• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.729-740
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• 2022

This study analyzed the effects of job stress and sleep disorders on sleepiness during the daytime for a night-shift urban railway crew. As a result of the analysis, measurements on a daytime sleepiness index were higher for the crew than those during other working hours, indicating that the degrees of sleepiness and drowsiness were severe. Afterwards, aromatic essential oils, which are generally known to help relieve sleep disorders and stress, were utilized to verify the effect on stress on night-shift workers. The experimental group treated with aromatherapy was found to show improved stress reduction and overall activity levels in the autonomic nervous system compared to an untreated control group. This study proves that night work by an urban railway crew negatively affects stress levels by increasing stress and negatively affects the autonomous nervous system, also showing that an aromatherapy treatment can be a good alternative to alleviate these conditions. The results of this study are expected to help prevent safety accidents by relieving the stress of nighttime workers.

• The Korean Society of Law and Medicine
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• v.22 no.4
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• pp.59-88
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• 2021

The National Assembly of the Republic of Korea recently enacted laws to fortify sanctions about data manipulation of pharmaceutical companies. The medicine approval system is the result of legislative efforts to prevent accidents that caused damages to patients' life and health. The medicine approval system is based on the trust that the data submitted by pharmaceutical companies is not manipulated. The Supreme Court of Korea clarified that strict standard shoud be required to secure the medicine safety in Supreme Court Decision 2008Du8628 decided November 13, 2008. We agree. This paper suggest legislation to weaken the economic incentives for pharmaceutical companies to choose data manipulation by minimizing the expected profit. In addition to revoking the marketing authorization of the medicine, the 'unfair' profits the pharmaceutical company has earned must be recovered. In addition, in order to increase the possibility to discover data manipulation, it is necessary to strengthen the review capacity and to activate the whistle-blowing.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.559-575
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• 2021

Due to the increase in ground excavation work, the possibility of ground subsidence accidents is increasing. And it is very difficult to prevent these risk fundamentally through institutional reinforcement such as the special law for underground safety management. As for the various cases of urban ground excavation practice, the ground subsidence behavior characteristics which is predicted using various information before excavation showed a considerable difference that could not be ignored compared to the results real construction data. Changes in site conditions such as seasonal differences in design and construction period, changes in construction methods depending on the site conditions and long-term construction suspension due to various reasons could be considered as the main causes. As the countermeasures, the safety management system through various construction information is introduced, but there is still no suitable system which can predict the effect of excavation and risk assessment. In this study, a web-based system was developed in order to predict the degree of impact on the ground subsidence and surrounding structures in advance before ground excavation and evaluate the risk in the design and construction of urban ground excavation projects. A system was built using time series analysis technique that can predict the current and future behavior characteristics such as ground water level and settlement based on past field construction records with field monitoring data. It was presented as a geotechnical data visualization (GDV) technology for risk reduction and disaster management based on web-based system, Using this newly developed web-based assessment system, it is possible to predict ground excavation impact prediction and risk assessment.

• Journal of the Society of Disaster Information
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• v.17 no.2
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• pp.306-318
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• 2021

The dispatch law has a negative impact on safety management at construction sites as the command and command relationship to safety assistants of the original contractor are applied to the dispatch law. Purpose: The purpose is to study the importance and impact of safety management according to the dispatch law, and to propose a direction for safety management so that safety assistants can actively and proactively prevent accidents. In this study, we used AHP analysis techniques for experts to achieve the final goal and verified the suitability through logistic regression. Method: AHP analysis technique is used for experts and workers and logistic regression analysis is conducted. Result: The result of analyzing scenario data where the dispatch method can be applied showed the importance in the order of education (SkillUp education), management (work-time management) and direct instructions (feedback instruction). In logistic regression analysis, feedback is the factor that affects direct instruction, and in education management, the ratio of education management is 3.42 times lower than that of other groups when only the team leader of the company gives work instructions. Conclusion: The management of feedback and education is more important than anything else within the range in which the dispatch method is not applied, and the expansion of non-face-to-face online education is judged to avoid the violation of dispatch method because the expansion of non-face-to-face online education due to covid 19 recently has brought more various target for safety education.

• Journal of Navigation and Port Research
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• v.45 no.3
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• pp.109-116
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• 2021

The explosion of a chemical tanker ship during cargo transshipment via double-banking at Ulsan Port, resulted in major damage including fires involving nearby ships. As a follow-up measure to prevent the recurrence of similar accidents, the 'Safety Management of Dangerous Goods in Port' was established, and the designation of a transshipment pier for dangerous goods is required given the risk of explosion and the impact on major facilities in the port. This study evaluated the Fire & Explosion Index of major transshipment cargoes in Ulsan Port to design a transshipment pier based on the Explosion Risk Assessment. Based on the results of Fire & Explosion Index evaluation of styrene monomer and benzene, severe explosion risk was confirmed, and the exposure radius was calculated. Based on the results of the exposure radius, the risk range for each major pier was calculated, and 12 terminals were proposed as transshipment pier candidates considering port facilities, surrounding dangerous facilities, and residential aspects. Since the results of the study suggest transshipment piers based on the risk radius alone, maritime traffic safety, pier and mooring facilities, safety facilities and accessibility for emergency response should be considered comprehensively to designate actual transshipment piers.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.4
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• pp.1-25
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• 2021

In order to respond and prevent underground safety accidents, the Korean government has been preparing a submitting completion drawing web system project for converting the current manual-based 3D Underground Geospatial Map construction and its update system to an automation-based 3D underground information construction. However, research on standard drawings required for the automatic update of 3D underground structures is insufficient, so detailed research is needed. In this research paper, a standard map-based 3D underground structure construction plan was presented for the six types of underground structures constituting the 3D Underground Geospatial Map, enabling rapid and accurate drawing data creation and systematically 3D underground structure drawing data could be managed. In addition, we developed a 3D construction drawing tool that can be used in underground information practice so that ordinary CAD program users can easily produce processing drawings. The results derived from this paper are expected to be major reference materials for the establishment of standard frameworks and practical application guidelines for the construction of 3D underground structures in the future.

• 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 for structural maintenance and inspection
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• v.26 no.6
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• pp.230-237
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• 2022

It is essential that service life of reinforced concrete structures in economic and safety aspects should be secured. It is well-known that chloride attack is a typical deterioration mechanism in field concrete structures. To prevent serious accidents like collapse, many studies have been conducted to increase resistance of chloride ingress using concrete mixed with GGBS. The usage of GGBS concrete is nowadays mandatory. Since most concretes in the field are unsaturated, study regarding chloride absorption is necessary, but many studies have focused on the chloride diffusion phenomenon. Methods for evaluating chloride absorption are cost and improper in the field. It is necessary to develop a simple method for evaluating chloride absorption in practice. This study evaluated resistance of chloride ingress in GGBS concretes with impedance measurement and absorption test. From the results, it was confirmed that the contents of absorbed chloride were linearly correlated with the measured electrical resistivities (or conductivities) in the concrete. At the end of the test, the electrical conductivities were 250.8 S/m (w/b=0.4) and 303.1 S/m (w/b=0.6) for PC concretes, and 2.6 S/m (w/b=0.4) and 64.4 S/m (w/b=0.6) for GGBS concretes, respectively. Considering influencing factors for chloride absorption and impedance measurement, chloride ingress into concrete is mainly affected by pore structures due to replacement of GGBS. Especially, formations of pore structure are different with binder, thereby binders should be considered in building reinforced concrete structures exposed to chloride environments.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.6
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• pp.175-181
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• 2022

The condition of infrastructure deteriorates as the service life increases. Since most infrastructure in South Korea were intensively built during the period of economic growth, the proportion of outdated infrastructure is rapidly increasing now. Aging of such infrastructure can lead to safety accidents and even human casualties. To prevent these issues in advance, periodic and accurate inspection is essential. For this reason, the need for research to detect various types of damage using computer vision and deep learning is increasingly required in the field of remotely controlled or autonomous inspection. To this end, this study proposed a neural network structure that can detect concrete damage by classifying it into three types. In particular, the proposed neural network can detect them more accurately through a hierarchical learning technique. This neural network was trained with 2,026 damage images and tested with 508 damage images. As a result, we completed an algorithm with average mean intersection over union of 67.04% and F1 score of 52.65%. It is expected that the proposed damage detection algorithm could apply to accurate facility condition diagnosis in the near future.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.1
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• pp.9-14
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• 2022

In this study, a smart jack-up system was developed to prevent safety accidents by performing risk analysis when a structure is lifted for maintenance. A quantitative risk analysis program that can analyze the risk using the pairwise comparison matrix analysis method was developed. The risk was analyzed in real-time for the lifting structure by connecting the program with an automatic jack-up system. Displacements were measured by the IR sensor among the components of the automatic jack-up system, and the displacements were provided to the quantitative risk analysis program. To confirm the performance of the smart automatic jack-up system, experiments were conducted on bridge and risk analysis was performed when a superstructure was lifted. A linear variable differential transformer (LVDT) was also installed on the bridge to verify the performance of the smart automatic jack-up system. The maximum displacements were measured using the devices, and the declinations were compared. The performance of the simultaneous operation of the jack-up device was verified by the analysis of variance (ANOVA).