• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.42.2-42.2
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• 2013

The F-GAMMA (FERMI-GST AGN Multi-frequency Monitoring Alliance) project is a program for the monthly monitoring of the broad-band spectra of currently about 90 selected Fermi-GST AGNs. F-GAMMA utilizes several facilities in cm, mm, sub-mm, infrared and optical bands, achieving an unprecedented coverage for the study of the spectral evolution of powerful relativistic jets in AGNs. The KVN joined the F-GAMMA project in May 2011, aiming to monitor flux density at 22 and 43 GHz. We present the preliminary results of flux density variability, evolution of spectral index, and modulation index.

• The Korean Journal of Health Service Management
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• v.11 no.4
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• pp.145-155
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• 2017

Objectives : To investigate the factors affecting bone mineral density in across stratified postmenopausal ages. Methods : Data from 1,698 subjects who completed the 2010-2011 National Health and Nutrition Survey were analyzed using SPSS Statistics 21.0 The $x^2$ test and one way (ANOVA) were used to verify the relationship between general characteristics and health behaviors and the prevalence of osteoporosis. Logistic regression analysis was used to verify the factors Influencing bone mineral density. Results : The bone mineral density distribution was the highest among those with osteopenia, with proportions of 21.8% in healthy subjects, 58.1% in osteopenia, and 20.0% in those with osteoporosis. The distribution of osteoporosis by age group was 5.2% among subjects in their 50s, 15.4% among those in their 60s, and 42.4% among those in their 70s. In multivariate logistic regression analysis, the prevalence of osteoporosis according to ages was significantly correlated with age, educational level, body mass index(BMI), and parity 4 of more than 1-2 babies. Conclusions : Although age is an uncontrollable factor in the prevention of osteoporosis, educational level and BMI are correctable factors to maintain bone mineral density. There is a need to maintain healthy BMI and expand osteoporosis prevention education.

• Journal of the Korean Wood Science and Technology
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• v.17 no.4
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• pp.77-82
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• 1989

In this study the oxygen index method was used to compare the duration of flaming and the rate of weight loss at the level of 6 and 9mm panel thicknesses among solid wood, plywood, particleboard, and medium density fiberboard. The obtained results were as follows: 1. In 9mm-thick panels, the combustibility was the largest in lauan solid wood followed by medium density fiberboard. particleboard. and plywood. 2. Medium density fiberboard was burned more easily than plywood in 6mm-thick panels and the higher oxygen concentration was needed as the panel thickness increased. 3. The oxygen indices of 9mm-thick panels were 29.0 in lauan solid wood, 31.4 in medium density fiberboard, 33.0 in particleboard, and 33.4 in plywood and those of 6mm-thick panels were 28.3 in medium density fiberboard and 29.7 in plywood. 4. The rate of weight loss was the largest in lauan solid wood followed by medium density fiberboard, plywood, and particleboard.

• International Journal of Highway Engineering
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• v.19 no.5
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• pp.89-96
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• 2017

PURPOSES: This study aims to develop a rational procedure for estimating the pavement roughness index considering vehicle wandering. METHODS : The location analysis of the passing vehicle in the lane was performed by approximately 1.2 million vehicles for verification of the wandering distribution. According to verification result, the distribution follows the normal distribution pattern. The probability density function was estimated using each lane's wandering distribution model. Then the procedure for applying a weighted value into the lane profile was conducted using this function. RESULTS : The modified index, MRIw, with consideration towards applying the wandering weighted value application was computed then compared with MRI. It was found that the Coefficient of Variation for distribution of lateral roughness index in the lane was high in the case of a large difference between each index (i.e., MRIw and MRI) observed. CONCLUSIONS : This result confirms that the new procedure with consideration of the weight factor can successfully improve the lane representative characteristics of the roughness index.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.140-144
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• 2006

This study was performed to investigate the effect of organic characteristics and feed water solution chemistry on membrane fouling index such as Silt Density Index (SDI) and Modified Fouling Index (MFI). Specifically, Aldrich humic acids (AHA) and Suwannee river humic acids (SHA) were used in SDI/MFI experiments. Higher SDI values were observed with increasing organic concentration. AHA with larger molecular weight (MW) and SUVA (${\approx}UV_{254}/TOC$) resulted in higher SDI values, compared to SHA. The feed solution chemistry (i.e, pH, ionic strength, and hardness) also affects SDI values to some degree. In particular, SDI increased with increasing hardness ($Ca^{2+}$) concentration for AHA. Unlike SDI, the MFI developed on the basis of particle cake filtration theory, was not accurately assessed due to internal fouling by organics such as pore adsorption and subsequent pore blocking.

• Journal of Preventive Medicine and Public Health
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• v.49 no.6
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• pp.367-375
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• 2016

Objectives: The established theory that breast density is an independent predictor of breast cancer risk is based on studies targeting white women in the West. More Asian women than Western women have dense breasts, but the incidence of breast cancer is lower among Asian women. This meta-analysis investigated the association between breast density in mammography and breast cancer risk in Asian women. Methods: PubMed and Scopus were searched, and the final date of publication was set as December 31, 2015. The effect size in each article was calculated using the interval-collapse method. Summary effect sizes (sESs) and 95% confidence intervals (CIs) were calculated by conducting a meta-analysis applying a random effect model. To investigate the dose-response relationship, random effect dose-response meta-regression (RE-DRMR) was conducted. Results: Six analytical epidemiology studies in total were selected, including one cohort study and five case-control studies. A total of 17 datasets were constructed by type of breast density index and menopausal status. In analyzing the subgroups of premenopausal vs. postmenopausal women, the percent density (PD) index was confirmed to be associated with a significantly elevated risk for breast cancer (sES, 2.21; 95% CI, 1.52 to 3.21; $I^2=50.0%$). The RE-DRMR results showed that the risk of breast cancer increased 1.73 times for each 25% increase in PD in postmenopausal women (95% CI, 1.20 to 2.47). Conclusions: In Asian women, breast cancer risk increased with breast density measured using the PD index, regardless of menopausal status. We propose the further development of a breast cancer risk prediction model based on the application of PD in Asian women.

• Korean Journal of Radiology
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• v.24 no.9
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• pp.849-859
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• 2023

Objective: The prognostic value of the volume and density of skeletal muscles in the abdominal waist of patients with colon cancer remains unclear. This study aimed to investigate the association between the automated computed tomography (CT)-based volume and density of the muscle in the abdominal waist and survival outcomes in patients with colon cancer. Materials and Methods: We retrospectively evaluated 474 patients with colon cancer who underwent surgery with curative intent between January 2010 and October 2017. Volumetric skeletal muscle index and muscular density were measured at the abdominal waist using artificial intelligence (AI)-based volumetric segmentation of body composition on preoperative pre-contrast CT images. Patients were grouped based on their skeletal muscle index (sarcopenia vs. not) and muscular density (myosteatosis vs. not) values and combinations (normal, sarcopenia alone, myosteatosis alone, and combined sarcopenia and myosteatosis). Postsurgical disease-free survival (DFS) and overall survival (OS) were analyzed using univariable and multivariable analyses, including multivariable Cox proportional hazard regression. Results: Univariable analysis showed that DFS and OS were significantly worse for the sarcopenia group than for the non-sarcopenia group (P = 0.044 and P = 0.003, respectively, by log-rank test) and for the myosteatosis group than for the non-myosteatosis group (P < 0.001 by log-rank test for all). In the multivariable analysis, the myosteatotic muscle type was associated with worse DFS (adjusted hazard ratio [aHR], 1.89 [95% confidence interval, 1.25-2.86]; P = 0.003) and OS (aHR, 1.90 [95% confidence interval, 1.84-3.04]; P = 0.008) than the normal muscle type. The combined muscle type showed worse OS than the normal muscle type (aHR, 1.95 [95% confidence interval, 1.08-3.54]; P = 0.027). Conclusion: Preoperative volumetric sarcopenia and myosteatosis, automatically assessed from pre-contrast CT scans using AI-based software, adversely affect survival outcomes in patients with colon cancer.

• Journal of Korean society of Dental Hygiene
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• v.12 no.5
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• pp.943-952
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• 2012

Objectives : The purpose of this study was to examine the impact of the systemic osteoporosis of Korean adults on their periodontal diseases and CPI index based on the data of their systemic osteoporosis. Methods : The third-year raw data of the 4th 2009 National Health & Nutrition Survey that turned out to be representative and reliable were utilized. The subjects in this study were 7,285 adults who were over the age of 19 and got both of health and dental checkups. As for data analysis, the statistical packages PASW 19.0 and SAS 9.0 were employed. Results : The most periodontal diseases were found in those who had osteoporosis in the entire parts, entire femur, femoral neck and spiral bone, but there was no significant relationship between periodontal diseases and osteoporosis. As for the connections between peridontal diseases and osteoporosis, the adults who had femoral neck osteoporosis had a 2.057-fold less bone mass than those who had a normal bone density in this part, and the former's periodontal diseases increased in proportion to that. There was consequently a statistically significant relationship between the two(p<0.05). Among the prevalence factors of osteoporosis, a lower entire femur bone mineral density led to a lower CPI index(p<0.01), and a lower femoral neck bone mineral density led to a higher CPI index(p<0.05). Thus, there was a significant relationship between osteoporosis and the oral health indicator. Conclusions : The above-mentioned findings confirmed that in terms of the relationship among the periodontal diseases, CPI index and osteoporosis of Korean adults, a higher risk of osteoporosis affected the increase of chronic periodontal diseases.

• Journal of Korean Society of Forest Science
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• v.81 no.2
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• pp.139-145
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• 1992

A planning method of optimum forest road was tested in the compartment II of Kangweon National University Forests by using a digital terrain model under four evaluation factors, i. e., minimum road length, average skidding distance, exploitative index, and ratio of inaccessible points. The results of the study were as follows : 1. Optimum forest road design based on the minimum road length was shown as 6035.6m, 12.73m/ha, 279.9m, 1.43, and 15.7% for total road length, forest road density, average skidding distance, exploitative index, and ratio of inaccessible points, respectively. 2. Optimum forest road design based on the average skidding distance was shown as 7828.5m, 16.52m/ha, 198.4m, 1.31, and 4.0% for total road length, forest road density, average skidding distance, exploitative index, and ratio of inaccessible points, respectively. 3. Optimum forest road design based on the exploitative index was shown as 7410.6m, 15.64m/ha, 210.9m, 1.26, and 5.0% for total road length, forest road density, average skidding distance, exploitative index, and ratio of inaccessible points, respectively. 4. Optimum forest road design based on the ratio of inaccessible points was shown as 8307.1m, 17.53 m/ha, 184.9m, 1.29, and 2.5% for total road length, forest road density, average skidding distance, exploitative index, and ratio of inaccessible points, respectively.

• Fire Science and Engineering
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• v.17 no.4
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• pp.36-41
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• 2003

This experimental study shows the combustion characteristics for each coating thickness of water and oil paint which are used as fire retardant paints that prevent fire propagation through cables in underground culverts and trays. To evaluate combustion characteristics, smoke density(ASTM E 662) and Limited Oxygen Index(ASTM D 2863) experiment method was used. As the results of this study, the combustion characteristics of fire retardant paints produced the following : (a) The molt suitable coating thickness of fire retardant paint was 1.5∼2.0 mm in water paint and 0.2 mm in oil paint. (b) Flaming method in experiments of smoke density were found to be higher than Non-flaming method. (c) Water paint has the fire retardant effect and characteristics better than oil paint in measurement results of smoke density and oxygen index. (d) The oxygen index of water and oil fire retardant was able to know that it was satisfied a standard (30 or above).