• Tunnel and Underground Space
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• v.21 no.3
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• pp.235-243
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• 2011

In this study, a control blast method, which utilizes crack guide holes, is suggested to achieve smooth fracture plane and minimize blast damage zone (BDZ) in smooth blasting. In order to verify the effectiveness of crack guide holes on the fracture plane control in blasting, fracture process analyses which consider regular smooth blasting and guide hole smooth blasting had been conducted and the fracture planes resulting from the analyses had been compared. The analyses models considered the ignition of the blast holes using detonation cords and each guide hole placed between blast holes. From the results, the smooth blasting utilizing guide holes showed lower fracture plane roughness than regular smooth blasting method in the hole spacing range between 20 to 40cm.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.1
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• pp.51-56
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• 2006

A computer code was developed to simulate both the thermal stresses introduced during the post-filling stage and the in-plane deformation after ejection process by finite element method based on the plane stress theory. The computer simulation was applied to the mold design of a 2 inch light guide plate (LGP) for thin film transistor (TFT)-liquid crystal displays (LCD). With injection molding experiments based on the design of experiments (DOE) technique, the influences of the processing conditions in injection molding on brightness and uniformity of the LGP were investigated, and the optimal processing parameters were selected to increase the brightness and uniformity. The verification experiment showed that the brightness and uniformity of the LGP were increased dramatically under the selected optimal processing conditions.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.422-428
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• 2002

In this study, actuator, sensor, guide, power transmission element and control method are considered for ultra-precision positioning apparatus. Through previous process, single plane X-Y stage with ultra-precision positioning is manufactured. Global stage for the purpose of materialization with robust system, is combined by using AC servo motor and ball screw and rolling guide. And ultra-precision positioning system is developed by micro stage with elastic hinge type and piezo element. global servo and micro servo for the purpose of materialization positioning accuracy with nm(nanometer) are controlled simultaneously by using incremental encoder and laser interferometer as displacement measurement sensor. Through previous process, ultra-precision positioning system (100mm stroke and ${\pm}$ 10nm positioning accuracy) with single plane X-Y stage are materialized.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.5
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• pp.65-72
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• 2002

In this study, actuator, sensor, guide, power transmission element and control method are considered for ultra-precision positioning apparatus. Through previous process, single plane X-Y stage with ultra-precision positioning is manufactured. Global stage for the purpose of materialization with robust system, is combined by using AC servo motor and ball screw and rolling guide. And ultra-precision positioning system is developed by micro stage with elastic hinge type and piezo element. global servo and micro servo for the purpose of materialization positioning accuracy with nm(nanometer) are controlled simultaneously by using incremental encoder and laser interferometer as displacement measurement sensor. Through previous process, ultra-precision positioning system(100mm stroke and $\pm$ l0nm positioning accuracy) with single plane X-Y stage are materialized.

• The Journal of Advanced Prosthodontics
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• v.7 no.1
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• pp.76-84
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• 2015

This article reviews the topic of how to identify and develop a removable partial denture (RPD) path of placement, and provides a literature review of the concept of the RPD path of placement, also known as the path of insertion. An optimal RPD path of placement, guided by mutually parallel guide planes, ensures that the RPD flanges fit intimately over edentulous ridge structures and that the framework fits intimately with guide plane surfaces, which prevents food collecting empty spaces between the intaglio surface of the framework and intraoral surfaces, and ensures that RPD clasps engage adequate numbers of tooth undercuts to ensure RPD retention. The article covers topics such as the causes of obstructions to RPD intra-oral seating, the causes of food collecting empty spaces that may exist around an RPD, and how to identify if a guide plane is parallel with the projected RPD path of placement. The article presents a method of using a surgical operating microscope, or high magnification (6-8x or greater) binocular surgical loupes telescopes, combined with co-axial illumination, to identify a preliminary path of placement for an arch. This preliminary path of placement concept may help to guide a dentist or a dental laboratory technician when surveying a master cast of the arch to develop an RPD path of placement, or in verifying that intra-oral contouring has aligned teeth surfaces optimally with the RPD path of placement. In dentistry, a well-fitting RPD reduces long-term periodontal or structural damage to abutment teeth.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.324-327
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• 2002

For the characterization of arbitrary shaped printed circuit board, lossy transmission line grid model based on SPICE netlist and analytical plane model based on the segmentation method are proposed in this paper. Two methods are compared with an arbitrary shaped power/ground plane. Furthermore, design considerations for the complete power distribution network structure are discussed to ensure the maximum value of the PDN impedance is low enough across the desired frequency range and to guide decoupling capacitor selection.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.6
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• pp.24-32
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• 2004

The effects of guide vanes and tip clearances on the characteristics nf axial flow fans are investigated both computationally and experimentally. Performance test of fans carried out in full scale shows considerable effects of tip clearance between rotor tip and duct on the characteristics of fans. The tested results are compared with the computation based on the finite volume method to solve the Navier-Stoke equations with $textsc{k}$-$\varepsilon$ turbulence model. The comparison shows good agreements between experimental and computational results. In addition, the effects of shape of guide vanes are numerically studied. The results show that increased volume of separated region around the guide vane reduces the recovery of tangential component of kinetic energy in the wake, resulting in loss of efficiency

• Journal of Korean Society of Steel Construction
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• v.9 no.1 s.30
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• pp.65-79
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• 1997

Composite materials are consist of two or more different materials to produce desirable properties for structural strength. Because of their superiority in strength, corrosion resistance, and weight reduction, they are used extensively as structural members. The objective of this study is to present the effectivness of the laminated composite elements by analyzing in-plane displacement and stress of the anisotropic laminated annular elements. Anisotropic laminated structures are very difficult to analyze and apply, compared with isotropic and orthotropic cases for arbitrary boundaries and fiber angle -ply. Boundary conditions for the examples used in this study consist of two opposite edges clamped and the other two edges free, and finite difference method is used in this study for numerical analysis. From the numerical result, it is found that the program used in this study can be used to obtain the displacement of the straight beams considering it's transverse shear deformation as well as anisotropic laminated elements. Several numerical examples show the advantages of the stiffness increase when the angle-ply composite materials are used. Therefore it gives a guide in deciding how to make use of fiber's angle for the subtended angle, load cases, and boundary conditions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4405-4418
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• 2016

Automatic image completion techniques have difficulty processing images in which the target region has multiple planes or is non-facade. Here, we propose a new image completion method that uses belief propagation based on planar priorities. We first calculate planar information, which includes planar projection parameters, plane segments, and repetitive regularity extractions within the plane. Next, we convert this planar information into planar guide knowledge using the prior probabilities of patch transforms and offsets. Using the energy of the discrete Markov Random Field (MRF), we then define an objective function for image completion that uses the planar guide knowledge. Finally, in order to effectively optimize the MRF, we propose a new optimization scheme, termed Planar Priority-belief propagation that includes message-scheduling-based planar priority and dynamic label cropping. The results of experiment show that our approach exhibits advanced performance compared with existing approaches.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.469-475
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• 2003

The performance of a centrifugal compressor composed of an impeller, tandem diffuser rows and axial guide vanes has been predicted numerically and compared with available experimental results on its design rotational speed. The pitchwise-averaged mixing plane method was employed for the boundaries between rotor and stator to obtain steady state solutions. The overall characteristics showed differently according to the relative positions of tandem diffuser rows while the characteristics of impeller showed almost identical. The numerical results agree with the measured data in respect of their tendency. It turned out that 0% of relative positions is the worst case in terms of static pressure recovery and efficiency. According to the experimental results, some pressure fluctuations and malfunction of the compressor were observed for 75% case. However, this numerical calculation using mixing plane method did not capture any of those phenomena. Thus, unsteady flow calculation should be performed to investigate the stability of the compressor caused by different diffuser configuration.