• Advances in materials Research
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• v.2 no.2
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• pp.93-98
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• 2013

Objective of this study is to calculate gamma buildup factors for pointed and isotropic gamma sources in depleted uranium, uranium dioxide, natural uranium, tin, water and concrete using MCNP4C code. The thickness of the media ranges from 0.5 to 10 mean-free-path (mfp) and gamma energy ranges from 0.5 to 10 MeV. Owing to the outstanding accuracy of MCNP in calculation involving gamma interaction, results fairly match those reported previously. The maximum relative error is 2%.

• Advances in environmental research
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• v.1 no.3
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• pp.211-221
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• 2012

Bromadiolone (BRD), a second generation anticoagulant often applied to the living environment to control rodents, is usually considered to have low environmental toxicity due to its poor solubility in water. In this study of the effect of humic acid (HA) on BRD using electronic absorption spectroscopy, it has been observed that BRD is appreciably solubilized even in low concentrations of aqueous HA solutions. The BRD solubilization efficiency of aqueous HA was found to be $2.39{\pm}0.14$ ($4.53{\pm}0.26{\mu}M\;ppm^{-1}$). It was also seen that BRD is reasonably solubilized in aqueous extract of farm soil.

• Korean journal of communication and information
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• v.41
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• pp.108-144
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• 2008

This study examines how the watchdog concert in journalism field has been created and develope4 Related studies found that the watchdog is related not so muck with free press theory as with a privilege awarded to the press because the press serves for the public interests. It was found that in the U.S., the watchdog concept was derived from the a lot of libel cases in the late 1890s. At the time, the newspaper owners and editors continuously claimed the very protection over vulnerability of newspaper's collecting, reporting, and printing news. While, in Korea, the concept of watchdog emerged in the late 1990s after the establishment of the Constitution Court. Even though the watchdog concert was accepted very late by the Korean courts, it is believed to be a kind of special privilege to prevent the press from being recklessly regulated in libel cases. Rather, the Korean courts expand the extent of the role of the press as a watchdog by deciding that not only the public officials and politicians but also other socially influential public figures could be included in the criticism from the press. However, how these court decisions can be practically implemented depends upon how the court apply the probability of the press to believe the news true and intention of malice in writing and publishing the stories.

• Journal of Society of Preventive Korean Medicine
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• v.27 no.3
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• pp.1-12
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• 2023

Objectives : The aim of this study is to analyze the news articles related to Korean Medicine(KM) and compare trends in news reports from 2018 to 2022. Method : News articles related to KM were collected through the BigKinds, the news bigdata service of the Korea Press Foundation. News reports from 1 January 2018 to 31 December 2022 were searched. 2,950 news articles out of a total of 12,497 met the inclusion criteria. First, quantitative changes in media coverage were analyzed by year, media outlet, and month. For qualitative analysis, two authors independently coded the content of news articles, discussed them until consensus, and consulted with a third researcher to classify them. In addition, keywords extracted by the BigKind's Topic Rank algorithm were compared and analyzed in each year. Results : The number of news articles on KM decreased by 42% in 2022 compared to 2018. Over a fiveyear period, the Naeil Shinmun reported the most on KM among newspapers, while the Hankyoreh did the least. Among broadcasters, YTN reported the most and SBS did the least. When analyzing the reports by category, the most common was 'treatment', followed by 'prevention' and 'scientification'. As a result of extracting keywords with high weight and frequency, 'immunity' and 'immune system' ranked the first and second in 2018, while 'COVID 19' and 'medical law violation' did in 2022. Conclusion : The decrease in media reports on KM during the COVID-19 epidemic period seems to be due to the limited role of KM in responding to infectious diseases, and efforts to expand the scope of KM can induce increased media reports and social interest.

• Membrane and Water Treatment
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• v.11 no.1
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• pp.1-10
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• 2020

An understanding of particle-particle interactions in filtration requires studying the detachment as well as the attachment of nanoparticles. Nanoparticles captured in a granular media filter can be released by changing the physicochemical factors. In this study, the detachment of captured silver nanoparticles (AgNPs) in granular media filtration was examined under different ionic strengths, ion type, and the presence or absence of natural organic matter (NOM). Filtration velocity and ionic strength were chosen as the physical and chemical factors to cause the detachment. Increasing filtration velocity caused a negligible amount of AgNP detachment. On the other hand, lowering ionic strength showed different release amounts depending on the background ions, implying a population of loosely captured particles inside the filter bed. Overall detachment was affected by ionic strength and ion type, and to a lesser degree by NOM coating which resulted in slightly more detachment (in otherwise identical conditions) than in the absence of that coating, possibly by steric effects. The secondary energy minimum with Na ions was deeper and wider than with Ca ions, probably due to the lack of complexation with citrate and charge neutralization that would be caused by Ca ions. This result implies that the change in chemical force by reducing ionic strength of Na ions could significantly enhance the detachment compared to that caused by a change in physical force, due to a weak electrostatic deposition between nanoparticles and filter media. A modification of the 1-D filtration model to incorporate a detachment term showed good agreement with experimental data; estimating the detachment coefficients for that model suggested that the detachment rate could be similar regardless of the amount of previously captured AgNPs.

• Journal of the Korean Society for information Management
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• v.41 no.2
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• pp.269-294
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• 2024

This study analyzed the news media coverage of QRcodes in Korea over a 16-year period (2008 to 2023). A total of 13,335 articles were extracted from the Korea Press Foundation's BigKinds. A quantitative and content analysis was conducted on the news frames. The results indicated that the quantity of news coverage has increased. The greatest quantity of news coverage was observed in 2020, and the most frequently discussed topic in the news was 'IT_Science'. The results of the keyword analysis indicated that the primary words were 'QRcode', 'smartphone', 'service', 'application', and 'payment'. The news media primarily focused on the QRcode's ability to provide instant access and recognition technology. This study demonstrates that advanced information and communication technologies and the increased prevalence of mobile devices have led to a rise in the utilization of QRcodes. Furthermore, QRcodes have become a significant information media in contemporary society.

• Earthquakes and Structures
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• v.10 no.4
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• pp.829-847
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• 2016

Generally seismic isolation is achieved by supporting the structure on laminated rubber bearings, friction pendulum bearings, roller bearings etc. Very little work has been performed using soil as a base isolation media. Experiments and analytical work has been performed on a structural model with isolated footing and found encouraging results. Details of this work are presented in this paper.

• Geomechanics and Engineering
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• v.4 no.4
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• pp.281-294
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• 2012

Filtration using granular media such as quarried sand, anthracite and granular activated carbon is a well-known technique used in both water and wastewater treatment. A relatively new pre-filtration method called pebble matrix filtration (PMF) technology has been proved effective in treating high turbidity water during heavy rain periods that occur in many parts of the world. Sand and pebbles are the principal filter media used in PMF laboratory and pilot field trials conducted in the UK, Papua New Guinea and Serbia. However during first full-scale trials at a water treatment plant in Sri Lanka in 2008, problems were encountered in sourcing the required uniform size and shape of pebbles due to cost, scarcity and Government regulations on pebble dredging. As an alternative to pebbles, hand-made clay pebbles (balls) were fired in a kiln and their performance evaluated for the sustainability of the PMF system. These clay balls within a filter bed are subjected to stresses due to self-weight and overburden, therefore, it is important that clay balls should be able to withstand these stresses in water saturated conditions. In this paper, experimentally determined physical properties including compression failure load (Uniaxial Compressive Strength) and tensile strength at failure (theoretical) of hand-made clay balls are described. Hand-made clay balls fired between the kiln temperatures of $875^{\circ}C$ to $960^{\circ}C$ gave failure loads of between 3.0 kN and 7.1 kN. In another test when clay balls were fired to $1250^{\circ}C$ the failure load was 35.0 kN compared to natural Scottish cobbles with an average failure load of 29.5 kN. The uniaxial compressive strength of clay balls obtained by experiment has been presented in terms of the tensile yield stress of clay balls. Based on the effective stress principle in soil mechanics, a method for the estimation of maximum theoretical load on clay balls used as filter media is proposed and compared with experimental failure loads.

• Korean journal of communication and information
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• v.56
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• pp.71-85
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• 2011

This thesis reviews the process in which the regulation systems against ownership concentration of newspapers established with the opportunity of legislation of the periodical act in 1987 was reinforced as they were all amended to the newspaper act in 2005 and as they were again amended in 2009 it came to confront crisis in the aspect of press law legislation history. The regulation systems against ownership concentration of newspapers established based on the principle of legality of newspaper function in the Clause 3, the Article 21 of Constitution was reinforced as the newspaper act in 2005 and in 2006 they began to shrink following the Constitution Court decision against newspaper act. As newspaper act and broadcast act are revised in 2009, regulation against combining the management of newspapers with broadcast and regulation against owning multiple number of newspapers came not to exist. Because in this process, the opposition party also allowed limited cross-ownership of newspaper and broadcast, it can be said that the system of newspaper ownership regulation confronted the crisis of dissolution. The instruction of regulation alleviation in a short period of time in spite of the fact that regulation alleviation which allows cross-ownership of newspaper and broadcast is the matter of policy that should be decided after long-term review of the change of media environment and the progress of the power of domination of public opinion is dangerous. Newspapers are strong media with terrestrial broadcast in formation of public opinion on politics. It's because it is difficult to ignore the worry that the power of domination of public opinion of the newspapers which are in oligopoly of newspaper public opinion market can be spreaded to the territory of report broadcast. From the point of view that there is probability for democracy to be ultimately threatened due to the shrink of political Darwinism caused by concentration of media ownership, the alleviation of ownership concentration of newspapers should have premise of long-term social discussion.

• Korean journal of communication and information
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• v.22
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• pp.249-272
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• 2003

This study discusses on the historical origin of audience's boycott movement to the Korean press. Two historical cases of audience's boycott movement in the early 1920s were analyzed in this study. The first boycott was resolved by the counterforce to the public funeral of Yunsik Kim in February of 1922. This case can be estimated as the historical origin of audience's boycott movement in the Korean media history. The second case was carried out by the National Convention of the Youth Parties in March of 1923. The target of these two cases were The Dong-A Ilbo. And these boycott movement were caused by the conflict and competition between nationalists and socialists in the national independence movement. These two parties were incompatible in the ideology and method of national independence struggle. In the course of their conflict and competition for the initiative socialist party resolved and carried out the boycott movement to The Dong-A Ilbo, because it was regarded as the advocate of the nationalist party.