• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.4
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• pp.140-144
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• 2014

Co-(0.7 wt%) and Pr-(2.0, 3.5 or 5.0 wt%) doped cubic zirconia ($ZrO_2:Y_2O_3=50:50wt%$) single crystals grown by a skull melting method were heat-treated in $N_2$ at $1150^{\circ}C$ for 5 hrs. The brown colored as-grown single crystals were changed into either dark brownish green, greenish blue and light green color after the heat treatment. Before and after the heat treatment, the YSZ (yttria-stabilized zirconia) single crystals were cut for wafer form (${\phi}7.5mm{\times}t3mm$). The optical and structural properties were examined by UV-VIS spectrophotometer and X-ray diffraction. Absorption by $Co^{2+}$(${\fallingdotseq}589nm$: ${\Gamma}_8[^4A_2(^4F)]{\rightarrow}{\Gamma}_8+{\Gamma}_7[^4T_1(^4F)]$, ${\fallingdotseq}610nm$: ${\Gamma}_8[^4A_2(^4F)]{\rightarrow}{\Gamma}_8[^4T_1(^4F)]$], ${\fallingdotseq}661nm$: ${\Gamma}_8[^4A_2(^4F)]{\rightarrow}{\Gamma}_6[^4T_1(^4F)]$]) and $Pr^{3+}$(${\fallingdotseq}450nm$: ${^3}H{_4}-{^3}P{_2}$, ${\fallingdotseq}473nm$: ${^3}H{_4}{\rightarrow}{^3}P{_1}$, ${\fallingdotseq}484nm$: ${^3}H{_4}{\rightarrow}{^3}P{_0}$), change of ionization energy and lattice parameter were confirmed.

• Microbiology and Biotechnology Letters
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• v.5 no.3
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• pp.133-140
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• 1977

The results of electron microscopic studies on the cell fine structure of Nocardia sp the location of tellurite-reducing enzyme and the reduction part of T. T. C. (Triphenyl tetrazonium chloride) were summarized as follows. As the fine structure of the cell, the membrane-like structure with unit membrane was distributed in the cytoplasm. The membrane-like structure had complicate forms: some of membrane-like structure appeared spiral form. As the metal tellurium salt appeared in the cytoplasm, it is obvious that tellurite and tellurate-reducing enzymes are present in the cytoplasm. Reduction of T. T. C. took place in the cell membrane and the intracellular membrane-like structure. Therefore, it was thought that reduction of tellurate and T. T. C. took place in different parts. T. T. C. formazane formed in the cell was reoxidized by osmic acid which was used as a fixation reagent for the electron microscopic specimen preparation. As 95％ T. T. C. formazane was soluble in ethanol and embedding materials and removed out of the cell, an originally formed formazane appeared as electron light part on the electron microscopic image.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.829-846
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• 2015

This study was conducted to determine the effects of organic fertilization rates on the nutrient accumulation and recovery in radish (Raphanus sativus L.) as well as growth and yield of radish in Jeju island. An understanding the relationships between organic fertilization rate, crop nutrient recovery and crop yield can assist in making organic fertilizer recommendation which balances crop value and environmental risk in organic cultivation. Nitrogen (T-N), phosphate ($P_2O_5$) and potassium ($K_2O$) were applied at 0, 115-35-40, 230-70-80 (standard application rate), 460-140-160, 230-200-100 (recommended application rate) and 158-53-35 kg/ha (customary application rate), respectively as the broadcast application of mixed organic fertilizer (N 4.5% - $P_2O_5$ 1.5% - $K_2O$ 1%) in combination with langbeinite ($K_2O$ 22%), 100% at sowing period. The organic fertilizer was made of organic materials like oil cakes. Total yield of radish, as fresh weight of roots, increased with increasing organic fertilizer doses to a maximum at rate of standard or soil-testing application. Nitrogen, phosphate and potassium accumulations of radish increased curvilinearly with increasing organic fertilization rate to a maximum at rate of N 460 - $P_2O_5$ 140 - $K_2O$ 160 kg/ha. However, nitrogen, phosphate and potassium use efficiency of applied organic fertilizer decreased curvilinearly or linearly with increasing organic fertilization rate. Application of organic fertilizer in combination with langbeinite (as a potassium source) had significant effect on the yield of radish. Organic fertilization on a basis of standard or soil-testing application rate is recommended for maximun radish yield in organic cultivation.

• Hwankyungkyoyuk
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• v.21 no.3
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• pp.13-25
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• 2008

This study examined the educational effects of journal writing on environmental literacy of elementary students. Thirty-one 3rd grade students were involved in the journal writing which is considered as one of the most frequently performed writing activities in elementary students. Topics for the journal writing were chosen from a textbook on the environment. Before and after the journal writing, an instrument was used to measure the environmental literacy of the students. The environmental literacy instrument was originally developed by Jin (2004) then were modified by Kim (2005) for elementary students. The results of this study are as follows. The environmental literacy of the students, on average, was improved from 140.84 (74.5%) to 161.84 (85.6%) after the journal writing and the difference was statistically significant(t=7.46, p<.001). The environmental literacy scores were significantly improved in every variable after the journal writing: ecological knowledge(t=3.60, p<.01), environmental sensitivity(t=2.54, p<.05), knowledge of environmental issues(t=3.11, p<.01), environmental attitude(t=5.92, p<.001), environmental concern(t=5.27, p<.001), sense of environmental crisis(t=2.97, p<.01), environmental issue investigation and action strategy knowledge (t=2.34, p<.05), environmental skill(t=4.86, p<.001), locus of control(t=5.63, p<.001), and responsible environmental behavior(t=4.64, p<.001). This study also shows that improvement of the students was statistically significant in each of the four levels of goals in environmental education: EE goal level I (t=4.22, p<.001), level II (t=7.53, p<.001), level III(t=5.01, p<.001), and level IV(t=5.46, p<.001). The results imply that the journal writing on the environment is effective in cultivating elementary students' environmental literacy and in achieving goals in environmental education.

• The Journal of Korean Academic Society of Nursing Education
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• v.22 no.4
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• pp.567-576
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• 2016

Purpose: This study was conducted to test the effects of flipped learning for undergraduate nursing students. Methods: The study was a nonequivalent control group pretest-posttest design. Participants were 140 nursing students (experimental group=70, control group=70). The flipped learning was provided for 6 times (18 hours). Data were collected between March 7 and May 30, 2016. Data were analyzed using Chi-square, t-test, paired t-test with SPSS/WIN 22.0. Results: The results showed that self-efficacy (t=4.67, p<.001), critical thinking disposition (t=6.55, p<.001), and communication competence (t=3.57, p=.001) were significantly higher than in the experimental group than in the control group. Conclusion: The study findings suggest that the flipped learning has proven to be influential educational program for improving the self-efficacy, critical thinking disposition, and communication competence of nursing students. The flipped learning was an effective teaching program for nursing student, and need to develop other nursing major subjects.

• Journal of Korean Society of Forest Science
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• v.103 no.1
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• pp.87-97
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• 2014

This study was conducted to provide field-based harvesting study information which can be used to select an optimal cable system for certain work conditions on steep grounds (> $20^{\circ}$ ground slope) in Korea. To accomplish this study objectives, we evaluated three cable yarding systems (RME-300T tower-yarder, Chuncheon tower-yarder, FARMI tractor winch) working in typical work conditions for their yarding productivity and operational efficiency. Those yarders are commonly used for removing logs or trees on steep grounds in Korea. Under the same work conditions (average DBH of tree to be cut, 20 cm; yarding distance, 60 m; lateral yarding distance, 10 m; and machine utilization rate, 70%), the average productivities were $33.04m^3$/day, $38.47m^3$/day, and $14.17m^3$/day for RME-300T, Chuncheon tower-yarder, and FARMI, respectively. Our standardized cost comparison study also showed that the yarding cost was highest at $37,835won/m^3$ with FARMI, followed by RME-300T at $25,105won/m^3$ for the same work conditions. We found the lowest yarding cost with the Chuncheon tower-yarder at $20,520won/m^3$ which was resulted primarily from high yarding productivity at the yarding distance (60 m). Our analysis suggested that a small machine such as FARMI could be a low-cost yarding machine option for a cable yarding job with a short yarding distance (40 m or less). The Chuncheon tower-yarder is well suited for a mid-range yarding distance job in Korea, ranged between 40 to 140 m. If yarding distance were longer than 140 m, the RME-300T tower yarder appears to be most cost-effective.

• Polymer(Korea)
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• v.36 no.4
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• pp.440-447
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• 2012

The branched copolyester was synthesized and its molecular weight, $T_g$, 1/2 method temperature ($T_{1/2}$) and rheological properties were characterized for the application of toner binder. The linear copolyester had low molecular weight and melt elasticity obtained by dimethylterephthalate (DMT), ethylene glycol (EG) and 2,2-bis(4-(2-hydroxypropoxy) phenyl)propane (HPP). The branched copolyesters prepared with various branching agents such as 2-(hydroxymethyl)-2-ethylpropane-1,3-diol (trimethylol propane, TMP), 2,2-bi(hydroxymethyl)-1,3-propanediol (pentaerythritol, PER), 1,2,4-benzenetricarboxylic anhydride (trimellitic anhydride, TMA) and glycerol to improve the physical properties of the linear copolyester. The effect of branching agents on the molecular weight and melt elasticity of the branched copolyester was examined. The branched copolyesters prepared by adding over 15 mol% of branching agent showed relatively high molecular weight and melt elasticity, and $T_{1/2}$ value of $140^{\circ}C$. Therefore, the highly branched copolyesters were deemed suitable as a hot-melt toner of laser print process.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.136-140
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• 2002

In this paper, newly constructed 5.6 ㎓ ring resonator by using a T-Junction and a parallel transmission line. The resonator's size reduced twice more than a current ring and a hair-pin resonator at this paper's center frequency The loaded Q value is 240∼250 at center frequency. also, It was explained by RLC equivalent equation for the resonator.

• Journal of the Korean Chemical Society
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• v.6 no.2
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• pp.155-157
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• 1962

A tiny dust found at the balcony of the Institute indicated about 8,0000 counts per minute by T.G.C.-2 Geiger-Muller tube (1.8mg/$cm^2$ window-thickness) at the distance of 2cm from the window. The main fission fragments, as identified by the present analysis, are 12.5day Ba-140 and 33.1 day Ce-141. The gamma energies were determined using $2"{\times}2"$ NaI(Tl) scintillation detector connected to RCL-256 channel pulse heigt analyzer. The beta energies were evaluated by Feather plot.

• Communications for Statistical Applications and Methods
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• v.13 no.1
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• pp.135-140
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• 2006

The paper by Paik (1985) introduced a structural property of the designs which was related to the concordance matrix $NN^{t}$ of the design. This special property was termed Property-C. The designs which have Property-C need not calculation of the generalize inverse of C matrix for solution of reduced normal equation. Paik also mentioned that some block designs belong to Property-C. This paper show the Extended Group Divisible designs defined by Hinkelmann (1964) are included in Property-C.