• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.3
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• pp.97-103
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• 2001

This paper has focused on the Optimization of the cutting parameters for urning operation based on the Taguchi method. Four cutting parameters. nemely, cutting speed, feed depth of cut and nose radius are optimized with consideration of the surface roughness. The design and analysis of experiments are conducted to study the performance characteristic. The effects of these parameters on the surface roughness have been investigated using signal-to-noise(S/N) ratio and analy-sis of variance(ANOVA). The experiments have been performed using coated tungsten carbide inserts without any cutting fluid. Experimental results illustrate the effectiveness of this approach.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.309-316
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• 2017

In shuttle vans designed to transport children, the recognition of a child's approach and departure is very important. Ultrasonic sensors are generally used for a short distance around a vehicle. Although ultrasonic sensors are cheaper than other ADAS sensors, the number of sensors installed in a van should be optimized. In order to recognize the presence of a child around a shuttle van, this paper proposes the placement of ultrasonic sensors in the van. Considering the turning radius of the van and the distance from each sensor to a child, collision risk is classified as 'safe', 'warning', and 'danger'. The sensor placement and the recognition algorithm are verified in a virtual driving environment.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.456-461
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• 2001

This paper depicts the weak shock wave propagating inside some kinds of pipe bends. Computational work is to solve the two-dimensional, compressible, unsteady Euler Equations. The second-order TVD scheme is employed to discretize the governing equations. For the computations, the incident normal shock wave is assumed at the entrance of the pipe bend, and its Mach number is changed between 1.1 and 1.7. The turning angle and radius of the curvature of the pipe bend are changed to investigate the effects on the shock wave structure. The present computational results clearly show the shock wave reflection and diffraction occurring in the pipe bend. In particular, the vortex generation, which occurs at the edge of the bend, and its shedding mechanism are discussed in details.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.581-584
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• 2003

The austenitic STS 304 stainless steel was turned to clarify the effects of tool geometry on the tool wear. The wear of TiN-TiCN-TiC-TiAlN coated tungsten carbide tool was the smallest, exhibiting larger wear in the order of Si-Al-O-N ceramic, TiN coated tungsten carbide, TiN-TiCN-TiN coated tungsten carbide, TiC-TiN cermet and M20 tungsten carbide tools at the same cutting conditions. The S-type tool of M20 with large approach angle showed the longest tool life of all tools used in this tests due to preventing the groove wear of the side cutting edge. The wear of the S-type tool with the rake angle of 15$^{\circ}$became smaller than with that of -5$^{\circ}$, but the tool with the nose radius of 0.8mm did not perform much better with increasing the rake angle.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.8
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• pp.942-950
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• 2011

Automation is important in modern agricultural environment, which demands the highest level of technology. In the paper an independent four-wheel steering driving platform is developed especially for horticulture in glass house farm. Mathematical modeling of the four wheel system is carried out for smooth movement. The relationships between steering angle, the turning radius, and escape trajectory are simulated using the dynamic analysis program. Optimal driving algorithm is sought through the performance evaluation.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.3
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• pp.103-110
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• 1997

This study provides the useful actual data instead of the experience data using in industrial fields. Especially, values of each components of cutting force are effective in the rake angle, setting angle and cutting area. Many researches have been made on the work piece materials, kinds of bite materials, rake angle, nose radius and depth of cut, but a few on the bite setting angle. In order to select optimal cutting speed, it was summarized the following results are achieved; A chieved that an affect of cutting resistance on the setting angle is a little under giving experimental conditions and therefore a worker can be choose the value of it randomly.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.1
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• pp.98-102
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• 2015

This paper proposes an autonomous navigation method for a nonholonomic mobile robot, based on the generalized Voronoi diagram (GVD). We define the look-ahead point for a given motion constraint to determine the direction of motion, which solves the problem of a minimum turning radius for the real nonholonomic mobile robot. This method can be used to direct the robot to explore an unknown environment and construct smooth feedback curves for the nonholonomic robot. As the trajectories can be smoothed, the position of the robot can be stabilized in the plane. The simulation results are presented to verify the performance of the proposed methods for the nonholonomic mobile robot. Furthermore, this approach is worth drawing on the experience of any other mobile robots.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.25-33
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• 2013

All-wheel steering (AWS) system is applied to articulated vehicles to reduce turning radius. The swing-out suppression algorithm is applied to AWS ECU, a key component of AWS system. The swing-out suppression algorithm applied to AWS ECU has a problem when velocity of vehicle is changed. In this paper, new algorithm based on moving distance that solve velocity problem is proposed. The HILS simulation and the test articulated bus is used to validate algorithm.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2151-2155
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• 2008

The tilting train express (TTX) is able to tilt its body toward to the center of the turning radius on curved railways. TTX can travel at higher speed than the existing normal railway vehicles due to the tilting mechanism decreasing centrifugal force. Also, a new suspension system is required for TTX which has proper stiffness constants and damping ratios because it has different suspension characteristics with the others. Therefore, the suspension systems need to be optimized to maximize dynamic characteristic of the railway vehicle. To optimize the dynamic characteristics of TTX, sensitivity analysis should be onde to identify design variables. In this paper, Design of Experiments(DOE) is used for the sensitivity analysis of TTX.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.278-283
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• 2009

The bimodal tram with a pivoting joint has difficulty in making a sharp turn because of their long body and wheel base. Therefore, applying AWS(all wheel steering) to the bimodal tram is effective to reduce the turning radius. In the present study, HILS(hardware in the loop simulation) system for the AWS ECU test was developed, which consists of the components used in real vehicles. The data obtained from the HILS system also satisfied the dynamics simulation without any error on the operation control.