• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.341.1-341
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• 1999

• Journal of Electrical Engineering and Technology
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• v.7 no.6
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• pp.959-964
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• 2012

Internal pressure of vacuum interrupter (VI) is one of the most important parameters in VI operation and may increase due to the outgassing from the materials inside VI or gas permeation through metal flange or ceramic vessel. The increase of the pressure above a certain level leads to the failures of switching or insulation. Therefore, an effective pressure check of VI is essential and an analysis of partial discharge (PD) characteristics is an effective monitoring method to identify the degree of the internal pressure of VI. This paper introduces a research work on monitoring the internal pressure of VI by analyzing PDs which were measured using a capacitive PD coupler. The authors have developed cost effective capacitive coupler based on the ceramic material that has an excellent insulation properties and the main component of the capacitive coupler is made by SrTiO3. Detectable internal pressure range and distinguishability of the internal pressure of VI were investigated. From the PD tests results, the internal pressure range, from $10^{-2}$ torr to 500 torr, can be monitored by PD measurements using the capacitive coupler and PD inception voltage (PDIV) follows the Paschen's law. In addition, rise time of PD pulse at 13.2kV decreases with the increase of the internal pressure of VI.

• Journal of the Korean Geosynthetics Society
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• v.23 no.2
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• pp.19-27
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• 2024

Geotechnical structures such as dams, tunnels, and slopes require regular inspection and monitoring to ensure stability. Domestically, drones and accelerometers have become common tools for inspecting and monitoring various structures. However, drones have difficulty identifying internal changes in structures and the subsurface, and accelerometers generally serve for seismic design or strain measurement purposes. Therefore, this paper proposes to utilize accelerometers to monitor the internal information of the ground on a real-time or periodic basis. The proposed method utilizes a part of the analysis technique from the SASW test to monitor the stability and state changes of geotechnical structures. Cases where SASW was used to evaluate the safety of geotechnical structures, such as slopes, dams, and tunnels, were reviewed to verify the suitability of the technology. To make the proposed method more practical, the study considered using only the first-step analysis to derive the dispersion curve rather than the second-step analysis to determine the shear wave velocity profile, which requires complex analysis. The proposed technique is expected to enable the continuous monitoring and inspection of geotechnical structures by utilizing accelerometers.

• Journal of Internet Computing and Services
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• v.18 no.3
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• pp.71-83
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• 2017

In recent years, by utilizing the greatest strengths of process mining, the various research activities have been actively progressed to use auditing work of business organization. On the other hand, there is insufficient research on systematic and efficient analysis of massive data generated under big data environment using process mining, and proactive monitoring of risk management from audit side, which is one of important management activities of corporate organization. In this study, we intend to realize Hadoop-based internal audit integrated real-time monitoring system in order to detect the abnormal symptoms in prevent accidents in advance. Through the integrated real-time monitoring system for purchasing audit, we intend to realize strengthen the delivery management of purchasing materials ordered, reduce cost of purchase, manage competitive companies, prevent fraud, comply with regulations, and adhere to internal control accounting system. As a result, we can provide information that can be immediately executed due to enhanced purchase audit integrated real-time monitoring by analyzing data efficiently using process mining via Hadoop-based systems. From an integrated viewpoint, it is possible to manage the business status, by processing a large amount of work at a high speed faster than the continuous monitoring, the effectiveness of the quality improvement of the purchase audit and the innovation of the purchase process appears.

• Journal of Veterinary Clinics
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• v.17 no.1
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• pp.187-193
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• 2000

Fifteen adult Korea Jin-do dogs were studied by echocardiography to obtain the basic data of the imaging planes and normal references ranges to the aorta and pulmonary artery internal dimension. Measurements of aortic root internal dimension(AOID) and right pulmonary artery internal dimension (RPAID) were made at modified pulmonary arteries level short-axis view and left ventricular outflow tract long-axis view. The aortic root internal dimension and right pulmonary artery internal dimension at modified pulmonary arteries level short-axis view were 18.7$\pm$1.3mm (mean$\pm$SD) and 10.1$\pm$0.8mm, respectively. And RPAID/AOID was 0.5$\pm$0.1mm. The aortic root internal dimension and right pulmonary artery internal dimension at left ventricular outflow tract long-axis view were 19.3$\pm$1.6 mm and 10.7$\pm$1.3mm, respectively. And RPAID/AOID was 0.5$\pm$0.1mm. These results indicate that modified pulmonary arteries level short-axis view is useful planes to examine the aortic root and pulmonary arteries, and aortic root internal dimension is significantly higher(40~50%)than the right pulmonary artery internal dimension. Therefore measurements of aortic root internal and right pulmonary artery internal dimension can be used for monitoring dilation of pulmonary artery.

• Environmental Analysis Health and Toxicology
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• v.22 no.1 s.56
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• pp.1-8
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• 2007

Biological monitoring, analyses of internal dose for exposure to toxicants, has been thought as one of the belt approaches for risk assessment. As the amount detected in human samples is generally very low, typically in the parts-per-bilion (ppb) or parts-per-trillion (ppt) range, analytic technologies such at HPLC, GC/MS, LC/MS, and LC/MS/MS have been continuously developed. In addition, route specific and sensitive exposure biomarkers have been developed for proper biological monitoring. PBPK modeling, particularly reverse dosimetry, has been emphasized as an useful method via interpretation of biological monitoring results for regulation of toxicants. Thus, this review is focused on the use of PBPK dosimetry models for toxicology research and risk assessment in Korea.

• Journal of Distribution Science
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• v.22 no.4
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• pp.59-68
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• 2024

Purpose: The function of internal audit is to help achieve company goals and targets by minimizing the impact of business risks. The distribution of internal audit activities in carrying out control and supervision covers all aspects or activities at all levels of management. The aim of the research is to determine the distribution of risk-based internal audit effectiveness assessments in companies. Data and Research Design Methodology: Researchers examined research trends regarding things that could influence the distribution of the effectiveness of the internal audit function from 2007 to 2023.This research used a systematic literature review (SLR) research method. This research used 23 papers sourced from the Scopus database. Results: The distribution of the effectiveness of audit services provided by internal auditors is more influenced by the personal characteristics of internal auditors and has little to do with the leadership of the chief internal auditor, technology, and risk management. Conclusion: The distribution of monitoring services provided by internal auditors covers all levels of departments or divisions of the organization. The assessment of internal audit effectiveness is more influenced by the auditor's personal attributes such as independence, competence, and management support.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.17-20
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• 2005

In-situ structural health monitoring of filament wound pressure tanks were conducted during water-pressurizing test using embedded fiber Bragg grating (FBG) sensors. We need to monitor inner strains during working in order to verify the health condition of pressure tanks more accurately because finite element analyses on filament wound pressure tanks usually show large differences between inner and outer strains. Fiber optic sensors, especially FBG sensors can be easily embedded into the composite structures contrary to conventional electric strain gages (ESGs). In addition, many FBG sensors can be multiplexed in single optical fiber using wavelength division multiplexing (WDM) techniques. We fabricated a standard testing and evaluation bottle (STEB) with embedded FBG sensors and performed a water-pressurizing test. In order to increase the survivability of embedded FBG sensors, we suggested a revised fabrication process for embedding FBG sensors into a filament wound pressure tank, which includes a new protecting technique of sensor heads, the grating parts. From the experimental results, it was demonstrated that FBG sensors can be successfully adapted to filament wound pressure tanks for their structural health monitoring by embedding.

• Corrosion Science and Technology
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• v.4 no.5
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• pp.178-190
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• 2005

In order to develop a new corrosion sensor for detecting and monitoring the external and internal corrosion damage of buried pipeline, the electrochemical property of sensors and the correlation of its output to corrosion rate of steel pipe, were evaluated by electrochemical methods in two soils of varying resistivity (5,000 ohm-cm, 10,000 ohm-cm) and synthetic tap water environments. In this paper, two types of galvanic probes were manufactured: copper-pipeline steel (Cu-CS) and stainless steel-pipeline steel (SS-CS). The corrosion behavior in synthetic groundwater and synthetic tap water for the different electrodes was investigated by potentiodynamic test. The comparison of the sensor output and corrosion rates revealed that a linear relationship was found between the probe current and the corrosion rates. In the soil resistivity of $5,000{\Omega}-cm$ and tap water environments, only the Cu-CS probe had a good linear quantitative relationship between the sensor output current and the corrosion rate of pipeline steel. In the case of $10,000{\Omega}-cm$, although the SS-CS probe showed a better linear correlation than that of Cu-CS probe, the Cu-CS probe is more suitable than SS-CS probe due to the high current output.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.739-744
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• 2000

Concrete structures generally have cracks, so for the safety and durability of structures, studies to detect cracks using nondestructive tests have been treated in great deal. In order to assure the reliability of concrete structure, microscopic fracture behavior and internal damage progress of concrete under the loading should be fully understood. The purpose of this study predicts location of initial crack and measures direction of crack propagation for on-line monitoring before the crack really grows in structures by using two-dimensional Acoustic Emission(AE) source location based on rectangular method with three-point bending test. This will allow efficient maintenance of concrete structure through monitoring of internal cracking based on AE method.