• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.55-62
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• 2002

A burr has been defined as undesirable projection of material formed as the result of plastic flow from a cutting or shearing operation. It is unavoidable in all kinds of machining operation. As a result, burr makes troubles on manufacturing process due to deburring cost, quality of products and productivity. In face milling operation, burrs are formed along five edges on the workpiece. In this study, the primary interest is about exit burr The influence of the cutting parameters on the formation of exit burrs in face milling will be described experimentally. Using the results of experimental study, burr types are classified according to appearance and formation mechanism in exit burr. The burr formation mechanism in each type of burr is suggested. Data bases are developed to predict burr formation result.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.346-351
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• 2001

The technique of high speed machining is widely studied in machining field. Because the high efficiency and accuracy in machining can be obtained in high speed machining. Unfortunately the development of tool for high speed machining is not close behind that of machining tool. So in this study, we made 4 types flat end mill for obtaining data according to tool shape. Especially, we concentrated in helix angle and number of cutting edge. First we confirmed cutting condition by several experiments and measuring cutting force, tool life, tool wear and chip shape according to cutting length. In results, we acquired the fact that 45 degree helix angle and six cutting edge tool is suitable for high speed machining.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.125-129
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• 1996

In this study, a method is proposed for the cutting force prediction of Ball-end milling process using Z-map is proposed. Any types of cutting area generated from previous cutting process can be expressed in z-map data. Cutting edge of a ball-end mill is divided into a set of finite cutting edges and the position of this edge is projected to the cross-section plane normal to the Z-axis. Comparing this projected position with Z-map data of cutting area and determining whether it is in the cutting region, total cutting force can be calculated by means of numerical integration. A series of experiments such as side cutting and upward/downard cutting was performet to verify the simulated cutting force.

• Journal of Korean Association for Spatial Structures
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• v.12 no.4
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• pp.57-69
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• 2012

This study investigated the behaviors of the gabled hyperbolic paraboloid shell structure subjected to differential settlement and the horizontal displacement due to the elongation of tie rod/beam on supports. Two types of shell structure with different roof slopes are used in study; conventional type which has perimeter beams around the shell panel, and simple type which removes the edge beams along the slab edge line. The effect of the removal of edge beam under vertical or horizontal displacement on supports, and the roof slope was compared using the finite element analysis.

• Structural Engineering and Mechanics
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• v.15 no.6
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• pp.685-704
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• 2003

The buckling and vibration characteristics of stiffened plates subjected to in-plane concentrated edge loading are studied using finite element method. The problem involves the effects of non-uniform stress distribution over the plate. Buckling loads and vibration frequencies are determined for different plate aspect ratios, boundary edge conditions and load positions. The non-uniform stresses may also be caused due to the supports on the edges. The analysis presented determines the initial stresses all over the region considering the pre-buckling stress state for different kinds of loading and edge conditions. In the structural modeling, the plate and the stiffeners are treated as separate elements where the compatibility between these two types of elements is maintained. The vibration characteristics are discussed and the results are compared with those available in the literature and some interesting new results are obtained.

• Structural Engineering and Mechanics
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• v.4 no.5
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• pp.569-586
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• 1996

A new three-dimensional 8-node solid element with rotational degrees of freedom is presented. The proposed element is established by adding rotational degrees of freedom to the basic 8-node solid element. Thus the element has three translations and three rotational degrees of freedom per node. The corner rotations are introduced by transforming the hierarchical mid-edge displacements which are parabolic shape along an edge. The derivation of the element is based on the mixed variational principles in which the rotations are introduced as independent variables. Several types of non-conforming modes are selectively added to the displacement fields to obtain a series of improved elements. The resulting elements do not have the spurious zero energy modes and Poisson's ratio locking and pass patch test. Numerical examples show that presented non-conforming solid elements with rotational degrees of freedom show good performance even in the highly distorted meshes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.107-108
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• 2016

Our study proposes the methods of distinguishing vehicle types using the interval and size of the car. The car videos converts the basic RGB model to Gray model for use and through Canny Edge Direction, it eliminates the background of the car while obtaining feature points through the detection of contours.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.308-311
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• 1998

Some nondestructive diagnostic methods including various types of corrosion sensors have been investigated. Under these conditions, a new structure of sensor that has a pair of electrode and magneto-supply was proposed. In order to detect the edge of the iron rust part, three-poles touch-type corrosion sensor is now proposed. The iron rust pattern where the sensor touches is estimated by means of the impedance of the sensor, and the edge of the iron rust is recognized by comparing the three measured impedances. As the result, our proposed sensor is useful to detect the initial state of iron rust.

• Steel and Composite Structures
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• v.1 no.2
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• pp.201-212
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• 2001

In order to investigate the effect of the loading rate on the mechanical behavior of SRC shearwalls, we conducted the lateral loading tests on the 1/3 scale model shearwalls whose edge columns were reinforced by H-shaped steel. The specimens were subjected to the reversed cyclic lateral load under a variable axial load. The two types of loading rate, 0.01 cm/sec for the static loading and 1 cm/sec for the dynamic loading were adopted. The failure mode in all specimens was the sliding shear of the in-filled wall panel. The edge columns did not fail in shear. The initial lateral stiffness and lateral load carrying capacity of the shearwalls subjected to the dynamic loading were about 10% larger than those subjected to the static loading. The effects of the arrangement of the H-shaped steel on the lateral load carrying capacity and the lateral load-displacement hysteresis response were not significant.

• IE interfaces
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• v.13 no.4
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• pp.703-708
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• 2000

In manufacturing processes, manufacturing features always deviate somewhat from their nominal design specifications due to several types of errors. This study suggests a fitting algorithm of the geometric profile parameters of leading and trailing edges for turbine compressor airfoils. In reality, industry personnels inspect the airfoil profile by trial-and-error method to determine the geometric feature parameters. In this study we propose an exploration approach based on factorial design with center point to minimize the effect of measurement errors caused by probe slip. By adopting the fitting method developed in this paper, one can enhance the precision and efficiency of fitting the airfoil edge profile.