• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.549-558
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• 2021

In order to keep infrastructures such as tunnels and underground facilities safe, cracks of concrete lining in tunnel should be detected by regular inspections. Since regular inspections are accomplished through manual efforts using maintenance lift vehicles, it brings about traffic jam, exposes works to dangerous circumstances, and deteriorates consistency of crack inspection data. This study aims to provide methodology to automatically extract cracks from tunnel concrete lining images generated by the existing tunnel image acquisition system. Specifically, we train a deep learning based semantic segmentation model with open dataset, and evaluate its performance with the dataset from the existing tunnel image acquisition system. In particular, we compare the model performance in case of using all of a public dataset, subset of the public dataset which are related to tunnel surfaces, and the tunnel-related subset with negative examples. As a result, the model trained using the tunnel-related subset with negative examples reached the best performance. In the future, we expect that this research can be used for planning efficient model training strategy for crack detection.

• Journal of Korean Society of Archives and Records Management
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• v.22 no.4
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• pp.25-43
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• 2022

The ultimate record management's purpose is preservation and utilization. However, the National Archives of Korea (NAK)s Portal has problems such as search system aging and search tools dualization. As a result, the users' search satisfaction is not satisfied, and the improvement demand increases. This study aimed to evaluate the NAK's search quality as a preliminary study for NAK search system advancement. To this end, we analyzed the current status of CAMS and NAK's Portal. Then, we established the test sets and evaluated the NAK's Portal quality from the user's point of view. Evaluation results were analyzed using Precision, Recall, F-score, and MRR. The analysis results showed that the overall search performance was low, particularly in the "advanced subject search," which showed low performance in Precision, Recall, and MRR. Thus, improvement is urgently needed. The test sets established for this study are expected to be used as a basis for objectively measuring the improvement of the search performance after the NAK search system advancement.

• Korean Journal of Construction Engineering and Management
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• v.23 no.5
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• pp.43-55
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• 2022

Since assembled temporary equipment is widely used for construction work that should be carried out before this construction begins, it is essential to secure quality during assembly and prevent safety accidents caused by assembled temporary equipment after installation. However, it was investigated that most construction site managers are not aware of its importance, such as recognizing the quality management of assembled temporary equipment as a task of managing temporary structures that are dismantled after installation for this construction. The quality management work of assembled temporary equipment at the construction site is carried out in different ways for each construction site because there is no formalized procedure and the subject of performing. In addition, it is analyzed that the manager of the general construction company inspects and reflects the parts that need to be inspected without evidence, so transparency is not guaranteed and the result leads to a serious disaster. Therefore, the purpose of this study is to establish a document preparation-oriented system that provides systematic quality evaluation and management procedures for securing the quality of assembled temporary equipment, develops a checklist for quality evaluation and management, and supports history management on the web.

• Journal of the Korea Institute of Building Construction
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• v.24 no.1
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• pp.109-120
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• 2024

For successful waterproofing construction, it is very important to secure construction quality as well as material performance of waterproofing materials used in construction. Due to the long-term cost reduction policy following the economic downturn in the construction market, most construction companies are using general low-priced waterproof materials rather than high-quality waterproof materials without clear quality control standards. Without clear education on construction, construction is being carried out with meaning only on construction activities. In addition, the waterproofing method applied in combination is a situation where water leakage occurs due to waterproofing failure due to insufficient construction quality because the construction method is complicated. Therefore, it is necessary to review the quality control measures(design, materials, construction) for successful waterproofing work and improve problems that are derived so that stable waterproofing work can be done. In order to expect the leakage prevention effect of a building, first, it is required to select appropriate materials for each part of the building and environment in the design stage, and the selected materials must satisfy all items of the Korean Industrial Standard(KS). Second, to secure the quality of waterproofing construction, sincere construction by workers is required. In this paper, we tried to describe "review of waterproof design", "constructor education", "site inspection", and "criticism(correction/supplementation)" as quality control measures after material selection.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.4
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• pp.365-384
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• 2024

The development of scanning technology is accelerating for safer and more efficient automated inspection than human-based inspection. Research on automatically detecting facility damage from images collected using computer vision technology is also increasing. The pixel size, quality, and quantity of an image can affect the performance of deep learning or image processing for automatic damage detection. This study is a basic to acquire high-quality raw image data and camera performance of a mobile tunnel scanning system for automatic detection of damage based on deep learning, and proposes a method to quantitatively evaluate image quality. A test chart was attached to a panel device capable of simulating a moving speed of 40 km/h, and an indoor test was performed using the international standard ISO 12233 method. Existing image quality evaluation methods were applied to evaluate the quality of images obtained in indoor experiments. It was determined that the shutter speed of the camera is closely related to the motion blur that occurs in the image. Modulation transfer function (MTF), one of the image quality evaluation method, can objectively evaluate image quality and was judged to be consistent with visual observation.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.4
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• pp.36-50
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• 2012

This study was carried out to find contradiction factors on laws for children's activity spaces and facilities and to suggest the rational options to control and manage those spaces and facilities by environmental and landscape planning methods. The results of this study are as follows: 1. The major laws related to the environmental safety for children's activity spaces are "Environmental Health Act (ERA)" for managing the environmental safety of children's activity spaces; "Safety Supervision Law of Children's Play Facilities(SSLCPF)" for the inspection and management for safety of children's play facilities; "Quality Management and Industrial Products Safety Management Law(QMIPSML)" for managing safety certification on children's play equipments. 2. The interior space such as "living room" by the Children's Welfare Law(CWL), "Children Park" by the Act on Urban Parks and Green Spaces(AUPGS), "classroom" on private educational institutes by the Act on Establishment and Operation Private Lesson and Training(AEOPLT) and "nursing room" of child care center smaller than $430m^2$ are needed to be managed as an activity space. 3. In order to reduce industrial burden in the production, establishment, construction, and operation and to minimize unwilling extra burden in the administration effort due to legally double regulate, it is necessary to mitigate the inspections on the equipment certificate from QMIPSML and overlapped or different factors and standards must be unified. With this study, the landscape domain could he enlarged from producing, import of play equipment and establishment, construction and operation of play facilities for a comprehensive range of activity spaces, and the landscape industry such as engineering industry, academic research, management, etc.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.2
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• pp.163-169
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• 2015

In many nuclear power plant sites in Korea, high density storage racks were installed in the spent fuel pool to expand the spent fuel storage capacity. Nevertheless, the capability of the Hanbit nuclear site will be saturated by 2024. Also, 10 NPPs will reach their design life expiration date by 2029. In the case of the US, SFPI (Spent Fuel Pool Island) operated temporarily as a spent fuel storage option before spent nuclear fuels were transported to an interim storage facility or a final disposal facility. As a spent fuel storage option after shutdown during decommissioning, the SFPI concept can be expected to have the following effects: reduced occupational exposure, lower cost of operation, strengthened safety, and so on. This paper presents a case study associated with the regulations, operating experiences, and systems of SFPI in the US. In conclusion, the following steps are recommended for applying SFPI during decommissioning in Korea: confirmation of design change scope of SFPI and expected final cost, the submission of a decommissioning plan which is reflected in SFPI improvement plans, safety assessment using PSR, application of an operating license change for design change, regulatory body review and approval, design change, inspection by the regulatory body, education and commissioning for SFPI, SFPI operation and periodic inspection, and dismantling of SFPI.

• Journal of radiological science and technology
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• v.37 no.1
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• pp.1-6
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• 2014

Breast shooting performance management and quality control of the generator is applied to the amount of current IEC(International Electrotechnical Commission) 60601-2-45 tube voltage and tube current are based on standards that were proposed in the analysis of the test results were as follows. Tube voltage according to the value of the standard deviation by year of manufacture from 2001 to 2010 as a 42-3.15 showed the most significant, according to the year of manufacture by tube amperage value of the standard deviation to 6.38 in the pre-2000 showed the most significant, manufactured after 2011 the standard deviation of the devices, the PAE(Percent Average Error) was relatively low. This latest generation device was manufactured in the breast of the tube voltage and tube diagnosed shooting the correct amount of current to maintain the performance that can be seen. The results of this study as the basis for radiography diagnosed breast caused by using the device's performance and maintain quality control, so the current Food and Drug Administration "about the safety of diagnostic radiation generator rule" specified in the test cycle during three years of self-inspection radiation on a radiation generating device ensure safety and performance of the device using a coherent X-ray(constancy) by two ultimately able to keep the radiation dose to the public to reduce the expected effect is expected.

• Journal of Korean Society of Disaster and Security
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• v.7 no.2
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• pp.17-24
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• 2014

Recently, many accidents occur frequently because sprinklers aren't installed or don't work right when there are outbreak of fire in houses and aggregate buildings. Therefore, they can result in damage for humans and loss of property. Sprinklers are the most appropriate which can extinguish buildings' fire in the initial stages. Through lack of legal system, in domestic cases, sprinklers cannot operate their inherent performance. Domestic standard simply classifies installation objects according to types of business and forms of buildings, also divides into uses and floors of buildings. Especially it only regulates that sprinklers must be installed every floors in particular fire buildings that have more than eleven floors. While it doesn't need to install sprinklers below ten floors, so we are threatened the safety. In this study, we derived causes and implications by analyzing concepts of sprinklers facilities, installation standards in domestic and foreign legal system, and recent cases that expanded damages in fire accidents because of weak point of installation and control standards. In domestic cases, as a result, government has to provide an institutional strategy and law that regulate duty to install sprinklers to all aggregate buildings regardless of floors in terms of new buildings. Also, if someone who has existing buildings wanted to install them, government would guarantee subsidy to encourage installation. In addition, government supervises fire-fighting activities when there are fire by compensating standards about regular inspection by a qualified technician, operation and maintenance of sprinklers as well as reinforcement of administrative criteria.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.679-685
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• 2018

In order to reduce marine accidents using advanced information and communication technology, various research and development projects are conducted globally on e-Navigation related technologies and services. Existing studies do not provide policy measures for LTE-M. In order for these technologies and services to be installed on vessels and to contribute to the prevention of accidents at sea, the law should be expand operational organizations and systems. In particular, communication equipment and related technical standards should be prepared, and its digital communication technology (LTE-M, VDES, Digital-MF / HF, etc.) In this study, we conducted short, medium, and long term performance assessment of the identification system and the policy for effective implementation of Korean e-Navigation. We presented a visible plan of the relevant policy. For example, e-Navigation core services, e-Navigation communication networks and operating systems, e-Navigation international standard leading technologies and e-navigation services activated in the field. To do this, we conducted research based on the progress data of the Korean e-Navigation project, which was led by the Ministry of Maritime Affairs and Fisheries, and conducted research discussions with practitioners and experts in related fields. As a result of this study, it is expected that the proposed policies will contribute to the reduction of marine accidents, the promotion of the maritime industry and the development of additional government policies for national security.