• International journal of advanced smart convergence
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• 제1권2호
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• pp.43-46
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• 2012

We analyzed a periodic thick mushroom structure for use as an artificial magnetic conductor using mode-matching method. The fields in each region were represented by either Floquet modes or waveguide modes. By applying tangential electric and magnetic field continuity conditions and using matrix equations, unknown coefficients and dispersion diagram were calculated. The proposed model can account for the effects of oblique incidence. Simulation time using the method was much faster than the commercial tools. We found that the current method produces accurate results of reflection phase and dispersion diagram.

• Proceedings of the IEEK Conference
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.877-880
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• 1999

A rigorous formulation is suggested〔l,2,3〕 in solving the scattering of plane waves by a dielectric wedge. Correcting surface currents are expanded in a Neumann series of fractional orders to meet the edge condition of static limit〔4〕. For the better converging series, the modified Neumann series satisfying the static limit edge condition and the radiation condition are suggested here for the surface currents having two different wave numbers of air and dielectric〔4〕. This representation gives accurate solutions over the whole region including the grazing incidence of the plane waves upon the dielectric wedge of large permittivities.

• Journal of the Korean Institute of Telematics and Electronics A
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• 제31A권2호
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• pp.60-66
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• 1994

The scattering problem by E-polarized plane wave with oblique incidence on a tapered resistive strip grating with infinite resistivity at strip-edges is analyzed by the method of moments in the spectral domain. Then the induced surface current density is expanded in a series of Ultraspherical polynomials of the zeroth order. The expansion coefficients are calculated numerically in the spectral domain, the numerical results of the geometricoptical reflection coefficient for the tapered resistivity in this paper are compared with those for the existing uniform resistivity. And the position of sharp variation points in the magnitude of the geometric-optical reflection coefficient can be moved by varying the incident angle and the strip spacing. It is found out that these sharp variation points are due to the transition of higher modes between the propagation mode and the evanescent mode.

• Neonatal Medicine
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• 제18권1호
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• pp.23-33
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• 2011

The etiology of thrombosis is multifactorial and involves the interaction of inherited and acquired risk factors. Many neonatal thromboembolic disorders are iatrogenic and their incidence is likely to increase as advancements are made in neonatal care. Among pediatric populations, neonates have the highest risk for thrombosis secondary to the unique developmental hemostatic system, inherited prothrombotic disorders, and perinatal clinical conditions. Central venous and arterial catheters present the greatest risk for developing thromboembolisms in neonates. Both venous and arterial thromboses have been reported in a variety of anatomic locations. Prompt identification and appropriate management of thromboembolisms is critical for avoiding life-threatening complications. To date, few data are currently available regarding the contribution of inherited and acquired prothrombotic disorders in the pathogenesis of neonatal thromboembolism. In particular, a lack of information about neonatal thromboembolism in Korea has inhibited the development of appropriate guidelines for diagnosing thromboembolisms in neonates. An overview of the current knowledge about the role of inherited and acquired risk factors for neonatal thromboembolism in the West and a detailed description of common neonatal thromboembolic diseases is reviewed.

• The Korean Journal of Pain
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• 제28권3호
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• pp.177-184
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• 2015

Herpes zoster (HZ) is a transient disease caused by the reactivation of latent varicella zoster virus (VZV) in spinal or cranial sensory ganglia. It is characterized by a painful rash in the affected dermatome. Postherpetic neuralgia (PHN) is the most troublesome side effect associated with HZ. However, PHN is often resistant to current analgesic treatments such as antidepressants, anticonvulsants, opioids, and topical agents including lidocaine patches and capsaicin cream and can persist for several years. The risk factors for reactivation of HZ include advanced age and compromised cell-mediated immunity (CMI). Early diagnosis and treatment with antiviral agents plus intervention treatments is believed to shorten the duration and severity of acute HZ and reduce the risk of PHN. Prophylactic vaccination against VZV can be the best option to prevent or reduce the incidence of HZ and PHN. This review focuses on the pathophysiology, clinical features, and management of HZ and PHN, as well as the efficacy of the HZ vaccine.

• Journal of the Korea institute for structural maintenance and inspection
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• 제7권1호
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• pp.259-266
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• 2003

Recently, the premature corrosion for reinforced concrete structure exposed to chloride bring about a serious problem in concrete structures. Specially, the concrete structures of sea coast are exposed much to chloride which make rapid corrosion. Thus, construction activities and maintenances for marine facilities are more demanded than those for land structures. The results of this study have been analysed to identify the extent of chloride content and incidence of carbonation for construction age. After measuring chloride content in concrete, it was conclued that about 90% of all tests on concrete samples exceed the acceptable maximum limit to risk of chloride-induced carbonation. The carbonation rate coffnient by age of train structures in the east eatimated 6. 55, 4.76 grater than 3. 727. In the basis of this result, it is necessary to maintenance for the important train facilities with the regular tests of chloride and carbonation.

• Proceedings of the KIEE Conference
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.125-128
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• 1987

This paper deals with the topological observability analysis and the derivation of a reliability evaluation formula of a measurement system for state estimation. An analogy of the DC power flow method to the DC circuit analysis is introduced, and all the relationship between power flows and phase angles are replaced by the corresponding current-voltage relation. As a result, a set of topological measurement equation expressed in the form of the incidence matrix is derived for the topological analysis, and the observability test is carried out by examining the rank of the measurement matrix. The reliability evaluation formula was derived experimentally by testing the observability of sample systems of IEEE-14, IEEE-3.0, IEEE-57.

• Radiation Oncology Journal
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• 제36권2호
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• pp.163-170
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• 2018

Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor of the skin initially believed to arise from the Merkel cells. In the community setting a general radiation oncologist may only encounter this pathology in a handful of cases over the course of their career. Due to the low incidence of this malignancy, few prospective randomized controlled trials have ever been conducted and therefore guidelines are based on relatively lower levels of evidence upon which the clinical recommendations are made. We discuss the case of a female in her 90s presenting with a classic MCC primary lesion, as well as satellite lesions proximal to both the primary and the draining regional lymph nodes with no evidence of nodal involvement. Here we discuss the presentation, management, treatment planning, underlying pathology, results and sequelae of treatment. We also review new treatment modalities, and the most current staging systems and guidelines.

• Journal of Korea Society of Industrial Information Systems
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• 제8권2호
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• pp.1-6
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• 2003

A theoretical method for the TE polarized electromagnetic scattering on a periodic strip grating over a grounded dielectric slab is considered. The numerical results for an analysis of the plane wave scattering from the structure are presented such as normalized mode amplitude and relative reflected power against normalized dielectric slab height, relative reflected power against angle of incidence and distribution of strip current density. Detailed discussions on the Bragg blazing phenomena observed in the geometry are give.

• Journal of the East Asian Society of Dietary Life
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• 제4권1호
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• pp.113-122
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• 1994

This study was designed to assess the current status of infant feeding through an retrospective survey on feeding method. The survey was executed for 417 mothers bringing up a child below 24 months in Seoul and Kyunggi-Do province from September to October, 1993. Analysing a few influential environmental factors while assessing the level of knowledge today's mother have on infant feeding. Incidence of breast feeding was 27.8% of the interviewed mothers, which showed lower percentages than those of previous surveys. This research proved the major influencing factor generally depended on its mother rather than babies. Generally mothers knew the information of infant feeding, but their knowledge actually didn't work. The source of mothers' informations on the infant nutrition showed the grandmother, books and magazines, doctor were many by the order. among the reasons of resent formula and mixed feeding, lack of breast milk' was the commonest as 50.5% and the next reason was 'because of job' as 12.6%.