• 제목/요약/키워드: on-off control

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

  • 윤신일;박근효;한상보
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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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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논 표면 탈립 벼 종자의 월동중 발아력변화와 월동후 포장 출현 및 생육 (Germinability during Overwintering, Field Emergence, and Growth of Shattered Rice Seeds on Paddy Field)

  • 송영주;권영립;오남기;고복래;황창주;박건호
    • 한국작물학회지
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    • 제37권1호
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    • pp.37-44
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    • 1992
  • 벼 콤바인 수확답에서 탈립된 종자의 월동중 활성검정 및 품종별 탈립량에 따른 이형주 발생정도와 양상을 검토, 벼 종자 순도유지에 관한 기초자료로 활용코저 하였던바 아래와 같은 결과를 얻었다. 1. 탈립종자의 시기별 발아율은 일반형, 통일형 모두 경과시기가 길어질수록 낮아지는 경향이었으며, 발아세의 경시적 변화도 같은 경향을 보였다. 2. 조사시기에 따른 종자 단백질의 전기영동적 차이에 있어서 팔공벼, 삼강벼 공히 단백질 Band에 농ㆍ담의 차이가 있었다. 3. 생태형별 이형주 발생율은 일반형 품종이 통일형 품종에 비하여 이형주는 대비품종에 비해 초장, 주당경수, 엽장, 절간장, 수장 및 수당립수 등의 형질이 저하되는 경향이었다. 또한 1차 지경보다는 2차지경에서 저하율이 컸으며 수당 영화수에 대한 상관정도는 2차지경이 높았다. 4. 이형주 종자의 발아능력은 대비품종에 비해 대차가 없었고 종자수량에 있어서 일반형 품종이 평균 5.1kg /10a, 통일형 품종이 평균 0.9kg /10a 였으며, 생태형별 대비품종에 대한 혼입비율은 일반형 품종이 0.7%, 통일형 품종이 0.1% 정도였다.

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

  • 김희중;이동훈;김정욱;정재현
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
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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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일차계통의 최적제어에 관한 연구 (Optimal Control of a First Order System)

  • 송문현;하주식
    • Journal of Advanced Marine Engineering and Technology
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    • 제18권4호
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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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릴레이 회로의 확장된 마크흐름선도 변환 (The Relay Circuits Translation to EMFGs)

  • 여정모;백형구
    • 제어로봇시스템학회논문지
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    • 제9권11호
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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.

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

  • 황민영;최창용;구상모
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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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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양자효과를 고려한 실리콘 나노선 트랜지스터의 채널 크기에 따른 전도 및 전하분포 특성 시뮬레이션 (Simulation of Channel Dimension Dependent Conduction and Charge Distribution Characteristics of Silicon Nanowire Transistors using a Quantum Model)

  • 황민영;최창용;문경숙;구상모
    • 한국전기전자재료학회논문지
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    • 제22권9호
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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.

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

  • 이상엽;송재경;박경훈;원항연;김정준;한지희
    • 한국균학회지
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    • 제44권3호
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    • pp.176-183
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    • 2016
  • Bacillusvelezensis CC112 균주는 인삼 잘록병을 일으키는 Rhizoctonia solani를 비롯한 여러 식물병원균의 균사 생장을 억제하였다. 인삼 잘록병균 R. solani에 대하여 B. velezensis CC112 균주를 Luria-Bertani (LB)와 Bacillus-soytone medium 배지에 배양한 10배 희석액의 종자침지처리와 LB 배지에 배양한 10배 희석액을 토양관주처리하여 65.8%, 67.1%와 64.2% 방제효과를 나타냈다. B.velezensis CC112 균주의 시제품을 100배로 희석하여 토양관주처리하여 R. solani에 77.3%, Pythium sp.에 65.7% 방제효과를 각각 나타내었다. 이들 결과에서 B. velezensis CC112 균주는 인삼 잘록병의 방제에 유망한 미생물살균제가 될 수 있다.

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

  • 전원석;방두열;최광훈;권대규;김남균;이성철
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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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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반 잠수식 복수부선의 진수설계 (Development of float off Operation Design for Mdlti Semi-submersible Barges with Symmetrical Stability Casings)

  • 양영태;최문길;이춘보;박병남;성석부
    • 한국해양공학회지
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    • 제17권2호
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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.