• Parasites, Hosts and Diseases
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• v.29 no.3
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• pp.217-226
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• 1991

Three morphological types of the genus Metagonimus were found encysted in the dace, Tribolodon tacganowskii, caught from the Sumjin River, Korea. They include Metagonimus Yokogawa type (M. yokogawai) , Miyata type, and Koga type according to Saito's classification. The metacercariae were experimentally fed to rats and hamsters and a total of 1,624 Metagonimus worms were recovered from their small intestine. The number of each type was 820 for Yokogawa type, 688 for Miyata type, 46 for Koga type, and 70 undetermined. The major differential keys between Yokogawa and Miyata types were in the position of two testes, distribution of uterine tubules, and size of the eggs, and the keys between Miyata and Koga types were in the position of two testes, distribution of vitelline follicles, and size of the eggs. The validity of Miyata type as a specific level should be retained until more convincing evidences are obtained. Koga type is regarded as a synonym of M. takahashii. The present results reveal that there are 3 morphological types of Metagonimus whose larvae are encysted in the dace, T. tacganowskii, from the Sumjin River. Key words: Metagcnimus yokogawai, morphological types, rats, hamsters, dace ( Tribolodon tacxanowskii) , Sumjin Rver.

• Imaging Science in Dentistry
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• v.51 no.4
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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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• v.13 no.3
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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.

• Journal of the Korean Society of Industry Convergence
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• v.1 no.2
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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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• v.8 no.1
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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.

• Proceedings of KHEA Conference
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• 1997.07a
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• pp.210-210
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• 1997

• Structural Engineering and Mechanics
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• v.19 no.5
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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.

• Superconductivity and Cryogenics
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• v.20 no.2
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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.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.1
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• pp.23-41
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• 2010

This research applies the climbing learning method that, a Japanese professor, Saito Noboru established and practiced, to fourth and sixth graders in an elementary school in order to analyze its effect on mathematical creativity, attitude toward mathematical creativity, so called CAS(Creative Attitude Scale) and academic achievement of the subject. The goal is to explore methods that can enhance students' mathematical creativity. To address these tasks, the research developed a teaching-learning scheme and learning structure chart that applies the climbing learning method. Next, the research organized two homogeneous groups among 124 students in fourth and sixth grades in S elementary school, located in the city of Busan. The experiment group went through classes that applied climbing learning method, while the control group received regular teaching. The following describes the research findings. After the experiment, the research conducted t-test for the independent sample based on the test result in terms of mathematical creativity, CAS and academic achievement of the subject. For mathematical creativity, all four constructing factor showed statistically significant differences at significance level of 5%. For CAS, statistically significant difference was revealed at significance level of 0.1%. However, in regard to a test of academic achievement for fourth and sixth graders, statistically significant difference was not detected at significance level of 5% even though the average score of the students in the experiment group was higher by 6 points. The research drew the following conclusion. Firstly, classes that apply climbing learning method can be more effective than regular classes in enhancing mathematical creativity of elementary school students. Secondly, the climbing learning method has positive impact on inclination for mathematical creativity of elementary school students. The research suggests that the climbing learning method can be an effective teaching-learning tool to improve students' mathematical creativity and inclination for mathematical creativity.

• Structural Engineering and Mechanics
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• v.23 no.1
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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.