• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.43-46
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• 2004

Recently many research activities on the diagnosis of stator winding insulation of high-voltage motors have been reported. Most of them utilize a trend analysis of partial discharges. In this paper, a novel on-line monitoring system for an insulation diagnosis is proposed. This system displays magnitude and phase angle distribution of partial discharge. The partial discharge activities can be interpreted more precisely by these techniques.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1185-1192
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• 2001

This paper reviews available techniques for monitoring corrosion of steel in concrete. The need for early detection and diagnosis of corrosion related deterioration in reinforced structures is widely acknowledged. This is particularly important in reinforced concrete structures on account of the economic and social significance of the problem. The current generally used on-site procedure for corrosion monitoring of reinforced structures employs a method of half-cell surface potential measurements. While the technique has provided a useful means of delineating areas of high or low corrosion risk, there are difficulties in its use and interpretation when assessing rates of deterioration. Electrochemical techniques are by far the most suitable for corrosion monitoring purpose and meet most of the requirements. The aim of this paper is to describe the electric resistance sensor(ER sensor) and electrochemical techniques employed to monitor and estimate corrosion rates of reinforcement. Early detection and diagnosis of corrosion hazards allows preventive measures to be taken, hence the typically expensive repair of severely deteriorated structures can be avoided.

• Journal of Industrial Technology
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• v.34
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• pp.61-66
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• 2014

Recently, Because the consumption of electricity is increased, having stable electricity supply and diagnosis of the power device is important. In this paper, I propose a diagnostic techniques of the leakage current for switchgear based on LabVIEW NI's. Using the data obtained from the leakage current sensor installed in switchgear panels, in performed continuously diagnosis, notifications and warnings can be the administrator immediately results. It is expected accordingly, the administrator will be able to take prompt action. Using the virtual switchgear with a PXI NI's, war tested the proposed techniques.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.182-183
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• 2007

Recently, diverse techniques for diagnosis on power equipments of the live wire conditions are developed. These techniques are very important that find out the fault signs in power equipments. This paper is Compared with Ultra-Violet and Ultra-Sonic Generated by an Insulator at 22.9kV. The volume of UV images are increased by the square of the applied voltage. The output signals of ultrasonic are detected at about 20kV to 30kV. Hereafter, through the continuous DAQ and analysis, these techniques are the effective method for the improvement of the exciting diagnosis.

• The Korean Journal of Cytopathology
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• v.7 no.1
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• pp.1-11
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• 1996

From the concepts of cellular pathology and of exfoliative cytology, as elucidated by Virchow and Papanicolaou respectively in the late 19th and early 20th century, have evolved the primary methods for the diagnosis of cancer today. From Papanicolaou's concept of exfoliative cytology developed fine needle aspiration biopsy in the early 1960's, this has become a major diagnostic procedure and has contributed to a significant reduction in open biopsies and, therefore, to medical cost-effectiveness immunobiochemical techniques provided us with a supplement to cancer diagnosis in the 1980's. The immunoperoxidase method, using monoclonal antibodies, is applied primarily as an ancillary measure to elucidate the nature of cancers The availability of specific monoclonal antibodies has greatly facilitated the identification of cell products or surface markers. For example, antibodies directed against intermediate filaments have proved to be of value in determining the histogenesis oi poorly differentiated neoplasms. Tumor markers may serve as biochemical indicators of the presence of a neoplasm. They can be detected In plasma and other body fluids. Their concentration can be applied as a diagnostic test, for monitoring the clinical course of known cancer, and as a screening measure to detect certain cancers in a population at risk. Flow cytometry is a useful tool for distinguishing several cell characteristics, such as the immunophenotype of leukemia-lymphoma cells, the DNA content of neoplastic cells, and cell proliferation rate. Molecular biologic techniques provided a giant step for the management of cancer patients encompassing diagnosis, prognostic evaluation, and therapy. Nucleic acid hybridization techniques are utilized as Southern, Northern, and dot blots and in situ hybridization. Molecular biology and its techniques may bring a blight new horizon for understanding cancer biology and in designing therapy on the basis of gene manipulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1780-1785
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• 2016

This paper presents few case studies of state diagnosis of XLPE cables using very low frequency techniques. The power cables of 22.9kV which have installation fault were assessed using VLF technique in addition to other techniques like insulation resistance and DC voltage withstand test. From the experimental results, The dielectric loss($tan{\delta}$) values of degradation of the cable(joint, knife, needle) at $U_0$ were 5.839, 5.526 and 6.251, respectively and all values were "further study advised". VLF PD measurement was also found defective portion. These method was effective in defect to fault in the degradation of the cable. However, the breakdown did not occur in the degradation of the cable because of properties of XLPE insulation. Few case studies of using VLF $tan{\delta}$ diagnosis for fault are measured and analyzed. The $tan{\delta}$ values at $U_0$ were "further study advised" or "action required".

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1631-1635
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• 2016

Helicobacter pylori infection plays an important role in the pathogenesis of chronic gastritis, peptic ulcer disease and gastric malignancy. A diagnosis of infection is thus an important part of a treatment strategy of many gastrointestinal tract diseases. Many diagnostic tests are available but all have some limitations in different clinical situations and laboratory settings. A single gold standard cannot available, but be used for diagnosis of Helicobacter pylori infection in daily clinical practice in all areas, so several techniques have been developed to give reliable results, especially focusing on real time endoscopic features. The narrow band imaging system (NBI) and high resolution endoscopy are imaging techniques for enhanced visualization of infected mucosa and premalignant gastric lesions. The aim of this article is to review the current diagnostic options and possible future developments detection of Helicobacter pylori infection.

• Nuclear Engineering and Technology
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• v.46 no.6
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• pp.737-752
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• 2014

As condition-based maintenance (CBM) has risen as a new trend, there has been an active movement to apply information technology for effective implementation of CBM in power plants. This motivation is widespread in operations and maintenance, including monitoring, diagnosis, prognosis, and decision-making on asset management. Thermal efficiency analysis in nuclear power plants (NPPs) is a longstanding concern being updated with new methodologies in an advanced IT environment. It is also a prominent way to differentiate competitiveness in terms of operations and maintenance costs. Although thermal performance tests implemented using industrial codes and standards can provide officially trustworthy results, they are essentially resource-consuming and maybe even a hind-sighted technique rather than a foresighted one, considering their periodicity. Therefore, if more accurate performance monitoring can be achieved using advanced data analysis techniques, we can expect more optimized operations and maintenance. This paper proposes a framework and describes associated methodologies for in-situ thermal performance analysis, which differs from conventional performance monitoring. The methodologies are effective for monitoring, diagnosis, and prognosis in pursuit of CBM. Our enabling techniques cover the intelligent removal of random and systematic errors, deviation detection between a best condition and a currently measured condition, degradation diagnosis using a structured knowledge base, and prognosis for decision-making about maintenance tasks. We also discuss how our new methods can be incorporated with existing performance tests. We provide guidance and directions for developers and end-users interested in in-situ thermal performance management, particularly in NPPs with large steam turbines.

• Journal of Korean Society for Quality Management
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• v.51 no.2
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• pp.223-245
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• 2023

Purpose: This study aim to identify the trends in AI-based PHM technology that can enhance reliability and minimize costs. Furthermore, this research provides valuable guidelines for future studies in various industries Methods: In this study, I collected and selected AI-based PHM studies, established classification criteria, and analyzed research trends based on classified fields and techniques. Results: Analysis of 125 domestic studies revealed a greater emphasis on machinery in both diagnosis and prognosis, with more papers dedicated to diagnosis. various algorithms were employed, including CNN for image diagnosis and frequency analysis for signal data. LSTM was commonly used in prognosis for predicting failures and remaining life. Different industries, data types, and objectives required diverse AI techniques, with GAN used for data augmentation and GA for feature extraction. Conclusion: As studies on AI-based PHM continue to grow, selecting appropriate algorithms for data types and analysis purposes is essential. Thus, analyzing research trends in AI-based PHM is crucial for its rapid development.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.89-93
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• 2000

Recently many research activities on the diagnosis of stator winding insulation of large rotating machines have been reported. Capacitive couplers are widely used as sensors for on-line partial discharge (PD) measurement of high voltage rotating machines. This paper presents laboratory test to compare Stator Slot Coupler (SSC), Resistance Temperature Detector (RTD), 80 [pF] coupler and 500 [pF] coupler for on-line PD measurement of rotating machines. And a novel on-line monitoring system for an insulation diagnosis is proposed.