• Korean Journal of Soil Science and Fertilizer
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• v.48 no.3
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• pp.194-204
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• 2015

Six study sites in Gumi, Goryeong in Gyeongbuk province and Naju in Jeonnam province were selected to investigate soil properties of poorly drained horizons in paddy soils. The horizons were re-established layers which were parent material layers originated from fluvial deposits. Topsoil layers were differentiated from piled parent materials while soil structure of the topsoil layer was massive with striated microstructure. Compaction at soil re-establishment and a lack of structure and aggregate development in these soils may cause the limitation of vertical water movement and result in poorly drained horizons. Soil samples were taken from paddy fields with top soils of sandy loam, silt loam and silty clay loam and re-established soils of coarse and fine texture. The samples were taken from each horizon for the analyses of soil chemical and mineral properties. Soils with re-established soils of coarse texture had greater amounts of sands from top soil texture distributions, while soils with fine texture had greater amounts of silts. Chemical properties of top soils were analyzed from rice cultivated soils at the time of re-establishments and one year after the re-establishments. The coarse texture of the re-established horizons decreased in EC values from 0.23 to $0.11(dS\;m^{-1})$, available phosphate values from 112 to $54(mg\;kg^{-1})$, and exchangeable Ca values from 6.6 to $4.9(cmol_c\;kg^{-1})$. On the other hand, soils with fine texture showed decrease only in pH and exchangeable Ca values. Especially, organic matter and available phosphate contents showed heterogeneous distributions from each horizon. This result may be caused by mixture of plough layer and subsurface layer during and consolidation. Hydraulic conductivity values were low at the boundaries of top soil and parent material layers except SL/coarse soil. Soil microstructure was massive structure without soil clods or pores and showed striated structure. Therefore, re-established paddy fields with fluvial deposits as parent material layers showed limited vertical movements of soil water because of occurrence of compacted layers and less-development of soil clods and aggregates.

• Korean Journal of Veterinary Research
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• v.36 no.1
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• pp.83-91
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• 1996

Activation of $K^+$ channels induces relaxation of smooth muscles by reducing electrical excitability and cytosolic free $Ca^{2+}$ level. ${\beta}$-adrenergic agonist isoproterenol is known to induce relaxation of the uterine smooth muscle by membrane hyperpolarization and $K^+$ efflux. Recently it is suggested that the activity of $Ca^{2+}$-activated $K^+$ channel was increased by isoproterenol in the uterine myocytes isolated from myometrium of the pregnant rat. However, the type of $K^+$ channel mediating the relaxant effect of isopreterenol in the tissue level has not yet studied. In this work, we investigated the type of $K^+$ channels involved in the isoproterenol-induced relaxation of uterine smooth muscle by measuring the integrated insometric tension of the estrogen-treated isolated nonpregnant rat uterus. Contraction of uterine tissue was induced by oxytocin (0.2nM, 2~3 contractions/min) or high KCl(20~80mM). The result are as follows : 1. Isoproterenol($10^{-10}{\sim}10^{-4}M$) inhibited oxytocin-induced contraction of isolated rat uterus($EC_{50}=1.17{\times}10^{-10}M$). 2. Isoproterenol($10^{-10}{\sim}10^{-4}M$) effectively inhibited uterine contraction induced by low KCl(20~40mM) but little those induced by high KCl(60~80mM). 3. Relaxant effect of isoproterenol($10^{-10}{\sim}10^{-4}M$) on 0.2nM oxytocin-induced contraction was effectively reduced by 4-aminopyridine(3, 10mM) but little by TEA(10~30mM), $Ba^{2+}$($1{\sim}30{\mu}M$) and glibenclamide($100{\mu}M$). Our data suggest that the relaxant effect of isoproterenol is mediated by the $K^+$ channel(s) which can be blocked by 4-aminopyridine.

• Food Science of Animal Resources
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• v.28 no.2
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• pp.196-203
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• 2008

This study was carried out to investigate the effect of sawdust-bedded thickness in floors (SBTF) of Hanwoo on meat quality of M. longissimus after slaughter. The 7 mon-aged bulls (22 heads) were housed in single sheds ($3{\times}8\;m^2$/animal) bedded with sawdust of 10, 15, and 20 cm thickness for 20 mon prior to slaughter. The M. longissimus from carcasses were then stored at $4{\pm}0.2^{\circ}C$ for 9 d. SBTF had no significant effect on carcass traits and pH, water-holding capacity, drip loss, cooking loss, Warner-Bratzler shear force, aroma pattern with electronic nose, and sensory attributes of beef. The 20 cm group had the highest crude fat and the lowest n6/n3 (p<0.05). At 9 d, the 10cm group showed the highest total reducing ability and the lowest TBARS content (p<0.05). During storage, the 10 and 20 cm groups had lower MetMb content, higher OxyMb content, and redder meat color than the 15 cm group (p<0.05).

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.1
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• pp.23-41
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• 2010

This research applies the climbing learning method that, a Japanese professor, Saito Noboru established and practiced, to fourth and sixth graders in an elementary school in order to analyze its effect on mathematical creativity, attitude toward mathematical creativity, so called CAS(Creative Attitude Scale) and academic achievement of the subject. The goal is to explore methods that can enhance students' mathematical creativity. To address these tasks, the research developed a teaching-learning scheme and learning structure chart that applies the climbing learning method. Next, the research organized two homogeneous groups among 124 students in fourth and sixth grades in S elementary school, located in the city of Busan. The experiment group went through classes that applied climbing learning method, while the control group received regular teaching. The following describes the research findings. After the experiment, the research conducted t-test for the independent sample based on the test result in terms of mathematical creativity, CAS and academic achievement of the subject. For mathematical creativity, all four constructing factor showed statistically significant differences at significance level of 5%. For CAS, statistically significant difference was revealed at significance level of 0.1%. However, in regard to a test of academic achievement for fourth and sixth graders, statistically significant difference was not detected at significance level of 5% even though the average score of the students in the experiment group was higher by 6 points. The research drew the following conclusion. Firstly, classes that apply climbing learning method can be more effective than regular classes in enhancing mathematical creativity of elementary school students. Secondly, the climbing learning method has positive impact on inclination for mathematical creativity of elementary school students. The research suggests that the climbing learning method can be an effective teaching-learning tool to improve students' mathematical creativity and inclination for mathematical creativity.

• Journal of Information Management
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• v.42 no.3
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• pp.1-26
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• 2011

The domain of LED is analyzed for describing the current status of Korea's R&D in the domain comparing with those of others quantitatively. Fourteen sub-domains of LED manufacturing technology are selected and the time span for analysis is ten-year: 2001-2010. Bibiliometric analysis is performed by the unit of publication, core researcher, institution and country. Strategical diagram is also produced with devised two indicators: NGI and NPI. As a result, Korea is competitive in the area of Chip Scale Package, but R&D supports in another promising areas, such as large-caliber sapphire wafer, are necessary. It is also revealed that research activities are expanded dominantly in academia, but practical technologies are developed in industrial circle. It is suggested that to support core corporate and to encourage industrial-academic collaboration is essential for systematical technology development and high achievement in prominent areas.

• Culinary science and hospitality research
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• v.18 no.4
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• pp.183-198
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• 2012

The purpose of this study is to determine potential effectiveness of sourdough starter powder (made of Korean wheat flour) in the quality characteristics of bread and in the substitution effect of a dough improver in bread baking. The bread containing sourdough starter powder was considered to be most suitable for making sourdough bread. As a result, SP 10 showed the best fermentation rate and the highest volume and specific volume. In sensory testing, SP 10 was most preferable among others. According to experimental comparison between optimal addition ratio of SP 10 and other sourdough starter powder products available in Korean domestic market, SI had the highest fermentation rate, highest volume and specific volume. Analysis of texture showed that SI was soft with the lowest hardness and the highest elasticity. Sensory test showed that SI was most preferable of all, and SP 10 was more preferable than BP. It was concluded that SP 10 was not less preferable in the aspect of preference at sensory test than other products. Hence, it is expected that sourdough starter powder made of Korean wheat flour will be possibly more popular and effective in replacing some portion of dough improver of baking.

• Journal of the Korean Magnetics Society
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• v.24 no.6
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• pp.197-201
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• 2014

As the importance of rare metal is increasing globally, Japan introduced the concept of Strategic Elements in 2004, and started Strategic Elements Project in 2007. The Goal of this project run by MEXT (Ministry of Education, Culture, Sports, Science and Technology) is to develop high-function materials and components that do not use rare or harmful elements by studying the role and characteristics of the elements that compose materials and components and decide their functions and characteristics. In September 2010, Japanese coast guard arrested a Chinese fishing boat near Senkaku Islands (Diaoyudao Islands by China), which escalated to the territory issue and eventually a big diplomatic and economic conflict. In order to put pressure on Japanese Government, China used an economic option, which is the ban of rare earth export to Japan. This incident doubled Japan's motivation to develop Strategic Elements and put more efforts into this Project. MEXT set the following three research areas in February 2012: Study of alternative materials using sufficient and harmless elements, Study of applications for the high-functions of Strategic Elements, Study of practical design for components using Strategic Elements. Through a course of gathering the opinion of professionals, MEXT settled down with the following 4 research and study areas for the Strategic Elements Project in June 2012. 1. Magnetic materials to replace Dy, Nd. 2. Catalyst/Battery materials to replace Pt, Rh/Li, Co. 3. Electronic materials to replace In, Ta. 4. Structural materials to replace Nb, Mo. This paper deals with the first area and reviews the results of the research and study as of now.

• The Korean Journal of Financial Management
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• v.25 no.3
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• pp.33-78
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• 2008

This paper empirically examines whether firms engage in a dynamic adjustment process toward target capital structure and, whether there is a target capital structure or mean reverting using the partial adjustment model while allowing for costly adjustment. Also we investigate the empirical determinants of optimal target capital structure in long term equilibrium. As a result, our empirical model captures at least several important features of capital structure behavior for Korean listed firms. First, Korean firms pursue target capital structure and also there is mean reverting phenomenon. Second, Non-Chaebol and small firm in adjustment speed is faster than Chaebol and large firm. Third, even capital market restricts the adjustment speed interestingly. Fourth, Korean firms have target behavior according to a degree of observed gap. Fifth, Korean firms close about one-fourth of the gap between their actual and target debt ratios within one year and thence targeting behavior explains far more of the observed changes in capital structure than market timing or pecking order considerations. Sixth, capital market is significant in determining optimal capital structure.

• Journal of Digital Convergence
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• v.13 no.9
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• pp.369-375
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• 2015

We investigated the prevalence of fungi isolated from a university-affiliated hospital during 6 years (2006-2011) to provide relevent information for the patient management. The general characteristics of the clinical isolates and gender, age, and type of specimens were analyzed. Among a total of 163,530 requested samples to culture for the Laboratory of Clinical Microbiology, Department of Laboratory Medicine, Gyeongsang National University Hospital in the Republic of Korea, 5,387 (3.3%) showd positive results for fungi. The most prevalent isolates were Candida albicans 41.9%, Candida glabrata 15.5%, and Candida tropicalis 14.6%. Total isolates of fungi increased from 526 in 2006 to 1,145 in 2011. They were most commonly isolated from sixties (27.0%) and seventies (26.5%). The most common clinical specimen was urine (44.8%). Males (52.4%) were slightly more than females (47.6%). In the future, a nationwide survey and additional antifungal convergence drugs susceptibility results will provide more useful information.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.43-59
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• 2017

This study presents the prediction methodology of debris flow occurrence areas using the SINMAP model. Former studies used a single calibration region applying some of the soil test results to predict debris flow occurrence in SINMAP model, which couldn't subdivide the soil properties for the target areas. On the other hands, a multi-calibration region using a detailed soil map and soil strength parameters (c, ${\phi}$) for each soil series to make up for limitation of former studies is proposed. In this process, soils with soil erodibility factor (K) are classified into three types: 1) gravel and gravelly soil. 2) sand and sandy soil, and 3) silt and clay. In addition, T/R estimation method using mean elevation of target area instead of T/R method using actual occurrence time is suggested in this study. The suggested method is applied to Seobyeok-1 ri area, Bonghwa-gun where debris flow occurred. As a result of comparison between two T/R estimation method, both T/R estimations are almost equal. Therefore, the suggested methodologies in this study will contribute to set up the national-wide mitigation plan against debris flow occurrence.