• 한국공작기계학회논문집
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• 제15권4호
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• pp.44-48
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• 2006

Recently, demand the ultra precision product which is increasing rapidly is used extensively frontier industry field such as semi-conductor, computer, aerospace, precision machine. Ultra precision processing is the portion that is very needed to NT in the field of mechanical engineering. The latest date, together with radical advancement of electronic and photonics industry, necessity of ultra precision processing is on the increase for the manufacture of various kernel parts those are connected with these industrial fields. Specially, require motion accuracy of high resolution of nm order in stroke of hundreds millimeters according as diameter of processing object great and processing accuracy rises. In this case ,the response speed absolute delay because inertial mass of moving part is very large. Therefore, real time motion error compensation becomes very hardly. In this paper, we used ultra precision cutting unit(UPCU) to cope such problem. a UPCU is designed and tested to obtain sub-micrometer from accuracy in diamond turning of flat surfaces. The thermal growth spindle error is compensated for real time using a UPCU driven by piezoelectric actuator along with a laser encoder displacement sensor.

• 농촌지도와개발
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• 제13권2호
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• pp.299-312
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• 2006

This study reported on the cases about gender inequality in agriculture. Generally women have experienced something in vague situation as unequal to men in rural and agriculture. Despite of some women's have been complaining about this problem, it is not easy why and how many times they have been suffering. In this report, to get the information of gender unequality in agricultural laws and policies, the data was gathered by two steps. The first step, 175 cases into nine types was collected from leaders of several women farmer's associations, and after that, 60 cases selected to be interviewed by a specialist panel. The second step, it was analyzed the interviewed 60 cases based on real conditions compared with laws of items of policies. Among the cases, it was analyzed 8 rural women's who had been experienced to receive the inappropriate compensation in an unexpected accidents. From these cases, it was drew up some suggestions as follows; to make a rule to certify of the identity of woman farmer, and to build in a monitoring system of gender equality in agriculture.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 춘계 학술논문 발표대회
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• pp.7-10
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• 2008

As the land price in the downtown area increases, buildings are becoming bigger, deeper and higher. Consequently, the importance of underground construction has increased. Although construction engineers make every effort to complete underground construction without any problem, construction failures like landslides and the collapse of a retaining wall occur because of the uncertainty of the soil conditions as well as the unexpected risks of excavation work. In order to prevent potential excavation accidents, it is essential to understand the causes and impacts of such accidents. However, there are only a few examples of construction failures, which show the economic impact on accidents during excavation because of the sensibility of the information. This paper presents two cases of excavation accidents, which were investigated by construction insurance company. The compensation for the accidents paid by the insurance company was compared with the estimated costs calculated based on the estimation method for excavation accidents proposed by our previous study. The comparison results showed that the estimate calculated by our method was much less than the actual compensation because the estimate solely focused on the construction costs whereas the compensation included other external factors.

• 한국통신학회논문지
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• 제40권4호
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• pp.740-749
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• 2015

종래의 LED(Light Emitting Diode) 조명을 사용한 가시광 통신에서 송수신기 회로 사이의 통신 거리가 증가함에 따라 가시광 채널의 페이딩과 채널의 경로손실 특성으로 인해 가시광 수신 회로의 포토다이오드에서 수신된 신호는 불규칙한 크기이며 감쇠된 특성을 가진다. 이런 문제점을 극복하기 위해, 이 논문에서는 가시광 통신의 통신거리 확장을 위해 반드시 필요한 거리 보상 회로가 내장된 비교기 문턱 전압 기반의 가시광 통신 회로를 제안하여 설계하고 가시광 시스템 시스템을 구현한다. 또한, 구현된 문턱값 기반 가시광 통신 시스템을 통신 거리와 통신 시스템 속도에 따라 종래 가시광 통신 시스템과 비교하여 제안된 방식시스템의 성능을 분석한다.

• Journal of Advanced Marine Engineering and Technology
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• 제18권4호
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• pp.102-111
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• 1994

This article deals with the problem of designing a robust algorithm for the motion control of robot manipulator whose nonlinear dynamics contain various uncertainties. To ensure high performance of control system, a model-based feedforward compensation with continuous robust control has been developed. The control structure based on the deterministic approach consists of two parts : the nominal control law is first introduced to stabilize the system without uncertainties, then a robust nonlinear control law is adopted to compensate for both the resulting errors(or structured uncertainties) and unstructured uncertainties. The uncertainties assumed in this study are bounded by polynomials in the Euclidean norms of system states with known bounding coefficients. The presented control scheme is relatively simple as well as computationally efficient. With a feasible class of desired trajectories, the proposed control law provides sufficient criteria which guarantee that all possible responses of the closed-loop system are uniformly ultimately bounded in the presence of uncertainties. Therefore, the control algorithm proposed is shown to be robust with respect to the involved uncertainties.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (2)
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• pp.688-690
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• 2004

In this paper, we propose a new method of removing glasses from human frontal facial images. We first detect the regions occluded by the glasses, and generate a natural looking facial image without glasses by recursive error compensation using PCA reconstruction. The resulting image has no trace of the glasses frame, nor of the reflection and shade caused by the glasses. The experimental results show that the proposed method provides an effective solution to the problem of glasses occlusion, and we believe that this method can also be used to enhance the performance of face recognition systems.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.100-109
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• 2017

This paper proposes performance improvement schemes for sensorless PMSM control drive using a four-switch three-phase inverter (so-called B4 inverter). In the proposed scheme, the back-EMF estimation-based sensorless control algorithm is used to control the brushless PMSM without position sensors. In order to have stable operation, this paper presents a gain adjustment scheme that compensates the reduction of stable sensorless operation range as long as the rotor speed increases. In B4 topology, the center point of dc-link capacitors is connected to 3-phase load, and it is prone to have the load current distortion. Hence, to mitigate this problem, a distortion compensation scheme by modifying voltage commands using measured dc-link potentials is proposed in this paper. The validity of the proposed method is evaluated by simulations and experiments.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2019년도 추계학술대회
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• pp.188-190
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• 2019

Long-term global motion compensation (LT-GMC) was designed to compensate camera motion effectively. The LT-GMC warps a reference picture according to an estimated affine/homography model and stores it in its decoded picture buffer for long-term reference. Most previous works on LT-GMC have focused on improving quality of the warped picture, however, there has been only little consideration on the overhead of its motion coding. In this paper, we address this problem and propose a method, namely Scaling Predictor, to reduce the motion coding overhead for LT-GMC. Our experiment has shown BD-Rate reduction of 1.40% over conventional LT-GMC scheme by applying the proposed method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.606-610
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• 2001

Voltage harmonics resulting from current harmonics produced by the nonlinear loads have become a serious problem in many systems. Moreover momentary interruptions and voltage sags are responsible for many of the power quality problems found in typical industrial plants. In this paper, proposed power system using series active power filter is not only harmonic compensation but also harmonic isolation between supply and load, and voltage regulation and unbalance compensation. The effectiveness of the proposed system is verified through computer simulations and experiments

• 한국지능시스템학회논문지
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• 제11권6호
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• pp.558-562
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• 2001

In this paper, a fuzzy hyperresolution principle called CFHR. Compensatory Fuzzy Hyperresolution, with positive compensation facility is proposed. Usually hyperresolution has several terms of conditon parts. Theser terms have to be connected by the an connective. If the main/max operator to be used the and operation, there is some dependency problem of the min/max operator. So , we propose a compensatory operator EGM and applied it to the CFHR, We show the CFHR does more meaningful reasoning than existing method. We also prove the completeness of CFHR.