• Education of Primary School Mathematics
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• v.20 no.2
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• pp.177-192
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• 2017

In theory, mixed methods that incorporate both quantitative and qualitative approaches can maximize strengths of each method while minimize the short comings of each. Mixed methods research is a feature of educational research nowadays, and the number of studies applied mixed methods research has been gradually increasing. This study investigates how mixed methods research was applied in the field of mathematic education, especially focusing on how qualitative and quantitative methods are combined to best address their research questions. With this in mind, this study carefully selects and analyzes 4 research articles that used mixed methods and were published by Journal of Elementary Mathematics Education in Korea in 2015. This study provides detailed result of qualitative analysis on mixed methods research while other a few previous analysis on mixed methods research were tend to focusing on quantitative analysis, producing numeric quantitative information. The result of this study provides practical and in-depth analysis on how to improve validity and possibility of mixed methods research, addressing alternative ways to combine two different research methods and key elements to take into account.

• Macromolecular Research
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• v.17 no.2
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• pp.110-115
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• 2009

The electrical, morphological and rheological properties of melt and dry mixed composites of poly ethylene (PE)/graphite (Gr), polypropylene (PP)/Gr and PP/nickel-coated carbon fiber (NCCF) were investigated as a function of filler type, filler content and processing temperature. The electrical conductivities of dry mixed PP/NCCF composites were increased with decreasing processing temperature. For the melt mixed PP/NCCF composites, the electrical conductivities were higher than those of the melt mixed PE/Gr and PP/Gr composites, which was attributed to the effect of the higher NCCF aspect ratio in allowing the composites to form a more conductive network in the polymer matrix than the graphite does. From the results of morphological studies, the fillers in the dry mixed PP/NCCF composites were more randomly dispersed compared to those in the melt mixed PP/NCCF composites. The increased electrical conductivities of the dry mixed composites were attributed to the more random dispersion of NCCF compared to that of the melt mixed PP/NCCF composites. The complex viscosities of the PP/Gr composites were higher than those of the PP/NCCF composites, which was attributed to the larger diameter of the graphite particles than that of the NCCF. Furthermore, the fiber orientation in the 'along the flow' direction during melt mixing was attributed to the decreased complex viscosities of the melt mixed PP/NCCF composites compared those of the melt mixed PP/Gr composites.

• Journal of the Korean Society of Food Culture
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• v.29 no.4
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• pp.355-363
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• 2014

The purpose of this study was to investigate the rheological characteristics of medium wheat flour mixed with bamboo leaf and lotus leaf powders. Rheological properties of the mixed flours were tested based on falling number, color, RVA, farinogram, and rheofermentometer analyses. Falling numbers increased with addition of bamboo leaf and lotus leaf powders. The L values of all mixed flours were less than that of control. The 1% mixed flour sample containing bamboo leaf and lotus leaf powders was not significantly different from 3% mixed flour. The a values of the mixed flour decreased as bamboo and lotus powders increased, whereas b values increased. Addition of bamboo leaf and lotus leaf powders to flour reduced peak viscosity, holding strength, and final viscosity. The set back values of mixed wheat flour containing bamboo leaf powder were lower than those of mixed wheat flour containing lotus leaf powder, suggesting that bamboo leaf powder suppressed retrogradation of flour compared to lotus leaf powder. In the farinogram, the water absorption and consistency of the flours containing bamboo and lotus leaf powders increased, whereas development time and stability decreased. The fermentation time of dough with lotus leaf powder was less than that of dough with bamboo leaf powder.

• Korean journal of food and cookery science
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• v.19 no.4
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• pp.511-520
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• 2003

This study was carried out to determine the effects of various contents of kiwifruit contents on the quality characteristics of mixed polysaccharide gels made from $\kappa$-carrageenan and locust bean gum. The color value, gelling temperature, melting temperature, break down rate, syneresis, rupture properties, TPA properties and sensory properties of mixed polysaccharide gels with various contents of kiwifruit contents were measured. As the kiwifruit contents was increased, the lightness (L), yellowness (b) and greenness (-a) of the mixed polysaccharide gels increased. There were no differences in the color values of gels during storage. As the kiwifruit content was increased, the gelling and melting temperatures of the mixed polysaccharide gels also increased. The mixed polysaccharide gels with high kiwifruit contents were difficult to melt, and it seemed that the addition of kiwifruit to the mixed polysaccharide gels could improve the thennal stability of the gels. The syneresis of the gel increased with increasing storage time, whereas the addition of kiwifruit to the gel resulted in suppression of syneresis. With regard to the rupture properties, stress, energy and strain, they were all decreased with increasing kiwifruit contents. The TPA properties, adhesiveness, hardness and chewiness increased and cohesiveness decreased with increasing kiwifruit contents. The results showed that the gel became tough and adhesive, and could be easily broken under small deformation, with increasing kiwifruit contents. The sensory evaluation showed that the green color, aroma, sweetness and sourness increased with increasing kiwifruit contents. The texture, adhesiveness, springiness and cohesiveness decreased, and brittleness and hardness increased, with increasing kiwifruit contents. The overall acceptability of the gel with 30% kiwifruit content was the highest. Thus, mixed polysaccharide gels made from kiwifruits could be useful, as the addition of kiwifruit to a mixed polysaccharide gel results in a good aroma, taste and stability, despite a lowering of the textural properties.

• The Korean Journal of Community Living Science
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• v.15 no.4
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• pp.89-96
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• 2004

This study is to investigate the effect of dietary mixed protein and L-carnitine supplementation on lipid metabolism in the rats fed high fat diet. Six experimental groups were organized and each group had eight Sprague-Dawley male white rats with the initial weight of around 180g. The six experimental groups were CO(supplemented with casein), CC(supplementedwith casein and cartinine), ISO(supplemented with isolated soy protein), ISC(supplemented with isolated soy protein and cartinine), CIM(supplemented with casein and isolated soy protein), and CIC(supplemented with casein, isolated soy protein and cartinine). Each group was supplemented with the experimental diet for four weeks, and carnitine contained 3efo of the diet. The results were as follows; 1. There was no significant difference in food intake among the experimental groups. The weight increased more significantly in the group supplemented with the mixed protein than in the group supplemented with casein(p<0.05).2. There was weight reduction effect by the supplementation of carnitine(p<0.05), however no weight reduction effect by the supplementation of carnitine was observed in the group supplemented with the mixed protein and isolated soy protein. 3. Food efficiency was lower in the group supplemented with the mixed protein than in the group supplemented with casein (p<0.05), however it was similar in the group supplemented with isolated soy protein.4. Serum total lipid and se겨m total cholesterol were lower in the group supplemented with mixed protein than in the group supplemented with casein(p<0.05). 5. There was no significant difference of serum triglyceride, HDL-cholesterol, and LDL-cholesterol among the experimental groups. 6. Liver triglyceride was the highest in the group supplemented with mixed protein (p<0.05), and there was no significant difference of liver total lipid and total cholesterol among the experimental groups. 7. In the groups supplemented with mixed protein, the level of liver TBARS showed the lowest when casein was supplemented(p<0.05), and there was no significant difference of GSH-Px activities among the experimental groups. In summary, when mixed protein was supplemented to the rats weight gain and food efficiency were similar with those in the group supplemented with isolated soy protein, however they were lower than those in the group supplemented with casein. The effect of carnitine on weight was not observed in the group supplemented with mixed protein and isolated soy protein, however it was observed in the group supplemented with casein. Serum Total lipid and total cholesterol were lower than those in the group supplemented with casein. Liver total triglyceride was high in the group supplemented with mixed protein, and the antioxidant effect was observed in the group supplemented with mixed protein.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.137-145
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• 2004

Limestone zone in korea have been distributed to diagonal line so that it is wide from the Gangwondo to the Jeonlanamdo. The limestone cavity and fractured zone were formed by chemical weathering. Limestone cavity and fractured zone was reinforced with cemented milk(w/c=60%)by high pressure jet grouting by tripple -pipe to establish bridge foundation on the ground condition like limestone cavity. To analyze property of limestone and solid of cement milk(w/c=65%), mixed solid of cement, core NX size in the limestone cavity and fractured zone and compressive strength. Seismic tomograpy exploration was pcrforn1cd to analyze deformation modulus of limestone. The analysis suggests that deformation modulus of limestone has effect on uniaxial compressive strength, seismic velocity, seismic elasticity modulus. Average static elasticity modulus of limestone is $5.08{\times}10^5kgf/cm^2$, cement and coal mixed solid is $0.25{\times}10^5kgf/cm^2$, $0.095{\times}10^5kgf/cm^2$. Average seismic velocity of limestone is 5.240m/sec, cement and coal mixed solid is 2,211.3m/sec, 1,447.5m/sec. Average uniaxial compressive strength of limestone was $1,221.3kgf/cm^2$ and limestone specimen mixed with cement milk and solid of cement milk mixed with coal were $125.22kgf/cm^2$, $35kgf/cm^2$ each other. Average friction angle of limestone was $49.14^{\circ}$ and limestone specimen mixed with cement milk and solid of cement milk mixed with coal were $38.39^{\circ}, 25.83^{\circ}$ each other. Average cohesion of limestone was $137.7kgf/cm^2$ and limestone specimen mixed with cement milk and solid of cement milk mixed with coal were $23.5kgf/cm^2$, $15.5kgf/cm^2$ each other. Average deformation modulus of limestone was $2.84{\times}10^5kgf/cm^2$ and limestone specimen mixed with cement milk and solid of cement milk mixed with coal were $0.4{\times}10^5kgf/cm^2, 0.12{\times}10^5kgf/cm^2$ each other. It was analyzed that the elasticity and uniaxial compressive strength, seismic velocity of solid of cement milk mixed limestone pieces and coal had an highly interrelation regardless of existence of limestones pieces and coal but it had shown that limestones had an lower interrelation. In case of field seismic velocity and deformation of limestone, SIC solid of cement milk mixed with coal and limestone pieces had an highly interrelation.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.438-447
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• 2020

The critical micelle concentration (CMC) values of the mixed surfactant systems and the solubilization conatant (K_s) values of 4-ethylaniline in those solutions were measured and analyzed by the UV-Vis method. As a result, the mixed surfactant systems of TTAB/LSB and TTAB/TX-100 did not deviate significantly from ideal mixed micellization. However, the mixed systems of SDS/LSB and SDS/TX-100 showed great negative deviations from ideal mixed model. These differences showed that the intensity of the interaction between two components in the mixed micelle was different for each mixed system and that these differences greatly influenced the solubilization of 4-ethylaniline by a mixed surfactant system. Among pure surfactants, an anionic surfactant such as SDS showed a greater K_s value than other ionic surfactants, and the K_s value by each surfactant system decreased in the order of SDS≫TTAB≧LSB>TX-100. In addition, the K_s values of all the mixed surfactant systems were higher than those of the pure surfactants constituting the mixed systems.

• Korean Journal of Social Welfare
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• v.61 no.2
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• pp.215-246
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• 2009

This study examined the perceptions of and attitude towards mixed-race and investigated the factors affecting them and their influence on discriminative behavior. For the study, a survey was conducted with residents residing in Seoul and its suburb. The results showed that the perceptions of and attitudes towards mixed-race, generally, were not so negative and positive in all three types of mixed-race, Caucasian-korean, Asian-korean, and African-korean. In addition, the perceptions of and attitudes toward mixed-race were partly different by the type of mixed race. That is, there were more positive perceptions of and more favorable attitudes towards the Caucasian-korean in Asian-korean and African-korean, and there were less positive perceptions of and less favorable attitudes towards Asian-korean than in African-korean. With regard to the factors affecting the perceptions and attitudes, racism was a factor affecting commonly the perception of and attitudes towards all types of mixed-race. The attitudes towards mixed-race had an influence on the discriminative behavior in all types of mixed-race, and, only in the African-korean, the perception of mixed race affected the discriminative behavior. These results suggest insights for what efforts should be made to improve mixed-race's welfare.

• Journal of Mechanical Science and Technology
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• v.17 no.6
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• pp.796-804
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• 2003

The use of fracture mechanics has traditionally concentrated on crack growth under an opening mechanism. However, many service failures occur from cracks subjected to mixed-mode loading. Hence, it is necessary to evaluate the fatigue behavior under mixed-mode loading. Under mixed-mode loading, not only the fatigue crack propagation rate is of importance, but also the crack propagation direction. In modified range 0.3$\leq$a/W$\leq$0.5, the stress intensity factors (SIFs) of mode I and mode II for the compact tension shear (CTS) specimen were calculated by using elastic finite element analysis. The propagation behavior of the fatigue cracks of cold rolled stainless steels (STS304) under mixed-mode conditions was evaluated by using K$\_$I/ and $_{4}$ (SIFs of mode I and mode II). The maximum tangential stress (MTS) criterion and stress intensity factor were applied to predict the crack propagation direction and the propagation behavior of fatigue cracks.

• Bulletin of the Korean Mathematical Society
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• v.50 no.1
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• pp.321-341
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• 2013

In this paper, we discuss the a posteriori error estimates of the semidiscrete mixed finite element methods for quadratic optimal control problems governed by linear hyperbolic equations. The state and the co-state are discretized by the order $k$ Raviart-Thomas mixed finite element spaces and the control is approximated by piecewise polynomials of order $k(k{\geq}0)$. Using mixed elliptic reconstruction method, a posterior $L^{\infty}(L^2)$-error estimates for both the state and the control approximation are derived. Such estimates, which are apparently not available in the literature, are an important step towards developing reliable adaptive mixed finite element approximation schemes for the control problem.