• Journal of the Korea Institute of Building Construction
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• v.22 no.5
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• pp.519-530
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• 2022

As online commerce increases, the construction of large logistics buildings worldwide is exploding. Most of these buildings have the characteristics of long span and heavy loaded and use precast concrete components, a pin joint structure, for rapid construction. However, due to construction safety and structural stability requirements, the pin joint structure has many limitations in terms of the erection of the PC member, which increases the time and cost. A structural frame connected with steel joints between precast concrete components, called a SMART frame, has been developed, which addresses these constraints and risks. However, the effect of the appllication of a SMART frame on the time aspect has not been analysed. The study is a time reduction effect analysis of a SMART frame for long span and heavy loaded logistics buildings. For this study, the authors select a case site erected using existing PC components, and compare the time reduction with the SMART frame erection simulations. Through this analysis, it was found that a time reduciton about 4 months, approximately 48% of the conventional PC installation period could be achieved. If the SMART frame is applied when carrying out future large-scale logistics building projects, it can be expected to have the effect of significantly shortening the construction period compared to the conventional method.

• Convergence Security Journal
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• v.22 no.4
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• pp.161-168
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• 2022

After the corona virus, as non-face-to-face services are activated, domain services that guarantee integrity by embedding sensing information of the Internet of Things (IoT) with block chain technology are expanding. For example, in areas such as safety and security using CCTV, a process is required to safely update firmware in real time and to confirm that there is no malicious intrusion. In the existing safe security processing procedures, in many cases, the person in charge performing official duties carried a USB device and directly updated the firmware. However, when private blockchain technology such as Hyperledger is used, the convenience and work efficiency of the Internet of Things environment can be expected to increase. This article describes scenarios in how to prevent vulnerabilities in the operating environment of various customers such as firmware updates and device changes in a non-face-to-face environment. In particular, we introduced the optimal blockchain technique for the Internet of Things (IoT), which is easily exposed to malicious security risks such as hacking and information leakage. In this article, we tried to present the necessity and implications of security management that guarantees integrity through operation applying block chain technology in the increasingly expanding Internet of Things environment. If this is used, it is expected to gain insight into how to apply the blockchain technique to guidelines for strengthening the security of the IoT environment in the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.785-791
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• 2023

Risk management is essential for preventing accidents arising from uncertainties in TBM tunnel projects, especially concerning managing the risk of TBM tunnel collapse, which can cause extensive damage from the tunnel face to the ground surface. In addition, prioritizing risks is necessary to allocate resources efficiently within time and cost constraints. Therefore, this study aimed to establish a TBM risk database through case studies of TBM accidents and determine a risk priority for TBM tunnel collapse using the Bayes theorem. The database consisted of 87 cases, dealing with three accidents and five geological sources. Applying the Bayes theorem to the database, it was found that fault zones and weak ground significantly increased the probability of tunnel collapse, while the other sources showed low correlations with collapse. Therefore, the risk priority for TBM tunnel collapse, considering geological sources, is as follows: 1) Fault zone, 2) Weak ground, 3) Mixed ground, 4) High in-situ stress, and 5) Expansive ground. In practice, the derived risk priority can serve as a valuable reference for risk management, enhancing the safety and efficiency of TBM construction. It provides guidance for developing appropriate countermeasure plans and allocating resources effectively to mitigate the risk of TBM tunnel collapse.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.555-564
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• 2017

The current radiation risk assessment for occupational exposure is based on the measured exposure dose and health checkups of workers. This people-centered risk assessment may occur errors because absence of using personal dosimeter or unrelated health symptoms of individuals lead to difficulties in obtaining accurate data from workers. In addition, although the established legal upper dose limit was used as a reference for the assessment, it does not imply that this limit is the optimal dose of radiation workers should get; ALARA principle should always be appreciated. Therefore, a new risk assessment model that can take account of all the important factors and implement optimization of radiation protection is required at the national level. In this paper, based on the KOSHA Risk Assessment, we studied on the workplace-centered risk assessment model for radiation field rather than the people-centered. The result of the study derived a right model for radiation field through the analysis of the risk assessment methods in various fields and also found data acquisition methods and procedures for applying to the model. Multidimensional model centering on the workplace will enables more accurate radiation risk assessment by using a risk index and radar plot, and consequently contribute to the efficient worker management, preemptive worker protection and implementation of optimization of radiation protection.

• Knowledge Management Research
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• v.21 no.3
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• pp.229-247
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• 2020

In the remarkable growth of P2P financial platform in the field of knowledge management, only companies with big data and machine learning technologies are surviving in fierce competition. The ability to analyze borrowers' credit is most important, and platform companies are also recognizing this capability as the most important business asset, so they are building a credit evaluation system based on artificial intelligence. Nonetheless, online P2P platform providers that offer related services only act as intermediaries to apply for investors and borrowers, and all the risks associated with the investments are attributable to investors. For investors, the only way to verify the safety of investment products depends on the reputation of P2P companies from newspaper and online website. Time series information such as delinquency rate is not enough to evaluate the early stage of Korean P2P makers' credit analysis capability. This study examines the credit analysis procedure of P2P loan platform using artificial intelligence through the case analysis method for well known the top three companies that are focusing on the credit lending market and the kinds of information data to use. Through this, we will improve the understanding of credit analysis techniques through artificial intelligence, and try to examine limitations of credit analysis methods through artificial intelligence.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.417-428
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• 2023

The demolition of domestic infrastructures mirrors other significant construction initiatives in presenting a markedly high accident rate. A comprehensive investigation into the origins of such accidents is crucial for the prevention of future incidents. Upon detailed inspection, the causes of demolition construction accidents are multifarious, encompassing unsafe worker behavior, hazardous conditions, psychological and physical states, and site management deficiencies. While statistics relating to demolition construction accidents are consistently collated and reported, there exists an exigent need for a more foundational cause categorization system based on accident type. Drawing from Heinrich's Domino Theory, this study classifies the origins of accidents(unsafe behavior, unsafe conditions) and human errors(human factors) as per the type of accidents experienced during demolition construction. In this study, a three-step model of QFD-FMEA(Quality Function Deployment - Failure Mode Effect Analysis) is employed to systematically categorize accident causes according to the types of accidents that occur during demolition construction. The QFD-FMEA method offers a technique for cause classification at each stage of the demolition process, including direct causes(unsafe behavior, unsafe environment), and human errors(human factors) through a tri-stage process. The results of this accident cause classification can serve as safety knowledge and reference checklists for accident prevention efforts.

• Explosives and Blasting
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• v.41 no.3
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• pp.62-72
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• 2023

The aging of plant structures due to industrialization in the 1970s has increased the demand for blast demolition. While blasting can reduce exposure to environmental pollution by shortening the demolition period, improper blasting design and construction plans pose significant safety risks. Thus, it is vital to consider optimal blasting demolition conditions and other factors through collapse behavior simulation. This study utilizes a 3-D combined finite-discrete element method (FDEM) code-based 3-D DFPA to simulate the collapse of a chimney structure in a thermal power plant in Seocheon, South Korea. The collapse behavior from the numerical simulation is compared to the actual structure collapse, and the numerical simulation result presents good agreement with the actual building demolition. Additionally, various numerical simulations have been conducted on the chimney models to analyze the impact of the duct size in the pre-weakening area. The no-duct, duct, and double-area duct models were compared in terms of crack pattern and history of Z-axis displacement. The findings show that the elapse-time for demolition decreases as the area of the duct increases, causing collapse to occur quickly by increasing the load-bearing area.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.70-77
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• 2023

In response to climate change, each country is proposing a goal to reduce greenhouse gases in its energy supply and demand plan, and the use of hydrogen gas is a topic that is always prioritized as an energy resource for implementation. A popular way to use this hydrogen gas is the use of hydrogen fuel cell vehicles, and expansion of hydrogen charging stations is essential for using these hydrogen fuel cell vehicles. However, there are several limitations to the expansion of hydrogen refueling stations, the most representative of which is resident acceptance. Most of the hydrogen charging stations currently built in Korea are located in the outskirts with low population density, so the inconvenience to hydrogen fuel cell vehicle users has not been resolved, and as a result, there has been no progress in the spread of hydrogen fuel cell vehicles. In this paper, we analyzed the consequences of accident damage to determine the risks of constructing a hydrogen charging station on a railroad site frequently used by citizens. The target hydrogen charging station site was a railroad depot in Busan, and there are trains, national highways, and commercial facilities around this site. Assuming the worst-case scenario, we would like to consider the safety of the hydrogen refueling station site by analyzing the area affected by the accident and its consequence.

• Journal of Navigation and Port Research
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• v.45 no.1
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• pp.33-41
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• 2021

In the last 5 years, a total of 567 accidents of operating vessels occurred under the influence of alcohol at sea, most of which occurred in fishing boats. Accidents caused by operating vessels under the influence of alcohol at sea are causing human and physical damages. There were 69 accidents caused by operating vessels under the influence of alcohol, leading to five deaths and one missing. The social damage due to operating vessels under the influence of alcohol is also increasing. Under the current law, punishment is given lightly compared to the seriousness of violation. In order to prevent the recurrence of accidents caused by operating vessels under the influence of alcohol, cases in Korea need to be analyzed. Regulations on the crackdown in foreign countries were compared to those in Korea and reviewed. In addition, risks of operating vessels under the influence of alcohol should be provided to ship workers while improving related laws and systems. In addition, efforts should be made to reduce the number of accidents due to operating vessels under the influence of alcohol by strengthening crackdowns on ships at sea so that accidents caused by operating vessels under the influence of alcohol could be prevented in advance in the future.

• Journal of Hospice and Palliative Care
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• v.8 no.1
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• pp.57-64
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• 2005

Cyclooxygenase-2 (COX-2) selective inhibitors were specifically developed to reduce the risks of gastrointestinal bleeding associated with other NSAID drugs. However, the APPROVe (Adenomatous Polyp Prevention on VIOXX) trials revealed that rofecoxib sometimes exerts prothrombotic effects. Meanwhile, cancer patients, who also carry a risk of thrombosis due to a variety of mechanisms, are often treated with COX-2 selective inhibitors, due to their relative gastrointestinal safety. This report concerns the case of a 46-year old woman with advanced cervical cancer, who had been treated with opioids and a COX-2 selective inhibitor (celecoxib) for 2 months, for the relief of pain associated with her cancer. The patient was admitted due to swelling of the left leg, which was also accompanied by pain. A computerized tomography scan revealed deep vein thrombosis occurring in multiple veins of both legs. After the administration of low-molecular weight heparin and oral warfarin, the patient's symptoms were relieved initially. However, her prothrombin time was found to be prolonged, necessitating the discontinuation of anticoagulation therapy. The patient's dyspnea worsened, ultimately resulting in her death. In conclusion, the administration of cox-2 selective inhibitors should be carefully considered in patients with a number of different risk factors, and assessed on a case-by-case basis.