• Journal of Environmental Health Sciences
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• v.43 no.3
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• pp.223-232
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• 2017

Objectives: In response to increased interest in the safety of children's products, a risk management system is being prepared through exposure assessment of hazardous chemicals. To estimate exposure levels, risk assessors are using deterministic and probabilistic approaches to statistical methodology and a commercialized Monte Carlo simulation based on tools (MCTool) to efficiently support calculation of the probability density functions. This study was conducted to analyze and discuss the usage patterns and problems associated with the results of these two approaches and MCTools used in the case of probabilistic approaches by reviewing research reports related to exposure assessment for children's products. Methods: We collected six research reports on exposure and risk assessment of children's products and summarized the deterministic results and corresponding underlying distributions for exposure dose and concentration results estimated through deterministic and probabilistic approaches. We focused on mechanisms and differences in the MCTools used for decision making with probabilistic distributions to validate the simulation adequacy in detail. Results: The estimation results of exposure dose and concentration from the deterministic approaches were 0.19-3.98 times higher than the results from the probabilistic approach. For the probabilistic approach, the use of lognormal, Student's T, and Weibull distributions had the highest frequency as underlying distributions of the input parameters. However, we could not examine the reasons for the selection of each distribution because of the absence of test-statistics. In addition, there were some cases estimating the discrete probability distribution model as the underlying distribution for continuous variables, such as weight. To find the cause of abnormal simulations, we applied two MCTools used for all reports and described the improper usage routes of MCTools. Conclusions: For transparent and realistic exposure assessment, it is necessary to 1) establish standardized guidelines for the proper use of the two statistical approaches, including notes by MCTool and 2) consider the development of a new software tool with proper configurations and features specialized for risk assessment. Such guidelines and software will make exposure assessment more user-friendly, consistent, and rapid in the future.

• Journal of the Korean earth science society
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• v.32 no.6
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• pp.602-612
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• 2011

Jeju Island, a volcanic island located in South Korea, has been one of the main targets of geophysical and/or geological studies because of its tectonic importance related to the volcanism and tectonic link to the southern part of the Korean Peninsula. Recently, as a number of broad-band magnetotelluric (MT) measurements were made, we have examined the deep part of the island. In such an insular setting, it is not easy to properly recover the deep structures such as the lower crust and the upper crust using MT data, because their low-frequency components are strongly affected by the surrounding sea of the island. In this study, we apply the sea-effect correction to the existing MT data collected at a total of 102 sites in Jeju Island. The sea-effect correction makes remarkable changes in the observed MT data at frequencies below 1 Hz, clearly indicating the existence of a conductive lower crust. The 2-D inversion results for both Jeju Southern Line (JSL) and Jeju Northern Line (JNL) show that the transition zone separating the resistive upper crust and conductive lower crust exists at a depth of 20 km on average.

• Journal of electromagnetic engineering and science
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• v.15 no.3
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• pp.142-150
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• 2015

Several reports supported that continuous exposure to 60 Hz magnetic field (MF) induces testicular germ cell apoptosis in vivo. We recently evaluated duration- and dose-dependent effects of continuous exposure to a 60 Hz MF on the testes in mice. BALB/c male mice were exposed to a 60 Hz MF at $100{\mu}T$ for 24 hours a day for 2, 4, 6, or 8 weeks, and at 2, 20 or $200{\mu}T$ for 24 hours a day for 8 weeks. To induce the apoptosis of testicular germ cell in mice, the minimum dose is $20{\mu}T$ at continuous exposure to a 60 Hz MF for 8 weeks, and the minimum duration is 6 weeks at continuous exposure of $100{\mu}T$. Continuous exposure to a 60 Hz MF might affect duration- and dose-dependent biological processes including apoptotic cell death and spermatogenesis in the male reproductive system of mice. The safety guideline of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) indicates that the permissible maximum magnetic flux density for general public exposure is $200{\mu}T$ at 60 Hz EMF (ICNIRP Guidelines, 2010). In the present study, we aimed to examine the expression of pro- and anti-apoptotic genes regulated by the continuous exposure to 60 Hz at $200{\mu}T$ in Sprague-Dawley rats for 20 weeks. The continuous exposure to 60 Hz at $200{\mu}T$ does not affect the body and testicular weight in rats. However, exposure to 60 Hz MF significantly affects testicular germ cell apoptosis and sperm count. Further, the apoptosis-related gene was scrutinized after exposure to 60 Hz at $200{\mu}T$ for 20 weeks. We found that the message level of endonuclease G (EndoG) was greatly increased following the exposure to 60 Hz at $200{\mu}T$ compared with sham control. These data suggested that 60 Hz magnetic field induced testicular germ cell apoptosis through mitochondrial protein Endo G.

• Journal of Navigation and Port Research
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• v.44 no.4
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• pp.298-304
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• 2020

The purpose of this study was to identify evaluation factors and analyze the relative importance among factors to select a suitable transportation method for transferring the increasing amount of transshipment at multiple terminals at the Busan new port. To accomplish this, the evaluation factors were selected through a literature survey and brainstorming of a group of experts associated with the port operation, and were classified into five major factors and 15 middle factors. The evaluation factors classified hierarchically were surveyed relative to workers in organizations such as shipping companies, port corporations, container terminals, and related ministries. The importance of each factor was calculated using the hierarchical analysis process (AHP). As a result of the importance analysis, priority was assigned in order of safety, productivity, investment efficiency, operational efficiency, and policy conformity. Through this, it was necessary to select a suitable transportation method for the transshipment cargo in terminals while focusing on the cargo and terminal security and preventing accidents. As a result of calculating from six ITT transportation candidates, the priority was determined in order of monorail, Autocon, and so on as ITT transportation suitable for the Busan new port..

• Journal of The Korean Dental Society of Anesthesiology
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• v.12 no.2
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• pp.93-97
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• 2012

Background: Some disabled patients show insufficient cooperation during dental treatment, and general anesthesia in an outpatient setting can be successfully administered. To minimize post-anesthetic complications is an essential issue, and strict discharge protocols are required for the safety of the patients. Post-anesthetic follow-ups using telephone calls can be applied to improve the quality of the outpatient care system. The authors evaluated the post-operative condition of patients after dental treatment under general anesthesia. Methods: Total 143 patients and their caregivers included in this study. The patients received general anesthesia for dental treatment in Seoul National University Dental Hospital, Clinic for Persons with Disabilities from July, 2011 to April, 2012. Telephone calls were given to the patients or their caregivers to collect information about the patients' systemic condition and anesthesia-related complications. Results: Among 131 patients with responses of telephone calls, 87 patients (66.4%) reported no discomfort, while 44 patients (33.6%) presented post-anesthetic complications. A total of 20 patients reported mild fever, 10 patients had vomiting, and 7 patients had sore throat. Other complications included nausea, fatigue, nasal bleeding, skin sore, and body rash. Among the patients with the history of epilepsy, 63.6% showed post-anesthetic discomfort or complication (P = 0.027, ${\chi}^2$ test). Conclusions: One third of dental patients who received general anesthesia due to insufficientcooperation complained discomfort after discharged from outpatient anesthetic care.

• The Journal of the Korea Contents Association
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• v.10 no.2
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• pp.421-432
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• 2010

In Korea, about 80 academic departments related to fire science are in operation throughout the country, but fire science is not included as a branch science in the science classification system acknowledged by the Ministry of Education, Science and Technology and its position as a science is not solid yet. In response to this problem, research is being made actively to establish fire science recently. This study aims at composing the fire service policy theory which is one of sub areas of fire science. First, the concept of fire service policy should be established, and fire service policies should be divided into different types. In addition, it is necessary to examine the direction of the development of fire service policies in Korea, and the unique characteristics of fire service policies should be described. Next, we will mention fire service policy making and participants, theories on the determinants of fire service policies, the execution of fire service policies, and the evaluation of fire service policies. Particularly, based on the peculiarity of fire service, it is necessary to explain policies on fire prevention and precaution, fire investigation, rescue and first aid, public campaigns for safety and prevention, fire insurance, etc. Finally, we suggest the future directions of fire service policies according to the change of environment in the future.

• Progress in Medical Physics
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• v.27 no.3
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• pp.139-145
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• 2016

With the development in field of industry and medicine, new machines and techniques are being launched. Moreover, the complexity of the techniques is associated to an increasing risk of incident. Especially, a small error in radiotherapy can lead to a serious patient-related incident, risk management is necessary in radiotherapy in order to reduce the risk of incident. However, in field of radiotherapy, there are no legally binding clauses for risk management and there is an absence of risk management systems at an institutional level. Therefore, we analyzed institutional status of risk management, reporting & classification systems, and risk assessment & analysis in 31 countries. For risk management and reporting systems, 65% of countries investigated had legislation or regulations; however, only 35% of countries used classification systems. It was found that 43% more countries had legislation for risk management in healthcare than those for radiotherapy; 19% more countries had reporting systems for healthcare than those for radiotherapy. For classification systems, 60% more countries had legislation, recommendation, and guidelines in the field of radiotherapy than those for healthcare. Recently, international institutes have published several reports for risk management and patient safety in radiotherapy, owing to which, countries adopting risk management for radiotherapy will gradually increase. Before adopting risk management in Korea, we should precisely understand the procedures and functions of risk management, in order to increase efficiency of risk management because classification & reporting system and risk assessment & analysis are connected organically, and institutional management is needed for high quality of risk management in Korea.

• Journal of the Society of Disaster Information
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• v.10 no.3
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• pp.420-430
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• 2014

Firefighters performing disaster response activities such as Fire Suppression Rescue First Aid in fire are being exposed in various adverse factors, heat, smoke, toxic gases, emotional stress, biological toxic factors and physical overload by unnatural ergonomic posture required for firefighters. But so far, there is the study for this problem only separately. There is no study about comprehesive analysis of exposed adverse factors in fire-related disaster response activities and countermeasures. The purpose of this study is to contiribute to solving the health problems and prevention of accidents of firefighters by extracting hazardous agents in disaster such as fire and by proposing countermeasures. After analyzing circumstances such as fire-suppression, rescue first aid and life-environment, exposure factors of fire are derived and exposure status is suggested according to physical chemical biological psychological aspects. The countermeasure against the noise of the physical exposure factors are proposed. The countermeasures such as protective equipment and clean room in chemical factors, infection prevention education, vaccination and periodic check system in biological factors, PTSD alleviation booth and mentoring in psychological factors are proposed.

• International Journal of Highway Engineering
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• v.14 no.1
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• pp.95-102
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• 2012

This study has been conducted to characterize the relations between the accident rate and the overlap section elements where the horizontal alignment and vertical alignment are overlapped. The researches were performed on Horizontal curve sections of 4-lane highways with 100km/h of design speed and speed limit. Korea Highway Corporation's Geographic Figurative Information System was adopted for geometric organization and Highway Traffic Accident Statistics was used. The results reveal that sections made of a single slope without vertical curve has greater accident rate than those with vertical curve, and that sections with 1 vertical curve are higher in the accident rate than those with over 2 vertical curve. For the sections with 1 vertical curve, SAG sections are higher than CREST sections and for the previous straight section of horizontal curve are higher than curved ones. In particular, when the road surface is wet, the accident rate is closely related with SAG vertical curves or leftward horizontal curved sections. This study will have meanings that it proposes the importance of design of road alignment by taking consideration of 3D synthetic alignment conditions for improvement of the road safety.

• Journal of Korean Society of Transportation
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• v.31 no.3
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• pp.19-32
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• 2013

The study aims to find the characteristics of children's crossing behavior on crosswalk in school zones. It considers accident occurrence and physical form of school zones. Seven elementary school zones were investigated. Using data collected by field observation and video recording, statistical analysis, CHAID algorithm analysis, and pattern analysis were performed. As a result, it was found that children's waiting, attention and distraction were related to the accident occurrence. While 69.1% children showed waiting-before-crossing behavior in low-accident occurrence crosswalk, 83.6% children showed non waiting-before-crossing behavior in high-accident occurrence crosswalk. Moreover, the ratio of waiting, attention behavior was found to be higher when the width of the crosswalk was wide and the distance from the school's entrance to the crosswalk was long. These research findings showed that children's behavior-oriented approach was required to improve safety in school zone.