• Title/Summary/Keyword: Horseshoe

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Improvement of the Flow Characteristics by Optimizing the Leading-Edge Shape Around Airfoil/Flat-Plate Junction (날개-평판 접합부에서의 날개 앞전 형상 최적화를 통한 유동특성 향상)

  • Cho, Jong-Jae;Kim, Kui-Soon
    • Journal of the Korean Society of Propulsion Engineers
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    • v.13 no.6
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    • pp.24-33
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    • 2009
  • The present study deals with the optimization of the leading edge shape around a wing-body junction to minimize the strength of the horseshoe vortex, which is one of the main factor generating the secondary flow losses. For this purpose, approximate optimization method is used for the optimization. The study is performed by using $FLUENT^{TM}$ and $iSIGHT^{TM}$. The total pressure coefficient for the optimized model was decreased about 9.79% compared with the baseline model.

Ca2+ Uptake of the Sarcoplasmic Reticulum-Microsome of Fine Structure Pectoralis Major Muscle in the rabbit and the Korean Greater Horseshoe Bat* (토끼와 한국관박쥐 대흉근의 근소포체 마이크로솜의 Calcium Uptake에 관한 연구)

  • 오영근;양원석
    • The Korean Journal of Zoology
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    • v.38 no.1
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    • pp.10-19
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    • 1995
  • 동면동물인 한국관박쥐(Korean greater horseshoe bat)와 비롱면 롱물인 토끼의 근소포체가 지니는 생리 및 근조직의 형태적 특징을 비교해 보고자 본 실험을 수행하여 다음과 같은 결론을 내렸다 Caffeine과 Mgcl2는 농도별로 처리하고, p연와 온도에 변화를 주는 등 각각의 생리조건하에서 한국관박쥐와 토끼 대흉근 근소포체 마이크로솜의 C32' 흡수정도가 다르게 나타났으며, Ca2'ATPase 활성 역시 상이함을 보였는데. 이로 미루어 보아 in vivo 상태에서 두 동물의 근소포체가 지니는 생리적 특성에 차이가 있을 것으로 추측된다. 형태학적 측면에서도 근심유의 수기와 미토콘드리아의 크기에 있어서 뚜렷한 차이를 발견할 수 있었는데. 이는 두 동물의 대흉근이 수행하는 운동의 종류와 관련이 있을 것으로 생각된다.

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Heat Flow Characteristics by Sectional Shapes in Underground Electric Power Tunnel (지하 전력구 단면 형상에 따른 터널내 열유동 특성)

  • Baek, Doo-San;Lee, Seung-Chul;Kwak, Dong-Kurl
    • Proceedings of the KIPE Conference
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    • 2015.07a
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    • pp.13-14
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    • 2015
  • This study has conducted a computational analysis to find out about characteristics of heat flow emitted from power lines when the sectional form of electric power tunnel that adopts forced ventilation is shaped like a rectangular, arch or horseshoe. The result of analysis shows that the temperature in the vicinity of the power line peaked at $70^{\circ}C$ when the sectional form is a rectangular, which indicates it is less affected by ventilation than the form of an arch or horseshoe.

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Bilateral Intralobar Pulmonary Sequestration with Horseshoe Lung A near suggestion about the treatment of pulmonary sequestration (마제상폐를 보이는 양측성 엽내형 폐격리증의 외과적 치료 -폐격리증치료에 대한 새로운 제안-)

  • 박종빈;김용희
    • Journal of Chest Surgery
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    • v.30 no.2
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    • pp.226-230
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    • 1997
  • This is a case report of surgical management of a bilateral intralobar pulmonary sequestration with horseshoe lung presenting with frequent U I with productive sputum. Simple chest X-ray showed pneumonic consolidation and infiltration on both lower lobes, and chest CT revealed multiple cystic lesions compatible with pulmonary sequestration. The aortography demonstrated two anomalous systemic arteries arising from the thoracic aorta just above the diaphragm to both sequestrums. Left lower lobectomy was performed through the left thoracotomy with ligations and divisions of the both systemic feeding arteries to the left and right sequestrum, and division of the isthmic portion of horseshoe lung without removal of right sequestrum. The patient was discharged on the postoperative loth day and followed-up till now without any sequelae and symptoms of residual right sequestration. The recent follow-up chest CT 5 months after the operation revealed spontaneous regression of the residual right sequestrum. Authors would suggested that only division of aberrant artery to sequestrum without lobectomy may be applied in uncomplicated ca e of intrapulmonary seqilestration.

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Evaluation of Ultimate Strength of Shear Connection in Steel Embedded Composite Girders (강재매입형 합성거더 전단연결부의 극한강도 평가)

  • Sim, Chang Su;Kim, Hyeon Ho;Han, Jeong Hoon;Lee, Pil Goo
    • Journal of Korean Society of Steel Construction
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    • v.18 no.4
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    • pp.405-416
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    • 2006
  • In composite girders with steel embedded in concrete as preflex beams, horseshoe connectors and bar connectors are commonly used to achieve composite action. Considering the requirements on the concrete cover in the thin concrete part surrounding a steel member, it has limitations with respect to the use of stud shear connectors, and significant bond and friction resistance can be generated. High horizontal shear strength between the casing concrete and the steel section is needed to introduce prestress to the concrete section in the form of preflex beams.In this paper, experiments on the evaluation of the static strength of horseshoe connectors and bar connectors were conducted and the effects of bonds were also considered. Based on the test results, current design codes were estimated and more general design guidelines that consider the design concept of Eurocode were proposed for the connectors. A strength evaluation according to failure and compared with the test results.

A comparison study of Bayesian high-dimensional linear regression models (베이지안 고차원 선형 회귀분석에서의 비교연구)

  • Shin, Ju-Won;Lee, Kyoungjae
    • The Korean Journal of Applied Statistics
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    • v.34 no.3
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    • pp.491-505
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    • 2021
  • We consider linear regression models in high-dimensional settings (p ≫ n) and compare various classes of priors. The spike and slab prior is one of the most widely used priors for Bayesian regression models, but its model space is vast, resulting in a bad performance in finite samples. As an alternative, various continuous shrinkage priors, including the horseshoe prior and its variants, have been proposed. Although each of the above priors has been investigated separately, exhaustive comparative studies of their performance have been conducted very rarely. In this study, we compare the spike and slab prior, the horseshoe prior and its variants in various simulation settings. The performance of each method is demonstrated in terms of the regression coefficient estimation and variable selection. Finally, some remarks and suggestions are given based on comprehensive simulation studies.

Free Vibrations of Horseshoe Symmetric Elliptic Arch: Using Boundary Conditions of Stress Resultants at Mid-Arc Revisited (마제형 대칭 타원 아치의 자유진동: 아치 정점의 합응력 경계조건 이용 재고(再考))

  • Lee, Byoung Koo;Lee, Tae Eun;Kim, Gweon Sik;Oh, Sang Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.3
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    • pp.191-200
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    • 2021
  • This paper deals with the boundary conditions of the stress resultants at the mid-arc for free vibration analyses of the arch. The considered arch is a horseshoe symmetric elliptic arch. The work dealing with the boundary conditions of the deflection at both ends of the arch has already been reported in the open literature. This revisited paper aims to study the suitability of the boundary conditions of the stress resultants at the mid-arc to be replaced by the boundary condition at both ends. In this study, the boundary conditions of the stress resultants at the mid-arc are newly derived based on the theory of the previous work, and natural frequencies and mode shapes are obtained using the new boundary conditions of the stress resultants. The numerical results of this paper confirm that the new boundary conditions have been validated according to previous studies and results of finite element ADINA.

Comparison of the acoustical performance of auditoria by shapes using acoustic simulation and listening tests (시뮬레이션과 청감실험을 통한 공연장 형태별 음향성능 비교분석)

  • Chanwoo Kang;Chan-Hoon Haan
    • The Journal of the Acoustical Society of Korea
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    • v.42 no.3
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    • pp.189-202
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    • 2023
  • In this study, the acoustic performance was analyzed by architectural shapes of the hall. There are four architectural shapes of halls. They are rectangular, horseshoe, surround, and fan-shape. Eight acoustic parameters were used to determine the acoustic performance. These are RT60, EDT, C80, BQI, LF, Gmid, G125 and ITDG. First, measurement data of famous concert halls around the world were analyzed. The correlation coefficient R was obtained by regression analysis of the relationship between the subjective ranking of the halls and the acoustic parameters. It was found that BQI, G, and ITDG have higher correlation coefficients R. Also the average of acoustic parameters for each architectural shape were obtained. The total acoustic performance for each shape was calculated by using the correlation coefficient R as a weight for each acoustic parameters. As a result, rectangular halls and horseshoe halls showed good acoustical performances. Second, 3D models of each architectural shape were created and acoustic simulation had been performed. The simulation was performed by creating 3D models of each four shapes of concert halls with the same volume and sound absorption coefficient. Listening test was carried out using the sound source which is created from impulse responses of 3D model. As a result, rectangular hall and horseshoe hall showed the best performance however surround hall and fan-shaped hall showed relatively poor performance.