• Title/Summary/Keyword: Arch size

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A STUDY ON RELATONS BETWEEN FACIAL SKELETAL PATTERNS AND DENTAL OCCLUSION (안골격형과 교합과의 상호관계에 대한 연구)

  • Chang, Young-Il
    • The korean journal of orthodontics
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    • v.12 no.1
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    • pp.21-26
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    • 1982
  • This study was undertaken to document relations between facial skeletal pattern and dental occlusion. The data in .this study were collected from pretreatment cephalometric radiographs and study models of patients' records present in the files of Orthodontic Department, Seoul National University Hospital. Patients were selected on the basis of a mandibular plane-sella nasion angle equal to or greater than $38^{\circ}$ (high SN-MP angle) or equal to or less than $26^{\circ}$ (low SN-MP angle). Patients in the mixed dentition and with missing permanent teeth were excluded for ease of assessing tooth size / arch circumference relationships and then 30 high SN-MP and 11 low SN-MP patients were selected among them. The mean age of these two groups of patients was high SN-MP, $12.8{\pm}1.23$ years and low SN-MP, $13.0{\pm}1.48$ years. The following conclusions were obtained. 1. In the maxilla and mandible the mean tooth size of high SN-MP patients was nearlly identical to the low SN-MP patients. 2. The mean maxillary arch circumference was increased in low SN-MP group compared with high SN-MP group and a smilar, but smaller, mean increase was present in mandible. 3. The difference between the mean maxillary circumference required and the mean maillary circumference present ranged from -4.8mm in the high SN-MP group to -1.3mm in the low SN-MP group. A small range of means occurred in the mandible (high SN-MP: -4.0mm to low SN-MP: -1.8mm). 4. In the maxilla and mandible the mean arch length was nearly identical in the high and low SN-MP groups. 5. The mean incisor inclination was increased as the SN-MP angle decreased in the maxilla and mandible. 6. The men distance of the maxillary first molar from anterior border of the pterygomaxillary fissure was nearly similar between high and low groups. 7. The mean mandibular intermolar width was increased from high SN-MP to low SN-MP patients.

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A Study on the Cause and the Effect of the Widths of Sung-Rye-Mun Gate Arches (숭례문 홍예너비와 도로 폭 및 문루 어간(御間)거리의 상관성 연구 - 화성(華城) 팔달문(八達門), 흥인지문(興仁之門)과 비교를 통하여 -)

  • Ryoo, Seong-Lyong
    • Journal of architectural history
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    • v.19 no.2
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    • pp.117-132
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    • 2010
  • The Great south gate of Seoul Castle, Sung-Rye-Mun, the east gate of Seoul Castle, Hung-In-Ji-Mun, the south gate of Hwa-Sung Castle, Pal-Dal-Mun and the north gate of Hwa-Sung Castle, Jang-An-Mun are typical significant castle gate of Chosun Dynasty. They have a lot in common with exterior. Additionally there are also something common in dimensions. At first, the arch dimensions of lower story is very similar and the columns of upper story are the regular intervals. Purpose of this study is to confirm similarities above mentioned were intended on purpose and if then what was the reason. The results of this study were described separately as follows. 1. The widths of the arches were based on each 16Cheok and 18Cheok. 2. The heights of the arches followed less strictly rule than the widths. 3. The widths of the arches, 16Cheok was same size as width of middle-size road (中路, Jung-Ro) inside the Castle town in Chosun Dynasty. 4. The widths of the arches, 16Cheok was the standard size of exit went through castle and then the standard size of road arrived at one's destination. 5. The widths of the arches had an effect on the intervals between the columns of the upper story. Finally we recognized that in Chos${\u{o}}$n Dynasty the widths of the gate arches in Seoul castle and Hwa-Sung castle had relevance to the city planning largely and widths of the gate arches had an effect on the intervals between the columns of the upper story partly.

Analysis of Slender RC Short Beams(a/d<2.5) with Vertical Stirrups using Nonlinear FEM (비선형유한요소해석을 이용한 수직 스터럽이 있는 RC 짧은 보의 해석)

  • Jeong, Jae-Pyong;Kim, Dae-Joong;Kim, Woo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.05a
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    • pp.259-264
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    • 2002
  • This paper describes an attempt to develop a unified design approach for reinforced concrete short beam failing in shear based on a Arch Factor. Designing for short beam in shear is not as straightforward as designing for flexure due to the complicated interdependency of the variables involved and to the nonexistence of a rational theory tn current design code. Shear failure of reinforced concrete beams with stirrups is influenced greatly because of the actual geometrical shape(a/d) of the concrete and flexural reinforcement steel ratio, stirrup reinforcement ratio and concrete compression strength, size effect etc. The objective of this paper is to present a pilot study to develop a simplified physical model for estimating shear behavior of reinforced concrete short beams. The Key idea incorporated with this model is the Arch factor, introduced by Kim and White.

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Analytical model for flexural and shear strength of normal and high-strength concrete beams

  • Campione, Giuseppe
    • Structural Engineering and Mechanics
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    • v.78 no.2
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    • pp.199-207
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    • 2021
  • In the present paper, an analytical model is proposed to determine the flexural and shear strength of normal and high-strength reinforced concrete beams with longitudinal bars, in the presence of transverse stirrups. The model is based on evaluation of the resistance contribution due to beam and arch actions including interaction with stirrups. For the resistance contribution of the main bars in tension the residual bond adherence of steel bars, including the effect of stirrups and the crack spacing of R.C. beams, is considered. The compressive strength of the compressed arch is also verified by taking into account the biaxial state of stresses. The model was verified on the basis of experimental data available in the literature and it is able to include the following variables in the resistance provision: - geometrical percentage of steel bars; - depth-to-shear span ratio; - resistance of materials; - crack spacing; - tensile stress in main bars; - residual bond resistance including the presence of stirrups;- size effects. Finally, some of the more recent analytical expressions able to predict shear and flexural resistance of concrete beams are mentioned and a comparison is made with experimental data.

Surgical Treatment of Occluded Aberrant Left Subclavian Artery with Right-sided Aortic Arch -A case report- (우측 대동맥궁을 가진 환자에서 이상 기시된 좌쇄골하 동맥 폐색의 수술적 치료 - 1예 보고)

  • Cho Yang Hyun;Ryu Se Min;Kim Hyun Koo;Cho Jong Ho;Sohn Young-sang;Choi Young Ho;Kim Hark Jei
    • Journal of Chest Surgery
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    • v.38 no.3 s.248
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    • pp.241-244
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    • 2005
  • A 57-year-old man with numbness and paresthesia of left arm is presented. There was no pulse in the left arm was absent and his chest radiograph suggested right-sided aortic arch. The aortogram showed right-sided aortic arch with Kommerell's diverticulum. The proximal portion of left subclavian artery was totally occluded and blood was being supplied through vertebral arteries to distal subclavian artery. He underwent bypass grafting between both subclavian arteries by an expanded polytetrafluoroethylene graft. Because the size of Kommerell's diverticulum was small, it need to be observed closely.

A study of panoramic focal trough for the six-year-old child (6세 아동을 위한 파노라마방사선사진 상층의 연구)

  • Kim Sang-Yeon;Cho Hang-Moon;Han Jin-Woo;Lee Sul-Mi
    • Imaging Science in Dentistry
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    • v.34 no.2
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    • pp.63-67
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    • 2004
  • Purpose: To make a focal trough (image layer) for an average maxillary dental arch of 6-year-old korean in panoramic radiography. Materials and Methods : Phantom for the maxillary dental arch was designed using intercanine width, intermolar width, tooth size, and interdental spacing to record the data of 6-year-old child. The characteristics of pre-corrected panoramic machine (for adult) was evaluated using the phantom, resolution test pattern for margin of the image layer, and metal ball for the center of the image layer. Panoramic image layer of the child was developed by means of decreasing the speed of film-cassette and positioning the phantom backwards, and then the characteristics of post-corrected panoramic machine (for child) were reevaluated. Results: At post-corrected panoramic image layer, beam projection angles at all interdental areas increased for about 2.6-3.8°, the position of the image layer was shifted toward the rotation center for about 2.5 mm at the deciduous central incisior area. The width of image layer decreased at all areas. Conclusion : Increased beam projection angle will reduce the disadvantage of tooth overlap, and the same form between the center of the image layer and dental arch will improve image resolution.

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Effectiveness of Arch Support Taping is Subjects With Excessive Foot Pronation: A Meta-analysis

  • Park, So-yeon
    • Physical Therapy Korea
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    • v.26 no.4
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    • pp.70-76
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    • 2019
  • Background: An excessive pronated foot is defined as a flattening or complete loss of the medial longitudinal arch. Excessive foot pronation is considered to have high risk factors of overuse injuries in the lower limb. Various treatments have been investigated in attempts to control excessive pronation. Objects: This meta-analysis identifies the effects of an anti-pronation taping technique using different materials. Methods: The electronic databases used include MEDLINE, the Physiotherapy Evidence Database (PEDro), Science Direct, the Korean Studies Information Service System (KISS), the Research Information Sharing Service (RISS), the Korea National Library, and the Korean Medical Database (studies published up to July 31, 2019). The database search used the following keywords: "foot drop" OR "foot arch" OR "foot pronation" OR "flat foot (pes planus)" AND "taping" OR "support." Eight eligible studies were analyzed to determine the effectiveness of anti-pronation taping in study and control groups. Results: The overall random effect size (Hedges'g) of the anti-pronation taping technique was 0.147 (95% confidence interval [CI]: -.214 to .509). When the effect (Hedges' g) was compared by the type of tape material, rigid tape (RT; Lowdye taping) was .213 (95% CI: -.278 to .704) and kinesiotape (KT; arch support taping) was -.014 (95% CI: -.270 to .242). Based on this meta-analysis, it was not possible to identify the extent to which anti-pronation taping was effective in preventing navicular drop, improving balance, or changing foot pressure. Only three of the eight eligible studies applied KT on excessive pronated feet, and the outcome measure areas were different to those of the RT studies. The KT studies used EMG data, overall foot posture index (FPI) scores, and rear foot FPI scores. In contrast, the RT studies measured navicular heights, various foot angles, and foot pressure. Conclusion: This review could not find any conclusive evidence about the effectiveness of any taping method for patients with pronated feet. Future studies are needed to develop the anti-pronation taping technique based on the clinical scientific evidence.

Prediction of Shear Strength in High-Strength Concrete Beams without Web Reinforcement Considering Size Effect (크기효과를 고려한 복부보강이 없는 고강도 콘크리트 보의 전단강도 예측식의 제안)

  • Bae, Young-Hoon;Yoon, Young-Soo
    • Journal of the Korea Concrete Institute
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    • v.15 no.6
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    • pp.820-828
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    • 2003
  • Recent research has indicated that the current ACI shear provision provides unconservative predictions for large slender beams and beams with low level of longitudinal reinforcement, and conservative results for deep beams. To modify some problems of ACI shear provision, ultimate shear strength equation considering size effect and arch action to compute shear strength in high-strength concrete beams without stirrups is presented in this research. Three basic equations, namely size reduction factor, rho factor, and arch action factor, are derived from crack band model of fracture mechanics, analysis of previous some shear equations for longitudinal reinforcement ratio, and concrete strut described as linear prism in strut-tie model deep beams. Constants of basic equations are determined using statistical analysis of previous shear testing data. To verify proposed shear equation for each variable, effective depth, longitudinal reinforcement ratio, concrete compressive strength and shear span-to-depth ratio, about 300 experimental data are used and proposed shear equation is compared with ACI 318-99 code, CEB-FIP Model code, Kim &Park's equation and Zsutty's equation. The proposed shear equation is not only simpler than other shear equations, it is but also shown to be economical predictions and reasonable safety margin. Hence proposed shear strength equation is expected to be applied to practical shear design.

A STUDY OF DENTAL CROWDING AND ITS RELATIONSHIP TO MANDIBULAR INCISOR SHAPE BY MODEL ANALYSIS IN ADOLESCENTS (청소년 석고 모형 분석에 의한 하악절치 형태와 치아밀집의 상관관계에 관한 연구)

  • Surh, Jeong-Eun;Baik, Hyoung-Seon
    • The korean journal of orthodontics
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    • v.25 no.5 s.52
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    • pp.593-604
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    • 1995
  • Mandibular incisor crowding is one of the most common features of malocclusion and is interesting characteristic in view of relapse and stability after orthodontic treatment. There are many potential factors in the etiology of lower anterior crowding. The tooth size variation is one of them, but biologic significance for the faciolingual width of the teeth has been overlooked. Peck and Peck reported that persons with ideal mandibular incisor alignment were shown to have incisor with smaller mesiodistal and larger faciolingual dimensions than persons with incisor crowding. On the basis of these findings they suggested MD/FL index as a clinical guideline for the assessment for lower incisor crowding. The present study was undertaken to examine the relationship between mandibular incisor crowding and mandibular incisor dimension, and determine their correlation with arch length discrepancy. 154 dental casts of people from 11 to 17 years of age were made, and were divided into normal group with irregularity index less than of 1, and crowding group with irregularity index greater than 1.The casts were measured and analyzed statistically. The results were as follows. 1. The mean mesiodistal width for mandibular incisor was larger in crowding group, and has significant difference in central inciosr measurement. There are no significant differences in the faciolingul width and MD/FL index. 2. Irregularity index has significant correlation coefficients with mesiodistal width and MD/FL index for mandibular incisor in crowding group, but no correlation with faciolingual width. It also has correlation with maxillary and mandibular arch length discrepancy, total tooth material, mandibular intercanine width, and mandibular inter first premolar width. 3. Upper and lower arch length discrepancy have significant correlation with mesiodistal width of mandibular incisor and overbite, but have no correlation with faciolingual width. Lower arch lenth discrepancy has significant correlation with MD/FL index for mandibular incisor and upper arch length discrepancy has correlation with MD/FL index for mandibular lateral incisor. 4. Significant differences were observed between normal and crowding group for the mandibular arch length discrepancy and overbite.

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Analysis on the Heat Exchange Efficiency of Kraft Recovery Boiler by Nose Arch Structure Using CFD (CFD를 활용한 크래프트 회수보일러 내부 노즈 아치 구조에 따른 열교환 효율 분석)

  • Jang, Yongho;Park, Hyundo;Lim, Kyung pil;Park, Hansin;Kim, Junghwan;Cho, Hyungtae
    • Applied Chemistry for Engineering
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    • v.32 no.2
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    • pp.149-156
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    • 2021
  • A kraft recovery boiler produces steam for power generation by the combustion of black liquor from the kraft pulping process. Since saturated steam became superheated in a superheater above the furnace, it is important to increase the heat exchange efficiency for the superheated steam production and power generation. A nose arch at the bottom of the superheater is important for blocking radiation from the furnace which causes corrosion of the superheater. But the nose arch is the main reason for creating a recirculation region and then decreasing the heat exchange efficiency by holding cold flue gas after the heat transfer to saturated steam. In this study, the size of recirculation region and the temperature of flue gas at the outlet were analyzed by the nose arch structure using computational fluid dynamics (CFD). As a result, when the nose arch angle changed from 106.5° (case 1) to 150° (case4), the recirculation region of flue gas decreased and the heat exchange efficiency between the flue gas and the steam increased by 10.3%.