• Earthquakes and Structures
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• v.10 no.3
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• pp.717-733
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• 2016

Trapezoidal Cemented Sand and Gravel Dam, namely Trapezoid CSG, is a new type of dam. Due to lack of dynamic studies in the field of CSG dam, this research was performed to analyze Trapezoidal CSG dam using dynamic Finite element method with ABAQUS Software. To investigate possible earthquake-induced damages, fragility curves are plotted based on damage index, the length of the cracks created at the dam base and the area of cracked elements in the dam. The seismic analysis indicated that minimum and maximum tensions are generated in the heel and toe of the dam, respectively. According to the fragility curves, with increase in PGA, the possibility of the exceeding the defined limit state is increased. However, the rate of increment is significantly reduced after PGA=0.4 g. Also, the same result is achieved for the second limit state. The "area of cracked elements" is more conservative criterion than the "crack length at the dam base", especially at PGA<0.4 g. As conclusion, CSG dams, despite of being made of poor materials in comparison with concrete dams, show good resistance, and even in some situations, better performance than the weighted concrete dams.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.2
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• pp.153-159
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• 2004

The purpose of this research is to investigate the performance of swirl combustion chamber diesel engine by changing the jet passage area, the depth and shape of the piston top cavity (main chamber). The performance of diesel engine with newly changed swirl combustion chamber was tested through the experimental conditions as engine speed, load and injection timing etc. The test results were compared and analyzed. And another purpose of this research is to make a new diesel engine that is satisfied fuel consumption and regulation value of exhaust gas. 1. The rate of fuel consumption was affected significantly by the jet passage area at the high speed and load than low speed and low load. The influence of jet passage large area was proven to decrease the rate of fuel consumption. 2. Smoke was affected significantly by the depth of the piston top cavity, but exhaust temperature and the rate of fuel consumption wasn't affected. The rate of fuel consumption was affected by changing injection timing. 3. The rate of fuel consumption, exhaust temperature and Smoke were affected significantly by the shape of the piston top cavity from rectangular to trapezoid. That is we have all high value. The exhaust smoke density and exhaust gas temperature depended sensitively on variation of the injection timing rather than the shape of the combustion chamber within the experimental conditions. 4. We made a new diesel engine that is satisfied design target values(sfc=190 g/hr, NOx + THC=6.0 g/KWh, PM=0.3 KWh), the rate of fuel consumption and emission standard etc., through changing injection timing at the maximum torque point and rated power point. Although we have a little high NOx value.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.8
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• pp.1420-1431
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• 2001

This research was done to classify lower body types by direct measurements, side and back view types from waistline to gluteal furrow line individually, and to analyze correspondence these lower body types with side and back view types from waistline to gluteal furrow line. The subjects of this study were 191 female college students from 18 to 25 years old residing in Pusan urban area. Type 1(long and slim) of lower body types by direct measurements was correspond with Type 1(slim curve) and Type 4(slim and protrusive hip) of side view and Type 3(wide and curve) and Type 4(trapezoid shape) of back view. Type 2(short and thick) of lower body types was correspond with Type 3(thick and droopy hip) of side view and Type 1(wide and straight) of back view. Type 3(short and slim) of lower body types was correspond with Type 2(slim and flat hip) of side view and Type 2(narrow and curve) of back view.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.9
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• pp.1386-1397
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• 2009

This study investigates costumes for ball jointed dolls under the theme of Bok-yo(服妖): The Lady in Early-middle Joseon with relic costumes as a reference. The Bok-yo style was spread universally for Joseon women in the $15^{th}-16^{th}$ centuries, but it is an uncommon theme in the area of media and traditional costume for dolls. Bok-yo (curious outfit), consisted of a Dang-jeogori with a golden brocade in the front bottom, manlike Jang-ot, wide Chima, and Jang-ot was dressed between Chima and the Dang-jeogori. To make correct patterns and approvals for idle bodies of female ball-jointed dolls, darts are added in the front vertical line and center back of the golden brocade Dan-jeogori for Joseon ladies. The pattern of the golden brocade Chima is made as a trapezoid shape for the thin waist of a doll, and the length of a deep-greened silk gauze The Jang-ot increased because of the length of the doll's legs. In addition, the kinds of investigated accessories, hair, traditional underwear for dolls are limited. Suggested is a closer cooperation between the investigated costume designers, doll companies, and accessory makers for the future market of ball jointed dolls.

• Transactions of Materials Processing
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• v.24 no.3
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• pp.187-193
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• 2015

The objective of the current study is to determine cross-sectional profile of intermediate dies in order to improve the plastic strain homogeneity which directly affects not only the dimensional accuracy but also the mechanical properties of final product by redesigning the intermediate dies using the conventional electric field analysis (EFA) method. Initially, the multi-pass shape wire drawing was designed by using the equivalent potential lines from EFA. The area reduction ratio was calculated from the number of passes in multi-pass shape wire drawing but constrained by the capacity of the drawing machine and the drawing force. In order to compensate for a concentration of strain in a region of the cross section of the wire, the process for multi pass wire drawing from initial round material to an intermediate die was redesigned again using the electric field analysis. Both drawing process designs were simulated by the finite element method in which the strain distribution and standard deviation plastic strain of the cross section of drawn wires were examined.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.3
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• pp.238-246
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• 2007

This study is aimed to elucidate the abnormal growth pattern of human fetal maxilla with cleft lip and palate (CLP). Total 71 fetal maxillae with CLP were obtained from aborted human fetuses. They were examined radiologically for the dimensional changes of maxillary trapezoid (MT) formed by maxillary primary growth centers (MxPGC)(Lee et al., 1992). In palatal radiogram of the CLP maxilla, the MT was traced by the anterior and posterior MxPGCs, and the dimensions of anterior and posterior maxillary widths, maxillary length, and MT length (MTL), and MT area were measured for evaluation of the basic growth pattern of the developing maxilla. The growth of anterior and posterior MxPGCs was severely retarded in the prenatal maxillae with CLPs, showing abnormal shape of MT. Cleft lip subjects without cleft palate also showed arrested growth of MT. Unilateral cleft lipalveolar cleft or cleft palate (UCL-AC/CP) and bilateral cleft lip-alveolar cleft or cleft palate (BCL-AC/CP) showed enhanced abnormal MT pattern. The abnormality of MT was most marked in BCL-AC/CP. It was also observed that the craniofacial malformations other than CLPs produced abnormal MT. In conclusion, the MT growth of prenatal CLP maxilla was severely arrested and resulting in abnormal MT shape on the palatal radiogram. BCL-AC/CP showed more protruded nasal septum than other types of CLPs, while UCL-AC/CP showed severe deviation of the protruded nasal septum towards the non-cleft side. Cleft lip only subjects also showed the abnormal growth of MT. These data suggest that the MT is primarily involved in CLPs, and MT shape could be utilized as a sensitive indicator for the analysis of maxillary malformation in different types of CLPs.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.7
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• pp.3-14
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• 2006

The objective of this study was to develop a GIS-based decision support system (GIS-USLE system) to estimate soil erosion and evaluate its effect on concentrated upland plots in Godang district, Korea. This system was developed for the ArcView environment using A VENUE script. Three modules were used in the GIS-USLE system, namely pre-processing, the USLE factors calculator module, and post-processing. This system benefits from a user friendly environment that allows users with limited computer knowledge to use it. This system was applied to 1,285 individual upland plots ranging from 0.005 to 1.347 ha in size with an average slope steepness of 14 %. The rainfall distributions were estimated using the three methods, namely Mononobe and Yen-Chow with Triangle and with Trapezoid type, and then used to calculate the rainfall erosivity factor. The soil erosion amounts from the 1,285 individual plots in the study area by 2 year return period with a 24h maximum rainfall amount of 154.6 mm were estimated at 5 tons/ha on average. Slope appeared to be the most important factor affecting soil erosion estimation, as expected. The prototype model was applied to the project area, and the results appeared to support the practical applications. By examining many fields simultaneously, this system can easily provide fast estimation of soil erosion and thus reveal the spatial pattern of erosion from fields in a region. This study will help estimate and evaluate soil erosion in concentrated upland districts and identify the best management practices.

• Journal of the Korean School Mathematics Society
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• v.15 no.1
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• pp.27-51
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• 2012

This paper analyzed the pedagogical content knowledge (PCK) presented in three novice teachers' mathematics instruction. PCK was analyzed in terms of the knowledge of mathematics content, the knowledge of students' understanding, and the knowledge of teaching methods. Teacher A executed a concept-oriented instruction with manipulative materials because she had difficulties in learning mathematics during her childhood. Teacher B attempted to implement an inquiry-centered instruction in the lesson of looking for the area of a trapezoid. Teacher C focused on the real-life connection to mathematics instruction. There were substantial differences among the teachers' PCK revealed in mathematics teaching, depending on their instructional goals. The detailed analyses of three teachers' teaching in terms of their PCK will give rise to the issues and suggestions of professional development for beginning elementary school teachers in mathematics teaching.

• Education of Primary School Mathematics
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• v.19 no.2
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• pp.113-125
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• 2016

The concept and measuring activities of the height of figures are essential to find the areas or volumes of the corresponding figures. For plane figures, the height of a triangle is defined to be the line segment from a vertex that is perpendicular to the opposite side of the triangle, whereas the height of a parallelogram(trapezoid) is defined to be the distance between two parallel sides. For the solid figures, the height of a prism is defined to be the distance of two parallel bases, whereas the height of a pyramid is defined to be the perpendicular distance from the apex to the base. In addition, the height of a cone is defined to be the length of the line segment from the apex that is perpendicular to the base and the height of a cylinder is defined to be the length of the line segment that is perpendicular to two parallel bases. In this study, we discuss some pedagogical problems on the concepts and measuring activities of the height of figures to provide alternative activities and suggest their educational implications from a teaching and learning point of view.

• The Research Journal of the Costume Culture
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• v.23 no.1
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• pp.126-144
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• 2015

The object of this study is to develop textile designs and fashion products based on the cultural resource of Jeju Bangsatop, which means a stone tower preventing misfortune and driving out evil spirits. The field surveys of 32 Bangsatops located at 17 villages in Jeju were conducted. As a result, unlike stone towers located in other regions, Jeju Bangsatops made with basalt. In addition, wood and stone birds, Dolhareungbang, and other sculptures are built on the tops. Jeju Bangsatops were classified into four types based on the body form of the tops: Conical, truncated conical, trapezoid, and irregular shaped Bangsatops. Jeju Bangsatops located in a area or a village are symmetrically arranged in direction of south and north, left and right, east and west, or face to face. The conical, truncated conical, and irregular shaped Jeju Bangsatops which are designated as folk cultural properties or which have the unique sculptures of stone birds and the statues of Dolhareungbang built on the tops were selected as motifs for textile pattern design. The 4 basic patterns of Jeju Bangstops were designed. The six creative textile designs were developed by the various repeat arrangements of the basic patterns and were printed on oxford cotton fabrics by digital textile printing (DTP) method. The sixteen products of wallets, bags, hats and shoes were actually made with the DTP fabrics, the DTP fabrics which were naturally dyed in gray and blue colors, or the DTP fabrics which were redesigned with textile crayon. Therefore, it is confirmed that Jeju Bangsatop could be very useful as a motif for the development of cultural products focusing on Jeju tourism souvenir market.