• Journal of the Korean Home Economics Association
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• v.39 no.7
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• pp.1-19
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• 2001

The purpose of this study are (1) to examine the types and the after-school child care for children from low-income(106) and middle-income(99) families and (2) to examine the needs and expectations for after-school child care program of low-income(107) and middle-income(100) mothers. The findings of this study are as follows ; (1) The percentage of self-care among children from low-income families are higher than the children from middle-income families. The after-school activities mainly consist of arts, music, physical and computer lessons. (2) The needs on the after-school care program with non-profit basis which is managed by public welfare systems are higher among the low-income mothers than the middle-income mothers. Many mothers want professional, non-profit, systematic and formal after-school care programs. Some suggestions are proposed for after-school care program which can meet needs of the children and the mothers from diverse economic and social backgrounds.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.5 s.176
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• pp.1323-1330
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• 2000

Recently, injection molding process became more popular than ever to produce large quantities of high precision products or optical products. Especially, optical disk that was made by injection mol ding process has been used for many years as a music play media or computer sub-device. The density of data in disk media has been increased continuously. But those optical disks can cause sensorial problems because of high birefringence or deformation from the residual stresses in the media. Therefore, it is necessary to study the effects of various process conditions on the final bireffingence structure in injection-molded disks for producing precision injection-molded products. In the present paper we have focussed on the effect of holding and compression pressures on the optical anisotropy remaining in the MOD by examining the gapwise distribution of birefringence and extinction angle. The effect of holding pressure was found to form the inner two bireffingence peaks. But the effect of compression pressure on the bireffingence distribution was found to make the uniform distribution near the center in the gapwise direction. Finally, the value of the birefringence near the wall decreased as the mold temperature increased.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.8
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• pp.708-719
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• 2007

In case of indoor gymnastics training floor, in view of its characteristics, since it is simultaneously required the related smooth communication between the coach and the player, also the acoustic performance regarding to the clearness of music, besides the sport activity, the consideration about the acoustic character has entered the stage as an indispensable element. On such viewpoint, recently constructed dome-typed gymnastic training floor was optimized acoustic design with remodeling through acoustic simulation test. And acoustic satisfaction degree and reaction was attempted to investigate about the gymnastics training floor estimating value of human's psychological(sensual) degree using auralization that enables to experience the virtual sound field at the stage of design. As the result of investigation about the research on the space of object, it could be known that the valuation regarding to the acoustic performance of 'after-improvement' was distinctly more refined than that of 'before-improvement'. It is now considering that such result of the study can be utilized as the useful data which enables to improve the retrenchment effect of the construction cost as well as the acoustic capability, by means of the prediction control on the acoustic problem from the stage of design, for the occasion when the similar indoor sport gymnasium is planning to build for the near future.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.6038-6053
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• 2017

In this study, we propose an automatic melody extraction algorithm using deep learning. In this algorithm, feature images, generated using the energy of frequency band, are extracted from polyphonic audio files and a deep learning technique, a convolutional neural network (CNN), is applied on the feature images. In the training data, a short frame of polyphonic music is labeled as a musical note and a classifier based on CNN is learned in order to determine a pitch value of a short frame of audio signal. We want to build a novel structure of melody extraction, thus the proposed algorithm has a simple structure and instead of using various signal processing techniques for melody extraction, we use only a CNN to find a melody from a polyphonic audio. Despite of simple structure, the promising results are obtained in the experiments. Compared with state-of-the-art algorithms, the proposed algorithm did not give the best result, but comparable results were obtained and we believe they could be improved with the appropriate training data. In this paper, melody extraction and the proposed algorithm are introduced first, and the proposed algorithm is then further explained in detail. Finally, we present our experiment and the comparison of results follows.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.193-197
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• 2003

Radar target identification can be achieved by using various radar signatures, such as one-dimensional(1-D) range profile, 2-D radar images, and 1-D or 2-D scattering centers on a target. In this letter, five 1-D scattering center extraction methods are discussed - TLS(Total Least Square)-Prony, Fast Root-MUSIC (Multiple Signal Classification), Matrix-Pencil, GEESE(GEneralized Eigenvalues utilizing Signal-subspace Eigenvalues), TLS-ESPRIT(Total Least Squares - Estimation of Signal Parameters via Rotational Invariance Technique), These methods are compared in the context of estimation accuracy as well as a computational efficiency using a noisy data. Finally these methods are applied to the target classification experiment with the measured data in the POSTECH compact range facility.

• The Journal of the Acoustical Society of Korea
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• v.19 no.3
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• pp.86-91
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• 2000

In this paper, we will discuss the characteristics of the magnitude and the phase of the piano sound in frequency domain by using the FFT(Fast Fourier Transform). The method deciding the parameters representing those sounds through the mathematical model is described. We used the curve fitting method for the modeling of the harmonic part of the sound including the fundamental frequency in order to minimize the errors between original sounds and modeled sounds. furthermore, we used the line segment approximation method for the modeling of the noise part around fundamental frequency. We also applied the same method for the phase model and could get the modeled sound to be similar to the original sound using the parameters. Therefore the high compression ratio comparing the modeled sound to the original sound is achieved.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.3820-3841
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• 2018

Most of the accidents occur due to drowsiness while driving, avoiding road signs and due to driver's distraction. Driver's distraction depends on various factors which include talking with passengers while driving, mood disorder, nervousness, anger, over-excitement, anxiety, loud music, illness, fatigue and different driver's head rotations due to change in yaw, pitch and roll angle. The contribution of this paper is two-fold. Firstly, a data set is generated for conducting different experiments on driver's distraction. Secondly, novel approaches are presented that use features based on facial points; especially the features computed using motion vectors and interpolation to detect a special type of driver's distraction, i.e., driver's head rotation due to change in yaw angle. These facial points are detected by Active Shape Model (ASM) and Boosted Regression with Markov Networks (BoRMaN). Various types of classifiers are trained and tested on different frames to decide about a driver's distraction. These approaches are also scale invariant. The results show that the approach that uses the novel ideas of motion vectors and interpolation outperforms other approaches in detection of driver's head rotation. We are able to achieve a percentage accuracy of 98.45 using Neural Network.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.04a
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• pp.436-440
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• 2008

Among those various facilities attached to the school building, the Auditorium is being utilized for not only the Exercise Activity but also for many purposes such as Culture, Public Performance, Education, Assembly and so on. In order to utilize in maximum such function of the multipurpose auditorium, an adequate acoustic design with regard to the Clarity of Voice and Music in accordance with its use-purpose should be accompanied. However, as the most part of multipurpose auditoriums is designed with high ceiling-height by its peculiar character, and due to use of the material of strong reflexibility, it is appearing the defect that excessively exposes the reverberation of sound. In order to make out an optimal acoustic condition within the broad space such as an auditorium, the acoustic characteristics must be considered from the planning stage, however in the most case, those acoustic problems are being settled through the repair works after construction. On such viewpoint, this Study intends to analyze the room acoustic characteristics from the planning stage using a computer simulation based on the blueprint of multipurpose auditorium in S High School located in Gwangju. It is considered that the material analyzed in such way could be practically applied as a fundamental material enables to improve the acoustic capability when a similar broad space is planned hereafter.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11C
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• pp.949-954
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• 2008

An ultrawide band (UWB) signal model is proposed to estimate the angle-of-arrivals of the signals arrived in clusters at an UWB receiver for a short-range, high-speed, indoor wireless communication system in an elliptical scattering environment. And a new estimation technique is proposed by modifying the conventional MUSIC algorithm. By using this estimation technique, the estimates of the two unknown parameter sets, angle-of-arrivals and distribution parameters, are obtained with the proposed UWB signal model. The proposed UWB signal model and estimation technique are verified through computer simulations in an ultrawide band communication environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2793-2799
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• 2013

This paper proposes an effective feature compensation method to improve speech recognition performance in time-varying background noise condition. The proposed method employs principal component analysis to improve the variational model composition method. The proposed method is employed to generate multiple environmental models for the PCGMM-based feature compensation scheme. Experimental results prove that the proposed scheme is more effective at improving speech recognition accuracy in various SNR conditions of background music, compared to the conventional front-end methods. It shows 12.14% of average relative improvement in WER compared to the previous variational model composition method.