• Title/Summary/Keyword: control period

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Sag Voltage Compensator using Diode Rectifier and Series Inverter (다이오드 정류기와 인버터를 이용한 순간 전압 강하 보상기)

  • 이준기;박덕희;김희중;한병문;소용철
    • Proceedings of the KIPE Conference
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    • 1999.07a
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    • pp.448-451
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    • 1999
  • This paper describes controller development for a dynamic voltage compensator using a shunt diode converter and series inverter. The control system was designed using 1/4 period integrator and vector relationship between the supply voltage and load voltage. A simulation model and scaled hardware model were developed for analyzing performance of the controller and the whole system. Both results confirm that the dynamic compensator can restore the load voltage under the fault of the distribution system.

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Heuristic Task Allocation for Multiprocessor Controller Systems Considering Shared Resource Access

  • Seon, Ryou-Myung;Hyun, Kwon-Wook
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.140.3-140
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    • 2001
  • This paper analyzes a blocking that is due to shared resource in multiprocessor system. A proposed analysis for shared resource suggests a scalable and amendable scheduling method about task allocation. An equation of shared resource blocking is proposed by a throughput at common bus and a ratio of throughput during time period, it is included a parameter of tasks scheduling. Using this equation, a new guideline for task allocation of multiprocessor is presented. Finally, in proposed system a model simulations for the proposed blocking model is given by a deterministic ratio of shared resource.

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Proper Decision for Maintenance Intervals of Equipment in Power Stations by Considering Maintenance Replacement Rate and Operation Rate

  • Nakamura, Masatoshi;Suzuki, Yoshihiro;Hatazaki, Hironori
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.157.3-157
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    • 2001
  • In this paper, the optimal maintenance scheduling for turbine with considering maintenance replacement rate was proposed in order to reduce the maintenance cost during the whole period of operation, meanwhile keeping current reliability of turbine. The proposed method is only based on a few limited available data with various factors relating to maintenance replacement and repair of turbine. The proposed method will be adopted by Kyushu Electric Power Co., Inc. from April in 2002 to determine the maintenance schedule of thermal power plants.

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An experimental study on the human upright standing posture exposed to longitudinal vibration

  • Shin, Young-Kyun;Arif Muhammad;Inooka Hikaru
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.77.2-77
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    • 2002
  • Human upright standing posture in the sagittal plane is studied, when it exposed in the antero-posterior vibration. A two link inverted pendulum model is considered and described its functional behavior in terms of ankle and hip joint according to the dominant joints that provides the largest contribution to the corresponding human reactionary motion. The data is analyzed, both in the time domain and the frequency domain. Subjects behave as a non-rigid pendulum with a mass and a spring throughout the whole period of the platform motion. When vision was allowed, each segment of body shows more stabilized.

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An Effective Stopping Rule for Software Reliability Testing

  • Yoon, Bok-Sik
    • International Journal of Reliability and Applications
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    • v.3 no.2
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    • pp.81-90
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    • 2002
  • The importance of the reliability of software is growing more and more as more complicated digital computer systems are used for real-time control applications. To provide more reliable software, the testing period should be long enough, but not unnecessarily too long. In this study, we suggest a simple but effective stopping rule which can provide just proper amount of testing time. We take unique features of software into consideration and adopt non-homogeneous Poisson process model and Bayesian approach. A numerical example is given to demonstrate the validity of our stopping rule.

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Current Status and Future Tasks of Clean Coal Technologies in the Asia Pacific Region

  • Son, Jae-Ek
    • Journal of Energy Engineering
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    • v.5 no.1
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    • pp.1-7
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    • 1996
  • Coal consumption in Asia is projected to increase by about 1.3 billion tons over the 1993-2010 period. The expansion in coal consumption for electricity generation is the dominant factor in the large increase in coal consumption. Without effective control measures, the projected increase in coal consumption will have a serious impact on environmental effects of increased coal use in Asia. Thus, the introduction of appropriate CCTs is considered essential to achieving the twin goals of expanded use of coal decreased environmental impacts.

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DEVELOPMENT OF AN AUTOMATIZED DIFFERENTIAL PHOTOMETRY SYSTEM FOR THE 61CM REFLECTOR OF SOBAEKSAN OBSERVATORY (소백산 천문대 61CM 반사망원경을 위한 자동 차등측광 시스템의 개발)

  • Park, Nam-Gyu
    • Publications of The Korean Astronomical Society
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    • v.8 no.1
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    • pp.185-197
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    • 1993
  • We developed an Automatized Differential Photometry System (ADPS) to achieve high time resolution and high efficiency in the photometric observations of short period variable stars. This ADPS has been introduced to the CCD camera system attached to the 6lcm Reflector at Sobaeksan Astronomy Observatory. Several new algorithms were devised for the controlling the telescope. the star recognition in a CCD frame and the aperture photometry, etc..As the result, the differential photometric observation was fully automatized without any manual control, and much faster data acquisition could be achieved over the conventional photoelectric differential photometry.

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Effects of Training in Art Criticism on Children's Aesthetic Responses and Expressive Abilities (미술비평 활동이 유아의 미적 반응 및 표현 능력에 미치는 영향)

  • Lim, Soo Jin;Lee, Jeong Wuk
    • Korean Journal of Child Studies
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    • v.20 no.2
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    • pp.187-204
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    • 1999
  • The 20 five-year-old kindergarteners in the experimental group participated in 14 art criticism activities over an 8 week period. Analysis of the data by frequency, percentage, and t-test showed differences between the experimental and control groups. The experimental group improved in Visual Cue-Attendance and Evaluative Judgmental categories. Children in the experimental group also showed higher scores in organization of pictures and materials in their expressive art work. There were no differences between groups in sequence and contents of expression.

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Extensive Adenomatoid Odontogenic Tumor of the Maxilla: A Case Report of Conservative Surgical Excision and Orthodontic Alignment of Impacted Canine

  • Moon, Jee-Won
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.36 no.4
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    • pp.173-177
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    • 2014
  • The present report describe the surgical therapy, clinical course, orthodontic treatment and morphological characteristics of an adenomatoid odontogenic tumor in the maxilla of an 11-year-old patient. The cystic tumor filled the maxillary sinus and involved a tooth. Marsupialization was accompanied by partial enucleation and applied traction to the affected tooth by a fixed orthodontic appliance. Healing was uneventful and no local recurrence was observed during a 1-year period of follow-up control.

COMMON-MODE VOLTAGE PULSE CANCELLATION METHOD BASED ON SPACE-VECTOR PWM IN CONVERTER-INVERTER SYSTEM

  • Lee, Hyeoun-Dong;Sul, Seung-Ki
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.171-175
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    • 1998
  • This paper proposes the advanced PWM method that can reduce common-mode voltage in three-phase PWM converter-inverter system. By the proper distribution of the zero-voltage vector of inverter, it is possible to cancel out a common-mode voltage pulse in a sampling period. Since the proposed PWM method maintains the effective-voltage vector, it does not affect the control performance of converter-inverter system. Without any extra hardware, overall common-mode voltage can be decreased by one-third compared with conventional PWM scheme.

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