• 제목/요약/키워드: protection wall

검색결과 283건 처리시간 0.027초

사면보호용(斜面保護用) 범용보강(凡用補强)콘크리트블록의 개발(開發) (Development of Common Reinforced Concrete Block for Slope Protection)

  • 유능환
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2005년도 학술발표논문집
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    • pp.404-409
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    • 2005
  • The reinforced concrete blocks for reinforced earth layer are combined with soil structures consisted of facing unit, reinforcing materials and soil. Those environmentally friendly facing units of reinforced concrete blocks are made of mine waste and tailing and that will be played a role of the effects of recycling use of wasted resources. The block are consisted of three types as curved or straight in order to control topography. The systems are also not limited to wall hight so that they are effectively used for protecting the slope of banking and cutting of earth works. The reinforced concrete blocks developed this time will be effectively applied for not only retaining wall, road, park, golf course, public office building constructions but also protecting of slope stabilization projects.

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와류발생기의 가진 주파수에 의한 열전달 향상 (Heat Transfer Enhancement by an Oscillating Frequency of Vortex Generator)

  • 방창훈;김정수;예용택
    • 한국안전학회지
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    • 제21권2호
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    • pp.7-14
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    • 2006
  • A Problem of low-velocity forced convection in a channel flow with heated wall is of practical importance and widely considered in the design of devices such as heat exchangers, and electronic equipments. Therefore, there is an urgent need for improving heat transfer performance of heated wall in the channel. In the present study, an oscillating vortex generator method is proposed to enhance the heat transfer in a channel. In this method, a rectangular bars are set in the upstream of heated region of the channel. The bars are forced to oscillate normal to the inflow, and then actively and largely generates transverse vortices behind the bars. As a result, this apparatus can enhance the heat transfer rates remarkably. Because of the interaction between the flow and oscillating bars, the variations of the flow and thermal fields become time-dependent state.

Sternal defect reconstruction using a double-barrel vascularized free fibula flap: a case report

  • Gravina, Paula Rocha;Chang, Daniel K.;Mentz, James A.;Dibbs, Rami Paul;Maricevich, Marco
    • Archives of Plastic Surgery
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    • 제48권5호
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    • pp.498-502
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    • 2021
  • Total and subtotal sternectomy oncological defects can result in large deficits in the chest wall, disrupting the biomechanics of respiration. Reviewing the current literature involving respiratory function and rib motion after sternectomy, autologous rigid reconstruction was determined to provide the optimal reconstructive option. We describe a novel technique for sternal defect reconstruction utilizing a double-barrel, longitudinally oriented, vascularized free fibula flap associated with rib titanium plates fixation. Our reconstructive approach was able to deliver a physiological reconstruction, providing rigid support and protection while allowing articulation with adjacent ribs and preservation of chest wall mechanics.

CLC를 활용한 공동주택 불연성능 외벽몰딩 개발 (Development of Non-flammable exterior design Molding using Cellular Light-weight Concrete)

  • 권해원;공민호;이창용;정갑철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2020년도 봄 학술논문 발표대회
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    • pp.54-55
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    • 2020
  • Recently, "The rules on the standards of evacuation and fire protection of buildings" require that non-burnable materials such as non-combustible and semi-non-combustible materials be used as the materials applied to the building's exterior walls, but styrofoam, which is a combustible material, has been applied a lot and became a social issue. In this study, we developed a non-combustible outer wall molding to secure construction and economic feasibility and free expression using CLC(CLC: Cellular Light-weight Concrete).

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경량칸막이 복합벽체의 가열온도에 따른 전도 열전달 특성 연구 (Study on the Characteristics of Conduction Heat Transfer According to the Heating Temperature of a Composite Wall in a Light-weight Partition)

  • 박상민;최수길;김시국
    • 한국화재소방학회논문지
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    • 제33권1호
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    • pp.60-68
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    • 2019
  • 본 논문은 실내 공간구획에 사용되는 경량칸막이 복합벽체의 가열온도에 따른 이면부로의 전도 열전달 특성에 관한 연구이다. 경량칸막이 벽체로 일반적으로 사용되고 있는 복합재료로 구성된 스터드 칸막이, SGP 칸막이, 샌드위치 패널, 우레탄폼 패널, 그라스울 패널을 실험시료로 선정하고, $200^{\circ}C$, $300^{\circ}C$, $400^{\circ}C$, $500^{\circ}C$의 가열온도를 하단부 표면에 1800 s 동안 인가하여 상단부 표면인 이면부로의 전도 열전달 특성을 분석하였다. 실험결과 가열온도가 최대 $500^{\circ}C$로 인가됨에 따라 최대 이면온도는 스터드 칸막이 $51.6^{\circ}C$, SGP 칸막이 $63.6^{\circ}C$, 샌드위치 패널 $317.2^{\circ}C$, 우레탄폼 패널 $124.9^{\circ}C$, 그라스울 패널 $42.2^{\circ}C$로 측정되었다. $500^{\circ}C$에서의 최대 전도 열전달율은 스터드 칸막이 17.16 W, SGP 칸막이 18.39 W, 샌드위치 패널 136.65 W, 우레탄폼 패널 14.34 W, 그라스울 패널 5.57 W로 측정되었다.

비행궤적에 따른 비행체 앞부분의 열 및 물질전달해석 (Heat and Material Transport Analysis on the Head of Vehicle along the Flight Trajectory)

  • 서정일;송동주
    • 한국군사과학기술학회지
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    • 제5권4호
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    • pp.88-96
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    • 2002
  • The CSCM Upwind method and Material Transport Analysis(MTA) have been used to predict the thermal response and shape changes for charring/non-charring material which can be used as thermal protection material(TPM) on blunt-body nose tip. We performed intensive flight trajectory simulations to compare 1-D MTA results with those of 2-D/Axisymmetric MTA by using MTAs and Navier-Stokes code. Theheat-transfer rate and pressure distribution were predicted at selected altitudes and wall temperature along the flight trajectory and the shape changes of blunt-body nose tip were predicted subsequently by using current procedure.

Trust and Risk based Access Control and Access Control Constraints

  • Helil, Nurmamat;Kim, Mu-Cheol;Han, Sang-Yong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제5권11호
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    • pp.2254-2271
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    • 2011
  • Access control in dynamic environments needs the ability to provide more access opportunities of information to users, while also ensuring protection information from malicious users. Trust and risk are essential factors and can be combined together in access control decision-making to meet the above requirement. In this paper, we propose the combination of the trust and risk in access control to balance information accessibility and protection. Access control decision is made on the basis of trustworthiness of users and risk value of permissions. We use potential relations between users and relations between permissions in access control. Our approach not only provides more access opportunities for trustworthy users in accessing permissions, but also enforces traditional access control constraints such as Chinese Wall policy and Separation of Duty (SoD) of Role-Based Access Control (RBAC) model in an effective way.

경호기법에 의한 위급상황의 발견과 대처 방안에 관한 고찰 (The consideration about prevention ways of discovery of emergency situation which is based on guard techniques)

  • 공배완
    • 한국재난정보학회 논문집
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    • 제6권2호
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    • pp.11-20
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    • 2010
  • All of the people or objects which are contacted during the activity of guard are added to range of objects. guard has to notice decision, question proposal, observation, accomplish to be happened them at the same time recognizing the steps as soon as possible. Before a lot of information of client are shown, guard expert has to search observation of materialization, extension of reservation, notification of business and causes of danger through personal interviews. Rapid communication system has to be assumed and effective caution, protection and shelter and following prevention are cooperated as well as has to care about safe of guard object by a protective wall. And also has to get out of the ground, keep the large shape when moves, prevent the trials of attack from the assassinators after takeing control over weapons.

건축물 창호의 화재안전설계를 위한 실험적 연구 (An Experimental Study on the Fire Safety Design of Windows in Building)

  • 이병흔;진승현;한지우;권영진
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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    • pp.10-11
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    • 2018
  • In the building, the opening penetrates the wall and serves as a spreading channel for smoke and flame in case of fire. In Korea, more than 1,500 fire plume are generated annually, and the number has increased by about 30% over the past five years. Therefore, in the case of windows protecting the opening, fire protection performance is important to prevent the spread of fire. However, in Korea, the standard for window is not clear. In this study, fire tests (EN 13823) for windows were conducted in Korea, and then fire protection performance of windows was compared. As a result of the experiment, PVC windows showed a phenomenon that they could not withstand the temperature during the fire experiment, and AL windows showed a difference in the degree of cracking of the glass.

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안트라사이트와 버미큘라이트를 혼입한 산화마그네슘 경화체의 흡착특성 (Adsorption properties of magnesium oxide matrix using anthracite and vermiculite)

  • 김대연;편수정;이동훈;이상수
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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    • pp.224-225
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    • 2018
  • Modern people are more interested in the indoor environment as they spend more time indoors than in the past. Among the air pollutants in the indoor air, ladon gas is a colorless, tasteless, odorless, inert gas produced by nuclear decomposition of naturally occurring uranium in rocks and soils. It has been proven that ladon gas is introduced into the room through cracks on the floor of the building or basement wall, and it causes various diseases such as lung cancer when exposed to radon during human breathing. The US Environmental Protection Agency (EPA) specifies 4pCi / L as a necessary measure for radon, and the Korea Environmental Protection Agency has implemented comprehensive indoor radon management measures since 2007. Therefore, in this study, we intend to adsorb and reduce radon in indoor air pollutants.

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