• The Korean Journal of Zoology
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• v.35 no.3
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• pp.339-343
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• 1992

버들치, 버들개의 공서지역에서 2종 사이의 종문제를 명확히 구명하기 위해 883개체를 채집하여 형태형 질과 유전자분석을 실시하여 생식적 격 리기작 여부를 조사한 결과는 다음과 같다. 2종 사이 에 잡종개체가 약 12%( n = 104) 발견되었다. 형 태분류형 질인 측선상부린수( SAL)의 경우 버들개와 버들치가 각각 SAL = 24.25$\pm$1, 32, 16.93 $\pm$ 0.92로 뚜렷한 차이를 나타내었으나 잡종개체는 평균 SAL = 19.56$\pm$1.80으로 중간값을 나타내었다. 잡종개체 중 F2 이상의 잡종개체 비율은 약 2.7%로 Fl(9"yp)에 비해 현저히 낮고, 잡종개체의 출현률이 기 대치보다 낮은 것으로 보아(P < 0.001) 2종간에 자유교배가 되지 않으며 따라서 Predating isolating mechanism이 작용한다고 보며 또한 잡종개체의 치사율이 높은 점으로 보아 이들사이에는 Postdating isolating mechanism도 동시에 작용한다고 사료되며 따라서 이들 2종은 비교적 최근에 분화된 별종임이 재확인 되었다. 되었다.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.331-337
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• 2015

By comparing and evaluating the neutron dose when running cyclotron in fixed type measuring machine and portable type measuring machine, we performed this study to see if there is any difference between the doses in both measuring devices. We performed correction 3 times for the portable type during the experiment. We measured the values 12 times for each correction, so total 36 times by using the fixed type and portable type once every 2 weeks from June 2012 to February 2014. The statistics for the portable type and fixed type for each experiment showed 0.186, 0.511, and 0.057, which are not statistically significant. Therefore, we have come to the conclusion that unless there is deviation based on the correction period of the portable type, correction of fixed type wouldn't be necessary. Also, reduction of social costs may be achieved if we install an alarm meter, which is relatively low priced compared to the high cost neutron measuring machine, when detecting higher level than the interested standard level.

• Journal of the Korea Society of Computer and Information
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• v.16 no.5
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• pp.135-145
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• 2011

These days, the research of a sensor data management system for USN based real-time monitoring application is active thanks to the development and diffusion of sensor technology. The sensor data is rapidly changeable, continuous and massive row level data. However, end user is only interested in high level data. So, it is essential to effectively process the row level data which is changeable, continuous and massive. In this paper, we propose a sensor data management system with multi-analytical query function using OLAP and anomaly detection function using learning based classifier. In the experimental section, we show that our system is valid through the some experimental scenarios. For the this, we use a sensor data generator implemented by ourselves.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.649-656
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• 1996

RELAP5/MOD3.1.2을 이용하여 영광3/4호기의 부분충수운전중 정지냉각계통 기능상실사고를 모의하였다. 이 해석은 노심에서 발생되는 증기를 가압기 Manway로 배출시켜 노심을 냉각할 경우, 증기발생기 2차측 냉각재 유무에 따르는 계통거동을 분석한 것이다. 해석결과, 노심에서의 비등은 사고후 약 6분 경에 발생하였으며, 증기발생기 2차측에 냉각재가 없는 경우는, 냉각재가 채워져 있는 경우보다 0.16 bar 더 높은 1.8 bar의 계통 압력을 나타내어, 현재의 운전절차서에 제시한 RWST의 수위 (70%)로는 중력주입이 불가능한 것으로 밝혀졌다. 이런 해석결과를 토대로 할 때, 부분충수 운전중 증기발생기 2차측 냉각재는 최소한 한 대에는 충수하고, RWST 수위 제한치도 84 % 이상으로 증가시키는 운전 절차서의 개정이 필요한 것으로 판단된다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.127-134
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• 2021

In this study, an anomaly detection (AD) algorithm was implemented to detect the failure of a marine air compressor. A lab-scale experiment was designed to produce fault datasets (time-series electric current measurements) for 10 failure modes of the air compressor. The results demonstrated that the temporal pattern of the datasets showed periodicity with a different period, depending on the failure mode. An AD model with a convolutional autoencoder was developed and trained based on a normal operation dataset. The reconstruction error was used as the threshold for AD. The reconstruction error was noted to be dependent on the AD model and hyperparameter tuning. The AD model was applied to the synthetic dataset, which comprised both normal and abnormal conditions of the air compressor for validation. The AD model exhibited good detection performance on anomalies showing periodicity but poor performance on anomalies resulting from subtle load changes in the motor.

• Sleep Medicine and Psychophysiology
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• v.9 no.1
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• pp.24-33
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• 2002

Objectives: Nasal continuous positive airway pressure (CPAP) corrected elevated blood pressure (BP) in some studies of obstructive sleep apnea syndrome (OSAS) but not in others. Such inconsistent results in previous studies might be due to differences in factors influencing the effects of CPAP on BP. The factors referred to include BP monitoring techniques, the characteristics of subjects, and method of CPAP application. Therefore, we evaluated the effects of one night CPAP application on BP and heart rate (HR) reactivity using non-invasive beat-to-beat BP measurement in normotensive and hypertensive subjects with OSAS. Methods: Finger arterial BP and oxygen saturation monitoring with nocturnal polysomnography were performed on 10 OSAS patients (mean age $52.2{\pm}12.4\;years$; 9 males, 1 female; respiratory disturbance index (RDI)>5) for one baseline night and another CPAP night. Beat-to-beat measurement of BP and HR was done with finger arterial BP monitor ($Finapres^{(R)}$) and mean arterial oxygen saturation ($SaO_2$) was also measured at 2-second intervals for both nights. We compared the mean values of cardiovascular and respiratory variables between baseline and CPAP nights using Wilcoxon signed ranks test. Delta ($\Delta$) BP, defined as the subtracted value of CPAP night BP from baseline night BP, was correlated with age, body mass index (BMI), baseline night values of BP, BP variability, HR, HR variability, mean $SaO_2$ and respiratory disturbance index (RDI), and CPAP night values of TWT% (total wake time%) and CPAP pressure, using Spearman's correlation. Results: 1) Although increase of mean $SaO_2$ (p<.01) and decrease of RDI (p<.01) were observed on the CPAP night, there were no significant differences in other variables between two nights. 2) However, delta BP tended to increase or decease depending on BP values of the baseline night and age. Delta systolic BP and baseline systolic BP showed a significant positive correlation (p<.01), but delta diastolic BP and baseline diastolic BP did not show a significant correlation except for a positive correlation in wake stage (p<.01). Delta diastolic BP and age showed a significant negative correlation (p<.05) during all stages except for REM stage, but delta systolic BP and age did not. 3) Delta systolic and diastolic BPs did not significantly correlate with other factors, such as BMI, baseline night values of BP variability, HR, HR variability, mean SaO2 and RDI, and CPAP night values of TWT% and CPAP pressure, except for a positive correlation of delta diastolic pressure and TWT% of CPAP night (p<.01). Conclusions: We observed that systolic BP and diastolic BP tended to decrease, increase or remain still in accordance with the systolic BP level of baseline night and aging. We suggest that BP reactivity by CPAP be dealt with as a complex phenomenon rather than a simple undifferentiated BP decrease.

• Journal of the Korea Convergence Society
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• v.12 no.6
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• pp.49-56
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• 2021

This study aimed to identify the factors affecting the health-related quality of life in terms of periodontal disease by using the data from 8,035 respondents aged ≥40 years, excepting those with cancers having an serious impact on the quality of life, in the seventh Korea National Health and Nutrition Examination Survey (KNHANES) (2016-2018). The risk of quality of life deterioration was 1.32 times higher in the periodontal disease group than in the healthy periodontal group, those who were ≥50 years of age and had ≥2 comorbidities showed lower quality of life in the periodontal disease group. These results have confirmed that adults with periodontal disease get aware of the adverse quality of life though they have only a few chronic conditions and are expected to be useful as basic data necessary to develop health promotion programs that can help prevent periodontal disease and improve the health-related quality of life for adults.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.275-283
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• 1999

Authors evaluated 152 patients at the department of Pediatric Dentistry in Seoul National University Hospital through clinical records and radiographs. And the following features were studied ; age, sex distribution, number of mesiodens per patients, location, status of eruption, shape and orientation of crown, and complication. From the above results, the relationship between features of mesiodens and complications were evaluated using chi-square analysis. 1. Complications due to the presence of mesiodens did not occur in 31.6%, delayed eruption of adjacent teeth was observed in 33.6%, midline diastema in 22.4%, rotation in 8.6%, displacement in 3.3%, and crowding in 0.7% of all evaluated patients. 2. As compared with the above 8.5 year group, in the under 8.5 year group, the frequency of complications was significantly higher(P<0.05). As compared with those positioned lingually, in mesiodens labially or within the arch the frequency of complications was significantly higher(P<0.01). Also, the frequency of complications was significantly higher when the mesiodens was tuberculate in form(P<0.05). 3. Of the 104 patients with complications, the frequency of delayed eruption was significant higher in the under 8.5 year group, and in above 8.5 year group, the frequency of malocclusion was significantly higher(P<0.05). When mesiodens were located in the midline region, the frequency of malocclusion was significant higher, while in case with laterally positioned mesiodens the frequency of delayed eruption was significantly higher(P<0.01).

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.535-539
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• 2011

This study was conducted to examine the bootstrap evaluation of the stem density and biomass expansion factor for Pinus rigida plantations in Korea. The stem density ($g/cm^3$) in less than 20 tree years were 0.460 while more than 21 tree years were 0.456 respectively. Biomass expansion factor of less than 20 years and more than 21 years were 2.013, 1.171, respectively. The results of 100 and 500 bootstrap iterations, stem density ($g/cm^3$) in less than 20 years were 0.456~0.462 while more than 21 years were 0.457~0.456 respectively. Biomass expansion factor of less than 20 years and more than 21 years were 1.990~2.039, 1.173~1.170, respectively. The mean differences between observed biomass factor and average parameter estimates showed within 5 percent differences. The split datasets of younger stands and old stands were compared to the results of bootstrap simulations. The stem density in less than 20 years of mean difference were 0.441~1.049% while more than 21years were 0.123~0.206% respectively. Biomass expansion factor in less than 20 years and more than 21 years were -1.102~1.340%, -0.024~0.215% respectively. Younger stand had relatively higher errors compared to the old stand. The results of stem density and biomass expansion factor using the bootstrap simulation method indicated approximately 1.1% and 1.4%, respectively.

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.8-14
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• 2005

Purpose : This study was peformed to study normative blood pressure data in full-term neonates that may be used to facilitate Identification of neonatal hypertension.Methods : 383 newborns born in our hospital from May 2003 to January 2004 were enrolled in this study Using an oscillometric device(BP-88 NEXT, COLIN Corp.), their blood pressures were measured more than one time within a week after birth. According to each clinical variable such as sex, delivery mode, birth weight, gestational age and presence of maternal disease or perinatal problems, we divided the population into groups and calculated the mean blood pressures of each group. We compared mean blood pressures between the divided groups according to each clinical variable statistically.Results : Mean systolic and diastolic blood pressure of the Population was 70.8$\pm$ 10.9 mmHg and 43.4 $\pm$ 8.0 mmHg, respectively. There was no satistically significant difference in blood pressure according to clinical variables. Mean systolic pressure showed positive correlation with birth weight and gestational age(r=0.1420, 0.03130).Conclusion : Our results are almost in agreement with Zubrow's data from 695 newborns in U.S.A, 1995. Our data may be helpful for early detection and management of neonatal hypertension, thereby maintaining renal function ,and preventing possible complications of renal disease.