• Journal of Navigation and Port Research
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• v.32 no.6
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• pp.499-503
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• 2008

As the conference result of MEPC in IMO, development of ballast water management system corresponding to newly established ballast water management standard (D2 regulation) of shipping is being made an active progress over the whole world. The ballast water management system should treat particular material of more than $10{\mu}m$ in high capacity of more than 500t per hour in the event of filtration process. Also, it is very difficult to develop a practical management system since a limited element which a narrow space of the ship should be designed in the minimal volume is assumed. Therefore, the study promoted a study on the next generation auto back wash media filter to overcome such a limited element. Also, the study performed pressure and flux measurement test followed by thickness of each filter medium for filtration by each size to grasp a relation between absorption and pressure at the time of vacuum filtration and mechanical analysis and turbidity change observation of filtered water after vacuum filtration.

• Environmental Analysis Health and Toxicology
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• v.23 no.1
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• pp.53-62
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• 2008

In the present study, the concentration levels of polychlorinated biphenyls (or PCBs) in the environments in Korea are estimated based on some measured data in Korea, in comparison with the data from the other countries. Even though PCBs were banned as electrical fluids in 1970s in Korea, PCBs are still detected in the environment. PCBs levels in Korea are greatly lower than those in other countries, which are gradually decreased as well. However, the measured data are not sufficient in both numbers and quality, to estimate the average PCBs levels in Korea. The regulation limit on polychlorinated biphenyls (or PCBs) is 2mg/kg (ppm), which is too low compared to 50 ppm of many other countries including U.S. With this strict regulation, there are many problems expected, for example, in the analysis of PCBs in the transformers using in the field as well as the safe treatment of PCBs. The risk assessment on the PCBs in the environment is surely necessary prior to the change in the limit. Also the PCBs concentration monitoring in the environmental media (i.e. air, water, soil and sediment) and exposure assessment will be essential for the accurate risk assessment. If the PCB-waste guideline maintain as 2 ppm after 10 years, the excess cancer risk of PCBs exposure by ambient air, drinking water and soil was $10^{-8}$. But if the guideline mitigate as 50 ppm after 10 years, the cancer risk was increased by $10^{-7}$. The ecological risk quotient by regulation change was not exceed '1'.

• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.36-50
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• 2020

YouTube as a news channel is gaining popularity because it offers more interesting and in-depth news than traditional news media. However, YouTube has been criticized for its distribution of false information (or fake news) in Korea. Politicians are actively proposing a variety of bills to regulate YouTube's false information and a lot of studies proposed how to regulate YouTube's false information. This study looked at the users' experience and perception of false information and identified factors that affected the regulation of YouTube news. The results showed that the conservatives and the moderate groups were exposed to false information more than the progressives, and those in their 60s believed that false information was distributed on YouTube rather those in their 20s to 50s. The more people value freedom of expression, the more people trust TV Chosun news, the more people tend to oppose the regulation of information on YouTube. On the other hand, it turns out that the more people trust the news on both terrestrial broadcasting networks and JTBC, and the more people value the enlightening aspects on the news, the more they approve of Youtube regulation.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.2
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• pp.42-48
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• 2012

In the 21st century, the printing industry as well as the IT industry has made rapid development. However, despite these technological advancement in the printing industry, it is still harmful for the environment, the state regulation is insufficient. Therefore, we studied the printability for the existing heat-set web inks and the newly created phenol-free eco-inks. This ink was made by reacting rosin and unsaturated dibasic acid and ester reactant, ester reactant was used instead of phenol. Printability test were used in the IGT printability tester. Experimental conditions, the temperature $22.7^{\circ}C$, humidity 57% under conditions of 0.6cc of ink supply, the print speed 1m/sec, pressures were set at 250N. As results of this study, we were able to get the following conclusions. The properties of phenol-free ink is the same as the existing inks. So we are thought to improve some characteristics such as dispersion, able to replace the existing ink.

• Research in Community and Public Health Nursing
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• v.27 no.1
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• pp.9-20
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• 2016

Purpose: The purpose of this study was to survey the current status of mental health education and need for mental health education enhancing protective factors in the elementary schools. Methods: We surveyed 10 school health teachers and 328 fifth- and sixth-grade students using 19- and 20-item questionnaires, respectively. Results: All of the teachers and 65.2% of the students replied that they were either teaching or being taught mental health in school. Topics covered suicide, depression, school violence, and Internet addiction. All of the teachers and 84.1% of the students expressed the need for mental health education enhancing protective factors in school. Both groups replied that two sessions are enough. The teachers preferred role play and discussion as teaching methods, and audiovisual materials and computer as instructional media. The students preferred lecture and role play as teaching methods, and audiovisual materials and smartphone as instructional media. Both groups ranked self-esteem, parent-child relationship, peer relationship, and emotional regulation as the most important topics to be covered in the education. Conclusion: There is a high demand for mental health education enhancing protective factors. Therefore, it is recommended to develop educational programs enhancing protective factors by enabling formal and informal learning using smartphone.

• Journal of the Korean Dietetic Association
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• v.10 no.1
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• pp.58-64
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• 2004

This study was performed to investigate the kinds of health food advertised and sold through media like printed matter, TV broadcasting or internet. It was found that fifty three percent of the health food was circulated through internet, 27% through printed matter, 9% through TV Broadcasting. When the health foods was classified, the proportion of special purpose nutritious foods was 36.1%, health aid foods 33.9%, uncooked powdered foods 18.5%, functional foods for health 4.9%, Ginseng products 3.9%, and tea 0.9%. The special purpose nutritious foods was composed of 59% of nutrition supplementary foods, 24% of dietary fiber foods, 9% of weaning foods, 7% of milk formula and 2% of HCA. Vegetable extracts occupied 21.1% of health aid foods, yeast 7.5%, mushroom extracts 7.0%, chitosan 6.2%, aloe 5.3%. Dried powdered type health food occupied the highest proportion. The other type were capsule(18.8%), tablet(18.1%), and liquid type(16.4%). When the health food was classified with health claim, the proportion of "nutrition supplementation" was the highest (23.9%), "diet" 14.9%, "ergogenic"(18.8%), "promoting bowel movement" 7.8%, "growth" 5.7%, "regulation of blood sugar" 4.5%, "improving of immunity"(2.4%) and anti-aging effect(2.4%).

• Reproductive and Developmental Biology
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• v.30 no.3
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• pp.163-167
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• 2006

The purpose of the present study was to establish culture conditions for the in vitro study of the neonatal piglet Sertoli cell. Isolation for the culture of Sertoli cell was established using collagenase and pancreatin digestion of testicular tissues. The effects of various culture media, fetal bovine serum(FBS), follicular stimulating hormone(FSH), epidermal growth factor(EGF) and insulin-transferrin-sodium selenite(ITS) on growth of neonatal piglet Sertoli cells were investigated. The mitogenic effects of Dulbecco's modified Eagle's medium+Ham's F-12 medium was higher than other media used in this experiment. The addition of 1% FBS in cultures was necessary for attachment of Sertoli cell clusters. However, except FBS and EGF, FSH and ITS did not stimulate Sertoli cell proliferation. When Sertoli cells isolated from neonatal piglets were cultured in Dulbecco's modified Eagle's medium+Ham's F-12 medium supplemented with 1% FBS, FSH EGF and ITS, the yield and plating efficiency of Sertoli cells were largely increased. Confluency of Sertoli cells was reached as early as 4 days of culture. The method described here reduces or eliminates many of the drawbacks of the conventional procedures used to isolate and culture of Sertoli cells, thus providing a useful tool in studies of growth kinetics and regulation of cell proliferation in vitro.

• Membrane and Water Treatment
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• v.10 no.2
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• pp.105-112
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• 2019

On the purpose of conform the more stringent government regulation for turbid stormwater from construction sites, the feasibility and availability of synthetic fiber placing after the conventional protection barrier were tested in this study. Initially, comparative work on the filtering performance of fiber media and conventional gravel filter was carried out, 27% higher filtration capacity was obtained under the similar operational conditions. The filter efficiency was about 20 to 52% with a varying filter depth of 5 to 15cm, presuming at extreme storm flow conditions (800-1500 m/day of filtration rates). Fiber filter was found to have a similar filtration prosperity as grain media; namely, the separation efficiency is directly and inversely proportional to filter depth and rate, respectively. The effects of filter aid (polyaluminium chloride) on filter performance was also investigated, it greatly affected the turbidity reduction at the dosage of 2 mg/L. At the time of breakthrough, a simple filter washing was carried out, herein, the solid recovery achieved over than 88% and greatly determined by operational parameters. Based on the operational data, the empirical models aimed for predicting filtration efficiency were established, which can effectively determine the required filter depth and filtration area in field.

• Korean Journal of Plant Tissue Culture
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• v.22 no.1
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• pp.35-39
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• 1995

In order to investigate the effects of gelling agent on rice anther culture, anthers of rice (Japonica cv Daecheongbyeo) were cultured on N$_{6}$ media supplemented with 0.8, 1.2 or 1.6% Junsei agar and 05, 0.4, 0.6, 0.8 or 1.0% Gelrite (Phytagel, Sigma). On Junsei agar media, the frequency of callus induction was decreased in proportion to agar concentration. The frequency of callus induction was more increased as 67.6% and 54.8% in media containing 0.4 and 0.6% Gelrite than in agar media. The frequency of plant regeneration and spontaneous doubled-diploid was directly proportional to Junsei agar and Gelrite concentration. The number of green and spontaneous doubled diploid plant was highest on 0.6% Gelrite medium. In order to optimize the concentration of growth regulators for the callus induction medium containing 0.6% Gelrite, anthers were cultured on N$_{6}$ media supplemented with 2mg/L NAA, 2 mg/L 2,4-D, 1mg/L NAA and 1mg/L 2, 4-D, or 1mg/L NAA, 1mg/L 2,4-D and 0.5mg/L kinetin. The maximum frequency of callus induction and plant regeneration was obtained from the medium supplemented with 2 mg/L NAA and 0.6% Gelrite. In conclusion the induction of embryogenic callus, the frequency of plant regeneration and in vivo chromosome doubling was more effective in Gelrite media than in Junsei agar media.dia.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.165-179
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• 2021

This study investigated that what strategies tobacco companies have taken for marketing tobacco and tobacco companies on news media, by reviewing the previous research analyzing the tobacco companies' documents and the news coverage of tobacco. The tobacco document studies showed that tobacco companies have created close relationships with news media, a quid pro quo, by providing advertising and diverse forms of sponsorships and obtaining favored treatment on news coverage and have built networks with journalists by supporting journalist organizations. They have also supported thinktank groups and pro-smoking groups so as to represent and advocate their perspectives and assertions on news media and have utilized sponsorship of art and culture as pseuo-event for publicizing tobacco and tobacco companies on news media. Futhermore, news coverage of tobacco showed that news media tended to deal with tobacco issues lukewarmly, without a clear position and perspective and deliver naturally tobacco industry's perspective and message that smoking is controvertial rather than totally undesirable and unacceptable. Also, the news coverages have often reflected tobacco industry's publicity strategies identified in tobacco industry documents. This study suggests how tobacco industry access and utilize news media to obtain favorable news coverage, and thus it provides a rational of why tobacco industry's publicity activities have to be regulated.