• International Journal of Aerospace System Engineering
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• v.7 no.1
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• pp.7-15
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• 2020

In this paper the crack growth, modeling, and simulation of the stiffened and un-stiffened cracked panels presented using commercially available finite element software packages. Computation of stresses and convergence of stress intensity factor for single edge notch (SEN) specimens carried out using the finite element method (FEM) and extended finite element method (XFEM) and compared with an analytical solution. XFEM techniques like cohesive segment method and LEFM using virtual crack closure technique (VCCT), used for crack growth analysis and presented results for un-stiffened and stiffened panels considering various crack domain. The non-linear analysis considering both geometric and material non-linearity on stiffened panels with various stringers like a blade, L, inverted T and Z sections the results were presented. Arrived at the optimum stringer section type for the considered panel under axial loading from the numerical analysis.

• Journal of Plant Biology
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• v.33 no.4
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• pp.315-320
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• 1990

We investigated the interaction of auxin and Ca2+ on coleoptile segment elongation in seedlings of Zea mays L. Seedlings imbibed and raised either in the presence of 10 mM CaCl2 (HC), or in the absence of Ca2+ (LC) were used. Exposure to 10-5M auxin of coleoptiles from either HC or LC seedlings resulted in strong promotion of elongation. However, longer latent period (90 min) of the auxin effect was observed in HC than in LC seedlings (20 min). The length of latent period observed in HC coleoptiles was proportional to the concentration of CaCl2. The latent period of auxin effect observed in HC seedlings was abolished by pretreatment of the coleoptiles with TMB-8 which inhibits IP3-induced Ca2+ release from the tonoplasts. In segments of LC seedlings, the promotive effect of IAA (10-5M) was abolished by treatment with 5 mM calcium but was reversible upon treatment of the segments with 5 mM EGTA. These results suggest that the effect of auxin on coleoptile elongation is closely related to intracellular Ca2+ level.

• 한국전자현미경학회:학술대회논문집
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• 2004.11a
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• pp.105-110
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• 2004

Cavernocypris gosuensis n. sp. (Cyprididiae, Cypridopsinae), a new subterranean ostracod species is described with figures of female valves, mouthparts, appendeges and SEM photos from Gosu cave, Danyang-Gun, Chungcheongbuk-Do in Korea. The new stygobiont speices is sixth of the genus Caveroncypris Hartmann, 1964 that characterized by both valeves with a median concave part in ventral view and two groove lines in dorsal view, the reduction of the furca, which is flagellum like in female and the left valve ventrally overlaps the right valve when the carapace is closed and can be distinguished from its congers by left valve with 6 muscle scars in innerpart, mandible palp with one claw and 3 setae on the terminal segment and without seta on the exterodistal border of segment III. The animals were collected within pH 7.31-8.74, temperature ($^{\circ}C$) 13.0-14.6 and dissolved oxygen (mg/l 6.75-14.84 from Aug.2003 to Sep.2004.

• Speech Sciences
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• v.7 no.3
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• pp.11-19
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• 2000

The present electropalatographic study reports the production of the allophones. i.e., [l] and [r], of Korean tap /r/ and their coarticulatory characteristics in /$C{\'{a}}r#g$/ and /$C{\'{a}}r#i$/ sequences. The finding that tap /r/ involves a complete oral closure with less lingual contact, i.e., apico-frontalveolar coupling. than lateralized /r/ which involves apico-bladealveolar coupling and tongue dorsum lowering for adequate airflow through either side and/or both of the tongue body suggests that the two allophones of the tap /r/ have different lingual gestures. Moreover. in comparison with the tap. the lateral exerts longer lingual contacts. The mean ratio between them is 3.7. In the sequences /Car#g/. the two adjacent antagonistic segments (i.e., /r/ and /g/) show mutual coarticulation effects taking on features of adjacent segment. but either of them is precisely constrained without blocking the formation of involved major lingual gestures for the other segment. In sequences /Car#i/ occurs anticipatory V-to-C coarticulation but not vocalic carryover effects. In both sequences. the allophones reveal insignificant wordinitial consonantal carryover coarticulatory effects and insignificant speaker-specific lingual contacts.

• Journal of Plant Biotechnology
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• v.5 no.2
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• pp.95-99
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• 2003

The leaf segments of garlic (Allium sativum L.) were cultured in vitro and determined optimal concentration of plant growth regulators and sugars for callus induction, multiple shoots regeneration and in vitro bulblet formation. Highest yield of callus was observed in the leaf segment culture on Murashige and Skoog (MS) medium supplemented with 1.0 mg/L 2,4-D, 30 g/L sucrose and 8 g/L agar. Regeneration rate of multiple shoots from callus was high in the MS medium supplemented with kinetin 3.0 + NAA 3.0 mg/L or SA 1.0 + NAA 3.0 mg/L, containing 30 g/L sucrose. High rate of bulblet formation was observed as the concentration of jasmonic acid increased from 0.5 to 2.0 mg/L in medium, whereas addition of gibberellic acid significantly suppressed bulblet formation. The rate of in vitro bulbing was as high as $96\%$ in MS medium supplemented with 2.0 mg/L jasmonic acid and 120 g/l sucrose after two month culture at $25{\pm}1^{\circ}C$ under 16 hours day light.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2632-2635
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• 2003

This paper designs a software signal generator for the new GPS L2 civil signal. The CM/CL code and the message structure of L2CS described in GPS ICD PPIRN-200C-007 are used in designing the signal generator. The output of the GPS signal generator is designed as the sampled IF data with the sampling frequency 5.7MHz and stored in the binary data format. By analyzing both the spectrum characteristics of the output signal and the correlation properties of the CM/CL code, the validation of the designed GPS signal generator is shown. It should be mentioned that the modeling of the GPS satellite constellation and the error sources remains for implementing the software space segment of GPS.

• English Language & Literature Teaching
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• v.17 no.4
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• pp.251-271
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• 2011

The present study analyzed Korean learners' production of English /z/-/$d{\Box}$/ and /z/-/${\Box}$/ contrasts in terms of native speaker judgments and acoustic measurements. Korean learner's production was judged to be either correct or incorrect by native English speakers. Correct and incorrect productions were then compared with productions of native speakers' in terms of acoustic analyses. The results indicated that Korean speakers' correct production was more similar to that of native speakers by sharing more acoustic cues. Incorrect production by Korean speakers indicated patterns either different or opposite from that of native speakers, confirming native speaker judgments. The results also revealed acoustic cues on which native speakers rely in judging L2 speech, thereby implying that the more consistent along with more number of acoustic cues used by native speakers may facilitate the acquisition of segment contrasts by L2 learners.

• Korean Journal of Pharmacognosy
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• v.27 no.4
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• pp.359-365
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• 1996

In order to product the saikosaponin which is one of the secondary product from Bupleurum falcatum efficiently through the tissue culture, several levels of agar and gellan gum as the gelling agent, 2,4-D as the growth regulator, and L-phenylalanine as the precursor were used with single or combination treatment on MS basal medium. Gellan gum was more effective than agar as the gelling agent in fresh and dry weight increase of callus induced from Bupleurum falcatum leaf segment. Gellan gum medium supplemented with L-phenylalanine produced 1.6 times of fresh weight more than that of agar. The fresh weight was remarkably high in gellan gum when the calli was treated with the combination of 2,4-D and L-phenylalanine similar to the single treatment of 2,4-D or L-phenylalanine. However, the saikosaponin content in callus was high in gellan gum with the single treatment of L-phenylalanine. Especially, the saikosaponin content in gellan gum supplemented with 1.0mg/L L-phenylalanine was 2 times(2.4 mg/g) higher than that in agar medium supplemented with 0.1 mg/L 2,4-D(0.9 mg/g).

• Korean Journal of Plant Tissue Culture
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• v.28 no.6
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• pp.329-333
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• 2001

Callus and shoot formation from medicinal crop, Lycium chinense Mill. cv. 'Cheongyang', as influenced by various media, explant sources and plant growth regulators were investigated. The rate of shoots formation, number of shoots, and fresh weight of shoots were the best on MS medium followed by B$_{5}$, WPH, and SH. Callus induction was more effective in leaf than internode segments, and was the best on MS medium containing 0.5 mg/L NAA with 0.2 mg/L BA. Effects of plant growth regulators in shoot formation were more effective in BA than TDA combined with NAA. Shoot formation from callus induced in leaf and internode segments was the best on MS medium containing 0.01 mg/L NAA with 0.2 mg/L BA.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.205-212
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• 1987

To examine the morphogenetic response, stem segments of 8 Populus spp. and 3 different explants of P. nigra var. italica were cultured on MS (Murashige and Skoog 1962) and WPM (Woody Plant Medium) medium containing various phytohormones. The results obtained were as follows: 1. Shoot regeneration and development from stem segment of 8 Populus spp. showed a quite difference according to the section and the species. All of the species of Leuce and Tacamahaca section did not form adventitious buds, while most of explants showed axillary or dormant bud elongation after 4 weeks. But P. nigra var. italica of Aigeiros section showed a successful adventitious bud formation (mean 5.4 buds per explant). 2. Leaf, petiole, and internode segment of P. nigra var. italica showed a quite differences according to media and ex plants upon the morphogenetic response. Adventitious bud formation from leaf was more abundant and readily initiated on the abaxial side than on the adaxial side. Mean number of 103 adventitious buds per explant was obtained from abaxial side of leaf segment cultured on WPM medium containing $0.2mg/{\ell}$ BAP for 5 weeks. 3. 2,4-D (2,4-dichlorophenoxy acetic acid) supplemented to media appeared to be negative upon the adventitious bud formation of P. nigra var. italica, while it promoted callus formation from all explants. Especially, NAA (${\alpha}$-naphtalene acetic acid) or NAA combination with BAP (6-benzylaminopurine) promoted root regeneration from the all explant of P. nigra var. italica in this study.