• 제목/요약/키워드: Synchronous Interaction

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A Collaborative Visual Language

  • Kim, Kyung-Deok
    • Journal of information and communication convergence engineering
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    • 제1권2호
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    • pp.74-81
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    • 2003
  • There are many researches on visual languages, but the most of them are difficult to support various collaborative interactions on a distributed multimedia environment. So, this paper suggests a collaborative visual language for interaction between multi-users. The visual language can describe a conceptual model for collaborative interactions between multi-users. Using the visual language, generated visual sentences consist of object icons and interaction operators. An object icon represents a user who is responsible for a collaborative activity, has dynamic attributes of a user, and supports flexible interaction between multi-users. An interaction operator represents an interactive relation between multi-users and supports various collaborative interactions. Merits of the visual language are as follows: supporting of both asynchronous interaction and synchronous interaction, supporting flexible interaction between multi-users according to participation or leave of users, supporting a user oriented modeling, etc. For example, an application to a workflow system for document approval is illustrated. So we could be found that the visual language shows a collaborative interaction.

Design of an Electromagnet with Low Detent Force and its Control for a Maglev Super-speed Vehicle

  • Lim, Jaewon;Kim, C.H.;Han, J.B.;Han, H.S.
    • Journal of Electrical Engineering and Technology
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    • 제10권4호
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    • pp.1667-1673
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    • 2015
  • The vibration and noise caused by the dynamic interaction between electromagnetic suspension and the linear synchronous motor stator beneath a flexible guideway remain problems in designing attractive Maglev trains. One possible method to reduce the sources of vibration is to minimize the detent force in the linear synchronous motor that creates variations in both lift force and thrust. This paper proposes lowering detent force by using separated core instead of single united core. The magnet is designed to adapt to the deflected guideway at a speed of 550km/h. This study will analyze the electromagnetic field and control performance, and how they relate to lift forces and dynamic responses.

영구자석 계자형 동기발전기의 고주파 저감을 위한 자기회로 최적설계 (Shape Optimization for the EMF Harmonics Reduction of PM Type Synchronous Generators)

  • 김영균;이재건;임양수;강규홍;홍정표;장기찬
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제50권10호
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    • pp.494-500
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    • 2001
  • This paper presents the shape optimization to minimize the BEMF(Back Electro-Motive Force) harmonics of PM type synchronous generators. RSM(Response Surface Methodology) is well adapted to make analytical model for a complex problem considering a lot of interaction of design variables. In this paper, RSM is used to find the optimal solution. The 2D-Finite Element Method is used to obtain the observer data of the BEMF and SQP(Sequential Quadratic Problem method) is used to solve the constrained nonlinear optimization problem.

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Implementation of Thrust Ripple Reduction for a Permanent Magnet Linear Synchronous Motor Using an Adaptive Feed Forward Controller

  • Baratam, Arundhati;Karlapudy, Alice Mary;Munagala, Suryakalavathi
    • Journal of Power Electronics
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    • 제14권4호
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    • pp.687-694
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    • 2014
  • This paper focuses on the analysis and compensation of thrust ripples in permanent magnet linear synchronous motors (PMLSM). The main drawback in PMLSMs is the presence of thrust ripples, which are mainly due to the interaction between the permanent magnets and armature slotted core. These thrust ripples reduce the performance of the drive system in high precision applications especially at low speeds. This paper analyzes thrust ripples using the discrete wavelet transform. These undesired thrust ripples are compensated by using an adaptive feed forward controller. It is observed that this novel controller reduces about 65 percent of the thrust ripples. An extensive simulation is performed through MATLAB and it is validated through experimental results using a d-SPACE system with a DS1104 control board.

양수발전소 동기전동기의 기동제어 알고리즘에 관한 연구 (A study developing control algorithm for Pumped-Storage Synchronous motor drive)

  • 강승우;박신현;김장목;임익헌;류호선;김진성
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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    • pp.467-471
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    • 2003
  • The large synchronous motor for the pumped-storage plant(or SFC : Static Frequency Converter) has to be brought up to 100$\%$ rated speed and synchronized with the AC power network. Starting the motor from rest is achieved by switching current into the stator winding so that interaction between this stator current and the rotor flux will cause the correct direction of torque to be developed so that the motor turns in the required direction. Starting ranges of the synchronous motor are divided into three regions. The first region Is at standstill, the second that is called by the forced commutation is from standstill to 5-8$\%$ of rated speed, and the third, which is called by the natural commutation, is from 5-8$\%$ of rated speed to 100$\%$ rated speed. So this paper describes three regions of the control techniques of the pumped-storage synchronous motor drive.

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초전도 선형동기전동기 추진 휠-레일 고속열차의 동특성 분석 (Dynamic Analysis of Wheel-Rail High Speed Train Propelled by Superconducting Linear Synchronous Motor)

  • 이진호;이창영;조정민;한영재
    • 한국산학기술학회논문지
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    • 제17권1호
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    • pp.119-125
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    • 2016
  • 본 논문에서는 기존 휠-레일 고속열차에 자기부상열차의 추진방법을 적용한 하이브리드 방식의 고속열차의 주행 동특성에 대해서 연구하였다. 초전도 선형동기전동기를 추진 동력으로 하는 휠-레일 방식의 고속열차는 강력한 추진력을 지니면서도 자기부상열차에 비해 기존 선로와의 호환성 및 경제성 측면에서 유리할 것으로 예상된다. 본 논문에서는 초전도 선형동기전동기를 기존의 휠-레일 고속철도에 적용하는 두 가지 방안에 대해서, 초전도 선형동기전동기 추진이 휠-레일 고속열차의 동특성에 미치는 영향을 살펴보기 위하여 초전도 선형동기전동기의 회전자와 고정자의 상호 작용을 검토하고 이를 포함한 차량의 동특성 모델을 구축하였다. 구축된 모델을 이용한 시뮬레이션을 통해 초전도 선형동기전동기의 회전자와 고정자의 상호 작용이 주행 중 고속 안정성, 승차감 및 가이드웨이 불규칙도에 미는 영향을 분석하였다.

Wind-induced responses of supertall buildings considering soil-structure interaction

  • Huang, Yajun;Gu, Ming
    • Wind and Structures
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    • 제27권4호
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    • pp.223-234
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    • 2018
  • In this study, a simplified three-dimensional calculation model is developed for the dynamic analysis of soil-pile group-supertall building systems excited by wind loads using the substructure method. Wind loads acting on a 300-m building in different wind directions and terrain conditions are obtained from synchronous pressure measurements conducted in a wind tunnel. The effects of soil-structure interaction (SSI) on the first natural frequency, wind-induced static displacement, root mean square (RMS) of displacement, and RMS of acceleration at the top of supertall buildings are analyzed. The findings demonstrate that with decreasing soil shear wave velocity, the first natural frequency decreases and the static displacement, RMS of displacement and RMS of acceleration increase. In addition, as soil material damping decreases, the RMS of displacement and the RMS of acceleration increase.

Fuzzy Modeling of a PMSM Chaotic System

  • Zhong Li;Joo, Young-Hoon;Park, Jin-Bae
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
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    • pp.153-156
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    • 2000
  • In this paper, a mathematical model of a permanent-magnet synchronous motor (PMSM) is derived, and the steady-state characteristics of this system, when subject to constant input voltages and constant external torque, are formulated. It is shown that the PMSM model can exhibit a variety of chaotic phenomena, under some choices of system parameters and external inputs. Based on TS fuzzy modeling methodology, the TS fuzzy model of the PMSM chaotic system is presented, so the interaction between fuzzy system and chaos can be explored, and then fuzzy-model-based control methodologies can be used to control chaos in chaotic systems. Computer simulations show that the strange attractors in the derived TS fuzzy system and original chaotic system are topologically equivalent.

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Halbach 배열 영구자석형 Planar Motor의 수직력 최소화 (Normal Force Minimization of the Synchronous Permanent Magnet Planar Motor with Halbach Magnet Array)

  • 김덕현;김규탁
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제55권11호
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    • pp.582-588
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    • 2006
  • This paper presents the characteristics analysis and normal force minimization of a synchronous permanent magnet planar motor(SPMPM) with Halbach magnet way. Firstly, the flux density distribution is calculated by analytical method; then, the characteristics of this SPMPM are evaluated, some experiments have been done to verify the analysis propriety and to investigate the interaction among the characteristics; At last, the normal force is minimized by using genetic algorithm and it is decreased from 672.83[N] to 144.24[N] remarkably.

Interactional Modifications in Text-based Chats between Korean and Japanese Students

  • Chu, He-Ra
    • 영어어문교육
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    • 제12권2호
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    • pp.1-18
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    • 2006
  • This study investigates the types of interactional modifications employed by Japanese and Korean university students during text-based chats. In particular, this study focuses on the role of a network-based medium on the use of interactional modifications, which have been claimed to facilitate interlanguage development. The results show that students use a variety of features of interactional modifications. The most used strategies were the use of paralinguistic features, framing, overt indication of understanding/agreement, and clarification checks, which reveals inconsistent results with findings from research on the negotiation of meaning in face-to-face interaction. Results suggest that the computer-mediated communication (CMC) environment requires the above mentioned strategies and students are able to adapt to this new context by employing alternative strategies. The majority of negotiations were generated by content and lexical items either to resolve communication problems or to better manage interactions, and very few negotiations occurred in terms of grammar. The findings suggest that text-based synchronous chats can be an effective tool for promoting interactive competence, but their effectiveness on grammatical development is uncertain.

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