• Title/Summary/Keyword: energy dissipating

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Evaluation of Response Modification Factore for Earthquake Resistant Design of Moment-Resisting Steel Frames (모멘트-연성 강구조물의 내진설계를 위한 반응수정계수의 평가)

  • 송종걸
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1997.10a
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    • pp.201-208
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    • 1997
  • In most seismic codes such as the Uniform Building Code(UBC), the response modification factor(or the force reduction factor)is used to reflect the capability of a structure in dissipating energy through inelastic behavior. The response modification factor is assigned according to structural system type. Ductile systems such as special moment-resisting steel frames are assigned larger values of the response modification factor, and are consequently designed for smaller seismic design forces. Therefore, structural damage may occur during a severe earthquake. To ensure safety of the structures, the suitability of the response modification factor used in aseismic design procedures shall be evaluated. The object of this study is to develop a method for the evaluating of the response modification factor. The validity of the evaluating method has been examined for several cases of different structures and different earthquake excitations.

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A Literature Study of Jianwang(健忘) : Forgetfulness(Amnesia) (건망(健忘)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Yu Geum-Ryoung;Chang Gyu-Tae;Kim Jang-Hyun
    • The Journal of Pediatrics of Korean Medicine
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    • v.13 no.1
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    • pp.1-16
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    • 1999
  • A literature study was progressed for oriental medical diagnosis and treatment for Jianwang(健忘) : forgetfulness(amnesia). In orental medicine, the reason of Jianwang(健忘) was congenital insufficiency(稟賦不足), meditational excessiveness(思慮過多), deficiency of heart(心虛), phlegm retention(痰飮), deficiency of kidney(腎裏), breakdown of the normal physiological coordination between the heart and the kidney(心腎不交), blood stasis(瘀血). The method of medical treatment was invigorating vital energy and enriching the blood(大補氣血), invigorating the heart and nourishing blood(補心養血), dissipating phlegm and relieving mental stress(化痰寧神), regulating the spleen corresponds to earth(理脾土), invigorating the heart and the kidney(補心腎), reinforcing the liver and the kidney(培肝腎), promoting blood circulation to remove blood stasis(活血祛瘀) and etc. Herbal medication was followed as those method. The prescription was commonly used as Guibitang(歸脾湯), Insuksan(仁熟散), Chunwangbosimdan(天王補心丹), Susunghwan(壽星丸), Samjohwan(蔘棗丸) and etc.

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Experimental Study on the Hysteretic Behavior of R/C Low-Rise Shear Walls under Cyclic Loads (반복하중을 받는 철근콘크리트 저형 전단벽의 이력거동에 관한 실험적 연구(II) -바벨형 단면(Barbell Shape)의 내력과 연성을 중심으로-)

  • 최창식;이용재;윤현도;이리형
    • Proceedings of the Korea Concrete Institute Conference
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    • 1991.10a
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    • pp.68-73
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    • 1991
  • Results of an experimental investigation of low-rise reinforced concrete shear walls with barbell cross section under cyclic loads are discussed and evaluated. Four halr scale models of test specimens with height to length ratio of 0.75 were experimented. The dimension of all walls is 1500mm wide $\times$ 950 mm high $\times$ 100 mm thick and the section of all boundary column at both ends is 200 mm $\times$ 200mm. Main variables are : design concept, vertical flexural reinflrcement ratios and reinforcement details(including crossed diagonal shear reinforcement in SW7 specimen). In SW7 specimen, maximum strength and consequently dissipating energy index were 1.45 and 1.28 times greater than those of SW6 specimen, respectively.

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Pontoon and Membrane Breakwater

  • Kee, S.T.
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.185-191
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    • 2003
  • A numerical study on the hydrodynamic properties of a floating flexible breakwater consisting of triple vertical porous membrane structures attached to a floating rigid pontoon restrained by moorings is carried out in the context of two-dimensional linear wave-flexible body interaction theory. The tensions in the triple membranes are achieved by hanging a clump weight from its lower ends. The clump weight is also restrained properly by moorings. The dynamic behavior of the breakwater was described through an appropriate Green function, and the fluid multi-domains are incorporated into the boundary integral equation. Numerical results are presented which illustrate the effects of the various wave and structural parameters on the efficiency of the breakwater as a barrier to wave action. It is found that the wave reflection and transmission properties of the structures depends strongly on the membrane length taking major fraction of water column, the magnitude of tensions on membrane achieving by the clump weight, proper mooring types and stiffness, the permeability on the membrane dissipating wave energy.

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Optimum of Damper Position for Steel Frame Structure on Seismic Design (내진설계 강골조 구조물의 감쇠기 위치 최적화)

  • Park, Soon-Eung;Park, Moon-Ho;Kim, Jin-Kyu
    • Journal of the Korean Society of Industry Convergence
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    • v.12 no.4
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    • pp.187-192
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    • 2009
  • This study is performing a seismic analysis on the steel frames structure with dampers and analyzing the dynamic behavior in order to examine their efficiency and study the optimum dampers position to the seismic design steel structure. To improve the ability against an earthquake, this study performed the time history analysis. Controling an earthquake is the way to minimize the damage of the steel structure by dissipating input energy generated by an earthquake.

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Experimental Study on Hydraulic Performance of Perforated Caisson Breakwater with Turning Wave Blocks (회파블록케이슨 방파제의 수리학적 성능에 관한 실험적 연구)

  • Kim, In-Chul;Park, Ki-Chul
    • Journal of Ocean Engineering and Technology
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    • v.33 no.1
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    • pp.61-67
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    • 2019
  • Recently, a perforated caisson breakwater with turning wave blocks was developed to improve the water affinity and public safety of a rubble mound armored by TTP. In this study, hydraulic model tests were performed to examine the hydraulic performance of a non-porous caisson and new caisson breakwater with perforated blocks for attacking waves in a small fishery harbor near Busan. The model test results showed that the new caisson was more effective in dissipating the wave energy under normal wave conditions and in reducing the wave overtopping rates under design wave conditions than the non-porous caisson. It was found that the horizontal wave forces acting on the perforated caisson were slightly larger than those on the non-porous caisson because of the impulsive forces on the caisson with the turning wave blocks.

High Power-Density LDC Design for Ultra-Compact Electric Vehicles (초소형 전기자동차용 고밀도 LDC 설계)

  • Kim, Tae-Won;Lee, Jae-Won;Kim, Jun-Min;Kim, Gu-Yong;Kim, Jun-Ho
    • The Transactions of the Korean Institute of Power Electronics
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    • v.26 no.3
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    • pp.199-204
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    • 2021
  • Ultra-compact electric vehicles have narrow space for power conversion devices. This work presents schemes to achieve the high-power density of a low-voltage DC-DC converter (LDC): simplifying a converter structure by using sync-buck topology, applying a planar inductor using PCB winding, and applying a plate-type heat sink. The heat sink is placed between two PCBs, which increases the contact surface between the PCB and the heat-dissipating device. It enables the miniaturization of the converter to improve the conditions of heat radiation. The validity of the proposed scheme is verified through the experiment using a 500 W(12 V, 41.67 A) prototype with an input voltage range from 58 V to 84 V.

Steel Rod Damper and Rocking Behavior (강봉 댐퍼와 록킹 거동)

  • Lee, Hyun-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.6
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    • pp.1-9
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    • 2020
  • In this study, a seismic reinforcement system was developed considering the rocking behavior of walls. The rocking behavior is to rotate left and right around the vertical axis of the wall, and the development system is a method of dissipating energy by installing a damper to a large displacement part. Developed steel rod damper was used, and steel rod diameter and length(aspect ratio) were selected as variables. As a result of the experiment, it was evaluated to have excellent seismic performance when the damper length was 260mm.

The Single-Cell Revelation of Thermogenic Adipose Tissue

  • Qi, Yue;Hui, Xiaoyan Hannah
    • Molecules and Cells
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    • v.45 no.10
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    • pp.673-684
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    • 2022
  • The past two decades have witnessed an upsurge in the appreciation of adipose tissue (AT) as an immunometabolic hub harbouring heterogeneous cell populations that collectively fine-tune systemic metabolic homeostasis. Technological advancements, especially single-cell transcriptomics, have offered an unprecedented opportunity for dissecting the sophisticated cellular networks and compositional dynamics underpinning AT remodelling. The "re-discovery" of functional brown adipose tissue dissipating heat energy in human adults has aroused tremendous interest in exploiting the mechanisms underpinning the engagement of AT thermogenesis for combating human obesity. In this review, we aim to summarise and evaluate the use of single-cell transcriptomics that contribute to a better appreciation of the cellular plasticity and intercellular crosstalk in thermogenic AT.

A New Zero-Current-Transition Forward Converter without Reset Turn (리셋 권선을 사용하지 않는 새로운 형태의 영전류 천이형 포워드 컨버터)

  • Eun-Seong, Baek ;Hyun-Chil, Choi
    • The Transactions of the Korean Institute of Power Electronics
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    • v.27 no.6
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    • pp.464-470
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    • 2022
  • A new type of soft-switching forward converter is proposed in this study. By adding only a few components, the inductor, diode, switch, and capacitor exhibit higher efficiency than the conventional forward converter. Therefore, the switching losses of the proposed forward converter are considerably reduced compared with those of the conventional forward converter. In addition, the reset winding is not used because of the capacitor employed in the auxiliary circuit. The auxiliary capacitor is adopted for zero-current-transition operation and for dissipating magnetization energy. The performance of the proposed forward converter is validated using experimental results from a 60 W, single-output, forward converter prototype, and design guidelines are presented.