• Title/Summary/Keyword: 시간지연적분

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Estimating System for Responsible Days of Schedule Delay for Construction Projects through Time Impact Analysis (건설공사 공기지연 영향분석을 통한 책임일수 산정체계 구축방안)

  • Kang, Leen-Seok;Kwon, Jung-Hee
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.5D
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    • pp.685-694
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    • 2008
  • Recently, construction projects are being gradually changed to large projects with complicated work processes. As a result, claims are increasing as well. Of these, the claims by delayed construction duration are given much weight in the general construction claims. To solve this problem, researches to estimate damages due to delay are carried out in research institutes by analyzing the causes of schedule delay. A system to easily estimate responsible days by analyzing the complicated processes needs for project manager. This study suggests a methodology based on the time impact analysis method, which can utilize the consequential analytical method with the consideration of reduced construction period. The suggested methodology is verified by comparing with actual data of case study by the computerized system for estimating the responsible days.

A Study on Delay Time and Capacitance Calculation for Interconnection Line in Multi-Dielectric Layer (다층 유전체에서의 Interconnection Line에 대한 커패시턴스와 지연시간 계산 방법에 관한 연구)

  • 김한구;곽계달
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.9
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    • pp.46-55
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    • 1992
  • This paper propose how to calculate the capacitance for VLSI interconnection lines in multi-dielectric layer. The proposed method is a expansive form of 3-dimensional direct intergral method developed in single-dielectric layer. We took into consideration the effect of multi-dielectric layer by using additional boundary condition instead of modified Green's function. It is used the potential equations in line surface and the electric field equations in dielectric interface as the boundary condition. RC delay time for interconnection line of multi-dielectric layer is obtained from the calculated capacitance value. At this time, we are used Al and WSiS12T as interconnection materials.

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The Third-Order Multibit Sigma-Delta Modulator with Data Weighted Averaging (Data Weighted Averaging을 이용한 3차 멀티비트 Sigma-Delta 변조기)

  • 김선홍;최석우;조성익;김동용
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.9
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    • pp.107-114
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    • 2004
  • This paper presents block and timing diagrams of the DWA(Data Weighted Averaging) to optimize a feedback time delay of the sigma-delta modulator. Through the MATLAB modeling, the optimized coefficients of the integrators are obtained to design the modulator. The fully differential SC integrators, feedback DAC, 9-level quantizer, and DWA are designed by considering the nonideal characteristics of the modulator. The designed third-order multibit modulator is fabricated in a 0.35${\mu}{\textrm}{m}$ CMOS process. The modulator achieves 75dB signal-to-noise ratio and 74dB dynamic range at 1.2Vp-p 825kHz input signal and 52.8MHE sampling frequency.

The Development of Anti-Windup Scheme for Time Delay Control with Switching Action Using Integral Sliding Surface (적분형 슬라이딩 서피스를 이용한 TDCSA(Time Delay Control With Switching Action)의 와인드업 방지를 위한 기법의 개발)

  • Lee, Seong-Uk;Jang, Pyeong-Hun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.8
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    • pp.1534-1544
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    • 2002
  • The TDCSA(Time Delay Control with Switching Action) method, which consists of Time Delay Control(TDC) and a switching action of sliding mode control(SMC), has been proposed as a promising technique in the robust control area, where the plant has unknown dynamics with parameter variations and substantial disturbances are preset. When TDCSA is applied to the plant with saturation nonlinearity, however, the so-called windup phenomena are observed to arise, causing excessive overshoot and instability. The integral element of TDCSA and the saturation element of a plant cause the windup phenomena. There are two integral effects in TDCSA. One is the integral effect occurred by time delay estimation of TDC. Other is the integral term of an integral sliding surface. In order to solve this problem, we have proposed an anti-windup scheme method for TDCSA. The stability of the overall system has been proved for a class of nonlinear system. Experiment results show that the proposed method overcomes the windup problem of the TDCSA.

Impact of Group Delay in RF BPF on Impulse Radio Systems (임펄스 라디오 시스템에서 RF 대역 통과 필터의 군지연 영향 분석)

  • Myoung Seong-Sik;Kwon Bong-Su;Kim Young-Hwan;Yook Jong-Gwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.4 s.95
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    • pp.380-388
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    • 2005
  • This paper presents analysis results of the effects of RF filter characteristics on the system performance of impulse radio. The impulse radio system transmits modulated pulses having very short time duration and information can be extracted in receiver side based on cross-correlation between received and transmitted pulses. Accordingly, the pulse distortion due to in-band group delay variation can cause serious system performance degradation. In general, RF bandpass filters inevitably cause group delay difference to the signal passing through the filter which is proportional to its skirt characteristic due to its resonance phenomenon. For time as well as frequency domain analysis, small signal scattering parameter $S_{21}$ and its Fourier transform are used to characterize output pulse waveform under the condition that the input and output ports are matched. The output pulse waveform of the filter is predicted based on convolution integral between input pulse and filter transfer function, and resulting BER performances in the BPM and PPM based impulse radio system are calculated.

Improved Response of the Plant with an Integrator and Long Dead Time (적분기와 큰 시간지연을 가지는 플랜트에 대한 응답특성 개선)

  • Yang, Seung-Hyun;Park, Yong-Sik;Hur, Myung-Jun;Lee, Suk-Won
    • Proceedings of the KIEE Conference
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    • 1999.11c
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    • pp.515-517
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    • 1999
  • This paper considers the design of the effective controllers for the plant with an integrator and a long deadtime. The structure of the new DTC(DeadTime Compensator) that has an additive filter is proposed. Our DTC shows the improved performance in set-point response and disturbance rejection. Especially the bad effect of the long deadtime in the disturbance rejection is fairly reduced by using the additive filter. Illustrative examples are provided to show the availability of the proposed controller.

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Stability of Time-delayed Linear Systems using an Improved Integral Inequality (개선된 적분부등식을 이용한 시간지연 선형 시스템의 안정성)

  • Kim, Jin-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.5
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    • pp.806-811
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    • 2017
  • This paper considers the delay-dependent stability of linear systems with a time-varying delay in the frame work of Lyapunov-Krasovskii functional(LKF) approach. In this approach, an integral inequality is essential to estimate the upper bound of time-derivative of LKF, and a less conservative one is needed to get a less conservative stability result. In this paper, based on free weighting matrices, an improved integral inequality encompassing well-known results is proposed and then a stability result in the form of linear matrix inequality is derived based on an augmented LKF. Finally, two well-known numerical examples are given to demonstrate the usefulness of the proposed result.

Improved Response of Time-Delay System with Integrator (적분기를 갖는 시간지연 시스템의 응답특성 개선)

  • Lee, Suk-Won;Yang, Seung-Hyun;Lee, Kyu-Yong
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.930-932
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    • 1999
  • Recently a new modified Smith predictor is proposed for a time-delay system with an integrator. It is shown that the approximate model yields the zero-steady state error and the disturbance compensator improved the transient response. But in case of mismatch between the plant's time-delay and model's time-delay, the overall response is not satisfactory. In this paper, it is proposed that the proper pole is added to the new modified smith predictor to improve the overall response.

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LMI-based Design of Integral Sliding Mode Controllers for Time-Delay Systems (시간 지연 시스템을 위한 적분 슬라이딩 모드 제어기의 LMI 기반 설계)

  • Choi, Han-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.12
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    • pp.2480-2483
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    • 2009
  • This paper presents an LMI-based method to design a integral sliding mode controller for a class of uncertain time-delay systems. Using LMIs we derive an existence condition of a sliding surface guaranteeing the asymptotic stability of the sliding mode dynamics. And we give a switching feedback control law. Our method is a generalization of the previous integral sliding mode control design methods. Since our method is based on LMIs, it gives design flexibility for combining various useful design criteria that can be captured in the LMI-based formulation. We also give LMI existence conditions of sliding surfaces guaranteeing a-stability or LQ performance constraint. Finally, we give a numerical design example to show the effectiveness of the proposed method.

Control characteristics of a refrigerant compressor test facility (냉매압축기 성능시험장치의 제어 특성)

  • Lee, J. Y.;Lee, D. Y.;Kim, K. H.;Nam, P. W.
    • 유체기계공업학회:학술대회논문집
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    • 1999.12a
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    • pp.46-51
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    • 1999
  • This paper describes the control charcteristics of thermal/flow systems. In thermal/flow systems, the transport lag plays as a dead time causing a deterioration of the controllability. Besides this, such many parameters including the temperature, pressure, and flow rate affect the system response that a control scheme which can deal with multi-input is required. Particularly in a refrigerant compressor test facility, the evaporator and condenser interact each other so that the change in the evaporator pressure cause the condenser pressure to change or vice versa. Therefore, to control the evaporator pressure, not only the cooling water flow rate in the evaporator but also the coolant flow rate in the condenser is considered. Meanwhile, the conventional PID controllers, which is suitable for a single input system, shows a large overshoot for a disturbance input. In this work, the predictive control scheme is introduced and its applicability is discussed for thermal/flow systems.

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