• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7509-7515
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• 2013

To assess the risk of cancers associated with sleep duration using meta-analysis of published cohort studies, we performed a comprehensive search using PubMed, Embase and Web of Science through October 2013. We combined hazard ratios (HRs) from individual studies using meta-analysis approaches. A random effect dose-response analysis was used to evaluate the relationship between sleep duration and cancer risk. Subgroup analyses and sensitivity analyses were also performed. Publication bias was evaluated using Funnel plots and Begg's test. A total of 13 cohorts from 12 studies were included in this meta-analysis, which included 723, 337 participants with 15, 156 reported cancer outcomes during a follow-up period ranging from 7.5 to 22 years. The pooled adjusted HRs were 1.06 (95% CI: 0.92, 1.23; P for heterogeneity =0.003) for short sleep duration, 0.91 (95% CI: 0.78, 1.07; P for heterogeneity <0.0001) for long sleep duration. In subgroup analyses stratified by cancer type, long duration of sleep showed an inverse relation with hormone-related cancer (HR=0.79; 95% CI: 0.65, 0.97; P for heterogeneity =0.009) and a greater risk of colorectal cancer (HR=1.29; 95% CI: 1.09, 1.52; P for heterogeneity =0.346). Further meta-analysis on dose-response relationships showed that the relative risks of cancer were 1.00 (95% CI: 0.99, 1.01; P for linear trend=0.9151) for one hour of sleep increment per day, and 1.00 (95% CI: 0.98, 1.01; P for linear trend=0.7749) for one hour of sleep increment per night. No significant dose-response relationship between sleep duration and cancer was found on non-linearity testing (P=0.5053). Our meta-analysis suggests a positive association between long sleep duration and colorectal cancer, and an inverse association with incidence of hormone related cancers like those in the breast. Studies with larger sample size, longer follow-up times, more cancer types and detailed measure of sleep duration are warranted to confirm these results.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.1
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• pp.29-37
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• 1999

In this study, we have prepared PLT thin films having various La concentrations by using sol-gel method and studied on the effect of La concentration on the electrical properties of PLT thin films. As the La concentration increases from 5mol% to 28mol%, the dielectric constant at 10kHz increases from 428 to 761, while the loss tangent decreases from 0.063 to 0.024. Also, the leakage current density at 150kV/cm has a tendency to decrease from 6.96${\mu}A/cm^2$ to 0.79${\mu}A/cm^2$. In the result of hysteresis loops of PLT thin films, the remanent polariation and the coercive field decrease from 9.55${\mu}C/cm^2$ to 1.10${\mu}C/cm^2$ and from 46.4kV/cm to 13.7kV/cm, respectively. With the result of the fatigue test on the PLT thin films, we have found that the fatigue properties are improved remarkably as the La concentration increases from 5 mol% to 28mol%. In particular, the PLT28) has paraelectric phase and its charge storage clensity and leakage current density at 5V are 134fC/${\mu}cm^2$ and 1.01${\mu}A/cm^2$, respectively. The remanent polarization and coercive field of the PLT(10) film are 6.96${\mu}C/cm^2$ and 40.2kV/cm, respectively. After applying of $10^9$ square pulses with ${\pm}5V$, the remanent polarilzation of the PLT(10) film decreases about 20% from the initial state. In the results, we conclude that the 10mol% and the 28mol% La doped PLT thin films are very suitable for the capacitor dielectrics of new generation of DRAM and NVFRAM respecitively.

• The Journal of Korean Academic Society of Nursing Education
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• v.9 no.1
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• pp.17-29
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• 2003

This study investigated the degree of self-care practice to maintain the stable respiratory function and the required respiratory nursing needs upon the elderly with chronic obstructive pulmonary diseases. The research subjects were 115 elderly people over 60 years old, who were diagnosed to have chronic obstructive pulmonary diseases (the mixed type, chronic bronchitis, bronchial asthma, emphysema) and were hospitalized in 3 university hospitals in Busan or treated as outpatient, and the data was collected over the period between June 1, 2002 and September 30, 2002. In order to measure the respiratory self-care practice degree and nursing needs of the subjects, the instrument on the self-care practice and the instrument on nursing needs were developed by the researcher. The research results are as follows: 1. The mean of respiratory self-care practice degree by the subjects was 2.41 out of 4 for each clause, and the degree of practicing general management was the highest(2.70), and nutrition control(2.66), respiratory exercise(2.65), expectoration of sputum (2.63), oxygen therapy(2.60), environment control(2.50), and medication control(2.36) succeeded. 2. The degree of self-care practice had a significant difference depending on age(F=2.82, P=0.02), frequency of hospitalization(F=3.11, P=0.01), and diagnosed disease(F=15.66, P=0.00). 3. The subjects nursing needs of respiratory system were 3.07 on the average out of 4.00, and 'I want to know how to prevent the infection of respiratory system such as cold scored the highest 3.83, while the clauses like 'want to know how to face the respiratory disorder properly'(3.77) and 'want the specific explanation of the symptoms of my disease'(3.66) also had scored high points. 4. The nursing needs of the respiratory system had a significant difference depending on diagnosed disease such as mixed type of chronic obstructive pulmonary diseases, emphysema, bronchitis, and asthma (F=6.70, P=0.00). The research showed that the subjects degree of self-care practice of respiratory system was low on the whole, while the nursing needs for managing respiratory organ were relatively high. Therefore, specific education concerning the nursing of the disease and self-care upon the elderly having chronic obstructive pulmonary disease is necessary.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.3
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• pp.205-216
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• 2017

Carbonaceous aerosols such as the equivalent black carbon (eBC), the elemental carbon (EC) and the organic carbon (OC) were monitored at the Seoul Olympic Park site ($37.521^{\circ}N$, $127.124^{\circ}E$) during the KORUS-AQ 2016 campaign using a Multi Angle Absorption Photometer (MAAP) and an OCEC Analyzer. Averaged mass concentrations of eBC, EC and OC were presented as $2.46{\pm}1.52{\mu}g/m^3$, $1.01{\pm}0.60{\mu}g/m^3$ and $4.85{\pm}2.60{\mu}g/m^3$, respectively. OC/EC ratio and mass absorption cross-section (MAC) of light absorbing aerosols were calculated as 2.32 and $14.8m^2/g$, respectively. Diesel OC concentrations were estimated from a source profile of diesel vehicles as well. eBC mass concentrations measured from May $26^{th}$ to May $27^{th}$, 2016 showed 40% higher than averaged eBC mass concentrations during campaign period. $PM_{2.5}$ concentrations measured in this period were also higher than average $PM_{2.5}$ concentrations. High eBC concentrations were observed from May $29^{th}$ to May $31^{st}$, 2016 and from June $9^{th}$ to June $11^{th}$, 2016, possibly due to morning rush hour and the effect of temperature inversion at night. Diurnal variations of eBC, EC and Diesel OC showed a typical pattern of metropolitan area. In the weekend, however, diurnal variations of eBC, EC and Diesel OC mass concentrations were different from those measured in the weekday. It is expected that this study can help to understand the relationship between carbonaceous aerosols in a metropolitan area.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.16
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• pp.6619-6625
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• 2014

Background: Numerous studies have explored the influence of XPD Lys751Gln and/or Asp312Asn polymorphisms on skin cancer susceptibility. However, the results remain inconclusive. To derive a more precise estimation, we conducted a comprehensive search to identify all available published studies and performed a meta-analysis. Materials and Methods: Electronic literature searches of the PubMed, CBM and CNKI databases were performed up to March 2014. Odds ratios (ORs) with 95% confidence intervals (CIs) were applied to assess the strength of associations. Results: Seventeen case-control studies were included with a total sample size of 6, 113 cases and 11, 074 controls for the XPD Lys751Gln polymorphism, and 10 studies (3, 840cases and 7, 637 controls) for the XPD Asp312Asn polymorphism were pooled for analysis. Overall, no significant associations were found between the XPD Lys751Gln polymorphism and skin cancer risk in any genetic model. On stratified analysis by tumor type, XPD Lys751Gln polymorphism was not associated with increased risk of non-melanoma skin cancer, but was significantly related with increased risk of cutaneous melanoma (Gln/Gln vs Lys/Lys: OR=1.15, 95%CI=1.02-1.29, p=0.023; dominant model: OR=1.09, 95%CI=1.01-1.18, p=0.036). For the XPD Asp312Asn polymorphism, no significant association with skin cancer risk was observed in overall or subgroup analyses. Conclusions: The present meta-analysis suggests that the XPD Lys751Gln polymorphism may contribute to the risk of cutaneous melanoma from currently available evidence. Further investigations are needed to obtain more insight into possible roles of these two polymorphisms in skin carcinogenesis.

• Korea Journal of Hospital Management
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• v.1 no.1
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• pp.108-135
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• 1996

This paper investigates the current feature of management strategy of hospitals in Korea, and examines the relationships between adoption of a particular strategic orientation and the hospitals environmental and organizational characteristics, strategic behaviors and management improvement activities, and financial performance. Data were collected from CEOs of 88 hospitals among 650 hospitals for a 13.5% response rate using the self-administered questionnaire by mail survey. The major findings that obtained are as follows: 1. Only 37.2% of response hospitals carried out strategic planning, Most of these hospitals established the first strategic planning in 1991(81.3%) and renovated strategic planning by 4 or 5 years(56.3%), and modified strategic planning with flexibility(59.4%). Most strategic plans were documented, but informalized(68.8%). And only 29.0% of these hospitals had independent planning division. 2. Hospital services that CEOs assessed rank ordered for their impact on profitability are as follows: i)diagnostic ultrasound facility, computerized tomography scanner, obstetric inpatient unit, therapeutic X-ray, and physical therapy at present. ii)diagnostic ultrasound facility, physical therapy, computerized tomography scanner, emergency department, and health screening at future. And the services rank ordered that CEOs hoped to introduce are as follows: emergency department, physical therapy, health screening, volunteer services, and computerized tomography scanner. 3. Using a typology developed by Miles and Snow(l978), the strategic orientation of response hospitals are shifting significantly from defenders in the past to analyzers in the present, and to prospectors in the future(p<.01). 4. With regard to hospital environmental and organizational characteristics such as ownership, physician training, location, bed size, and hospital management training career and specialty of CEOs, the four strategic orientation archetypes varied not significantly. But, hospitals with a analyser orientation in the present and a reactor orientation in the future perceived competition significantly higher than the other three archetypes(p<.05). 5. The four archetypes rank ordered in terms of appling strategic behaviors and management improvement activities are as follows: prospector, analyzer, reactor, and defender. 6. The four archetypes differed significantly in terms of their financial performance using revenue per bed(p<.05). Reactors and prospectors in terms of total revenue per bed, prospectors in terms of outpatient revenue per bed, and reactors and prospectors in terms of inpatient revenue per bed had the best performance.

• Journal of Periodontal and Implant Science
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• v.50 no.2
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• pp.121-131
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• 2020

Purpose: Dental implant-associated medication-related osteonecrosis of the jaw has been frequently reported in patients administered bisphosphonates (BPs) to prevent osteoporosis. The aim of this study was to investigate the effect of intermittent administration of parathyroid hormone (PTH) on peri-implant bone in the maxillae of ovariectomized rats systemically administered BPs. Methods: Thirty 8-week-old female Sprague-Dawley rats were randomly divided into 3 groups. The OVX-ZP group included ovariectomized rats administered 60 ㎍/kg of zoledronate once a week for 6 weeks and 30 ㎍/kg PTH after implant installation. The OVX-Z group included ovariectomized rats administered 60 ㎍/kg of zoledronate once a week for 6 weeks and saline after implant installation, and the control group included rats that underwent a sham operation and were then administered saline. Rats were sacrificed 4 weeks after implant placement for histomorphometric and micro-computed tomography (CT) analyses. Results: The average bone area percentage was greater in the OVX-ZP group than in the OVX-Z group (53.4%±4.0% vs. 28.9%±9.5%, P=0.01). The bone-to-implant contact ratio was 50.8%±1.4% in the OVX-ZP group and 16.9%±2.4% in the OVX-Z group (P=0.012). The average bone volume ratio as shown on micro-CT was 31.3%±19.8% in the OVX-ZP group and 19.4%±9.3% in the OVX-Z group (P=0.045). The OVX-ZP and OVX-Z groups displayed similar trabecular thickness (0.06±0.004 mm vs. 0.06±0.002 mm) (P>0.05) and trabecular separation (0.21±0.02 mm vs. 0.29±0.13 mm) (P>0.05). However, the number of trabeculae in the OVX-ZP group was significantly higher than that in the OVX-Z group (4.3±1.33/㎣ vs. 2.2±0.19/㎣) (P=0.024). Conclusions: The present findings indicate that intermittently-administered PTH can promote peri-implant bone formation and suggest that PTH administration may aid in effective treatment for medication-related osteonecrosis of the jaw after dental implantation.

• Ocean and Polar Research
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• v.41 no.4
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• pp.311-318
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• 2019

We analyzed the preliminary survey data (2014-2016) of macrobenthic community biomass (n = 112) from the wind farm area located in the southern part of the west coast of Korea and compared this data with data from the entire west coast (n = 369; 2006-2008). Modal classes from frequency distributions were 6 times higher in the latter (5 vs. 32 g/㎡). The mean and median values of the latter were 1.3 and 1.7 times higher (mean, 20.7 vs. 27.8 g/㎡; median, 17.1 vs. 29.5 g/㎡), and the maximum value was 3.4 times higher. Mood's median test showed significant difference at p-value = 0.01. We estimated the biomass-to-depth relationships from each data set by using Akaike Information Criterion and regarded the non-overlap of the 95% confidence intervals as indicating significant difference. The biomass was different from a 10 m depth below, and 3 times higher in the west coast at around 20 m compared with the maximum depth of the wind farm area. A local event of catastrophic sedimentation ranging from 1 to 2 m was observed in the wind farm during winter surveys. This could be a probable source of the lower biomass, but information on biomass seasonality and a natural experimental approach seem to be needed for the conduct of further studies. This study is meaningful in that it provided the background to assess future changes by understanding the lower level of benthic productivity in the area. We expect this study will contribute to the preparation of measures that can remove or mitigate the source of the lower biomass and improve the productivity of fishery resources in the area.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.5
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• pp.563-574
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• 2007

There seems to be a consensus among most people that visibility impairment is the most obvious indicator of air pollution. While considerable evidence on the association between air pollution and health outcomes including death and disease have been established, based on industrial complex areas or huge urban cities, time-series, case-crossover and cohort studies, scarce literature exists on the direct evidence for the association between visibility and adverse health outcomes. Our study is assessed the effect of air pollution measured by visibility impairment on respiratory mortality over a period of six years. Relative risks in respiratory deaths were estimated by a Poisson regression model of daily deaths between $1999{\sim}2004$. Daily counts of respiratory deaths as dependent variable was modelled with daily 24-hr mean visibility measurements (kilometers) as independent variable by means of Poisson regression. This model is controlled for confounding factors such as day of weeks, weather variables, seasonal variables and $PM_{10}$. The results in this study is observed the statistically significant association between an inverse health effect and visibility during the study period for respiratory mortality (percentage change in the relative risk for all aged -0.57%, 95% Cl, $-1.01%{\sim}-0.12%$; for $0{\sim}15$ aged -7.12%, 95% Cl, $-13.29%{\sim}-0.51%$; for 65+ aged -0.43%, 95% Cl, $-0.93%{\sim}-0.06%$ per 1 km increased in visibility). The effect size was much reduced during warm season. Visibility impairment resulting from air pollution is strongly associated with respiratory mortality, especially for children may be spent at outdoor. Our result provides a quick and useful indicator for eliciting the contribution of air pollution to the excess risk of respiratory mortality in Seoul, Korea.

• International Journal of Highway Engineering
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• v.20 no.1
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• pp.147-156
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• 2018

PURPOSES : The purpose of this study is to analyze the characteristics of the weight values of evaluation items by traffic safety project type. METHODS : In general, a large-scale investment in projects such as the traffic safety project requires economic analyses to be performed in advance. However, there is an argument for considering special characteristics of the traffic safety project. Therefore, this study conducted characteristic analysis of the weight values of evaluation items. The analysis consisted of two steps. The first step was hypothesis verification using analysis of variance (ANOVA). In this process, the authors examined whether the weight of evaluation items is the same regardless of the traffic safety project type. Based on the first step's results, the authors proceeded to the second step. The objective of this step was to analyze how different the weight values are by traffic safety project type using an analytic hierarchy process. RESULTS : According to the ANOVA test results, the benefit to cost ratios have different weight values based on traffic safety project type at the 0.01 significance level. The policy evaluation items, such as the plans connection, resident opinion, and regional equity, also showed the same results except that the result for the related plans connection was statistically significant at the 0.05 level. Based on the first step's result, the AHP analysis in the second step showed that the traffic safety projects for vulnerable users and pedestrians have very low weight values in economic evaluation factors compared with other safety project types. The weight values for vulnerable users and pedestrians were 0.29 and 0.26, respectively, in economic evaluation items. On the other hand, the weight values for other safety project types were around 0.6. Among the policy evaluation items, resident opinion showed a higher weight value than other factors, such as connection and regional equity items. CONCLUSIONS : The social and economic impact of a traffic safety project varies by project type and project characteristics. Although the economic approach is overarching and a reasonable methodology is applied for large-scale projects, it should be noted that the safety issue, especially for transportation of vulnerable uses, requires a non-economical approach. Based on the analysis results, this study suggests that the priority of the projects should be determined by separating them into independent assessment groups depending on their characteristics.