• Journal of Korean Institute of Industrial Engineers
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• v.24 no.3
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• pp.407-416
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• 1998

For fast Cholesky factorization, it is most important to reduce the number of nonzero elements by ordering methods. Generally, the minimum deficiency ordering produces less nonzero elements, but it is very slow. We propose an efficient implementation method. The minimum deficiency ordering requires much computations related to adjacent nodes. But, we reduce those computations by using indistinguishable nodes, the clique storage structures, and the explicit storage structures to compute deficiencies.

• Korean Journal of Computational Design and Engineering
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• v.12 no.2
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• pp.109-117
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• 2007

Three-dimensional mesh models have been widely used in various applications such as simulations, animations, and e-catalogs. In such applications the normal vectors of mesh models are used mainly for shading and take up the major portion of data size and transmission time paper over networks. Therefore a variety of techniques have been developed to compress them efficiently. In this paper, we propose the MOEC (Modified Octree Encoding Compression) algorithm, which allow multi lever compression ratios for 3D mesh models. In the algorithm, a modified octree has nodes representing their own positions and supporting a depth of the tree so that the normal vectors are compressed up to levels where the shading is visually indistinguishable. This approach provides efficient in compressing normals with multi-level ratios, without additional encoding when changing in compression ratio is required.

• Korean Journal of Pharmacognosy
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• v.41 no.4
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• pp.297-302
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• 2010

Lophatheri Herba is the aerial part of Lophatherum gracile Bronghiart(淡竹葉, Gramineae). 25~75 cm in length. Stem: cylindrical with nodes, empty inside, externally pale yellowish green. Leaf: dehiscent of lanceolate lamina, shrunken and rolled, 5~20 cm long, 10~35 mm wide; surface: pale green ~ yellowish green, parallel-formed with veins of square reticulate, more distinct of appearance on the lower surface. Banbusae Caulis In Taeniam is the stringy strip derived from the stem with the peeled-off epidermis of Phllostachys nigra Munro var. henosis Stapf, and Phllostachys bambusoides Siebold et Zuccarini(竹葉, Gramineae). Irregular in size and shape, thin plane ~ strip-shaped, sometimes powdery, sometimes 1~3 mm thick. Outer surface: pale green ~ yellowish green, sometimes grayish white L. gracile and P. nigra have different origins although they show similar morphologic features. We were able to distinguish between L. gracile and P. nigra which are almost indistinguishable through this study. AFLP(Amplifide Fragment Length Polymorphism) was more suitable for identifying differences between L. gracile and P. nigra in comparison with other genetic analysis using chemical analysis. Therefore. molecular biological methods are believed to be useful for discovering origins of herbal medicines.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8C
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• pp.645-654
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• 2012

In this paper, we consider a two-way relay (TWR) system, where two user nodes exchange their information within two transmission phases, by the help of a relay node adopting physical layer network coding. In the system, two users transmit their binary phase shift keying symbols simultaneously in the first phase, and the relay node decodes the XORed version of two user data and broadcasts it back to two users in the second phase. The performance of the system is analyzed in terms of the average end-to-end symbol error probability in Nakagami-m fading channels, for which a tight upper bound is derived in a closed form to provide an accurate and handy estimate on the performance. The results show that our upper bounds are almost indistinguishable from simulation results for various channel and system configurations. In addition, the optimal relay location and power allocation for various conditions can be obtained quickly with our analysis.