• Journal of Wetlands Research
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• v.9 no.1
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• pp.79-89
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• 2007

This paper provides a comprehensive overview of the present status of several environmental problems caused by emerging toxic substances such as persistent organic pollutants (POPs), endocrine disrupting chemicals (EDCs), and arsenic in various environmental media in Vietnam. Monitoring data reported during the 1990s demonstrated elevated contamination of DDTs in most of these compartments in Vietnam. Studies in frame of the Asia-Pacific Mussel Watch Program revealed that fish, mussels and resident birds from Vietnam contained higher concentrations of DDTs as compared to other countries in region, suggesting the role of Vietnamese environment as a significant emission source of DDT in the Southeast Asian region. The estimated dietary intakes of PCBs and DDTs for Vietnamese were relatively high among Asian developing countries, suggesting potential risk for humans posed by thesechemicals. Widespread contamination of some endocrine active compounds such as alkylphenols and phthalates was observed at various sites along the coasts of northern and middle Vietnam. The presence of significant source of bisphenol-A along Red River estuary was revealed with the concentrations comparable to those reported for developed nations. A case study on seasonal variation of alkylphenols and phthalates in surface water of river delta and estuary of north and middle Vietnam indicated the differences in distribution of these compounds between dry and rainy seasons. Higher concentrations of alkylphenols and phthalates were found in dry season in estuary; while the contrasting pattern was observed in the river delta, showing elevated residues in rainy season. This result suggests the different behavior of alkylphenols and phthalates in river delta and coastal environment. From ecotoxicological perspectives, concentrations of bis-phenol A and di(2-ethylhexyl)phthalates [DEHP] in surface water from some locations in Vietnam exceeded the guideline values for Ecotoxicological Effects and the Environmental Risk Limit, respectively, suggesting potential for toxic implications on aquatic wildlife. Widespread and elevated arsenic contamination was discovered inour recent surveys in groundwater in a large area of suburban areas of Hanoi city, the capital of Vietnam. The most recent investigation in 4 villages showed about more than 50 % of groundwater samples contained As concentrations exceeding 50 g/L (the WHO and Vietnamese standard). In particular, in Son Dong villages, 58 % of samples analyzed contained As concentrations higher than 200 g/L. Good correlations were found in As concentrations in water and hair and urine of peoples in corresponding families, suggesting the chronic exposure to As by people living in As-contaminated ground water areas. In Son Dong village, As levels in hair (mean: 1.7 mg/kg dry wt) and urine (g/g creatinine) exceeding the reference values recommended by WHO, suggesting potential for human risk posed by long term accumulation of As in human body. Future studies should be focused on the time trends of POPs and EDCs in biota in Vietnam in order to predict future trend of contamination and to reveal new clues for understanding possible toxic impacts on aquatic organisms. The issues of arsenic contamination in groundwater and their chronic toxic implications on human health should be systematically investigated in the future.

• Journal of the Korea Society of Computer and Information
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• v.19 no.4
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• pp.101-109
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• 2014

This paper aims to design and implement a collaborative learning system based on the augmented reality. The existing augment reality-based learning systems have just focused on interactivity between a system and learners without consideration of cooperability, thereby leading to an ineffective approach to encouraging an learning system to be more supportive and conducive of and to cooperation among learners. The collaborative learning system is a learning method, with which learners achieve a common objective through critical thinking and cooperative teamwork so as to seek solutions to such fulfillment. This requires positive interdependence, proactive interactions, a sense of responsibility shared by individuals as well as the group, and development of teamwork among learners. Educators and systems assume a critical role in helping the collaborative education be effective. An educator is responsible for defining a project at the outset of learning activities, organizing groups for learners, and providing evaluation criteria applied to a group's project activities. Meanwhile, a system shall support interactions to take place while facilitating learning activities. Furthermore, an educator shall provide a system for managing and evaluating activities involving interactions among learners. This paper suggests and embodies a collaborative learning system based on the augmented reality with consideration of the aforementioned collaborative education.

• Korean journal of applied entomology
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• v.56 no.1
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• pp.19-28
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• 2017

Polydnaviruses (PDVs) are a group of double-stranded DNA viruses symbiotic to some endoparasitoid wasps. Cotesia plutellae bracovirus (CpBV) is a PDV symbiotic to an endoparasitoid wasp, C. plutellae, parasitizing young larvae of Plutella xylostella. An early expressed gene, CpBV-ELP1, plays an important role in the parasitism by suppressing host cellular immunity by its cytotoxic activity against hemocytes. This study aimed to test its oral toxicity against insect pest by expressing it in a recombinant tobacco plant. A recombinant CpBV-ELP1 protein was produced using a baculovirus expression system and secreted to cell culture medium. The cell cultured media were used to purify CpBV-ELP1 by a sequential array of purification steps: ammonium sulfate fractionation, size exclusion chromatography, and ion exchange chromatography. Purified rCpBV-ELP1 exhibited a significant cytotoxicity against Spodoptera exigua hemocytes. CpBV-ELP1 was highly toxic to the fifth instar larvae of S. exigua by injection to hemocoel. It also showed a significant oral toxicity to fifth instar larvae of S. exigua by a leaf-dipping assay. CpBV-ELP1 was cloned into pBI121 vector under CaMV 35S promoter with opaline synthase terminator. Resulting recombinant vector (pBI121-ELP1) was used to transform Agrobacterium tumefaciens LBA4404. The recombinant bacteria were then used to induce callus of a tobacco (Nicotiana tabacum Xanthi) leaves and subsequent generation (T1) plants were selected. T1 generation tobacco plants expressing CpBV-ELP1 gave significant insecticidal activities against S. exigua larvae. These results suggest that CpBV-ELP1 gene can be used to control insect pests by constructing transgenic crops.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.143-150
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• 2018

With the rapid development of RF based high speed wireless communication technology, devices that can be applied to IoT networks based on RF bandwidth are rapidly spreading, nevertheless, the development speed of the RF communication is not possible to keep up with the spread of the RF band for wireless communication. In this situation, OWC technology that uses visible light source as a transmitter is attracting attention as a technology that can overcome the band exhaustion problem of RF based wireless communication technology. Although, due to the distortion of the LED illumination shape by camera exposure time and LED blinking period, the LED illumination detection rate is degraded and the RoI setting is inaccurate. In this paper, we propose an adaptive median filter applied LED illumination detection algorithm for low rate CamCom, it is possible to detect a clear RoI and LED illumination. This research will be able to play a role as a complementary material of RF based wireless communication technology efficiently.

• Management & Information Systems Review
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• v.29 no.1
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• pp.117-144
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• 2010

This paper planned to review positively the influence of leading variables - Functional benefits, Emotional benefits, Self-expressive benefits over Consumer-brand relationship, and the structural relationship between Consumer-brand relationship and Brand attachment, Word-of-mouse. For it, we verified our hypothesis utilizing Hierarchial chi-square analysis that was available to statistically verify the size between 2 paths out of Structural models As the result of research, Emotional benefits was more influential than Functional benefits in the formation of Consumer-brand relationship. Additionally, the influential difference between Emotional benefits and Self-expressive benefits was not found in the formation of Consumer-brand relationship. In other words, both Emotional benefits and Functional benefits were proved to have a positive influence on forming Consumer-brand relationship. On the other hand, Self expressive benefits played a more influential role than Functional benefit in the formation of Consumer-brand relationship. The fact was also proved that the higher the formation level of Consumer -brand relationship was, the greater positive influence over Brand attachment and Word-of-mouse Through the above results, it is more desirable to establish brand strategy for forming Consumer-brand relationship through Emotional benefits and Self expressive benefits rather than Functional benefits. Additionally, the Consumer-brand relationship formed by Value benefit is expected not only to get the level of attachment, showing like love, toward the brand deeper, but also to achieve the effect of positive, long term communication through voluntary Word-of-mouse.

• Journal of the Korean earth science society
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• v.28 no.1
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• pp.112-122
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• 2007

It is known that coal-derived fly ashes have the unique chemical composition and mineralogical characteristics. Since iron oxides in coal fly ash are enriched with heavy metals, the subsurface media including soils, underground water, and sea water are highly likely contaminated with heavy metals when the heavy metals are leached from fly ashes by water-fly ash interactions. The purpose of this study was to investigate how indigenous bacteria affect heavy metal leaching and mineralogy in fly ash slurry during the fly ash-seawater interactions in the ash pond located in Dangjin seashore, Korea. The average pH of ash pond seawater was 8.97 in nature. Geochemical data showed that microbial activity sharply increased after the 7th day of the 60-day course batch experiments. Compared with other samples including autoclaved and natural samples, ${SO_4}^{2-}$ was likely to decrease considerably in the fly ash slurry samples when glucose was added to stimulate the microbial activity. Geochemical data including Eh/pH, alkalinity, and major and trace elements showed that the bacteria not only immobilize metals from the ash pond by facilitating the chemical reaction with Mn, Fe, and Zn but may also be able to play an important role in sequestration of carbon dioxide by carbonate mineral precipitation.

• The Journal of Korean Academic Society of Nursing Education
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• v.9 no.2
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• pp.264-275
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• 2003

The purpose of this study were to develop a smoking preventive education program for elementary students and evaluate it's effectiveness. This study was a quasi experimental study under the nonequivalent control group with pretest-posttest design. The subjects of this study were 62 who are attending elementary school(31 for each group), 2 different district elementary school. The subjects were matched by grade, similar in anti-smoking educational background of smoking, as well as their residence and income level of their families. The instruments used in this study was 18 criterion referenced test items modeled by Dick & Carey that were developed by researchers for evaluating the subjects' knowledge and attitude about smoking. A pretest was administered a week before treatment The program given to the experimental group is composed of the texts explaining the poisonous substances in tobacco, social and cultural harmfulness of smoking to the body and psychology, indirect smoking, smoking of pregnant women, motives of smoking, refusal skills of smoking; and for the subjects' understanding and the better results of study - pictures, role play, discussion, text through computer based multi-media, puzzle searching for hidden pictures, cross-word puzzle, and finally compensation. The data were collected for 50 days form mid- September to the end of October in the year of 2000, composed of formative evaluation, pre-test and summative evaluation via 2 sessions. Accordingly, the collected data were analysed by t-test, paired t-test, repeated measure ANOVA by the SAS program. This research summarize the findings as follows; 1. There was a significant difference in knowledge between the experimental group(after 1 wks t=10.4680, p=.0001; after 4 wks t= 9.310, p=.0001) and control group(after 1 wks t=0.0420, p= .9669; after 4 wks t= -0.378 p=.7079) in between the results of 1 and 4 week after education in summative evaluation (F=27.45, P=.0001). 2. There was non statistical significant difference in attitude between the experimental group (after 1 wks t=1.2292, p=0.2286 ; after 4 wks t=1.330, p=0.1935) and control group (after 1 wks t=0.1819, p=0.8569 ; after 4 wks t=0.2970, p=0.7685) in between the results of 1 and 4 week after education in summative evaluation(F=0.71, P=0.494). To sum up, the statistics of conclusive analysis evaluative for the children under school age of the 'knowledge acquisition' about smoking harmfulness. On the other hand, as there was already sound attitude about smoking, the evaluation of attitude was non significant difference between control group and experimental group, just there was partially significant difference.

• Korean journal of communication and information
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• v.32
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• pp.295-332
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• 2006

This study inquires at behavior and attitude of gatekeepers at major Korean media in the process of selecting and covering newsmakers, with focusing on factors, paths and practices in making news on the people. The study assumes that gatekeepers' social networking process with social elites, based on birth places, alma mater and kinship, plays great role in making people in the news. The study applies methods of in-depth interviews with people-page gatekeepers and content analysis of news on newsmakers. The in-depth interviews and content analysis unveil that people-page gatekeepers tend to support high society and social elite group. Furthermore, through the process of news-making, the gatekeeper group shares social capital such as economic exchanges and socio-political influences with social elite group. The result of interviews and analysis confirm that social networking based on personal affiliation plays as an important factor in selecting and covering newsmakers. With in-depth analysis of news contents, the study finds out that social elite groups of top government officials, corporate CEOs, medical doctors, lawyers, judges, prosecutors, college professors, cultural celebrities and journalists, who are predominantly male, appear on people pages much frequently out of proportion. The content analysis also reveal that 'personal news,' which cover personal and private life or unilaterally promote newsmakers predominate in terms of frequency and amount over socially-important or pubic-interested 'public news.' In terms of news values, fragmentary news composed of sensational, personal and gossiping elements appear more frequently than socially-meaningful news with strong social issues and public messages.

• Korean journal of communication and information
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• v.58
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• pp.55-73
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• 2012

This study is critical research on the forming public opinion of SNS and participation behavior. Twitter is a typical SNS service, free school food and 10.26 re-and by-elections during the formation of public opinion on the impact have been investigated. Formation of public opinion about Twitter's analysis of the first research question, The case of free meals to support the Mayor Oh, rather than against Twitter were influential. 10.26 re-and by-elections Twitter in space, the Park' candidate than Na' candidate has formed a favorable opinion. Power twitterian and twitterian on the behavior of the second study involved analysis of the problem, For free meals, power twitterian were responsible for leading the public opinion. For 10.26 re-and by-elections, Power twitterian were more Park' candidates than Na' candidates. In addition, Park' candidates of twitterians were communicating more. Through traditional media in the process of forming public opinion was swayed by public opinion to the target people simply but SNS age people involved in the production and distribution of the issue and the issue has a leading role.

• Korean journal of communication and information
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• v.45
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• pp.463-495
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• 2009

Korea has started to pay attention to civic journalism in recent years while it initially emerged in the United State since late 1980s. Furthermore, albeit some discernable limitations, the Internet has played an important role in fertilizing civic journalism as indicated by the emergence of online news media and the increasing number of civic journalists engaged in the online activities. Whereas there are some patterns of civic journalism practice and the civic influence commonly observed in both countries, there are significant factors that distinguish th1e case of Korea from that of the U.S. The purpose of this study is to compare the two countries in terms of the patterns of civic journalism practice and civic influence. This goal has been achieved by analyzing ‘CNN iReport’ in the U.S. and ‘Ohmynews’ in Korea, both of which are prime civic journalism websites. Those websites have been compared in light of four standards of civic journalism: first, the degree of post-objectivism; second, the search for effective resolutions of social problems; third, civic engagement in the news making process to enhance bottom-up agenda setting; and finally, citizens’ interaction with the news. The results reveal that the American civic journalism website is more likely to shed light on deviating from the principle of objectivity and seeking alternatives and resolutions of social problems. Moreover, it effectively utilizes civic engagement in the news Abstracts 551 making process as indicated by the higher numbers of civic journalists and civic news resources. Also, readers’ interaction with the news was found to be more active in the iReport website than in the Ohmynews.