• 보건의료산업학회지
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• 제11권4호
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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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• 제17권4호
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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.

• 한국도로학회논문집
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• 제19권5호
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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.

• 한국물환경학회지
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• 제22권1호
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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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• 제49권6호
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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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• 제24권9호
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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.

• 한국치위생학회지
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• 제12권5호
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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.

• 한국산림과학회지
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• 제81권2호
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• pp.139-145
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• 1992

본(本) 연구(硏究)는 강원대학교(江原大學校) 임과대학부속(林科大學附屬) 연습림(演習林)의 제(第)2임반(林班)을 대상으로 수치지형도(數値地形圖)를 이용, 임도개설목적(林道開設目的)에 따른 4개의 평가인자(評價因子), 즉 최단임도개설장(最短林道開設長), 평균집재거리(平均集材距離), 개발지수(開發指數) 및 집재불능지점수(集材不能地點數)의 비율(比率) 등을 설정하여 각각의 평가인자(評價因子)에 적합한 최적임도노선(最適林道路線)의 배치계획(配置計劃)에 대하여 검토하였다. 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 최단임도개설장(最短林道開設長)에 의한 노선배치(路線配置)는 총연장(總延長) 6035.6m, 임도밀도(林道密度) 12.73m/ha, 평균집재거리(平均集材距離) 279.9m, 개발지수(開發指數) 1.43, 집재불능지점수(集材不能地點數)의 비율(比率)15.7% 이다. 2. 평균집재거리(平均集材距離)에 의한 노선배치(路線配置)는 총연장(總延長) 7828.501, 임도밀도(林道密度) 16.52m/ha, 평균집재거리(平均集材距離) 198.4m, 개발지수(開發指數) 1.31, 집재불능지점수(集材不能地點數)의 비율(比率) 4.0%이다. 3. 개발지수(開發指數)에 의한 임도노선배치(林道路線配置)는 총연장(總延長) 7410.6m, 임도밀도(林道密度) 15.64m/ha, 평균집재거리(平均集材距離) 210.9m, 개발지수(開發指數) 1.26, 집재불능지점수(集材不能地點數)의 비율(比率) 5.0%이다. 4. 집재불능지점수(集材不能地點數)의 비율(比率)에 의한 임도노선배치(林道路線配置)는 총연장(總延長) 8307.1m, 임도밀도(林道密度) 17.53m/ha, 평균집재거리(平均集材距離) 184.9m, 개발지수(開發指數) 1.29, 집재불능지점수(集材不能地點數)의 비율(比率) 2.5%이다.

• 한국화재소방학회논문지
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• 제17권4호
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• pp.36-41
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• 2003

본 연구에서는 지하공동구 및 트레이에 설치된 케이블의 화재시 화염전파를 막기 위해 사용되고 있는 수성 및 유성계 난연도료의 도포 두께별 연소특성을 파악하기 위해 연기밀도(ASTM E 662)와 산소지수 (ASTM D 2863) 시험법을 이용하여 실험을 수행하였다. 본 연구 결과, 난연도료의 연소특성은 다음과 같다. (a) 난연도료의 최적 두께는 수성계의 경우 1.5∼2mm, 유성계의 경우 0.2mm 것으로 나타났다. (b) 연기밀도는 Non-flaming방식보다 Flaming방식에서 더 높게 나타났다. (c) 연기밀도와 산소지수를 측정한 결과 수성계 난연도료가 유성계 난연도료 보다 연소특성이 우수한 것으로 나타났다. (d)수성 및 유성계 난연도료의 산소지수가 규격(30이상)에 만족함을 알 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.195.1-195.1
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• 2016

Currently, as Plasma application is expanded to the industrial and medical industrial, low temperature plasma applications became important. Especially in medical and biology, many researchers have studied about generated radical species in atmospheric pressure low temperature plasma directly adapted to human body. Therefore, so measurement their plasma parameter is very important work and is widely studied all around world. One of the plasma parameters is electron density and it is closely relative to radical production through the plasma source. some kinds of method to measuring the electron density are Thomson scattering spectroscopy and Millimeter-wave transmission measurement. But most methods have very expensive cost and complex configuration to composed of experiment system. We selected Michelson interferometer system which is very cheap and simple to setting up, so we tried to measuring electron density by laser interferometer with laser beam chopping module for measurement of temporal phase difference in plasma jet. To measuring electron density at atmospheric pressure Ar plasma jet, we obtained the temporal phase shift signal of interferometer. Phase difference of interferometer can occur because of change by refractive index of electron density in plasma jet. The electron density was able to estimate with this phase difference values by using physical formula about refractive index change of external electromagnetic wave in plasma. Our guiding laser used Helium-Neon laser of the centered wavelength of 632 nm. We installed chopper module which can make a 4kHz pulse laser signal at the laser front side. In this experiment, we obtained more exact synchronized phase difference between with and without plasma jet than reported data at last year. Especially, we found the phase difference between time range of discharge current. Electron density is changed from Townsend discharge's electron bombardment, so we observed the phase difference phenomenon and calculated the temporal electron density by using phase shift. In our result, we suggest that the electron density have approximately range between 1014~ 1015 cm-3 in atmospheric pressure Ar plasma jet.