• KIPS Transactions on Software and Data Engineering
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• v.12 no.8
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• pp.365-370
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• 2023

This paper aims to compare the performance of speech data classification into two groups, adult and elderly, based on the acoustic and linguistic characteristics that change due to aging, such as changes in respiratory patterns, phonation, pitch, frequency, and language expression ability. For acoustic features we used attributes related to the frequency, amplitude, and spectrum of speech voices. As for linguistic features, we extracted hidden state vector representations containing contextual information from the transcription of speech utterances using KoBERT, a Korean pre-trained language model that has shown excellent performance in natural language processing tasks. The classification performance of each model trained based on acoustic and linguistic features was evaluated, and the F1 scores of each model for the two classes, adult and elderly, were examined after address the class imbalance problem by down-sampling. The experimental results showed that using linguistic features provided better performance for classifying adult and elderly than using acoustic features, and even when the class proportions were equal, the classification performance for adult was higher than that for elderly.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.6
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• pp.732-742
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• 1985

Measurements of mean velocity and turbulence characteristics are obtained with a linearized constant temperature hot-wire anemometer in a two-dimensional turbulent jet discharging parallel to a flate. Wall static pressure distribution is also measure. The Reynolds number based on the jet nozzle width (D) is about 42,000 and the step height is 2.5D. The reattachment length is found to be 7.5D by using both wool tuft and oil methods. Upstream of the reattachment point, there exist double coherent structures and mean velocity, Reynolds stresses and triple product profiles are asymmetric about jet center line due to the influence of streamline curvature and recirculating flow region. Near the reattachment point, wall static pressure and turbulence quantities change its shape rapidly because of the large eddies by the solid wall. Especially, turbulence intensity has a maximum value in the reattachment regin, then decreases slowly in the redeveloping wall jet ragion. Downstream of X/D=14, a single large scale eddy structure is formed. Far downstream affer the reattachment(X/D.geq.18) mean velocity profile, the decay of maximum velocity and the variation of jet half width are nearly similar to those of plane wall jet, but the Reynolds stresses are higher than those of the latter.

• Journal of KSNVE
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• v.7 no.1
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• pp.71-79
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• 1997

The objective of this study is to investigate experimentally the effect of surface conditions of the plate on the impinging jet noise. The experimental results about the spectrum, the sound pressure level and the directivity are pressented and discussed in relation with the surface conditions. Regardless of the surface conditions, the pure tones of high level are generated at the same frequency band and the overall sound power level of impinging jets is much higher than that of the free jet. However, the velocity dependence of the sound pressure level and the directivity are different between smooth surfaces and rough surfaces. The dependence of sound pressure level on the jet velocity shows that the smooth surface generates quadrupole-type sound like free jets. However, the perforated or the rough surface radiates sound power exactly proportional to the sixth power of the jet velocity, indicating that the source is fixed dipole type. The directivities of 1/3 octave band sound pressure level for both the free and impinging jet show the peak directivity at 115$^\circ$ upstream, probably due to the refraction associated with velocity gradient.

• Water for future
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• v.29 no.2
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• pp.221-233
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• 1996

To investigate the hydrodynamic characteristics of a two-dimensional buoyant surface jet, the most important factors of the numerical analysis are the evaluation of the free surface and the turbulence transportation under the stratification. In present study, a numeriacal simulation model used with the semi-implicit method for pressure-linked equations (SIMPLE), the non-hydrostatic approximation and the algebraic stress model (ASM) is applied to investigate the vertical structure of internal flow hydrodynamically. The ASM enables to take account of anisotropy of turbulence, the damping effects of the density interface, and the free surface on the turbulence structure accurately. The ASM tested produces better agreement than the $\kappa-\varepsilon$ model with measurements by Nakatsuji (1984) on the flow development and turbulence structure. Applicability of the ASM to a two-dimensional buoyant surface jet is examined through comparison with experimental data.

• Journal of Korea Game Society
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• v.11 no.4
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• pp.93-104
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• 2011

This article inspected 16 game rating systems in the world to find out the trends of those. Mainly the perspective of freedom of expression is used to find out the implications of the trends. As the position of game becomes higher, the increase of game specialty rating institutions, the augmentation of self regulations rating institutions, the enlargement of freedom of expression in the area of game are revealed as trends. These trends are in the natural order of events that match with the development of game. We could know that rapid change and innovation is much needed.

• Journal of the Korean Geographical Society
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• v.46 no.3
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• pp.304-318
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• 2011

The types, distributional and shape properties of abandoned channels in Korea are classified and examined. There are 409 abandoned channels in Korea and they can be classified into the 6 types such as the incised meander cutoff, stream piracy, distributary, artificial incised meander neck-cutoff, channel straightening of free meander and distributary streams. The abandoned channels by incised meander neck-cutoff showing the most frequency with 266, have the topographical properties of high altitude and steep relief and frequently distribute in Gangwon and Gyeonbuk Province and in the upper reaches of main stream of Nakdong-River, and Dal-River and Pyeongchang-River, tributaries of Namhan-River. The most frequency areas of abandoned channels by distributary, channel straightening of free meander and distributary streams are the lower reaches of Namhan-River and main stream in the lower reaches of Nakdong-River, Mangyeong-River and Yeongsan-River, and Geumho-River, respectively. The abandoned channles by incised meandering neck-cutoff and stream piracy are relatively used as farmlands or forests due to the high altitude and relative altitude from the river bed.

• Tunnel and Underground Space
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• v.14 no.2
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• pp.79-85
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• 2004

수로터널은 일반적으로 상수 및 용수를 도수할 목적으로 설치하는 터널로서 기능상 여러가지로 분류할 수 있으나, 도로, 철도, 지하철 같은 교통터널(transportiontunnel)과는 달리 터널내에 수압의 작용이 반복되는 특징이 있으며, 이를 기본으로 하여 내수압의 작용 유무에 따라 자유수면(무압터널)터별과 압력터널로 분류된다(Fig. 1. 참조). 또한, 용도에 따라 상하수도 터널, 발전용 터널, 여수로(spillway) 터널, 가배수(diversion) 터널 및 방류(outlet) 터널로 분류되고 있다. 본 고에서는 이러한 수로터널 중 터널식 여수로에서 발생할 수 있는 공동현상(cavitation)에 대하여 발생원 인과 대처방안 및 피해사례에 대하여 정리하고자 한다.(중략)

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.640-643
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• 2016

오피니언 마이닝은 객관적인 정보를 필요로 하는 많은 분야에서 쓰이는 기법이다. 그러나 표현의 자유도가 높은 한글 Text를 분석하는 것은 상당히 어려운 일이다. 또한 한글 파괴 현상도 하나의 원인으로 대두되고 있다. 본 논문에서는 Text를 음소단위로 분할하는 Trigrarn-Signature 기법과 구문태그 패턴 기법을 통합한 새로운 상태 분류 기법을 제안했고, 만족, 불만, 낙담, 의문, 흥분 5가지 감정 분류를 시도했다. 이를 토대로 사용자의 정보를 그래프로 보여주는 시각화 시스템을 제안한다.

• Journal of the Korean Magnetics Society
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• v.21 no.6
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• pp.231-236
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• 2011

X-ray Free Electron Laser (XFEL) has been known to be a dream X-ray source opening an epoch in X-ray science with the characteristics of femtosecond pulse, perfect transverse coherence, and ultra-high brightness. Here we introduce the XFEL source shortly and report the status of the worldwide XFEL facilities, and then the experimental instrumentations for XFEL are reviewed in their conceptual classification scheme. Scientific examples and applications proposed in the research area of magnetism for XFEL are briefly mentioned. Finally are summarized the facility overview and the scientific proposals for PAL-XFEL project.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.5 no.1
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• pp.95-101
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• 2011

In this paper, we propose the gaussian mixture model based pattern classification algorithm of forearm electromyogram. We define the motion of 1-degree of freedom as holding and unfolding hand considering a daily life for patient with prosthetic hand. For the extraction of precise features from the EMG signals, we use the difference absolute mean value(DAMV) and the mean absolute value(MAV) to consider amplitude characteristic of EMG signals. We also propose the D_DAMV and D_MAV in order to classify the amplitude characteristic of EMG signals more precisely. In this paper, we implemented a test targeting four adult male and identified the accuracy of EMG pattern classification of two motions which are holding and unfolding hand.