• International Journal of Knowledge Content Development & Technology
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• v.3 no.1
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• pp.65-80
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• 2013

Today, citation index information is used as an outcome scale of spreading technology and encouraging research. Article citation information is an important factor to determine the authority of the relevant author. Google Scholar uses the article citation information to organize academic article search results with a rank algorithm. For an accurate analysis of such important citation index information, large amounts of bibliographic data are required. Therefore, this study aims to build a fast and efficient system for large amounts of bibliographic data, and to design and develop a system for quickly analyzing cited information for that data. This study also aims to use and analyze citation data to be a basic element for providing various advanced services to the academic article search system.

• Journal of the Korean Ceramic Society
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• v.28 no.12
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• pp.943-952
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• 1991

Lead zirconate titanate(PZT) powders and thin films were prepared from an alkoxide-based solution by sol-gel method. Gelation of synthesized complex solutions, pyrolysis and crystallization behaviors of the dried powder were studied in accordance with a water content and a catalyst. PZT thin films were formed by spin-casting method on silicon and platinum substrates, and characterized. Ester produced from the reactions was completely removed when drying of the gel was finished. Pyrolysis property of the dried PZT gels were changed in order water content, class of catalyst, and quantity of catalyst. Crystalline Pb phase was transiently formed near 250$^{\circ}C$. Basic catalyst is good additive for a formation of perovskite phase in the films, and acidic catalyst for a densified film structure. By the analysis of RBS, Pb element in the PZT films were diffused into silicon substrate, and the pores, may be produced due to local densification around some grains in the films, make an origin of fault in microstructure when holding time goes to be longer at 700$^{\circ}C$.

• Geomechanics and Engineering
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• v.30 no.2
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• pp.139-151
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• 2022

The mechanical properties of expansive soil are very unstable, highly sensitive to water, and thus easy to cause major engineering accidents. In this paper, the expansive soil foundation pit project of the East Huada Square in the eastern suburb of Chengdu was studied, the moisture content of the expansive soil was considered as an important factor that affecting the mechanics properties of expansive soil and the stability of the non-equal-length double-row piles in the foundation pit support. Three groups of direct shear tests were carried out and the quantitative relationships between the moisture content and shear strength τ, cohesion c, internal friction angle φ were obtained. The effect of cohesion and internal friction angle on the maximum displacement and the maximum bending moment of piles were analyzed by the finite element software MIDAS/GTS (Geotechnical and Tunnel Analysis System). Results show that the higher the moisture content, the smaller the matrix suction, and the smaller the shear strength; the cohesion and the internal friction angle are exponentially related to the moisture content, and both are negatively correlated. The maximum displacement and the maximum bending moment of the non-equal length double-row piles decrease with the increase of the cohesion and the internal friction angle. When the cohesion is greater than 33 kPa or the internal friction angle is greater than 25.5°, the maximum displacement and maximum bending moment of the piles are relatively small, however, once crossing the points (the corresponding moisture content value is 24.4%), the maximum displacement and the maximum bending moment will increase significantly. Therefore, in order to ensure the stability and safety of the foundation pit support structure of the East Huada Square, the moisture content of the expansive soil should not exceed 24.4%.

• Geomechanics and Engineering
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• v.28 no.6
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• pp.599-611
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• 2022

Tendon reinforced cemented soil is applied extensively in foundation stabilisation and improvement, especially in areas with soft clay. To solve the deterioration problem led by steel corrosion, the glass fiber-reinforced polymer (GFRP) tendon is introduced to substitute the traditional steel tendon. The interface bond strength between the cemented soil matrix and GFRP tendon demonstrates the outstanding mechanical property of this composite. However, the lack of research between the influence factors and bond strength hinders the application. To evaluate these factors, back propagation neural network (BPNN) is applied to predict the relationship between them and bond strength. Since adjusting BPNN parameters is time-consuming and laborious, the particle swarm optimisation (PSO) algorithm is proposed. This study evaluated the influence of water content, cement content, curing time, and slip distance on the bond performance of GFRP tendon-reinforced cemented soils (GTRCS). The results showed that the ultimate and residual bond strengths were both in positive proportion to cement content and negative to water content. The sample cured for 28 days with 30% water content and 50% cement content had the largest ultimate strength (3879.40 kPa). The PSO-BPNN model was tuned with 3 neurons in the input layer, 10 in the hidden layer, and 1 in the output layer. It showed outstanding performance on a large database comprising 405 testing results. Its higher correlation coefficient (0.908) and lower root-mean-square error (239.11 kPa) were obtained compared to multiple linear regression (MLR) and logistic regression (LR). In addition, a sensitivity analysis was applied to acquire the ranking of the input variables. The results illustrated that the cement content performed the strongest influence on bond strength, followed by the water content and slip displacement.

• Journal of the Korean School Mathematics Society
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• v.25 no.1
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• pp.61-77
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• 2022

This study looked at the deviation of each textbook, focusing on the detailed learning content related to the quadratic curve properties contained in high school geometry textbooks. Rather than criticizing the diversity of content elements covered in high school geometry textbooks and suggesting alternatives, it focused on analyzing the actual conditions of content element diversity. The curriculum specifies that the practical application of the quadratic curve should be emphasized so that student could recognize the usefulness and value. However, as a result of the analysis, it was confirmed that the purpose of the curriculum and the structure of the textbook did not match somewhat, the deviation of content elements for each textbook was quite large. In terms of acknowledging the diversity of teaching and learning, the diversity of each textbook on the methods of the introduction and the natures related to the quadratic curve can be fully recognized. But in our educational reality, which is aiming for the university entrance examination system through national evaluation such as CSAT, the results are too sensitive in society as a whole, so the diversity of expressions in mathematics textbooks is sometimes interpreted as a disadvantage of evaluation. It is time to reconsider the composition of textbooks that recognizes the diversity of content elements in textbook teaching and learning and at the same time reflects the aspect of equality in evaluation.

• Journal of the Korean Ceramic Society
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• v.55 no.4
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• pp.368-375
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• 2018

This study deals with the color formation of ceramic pigment in the $TiO_2$-SnO-ZnO system. We designed compounds to control the color formation depending on the composition using the Design of Experiment. The color coordinate values of synthesized pigments, $L^*a^*b^*$ were measured and statistically analyzed color for changing elements depending on its composition. The relationship between the major crystalline phases and chromaticity was examined using XRD, and the oxidation states of each element were analyzed by XPS. The synthesized pigments based on the compound design exhibited various color changes ranging from yellow-orange to green-blue and brown. The statistical analysis on the spectrophotometer results shows that $a^*$ and $b^*$ values decreased with $TiO_2$ content, and increased with SnO content. Yellow-orange color was detected with the main peak of SnO, and the green-blue color developed with the main peak of $Zn_2TiO_4$. The $a^*$ and $b^*$ values increased with increased SnO peak intensity, and decreased with increased $Zn_2TiO_4$ peak intensity. The results revealed that pigment color formation was influenced by changes in the main crystalline phases and crystalline intensity. However, XPS analysis of the oxidation states of each element showed little correlation with the pigment chromaticity result.

• Education of Primary School Mathematics
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• v.18 no.3
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• pp.235-247
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• 2015

This study analyzed what STEAM elements, except mathematical content, are contained in 2009 revised elementary school 3rd and 4th grade group mathematics textbooks. STEAM elements in the textbooks were examined by grade and by content area in the elementary school mathematics curriculum. According to the results, the difference between 3rd and 4th grade in the number of STEAM elements is almost not visible. Distribution of specific content areas could be seen that the distribution STEAM element is similar to the percentage distribution of the content area. However, the number of STEAM elements are different depending on the type of STEAM. The number of arts element is 448(67.6%) and this elements are seen the most. The number of representative art and cultural art is 344(51.9%) and 104(15.7%), respectively. The number of technology-engineering and science is 160(24.1%) and 55(8.3%), respectively. We need to developed to promote use of science element in next mathematics curriculum.

• Journal of Korean Home Economics Education Association
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• v.24 no.2
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• pp.135-154
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• 2012

The purpose of this study was to investigate the trends of HE exam questions through analyzing the examination items for secondary Home Economics(HE) teaching certification from 2002 to 2011. The results of the study were as follows: First, regarding the analysis on pedagogy of HE course, it accounted for 30.9% of the total questions, and recently, it increased to 35%. Regarding the ratio of questions by each evaluation element, 'practice of teaching and learning methods for HE course'(33.2%) had the highest ratio, and 'essence of the education of HE'(3.2%) had the lowest ratio. Second, regarding the analysis on eating habits, it amounted to 17.5% of the total questions, and recently reached 15%. With regard to the ratio of each evaluation element, 'cooking theory and practice'(26.1%) had the highest ratio, and 'culture of eating habits'(3.7%) had the lowest ratio. Third, regarding the analysis on clothing habits, it accounted 15% of the total questions, and recently reached 12.5%. With regard to the ratio of each evaluation element, 'clothing management'(25.1%) and 'production of clothing and living necessaries'(25.1%) had the highest ratio, and 'selection of clothing and self-expression'(3.0%) had the lowest ratio. Fourth, regarding the analysis on housing life, it accounted for 11% of the total questions, and recently reaches 12.5%. With regard to each evaluation element, 'the understanding of housing life culture'(22.5%) had the highest ratio, and 'the understanding of housing interior design'(10.7%) had the lowest ratio. Fifth, regarding the analysis on daily life as a consumer, it accounted for 12.4%, and recently reaches 12.5%. With regard to the ratio of each evaluation element 'management of domestic resources'(34%) had the highest ratio, and 'planning of entire life and domestic welfare'(0%) had the zero ratio. Sixth, regarding the analysis on family life, it accounted for 13.3% of the total questions, and recently reaches 12.5%. With regard to the ratio of each evaluation element, 'the understanding of family and the changes in family'(23.8%) had the highest ratio, and 'marriage and the development of family'(2%) had the lowest ratio.

• Advances in materials Research
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• v.4 no.4
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• pp.227-233
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• 2015

We present a method, supported by theoretical analysis, for optimizing the usage of the critical rare earth element dysprosium in $Nd_2Fe_{14}B$ (NdFeB)-based permanent magnets. In this method, we use Dy selectively in locations such as magnet edges and faces, where demagnetization factors are largest, rather than uniformly throughout the bulk sample. A200 nm thick Dy film was sputtered onto a commercial N-38, NdFeB magnets with a thickness of 3 mm and post-annealed at temperatures from $600-700^{\circ}C$. Magnets displayed enhanced coercivities after post-annealing and as much as a 5 % increase in the energy product, while requiring a total Dy content of 0.06 wt. % - a small fraction of that used in the commercial grade Dy-NdFeB magnets. By assuming all Dy diffused into NdFeB magnets, the improvement in energy product corresponds to a saving of over 1% Dy (critical element). Magnets manufactured using this technique will therefore be higher performing which would potentially broaden the application space of these magnets in the traction motors of hybrid and pure electric vehicles, and wind generators.

• Structural Engineering and Mechanics
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• v.92 no.2
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• pp.149-161
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• 2024

Previous research has identified inadequate flexibility in concrete pavements due to the use of high-strength concrete mixtures. This research investigates whether this problem can be addressed by partially replacing some fine and coarse aggregate components with waste rubber from shredded tires, the safe disposal of which otherwise is a major environmental concern. Using finite element software ABAQUS, this study analyses 3D pavement model behavior in terms of internal stress development and deflection at critical load points. This analysis is carried out for concrete slabs of differing waste rubber proportions and varying thicknesses. Results show that the maximum tensile stress is reduced, and maximum deflection is increased as the rubber content in pavement concrete slab is increased. The stresses and deflection of concrete pavement slab are reduced as the thickness of the slab is increased. The influence of increasing the base coarse modulus is significant in terms of reduction in tensile stress development. However, the reduction in deflection is found to be relatively marginal, especially in low-percentage rubberized pavement concrete slabs.