• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.12
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• pp.1373-1380
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• 2014

In order to calculate accurate traffic and traffic speed, qualified and sufficient GPS data should be provided. However, it is difficult to provide accurate traffic information using restricted GPS data from probe vehicles because of communication costs. This paper developed a algorithm that recovers links omitted by restricted GPS data with topology information, and calculate traffic speed with original links and recovered links. T traffic information service of city with a new algorithm can provide more accurate traffic and traffic speed than the original system.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.466-469
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• 2004

In this paper, real-time voice change method using pitch change technique is proposed to change one's voice to the other voice. For this purpose, sampling rate change method using DFT (Discrete Fourier Transform) method and time scale modification method using SOLA (Synchronized Overlap and Add) method is combined to change pitch. In order to evaluate the performance of the proposed method, voice transformation experiments were conducted. Experimental results showed that original speech signal is changed to the other speech signal in which original speaker's identity is difficult to find. The system is implemented using TI TMS320C6711DSK board to verify the system runs in real time.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.1
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• pp.18-23
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• 2013

In this paper we propose an image enhancement technique based on histogram specification method over local overlapping regions referred as Local Histogram Specification. First, both reference and original images are splitted into local regions that each overlaps half of its adjacent regions and general histogram specification method is used between corresponding local regions of reference and original image. However it produces noticeable boundary effects. Linear weighted image blending method is used to reduce this effect in order to make seamless image and we also proposed new technique dealing with over-enhanced contrast areas. We satisfied with our experimental results that showed better enhancement accuracy and less noise amplifications compared to other well-known image enhancement methods. We conclude that the proposed method is well suited for motion detection systems as a responsible part to overcome sudden illumination changes.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.903-905
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• 1999

In this paper, a novel sliding surface is proposed by defining a novel virtual state. This sliding surface has nominal dynamics of an original system and makes it possible that the Discrete-Time Sliding Mode Control(DSMC) technique is used with the various types of controllers. Its design Is based on the augmented system whose dynamics have a higher order than that of the original system. The reaching phase is removed by using an initial virtual state which makes the initial sliding function equal to zero.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.912-914
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• 1999

In this paper, the feedback linearization technique is used with the sliding mode control for discrete nonlinear systems. This combination of the two control techniques is achieved by Proposing a novel sliding surface which has the nominal dynamics of the original system controlled by feedback linearization technique. Its design is based on the augmented system whose dynamics have a higher order than that of the original system. The reaching Phase is removed by using an initial virtual state which makes the initial sliding function equal to zero.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.915-917
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• 1999

In this paper, a novel sliding surface is proposed by introducing a virtual state. This sliding surface has nominal dynamics of an original system and makes it possible that the Sliding Mode Control(SMC) technique is combined with the $H_{\infty}$ controller. Its design is based on the augument system whose dynamics have one higher order than that of the original system. The reaching phase is removed by setting an initial virtual state which makes the initial switching function equal to zero.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.906-908
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• 1999

In this paper, new sliding mode surfaces are proposed by defining novel virtual states. These sliding surfaces have nominal dynamics of an original system and makes it possible that the Sliding Mode Control(SMC) technique is used with the various types of controllers. Its design is based on the augmented system whose dynamics have m-th higher order than those of the original system where m is the number of inputs. The reaching phase is removed by setting the initial virtual states which makes the initial switching functions equal to zero.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.723-726
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• 2004

In this work, we have studied the CMP characteristics by mixing of original slurry and used slurry in order to investigated the possibility of recycle of used silica slurry. The removal rate and within-wafer non-uniformity (WIWNU) were measured as a function of different slurry composition. Also, we compared the CMP characteristics between self-developed KOH-based silica abrasive slurry and the original slurry. Our experimental results revealed comparable removal rate and good planarity with commercial products.

• ETRI Journal
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• v.42 no.3
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• pp.420-432
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• 2020

The reconstruction of archaeological fragments in 3D geometry is an important problem in pattern recognition and computer vision. Therefore, we implement an algorithm with the help of a 3D model to perform reconstruction from the real datasets using the slope features. This approach avoids the problem of gaps created through the loss of parts of the artifacts. Therefore, the aim of this study is to assemble the object without previous knowledge about the form of the original object. We utilize the edges of the fragments as an important feature in reconstructing the objects and apply multiple procedures to extract the 3D edge points. In order to assign the positions of the unknown parts that are supposed to match, the contour must be divided into four parts. Furthermore, to classify the fragments under reconstruction, we apply a backpropagation neural network. We test the algorithm on several models of ceramic fragments. It achieves highly accurate results in reconstructing the objects into their original forms, in spite of absent pieces.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.605-608
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• 2008

In this paper, a numerical investigation of three-dimensional, two-phase flow field around a butterfly valve is conducted. The butterfly valves that have different opening angles, $10^{\circ}{\sim}90^{\circ}$, and two profiles of the shaft boss are compared with various cavitation numbers and Reynolds numbers. This paper focused on the flow analysis in the original butterfly valve and new design butterfly valve in order to decrease cavitation and loss. It is found that the butterfly valve with a cone-type shaft boss greatly reduces the cavitation and loss, compared to the original shaft boss by 20${\sim}$30%.