• Title/Summary/Keyword: irregular sampling

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The Relationship Study between Cumulative Fatigue and Stress of Seafarers by Evaluating Autonomic Nervous Functions and Survey Studies (선원의 자율신경 기능평가에 의한 누적피로도 및 스트레스와 조사연구 사이의 관련성 연구)

  • Kim, Byeongjo;Lee, Junghun;Lee, Sookyoung;Kwon, Haeyeon;Kwon, Youngtae;Park, Yongsun;Chae, Byeonggeun
    • Journal of The Korean Society of Integrative Medicine
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    • v.6 no.4
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    • pp.1-13
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    • 2018
  • Purpose : The purpose of this study has been performed to find the relationship between seafarers' cumulative fatigue and stress by evaluating autonomic nervous functions and the results of surveys conducted using questionnaires. Methods : The subjects were seafarers working on various ships (home trade ships) of South Korea, who were healthy adults without any diseases, as confirmed through preliminary surveys were recruited through simple random sampling. A device that measures autonomic nervous functions by analyzing heart rate variability, which is also used often in clinical diagnoses and studies at universities, university hospitals, and general hospitals was used to measure the seafarers' cumulative fatigue and stress. Pearson's correlation analyses were also conducted to test the relationship between cumulative fatigue and stress measured by evaluating autonomic nervous functions and the results of surveys conducted with questionnaires. Results : There was no correlation between mean cumulative fatigue measured for each ship type and seafarers position through autonomic nervous functions evaluation and fatigue severity scale (FSS). There also was no correlation between the mean levels of stress measured for each ship type and seafarers position through autonomic nervous functions evaluation and survey scores of Korean occupational stress scale (KOSS). Conclusion : Therefore, in order to prevent man-made accidents in the sea among seafarers working with irregular port entry/departure schedules and under environments involving continued vibration, noises, and shaking, it is necessary to analyzed cumulative fatigue and stress scientifically and objectively, such as through autonomic nervous functions evaluation rather than through surveys.

Arrhythmia Classification using GAN-based Over-Sampling Method and Combination Model of CNN-BLSTM (GAN 오버샘플링 기법과 CNN-BLSTM 결합 모델을 이용한 부정맥 분류)

  • Cho, Ik-Sung;Kwon, Hyeog-Soong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.10
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    • pp.1490-1499
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    • 2022
  • Arrhythmia is a condition in which the heart has an irregular rhythm or abnormal heart rate, early diagnosis and management is very important because it can cause stroke, cardiac arrest, or even death. In this paper, we propose arrhythmia classification using hybrid combination model of CNN-BLSTM. For this purpose, the QRS features are detected from noise removed signal through pre-processing and a single bit segment was extracted. In this case, the GAN oversampling technique is applied to solve the data imbalance problem. It consisted of CNN layers to extract the patterns of the arrhythmia precisely, used them as the input of the BLSTM. The weights were learned through deep learning and the learning model was evaluated by the validation data. To evaluate the performance of the proposed method, classification accuracy, precision, recall, and F1-score were compared by using the MIT-BIH arrhythmia database. The achieved scores indicate 99.30%, 98.70%, 97.50%, 98.06% in terms of the accuracy, precision, recall, F1 score, respectively.

Who has a high level of food literacy, and who does not?: a qualitative study of college students in South Korea

  • Hyelim Yoo;Eunbin Jo;Hyeongyeong Lee;Eunji Ko;Eunjin Jang;Jiwon Sim;Sohyun Park
    • Nutrition Research and Practice
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    • v.17 no.6
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    • pp.1155-1169
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    • 2023
  • BACKGROUND/OBJECTIVES: Unhealthy food choices among young adults are common globally, and the incidence of chronic diseases, such as obesity, is rising. Food literacy (FL) is important for improving and maintaining individual health in a rapidly changing food environment and can form the basis for following a sustainable diet. Therefore, it is essential to improve FL among young adults, particularly college students, who are in the formative years of their lifelong food habits. This study examined the facilitators and barriers of FL and related dietary behavior among college students in South Korea. SUBJECTS/METHODS: This study recruited 25 college students with different residence types using convenience and snowball sampling. In-person, telephone, and video interviews were conducted from March to November 2021. The interview data were analyzed using framework analysis based on the socio-ecological model. RESULTS: At the individual level, prior good experiences with food were the most frequently mentioned facilitator. In contrast, the major barriers were a lack of knowledge, financial hardship, irregular schedules, and academic stress. At the interpersonal level, the influences of family and peers, such as early exposure to healthy eating habits and opportunities to have easy accessibility to farms and farming, are major facilitators, but the lack of a sense of community was the major barrier. At the environmental level, the major barriers were unfavorable food environments at home and in neighborhoods, such as the absence of kitchens in housing and large packaging of produce at markets. CONCLUSIONS: Many factors affected the students' FL and related healthy eating practices. These findings suggest that a campus-based FL program should be developed by reflecting on these facilitators and barriers.

Unit Loadings of Heavy Metals by Non-point Sources - Case Study in a Valley Watershed - (비점원에 의한 중금속 원단위 부하량 - 곡간지 유역을 중심으로 -)

  • Kim, Jin-Ho;Han, Kuk-Heon;Lee, Jong-Sik
    • Korean Journal of Environmental Agriculture
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    • v.27 no.1
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    • pp.35-43
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    • 2008
  • The study was carried out to estimate runoff loads of heavy metals in the valley watershed at the middle of South Korea, during farming season. There were no other pollution sources except agricultural activity. From 27 April 2006 to 31 October 2007, water samples were collected using two methods. The first method was regular sampling wherein water samples were taken every two weeks; and the other method was through regular sampling when water were collected during each rainfall event. Results showed that heavy metals were found in the water from the regular samples, and were highest during May and June. It was presumed that this might have been contributed by farming activities. Heavy metal concentration of the irregular samples was lower than regular samples. The correlation coefficient between each heavy metal of the regular samples were as follows: Fe-Al>Cr-Al>Fe-Cr>Mn-Fe. The correlation coefficient of the irregular samples were the following: Fe-Al>Fe-Cu is positive; and Pb-Cu>Ni-Al is negative. Measured pollutant loads of heavy metals in the valley watershed were : 2.047 kg $day^{-1}$ of Al, 0.008 kg $day^{-1}$ of Cd, 0.034 kg $day^{-1}$ of Cr, 0.311 kg $day^{-1}$ of Cu, 0.601 kg $day^{-1}$ of Fe, and 0.282 kg $day^{-1}$ of Zn in 2006; while in 2007, the following were observed: 2.535 kg $day^{-1}$ of Al, 0.026 kg $day^{-1}$ of Cd, 0.055 kg $day^{-1}$ of Cu, 0.727 kg $day^{-1}$ of Fe, and 0.317 kg $day^{-1}$ of Zn. In the analysis of data gathered, the loading rates of effluents from the valley watershed during the rainy season were : 79.8% of Al, 69.1% of Cu, 82.5% of Fe, and 69.1% of Zn in 2006; while 69.9% of Al, 67.5% of Cu, 70.4% of Fe, and 67.5% of Zn in 2007.

Semiweekly variation of Spring Phytoplankton Community in Relation to the Freshwater Discharges from Keum River Estuarine Weir, Korea (금강하구언 담수방류와 춘계 식물플랑크톤 군집의 단주기 변동)

  • Yih, Won-Ho;Myung, Geum-Og;Yoo, Yeong-Du;Kim, Young-Geel;Jeong, Hae-Jm
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.10 no.3
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    • pp.154-163
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    • 2005
  • Irregular discharges of freshwater through the water gates of the Keum River Estuarine Weir, Korea, whose construction had been completed in 1998 with its water gates being operated as late as August 1994, drastically modified the estuarine environment. Sharp decrease of salinity along with the altered concentrations of inorganic nutrients are accompanied with the irregular discharges of freshwater into the estuary under the influence of regular semi-diurnal tidal effect. Field sampling was carried out on the time of high tide at 2 fixed stations(St.1 near the Estuarine Weir and St.2 off Kunsan Ferry Station) every other day for 4 months from mid-February 2004 to investigate into the semi-weekly variation of spring phytoplankton community in relation to the freshwater discharges from Keum River Estuarine Weir. CV(coefficient of variation) of salinity measurements was roughly 2 times greater in St.1 than that in St.2, reflecting extreme salinity variation in St.1 Among inorganic nutrients, concentrations of N-nutrients($NO_3^-,\;NO_2^-$ and $NH_4^+$) were clearly higher in St.1, to imply the more drastic changes of the nutrient concentrations in St.1. than St.2 following the freshwater discharges. As a component of phytoplankton community, diatoms were among the top dominants in terms of species richness as well as biomass. Solitary centric diatom, Cyclotella meneghiniana, and chain-forming centric diatom, Skeletonema costatum, dominated over the phytoplankton community in order for S-6 weeks each (Succession Interval I and II), and the latter succeeded to the former from the time of <$10^{\circ}C$ of water temperature. Cyanobacterial species, Aphanizomenon Posaquae and Phormidium sp., which might be transported into the estuary along with the discharged freshwater, occupied high portion of total biomass during Succession Interval III(mid-April to late-May). During this period, freshwater species exclusively dominated over the phytoplankton community except the low concentrations of the co-occurring 2 estuarine diatoms, Cyclotella meneghiniana and Skeletonema costatum. During the 4th Succession Interval when the water temperature was over $18^{\circ}C$, the diatom, Guinardia delicatula, was predominant for a week with the highest dominance of $75\%$ in discrete samples. To summarize, during all the Succession Intervals other than Succession Interval III characterized by the extreme variation of salinity under cooler water temperature than $18^{\circ}C$, the diatoms were the most important dominants for species succession in spring. If the scale and frequency of the freshwater discharge could have been adjusted properly even during the Succession Interval III, the dominant species would quite possibly be replaced by other estuarine diatom species rather than the two freshwater cyanobacteria, Aphanizomenon flosaquae and Phormidium sp.. The scheme of field sampling every other day for the present study was concluded to be the minimal requirement in order to adequately explore the phytoplankton succession in such estuarine environment as in Keum River Estuary: which is stressed by the unpredictable and unavoidable discharges of freshwater under the regular semi-diurnal tide.

Lead Transport in Groundwater in Door County, Wisconsin (위스컨신주 도어지역의 지하수내 납성분의 이동)

  • Woo, Nam C.
    • Economic and Environmental Geology
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    • v.27 no.1
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    • pp.93-100
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    • 1994
  • This study examined the mechanisms of lead transport in the groundwater system and those of irregular detections in groundwater in Door County, Wisconsin. During the spring recharge period in 1991, water-level movement and water-quality change were monitored from two monitoring wells equipped with three piezometers each and from five house wells, respectively. Water-level responses to recharge events were fast with a relatively short lag time ranging from 3 to 10 days, indicating that recharge of groundwater occurs through the high hydraulic conductivity (K) zones in the Silurian dolomite aquifer system. Lead was detected only on particles filtered from groundwater, but not in dissolved state. Concentrations ranged from 0.2 to $7.1{\mu}g/mg$, converted into the total lead concentration in groundwater ranging from $0.3{\mu}g/l$ to $4.7{\mu}g/l$. A lag time between recharge events and peak particle movement at the sampled wells was estimated to range from 19 to 22 days. Due to the particulate nature of lead in groundwater, only the wells connected with the high K zones detect lead, causing the spatial variation. In a given well, lead concentration varies at different sampling times due to the variation in the initial amounts of lead-carrying particles introduced into the groundwater system during recharge events, the lag in particle transport and the dispersion of lead-carrying particles along the advective flowpaths.

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A Study on the Sleep/Activity pattern in Normal Early Infants using NCASA (Nursing Child Assessment Sleep/Activity Record) (NCASA(Nursing Child Assessment Sleep/Activity Record)를 이용한 초기 영아의 수면/활동 양상 연구)

  • Park, Hae-Sun;Lee, Yeong-Eun
    • Korean Parent-Child Health Journal
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    • v.3 no.1
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    • pp.46-59
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    • 2000
  • The purpose of this study is to determine whether the NCASA (Nursing Child Assessment Sleep/Activity Record) would be suitable to evaluate and to provide the basic resources for a Korean model of sleep/activity patterns during the first 6 months Korean infants' lives and to provide a basis for nursing intervention for mothers of early infants. The subjects of this study were 94 normal infants from birth to 6 months of age who visited the postpartum care center and two general hospitals located in Pusan from February 1 to April 28, 2000. The method of data collection was through convenient sampling. The instrument of this study was the NCASA translated by the Korean parent Child Health Academic Association. The collected data were analysed by mean, standard deviation, frequency percentage and ANOVA, Post Hoc test by use of SPSS/PC. The conclusions obtained from this study are summarized as follows: 1. The mean amount of daytime sleep was 8.06 hours. The mean amount of nighttime sleep was 6.31 hours. The mean amount of total daily sleep was 14.37 hours. The mean of the longest sleep period was 5.20 hours. The mean regularity of daytime sleep was 25.84%. The mean regularity of nighttime sleep was 77.69%. The mean regularity of total daily sleep was 42.60%. The mean frequency of nighttime wakenings was 2.33 times. 2. The mean amount of daytime activity was 8.25 hours. The mean amount of nighttime activity was 1.39 hours. The mean amount of daily total activity was 9.64 hours. The mean of the longest activity period was 3.80 hours The mean frequency of daytime feeding was 5.69 times. The mean frequency of nighttime feeding was 2.08 times. The mean frequency of total daily feeding was 7.74 times. The mean frequency regularity of feeding was 54.62%. The mean frequency of wakenings was 5.14 times. The mean frequency of crying was 1.90 times. 3. According to an analysis of sleep patterns based on an infant's age, there were some significant differences in the following factors: amount of daytime sleep(p<.001), amount of night time sleep(p<.05), amount of total daily sleep (p<.001), longest sleep period(p<.001), regularity of daytime sleep(p<.001), regularity of nighttime sleep(p<.01), regularity of total daily sleep(p<.001), frequency of nighttime wakenings(p<.001). 4. According to an analysis of activity patterns based on an infant's age, there were some significant differences in the following factors: amount of daytime activity(p<.001), amount of nighttime activity(p<.01), amount of total daily activity(p<.001), longest activity period(p<.05), frequency of nighttime feeding(p<.01), frequency of wakenings(p<.001). 5. The mean amount of a mother's day time was 16.30 hours. The mean amount of a mother's night time was 7.70 hours. In conclusion, the initial irregular sleeping and activity patterns of the early infant became regurized as the infant grew older and estabilished firmer patterns of sleeping and of activity.

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Characteristics of Zooplankton Community in the Udolmok Waterway, Korea (울돌목 수로 동물플랑크톤의 군집 특성)

  • Yoo, Jeong-Kyu;Jung, Jung-Ho;Nam, Eun-Jung;Myung, Chul-Soo
    • Korean Journal of Environmental Biology
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    • v.24 no.2 s.62
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    • pp.201-211
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    • 2006
  • 55 zooplankton taxa including 35 copepoda were observed in the Uldolmok waterway during the sampling period from August 2003 to April 2004. Neritic species showed the seasonal species fluctuation, and oceanic warm-water species occurred throughout the year. The number of taxa tended to increase at the flood tide from low tide to high tide, and to decrease at the ebb tide from high tide to low tide. Therefore, species composition of zooplankton in the Uldolmok waterway seemed to be affected by the inflow of oceanic waters with oceanic species all the year round. Total abundance of zooplankton ranged from 104 (February 2004) to 2,717 indiv. $m^{-3}$ (August 2003). According to the tidal cycle, the change of total abundance was more irregular and variable in November 2003 and February 2004 than August 2003 and April 2004. In August 2003 and April 2004, total abundance was low at the strong tide, and was high at low and high tide when tidal current was weak. Average abundances of dominant species such as Paracalanus indicus, Cirripedia nauplii and Acartia hongi were on the order of twice higher at ebb tide than flood tide. However, their abundances were also subject to wide fluctuation within flood tide and ebb tide. The changes of environmental parameters such as water temperature, salinity and chlorophyll-a concentration were negligible along the tidal periods in the Uldolmok waterway. Therefore, the advection, transfer and loss of zooplankton population derived from strong tidal current and eddy formed by the local difference of tidal velocity lead temporal variation of zooplankton community more complex and variable in the Uldolmok waterway.

Statistical Model of 3D Positions in Tracking Fast Objects Using IR Stereo Camera (적외선 스테레오 카메라를 이용한 고속 이동객체의 위치에 대한 확률모델)

  • Oh, Jun Ho;Lee, Sang Hwa;Lee, Boo Hwan;Park, Jong-Il
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.1
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    • pp.89-101
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    • 2015
  • This paper proposes a statistical model of 3-D positions when tracking moving targets using the uncooled infrared (IR) stereo camera system. The proposed model is derived from two errors. One is the position error which is caused by the sampling pixels in the digital image. The other is the timing jitter which results from the irregular capture-timing in the infrared cameras. The capture-timing in the IR camera is measured using the jitter meter designed in this paper, and the observed jitters are statistically modeled as Gaussian distribution. This paper derives an integrated probability distribution by combining jitter error with pixel position error. The combined error is modeled as the convolution of two error distributions. To verify the proposed statistical position error model, this paper has some experiments in tracking moving objects with IR stereo camera. The 3-D positions of object are accurately measured by the trajectory scanner, and 3-D positions are also estimated by stereo matching from IR stereo camera system. According to the experiments, the positions of moving object are estimated within the statistically reliable range which is derived by convolution of two probability models of pixel position error and timing jitter respectively. It is expected that the proposed statistical model can be applied to estimate the uncertain 3-D positions of moving objects in the diverse fields.

Effects of life style on psychosomatic a subjective a symptoms of the dental technology students (일 대학 치기공과 재학생의 생활습관이 심신 자각증상에 미치는 영향)

  • Kwon, Soon-Suk;Lee, Hye-Eun
    • Journal of Technologic Dentistry
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    • v.38 no.1
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    • pp.37-49
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    • 2016
  • Purpose: This research is performed through the analysis of the dental technology students' life-style factors of their daily lives that have a close relation with health, and the self-reported symptoms which are related to psychosomatic diseases, for the production of basic data for the change of life-styles and the development of educational programmes. Methods: This research has been performed through questionnaires from the beginning of October of 2014 till the end of November through the Dental Technology students of G-do, chosen by random sampling method after informed consent, where out of the 270 papers, 258 results were used for the analysis. Results: Firstly, the results of the research was as follows: Non-smokers accounted for 61.2%, student who did not do regular physical activities accounted for 50.4%, students who had sleeping hours of 6 to 7 hours accounted for 35.7%, students who eat snacks accounted for 63.2%, students who eat breakfast once to twice a week accounted for 30.6%, students who had an average number of drinks of once to twice a week accounted for 39.9%, and students with BMI of '$18.5^{\circ}{{\neq}}22.9$' accounted for 56.2%, being the highest. Secondly, in gender, smoking (p<.001), regular physical activity (p<.001), BMI (p<.001), eat snacks (p<.05), average number of drinks (p<.05), and of the health check-up, eat breakfast (p<.05), of the year level, eat snack (p<.01), BMI (p<.01), hours of sleep (p<.05), of major satisfaction, regular physical activity (p<.01), and BMI (p<.05), and there was a significant statistical difference, but there were no significant statistical difference in religion. Thirdly, of the bodily self-reported symptoms of the correlation analysis within the life-style variables and the self-reported symptoms, multiple subjective symptoms (I), respiratory (A), eye and skin (B), and digestive organs (C) were the highest in the correlation analysis with regular physical activity (p<.01), and of mental health, impulsiveness (H), mental instability (J), and depression (K) showed highest results in correlation analysis with regular physical activity (p<.01, p<.05), lie scale (L) and irregular and life (G) with eat breakfast (p<.01), and aggressiveness (F) with BMI (p<.01), showed highest results in correlation analysis. Fourthly of the Dental technology students' bodily self-reported symptoms, life-style factors which had a statistically significant effect appeared to be regular physical activity (p<.001) and BMI (p<.05), and of the mental self-reported symptoms, causes that did not have statistically significant effect appeared to be regular physical activity (p<.05) and eat breakfast (p<.05). Conclusion: This research concludes that in order to develop correct life-style habits for health promotion and reduce self-reported symptoms related to the Dental Technology students' diseases, education for the recognition of the necessity of self health promotion must be conducted, and a education programme scheme for the Dental technology curriculum for practicing the correct life-style habits in daily life is required.