• Proceedings of the Korea Information Processing Society Conference
• /
• 2024.05a
• /
• pp.576-579
• /
• 2024

경제 위기 대비를 위해 인공지능을 활용한 주식시장 변동성 이상을 탐지하는 목적을 가지고 있다. 글로벌 이슈와 경제 위기 대비를 위해 주식시장 변동성 예측의 중요성이 부각되고 있으며, 기존의 주식시장 변동성 지수인 VIX 의 한계로 인해 더 복잡한 모델 및 인공지능을 활용한 연구에 관심이 집중되고 있다. 기존의 주식시장 변동성 예측에 관한 연구들은 통계적인 방법을 사용했으며 인공지능을 이용한 연구 또한 대부분 이상치 구간을 표시하여 예측을 목표로 하고 있으나 이러한 접근법은 라벨이 있는 데이터 수집 어려움, 클래스 불균형 문제가 있다. 본 연구는 인공지능을 활용한 주식시장 변동성 탐지에 기여하고 지도 학습 방식 대신 비지도 학습 기반의 이상탐지모델을 사용하여 주식시장 변동성을 예측하는 새로운 방법론을 제안한다. 본 연구에서 개발한 인공지능 모델은 IsolationForest 모델을 활용하며, 시계열 데이터를 전처리한 후 정상성을 확보하는 등의 과정을 거친다. 실험 결과로 인공지능 모델이 주요 경제이슈를 이상치로 검출하는 성능을 확인하였으며 재현율 약 93.6%, 정밀도 100%로 높은 성능을 달성했다.

• Journal of dental hygiene science
• /
• v.16 no.6
• /
• pp.472-480
• /
• 2016

In this study, 110 adults aged 40 to 69 years were surveyed from April 28, 2016, to May 28, 2016 to analyze their periodontal status according to daily stress, coping methods, and oral health behavior. The collected data were analyzed using the t-test, one-way analysis of variance, and hierarchical multiple regression. Daily stress levels of all subjects were most frequent potential risk 64.5% of the subjects, the high risk 19.1% and 16.4% of the health group. Regarding stress coping methods, active methods recorded 2.46, passive methods recorded 2.32. Regarding oral health behaviors, subjects brushed an average of 2.45 times daily, for an average of 2 minutes. Futhermore, 69.1% of subjects brushed before bedtime and 89.1% practiced scaling. Regarding periodontal status, the O'Leary index was 73.45, gingivitis index was 1.30, an average of 2.83 quadrants possessed a periodontal pocket. The hierarchical multiple regression analysis identified, type of employment (${\beta}=-0.348$), scaling (${\beta}=-0.253$), and age (${\beta}=0.244$) as factors that influence the number of quadrants possessing a periodontal pocket. These results confirmed that the oral health behavior of scaling, but not stress levels of coping methods, strongly influenced periodontal status.

• Clinical and Experimental Pediatrics
• /
• v.50 no.9
• /
• pp.862-867
• /
• 2007

Purpose : The impulse oscillometry (IOS) is applicable to young children because it requires minimal cooperation and a non-invasive method to measure the mechanics of respiratory system. This study aimed to develop the reference values in school-aged children in Korea, using IOS which is a modification of forced oscillation technique (FOT). Methods : Measurements were performed in 92 previously untrained healthy children, aged 7 to 12 years old, using IOS. We analyzed the relationships between the data about their age, height, weight, body surface area (BSA), body mass index (BMI) and the result of IOS using the linear regression test. Results : The success rate of IOS was 92.4%. Stepwise multiple regression of resistance of respiratory system (Rrs) and reactance of respiratory system (Xrs) in natural form for age, height, weight, BSA, BMI showed that height was the most significant predictor and altogether of 5 variables explained the Rrs and Xrs most. Our regression equations at multiple frequencys were comparable to published reference values, especially about the Rrs obtained at 5 Hz. Conclusion : IOS is a feasible method to measure the respiratory resistance in untrained children. We got the reference values using IOS and it seems to be useful to diagnose a variety of respiratory diseases.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.24 no.1
• /
• pp.70-78
• /
• 1991

Both long period of summer drought and unusual high water temperature in 1988 caused the harmfull effect to the aquacultural organisms in south coast of Korea. One of those was the mass mortality of arkshell seedlings in Jinhae Bay. The purpose of this study was to verify the effects of environmental factors on arkshell seedlings by investigating not only water quality and food organisms in culturing grounds, but also meteorological conditions. Water temperature in November was higher at $2.0^{\circ}C$ than mean water temperature and the concentration of total inorganic nitrogen and N/P ratio were $0.38{\mu}g-at/l,$ 0.98, respectively which indicated the exhaustion of nutrients, especially nitrogen in the study area. In analysis of phytoplankton population structure, species diversity index(H) , equitability-index(e), species richness $index(d_1)$ were low, but dominance $index({\delta}_2)$ was high at the value of 98.4 and dominant species was Nitzschia pungens. In conclusion, it seems that mass .mortality of arkshell seedlings in November was resulted from the metabolism disorder with poor food organism under the unstable marine environment.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 2005.10a
• /
• pp.111-114
• /
• 2005

1. 증체량 이유자돈 시부터 비육돈 완성기간까지 비육 전체 기간동안의 증체량은 다음과 같이 분석되었다. 처리별 암컷의 증체량은 생봉독처리 2구에서 99.08kg으로 가장 높았고, 생봉독처리 1구에서 99.08kg, 무처리구에서 95.88kg, 생봉독처리 3구에서 93.50kg 순으로 최고치와는 5.58kg의 차이를 보여주었으며 대조구와는 3.2kg 증체량이 높아 3.3% 증체율이 높았다. 거세돈에서의 처리별 증체중은 생봉독 처리 2구에서 102.23kg으로 가장 높았고, 다음은 생봉독처리 1구에서 101.79kg, 무처리구에서는 88.96kg, 생봉독 3처리구에서는 95.76kg의 순으로 나타냈다. 따라서 최고치와 최저치의 차이는 6.47kg으로 유의한 수준차(p<0.05)로 나타났으며 대조구보다는 3.2kg의 증체량 차이로서 암컷과 같은 수준으로 나타났다. 2. 사료효율 비육 전체기간 동안의 처리별 암수간 평균 두당 사료섭취량과 사료효율은 다음과 같다. 암컷의 평균 사료효율은 생봉독 처리 1구에서 2.55로 처리구중에서 가장 우수하였고, 다음은 생봉독처리 2구와 대조구에서 2.56으로 동일하게 분석되었으며, 생봉독 3처리구에서 가장 저조한 2.62의 순으로 분석되어 사료효율 0.07 차이로 2.3%의 차이를 보여주었다. 발육성적이 가장 높은 생봉독 2처리구에서는 255kg의 사료를 섭취하여 2.54의 최적의 사료효율을 보여주어 사료 효율면에서도 생봉독 2처리구에서 가장 경제성이 높은 것으로 분석되었다. 3. 육성율 및 생산지수 폐사수는 생봉독 처리 3구에서 2두(자웅 각 1두)가 발생하여 육성율 95%로 처리구중에서 가장 저조하였고, 다음은 대조구 1두가 발생하여 육성율 97.5%를 보여주었는데 비하여 생봉독처리 1구와 2구에서는 폐사돈이 발생하지 않아 육성율 100%를 보여주었다. 생산지수는 대조구를 100으로 기준하였을 때 생봉독처리 2구에서 107.87로 가장 우수하였으며, 생봉독 처리 1구에서 106.22, 가장 저조한 처리구는 폐사수가 많은 생봉독 처리 3구에서 94.73으로 나타내었다. 이상과 같이 생봉독 처리 2구에서 가장 우수한 생산효과를 나타내었다. 4. 생산성 향상 효과 처리별 대조구(100) 대비 사료섭취량은 생봉독 처리 3구에서 97.22로 가장 낮았고, 기타 처리구는 1.19${\sim}$1.59의 처리를 보이고 있는데 비하여, 대조구(100) 대비 증체율에서는 생봉독 처리 2구에서 103.30으로 3.30%가 높았다.

• Journal of dental hygiene science
• /
• v.8 no.4
• /
• pp.395-401
• /
• 2008

This study was carried out in order to offer basic data available for being helpful to promoting periodontal health, by analyzing effects in socio-demographical and health-behavior characteristics on index of evaluating periodontal status. The study conducted a survey for the 151 adults aged 30 to 59 from October. 1, 2006 to March. 30, in 2007. The collected data were analyzed with t-test and one-way of variance using SPSS 12.0. Then, the following result were obtain. 1. sociodemographic and health-behavior characteristics is not related to O'Leary plaque index, Loe & Silness gingival index. 2. The number of sextants possessing periodontal pocket was higher in men(3.34) than women(2.43), also statistically significant difference in the occupational fields. Smoker(3.38) was higher than non-smoker(2.72), and it was higher over 3 times a week than almost no drinking as for frequence alcohol intake. 3. The amount of loss for inter-dental alveolar crest was higher in men(71.79) than women(42.24), was highest of the 'professional' in the occupational fields, and smoker(67.23) was higher than non-smoker(48.22). 4. There was significantly difference in the number of missing tooth between age and frequence of alcohol intake. These results that occupational fields, smoking and alcohol intake were related to the number of sextants possessing periodontal pocket and amount of loss for inter-dental alveolar crest.

• Journal of dental hygiene science
• /
• v.17 no.2
• /
• pp.168-174
• /
• 2017

This study was conducted to provide basic data on the relationship between the happiness and job satisfaction of dental hygienists. The research subjects were 264 dental hygienists in Busan and Gyeongsangnam-do. The study was conducted using structured questionnaires and the collected data were analyzed using IBM SPSS software, ver. 20.0. The happiness index, which was based on general characteristics, showed the greatest significant differences in life satisfaction (p<0.05) among adults over 36 years of job experience, negative emotions (p<0.01) among adults under 25 years of job experience, and negative emotions (p<0.05) among adults with 4~10 years of job experience. The factors that improved the job satisfaction of dental hygienists were life satisfaction, prime duty at the work place, and a positive effect. On the contrary, negative emotions lowered the job satisfaction. The happiness of the dental hygienist is an important factor not only for the improvement of the hygienist's personal quality of life, but also the patient's health. It is necessary for dental hygienists to maintain good relationships with coworkers during in the workplace, as well as employers, to have an administrative system that offers proper compensation, improvement of the work environment, and opportunities to improve professionalism at the workplace.

• Journal of dental hygiene science
• /
• v.12 no.5
• /
• pp.469-476
• /
• 2012

The purpose of this study to grasp the effects of the stress coping method on the periodontal disease in order to provide raw data for the studies on the development of the training for effective stress copying method resulting in improvement in prevention, occurrence, and progression of periodontal disease. Data were collected from total of 326 subjects in their forties and fifties, during the period from March to October 2011. Using questionnaire and examination of periodontal health, and were analyzed using frequency, t-test, multivariate analysis of variance, multiple regression by SPSS ver. 19.0 (IBM Co., USA). The higher emotion-focused stress coping ($\beta$=0.341), the higher the gingival index, the higher the emotion-focused stress coping ($\beta$=0.239) the deeper the pocket depth, the higher the emotion-focused stress coping ($\beta$=0.158) the higher clinical attachment loss, showed statistically significant positive association. This study suggests that the dental clinic institute needs to implement education program including stress management and coping method improvement in order to prevent periodontal disease and make the occurrence and progression to be managed by professionals.

• Journal of Korea Water Resources Association
• /
• v.34 no.1
• /
• pp.31-43
• /
• 2001

The friction factor of commercial pipe varies with wide range depending on pipe type and pipe size. Various methods can describe the wide variation of friction factor with good accuracy, but they normally require an iteration process even for solution of a simple case. Power law can result in an explicit form of solver so that the power law is rigorously employed for the development of direct solution technique. The parameters used in the present form of power law are allowed to haute some variation with pipe size and Reynolds number as well as pipe type for wider coverage with good accuracy, while Hazen-Williams equation permits limited variation which accounts only for the roughness or the pipe type. Furthermore secondary loss is considered in the development of explicit equations for design of commercial pipes.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.1781-1786
• /
• 2009

최근 들어 하천의 자동유량측정에 많이 활용되고 있는 고정식 음파도플러유속계는 여러 개의 셀 유속 자료를 제공한다. 이러한 유속 자료들은 단면의 특정 위치에 고정되어 있어 수심 변화에 따라 변화하는 최대유속 구역을 직접 측정할 수 없으므로 최대유속과 평균유속 사이의 단순한 관계를 활용하여 유량 산정을 하기는 곤란하다. 다만, 단면상의 여러 지점에 대한 유속 측정치를 얻을 수 있다는 점을 이용하여 모의된 유속분포와 결부하면 유량을 산정하는데 활용 가능하다. 본 연구에서는 Chiu(1988)가 제안한 단면의 무차원적 유속분포를 모의하는 확률론적 유속분포 공식과 고정식 ADVM의 유속자료를 활용하여 유량을 산정하는 방법을 검토하였다. 유속분포 공식의 주요 매개변수 중에서 최대유속과 평균유속의 관계를 나타내는 �� 은 ADVM이 설치된 단면 및 인접 단면에서 ADCP로 측정한 자료를 이용하여 도출하였으며, $\beta$와 h는 국내 하천에 대한 자료 분석을 통해 얻어진 값을 사용하였다. 2006년부터 2007년까지의 유량이 비교적 안정된 11개 케이스의 댐 방류량 조건 및 동일한 지점에서 개발된 유속지수법 유량과 상호 비교하였으며, 그 결과 댐방류량 대비 상대오차가 평균 6.44%로 유속지수법의 7.43%에 비해 약간 크지만 유량 산정이 비교적 정확하게 이루어짐을 확인할 수 있었다. 또한 연속 유량 측정 결과 여수로 방류량에 대해서 약 10.6%의 오차를 나타내고 있었다. 한편, 보다 고유속 구역을 측정할 목적으로 2008년에 기존의 ADVM에 추가로 1.25m 높은 위치에 홍수 측정을 위한 저주파 ADVM을 설치하여 운영할 경우 2008년의 4개 케이스에 대해 댐방류량 대비 2.1%의 상대오차를 나타내어 3.9%의 유속지수법에 비해 약간의 개선효과가 있었으며, 이 역시 유량을 비교적 잘 산정하는 것으로 나타났다.