• 농업과학연구
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• 제43권3호
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• pp.394-400
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• 2016

The objective of this study was to estimate the environmental factors affecting milk ${\beta}$-hydroxybutyric acid (BHBA) and acetone (Ac) concentrations in Holstein cattle. A total of 264,221 test-day records collected from the Korea Animal Improvement Association (KAIA) during the period of 2012 to 2014 were used in this study. Analysis of variance (ANOVA) was performed to determine the factors significantly affecting ketone body concentrations. Parameters considered in the model were season of test, season of calving, parity, lactation stage, and milk collecting time (AM and PM). According to the ANOVA, the $R^2$ for milk BHBA and Ac were 0.5226 and 0.4961, respectively. 'Season of test' showed a considerable influence on ketone body concentration. Least square (LS) means for milk BHBA concentrations was the lowest ($39.04{\mu}M$) in winter while it increased up to $62.91{\mu}M$ in summer. But Ac concentration did not significantly change along with 'season of test'. The means of milk BHBA and Ac concentrations were high at first lactation stage, low around second lactation stage, and then gradually increased. Cows milked in the morning had lower mean BHBA and Ac concentrations ($48.49{\mu}M$ and $121.69{\mu}M$, respectively) in comparison to those milked in the evening ($53.46{\mu}M$ and $130.42{\mu}M$, respectively). The LS means of BHBA and Ac slightly increased over parities. These results suggest that proper maintenance of milk collection, herd management programs, and evaluation of ketone body levels in milk should be considered for the efficient management of resistance to ketosis.

• 한국통신학회논문지
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• 제28권10C호
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• pp.936-941
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• 2003

최근에 소개된 density evolution 기법은 sum-product 알고리즘에서 LDPC 부호가 갖는 성능의 한계를 분석하였다[1]. 또한. Iterative decoding 알고리즘에서 전달되는 정보가 Gaussian 확률분포를 갖는 점을 이용하여 기존의 density evolution 기법을 단순화 시킨 연구결과가 소개되었다[2]. 한편. LDPC 부호의 한계 성능을 sum-product가 아닌 min-sum 알고리즘에서 분석한 결과가 최근에 발표되었다[3]. 본 논문에서는 이러한 일련의 연구 결과를 바탕으로 min-sum 알고리즘을 이용하면서 Gaussian 확률 분포 특성을 이용한 density evolution 기법을 소개한다. 제안된 density evolution 기법은 기존의 방법보다 적은 계산으로 정확한 threshold를 구할 수 있으며. 그 결과가 numerical simulation 결과와 잘 일치함을 나타내었다.

• 기본간호학회지
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• 제25권3호
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• pp.176-184
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• 2018

Purpose: Purpose of this study was to investigate relationships and influence of peripheral neuropathy, sleep, and quality of life in patients with gastric cancer who are receiving chemotherapy. Methods: Participants were 131 patients with gastric cancer being treated at a chemotherapy outpatient clinic and receiving chemotherapy. Data were analyzed using descriptive statistics, t-test, ANOVA, and multiple regression analysis with the SPSS program. Results: Mean score for peripheral neuropathy was 24.66, for sleep, 6.71 and for quality of life, 67.69. Peripheral neuropathy had a significant positive correlation with sleep (r=.26, p=.003) and sleep had a significant negative correlation with quality of life (r=-.50, p<.001). The regression model explaining quality of patients'lives was significant (F=11.91, p<.001), peripheral neuropathy, sleep, and pain due to anticancer drugs and number ofneurotoxic anticancer drugs explained 25.1% of the variance in quality of life and sleep was the most important factor. Conclusion: To improve the quality of life for these patients, individualized nursing interventions for pain should be provided according to number of anticancer drugs in the chemotherapy. Also there is a need to identify ways to assess peripheral neuropathy and sleep disorders that are appropriate in the treatment and reduce side effects during treatment.

• 여성건강간호학회지
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• 제26권2호
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• pp.171-179
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• 2020

Purpose: This study aimed to investigate the effects of exposure to endocrine disruptors, burnout, and social support from peers on premenstrual syndrome (PMS) in nurses. Methods: This descriptive correlational study was conducted among 122 nurses under the age of 49 working at a university hospital. The participants answered self-report questionnaires. The data were analyzed using the t-test, analysis of variance, Pearson or Spearman correlation coefficients, and hierarchical multiple regression in IBM SPSS version 23.0. Results: The mean age of the nurses was 28.9 years. Of these nurses, 49.2% were working in a general ward, 24.6% in the intensive care unit, 14.8% in the emergency room, and 11.4% in an outpatient department. The explanatory power of the model was 38.3%, and it was statistically significant (F=11.74, p≤.001). Exposure to endocrine disruptors (β=0.32, p<.001) was the most powerful variable affecting PMS, followed by burnout (β=0.27, p=.001), working in the intensive care unit or emergency room (β=0.22, p=.003), family history of PMS (β=0.19, p=.009), and support from coworkers (β=-0.15, p=.043). Conclusion: Based on these findings, it is necessary to develop an intervention program to reduce the symptoms of PMS. Additionally, further studies are needed to develop and evaluate measures to minimize exposure to endocrine disruptors and burnout in order to alleviate PMS among nurses.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.32-32
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• 2019

The aim of this study was to provide basic guidelines for conservation and management of endangered plants in the national parks of Korea. Iris dichotoma Pall. (Iridaceae), which is a popular garden plant, is considered a second-class endangered species by Korean government and it is listed as a EN (Endangered) species in Red Data Book of Korea. We analyzed ecological conditions of I. dichotoma habitats based on vegetation properties and soil characteristics. This species which is known to inhabit in grassland adjacent to the ocean of lowlands slope and its population was located at an elevation of 8 m to 11 m. In the study sites, the mean of soil organic matter, total nitrogen and soil pH were 6.16%, 0.234% and 5.39 respectively. Additionally, the genetic variation and structure of three populations were assessed using ISSR (Inter Simple Sequence Repeat) markers. The genetic diversity of I. dichotoma (P = 59.46%, H = 0.206, S = 0.310) at the species level was relatively high. Analysis of molecular variance (AMOVA) showed 82.1% of the total genetic diversity was occurred in within populations and 17.9% variation among populations. Lastly, we developed predicted distribution model based on climate and topographic factors by applying SDMs (Species Distribution Models). Consequently, current status of I. dichotoma habitats is limited with natural factors such as the increase of the coverage rate of the herbs due to ecological succession. Therefore, it is essential to establish in situ and ex situ conservation strategies for protecting natural habitats and to require exploring potential and alternative habitats for reintroduction.

• 한국학교보건학회지
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• 제32권2호
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• pp.67-76
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• 2019

Purpose: The purpose of this study was to explore self-directed learning ability and its affecting factors among undergraduate students. Methods: A descriptive cross-sectional study design was used. Using a convenience sampling method, data were collected from 196 undergraduate students enrolled in one national university. Negative psychological tendency (i.e. Type D personality), academic engagement, and self-directed learning ability were assessed using a structured questionnaire. Data were analyzed by descriptive statistics, t-test, and analysis of covariance, Pearson's correlation coefficients, and stepwise multiple linear regression, using SPSS/WIN 23.0 program. Results: The mean age of the students was $21.61{\pm}2.40years$ and 56.6% were male students. Approximately, one third (n=67, 34.2%) of the students had Type D personality. The average scores of academic engagement and self-directed learning ability were $3.01{\pm}1.14$ and $3.46{\pm}0.50$, respectively. After controlling for sociodemographic variables, the Type D personality and academic engagement were significant predictors of self-directed learning ability (${\beta}=.64$, p<.001; ${\beta}=-.13$, p=.021, respectively). This model explained 53.6% of the variance in self-directed learning ability. Conclusion: The study identified that Type D personality and academic engagement affect self-directed learning ability of undergraduate students, one in a negative way, the other in a positive way. Educators and educational policy makers need to make efforts to include interventions and strategies that increase academic engagement and change negative psychological dispositions such as D-type personality in the undergraduate education curriculum.

• 대한간호학회지
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• 제49권3호
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• pp.340-348
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• 2019

Purpose: This study aimed to investigate the nutritional status of liver transplantation (LT) recipients and explore certain factors that influence nutritional status, including dietary patterns and physical activities. Methods: This was a cross-sectional, descriptive study. The subjects included 211 LT recipients at a medical center outpatient clinic located in Seoul, Korea. The nutritional status, dietary patterns, and physical activities of each subject were measured using the body mass index (BMI), Mini Dietary Assessment (MDA), and Global Physical Activity Questionnaire. Independent t-test, one-way analysis of variance, and multiple linear regression analysis were used to analyze the data. Results: The percentages of living and deceased donor LTs were 81.0% and 19.0%, respectively. The mean BMIs pre- and post-LT were 23.88 and $23.16kg/m^2$, respectively, and the average MDA score was 36.55. More than 60.0% of the subjects had a moderate or high level of physical activity. In multivariate analysis, a higher BMI before LT (${\beta}=.72$, p<.001), a lower Model for End-stage Liver Disease (MELD) score (${\beta}=-.18$, p<.001), and being male (${\beta}=-.10$, p=.024) contributed to better nutritional status post-LT. Patients within six months of LT were less engaged in muscle exercises than those post six months of LT (p=.020). Conclusion: LT recipients in Korea have good nutritional status and a good level of physical activity. To improve recipients' post-LT nutritional status, the pre-LT nutritional status should be considered, particularly in those with a higher MELD score. In addition, physical activity including muscle-strengthening exercises should be encouraged from an earlier stage.

• 대한치과교정학회지
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• 제51권4호
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• pp.231-240
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• 2021

Objective: This outcome analysis study evaluated the actual positions of the orthodontic miniplate and miniplate anchoring screws (MPASs) and the risk factors affecting adjacent anatomic structures after miniplate placement in the mandibular incisal area. Methods: Cone-beam computed tomographic images of 97 orthodontic miniplates and their 194 MPASs (diameter, 1.5 mm; length, 4 mm) in patients whose miniplates provided sufficient clinical stability for orthodontic treatment were retrospectively reviewed. For evaluating the actual positions of the miniplates and analyzing the risk factors, including the effects on adjacent roots, MPAS placement height (PH), placement depth (PD), plate angle (PA), mental fossa angle (MA), and root proximity were assessed using the paired t-test, analysis of variance, and generalized linear model and regression analyses. Results: The mean PDs of MPASs at positions 1 (P1) and 2 (P2) were 2.01 mm and 2.23 mm, respectively. PA was significantly higher in the Class III malocclusion group than in the other groups. PH was positively correlated with MA and PD at P1. Of the 97 MPASs at P1, 49 were in the no-root area and 48 in the dentulous area; moreover, 19 showed a degree of root contact (19.6%) without root perforation. All MPASs at P2 were in the no-root area. Conclusions: Positioning the miniplate head approximately 1 mm lower than the mucogingival junction is highly likely to provide sufficient PH for the P1-MPASs to be placed in the no-root area.

• Imaging Science in Dentistry
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• 제51권1호
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• pp.1-7
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• 2021

Purpose: The aim of this study was to assess artifacts generated in cone-beam computed tomography (CBCT) of 3 types of dental implants using 3 metal artifact reduction (MAR) algorithm conditions (pre-acquisition MAR, post-acquisition MAR, and no MAR), and 2 peak kilovoltage (kVp) settings. Materials and Methods: Titanium-zirconium, titanium, and zirconium alloy implants were placed in a dry mandible. CBCT images were acquired using 84 and 90 kVp and at normal resolution for all 3 MAR conditions. The images were analyzed using ImageJ software (National Institutes of Health, Bethesda, MD) to calculate the intensity of artifacts for each combination of material and settings. A 3-factor analysis of variance model with up to 3-way interactions was used to determine whether there was a statistically significant difference in the mean intensity of artifacts associated with each factor. Results: The analysis of all 3 MAR conditions showed that using no MAR resulted in substantially more severe artifacts than either of the 2 MAR algorithms for the 3 implant materials; however, there were no significant differences between pre- and post-acquisition MAR. The 90 kVp setting generated less intense artifacts on average than the 84 kVp setting. The titanium-zirconium alloy generated significantly less intense artifacts than zirconium. Titanium generated artifacts at an intermediate level relative to the other 2 implant materials, but was not statistically significantly different from either. Conclusion: This in vitro study suggests that artifacts can be minimized by using a titanium-zirconium alloy at the 90 kVp setting, with either MAR setting.

• 한국해안·해양공학회논문집
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• 제33권6호
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• pp.333-344
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• 2021

해양모니터링 자료에서 빈번하게 발생하는 장기결측구간의 자료 보충기법을 제안한다. 제안하는 방법은 결측구간의 장기변동 추세 성분과 단기변동 잔차성분을 추정하여 조합하는 방식으로 결측구간의 미지 정보를 추정한다. 이 방법을 이용하여 울릉도 해상부이 자료의 수온 항목, 약 1개월 정도의 장기결측 구간의 자료를 보충하였으며, 부이에서 관측하는 자료 항목에 대해서도 결측 보충을 수행하였다. 보충된 자료는 항목에 따라 차이를 보이지만 변동양상이 적절하게 재현되는 것으로 파악되었다. 이 방법은 추세추정과 잔차 반영에 따른 편향오차와 분산오차가 발생하지만, 장기결측으로 인한 통계적인 측도 추정의 편향오차는 크게 절감하는 것으로 파악되었다. 결측보충 모형의 추정 RMS 오차의 평균과 90% 신뢰구간은 각각 0.93, 0.35~1.95 범위이다.