• Title/Summary/Keyword: exterior mechanism

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Interaction of internal forces of exterior beam-column joints of reinforced concrete frames under seismic action

  • Zhou, Hua;Zhang, Zhisheng
    • Structural Engineering and Mechanics
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    • v.44 no.2
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    • pp.197-217
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    • 2012
  • Detailed analysis of internal forces of exterior beam-column joints of RC frames under seismic action is reported in this paper. A formula is derived for calculating the average joint shear from the column shears, and a formula is proposed to estimate torque in eccentric joints induced by seismic action. Average joint shear stress and strain are defined consistently for exterior joints, which can be used to establish joint shear constitutive relationship. Numerical results of shear, bending moment and torque in joints induced by seismic action are presented for a pair of concentric and eccentric exterior connections extracted from a seismically designed RC frame, and two sections located at the levels of beam bottom and top reinforcement, respectively, are identified as the critical joint sections for evaluating seismic joint behavior. A simplified analysis of the effects of joint shear and torque on the flexural strengths of the critical joint sections is made for the two connections extracted from the frame, and the results indicate that joint shear and torque induced by a strong earthquake may lead to "joint-hinging" mechanism of seismically designed RC frames.

Numerical analysis on curtain cooling in Liquid Rocket Engine of 10tf-thrust Level using Kerosene as a Fuel (케로신을 연료로 하는 10톤급 액체로켓엔진의 막 냉각에 관한 해석적 연구)

  • 남궁혁준;한풍규;조원국
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2003.10a
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    • pp.78-82
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    • 2003
  • The cooling mechanism for a regenerative cooling liquid rocket engine of 10tf-thrust using kerosene as a fuel was studied from the viewpoint of curtain cooling. Based on the concept of a highly-stratified gas flow in the combustion chamber, the cross section of the combustion chamber was spilt into 2 independent parts, core and exterior part. Additional fuel is injected into the exterior section and gas temperature can be reduced in the exterior section. Consequently, the heat flux into the coolant and wall temperature are reduced and the thermal stability of a liquid rocket engine could be improved.

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A Study on the importance of makwon(膜原) in seupyeoljeung(濕熱證) - Based on the Seupyeoljobyeon(濕熱條辨) - (습열증(濕熱證)에서 막원(膜原)의 중요성(重要性)에 대한 고찰(考察) - "습열조변(濕熱條辨)"을 중심으로 -)

  • Kim, Sang-Hyun;Baik, You-Sang;Jeong, Chang-Hyun;Jang, Woo-Chang
    • Journal of Korean Medical classics
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    • v.25 no.4
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    • pp.85-94
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    • 2012
  • The concept of makwon(膜原) holds great importance in the texts of Seup-yeoljobyeon(濕熱條辨). Research on the concept was based on Seolsaengbaek(薛生白)'s medical theories organized by Wang Maengyeong(王孟英). The results are as follows. Seolsaengbaek describes makwon as half-exterior half-interior(半表半裏) of yang-myeong(陽明) and half-exterior half-interior of the body. The half-exterior half-interior in these definitions each hold a different meaning. In half-exterior half-interior of yang-myeong, it refers to its mediating function, focusing on the location of makwon as yang-myeong. In half-exterior half-interior of the body, it refers to an intersection where the pathological mechanism of damp-heat disease(seup-yeoljeung 濕熱證) begins, and also where the course of the disease changes. This is why treatment of the makwon is included in treating many damp-heat disease symptoms. The conditions derived from the original damp-heat disease can follow the designated prognosis, or follow a reversed course. Because of its intersecting role, treating the makwon can help prevent aggravation. In treatment, consideration of the healthygi(jeonggi 正氣), the bodily fluids(jinaek 津液) with an understanding of the various prognosis is crucial.

Seismic Experiment of Precast Concrete Exterior Beam-Column Joint Using Bolt Type Connection and Prestressing Method (볼트 접합 및 프리스트레스를 적용한 프리캐스트 콘크리트 보-기둥 외부접합부의 내진실험)

  • Lee, Dong-Joo;Lee, Ju-Dong;Oh, Tae-Soo;Kang, Thomas H.K.
    • Journal of the Korea Concrete Institute
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    • v.26 no.2
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    • pp.125-133
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    • 2014
  • In this study, experimental research was carried out to investigate the seismic and structural performance of precast concrete exterior beam-column joints using bolt type connection and prestressing method. A total of five full-scale exterior beam-column joints were constructed and tested under reversed cyclic loading, controlled by displacement. Results of the test are as follows: Energy dissipation capacity and pinching phenomenon of PC beam-column joints showed disadvantageous behavior compared to RC beam-column joints. However, drift capacity of the PC joint was excellent. Also, yield mechanism concentrated on embedded nuts was suitable as an exterior beam-column joint of lateral load resistance frame. Additional application of prestressing method was also very effective to control excessive pinching and cracking in the joint region, and thus improved an overall seismic performance of the PC joint.

An Investigation on the Existing Literature to Prevent Fire Spread of High-rise Buildings (고층 건축물의 화재확대방지를 위한 기존 문헌 조사)

  • Lee, Byeong-Heun;Kwon, Young-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.102-103
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    • 2021
  • In Korea, starting with the Busan residential-commercial fire in 2010, the frequency of fire expansion in high-rise buildings has been continuously increasing. In the case of such large-scale fires, most of the fires generated from the inside tend to expand to the upper floors by riding the exterior material or exterior wall panels through the process of being ejected to the outside. It has been revised so that combustible exterior materials cannot be used in buildings. However, due to the legal fluoride level, the fire risk of high-rise buildings is still high, such as the case of a 33-story residential-commercial fire in Ulsan. In order to prevent such fire expansion, it is considered that it is necessary to first understand the nature of the fire occurring inside and the mechanism of the fire expansion in the upper floor. The purpose of this study is to propose improvements in domestic fire safety design through a review of existing literature to prevent fire expansion of high-rise buildings.

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Influence of Joint on Retrofitting Effect by Exterior Steel Frames of Existing RC Buildings (외부접합공법의 내진보강효과에 미치는 접합부의 영향)

  • Ahn, Choong Weon;Min, Chan Gi;Noh, Eun Choul;Han, Hong Soo;Kim, Tae Wan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.19 no.4
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    • pp.183-194
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    • 2015
  • In this paper, Nonlinear Static Pushover analysis method(NSP) is proposed which apply to RC buildings reinforced by external retrofit for seismic performance. Based on previous analysis and research, NSP is more developed by connection nonlinearity according to shear resistance mechanism such as dowel and adhesive resistance as major shear resistance elements. According to the proposed method, structural analysis for example buildings was carried out to evaluate seismic performance of buildings. And, it was confirmed that depending on shear strain and characteristics of joint resistant of external retrofitting are different from internal retrofitting. Furthermore, the strength reduction coefficient of the anchor needs to be considered at the joint design.

A Study on The Disease Mechanism and Treatment of The So-eumin Exterior Disease of "Dong-uisusebowon(東醫壽世保元)" -On Ikgi(益氣) and Seung-yang(升陽)- ("동의수세보원(東醫壽世保元)" 소음인(少陰人) 표병(表病)의 병기(病機) 및 치법(治法)에 대한 고찰(考察) - 익기(益氣)와 승양(升陽)을 중심으로 -)

  • Park, Su-Hyun;Jeong, Chang-Hyun;Jang, Woo-Chang
    • Journal of Korean Medical classics
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    • v.23 no.2
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    • pp.235-270
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    • 2010
  • This paper studies the main treatment methods, Ikgi(益氣) and Seung-yang(升陽) applied frequently by Lee Jema(李濟馬) on the exterior disease of So-eumin(少陰人), one of the four constitutions. The methodology of this paper is to understand the pharmacology of "Dong-uisusebowon(東醫壽世保元)" by examining the formulas applied by Lee Jema. I have examined the organization of formulas in "Dong-uisusebowon(東醫壽世保元)" beforehand to categorize the formulas applicable in this study according to an objective standard. I have analyzed the prescriptions applied to So-eumin exterior disease. As a result, I could see that in the case of Ulgwang(鬱狂) syndrome, Ikgi(益氣) and Seung-yang(升陽) methods were mainly applied, but as the disease progressed, Seung-yang(升陽) was withdrawn while Ikgi(益氣) was stressed. Likewise, in the case of Mang-yang(亡陽), both methods were mainly adopted, but as the patients got worse, the level of Seung-yang(升陽) was maintained and that of Ikgi(益氣) was elevated with the addition of Buja(附子). Through this process, we could verify the overall action of Ikgi(益氣), Seung-yang(升陽) and Buja(附子). Originally, the two methods of Ikgi(益氣) and Seung-yang(升陽) are intimately related, but by analyzing the overall functions of the two methods, we could see that Seung-yang(升陽) and Buja(附子) support the Yang gi of the interior of So-eumin, while Ikgi(益氣) resolves inner stagnation of Yang gi and emits the cold pathogen of the exterior. Also, in the course of treatment, Ikgi(益氣) could only be realized after securing Seung-yang(升陽).

A Study on the Development of Diagnostic Index for the Ordinary Symptom of Soyangin (소양인 소증 진단평가지표 개발 연구)

  • Cho, Young;Lee, Jun-Hee
    • Journal of Sasang Constitutional Medicine
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    • v.32 no.4
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    • pp.45-64
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    • 2020
  • Purpose This study was to develop and study 'Diagnostic Index for the Ordinary Symptom of Soyangin'. Methods The main diagnosis and evaluation index symptoms of Soyangin were extracted based on 『Donguisusebowon』 and Clinical Practice Guidelines for Sasang Constitutional Medicine Symptomatology; CPG for soyangin. The selected ordinary symptoms were divided into 4 categories such as Exterior-Cold ordinary symptom (表寒素證), Exterior-Disease unfavorable's ordinary symptom (表病逆證素證), Interior-Heat ordinary symptom (裏熱素證), Interior-Disease unfavorable's ordinary symptom (裏病逆證素證) of Soyangin and translated into Korean. And the inclusion, importance and translation validity of major diagnosis and assessment indicators of Soyangin were surveyed online by a group of Sasang constitutional experts. Results & Conclusions 29 ordinary symptoms and pathological mechanism were selected from references and translated into 51 Korean symptoms. After inclusion yes or no survey by expert group, 45 symptoms were selected. The importance survey showed that 'Have a soft stool' of Exterior-Cold ordinary symptom indication, '(If you're stressed, if you're not in good health) Have a soft stool or diarrhea' of Exterior-Disease unfavorable's ordinary symptom, 'The feces harden easily' of Interior-Heat ordinary symptom and '(If you're stressed, if you're not in good health) Have an upset stomach' of Interior-Disease unfavorable's ordinary symptom were the most important. Finally, [Diagnostic Index for the Ordinary Symptom of Soyangin] was completed after survey of translation validity, reflection of individual opinions by the expert committee, and application of weighted value calculated from the importance survey.

Tentative Analysis on the Reasons of China's Lags in Neoteric Mathematics

  • Zhang, Xiong
    • Research in Mathematical Education
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    • v.12 no.2
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    • pp.143-149
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    • 2008
  • Before the 14th century, China had been thought as one of the countries with the most developed mathematics all along. But after the 16th century, Chinese mathematics increasingly walked up to the eclipse. The main reasons include the following points. First, the development of neoteric mathematics was closely associated with the social industrialization, but the lags in feudal China seriously blocked the development of the capitalistic seed, and China was still in the agricultural society then and couldn't step into the industrial society, which impeded the development of mathematics concerned with the industry and commerce. Second. the increasingly carrion feudalization was one of the essential reasons to block the development of Chinese neoteric mathematics. Finally, seeing about the developing logics of Chinese neoteric mathematics, we can find it was a scattered and experiential mathematical knowledge without strict and rational self-organizing structure system, which had the limitations existing in its interior mechanism.

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Literatural study of the cause and mechanism of Eye Disease (眼病의 病因 病機에 對한 文獻的 考察)

  • Gang, Seung-Won;No, Seok-Seon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.5 no.1
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    • pp.27-44
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    • 1992
  • The cause and mechanism of eye diseases are follow in biblography. The etiological factor of eye diseases are nearly caused by heat. It is important to distinguish deficiency and substance. In external etiologic factors wind-fever is most of all in six exogenous factors. In internal etiologic factors xu(deficiency) of kidney, blood and fire of seven emotions are lots. In factors other than the internal and external, eating greasy food and hyper-caloric food are a lot of case. In relation with the yin-yang andxu-shi, ther are a lot of eye diseases symptom as dark-dizziness due to the yin-xu of hepatic-kidney. According to eight principles of differentiation of syndromes, syndromes of exterior, heat, shi, almost fall into the category of yang and syndromes of interior, cold, xu, nearly fall into the category of yin. In interior treatment, inducing wind and clearing heat, using Qi and tonifying blood, tonifying and suing of hepatic-kid ney are useful and often used treatment.

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