• 제목/요약/키워드: Soft engineering

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Assessment of seismic retrofitting for soft-story buildings using gapped inclined brace system

  • Tohamy, Mohamed. A.;Elsayed, Mostafa. M.;Akl, Adel. Y.
    • Earthquakes and Structures
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    • v.22 no.3
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    • pp.319-330
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    • 2022
  • Retrofit of soft-story buildings due to seismic loads using Gap-Inclined-Brace (GIB) system is considered a new retrofit technique that aims to maintain both strength and stiffness of structure. In addition, it provides more ductility and less P-delta effect, and subsequently better performance is observed. In this paper, the effect of the eccentricity between GIB and the retrofitted column due to installation on the efficiency of the retrofitting system is studied. In addition, a modification in the determination method of GIB properties is introduced to reduce the eccentricity effect. Also, the effect of GIB system on the seismic response of mid-rise buildings with different heights considering soft-story at various heights has been studied. A numerical model is developed to study the impact of such system on the response of retrofitted soft-story buildings under the action of seismic loads. To achieve that goal, this model is used to perform a numerical investigation, by considering five case study scenarios represent several locations of soft-story of two mid-rise reinforced concrete buildings. At first, Non-linear static pushover analysis was carried out to develop the capacity curves for case studies. Then, Non-linear time history analyses using ten earthquake records with five peak ground accelerations is performed for each case study scenario before and after retrofitting with GIB. The results show that large GIB eccentricity reduce the ultimate lateral resistance and deformation capacity of the retrofitting system. Moreover, the higher the retrofitted building, the more deformation capacity is observed but without significant increase in ultimate lateral resistance.

Zero Voltage Soft Switching PWM High-Frequency Inverter with Active Inductor Snubber for Induction Heated Roller in New Type Copy Machine

  • Muraoka S.;Feng Y.L.;Kunimoto H.;Chandhaket S.;Okuno A.;Nakaoka M.
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.75-79
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    • 2001
  • This paper presents a novel version of an active voltage clamped ZVS-PWM high frequency inverter using IGBTs for electromagnetic induction eddy current-based rolling drum heating in new generation copy and printing machines in consumer business use. The operating principle of this inverter circuit and unique features are described herein. Its constant frequency duty cycle (asymmetrical PWM) controlled voltage source quasi-resonant soft switching high frequency inverter employing IGBTs is proposed, which is capable of achieving stable and efficient zero voltage soft switching commutation over a widely specified power regulation range from full power to low power. The operating performances in a steady state of this inverter is discussed and evaluated on basis of simulation and experimental results as an induction heated roller in new generation copy machine.

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Development of Induction Heated Hot Water Producer using Soft Switching PWM High Frequency Inverter

  • Fujita Kentarou;Moisseev Serguei;Gaimage Laknath;Chandhaket Sarawouth;Muraoka Hidekazu;Nakaoka Mutsuo
    • Proceedings of the KIPE Conference
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    • 2003.07b
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    • pp.491-494
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    • 2003
  • This paper presents a new conceptual electromagnetic induction eddy current-based stainless steel plate spiral type heater for heat exchanger or Dual Packs Heater in hot water producer, boiler steamer and super heated steamer, which is more suitable and acceptable for new generation consumer power applications. In addition, all active clamped edge resonant PWM high frequency inverter using trench gate IGBTs power module can operate under a principle oi zero voltage soft communication with PWM is developed and demonstrated for a high efficient Induction heated hot water producer and boiler in the consumer power applications. This consumer induction heater power appliance using active clamp soft switching PWM high frequency inverter is evaluated and discussed on the basis of the simulation and experimental results.

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The Influence of Charged Static Electricity on LCD Glass and Neutralization Characteristic by Soft X-ray

  • Choi, Chang-Hoon;Han, Sang-Ho;Park, Sun-Woo;Yun, Hae-Sang
    • Journal of Information Display
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    • v.1 no.1
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    • pp.52-58
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    • 2000
  • We observed that static electricity has an influence on the etching unformity of dry etching process. When the static electricity was applied from-200[V]to-1000[V] on glass substrates, the etching rate uniformity was changed to 1.5%-15%. In this experiment, the soft X-ray to neutralize static electricity was adopted as ore of neutralization methods. As an experimental result, soft X-ray irradiation improved neutralization capability on the surface of LCD glass substrate within the short time, about 15-30sec. The difference of etching rate uniformity was below 0.5%.

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Soft Switching Three Phase Inverter with Two Auxiliary Switches

  • Mahdavi, Mohammad;Amini, Mohammad Reza;Emrani, Amin;Farzanehfa, Hosein
    • Journal of Power Electronics
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    • v.11 no.6
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    • pp.787-792
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    • 2011
  • In this paper, a new three phase soft switching inverter is presented. All of the semiconductor elements of this converter are soft switched. Employing only two auxiliary switches as DC-link switches and a simple control circuit are the advantages of the proposed inverter. The analytical equations and operating modes of the presented inverter are explained in details. The design considerations are presented and the experimental results verify the theoretical analysis.

Basic Study of a Phase-Shifted Soft Switching High-Frequency Inverter with Boost PFC Converter for Induction Heating

  • Kawaguchi, Yuki;Hiraki, Eiji;Tanaka, Toshihiko;Nakaoka, Mutsuo
    • Journal of Power Electronics
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    • v.8 no.2
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    • pp.192-199
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    • 2008
  • This paper is mainly concerned with a high frequency soft-switching PWM inverter suitable for consumer induction heating systems. The proposed system is composed of a soft switching chopper based boost PFC converter stage with passive snubber and phase shifted PWM controlled full bridge ZVZCS high frequency inverter stage. Its fundamental operating performances are illustrated and evaluated in the experimental results. Its effectiveness is substantially proved on the basis of the experimental results from a practical point of view.

COMPUTER SIMULATION OF MAGNETIC PROPERRTIES OF SPRING MAGNETS

  • Kitajima, N.;Inoue, H.;Kanai, Y.;Fukunaga, H.
    • Journal of the Korean Magnetics Society
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    • v.5 no.5
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    • pp.404-407
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    • 1995
  • Magnetic properties of model exchange-spring magnets, which are composed of magnetically soft and hard grains, were calculated by means of computer simulation. The dependence of the magnetic properties on the strength of intergrain exchange interaction and the amount of soft grains was studied. The existence of soft grains enhanced the remanence remarkably, and the remanence over $0.8M_{s}$ was obtained in the model magnets containing 25% or more soft grains by volume. The calculated coercivity vs. the strength of the exchange interaction curves showed a peak at a critical strength of the exchange interaction, although the remanence increased monotonously with increase in the strength of the exchange interaction. Thus the maximum energy product also reached a peak around the same critical strength. The calculated maximum energy product exceeded $300kJ/m^{3}$ when the magnet is assumed to be composed of $Fe_{3}B$ and $Nd_{2}Fe_{14}B$.

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