• Title/Summary/Keyword: Cnu

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Analysis on Antioxidant Activity of the New Developed Waxy Corn Hybrids

  • Lee, Moon-Sub;Yang, Jae-Hyeon;Lee, Gyeong-Eun;Lee, Hee-Bong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.60 no.2
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    • pp.185-189
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    • 2015
  • A total of CNU 28 colored hybrids developed at the Chungnam National University were evaluated to identify new cultivars with functionality. These color waxy corn hybrids appeared to have high antioxidant activity. The SOD activity in the developed color waxy corn was high; CNU13H-3, in white hybrid, and CNU13H-44, in yellow hybrid, was 5% and 27% higher than the Yeonnong and Daehakchal Gold 1 of control hybrids, respectively. The DPPH activity in CNU13H-44, of yellow hybrid, and CNU13H-75 of purple hybrid were high as 32.6 mg/g and 40.1 mg/g, respectively. We have already reported that color hybrids have high antioxidant activity. In this study also was same results. On the basis of our findings, these hybrids will be planted in next time to compare their productivity and area adaptation.

A Study on the Decrease of the Unclamping time using Hydraulic Circuit (유압 회로를 이용한 초고속 스핀들의 언클램핑(unclamping) 시간 저감 방안 연구)

  • Chung W.J.;Lee C.M.;Cho Y.D.;Whang Y.K.;Chung D.W.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1745-1748
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    • 2005
  • According to the demand of the high productivity, the interest of manufacturing skills is growing in industrial society. Especially the high speed spindle in machining center becomes important these days. The exchange time of the tool in machining center usually calls T-T(tool to tool) time. Detailly explaning, It is influenced by the unclamping time. Affecting factors of the unclamping time are various(the hydraulic system, drawbar mass, a flow meter, disc spring, a piston diameter, pipe diameters, and so on). In this study, we could find factors that decrease the unclamping time and verify it for softwares.(AMESim $4.0^{(R)}$ & visual Nastran $4D^{(R)}$)

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A Study on Rotating Balancing of High-speed spindle by using $ADAMS^(R)$ ($ADAMS^(R)$를 이용한 초고속 스핀들의 회전 밸런싱 (Balancing)에 대한 연구)

  • Cho Y.D.;Chung W.J.;Lee C.M.;Yoon S.H.;Whang Y.K.;Park G.B.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.560-563
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    • 2005
  • According to the demand of the high productivity, the interest of manufacturing skills is growing in industrial society. Especially the high-speed spindle in machining center becomes important these days. The rotating accuracy of the spindle in machining center concerns the centrifugal force. In detail explaining, it is influenced by the unbalance mass. In this study, we could find changes of the vibration caused by condition (increased mass, rotating speed, position) of unbalance mass and verify it using a software - $ADAMS^(R)$ With this study, it will help workers on the spot solve the problems concerning unbalance mass.

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Implementation of Power Management for CNU_RTOS (CNU_RTOS를 위한 Power Management 구현)

  • Oh, seung-take;Lee, cheol-hoon
    • Proceedings of the Korea Contents Association Conference
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    • 2012.05a
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    • pp.27-28
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    • 2012
  • 최근 테블릿 PC 및 스마트폰과 같은 휴대용 전자제품의 사용량이 증가되고 있다. 이러한 휴대용 기기들은 배터리로 동작하기 때문에 실제 사용시간이 제한된다는 특징을 가진다. 이렇게 배터리로 동작하는 임베디드 시스템은 애플리케이션을 보다 오랜 시간 동안 동작할 수 있도록 저전력 기법이 적용된 운영체제를 필요로 한다. 본 논문에서는 스마트폰과 같은 휴대용 기기들에서 사용할 수 있는 실시간 운영체제인 CNU_RTOS에 S3C2440 칩셋에서 제공하는 CPU 상태 모드를 이용한 저전력 기법을 구현하여 전력 감소율을 측정하였다.

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The Design of the Controller for Bio-wrap Winding Machine using Muti-variable Decentralized Control Technique (다중 변수 분산 제어기법을 이용한 생분해성 랩 와인딩 기계의 제어기 설계)

  • Kim H.S.;Park W.C.;Shen Y.D.;Yang S.M.;Kee C.D.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1450-1454
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    • 2005
  • In this paper, the control strategy of the tension and speed based a prototype bio-wrap winding machine is developed. The decentralized control strategy using PID control algorithm applied for each subsystem is proposed to control the each system's desired outputs, because the tension of each subsystem effects that of next roll system. The computer simulations and the experiment results are presented to show that the proposed control scheme is feasible for a prototype bio-wrap winding machine.

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Vibration Control of Rotor Using Time Delay Control (시간지연 제어기법을 이용한 회전체 진동제어)

  • Xuan D.J.;Choi W.K.;Shen Y.D.;Kim Y.B.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1828-1831
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    • 2005
  • Time Delay Control (TDC) method was proposed as a promising technique in the robust control area, where the plants have unknown dynamics with parameter variations and substantial disturbances are present. In this paper we concerns vibration control of rotor system using TDC. Based on the rotor system model, the TDC is designed, and the PD-controller is also designed for comparison. The simulation results show that the TDC is much robust than the PD-controller to the unknown dynamics with parameter variations and disturbances.

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The Development of Performance Evaluation System for Air-Operated Actuaotr (공기구동기 성능평가 시스템 개발)

  • Cho T.D.;Yang S.B.;Lee H.Y.;Yang S.M.;Kwon B.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1770-1773
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    • 2005
  • The performance evaluation of AOV(air-operated valve) requires the processes to confirm the actuator system capability. It is necessary to evaluate the thrust of the air actuator for the margin evaluation. In this paper, to evaluate and analysis the air actuator, the performance test system and operating program are developed. This system is composed of several sensors such as pressure sensor, LVDT, and LoadCell which are used to get the data for evaluation. The LabVIEW was used for developing the operating program. The test system and operating program are proved through the actual test of the diaphragm actuator.

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Modeling for Tension Control of the Bio-Wrap Winding Machine (생분해성 랩 와인딩 기계의 장력제어를 위한 모델링)

  • Park W.C.;Kim H.S.;Kim D.I.;Yang S.M.;Kee C.D.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1901-1905
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    • 2005
  • This Paper describes the mathematical modeling and control of the tension and the speed of moving Bio-wrap in a wrap winding machine. In winding process, important control specifications include the regulation of wrap tension and velocity. In this research, a tension and velocity model has been developed for winding processes. A prototype winding system has been constructed, and the controller has been implemented in a real time PC-based environment. The tension control system is modeled a MIMO of the two-input and four-output system. The performance of the modeled system has been evaluated via simulation using MATLAB and experiments.

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Simulation of active vibration control using phase adjusting method with high speed flexible rotor system (초고속 유연회전체의 위상조절법을 이용한 능동진동제어 시뮬레이션)

  • Na J.B.;Kim K.S.;Lee W.C.;Kim C.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.425-426
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    • 2006
  • This study proposes a new simulation method of high speed rotor system with the dynamic model using multi body dynamic analysis tool and with a new phase modulating technique as a system control algorithm. A dynamic model of high speed rotor system was built by, ADAMS, commercial multi body dynamic program. The phase modulating technique is a new control algorithm for a rotor system. This algorithm can control system using an adaptive proportional gain and an adaptive phase which are obtained from periodical input signal. To make control system, a ADAMS model and component parameters and phase controller was composed by Matlab Simulink And simulate it.

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