• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.135-138
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• 2007

We may have had experience to use meaning of stress once at least. Because various mental and physical frustration, conflict, deprivation, and pressure have been happened around the us while we live our whole life. The stress is always existing at our surroundings as much. Now, most stress measurement method is composed of mental method and physical method. The accuracy of stress grade lacks to the disproportion of subjectivity, objectivity, and a science trait. Therefore, in this paper, we propose the index processing algorithm for a stress relief better, after mixing mental measurement result and physical measurement result.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.1 no.1
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• pp.107-114
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• 1998

Purpose: The purpose of our study is to provide useful information for me-asurement methods of childhood obesity and to provide clinical significance of bioelectrical impedance analysis. Methods: We measured height, weight, waist to hip ratio, skinfold thickness and bioelectrical impedance from 206 elementary students in Kwangju from May to July 1997. Results: In males; 1) There were statistically high correlations between tri-ceps skinfold thickness and body mass index (BMI), percentage of body fat (%BF), weight, Rohler index (RI), total fat weight (TFW), waist to hip (W/H) ratio, height, lean body mass (LBM) (all, p<0.001). 2) There were statistically high correlations between subscapular skinfold thickness and BMI, RI, weig-ht, %BF, TBW (all, p<0.001). 3) There were statistically high correlations between %BF and BMI, triceps skinfold thickness, RI, TFW, subscapular skinfold thickness, weight (all, p<0.001). In females; 4) There were statistically high correlations between triceps skinfold thickness and BMI, weight, LBM, height, %BF (all, p<0.001). 5) There were statistically significant correlations between subscapular skinfold thickness and BMI, weight, LBM, RI, height. 6) There were statistically high correlations between percentage of body fat and BMI, RI, triceps skinfold thickness. The percentage of body fat according to the bioelectrical impedance analysis highly correlated with that calculated by skinfold thickness in males (r＝0.57, p<0.01) and in females (r＝0.30, p<0.01). Conclusion: The results of our study suggests that bioelectrical impedance analysis is a useful method of estimating body fat in the childhood obesity.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.123-123
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• 2017

식물공장 내 작물의 생육은 제공되는 인공광원의 광원 및 광질에 영향을 받으며, 광흡수 파장에 따라 다르다. 또한 광합성에 효과적인 형태의 빛의 계속적인 빛의 조사보다는 광 펄스를 조절하여 공급하여 준다면 더욱더 효과적인 생육 환경을 제공해 줄 수 있다. 식물의 최적 생장을 위해 특정 파장대의 빛을 선택적으로 조사할 수 있는 LED특성을 사용하여 UV광원을 포함한 인공광원의 펄스폭 변조에 따른 적치마 상추의 생육특성을 알아보고자 하였다. 광환경은 Red(660 nm), Blue(450 nm), UV(395 nm) LED를 8:1:1 비율로 광량 $160{\mu}mol{\cdot}m^2{\cdot}s^{-1}$, 주파수 1.25, 2.5, 3.75, 5.0 kHz로 조사하여 주었으며, 온도 $20{\sim}23^{\circ}C$, 습도 50~60%, $CO_2$농도 1,000 ppm으로 조성하여 주었다. 아시아종묘 적치마상추를 파종 후 18일 째 되는날 정식, 정식 후 14일 28일 째 되는날 SPAD, 지상부 지하부의 생체중 및 건물중, 엽폭, 엽장을 측정하였으며, 측정한 엽폭과 엽장을 이용하여 엽형지수 산출, 지상부 지하부 생체중 값을 이용하여 S/R율을 산출하였다. SPAD 측정결과 생육시기가 증가할수록 SPAD함량은 감소하였으며, 1.25와 2.5 kHz에서 생육 시기 증가에 대한 SPAD함량 감소가 컸고, 3.75와 5.0 kHz의 경우 SPAD함량의 감소량은 작았다. 지상부 생체중은 3.75 kHz에서 121.51 g으로 가장 높은 값을 나타냈으며, 2.5, 1.75, 5.0 kHz 순으로 높은 값을 나타났다. 지하부 생체중의 경우 3.75 kHz에서 31.31 g으로 가장 높은 값을 나타냈으며 2.5, 5.0, 1.25 kHz 순으로 높게 나타났다. 엽형지수는 생육 시기가 증가에 따라 감소하는 것으로 나타났으며, 1.75, 2.5, 5.0, 3.75 kHz 순으로 크게 나타났다. 지상부 건물중 측정결과는 지상부 생체중 결과와, 지하부 건물중의 측정결과는 지하부 생체중 결과와 동일하였다. S/R율은 1.75 kHz를 제외하고 생육시기가 증가할수록 S/R율은 감소하는 것으로 나타났으며, 주파수가 높아질수록 S/R율은 감소하는 것으로 나타났다. 엽형지수는 엽폭/엽장으로 엽형지수를 산출한 결과로 값이 작을수록 엽폭이 넓은 형태를 의미하며, 생체중값이 가장 크게 나타났던 3.75 kHz에서 엽형지수의 값이 가장 낮게 나타났으며 3.75 kHz를 제외하고 주파수가 높을수록 엽형지수의 값이 낮게 나타났다. 이에 주파수에 따른 적상추의 생육은 3.75 kHz에서 가장 좋은 것으로 판단할 수 있었다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.11a
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• pp.145-149
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• 1999

본 연구에서는 20 대 남자 대학생 45 명에게 세단계의 난이도를 갖는 덧셈연산을 수행하게 하여 반복 연산 스트레스를 유발시켰고, 각각의 피검자들로부터 생체신호를 측정하였다. 측정된 생체신호로부터 8 개의 감성 파라메터를 추출하였다. 연산스트레스의 감성지수화를 위하여 세단계의 감성지수 인식 시스템을 구성하였으며 각 단계의 감성지수 판별을 위하여 선형 판별 알고리즘을 이용하였다. 판별성능 분석은 Cross Validation 을 통하여 수행하였으며 연산스트레스의 감성지수 인식율은, 학습용 데이타에서는 77.66% Cross Validation 에서는 63.02%의 일반화된 감성지수 인식성능을 보였다.

• Progress in Medical Physics
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• v.7 no.1
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• pp.25-35
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• 1996

Optical measurements of turbid biological tissue have provided a means to study tissue metabolism, tissue blood perfusion and blood oxygenation non-invasively. We used the red light of 660nm and infrared of 880nm to measure the blood fractional volume and oxygen saturation of biological tissue. In vivo reflectance data were obtained the physiological change from the deep tissue in human subject. The data evaluation was assessed by examining the slopes of the plotter index for the changes in oxygen saturation and blood fraction volume. The index is the natural logarithm of the ratio of reflected light intensity from measured medium to reference intensity at each wavelength. According to the experimental results, oxygen index changes significantly in the muscle of calf during exercise.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.862-865
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• 2005

해면골에 대한 평가는 일반적으로 골밀도를 기준으로 평가하지만, 골밀도는 뼈의 특성을 70-80% 정도만 설명하는 것으로 알려져 있다. 이에 따라 골밀도로 설명이 되지 않는 나머지 특성을 뼈 미세구조의 형태학적 특성을 이용하여 설명하려는 노력이 생체역학 분야에서 오랫동안 있어 왔다. 본 연구는 CAD/CAM 분야의 feature extraction 기술을 이러한 생체역학 분야에 접목함으로써 뼈의 미세구조 평가를 위한 새로운 형태학적 지수 개발의 가능성을 탐색하고자 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1717-1722
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• 2008

A number of tools and equipment can measure the degree of stress. Stress measurement includes both psychological and physiological measurements. Considering only one of these elicits subjective or objective deficiency. Overcoming this problem requires a new stress index that combines these two measurements. Following people's personal traits, the measurement results also appear in diverse ways, but we can consider and study the general case obtained on the basis of the measurement tool. By using the index obtained by the psychological and physiological measurement tools, we obtain an integrated stress index. Therefore, we choose to use four stress measurement tools. The index of the result of each measurement tools is referred to as the multi-index. These indices are plotted on coordinates to analyze and diagnose the balance and tendency of the stress.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.4
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• pp.263-267
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• 2013

Long-term (from 1995 to 2012) data of phytoplankton biomass (chlorophyll-a, Chl-a) and water quality were analyzed to investigate trends of eutrophication in downstream of Nakdong River (Mulgum). Long-term annual average concentration of water quality parameters and phytoplankton biomass at Mulgum showed an decreasing trends for 18 years. Phytoplankton biomass was high from annually December to March. Trophic state was evaluated as the eutrophic state annually from 1995 to 2012 by TSI (trophic state index) by Aizaki. From the results of simple regression analysis, correlation coefficient between Chl-a concentration and BOD concentration was high ($r^2$ = 0.82).

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.48-56
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• 2019

The objective of this study was to examine measuring agreement between middle phalanx of the third finger and cervical vertebrae analysis for assessing skeletal maturity according to body mass index percentile. A retrospective chart view was used to select patients with body mass index data, hand - wrist radiographs and lateral cephalograms of same day. The patients were divided into 4 groups by body mass index percentile. The hand - wrist radiographs were analyzed using modified middle phalanx of the third finger method and the lateral cephalograms were categorized according to cervical vertebral maturation stage. The degree of agreement between the 2 methods of analyzing skeletal maturation was measured by calculating weighted kappa statistic according to body mass index percentile group. There was a good agreement between the 2 methods in the entire body mass index percentile group. According to the body mass index percentile group, the agreement was found to be different, and the pattern was different between boys and girls. Pediatric dentist should consider sex and weight status when evaluating growing children and adolescents because it can affect the agreement of 2 method of analyzing skeletal maturation.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.38-47
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• 2019

The most common cause of mouth breathing is obstacles caused by mechanical factors in upper airway. Mouth breathing could be consequently pathological cause of sleep-disordered breathing. Sleep-disordered breathing in children can cause growth disorders and behavioral disorders. The purpose of this study was to investigate relationship between upper airway and sleep-disordered breathing in children with mouth breathing. Twenty boys between 7 - 9 years old who reported to have mouth breathing in questionnaire were evaluated with clinical examination, questionnaires, lateral cephalometric radiographs, and portable sleep testing. This study assessed apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) for the evaluation of sleep-disordered breathing and was done to investigate the correlation between these values and the upper airway width measured by lateral cephalometric radiographs. There was no significant correlation with the size of the tonsils (p = 0.921), but the adenoid hypertrophy was higher in the abnormal group than in the normal group (p = 0.008). In the classification according to AHI and ODI, retropalatal and retroglossal distance showed a statistically significant decrease in the abnormal group compared to the normal group (p = 0.002, p = 0.001). As AHI and ODI increased, upper airway width tended to be narrower. This indicates that mouth breathing could affect the upper airway, which is related to sleep quality.