• Journal of Mechanical Science and Technology
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• v.16 no.3
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• pp.320-326
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• 2002

A modeling method for the vibration analysis of rotating composite cantilever plates is presented in this paper. The coupling effects between inplane motions and the bending motion are considered and explicit mass and stiffness matrices are derived for the modal analysis. Numerical results are obtained and some of them are compared to those of a commercial program to confirm the accuracy of the present method. Numerical results show that the coupling effects become important only when laminates are stacked up unsymmetrically. Incidentally, natural frequencies loci veering, loci crossing, and associated mode shape variations are observed.

• Journal of the Korean Institute of Gas
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• v.19 no.5
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• pp.13-19
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• 2015

This paper presents a hydraulic fracture propagation model to describe propagation more realistically. In propagating the hydraulic fractures, we have used two criteria: maximum tangential stress to determine the fracture initiation angle and whether a hydraulic fracture intersects a natural fracture. The model was validated for the parameters relevant to fracture propagation, such as initiation angle and crossing ability through natural fracture. In order to check whether a hydraulic fracture crosses a natural fracture, the model results on crossing state excellently matched with the experimental data. In the sensitivity analysis for direction of maximum horizontal stress, frictional coefficient of fracture interface, and natural fracture orientation, the results show that hydraulic fracture intersects natural fracture, and then, propagated suitably with theoretical results according to fracture interaction criterion. In comparison of this model against vertical fracture approach, it was ascertained that there are discrepancies in fracture connectivity and stimulated reservoir volume.

• The Korean Journal of Mycology
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• v.25 no.2 s.81
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• pp.111-120
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• 1997

The characteristics of monosporous isolates of winter mushroom [Flammulina velutipes (Curt. ex Fr.)] were investigated to obtain useful breeding materials. Within monokaryons from cultivars which have a white colored fruitbody showed narrow genetic variation, while domestic strains which have a brown colored fruitbody showed wide variation. The mating type of the white strains was A1A2B1B2 genotype, but that of the domestic brown strains were A3A4B3B4. In intra-crossing, the genetic stability of dikaryons mated by monokaryons from white strain was less than that of parents. While in brown strain, dikaryons with high yield and color variation were obtained.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.407-413
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• 2001

A modeling method for the vibration analysis of rotating composite cantilever plates is presented. Explicit mass and stiffness matrices are derived by considering the coupling effects between extensional motions and the bending motion, To confirm the accuracy of the method presented in this study, numerical results are obtained and compared to those of a commercial program. Numerical results show that the coupling effect among the three motions becomes important for the accurate estimation of natural frequencies as laminates are stacked up unsymmetrically. Also, natural frequencies loci veering, loci crossing, and mode shape variations are observed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.283-294
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• 2018

An accurate pedestrian-delay model is essential for the pedestrian-oriented evaluation of signalized intersection (SI). The crossing behaviors of pedestrians at signalized pedestrian crosswalks (SPCs) are various, and their arrival behaviors consist of two types, random and platoon. It is natural, hence, that the behaviors of pedestrian crossing and arrival should be considered in order to estimate accurate pedestrian delay. Despite this necessity, a simple pedestrian-delay model that cannot explain these behaviors of pedestrian movements is still recommended in Highway Capacity Manual (HCM). For these reasons, a pedestrian-delay model, suitable for various SPCs and SIs, is required to make pedestrian-oriented decisions on the design and operation of various SPCs and SIs. This paper proposes a novel pedestrian-delay model that is based on the behaviors of pedestrian crossing and arrival. The proposed model consists of two sub models: the one for SPC and the other for SI. The SPC delay model was developed based on the behaviors of pedestrian crossing during pedestrian green time. The SI delay model was designed based on the behaviors of pedestrian crossing and platoon arrival. The results of a numerical simulation showed that the proposed delay model can successfully overcome the under- and overestimation problems of the HCM model with explaining various behaviors of pedestrian crossing and arrival.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.194-200
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• 1998

The difference in leaf bud flushing times of Quercus species and their hybrids was compared among the trees from natural forest, seedlings from natural pollination and artificial crossing. In the natural forest of the Hiruzen experimental forest of Tottori University, Japan, Quercus species flushed in the order of Q. crispula > Q. anguste-lepidota > Q. takatorensis ${\fallingdotseq}$ Q. serrate > Q. dentata. The flushing time of seedlings from natural pollination was in the order of Q. aliena ${\fallingdotseq}$ Q. crispula > Q. angustelepidota > Q. takatorensis ${\fallingdotseq}$ Q. serrate > Q. dentata. The flushing times of $F_1$ hybrids by artificial crossing were between those of parental species. From the result of interspecific hybridization, it is shown that the earliness of flushing in Quercus species is a genetic character considered hereditable to progenies.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.485-489
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• 1999

The germination percentages of Quercus hybrid seeds produced in 1994 using stored pollens were low. The survival rate and height growth within 2 years differed according to crossing combinations. The survival rate and growth of seedlings from hybrid seeds produced in 1991 and 1993 were investigated. The survival rates of five-year-old and three-year-old seedlings were from 71 to 100% and from 33 to 100%, respectively. The survival rates differed according to cross combinations. The mortality of seedlings increased in proportion to the increase of percentages of dwarf seedlings. The growth of five-year-old seedlings, of which mother tree was Q. aliena, was the best. The growth of seedlings produced by artificial crossing tended to be worse than that of natural crossing.

• Journal of the Korean Mathematical Society
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• v.45 no.5
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• pp.1341-1360
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• 2008

In this paper we investigate the projections of bouquet graph B with two cycles. A projection of B is said to be trivial if only trivial embeddings are obtained from the projection. It is shown that, to cover all nontrivial projections of B, at least three embeddings of B are needed. We also show that a nontrivial projection of B is covered by one of some two embeddings if the image of each cycle has at most one self-crossing.

• Proceedings of the Korean Society of Crop Science Conference
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• 1992.05a
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• pp.26-27
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• 1992

• Plant Resources
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• v.7 no.2
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• pp.141-146
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• 2004

Frequent occurrence of off-type plants in a given cultivar has been a serious problem in both breeder's and farmer's fields. An experiment was designed to examine the differences in rate of occurrence of off-type plants among Tongil-type cultivars (high yielding cultivars derived from indica/japonica hybridization) from which the possible cause of higher occurrence of off-type plant in a specific cultivar was deduced. Among five Tongil-type cultivars examined for morphological variant in the field, only one cultivar, Dasanbyeo, had off-type plants. When analyzed with SSR markers, off-type plants showed different band patterns from original cultivar, having several extra bands in addition to cultivar-specific band, suggesting that off-type plants were originated from Dasanbyeo, rather than originated from mixing or mishandling of seed materials with other cultivars. The possible cause of off-type occurrence seems to be natural pollination with other cuItivars adjacent to the original cultivar during seed multiplication. This was supported from the observation that self-crossed progeny of the off type plants showed a wide range of variation of agronomic traits which could not be observed when there was a smaller introduction of genes to the fixed germplasm as happened in the case of cultivar mutation. Another evidence supported this idea that Dasanbyeo showed much of difference in floral organ and behavior to other cultivar to be subjected to higher out-crossing than other cultivars examined.