• Parasites, Hosts and Diseases
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• 제29권3호
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• pp.217-226
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• 1991

섬진강 유역(경남 하동군)산 황어(Tribelodon taczanowskii)로부터 Metagonimus속 피낭유충을 다수 검출하고 실험적으로 흰쥐와 햄스터에 감염시킨 후 소장으로부터 성충을 얻어 관찰한 바 Saito(1984)의 분류에 따라 Metagonimus Yokogawa형 (M. yokogawai), Miyata형 및 Koga형 등 3가지로 나눌 수 있었다. 실험감염 결과, 흰쥐 4마리 및 햄스터 4마리로부터 Metagonimus 충체 총 1,624마리를 회수하였고 그 중 Yokogawa형은 820마리, Miynta형은 688마리, Koga형은 46마리이었다. 나머지 충체 70마리는 유형을 결정하기 어려웠다. Yokgawa형과 Miyata형의 주요 감별정은 두 고환의 위치, 자궁관의 분포 및 충란의 크기 등이었고, Miyata형과 Koga형의 감별점은 두 고환의 위치, 난환선의 분포, 충란의 크기 등이었다. 이들 유형 특히 Miyata 형의 별종 가능성에 대해서는 많은 증거가 얻어질 때까지 이를 유보해야 할 것으로 생각되고, Koga형은 중간숙주의 차이 이외에는 형태학적으로 Takahashi형 (M. takahashii)과 전혀 차이가 인정되지 않으므로 이와 동일한 것으로 취급하는 것이 옳을 것으로 판단되었다. 이상의 결과로 섬진강산 황어에는 3가지 유형의 Metagonimus가 피낭하고 있음을 확인하였다.

• Imaging Science in Dentistry
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• 제51권4호
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• pp.413-419
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• 2021

Purpose: The aim of this in vitro study was to assess the role of bandwidth on the area of magnetic resonance imaging (MRI) artifacts caused by orthodontic appliances composed of different alloys, using different pulse sequences in 1.5 T and 3.0 T magnetic fields. Materials and Methods: Different phantoms containing orthodontic brackets (ceramic, ceramic bracket with a stainless-steel slot, and stainless steel) were immersed in agar gel and imaged in 1.5 T and 3.0 T MRI scanners. Pairs of gradient-echo (GE), spin-echo (SE), and ultrashort echo time (UTE) pulse sequences were used differing in bandwidth only. The area of artifacts from orthodontic devices was automatically estimated from pixel value thresholds within a region of interest (ROI). Mean values for similar pulse sequences differing in bandwidth were compared at 1.5 T and 3.0 T using analysis of variance. Results: The comparison of groups revealed a significant inverse association between bandwidth values and artifact areas of the stainless-steel bracket and the self-ligating ceramic bracket with a stainless-steel slot(P<0.05). The areas of artifacts from the ceramic bracket were the smallest, but were not reduced significantly in pulse sequences with higher bandwidth values(P<0.05). Significant differences were also observed between 1.5 T and 3.0 T MRI using SE and UTE, but not using GE 2-dimensional or 3-dimensional pulse sequences. Conclusion: Higher receiver bandwidth might be indicated to prevent artifacts from orthodontic appliances in 1.5 T and 3.0 T MRI using SE and UTE pulse sequences.

• Safety and Health at Work
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• 제13권3호
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• pp.302-307
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• 2022

Background: In Brazil, asbestos was intensively used from the 1960s until its ban in 2017. Mesothelioma, asbestosis, and pleural plaques are typical asbestos-related diseases (ARD-T). To create an ARD-T national database, death records from 1996-2017 were retrieved from several health information systems (HIS). Methods: All national HIS containing coded diagnoses (ICD-10) and death information were obtained. Linkage was performed to create a single database of ARD-T death records, either as underlying or contributory causes, in adults aged 30 years and older. Results: A total of 3,057 ARD-T death records were found, 2,405 (76.4%) of which being malignant mesotheliomas (MM). Pleural MM (n = 1,006; 41.8%) and unspecified MM (n = 792; 32.9%) prevailed. Male to female MM ratio (M:F) was 1.4:1, and higher ratios were found for non-malignant ARD-T: 3.5:1 for asbestosis and 2.4:1 for pleural plaques. Male crude annual mesothelioma mortality (CM_mm ×1,000,000) was 0.98 in 1996 and 2.26 in 2017, a 131.1% increment, while for females it was 1.04 and 1.25, a 20.2% increase, correspondingly. The small number of deaths with asbestosis and pleural plaques records precluded conclusive interpretations. Conclusions: Even with the linkage of several HIS, ARD-T in death records remained in low numbers. MM mortality in men was higher and showed a rapid increase and, along with non-malignant ARD-T, higher M:F ratios suggested a predominant pattern of work-related exposure. The monitoring of workplace and environmental asbestos exposure needs to be improved, as well as the workers surveillance, following the recent Brazilian ban.

• 한국산업융합학회 논문집
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• 제1권2호
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• pp.41-48
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• 1998

This experimental study describes atomization characteristics of spray-spray impingement. Effect of the impingement location and angle on the penetration and the sauter mean diameter of the impinged spray were investigated. Experiment were performed under ranging from 50kPa to 250kPa spray pressure, ranging $30^{\circ}C$ to $135^{\circ}C$ angle on the penetration and free spray. In the case of this experimental, sauter mean diameter $D_{32}$ tends to decrease and duration of film disintegration $t_f$ to decrease, when spray pressure and angle on the penetration is increased. Sauter mean diameter $D_{32}$ were about 20% to be smaller compared with a free spray to jet-jet impingement and 30% to be smaller compared with a free spray to spray-spray impingement.

• Progress in Superconductivity
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• 제8권1호
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• pp.1-7
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• 2006

We have developed magnetocardiography(MCG) and impedance magnetocardiography(I-MCG) for detecting heart disease by using dc-SQUID technology. The MCG system, using low-Tc SQUID, is being applied commercially for diagnosing heart disease. Using the low-Tc MCG system, many clinical studies on detection of abnormality have been performed. Furthermore, we have developed a portable MCG system using high-Tc SQUID. For detecting changes in kinetic impedance in the heart, an I-MCG system has been demonstrated. The I-MCG system could detect the mechanical movement of the heart. In this report, we review current clinical applications of magnetocardiography and impedance magnetocardiography.

• 대한가정학회:학술대회논문집
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• 대한가정학회 1997년도 Program & Abstracts * The 7th Korea-Japan Home Economics Joint Syposium
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• pp.210-210
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• 1997

• Structural Engineering and Mechanics
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• 제19권5호
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• pp.503-517
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• 2005

The parametric dynamic stability of an asymmetric sandwich beam with viscoelastic core on viscoelastic supports at the ends and subjected to an axial pulsating load is investigated. A set of Hill's equations are obtained from the non-dimensional equations of motion by the application of the general Galerkin method. The zones of parametric instability are obtained using Saito-Otomi conditions. The effects of shear parameter, support characteristics, various geometric parameters and excitation force on the zones of instability are investigated.

• 한국초전도저온공학회지:초전도와저온공학
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• 제20권2호
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• pp.15-22
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• 2018

The present article briefly overviews the plan for a new project on joint technology for HTS wires/cables and describes the development plan for the world's highest field NMR magnet, which is a major development item in the project. For full-fledged social implementation of superconducting devices, high temperature superconducting (HTS) wire is a key technology since they can be cooled by liquid nitrogen and they can generate a super-high magnetic field of >>24 T at liquid helium temperatures. However, one of the major drawbacks of the HTS wires is their availability only in short lengths of a single piece of wire. This necessitates a number of joints being installed in superconducting devices, resulting in a difficult manufacturing process and a large joint resistance. In Japan, a large-scale project has commenced, including two technical demonstration items: (i) Development of superconducting joints between HTS wires, which are used in the world's highest field 1.3 GHz (30.5 T) NMR magnet in persistent current mode; the joints performance is evaluated based on NMR spectra for proteins. (ii) Development of ultra-low resistive joints between DC superconducting feeder cables for railway systems. The project starts a new initiative of next generation super-high field NMR development as well as that of realization of better superconducting power cables.

• 한국초등수학교육학회지
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• 제14권1호
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• pp.23-41
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• 2010

본 연구는 일본의 제등승(齊藤昇)(Saito Noboru) 교수에 의해 실천 연구되었던 등산학습법을 초등학교 4, 6학년 학생들에게 적용하여 수학적 창의성과 수학적 창의성 태도, 수학 학업성취도에 미치는 효과를 분석함으로써 수학적 창의성을 신장시킬 수 있는 방안을 모색하는데 그 목적을 두었다. 본 논문에서는 실험집단과 비교집단을 형성하여 t-검증한 결과, 등산학습법이 수학적 창의성 및 수학적 창의성 태도에는 긍정적인 영향을 주었으나 학업성취에서는 유의미한 차이를 나타내지 못했다는 결과와 함께 이러한 결과에 대한 논의와 수업전략을 언급한다.

• Structural Engineering and Mechanics
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• 제23권1호
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• pp.29-42
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• 2006

This paper describes the design scheme of the three-dimensional structures based on the concept of the cellular automata simulation. The cellular automata simulation is performed according to the local rule. In this paper, the local rule is derived in the mathematical formulation from the optimization problem. The cell density is taken as the design variable. Two objective functions are defined for reducing the total weight of the structure and obtaining the fully stressed structure. The constraint condition is defined for defining the local rule. The penalty function is defined from the objective functions and the constraint condition. Minimization of the penalty function with respect to the design parameter leads to the local rule. The derived rule is applied to the design of the three-dimensional structure first. The final structure can be obtained successfully. However, the computational cost is expensive. So, in order to reduce the computational cost, the material parameters $c_1$ and $c_2$ and the value of the cell rejection criterion (CRC) are changed. The results show that the computational cost depends on the parameters and the CRC value.