• Journal of Korea Multimedia Society
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• v.11 no.3
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• pp.331-340
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• 2008

In order to make load balancing, workload information of nodes should be informed to the network. In a load balancing algorithm[13] based on the SBIBD(Symmetric Balanced Incomplete Block Design), each node receives global workload information by only two round message exchange with O (${\upsilon}{\sqrt{\upsilon}}$) traffic overhead, where ${\upsilon}$ is the number of nodes. It is very efficient but works well only when ${\upsilon}=p^2+p+1$ for a prime number p. In this paper, we generate a special incidence structure in order for the algorithm works well for an arbitrary number of nodes. In the experiment with w,($5{\leq}w{\leq}5,000$), nodes and more than 80% of receiving workload information, traffic overhead was less than O ($w{\sqrt{w}})$ and the result for standard deviation of traffic overhead showed that each node has largely balanced amount of traffic overhead.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.4
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• pp.73-82
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• 2016

Recently, automobile industries have been developing many structural automotive parts made of thin, high-strength steel strips to produce safer and more environmentally friendly cars. The roll forming process has been considered one of the most efficient processes in manufacturing high-strength steel parts because it is a high-speed process that forms sheets in increments. However, most automotive parts vary longitudinally in their cross-sections. Therefore, it is difficult to apply the roll forming process to automotive parts made of high-strength steel. A variable section roll forming process has been proposed in recent studies. The rotational axes of the forming rolls are fixed, and the forming rolls have three-dimensional shape. As such, the cross-section of the part varies linearly along its length, and the angle between the bend line and longitudinal axis is less than 1 degree. Thus, the rate of cross-sectional variation along the length is relatively small. In this study, the rate of cross-sectional change along the length of a forming roll has been increased. Moreover, the angle between the bend line and longitudinal axis has been increased up to 15 degrees. The variable sections of the forming rolls have been designed for high strength steel parts with a symmetric u-type cross-section that varies linearly and symmetrically along the longitudinal axis.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.2
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• pp.192-197
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• 2017

In this paper, image filter optimization method based on common sub-expression elimination is proposed for low-power image feature extraction hardware design. Low power and high performance object recognition hardware is essential for industrial robot which is used for factory automation. However, low area Gaussian gradient filter hardware design is required for object recognition hardware. For the hardware complexity reduction, we adopt the symmetric characteristic of the filter coefficients using the transposed form FIR filter hardware architecture. The proposed hardware architecture can be implemented without degradation of the edge detection data quality since the proposed hardware is implemented with original Gaussian gradient filtering algorithm. The expremental result shows the 50% of multiplier savings compared with previous work.

• Transactions of Materials Processing
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• v.11 no.4
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• pp.363-370
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• 2002

In this study, an optimal design technique was investigated for determining appropriate dimensions of components of the die set used in the extrusion process. For this, an axi-symmetric elastic finite element program for the analysis of deformation of the shrink fitted die set was developed with the Lagrange multiplier method to implement the constraint condition of shrink fit of stress ring. By coupling the rigid-viscoplastic analysis of extrusion process by CAMPform and elastic analysis of the die set, the optimization study was made by employing optimization program DOT. Considering the various assembly conditions, optimal design was determined for a single stress ring case. It is construed that the proposed design method can be beneficial for improving the tool life of cold extrusion die set at practice.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.1
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• pp.26-32
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• 2001

An ecpert system for rotationally symmetric deep drawing products has been developed. The application for non-axisymmetric components, however, has not been reported yet. This study construsctus and expert system for non-axisymmetric motor frame which shape is classified into ellipse in deep draqing process and investigates process sequence design with elliptical shape. The developed system consists of four modules. The first is recognition of calculate surface area for non-axisymmetric products. The third is blank design module the creates an oval-shaped blank with the same surface area. The fourth is a processplanning module based on production rules that play the best important roles in an expert system for manufacturing .The production rules are generated and upgraded by interviewing field engineers. Especially, drawing coefficient, punch and die radii for elliptical shape products are considered as main design parameters. The constructed system for elliptical deep drawing product would be very useful to reduce lead time and improve accuracy for products.

• Journal of applied mathematics & informatics
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• v.14 no.1_2
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• pp.343-351
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• 2004

In order to maintain load balancing in a distributed system, we should obtain workload information from all the nodes on network. This processing requires $O(v^2)$ communication overhead, where v is the number of nodes. In this paper, we present a new synchronous dynamic distributed load balancing algorithm on a (v, k ＋ 1, 1)-configured network applying a symmetric balanced incomplete block design, where $v\;=\;k^2$\;＋\;k\;＋\;1$. Our algorithm needs only $O(\sqrt[v]{v})$ communication overhead and each node receives workload information from all the nodes without redundancy. Therefore, load balancing is maintained since every link has the same amount of traffic for transferring workload information.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.10 no.1
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• pp.42-47
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• 1985

An efficient logic circuit for realizing the function which has output of 1 diagonaly and design for multivalued logic circuit using with ROM structure which has two output at once are presented. The circuits presented are suited for the circuit design of a symmetric multivalued truth tables and the circuit design of multivalued truth tables with many independent variables. Also, they are applied to the multivalued truth tables of Galois field(GF).

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.41-44
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• 1987

This paper is studied on the improvement of an efficiency and power factor for the single-phase induction motor with non-symmetrical cores. Since the motor construction having non-symmetrical core has the effect of reluctance torque and the rearrangement of revolving field, if core and winding design were optimized, the simple and economical permanent-capacitor-motor will be design. The most significant design variables are the degree of dissymmetry, the location of windings, and the turn-ratio between the main and auxiliary winding.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.769-770
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• 2006

This paper proposes the design method of a magnetic suspension that can control external vibration caused by low frequencies on the external vibrations by low frequencies. The magnetic suspension with individual controls is able to compensate the vibrations unlike a mechanical suspension. In the magnetic suspension, two characteristics are required. Firstly, magnetic motive force(MMF) by armature winding must be increased linearly. Secondly, identical magnitude of output force should be produced as direction of MMF. In this paper, axis-symmetric finite element analysis is used for magnetic field analysis. In order to optimize magnetic suspension, response surface methodology combined with experimental design is applied to investigate the characteristics and optimize the magnetic suspension for vibration -free table.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.1
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• pp.209-215
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• 2000

Precision forging technology that can control flow velocity of workpiece have been developed to minimize the amounts of machining. To get the uniform rib length, flow velocity distribution is needed to be estimated and controlled. Computer-aided design is known for very effective to estimate the deformation behavior and design the die for controlling the flow velocity. In this study, die design to control the deformation velocity are investigated using the DEFORM-2D about rib-web shape parts. Also we can get uniform rib length by enforcing the back pressure at end section of rib. The applied load of back pressure farming is lower than that of conventional forging. These results are analysed and confirmed by the experiment.