• Journal of Sensor Science and Technology
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• v.6 no.4
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• pp.328-336
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• 1997

The CdSe thin films were grown on the Si(100) wafers by a hot wall epitaxy method (HWE). The source and substrate temperature are $600^{\circ}C$ and $430^{\circ}C$ respectively. The crystalline structure of epilayers was investigated by double crystal X-ray diffraction(DCXD). Hall effect on the sample was measured by the van der Pauw method and studied on the carrier density and mobility dependence on temperature. From Hall data, the mobility was increased in the temperature range 30K to 150K by impurity scattering and decreased in the temperature range 150k to 293k by the lattice scattering. In order to explore the applicability as a photoconductive cell, we measured the sensitivity(${\gamma}$), the ratio of photocurrent to darkcurrent(pc/dc), maximum allowable power dissipation(MAPD), spectral response and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in Cu vapor compare with in Cd, Se, air and vacuum vapour. Then we obtained the sensitivity of 0.99, the value of pc/dc of $1.39{\times}10^{7}$, the MAPD of 335mW, and the rise and decay time of 10ms and 9.5ms, respectively.

• Journal of Science Education
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• v.40 no.2
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• pp.166-188
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• 2016

The purpose of this study was to analyze the utilization of history of science and STEAM and the elementary school teachers' perceptions about design-based STEAM instruction applying the history of science in science class. To research the utilization of the history of science and STEAM in elementary science class, educational value of design-based STEAM instruction applying the history of science, the questionnaire was revised based on research conducted by Lee & Shin(2014), Park et al.(2010), Shin & Han(2011) and developed questionnaire a total of 20 questions. It was administered to reply the questionnaire to 201 teachers of elementary school in D and G area. The results of this study were as follows: elementary school teachers did not teach actively the history of science, made it read students by simply introducing himself. They did not teach actively STEAM due to not enough time(busy to take a magnitude). They were difficult to teach, but the most focused on the 'Creative Problem-solving' process. And elementary school teachers perceived positively about the educational value of design-based STEAM instruction applying the history of science. Especially, they perceived that it can help elementary school students find a hint for solving the problem through examples of cases of scientific principles and a scientist. In conclusion, it implicates that it is need to regard elementary school teachers' perceptions on application of the history of science and STEAM, and develop specific design-based STEAM program applying the history of science in order to be applied successfully in elementary school for the STEAM settlement.

• Science of Emotion and Sensibility
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• v.15 no.3
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• pp.389-398
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• 2012

Virtual worlds have pursued reality as if they actually exist. In order to evaluate the sense of reality in the computer-simulated worlds, several subjective questionnaires, which include specific independent variables, have been proposed in the literature. However, the questionnaires lack reliability and validity necessary for defining and measuring the virtual realization. Few studies have been conducted to investigate the effect of visual factors on the sense of reality experienced by exposing to a virtual environment. Therefore, this study was aimed at reinvestigating the variables and proposing a more reliable and advisable questionnaire for evaluating the virtual realization, focusing on visual factors. Twenty-one questions were gleaned from the literature and subjective interviews with focused groups. Exploratory factor analysis with oblique rotation was performed on the data obtained from 200 participants(females: 100) after exposing to a virtual character image described in an extreme way. After removing poorly loading items, remained subsets were subjected to confirmatory factor analysis on the data obtained from the same participants. As a result, 3 significant factors were determined to efficiently measure the virtual realization. The determined factors included visual presence(3 subset items), visual immersion(7 subset items), and visual interactivity(4 subset items). The proposed factors were verified by conducting a subjective evaluation in which participants were asked to evaluate a 3D virtual eyeball model based on the visual presence. The results implicated that the measurement method was suitable for evaluating the degree of the virtual realization. The proposed method is expected to reasonably measure the degree of the virtual realization.

• Journal of Embryo Transfer
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• v.18 no.3
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• pp.171-178
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• 2003

This study was conducted to investigate the effect of electric fusion methods on cell fusion rate and embryo development by somatic cell nuclear transfer in Korean Native Cattle. The KNC ear cell was cultured in vitro for confluence in serum starvation condition(DMEM＋0.05％ FBS) for cell confluence. The zona pellucida of IVM oocytes were partially dissection using micro pipette. Ear cells were transferred into an enucleated oocyte. The reconstructed embryos were electrically fused with Zimmermann Cell Fusion Medium(ZCFM). Nuclear transfer embryos were activated with a combination of 10${\mu}{\textrm}{m}$ calcium ionophore(5 min) and 2.0mM 6-DMAP(3 hr). The activated embryos were cultured in CR1 -aa medium contains 0.3％ BSA or 10％ FBS at 37$^{\circ}C$, 90％ $N_2$, and 5％ $CO_2$in incubator for 6 days. The fusion rates were 51.6％(chamber) and 68.9％(needle), respectively and there were significantly difference between the fusion method(P<0.05). But, lysis rates were not significantly different(10.7％, 11.5％), respectively. The cleavage rates were significantly different between the chamber method(73.2％) and needle method(80.3％), respectively(P<0.05). The rates of early embryos(2∼4cells) and blastocysts of chamber and needle methods were 54.1％, 61.1％ and 18.4％, 26.3％ respectively, and needle method was significantly higher than chamber method(P<0.05). But, morulae formation rate were not significantly differences between the chamber(6.7％) and needle(6.2) method(P <0.05). These result suggest that electric fusion of needle method was to be profitable for nuclear transfer embryo fusion rate, blastocyst formation rate and reduce of oocyte lysis.

• Journal of Embryo Transfer
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• v.18 no.1
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• pp.69-73
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• 2003

This study was undertaken to investigate the effect of three different porcine IVM media, TCM-199, mSOF and NCSU-23 on early development of porcine spontaneous parthenogenotes. Spontaneous parthenogenotes were induced by a prolonged culture of porcine oocytes in each medium. In Experiment 1, oocytes derived from gilts were matured in three IVM media and maturation of oocytes was evaluated by the status of chromatin configuration. Oocytes matured in mSOF, NCSU-23 and TCM-199 showed no significant difference (P>0.05) in maturation. Maturation rates at 48h after IVM were 83.1$\pm$2% (mSOF), 78.0$\pm$3% (NCSU-23) and 83.5$\pm$2% (mSOF), 78.0$\pm$3% (NCSU-23) and 83.5$\pm$2% (TCM-199). In Experiment 2, pronucleus formation and development to 6~8 cell stage of pig oocytes activated spontaneously. Pronucleus formation, cleavage rate and development to 6~8 cell embryos of porcine spontaneous parthenogenotes were assessed at 55~58 h, 96 h and 168h after IVM, respectively. Pronucleus formation (5.4$\pm$2% and 3.7 $\pm$ 1% vs 1.7 $\pm$ 3%) and development to the 6$\pm$8 cell (3.2$\pm$3% and 4.0$\pm$1% vs 1.4$\pm$3%) was significantly (P<0.05) higher in mSOF or NCSU-23 than TCM-199. In conclusion, the present study showed that oocytes matured in mSOF and NCSU-23 were spontaneously activated with higher frequency.

• Journal of Embryo Transfer
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• v.29 no.3
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• pp.265-271
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• 2014

Implementation of smart embryo technologies in cattle e.g. ovum pick-up followed by in vitro embryo production (OPU-IVP). Seasonal variation is important factor for follicular growth, oocytes quality, quantity and developmental competence. Therefore the aim of present study was carried out to investigated whether the seasons (hot and cool) effect on follicular development, oocyte recovery and subsequent embryo development. Follicular oocytes were aspirated from Korean native cows (Hanwoo) by the ovum pick-up (OPU) method, which was performed 24 times during two different seasons, the hot (July to September) and cool (October to December), from OPU donors. The recovered oocytes were classified according to morphological categories and used for in vitro embryo production (IVEP). The mean number of total follicles was significantly higher (p<0.05) during the hot season ($18.32{\pm}2.26$) compared to cool season ($15.41{\pm}3.34$). Furthermore, seasons did not significantly effect on the number of oocytes recovered (hot season: 41.16% vs. cool season: 46.14%). However, the average number of Grade A oocytes was significantly greater during hot ($1.75{\pm}1.86$) season compared to the cool season ($1.00{\pm}1.46$), but there was no significant difference of other grades oocytes. The cleavage rate (hot: 66.67% vs. cool: 63.3%) and embryo development (hot: 58.95% vs. cool: 56.97%) did not differ significantly between the seasons. In conclusion, the results of present study suggest that the season (hot and cool) does not have effects on the oocyte recovery and embryo developmental competence of in vitro cultured embryos.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.10
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• pp.61-71
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• 1971

This study was conducted in order to investigate the effects of slaked lime and borax on the Akiochi paddy field. The pot trial(slaked lime was treated 0, 6, 10, 15g and borax 0, 0.75, 1.5g per pot) and the field trial(slaked lime was treated 0, 100, 200kg and borax 0, 10, 30, 50kg per 10are) respectively. The results are summarized as fo11ows. I. Pot Trial: 1. In a heavy treated of borax, appeared chlorosis on whole leaves(bottom) in early growing stage, However, in about 25 days after transplanting, these chlorosis were disappeared gradually. And in proportion to close by maturity after the ear-heading, changed to dark brown color and rolled at the end of upper leaves, finally withered. At the same time the part of the end of grains was also colored to dark brown. 2. Slaked lime effected to increase the ti1lering, hence increased the number of ear, on the other hand, borax showed the tendency of repression the tillering, conversely. 3. Borax effected to hurried up to heading date of rice plant, to which borax had been the plot of B$_1$ to 3 days and B$_2$ to 5 days, hurried up than control respectively, regardless of the quantities of slaked lime application. 4. According to the application of borax, the length of culm were shortened, otherwise the length of panicle were longished, then no recognized the. independent effect of slaked lime. 5. The number of grains per panicle were seemed like increased by treatment of slaked lime, but the grain were decreased in the heavy treatment of slaked lime and borax. These phenomena were showed in ratio of maturity likely tendency as above. 6. In the 1, 000 grains weight of brown rice, in the case of slaked lime was almost no significant, otherwise by increase the application of borax, increased the weight of 1, 000 grains and the size of the grains was greater. 7. The weight of rough rice and straw were showed the same tendency as the number of grains and maturity ratio. particularly, showed the phenomenon of the reduction by the heavy application of borax. II. Field trial: 1. In a heavy treated of borax, appeared chlorosis in a early growing stage, according to close by maturiting date after the ear-heading changed to dark brown the end of upper leaves, finally dried. 2. Slaked lime application accelerated the growth and increased the number of ear, but borax showed the tendency of repression the tillering. 3. Borax effected to hurried up to heading date of rice plant, according to heavy treatment of borax quickened heading date for 4 to 5 days. 4. As a whole, culm length was repressed by borax treatment. 5. Borax application 10kg per 10are advanced progress the maturity, but in the case of above 30kg per 10are of borax showed the tendency obstruction the maturity. 6. The yield of rough rice and brown rice recognized the independent effect of slaked lime and borax, respectively. the yield was decreased by the abundant of borax.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.6 s.165
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• pp.837-847
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• 2007

1,098 pieces of photographs($1995{\sim}2002$) of men's suit style have been classified according to fashion images in order to examine features and change aspects with statistical analysis. The findings of examining features of the trend by year with test of homogeneity, correspondence analysis, biplots, correlation analysis and regression analysis are as follows: (a) there are significant differences on fashion images as the trend by yew with test of homogeneity, (b) there are remarkable differences on the fashion trend by year with correspondence analysis and biplots. (c) There are significant correlations for appearance among fashion images by its frequency through correlation analysis, and (d) it is assumed that fashion images are going to be gradually outstanding according to regression analysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.293-303
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• 2017

To elucidate the physiological responses of rice plants to the essential mineral silicon (Si), we assessed the effects of treatments with Si, nitrogen ($NH_4NO_3$; ammonium nitrate), and calcium ($CaCl_2$; calcium chloride), independently or in combination on mineral uptake rates and levels of the hormones abscisic acid (ABA), gibberellin ($GA_1$) and jasmonic acid (JA). We found that nitrogen and calcium uptake was inhibited by Si application. However, solo application of nitrogen or calcium did not affect Si uptake. Compared to the untreated plants, the application of Si, $NH_4NO_3$ or $CaCl_2$ increased the endogenous hormone levels in treated plants. In particular, the concentrations of $GA_1$ and JA increased significantly after the application of Si or $NH_4NO_3$. The level of $GA_1$ observed after a treatment (solo or combine) with Si, and $NH_4NO_3$ was higher than that of the control. By contrast, independent application of $CaCl_2$ or a combined treatment with Si and $CaCl_2$ did not alter $GA_1$ levels. The highest level of $GA_1$ was present in plants given a combination treatment of Si and $NH_4NO_3$. This effect was observed at all time points (6 h, 12 h and 24 h). Endogenous JA contents were higher in all treatments than the control. In particular, a combination treatment with Si and $NH_4NO_3$ significantly increased the JA levels in plants compared to other treatments at all time points. A small increase in JA levels was observed after 6 h in plants given the $CaCl_2$ treatment. However, JA levels did not differ between plants given a $CaCl_2$ treatment and controls after 12 h or 24 h of exposure. We conclude that treatment with $CaCl_2$ alone does not affect endogenous JA levels in the short term. Endogenous ABA contents did not show any differences among the various treatments.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.4
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• pp.235-243
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• 2007

In order to understand the water mass properties in the southern location of the East Sea in the Korean coasts, the vertical distributions (down to 2,000 m deep) of water temperature, salinity, and dissolved inorganic nutrients were determined in April of 2005. The water mass of the surveyed location showed distinct vertical layers; highly saline surface, surface mixing layer, and thermocline of low temperature and salinity. The water layer below 300 m was characterized by water temperature lower than $1^{\circ}C$ and salinity 34.06, showing a representative water mass of the East Sea. The inorganic nutrients rapidly increased from 200m in the northern and southern parts around Ulleung Basin. A marked environmental difference was found between two layers separated by thermocline. The upper layer of the thermocline was oligotrophic and the vertical distribution of nutrient was very stable. In the water layer between 100 and 200m the nutrients slightly increased but remained still stable. From southern coasts to northeastern Ulleung, the water mass properties were site specific; the thickness of the surface mixed layer and nutricline showed a trend diminishing toward the northern locations probably due to diminished influence of Tsushima water. Redfield ratio (N:P=16:1) based on the ratio of chemical composition in organism revealed that nitrogen value continuously decreased to less than 16 with the water depth down to loom from the thermocline. The value in the water layer deeper than 100 to 200 m, thereafter, showed an increasing trend (over 16). This result was further supported by the finding of lower chlrophyll a content in the layer.