• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.2
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• pp.251-256
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• 2008

Many researchers are studying about human Brain-Computer Interface(BCI) that it based on electroencephalogram(EEG) signals of multichannel. The researches of EEG signals are used for detection of a seizure or a epilepsy and as a lie detector. The researches about an interface between Brain and Computer have been studied robots control and game of using human brain as engineering recently. Especially, a field of brain studies used EEG signals is put emphasis on EEG artifacts elimination for correct signals. In this paper, we measure EEG signals as human emotions and divide it into five frequence parts. They are calculated related the percentage of selecting range to total range. the calculating values are compared standard values by Bayesian Network. lastly, we show the human face avatar as human Emotion.

• The Journal of the Acoustical Society of Korea
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• v.21 no.8
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• pp.703-707
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• 2002

This paper proposes new method for predicting sound power emitted from the control valve and piping system. The sound power level measurement method using the reverberation chamber is much easy to apply in the field compared to the method using the anechoic chamber. Measured sound power was used to determine the coefficients of the equation predicting sound power level. The noise prediction equation was developed at relative flow coefficient, 0.11. The sound power level predicted is in good agreement with the measured value. Proposed method can be used to express the noise characteristics of the control valves.

• The Journal of the Acoustical Society of Korea
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• v.24 no.8
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• pp.431-440
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• 2005

The precise measurement of ultrasonic power is important to the qualify assurance and the safety of medical ultrasonic equipments In the Present work, a brier theory was introduced to determine the ultrasonic Power from the time valving balance-indication due to the radiation force acting on an absorbing target and/or other causes such as buoyancy during the repetition of on/off behavior of ultrasonic irradiation. The developed automated system measuring the ultrasonic power was described in detail with the precise mechanical alignment tool , the electric signal generation network, the control and measurement network and the appropriate procedure. The ultrasonic power measured by the developed system was compared to the reference data calibrated by the other national metrology institute at 1 MHz, 5 MHz, 10 MHz, and 15 MHz over the range 10 mW to 10 W. Their relative differences are within $5\%$.

• Journal of Korean Society of Transportation
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• v.20 no.2
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• pp.17-26
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• 2002

Driver's psychophysiological load is one of the key measures for evaluating the safety of the highway. The purpose of this study is to propose and to test the methodology of evaluating the length limit of tangent section using driver's psychophysiological load. Driver's psychophysiological data is represented by the data acquire by frontal and occipital lobe. In order to compare the differences between tangent segments and the orders, real road driving experiments were performed. We collected psychophysiological data during the operation of vehicles. The experimental data were analyzed using FFT (Fast Fourier Transform) and relative power spectrum tools. These routine produces the beta value which is a major factor in consideration of driver's condition. The results in this study are summarized as follows: (1) A new methodology of evaluating the length limit in tangent section of highway using driver's psychophysiological load was proposed. (2) It was observed that driver's work load at tangent section was three times lower than that at the other section types. The beta value at tangent section is 2.219, while that at general section is 0.821. (3) It was observed that the driver's work load was significantly dropped to 0.428 after the continuous driving of 4.2km tangent section. (4) Based on the experimental subjects(from 27 Years to 31). we suggest that 30 times of design speed(3.0 km) could be acceptable as the length limit of tangent section in highway rather than the Previous limit which is 20 times of design speed(2.0km).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.162-169
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• 2020

This study was conducted from November 25 to December 4, 2019, to unmask differences in physical fitness based on the weight class of high school Ssirum elite-players. A total of 28 high school Ssirum elite-players were compared and analyzed by measuring physical factors (muscle strength/power, agility, anaerobic power, aerobic ability, flexibility, and isokinetic muscle function) by weight class. Data were analyzed using SPSS ver. 23.0. One-way ANOVA was used for comparison between groups. There was no difference by weight class in terms of grip strength, sit-ups, sergeant jump, long jump, flexibility, side step, and reaction time. Evaluation of back muscle strength revealed that the group with more than 100 kg had greater strength than lower weight categories, whereas it was lower in the sit-ups, 20 m shuttle run and the relative values anaerobic power. Considering isokinetic muscle function, no difference was observed between the groups of back muscle strength and knee joint. The results of this study indicate that amongst the high school Ssirum elite-players, there is no difference in muscle power, flexibility, agility, and anaerobic average power per body weight, isokinetic trunk strength, and knee flexion strength, when evaluated according to weight class.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.78-86
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• 2014

In this paper, a novel intensity-based fiber optic vibration sensor using a mass-spring structure, which consists of four serpentine flexure springs and a rectangular aperture within a proof mass, is proposed and its feasibility test is given by the simulation and experiment. An optical collimator is used to broaden the beam which is modulated by the displacement of the rectangular aperture within the proof mass. The proposed fiber optic vibration sensor has been analyzed and designed in terms of the optical and mechanical parts. A mechanical structure has been designed using theoretical analysis, mathematical modeling, and 3D FEM (Finite Element Method) simulation. The relative aperture displacement according to the base vibration is given using FEM simulation, while the output beam power according to the relative displacement is measured by experiment. The simulated sensor sensitivity of $15.731{\mu}W/G$ and detection range of ${\pm}6.087G$ are given. By using reference signal, the output signal with 0.75% relative error shows a good stability. The proposed vibration sensor structure has the advantages of a simple structure, low cost, and multi-point sensing characteristic. It also has the potential to be made by MEMS (Micro-Electro-Mechanical System) technology.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1164-1171
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• 2008

The present study, which is about a ceramic waveguide filter for UMTS, designed a filer using a circuit and structure simulator, suggested a design method at a required frequency band, and developed a waveguide filter, which can be applied at a power of over 50W and be miniaturized, through implementing the design and examining related variables and characteristics. In the results of designing a waveguide filter with the center frequency of 1,950 MHz and 2,140 MHz and examining its characteristics, bandwidth was 60MHz, insertion loss was below 1.0dB, return loss was over 20dB, and attenuation at the relative frequency band was over 60dB. In the results of a power station test, the characteristics did not change and internal temperature was below $30^{\circ}C$ at 50.8W, and this confirmed that the filter is usable at over 50W.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.1
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• pp.89-94
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• 2021

In this paper, we presented the results of analysis with data obtained through EEG measurements to confirm the effect of musical stimulus when performing mathematical tasks. While the subject was solving a mathematical task, favorite and unfavorite music classified according to the subject's preference were presented as musical stimulus and the tasks were divided into memorization task and procedure task. The data measured in the EEG experiments was divided into theta waves, SMR waves and mid-beta waves which are the frequency bands related to concentration to compare the relative power spectrum values. In our results, in the case of comparing no music with favorite music and no music with unfavorite music, a significant difference was observed in the several channels, and the average difference was shown in the channels F3 and F4 of the frontal lobe. In that channels, the power was found to be greater when the music was presented than the case where there was no music. Depending on the subject's preference, it was confirmed that favorite music showed greater brain activity than unfavorite music.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.165-165
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• 2017

모돈은 사육 특성상 제한된 파일롯 공간 안에 장시간 머물기 때문에 과중한 몸무게에 의한 지제 이상, 섭식 등의 불량, 수면상태의 불량 등을 지속적으로 관찰해야 하는 대상이다. 측면에 다수의 초음파 센서를 설치하여 기립의 상태 및 운동 시 몸체 궤적의 특성을 분석하여 종합적으로 모돈의 행동 특성을 정량화 하고자 하였다. 이 과정에서 계측 신호의 값을 대수적으로 비교하는 방식에 한계가 있음을 발견하였고, 이를 해결하고자 10 Hz/Ch 내외의 시계열 상대거리 궤적 신호를 주파수 도메인으로 변경하여 분석을 수행하였다. 일정 주파수에 집중되어 있는 주파수 값의 크기 변화(파워 스펙트럼 밀도)를 기준으로 모돈의 움직임의 정상 상태 유무 판별이 가능하였다. 단, 이러한 분석은 계측 데이터를 일괄 처리 방식으로 분석하는 방법으로 도출이 되었으므로, 계측과 정량 분석을 동시에 수행하기 위한 개선이 필요하였다. 계측 시스템에서 사용한 마이크로 프로세서는 Nucleo-446(STMelectronics, CA, USA)로 180 Mhz의 클럭 속도로 작동하나, 총 100 Hz 내외의 16비트 계측 신호에 대해 추가적으로 FFT 등의 주파수 변환 신호 처리를 수행하기에는 연산 능력이 부족하였다. 한편, 주파수 분석의 주기를 1분 단위로 할 경우 처리해야할 정보의 크기는 $100{\times}60{\times}5{\times}2Byte$ 이므로 1분 내에 해당 연산을 종료할 수 있는 추가의 연산 장치가 필요하였다. 계측과 주파수 도메인 변환 연산을 동시에 수행하기 위하여 1 Ghz의 연산능력을 가진 ARM A9 계열의 초소형 멀티코어 AP인 NanoPi Neo Air(Friendlyarm, Guangzhou, China)을 선정하였다. 4개의 코어를 각각 계측, Median 필터링, Smoothing 연산, FFT 분석에 사용하여 1분 단위, 2분 단위, 5분 단위의 주파수 분석을 동시에 수행하였다. 병렬 연산 라이브러리는 오픈 소스인 MPICH(www.mpich.org)를 이용하였다. 상대적으로 여유있는 자원을 보유하고 코어를 실시간으로 결정하여 다수의 모돈 개체 동시 모니터링을 위한 네트워크 연결 역할을 동시에 수행하도록 하였다. 1주일 내외의 요인 실험 수행 결과, 약 70 Mbyte의 데이터가 축적이 되었으며, 1분 단위, 2분 단위, 5분 단위의 주파수 도메인 변환 후 결과를 동시에 취득할 수 있었다. 일부 주파수 도메인 상의 파워 밀도 값이 모돈의 행동 특성에 분석에 유효한 정보를 제공함을 발견하였다. 모돈사 내 현장 보급이 가능한 초소형 AP와 멀티 코어 기반 병렬 처리 기법을 이용한 현장 진단 시스템 개발 연구를 지속적으로 수행할 것이다.

• Journal of Korea Game Society
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• v.15 no.2
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• pp.105-114
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• 2015

We propose a real time user interface that utilizes emotion recognition by physiological signals. To improve the problem that was low accuracy of emotion recognition through the traditional EEG(ElectroEncephaloGram), We developed a physiological signals-based emotion recognition system mixing relative power spectrum values of theta/alpha/beta/gamma EEG waves and autonomic nerve signal ratio of ECG (ElectroCardioGram). We propose both a data map and weight value modification algorithm to recognize six emotions of happy, fear, sad, joy, anger, and hatred. The datamap that stores the user-specific probability value is created and the algorithm updates the weighting to improve the accuracy of emotion recognition corresponding to each EEG channel. Also, as we compared the results of the EEG/ECG bio-singal complex data and single data consisting of EEG, the accuracy went up 23.77%. The proposed interface system with high accuracy will be utillized as a useful interface for controlling the game spaces and smart spaces.