• Computers and Concrete
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• v.32 no.6
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• pp.615-623
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• 2023

Crack detection is an essential method to ensure the safety of dam concrete structures. Low-quality crack images of dam concrete structures limit the application of neural network methods in crack detection. This research proposes a modified attentional mechanism model to reduce the disturbance caused by uneven light, shadow, and water spots in crack images. Also, the focal loss function solves the small ratio of crack information. The dataset collects from the network, laboratory and actual inspection dataset of dam concrete structures. This research proposes a novel method for crack detection of dam concrete structures based on the U-Net neural network, namely AF-UNet. A mutual comparison of OTSU, Canny, region growing, DeepLab V3+, SegFormer, U-Net, and AF-UNet (proposed) verified the detection accuracy. A binocular camera detects cracks in the experimental scene. The smallest measurement width of the system is 0.27 mm. The potential goal is to achieve real-time detection and localization of cracks in dam concrete structures.

• Journal of the Korea Safety Management & Science
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• v.24 no.2
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• pp.163-169
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• 2022

Recently, in Korea, if a very large forest fire occurs due to the people's carelessness, it is of great interest because it spreads into a large forest fire. If a wildfire spreads and becomes large, it will inflict great damage (appointment and property), and the damage is irreversible. The best way to extinguish a wildfire is to prevent it before it occurs. If a forest fire occurs due to a failure in prevention, the early firefighting activities to prevent the progress of the forest fire by promptly dispatching it by reporting it and approaching the site as soon as possible should now be managed with a systematic integrated management system. To do so, it is necessary to prepare a preventive system, such as issuing warnings for each weather condition by the Korea Forest Service, consisting of cooperation (support) activities for forest fire prevention by related organizations, etc. In order to minimize the loss of precious lives and forests, measures have been taken to establish a system, to establish a prompt and accurate situation reporting system, and to establish an integrated command system (ICS) for on-site commanders.

• Journal of Korea Multimedia Society
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• v.10 no.12
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• pp.1671-1678
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• 2007

In these days, Disaster Management Systems have still put emphasis on its recovery more than the prevention of disaster events. However, the countermeasure of restoration has limitations to prevent the caused loss because the disasters often happen and are massive. Therefore, we propose a disaster prevention system for supporting the safe urban. In this paper, we try to construct a real-time monitoring system to prevent disaster events using new technologies such as Wireless Sensor Networks (WSN) and Geographic Information System (GIS). As a prototype to simulate the fire disasters on real-time, we construct gas sensors and temperature sensors. Our system consists of a WSN system to collect data of the gas and temperature sensors and to monitor the situation information. Our contribution is to provide a prototype application to prevent the disasters from the fire by constructing a WSN system with gas and temperature sensors.

• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.389-401
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• 2024

In recent decades, numerous instances of blockages have been reported in coastal nuclear power plants globally, leading to serious safety accidents such as power reduction, manual or automatic power loss, or shutdown of nuclear power units. Loss or shortage of cooling water may compromise the reliability of the cooling water system, thus threatening the operational safety of power plants and resulting in revenue reduction. This study provides a comprehensive review of the current state of cooling water system safety in coastal nuclear power plants worldwide and the common challenges they face, as well as the relevant research on cooling water system safety issues. The research overview and progress in investigation methods, outbreak mechanisms, prevention and control measures, and practical cases of blockages were summarized. Despite existing research, there are still many shortcomings regarding the pertinence, comprehensiveness and prospects of related research, and many problems urgently need to be solved. The most fundamental concern involves understanding the list of potential risks of blockages and their spatially distributed effects in surrounding waters. Furthermore, knowledge of the biological cycles and ecological habits of key organisms is essential for implementing risk prevention and control and for building a scientific and effective monitoring system.

• Convergence Security Journal
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• v.24 no.3
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• pp.3-11
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• 2024

Information security is crucial not only for protecting against external cyber-attacks but also for identifying and blocking internal data leakage risks in advance. To this end, many companies and institutions implement digital rights management(DRM) document security solutions, which encrypt files to prevent content access if leaked, and data loss prevention(DLP) solutions, which control devices such as USB ports on computing equipment to prevent data leaks. At a time when efforts to prevent internal data leaks are crucial, there is a growing need for control policies such as device control and the identification of information assets in standalone network environments, which could otherwise fall into unmanaged domains. In this study, we propose a Generation-Distribution-Application model for device control policies that are uniquely applied to standalone information assets that are not connected to internal networks. To achieve this, we developed an authentication technique linked with the asset management system, where information assets are automatically registered upon acquisition. This system allows for precise identification of information assets and enables flexible device control, and we have designed and implemented a system based on these principles.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.1
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• pp.61-72
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• 2023

The increase in the rearing intensity of pigs has caused deterioration in the pig house's internal environment such as temperature, humidity, ammonia gas, and so on. Traditionally, the widely used method to control the internal environment was through the manipulation of the ventilation system. However, the conventional ventilation system had a limitation to control the internal environment, prevent livestock disease, save energy, and reduce odor emission. To overcome this problem, the air-recirculated ventilation system was suggested. This system has a semi-closed loop ventilation type. For designing this system, it was essential to evaluate the ventilation rates considering the pressure loss of ducts. Therefore, in this study, pressure loss calculation and experiment were conducted for the quantitative ventilation design of a semi-closed loop system. The results of the experiment showed that the inlet through which external air flows should always be opened. In addition, it was also found that for the optimum design of the semi-closed loop ventilation system, it was appropriate to install a damper or a backflow prevention device rather than a ventilation fan.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.899-906
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• 2017

This paper proposes an inter-floor noise prevention system using an open-source controller. In the proposed system, Arduino which is a widely used open source controller analyzes sound signals and vibration signals with fast fourier transform. When the magnitude of the band-passed signal excesses the noise reference considering transmission loss of a panel or a wall, the system displays warning messages on an LCD module and a mobile device for users to be aware of the noise condition. In the experiment, the system has succeeded extracting and processing the band-passed signals between 130 Hz ~ 1040 Hz. When the magnitude of the extracted signal that is subtracted from the transmission loss exceeds 45 dB, the system has displayed the warning message on an LCD module and a mobile devicefor noise reduction.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.4
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• pp.451-453
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• 2016

In this paper, we propose a Load Balance System for SFC based on DLP solution. SFC based on DLP solution does not distribute to the user data and each DLP server manages all traffic generated by the user device. When using existing algorithms such as the Load Balance Round Robin, Least Connection does not consider the resource usage of DLP server so traffic is not efficiently distributed due to different user traffic usage. It causes system failure and overload of the DLP server. Therefore, we propose the architecture of a Load Balance system for SFC based on DLP solution to perform the Load Balance based on the resource usage of DLP server through a LBM server in this paper.

• Nuclear Engineering and Technology
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• v.48 no.5
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• pp.1174-1183
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• 2016

Hydrogen release during severe accidents poses a serious threat to containment integrity. Mitigating procedures are necessary to prevent global or local explosions, especially in large steel shell containments. The management of hydrogen safety and prevention of over-pressurization could be implemented through a hydrogen reduction system and spray system. During the course of the hypothetical large break loss-of-coolant accident in a nuclear power plant, hydrogen is generated by a reaction between steam and the fuel-cladding inside the reactor pressure vessel and also core concrete interaction after ejection of melt into the cavity. The MELCOR 1.8.6 was used to assess core degradation and containment behavior during the large break loss-of-coolant accident without the actuation of the safety injection system except for accumulators in Beznau nuclear power plant. Also, hydrogen distribution in containment and performance of hydrogen reduction system were investigated.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.188-188
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• 2016

The Mekong which is one of the world's most significant rivers plays an extremely important role to South East Asia. Lying across six riparian countries including China, Myanmar, Thailand, Laos, Cambodia and Vietnam and being a greatly biological and ecological diversity of fishes, the river supports a huge population who living along Mekong Basin River. Therefore, much attention has been focused on the giant Mekong Basin River, particularly, the soil erosion and sedimentation problems which rise critical impacts on irrigation, agriculture, navigation, fisheries and aquatic ecosystem. In fact, there have been many methods to calculate these problems; however, in the case of Mekong, the available data have significant limitations because of large area (about 795 00 km2) and a failure by management agencies to analyze and publish of developing countries in Mekong Basin River. As a result, the Universal Soil Loss Equation (USLE) model in a GIS (Geographic Information System) framework was applied in this study. The USLE factors contain the rainfall erosivity, soil erodibility, slope length, steepness, crop management and conservation practices which are represented by raster layers in GIS environment. In the final step, these factors were multiplied together to estimate the soil erosion rate in the study area by using spatial analyst tool in the ArcGIS 10.2 software. The spatial distribution of soil loss result will be used to support river basin management to find the subtainable management practices by showing the position and amount of soil erosion and sediment load in the dangerous areas during the selected 56- year period from 1952 to 2007.