• 제목/요약/키워드: Chung Nam Dae

검색결과 312건 처리시간 0.024초

고속정보 전송에 의한 디지탈 ATS 시스템 (Digital ATS system by High Speed Information Transmission)

  • 박정수;장대식;김양모
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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    • pp.519-522
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    • 1995
  • ATS Systems are activated against the over-running and the crashes between trains. Up to now, ATS Systems have been constituted analog systems adopting the changed frequency method or amplitude modulation, which is impossible to give any essential informations. In this paper, it is dealt with digital ATS Systems which are replaced the former ATS Systems in the advanced nation of railways. Especially, this paper shows the possibility of any developments for the digital ATS Systems by the experiment of digital ATS Systems by Frequency Shift Keying method.

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FSK에 의한 디지탈 ATS시스템 (Digital ATS system by FSK)

  • 박정수;장대식;김양모
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 하계학술대회 논문집 A
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    • pp.460-462
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    • 1995
  • ATS Systems is activated against the over-running and the crashes between trains. Up to now, ATS Systems have been constituted analog systems adopting the changed frequency method or amplitude modulation, which is impossible to give any essential informations. In this paper, it is dealt with. digital ATS Systems which are replaced the former ATS Systems in the advanced nation of railways. Especially, this paper shows the possibility of any developments for the digital ATS Systems by the experiment of digital ATS systems by Frequency Shift Keying method.

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SSR을 제어하기 위한 직렬 보상 캐패시터에 관한 연구 (A study on series compensation capacitors to control subsynchronous resonance)

  • 김성남;이승환;이훈구;김용주;한경희;정연택
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 하계학술대회 논문집 A
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    • pp.434-436
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    • 1995
  • This paper was to determine the feasibility of controlling subsynchronous resonance(SSR) by the fast modulation of series compensation capacitors. The presence of subsynchronous currents in the system was detected by a subsynchronous relay which was modeled by the transient analysis of control systems (TACS) in the electromagnetic transients program (EMTP). The capacitor segments were switched by bi-directional thyristor swtiches. The paper proved that effective control of SSR can be obtained only by the detuning of the system and the removal or blocking of subsynchronous energy from the system.

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High-Speed Transformer for Panoptic Segmentation

  • Baek, Jong-Hyeon;Kim, Dae-Hyun;Lee, Hee-Kyung;Choo, Hyon-Gon;Koh, Yeong Jun
    • 방송공학회논문지
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    • 제27권7호
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    • pp.1011-1020
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    • 2022
  • Recent high-performance panoptic segmentation models are based on transformer architectures. However, transformer-based panoptic segmentation methods are basically slower than convolution-based methods, since the attention mechanism in the transformer requires quadratic complexity w.r.t. image resolution. Also, sine and cosine computation for positional embedding in the transformer also yields a bottleneck for computation time. To address these problems, we adopt three modules to speed up the inference runtime of the transformer-based panoptic segmentation. First, we perform channel-level reduction using depth-wise separable convolution for inputs of the transformer decoder. Second, we replace sine and cosine-based positional encoding with convolution operations, called conv-embedding. We also apply a separable self-attention to the transformer encoder to lower quadratic complexity to linear one for numbers of image pixels. As result, the proposed model achieves 44% faster frame per second than baseline on ADE20K panoptic validation dataset, when we use all three modules.

Screening of 3-Hydroxy-3-Methylglutaryl-Coenzyme a Reductase Inhibitors in vitro and Its Application to Pullets

  • Yeom, Keum-Hee;Hwang, Suk-Yeun;Lee, Kyung-Woo;Woo, Moon-Sook;Park, Sun;Min, Dae-Gyu;Lee, Bong-Duk;Sung, Chang-Keun
    • Preventive Nutrition and Food Science
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    • 제4권1호
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    • pp.70-74
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    • 1999
  • The primary objective of these studies was to screen the materials showing inhibitions of HMG-CoA reductase in vitro. The secondary objective was to determine the effect of garlic, lovastatin and copper on cholesterol concentrations in plasma. liver and brease muscle of pullets. In experiment 1, the degree of inhibition of the selective samples on HMG-CoA reductase activity was determined in vitro. The inhibition rate of water soluble garlic extracts, lovastatin and copper to HMG-coA reductase activity were 51.3%, 87.5%, and 82.0% respectively . In experiment 2, control diet (basal diet), garlic powder (3% in diet) , lovastatin (300mg/kg of diet) and copper(200mg/kg of diet) were fed to pullets in order to investigate the changes of cholesterol concentration in plasma and tissues. Plasma total cholesterol , and LDL-cholesterol were significantly reduced in pullets fed a diet containing 3 % garlic powder. However, coper significantly increased total cholesterol compared to controls and lovastatin did not affect plasma chholesterol concentration . Total cholesterol inlover and breast muscle inpullets were not affectedb y adding cholesterol lowering materials to the diets. The data suggests that it is not easy for HMG-CoA reductase inhibitors to reduce cholesterol levels in the body due to complication in cholestrol metabolism . However, garlic administration can lower the levels of plasma cholesterol in pullets.

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폐에 전이된 활막육종의 세침흡인 세포학적 소견 - 1 예 보고 - (Fine Needle Aspiration Cytology of Metastatic Synovial Sarcoma to the Lung - A Case Report -)

  • 강동욱;민성기;강길현;강대영
    • 대한세포병리학회지
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    • 제4권2호
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    • pp.171-175
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    • 1993
  • Synovial sarcoma us a rare malignant neoplasm of the soft tissue arising in the lower extremity, inguinal area, and upper arm. The majority occurs in patients between the age of 15 and 40 years. The histologic diagnosis is based on the classical biphasic type with the distinct epithelial and spindle cell components. We have recently encountered a case of metastatic synovial sarcoma of the lung diagnosed by fine needle aspiration cytology. A 34-year-old man was admitted because of a palpable mass on the antero-lateral side of the right tibia for 3 years. On admission, a well demarcated metastatic pulmonary nodule, measuring 5 cm in diameter, was also identified in the simple chest X-ray. Resection of the lower leg mass revealed typical histologic features of biphasic synovial sarcoma. Aspiration cytology of the pulmonary nodule revealed numerous clusters of spindle cells admixed with groups of epithelial cells. The epithelial cells had moderate-sized, round to oval shaped, and hyperchromatic nuclei. The cytoplasm was clear, but not distinctive. Interspersed tell elements were fibroblast-like spindle cells having elongated hyperchromatic nuclei.

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공간벡터 PWM을 이용한 유도전동기의 속도제어에 관한 연구 (A Study on Speed Control of Induction Motor using Space Vector PWM)

  • 김영곤;최정환;이승환;김성남;이훈구;한경희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 A
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    • pp.476-478
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    • 1996
  • This paper is on speed control of induction motor using space vector PWM. Indirect vector control which controls independantly flux and torque current component in order to drive induction motor, is applied for driving motor. Voltage sourced inverter with space vector PWM is used to generate the practically perfect sinusoidal flux density in induction motor. The appropriateness of speed control is proven by appling IP(Integral-proportional) controller which is known to have a good speed response and still to have less overshoot than the now used PI(Proportional-Integral) controller.

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