• Journal of the Korean Society of School Health
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• v.36 no.3
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• pp.82-91
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• 2023

Purpose: This study aims to identify gender-based differences in factors related to smartphone overdependence among middle school students. Methods: The subjects of the study were middle school students who participated in the 16th Korea Youth Risk Behavior Survey (2020). Frequency analysis, the Rao-Scott χ² test, and multiple logistic regression were performed using SPSS 27.0. Results: Identified risk factors were grade level, self-reported health, self-reported happiness, loneliness, smoking, drinking, poor sleep quality, physical activity, and generalized anxiety disorder, which were commonly found in all participants. Additionally, stress was found related only in boys, while the residential area and depression showed associations only in girls. In particular, the more severe was the level of generalized anxiety disorder, the higher was the risk ratio of the high-risk group, compared to the potential-risk group. Conclusion: Based on the findings of the study, a customized strategy that considers gender differences should be developed in order to prevent smartphone overdependence in middle school students.

• Journal of Korean Society of Transportation
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• v.24 no.5 s.91
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• pp.89-108
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• 2006

Korea has been entering the ageing society as the population of age over 65 shared over 7% since the year 2000. The ageing society needs to have transportation facility considering elderly people's travel behavior. This study aims to understand the elderly people's travel behavior using recent data in Korea. The activity schedule approach begins with travel outcomes are part of an activitv scheduling decision. For tho?e approach. used discrete choice models (especially. Nested Logit Model) to address the basic modeling problem capturing decision interaction among the many choice dimensions of the immense activity schedule choice set The day activity schedule is viewed as a sot of tours and at-home activity episodes tied togather with overarching day activity pattern using the Seoul Metropolitan Area Transportation Survey data, which was conducted in June, 2002. Decisions about a specific tour in the schedule are conditioned by the choice of day activity pattern. The day activity scheduling model estimated in this study consists of tours interrelated in a day activity pattern. The day activity pattern model represents the basic decision of activity participation and priorities and places each activity in a configuration of tours and at-home episodes. Each pattern alternative is defined by the primary activity of the day, whether the primary activity occurs at home or away, and the type of tour for the primary activity. In travel mode choice of the elderly and non-workers, especially, travel cost was found to be important in understanding interpersonal variations in mode choice behavior though, travel time was found to be less important factor in choosing travel mode. In addition, although, generally, the elderly was likely to choose transit mode, private mode was preferred for the elderly over 75 years old owing to weakened physical health for such things as going up and down of stairs. Therefore. as entering the ageing society, transit mode should be invested heavily in transportation facility Planning tor improving elderly transportation service. Although the model has not yet been validated in before-and-after prediction studies. this study gives strong evidence of its behavioral soundness, current practicality. and potential for improving reliability of transportation Projects superior to those of the best existing systems in Korea.

• Korean Journal of Materials Research
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• v.22 no.6
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• pp.316-320
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• 2012

$Co_3O_4$, $Al_2O_3$ and $Co_3O_4$/$Al_2O_3$ mesoporous powders were prepared by a sol-gel method with starting matierals of aluminum isopropoxide and cobalt (II) nitrate. A P123 template is employed as an active organic additive for improving the specific surface area of the mixed oxide by forming surfactant micelles. A transition metal cobalt oxide supported on alumina with and without P123 was tested to find the most active and selective conditions as a heterogeneous catalyst in the reaction of styrene epoxidation. A bBlock copolymer-P123 template was added to the staring materials to control physical and chemical properties. The properties of $Co_3O_4$/$Al_2O_3$ powder with and without P123 were characterized using an X-ray diffractometer (XRD), a Field-Emission Scanning Electron Microscope (FE-SEM), a Bruner-Emmertt-Teller (BET) surface analyzer, and $^{27}Al$ MAS NMR spectroscopy. Powders with and without P123 were compared in catalytic tests. The catalytic activity and selectivity were monitored by GC/MS, $^1H$, and $^{13}C$-NMR spectroscopy. The performance for the reaction of epoxidation of styrene was observed to be in the following order: [$Co_3O_4$/$Al_2O_3$ with P123-1173 K > $Co_3O_4$/$Al_2O_3$ with P123-973 K > $Co_3O_4$-973 K>$Co_3O_4$/$Al_2O_3$-973 K > $Co_3O_4$/$Al_2O_3$ with P123-1473 K > $Al_2O_3$-973 K]. The existence of ${\gamma}$-alumina and the nature of the surface morphology are related to catalytic activity.

• Korean Journal of Materials Research
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• v.21 no.3
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• pp.180-185
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• 2011

This study is aimed to increase the activity of cathodic catalysts for PEMFCs(Polymer Electrolyte Membrane Fuel Cells). we investigated the temperature effect of 20wt% Pt/C catalysts at five different temperatures. The catalysts were synthesized by using chemical reduction method. Before adding the formaldehyde as reducing agent, process was undergone for 2 hours at the room temperature (RT), $40^{\circ}C$, $60^{\circ}C$, $80^{\circ}C$ and $100^{\circ}C$, respectively. The performances of synthesize catalysts are compared. The electrochemical oxygen reduction reaction (ORR) was studied on 20wt% Pt/C catalysts by using a glassy carbon electrode through cyclic voltammetric curves (CV) in a 1M H2SO4 solution. The ORR specific activities of 20wt% Pt/C catalysts increased to give a relative ORR catalytic activity ordering of $80^{\circ}C$ > $100^{\circ}C$ > $60^{\circ}C$ > $40^{\circ}C$ > RT. Electrochemical active surface area (EAS) was calculated with cyclic voltammetry analysis. Prepared Pt/C (at $80^{\circ}C$, $100^{\circ}C$) catalysts has higher ESA than other catalysts. Physical characterization was made by using X-ray diffraction (XRD) and transmission electron microscope (TEM). The TEM images of the carbon supported platinum electrocatalysts ($80^{\circ}C$, $100^{\circ}C$) showed homogenous particle distribution with particle size of about 2~3.5 nm. We found that a higher reaction temperature resulted in more uniform particle distribution than lower reaction temperature and then the XRD results showed that the crystalline structure of the synthesized catalysts are seen FCC structure.

• 보존과학연구
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• s.26
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• pp.103-126
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• 2005

Coprostanol is a metabolic product of cholesterol, formed by microbial action in the mammalian gut. This chemical compound is the major sterol in human and has been routinely studied as a biomarker of sewage pollution in marine and lacustrinesediments. This has led to the search for coprostanol as a biomarker in archaeologicalsoils, in order to detect the presence of fecal material. In this study, five samples of archaeological soils excavated at Wanggung ri, Iksancity, were used to assess the possibility of using coprostanol as indicators of ancient human activity in archaeological areas. The sampled soils were analyzed MXRD,EDXRF for their physical and chemical properties. And coprostanol was analysed byGC/MSD, using SIM method to detect and quantify specific compound. The results showed the soils were composed of quartz and feldspars, inorganicelement such as $SiO_2$, $Al_2O_3$, $Fe_2O_3$ etc. Moreover, the result from the analysis wasindicated that the specific compound is coprostanol. The coprostanol was determined at $0.16~1.01\mug$/g in the range of concentrations. This finding indicate that clear promise exists for the exploitation of coprostanol as biomarker of ancient human activity inarchaeological survey. Therefore such studies can serve to increase the confidence we place on biomarker-based methodologies for assessing fecal pollution. The application of this methodology has proved a simple and effective way of searching for that pattern in successively more aged deposits either known or suspected to contain fecal material. And the more scientific analysis of the soils will be showed to utility of the area ancient dietary life style, ancient environment.

• Journal of Korean Medicine for Obesity Research
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• v.9 no.1
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• pp.1-14
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• 2009

Complex microbial communities play an important role in the human health and co-evolved with human in the form of symbiosis. Many literatures provide new evidences that the increased prevalence of obesity cannot be attributed solely to changes in the human genome, nutritional habits, or reduction of physical activity in our daily lives. The intestinal flora was recently proposed as an environmental factor responsible for the control of body weight and energy metabolism. A number of studies suggest that the modulation of gut microbiota affects host metabolism and has an impact on energy storage and demonstrated a role for the gut microbiota in weight gain, fat increase, and insulin resistance. Variations in microbiota composition are found in obese humans and mice and the microbiota from an obese mouse confers an obese phenotype when transferred to an axenic mouse. As well, the gut microbial flora plays a role in converting nutrients into calories. Specific strategies for modifying gut microbiota may be a useful means to treat or prevent obesity. Dietary modulations of gut microbiota with a view to increasing bifidobacteria have demonstrated to reduce endotoxemia and improve metabolic diseases such as obesity. The fermentation of medicinal herbs is intended to exert a favorable influence on digestability, bioavailability and pharmacological activity of herbal extract. Therefore we also expect that the fermented herbal extracts may open up a new area to treat obesity through modulating gut microbiota.

• Journal of Fisheries and Marine Sciences Education
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• v.20 no.2
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• pp.222-235
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• 2008

The study analyzed 343 government-authorized and officially approved textbooks of the Seventh Curriculum's specialized subjects in high school from March to September, 2007. The textbooks were categorized into the area of agriculture, industry, commerce, household and business, science, foreign languages and physical exercise and analyzed in terms of the target and content areas of marine education. And the findings were as follows: First, among the textbooks in the seven groups serving as the focus of this study, 19.8% have oceanic-related information but pages including ocean contents occupy only 0.8%. Consequently ocean-related contents are scarcely included. The ocean-related contents are necessary to be treated goals. Second, the goals of school oceanic education are focused in vocational subjects. In order of commonality, information & knowledge are most frequent, then functionality, followed by activity & participation. There was no education provided focusing on value & attitude. Given that school oceanic educations were selected for promoting the importance of the ocean and highlighting the problems of the ocean, the lack of information & knowledge is of concern. The goals of oceanic education should be augmented to actively and positively participate in the solutions of the problems with knowledge, ocean-friendly value & attitude, and increased activity & participation. Third, the contents of school oceanic education commonly focuses on the relationships of oceans and humans, oceans and ecology, and artificial oceanic environments and facilities. Less common but still introduced are ocean resources, sea pollution, sea preservation and measures. Yet, in contrast there is a lack of education in the ethics of sea preservation.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.6
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• pp.679-687
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• 2007

Nanoscale zero valent ion (nZVI) technology is emerging as an innovative method to treat contaminated groundwater. The activity of nZVI is very high due to their high specific surface area, and supporting this material can help to preserve its chemical nature by inhibiting oxidation. In this study, nZVI particles were attached to granular ion-exchange resin through borohydride reduction of ferrous ions, and chemical reduction of nitrate by this material was investigated as a potential technology to remove nitrate from groundwater. The pore structure and physical characteristics were measured and the change by the adsorption of nZVI was discussed. Batch tests were conducted to characterize the activity of the supported nZVI and the results indicated that the degradation of nitrate appeared to be a pseudo first-order reaction with the observed reaction rate constant of $0.425h^{-1}$ without pH control. The reduction process continued but at a much lower rate with a rate constant of $0.044h^{-1}$, which is likely limited by mass transfer. To assess the effects of other ions commonly found in groundwater, the same experiments were conducted in simulated groundwater with the same level of nitrate. In simulated groundwater, the rate constant was $0.078h^{-1}$ and it also reduced to $0.0021h^{-1}$ in later phase. The major limitation in application of ZVI for nitrate reduction is ammonium production. By using a support material with ion exchange capacity, the problem of ammonium release can be solved. The ammonium was not detected in the batch test, even when other competitive ions such as calcium and potassium existed.

• Journal of Preventive Medicine and Public Health
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• v.55 no.2
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• pp.153-163
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• 2022

Objectives: This study divided the factors that affect participation in health screenings into individual, household, and regional levels and conducted a multi-level analysis to identify the factors related to participation in health screenings. Methods: Participants from the 2017 Community Health Survey were classified into 2 groups (under 40 and 40 or older). A multi-level logistic regression analysis was conducted to identify the factors that affected participation in health screenings. Results: The screening rate of the participants was 69.7%, and it was higher among participants aged 40 and older (80.3%) than it was among participants younger than 40 (49.8%). At the individual level, the factors that influenced participation in health screenings included age, economic activity, smoking status, physician-diagnosed hypertension, and a moderate or high physical activity level. At the household level, the odds ratio of participation in health screenings was high for participants who lived in single-person households, lived with a spouse, earned a high monthly household income, and were not beneficiaries of national basic livelihood security. At the regional level, the odds ratio at the 95% confidence interval level of participation in health screenings was high for participants who had trust in the local community and lived in an area with a proportionally high social welfare budget. Conclusions: This study analyzed nationalwide data and confirmed that individual, household, and regional characteristics affected participation in health screenings. Therefore, policies that prioritize the improvement of regional level factors and especially household level factors are likely to be the most effective for improving the screening rate.

• The Journal of Korean Medicine
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• v.32 no.6
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• pp.30-40
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• 2011

Objectives: The purpose of this study was to determine whether gocho (苦椒) extract mesotherapy can effectively reduce weight and abdominal fat in obese patients. Methods: Forty obese participants were recruited and randomly assigned to two groups. Five participants dropped out voluntarily during the course of the study and four men were excluded from the analysis to avoid gender bias. Results are presented on a total of thirty-one women. Over an eight-week period, the treatment group (n=13) received gocho (苦椒) extract injections (100mcg/3cc) in the abdominal skin, twice per week; the control group (n=18) received normal saline injections (3cc). A mixed lidocaine and prilocaine cream (2.5%/2.5% EMLA cream) was applied before the injection. At baseline and 8 weeks, body weight, body-mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), abdominal fat, energy expenditure, and questionnaires (eating attitudes and physical activity) were evaluated in both groups. Results: Reductions in body weight (p<0.005), BMI, and WC (p<0.05) were greater in the treatment group. WHR, total fat area, and visceral fat area decreased only in the treatment group (p<0.05). Resting metabolic rate (RMR) change was correlated with weight loss only in the control group (r=-0.498, p<0.05). Before and after the treatment, there were no significant differences between the two groups in questionnaire variables (p>0.05). Conclusion: his study suggests that abdominal gocho (苦椒) extract mesotherapy might be an effective way to promote weight and abdominal fat loss in obese Korean women.