• The Transactions of the Korea Information Processing Society
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• v.3 no.1
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• pp.43-54
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• 1996

This paper presents new heuristic search algorithms for searching rectilinear r(L1), link metric, and combined shortest paths in the presence of orthogonal obstacles. The GMD(GuidedMinimum Detour) algorithm combines the best features of maze-running algorithms and line-search algorithms. The SGMD(Line-by-Line GuidedMinimum Detour)algorithm is a modiffication of the GMD algorithm that improves efficiency using line-by-line extensions. Our GMD and LGMD algorithms always find a rectilinear shortest path using the guided A search method without constructing a connection graph that contains a shortest path. The GMD and the LGMD algorithms can be implemented in O(m＋eloge＋NlogN) and O(eloge＋NlogN) time, respectively, and O(e＋N) space, where m is the total number of searched nodes, is the number of boundary sides of obstacles, and N is the total number of searched line segment. Based on the LGMD algorithm, we consider not only the problems of finding a link metric shortest path in terms of the number of bends, but also the combined L1 metric and Link Metric shortest path in terms of the length and the number of bands.

• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1456-1460
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• 2000

Objectives : Transpedicular screw fixation has become an important method for internal fixation in variety of disorders. However, acceleration of degeneration at the adjacent segment in any follow. The goal of this study is to review the change of motion ranges of vertebral joints adjacent to fused level in lumbar spine. Methods : This study consists of 22 patients with degenerative spinal instability. Treatment of spinal instability includes posterior fusion with transpedicular screw fixation or transpedicular screw fixation with posterior lumbar interbody fusion. The flexion-extension angle(FEA) was measured from dynamic views of lumbar spine taken both at preoperative and post operative period. Results : The FEA of upper vertebral joint adjacent(FEA-u) to a fused L4-5 level was increased(p＝0.010). The FEA-u was increased in case of L5-S1 fusion(p＝0.025). The change of FEA-u in case of L5-S1 fusion was greater than that in L4-5 fusion(p＝0.013). Conclusion : After L4-5 fusion, there seems to be more meaningful increase in FEA of L3-4 than that of L5-S1. The reason may be due to the damage of L3-4 facet joints during the operation, the other possible explanation may be the anatomical stability of L5-S1 vertebral joint. The change of FEA-u of L5-S1 fusion is increased more than that of L4-5 fusion. Because there are compensations in the adjacent vertebrae both above and below the fused L4-5, the compensatory motion in FEA-u of L5-S1 fusion was greater than that of the L4-5 fusion.

• Journal of Plant Biotechnology
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• v.33 no.1
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• pp.57-62
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• 2006

Several methods for determining the response of corn to glyphosate were investigated to provide a fast and reliable method for identifying glyphosate-resistant corn in vivo. Two bioassays were developed. One assay is named 'whole plant / leaf growth assay', in which the herbicide glyphosate is applied on the upper part of 3rd leaf and the growth of herbicide-untreated 4th leaf is measured at 3 day after treatment. in this assay, the leaf growth of conventional corn was inhibited in a dose dependent from 50 to $1600{\mu}g/mL$ of glyphosate and growth inhibition at $1600{\mu}g/mL$ was 55% of untreated control. The assay has the potential to be used especially in the case that the primary cause of glyphosate resistance is related with a reduction of the herbicide translocation. Another assay is named 'leaf segment / shikimate accumulation assay', in which the four excised leaf segments ($4{\times}4mm$) are placed in each well of a 48-well microtiter plate containing $200{\mu}L$ test solution and the amount of shikimate is determined after incubation for 24 h in continuous light at $25^{\circ}C$. In this assay, 0.33% sucrose added to basic test solution enhanced a shikimate accumulation by 3 to 4 times and the shikimate accumulation was linearly occurred from 2 to $8{\mu}g/mL$ of glyphosate, showing an improved response to the method described by Shaner et al. (2005). The leaf segment / shikimate accumulation assay is simple and robust and has the potential to be used as a high throughput assay in the case that the primary cause of glyphosate resistance is related with EPSPS, target site of the herbicide. Taken together, these two assays would be highly useful to initially select the lines obtained after transformation, to investigate the migration of glyphosate-resistant gene into other weeds and to detect a weedy glyphosate-resistant corn in field.

• Speech Sciences
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• v.11 no.1
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• pp.131-145
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• 2004

The informative or important entities in utterances are focused and the focused items are usually accompanied by changes in phonetic manifestation. Phonetic realizations triggered by focus include changes of tonal contours as well as segmental strengthening. Focus in Korean is characterized by new phrase initiation, dephrasing, and initial tone contour with an enlarged pitch range in addition to segmentally lengthened initial segment. Focusing on the prosodic cues which play an important role in delivering the speakers' intention, this study aims to find out what intonational characteristics of Korean focus are realized by English learners of Korean. The English learners are divided into two groups according to their fluency in Korean, and the differences in focus realization between each group are discussed. Furthermore, the phonological and phonetic realizations of focus by English learners of Korean are compared to those by Korean native speakers. The results of this study yields two suggestions for Korean intonation education of L2 learners. First, the comparison between the two speaker groups can give better understanding in how and why the Korean intonation of English speakers is different from that of Koreans. Second, each phonological and phonetic characteristic of focus realization can weigh differently and its realization provides a criterion for evaluation of L2 Korean proficiency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.6
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• pp.972-982
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• 2001

FMM(Fast Multipole Method) is suitable numerical method for radar cross section calculation of arbitrary large conducting bodies due to reduction of computation time. The accuracy of the numerical results, however, can influenced by selection of grouping method and segment length, in particular, far the case that cross section of the scatter is of the narrow width elliptical type. So, we describe the FMM method which can be deal effectively with such difficulties for both TM and TE polarization case. In order to check the present method the results are compared with those obtained by Method of Moments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.907-910
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• 2005

Although several artificial disc designs have been developed for the treatment of discogenic low back pain, biomechanical change with its implantation was rarely studied. To evaluate the effect of artificial disc implantation on the biomechanics of functional spinal unit, nonlinear three-dimensional finite element model of L4-L5 was developed with 1-mm CT scan data. Two models implanted with artificial discs, SB $Charit\acute{e}$ or Prodisc, via anterior approach were also developed. The implanted model predictions were compared with that of intact model. Angular motion of vertebral body, force on spinal ligaments and facet joint, and the stress distribution of vertebral endplate for flexion-extension, lateral bending, and axial rotation with a compressive preload of 400 N were compared. The implanted model showed increased flexion-extension range of motion and increased force in the vertically oriented ligaments, such as ligamentum flavum, supraspinous ligament and interspinous ligament. The increase of facet contact force on extension were greater in implanted models. The incresed stress distribution on vertebral endplate for implanted cases indicated that additinal bone growth around vertebral body and this is matched well with clinical observation. With axial rotation moment, relatively less axial rotation were observed in SB $Charit\acute{e}$ model than in ProDisc model.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.853-858
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• 2001

The PSC bridge being built by ILM may have greater bending moment during its construction rather than after completion. When it occurs, Engineer should suggest to reduce stress-resultants than to make bigger cross-section with considering stability ,economics, and proper span-to-depth ratio. The used method is to install extruded nose at the end of girder. It substitutes the weighted segment for the light. From the reference, the stiffness of extruded nose, is 1/10 of the main girder, and the length is 60 to 70% of the length of the span, with little justification. In this study, the proper length and stiffness of the nose element is determined by the parametric study and idealizing procedure. The results about the extruded nose through the mixing of the parameter of its stiffness and length, the proper length of extruded nose is 80% of the longest span and the proper stiffenss is 13% of the bending stiffness of the superstructure and the proper length of extruded nose is 70% of the longest span and the proper stiffness is 9.5% of the bending stiffness of the superstructure.

• Journal of Plant Biotechnology
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• v.7 no.2
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• pp.129-134
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• 2005

Callus induction from a leaf explant has been achieved in Lilium Oriental hybrid 'Casa Blanca'. The highest frequency of callus induction was obtained on MS medium supplemented with 0.5 mg/L BA and 2.0 mg/L NAA after 2 months of culture. The cultures maintained continuously without change in color and type of callus when they cultured in the dark. Plantlet regeneration with a high frequency was achieved from induced calli on the same medium. A number of shoots are formed from one cluster of callus, and bulblets developed into intact plantlets after transfer to hormone-free MS medium. No phenotypic variations were observed among regenerants. Enhancement in plantlet regeneration via callus formation would be expected to facilitate the efficiency of transformation of this Oriental hybrid 'Casa Blanca'.

• Current Research on Agriculture and Life Sciences
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• v.31 no.2
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• pp.94-100
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• 2013

An efficient plant regeneration protocol is developed for a standard-type chrysanthemum. When petal segments derived from flower buds (4 or 8cm in diameter) were used as the culture material, the highest shoot regeneration frequency (96%) was obtained on a Murashige and Skoog (MS) medium supplemented with 0.5 mg/L IAA, 2 mg/L BA, 3% sucrose, and a 0.8% agar. Pre-culturing the explants under dark conditions for 14 days produced better results for the shoot regeneration frequency than the explants cultured under a continuous 16 h photoperiod ($40{\mu}molm^{-2}s^{-1}$). The shoot regeneration frequency ranged from 19.0% for the Shinmato cultivar to 89.1% for the Baeksun cultivar. Activated charcoal (0.2%) enhanced the root formation of the regenerated shoots in a hormone-free MS medium. The rooted plantlets were acclimatized and successfully established in a greenhouse.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.260-266
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• 2011

An efficient protocol was established for high frequency somatic embryogenesis through a callus culture of Coelogyne cristata. The best frequency of callusing was obtained from a PLB segment (3-5 mm) cultured on MS medium supplemented with coconut water (CW) and a combination of both 3 $mg{\cdot}L^{-1}$ of 2,4-D and BA. When the calli were sub-cultured on the MS medium without any PGRs, the average number of somatic embryos were higher than those with PGRs treatment. NAA is the most critical factor among PGRs, which dramatically hindered for the formation of a somatic embryo. The efficacy of the addition of coconut powder (CP) for somatic embryogenesis was almost the same in all treatments. However, the number of somatic embryos formed distinctly depended on age of the callus. The somatic embryos converted into healthy plants with well-developed shoots on the same medium. Plantlets showed the best responses of root and shoot growth when transferred to $\frac{1}{2}$ MS medium containing 1.5 $g{\cdot}L^{-1}$ of activated charcoal. All plants with above 3.0-cm-high were successfully acclimatized in the greenhouse.