• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.297-300
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• 2002

In this paper, we propose a post-processing method to reduce the blocking artifacts. We perform the post-processing only in the spatial domain so that it is readily applicable to real-time video decoder. Many approaches proposed so far for deblocking deal with only The luminance signal. but here we propose processing the chrominance signals as well since the low bit rare application where the blocking artifacts are most problematic suffers significantly from the color misalignment caused by blocking artifacts occurring to chrominance data as well. The proposed method is composed of low pass filtering in two steps considering the edge direction. The first step is the IIR low pass filtering in the diagonal direction, and the second step is another IIR low pass filtering in horizontal and vertical directions.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.1
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• pp.87-93
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• 2001

A reliable analytic model that determines the exit cross sectional shape a workpiece(material) in round-oval (oroval-round) pass sequence has been developed. The exit cross sectional shape of an outgoing workpiece is predicted by using the linear interpolation of the radius of curvature of an incoming workpiece and that of roll groovw to the roll axis direction. The requirements placed on the choice of the weighting function were to ensure boundary conditions specified. The validity of the analytic model has been examined by not rod rolling experiment with the roll gap and specimen size changed. The exit cross sectional shape and area of the workpiece predicted by the proposed analytic model were good agreement with those obtained experimentally. We found that the analytic model has not only simplicity and accuracy for practical usage but also save a large amount of computational time compared with finite element method.

• Journal of Power System Engineering
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• v.10 no.2
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• pp.36-40
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• 2006

In order to prevent the environmental pollution, the dryers are commonly used to treat sludge that one of sewages is polluting the quality of water. Generally, the drying method is various as to the property of material and use. Rotary dryer is a good apparatus to treat them. It is the way that is to make substance transmission and heat using hot air between sludge particle and heated gas. In this paper, we developed a 3-pass rotary dryer for a design program for the 3-pass rotary dryer with various conditions. The working conditions of dryer are a raw sludge feed rate, input & output water content and operation time etc.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.119-122
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• 1991

In this paper, a new adaptive IIR notch filter employing all pass filter is proposed. Proposed all pass filter is composed of all pole and all zero sections, each of which utilizes modulation lattice filter [11]. And, adaption algorithm for proposed notch filter is also derived. In addition, the error surface for proposed IIR adaptive notch filter is analyzed. Computer simulation results reveal that the proposed adaptation algorithm works well for low SNR(signal to noise ratio) single and multiple sinusoids. And it is shown that for estimation time varying frequency, the parameter which is related to notch bandwidth is important than any other parameters.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.121-126
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• 2012

We propose a novel technique that records the horizontal-parallax-only (HPO) hologram of a real object using optical scanning holography (OSH). The proposing HPO-OSH is composed of a conventional OSH and an electronics low pass filter. When we scan an object along vertical direction before horizontal direction, the electronic low pass filter filters the vertical fringes with preserving horizontal fringes and gives an HPO hologram. To the best of our knowledge, this is the first time to record the HPO hologram using OSH without either truncation of the scanning beam or digital post processing.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.385-388
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• 1996

A time delay controller with state feedback is proposed for azimuth motion control of the frictionless positioning device which is subject to the variations of inertia in the presence of measurement noise. The time delay controller, which is combined with a low-pass filter to attenuate the effect of measurement noise, ensures the asymptotic stability of the closed loop system. It is found that the low-pass filter tends to increase the robustness in the design of time delay controller as well as the gain and phase margins of the closed loop system. Numerical and experimental results support that the proposed controller guarantees a good tracking performance irrespective of the variation of inertia and the presence of measurement noise.

• Journal of Power Electronics
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• v.8 no.1
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• pp.91-100
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• 2008

The d-q harmonic detecting algorithms are dominant methods to generate current references for active power filters (APF). They are often implemented in the synchronous frame and time domain. This paper researches the frequency characteristics of d-q synchronous transformations, which are closely related to the analysis and design issues of control system. Intuitively, the synchronous transformation is explained with amplitude modulation (AM) in this paper. Then, the synchronous filter is proven to be a time-invariant and linear system, and its transfer function matrix is derived in the stationary frames. These frequency-domain models imply that the synchronous transformation has an equivalent effect of frequency transformation. It is because of this feature, the d-q method achieves band-pass characteristics with the low pass filters in the synchronous frame at run time. To simplify these analytical models, an instantaneous positive-negative sequence frame is proposed as expansion of traditional symmetrical components theory. Furthermore, the synchronous filter is compared with the traditional bind-pass filters based on these frequency-domain analytical models. The d-q harmonic detection methods are also improved to eliminate the inherent coupling effect of synchronous transformation. Typical examples are given to verify previous analysis and comparison. Simulation and experimental results are also provided for verification.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.33-39
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• 1999

This study was conducted to confirm the effect of bypass dust on the hydration and mechanical properties of the cement pastes and mortar obtained from ordinary Portland cement (OPC), OPC-slag and OPC-fly ash system. The rate of heat evolution is accelerated with the content of By-pass Dust(BD). total heat evolution increased because alkali-chlorides activated the hydration of blended cement. Compressive strength and bound water content show maximum value at 5wt% By-pass Dust(BD) on each curing time in ordinary Portland cement and slag blended cement. Ca(OH)2 content of Ordinary Portland Cement increased as the content of BD and curing time. In blended cement, the formation of Ca(OH)2 is active at early hydration stage. By pozzolanic reaction, the content of Ca(OH)2 is decreased as curing time goes by. According to the BD content stable chlorides complex of Friedel's salt (C3A·CaCl2·10H2O) is created. Due to the hydration activation effect of chlorides and alkali we observed Type II C-S-H, which developed into densest microstructure.

• Fire Science and Engineering
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• v.22 no.5
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• pp.67-71
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• 2008

This experimental study showed the tracking characteristics of contaminated insulating materials of RCD. Electrolytes is made by IEC(International Electrotechnical Commission) 60589, NaCl added to deionized water as each 0.1 wt%. The used test equipment is application to KS(Korean Industrial Standard) C IEC 60112. The used samples is RCD(Residual Current Device) of tree companies. It is investigated carbonic electric conductive pass growth time and tracking growth form that contaminated insulators materials of RCD. As a result, carbonic electric conductive pass growth time and tracking growth form was different each companies. Track growth time of contaminated insulating materials was faster than non-contaminated.

• CELLMED
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• v.12 no.4
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• pp.15.1-15.3
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• 2022

The purpose of this study is to examine the joy, anger, sorrow, and pleasure of Koreans in Arirang songs. Arirang is a representative song that strengthens the collective identity and social bond of Koreans. For Koreans who mainly eat rice, Arirang represents rice, life, and reason for its existence. Koreans have been singing Arirang together for a long time, overcoming pain, sadness, and hardships and consoling their minds and bodies. Arirang is a national music that is loved more and sung more often than the national anthem. The hill on the mountain is not a place to stay. The pass is a passing place. This gives us a lot of thought. We have various difficulties living in the world. The word Arirang means that Arirang is not one state. The end of joy, anger, sorrow, and pleasure is surely a joy. Arirang Pass (Arirang Gogae) is not a staying pass, but a crossing pass. Arirang, which contains joy, anger, sorrow, and pleasure, is a soul song and a consolation medicine for mental and physical health. We suggest that Arirang song compared to standard care may have beneficial effects on anxiety, hope, pain, and depression in patients.