• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.178-186
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• 2006

Community structures of fish in six small eutrophied lakes, located in Gyeonggi province, Korea were investigated from September 2003 to August 2004. Total number of fish species was 33 species of 13 families in which five Korean endemic species such as Rhodeus uyekii, Squalidus gracilis majimae, Abbottina springeri, Iksookimia koreensis, and Odontobutis interrupta were found. Dominant species in the lakes was Hemiculter leucisculus. Both Zacco platypus and Pseudorasbora parva were numberous as subdominant species. In particlilar, Micropercops swinhonis known as partly distributed in the Jeonlabukdo was first recorded in Lake Wangsong and Heungbu which are located in the Gyeonggi province. In lake Myukwoo, Wangsong, and Heungbu, the proportion of Pelagic and omnivorous fish were high, reflecting that fish habitat is poor. A CPUE based fish production was the lowest in Lake Geumgwang of which lake is relatively favorable, whereas it was higher in eutriphied lakes suchs as Dukwoo, Myukwoo and Heungbu lakes.

• Journal of The Korean Association For Science Education
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• v.19 no.1
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• pp.29-40
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• 1999

The purpose of the present study was to test hypothesis that, because it uses tri-dimensional sensory pathway which have been showed a higher rate of neural activities than uni- or bi-dimensional's, lab-activity-based instruction is more effective teaching strategy in learning science than verbal-based instruction. In the present study, manipulative teaching strategy that uses visual, somatosensory and auditory information pathway was regarded as a mode of tri-dimensional sensory inputs. In addition, verbal teaching strategy that uses mainly auditory and a little visual information pathway was used as a mode of bi-dimensional sensory inputs. Fifty-six students who failed to successfully solve two proportional reasoning tasks (i.e., pouring water tasks) were sampled for this research from a junior high school. The subjects were randomly divided into a manipulative or a verbal teaching group, and given manipulative or verbal tutoring on the use of proportional reasoning strategies and a test of proportional reasoning during instruction. The results showed that manipulative group's performance on the test of proportional reasoning during instruction showed significantly higher performance than verbal group's (t=2.45, p<0.02). The present study also discussed some educational implications of the results.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.344-352
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• 2015

This study aims to identify the difference in the starting time of the dawn chorus of different species of birds and related environmental conditions. For this study, the bird songs were recorded every 2 hours a day starting from 2 hours before sunrise for a whole spring season (from April to June, 2014) in Korea. The recorded sounds were analyzed to find the starting time of each species' song by sonogram pattern using a sound analyzing program (Adobe Audition CC). To analyze the relationship between the environmental conditions and the time of the birdsong of each species, we collected the data of environmental conditions: daily precipitation, Julian date, time of sunrise and moonrise, temperature data and twilight time from the Korea Meteorological Office. As a result of this study, it was found that there are several statistical correlation between the starting time of the birdsong and environmental conditions (every environmental condition except daily precipitation and time of moonrise). Also, the difference of the starting time among each species were identified. The species were divided into 3 groups (early, mid and late) by their wake-up time. Ring-necked pheasant and yellow-throated bunting were categorized as 'Early' group and all woodpeckers were categorized as'Late' group. This study is significant as it first presented a classification of wild birds in Korea by the starting time of their dawn chorus. However, further studies are required to identify why each species to do their dawn singing at different times.

• The Journal of Society for e-Business Studies
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• v.17 no.2
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• pp.129-147
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• 2012

Collaborative filtering (CF), one of the most successful recommendation techniques, has been used in a number of different applications such as recommending web pages, movies, music, articles and products. One of the critical issues in CF is why recommendation performances are different depending on application domains. However, prior literatures have focused on only data characteristics to explain the origin of the difference. Scant attentions have been paid to provide systematic explanation on the issue. To fill this research gap, this study attempts to systematically explain why recommendation performances are different using structural indexes of social network. For this purpose, we developed hypotheses regarding the relationships between structural indexes of social network and recommendation performance of collaboration filtering, and empirically tested them. Results of this study showed that density and inconclusiveness positively affected recommendation performance while clustering coefficient negatively affected it. This study can be used as stepping stone for understanding collaborative filtering recommendation performance. Furthermore, it might be helpful for managers to decide whether they adopt recommendation systems.

• Informatization Policy
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• v.27 no.1
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• pp.92-114
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• 2020

The purpose of this study is to analyze people's motivations to use the National Petition service of CheongWaDae, the Presidential Office of Korea. The online space has been used as a testbed of deliberative democracy. In fact, a wide variety of public opinions are being formed and gaining sympathy through the E-Petitions and Daum's Agora. In this regard, President Moon's government launched a petition site to gather public opinions. For any petition agreed on by more than 20,000 people within 30 days, the relevant ministry or the President's office must provide answers or feedback. This study wants to figure out how this National Petition is different from previous platforms like Agora or E-Petitions and why it is so well-received by people. This study uses a mix of both qualitative and quantitative methods. First, we conducted a focus group interview to factorize experiences of using the National Petition into measurable constructs. Second, we did a survey o 156 Koreans who had experienced the National Petition. Results show that symbolism, usefulness, gratification, and trust have positive impact on continuous usage intention. This study argues that symbolism, usefulness, gratification, and trust factors should be in place rather than technical aspects in order to increase the actual participation of users on the online platform of deliberative democracy. In addition, this study is meaningful in that it examined how different the CheongWaDae's National Petition is from the existing platforms for collecting public opinions and analyzed factors that encourage continuous use.

• Journal of Service Research and Studies
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• v.9 no.2
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• pp.77-88
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• 2019

Appropriation means the process of transforming resources to property. John Locke earlier investigated the appropriation process of natural resources into the land property, which grounded the jurisprudential base of the private ownership of the land. In the same way human resources are transformed into the human assets. Appropriation process, very rarely studied so far, in this case of human property is the focus of this paper. The appropriation of intangible property is by far easier than the appropriation of tangible property. Learning is a process of embodiment, which naturally mean the process of appropriation. For the material resources which exist out of human body, appropriation necessary need special philosophical and institutional justification. In the process appropriation for intangibles, investigator found, appropriator and learner either can be same, or can be differentiated. In the former case substantial human assets are created while in the latter relational human assets are built. After the discussion of appropriation process, Investigator proceeds to the problem of visualizing the invisibles. Evaluation and assessment issue were discussed in this perspective. Qualification system is particularly noted as a system to regulate substantial human assets including their issuing and registration. The work done in this paper would contribute in understanding the law of education and the law of qualification.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.3
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• pp.170-177
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• 2006

As a rapid and quick bioactive compound evaluation technique, in this study we utilized a automatic system of High Throughput Screening (HTS) to investigate DPPH radical scavenging efficacy of seaweeds, collected from Jeju Island in Korea. In this study, 6 species of green seaweeds, 18 species of brown seaweeds and 22 species of red seaweeds extracted with methanol at $20^{\circ}C$ and $70^{\circ}C$ were subjected to HTS. Of the green seaweeds tested, Enteromorpha compressa (20G6) of the green seaweeds showed DPPH radical scavenging activity of over 60%. On the other hand, the other green seaweeds showed poor DPPH radical scavenging activities (lees than 40%) at 1 mg/ml. Sargassum siliquastrum (20B17, 70B17), Dictyota dichotoma (70B1), Sargassum coreanum (70B16) and Ecklonia cava (70B26) among the brown seaweeds showed significantly high DPPH radical scavenging activity with 96%, 97%, 92%, 92%, 87%. Polysiphonia japonica (20R24), Schizymenia dubyi (20R17), Gelidium amansii (20R18) and Acrosorium flabellatum (20R23) among the red seaweeds showed remarkable DPPH radical scavenging activity of over 90%.

• Education of Primary School Mathematics
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• v.14 no.3
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• pp.277-291
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• 2011

It is necessary for the teacher to understand why teach mathematics in order to implement the visions and expectations of the national mathematics curriculum in her actual classroom. This study conducted a survey of examining how elementary school teachers might understand the purpose of teaching mathematics. The results of this study showed that teachers' conceptions of the purpose of teaching mathematics were related mainly to the development of logical thinking, practical use of mathematics in everyday life, and a tool for studying other subjects or disciplines. However, teachers did not perceive much other purposes of mathematics education such as understanding the world, appreciating aesthetic value of mathematics, and developing communicative ability as well as sociality. Whereas teachers did not think of the significance of mathematics as an intellectual field when asked to write down how they would explain students why they had to learn mathematics, they tended to strongly agree it in the Likert-scale responses. Teachers' conceptions were not different according to their gender but teachers with less than five years' teaching experience were relatively negative than others with more experience. Given these results, this study provided issues and implications of teachers' conceptions of the purpose of teaching mathematics.

• Journal of Gifted/Talented Education
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• v.23 no.4
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• pp.505-521
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• 2013

The purpose of the study is the find out current status and key factors of attendance in private education of gifted students. The results show that 95.9% of gifted students and 94.6% of general students are currently participating in private education. Most percentages of students took English and math programs at the private institutes. Average amount of time students spend for private education was 2~3 hours per day, and most percentage of parents spent 400,000~600,000 won per month for their children's private education. There were no significant differences between the gifted and the general students in the aspects of private education statuses. Regarding the key factors of attendance in private education, improvement of study related skills, school grade management, and influences of surroundings, such as parents and friends, were showed as significant variables in gifted students group. Interestingly, influences of surroundings showed negative effect. For general students and their parents, improvement of study related skills and school grade management factors were significant variables. And for the parents of gifted students, improvement of study related skills and entering higher level schools appeared as significant factors for the participation in private education. Implications of the study were discussed in depth.

• Korean Journal of Microbiology
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• v.27 no.1
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• pp.1-9
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• 1989

The locations of 5' ends as well as the splicing pattern of viral poly A(-) 19S RNA from monkey cells infected with SV40 were determined by a modification of primer extension method. The 5' end of this RNA mapped at the major cap site at nucleotide residue 325, used most frequently by SV40 late RNAs. The intron from nt.373 to nt.558 was removed as the ordinary cytoplasmic poly A(+) 19S RNA. The 3'end of this RNA was very heterogeneous and distributed over 1 kb upstream of polyadenylation site, as determined by S1 nuclease mapping. The reason for this normally initiated and spliced RNA to accumulate in the nucleus was investigated. In order to test whether the presence of unused 3' splice region on this RNA caused such subcellular distribution, cells were transfected with SV40 mutant KNA containing deletion around 3' splice site. The RNA deleted of 3' splice region accumulated mainly in the cytoplasm. This accumulation did not result from the increased stability of the RNA due to the deletion, since the wild type and mutant RNAs exhibited similar half lives after chase with actinomycin D. Therefore it is likely that the 19S spliced RNA is hindered from being transported into the cytoplasm due to some pre-splicing complexes formed at the unused 3' splice site.