• 대한전기학회논문지:시스템및제어부문D
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• 제50권7호
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• pp.325-331
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• 2001

A dynamic anti-windup method for state delayed control systems with input saturation is considered. Under the assumption that a linear controller has been designed for a state delayed control system based on the existing design technique which shows desirable nominal performance, an additional compensator is incorporated to provide a graceful performance degradation despite of input saturation. By regarding the difference of the controller states in the absence and presence of input saturation as an objective function, the dynamic compensator which minimizes it is determined explicitly. The proposed dynamic compensator is the closed form of plant and controller parameters. The proposed method not only provides graceful performance degradation, but it also guarantees the total stability of resulting systems. An illustrative example is provided to show the effectiveness of the proposed method.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권12호
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• pp.542-548
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• 2002

We consider an unknown linear time invariant plan with static load disturbance. A saturation function nonlinear element is sued to find th one point information in the frequency domain. We analyze an asymmetric self-oscillation caused by static load disturbance with relay feedback and saturation function feedback. We propose a new method to tune a PID controller using a saturation nonlinear feedback element in the presence of asymmetric oscillation. The proposed method does not require the knowledge of plant d.c. gain with an asymmetric oscillation in the plat output.

• 물과 미래
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• 제28권5호
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• pp.129-140
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• 1995

다공성 매질에서의 불포화-포화 흐름을 묘사하는 Richards 방정식을 이용한 수치실험을 통하여 경사면에서 지표포화지역-중간류유출 정상류 관계 및 지표포화지역-흙수분저류량 정상류 관계를 유도하였다. 수치실험에서는 지형인자 및 토양 수리특성의 변화가 지표포화지역-중간류유출 관계에 미치는 민감도를 분석하고, 지표포화지역을 중간류유출 또는 흙수분저류량의 함수로 표시하는 멱법칙을 결정하였다.

• 전력전자학회논문지
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• 제25권4호
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• pp.261-268
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• 2020

Transformer saturation in full bridge (FB) isolated DC-DC converters is caused by uneven switching speeds and voltage drops in semiconductor devices and mismatched gate signals. In order to prevent transformer saturation, most popular and widely used approach is to insert a capacitor in series with the transformer windings. This study conducts extensive analyses on transformer saturation and the effect of DC blocking capacitors when they are placed in the primary or secondary windings of a transformer. The effect of the DC blocking capacitors is verified in voltage-fed and current-fed FB converters.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.579-582
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• 2015

Mean-Shift 알고리즘은 객체 모델과 객체 후보 영상에서 색상 히스토그램 분포의 유사도를 이용하여 객체를 추적하는 강인한 알고리즘이다. 그러나 색상정보를 이용한 Mean-Shift 알고리즘은 객체와 배경이 비슷한 색상 분포를 가질 경우에 추적에 실패할 수 있는 단점이 있다. 이러한 단점을 보완하기 위해 배경과 객체를 분리할 정보를 색상(hue)과 채도(saturation) 영상에서 각각 4비트의 bit-plane을 조합한 새로운 영상을 사용한 강인한 객체 추적 알고리즘을 구현한다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권2호
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• pp.116-122
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• 2000

In the high speed range for salient type synchronous reluctance motor, the effect of iron loss can not be negligible. We have investigated the voltage equations including iron loss from the model that is added the equivalent iron loss in the equivalent inductance in series. In this paper, we derive Ld linear approximate equation from saturation range of Ld, Lq vs applied voltage characteristics and obtain equations including saturation and iron loss related to maximum torque control using Ld. The effect of saturation and iron loss is investigated under maximum torque control. And we show that the proposed maximum torque control scheme achieves the desired performances through experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.64-66
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• 2000

This paper presents an algorithm for detecting current transformer (CT). At the instants of beginning and end of saturation, the increment of the secondary current is reduced significantly, depending on the residual flux and saturation time. Thus, the third difference of the current is used to detect saturation in this paper. If the third difference is less than threshold the CT is at the beginning/end of saturation. The proposed detection method is unaffected by the amount of residual flux. The results of various tests with residual flux from -80% to +80% indicate satisfactory performance of the method.

• 전기전자학회논문지
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• 제2권2호
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• pp.263-269
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• 1998

릴레이 대신 포화함수를 이용하여 선형 플랜트의 극한 이득과 주기를 결정하였다. 포화함수를 사용함으로서 플랜트의 고주파 성분을 감소 시켜 묘사함수 사용에 의한 극한이득과 주기 결정의 정확도를 증가시켰다. 또한 적절한 포화함수를 사용할 수 있는 간단한 절차를 기술하였으며 진동이 발생하지 않는 플랜트에 대해서 지연요소를 이용한 자동동조 방법을 제시하였다.

• Clinical and Experimental Pediatrics
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• 제54권9호
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• pp.359-362
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• 2011

There is a delicate balance between too little and too much supplemental oxygen exposure in premature infants. Since underuse and overuse of supplemental oxygen can harm premature infants, oxygen saturation levels must be monitored and kept at less than 95% to prevent reactive oxygen species-related diseases, such as retinopathy of prematurity and bronchopulmonary dysplasia. At the same time, desaturation below 80 to 85% must be avoided to prevent adverse consequences, such as cerebral palsy. It is still unclear what range of oxygen saturation is appropriate for premature infants; however, until the results of further studies are available, a reasonable target for pulse oxygen saturation ($SpO_2$) is 90 to 93% with an intermittent review of the correlation between $SpO_2$ and the partial pressure of arterial oxygen tension ($PaO_2$). Because optimal oxygenation depends on individuals at the bedside making ongoing adjustments, each unit must define an optimal target range and set alarm limits according to their own equipment or conditions. All staff must be aware of these values and adjust the concentration of supplemental oxygen frequently.

• Smart Structures and Systems
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• 제8권5호
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• pp.449-470
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• 2011

During the last thirty years many structural control concepts have been proposed for the reduction of the structural response caused by earthquake excitations. Their research and implementation in practice have shown that seismic control of structures has a lot of potential but also many limitations. In this paper the importance of two practical issues, time delay and saturation effect, on the performance of controlled structures, is discussed. Their influence, both separately and in interaction, on the response of structures controlled by a modified pole placement algorithm is investigated. Characteristic buildings controlled by this algorithm and subjected to dynamic loads, such as harmonic signals and actual seismic events, are analyzed for a range of levels of time delay and saturation capacity of the control devices. The response reduction surfaces for the combined influence of time delay and force saturation of the controlled buildings are obtained. Conclusions regarding the choice of the control system and the desired properties of the control devices are drawn.