• Title/Summary/Keyword: Impact load

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Embossed Structural Skin for Tall Buildings

  • Song, Jin Young;Lee, Donghun;Erikson, James;Hao, Jianming;Wu, Teng;Kim, Bonghwan
    • International Journal of High-Rise Buildings
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    • v.7 no.1
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    • pp.17-32
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    • 2018
  • This paper explores the function of a structural skin with an embossed surface applicable to use for tall building structures. The major diagrid system with a secondary embossed surface structure provides an enhanced perimeter structural system by increasing tube section areas and reduces aerodynamic loads by disorienting major organized structure of winds. A parametric study used to investigate an optimized configuration of the embossed structure revealed that the embossed structure has a structural advantage in stiffening the structure, reducing lateral drift to 90% compared to a non-embossed diagrid baseline model, and results of wind load analysis using computational fluid dynamics, demonstrated the proposed embossed system can reduce. The resulting undulating embossed skin geometry presents both opportunities for incorporating versatile interior environments as well as unique challenges for daylighting and thermal control of the envelope. Solar and thermal control requires multiple daylighting solutions to address each local façade surface condition in order to reduce energy loads and meet occupant comfort standards. These findings illustrate that although more complex in geometry, architects and engineers can produce tall buildings that have less impact on our environment by utilizing structural forms that reduce structural steel needed for stiffening, thus reducing embodied $CO^2$, while positively affecting indoor quality and energy performance, all possible while creating a unique urban iconography derived from the performance of building skin.

The Effects of Volume Ratio and Shape on the Formation of Adiabatic Shear Band in WHA (텅스텐 중합금의 부피분율, 입자형상에 따른 단열전단밴드 형성 연구)

  • 이승우;송흥섭;문갑태
    • Transactions of Materials Processing
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    • v.11 no.8
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    • pp.682-690
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    • 2002
  • The formation of adiabatic shearband in tungsten heavy alloys(WHA) was studied in this investigation. Five prismatic specimens were loaded by high velocity impacts and treated as plane strain problems. To find out the effect of particle's volume ratio, specimens containing 81%, 93% and 97% volume percents of tungsten particles were used. Also the effects of particle's geometry and size on the formation of shearband were studied for 81% volume percent alloys by small size particle model, large size particle model and undulated particle models, and the results were discussed.be used to diagnose the causes of necking and fracture in industrial practice and to investigate whether these defects were caused by material property variation, changes in lubrication, or incorrect press settings. In non-axisymmetric deep drawing, three modes of forming regimes are found: draw, stretch, plane strain. The stretch mode for non-axisymmetric deep drawing could be defined when the major and minor strains are positive. The draw mode could be defined when the major strain is positive and minor strain is negative, and plane strain mode could be defined when the major strain is positive and minor strain is zero. Through experiments the draw mode was shown on the wall and flange are one of a drawn cup, while the plane strain and the stretch mode were on the punch head and the punch corner area respectively, We observed that the punch load of elliptical deep drawing was decreased according to increase of die corner radius and the thickness deformation of minor side was more large than major side.

HIV/AIDS Management: Dolutegravir Based Antiretroviral Drug Therapy

  • John, Ikpeama Osita;Emmanuel, Okoh Emeka;Anthonia, Ikpeama Chizoba;Joy, Ikpeama Chinwe;Adimabua, Okafor Patrick;Osazuwa, Igbineweka Osa;Andrew, Ikpeama Emeka;Mariam, Onuzulike Nonye;Gami, Hilary Tumba
    • The Korean Journal of Food & Health Convergence
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    • v.6 no.4
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    • pp.17-19
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    • 2020
  • HIV/AIDS disease still remain a global pandemic and it's management has undergone series of treatment changes and improvement although there is still no permanent cure.Dolutegravir belongs to a group of HIV drugs called integrase inhibitors. Integrase inhibitors block an HIV enzyme called integrase. By blocking integrase, integrase inhibitors prevent HIV from multiplying and can reduce the amount of HIV in the body.Dolutegravir combination based regimen has turned out to be very effective (antiviral) with negligible rare side effects on clients. This drug (Dolutegravir based regimen) combination has successfully increased the appetite for food of all the clients, unlike others and has shown to reduce viral load in the most shortest period ever. It can be deduced that development of resistant mutant virus will be reduced if not eliminated with dolutogravir based regimen.The role of Continuous adherence counseling has shown to improve clients treatment management. It is important to note that the availability of food has direct effect on the economic status or financial weight on the client. Hence the progress that is increase in body mass index (BMI) is a direct impact of the availability of food for the clients.

Analysis for Optimal Rail Grinding Amount by Rolling Contact Fatigue Test in High Speed Railway (구름접촉피로시험을 통한 고속철도 레일연마량 분석)

  • Sung, Deok-Yong;Chang, Ki-Sung;Park, Yong-Gul
    • Journal of the Korean Society for Railway
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    • v.15 no.2
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    • pp.141-146
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    • 2012
  • The rail surface defects which are generated on repeated rolling contact fatigue are getting increased according to high speed, high density, and minimum weight. In addition, Increasing noise and vibration are affected by these also impact load generated as well. Because of this phenomenon, more serious and critical damages were occurred. In fact, in order to control them, the rail grinding amount in Korea. This study evaluated how depth of hardening on rail surface is formed and suggested optimal rail grinding amount by RCF(rolling contact fatigue) test with generated contact pressure between KTX wheel and UIC60 rail by applying FEM analysis. Therefore, the amount was generated approximately 0.2mm/20MGT to maintain integrity of rail surface by getting rid of depth of hardening on rail according to rail accumulated passing tonnage.

MAC Aware Multi-Channel Routing Protocol for Multi-Interface Ad-Hoc Wireless Networks (다중-인터페이스 애드-혹 무선 네트워크를 위한 MAC 인식 다중-채널 라우팅 프로토콜)

  • Lim, Hunju;Joung, Sookyoung;Lee, Sungwha;Park, Inkap
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.5
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    • pp.249-258
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    • 2013
  • In multi-hop ad hoc networks, multi-interface multi-channel architecture is being noticing as methodology to improve the effective bandwidth and end-to-end throughput, But since existing routing metrics designed for networks based on single-interface exactly can not reflects the nature of networks based on multi-interface multi-channel, we are not expected the effect of throughput improvement. there had been proposal of MCR that discover high throughput by using metrics such as channel diversity and interface switching cost. however, MCR have an problem that is degraded it's performance in congested networks, because it not reflects the impact of traffic load. in this paper, we propose MAMCR metric, which select high throughput paths under congested conditions by combination MCR with channel access time metric, and conform it's the effect of performance improvement by ns-2 simulation.

A Study on the Mechanism of Recycled Sand Dry Manufacturing System (순환잔골재 건식생산시스템의 메커니즘에 관한 연구)

  • Choi, Hyeong-Gil;Kim, Young-Bong;Na, Chul-Sung;Lee, Eui-Bae;Kim, Gyu-Yong;Kim, Moo-Han
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.481-484
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    • 2008
  • Recently, the recycling and reusing of construction and demolition waste concrete is urgently required because waste concrete is greatly increased according to the rapid increasing of urban redevelopment project, but the problem solution for demand and supply unbalance of fine aggregate is urgently required because of the restriction of collecting sea fine aggregate. So the utilization of high quality recycled fine aggregate using construction and demolition waste concrete as new fine aggregate for construction industry is urgently. Accordingly, In this study, As recycled fine aggregate manufacturing technology with exceeding in economical efficiency, reduction efficiency of environmental load and quality improvement effect of recycled fine aggregate, it is to develop dry manufacturing system composed specific gravity separator of high-speed rotation impact type and centrifugal Force Powder Collector, etc. And it is to examine mechanism of recycled sand dry manufacturing system.

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Foundation Design the 151 story Incheon Tower in Reclamation Area

  • Abdelrazaq, Ahmad;Badelow, Frances;Kim, Sung-Ho;Park, Yung-Ho
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.157-171
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    • 2009
  • A 151 storey super high-rise building located in an area of reclaimed land constructed over soft marine clay in Songdo, Korea is currently under design. This paper describes the design process of the foundation system of the supertall tower, which is required to support the large building vertical and lateral loads and to restrain the horizontal displacement due to wind and seismic forces. The behaviour of the foundation system due to these loads and foundation stiffness influence the design of the building super structure, displacement of the tower, as well as the raft foundation design. Therefore, the design takes in account the interactions between soil, foundation and super structure, so as to achieve a safe and efficient building performance. The site lies entirely within an area of reclamation underlain by up to 20m of soft to firm marine silty clay, which overlies residual soil and a profile of weathered rock. The nature of the foundation rock materials are highly complex and are interpreted as possible roof pendant metamorphic rocks, which within about 50m from the surface have been affected by weathering which has reduced their strength. The presence of closely spaced joints, sheared and crushed zones within the rock has resulted in deeper areas of weathering of over 80m present within the building footprint. The foundation design process described includes the initial stages of geotechnical site characterization using the results of investigation boreholes and geotechnical parameter selection, and a series of detailed two- and three-dimensional numerical analysis for the Tower foundation comprising over 172 bored piles of varying length. The effect of the overall foundation stiffness and rotation under wind and seismic load is also discussed since the foundation rotation has a direct impact on the overall displacement of the tower.

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A Study on Socio-Economic Effects of Italian Ports (이탈리아 항만의 사회경제학적 효과에 대한 연구)

  • D'agostini, Enrico;Ryoo, Dong-Keun
    • Journal of Navigation and Port Research
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    • v.41 no.4
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    • pp.243-250
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    • 2017
  • Seaports are not longer considered to be single entities for which the main activity is to load and discharge cargo, but rather as fundamental hubs within a complex supply chain serving global production networks. From a public perspective, they hold a key role in terms of their economic impact at the local, regional and national level by generating value added activity and employment. This issue is becoming increasingly pivotal for ports and their stakeholders. The objective of the study is to estimate a regression model of the value added activity and employment figures of 17 Italian ports for which there are no publications available. Concerning port system reform in Italy, the research intends to provide policy makers with a tool to measure the effects produced by ports and their importance to local communities and regions. The paper finds that in all Italian ports, the direct effects are larger than the indirect effects, and the bigger socio-economic effects are found in the biggest ports.

An Analysis for the Efficient Dissemination of Beacon Messages in Vehicle-to-Vehicle (V2V) Communications (자동차 간 통신에서 비컨 메시지의 효율적인 방송을 위한 성능 분석)

  • Nguyen, Hoa-Hung;Bhawiyuga, Adhitya;Jeong, Han-You
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.6C
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    • pp.483-491
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    • 2012
  • In vehicle-to-vehicle (V2V) communications, each vehicle should periodically disseminate a beacon message including the kinematics information, such as position, speed, steering, etc., so that a neighbor vehicle can better perceive and predict the movement of the vehicle. However, a simple broadcasting of such messages may lead to a low reception probability as well as an excessive delay. In this paper, we attempt to analyze the impact of the following key parameters of the beacon dissemination on the performance of vehicular networks: beacon period, carrier-sensing range, and contention window (CW) size. We first derive a beacon period which is inversely proportional to the vehicle speed. Next, we mathematically formulate the maximum beacon load to demonstrate the necessity of the transmit power control. We finally present an approximate closed-form solution of the optimal CW size that leads to the maximum throughput of beacon messages in vehicular networks.

A Study of the Implementation of Wireless Sensor Network based Entrance Control Management Systems on the Hazard Area (무선센서네트워크 기반의 위험지역 출입통제관리 시스템 구축에 관한 연구)

  • Kim, Dae-Soek;Lee, Kyung-Ho;Lee, Jung-Min;Nam, Byeong-Wook;Park, Kae-Myoung
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.6
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    • pp.597-603
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    • 2014
  • The cargo of ships and offshore structures is the number of oil of combustibility and volatile, oil processing cargo. Furthermore heavy cargo of the vehicle or container box or bulk cargo are occupied the remainder of cargo. In addition, there is a possibility to move the location of the cargo and the vessel because it is received periodic / non-periodic a load of wave and ocean current. Therefore a shipboard hazard is much greater than onshore industry hazard. Monitoring and preparation for safety are necessary things because there is always risk of accidents arise from the impact of the freight and cargo of ships and offshore structures. In this study, we conducted a study with respect to the introduction of the wireless sensor network monitoring system to ensure the safety of the crew and workers on shipboard.