• Research in Mathematical Education
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• v.23 no.2
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• pp.93-111
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• 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.

• Journal of Convergence for Information Technology
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• v.10 no.9
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• pp.251-261
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• 2020

The purpose of this research is to examine the relationship between motivation, reliability, satisfaction, and sustainability of YouTube content and suggest the implications needed for content consumption or production of beauty workers in the future as K-beauty's interest is increasing due to the global Hallyu craze, and beauty industry workers are also watching YouTube hair care content and exchanging the latest trends. The analysis methods included frequency analysis, factor analysis, reliability analysis, correlation analysis, and multi-recovery analysis. As a result, the correlation between the motivation for content use, reliability, satisfaction, and persistence was shown, the motivation for content use was statistically significant (+) and the impact of content reliability on YouTube content satisfaction and sustainability (a significant statistical+).

• Nuclear Engineering and Technology
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• v.48 no.6
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• pp.1396-1403
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• 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.

• Journal of the Korea Concrete Institute
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• v.18 no.2 s.92
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• pp.219-226
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• 2006

The effects of binder content and PA content on the flexural, compressive and impact strengths, water absorption and frezzing and thawing of polymer concrete using mixed waste plastics are examined. As a result the flexural, compressive and impact strengths of the polymer concretes using mixed waste plastics tend to increase with increasing binder content and filler content, regardless of the PA content. The flexural, compressive and impact strengths of the polymer concretes using mixed waste plastics decrease with increasing PA content. The water absorption of the polymer concretes using mixed waste Plastics tend to decreased with increasing binder content, regardless of the PA content. The durability factor of the polymer concretes using mixed waste plastics tend to increased with increasing binder content. However, the durability factor of the polymer concretes using mixed waste plastics tend to decreased with increasing PA content.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.2
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• pp.141-147
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• 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
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• v.38 no.2
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• pp.108-116
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• 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.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09c
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• pp.129-134
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• 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
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• v.28 no.5
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• pp.111-119
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• 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)
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• v.14 no.3
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• pp.1065-1085
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• 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
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• v.29 no.5
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• pp.99-105
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• 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.