• Title/Summary/Keyword: Residual capacity

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Control of Hydroxyl Group Content in Sol-Gel-Derived Sols for Waveguide Optical Matrix (Waveguide Optical Matrix 용 졸-겔 코팅졸의 OH 함량 제어)

  • 안복엽;석상일;김주현;권정오
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.03a
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    • pp.55-55
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    • 2003
  • Recently, with the rapid development of the waveguide division multiplexing (WDM) systems for large capacity and flexibility of information network, the broad band 1.5$\mu\textrm{m}$ erbium-doped waveguide amplifier (EDWA) become important. The main factors affecting the performance of sol-gel-based waveguides are non-radiative relaxation channels due to rare-earth concentration quenching and to vibration of the OH groups Therefore, the sol-gel process has to be carefully controlled in order to minimize the residual OH content.

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A Study on Charging Efficiency Variability by Utilizing Remaining Capacity of EV DC Charging Facility Batteries of Railway Electric Power Grids (철도전력망을 이용한 EV DC 충전설비 배터리 잔존용량에 따른 충전효율 가변성 연구)

  • Kim, Ki-Suk;Jung, Ho-Sung;Park, Young;Park, Chan-Bae;Park, Chul-Min;Jang, Gil-Soo
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.2171-2172
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    • 2011
  • Recently, while interests on supply of electric vehicles have increased there still are insufficient charging facilities. As a solution to this matter, using electric power grids that constantly retain about 30~50[%] residual power is being considered. Therefore proposed in this paper railway, is a method to establish a charging infrastructure to utilize railway DC power grids. In addition we designed a high-speed DC charging system, and simulated improvements of the charging structure's charging efficiency according to remaining capacity of batteries.

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Modelling seismically repaired and retrofitted reinforced concrete shear walls

  • Cortes-Puentes, W. Leonardo;Palermo, Dan
    • Computers and Concrete
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    • v.8 no.5
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    • pp.541-561
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    • 2011
  • The Finite Element Method (FEM) was employed to demonstrate that accurate simulations of seismically repaired and retrofitted reinforced concrete shear walls can be achieved provided a good analysis program with comprehensive models for material and structural behaviour is used. Furthermore, the analysis tool should have the capability to retain residual damage experienced by the original structure and carry it forward in the repaired and retrofitted structure. The focus herein is to provide quick, simple, but reliable modelling procedures for repair and retrofitting strategies such as concrete replacement, addition of diagonal reinforcing bars, bolting of external steel plates, and bonding of external steel plates and fibre reinforced polymer sheets, thus illustrating versatility in the modelling. Slender, squat, and slender-squat shear walls were investigated. The modelling utilized simple rectangular membrane elements for the concrete, truss bar elements for the steel and FRP retrofitting materials, and bond-link elements for the bonding interface between steel or FRP to concrete. The analyses satisfactorily simulated seismic behaviour, including lateral load capacity, displacement capacity, energy dissipation, hysteretic response, and failure mode.

Increments of Elastic Lad Carrying Capacity of Compound Cylinder by Using Modified-Shrink-Fit Method (修正죔맞춤 방법 을 이용한 複合圓통 의 彈性負荷能力 의 증대)

  • 정성종;홍창선
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.7 no.3
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    • pp.335-343
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    • 1983
  • Modified-Shrink-Fit(MSF) method of compound cylinder is studied to increase elastic load carrying capacity (ELCC) of pressure vessel. The autofrettage and the shrink-fit processes are used to study the MSF process. Theoretical analyses based on the Tresca yield criterion, Hencky's total strain theory and elastic linearly strain-hardening material are carried out to derive closed form solutions. Experimental results are compared with theoretical results with various diameter ratios between outer (SM45C) and inner (SM20C) bloc cylinder. For various diameter ratios, increments of ELCC have errors in strains vs. internal loading pressures between experimental and theoretical results. But experimental results show good agreements with theoretical results in reyield pressurizing state. The increments of ELCC of compound cylinder manufactured by the MSF process is proved by measuring the residual stresses.

Network Selection Algorithm Based on Spectral Bandwidth Mapping and an Economic Model in WLAN

  • Pan, Su;Zhou, Weiwei;Gu, Qingqing;Ye, Qiang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.1
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    • pp.68-86
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    • 2015
  • Future wireless network aims to integrate different radio access networks (RANs) to provide a seamless access and service continuity. In this paper, a new resource denotation method is proposed in the WLAN and LTE heterogeneous networks based on a concept of spectral bandwidth mapping. This method simplifies the denotation of system resources and makes it possible to calculate system residual capacity, upon which an economic model-based network selection algorithm is designed in both under-loaded and over-loaded scenarios in the heterogeneous networks. The simulation results show that this algorithm achieves better performance than the utility function-based access selection (UFAS) method proposed in [12] in increasing system capacity and system revenue, achieving load balancing and reducing the new call blocking probability in the heterogeneous networks.

The Reinforcement Effect of Stone Columns on Refuse Landfill (매립지반에 적용된 쇄석말뚝의 보강효과)

  • Lee, Bong-Jin;Bae, Woo-Seok;Lee, Jun-Dae
    • Journal of the Korean Society of Safety
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    • v.15 no.2
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    • pp.97-102
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    • 2000
  • This paper presents the design, construction and performance of ground treatment to support road embankment on refuse landfill. Long-term settlement of refuse landfill is analysised by Sower and Yen/scanlon. As a results of site test, predicting settlement excess the allowable settlement and ultimate bearing capacity is not satisfied. The effectiveness of DDR(Deep Dynamic Replacement) is monitered by field tests (SPT, PBT, PMT) before, during and after construction of the stone columns. The ultimate bearing capacity for reinforced landfill by stone columns obtained from the in-situ test results has been compared with the existing theories. In municipal wastes landfill, settlement after treatment using stone column is satisfied to allowable residual settlement. Therefore, long-term stability can be gain in these cases.

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Analysis on the Pumping Characteristics of a Commercial Cryopump (상용 크라이오펌프의 배기특성 분석)

  • 인상렬;박미영
    • Journal of the Korean Vacuum Society
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    • v.12 no.2
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    • pp.86-92
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    • 2003
  • The pumping characteristics of a commercial UHV cryopump with a G-M refrigerator for various gases were investigated. The pumping speeds as a function of pumped amount of $H_2,\; D_2,\; He,\; Ar,\; N_2$, CO and the pumping capacity of $N_2$ were measured and the trend was theoretically analyzed. The spectrum change of the residual gas was also investigated during cyropump operation.

Seismic performance evaluation of moment frames with slit-friction hybrid dampers

  • Lee, Joonho;Kim, Jinkoo
    • Earthquakes and Structures
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    • v.9 no.6
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    • pp.1291-1311
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    • 2015
  • This study investigates the seismic energy dissipation capacity of a hybrid passive damper composed of a friction and a hysteretic slit damper. The capacity of the hybrid device required to satisfy a given target performance of a reinforced concrete moment resisting frame designed with reduced design base shear is determined based on the ASCE/SEI 7-10 process, and the seismic performances of the structures designed without and with the hybrid dampers are verified by nonlinear dynamic analyses. Fragility analysis is carried out to investigate the probability of a specified limit state to be reached. The analysis results show that in the structure with hybrid dampers the residual displacements are generally reduced and the dissipated inelastic energy is mostly concentrated on the dampers. At the Moderate to Extensive damage states the fragility turned out to be smallest in the structure with the hybrid dampers.

A Study on the Hysteretic Characteristics of Self-Centering Disc Spring Brace (셀프 센터링이 가능한 디스크 스프링 브레이스의 이력특성에 관한 연구)

  • Park, Byung-Tae;Shin, Dong-Hyeon
    • Journal of Korean Association for Spatial Structures
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    • v.23 no.4
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    • pp.89-96
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    • 2023
  • The seismic retrofits of existing structures have been focused on the control of structural responses which can be achieved by providing displacement capacity through inelastic ductile action at supplemental devices. Due to their hysteretic characteristics, it is expected to sustain damage through repeated inelastic behaviors including residual deformation which might increase repair costs. To solve such drawbacks of existing yielding devices, this study proposes a self-centering disc spring brace that sustains large axial deformation without structural damage while providing stable energy dissipation capacity. The hysteretic behaviors of suggested brace are first investigated based on the quasi-static cyclic test procedure. Experimental results present the effective self-centering behavior and an analytical model is then suggested in order to reasonably capture the flag-shaped hysteretic behavior of the disc spring brace.

Experimental and numerical investigation on the seismic behavior of the sector lead rubber damper

  • Xin Xu;Yun Zhou;Zhang Yan Chen;Song Wang;Ke Jiang
    • Earthquakes and Structures
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    • v.26 no.3
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    • pp.203-218
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    • 2024
  • Beam-column joints in the frame structure are at high risk of brittle shear failure which would lead to significant residual deformation and even the collapse of the structure during an earthquake. In order to improve the damage issue and enhance the recoverability of the beam-column joints, a sector lead rubber damper (SLRD) has been developed. The SLRD can increase the bearing capacity and energy dissipation capacity, and also demonstrating recoverability of seismic performance following cyclic loading. In this paper, the hysteretic behavior of SLRD was experimentally investigated in terms of the regular hysteretic behavior, large deformation behavior and fatigue behavior. Furthermore, a parametric analysis was performed to study the influence of the primary design parameters on the hysteretic behavior of SLRD. The results show that SLRD resist the exerted loading through the shear capacity of both rubber parts coupled with the lead cores in the pre-yielding stage of lead cores. In the post-yielding phase, it is only the rubber parts of the SLRD that provide the shear capacity while the lead cores primarily dissipate the energy through shear deformation. The SLRD possesses a robust capacity for large deformation and can sustain hysteretic behavior when subjected to a loading rotation angle of 1/7 (equivalent to 200% shear strain of the rubber component). Furthermore, it demonstrates excellent fatigue resistance, with a degradation of critical behavior indices by no more than 15% in comparison to initial values even after 30 cycles. As for the designing practice of SLRD, it is recommended to adopt the double lead core scheme, along with a rubber material having the lowest possible shear modulus while meeting the desired bearing capacity and a thickness ratio of 0.4 to 0.5 for the thin steel plate.