• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.2
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• pp.1-10
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• 2004

Urban parks provide good services to the community, and they are enhanced by citizen participation. For that especially, organizational and continued volunteering can be a key strategy. The purpose of this study is to establish factors on promoting the continuity of volunteering in voulatary associations of urban parks. Variables of continuity are continual will, continual time, and psychological continuance motive. To add to this, this study is intended to inquiry about recognition and compensation that volunteers want to receive. The major findings are as follows: First, The main participantes were housewives with high education. Second, Continual will was influenced by gender, profession, the satisfactory degree for individual pursuit an ideal, and the degree of confidence with members. Third, Continual time was influenced by profession and individual network in community. Forth, Continual motive was influenced by individual network in community, the result-analysis behavior of related government organ, the degree of confidence and the degree of ties with members. Finally, Volunteers wanted to receive the volunteering expenses, the compensation about accident, and emotional recognitions. In sum : to ensure the continuity of volunteering, first, recruiting of volunteers is demanded to select a major target group in the community. Second, a voulatary association helps to make confidence and ties with members. Third, the related government organ strives for volunteers to have a positive recognition of the organ's attitudes, for the volunteer association to have a clearly distinguished area of action from the organ's one, and a co-operative system. Finally, an institution needs to be established to give emotional recognitions as well as volunteering expenses and acompensation for accidents.

• Microbiology and Biotechnology Letters
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• v.13 no.4
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• pp.339-344
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• 1985

Cephalosporin C(CPC) inhibited the growth of Cephalosporium acremonium M-113, a potent CPC producer derived from C acremonium ATCC 20339. Similar inhibitory effects of CPC were also observed in growth of C. acremonium ATCC 20339 and ATCC 14553. Minimum inhibitory concentrations (MIC) of CPC on the growth of conidia and hyphae of C. acremonium M-113 were 200-500 and 3000-4000$\mu\textrm{g}$/$m\ell$ respectively in synthetic medium. MIC values were increased in complex media. The inhibitory effect of CPC was due to CPC-exerted inhibition of amino acids uptake by the cells. 3'-Group of CPC might be important in its inhibitory action. In audition, CPC itself could be utilized by the cells as a nitrogen source under nitrogen limited condition.

• 대한공업교육학회지
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• v.33 no.1
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• pp.213-232
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• 2008

The purpose of this study is that after developing and applying multimedia rich project-based learning methods in a Korean Special high school(Industrial and Technical Area), to provide how the learners recognize the effectiveness for it and to obtain the implication from effectiveness which they recognized. This study was conducted as action research based on a high school situation. The study included 100 participants in two classes purposively selected from 9 classes at 450 student high school. Data were collected through observations, surveys and interview. Results indicated the multimedia rich project-based learning allowed students to understand the contents of major subject overall, improve the handling skill for computer multimedia and be better at investigating and organizing skill for subject content. Also, it allowed them to improve interaction among students and participation, motivation, satisfaction, interest and confidence for learning. And there was close cooperation with and among group members to create better products.. Finally, the flexibility in the project-based learning environment allowed the participants to make decisions about their abilities, resources, and plans. Recommendations and implications for teacher educators as well as inservice and preservice teachers are also presented.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.227-232
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• 2006

In this paper, a Kalman filter application for GDSS(Group Digital Surveillance System) developed to protect an aquaculture farms is discussed GDSS is composed by a WIWAS(Watching, Identification, Warning, and Action System) and a FDS(Fishery Detection System) that will monitor incoming and outgoing vessels in the aquaculture farms. In the FDS, a tracking function to track vessels without F-AIS(Fishery Automatic Identification System) is needed and the Kalman filter is applied to track vessels around the aquaculture farms. Some simulation results for the multi-objects with white noise is presented and the adaptation possibility for tracking system is discussed.

• Nutrition Research and Practice
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• v.2 no.2
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• pp.80-84
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• 2008

Beneficial effects of dehydroepiandrosterone (DHEA) supplement on age-associated chronic diseases such as cancer, cardiovascular disease, insulin resistance and diabetes, have been reported. However, its mechanism of action in hepatocellular carcinoma in vivo has not been investigated in detail. We have previously shown that during hepatocellular carcinogenesis, DHEA treatment decreases formation of preneoplastic glutathione S-transferase placental form-positive foci in the liver and has antioxidant effects. Here we aimed to determine the mechanism of actions of DHEA, in comparison to vitamin E, in a chemically-induced hepatocellular carcinoma model in rats. Sprague-Dawley rats were administered with control diet without a carcinogen, diets with 1.5% vitamin E, 0.5% DHEA and both of the compounds with a carcinogen for 6 weeks. The doses were previously reported to have anti-cancer effects in animals without known toxicities. With DHEA treatment, cytosolic malate dehydrogenase activities were significantly increased by ${\sim}5$ fold and glucose 6-phosphate dehydrogenase activities were decreased by ${\sim}25%$ compared to carcinogen treated group. Activities of Se-glutathione peroxidase in the cytotol was decreased siguificantly with DHEA treatment, confirming its antioxidative effect. However, liver microsomal cytochrome P-450 content and NADPH-dependent cytochrome P-450 reductase activities were not altered with DHEA treatment. Vitamin E treatment decreased cytosolic Se-glutathione peroxidase activities in accordance with our previous reports. However, vitamin E did not alter glucose 6-phosphate dehydrogenase or malate dehydrogenase activities. Our results suggest that DHEA may have decreased tumor nodule formation and reduced lipid peroxidation as previously reported, possibly by increasing the production of NADPH, a reducing equivalent for NADPH-dependent antioxidant enzymes. DHEA treatment tended to reduce glucose 6-phosphate dehydrogenase activities, which may have resulted in limited supply for de novo synthesis of DNA via inhibiting the hexose monophophaste pathway. Although both DHEA and vitamin E effectively reduced preneoplastic foci in this model, they seemed to fimction in different mechanisms. In conclusion, DHEA may be used to reduce hepatocellular carcinoma growth by targeting NADPH synthesis, cell proliferation and anti-oxidant enzyme activities during tumor growth.

• Korean Journal of Metals and Materials
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• v.49 no.12
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• pp.983-988
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• 2011

Failure analyses of the screws in spinal fixation devices were carried out. The fractured screws were retrieved from a patient who had spinal surgery in the thoracic vertebrae from number 10 to 15. The failure occurred one month after the removal of the braces. Microstructures and fracture surfaces were examined by optical and scanning electron microscopy. The microstructures of the screws corresponded to annealed Ti-6Al-4V bar. However, in the vicinity of the screw surface, there was an insufficient number of fine precipitates. Fracture surfaces showed typical fatigue failure modes. Regarding the fact that no machining defects were detected, fatigue crack initiation might have been caused by the lack of precipitates near the screw surfaces. Only the fourth of five fixed screws was severely stress-concentrated by the action of the spinal bones, while the stress of the 4th screw was decreased to half of its acceptable level when the screw was supplemented by one more, which might have been fixed in the 6th vertebra under the 5th position by the switching of its position. The stress simulation was conducted by ANSYS with 3D CAD of PRO/E in order to understand the stress concentration behavior and to provide an effective spinal surgery guide.

• Korean Journal of Family Social Work
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• no.60
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• pp.101-132
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• 2018

The aim of this qualitative study was to explore and understand the roles, efforts, difficulties and challenges parents have in the process of raising teenage children and supporting their career development in the underprivileged families. The research was conducted through focus group interviews with low-income parents, with support from 11 local community welfare centers nationwide, and then thematic analysis was done with collected data. And we could draw on findings on the difficulties those parents are dealing with while assisting career plans of their children, the endeavors they make when doing so, the helpful support from the society, and things to be done in the future. With the results, we provide final recommendations on family-centered action plans and the roles of community welfare center that can effectively assist career development of teenage kids in the process of child upbringing of the underprivileged families.

• Bulletin of the Korean Chemical Society
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• v.15 no.10
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• pp.873-881
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• 1994

The approximate rate and stoichiometry of the reaction of excess diisobutylaluminum hydride-dimethyl sulfide complex($DIBAH-SMe_2$) with organic compounds containing representative functional group under standardized conditions (toluene, $0{\circ}C$) were examined in order to define the reducing characterstics of the reagent and to compare the reducing power with DIBAH itself. In general, the reducing action of the complex is similar to that of DIBAH. However, the reducing power of the complex is weaker than that of DIBAH. All of the active hydrogen compounds including alcohols, amines, and thiols evolve hydrogen slowly. Aldehydes and ketones are reduced readily and quantitatively to give the corresponding alcohols. However, $DIBAH-SMe_2$ reduces carboxylic acids at a faster rate than DIBAH alone to the corresponding alcohols with a partial evolution of hydrogen. Similarly, acid chlorides, esters, and epoxides are readily reduced to the corresponding alcohols, but the reduction rate is much slower than that of DIBAH alone. Both primary aliphatic and aromatic amides examined evolve 1 equiv of hydrogen rapidly and are reduced slowly to the amines. Tertiary amides readily utilize 2 equiv of hydride for reduction. Nitriles consume 1 equiv of hydride rapidly but further hydride uptake is quite slow. Nitro compounds, azobenzene, and azoxybenzene are reduced moderately. Cyclohexanone oxime liberates ca. 0.8 equiv of hydrogen rapidly and is reduced to the N-hydroxylamine stage. Phenyl isocyanate is rapidly reduced to the imine stage, but further hydride uptake is quite sluggish. Pyridine reacts at a moderate rate with an uptake of one hydride in 48 h, while pyridine N-oxide reacts rapidly with consumption of 2 equiv of hydride for reduction in 6h. Similarly, disulfides and sulfoxide are readily reduced, whereas sulfide, sulfone, and sulfonic acid are inert to this reagent under these reaction conditions.

• Journal of Digital Convergence
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• v.19 no.10
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• pp.521-533
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• 2021

The purpose of this study is to explore the self-directed learning experiences of nursing student in an online learning. Data collection was conducted through three focus group interviews from July to August 2021, and the subjects of the study were 15 nursing students who experienced online learning. For analysis, all interviews were recorded and transcribed as the participants said, and analyzed using qualitative content analysis. As a result of the study, 4 categories and 11 subcategories were derived. The four categories which nursing students experienced on online self-directed learning were 'cognitive action of learning motivation', 'preparing my own learning strategy through reflection', 'creating an environment that supports learning', and 'effective online instructional design and enthusiasm of instructors.' The results of this study can be used as basic data for preparing self-directed learning strategies of nursing students in online learning.

• Korean Journal of Pharmacognosy
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• v.52 no.4
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• pp.242-250
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• 2021

Artemisia frigida Willd (AW, Fringed sagewort), which is widespread in Mongolia, is a well-known medicinal plant as a member of the Compositae family. This study aims to explore the gastroprotective effect of water extract of AW on 150 mM HCl/60% ethanol-induced acute gastritis in 5 week old male ICR mice. Total polyphenols, total flavonoid contents, and anti-oxidant activity in vitro in AW were evaluated. First, the gross area of gastric mucosal damage was measured. Then western blot analysis was conducted to determine the possible mechanisms of action underlying the effects of AW. AW administration decreased gastric mucosal damage. Moreover, the group with AW treatment effectively inhibited nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression associated with oxidative stress. AW treatment enhanced an anti-oxidant effect through the increase of anti-oxidant proteins. Besides, the increased expressions of inflammatory cytokines induced by nuclear factor-kappa B (NF-κB) activation are alleviated through AW treatment. Taken together, AW exerted a gastroprotective effect against gastric mucosal damage. These results indicate that AW could have the potential used as a natural therapeutic drug for the treatment of acute gastritis.