• Title/Summary/Keyword: Phase Sequence Set

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A Low Cost Speed Control System of PM Brushless DC Motor Using 2 Hall-ICs (2 Hall-ICs를 이용한 저가형 PM Brushless DC Motor속도 제어)

  • Kim D. K.;Yon Y. H.;Woo M. S.;Won C. Y.;Choe Y. Y.
    • Proceedings of the KIPE Conference
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    • 2003.11a
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    • pp.132-136
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    • 2003
  • Generally, PM BLDC drive system is necessary that the three Hall-ICs evenly be distributed around the stator circumference and encoder be installed in case of the 3 phase motor. So, the Hall-ICs are set up in this motor to detect the main flux from the rotor, and the output signal from Hall-ICs is used to drive a power transistor to control the winding current. However, instead of using three Hall-ICs and encoder, we used only two Hall-ICs for the permanent magnet rotor position and for the speed feedback signals, and also for a micro controller of 16-bit type (80C196KC) with the 3 phase PM BLDC whose six stator and two rotor designed. Two Hall-IC Hc and $H_B$ are placed on the endplate at 120 degree intervals, and with these elements, we estimated information of the others phase in sequence through a rotating rotor.

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Silent Magnetic Resonance Imaging Using Rotating and Projection Reconstruction (회전 경사자계와 사상 재구성을 이용한 무소음 자기 공명 영상법)

  • Chung, S.T.;Park, S.H.;Cho, Z.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.555-558
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    • 1997
  • A new approach to silent MR imaging using a rotating DC gradient has been explored and experimentally studied. As is known, acoustic or sound noise has been one of the major problems in handling patients, mainly due to the fast gradient pulsings in interaction with the main magnetic field. The sound noise is also proportionally louder as the magnetic field strength becomes larger. In this article, we have described a new imaging technique using a mechanically rotating DC gradient coil as an approach toward silent MR imaging, i.e., a mechanically rotated DC gradient effectively replaces both the phase encoding as well as the readout gradient pulsings and data obtained in this manner provides a set of project ion data which later can be used or the projection reconstructionorwithsomeinterpolation techniques one can also perform conventional 2-D FFT (Fast Fourier Transform) image reconstruction. We found, with this new technique, that the sound noise intensity compared with the conventional imaging technique, such as spin echo sequence, is reduced down to -20.7 dB or about 117.5 times. The experimental pulse sequence and its principle are described and images obtained by the new silent MR imaging technique are reported.

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Construction of a Transcriptome-Driven Network at the Early Stage of Infection with Influenza A H1N1 in Human Lung Alveolar Epithelial Cells

  • Chung, Myungguen;Cho, Soo Young;Lee, Young Seek
    • Biomolecules & Therapeutics
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    • v.26 no.3
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    • pp.290-297
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    • 2018
  • We aimed to understand the molecular changes in host cells that accompany infection by the seasonal influenza A H1N1 virus because the initial response rapidly changes owing to the fact that the virus has a robust initial propagation phase. Human epithelial alveolar A549 cells were infected and total RNA was extracted at 30 min, 1 h, 2 h, 4 h, 8 h, 24 h, and 48 h post infection (h.p.i.). The differentially expressed host genes were clustered into two distinct sets of genes as the infection progressed over time. The patterns of expression were significantly different at the early stages of infection. One of the responses showed roles similar to those associated with the enrichment gene sets to known 'gp120 pathway in HIV.' This gene set contains genes known to play roles in preventing the progress of apoptosis, which infected cells undergo as a response to viral infection. The other gene set showed enrichment of 'Drug Metabolism Enzymes (DMEs).' The identification of two distinct gene sets indicates that the virus regulates the cell's mechanisms to create a favorable environment for its stable replication and protection of gene metabolites within 8 h.

A Proof Method of Logic Programs in Parallel Environment (병렬화를 위한 논리 프로그램의 증명 방법)

  • 이원석
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.3
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    • pp.425-438
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    • 1993
  • Due to the producer-consumer dependency of shared variables, the potential parallelism embeded in the logic programming language has not been fully examined. The method proposed in this paper eliminates the dependency of shared variables by introducing number-sequenced variables in expanding an AND-OR proof tree. Basically, the execution of a logic program can be divided into two phases : expanding an AND-OR tree and proving the tree by matching facts with leaf nodes. In the course of the first phase, a set of number-sequenced variables are produced by expanding an AND-OR tree in the breadth-first searching. Based on the information of number-sequence, each of them is verified in the second phase in order to prove the tree. Consequently, the proposed algorithm can explore more parallelism without the dependency of shared variables.

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Identification of csp Homolog in Bradyrhizobium japonicum

  • No, Jae-Sang;Yu, Ji-Cheol;So, Jae-Seong
    • 한국생물공학회:학술대회논문집
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    • 2001.11a
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    • pp.602-605
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    • 2001
  • Low-temperature adaptation and protection for environmental stresses were studied in the gram-negative soil bacterium Bradyrhizobium japonicum 61A101c. B. japonicum was more resistant to alcohol, $H_2O_2$, heat and freezing following a pretreatment at $4^{\circ}C$, resulting in approximately 10 to 1,000 folds increased survival compared to mid-exponential-phase cells grown at an optimal temperature at $28^{\circ}C$. This phenomena relate to the cold shock protein expressed when cells are exposed to a downshift in temperature. To confirm the presence of cold shock protein genes in B. japonicum, a PCR strategy was employed using a degenerate primer set, which successfully amplified a putative csp gene fragment. Sequence analysis of the PCR product(200bp) revealed csp-like sequences that were up to 96% identical to csp gene of S. typhimurium.

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A Study of Function Verification of Digital Excitation System with Real Time Simulator (시뮬레이터 탑재형 디지털 여자시스템 기능검증 시험에 관한 연구)

  • Ryu, Ho-Seon;Shin, Man-Su;Lee, Joo-Hyun;Lim, Ick-Hun
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1191-1192
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    • 2011
  • We released new triple redundant digital excitation system with real time generator-turbine simulator. One of its great merits is the real time generator-turbine simulator when it was compared with the other products. If excitation system is tripped by unexpected faults, Maintenance man can do easily performance test of digital excitation control board, sequence relay and thyristor switching device of phase controlled rectifier without manufacturer's support. For the verification of this system, It was tested with an actual excitation system implemented on 5kVA M-G Set. After finishing the tests, the trial product will be installed and operated at a 500MW thermal power plant.

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Feature-Strengthened Gesture Recognition Model based on Dynamic Time Warping (Dynamic Time Warping 기반의 특징 강조형 제스처 인식 모델)

  • Kwon, Hyuck Tae;Lee, Suk Kyoon
    • KIPS Transactions on Software and Data Engineering
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    • v.4 no.3
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    • pp.143-150
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    • 2015
  • As smart devices get popular, research on gesture recognition using their embedded-accelerometer draw attention. As Dynamic Time Warping(DTW), recently, has been used to perform gesture recognition on data sequence from accelerometer, in this paper we propose Feature-Strengthened Gesture Recognition(FsGr) Model which can improve the recognition success rate when DTW is used. FsGr model defines feature-strengthened parts of data sequences to similar gestures which might produce unsuccessful recognition, and performs additional DTW on them to improve the recognition rate. In training phase, FsGr model identifies sets of similar gestures, and analyze features of gestures per each set. During recognition phase, it makes additional recognition attempt based on the result of feature analysis to improve the recognition success rate, when the result of first recognition attempt belongs to a set of similar gestures. We present the performance result of FsGr model, by experimenting the recognition of lower case alphabets.

Performance Analysis of Modulator using Direct Digital Frequency Synthesizer of Initial Clock Accumulating Method (클록 초기치 누적방식의 직접 디지털 주파수 합성기를 이용한 변조기의 성능해석)

  • 최승덕;김경태
    • Journal of the Korean Institute of Telematics and Electronics T
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    • v.35T no.3
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    • pp.128-133
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    • 1998
  • This paper is study on performance analysis of modulator using direct digital frequency synthesizer of Initial Clock Accumulating Method. It has been generally used for PLL or digital frequency synthesizing method to be synthesizd randomly chosen frequency state. In order to improve disadvantage of two methods, we constructed modulator system using DDFS of Initial Clock Accumulating Method. We also confirmed the coherence frequency hopping state and possibility of phase control. The results obtained from the experiments are as follows; First, the synthesized output frequency is proportional to the sampling frequency, according to index, K. Second, the difference of the gain between the basic frequency and the harmonic frequencies was more than 50 [dB], that is, this means facts that is reduced the harmonic frequency factor. Third, coherence frequency hopping state is confirmed by PN code sequence. Here, we confirmed the proposed method cut switching time, this verify facts that is the best characteristic of the frequency hopping. We also verified the fact that the phase varies as the adder is operated set or reset.

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Speed Control of Three Phase Slotless PM BLDC Motor Using Single Sensor (Single Sensor를 이용한 3상 슬롯리스 PM BLDC 전동기의 속도제어)

  • Yoon Y. H.;Kim Y. C.;Lee S. S.;Won C. Y.;Choe Y. Y.
    • The Transactions of the Korean Institute of Power Electronics
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    • v.9 no.6
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    • pp.536-543
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    • 2004
  • Slotless Permanent Magnet Brushless DC Motor(PM BLDC) with the characteristics of high speed and power density has been more widely used In Industrial and factory machine. Generally, PM BLDC meter is necessary that the three Hall-lCs evenly be distributed around the stator circumference in case of the 3 phase motor. The Hall-ICs are set up in PM BLDC Motor to detect the main flux from the rotor. therefore the output signal from Hall-ICs is used to drive a power transistor to control the stator winding current. However, instead of using three Hall-ICs, if it used only one Hall-IC, we can estimate information of the others phase in sequence through a rotor This paper identified the characteristics and performance by using one Hall-IC with the 3-phase, 2-pole, 6-slot PM BLDC motor.

Low Cost Speed Control System of PM Brushless DC Motor Using 2 Hall-ICs (2Hall-ICs를 이용한 저가형 PM Brushless DC Motor 속도 제어)

  • 윤용호;우무선;김덕규;원충연;최유영
    • The Transactions of the Korean Institute of Power Electronics
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    • v.9 no.4
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    • pp.311-318
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    • 2004
  • Generally, PM BLDC drive system is necessary that the three Hall-ICs evenly be distributed around the stator circumference and encoder installed in case of the 3 phase motor. The Hall-ICs are set up in this motor to detect the main flux from the rotor. So the output signal from Hall-ICs is used to drive a power transistor to control the stator winding current. Instead of using three Hall-ICs and encoder, this paper uses only two Hall-ICs for the permanent magnet rotor position and for the speed feedback signals, and uses a micro controller of 16-bit type(80C196KC) with the 3 phase PM BLDC whose six stator and two rotor designed. Two Hall-IC Hc and $H_B$ are placed on the endplate at 120 degree phase difference. With these elements, we estimate information of the other phase in sequence through a rotating rotor.