• Journal of dental hygiene science
• /
• v.18 no.4
• /
• pp.210-217
• /
• 2018

Periodontal disease is a chronic inflammatory disease that affects quality of life and nutrition. Several studies have demonstrated a link between periodontal disease and low bone density, and vitamin D is expected to have a beneficial effect on periodontal disease as well as on bone mineral density and anti-inflammatory effects. The purpose of this study was to identify the association between periodontal disease and vitamin D because the results are different in some studies and there is a lack of research in Korea. In this study, we conducted a multiple linear regression analysis of 8,783 subjects among 23,626 subjects who were older than 20 years of age, who had serum vitamin D levels and periodontal disease, who had three years of the National Health and Nutrition Survey that was conducted in Korea from 2012 to 2014. We examined the relationship between serum vitamin D levels and periodontal disease. Tooth loss and vitamin D levels were negatively correlated (${\beta}=-0.028$, p=0.008). In addition, the prevalence of periodontal disease was found to be higher in men younger than 50 years of age with lower vitamin D levels (Q1: 1.769 [1.125~2.782], Q2: 1.182 [0.743~1.881], Q3: 0.676 [0.400~1.881]; p=0.001). Low vitamin D levels and periodontal disease are common diseases in primary care. Vitamin D supplementation is expected to have favorable effect on periodontal disease and falls, osteoporosis, osteoarthritis, and cancer. Therefore, patients with periodontal disease may benefit from periodic vitamin D management to improve quality of life as well as to manage periodontal disease. In addition, as shown in this study, not only elderly individuals, but also men younger than 50 years of age are related to periodontal disease, so there should be interest in controlling the levels of vitamin D in adults.

• Korean Journal of Soil Science and Fertilizer
• /
• v.21 no.2
• /
• pp.183-193
• /
• 1988

The relationship between the sulfur fertilization, and the quality and yield of garlic was investigated. The garlic was grown in pot and field at the five fertilization levels of sulfur. The growth characteristics, yield and flavour components of the garlic were studied. The results were summarized as follows; 1. The sulfur applications contributed to a weight and yield of the bulb in SP-10 (10kg/10a) and SF-20 (20kg/10a) significantly, respectively. 2. From the volatile oil obtained by steam distillation of garlic, fourteen organie sulfur components were separated, identified and quantified by GC and GC/MASS and the SP-10 and SF-20 were higher in the concentration of the flavour components in the volatile oil than other treatments. 3. It is considered that the organic sulfur components were synthesized in the top and transported to the bulb of the garlic. 4. In conclusion, SF-20, 20kg/sulfur per 10a, could be recommended to get maximum yield and a good quality of garlic in view of evaluation through the contents of organic sulfur components in the volatile oil and the yield of the bulb.

• Journal of Distribution Research
• /
• v.13 no.1
• /
• pp.1-33
• /
• 2008

As the interest in the business-to-business(B2B) electronic commerce is increasing, many companies are participating in the B2B e-Marketplaces. The e-Marketplace is defined as the virtual market that many players take part in to transact. The e-Marketplace has an influenced on the manner in which organizational buyers and sellers interact. As a result, it is important to develop an understanding of the behaviors of firms that use these electronic marketplaces. The purpose of this study is to develop a comprehensive model for trust and commitment of B2B e-Marketplace and empirically to examine their structural relationships. Drawing from trust and commitment theory in the interorganizational relationship and B2B electronic commerce context, this study identifies network externality, interactivity, justice, quality of information sharing, institutional assurance as the determinants of trust and commitment of e-Marketplace. The proposed model hypothesized that (1) trust is a function of network externality, interactivity, justice, quality of information sharing, institutional assurance, (2) attitudinal and behavioral commitment is a function of trust, (3) behavioral commitment is a function of attitudinal commitment. The proposed model is tested using organizational-level survey data from 187 buying organizations that conduct business in MRO e-Marketplaces. The data were tested by reliability test, correlation analysis, exploratory factor analysis, confirmatory factor analysis and covariance structure analysis. The results indicate that (1) trust is influenced by network externality, interactivity, justice, institutional assurance, (2) attitudinal commitment and behavioral commitment is influenced by trust (3) behavioral commitment is influenced by attitudinal commitment. Also, the empirical results confirmed that trust play a strong, central role in determinging e-Marketplace commitment. The key theoretical contribution of this research is that it begins to extend interorganizational information system literature in areas such as B2B Internet e-Marketplace. Managerially, this study contributes tn the understanding of the role of B2B e-Markeplace providers in Internet situation. And Limitations of this study and guidelines for future researches are also discussed.

• Progress in Medical Physics
• /
• v.9 no.4
• /
• pp.195-200
• /
• 1998

Purpose: When an elongated x-ray field is used for treating a patient, the equivalent- field method is commonly used for the output calculation. This study is intended for investigating potential factors such as, beam quality, field elongation ratio, and depth of measurement, which might effect on the applicability of the equivalent square technique for output calculation. The derivation of a 'rule of thumb' for the application criteria of the equivalent-field method is also aimed. Materials and Methods: Three x-ray beams, 4-, 6- and 10-MV, were employed for this study. Width of the rectangular field was ranged from 5-40 cm and the elongation ratio (length/width) 1:0 to 10:0. An elongation effect was measured in a water phantom at three different depths, dmax, 5-cm, and 10-cm. For an elongated field and its equivalent square field, the output factor was measured and the difference in the output factor were examined between two fields. Results and Discussions: As the elongation ratio increases, a larger discrepancy in outputs is observed between the elongated rectangular field and its corresponding equivalent square field. Output was measured larger for an elongated field than for its corresponding equivalent square field and the maximal difference over 10 % was found. The difference was found larger for the smaller field with the same elongation ratio. The effect of the beam quality and the depth of measurement on the output difference was minimal. Conclusion: Based on the study, there is criteria for the application of the method for output calculation. For the combination of long axis and elongation ratio whose relationship satisfies Elongation ratio < (0.48) (Long axis) - 0.5, the equivalent-field method is valid for output calculation within 2 % for the field whose long axis < 25-cm. For other combinations, instead of using the equivalent-field method, direct output measurement is recommended. This criteria can be applied for 4-10 MV x-ray beams up to 10-cm depth.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.12 no.1
• /
• pp.35-46
• /
• 2009

In order to investigate spatial and temporal distributional characteristics of major water qualities in the Saemangeum area during the Saemangeum dike construction, salinity, COD, dissolved nutrients(DIN, Silicate) and heavy metals were analyzed from the surface water collected in April, May, August and November 2002. The overall value of Salinity, COD, DIN, and silicate in surface waters were in the range of $13.08{\sim}31.96\;psu$, $0.12{\sim}3.43\;mg/L$, $0.001{\sim}2.638\;mg/L$, and $0.010{\sim}3.181\;mg/L$, respectively. The COD and DIN in each survey showed the highest concentration at the mouth of Mangyeong river estuary(St. 1) where freshwater flow into the Saemangeum area. The concentrations of nutrients were high in the inner part of the Saemangeum dike with low-salinity, and low nutrients in the outer part of the dike with high-salinity, which strongly indicated that concentrations were adjusted by physical mixing. The ranges of dissolved metals and acid-soluble Hg in surface seawater were $0.006{\sim}0.115{\mu}g/L$ for Co, $0.26{\sim}0.114{\mu}g/L$ for Ni, $0.14{\sim}0.93{\mu}g/L$ for Cu, $0.04{\sim}0.53{\mu}g/L$ for Zn, $0.010{\sim}0.043{\mu}g/L$ for Cd, $0.010{\sim}0.795{\mu}g/L$ for Pb, and $0.25{\sim}4.16{\mu}g/L$ for Hg. The highest concentrations of some metals except for Cd were found at the estuary(Sts. 1 or 3). In most cases, a decreasing order of metal concentrations towards open sea(low-salinity$\rightarrow$high-salinity) was observed and showed positive relationship with DIN and silicate caused by land base pollutants input. On the other hand, due to Cd desorption from suspended solids in saline water, dissolved Cd concentrations were high in high-salinity area and low in low-salinity. In November, Co, Zn, Cu and Pb were relatively high in the northern area of the outer-side of Saemangeum, which was only influenced by the Geum river discharge. The concentrations of most dissolved metals of this study were lower than those of the past data in this area, but higher than those in Lena river estuary under the pristine environment.

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.4
• /
• pp.404-411
• /
• 2007

Adsorption performance of odorous compounds such as geosmin and 2-MIB on granular activated carbon were evaluated in this study. The coal-based activated carbon was found more effective than other carbons in adsorption of geosmin and 2-MIB. The wood-based virgin activated carbon was less effective than coconut- and coal-based carbon in adsorption nevertheless having larger pore volume and specific surface area than others carbons. The maximum adsorption capacity(X/M) of coal-based activated carbon for geosmin and 2-MIB was $1.2\sim1.9$ and $2.1\sim2.6$ times larger than coconut- and wood-based virgin activated carbon, respectively. Carbon usage rate (CUR) of coal-, coconut- and wood-based virgin activated carbons for geosmin and 2-MIB were 1.72 and 1.44 g/day, 1.72 and 2.05 g/day and 2.12 and 1.90 g/day, respectively. In the evaluation of adsorption isotherm of geosmin and 2-MIB for coal-, coconut- and wood-based virgin activated carbons, k value of 2-MIB was lower than geosmin, It menas 2-MIB is more difficult to remove by activated carbon adsorption than geosmin. The relationship of max. adsorption versus total pore volume of coconut- and wood-based virgin and used activated carbon for geosmin and 2-MIB were $y=264,459\times-79,047(R^2=0.95)$, $y=319,650\times-101,762(R^2=0.93)$.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.6
• /
• pp.4335-4347
• /
• 2015

The objective of this study was to investigate $PM_{10}$ and $CO_2$ concentrations in the classrooms of 286 elementary schools in Suwon, Ansan, and Hwaseong in the province of Gyeonggi between August 2008 and December 2012. By gaining an understanding of the environmental factors that influence these concentrations, this study also aimed to establish a management plan for indoor air quality in schools, which substantially affects the health of elementary students. When the schools were classified by region, no statistically significant difference in $PM_{10}$ concentration was observed. However, $PM_{10}$ concentration was relatively high in industrial areas and low in rural areas. No difference in $CO_2$ concentration was observed among the surveyed cities. Analysis of annual $PM_{10}$ concentration showed that the highest values for Suwon and Hwaseong occurred in 2008 and 2009, respectively (p<0.01). In the case of Ansan, the highest concentration occurred during 2009, but the difference was not significant compared to the other years. Analysis of the annual $CO_2$ concentration of each city shows no significant difference among the cities (p-value=0.366,0.730,0.210). According to a time series analysis of $PM_{10}$ and $CO_2$ by season, from autumn 2008 to winter 2012, $PM_{10}$ concentration was high during 2009, then it gradually decreased until 2012, and started to increase again. While no difference in annual $CO_2$ concentration was observed, the concentration had a tendency to be higher in spring and winter than in summer. By analyzing the relationship between $PM_{10}$ and $CO_2$ and the environmental factors (years of construction, average students of classroom, temperature, and humidity), it showed a significant negative correlation was found between $CO_2$ and the environmental temperature and humidity, at -0.329 and -0.188, respectively (p<0.01).

• ANNALS OF ANIMAL RESOURCE SCIENCES
• /
• v.29 no.4
• /
• pp.150-157
• /
• 2018

The Zygote arrest 1 (ZAR1) gene is known to affect early embryonic development in various vertebrates. In this study, we performed the association analysis to check whether there is any significant relationship between semen kinematic characteristics and the ZAR1 gene. To determine semen kinematic characteristics, we measured motility (MOT), straight-line velocity (VSL), curvilinear velocity (VCL), average path velocity (VAP), linearity (LIN), straightness (STR), amplitude of lateral head displacement (ALH), and beat cross frequency (BCF) of spermatozoa in boars. In order to detect single nucleotide polymorphisms (SNPs), we extracted genomic DNA from multiple Duroc boars, and then subsequently used them in sequencing reactions. As a result, three SNPs were detected in the intronic region of ZAR1 gene (g.2435T>C in intron 2, g.2605G>A and g.4633A>C in intron 3 ). SNPs g.2435T>C and g.2605G>A were significantly associated with MOT (p<0.01) and VSL (p<0.05), and g.4633A

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.64 no.2
• /
• pp.127-136
• /
• 2019

Sweet sorghum (Sorghum bicolor L. Moench), compared to traditional crops, has been evaluated as a useful crop with high adaptability to the environment and various uses, but cultivation has not expanded owing to a lack of related research and information in Korea. This study was conducted to estimate heading date in 'Chorong' sweet sorghum based on climate data of the last 30 years (1989 - 2018) from six regions (Jeonju, Buan, Jeongup, Imsil, Namwon, and Jangsu) in Jellabuk Province. In addition, we compared the growth and quality factors by sowing date (April 10, April 25, May 10, May 25, June 10, June 25, and July 10) in 2018. Days from sowing to heading (DSH) increased to 107, 96, 83, 70, 59, 64, and 65 days in order of the sowing dates, respectively, and the average was 77.7 days. The effective accumulated temperature for heading date was $1,120.3^{\circ}C$. The mean annual temperature was the highest in Jeonju, followed in descending order by Jeongup, Buan, Namwon, Imsil, and Jangsu. The DSH based on effective accumulated temperature gradually decreased in all sowing date treatments in the six regions during the last 30 years. DSH of the six regions showed a negative relationship with mean temperature (sowing date to heading date) and predicted DSH ($R^2=0.9987**$) calculated by mean temperature was explained with a probability of 89% of observed DSH in 2017 and 2018. At harvest, fresh stem weight and soluble solids content were higher in the April and July sowings, but sugar content was higher in the May 10 ($3.4Mg{\cdot}ha^{-1}$) and May 25 ($3.1Mg{\cdot}ha^{-1}$) sowings. Overall, the April and July sowings were of low quality and yield, and there is a risk of frost damage; thus, we found May sowings to be the most effective. Additionally, sowing dates must be considered in terms of proper harvest stage, harvesting target (juice or grain), cultivation altitude, and microclimate.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.5
• /
• pp.2293-2303
• /
• 2013

Objective: This study aims to determine whether national patient safety indicators (PSIs) can be calculated. Methods: Using PSI criteria from Organization for Economic Co-Operation and Development (OECD) Health Technical Papers 19 based on the Agency for Healthcare Research and Quality (AHRQ), PSIs were identified in the Korean National Hospital Discharge In-depth Injury Survey (KNHDIIS) database for 875,622 inpatient admissions between 2004 and 2008. Logistic regression was used to estimate factors of variations for PSIs. Results: From 2004 to 2008, 3,084 PSI events of 8 PSIs occurred for over 80 thousands discharges. Rates per 1,000 events for decubitus ulcer (PSI3, 4.88), foreign body left during procedure (PSI5, 0.05), postoperative sepsis (PSI13, 1.32), birth trauma-injury to neonate (PSI17, 7.92) and obstetric trauma-vaginal delivery (PSI18, 32.81) are all identified between ranges from maximum to minimum of OECD rates, respectively. However, rates per 1,000 events for selected infections due to medical care (PSI7, 0.22), postoperative pulmonary embolism or deep vein thrombosis (PSI12, 0.90) and accidental puncture or laceration (PSI15, 0.71) are below the minimum of OECD range. 7 PSIs except PSI 18 showed statistically significant relationship with number of secondary diagnoses. When adjusting patient characteristics, there are statistically significant different rates according to bed size or location of hospitals. Conclusion: This is the first empirical study to identify nationally number of adverse events and PSIs using administrative database. While many factors influencing these results such as quality of data, clinical data and so on are remain, the results indicate opportunities for estimate national statistics for patient safety. Furthermore outcome research such as mortality related to adverse events is needed based on results of this study.