• 경영과학
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• 제19권1호
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• pp.179-188
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• 2002

Ventures through technological innovation are increasingly suggested as one of the main engines for economic growth that can help control inflation and black trade balance. The Purpose of this study is to extract the network performance factors for ventures according to ventures life cycle. For the Purpose, the existing studies were examined into start-up company, entrepreneurial firm, smell firms with competitive advantage against large firms, and ventures network activity. And 63 samples from ventures in Korea were taken and analyzed empirically. The analyses and results are (1) the actual conditions of network activity on ventures; (2) the investigation of relationship between network activity and performance of ventures by venture's life cycle through the observations of Korean ventures. From the results, It Is also found that factors such as external environment and a ventures life cycle have been considered as the main influences on the performance of ventures. In addition, limitations and suggestions for further studies are noted.

• 한국환경과학회지
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• 제14권7호
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• pp.669-674
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• 2005

Catalytic combustion of toluene was investigated on $CuOx/SnO_2-ZrO_2\;CuOx/SnO_2\;CuOx/ZrO_2$ catalysts prepared by impregnation. Characteristics of catalysts loaded on binary support and single support were observed by TPR, TPO, XRD, XPS techniques. The results on catalytic combustion showed that binary supports improve the activity of copper in the combustion of toluene. The reason for high catalytic activity on toluene combustion of $CuOx/SnO_2-ZrO_2$ catalyst was ascribed to oxidation$\cdot$reduction activity at low temperatures and stability of oxidation state after reduction.

• 한국초등과학교육학회지:초등과학교육
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• 제23권4호
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• pp.279-286
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• 2004

The purpose of this study is to develop and apply effective teaching strategies and program for the gifted-in-science. The teaching material for the gifted students was focussed on microscope. This study consists of three steps according to the enrichment triad model of Renzulli. Firstly, the gifted students investigate and express themselves for theological backgrounds, for examples, kinds, structure and use in various ways of microscope. It is to provide basic data for the effective ideas and interest which help students have the appropriate microscopic conceptions. In the second step, it contains understanding of a term and function of microscope, making of simple microscope, principle of a statue focusing and size estimation of an outline of subjects by scientific investigation activity. Lastly, it focussed on enlargement of post-learning through investigation of relationship with inter-science and experiments using microscope. Therefore, it was concluded that this study may help teachers reconsider scientific program development for the gifted or enriched students and to be successful in the teaching-learning processes.

• 한국초등과학교육학회지:초등과학교육
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• 제38권4호
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• pp.453-464
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• 2019

In this study, the types of inquiry activities in the $5^{th}$ & $6^{th}$ grade science textbooks according to the 2015 revised science national curriculum were analyzed and compared according to grade level and science area. Science textbooks for elementary school $5^{th}$ & $6^{th}$ graders contain quite diverse types of inquiry activities, which are student-centered inquiry activities. There were comparatively higher proportions of inquiry types such as experiment & observation and simulation, but relatively lower of inquiry types of investigation-discourse & presentation, discussion, expression. Elementary science textbooks are expected to cultivate science key competencies for elementary school students. Considering the science area, the motion & energy, substances, earth & space, and integration areas had the most experiment & observation among activity types, while the life area had the most simulation activities. Even in some area of the 6th grade science textbook, there was little or no data interpretation, discussion, and simulation activities. In order to achieve the goal of elementary science education, science textbooks should be developed considering the revision of future elementary science curriculum.

• 보건의료산업학회지
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• 제8권1호
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• pp.65-73
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• 2014

The purpose of this study is to analyze the correlation between cognition, depression and leisure activity in elderly people above 65 years of age, and to improve their health and quality of life by providing baseline data for occupational therapy intervention. This investigation was performed on 118 elderly people above 65 years of age who lived in local community and two senior welfare centers. In order to collect the data, we used MMSE-K, KDS, Questionnaire for leisure activity. The depression of elderly people was negatively correlated with their cognition(p<.01) and leisure activity(p<.001), whereas cognition was positively correlated with their leisure activity(p<.01). In conclusion, the correlation between cognition, depression and leisure activity of elderly people appeared statistically significant. Therefore, leisure activity program should be designed through additional research and effectively provided in nursing home and community senior welfare center to prevent depression increase and cognitive decline.

• 대한수의학회지
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• 제4권1호
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• pp.15-17
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• 1964

Scabby burley collected in Kyong Sang Nam Do fed to healthy dogs, age less than 2 years, old and determined the Choline-Esterase Activity in blood of dogs. The results obtained in this investigation are summarized as follows. 1. Choline-Esterase Activity in the blood of dogs fed Scabby barley has been decreased. 2. The poisionous component of the Scabby barley thought to be Anticholinesterase.

• Food Science and Biotechnology
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• 제18권2호
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• pp.506-512
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• 2009

The antimicrobial activity of water and ethanol extracts from 30 species of algae was measured using the agar diffusion method and minimum inhibitory concentration (MIC) test. In agar diffusion method, the 95% ethanol extracts from 12 of the algae showed growth inhibition against the tested microorganisms. In particular, Ishige okamurai, Ecklonia stolonifera, Sargassum siliquastrum, Sargassum thunbergii, Colpomenia bullosa, and Ecklonia cava had strong antibacterial activities against Gram-positive bacteria at 4 mg/mL. In the results of the MIC test, S. siliquastrum showed the most antimicrobial activity, where its MIC values ranged from 0.005 to 0.0075% against Listeria monocytogenes, Clostridium perfringens, and Basillus subtilis. In the thermal stability test, for the ethanol extracts of I. okamurai, E. cava, S. siliquastrum, S. thunbergii, and C. bullosa, the extracts proved to maintain high antimicrobial activities when they were treated at $121^{\circ}C$ for 15 min. In the pH stability test, the antimicrobial activity of the S. siliquastrum ethanol extract was stable from pH 2 to 10, whereas the activity of the other species ethanol extracts were weakened under pH 10 against several microbes.

• Ocean and Polar Research
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• 제33권3호
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• pp.255-263
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• 2011

The aim of this investigation was to evaluate antioxidant activity of crude extracts from the halophyte Vitex rotundifolia, their solvent fractions, and isolated compounds (1-3). Antioxidant capacity was determined by measuring DPPH radical, and authentic $ONOO^-$ and $ONOO^-$ generated from 3- morpholinsydnonimine (SIN-1) in vitro as well as degree of occurrence of intracellular ROS, NO and GSH in mouse macrophage Raw 264.7 cells. From comparative analysis, MeOH extract, n-BuOH, and 85% aq. MeOH solvent fractions showed significant antioxidant effect in DPPH radical and $ONOO^-$ assay systems. Activity-guided purification of n-BuOH and 85% aq. MeOH fractions led to the isolation of flavonoids 1-3. Among them, compound 1 exhibited excellent antioxidant effect in all bioassay systems tested. On the other hand, compounds 2 and 3 revealed potent inhibitory effect against $ONOO^-$ generated from SIN-1, comparable with the positive control penicillamine.

• Journal of Microbiology and Biotechnology
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• 제18권10호
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• pp.1729-1734
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• 2008

Chitosan, a cationic polysaccharide, has been widely used as a dietary supplement and in a variety of pharmacological and biomedical applications. The antifungal activity and mechanism of action of low molecular weight water-soluble chitosan (LMWS-chitosan) were studied in fungal cells and vesicles containing various compositions of fungal lipids. LMWS-chitosan showed strong antifungal activity against various pathogenic yeasts and hyphae-forming fungi but no hemolytic activity or cytotoxicity against mammalian cells. The degree of calcein leakage was assessed on the basis of lipid composition (PC/CH; 10:1, w/w). Our result showing that LMWS-chitosan interacts with liposomes demonstrated that chitosan induces leakage from zwitterionic lipid vesicles. Confocal microscopy revealed that LMWS-chitosan was located in the plasma membrane. Finally, scanning electron microscopy revealed that LMWS-chitosan causes significant morphological changes on fungal surfaces. Its potent antibiotic activity suggests that LMWS-chitosan is an excellent candidate as a lead compound for the development of novel anti-infective agents.

• 한국분말재료학회지
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• 제18권6호
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• pp.538-545
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• 2011

This study shows that catalytic activity of bimetallic RhPt nanoparticle arrays under CO oxidation can be tuned by varying the size and composition of nanoparticles. The tuning of size of RhPt nanoparticles was achieved by changing concentration of rhodium and platinum precursors in one-step polyol synthesis. Two-dimensional RhPt bimetallic nanoparticle arrays in different size and composition were prepared through Langmuir-Blodgett thin film technique. CO oxidation was carried out on these two-dimensional nanoparticle arrays, revealing higher activity on the smaller nanoparticles compared to the bigger nanoparticles. X-ray photoelectron spectroscopy (XPS) results indicate the preferential surface segregation of Rh compared to Pt on the smaller nanoparticles, which is consistent with the thermodynamic analysis. Because the catalytic activity is associated with differences in the rates of $O_2$ dissociative adsorption between Pt and Rh, this paper suppose that the surface segregation of Rh on the smaller bimetallic nanoparticles is responsible for the higher catalytic activity in CO oxidation. This result suggests a control mechanism of catalytic activity via synthetic approaches of colloid nanoparticles, with possible application in rational design of nanocatalysts.