• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.10
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• pp.1941-1948
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• 2016

The incident during commuting to school happened frequently in these days, such that the government announced the student commuting safety policy for addressing to implement the safety management system of the unsafer school commuting zone. In this paper, a commuting tracking system is proposed that notifies the location of vehicles and the boarding status of student using BLE beacon and smart phone GPS function. The commuting tracking system that gets the data from the system server of driver's smart phone GPS location and UUID of the beacon which had provided students has configured to provide notifications to parents and related administrators. It provides real-time information about whether a student boarding, boarding times and bus locations for parents and administrators. It verifies the disembarking time for each student and also provides to driver to secure if any student tries to board the wrong school bus and if any students is left behind in the bus.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.6
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• pp.735-749
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• 2008

For the development of the original technique of structural safety assessment of Cargo Containment System(CCS) in membrane type LNG carriers, it is necessary to understand the characteristics of dynamic response behavior of CCS structure under sloshing impact pressure. In the previous study, the wet drop impact response analyses of CCS structure in membrane Mark III type LNG carriers were carried out by using Fluid-Structure Interaction(FSI) analysis technique of LS-DYNA code, and were also validated through a series of wet drop experiments for the enhancement of more accurate shock response analysis technique. In this study, the characteristics of structural shock response behaviors of CCS structure were sufficiently figured out by careful examinations of the effects of specimen weight, drop height, incident angle, corrugation and stiffness of inner hull on its shock response behaviors. The shock response analysis of upward shooting fluid to inner hull was performed, and the reason of faster strain response than shock pressure one was also figured out.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.1
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• pp.11-16
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• 2020

The rotational stability of an interlocking caisson breakwater was studied. Using the analytical solution for the linear wave incident to the infinite breakwater, the phase difference effect of wave pressures in the direction of the breakwater baseline is considered, and Goda's wave pressure formula in the design code is adopted to consider the nonlinearity of the design wave. The rotational safety factor of the breakwater was defined as the ratio of the rotational frictional resistance moment due to caisson's own weight and the acting rotational moment due to the horizontal and vertical wave forces. An analytical solution for the rotational center point location and the minimum safety factor is presented. Stability assessment formula were proposed to be applicable to all design wave conditions used in current port and harbor structure design such as regular waves, irregular waves and multi-directional irregular waves.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.692-703
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• 2014

The purpose of this study is to clarify the problems and causes of OSC system of the KCG. In the disaster of sea, the possibility that could expect a reasonable decision making is low. The study has carried out for the different point of view of the problems. The problems have been revealed through the theory and analysis of structural and non-structural aspects for the OSC system, such as inefficient organization system, failure of reasonable decision making, lack of communication with the field. The conclusions of the study have been proposed such as an advanced On-Scene Command system, efficient organization, the training of professional staff, the creating of open organizational culture.

• Polymer(Korea)
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• v.38 no.1
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• pp.1-8
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• 2014

The effects of surface color and morphology on the mar behaviors of urethane-acrylate coated surfaces were examined. The superiority of mar resistance was observed in the order of white, red and black-colored samples. This can be explained by a contrast effect. In other words, in case of black colored sample, it takes place the defuse reflection of the incident light on the damaged region where mar damage exerts, leading to whitening phenomenon. Therefore, the damaged region is easily recognized by contrasting the black background. On the other hand, it is difficult for the white-colored sample to perceive the mar-damaged area by the white background acting as protecting coloration. As the gloss of urethane-acrylate coated surface increases, it is observed that there is an increase in the number of carbonyl (-C=O) function group, amount of ethylene and silica. The enhancements of surface rigidity by adding the silica particles and formation of carbonyl function groups by the surface oxidation lead to the increase in mar resistance, while the increase of polyethylene wax is responsible for the improved gloss and smooth-faced surface. Based on the above findings, technical approaches leading the improvement of mar resistance of the urethane-acrylate coated surface are discussed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.829-833
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• 2017

Recently, pirate incidents involving passing ships have been continuously occurring in the seas southwest of the Philippines, the Sulu Sea and the Celebes Sea. Pirates in these areas are members of the "Abu Sayyaf Group", which consists of Islamic armed rebels. They have abducted and confined 59 ship crews over the last 13 months to obtain money for group operations. The activities of these pirates, abducting and killing crews, have became a significant threat for marine security in the Sulu and Celebes Seas and for logistic activities in Asia. This study examines and analyzes 22 recent incidents in terms of ships gross tonnage, kind, nationality, incident time, location, etc. The identity of the Abu Sayyaf Group, which has been committing this piracy and represents the de facto power behind the actors responsible, is also unpacked, along with current challenges to resolving these conflicts. Finally, responses passing ships, shipping companies, related countries and the international community should make are proposed.

• Journal of radiological science and technology
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• v.44 no.6
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• pp.599-605
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• 2021

The International Electrotechnical Commission (IEC) 62494-1 has defined the exposure index (EI) that have a proportional relationship with the dose incident on the image receptor, and target exposure index (EI_T), deviation index (DI). In this study, an appropriate EI_T for skull radiography was established through the diagnostic reference level (DRL) and changes in DI were confirmed. Entrance surface dose (ESD) and EI were obtained using the computed radiography system displayed the EI as per IEC on console and skull phantom by experiment based on the national average exposure conditions announced in 2012 and 2019. And appropriate EI_T was established by applying the DRL in 2012 and 2019. As a results, the EI_T is changed according to the change in the DRL, and the exposure condition that becomes the ideal DI according to the change in the EI_T also has a difference of about 1.41 times. DRL is recommended to optimize the patient dose, however it is difficult to measure in real time at medical institutions whereas EI and DI are displayed on the console at the same time as exposure. When the EI_T is set based on the DRL and the DI is closed to an ideal value, it is useful as a patient dose management tool. Therefore, when the EI_T is periodically managed along with the revision of the DRLs, the patient dose can be optimized through the EI, EI_T and DI.

• Journal of the Korea Institute of Building Construction
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• v.22 no.3
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• pp.259-268
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• 2022

Electric shutters for buildings are being developed in Korea and abroad on a regular basis and can be used in different types of buildings such as company buildings and fire stations, etc. However, the fall risk factors induced by a variety of functions of building electric shutters require safety control. We reviewed the technological trends and legal standards in Korea and abroad, analyzed incident cases, and identified fall risk factors requiring control. We inspected all the building electric shutters in Korea based on the fall risk factors. As a result, we identified 91 noncompliance cases, in 69 percent of all 132 locations. In this study, backed by the inspection results, we suggest a check list to prevent the fall of building electric shutters to ensure safety and conduct verification using a focus group interview.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.466-468
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• 2012

선박산업에서의 국내외 해양사고 통계에 의하면, 모든 해양사고의 80% 정도가 직접적 또는 간접적으로 관련된 인적요인(Human Factors)에 의하여 발생한다고 보고되고 있다. 이러한 해양사고의 원인을 규명함으로써 유사 해양사고의 발생을 방지하고, 또한, 해양사고 조사에 있어서 공통적인 접근방법의 이용과 국가 간의 협력을 증진시키기 위한 목적으로, IMO(International Maritime Organization)에서는 해양사고 인적요인 조사지침(Guidelines for the Investigation of Human Factors in Marine Casualties and Incidents)을 포함한 해양사고조사코드(Casualty Investigation Code: Code of the International Standards and Recommended Practices for a Safety Investigation into a Marine Casualty or Marine Incident)를 채택하였으며, 동 코드는 2010년 1월 1일 발효되었다. 이에 따라, 해양안전심판원에서는, 3단계 절차로 구성된 인적요인 조사 및 분석 방법론을 제안하고, "해양사고 인적요인 분석 매뉴얼"을 마련하였다. 본 논문에서는, 해양안전심판원에서 제안한 인적요인 조사 및 분석 방법론을 실제 해양사고에 적용하여 인적요인 조사분석 모델의 적용사례를 마련하고, 분석 모델을 검토 및 보완하고자 한다.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.3
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• pp.41-48
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• 2014

This paper provides the design of system software for the management of radiation dose that is generated by using computerized tomography(CT). Recently, the radiation leakage incident of Japanese nuclear power plant was in the news internationally and there is a growing interest not only in nuclear power plant but in medical radiation exposure. In spite of the fact that currently safety management of radiation is under control only the workers of the radiation involved, now the exposure management of patients have been required. As surgery and inspections using the radiation have increased, this medical radiation exposure is increasing too. But it is a real situation that medical institutions don't know the level of radiation exposure applied to the patient. Therefore, a system for managing the radiation exposure of a patient from the medical institution is required. This paper proposes a design of a software program that manages the radiation exposure of CT which is a typical imaging tool to use the radiation in the medical institution. By check the amount of radiation dose and set the limit of dose, we would be of help to optimize the medical exposure of the patient.