• Proceedings of the KSME Conference
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• 2003.11a
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• pp.822-827
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• 2003

Experiments were done for the three dimensional unsteady flow in a counter rotating axial flow fan under stable operating condition. Flow fields in a counter rotating axial flow fan were measured at cross-sectional planes of the upstream and downstream of each rotor. Cross sectional flow patterns were investigated through the acquired data by the $45^{\circ}$ inclined hot-wire. Flow characteristics such as tip vortex, secondary flow and tip leakage flow were confirmed through axial, radial and tangential velocity vector plot. Swirl velocity, which was generated by the front rotor, was recovered in the form of static pressure rise by the rear rotor except for hub and tip regions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.445-450
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• 1995

This paper deals with conversion from STL file to Slice cross-sectional information for Stereolithography. The STL file consist of three vertices of triangle and normal vectors in order to represent three dimension shape, but It is very difficult to convert STL file intoSlice file directly, because of file size from one Mbyte to tens of Mbytes. So, The system is accomplished data flow such as neutral.dat, .SL1, .SL2, .SL3, and .SLC file. The data processing is as follows: 1. Create a neutral file including common information. 2. Modify STL file within effective scope of SLA. 3. Calculate a point of intersection between plane equation and line equation. 4. Sort z values by increasing order. 5. Search closed loop by method of singlylinked linear list. The system is developed by using Borland C++ 3.1 compiler in the environment of Pentium PC. We get a satisfactory prototype as a result of application about a lot of household electrical appliances.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.2
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• pp.302-312
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• 1994

In this study, a fuzzy theory is introduced to control the cross-sectional strip shape in cold rolling. A fuzzy controller is developed based on the production data and the operational knowledge. The cold rolled products are characterized into several types based on their irregularities. For each type of irregular strip shape, fuzzy controller calculates the changes of bender forces of work and intermediate rolls using fuzzy control algorithm. To simulate the continuous shape control, fuzzy controller is linked with emulator which is developed using neural network. The developed fuzzy controller and emulator simulate the cold rolling process until the irregularities converge to the tolerable range to produce unifrom cross-sectional strip shape. The results from this simulation are reasonable for various irregular strip shapes.

• Structural Engineering and Mechanics
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• v.49 no.6
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• pp.673-685
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• 2014

The topic of this study is to strengthen cracked beams with prefabricated RC U cross-sectional plates. The damaged beams were repaired by epoxy based glue. The repaired beams were strengthened using prefabricated plates. The strengthening plates were bonded to the bottom and side faces of the beams by anchorage rods and epoxy. The strengthened beams were incrementally loaded up to maximum load capacities. The experimental results were satisfactory since the load carrying capacities of damaged beams were increased approximately 76% due to strengthening. It was observed that strengthening plates had a dominant effect on the performance of beams in terms of both the post-elastic strength enhancement and the ductility. The experimental program was supported by a three-dimensional nonlinear finite element analysis. The experimental results were compared with the results obtained from the beam modeled with ANSYS finite element program.

• Journal of the Korean Society of Visualization
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• v.18 no.1
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• pp.44-49
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• 2020

Neutron radiography has been widely used in many research areas due to its different characteristics from X-rays. Neutron tomography is a powerful tool because it can clearly show the inside of an object that the eye cannot see. However, generally, commercial software is used for the reconstruction of neutron tomography. It means that maintenance costs are incurred and analysis is inefficient in some cases. In this respect, our own image processing code is required to reconstruct neutron images efficiently. In this study, an image processing code is developed for reconstruction of cross-sectional images from neutron radiography taken from the side of the object. Using the developed code, cross-sectional images of the sample are successfully reconstructed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.10
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• pp.1294-1302
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• 1997

For the purpose of investigating the impulsive noise at the exit of high-speed railway tunnel and the pressure transients inside the tunnel, experiments were carried out using a shock tube with an open end. A great deal of experimental data were obtained and explored to analyze the peak pressures and maximum pressure gradients in the pressure waves. The effects of the distance and cross-sectional area ratio between two-continuous tunnels on the characteristics of the pressure waves were investigated. The peak pressure inside the second tunnel decreases for the distance and cross-sectional area ratio between two tunnels to increase. Also the peak pressure and maximum pressure gradient of the pressure wave inside the second tunnel increase as the maximum pressure gradient of initial compression wave increases.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.35.1-35
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• 2001

The aim of our study is to automatically analyze how textile is woven which has complicated structure, such as textile with multi-layer structure. For this purpose, we propose a method to reconstruct a textile structure of a textile is visualized. Then, the anteroposterior sections of the same yarn on the cross sectional images is associated each other by superimposing them. Therefore, by this method, 3-D information of each yarn is obtained and the 3-D shape of each yarn is independently expressed. In this research, a 3-D reconstruction of a plain weave fabric is performed.

• Transactions of Materials Processing
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• v.31 no.6
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• pp.394-403
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• 2022

In the automotive industry, cold-drawn austenitic stainless steel is commonly used to handle high fuel pressures in gasoline direct injection (GDI) engines. In this study, we analyzed the effects of main process variables such as cross-sectional shape, drawing speed and friction coefficient on the microstructure, hardness and residual stress of the drawn material in the two-step cold drawing process. By changing the cross-sectional shape in the first-step cold drawing, the possibility of improving the shape accuracy or physical properties of the finally cold-drawn fuel rail pressure sensor product was investigated.

• Restorative Dentistry and Endodontics
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• v.42 no.3
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• pp.216-223
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• 2017

Objectives: The aim of this study was to compare the mechanical properties of various nickel-titanium (NiTi) files with similar tapers and cross-sectional areas depending on whether they were surface-treated. Materials and Methods: Three NiTi file systems with a similar convex triangular cross-section and the same ISO #25 tip size were selected for this study: G6 (G6), ProTaper Universal (PTU), and Dia-PT (DPT). To test torsional resistance, 5 mm of the straightened file's tip was fixed between polycarbonate blocks (n = 15/group) and continuous clockwise rotation until fracture was conducted using a customized device. To evaluate cyclic fatigue resistance, files were rotated in an artificial curved canal until fracture in a dynamic mode (n = 15/group). The torsional data were analyzed using 1-way analysis of variance and the Tukey post-hoc comparison test, while the cyclic fatigue data were analyzed using the Mann-Whitney U test at a significance level of 95%. Results: PTU showed significantly greater toughness, followed by DPT and G6 (p < 0.05). G6 showed the lowest resistance in ultimate torsional strength, while it showed a higher fracture angle than the other files (p < 0.05). In the cyclic fatigue test, DPT showed a significantly higher number of cycles to failure than PTU or G6 (p < 0.05). Conclusions: Within the limitations of this study, it can be concluded that the torsional resistance of NiTi files was affected by the cross-sectional area, while the cyclic fatigue resistance of NiTi files was influenced by the surface treatment.

• Physical Therapy Korea
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• v.23 no.2
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• pp.20-34
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• 2016

Background: It is necessary to find and develop the effective way of intervention for patients with neck pain, since the neck pain is becoming increasingly common throughout the world. To identify the altered motor control in patient with neck pain would be informative to find and develop the effective way of intervention. Objects: The aim of this study was to review literature regarding the altered motor control in patients with neck pain, measured by using surface electromyography (sEMG), ultrasonography, and functional magnetic resonance imaging (fMRI), and to suggest prospective research work on neck pain. Methods: Case-control (neck pain/healthy) studies published between 2004 and 2015 that investigated neck muscle activation, thickness, cross-sectional area, and fat infiltrate were searched in Scopus, PubMed, and ScienceDirect. Twenty-eight articles were included in this study. Results: sEMG, ultrasonography, and fMRI were used complementarily to investigate the altered superficial and deep neck muscle activation, thickness, cross-sectional area, and fat infiltrate in patients with neck pain. They showed the following altered motor control when compared retrospectively with healthy subjects or during specific functional tasks: (1) increased superficial muscle activation, (2) lesser deep muscle thickness, (3) smaller cross-sectional area of the deep muscle, and (4) greater fat infiltrate in deep muscles. In particular, among the women, the office workers showed higher muscle activation of superficial neck muscles during functional tasks, although they did not have neck pain, than those who were not office workers. Conclusion: Studies revealed that patients with neck pain showed an altered motor control when compared with healthy subjects by using various assessment modalities. Understanding this phenomenon would help researchers design an effective intervention for alleviating neck pain or to evaluate the effectiveness of the intervention. In addition, we recommend that female office workers take measures to care for their necks before developing neck pain.