• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.11 s.254
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• pp.1461-1471
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• 2006

This paper presents the mathematical model for rolling behaviors of a small regular polygonal part on an inclined plane. Throughout the numerical analysis performed with the simulation program which has been experimentally validated, it is shown that the number of edges of the rolling polygonal part can be a measure for the energy dissipation rather than the coefficient of friction. The appropriate slope angle has been found to be around 20 degree for roughness-separation as well as shape-separation of polygonal parts which have small number of edges. In additions, the vibratory motion applied to the inclined plane is able to cause mixed parts to be separated more effectively according to the shape or the roughness. Finally, a couple of parts separation methods based on the analysis results are presented, and are validated through the numerical simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.787-792
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• 1996

The method of manipulation by striking a part and letting it slide until it comes to rest, has been very little studied. However, the manipulation method is not uncommon in our daily lives. We analyze the dynamic behavior of a rigid polygonal part being striked and sliding on a horizontal surface under the action of fiction. There are two parts in this problem; one is the impact problem, and the other is the sliding problem. We characterize the impact and sliding dynamics with friction for polygonal parts, and present the possibility of reverse calculation for motion planning of striking operations. Using a high speed video camera, the computer simulation results are experimentally verified.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.11
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• pp.1111-1118
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• 2006

This paper covers topics related to the investigations for the problem of sensorless vibratory orienting of polygonal parts with high probability through dynamic simulation. The author's program for mechanical systems with changing topologies was experimentally validated and was used as a simulation and design tool for motion behaviors of the vibratory parts-orienting system in the dynamic environment. A flat level vibrating bar is proposed as a means of orienting parts. Dynamic manipulation, in which a part is repeatedly caught and tossed by the bar without sensing, forms the fundamental manipulation strategy. This paper presents how to plan vibratory manipulation strategies that can orient a small rigid polygonal part using interaction between the part and the vibrating bar without requiring sensing. The planned motion strategies have been experimentally validated to show how the dynamic simulation can be used to find favorable vibration parameters for a given part without knowledge of their initial orientations.

• Laser Solutions
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• v.1 no.1
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• pp.24-29
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• 1998

A new wide laser beam optical system for the laser materials processing has been developed with a polygonal mirror. It consists of polygonal mirror and cooling part that prevents the surface of rotating polygonal mirror from damage by heat. The polygonal minors have been designed and made as 24 and 30 facets in pyramid type. This system provides a uniform linear laser heat source with the surface scanning width from 15 to 50mm according to the scanning height To examine the wide laser beam, He-Ne laser is used. Also, Acryl is used to confirm the laser beam pattern by bum-pattern print To analyze the energy distribution of the wide laser ben empirical values and theoretical values are compared and discussed. To improve the efficiency of the wide laser beam optical system, methods are suggested by the optical theories. For larger area processing like turbine blade, drawing blade, cold roller and guide plate, optimal overlapping locations have been calculated and analyzed by geometric and optical theories.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.4
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• pp.126-135
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• 1997

A sensorless motion planner which succeeds in grasping a polygonal part firmly into a desired orientation has been developed through the dynamic analysis. The analytical results on the impact process with friction are used for modeling the contact motionduring the parallel-jaw grasp operation, which is com- posed of the pushing and the squeezing process. The developed planner succeeds in grasping a part into a specified orientation in the face of uncertainties of initial position and orientation of the part, motion direction of the finger, and the physical parameters such as the coefficients of friction and restitution. The motion planner has been fully implemented into a viable package on the computer system, and verified experimentally. The motion of parts is recorded using a high-speed video camera, and then compared to the results of the planner and the graphic simulation results that illustrate the simulated motion of the grasp operation.

• Journal of IKEEE
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• v.25 no.3
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• pp.485-492
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• 2021

In this paper, we propose the development of a defect inspection system for polygonal containers. Embedded board consists of main part, communication part, input/output part, etc. The main unit is a main arithmetic unit, and the operating system that drives the embedded board is ported to control input/output for external communication, sensors and control. The input/output unit converts the electrical signals of the sensors installed in the field into digital and transmits them to the main module and plays the role of controlling the external stepper motor. The communication unit performs a role of setting an image capturing camera trigger and driving setting of the control device. The input/output unit converts the electrical signals of the control switches and sensors into digital and transmits them to the main module. In the input circuit for receiving the pulse input related to the operation mode, etc., a photocoupler is designed for each input port in order to minimize the interference of external noise. In order to objectively evaluate the accuracy of the development of the proposed polygonal container defect inspection system, comparison with other machine vision inspection systems is required, but it is impossible because there is currently no machine vision inspection system for polygonal containers. Therefore, by measuring the operation timing with an oscilloscope, it was confirmed that waveforms such as Test Time, One Angle Pulse Value, One Pulse Time, Camera Trigger Pulse, and BLU brightness control were accurately output.

• Journal of The Geomorphological Association of Korea
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• v.21 no.4
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• pp.19-40
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• 2014

Rock rebound values and chemical compositions of Gamak island at Sangha, Gochang, Jeollabuk do are analysed as a part of geomorphic survey of that area. Some corestones are formed by deep weathering found from the summit of rock mass of Gamak island, while the rocks a part of weathering front are exposed at the foot of the island. Rebound values of rock increase toward coastal plain, so summit would be weak in resistance to erosion. It can be assumed that chemical weathering is more active at the summit by the chemical index of alteration and changes in chemical composition ratio. However it should be mentioned that the samples are taken from the surface of the rock mass that more fresh part will be exposed when the weathered parts are removed. The chemical composition and CIA values of the polygonal cracks found from on the surface of weathering rind showed that this part has values between those of the summit and the footslope. The bottom of weathering rind with polygonal cracks has higher CIA value than those of the surface. Though it supports the result from the Bisul Mt., there also difference in the ratio of SiO2. It looks caused by the difference in weathering environment and chemical difference in parent rock. In summary Gamak island is the remnants of weathering front after removal of weathered material. The removal processes are more active at the footslope where the coastal processes are stronger than the summit.

• The Korean Journal of Cytopathology
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• v.17 no.1
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• pp.69-74
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• 2006

Alveolar soft part sarcoma (ASPS) is a rare soft tissue sarcoma, which occurs predominantly in adolescents and young adults. The cytological characteristics of this condition have been described only rarely in the literature. Here, we report a case of alveolar soft part sarcoma. A 28-year-old man presented with a mass in his right buttock, which had persisted for three years. The mass was subjected to a fine needle aspiration cytology (FNAC). The smears were cellular. The observed tumor cells were round or polygonal, and exhibited vesicular nuclei with prominent nucleoli and finely granular cytoplasm. Naked nuclei were frequently detected. Tumor cells were arranged singularly, but occasionally in a pseudoalveolar pattern.

• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.925-930
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• 2002

This paper discusses techniques for embedding data into 3D polygonal models of geometry. Much researches of Watermarking had been gone as element technology of DRM (digital rights management). But, few research had gone to 3D polygonal model. Most research is limited at text document, 2D image, animation, music etc. RP system is suitable a few production in various goods species, and it is used much in industry to possible reason that produce prototype and find error or incongruent factor at early stage on design in product development childhood. This paper is research about method that insert watermark in STL ( stereolithography) file that have 3D shape model. Proposed algorithm inserts watermark in normal vector region and facet's interior region of 3D shape data. For this reason, 3D shape does not produce some flexure and fulfill invisibility of watermark. Experiment results that insert and extract watermark in normal netter region and facet's Interior region of 3D shape data by proposed algorithm do not influence entirely in 3D shape and show that insertion and extraction of watermark are possible.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.12 no.1
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• pp.13-23
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• 2008

In [7, 8], they proposed a new singular function(NSF) method to compute singular solutions of Poisson equations on a polygonal domain with re-entrant angles. Singularities are eliminated and only the regular part of the solution that is in $H^2$ is computed. The stress intensity factor and the solution can be computed as a post processing step. This method was extended to the interface problem and Poisson equations with the mixed boundary condition. In this paper, we give NSF method for the Helmholtz equations ${\Delta}u+Ku=f$ with homogeneous Dirichlet boundary condition. Examples with a singular point are given with numerical results.