• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.2
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• pp.74-85
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• 2003

The purpose of this study is to investigate present situation of recovery and treatment of waste home appliances, and to supply basic data for active reuse and recycling of waste home appliances. Among waste home appliances, refrigerator comprise 30.7%, television 37.8%, washing machine 22.9% and air conditioner 0.3%. Local government collected 46.2% of waste home appliances, producer and agent collected 49.7%, recycling center 4.1%. Seventeen percentage of waste home appliances are reused, 65% are recycled, and 18% are landfilled or incinerated. To improve the recycling activity of waste of home appliances, it is important to establish private reuse and recycling organization. It is also necessary to improve waste deposit and refund system for efficient recycling by decent financial support. Extension of a term of usage is another method to minimize waste home appliances. Finally, intensive education for consumer is necessary for waste minimization. Some portion of recycling and treatment cost can be allocated to the local government and large private business can shred and recycle waste home appliances.

• Research in Plant Disease
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• v.12 no.1
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• pp.40-45
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• 2006

The plant defence activator, Acibenzolar-S-methyl [benzo (1,2,3) thiadiazole-7-carbothioic acid-S-methyl ester, ASM] was assayed on tomato seedlings for its ability to induce resistance against Botrytis cinerea, the causal agent of gray mold in tomato. Pre-treatment of plants with ASM reduced the severity of the disease as well as the growth of the mycelium in plants. In ASM treated plants, reduction in disease severity (up to 55%) was correlated with suppression of mycelia growth (up to 46.5%) during the time course of infection. In plants treated with ASM, activities of peroxidase were determined as markers of resistance. Applications of ASM induced Progressive and significant increase of the enzyme in locally treated tissues. Such responses were expressed earlier and with a much higher magnitude when ASM-treated seedlings were challenged with the pathogen, thus providing support to the concept that a signal produced by the pathogen is essential for triggering enhanced synthesis and accumulation of the enzymes. No such activities were observed in water-treated control plants. Therefore, the slower symptom development and reduction in mycelium growth in ASM treated plants might be due to the increase in activity of oxidative and antioxidative protection systems in plants.

• Journal of the Korean School Mathematics Society
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• v.22 no.3
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• pp.329-350
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• 2019

Productive struggle is a student's persevering effort to understand mathematical concepts and solve challenging problems that are not easily solved, but the problem can lead to curiosity. Productive struggle is a key component of students' learning mathematics with a conceptual understanding, and supporting it in learning mathematics is one of the most effective mathematics teaching practices. In comparison to research on students' productive struggles, there is little research on preservice mathematics teachers' productive struggles. Thus, this study focused on the productive struggles that preservice mathematics teachers face in solving a non-routine mathematics problem. Polya's four-step problem-solving process was used to analyze the collected data. Examples of preservice teachers' productive struggles were analyzed in terms of each stage of the problem-solving process. The analysis showed that limited prior knowledge of the preservice teachers caused productive struggle in the stages of understanding, planning, and carrying out, and it had a significant influence on the problem-solving process overall. Moreover, preservice teachers' experiences of the pleasure of learning by going through productive struggle in solving problems encouraged them to support the use of productive struggle for effective mathematics learning for students, in the future. Therefore, the study's results are expected to help preservice teachers develop their professional expertise by taking the opportunity to engage in learning mathematics through productive struggle.

• Education of Primary School Mathematics
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• v.20 no.4
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• pp.253-266
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• 2017

The purpose of the study was to investigate the perceptions of Elementary school teachers on mathematics instruction. To do this, 7 test items were developed to obtain data on teacher's perception of mathematics instruction and 73 teachers who take mathematical lesson analysis lectures were selected and conducted a survey. Since the data obtained are all qualitative data, they were analyzed through coding and similar responses were grouped into the same category. As a result of the survey, several facts were found as follow; First, When teachers thought about 'mathematics', the first words that come to mind were 'calculation', 'difficult', and 'logic'. It is necessary for the teacher to have positive thoughts on mathematics and mathematics learning, and this needs to be stressed enough in teacher education and teacher retraining. Second, the reason why mathematics is an important subject is 'because it is related to the real life', followed by 'because it gives rise to logical thinking ability' and 'because it gives rise to mathematical thinking ability'. These ideas are related to the cultivating mind value and the practical value of mathematics. In order for students to understand the various values of mathematics, teachers must understand the various values of mathematics. Third, the responses for reasons why elementary school students hate mathematics and are hard are because teachers demand 'thinking', 'because they repeat simple calculations', 'children hate complicated things', 'bother', 'Because mathematics itself is difficult', 'the level of curriculum and textbooks is high', and 'the amount of time and activity is too much'. These problems are likely to be improved by the implementation of revised 2015 national curriculum that emphasize core competence and process-based evaluation including mathematical processes. Fourth, the most common reason for failing elementary school mathematics instruction was 'because the process was difficult' and 'because of the results-based evaluation'. In addition, 'Results-oriented evaluation,' 'iterative calculation,' 'infused education,' 'failure to consider the level difference,' 'lack of conceptual and principle-centered education' were mentioned as a failure factor. Most of these factors can be changed by improving and changing teachers' teaching practice. Fifth, the responses for what does a desirable mathematics instruction look like are 'classroom related to real life', 'easy and fun mathematics lessons', 'class emphasizing understanding of principle', etc. Therefore, it is necessary to deeply deal with the related contents in the training courses for the improvement of the teachers' teaching practice, and it is necessary to support not only the one-time training but also the continuous professional development of teachers.

• Applied Biological Chemistry
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• v.32 no.1
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• pp.23-29
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• 1989

Biochemical consequence of the accumulation in cells of superoxide $(O^{-}_{2})$ which was proposed to be probably a common chemical factor in the secondary process of the mechanism of chilling injury as well as in the visible light photodamage in cells of higher plants, has been investigated in the present work. Especially focused was the destructive effect of $O^{-}_{2}$ on the biochemical activity of mitochondria, as informations which support the suggestion that mitochondrial inner membrane is the major site of $O^{-}_{2}$ production have been collected. Mitochondria and submitochondrial particles (SMP) were prepared from soybean hypocotyls for this case study. When SMP were treated with the electrolytically produced $O^{-}_{2}$ they suffered not only inhibition of the membrane-bound enzymes as demonstrated by cytochrome c oxidase, but also lipid peroxidation of membrane as proved by malondialdehyde production. Malate dehydrogenase present in the protein extract from mitochondrial matrix was also inhibited by the $O^{-}_{2}$ treatment. These results exhibited the chaotic effect of the overproduction and accumulation of $O^{-}_{2}$ in cells under a certain abnormal circumstance such as environmental stress on the physiological function of mitochondrial; disruption of the cellular metabolic pathways and the structural integrity of membrane.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.307-313
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• 1994

We have previously shown that crude water extract of Euonymus alatus (EA) had strong prophylactic effect against chemically induced-and tumor cell implanted-cancer, and that the mechanisms responsible for its antitumor effects were due to nonspecific enhancement of the NK cell activities and the cell mediated immunity. However, it was unknown that any components of crude extract did work so, since it consisted of several components. In this paper, we fractionated the crude watar EA-extract into several fraction such as hexane-, ethylether-, ethyl acetate-, n-butanol- and water soluble-fraction, and screened the immune regulating activities of each fraction by the evaluation of lymphokine production and activated lymphocyte proliferation. As a result of the component fraction of EA-extract, it was found that n-butanol fraction was a potent immunostimulator, and the remained water soluble fraction also contained some stimulator, But, other fraction did not showed any remarkable effect. It is therefore suggested that EA-glycosides in n-butanol fraction may be new one of the potent biological response modifiers. The present study was also undertaken in an efforts to investigate the effects of elm-bark(EB, Ulmus clavidiana var japonica), which has been used for curing ulcer and inflammation as a folk medicine without any kind of experimental evidence to support this, on the cellular- and humoral-immune responses, lymphocyte function and NK cell activities in mice. Regardless of time and duration of EB-treatment, Arthus reaction and antibody response to SRBC were not modified by EB, but delayed hypersensitivity to SRBC was significantly enhanced only when EB was treated prior to SRBC-sensitization. EB slightly inhibited the proliferation responses of splenocytes to PHA-stimulation, but it significantly augmented the responses of these cells to S aureus Cowan 1 and Con A-activation, and these effects were manifested only when EB was added at culture initiation. EB did not influence Ig secretion of spleen cells but it significantly augmented the Con A-induced 1L 2 and MIF production of splenocytes. NK cell activities of splenocytes were markedly riled when effector cells were pretreated with EB and this augmentation was dine to the increase of binding affinity of effector cells to target cells and the target cell lytic activities of effector cells. These results led to the conclusion that EB triggers increase of cellular immune responses, such as delayed hypersensitivitiy, lymphokine production and NK cell activities. Also these results suggested that EB contains potent immune stimulants, which may provide the rational basis for their therapeutic use as one of the new biological response modifiers.

• Environmental and Resource Economics Review
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• v.17 no.1
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• pp.165-196
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• 2008

This paper reports a quantitative meta analysis of the economic impacts of localized noxious and contaminated sites. Using either hedonic property value or stated preference methods, economists have studied the effects of contamination or noxious activities, or the benefits realized from their elimination, on real estate prices at more than 40 sites. In support of wise public and private investments in environmental quality, most of these studies aim to inform decision makers about the benefits of remediation and cleanup. Their results vary considerably, but there has been no previous systematic effort to analyze the differences and identify shared insights. This study uses established methods of meta analysis to identify points of agreement and differences in this body of literature. The studies are characterized by the type of site, modeling approach, geographic extent of impacts, data features, and other key factors that underlie their value estimates. The impact estimates are normalized as proportional effects on property values. This study attempts to discover whether the estimated economic impacts of contamination or noxious activity differ according to these characteristics of the studies, and whether anything general can be said about the economic consequences of site contamination and remediation. Bivariate, multivariate, and logit techniques are applied to the data. The results suggest that the property value is the most sensitive to water base contamination, published case studies result in systematically greater environmental value than those in unpublished reports, and real estate markets show responses to environmental condition changes.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.1
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• pp.18-27
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• 2020

The correct distinction of carbapenem-resistant Enterobacteriaceae (CRE) and ccarbapenemase producing Enterobacteriaceae (CPE) and the rapid detection of CPE are important for instituting the correct treatment and management of clinical infections. Screening protocols are mainly based on cultures of rectal swab specimens on selective media followed by phenotypic tests to confirm a carbapenem-hydrolyzing activity, the rapid carbapenem inactivation method, lateral flow immunoassay, the matrix-assisted laser desorption ionization-time-of-flight test and molecular methods. The CPE is accurate for detection, and is essential for the clinical treatment and prevention of infections. A variety of phenotypic methods and gene-based methods are available for the rapid detection of carbapenemases, and these are expected to be routinely used in clinical microbiology laboratories. Therefore, to control the spread of carbapenemase, many laboratories around the world will need to use reliable, fast, high efficiency, simple and low cost methods. Optimal effects in patient applications would require rapid testing of CRE to provide reproducible support for antimicrobial management interventions or the treatment by various types of clinicians. For the optimal test method, it is necessary to combine complementary test methods to discriminate between various resistant bacterial species and to discover the genetic diversity of various types of carbapenemase for arriving at the best infection control strategy.

• Journal of Digital Convergence
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• v.14 no.4
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• pp.69-78
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• 2016

The purpose of this study is to analyze convergent effects of team interaction and team metacognition of participants on a continuous participation in the university learning community. We developed 19 items of team interaction and 17 items of team metacognition through literature review. The subjects were 113 students who participated in learning community in A university. The results are as follows. First, team interaction level and team metacognition level can affect a continuous participation in learning community. The higher team interaction is and the lower team metacognition is, the higher continuous participation is. Second, among team interaction factors that affect a continuous participation in learning community, the more number of learning is and the more encouragement of one another is, the higher continuous participation is. But the less participation of members is, the less flow to learning is, and the less learning time is, the lower a continuous participation is. Third, among team metacognition factors that affect a continuous participation in learning community, the more number of learning is, the higher continuous participation is. But the more use of various learning tools is and the more learning time is, the lower continuous participation is. Based on these results, the convergent ways of support for continuous participation in the university learning community are as follows. First, supporting system is needed to induce students to experience the positive atmosphere of learning community by increasing number of learning to facilitate team interaction and urging them to encourage one another. Second, providing the effective utilization method is necessary for students to fully acknowledge the necessity and value of team metacognition activity.

• Korean Security Journal
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• no.55
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• pp.117-141
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• 2018

Police crime statistics report that residential housing such as apartment, low rise, detached houses is the second most vulnerable to crime, which is closely followed by the number of street crimes. Also residential houses are often exposed to quality-of-life crime, e.g burglary. It threatens the basic human rights of house residents in terms of safety and comfort within the urban living environment. This study examines related precedent studies regarding the vulnerability of residential housing including studios, multi-family housing from the viewpoint of crime prevention through environment design(CPTED), extracted the elements and items suitable for the safety of residential facilities and the certification evaluation indicators and check items to be the basis for the checklist are derived. Based on these evaluation indicators and inspection items, we conducted on-site surveys of residential facilities in three areas of Seoul, Yongin and Asan, and the final draft of the checklist was revised based on the results of the field survey. There are 43 items on the 7 fields of evaluation in the final version of checklist, 11 items in the management and operation, 20 items in the surveillance, 7 items in the access control, 1 item in the territoriality, 2 items in the activity support, and 2 items in the security and safety facilities. In addition, various points of interest were added to allow the administrator of the residential facility to earn points for special measures taken for safety. This checklist can be appropriately modified and utilized in consideration of the characteristics of each facility. Korean national police agency has CPOs to check the residential facilities in their jurisdiction using checklists and to certify excellent facilities with high level of safety.