• Title/Summary/Keyword: Safe design

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Study of Structural Design Method of Friction Pendulum System for Fail Safe of a Sky-Bridge (스카이브릿지의 안전성확보를 위한 FPS 설계방법에 대한 연구)

  • Kim, Hyun-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.7
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    • pp.3502-3507
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    • 2013
  • If a sky-bridge is rigidly connected to adjacent buildings, the irregularity of the connected structures is increased resulting in providing a worse seismic behavior. Therefore, a friction pendulum system (FPS) or lead rubber bearing (LRB) is frequently used for the connection system between a sky-bridge and building structures. These connection systems should be carefully designed to prevent a skyfall of a sky-bridge subjected to severe seismic loads. In this paper, the inevitable structural design procedures for a sky-bridge connection system using a friction pendulum system without uplift resistance capacity have been investigated. To this end, Nuri Dream Square building structure is used as a example structure. The structural design process of a friction pendulum system for fail safe of a sky-bridge has been proposed in this paper by evaluating structural responses of the sky-bridge and building structures subjected to earthquake loads.

DESIGN AND STRUCTURAL ANALYSIS OF DOME ENCLOSURE FOR TRACKING ARTIFICIAL SPACE OBJECTS (인공우주물체 추적용 완전 개폐형 돔의 설계 및 구조해석)

  • Seol, K.H.;Kim, S.J.;Jang, M.;Min, S.W.;Mun, B.S.;Baek, K.M.
    • Publications of The Korean Astronomical Society
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    • v.22 no.4
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    • pp.211-217
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    • 2007
  • We have been making dual dome enclosures which are useful to track artificial space objects at SSNT (Space Science and Technology Lab.) Kyung Hee University. We verified the safety of the dome enclosures using basic design and structure analyses before manufacturing them, and then performed an optimization analysis for economic and safe systems. The dome enclosure has a fully-open type structure to smoothly operate a telescope made in the style of altazimuth mount with very fast tracking. It is also designed to be safe against extreme weather conditions. The general structure of the observatory system consists of the dual dome enclosures at the top of a container. For the structural analyses, we consider the following two methods: (1) gravitational sustain analysis - how the structure supporting the dome withstand the weight of the dome, and (2) wind load analysis that considers the effect of the wind velocity at the region where the observatory is located. The result of overall deformation is found to be less than 0.551mm and the result of equivalent stress is found to be 20.293Mpa, indicating that the dual dome system is reasonably designed. This means structurally to be safe.

Environment Adaptive Emergency Evacuation Route GUIDE through Digital Signage Systems

  • Lee, Dongwoo;Kim, Daehyun;Lee, Junghoon;Lee, Seungyoun;Hwang, Hyunsuk;Mariappan, Vinayagam;Lee, Minwoo;Cha, Jaesang
    • International Journal of Advanced Culture Technology
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    • v.5 no.1
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    • pp.90-97
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    • 2017
  • Nowadays, the most of commercial buildings are build-out with complex architecture and decorated with more complicated interiors of buildings so establishing intelligible escape routes becomes an important case of fire or other emergency in a limited time. The commercial buildings are already equipped with multiple exit signs and these exit signs may create confusion and leads the people into different directions under emergency. This can jeopardize the emergency situation into a chaotic state, especially in a complex layout buildings. There are many research focused on implementing different approached to improve the exit sign system with better visual navigating effects, such as the use of laser beams, the combination of audio and video cues, etc. However the digital signage system based emergency exit sign management is one of the best solution to guide people under emergency situations to escape. This research paper, propose an intelligent evacuation route GUIDE that uses the combination centralized Wireless Sensor Networks (WSN) and digital signage for people safety and avoids dangers from emergency conditions. This proposed system applies WSN to detect the environment condition in the building and uses an evacuation algorithm to estimate the safe route to escape using the sensor information and then activates the signage system to display the safe evacuation route instruction GUIDE according to the location the signage system is installed. This paper presented the prototype of the proposed signage system and execution time to find the route with future research directions. The proposed system provides a natural intelligent evacuation route interface for self or remote operation in facility management to efficiently GUIDE people to the safe exit under emergency conditions.

A Study on Decision of Minimum Required Channel Width Considering Ship Types by Fast Time Simulation (배속 시뮬레이션 기반의 선종별 최소 항로 폭에 관한 연구)

  • Kim, Hyun-suk;Lee, Yun-sok
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.4
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    • pp.309-316
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    • 2020
  • Waterway design should prioritize appropriate channel width to ensure preferential safe passage for the arrival and departure of vessels. To calculate the minimum channel width required for safe passage a comprehensive review of several factors is required. These factors include vessel maneuverability, determined by vessel size, type and speed; environmental factors such as wind, tide, and wave action; human factors, including personal experience and operator judgment as well as marine traffic and navigation support facilities for decision making. However, the Korean channel width design standard is based only on vessel length, and requires improvement when compared with the standards of PIANC, USA, and Japan. This study aims to estimate the appropriate channel width required for one-way traffic in a straight channel, considering various vessel and environmental factors, using Fast Time Simulation (FTS). When the wind speed is 25 knots, with a current speed of 2 knots and a normal vessel speed of 10 knots FTS shows that a 150K GT Cruise Ship requires a minimum channel width of 0.67-0.91 the vessel length (L), whereas a 120K TEU Container Ship and a 300K DWT VLCC require 0.79-1.17 and 1.02-1.59, respectively. Such results can be used to calculate the minimum channel width required for safe passage as an improved Korean design standard.

An Analysis of Transient Characteristics on Grounding Systems in the Radio Relay Station (무선중계소 접지계의 과도특성 해석)

  • Wang Kim
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.9
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    • pp.1-5
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    • 1993
  • The surge impedance of grounding systems must be accurately computed for a safe grounding design. Specifically, the case of radio relay station in a mountaintop region is required special design method using transient analyses. To approach these design objectives, this paper presents an algorithm to compute the surge impedance of two or more grounding systems using the Laplace Transform technique and deals with the analysis of the transient characteristics on grounding systems. Also, simulation results are compared with the measured data to prove the validity of the algorithm.

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Driving Concept Development for Elderly Drivers (고령 운전자를 위한 안전 시스템 개발 연구)

  • Jung, Sebin
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.3
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    • pp.234-240
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    • 2014
  • Driving-related injuries associated with elderly drivers are on the rise, although the overall rate of driving-related injuries has decreased. To determine the causes of this trend, we researched existing vehicle systems that use different sensors and signals to promote safe driving. We found that although the systems alert drivers to potential collisions and assist them in finding a location easily, they were created by people who rarely use the systems in their daily lives. For the most part, they're not created by people with driving difficulties caused by health problems, which in turn often afflict the elderly. To address this issue, we analyzed the drawbacks of the current systems and used a focus group of people with body conditions that have declined due to age to discover the problems they encounter while driving. With the focus group, we used diverse research activities, such as observation and interview to demonstrate how new system concepts could be developed for the elderly. Finally, we propose that adequate system concepts for the elderly would improve driving safety and provide a more enjoyable driving environment for this population.

Design of the Air Pressure Pick-up Head for Non-Contact Wafer Gripper (비접촉식 웨이퍼 그리퍼용 공압 파지식 헤드 설계)

  • Kim, Joon-Hyun
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.3
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    • pp.401-407
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    • 2012
  • The recent manufacturing process in the thin wafers and flat panel necessitate new approaches to reduce handling fragile and surface-sensitive damage of components. This paper presents a new pneumatic levitation for non-contact handling of parts and substrates. This levitation can achieve non-contact handling by blowing air into an air pressure pick-up head with radial passages to generate a negative pressure region. Negative pressure is caused by the radial air flow by nozzle throat and through holes connecting to the bottom region. The numerical analysis deals with the levitational motion with different design factors. The dynamic motion is examined in terms of force balance(dynamic equilibrium) occurring to the flow field between two objects. The stable equilibrium position and the safe separation distance are determined by analyzing the local pressure distribution in the fluid motion. They make considerable design factors consisting the air pressure pick-up head. As a result, in case that the safe separation distance is beyond 0.7mm, the proposed pick-up head can levitate stably at the equilibrium position. Furthermore, it can provide little effect of torque, and obtain more wide picking region according to the head size.