• Title/Summary/Keyword: on-off control

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Vibration Control of Hvbrid Smart Structure Using PZT Patches and ER Fluids (PZT와 ER유체를 적용한 복합지능구조물의 진동제어)

  • Yun, Shin-Il;Park, Keun-Hyo;Han, Sang-Bo
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.734-739
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    • 2003
  • Many types of smart materials and control laws are available to actively adjust the structure from various external disturbances. Usually, a certain type of control laws to activate a specific smart material is well established, but the effectiveness of the control scheme is limited by the choice of the smart materials and the responses of the structure. ER fluid is adequate to provide relatively large control force, on the other hand, the PZT patches are suitable to provide small but arbitrary control forces at any point along the structure. It was found that active vibration control mechanism using ER fluid failed to suppress the excitation off the resonant frequency with changed structural characteristics along the frequency response function of the closed loop of the control system. To compensate this additional peak of the closed loop system, PPF control using PZT as an actuator is added to construct a hybrid controller.

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Germinability during Overwintering, Field Emergence, and Growth of Shattered Rice Seeds on Paddy Field (논 표면 탈립 벼 종자의 월동중 발아력변화와 월동후 포장 출현 및 생육)

  • 송영주;권영립;오남기;고복래;황창주;박건호
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.37 no.1
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    • pp.37-44
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    • 1992
  • Germinability, electrophoretic variation of protein of shattered seeds during overwintering and characteristic of main agronomic traits of off-type rice plant occurring in paddy field harvested by combine were investigated. Germinability of shattered seed decreased as time goes in paddy field in both Japonica and Tongil type varieties. Electrophoretic protein bands become more and more light as time goes. Occurrence of off-type rice plant was higher in Japonica varieties than in Tongil type varieties. Off-type rice plant was shorter in plant height, leaf length, tiller number per hill, internode length, panicle length and spike let number per panicle. Germinability of seeds of off-type rice plant as not significantly different compared to the control variety. Yield of off-type plants of Japonica varieties was on average 5.1kg / 10a and that of Tongil type varieties was on average 0.9kg /10a. Mixing ratio to the control variety was about 0.7% in Japonica varieties and that of Tongil type varieties was about 0.1%.

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A Study on the Remote Manufacturing System for the developing of Direct Numeric Control System using the Vericut Applications (Vericut으로 구현한 원격 가공 시스템)

  • 김희중;이동훈;김정욱;정재현
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2002.05a
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    • pp.205-208
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    • 2002
  • The vericut is one of the best CAM application for manufacturing data verification system. It is much applied in most manufacturing company for checking the manufacturing work. Using it a off-line manufacturing system is connected for on-line working on local area network. First, we choose the serial communication to chain an off-line manufacturing system and a personal computer which link with the server running the vericut.

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Optimal Control of a First Order System (일차계통의 최적제어에 관한 연구)

  • 송문현;하주식
    • Journal of Advanced Marine Engineering and Technology
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    • v.18 no.4
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    • pp.77-83
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    • 1994
  • In this paper, an optimal control of first order systems is discussed. The control system comprises a main controller and an auxiliary controller. The main controller is designed based on the LQ control scheme including an integrator to remove the off-set. The non-linear auxiliary controller is added parallely to the main controller to obtain a finite time settling control. The control parameters under variation of the system and various coefficients of the performance indices are computed numerically, and the control responses for the system with the proposed controllers demonstrated the usefulness of the control method.

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The Relay Circuits Translation to EMFGs (릴레이 회로의 확장된 마크흐름선도 변환)

  • 여정모;백형구
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.11
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    • pp.952-957
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    • 2003
  • We propose how to translate relay circuits to the EMFGs(Extended Mark Flow Graphs) formally and analyze the original one by using the mark flow of it. Firstly, the concepts of the output condition, the output-on condition and the output-off condition are introduced in the relay circuits. These can be used to find the structure and the operation of respective relay outputs but the sequential operations of them cannot be obtained from these. Secondly, a relay circuit is translated to the corresponding EMFG as the all output-on conditions and all output-off conditions of it are translated to EMFGs. For the adequate translation, the condition arc and the concepts of the generation transition and the degeneration transition are introduced, and the duality for the simplification of the result. Thirdly, we analyze the operation of the original circuit by analyzing the mark flow of the resulting EMFG. We can achieve easy and fast analysis based on the EMFG's operation algorithm. Finally, we apply these to the relay circuit for an electric furnace and analyze its operation with the mark flow of the resulting EMFG. The formal translation from relay circuits to EMFGs makes the analysis easy so that these results can be used to design, modelling, the fault detection and the maintenance.

Simulation of channel dimension dependent conduction and charge distribution characteristics of silicon nanowire transistors using a quantum model (양자모델을 적용한 실리콘 나노선 트랜지스터의 채널 크기에 따른 전도 및 전하분포 특성 시뮬레이션)

  • Hwang, Min-Young;Choi, Chang-Yong;Koo, Sang-Mo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.04b
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    • pp.77-78
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    • 2009
  • We report numerical simulations to investigate of the dependence of the on/off current ratio and channel charge distributions in silicon nanowire (SiNW) field-effect transistors (FETs) on the channel width and thicknesses. In order to investigate the transport behavior in devices with different channel geometries, we have performed detailed two-dimensional simulations of SiNWFETs and control FETs with a fixed channel length L of 10um, but varying the channel width W from 5nm to 5um, and thickness t from 10nm to 30nm. We have shown that $Q_{ON}/Q_{OFF}$ drastically decreases (from ${\sim}2.9{\times}10^4$ to ${\sim}9.8{\times}10^3$) as the channel thickness increases (from 10nm to 30nm). As a result of the simulation using a quantum model, even higher charge density in the bottom of SiNW channel was observed than that in the bottom of control channel.

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Simulation of Channel Dimension Dependent Conduction and Charge Distribution Characteristics of Silicon Nanowire Transistors using a Quantum Model (양자효과를 고려한 실리콘 나노선 트랜지스터의 채널 크기에 따른 전도 및 전하분포 특성 시뮬레이션)

  • Hwang, Min-Young;Choi, Chang-Yong;Moon, Kyoung-Sook;Koo, Sang-Mo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.9
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    • pp.728-731
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    • 2009
  • We report numerical simulations to investigate of the dependendce of the on/off current ratio and channel charge distributions in silicon nanowire (SiNW) field-effect transistors (FETs) on the channel width and thicknesses. In order to investigate the transport behavior in devices with different channel geometries, we have performed detailed two-dimensional simulations of SiNWFETs and control FETs with a fixed channel length L of $10\;{\mu}m$, but varying the channel width W from 5 nm to $5\;{\mu}m$, and thickness t from 10 nm to 30 nm. We have show that $Q_{ON}/Q_{OFF}$ drastically decreases (from $^{\sim}2.9{\times}10^4$ to $^{\sim}9.8{\times}10^3$) as the channel thickness increases (from 10 nm to 30 nm). As a result of the simulation using a quantum model, even higher charge density in the bottom of SiNW channel was observed then in the bottom of control channel.

Biocontrol of Ginseng Damping-off by Bacillus velezensis CC112 (Bacillus velezensis CC112 균주의 인삼 잘록병에 대한 생물적 방제)

  • Lee, Sang Yeob;Song, Jaekyeong;Park, Kyeong Hun;Weon, Hang Yeon;Kim, Jeong Jun;Han, Ji Hee
    • The Korean Journal of Mycology
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    • v.44 no.3
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    • pp.176-183
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    • 2016
  • Bacillus velezensis CC112 inhibited the mycelial growth of several plant pathogens, including Rhizoctonia solani, causing damping-off on ginseng. The control efficacies of B. velezensis CC112 against R. solani by seed dipping in LB and BSM broth diluted 10 times, soil dipping, and soil drenching with LB broth diluted 10 times were 65.8%, 67.1%, and 64.2%, respectively. Treatment of soil drenching with the 100 times diluted prototype of B. velezensis CC112 against R. solani and Pythium sp. by soil revealed control efficacies of 77.3% and 65.7%, respectively. These results indicate that B. velezensis CC112 is a prospective biofungicide for the biological control of ginseng damping off.

Temperature Control of the Aluminum Plate using Peltier Element (펠티어 소자를 이용한 알루미늄 판의 온도 제어)

  • 전원석;방두열;최광훈;권대규;김남균;이성철
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.764-767
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    • 2004
  • This paper present the temperature control of aluminum plate using Peltier element. Peltier effect is heat pumping phenomena by electric energy as one of the thermoelectric effect. So if current is asserted to Peltier element, it absorbs heat from low temperature side and emits to high temperature side. In this experiment, Peltier element is used to control the temperature of small aluminum plate with ON/OFF control scheme and fan ON/OFF. As the result of experiments, it is proper to act fan only while cooling duration and there exist a proper cooling current to drop temperature rapidly. It takes about 100sec to increase to 7$0^{\circ}C$ and drop to 35$^{\circ}C$ of aluminium plate temperature and about 90sec to increase to 7$0^{\circ}C$ and drop to 4$0^{\circ}C$ in ambient temperature 3$0^{\circ}C$ while fan is on only in cooling duration. Future aim is to realize more rapid temperature control and develop SMHA(special metal hydride actuator) by using Peltier element to heating and cooling.

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Development of float off Operation Design for Mdlti Semi-submersible Barges with Symmetrical Stability Casings (반 잠수식 복수부선의 진수설계)

  • 양영태;최문길;이춘보;박병남;성석부
    • Journal of Ocean Engineering and Technology
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    • v.17 no.2
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    • pp.72-76
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    • 2003
  • This paper presents the design concept and operation results of float-off for FSO (340,000 DWT Class, ELF AMENAM KPONO Project) built on the ground, without dry dock facilities. It was the first attempt to build FSO, completely, on the ground and launch it using DBU (Double Barge Unit, which was connected by rigid frame structure.) The major characteristics of FSO, which are similar to general VLCC type hull, including topside structure, weigh 51,000 metric ton. In order to have sufficient stability during the deck immersion of DBU, while passing through a minimum water plane area zone, proper trim control was completed with LMC (Load Master Computer). The major features of the monitoring system include calculation for transverse bending moment, shear force, local strength check of each connector, based on component stress, and deformation check during the load-out and float-off. Another major concern during the operation was to avoid damages at the bottom and sides of FSO, due to motion & movement after free-floating; therefore, adequate clearances between DBU and FSO were to be provided, and guide posts were installed to prevent side damage of the DBU casings. This paper also presents various measures that indecate the connector bending moment, damage stability analysis, and mooring of DBU during float off.