• International Journal of Human Ecology
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• v.14 no.1
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• pp.41-55
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• 2013

The purpose of this study was to analyze human upper body surface changes at the shoulder and back area. The body surface data were analyzed in terms of muscle and bone displacement in dynamic postures. Body surface data were collected with a 3D body scanner. The body surface was scanned at the static and four baseball batting postures. The body surface dimensions over the deltoids, scapulae and trapezius were measured. The results show that the vertical measurements of the deltoids increased by 20%. The horizontal measurements of the axilla of the back increased. The surface of the trapezius was elongated by over 10%, and the lower back musculature was elongated by about 50%. The results of this study showed that changes in back body surface caused by upper arm movements. It was influenced by the deltoid articulated with the humeri and the scapulae and trapezius. These body surface changes caused by muscle activities and ranges of motion can be used to design functional clothing.

• Journal of Mechanical Science and Technology
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• v.20 no.12
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• pp.2034-2042
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• 2006

In this study, a complete 3D surface reconstruction method is proposed based on the concept that the vertices, of surface model can be completely matched to the unstructured point cloud. In order to generate the initial mesh model from the point cloud, the mesh subdivision of bounding box and shrink-wrapping algorithm are introduced. The control mesh model for well representing the topology of point cloud is derived from the initial mesh model by using the mesh simplification technique based on the original QEM algorithm, and the parametric surface model for approximately representing the geometry of point cloud is derived by applying the local subdivision surface fitting scheme on the control mesh model. And, to reconstruct the complete matching surface model, the insertion of isolated points on the parametric surface model and the mesh optimization are carried out. Especially, the fast 3D surface reconstruction is realized by introducing the voxel-based nearest-point search algorithm, and the simulation results reveal the availability of the proposed surface reconstruction method.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.10
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• pp.595-603
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• 2005

This Paper proposes the tire mold number identification method which reads the letters on a tire surface with 3D. It is very difficult to separate the letters from the background of an image since the letters on a tire surface is an embossed data. There was many studies to read the letters on a tire surface for the factory automation, however, it was very difficult to separate the letters from the background of an image since the letters on a tire surface is embossed black characters on the black ground. In this study, we first developed the method to find the location of tire mold number, which is used to classify the tire size, from the embossed letters on a tire surface using 3-dimensional laser profile camera which is not affected by the lighting condition, then developed the method to separate the mold number from that location. As a result, we were able to contribute to automate the tire size classification which has been manually performed by operators previously.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.253-254
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• 2002

Based on 3-D surface morphology measurements of C.G. irons, the fractal analyses were made on relationship between dry sliding surface morphology and the fractal dimension. It is revealed that the values of fractal dimensions ($D_f$) of sliding surfaces are in the range between 1-2, which are closely related to the surface morphologies. With the increase in depths of grooves or pits, the $D_f$ values increase. At the same time, the increases in densities of the grooves also cause the $D_f$ values to increase. At last, relationship among $D_f$ and friction coefficient as well as wear rate is discussed.

• The Journal of Korean Physical Therapy
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• v.25 no.1
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• pp.16-22
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• 2013

Purpose: This study evaluated the validity of measuring paravertebral muscle function with 3D-NEWTON (Hanmed, Korea) by assessing the correlation between Biodex (Biodex, USA) and surface electromyography (EMG). Methods: Nineteen healthy adults participated. The function of their paravertebral muscle was measured in three ways. Maximum endurance time was measured in seconds when 3D-NEWTON was inclined forward for assessing extensor function, and inclined backward for assessing flexor function. Using surface EMG, maximum muscle activity was obtained from the eractor spinae and rectus abdominis during the 3D-NEWTON measurement. Maximum muscle activity was the mean activity from 10 seconds when the root mean squared firing data was highest. Through Biodex the peak torques of the extensor and flexor were measured during isometric exercises. The Spearman correlation coefficiencts from 3D-NEWTON, surface EMG, and Biodex were calculated. Results: The data from surface EMG and Biodex were statistically correlated when measured for flexor function, but less so for extensor function. In the case of 3D-NEWTON, the correlation coefficient with Biodex was 0.50 (p=0.05), while the coefficient with surface EMG was 0.53 (p=0.02) when measured for extensor function. Similarly, the correlation coefficienct with Biodex was 0.60 (p=0.01), while the surface EMG was 0.51 (p=0.03) for flexor function. Conclusion: 3D-NEWTON was a useful method for measuring paravertebral muscle function and can give helpful information for treating people with diseases associated with the lumbar spine.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.10 no.1
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• pp.31-45
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• 2006

Recently advanced device and sophisticated manufacture process by high-density, high-integration require critical inspection criteria in SMT(surface mounting technologies). Especially for solder paste which come out over 60% of inferior goods of all product, 3-dimensional inspection replaces 2-D inspection as a effectiveness substitute of this trend. Therefore this paper proposes a fast 3-D inspection system and measurement algorithm automatically inspecting 3-D solder paste of PCB in SMT assembly line. The proposed method generates 3-D surface of data using B-spline algorithm and then extracts to inspect the pad.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.10
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• pp.119-124
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• 2000

One of the main problems in 3D shape measuring systems that use the triangulation of line-shaped laser light is precise center line detection of line-shaped laser stripe. The intensity of a line-shaped laser light stripe on the CCD image varies following to the reflection angles, colors and shapes of objects. In this paper, a new center line detection algorithm to compensate the local intensity variation on a line-shaped laser light stripe is proposed. The 3-D surface shape measuring system using the proposed center line detection algorithm can measure 3-D surface shape with enhanced measurement resolution by using the dynamic shape reconstruction with adaptive pattern clustering of the line-shaped laser light. This proposed 3-D shape measuring system can be easily applied to practical situations of measuring 3-D surface by virtue of high speed measurement and compact hardware compositions.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.91-98
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• 2014

The purpose of this research is to investigate optimum machining conditions to improve the quality of die using the CAD/CAM system(Power Shape/Power Mill) and 3D printing. Surface roughness is widely used as an index for processing degree of accuracy. The Power Shape was used to model the shape of product. And the model shape is confirmed by 3D printing system(BFB-3000). Also, tool path and NC-codes were generated using Power Mill. Finally, the product was cut using CNC machine(NBS-2025). The cutting time and surface roughness were measured by measuring instrument. And then this process was repeated by changing the conditions to find optimal machining conditions. The surface roughness behavior with regard to specific factors were analyzed. Through this study, the optimal machining condition can be obtained.

• Journal of the Ergonomics Society of Korea
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• v.24 no.2
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• pp.85-91
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• 2005

To understand the basic relationship between 3D curved surface model and 2D pattern, simplified torso model was generated by commercial CAD program (IDEAS). 3D torso model was then divided into different blocks and unfolded into a flat pattern as in ordinary works of clothing item design. As results, 2D pattern development of different part of 3D torso model was attempted and analyzed mathematically. It was found that different height, radius and tangent slope of 3D blocks resulted in different 2D pattern. The relationships between the shape parameters of 3D torso blocks and those of 2D patterns were analyzed using regression equations. Direct way of drawing a 2D pattern of corresponding 3D torso block was also illustrated for the convenience of pattern making using conventional measurements of upper/ lower radii and height of 3D torso block.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.9_10 s.146
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• pp.1359-1368
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• 2005

When we develop the tight-fit 2D pattern from the 3D scan data, segmentation of the 3D scan data into several parts is necessary to make a curved surface into a flat plane. In this study, Garland's method of triangle simplification was adopted to reduce the number of data point without distorting the original shape. The Runge-Kutta method was applied to make triangular patch from the 3D surface in a 2D plane. We also explored the detailed arrangement method of small 2D patches to make a tight-fit pattern for a male body. As results, minimum triangle numbers in the simplification process and efficient arrangement methods of many pieces were suggested for the optimal 2D pattern development. Among four arrangement methods, a block method is faster and easier when dealing with the triangle patches of male's upper body. Anchoring neighboring vertices of blocks to make 2D pattern was observed to be a reasonable arrangement method to get even distribution of stress in a 2D plane.