$) 부정교합자 중측모 두부방사선 계측사진상에서 하악 평면각(SN-Mandibular plane; 정상인의 평균 32 ${\pm}$ 5$^{\circ}$)이 1.5 SD이상(39.5$^{\circ}$이상)인 환자 37명 (남자 18명, 여자 19명 )을 hyperdivergent군(Group B)으로, 하악 평면각이 정상치의 0.5 SD이내인(32 ${\pm}$ 2.5$^{\circ}$) 40명 (남자 20명, 여자 20명)을 neutral군(Group C)으로 분류하였고 11개의 치과대학 교정과에서 선별한 정상교합과 정상적인 안모를 가진 성인 24) 중 41명(남자 20명, 여자 21명)을 정상교합군(Group A)으로 하여 이 세 군을 대상으로 연구하여 다음과 같은 결론을 얻었다. 1. 골격성 III급 부정교합군내에서 수직적인 양상에 따른 폭경 비율은 유의할 만한 차이가 없었다. 2. 정상교합군과 III급 부정교합군의 상, 하악 기저골에 대한 치아간 폭경 비율의 비교에서 상악에서는 III급 부정교합군의 비율이 더 컸고(p<0.001), 하악에서는 제 1대구치 부분을 제외한 모든 항목에서 III급 부정교합군의 비율이 작아서(p<0.001) III급 부정교합군이 정상교합군에 비해 기저골에 대해 상악 치아가 더 협측으로 경사되고, 제1대구치를 제외하고 기저골에 대해 하악 치아가 설측 경사되어 횡적인 치성보상이 잘 되어 있는 것으로 나타났다(p<0.001). 3. 정상교합군과 III급 부정교합군의 상악에 대한 하악의 치아간 폭경 비율의 비교에서 모든 부분에서 유의할 만한 차이가 없었다. 4. 정상교합군과 III급 부정교합군의 상악에 대한 하악의 기저골 폭경 비율의 비교에서 모든 부위에서 III급 부정교합군이 정상교합군보다 더 커서(p<0.0001) III급 부정교합군의 상악 기저골 폭경이 하악보다 더 좁게 나타났다.

• 한국운동역학회지
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• 제25권4호
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• pp.489-498
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• 2015

Objective : The purpose of this study was to analyze the effects of the windlass mechanism in trail-walking shoe prototypes that can effectively support arches. A study of these effects should help with the development of a first-rate trail-walking shoe development guide for the distribution of quality information to consumers. Methods : The subjects were ten adult males who volunteered to participate in the study. Shoes from three companies, which will be referred to as Company S (Type A), Company M (Type B), and Company P (Type C), were selected for the experiment. The subjects wore these shoes and walked at a speed of 4.2 km/h, and as they tested each shoe, the contact area, maximum pressure average, and surface force were all measured. Results : Shoe Type A showed a contact area of $148.78{\pm}4.31cm^2$, Type B showed an area of $145.74{\pm}4.1cm^2$, and Type C showed an area of $143.37{\pm}4.57cm^2$ (p<.01). Shoe Type A demonstrated a maximum average pressure of $80.80{\pm}9.92kPa$, Type B an average of $85.72{\pm}11.01kPa$, and Type C an average of $89.12{\pm}10.88bkPa$ (p<.05). Shoe Type A showed a ground reaction force of $1.13{\pm}0.06%BW$, Type B a force of $1.16{\pm}0.04%BW$, and Type C a force of $1.16{\pm}0.03%BW$ (p<.05). Conclusion : The Type A trail-walking shoe, which was designed with a wide arch from the center of the forefoot to the front of the rearfoot showed excellent performance, however, more development and analysis of the windlass mechanism for a variety of arch structures is still necessary.

• 산업기술연구
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• 제22권B호
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• pp.199-209
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• 2002

This research is experimental thesis to prepare the structural safety of the upper bridge for support type on tunnel and the effect of settlement. Unit weight test and uni-axial compression test have been performed to simulate the physical property of foundation on the tunnel. Tunnel model of slip form type for centrifuge model has been developed to performed the tunnel excavation while field stress is activated. And the support type of tunnel such as umbrella arch method and large diameter steel pipe reinforce method has been tested for the centrifuge model. After the analysis of experiment, results show that internal displacement of large diameter steel pipe reinforce method is smaller than that of the umbrella arch method.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.223-226
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• 2007

In current specification, modification factor(B) for web-tapered beam is used to account for the stress gradient and the restraining effect for adjacent spans. However, because these effects are considered together in modification factor, this paper revaluate the accuracy of the modification factor used in current specification. Also this paper investigate the flexural torsional buckling strength of laterally fixed thin-walled arch with doubly symmetric section using the analytical and numerical method. From this investigate the concept of effective length to consider the out-of-plane boundary condition for straight column or beam is not applicate for the flexural-torsional buckling of laterally fixed arches.