• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2006년도 춘계 학술발표회 논문집
• /
• pp.1334-1339
• /
• 2006

Dynamic response of buried pipelines both in the axial and the transverse directions on concrete pipe and steel pipe, FRP pipe were investigated through a forced vibration analysis. The dynamic behavior of the buried pipelines for the forced vibration is found to exhibit two different forms, a transient response and a steady state response, depending on the time before and after the transfer of a seismic wave on the end of the buried pipeline. The former is identified by a slight change in its behavior before the sinusoidal-shaped seismic wave travels along the whole length of the pipeline whereas the latter by the complete form of a sinusoidal wave when the wave travels throughout the pipeline. The transient response becomes insignificant as the wave speed increases. From the results of the dynamic responses at the many points of the pipeline, we have found that the responses appeared to be dependent critically on the boundary end conditions. Such effects are found to be most prominent especially for the maximum values of the displacement and the strain and its position.

• 전기의세계
• /
• 제26권6호
• /
• pp.55-58
• /
• 1977

This paper deals with the transient analysis of an amplidyne dc voltage regulating system under the following conditions: (1) assuming all the components of the system to be linear, (2) considering the effect of amplidyne saturation. The mathematical technique employed is state variables method. The calculated response curves are compared with the experimental results obtained on a practical system. The main results can be summerized as follows: 1) The effect of amplidyne saturation on the transient response of a dc voltage regulating system is to reduce the overshoot and setting time. 2) With the increase in level of the step reference voltage, the system response becomes apesiodic. 3) The steady output voltage is reduced appreciably compared to the linear case.

• Structural Engineering and Mechanics
• /
• 제54권4호
• /
• pp.771-792
• /
• 2015

In the paper we study dynamic response of a finite, simply supported Timoshenko beam subject to a moving continuously distributed forces. Three problems have been considered. The dynamic response of the Timoshenko beam under a uniform distributed load moving with a constant velocity v has been considered as the first problem. Obtained solutions allow to find the response of the beam under the interval of the finite length a uniformly distributed moving load. Part of the solutions are presented in a closed form instead of an infinite series. As the second problem the steady-state vibrations of the beam under uniformly distributed mass $m_1$ moving with the constant velocity has been considered. The vibrations of the beam caused by the interval of the finite length randomly distributed load moving with constant velocity is considered as the last problem. It is assumed that load process is space-time stationary stochastic process.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
• /
• pp.891-894
• /
• 1993

To improve limitations of fuzzy PI controller especially when applied to high order systems, we propose two types of fuzzy logic controllers that take out appropriate amounts of accumulated control input according to fuzzily described situations in addition to the incremental control input calculated by conventional fuzzy PI controllers. The structures of the proposed controller were motivated by the problems of fuzzy PI controllers that they generally give inevitable overshoot when one tries to reduce rise time of response especially when one tries to reduce rise time of response especially when a system of order higher than one is under consideration. Since the undesirable characteristics of the fuzzy PI controller are caused by integrating operation of the controller, even though the integrator itself is introduced to overcome steady state error in response, we propose two fuzzy controllers that fuzzily clear out integrated quantities according to situation. The first contr ller determines the fuzzy resetting rate by situations described fuzzily by error and error rate, and the second one by error and control input. The two structures both give reduced rise time as well as small overshoot. To show the usefulness of the proposed controller, that are applied to systems that are difficult to get satisfactory response by conventional fuzzy PI controllers.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2019년도 춘계학술대회
• /
• pp.186-189
• /
• 2019

본 기법(CORD)은 2016년부터 착수한 한국형 e-Navigation사업 중 한화시스템의 대용량 데이터 처리 플랫폼(Data Service Platform, 이하 DSP)의 현장 운용성을 증대시키기 위해 실시간으로 DSP의 상태를 진단하는 알고리즘이다. 항해 중인 선박이 DSP에 요청하는 다양한 서비스에 즉시 응답하기 위해서는 DSP의 논리적, 물리적 오류 발생 가능한 상황을 인지하고 부하를 최소화하여 DSP가 항상 정상상태를 유지하도록 하는 것이 중요하며, 이는 현장 운용성을 극대화, 즉 끊김없는(Seamless) 서비스의 제공과 일맥상통한다. 따라서 DSP의 자원 및 동작 상태를 실시간으로 감시하고 다수의 선박요청을 최적으로 재구성하여 DSP의 정상상태를 유지시키는 기능을 구현함으로써, 선박 요청에 대한 DSP의 응답소요시간의 저감 및 선박 서비스의 제공 성공률을 비약적으로 향상시켜 DSP의 운용성 증가를 실현하게 하였다.

• 전자공학회논문지B
• /
• 제30B권12호
• /
• pp.87-97
• /
• 1993

To improve the limitation of fuzzy PI controller when is applied to systems of order higher than one, a fuzzy PI controller that fuzzily resets or amplifies the accumulated control input according to fuzzy rules defined on (error, change of error) space is proposed. The proposed controller structure was motivated by the characteristics of fuzzy PI controller that it generally gives unevitable large overshoot in trial of reducing rise time of response especially when a system of order higher than one is considered. Based on the observation that the undesirable characteristics of the fuzzy PI controller is caused by integrating control input excessively, even though the integrator is introduced to overcome steady state error, we propose a controller that clear out or doubles integrated control input in a fuzzy manner according to the situation to reduce rise time as well as overshoot. To show the usefulness of the proposed controller, it is applied to the systems that are difficult to stabilize or difficult to get satisfactory response by conventional fuzzy PI controllers.

• 전자공학회논문지B
• /
• 제30B권5호
• /
• pp.109-119
• /
• 1993

To improve limitations of fuzzy PI controllers especially when applied to systems of order higher than one, we propose a fuzzy PI controller that takes out appropriate amounts of accumulated control input according to fuzzily described situations in addition to the calculation of incremental control input as in the case of conventional fuzzy PI controllers. The structure of the proposed controller was motivated by the characteristics of fuzzy PI controller that it generally gives inevitable overshoot when one tries to reduce rise time of the response especially when a system of order higher than one is under consideration. Since the undesirable characteristics of the fuzzy PI controller is caused by integrator of the controller, even though the integrator is introduced to overcome steady state error of response, we propose a controller that fuzzily clears out integrated quantities according to situation to give reduced rise time as well as small overshoots. To show the usefulness of the proposed controller, it is applied in simulations to such systems as are difficult to stabilize or difficult to get satisfactory responses by conventional fuzzy PI controllers.

• Journal of Biosystems Engineering
• /
• 제21권2호
• /
• pp.155-166
• /
• 1996

A direct injection sprayer was designed using the concepts of injection mixing and total flow control, flowrate-based system compensating for the variation of forwarding speed. A metered rate, proportionally to the actual diluent flow rate, of a tracer chemical was injected directly into the diluent stream. The injection of chemical may improve the precision and safety of chemical application process. The control system was evaluated for the variables of the control interval, tolerances and sensitivities of flow regulation valve and injection pump. Performance of the system was assessed as that the response time of flow rate, response time of injection rate, absolute steady state error, and the coefficient of variance(C.V.) of concentration were 8.5 and -0.53 seconds, 0.067 lpm(0.8%) and 3.15%, respectively, at optimal parameters of control interval of 1.0 sec, fast sensitivity of flow regulation valve, medium sensitivity of injection pump and medium tolerance of flow rate. Performance of the system can be improved by increasing the sensitivity of flow regulating valve and employing a high resolution velocimeter, such as Doppler radar.

• 대한의용생체공학회:의공학회지
• /
• 제2권2호
• /
• pp.145-150
• /
• 1981

In this paper, we measured the tracking response time of horizontal eye movement to the target moving according to the square waveform to investigate the predictive characteristics of the human oculomotor system. And in the experiment we used the square waves with an amplitude of 5 degree and frequencies o.1, 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 Hz. Random occurrences of the human eye movement reponse time were analyzed using a finite Markov chain process and we found the results as follows. From both the experimental and theoretical results, we found the trend showing that Predictive characteristics moved from the transient state to the steady state.

• 설비공학논문집
• /
• 제24권4호
• /
• pp.306-314
• /
• 2012

Several numerical or analytical models have been proposed to analyze the thermal response of vertical ground heat exchangers (GHEX). However, most models are valid only after several hours of operation since they neglect the heat capacity of the borehole. Recently, the short time response of the GHEX became important in system simulation to improve efficiency. In this paper, a simple new method to evaluate the short time response of the GHEX by using an analogy model of electric circuit transient analysis was presented. The new transient heat exchanger model adopting the concept of thermal capacitance of the borehole as well as the steady-state thermal resistance showed the transient thermal resistance of the borehole. The model was validated by in-situ thermal response test and then compared with the DST model of the TRNSYS program.