• 문화기술의 융합
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• 제10권4호
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• pp.357-365
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• 2024

본 연구는 그림책 감상을 통한 유아의 로봇 활용 놀이가 순서적 사고에 미치는 영향을 알아보고자 한다. 이를 위해 서울시에 위치한 각 유치원 만 5세 15명의 유아를 대상으로 J유치원(실험집단)은 '그림책 감상 로봇 활용 놀이'를 지원하였으며, C유치원(비교집단)은 '그림책 감상 자유놀이'를 지원하였다. 두 집단의 놀이 경험의 차이를 알아보기 위해 순서적 사고 검사도구를 활용하여 놀이지원 전과 후에 대한 점수자료를 수집하였으며, 수집된 자료는 SPSS 28.0프로그램을 활용하여 사전점수를 공변인으로 한 사후점수를 ANCOVA(공분산분석)를 실시하였다. 그 결과, 그림책 감상을 통한 로봇 활용 놀이를 경험한 실험집단은 비교집단에 비해 순서적 사고의 총점과 하위 영역인 역학, 행동, 의도에서 모두 유의미하게 향상된 것으로 나타났다. 이러한 연구결과는 유아 주도의 창의적인 놀이매체로서 로봇의 가치를 발견하고, 미래사회의 역량으로 그 중요성이 강조되고 있는 순서적 사고 역량을 증진할 수 있도록 지원하는 놀이연구로서 가치가 있다.

• 아동학회지
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• 제13권2호
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• pp.33-51
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• 1992

The purpose of this study was to investigate activities of kindergarteners in the mathematics corner. The study included an analysis of children's interactions with mathematics materials and of children's peer interactions during mathematics activities. The subjects were 47 children aged three to four and 72 children aged four to five from four classes of two kindergartens in Kwangju. Children's math activities during free play sessions were observed and audiotaped. The data were coded by the categories of children's peer interactions and types of mathematics manipulations. The characteristics of children's peer interactions and materials frequently selected by the subjects were identified. The results indicated that (1) most of the math materials were for passive manipulation that require children to respond according to predetermined conditions like the rules of games, but (2) the materials that children liked to play with were active manipulative materials that require diversity and flexibility of children's thinking and allow several choices for solutions, and (3) children's peer interactions during math activities were categorized into unilateral and reciprocal/collaborative peer interaction type.

• Journal of Plant Biology
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• 제9권1_2호
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• pp.1-6
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• 1966

Using the Chlorella cells which had been uniformly labeled with $^{32}P$, the distribution of phosphorus in various fractions of cell material was investigated. Uniformly $^{32}P$-labeled Chlorella cells were further grown in a P-free medium, and some protions of the cells were taken out at intervals during the culture, and subjected to analyze the contents of $^{32}P$ in various fractins of the cell constituents. 2. Analysis of the $^{32}P$-labeled Chlorella cells showed that the highest in P-content was the fraction of RNA followed by those of lipid, RNA-polyphosphate complex, acid-insoluble polyphosphate, acid-soluble polyphosphate, DNA and protein. 3. During the culture of $^{32}P$-labeled Chlorella cells in a P-free medium, amounts of phosphate in DNA, protein and lipid fractions increased, while the P-contents in the fraction of RNA-polyphosphate complex decreased as well as those of acid-insoluble polyphosphate and acid-soluble polyphosphate fractions. 4. It was inferred that phosphorus used in the syntheses of DNA and protein was taken from polyphosphates of the cells, and RNA-polyphosphate complex would play an important role as a phosphate pool.

• Steel and Composite Structures
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• 제26권3호
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• pp.273-287
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• 2018

Buckling and free vibration analysis of sandwich micro plate (SMP) integrated with piezoelectric layers embedded in orthotropic Pasternak are investigated in this paper. The refined Zigzag theory (RZT) is taken into consideration to model the SMP. Four different types of functionally graded (FG) distribution through the thickness of the SMP core layer which is reinforced with single-wall carbon nanotubes (SWCNTs) are considered. The modified couple stress theory (MCST) is employed to capture the effects of small scale effects. The sandwich structure is exposed to a two dimensional magnetic field and also, piezoelectric layers are subjected to external applied voltages. In order to obtain governing equation, energy method as well as Hamilton's principle is applied. Based on an analytical solution the critical buckling loads and natural frequency are obtained. The effects of volume fraction of carbon nanotubes (CNTs), different distributions of CNTs, foundation stiffness parameters, magnetic and electric fields, small scale parameter and the thickness of piezoelectric layers on the both critical buckling loads and natural frequency of the SMP are examined. The obtained results demonstrate that the effects of volume fraction of CNTs play an important role in analyzing buckling and free vibration behavior of the SMP. Furthermore, the effects of magnetic and electric fields are remarkable on the mechanical responses of the system and cannot be neglected.

• 천문학회보
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• 제38권2호
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• pp.59.2-59.2
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• 2013

The luminosity evolution of Type Ia supernova (SN Ia) and dust extinction play major roles in the systematic uncertainties in the SN cosmology. In order to overcome these obstacles, here we propose to use GMT-GMACS to take spectra for early-type host-galaxies of SNe Ia in the redshift range between 0.2 and 1.0. This high-redshift sample will be taken from Dark Energy Survey (DES), which expects more than 200 early-type hosts at this redshift range. They will be compared with nearby early-type hosts, for which we are now obtaining low-resolution spectra. We will select host-galaxies of same population age range for both nearby and high-redshift samples to reduce the possible evolution effect. Since we are dealing with early-type galaxies, our test is also less affected by dust extinction. We expect that our evolution-free and dust-free dark energy test will provide more robust results on the nature of dark energy.

• 약학회지
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• 제49권2호
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• pp.174-179
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• 2005

The human skin is constantly exposed to environmental irritants such as ultraviolet, smoke, chemicals. Free radicals and reactive oxygen species (ROS) caused by these environmen tal facts play critical roles in cellular damage. These irritants are in themselves damaging to the skin structure but they also participate the immensely complex inflammatory reaction. The purpose of this study was to investigate the skin cell protective effect of Campsis grandiflora extract on the UVB-irradiated human dermal fibroblasts (HDFs). We tested free radical and superoxide scavenging effect in vitro. C. grandiflora extracts had potent radical scavenging effect by 82% at $100{\mu}g/ml$, respectively. For testing intracellular ROS scavenging activity the cultured HDFs were analyzed by increase in DCF fluorescence upon exposure to UVB 20 $MJ/cm^2$ after treatment of C.grandiflora extracts. The results showed that oxidation of CM-DCFDA was inhibited by C.grandiflora extracts effectively and C.grandiflora extracts has a potent free radical scavenging activity in UVB- irradiated HDFs. In ROS imaging using confocal microscope we visualized DCF fluorescence in HDFs directly. In conclusion, our results suggest that C.grandiflora can be effectively used for the prevention of UV-induced adverse skin reactions such as radical production, and skin cell damage.

• 한국항공운항학회지
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• 제16권4호
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• pp.54-62
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• 2008

International organizations related to air transport such as ICAO, IATA, ACI are forecasting that the number of passenger will grow about 4.4% annually up to 2015. Therefore, the innovation of given system technology and operation procedure is required in global scale to cope with the increase of air traffic demand. CNS/ATM infrastructure based on satellite is considered to play key role in order to solve the problems due to the dramatic increase of air traffic demand over the world. Free flight concept in the air transport operation has been proved with CNS/ATM infrastructure especially in USA and Europe. Therefore, it is necessary to develop key technologies to overcome technology gap and to secure international competitiveness in Korea. ADS-B is an important issue, and new element technologies should be considered as essential items which were shown in Capstone project. Nowadays, the free flight concept is combined to Air Transport Road Map such as NextGen project in USA, SESAR in Europe. In this process, free flight is included in the concepts such as ATM(Air Traffic Management), aviation security and safety, environmental protection and economy development, wide area weather variable reduction service, information integration and application between the related authorities (civil/military) etc. The purpose of research is to establish mid-term and long-term infrastructure plan and strategy for free flight realization in Korea. The analysis of action target and equipment construction status, phase construction plan of infrastructure has been performed by considering mid-term and long-term free flight plans of USA and Europe.

• 한국농촌건축학회논문집
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• 제22권3호
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• pp.9-16
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• 2020

The trend emphasizes children-oriented, play-oriented ecological education programs for children's ecological education. And most of these nature -friendly and eco-friendly education takes place outdoors. Therefore, outdoor space planning is important in childcare facilities. This case study aims to analyze the actual conditions of outdoor spaces in daycare centers and to provide standard data for outdoor space planning. In order to provide basic data on the improvement direction and planning standards of outdoor spaces, this present study conducted the composition, utilization status and related problems of outdoor spaces for nature -friendly ecological education in childcare facilities. Accordingly, outdoor space planning for ecological education should consider outdoor space characteristics such as free and easy accessibility between indoor and outdoor spaces, openness of space, flexibility, dynamic/static space, and nature affinity. Therefore, for an ecological education environment, children should be able to freely approach nature and play in the natural environment without any restrictions and artificial controls. Also, in urban areas, natural environment such as parks and open spaces should be considered as outdoor play spaces for children.

• 유통과학연구
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• 제15권4호
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• pp.41-57
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• 2017

Purpose - With the growth of the duty free shop field and an increase in the executive interest in it, it becomes necessary to examine if PBZ (1988) SERVQUAL could be applied to duty free shop service reflecting on this increased interest and the importance of marketing strategy alternative managing multinational customers. Therefore, the present research focused on the comparison of Korean and Chinese consumers. We examined how service quality would affect relationship quality and customer loyalty. Research design, data, and methodology - Surveys were distributed to 235 Korean and 220 Chinese consumers who have visited a Korean duty free shop. We analyzed frequency analysis, mean difference analysis, and reliability analysis, exploratory factor analysis, confirmatory factor analysis, structural equation model analysis, and multi-group analysis. Results - First, perceived tangibles, responsiveness, empathy, assurance, price benefits, product diversity, and IT convenience of duty free shop service all appeared to be positive effect on customer satisfaction; at the same time, only tangibles, responsiveness, empathy, assurance, and price benefits positively affected customer trust. Secondly, customer satisfaction and trust that are the components of the relationship quality appeared to be positive effect on customer loyalty. Thirdly, customers' satisfaction was found to play a full mediating role effect among all of the service quality factors with customer loyalty; however, customer trust was found to have the mediating effects only with tangibles, empathy, assurance, and price benefits. Fourthly, we found a difference between how service quality influences relationship quality and how service quality influences customer loyalty as a function of different nationality. As a result, it appeared that price benefits and IT convenience affected customer satisfaction more among Koreans than among Chinese. Finally, it appeared that customer satisfaction and trust affected customer loyalty more among Chinese than among Koreans. Conclusions - The results of this study contribute to the theoretical knowledge, but also provide strategic alternatives to enhance differentiation, international competence of enterprises led by duty free shop and service quality improvement and customer loyalty of enterprises are drawn as a foundation for constructing international customer relationship in future global era.

• BMB Reports
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• 제28권1호
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• pp.33-39
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• 1995

The Gelatinases (typeIV collagenases) are metalloproteinases that may play an important role in tumor invasion and metastasis. Progelatinase A was purified from a conditioned medium of T98G human glioblastoma cells. TIMP-2 complexed progelatinase A and free progelatinase A were separated by heparin affinity HPLC. The final product was homogeneous on SDS-PAGE, with a molecular weight of 64,000 daltons without reduction. TIMP-2 and free progelatinase A were separated from TIMP-2 complexed progelatinase A by reverse-phase HPLC in the presence of trifluoroacetic acid. TIMP-2 complexed progelatinase A was resistant to activation by p-aminophenyl mercuric acetate (APMA), and showed less than 20% of the activity of the TIMP-2 free active enzyme. TIMP-2 free progelatinase A was easily activated to the mature form with a molecular weight of 57,000 daltons by APMA and showed high activity compared to the TIMP-2 complexed enzyme.