• 제목/요약/키워드: Closed-chain

검색결과 208건 처리시간 0.028초

Derivation of Zeros from Externally-loaded Feed-forward Element of Filter Network

  • Um, Keehong;Yoo, Sooyeup;Pinthong, Chairat
    • International Journal of Internet, Broadcasting and Communication
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    • 제6권1호
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    • pp.9-12
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    • 2014
  • We present a mathematical method for calculation of transmission zero locations, determining a filtering characteristics of two-port systems. By adjusting element values based on the zero locations, the frequency-selectivity is characterized. The characteristic polynomial of ladder networks in externally-loaded feed-forward systems is considered by adopting chain matrices for subsystems. This method can be extended to other types of lumped systems with cross-coupled sections. We find out the zeros by solving characteristics polynomials of closed-form expressions in terms of Laplace impedances of elements. The pairs of complex zeros are shown to be solely from the cross-coupled portion of the system.

커튼월 물류 관리 효율화를 위한 SOA 적용 모델 개발 방향 제시 (A Study on a SOA-based Application Model for Curtain Wall Supply Chain Management efficiency)

  • 안치선;황경훈;윤수원;진상윤
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 춘계 학술논문 발표대회 1부
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    • pp.141-143
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    • 2011
  • A Study on the Curtain Wall parts that appear to cause problems and to improve information exchange system by applying the model of SOA-based development directions are suggested. Availability of the IT industry than other industries that have closed in the field of construction such as SOA. IT systems for the compatibility of the information being sought may be applied. In the future adoption of SOA and Web service-based approach to information exchange with suppliers and improving the efficiency of information for the construction to cover the entire field of research will be conducted as a SOA system.

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병렬형 모션 시뮬레이터의 기구학적 해석과 강인 궤적추종 PID 제어기의 설계 (Kinematics and Robust PID Trajectory Tracking Control of Parallel Motion Simulator)

  • 홍성일
    • 한국군사과학기술학회지
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    • 제10권3호
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    • pp.161-172
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    • 2007
  • This article suggests an inverse kinematics analysis of a two degree of freedom spatial parallel motion simulator and design methodology of the robust PID controller. The parallel motion simulator consists of a fixed base and a moving frame connected by two serial chains, with each serial chain containing one revolute joint and two passive spherical joint. First, an inverse kinematics problems are solved in order to find the joint variable necessary to bring the end effector to track the desired trajectory. Second, an inverse optimal PID controller is proposed to track trajectories in the face of uncertainty. And the $H_{\infty}$ optimality and robust stability of the closed-loop system is acquired through the PID controller. Finally numerical results show the effectiveness of the PID controller that is designed by square/linear tuning laws.

선택적 이동평균(S-MA) 관리도의 ARL (The ARL of a Selectively Moving Average Control Chart)

  • 임태진
    • 품질경영학회지
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    • 제35권1호
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    • pp.24-34
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    • 2007
  • This paper investigates the average run length (ARL) of a selectively moving average (S-MA) control chart. The S-U chart is designed to detect shifts in the process mean. The basic idea of the S-MA chart is to accumulate previous samples selectively in order to increase the sensitivity. The ARL of the S-MA chart was shown to be monotone decreasing with respect to the decision length in a previous research [3]. This paper derives the steady-state ARL in a closed-form and shows that the monotone property is resulted from head-start assumption. The steady-state ARL is shown to be a sum of head-start ARL and an additional term. The statistical design procedure for the S-MA chart is revised according to this result. Sensitivity study shorts that the steady-state ARL performance is still better than the CUSUM chart or the Exponentially Weighted Moving Average (EWMA) chart.

The Study of Gain Optimization of Sliding Model Controller with Sliding Perturbation Observer by using of Genetic Algorithm

  • K.S. You;Park, M.K.;Lee, M.C.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.495-495
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    • 2000
  • The Stewart platform manipulator is a closed-kinematis chain robot manipulator that is capable of providing high st겨ctural rigidity and positional accuracy. However, this is a complex structure, so controllability of the system is not so good. In this paper, it introduces a new robust motion control algorithm using partial state feedback for a class of nonlinear systems in the presence of modelling uncertainties and external disturbances. The major contribution of this work introduces the development and design of robust observer for the slate and the perturbation w.hich is integrated into a variable structure controller(VSC) structure. The combination of controller/observer gives rise to the robust routine called sliding mode control with sliding perturbation observer(SMCSPO). The optimal gains of SMCSPO are easily obtained by genetic algorithm. Simulation and experiment are presented in order to apply to the stewart platform manipulator. There results show highly' accuracy and performance.

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반응성 기포개방제를 이용한 개방기포형 경질우레탄폼 (Open-Cell Rigid Polyurethane Foam Using Reactive Cell Opening Agents)

  • 안원술
    • 한국산학기술학회논문지
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    • 제14권5호
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    • pp.2524-2528
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    • 2013
  • 일반적인 독립기포형 경질폴리우레탄 폼을 만들기 위한 formulation으로부터 개방기포형 경질 우레탄 폼을 얻기 위하여 반응성 기포개방제로서 1-butanol 및 12HSA (12-hydroxystearic acid)의 금속염인 Li-12HSA를 첨가제로 사용하여 만들어진 샘플의 물성과 기포개방 특성에 관한 연구를 진행하였다. 4.0 phr의1-butanol을 단독으로 사용할 때에 비하여 2 phr의 Li-12HSA를 복합하여 사용할 때의 기포개방율은 10.5%에서 98.0%로 현저한 개선효과를 나타내었다. 연구의 결과로서, 반응에 의하여 부피가 큰 막대형 분자를 우레탄 측쇄로 도입함으로서 독립기포형 경질 우레탄 폼의 기포크기나 밀도, 및 열전도율 등의 큰 변화없이 완전 개방기포형 경질 우레탄 폼을 얻을 수 있음을 보여주었다.

네트워크중심전(NCW)을 위한 UMPC 기반 데이터 링크 시스템 설계 및 구축 (The Design and Implementation of the Data Link System based on the Off-the-shelf Ultra Mobile Personal Computer for Network Centric Warfare(NCW))

  • 심동섭;김기형
    • 한국군사과학기술학회지
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    • 제12권2호
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    • pp.175-181
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    • 2009
  • All of the military aircrafts in Korea Air Force are administered and operated together in the same system regardless of whether they are equipped with the data communication capability or not. The absence of the data communication capability in some of the aircrafts might increase whole kill chain hour at the point of the Network Centric Warfare achievement. Network synergy effects cannot also be desired if the section which is not connected to the network influences to the whole tactical network. Equipping aircrafts with the data communication capability could be done by upgrading the aircrafts, but resulting in high costs and long updating time. This paper is a research about the design and implementation of the UMPC based Data Link System to aircrafts that do not have the data communication capability. The proposed system grafts the UHF-based wireless modem technology and the aircraft flight mission support software onto the off-the-shelf UMPC and GPS system. The employed UHF radio equipment allows communicating tactic data with another aircrafts on the air, the ground control point, and even the Tactical Air Control Party(TACP) control vehicle that achieve missions with aircrafts. It thereby increases such capabilities as navigation aid, situation awareness, quick target identification and attack. We also applied Closed Air Support(CAS) scenarios, which is very close to the real environment, to the experiments of the proposed system. The experimental results show that the proposed system could support the data communication capability effectively and the flight mission at low costs of money and time.

Effect of Chitosan on Expression of Osteogenic Genes during the Healing of Rat Extraction Socket

  • Youn, Gap-Hee;Jung, Seunggon;Lee, Tae-Hoon;Kook, Min-Suk;Park, Hong-Ju;Oh, Hee-Kyun
    • Journal of Korean Dental Science
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    • 제7권2호
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    • pp.58-65
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    • 2014
  • Purpose: This study was performed to evaluate the effect of chitosan combined with absorbable gelatin compressed sponge on the expression of osteoblastic differentiation marker genes during the healing of rat extraction socket. Materials and Methods: Twenty-four male Wistar rats were used. In control group, the extraction socket was closed with suture. In chitosan group, the socket was filled with chitosan combined with Gelfoam (Pharmacia & Upjohn Co.) and closed with suture. In each group, the animals were sacrificed at 3 days, 1 week, 2 weeks, and 4 weeks postoperatively. The expression of osteoblastic differentiation marker genes, including BSP, OCN, Runx2, and Col1 were quantified by real-time polymerase chain reaction. Result: Compared to control group, the mRNA level of BSP in chitosan group increased significantly at 2 weeks after extraction and the level of OCN decreased significantly at 3 days and 4 weeks after extraction (P<0.05). The mRNA levels of OCN, Runx2, and Col1 in chitosan group increased slightly at 2 weeks after extraction, but there was no statistical difference between groups. Conclusion: The results indicate that chitosan has some effects on the expression of osteogenic genes during the healing of extraction sockets.

Effect of lower extremity resistance exercise on gait performance in a patient with systemic lupus erythematosus with cerebral infarction and lower extremity vasculitis: a case study

  • Oh, Yongseop;Woo, Youngkeun
    • Physical Therapy Rehabilitation Science
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    • 제5권2호
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    • pp.106-112
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    • 2016
  • Objective: This study was conducted to investigate the effects of resistant exercise on the gait performance of a patient with systemic lupus erythematosus (SLE) patient. Design: A case study. Methods: A 30-year-old male adult who had been diagnosed with systemic lupus erythmatosus (SLE) in April 2013, right middle cerebral artery infarction, and with left hemiplegia agreed to participate in this case study. Patient was unable to walk due to being affected with adynamia. Due to developing necrotizing vasculitis on the left lower extremity, patient underwent a myotomy on the left thigh. The patient was trained with a progressive resistant exercise program for 8 weeks. An intensity of 15 RM was used for the resistant exercises and the resistance level was increased progressively in order to improve the muscle power of the patient. Methods used to increase resistance included changing positions, providing mechanical resistance instead of manual resistance, transitioning from open kinetic chain to closed kinetic chain exercises, and changing the colors of the theraband to those with increase level of resistance. Outcome measures included the 5-repetition sit-to- stand test (5RSST), Timed Up & Go (TUG), and 10-meter walk test (10MWT). In addition, the GAITRite was used to assess the spatio-temporal gait variables, including gait speed, cadence, stride length of the left side, and double limb support pre and post-intervention. Results: The patient was able to perform sit-to- stand after two weeks of performing the resistant exercises. The patient was able to walk after 4 weeks, and the patient's overall gait performance had improved after 8 weeks. All of the variables had improved after each week. Conclusions: The results of this case study may be used to enhance future efforts to objectively evaluate resistant exercises during gait performance in persons affected by SLE.

가변 샘플링 간격(VSI)을 갖는 적응형 이동평균 (A-MA) 관리도 (An Adaptive Moving Average (A-MA) Control Chart with Variable Sampling Intervals (VSI))

  • 임태진
    • 대한산업공학회지
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    • 제33권4호
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    • pp.457-468
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    • 2007
  • This paper proposes an adaptive moving average (A-MA) control chart with variable sampling intervals (VSI) for detecting shifts in the process mean. The basic idea of the VSI A-MA chart is to adjust sampling intervals as well as to accumulate previous samples selectively in order to increase the sensitivity. The VSI A-MA chart employs a threshold limit to determine whether or not to increase sampling rate as well as to accumulate previous samples. If a standardized control statistic falls outside the threshold limit, the next sample is taken with higher sampling rate and is accumulated to calculate the next control statistic. If the control statistic falls within the threshold limit, the next sample is taken with lower sampling rate and only the sample is used to get the control statistic. The VSI A-MA chart produces an 'out-of-control' signal either when any control statistic falls outside the control limit or when L-consecutive control statistics fall outside the threshold limit. The control length L is introduced to prevent small mean shifts from being undetected for a long period. A Markov chain model is employed to investigate the VSI A-MA sampling process. Formulae related to the steady state average time-to signal (ATS) for an in-control state and out-of-control state are derived in closed forms. A statistical design procedure for the VSI A-MA chart is proposed. Comparative studies show that the proposed VSI A-MA chart is uniformly superior to the adaptive Cumulative sum (CUSUM) chart and to the Exponentially Weighted Moving Average (EWMA) chart, and is comparable to the variable sampling size (VSS) VSI EWMA chart with respect to the ATS performance.