• 한국수학교육학회지시리즈C:초등수학교육
• /
• 제20권2호
• /
• pp.177-192
• /
• 2017

본 연구는 수학교육연구에서 적용되고 있는 혼합연구법이 질적연구와 양적연구를 어떻게 결합하여 활용하고 있는가를 탐색해 보고자 한다. 구체적으로 수학교육분야에서 질적연구와 양적연구의 혼합이 방법론적으로 어떠한 시사점과 과제를 줄 수 있는가를 탐구하고자 한다. 이와 같은 연구 목적을 달성하기 위하여, 본 연구에서는 한국초등수학교육학회에서 발간하는 '초등수학교육학회지'에 2015년 게재된 전체 32편의 논문 중, 혼합연구법을 적용한 4편의 논문을 분석 대상으로 선정하였다. 기존의 선행연구들에서는 혼합연구에 대한 분석 결과를, 일반적인 양적연구의 결과와 유사하게 비교 항목별로 수치화시키며 양적인 정보를 중심으로 간략하게 설명하는 경향이 있어 왔다. 이와는 대조적으로, 본 연구에서는 질적 연구자의 관점에서 질적연구와 양적연구의 장점을 최적화할 수 있는 방안을 상세하게 논의하는 형식으로 분석 결과와 시사점을 제시하고 있다.

• Macromolecular Research
• /
• 제17권2호
• /
• pp.110-115
• /
• 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.

• 한국식생활문화학회지
• /
• 제29권4호
• /
• pp.355-363
• /
• 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.

• 한국식품조리과학회지
• /
• 제19권4호
• /
• pp.511-520
• /
• 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.

• 한국지역사회생활과학회지
• /
• 제15권4호
• /
• pp.89-96
• /
• 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.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2004년도 춘계학술발표회
• /
• pp.137-145
• /
• 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.

• 한국응용과학기술학회지
• /
• 제37권3호
• /
• pp.438-447
• /
• 2020

혼합계면활성제들의 임계미셀농도(CMC)값과 그 용액에서 4-ethylaniline의 가용화상수(K_s) 값을 UV-Vis법으로 측정하고 분석하였다. 그 결과 TTAB/LSB와 TTAB/TX-100 혼합계면활성제들은 이상적 혼합 미셀화로부터 크게 벗어나지 않았다. 그러나 SDS/LSB와 SDS/TX-100 혼합시스템은 큰 음의 벗어남을 보였다. 이러한 차이는 미셀 상에서 두 성분들의 상호작용의 세기가 서로 다름으로 나타났으며, 이것들이 4-ethylaniline의 가용화에 크게 영향을 미침을 알 수 있었다. 순수 계면활성제 중에 음이온 계면활성제인 SDS가 다른 계면활성제보다 더 큰 K_s값을 보였으며, K_s값은 SDS≫TTAB≧LSB>TX-100 순으로 감소하였다. 그리고 혼합계면활성제에 의한 K_s값은 그것을 구성하는 순수 계면활성제의 K_s값보다 더욱 큰 값을 나타내었다.

• 한국사회복지학
• /
• 제61권2호
• /
• pp.215-246
• /
• 2009

본 연구에서는 점차 다문화 되어가는 한국사회에서 혼혈인에 대한 인식과 태도가 어떠한 양상으로 나타나고 있으며, 이러한 인식과 태도에 영향을 미치는 요인은 무엇인지, 그리고 이것이 혼혈인에 대한 차별행위에 어떠한 영향을 미치는지를 낙인개념에 근거하여 살펴보았다. 이를 위해 서울을 비롯한 수도권 지역에 거주하는 성인 남녀를 대상으로 설문조사를 실시하였다. 분석결과에 의하면, 혼혈인에 대한 인식과 태도는 백인 혼혈인, 아시아계 혼혈인, 흑인 혼혈인 세 유형 모두에서 전반적으로 부정적이지는 않았지만 그리 긍정적이지도 않은 것을 볼 수 있었다. 또한 혼혈인에 대한 인식과 태도는 혼혈인 유형에 따라 부분적으로 차이를 보이는 것으로 나타났는데, 대체로 백인 혼혈인 보다 아시아계 혼혈인과 흑인 혼혈인에 대해 그리고 흑인 혼혈인보다 아시아계 혼혈인에 대해 덜 긍정적인 인식과 덜 호의적인 태도를 보이는 것으로 나타났다. 혼혈인에 대한 인식과 태도에 영향을 미치는 요인과 관련하여, 인종주의는 세 유형의 혼혈인 대한 인식과 태도 모두에 공통으로 영향을 미치는 요인이었으며, 자민족중심주의/세계주의 성향은 백인 및 흑인 혼혈인에 대한 인식과 백인 및 아시아계 혼혈인에 대한 태도에 유의미한 영향을 미치는 요인인 것으로 나타나 인종주의와 자민족중심주의/세계주의가 혼혈인에 대한 낙인에 영향을 미치는 주된 요인이라는 것을 알 수 있었다. 또한, 세 유형의 혼혈인 모두에서 혼혈인에 대한 태도는 차별행위에 유의미한 영향을 미치는 것으로 나타났으나 혼혈인에 대한 인식은 흑인의 경우에 있어서만 차별행위에 유의미한 영향을 미치는 요인인 것으로 나타났다. 이러한 결과는 한국사회에서 혼혈인의 복지를 향상시키기 위해 보다 근본적인 차원에서 어떠한 노력이 필요한지 이에 대한 논의의 근거를 제공해 준다.

• Journal of Mechanical Science and Technology
• /
• 제17권6호
• /
• pp.796-804
• /
• 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.

• 대한수학회보
• /
• 제50권1호
• /
• pp.321-341
• /
• 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.