• 한국수학교육학회지시리즈D:수학교육연구
• /
• 제23권2호
• /
• pp.93-111
• /
• 2020

The purpose of this study was to examine mathematics teachers' perceptions of multicultural education. To achieve this goal, the study explored how 10 elementary mathematics teachers noticed multicultural content in a mathematics textbook. Building upon noticing framework (Jacobs, Lamb, & Philipp, 2010), we first examined teachers' attention toward multicultural content in a mathematics textbook. Then, we examined teachers' interpretation of the content. We employed a content analysis approach to examine the collected data. The results indicated that most mathematics teachers held a content integration perspective. Their view was that "multicultural education" referred to learning about the diverse cultures of different countries. Moreover, although they noticed some multicultural content in the textbook, they wanted to discuss them in superficially descriptive ways and avoid talking about social justice issues. Additionally, some teachers believed that mathematics is a culture-free subject. They argued that multicultural content should not be presented in mathematics textbooks. We also discussed uncommon themes, which were reported by only a few mathematics teachers.

• 융합정보논문지
• /
• 제10권9호
• /
• pp.251-261
• /
• 2020

본 연구의 목적은 전 세계적인 한류의 열풍으로 K-beauty의 관심이 높아지고, 뷰티산업 종사자들도 유튜브 헤어미용 콘텐츠를 시청하며 최신 트랜드를 교류하고 있어 유튜브 콘텐츠의 이용동기와 신뢰도, 만족도, 지속이용의도의 관계를 살펴 보고, 향후 뷰티 종사자의 콘텐츠 소비 또는 제작 시 필요한 시사점을 제시하기 위함이다. 분석방법은 빈도분석, 요인분석, 신뢰도분석, 상관관계분석, 다중회귀분석 등을 하였고, 그 결과 콘텐츠 이용동기, 신뢰도, 만족도, 지속이용의도 간 상호 정(+)의 상관관계가 나타났고, 콘텐츠 이용동기가 유튜브 콘텐츠 만족도, 지속이용의도에 통계적 유의하게 정(+)의 영향이 나타났으며, 콘텐츠 신뢰도가 유튜브 콘텐츠 만족도와 지속이용의도에 통계적 유의하게 정(+)의 영향을 나타나는 것을 알 수 있었다. 따라서 콘텐츠에 대한 질적 향상을 통해 차별화 된 유튜브 콘텐츠 개발 및 제작으로 뷰티산업 발전에 기여할 수 있는 계기가 되길 바란다.

• Nuclear Engineering and Technology
• /
• 제48권6호
• /
• pp.1396-1403
• /
• 2016

In this study, fast-curing shielding materials were prepared with a two-component polyurethane matrix and a filler material of PbO through a one-step, laboratory-scale method. With an increase in the filler content, viscosity increased. However, the two components showed a small difference. Curing time decreased as the filler content increased. The minimum tack-free time of 27 s was obtained at a filler content of 70 wt%. Tensile strength and compressive strength initially increased and then decreased as the filler content increased. Even when the filler content reached 60 wt%, mechanical properties were still greater than those of the matrix. Cohesional strength decreased as the filler content increased. However, cohesional strength was still greater than 100 kPa at a filler content of 60 wt%. The ${\gamma}$-ray-shielding properties increased with the increase in the filler content, and composite thickness could be increased to improve the shielding performance when the energy of ${\gamma}$-rays was high. When the filler content was 60 wt%, the composite showed excellent comprehensive properties.

• 콘크리트학회논문집
• /
• 제18권2호
• /
• pp.219-226
• /
• 2006

본 연구에서는 복합 재질 폐플라스틱을 재활용한 폴리머콘크리트의 압축, 휨 및 충격강도, 흡수율 및 동결융해저항성에 미치는 결합재 첨가량 및 PA 혼입량의 영향에 대하여 연구하였다. 그 결과 복합 재질 폐플라스틱을 재활용한 폴리머콘크리트의 압축, 휨 및 충격강도는 PA 혼입량에 관계없이, 결합재 첨가량 및 충전제 혼입량의 증가에 따라 증가하는 경향을 나타냈다. 하지만, PA 혼입량의 증가에 따라서는 감소하는 경향을 보였다. 복합 재질 폐플라스틱을 재활용한 폴리머콘크리트의 흡수율은 PA 혼입량에 관계없이, 결합재 첨가량의 증가에 따라 감소하는 경향을 나타냈다. 하지만 PA 혼입량의 증가에 따라서는 증가하는 경향을 나타냈다. 복합 재질 폐플라스틱을 재활용한 폴리머콘크리트의 내구성 지수는 결합재 첨가량의 증가에 따라 증가하였으나, PA 혼입량에 따라서는 감소하는 경향을 보였다.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제2권2호
• /
• pp.141-147
• /
• 2001

This study was carried out to find out whether there exists any content variation in 1-deoxynojirimycin (DNJ) among regional and varietal mulberry leaves. HPLC analysis was performed for 22 samples collected from several localities in Korea and Tsushima Islands Japan. The highest content was observed in the Cheongilppong sample collected at Youngchun City, Kyungsangbuk Province (1,882.7 $\mu\textrm{g}$/g DW), whereas lowest content was observed in the Cheongilppong sample collected at Jiniu City, Kyungsangnam Province (395.65 $\mu\textrm{g}$/g DW). In the comparison of regional samples of Kaeryangppong variety, DNJ content was highest in the order of Woniu City (1,460.1) > Boungun (999.85) > Hweongsung-gun (939.12) > Cheongju City (688.78). In case of Cheongilppong, DNJ content was highest in the order of Youngchun City (1.882.8) > Sanchung-gun (1,125.3) > Sunchon City (649.17) > Byunsan-myon (441.54) > Jinju City (395.65). Average content of regional samples was higher in Kaeryangppong (1,021.7 $\mu\textrm{g}$/g DW) than that of Cheongilppong (898.87 $\mu\textrm{g}$/g DW). Average DNJ content of the wild mulberry loaves collected from Cheju Island and Tsushima Island (1,012.9$\mu\textrm{g}$/g DW) was high enough to reach to that of the regional Kaeryangppong samples. In the comparison among varietal samples collected in Suwon, the highest DNJ content was observed in YK209 (768.16 $\mu\textrm{g}$/g DW), amongst overall low DNJ content of the varietal samples. Considering a few pieces of information from our data, DNJ content appears not to be influenced solely by annual temperature of the planted areas.

• Journal of the Korean Wood Science and Technology
• /
• 제38권2호
• /
• pp.108-116
• /
• 2010

This paper explains the effects of wood drying on treatability (as determined by water uptake) of Japanese red pine (Pinus densiflora S. et Z.) at the sevenmoisture content (MC) levels above and below the fiber saturation point (FSP). According to the experimental results, it was found that water uptake (as the percentage of void volume filledwith distilled water, VVF%) was influenced by level of moisture content and percentage of void volume filled was improved effectively by kiln drying process. A significant relationship between moisture content and treatability was established. Permeability and liquid uptake were decreased above the FSP due to the effect of the less void space available in wood. Even though increased liquid uptake was observed at lower moisture content, no significant differences was observed moisture content below 20%. Therefore, this species need to be initially dried below FSP before treated with liquids. But drying moisture content below 10% might not be economical for the commercial purpose comparing drying the wood between 10 and 20% moisture content. The result of this study inferred that the treatability of pine wood can be improved by reducing the moisture content up to a certain level of 10~20% for allowing better performance.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 추계 학술발표회 3차
• /
• pp.129-134
• /
• 2010

This paper investigates effects of rubber inclusion on the strength and physical characteristics of rubber.added composite geomaterial (CGM) in which dredged soils, crumb rubber, and bottom ash are reused for recycling. Several series of test specimens were prepared at 5 different percentages of rubber content (i.e. 0%, 25%, 50%, 75%, and 100% by weight of the dry dredged soil) and three different percentages of bottom ash content (i.e. 0%, 50% and 100% by weight of the dry dredged soil). The mixed soil specimens were subjected to unconfined compression test and elastic wave test to investigate their unconfined compressive strengths and small strain properties. The values of bulk unit weight of the CGM with bottom ash content of 0% and 100% decrease from 14kN/$m^3$ to 11kN/$m^3$ and 15kN/$m^3$ to 12kN/$m^3$, respectively, as rubber content increases, because the rubber had a specific gravity of 1.13. The test results indicated that the rubber content and bottom ash content were found to influence the strength and stress-strain behavior of CGM. Overall, the unconfined compressive strength, and shear modulus were found to decrease with increasing rubber content. Among the samples tested in this study, those with a lower rubber content exhibited sand-like behavior and a higher shear modulus. Samples with a higher rubber content exhibited rubber-like behavior and a lower shear modulus. The CGM with 100% bottom ash could be used as alternative backfill material better than CGM with 0% bottom ash. The results of elastic wave tests indicate that the higher rubber content, the lower shear modulus (G).

• Journal of Acupuncture Research
• /
• 제28권5호
• /
• pp.111-119
• /
• 2011

Objective : Facial embedding therapy is a korean medical treatment technique for face lifting. The authors aimed to evaluate the effects of embedding therapy on facial skin elasticity and moisture content. This paper was written to provide objective datas about Facial embedding therapy. Results : Mean elasticity of both $ST_3$ increased after facial embedding therapy. skin elasticity of both $ST_3$ showed significant improvement. Mean moisture content of both $ST_3$ increased after facial embedding therapy. skin moisture content of both $ST_3$ showed significant improvement. Conclusion : Mean elasticity and moisture content of both $ST_3$ increased after facial embedding therapy. Facial embedding therapy may be an effictive treatment for improving elasticity and moisture content of skin in clinic.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제14권3호
• /
• pp.1065-1085
• /
• 2020

With rapid growth of content demands, device-to-device (D2D) content sharing is exploited to effectively improve the service quality of users. Considering the limited storage space and various content demands of users, caching schemes are significant. However, most of them ignore the influence of the asynchronous content reuse and the selfishness of users. In this work, the user preferences are defined by exploiting the user-oriented content popularity and the current caching situation, and further, we propose the social-aware rate, which comprehensively reflects the achievable contents download rate affected by the social ties, the caching indicators, and the user preferences. Guided by this, we model the collaborative caching problem by making a trade-off between the redundancy of caching contents and the cache hit ratio, with the goal of maximizing the sum of social-aware rate over the constraint of limited storage space. Due to its intractability, it is computationally reduced to the maximization of a monotone submodular function, subject to a matroid constraint. Subsequently, two social-aware collaborative caching algorithms are designed by leveraging the standard and continuous greedy algorithms respectively, which are proved to achieve different approximation ratios in unequal polynomial-time. We present the simulation results to illustrate the performance of our schemes.

• Journal of Welding and Joining
• /
• 제29권5호
• /
• pp.99-105
• /
• 2011

In this study, effect of Si content on nugget diameter in electric resistance spot welded dual-phase(DP) steel was investigated. The cold rolled DP steels with different Si content (0.5, 1.0, 1.5, 2.0 wt.%) were used and thickness of those sheet was 1.2mm. With increasing Si content, nugget diameter was increased at the same welding current. This is attributed to increase of heat input result from high resistivity. Also, nugget diameter was increased with an increase in Si content for the same heat input. For this reason, the melting point of DP steel is lowered with an increase in the Si content. And solid DP steel can easily be transformed to a liquid phase because the low melting point. Finally, a prediction formula for the nugget diameter(N.D.) could be obtained in terms of heat input(Q) and melting point(M.P) as follows: N.D.(mm) = 0.11Q(J) - 0.0031 M.P.($^{\circ}C$) + 0.32.