Periodontal disease is a chronic but treatable condition which often does not cause pain during the initial stages of the illness. Lack of awareness of symptoms can delay initiation of treatment and worsen health. The aim of this study was to develop and compare different risk prediction models for periodontal disease using machine learning algorithms. We obtained information on risk factors for periodontal disease from the Korea National Health and Nutrition Examination Survey (KNHANES) dataset. Principal component analysis and an auto-encoder were used to extract data on risk factors for periodontal disease. A synthetic minority oversampling technique algorithm was used to solve the problem of data imbalance. We used a combination of logistic regression analysis, support vector machine (SVM) learning, random forest, and AdaBoost to classify and compare risk prediction models for periodontal disease. In cases where we used principal component analysis (PCA) to extract risk factors, the recall was higher than the feature selection method in the logistic regression and support-vector machine learning models. AdaBoost’s recall was 0.98, showing the highest performance of both feature selection and PCA. The F1 score showed relatively high performance in Ada- Boost, logistic regression, and SVM learning models. By using the risk factors extracted from the research results and the predictive model based on machine learning, it will be able to help in the prevention and diagnosis of periodontal disease, and it will be used to study the relationship with various diseases related to periodontal disease.

The optimal determination of seeding rate is critical to minimizing uncertainties about the large variations observed in forage quality and productivity when alfalfa is cultivated under different geographical areas and growing conditions. The objective of this investigation was to provide information about the proper seeding rate according to harvest timing for alfalfa cultivation in the Northern regions of Korea. Alfalfa was sown in September 2018 at a seeding rate of 20, 30 or 40 kg/ha and harvested four times in 2019: May 3, July 2, September 11, and October 13. Regardless of seeding rate, alfalfa plant height was longest at the third harvest (113 cm) and the shortest in the last annual harvest (43.8 cm). However, seeding rate had no effect on alfalfa plant height at any harvest. Forage relative feed value was increased in the first cutting but decreased in the third cuttings as seeding rate increased. However, seeding rate had slight effect on alfalfa forage quality components at the second and fourth cuttings. Total annual DM and crude protein production (in 4 harvests) was greater at higher seeding rates. Plots seeded at a rate of 40 kg/ha produced on average 1,257 and 2,620 kg/ha more forage (DM basis) than those seeded at a rate of 30 or 20 kg/ha, respectively. Forage DM production at the first, second, third, and fourth harvests accounted for 36.1, 24.0, 27.1, and 12.8 % of total annual DM production, respectively. Overall, small differences were seen when alfalfa seeding rate was different but maximum forage DM production (in four harvests) was detected when seeding rate was 40 kg/ha. These data could be useful to the alfalfa growers by allowing them to make more accurate trade-offs between seed price and the expected magnitude of forage yield gains in order to select the best seeding rate.

Cutting management has been identified as a critical factor in the alfalfa production systems because it has a significant impact on maximizing yield and maintaining the forage quality. The objective of this experiment was to determine the proper cutting height according to harvesting time for optimizing nutrient yield and forage nutritive quality of alfalfa grown in alpine regions of Korea. Alfalfa was sown at a seeding rate of 30 kg/ha in August 2018 and harvested at four cuttings in 2019 (3 May, 2 July, 11 September, and 13 October). Cutting heights were adjusted at 5, 15, and 25 cm above the soil surface. Alfalfa plant was tallest at the third cutting (109 cm), which was on average 35 cm taller than the first or second cutting. Relative feed value (RFV) remained unaffected by cutting height at the first harvest, but increased consistently in subsequent harvests as cutting height increased. Alfalfa collected at the first and fourth cuttings had the highest RFV (mean 152), which was on average 8 and 67 units higher than the second and third harvests, respectively. At each harvest, in vitro dry matter digestibility was highest in alfalfa cut at a 25-cm height. Dry matter (DM) production at each cutting height was highest in the first cutting, accounting for on average 36-37% of total annual DM production, and lowest in the fourth harvest, accounting for about 11-13% of the total DM yield. The total dry matter production (in four harvests) was 4,218 kg/ha higher when alfalfa was subjected to a cutting height of 5 cm rather than 25 cm. Cutting height had no effect on total crude protein yield, but from the first to fourth cutting, the protein yield followed a decreasing trend. Finally, there were visible declines in forage nutritive quality when alfalfa was cut at a shorter height. However, the magnitude of difference in total forage yield may outweigh the slight decline in forage quality when alfalfa is cut at a lower height. The findings of this study could help the alfalfa growers make better harvest management decisions.

최근 다양한 유기재배 작물의 뿌리를 가해하는 굼벵이류의 피해가 증가하고 있으나, 굼벵이류는 토양 내 발생하는 특징으로 인해 발생시기 및 그 종류에 대한 확인이 어려운 해충이다. 피해를 끼치는 굼벵이의 발생을 파악하기 위해 고구마 유기재배지에 페로몬 트랩을 이용하여 굼벵이의 성충의 종류 및 발생 동향을 조사하였다. 조사지는 무안 유기재배농가와 국립농업과학원 완주군 포장에서 이루어졌다. 3종의 풍뎅이 페로몬 루어를 유인제로 사용하였으 며 6월 초부터 8월 말까지 조사지에 트랩을 설치하여 포획된 풍뎅이를 수집하여 동정을 하였다. 유기재배포장에서 포획된 종은 큰검정풍뎅이, 콩풍뎅이, 청동풍뎅이, 녹색콩풍뎅이, 별줄풍뎅이 등의 풍뎅이와 흰점박이꽃무지 등이 주로 채집되었다. 유기재배 고구마포장에서 풍뎅이 발생소장을 조사한 결과 최대로 발생한 시기는 7월초였다.

원전 해체 공정 중 절단 및 용융작업에서 발생되는 방사성 에어로졸은 작업종사자의 호흡을 통해 내부 피폭을 유발하게 된다. 이에 따라 해체 중 방사성 에어로졸로 인한 작업종사자의 내부피폭 평가가 필요한 실정이다. 정확한 내부피폭평가를 위해서는 작업종사자의 작업환경 실측값이 필요하지만 실측에 어려움이 있을 시에는 국제방사선방호위원회(ICRP)에서 제시하는 섭취량 분율 및 입자 크기 등의 권고 값을 통해 내부피폭선량을 추정할 수 있다. 본 논문에서는 입자 크기의 선정은 ICRP에서 권고하는 작업종사자의 고려 입자 크기인 5 μm을 적용하였다. 발생량의 경우, 불가리아의 Kozloduy 부지 내의 용융시설에서 발생 된 에어로졸의 포집량 데이터를 이용하여 섭취량을 산정하였다. 또한 이를 이용해 작업종사자의 체내 및 배설물에서의 방사능 수치를 계산하고 BiDAS 전산코드를 통해 내부피폭 평가를 수행하였다. Type M이 0.0341 mSv, Type S가 0.0909 mSv로 두 흡수 형태 각각 국내 연간 선량 한도의 0.17%, 0.45% 수준을 나타내었다.

Japanese pine sawyer beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae) is considered as a serious pest in pine trees. To develop an eco-friendly strategy to manage this forest insect, we collected entomopathogenic fungi from Korean soil and assessed their virulence against the adults of the insect in laboratory conditions. As a result, two isolates with conidial suspension (1.0×107conidia/ml), showed 87% and 90% mortality 12 days after fungal treatment, respectively. We assessed the potential of the fungi-derived destruxin and protease as additives to the fungal isolates, and they showed insecticidal activity via feeding and spraying treatments. Finally, we produced fungal conidia in massive solid cultures and formulated wettable powders, and now studying optimal conditions of oil-based formulation with two isolates. Based on these results, we are evaluating the control efficacy of the fungal agents against M. alternatus in field conditions.

In this study, several approaches in evaluating moisture sensitivity of asphalt mixtures were investigated and compared. To evaluate the moisture damage resistance, twenty types of asphalt mixtures with and without anti stripping additives were tested in the laboratory. Uniaxial compressive strength (UCS) and indirect tensile (IDT) testing were performed to determine the Tensile Strength Ratio (TSR) and Cohesion Strength Ratio (CSR). Stone Mastic Asphalt (SMA) mixtures were found to provide good moisture damage resistance compared to other mixtures. It also does not require anti stripping additives to improve its moisture resistance. Moreover, the correlation coefficient between the TSR test and CSR tests is 0.99 with an average error of 1.5%, which indicates that the TSR test following AASHTO T-283 is still the most reasonable criteria in evaluating the moisture damage of AC mixtures. Marshall Stability Ratio (MSR) and Marshall Stability to Flow Ratio (MSFR) were conducted and were compared to TSR test results. It was found that MSFR value may be used to evaluate the moisture damage resistance of AC mixtures instead of TSR test. Finally, Dynamic Immersion (DI) test was performed to evaluate moisture resistance for loose asphalt mixtures. The DI results showed good correlation also when evaluating moisture resistance compared to TSR. When using DI testing in evaluating moisture resistance, it is recommended to test after 48 hours since it showed higher correlation with the TSR values. Further study is recommended to improve current testing evaluating moisture susceptibility of asphalt mixtures to properly associate it with TSR values.

Recently, N-terminal pro-brain natriuretic peptide (NTproBNP) has been widely used in the areas of diagnosis, monitoring treatment efficiency, and prognosis for various heart diseases, especially heart failure (HF). In this paper, we try to estimate the prognostic significance of NT-proBNP as a risk evaluation marker in Non-ST-segment Elevation Myocardial Infarction (NSTEMI) patients. We selected NSTEMI patients who underwent percutaneous coronary intervention (PCI) primarily using a drug-eluting stent within 24 h after the onset of chest pain. We compared incidences of major adverse cardiac events (MACE) including death, myocardial infarction (MI), stent thrombosis (ST), and target vessel revascularization (TVR) in two patient groups according to a high or low serum concentration of NT-proBNP, which was measured in the emergency room (ER). We intend to minimize selection bias selecting comparing groups, considering covariate of observed variables together using propensity score matching (PSM) and propensity score weighting (PSW) based on propensity score (PS) to control the difference in baseline characteristics between high- and low NT-proBNP groups. We found that as the log NT-proBNP value increases by 1 through a hazard function of COX’s analysis, the risk of MACE increases by 1.312 times. This result indicated that the NT-proBNP level on ER admission can be used as a significant prognostic indicator to estimate 1 year of MACE in NSTEMI patients who were treated with PCI within 24 h after the onset of chest pain.

The purpose of this study was to investigate the complex ankle exercises on balance. 22 participants (male: 14, female: 8) with functional ankle instability were participated. Functional ankle instability was selected to be less than 24 points using the Cumberland ankle instability tool (CAIT) with people who had severe ankle sprain and then experiencing ankle giving way. A total of 20 minutes performed three times a week for four weeks with muscle strength and balance exercises. Muscle strengthening exercise was performed with Theraband, and balance exercise was performed with unstable support plates. Biodex balance systemⓇ was used to measure static and dynamic balance. The dynamic balance was selected in grade 2, 4, and 8. The static and dynamic balance (grade: 2, 4,and 8) balance was significantly decreased in anterior-posterior, and medial-lateral directions (p<.05). The instability was significantly increased after exercise (p<.05). These results suggest that complex exercises are beneficial to decreasing the functional ankle instability.

The purpose of this study was to investigate the effects of low-intensity cardiac rehabilitation exercise on the cardiac function and the degree of fibrosis in an older white rat model. This study used male Sprague- Dawley white rats that were 50 weeks old. After the acute myocardial infarction induction, Twenty of the rats were randomly allocated into an experimental group and a control group, and each of the groups consisted of 8 rats. In the experimental group, the exercise was conducted for six weeks, 30 minutes a day, five days a week, using a Rotarod treadmill for animals. The degree of myocardial fibrosis was significantly repressed in the experimental group(13.69±1.90%) and in the control group(15.67±1.54%)(p<0.05). However, fractional shortening and ejection fraction did not show a significant difference. The results of this study suggest that cardiac rehabilitation with low intensity treadmill exercise repress the myocardial fibrosis.