• Journal of Radiation Protection and Research
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• v.43 no.4
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• pp.154-159
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• 2018

Background: To prevent small leakage accidents, a real-time and direct detection system for small leaks with a detection limit below that of existing systems, e.g. $0.5gpm{\cdot}hr^{-1}$, is required. In this study, a small-size beta detector, which can be installed inside the reactor containment (CT) building and detect small leaks directly, was suggested and its feasibility was evaluated using MCNPX simulation. Materials and Methods: A target nuclide was selected through analysis of radiation from radionuclides in the reactor coolant system (RCS) and the spectrum was obtained via a silicon detector simulated in MCNPX. A window was designed to reduce the background signal caused by other nuclides. The sensitivity of the detector was also estimated, and its shielding designed for installation inside the reactor CT. Results and Discussion: The beta and gamma spectrum of the silicon detector showed a negligible gamma signal but it also contained an undesired peak at 0.22 MeV due to other nuclides, not the $^{16}N$ target nuclide. Window to remove the peak was derived as 0.4 mm for beryllium. The sensitivity of silicon beta detector with a beryllium window of 1.7 mm thickness was derived as $5.172{\times}10^{-6}{\mu}Ci{\cdot}cc^{-1}$. In addition, the specification of the shielding was evaluated through simulations, and the results showed that the integrity of the silicon detector can be maintained with lead shielding of 3 cm (<15 kg). This is a very small amount compared to the specifications of the lead shielding (600 kg) required for installation of $^{16}N$ gamma detector in inside reactor CT, it was determined that beta detector would have a distinct advantage in terms of miniaturization. Conclusion: The feasibility of the beta detector was evaluated for installation inside the reactor CT to detect small leaks below $0.5gpm{\cdot}hr^{-1}$. In future, the design will be optimized on specific data.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.655-658
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• 2007

Characteristics of Al cathode films deposited by using specially designed twin target sputter (TTS) system were investigated. It was found that Al cathode films prepared by TTS were amorphous structure with nanocrystallines due to low substrate temperature and OLEDs fabricated using TTS system have low leakage current density at reverse bias because of effective confinement of energetic particles during sputtering process.

• Journal of Internet Computing and Services
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• v.25 no.4
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• pp.87-96
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• 2024

Information power has been a major criterion for wealth disparity in human history, and since the advent of the Fourth Industrial Revolution, referred to as the data economy era, personal information has also gained economic value. Additionally, companies collect and analyze customer information to use as a marketing tool, providing personalized services, making the collection of quality customer information crucial to a company's success. However, as the amount of data held by companies increases, crimes of stealing personal information for financial gain have surged, making corporate customer information a target for criminals. The leakage of personal information and its circumstances lead to a decline in corporate trust from the customer's perspective, threatening corporate sustainability with falling stock prices and decreased sales. Therefore, companies find themselves in a paradoxical situation where the utilization of personal information is increasing while the risk of personal information leakage is also growing. This study used the news big data analysis system, BIG KINDS, to analyze major keywords before and after media coverage on personal information leaks, examining domestic media coverage trends. Through this, we identified the impact of personal information leakage on corporate sustainability and analyzed the connection between personal information protection and sustainable corporate management. The results derived from this study are expected to serve as foundational data for companies seeking ways to enhance sustainable management while increasing the utilization of personal information.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1355-1366
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• 2020

A review of the documentation and an interpretation of the NEA-1517/74 and NEA-1517/80 shielding benchmarks (measurements of photon leakage flux from a hollow sphere with a central 14 MeV neutron source) from the SINBAD database with the Monte Carlo code MCS and the most up-to-date ENDF/B-VIII.0 neutron data library are conducted. The two analyzed benchmarks describe satisfactorily the energy resolution of the photon detector and the geometry of the spherical samples with inner beam tube, tritium target and cooling water circuit, but lack information regarding the detector geometry and the distances of shields and collimators relatively to the neutron source and the detector. Calculations are therefore conducted for a sphere model only. A preliminary verification of MCS neutron-photon calculations against MCNP6.2 is first conducted, then the impact of modelling the inner beam tube, tritium target and cooling water circuit is assessed. Finally, a comparison of calculated results with the libraries ENDF/B-VII.1 and ENDF/B-VIII.0 against the measurements is conducted and shows reasonable agreement. The MCS and MCNP inputs used for the interpretation are available as supplementary material of this article.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.848-859
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• 2016

System failures in thermal power plants (TPPs) can lead to serious losses because the equipment is operated under very high pressure and temperature. Therefore, it is indispensable for alarm systems to inform field workers in advance of any abnormal operating conditions in the equipment. In this paper, we propose a clustering-based fault detection method for steam boiler tubes in TPPs. For data clustering, k-means algorithm is employed and the number of clusters are systematically determined by slope statistic. In the clustering-based method, it is assumed that normal data samples are close to the centers of clusters and those of abnormal are far from the centers. After partitioning training samples collected from normal target systems, fault scores (FSs) are assigned to unseen samples according to the distances between the samples and their closest cluster centroids. Alarm signals are generated if the FSs exceed predefined threshold values. The validity of exponentially weighted moving average to reduce false alarms is also investigated. To verify the performance, the proposed method is applied to failure cases due to boiler tube leakage. The experiment results show that the proposed method can detect the abnormal conditions of the target system successfully.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.9
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• pp.844-853
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• 2016

Generally, the compromising electromagnetic emanations are generated from LCD(Liquid Crystal Display) monitor which is typical output component of computer. Because display information transmitted to LCD monitor is included in these emanations, there are risks about information leakage of monitor by eavesdropping of leaked signal. So, analysis about possibility of information leakage is necessary because electromagnetic security through the electromagnetic emanations is being at issue. In this paper, the possibility of display information leakage are demonstrated by analyzing the electromagnetic emanations from desktop and laptop monitors. The characteristics of leaked signal from LCD monitor is verified by analyzing display mechanism and the electromagnetic emanations are measured in the long distance by eavesdropping experiment. Also, threat of information leakage is confirmed by recovering display information with several signal processing technique and comprising with target display.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.3
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• pp.101-108
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• 2006

This paper describes the design, fabrication, and measured results of a W-band Cassegrain antenna suitable for the target detecting fuze sensor. The Cassegrain antenna is designed using MATLAB and MWS of CST. We use the multi-mode horn antenna as a feeder. The measurement results are as follows: The gain is about 41dB; SLL is 17.7dB; 3dB beamwidth is about $1.51^{\circ}$ in E-plane and $1.45^{\circ}$ in H-plane. The magnitude of leakage signals is about 43.5mVpp when the fabricated antenna and the transceiver of the fuze sensor ire combined. As a result, the designed W-band Cassegrain antenna could be quite applicable to the target detecting fuze sensor.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.409-423
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• 2023

In this study, we analyzed how the revenue water ratio(RWR) is affected by changes in conditions of the water supply area, such as the ratio of aging pipes, maintenance conditions, and revenue water. As a result of analyzing the impact of pipe aging and maintenance conditions on the RWR, it was confirmed that the RWR could be decreased if the pipe replacement project to improve the aging pipe ratio was not carried out and proper maintenance costs were not secured. It was also confirmed that an increase in the revenue water could be operated to facilitate the achievement of the project's target RWR. In contrast, a decrease in the revenue water due to a population reduction could affect the failure of the target RWR. In addition to analyzing the causes of variation in the RWR, the calculation of estimated project costs was considered by using leakage reduction instead of RWR from recent RWR improvement project cost data. From this analysis, it was reviewed whether the project costs planned to achieve the target RWR of the RWR improvement project in A city were appropriate. In conclusion, the RWR could be affected by variations in the ratio of aging pipes, maintenance conditions, and revenue water, and it was reasonable to consider not only the construction input but also the input related to RWR improvement, such as leakage reduction, when calculating the project cost.

• Journal of the Korean Ceramic Society
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• v.35 no.3
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• pp.294-302
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• 1998

$Pb_{1+x}$($Fe_{0.5}$$Nb_{0.5}$)$O_3$ films have been synthesized on Pt/Ti/$SiO_2$/Si substrates using rfmagnetron sputtering Concentration of Fe and Nb in the deposited films was adjusted to near stoichiometry through the control of target composition, Films deposited with adjusted to near stoichiometry showed better electrical properties such as dielectic and leakage characteristics. Crystallinity and dielectric constant increased with increasing excess PbO upto 9 mol% This study also showed that dielectric constant and leakage current characteristics improved by optimum content of $O_2$ flow during deposition.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1175-1177
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• 2011

The SBN thin films were deposited on Pt/Ti/$SiO_2$/Si and p-type Si(100) substrate by rf magnetron sputtering method using $Sr_{0.7}Bi_{2.3}Nb_2O_9$ ceramic target. SBN thin films deposited were annealed at 600~800[$^{\circ}C$] by furnace in oxygen atmosphere during 40min. The polarization characteristics have been investigated to confirm the possibility of the SBN thin films for the application to destructive read out ferroelectric random access memory. The maximum remanent polarization and the coercive voltage are 0.6[${\mu}C/cm^2$], 1.2[V] respectively at annealing temperature of 800[$^{\circ}C$]. The leakage current density was the $2.57{\times}10^{-6}[A/cm^2]$ at an applied voltage of 5[V] at annealing temperature of 650[$^{\circ}C$]. Also, the fatigue characteristics of SBN thin films did not change up to $10^8$ switching cycles.