• Journal of The Korean Astronomical Society
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• v.36 no.3
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• pp.97-103
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• 2003

We now have more than 70 multiple image gravitational lens systems. Since gravitational lensing occurs through gravitational distortions in cosmic space, cosmological informations can be extracted from multiple image systems. Specifically, Hubble constant can be determined by the time delay mea-surement, curvature of the universe can be measured by the distribution of image separations in lens systems, and limits on matter density and cosmological constant can be set by the statistics of gravitationallens systems. Uncertainties, however, still exist in various steps, and results may be taken with some caution. Larger systematic survey and better understanding of galaxy properties would definitely help.

• Journal of the Korean Magnetic Resonance Society
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• v.8 no.1
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• pp.62-69
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• 2004

Bicyclolactones obtained from the Diels-Alder cycloaddition of 3,5-dibromo-2-pyrone can undergo various palladium catalyzed cross coupling reactions to afford aryl bicyclolactones. The resulting coupled products can be readily converted into various 3-OH cyclohexenes via lactone ring openings, while those bearing dienyl units underwent highly diastereoselective Diels-Alder cycloadditions with selected dienophiles to funish multiply functionalized polycarbocycles. Bromo-bicyclic diene furnished two different diastereomers endo-form (62%) and exo-form (38%) upon cycloadditions with N-Et maleimide (NEM), and their stereochemistries were identified with NMR.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.3
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• pp.12-23
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• 2007

Frequently spraying of natural starch slurry onto the formed wet web has been adopted to improve properties of paperboards. This conventional starch spraying technique, however, becomes less effective in strength improvement. In this study the effects of various factors including wet web dryness, quantity of starch slurry sprayed, and drying temperature on paperboard properties were investigated. Migration of starch granules into the webs appeared to cause a reduction in plybond strength when the web dryness was lower than this level. Wet webs should contain enough water to swell the starch granules, and at the same time they should be heated to a temperature high enough for complete cooking of the sprayed starches to occur. This suggested that preheating of the wet web can be employed to improve the plybond strength.

• International Journal of Industrial Entomology and Biomaterials
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• v.21 no.1
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• pp.117-125
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• 2010

The tropical tasar silkworms, Antheraea mylitta (D) produce famous silk 'Kosa' in central part of India. Due to outdoor rearing it became susceptible to viral infection including cytoplasmic polyhedrosis virus (CPV). The common mode of entry of cytoplasmic polyhedrosis virus is per os and cause gresserie disease to the larvae. Histopathological studies elucidated the insect CPV virus produces infective polyhedral inclusion bodies (PIBs) in the midgut cell cytoplasm of virus infected fifth instar larvae. The PIBs multiply enormously in the cytoplasm without invading the nucleus. Ultrastructural studies confirmed the pathological effects of CPV on in midgut cell cytoplasm. The multiplication of polyhedral inclusion bodies took place into the vacuoles and form virogenic stromata in the cytoplasm of cells. However, the encapsulations of polyhedral inclusion bodies into the polyhedrin protein occurred and polyhedra were released into the lumen. At the late stage of infection, cells showed the regressed cytoplasmic organelles with large vacuoles and elongated mitochondria. Hence, the horizontal transmission of CPV causing the midgut cells disintegration in the tasar silkworm, Antheraea mylitta (D) confirmed during infection.

• Journal of Microbiology
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• v.43 no.spc1
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• pp.118-131
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• 2005

Vibrio vulnificus is an opportunistic pathogen of humans that has the capability of causing rare, yet devastating disease. The bacteria are naturally present in estuarine environments and frequently contaminate seafoods. Within days of consuming uncooked, contaminated seafood, predisposed individuals can succumb to sepsis. Additionally, in otherwise healthy people, V. vulnificus causes wound infection that can require amputation or lead to sepsis. These diseases share the characteristics that the bacteria multiply extremely rapidly in host tissues and cause extensive damage. Despite the analysis of virulence for over 20 years using a combination of animal and cell culture models, surprisingly little is known about the mechanisms by which V. vulnificus causes disease. This is in part because of differences observed using animal models that involve infection with bacteria versus injection of toxins. However, the increasing use of genetic analysis coupled with detailed animal models is revealing new insight into the pathogenesis of V. vulnificus disease.

• Korean Journal Plant Pathology
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• v.10 no.1
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• pp.18-24
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• 1994

Multiplications and pathogenic reactions of different pepper and tomato strains of Xanthomonas campestris pv. vesicatoria were evaluated in the most upper leaves of pepper and tomato plants at different growth stages. Hypersensitive reactions were induced in mature pepper plants by inoculation with only the tomato strains but not with the pepper strains, suggesting the expression of age-related resistance in pepper plants. The age-related resistance also seems to be correlated with an apparent inability of the bacteria to multiply as extensively in mature as in young plants. No significant differences among the Korean and U. S. pepper cultivars tested were found in bacterial multiplication, irrespective of bacterial stain or plant growth stage. Korean tomato cultivars tested also were highly susceptible to either tomato or pepper strains during the development of tomato plants.

• Journal of the Korean Physical Society
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• v.73 no.10
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• pp.1512-1518
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• 2018

The problem of scalar wave scattering by a sphere on or near a planar substrate is analytically solved. The solution is a set of wave functions coming in the form of infinite series of spherical and plane waves. In air, the incident plane wave is either scattered by the sphere or reflected from the substrate. A part of these scattered or reflected waves propagate to the other object where it is reflected and scattered again. Such processes of scattering and reflection repeat in turn indefinitely to generate multiply scattered waves, which are represented in the corresponding terms in the infinite series. The term in the series can be arranged in a recognizable manner to explicitly reveal the involved process and the multiplicity of scattering.

• International Journal of Reliability and Applications
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• v.4 no.1
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• pp.41-50
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• 2003

This paper represents the first comprehensive comparison of the Newton-Raphson's method and Simple Iterative Procedure (SIP) in the maximum likelihood estimation of the two-parameter Weibull distribution. Computer simulation is employed to compare these two methods for multiply censored, singly censored data (Type I or Type Ⅱ censoring) and complete data. Results indicate the Newton-Raphson's with the Menon's estimated value, as an initial point remains the effective iterative procedure for estimating the parameters.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.712-714
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• 2012

D2D(Device-to-Device) 통신은 이동통신망을 기반으로 동작할 경우 이동통신망의 자원을 재사용함으로써 주파수 자원사용의 효율성을 높일 수 있다. 그러나 D2D 통신 단말(DUE; D2D user equipment)이 이동통신망의 자원을 재사용하는 경우 동일자원을 사용하는 이동통신개체와 DUE 간 및 D2D 통신 쌍 간에 신호 간섭이 발생할 수 있어 이를 고려한 자원할당기법에 대한 연구가 필요하다. 본 논문에서는 다수의 DUE가 이동통신망의 상향링크 자원을 다중으로 재사용할 때 이동통신개체 및 DUE가 달성가능 한 주파수 효율을 고려하여 DUE에게 자원을 할당함으로써 셀 수율을 향상시킬 수 있는 자원할당 기법을 제안한다.

• Bulletin of the Korean Mathematical Society
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• v.58 no.2
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• pp.419-431
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• 2021

In this paper we discuss the classical problem of finding conditions on the entire coefficients A(z) and B(z) guaranteeing that all nontrivial solutions of f" + A(z)f' + B(z)f = 0 are of infinite order. We assume A(z) is an entire function of completely regular growth and B(z) satisfies three different conditions, then we obtain three results respectively. The three conditions are (1) B(z) has a dynamical property with a multiply connected Fatou component, (2) B(z) satisfies T(r, B) ~ log M(r, B) outside a set of finite logarithmic measure, (3) B(z) is extremal for Denjoy's conjecture.