• 제목/요약/키워드: Closed-loop operation

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곁인대가 파열되고 주관절이 탈구된 개에서 이중 Locking-loop 봉합법의 치료효과 (Therapeutic Effect of a Double Locking-loop Suture Pattern on the Elbow Luxation with Rupture of Collateral Ligament in a Dog)

  • 이재영;김중현;김소섭;이승근;최석화
    • 한국임상수의학회지
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    • 제21권4호
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    • pp.406-408
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    • 2004
  • A nine-month-old male Jindo with non weight-bearing on the right forelimb in flexed position, pain and edema of the elbow, and resist elbow extension was brought to the Veterinary Teaching Hospital, Chungbuk National University. Elbow radiographs showed loss of humeroradial joint space and lateral displacement of the radius and ulna. Closed reduction was reported the best therapy in most cases of luxation of the elbow but conservative reduction was impossible. Open reduction of the luxated elbow was performed and ruptured collateral ligaments were identified. Displaced elbow was required bloody surgical operation and gentle reduction to restore elbow joint. Internal reduction of choice for elbow luxation with rupture of collateral ligament in the dog was a double locking-loop suture pattern. To ensure secure grasping of parallel bundles of ligament fibers to transverse bites of each suture were placed superficial to the longitudinal bites. All ligaments were repaired with 3-metric (size 2 USP) monofilament polypropylene suture. No complications have been noted during a five-month follow up.

Investigation of Open-Loop Transmit Power Control Parameters for Homogeneous and Heterogeneous Small-Cell Uplinks

  • Haider, Amir;Sinha, Rashmi Sharan;Hwang, Seung-Hoon
    • ETRI Journal
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    • 제40권1호
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    • pp.51-60
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    • 2018
  • In Long Term Evolution (LTE) cellular networks, the transmit power control (TPC) mechanism consists of two parts: the open loop (OL) and closed loop. Most cellular networks consider OL/TPC because of its simple implementation and low operation cost. The analysis of OL/TPC parameters is essential for efficient resource management from the cellular operator's viewpoint. In this work, the impact of the OL/TPC parameters is investigated for homogeneous small cells and heterogeneous small-cell/macrocell network environments. A mathematical model is derived to compute the transmit power at the user equipment, the received power at the eNodeB, the interference in the network, and the received signal-to-interference ratio. Using the analytical platform, the effects of the OL/TPC parameters on the system performance in LTE networks are investigated. Numerical results show that, in order to achieve the best performance, it is appropriate to choose ${\alpha}_{small}=1$ and $P_{o-small}=-100dBm$ in a homogenous small-cell network. Further, the selections of ${\alpha}_{small}=1$ and $P_{o-small}=-100dBm$ in the small cells and ${\alpha}_{macro}=0.8$ and $P_{o-macro}=-100dBm$ in the macrocells seem to be suitable for heterogeneous network deployment.

무진동 크레인의 구현을 위한 여러가지 제어방식의 비교 연구 (Comparison Study of Various Control Schemes for the Anti-Swing Crane)

  • 윤지섭
    • 대한기계학회논문집
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    • 제19권9호
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    • pp.2399-2411
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    • 1995
  • Crane operation for transporting heavy loads inherently causes swinging motion at the loads due to crane's acceleration or deceleration. This motion not only lowers the handling safety but also slows down the handling process. To complement such a problem, Korea Atomic Energy Research Institute(KAERI) has designed several anti-swing controllers using open loop and closed loop approaches. They are namely a pre-programmed feedback controller and a fuzzy controller. These controllers are implemented on a 1-ton crane system at KAERI and their control performances are compared. Test operations show that the new controllers are superior to that of conventional cranes in terms of robustness to the disturbances and adaptation capability to the change of rope length.

Practical Implementation of an Interleaved Boost Converter for Electric Vehicle Applications

  • Wen, Huiqing;Su, Bin
    • Journal of Power Electronics
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    • 제15권4호
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    • pp.1035-1046
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    • 2015
  • This study presents a practical implementation of a multi-mode two-phase interleaved boost converter for fuel cell electric vehicle application. The main operating modes, which include two continuous conducting modes and four discontinuous conducting modes, are discussed. The boundaries and transitions among these modes are analyzed with consideration of the inductor parasitic resistance. The safe operational area is analyzed through a comparison of the different operating modes. The output voltage and power characteristics with open-loop or closed-loop operation are also discussed. Key performance parameters, including the DC voltage gain, input ripple current, output ripple voltage, and switch stresses, are presented and supported by simulation and experimental results.

네트워크 표현을 이용한 트윈서보 시스템의 모델링과 강건 동기 동작 제어 (Modeling and Robust Synchronizing Motion Control of Twin-Servo System Using Network Representation)

  • 김봉근;최현택;정완균;서일홍;송중호
    • 제어로봇시스템학회논문지
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    • 제6권10호
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    • pp.871-880
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    • 2000
  • A twin-servo mechanism is used to increase the payload capacity and assembling speed of high precision motion control systems such as semiconductor chip mounters. In this paper, we focus on the modeling of the twin-servo system and propose its network representation. And also, we propose a robust synchronizing motion control algorithm to cancel out the skew motion of the twin-servo system caused by different dynamic characteristics of two driving systems and the vibration generated by high accelerating and decelerating motions. The proposed control algorithm consists of separate feedback motion control algorithms for each driving system and a skew motion compensation algorithm. A robust tracking controller based on internal-loop compensation is proposed as a separate motion controller and its disturbance attenuation property is shown. The skew motion compensation algorithm is also designed to maintain the synchronizing motion during high speed operation, and the stability of the whole closed loop system is proved based on passivity theory. Finally, experimental results are shown to illustrate control performance.

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열원 냉각용 루프 써모사이폰의 작동 특성 (Performance Characteristics of a Loop Thermosyphon for Heat Source Cooling)

  • 최두성;송태호
    • 대한기계학회논문집B
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    • 제28권12호
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    • pp.1475-1483
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    • 2004
  • Loop thermosyphon(LTS) has many good characteristics such as low thermal resistance, no power consumption, noiseless operation and small size. To investigate the overall performance of LTS, we have performed various experiments varying three parameters: input power of the heater, working fluid(water, ethanol, FC3283) and filling ratio of the working fluid. At a combination of these parameters, temperature measurements are made at many locations of the LTS. The temperature difference between the evaporator and the condenser is used to obtain the thermal resistance. In addition, flow visualization using a high speed camera is carried out. The thermal resistance is not constant. It is lower at higher input power, which is one of the distinct merits of LTS. Flow instabilities are frequently observed when changing the working fluid, the input power and the filling ratio. The results show that the LTS can be readily put into practical use. Future practical application in electronic cooling is recommended.

Modeling of the Drying Process in Paper Plants

  • 황기석;여영구;이영준;강홍
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2003년도 추계학술발표논문집
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    • pp.272-290
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    • 2003
  • In this study a model for the drying process in paper production plants was developed based on the mass and heat balances around drying cycles. Relationships for the heat transfer coefficients between the web and the air as well as between the drying cylinder and the web were extracted from the closed-loop plant operation data. It was found that the heat transfer coefficients could be represented effectively in terms of moisture content, basis weight and reel velocity. The effectiveness of the proposed model was illustrated through numerical simulations. From the comparison with the operation data, the proposed model represents the paper plant being considered with sufficient accuracy.

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Modeling of the Drying Process in Paper Plants

  • Hwang, Ki-Seok;Yeo, Yeong-Koo;Yi, Sung-Chul;Dongjun Seo;Hong Kang
    • 펄프종이기술
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    • 제35권5호
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    • pp.53-61
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    • 2003
  • In this study a model for the drying process in paper production plants was developed based on the mass and heat balances around drying cycles. Relationships for the heat transfer coefficients between the web and the air as well as between the drying cylinder and the web were extracted from the closed-loop plant operation data. It was found that the heat transfer coefficients could be represented effectively in terms of moisture content, basis weight and reel velocity. The effectiveness of the proposed model was illustrated through numerical simulations. From the comparison with the operation data, the proposed model represents the paper plant being considered with sufficient accuracy.

Adaptive compliant control for scara manipulator

  • Yee, Yanghyi;Ka, Minho;Kim, Sungwoo;Park, Mignon;Lee, Sangbae
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.1322-1326
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    • 1990
  • In this paper, compliant motion control of a manipualator in manipulator is proposed by using the self-tuning adaptive controller. Compliant motion is needed in order to applicated to complicated and accurate fields such as assembly operation in which several parts are matched. For a control method of compliant motion hybrid control is used so forces and position control are proposed selectively through a closed feedback loop. By contacting with environment, the uncertainties higher. Self-tuning controller which adapts to variable dynamic response is applied to compliant motion control in order to satisfy the desired operation. The applicability of the suggested algorithm was confirmed by simulation of the contour tracking task of four joint manipulator.

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스카라 로보르에 대한 순응성 제어에 관한 연구 (A Study on Compliance Control of a SCARA Robot)

  • 이양희;도미선;김승우;박민용;이상배
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1990년도 하계학술대회 논문집
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    • pp.514-517
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    • 1990
  • In this paper, compliant motion control of a manipualator in manipulator is proposed by using the self-tuning adaptive controller. Compliant motion is needed in order to applicated to complicated and accurate fields such as assembly operation in which several parts are matched. For a control method of compliant motion hybrid control is used so forces and position control are proposed selectively through a closed feedback loop. By contacting with environment, the uncertainties higher. Self-tuning controller which adapts to variable dynamic response is applied to compliant motion control in order to satisfy the desired operation. The applicability of the suggested algorithm was confined by simulation of the contour tracking task of four joint manipulator.

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