• Journal of Aerospace System Engineering
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• v.13 no.1
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• pp.29-37
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• 2019

The objective of this study was to investigate the influence of the blade shape on the impeller performance, for design optimizing of the high airflow impeller. First, the quantity, angle, and length of blades, which are considered to have a large influence on the impeller performance, were selected as design variables. Then, 27 cases of impeller shapes were selected according to the design of experiment (DOE). To predict the conduct of the blower based on the selected impeller shape, flow analysis was performed using the immersed solid method of ANSYS CFX. In the CFD results, the highest airflow was expected in the impeller having a combination of 50 EA, $6^{\circ}$ and 5 mm. Finally, a blower with the original impeller shape and the optimized impeller shape was fabricated using a 3D printer, and the analysis tendency and experimental tendency were verified through experiments.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.5
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• pp.459-469
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• 2011

There are various factors for determining object shape, such as size, slope and its direction, curvature, length, surface, angles between lines or planes, distribution of the model key points, and so on. Most of the object description and recognition methods are for the 2D space not for the 3D object space where the objects actually exist. In this study, 3D chain code operator, which is basically extension of 2D chain code, was proposed for object description and analysis in 3D space. Results show that the sequence of the 3D chain codes could be basis of a top-down approach for object recognition and modeling. In addition, the proposed method could be applicable to segment point cloud data such as LiDAR data.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.34-39
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• 2005

In this study, 3-D nozzle shape and the shape of nozzle at exit plane were adopted as design parameter of 3-D supersonic nozzle and numerical analyses for these parameters have been performed to investigate the flow and performance characteristics for design parameters of the turbine. Firstly, comparing results for nozzle shape, rectangular nozzle had less total pressure loss occurred in axial gap and more power by 1.5% than circular nozzle did. Next, comparing the results for the shape of nozzle at exit plane, it is found that the performance of partial admission turbine was largely depended upon the gap between nozzle wall at exit plane and the hub / tip of rotor blade and the length between nozzles.

• Korean Journal of Computational Design and Engineering
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• v.20 no.2
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• pp.145-158
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• 2015

ISO 15926 is an international standard for the sharing and integration of plant lifecycle information. Plant design data consist of logical configuration, equipment specifications, 2D piping and instrument diagrams (P&IDs), and 3D plant models (shape data). Although 3D computer-aided design (CAD) data is very important data across the plant lifecycle, few studies on the exchange of 3D CAD data using ISO 15926 have been conducted so far. For this, we analyze information requirements regarding plant 3D design in the process industry. Based on the analysis, ISO 15926 templates are defined for the representation of constructive solid geometry (CSG) - based 3D design data. Since system environments for 3D CAD modeling and Semantic Web technologies are different from each other, we present system architecture for processing and visualizing plant 3D design data in the Web Ontology Language (OWL) format. Through the visualization test of ISO 15926-based 3D design data for equipment with a prototype system, feasibility of the proposed method is verified.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.1
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• pp.41-47
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• 2011

In this study, the structural analysis of cooling fan is combined with 3-D flow analysis by using CFD on fluid domain. The smoothly cooling flow with optimum design of cooling parts is essential at automotive combustion engine. The fan shape is modeled with three kinds of shape by varying the radius of the fan blade. By the results of analysis, the flow at Model I is more uniform than Model II or III. And the displacement at Model I is less than Model II or III. As the flow resistance of cooling fan at Model I decreases more than Model II or III, the efficiency becomes better.

• Fashion & Textile Research Journal
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• v.19 no.6
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• pp.786-794
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• 2017

The purpose of this study is to analyze and classify breast shape of women aged 11~15 using 3D body scan data. In this study, 250 women's body scans were selected from the 6th Size Korea dataset, and 30 items from each of the scan were measured using RapidForm XOR 3 program. The principal component analysis and cluster analysis were conducted using statistical program SPSS 17.0. The five principal components were identified; breast drooping and breast capacity, size from chest to under bust area, breast protrusion, breast height, and under breast angle & outer distance of breast. As the results of cluster analysis, woman's breast types were classified into four types. The breast type 1 was protrusion type (25.1%) which is considered as the breast maturity stage. The breast type 2 had the most drooped breast covering a large area (20.2%). The breast type 3 had the least prominent breast with a highest nipple point, which was considered as the early breast development stage (38.9%). The breast type 4 had the obesity of the chest and breast circumferences with the slightly prominent and the least drooped breast (15.8%). This study can provide fundamental information to develop sizing system and brassiere pattern for junior girls.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.847-849
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• 1996

As the power demands increases, one of the most important data is inside electric field of equipment in designing of insulators ami insulated wire for EHV distribution line. So far finite element analysis method is widely used to calculate this electric field. However as the shape of insulator becomes complicated, it is difficult in producing the mesh which suitable the shape. Especially, we have many difficulty that produce dense fine mesh only where the electric field is concentrated. Therefore in this paper, we perform the each conditional analysis of electric field using the Maxwell 3D Simulator to recover this defects. And we try to analyze electric field through the conventional 2 dimensional and 3 dimensional analysis in case of salt contamination on the surface of a insulator.

• Journal of the Korean Society of Costume
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• v.55 no.3 s.93
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• pp.69-80
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• 2005

The anatomical structure of the head and face are influenced by environmental factors. Therefore in this study we had undertaken to determine normal values of the head and face by 3D measurement in the 384 normal Korean male adults to find out craniofacial characteristics of Korean male adults by the age group. From the basic statistical data analysis, vertex-tragion and the length between the pupils were the longest in their twenties and grew shorter in elderly groups. According to the analysis of the craniofacial proportion, the head type of Korean male adults was short-headed. The statistically noticeable differences were found in the measurement of the left and the right sides of face in the age groups of 20, 30, 40, and 50. The results of the factor analysis of the age group showed two groups which were classified to 20, 40, 50 ages and 30, 60 ages. The order of factor analysis was as follows; the perpendicular length, the horizontal length, and the width (from highest).

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.1
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• pp.66-73
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• 2021

In this paper, we analyzed and considered the precision of parts produced by 3D printing methods. For the latch systems applied to the Wingline folding doors, the 3D shape of the door hinge part was printed using FDM and DLP methods. Then, the 3D printed shape was scanned to measure the dimensions and dimensional changes of the actual model. In the comparison and analysis of the 3D printed door hinge parts, because the output filling density is 100% owing to the characteristics of DLP 3D printing, the filling density in FDM 3D printing was also set to 100%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.470-476
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• 2019

The braking force for a train is generally provided by compressed air. The pressure valve system that is used to apply appropriate braking forces to trains has a complex flow circuit. It is possible to make a channel shape that can increase the flow efficiency by 3D printing. There are restrictions on the flow shape design when using general machining. Therefore, in this study, the compressed air flow was analyzed in a pressure valve system by comparing flow paths made with conventional manufacturing methods and 3D printing. An analysis was done to examine the curvature magnitude of the flow path, the diameter of the flow path, the magnitude of the inlet and reservoir pressure, and the initial temperature of the compressed air when the flow direction changes. The minimization of pressure loss and the uniformity of the flow characteristics influenced the braking efficiency. The curvilinear flow path made through 3D printing was advantageous for improving the braking efficiency compared to the rectangular shape manufactured by general machining.