• Progress in Superconductivity and Cryogenics
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• v.16 no.1
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• pp.14-18
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• 2014

The mechanical, electrical and thermal characteristics of insulating materials may significantly affect the performance and reliability of electrical devices using superconductors. General method to provide insulating layer between coated conductors is wrapping coated conductor with Kapton tape. But uniform and compact wrapping without failure or delamination in whole coverage for long length conductor is not a simple task and need careful control. Coating of insulating layer directly on coated conductor is desirable for providing compact insulating layer rather than wrapping insulating layers around conductor. Ceramic added polymer has been widely used as an insulating material for electric machine because of its good electrical insulating properties as well as excellent heat resistance and fairy good mechanical properties. The insulating layer of coated conductor should have high breakdown voltage and possesses suitable mechanical strength and maintain adhesiveness at the cryogenic temperature where it is used and withstand stress from thermal cycling. The insulating and mechanical properties of polymer can be improved by adding functional filler. In this study, insulating layer has been made by adding ceramic particles such as $SiO_2$ to a polymer resin. The size, amount and morphology of added ceramic powder was controlled and their effect on dielectric property of the final composite was measured and discussed for optimum composite fabrication.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.3
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• pp.119-125
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• 2011

Implantation of an embryo occurs during the mid-secretory phase of the menstrual cycle, known as the "implantation window." During this implantation period, there are significant morphologic and functional changes in the endometrium, which is followed by decidualization. Many immune cells, such as dendritic and natural killer (NK) cells, increase in number in this period and early pregnancy. Recent works have revealed that antigen-presenting cells (APCs) and NK cells are involved in vascular remodeling of spiral arteries in the decidua and lack of APCs leads to failure of pregnancy. Paternal and fetal antigens may play a role in the induction of immune tolerance during pregnancy. A balance between effectors (i.e., innate immunity and helper T [Th] 1 and Th17 immunity) and regulators (Th2 cells, regulatory T cells, etc.) is essential for establishment and maintenance of pregnancy. The highly complicated endocrine-immune network works in decidualization of the endometrium and at the fetomaternal interface. We will discuss the role of immune cells in the implantation period and during early pregnancy.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.2
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• pp.139-144
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• 2003

Over 350 million people worldwide are chronic carriers of hepatitis B virus (HBV). Chronic viral infections of the liver can progress to cirrhosis, which may ultimately lead to hepatic failure or the development of hepatocellular carcinoma. There are two antiviral drugs on the market approved for clinical management of chronic HBV infections; interferon-alpha and the nucleoside analog lamivudine. However, they showed adverse side-effects. In the rational drug design for such therapies we would like to utilize antiviral drugs that inhibit the HBV replication in the liver. Investigation of natural extracts of silkworm exhibiting antiviral potential was held in the functional HBV polymerase activity and the release of virion particle in the HepG2.2.15 cell lines. HBV-producing transgenic mouse fed with silkworm DNJ molecule was shown as an inhibitor of serum HBV particles. We could represent this DNJ molecule as an antiviral potential complementing conventional therapies after preclinical tests against WHBV-infected animal model, woodchuck.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.121-127
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• 2003

Wave overtopping is one of the most important hydraulic responses of breakwater because it significantly affects its functional efficiency, the safety of transit and mooring on the rear side, wave transmission in the sheltered area, rear side armor stones and to some extent, the structural safety itself. In this study, hydraulic model tests has been carried out to investigate the influence of berm's size on overtopping rate by maximum overtopping rate and mean overtopping rate. The hydrodynamic characteristics of berm breakwater by the overtopping rate can be summarized as follows: 1. It is better to use maximum overtopping rate than to use mean overtopping rate for design of coastal structures in the point of view of stability. 2. When construct berm to decrease energy of waves that it was needed to make breaking conditions of wave on the berm. 3. Under the relative length of berm was over 0.13 overtopping rate was significantly decreased. 4. Overtopping rate affected significantly by the relative length of yhe berm than height of the berm.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.1
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• pp.55-62
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• 2020

It is necessary to develop digital flight control system by digital control technology to ensure stability and maneuverability of rotary helicopter. It is important to meet functional requirements of helicopter flight control system OFP and verify system reliability directly linked to flight safety as a core technology that avoids the transfer of technology by overseas advanced helicopter manufacturer. In this paper, we studied how to perform FMET for operational flight program of rotary automatic flight control system.

• Journal of the Korean Society of Safety
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• v.29 no.1
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• pp.86-92
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• 2014

This paper provides an integrated view on human and system interaction in advanced and automated systems, which adopting computerized multi-functional artifacts and complicated organizations, such as nuclear power plants, chemical plants, steel and semi-conduct manufacturing system. As current systems have advanced with various automated equipments but human operators from various organizations are involved in the systems, system safety still remains uncertain. Especially, a human operator plays an important role at the time of critical conditions that can lead to catastrophic accidents. The knowledge on human error helps a risk manager as well as a designer to create and control a more credible system. Several human error theories were reviewed and adopted for forming the integrated perspective: gulf of execution and evaluation; risk homeostasis; the ironies of automation; trust in automation; design affordance; distributed cognition; situation awareness; and plan delegation theory. The integrated perspective embraces human error theories within three levels of human-system interactions such as affordance level, psychological logic level and trust level. This paper argued that risk management process should dealt with human errors by providing (1) reasoning improvement; (2) support to situation awareness of operators; and (3) continuous monitoring on harmonization of human system interaction. This approach may help people to understand risk of human-system interaction failure characteristics and their countermeasures.

• Nuclear Engineering and Technology
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• v.39 no.1
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• pp.51-62
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• 2007

To efficiently design safety-critical systems such as nuclear power plants, with the requirement of high reliability, methodologies allowing for rigorous interactions between the synthesis and analysis processes have been proposed. This paper attempts to develop a reliability-centered design framework through an interactive process between Axiomatic Design (AD) and Fault Tree Analysis (FTA). Integrating AD and FTA into a single framework appears to be a viable solution, as they compliment each other with their unique advantages. AD provides a systematic synthesis tool while FTA is commonly used as a safety analysis tool. These methodologies build a design process that is less subjective, and they enable designers to develop insights that lead to solutions with improved reliability. Due to the nature of the two methodologies, the information involved in each process is complementary: a success tree versus a fault tree. Thus, at each step a system using AD is synthesized, and its reliability is then quantified using the FT derived from the AD synthesis process. The converted FT provides an opportunity to examine the completeness of the outcome from the synthesis process. This study presents an example of the design of a Containment Heat Removal System (CHRS). A case study illustrates the process of designing the CHRS with an interactive design framework focusing on the conversion of the AD process to FTA.

• Childhood Kidney Diseases
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• v.7 no.2
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• pp.234-238
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• 2003

Fanconi syndrome is a generalized functional disorder of the proximal tubule of the kidney and is characterized by aminoaciduria, glycosuria, hyperphosphaturia, dehydration, rickets, and growth failure. Nephrocalcinosis and hypercalciuria are rare manifestations of Fanconi syndrome. There is no case report of Fanconi syndrome complicated with nephrocalcinosis and hypercalciuria in Korea. A 6-year-old boy presented with genu valgum and waddling gaits for about 3 years. There was no family history of renal disease and his physical examination was normal except for genu valgum and corrected cleft lip and palate. Laboratory investigations showed generalized aminoaciduria, glycosuria, hyperphosphaturia, hypercalciuria, and low-molecular weight proteinuria including ${\beta}$-microglobulin. Serum 25-OH vitamin $D_3$ was within the normal range, and $1,25-(OH)_2$ vitamin $D_3$ was elevated. Bilateral renal medullary hyperechogenicity was demonstrated by ultrasonography. Analysis of the CLCN5 gene revealed no mutation. Here we describe a boy with Fanconi syndrome complicated with nophrocalcinosis and discuss the differential diagnosis.

• Molecules and Cells
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• v.21 no.1
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• pp.135-140
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• 2006

Cytoplasmic male sterility (CMS) in plants, which is due to failure to produce functional pollen, is a maternally inherited trait. Specific nuclear genes that suppress CMS, termed fertility restorer (Rf) genes, have been identified in several plants. In this study, Rfl-inked molecular markers in pepper (Capsicum annuum L.) were detected by bulked segregant analysis of eight amplified fragment length polymorphisms (AFLPs). Only AFRF8 was successfully converted to a cleaved amplified polymorphic sequence (CAPS) marker. This was named AFRF8CAPS and genotype determination using it agreed with that obtained with the original AFRF8. A linkage map with a total size of 54.1 cM was constructed with AFRF8CAPS and the seven AFLP markers using the Kosambi function. The AFRF8CAPS marker was shown to be closest to Rf with a genetic distance of 1.8 cM. These markers will be useful for fast and reliable detection of restorer lines during $F_1$ hybrid seed production and breeding programs in pepper.

• Geomechanics and Engineering
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• v.18 no.6
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• pp.661-668
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• 2019

Seismic vulnerability assessment is a useful tool for rational safety analysis and planning of large and complex structural systems; it can deal with the effects of uncertainties on the performance of significant structural systems. In this study, an efficient dynamic reliability approach, probability density evolution methodology (PDEM), is proposed for seismic vulnerability analysis of earth dams. The PDEM provides the failure probability of different limit states for various levels of ground motion intensity as well as the mean value, standard deviation and probability density function of the performance metric of the earth dam. Combining the seismic reliability with three different performance levels related to the displacement of the earth dam, the seismic fragility curves are constructed without them being limited to a specific functional form. Furthermore, considering the seismic fragility analysis is a significant procedure in the seismic probabilistic risk assessment of structures, the seismic vulnerability results obtained by the dynamic reliability approach are combined with the results of probabilistic seismic hazard and seismic loss analysis to present and address the PDEM-based seismic probabilistic risk assessment framework by a simulated case study of an earth dam.