• Title/Summary/Keyword: k-club

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Reduction of Electromagnetic Force in AC Distributed Winding of Fault Current Limiter under Short-Circuit Condition

  • Ghabeli, Asef;Yazdani-Asrami, Mohammad;Doroudi, Aref;Gholamian, S. Asghar
    • Journal of Magnetics
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    • v.20 no.4
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    • pp.400-404
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    • 2015
  • Various kinds of winding arrangements can be used to enable fault current limiters (FCL) to tolerate higher forces without resulting in a substantial increase in construction and fabrication costs. In this paper, a distributed winding arrangement is investigated in terms of its effects on the short-circuit forces in a three-phase FCL. The force magnitudes of the AC supplied windings are calculated by employing a finite element-based model in the time stepping procedure. The leakage flux and radial and axial force magnitudes obtained from the simulation are compared to those obtained from a conventional winding arrangement. The comparison shows that the distributed winding arrangement significantly reduces the radial and, especially, the axial force magnitudes.

Isolation and Characterization of Streptomyces sp. KACC 91027 Against Plasmodiophora brassicae

  • Kim, Seung-Hyung;Shin, Choon-Shik;Moon, Sang-Ik;Yi, Young-Sub;Choi, Gyung-Ja;Cho, Kwang-Yun;Song, Jae-Kyeong;Lim, Yoon-Gho
    • Journal of Microbiology and Biotechnology
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    • v.14 no.1
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    • pp.220-223
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    • 2004
  • Club root caused by Plasmodiophora brassicae is found in crucifers. Among the over hundreds of Streptomyces isolated from soil in Korea. One strain showed prominent activity against P. brassicae. The strain was identified based on 16S rDNA sequencing and the morphology by a method of scanning electron microscopy. An active compound in the fermented broth obtained from the strain was separated. Even though the complete assignments of the compound remain for future work, the results regarding the isolation and characterization of the strain with a certain activity against P. brassicae are shown in this paper.

Ultrastructure of the Integumentary System of the Amberjack, Seriola dumerili (Teleostei: Carangidae), from Korea (잿방어, Seriola dumerili 피부계의 전자현미경적 구조)

  • Jin, Young Guk;Lee, Jae Woo;Lee, Jung Sick
    • Korean Journal of Ichthyology
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    • v.17 no.4
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    • pp.248-254
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    • 2005
  • Integumentary structure of the amberjack, Seriola dumerili, was examined by light and transmission electron microscopy. Integument of the amberjack consists of epidermal and dermal layers. The epidermal thickness is about $28.32{\mu}m$. The epidermal layer could be classified into superficial, intermediate, and basal layers by morphology and position of the supporting cells. Secretory cells of the epidermal layer were classified into mucous cells and club cells in the amberjack. Mucous cells contained acidic mucous and were alcian-blue positive with AB-PAS (pH 2.5) reaction. The club cells contained well-developed rough endoplasmic reticula and large central vacuole. Also, filament-rich cells were identified in the epidermal layer. The dermal layer consists mainly of collagenous fiber, and it contains fibrocytes and pigment cells. The cytoplasm of fibrocyte had a well-developed rough endoplasmic reticulum. The pigment cells contained electron-dense melanin granules.

Effect of aggregate type on heated self-compacting concrete

  • Fathi, Hamoon;Lameie, Tina
    • Computers and Concrete
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    • v.19 no.1
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    • pp.33-39
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    • 2017
  • In this study, two types of aggregate were used for making self-compacting concrete. Standard cubic specimens were exposed to different temperatures. Seventy-two standard cylindrical specimens ($150{\times}300mm$) and Seventy-two cubic specimens (150 mm) were tested. Compressive strengths of the manufactured specimens at $23^{\circ}C$ were about 33 MPa to 40 MPa. The variable parameters among the self-compacting concrete specimens were of sand stone type. The specimens were exposed to 23, 100, 200, 400, 600, and $800^{\circ}C$ and their mechanical specifications were controlled. The heated specimens were subjected to the unconfined compression test with a quasi-static loading rate. The corresponding stress-strain curves and modulus of elasticity were compared. The results showed that, at higher temperatures, Scoria aggregate showed less sensitivity than ordinary aggregate. The concrete made with Scoria aggregate exhibited less strain. The heated self-compacting concrete had similar slopes before and after the peak. In fact, increasing heat produced gradual symmetrical stress-strain diagram span.

Design of Simple Neuro-controller for Global Transient Control and Voltage Regulation of Power Systems

  • Jalili-Kharaajoo Mahdi;Mohammadi-Milasi Rasoul
    • International Journal of Control, Automation, and Systems
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    • v.3 no.spc2
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    • pp.302-307
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    • 2005
  • A novel neuro controller based simple neuro-structure with modified error function is introduced in this paper. This controller consists of two independent controllers, known as the voltage regulator and the angular controller. The voltage regulator is used to modify terminal voltage for the purpose of tracking a reference voltage. The angular controller is utilized to guarantee the stability of the system. In this structure each neuron uses a linear hard limit activation function that depends on the controlled variable and its derivatives. There is no need for parameter identification or any off-line training data. Two proposed controllers are merged by a smooth switch to build a complete controller. The effectiveness of the proposed novel control action is demonstrated through some computer simulations on a Single-Machine Infinite-Bus (SMIB) power system.

Seismic behavior of special moment-resisting frames with energy dissipating devices under near source ground motions

  • Bayat, Mahmoud;Bayat, Mahdi
    • Steel and Composite Structures
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    • v.16 no.5
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    • pp.533-557
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    • 2014
  • In this study, the performances of the SMRF building equipped with energy dissipating devices are studied. Three types of these structures with different heights are considered. The Added Damping and Stiffness (ADAS) devices are used as energy dissipating devices in these structures. The behavior of these structures with ADAS devices subjected to near source ground motions are investigated. Three SMRF buildings with five, ten and fifteen-story, with ADAS devices were chosen. The nonlinear time history analysis was used by applying the near source ground motions with PERFORM 3D.V4 and conclusions are drawn upon an energy criterion. The effect of PGA variation and height of the frames are also considered based on the energy criterion.

Accurate semi-analytical solution for nonlinear vibration of conservative mechanical problems

  • Bayat, Mahmoud;Pakar, Iman
    • Structural Engineering and Mechanics
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    • v.61 no.5
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    • pp.657-661
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    • 2017
  • In this paper, it has been tried to propose a new semi analytical approach for solving nonlinear vibration of conservative systems. Hamiltonian approach is presented and applied to high nonlinear vibration systems. Hamiltonian approach leads us to high accurate solution using only one iteration. The method doesn't need any small perturbation and sufficiently accurate to both linear and nonlinear problems in engineering. The results are compared with numerical solution using Runge-Kutta-algorithm. The procedure of numerical solution are presented in detail. Hamiltonian approach could be simply apply to other powerfully non-natural oscillations and it could be found widely feasible in engineering and science.

A Study on a Robot Club, Whose School Implements a 5-dimension Education - Examples are from Bell International Academy - (비인가 대안학교에서 5차원 전면교육을 활용한 로봇 동아리 프로그램 운영에 관한 연구 -벨 국제아카데미 사례 -)

  • Hong, Lok-Ki;Kim, Eui-Jeong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.407-410
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    • 2013
  • This paper has been written to apply the lessons of this course through a 5-dimension education curriculum from BELL International Academy, an alternative school. By integration a 5-dimension education in the school, teachers may be able to have an impact on their students, A robot club in a 5-dimension educated school migh help motivate students to take the necessary steps to accomplish their goals.

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Analytical study on non-natural vibration equations

  • Bayat, Mahmoud;Pakar, Iman
    • Steel and Composite Structures
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    • v.24 no.6
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    • pp.671-677
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    • 2017
  • In this paper, two powerful analytical methods called Variational Approach (VA) and Hamiltonian Approach (HA) are used to solve high nonlinear non-Natural vibration problems. The presented approaches are works well for the whole range of amplitude of the oscillator. The first iteration of the approaches leads us to high accurate solution. Numerical results are also presented by using Runge-Kutta's [RK] algorithm. The full comparison between the presented approaches and the numerical ones are shown in figures. The effects of important parameters on the response of nonlinear behavior of the systems are studied completely. Finally, the results show that the Variational Approach and Hamiltonian approach are strong enough to prepare easy analytical solutions.

Soft-$golf^{TM}$ Shaft Kick Point and Stiffness due to the Difference in Performance Analysis (소프트 골프 샤프트의 킥 포인트와 강성의 차이에 따른 성능 분석)

  • Oh, H.Y.;Yu, M.;Kim, S.H.;Jang, J.H.;Kim, N.G.;Kim, D.W.
    • Journal of Biomedical Engineering Research
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    • v.31 no.3
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    • pp.227-233
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    • 2010
  • This study analyzed performance according to kick point and stiffness of Soft-$golf^{TM}$ shaft. This research team developed soft-$golf^{TM}$ as a new fusion sports with similar motions with golf and it can be learned safely for all age groups in 2002. The head of Soft-$golf^{TM}$ club is made of zinc alloy and has a mesh or a grid structure, and shaft uses carbon graphite to reduce the total weight of the club. To improve carry distance and to assure consistency of a ball during Soft-$golf^{TM}$ swing, this study manufactured shaft with various kick points (low, middle and high) and stiffness (stiff, regular, lady, morelady) and analyzed a swing motion with characteristics of each shaft presented in a dynamic condition such as a ball's speed, a head's torsion angle and a ball's deviation with ProAnalyst program through a high-speed camera taking pictures using a swing machine robot system(Robo-7). From all of the results, this study determined an appropriate shaft of Soft-$golf^{TM}$.