• Journal of Life Science
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• v.20 no.7
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• pp.983-990
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• 2010

Genus Spiraea is a woody species primarily distributed throughout Asia. Many species of this genus are important plants medicinally and ecologically. I evaluated a representative sample of the sixteen taxa with random amplified polymorphic DNA (RAPD) markers to estimate genetic relationships within genus Spiraea. In addition, RAPD analysis was also conducted to estimate the genetic diversity and population structure of these species. As the typical populations of Spiraea were small, isolated, and patchily distributed for natural populations, they maintained a low level of genetic diversity for polymorphic primers. The mean H was 0.117 across species. The Korean endemic species (S. chartacea) and patchily distributed species (S. betulifolia) showed fewer alleles per locus (mean 1.240 vs. 1.297), lower percent polymorphic locus (24.0 vs. 29.7), and lower diversity (0.092 vs. 0.121) than a relatively widely spread species. An assessment of the proportion of diversity present within species, $H_{POP}/H_{SP}$, indicated that about 87.8% the total genetic diversity was among species. Thus, the majority of genetic variation (87.8%) resided within species. The phylogenic tree showed three distinct groups. One clade includes S. prunifolia for. simpliciflora, S. thunbergii, S. chamaedryfolia var. ulmifolia, S. media, and S. cantoniensis. Another clade includes S. blumei, S. pubescens, S. chartacea, and S. chinensis. The other clade is the remaining seven species.

• Journal of Information Management
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• v.43 no.1
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• pp.109-134
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• 2012

This study, focusing on process of online Word-of-Mouth(oWOM) adoption in applications market which is a major issue of recent mobile industry, tried to empirically analyze how main characteristics of oWOM affect trust and process of oWOM adoption. To do this, based on understanding about applications market and precedent studies on online communication and Elaboration Likelihood Model(ELM), I developed the research model and proposed seven hypotheses. The subjects were smart phone users who ever used review in mobile applications market. The study method was questionnaire survey. As a result, trust in review was suggested as prerequisite for consumers to accept on-line review in mobile applications market. And it was empirically proved that for the customers to feel trust, these are necessary - positive assessment on argument quality, vividness of delivered explanation, and neutrality of message. The theoretical implications of this study are that based on studies on oWOM, factors affecting trust in review were explored in the environment of mobile applications market with less judgement clues for decision making compared to other on-line media and then, these factors were conceptualized. From the practical view, this study suggested implication on what attributes companies or developers can strategically utilize while investigating prerequisites of oWOM adoption.

• Journal of Legislation Research
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• no.44
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• pp.63-101
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• 2013

This article firstly explores into the concepts, components, and pictures of institutional realization of competition and diversity respectively on the premise that competition and diversity comprise the primary objectives to be pursued by the broadcasting-related laws which provide the concrete measures of media policy, and argues that while the competition objective has differentiation factors, there are also particularities in the diversity value in the broadcasting-related laws as sector-specific competition laws. Then assuming that special competition rules including structural regulatory measures particularly in the broadcasting market are required in order to realize values of competition and diversity harmoniously, this article suggests the following improvement directions for regulations aimed at protection of competition and diversity in the broadcasting-related laws. The first one is with the improvement method for regulations aimed at protection of competition. Regulation on share of audience as an ex ante regulation of status and regulation on prohibited activities as an ex post regulation of conduct may play important roles in substituting the causative regulation while seeking for diversity value. For this purpose, it is needed to develop a concrete method that incorporates diversity-related factors as consideration factors in the standard for determining illegality of prohibited activities by inference to methods of determining illegality in the competition law. The second one is with the improvement method for regulations aimed at protection of diversity. This could be considered from three viewpoints that are the setting of regulatory objectives, the identification of alternative regulatory measures, and the choice of regulatory measures and levels suitable for regulatory objectives. From these viewpoints, the regulatory framework should be improved mainly with institutional measures in which diversity value is used for tools of assessment and analysis, not just remaining as mere rhetorical devices, and whether or to what extent to maintain regulations seemingly unreasonable in terms of harmonization with economic objectives such as competition should be discreetly reviewed.

• 재활복지
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• v.20 no.4
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• pp.247-264
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• 2016

The Children's Home Inventory for Listening Difficulties (CHILD) questionnaire has been applied for assessing listening and communication difficulties in various home situations for children with hearing loss. The purpose of the study was to translate the CHILD questionnaire for parents into Korean and verify reliability and validity of Korean version of CHILD (CHILD-K). CHILD-K was completed by 55 parents of children (from ages 3~12 years) using cochlear implants (CI). Among the 55 children, 27 were in preschool and 28 in elementary. Internal consistency reliability of CHILD-K was verified by Chronbach's alpha. The mixed factorial ANOVA was conducted to compare the effects of the age group and situation factors (Quiet, Noise, Distance, Social, and Media factors) on the score of CHILD. The results indicated that CHILD-K showed excellent internal consistency reliability (${\alpha}=.96$). The CHILD scores among age groups were significantly different as the older age group resulted in higher scores in all situations except Distance. For both groups the mean scores for the Quiet situation were significantly higher than other situations, and the mean scores for the Social situation were significantly lower than other situations. Moreover, analysis showed that children with CI had difficulties in the Social situation combined with other situation factors. The results indicate that the Korean version of CHILD questionnaire is a reliable tool for the assessment of communication abilities in home situation in Korean-speaking children using CI.

• Journal of Wetlands Research
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• v.21 no.2
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• pp.181-190
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• 2019

Recently, Low impact development techniques, a form of nature-based solutions (NBS), were seen cost-efficient alternatives that can be utilized as alternatives for conventional stormwater management practices. This study evaluated the effectiveness of an infiltration trench (IT) and a small constructed wetland (SCW) in treating urban stormwater runoff. Long-term monitoring data were observed to assess the seasonal performance and cite the advantages and disadvantages of utilizing the facilities. Analyses revealed that the IT has reduced performance during the summer season due to higher runoff volumes that exceeded the facility's storage volume capacity and caused the facility to overflow. On the other hand, the pollutant removal efficiency of the SCW was impacted by the winter season as a result of dormant biological activities. Sediment data also indicated that fine and medium sand particles mostly constituted the trapped sediments in the pretreatment and media zones. Sediments in SCW exhibited a lower COD and TN load due to the phytoremediation and microbiological degradation capabilities of the system. This study presented brief comparison LID facilities equipped with pre-treatment zones. The identified factors that can potentially affect the performance of the systems were also beneficial in establishing metrics on the utilization of similar types of nature-based stormwater management practices.

• Journal of the Korean Society for Library and Information Science
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• v.56 no.2
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• pp.35-55
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• 2022

As altmetrics has received a lot of attention as an muti-dimensional impact assessment tool, it is necessary to verify whether it can supplement the citation-based research performance evaluation system. This study analyzed and compared the effects of each altmetrics sources on citation by sampling 1,600 high-cited papers published in the last 10 years (Sample A) and non-year-limited papers (Sample B) indexed in Scopus. In addition, it was analyzed whether the OA of the paper had a moderating effect on the numbers of cited-by, and the difference according to the samples was verified. As a result of the analysis, only the number of Mendeley bookmark readers was analyzed to have a positive (+) effect on the numbers of cited-by, and OA status had a significant moderating effect in both groups. However, in sample A, OA showed a reinforcing effect on cited-by, whereas Sample B showed a weakening effect, showing a difference. On the other hand, social mention such as media reports do not have a significant effect on the cited-by regardless of OA conditions, but they can be used to understand the social impact of non-academic mass readers.

• Clean Technology
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• v.28 no.2
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• pp.123-130
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• 2022

Nanoparticles are used in various fields such as chemistry, medicine, the environment, and information and communication. With the increasing use of engineered nanomaterials, exposure to nanoparticles is expected to increase in the workplace and the environmental media. However, while nanotechnology industries are expanding, research on the exposure assessment of nanomaterials to humans and the environment is only at a beginning stage. Especially, if nanoparticles with a size of 100 nm or less that are contained in nano-products are released unintentionally, they may pose potential risks to the human body through breathing or skin exposure. Therefore, in this work, the possibility of potential exposure of nanoparticles moving from the laboratory to the office was confirmed, and nanoparticle safety guidelines are proposed. A nano-collector was used to detect nanoparticles in the atmosphere, and through use of a scanning mobility particle sizer it was found that nanoparticle concentrations in the laboratory and the office tended to be similar. On the assumption that nanoparticles attached to a lab-coat move out of the laboratory, a lab-coat to which nanocarbon black was attached was shaken and the concentration of the remaining particles on the lab-coat determined. The results confirmed that sufficient amounts of nanoparticles attached to the lab-coat could move from the laboratory to the office along the path of a researcher; thus, safety guidelines for the handling of lab-coat nanoparticles are required.

• Korean Journal of Environmental Biology
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• v.41 no.1
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• pp.41-53
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• 2023

E171, a mixture of titanium dioxide, has been widely used as a food additive due to its whitening effect and low toxicity. However, it has been proven that E171 is no longer safe for public health. So far, there are insufficient studies on the toxic effects of E171 on organisms especially using standardized test methods. In this study, toxicity assessments of E171 to two aquatic species, water flea (Daphnia magna) and zebrafish (Danio rerio), were performed using modified standardized test methods based on the physicochemical properties of E171. The hydrodynamic diameter, polydispersity index, and turbiscan stability index (TSI) were measured to ensure the dispersion stability of E171 in exposure media during the test period. The EC₅₀ for immobilization of water flea was 141.7 mg L^-1 while zebrafish was not affected until 100 mg L^-1 of E171. Measurements of reactive oxygen species (ROS) and antioxidant enzyme activities confirmed that E171 induced oxidative stress, leading to the activation of superoxide dismutase and catalase in both water flea and zebrafish, although the expression of antioxidant enzyme genes differed between species. These results suggested the potential risk of E171 to aquatic organisms and provided toxicological insights into the impacts of E171 on the environment.

• Journal of Environmental Health Sciences
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• v.49 no.6
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• pp.312-323
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• 2023

Background: Environmental concentrations of substances can be estimated by K-CHESAR based on main, industrial, and use categories (MC/IC/UC) and ECETOC TRA based on environmental or specific environmental categories (ERC or spERC). Objectives: Three different systems for estimating environmental concentrations were compared to figure out their order with possible reasons along with relationship of regional predicted environmental concentrations (PEC_regional) and final PEC_local for various uses of a substance. Methods: Typical uses of the case substance and their corresponding ERCs were selected from the webpage of the European Chemical Agency. Proper MC/IC/UC and spERC were assigned to each ERC. Emission fractions were compared for each assessment code from the available database. PECs were calculated by three estimating systems: K-CHESAR using MC/IC/UC, ECETOC TRA using ERC, and ECETOC TRA using spERC with their default values for input parameters. Percentage of PEC_regional to PEC_local were manually calculated for each use. Results: Emission factors decreased in the order of ERC > MC/IC/UC > spERC. Values of the final PEC_local derived as sum of PEC_regional and Clocal decreased in the order of calculations using ECETOC TRA-ERC>KCHESAR with MC/IC/UC>ECETOC TRA-spERC for all environmental media. Percentages of PEC_{regional,water} to PEC_local,water ranged from 0 to 10.3% in industrial uses calculated with MC/IC/UC and ERC but 96.3 to 100% in wide dispersive uses of ERC and spERC where values of C_local,water are estimated to be very low. Conclusions: ECETOC TRA generated the most refined PNEC values with spERC and the least with ERC, while K-CHESAR with MC/IC/UC generated values between the two results. The ratio of PEC_regional to PEC_local can be a good measure for performing suitable estimation of PNECs according to use.

• Journal of Science Education
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• v.47 no.3
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• pp.251-262
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• 2023

In this study, we examine other factors that may contribute to the decline in students' academic performance and educational attainment. Many media reports, as well as previous studies, have suggested that virtual learning is the main reason for the decline in students' academic performance. However, the 2020 National Student Achievement Survey, which was conducted in conjunction with the COVID-19 Distance Learning Environment Student Survey, showed that students were highly satisfied with distance learning (70-80%), and the analysis of the National Assessment of Educational Achievement showed that students' academic performance had already been declining year by year since 2017, with a general downward curve. For further confirmation, we analyzed the performance of high school students on mock exams and found that their performance was not normally distributed, but rather a right-skewed U-shaped distribution with a shrinking number of medians and severe polarization. We found that this phenomenon is not simply because of the mode or quality of the virtual classroom, but to a variety of factors, including environmental influences such as care and management at home, changes in investment in private education, increased time spent on online devices while taking virtual classes at the bottom, and increased time spent watching online content, games, and videos that are not related to learning.