• Journal of Korean Institute of Industrial Engineers
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• v.17 no.1
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• pp.75-82
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• 1991

This research is concerned with Machine-Part Group Formation(MPGF) methodology for Flexible Manufacturing Systems(FMS). The purpose of the research is to develop a new heuristic algorithm for effectively solving MPGF problem. The new algorithm is proposed and evaluated by 100 machine-part incidence matrices generated. The performance measures are (1) grouping ability of mutually exclusive block-diagonal form. (2) number of unit group and exceptional elements, and (3) grouping time. The new heuristic algorithm has the following characteristics to effectively conduct MPGF : (a) The mathematical model is presented for rapid forming the proper number of unit groups and grouping mutually exclusive block-diagonal form, (b) The simple and effective mathematical analysis method of Rank Order Clustering(ROC) algorithm is applied to minimize intra-group journeys in each group and exceptional elements in the whole group. The results are compared with those from Expert System(ES) algorithm and ROC algorithm. The results show that the new algorithm always gives the group of mutually exclusive block-diagonal form and better results(85%) than ES algorithm and ROC algorithm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.11
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• pp.1912-1920
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• 1997

In the analysis of metal forming process, ALE(Arbitrary Lagrangian Eulerian) finite element methods have been increasingly used for the capability to control mesh independently from material flow. The methods can be divided into two groups i.e., coupled and split formulations. In the present work, the split ALE formulation is used for computational efficiency. A split ALE finite element method developed for rigid-viscoplastic materials and applied to the analysis of hot square die extrusion. Since thermal state greatly affects the product quality, an ALE scheme for temperature analysis is also presented. As computational examples, profile shapes as square and cross-like sections are chosen.

• Environmental Analysis Health and Toxicology
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• v.3 no.3_4
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• pp.17-28
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• 1988

The effects of perilla oil diet on the immune response in mice have been studied. ICR male mice were divided into 4 groups and were fed on the experimental diet for 4 weeks. Mice were sensitized and challenged with sheep red blood cell (S-RBC). Immune response were evaluated by antibody production, Arthus reaction, delayed type hypersensitivity (DTH), Rosette forming cell (RFC) and macrophage activity. The weight of body, liver, thymus and spleen were measured. The body weight was increased but thymus weight was not altered by them. The perilla oil diet decreased the weight of liver and spleen in mice. It reduced antibody production, Arthus reaction, DTH and RFC, macrophage activity. These results showed that the high perilla oil diet decresed more humoral and celluar immune response than the low perilla oil diet. It decreased the phagocytic activity on the reticuloendothelial system in mice.

• Environmental Analysis Health and Toxicology
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• v.3 no.3_4
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• pp.1-8
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• 1988

Experiment was performed to investigate the immunotoxicity of cadmium administered orally and the effect of ginseng petroleum ether fraction on it. Mice were given 3, 30, or 300 ppm cadmium as cadmium chloride orally in the drinking water and injection of ginseng petroleum ether fraction intraperitoneally for 4 weeks. Mice were sensitized and challenged u'ith sheep red blood cells (5-HBC). Immune response was evaluated by delayed type hypersensitivity (DTH), Rosette forming cell (RFC), phagocyte activity, and natural killer cell activity (NK cell activity). In the present study, cadmium suppressed the cellular immunity, It also depressed phagocyte activity very significantly in all cadmium-administered groups, NK cell activity in the cadmium-300 ppm administered group. Ginseng petroleum ether fraction showed restoring effect on the decrease in RFC by cadmium-administration. Remarkably, it showed very significant restoring effect on the depression of phagocyte activity induced by cadmium-administration. From this result, we suppose that the anti-tumor effect of ginseng ether or petroleum ether extract, which has been reported by some other researchers, is mainly due to the increase of phagocyte activity by it's administration.

• Korean Journal of Crystallography
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• v.10 no.1
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• pp.28-32
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• 1999

The title compound consisting of a calix[4]arene molecule with four phenyl rings arranged alternately in anti-orientation fashion, two propyloxy groups attached on the upper rim of calix[4]arene, and polyther chain with two phyenyl rings attached on the lower rim of calix[4]arene offers a big cavity inside a molecule with might a potential for forming host-guest complexes.

• Journal of the Korean Ceramic Society
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• v.45 no.2
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• pp.126-131
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• 2008

In this study, we prepared zirconia gel by the sol-gel method and investigated its photoluminescence properties by varying pyrolysis temperature. The addition of acetic acid into a Zr-alkoxide solution resulted in forming the bidentate ligands with Zr ions and producing a stable gel. At the pyrolysis temperature of $350^{\circ}C$, the zirconia nanocrystals with tetragonal structure gradually appeared in the gel. The PL intensity of the zirconia gel increased with increasing the pyrolysis temperature up to $350^{\circ}C$, but decreased above the temperature. Concurrently, its PL peak wavelength continuously shifted from ${\sim}440\;nm$ to ${\sim}550\;nm$ with the temperature. The PL characteristics of the zirconia gels were closely associated with decomposition of residual organic groups, the formation of the zirconia nanocrystals, and the tetragonal to monoclinic phase transformation.

• Journal of the Korean Data and Information Science Society
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• v.14 no.3
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• pp.511-523
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• 2003

Internet has become an important part of teenagers' life and has changed the life style of teenagers. Internet can be an useful tool for educating teenagers and also can be misused as a cyberspace for social problems. Recognizing that teenagers spend most of their free time enjoying internet and they form their own new life culture, it is needed to develop practical strategies for maximizing the positive effect of internet on the teenagers' culture. The purpose of this research is to suggest a desirable way for forming teenagers' healthy internet-based culture. The research was conducted by the survey of teenagers in the city of Pyongtaek on their use of internet and their problems The survey shows that most of teenagers are using internet in order to release the stress and most of them are hooked on it. It also indicates that cyber police and volunteer groups should be formed to help the desirable teenagers' internet-based culture.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.281-283
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• 2009

Forming Community is important to manage and provide the service in Ubiquitous Environments including embedded tiny computers. Community Computing is that members constitute the community and cooperate. A mutual exclusion problem occurs when many processors try to use one resource and race condition happens. In the expanded concept, a group mutual exclusion problem is that processors in the same group can share the resource but processors in different groups cannot share. As mutual exclusion problems might be in community computing environments, we propose algorithm which improves the execution speed using RMS (resource management service). In this paper describes proposed algorithm and proves its performance by experiments, comparing proposed algorithm with previous method using quorum-based algorithm.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.37.2-37.2
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• 2012

The A2199 supercluster at z=0.03 is one of the most massive system in nearby universe. In this supercluster, A2199 is kinematically connected to A2197 and several infalling galaxy groups. Thanks to a high-density environment and complex structures around A2199, this supercluster is an excellent laboratory for studying galaxy evolution. We determine the membership of galaxies in the supercluster using radial velocities of galaxies drawn from the SDSS spectroscopic DR7 data. We present an infrared view of this supercluster using AKARI and WISE data. We compare spatial distributions between early- and late-type galaxies, and also AGNs and star-forming galaxies. We also investigate how local and cluster-scale environments affect galaxy properties, such as IR-properties, star formation rates, and morphology transformations.

• Korean Journal of Computational Design and Engineering
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• v.6 no.2
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• pp.111-124
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• 2001

In this paper, we propose rounding operations on shell meshes, which give a constant or variable radius of rounding directly to sharp edges on a shell mesh. The rolling-ball methods for freeform surface rounding are introduced to devise the algorithms for these operations. Our algorithms consists of three steps as follows: detecting sharp edges, generating a rolling-ball surface contacting with two face groups adjacent to the sharp edges, and then replacing the rounding area of the original mesh with the mesh generated on the rolling-ball surface. In addition, this paper shows their application to the area of stamping die design. These operations enable CAE engineers to directly change the meshes of stamping tools without modification of CAD models for dies and regeneration of their meshes.