• 전기학회논문지P
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• 제57권1호
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• pp.22-29
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• 2008

In this paper, we propose an adaptive color enhancement algorithm. It is used for the flat panel displays (FPDs) such as LCD, PDP, and so on. The proposed algorithm consists of an adaptive linear approximation CDF(Cumulative Density Function) algorithm and an adaptive saturation enhancement algorithm. The one is for contrast enhancement which prevents an image from the distortion by luminance transient of an input image. The other is the algorithm which improves the saturation without the contour artifact and over-saturation, whose problems are generated during the enhancing saturation. In addition, it allows to achieve the high quality image using the saturation enhancement method for a preferred color of original image. Visual test and standard deviation of their histograms have been applied to evaluate the resultant output images of the proposed algorithm.

• Journal of Power Electronics
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• 제10권2호
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• pp.176-180
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• 2010

This paper deals with a control method to reduce the torque ripple of a permanent magnet synchronous motor (PMSM) for electric power steering (EPS) systems. Such an application requires a very low torque ripple in order to maintain a good steering feel. However, because of spatial limitations, it cannot help having a partial saturation in the iron core of the PMSM for an EPS system, and this saturation results in a significant torque ripple. Thus, this paper analyzes the torque ripple caused by the magnetic saturation of a PMSM and proposes a method with respect to inductance measurement to verify the partial saturation. In addition, it is shown that a compensation current is needed in order to minimize the torque ripple when a PMSM is driven in the high torque region. The estimation process of the current and the torque ripple decreased by the current are presented and verified with test results.

• 전기학회논문지
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• 제62권2호
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• pp.270-277
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• 2013

Single phase induction motor(SPIM) is used widely because it is driven by single phase source. However, the efficiency of the motor is not good due to saturation of magnetic material. To analyze the motor accurately, the magnetic saturation characteristics should be considered in analysis of equivalent circuit. In this paper, lumped parameter of circuit are derived from multi phase induction motor using method of symmetrical coordinates. Also, we presents a method for the equivalent circuit analysis of SPIM using magnetic saturation rate. The magnetic nonlinearity is considered deriving magnetizing reactance from voltage-current saturation curve. As a results, current characteristic, torque, output and efficiency are shown through analysis of equivalent circuit. A simulation results of SPIM will be used to improve the characteristics and efficiency of motor.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.223-226
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• 2005

In previous research, we proposed robust saturation controller which involves both actuator's saturation and structured real parameter uncertainties. This controller can analytically prescribed the upper and lower bounds of parameter uncertainties, and guarantee the closed-loop robust stability of the system in the presence of actuator's saturation. And the availability and the effectiveness of the proposed robust saturation controller were verified through numerical simulations. In this paper, we verify the robust stability of this controller through experimental tests. Especially, we show unstable cases of other controllers in comparison with this controller. Experimental tests are carried out in the laboratory using a two-story test structure with a hydraulic-type active mass damper.

• International Journal of Advanced Culture Technology
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• 제8권4호
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• pp.95-100
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• 2020

Recently, the problem of hypoxia caused by jogging is attracting attention. To solve this problem, this paper proposed a new solution. This paper proved that as a vocalization method of reading aloud, it is possible to increase air intake and activate lung function to exchange more air and obtain more oxygen. Then, blood oxygen saturation was used as an evaluation index for the body's oxygen content level to prove its effectiveness. A photoelectric pulse oximeter developed on the basis of different light absorption principles in blood was used to test blood oxygen saturation. Experimental results show that a certain degree of hypoxia is induced when a lot of oxygen is required due to jogging. Therefore, it was proved that the new vocal breathing method by reading books can increase the blood oxygen saturation of the body and improve the hypoxia of the body. Reading vocal breathing is a simple and efficient oxygen saturation recovery breathing method.

• 한국환경보건학회지
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• 제38권2호
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• pp.136-141
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• 2012

Objectives: The objective of this study was to investigate whether the ammonia nitrogen concentration of aqueous samples such as drinking water can be determined by measuring the saturation of the samples colored by indophenol method. Methods: A color saturation measurement system was constructed by connecting a notebook computer to an image acquisition device composed of a PC camera and a light source, and was then used to measure the saturation of samples colored by blue indophenol complex. Results: Between two available light sources, a fluorescent lamp was selected due to its demonstrating better linearity between color saturation and ammonia nitrogen concentration. Prediction by quadratic regression was more accurate than by linear regression, and prediction by quadratic regression in the concentration range of 0.1-1.0 $mg/l$ was more accurate than in the concentration range of 0.0-1.0 $mg/l$. Regression-based predictions over 0.25 $mg/l$, 0.55 $mg/l$ and 0.75 $mg/l$ concentrations were implemented both by spectrophotometric method and by measuring color saturation. In the case of 0.25 $mg/l$, the predicted concentration by spectrophotometric method was $0.256{\pm}0.0076\;mg/l$ and the predicted concentration by measuring color saturation was $0.246{\pm}0.0086\;mg/l$ (p=0.051). In the case of 0.55 $mg/l$, they were $0.561{\pm}0.0068\;mg/l$ and $0.564{\pm}0.0166\;mg/l$ (p=0.660). In the case of 0.75 $mg/l$, they were $0.755{\pm}0.0139\;mg/l$ and $0.762{\pm}0.0088\;mg/l$ (p=0.215). Conclusions: There were no statistically significant differences (p>0.05) between the data from the two methods in all three of the concentrations. Therefore, the color saturation measurement method proposed in this paper may be considered applicable for determining the ammonia nitrogen concentration of aqueous samples such as drinking water.

• 한국안전학회지
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• 제30권6호
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• pp.34-39
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• 2015

The study is aimed to develop fuzzy logic system that has overcurrent and saturation time as input variable and possibility of electrical fire as output variable by making bad conductor area with physical damage to indoor wiring. Most previous studies focused on thermal characteristics depending on the current size and no study considered the current size and saturation time at the same time. Therefore, the paper made into account current value and saturation time together. To this end, it created bad conductor area half the size of IV conductor (1.6 mm) on purpose and transmit electrical current from 10A to 60A by unit of 2A to find out the thermal characteristics and saturation time for current. Based on the data that came out, the study applied fuzzy logic and established the current and saturation time as input variable and chance of fire as output variable. As a result, the center of area of the system that depended only on the existing current value was 75 while the system that applied both current and saturation time presented the chance of fire at 92. It is found that the chance of bad conductor area and deteriorated insulation of electrical wire had current and saturation time as important variables. The data can be used as basic data like deteriorated wire insulation or operation features of circuit breaker in investigating the cause of electrical fire.

• 한국해양학회지:바다
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• 제24권3호
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• pp.389-399
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• 2019

동해 울릉분지의 탄산칼슘 포화상태를 1999, 2014, 2017, 2018년도 해양 조사를 통해 수집된 pH, 용존무기탄소(DIC), 총알칼리도(TA) 자료를 이용하여 계산하였다. 1999년에 비해 2010년대에 전 수심에서 탄산염 포화상태는 유의하게 감소하였다. 2018년 현재 방해석과 선석의 포화면 수심은 각각 약 500 m와 200 m로 상승하였다. 탄산칼슘 포화상태를 결정하는 주된 화학종인 탄산이온은 상층과 심층에서 다른 분포를 보였다: 상층에서는 약 $175{\mu}mol\;kg^{-1}$로 비교적 높고, 심층에서는 $50{\mu}mol\;kg^{-1}$ 이하로 아주 낮게 나타났다. 그러나 탄산이온 농도의 감소 경향은 심층보다 상층에서 두드러졌는데, 이는 2000년대에 대기에서 이산화탄소의 침투가 주로 상층에서 일어나는 것이 반영된 결과로 해석된다.

• 한국멀티미디어학회논문지
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• 제16권2호
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• pp.119-130
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• 2013

본 논문에서는 디지털 영상의 색상을 유지하면서 영상의 명암대비 향상과 함께 채도를 향상시키는 방법을 제시한다. 제안방법은 명암대비 향상 후 밝기 변화에 따른 시각적인 채도 변화를 보정하기 위해 최대색차신호 테이블을 이용한다. 최대색차신호 테이블로부터 휘도변화에 따른 가중치를 구하고, 입력 색차신호에 가중치를 곱하여 채도를 밝기에 적응적으로 보정한다. 또한 사용자가 입력한 만큼의 채도를 향상시키는 과정에서 과도한 채도 향상으로 인한 왜곡을 막기 위해 휘도와 색상에 따른 채도의 상관관계를 고려하여 색차신호가 올바른 색역에 사상될 수 있도록 한다. 다양한 특성을 갖는 영상에 대한 실험을 통해 제안방법은 기존방식과 비교하여 효과적으로 컬러 영상의 선명도를 향상시킴을 확인하였다.

• 한국군사과학기술학회지
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• 제19권6호
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• pp.698-702
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• 2016

Thermal imager is now regarded as one of the key observation devices for ISR activities and getting important more and more. As other detectors, however, the thermal detectors also have maximum input and therefore they will be saturated if the input IR energy exceeds the allowed range. The saturation in the thermal detector makes it impossible to distinguish the target from background, as a result, the thermal imager does not perform its own mission anymore. In order to get an insight related with the image saturation, this paper develops a saturation model for a thermal imaging system, not a thermal detector. The proposed modeling starts from analyzing the specification of a thermal imager. Coupled with the characteristic parameters of the object, the saturation model can be used to predict the distance on which the detector is saturated. The proposed saturation model prove its validity by applying it for the case of observing a flash-bang.