• 제목/요약/키워드: Bar structure

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Effect of anchorage and strength of stirrups on shear behavior of high-strength concrete beams

  • Yang, Jun-Mo;Min, Kyung-Hwan;Yoon, Young-Soo
    • Structural Engineering and Mechanics
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    • 제41권3호
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    • pp.407-420
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    • 2012
  • This study investigated possible ways to replace conventional stirrups used on high-strength concrete members with improved reinforcing materials. Headed bar and high-strength steel were chosen to substitute for conventional stirrups, and an experimental comparison between the shear behavior of high-strength concrete large beams reinforced with conventional stirrups and the chosen stirrup substitutes was made. Test results indicated that the headed bar and the high-strength steel led to a significant reserve of shear strength and a good redistribution of shear between stirrups after shear cracking. This is due to the headed bar providing excellent end anchorage and the high-strength steel successfully resisting higher and sudden shear transmission from the concrete to the shear reinforcement. Experimental results presented in this paper were also compared with various prediction models for shear strength of concrete members.

불교의식무용 챰의 제의적 연행 관념과 구조 -헤미스 쩨츄 챰을 중심으로- (The Ritualistic Concept and Structure of Cham in Hemis Tsechu)

  • 허동성
    • 공연문화연구
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    • 제25호
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    • pp.291-332
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    • 2012
  • 라마교 사원축제 시에 연행되는 챰(cham)은 티벳은 물론 인도, 네팔, 부탄, 몽골에 전승되어 온 불교 의식무용이다. 챰의 유형과 양식, 제차는 지역과 종파에 따라 변별되나 공통적으로 불법(佛法)에 거스르는 악을 응징함으로써 불법의 승리와 세상의 안과태평을 경축하기 위해 연행된다. 본고는 인도 북단의 라닥(Ladakh)의 헤미스(Hemis)사원에서 라마교의 개조 빠드마삼바바($Padm{\bar{a}}sambhava$; 연화생(蓮華生))의 탄신을 경축하기 위해 행해지는 쩨츄 챰을 대상으로 그 제의적 연행 관념과 구조를 고찰하였다. 그를 통해 신성현현과 제의적 공양, 시각화 명상, 만달라로서의 제의적 공간, 양식화된 연행의 제의적 함의, 점강적 공연 구조, 공연 동기의 대승성 등의 특성을 확인하였다.

대퇴 절단 장애인을 위한 4절 링크 구조의 전자 제어식 무릎형 의족 (Development of an Electronically Controlled Knee-Type Prosthetic Leg with a 4-Bar Linkage Structure for Lower Limb Amputee)

  • 이지운;우현수;안동영;조민;이학;김기영
    • 로봇학회논문지
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    • 제19권2호
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    • pp.159-168
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    • 2024
  • Lower limb amputees are increasing due to various reasons. It is difficult for lower limb amputees to walk without an assistive device such as a prosthetic leg. In this paper, an electronically controlled knee-type prosthetic leg with a 4-bar linkage structure for lower limb amputees was developed. The knee-type prosthetic leg has a 4-bar linkage structure and assists walking by using an integrated drive module. The torque is 90 Nm, the rotation speed is up to 120 deg, and it weight 1.9 kg, so it is lighter than a commercial prosthetic leg, so it can be used for a long time because there is less fatigue when walking. An integrated control board was developed by applying various sensors and microprocessor. The motor drive and encoder are built into the integrated drive module. The integrated control board and integrated drive module communicate using CAN. When a lower limb amputee wears a knee-type prosthetic leg and walks, it shows a shape similar to the swing phase graph of a normal people, and it is possible to walk naturally while walking.

CAD/CAM 시스템으로 제작한 Milled Bar를 이용한 하악 임플란트 피개의치 수복증례 (Rehabilitation using mandibular implant overdenture with CAD/CAM milled bar: A case report)

  • 반민희;양홍서;박상원;임현필;윤귀덕;신진호;박찬
    • 대한치과보철학회지
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    • 제55권3호
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    • pp.292-299
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    • 2017
  • 무치악 환자에서 치아 상실 후 오랜 기간에 걸친 치조골 흡수는 의치의 사용을 어렵게 한다. 하악 무치악 환자에게 두 개 혹은 네 개의 임플란트를 식립하여 임플란트 피개의치를 이용하는 방식은 쉽게 접근할 수 있고, 의치의 유지, 지지와 안정을 크게 향상시킬 수 있는 방법이다. 임플란트 피개의치에 사용되는 어태치먼트 중에서 milled bar는 기성 bar보다 상부 구조물의 견고한 안정성과 충분한 유지력을 얻기 위해 사용할 수 있으며, 최근 CAD/CAM system의 발달과 함께 기공과정이 간소화되어 이용이 용이하게 되었다. 본 증례는 오랜 기간 상, 하악 총의치를 사용했던 환자에게 상악은 전통적인 방식으로 제작한 총의치와 하악에 네 개의 임플란트를 식립하여 CAD/CAM milled bar를 이용해 하악 임플란트 피개의치로 수복하여 만족스러운 결과를 얻었기에 이를 보고하는 바이다.

Negative Turbulent Magnetic 𝛽 Diffusivity effect in a Magnetically Forced System

  • Park, Kiwan;Cheoun, Myung-Ki
    • 천문학회보
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    • 제46권2호
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    • pp.47.3-48
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    • 2021
  • We studied the large scale dynamo process in a system forced by helical magnetic field. The dynamo process is basically nonlinear, but can be linearized with 𝛼&𝛽 coefficients and large scale magnetic field $\bar{B}$. This is very useful to the investigation of solar (stellar) dynamo. A coupled semi-analytic equations based on statistical mechanics are used to investigate the exact evolution of 𝛼&𝛽. This equation set needs only magnetic helicity ${\bar{H}}_M({\equiv}{\langle}{\bar{A}}{\cdot}{\bar{B}}{\rangle},\;{\bar{B}}={\nabla}{\times}{\bar{A}})$ and magnetic energy ${\bar{E}}_M({\equiv}{\langle}{\bar{B}}^2{\rangle}/2)$. They are fundamental physics quantities that can be obtained from the dynamo simulation or observation without any artificial modification or assumption. 𝛼 effect is thought to be related to magnetic field amplification. However, in reality the averaged 𝛼 effect decreases very quickly without a significant contribution to ${\bar{B}}$ field amplification. Conversely, 𝛽 effect contributing to the magnetic diffusion maintains a negative value, which plays a key role in the amplification with Laplacian ∇2(= - k2) for the large scale regime. In addition, negative magnetic diffusion accounts for the attenuation of plasma kinetic energy EV(= 〈 U2 〉/2) (U: plasma velocity) when the system is saturated. The negative magnetic diffusion is from the interaction of advective term - U • ∇ B from magnetic induction equation and the helical velocity field. In more detail, when 'U' is divided into the poloidal component Upol and toroidal one Utor in the absence of reflection symmetry, they interact with - B • ∇ U and - U • ∇ B from ∇ × 〈 U × B 〉 leading to 𝛼 effect and (negative) 𝛽 effect, respectively. We discussed this process using the theoretical method and intuitive field structure model supported by the simulation result.

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BIM-Based Simulator for Rebar Placement

  • Park, U-Yeol
    • 한국건축시공학회지
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    • 제12권1호
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    • pp.98-107
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    • 2012
  • Reinforcing bars (rebar) comprise an integral part of a concrete structure, and play a major role in the safety and durability of the building. However, the actual placement or installation of rebar is not planned and controlled by the detailer. Recently, 4D simulations, using 3D model and scheduling software, have been used to improve the efficiency of the construction phrase. However, 4D simulators have not been introduced at the detailed level of work, such as rebar placement. Therefore, this paper suggests a BIM-based simulator for rebar placement to determine the sequence with which rebar is placed into the form. The system using Autodesk Revit API automatically generates rebar placement plans for a building structure, and labels the placement sequence of each individual bar or set of bars with ascending numbers. The placement sequence is then visualized using Autodesk Revit Structure 2012. This paper provides a short description of a field assessment and limits.

아유르베다'($\bar{A}yurveda$) 의경(醫經)에 관한 연구 (A Study of The Medical Classics in the '$\bar{A}yurveda$')

  • 김기욱;박현국;서지영
    • 동국한의학연구소논문집
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    • 제10권
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    • pp.119-145
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    • 2008
  • Through a simple study of the medical classics in the '$\bar{A}yurveda$', we have summarized them as follows. 1) Traditional Indian medicine started in the Ganges river area at about 1500 B. C. E. and traces of medical science can be found in the "Rigveda" and "Atharvaveda". 2) The "Charaka(閣羅迦集)" and "$Su\acute{s}hruta$(妙聞集)", ancient texts from India, are not the work of one person, but the result of the work and errors of different doctors and philosophers. Due to the lack of historical records, the time of Charaka(閣羅迦) or $Su\acute{s}hruta$(妙聞)s' lives are not exactly known. So the completion of the "Charaka" is estimated at 1st$\sim$2nd century C. E. in northwestern India, and the "$Su\acute{s}hruta$" is estimated to have been completed in 3rd$\sim$4th century C. E. in central India. Also, the "Charaka" contains details on internal medicine, while the "$Su\acute{s}hruta$" contains more details on surgery by comparison. 3) '$V\bar{a}gbhata$', one of the revered Vriddha Trayi(triad of the ancients, 三醫聖) of the '$\bar{A}yurveda$', lived and worked in about the 7th century and wrote the "$Ast\bar{a}nga$ $Ast\bar{a}nga$ hrdaya $samhit\bar{a}$ $samhit\bar{a}$(八支集) and "$Ast\bar{a}nga$ Sangraha $samhit\bar{a}$(八心集)", where he tried to compromise and unify the "Charaka" and "$Su\acute{s}hruta$". The "$Ast\bar{a}nga$ Sangraha $samhit\bar{a}$" was translated into Tibetan and Arabic at about the 8th$\sim$9th century, and if we generalize the medicinal plants recorded in each the "Charaka", "$Su\acute{s}hruta$" and the "$Ast\bar{a}nga$ Sangraha $samhit\bar{a}$", there are 240, 370, 240 types each. 4) The 'Madhava' focused on one of the subjects of Indian medicine, '$Nid\bar{a}na$' ie meaning "the cause of diseases(病因論)", and in one of the copies found by Bower in 4th century C. E. we can see that it uses prescriptions from the "BuHaLaJi(布唅拉集)", "Charaka", "$Su\acute{s}hruta$". 5) According to the "Charaka", there were 8 branches of ancient medicine in India : treatment of the body(kayacikitsa), special surgery(salakya), removal of alien substances(salyapahartka), treatment of poison or mis-combined medicines(visagaravairodhikaprasamana), the study of ghosts(bhutavidya), pediatrics(kaumarabhrtya), perennial youth and long life(rasayana), and the strengthening of the essence of the body(vajikarana). 6) The '$\bar{A}yurveda$', which originated from ancient experience, was recorded in Sanskrit, which was a theorization of knowledge, and also was written in verses to make memorizing easy, and made medicine the exclusive possession of the Brahmin. The first annotations were 1060 for the "Charaka", 1200 for the "$Su\acute{s}hruta$", 1150 for the "$Ast\bar{a}nga$ Sangraha $samhit\bar{a}$", and 1100 for the "$Nid\bar{a}na$". The use of various mineral medicines in the "Charaka" or the use of mercury as internal medicine in the "$Ast\bar{a}nga$ Sangraha $samhit\bar{a}$", and the palpation of the pulse for diagnosing in the '$\bar{A}yurveda$' and 'XiZhang(西藏)' medicine are similar to TCM's pulse diagnostics. The coexistence with Arabian 'Unani' medicine, compromise with western medicine and the reactionism trend restored the '$\bar{A}yurveda$' today. 7) The "Charaka" is a book inclined to internal medicine that investigates the origin of human disease which used the dualism of the 'Samkhya', the natural philosophy of the 'Vaisesika' and the logic of the 'Nyaya' in medical theories, and its structure has 16 syllables per line, 2 lines per poem and is recorded in poetry and prose. Also, the "Charaka" can be summarized into the introduction, cause, judgement, body, sensory organs, treatment, pharmaceuticals, and end, and can be seen as a work that strongly reflects the moral code of Brahmin and Aryans. 8) In extracting bloody pus, the "Charaka" introduces a 'sharp tool' bloodletting treatment, while the "$Su\acute{s}hruta$" introduces many surgical methods such as the use of gourd dippers, horns, sucking the blood with leeches. Also the "$Su\acute{s}hruta$" has 19 chapters specializing in ophthalmology, and shows 76 types of eye diseases and their treatments. 9) Since anatomy did not develop in Indian medicine, the inner structure of the human body was not well known. The only exception is 'GuXiangXue(骨相學)' which developed from 'Atharvaveda' times and the "$Ast\bar{a}nga$ Sangraha $samhit\bar{a}$". In the "$Ast\bar{a}nga$ Sangraha $samhit\bar{a}$"'s 'ShenTiLun(身體論)' there is a thorough listing of the development of a child from pregnancy to birth. The '$\bar{A}yurveda$' is not just an ancient traditional medical system but is being called alternative medicine in the west because of its ability to supplement western medicine and, as its effects are being proved scientifically it is gaining attention worldwide. We would like to say that what we have researched is just a small fragment and a limited view, and would like to correct and supplement any insufficient parts through more research of new records.

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메탄올-물 혼합액에서의 n-Alkylamine 염산염의 분 몰랄 부피 (Partial molal volumes of n-alkylamine hydrochlorides in methanol-water mixtures)

  • 엄태섭;윤상기;이익춘
    • 대한화학회지
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    • 제14권1호
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    • pp.51-59
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    • 1970
  • Methyl에서 n-butyl까지의 n-alkylamine 염산염동족체($RNH_3Cl$)의 "겉보기몰랄부피"(apparent molal volume)${\phi}_v$를 30$^{\circ}C$에서 여러가지 조성의 methanol-물 혼합액을 써서 측정하였다. 아민염의 농도는 0.01M까지, 밀도는 부력법을 적용하여 소수점이하 5위까지 택하였다. 관측된 ${\phi}_v$값을 무한대의 농도 쪽으로 extapolation하여 "분몰랄부피"(partial molal volume)$\bar{V}^{\circ}$V를 구하였다. 실험결과는 용질입자의 크기, charge 및 hydrophobic effect등에 관하여 논의되었고 또한 동족체간에일정한 몰랄부피차(${\Delta}\bar{V}^{\circ}$)를 갖는다는 사실과 아울러 혼합용매의 구조에 대하여도 검토하였다. 메탄올-물 0.1몰분율(m.f.)에서는 물의 구조증대로 cation의 "분몰랄부피($\bar{V}^{\circ}_+$)가 최소이고, 한편 0.4m.f. 에서는 charge 효과에 의한 electrostriction effect의 최대화 free volume이 최소라는 사실들이 관찰되었다.

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전기 영화가 인물과 역사를 소환하는 한 방식에 대해 - 영화 <황금시대>를 중심으로 (On a Way in which Biographical Film Summons Character and History - Focusing on the Film, The Golden Era -)

  • 진성희
    • 비교문화연구
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    • 제39권
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    • pp.287-308
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    • 2015
  • Biographical film is a genre narrativizing the actual person and history, and reproducing the character and history in a biographical film is in a dimension different from a film focused on a fiction. Discussion between these methods of narrative composition and image reproduction in a biographical film is also, in line with artistic/aesthetic problems and ethical/philosophical theses of the film text. This study discusses the phase of the way of reproduction of the actual person, $Xi{\bar{a}}o$ $H{\acute{o}}ng$ in the biographical film, The Golden Era and the time she lived in a biographical film and how the audience's discussion of the film and socio-cultural discourse differ depending on their attitude towards the cinematic introspection of the text. The narrative structure, the method of image reproduction and cinematic devices of the film, The Golden Era are completely off the point of the general format of the traditional biographical film. In The Golden Era, $Xi{\bar{a}}o$ $H{\acute{o}}ng$ and the history which she lived in did not revive depending on an omniscient subject's selective statement and meta-film structure. Ann Hui removed general, mythic images of $Xi{\bar{a}}o$ $H{\acute{o}}ng$ formed in the field of traditional Chinese culture and reproduced her through multilateral visions of a real, fictional narrator. Each spectator's judgment and interpretation of the film intervene in the multi-layered and sparse descriptions of the actual person's images and the era of the characters. Through this, it is possible to approach the uniqueness and authenticity a historical character, $Xi{\bar{a}}o$ $H{\acute{o}}ng$ and to have an opportunity of multi-layered reflection on how to secure a critical distance and make a perception in historical judgment.