• Title/Summary/Keyword: Designed-to-fail

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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.

Computer-Aided Crafting of Pulse Shapes for Broadband Heteronuclear Decoupling in the presence of Homonuclear Coupling

  • Lee, Chang-Jae
    • Journal of the Korean Magnetic Resonance Society
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    • v.3 no.1
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    • pp.36-43
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    • 1999
  • We present a pulse shape tailored for broadband decoupling for a system of spin-1/2's with scalar couplings as well. In crafting the pulse shape Coherent Averaging Theory and Fourier expansion method are used. The Fourier expansion coefficients are optimized numerically by applying the Simulated Annealing Method. The decoupling performance of the shaped pulse thus designed is then compared with the well-known composite pulse sequence, DIPSI-2. It is shown that the shaped pulse performs well even at the conditions where the DIPSI sequence begins to fail.

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The Study of Headway Improvement on Signaling System Des19n of Urban Transit (도시철도 신호시스템 설계에서의 운전시격 향상에 대한 연구)

  • Baek, Jong-Hyen;An, Tae-Ki;Jeong, Rag-Gyo;Han, Seong-Ho;Byun, Yeun-Sub;Park, Hyun-Jun
    • Proceedings of the KIEE Conference
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    • 1999.07a
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    • pp.492-494
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    • 1999
  • To improve safety operation of urban transit, compatible design of signaling system is most important factor at future train operation and management. Therefore, signaling system should be designed compatible transport demand of target year. In addition, signaling system should be designed improved train safety, based fail-safe principle. Most of all, to solve passenger concentration, high density and to improve efficiency of train operation. Headway improvement of train is most important. Train organization length of new urban transit as light rail is generally shorter than EMU. Therefore, to increase passenger service and operation efficiency, minimum headway of one minute in this system should be important required.

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Ultra-High-Speed PCB Design Methods (초고속 PCB 설계 기법)

  • Kim, Chang-Gyun;Lee, Seongsoo
    • Journal of IKEEE
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    • v.22 no.3
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    • pp.882-885
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    • 2018
  • Recently, signal integrity on PCB (printed circuit board) becomes very important as the system operation speed increases. So far, PCB is customarily designed to minimize area and cost. However, ultra-high-speed PCB often fail to operate properly, unless it is precisely and carefully designed considering dielectric characteristics, line width, line spacing, and impedance matching. This paper surveys many problems in ultra-high-speed PCB and various design methods to mitigate them.

Seismic Fragility Assessment of Ordinary RC Shear Walls Designed with a Nonlinear Dynamic Analysis (비선형 동적해석에 의해 내진설계된 철근콘크리트 보통 전단벽의 지진취약도 분석)

  • Jeon, Seong-Ha;Park, Ji-Hun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.23 no.3
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    • pp.169-181
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    • 2019
  • Seismic performance of ordinary reinforced concrete shear wall systems commonly used in high-rise residential buildings is evaluated. Three types of shear walls exceeding 60m in height are designed by performance-based seismic design. Then, incremental dynamic analysis is performed collapse probability is assessed in accordance with the procedure of FEMA P695. As a result, story drift, plastic rotation, and compressive strain are observed to be major failure modes, but shear failure occur little. Collapse probability and collapse margin ratio of performance groups do not meet requirement of FEMA P695. It is observed that critical wall elements fail due to excessive compressive strain. Therefore, the compressive strain of concrete at the boundary area of the shear wall needs to be evaluated with more conservative acceptance criteria.

Development of a Separable Glued-Laminated Timber (GLT)-Steel Beam for Eco-Friendly Construction and Dismantling of Buildings (건축물의 친환경 시공·해체를 위한 재료 분리형 GLT-Steel 보 개발)

  • Pang, Sung-Jun;Oh, Jung-Kwon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.23-24
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    • 2023
  • In this study, an easily recyclable separable glued-laminated timber (GLT)-steel beam was developed, and a structural design method was presented. The GLT and steel were mechanically composited using self-tapping screws. The GLT-steel beam was designed to fail in the compression of GLT. The bending moment and load-carrying capacity of the GLT-steel beam were predicted based on composite beam theory and compared with experimental test data. As a result, the GLT-steel beam exhibited ductile behavior, and compression failure of GLT was observed. The screw connection showed no damage while the steel plate was extended. The load-carrying capacity of GLT after failure was similar to the load resistance predicted by the compressive strength of GLT and the tensile strength of steel. This indicates that the ductile behavior of the GLT-steel beam can be safely designed by the tensile strength (yield) of steel.

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Design of High-Reliability eFuse OTP Memory for PMICs (PMIC용 고신뢰성 eFuse OTP 메모리 설계)

  • Yang, Huiling;Choi, In-Wha;Jang, Ji-Hye;Jin, Liyan;Ha, Pan-Bong;Kim, Young-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.7
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    • pp.1455-1462
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    • 2012
  • In this paper, a BCD process based high-reliability 24-bit dual-port eFuse OTP Memory for PMICs is designed. We propose a comparison circuit at program-verify-read mode to test that the program datum is correct by using a dynamic pseudo NMOS logic circuit. The comparison result of the program datum with its read datum is outputted to PFb (pass fail bar) pin. Thus, the normal operation of the designed OTP memory can be verified easily by checking the PFb pin. Also we propose a sensing margin test circuit with a variable pull-up load out of consideration for resistance variations of programmed eFuse at program-verify-read mode. We design a 24-bit eFuse OTP memory which uses Magnachip's $0.35{\mu}m$ BCD process, and the layout size is $289.9{\mu}m{\times}163.65{\mu}m$ ($=0.0475mm^2$).

Design of Inner Section Displacement Measurement System Using Multiple Node Networks (다중 노드 네트워크를 이용한 내공변위 계측 시스템)

  • 서석훈;우광준
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.6
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    • pp.20-26
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    • 2001
  • In this paper, we design tunnel inner section displacement measurement system which is composed of potentiometer-type displacement sensors, microcontroller-based intelligent sensing head and host computer for the management system and acquisition data. Multiple node communication bus connects the intelligent sensing heads with the host computer. For safe and re1iab1e network operation we use daisy-chain configuration, termination resistor, fail-safe biasing circuit. For tole enhancement of system utilization, we use modbus protocol. The acquisition data are transmitted to host computer and managed by database. Several data request conditions and sorting conditions are provided by management software. The utilization of designed system is confirmed by experiment.

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Pseudo-Dynamic Test for Seismic Performance Evaluation of RC Bridge Piers (실물 철근콘크리트 교각의 유사동적 실험에 의한 내진성능 평가)

  • 박창규;박진영;정영수;조대연
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.03a
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    • pp.250-257
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    • 2002
  • Pseudo dynamic test is an on-line computer control method to achieve the realism of shaking table test with the economy and versatility of the conventional quasi-static approach Pseudo dynamic tests of six full-size RC bridge piers have been carried out to investigate their seismic performance. For the purpose of precise evaluation, the experimental investigation was conducted to study the seismic performance of the real size specimen, which is constructed for highway bridge piers in Korean peninsula. Since it is believed that Korea belongs to the moderate seismicity region, five test specimens were designed in accordance with limited ductility design concept. Another one test specimen was nonseismically designed according to a conventional code. Important test parameters were transverse reinforcement and lap splicing. Lap splicing was frequently used in the plastic hinge region of many bridge columns. Furthermore, the seismic design code is not present about lap splice in Korean Roadway Bridge Design Code. The results show that specimens designed according to the limited ductility design concept exhibit higher seismic resistance. Specimens with longitudinal steel lap splice in the plastic hinge region appeared to significantly fail at low ductility level.

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Limited Ductile Capacity of Reinforced Concrete Bridge Pier with Longitudinal Steel Lap-splicing by Pseudo Dynamic Test (유사동적 실험에 의한 철근콘크리트 교각의 주철근 겹이음에 따른 한정연성능력)

  • 박창규;박진영;조대연;이대형;정영수
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.05a
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    • pp.885-890
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    • 2002
  • Pseudo dynamic test is an on-line computer control method to achieve the realism of shaking table test with the economy and versatility of the conventional quasi-static approach. Pseudo dynamic tests of four full-size RC bridge piers have been carried out to investigate their seismic performance. For the purpose of precise evaluation, the experimental investigation was conducted to study the seismic performance of the real size specimen, which is constructed for highway bridge piers in Korean peninsula. Since it is believed that Korea belongs to the moderate seismicity region, three test specimens were designed in accordance with limited ductility design concept. Another one test specimen was nonseismically designed according to a conventional code. Important test parameters were transverse reinforcement and lap splicing. Lap splicing was frequently used in the plastic hinge region of many bridge columns. Furthermore, the seismic design code is not present about lap splice in Korean Roadway Bridge Design Code. The results show that specimens designed according to the limited ductility design concept exhibit higher seismic resistance. Specimens with longitudinal steel lap splice in the plastic hinge region appeared to significantly fail at low ductility level.

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