• Journal of Environmental Health Sciences
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• v.44 no.1
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• pp.44-54
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• 2018

Objectives: To protect individuals working at the site as well as the surrounding general population from a chemical accident, several emergency exposure guidance levels have been used to set a level of concern for certain chemicals. However, a level of concern has not been established for many substances that are frequently used or produced in large quantities in Korean workplaces. In the present study, we investigated the guidance levels for protecting populations from chemical exposure and the estimation of level of concern using acute inhalation and oral toxicity data. Methods: The number of chemicals to which emergency exposure guidance levels (e.g., ERPG-2, AEGL-2, PAC-2, and IDLH) can be applied were determined among 822 hazardous chemicals according to the 'Technical Guidelines for the Selection of Accident Scenarios (revised December 2016)'. The ERPG and AEGL values were compared across all three tiers for the 31 substances that appeared on both lists. We examined the degree of difference between the emergency exposure guidance levels and the estimates of level of concern calculated from acute inhalation or acute oral toxicity data. Results: Among the 822 hazardous chemicals, emergency exposure guidance levels can be applied to 359 substances, suggesting that the estimates of level of concern should be calculated using acute toxicity data for 56.3% of the hazardous chemicals. When comparing the concordance rates of ERPG and AEGL for 31 substances, the difference between the two criteria was generally small. However, about 40% of the substances have values diverging by more than three-fold in at least one tier. Such discrepancies may cause interpretation and communication problems in risk management. The emergency exposure guidance levels were similar to the estimates of level of concern calculated using acute inhalation toxicity data, but the differences were significant when using acute oral toxicity data. These results indicate that the level of concern derived from acute oral toxicity data may be insufficient to protect the population in some cases. Conclusion: Our study suggests that the development of standardized guidance values for emergency chemical exposure in the Korean population should be encouraged. It is also necessary to analyze acute toxicity data and fill the information gaps for substances that are important in Korean workplace situations.

• Journal of the Korean Institute of Rural Architecture
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• v.11 no.2
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• pp.29-36
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• 2009

The recently research shows that the many tourists of Suanbo hot spring waters haven't satisfied the service. These reasons due to that they did not properly consider the satisfaction of tourists' services and index. However, satisfaction level of hot spring waters tourists is interacted complicatedly with various factors, the interactions are not easily identified. A structural equations model is adopted to capture the complex relationships among variables. In the model estimation, we used 140 survey data of Suanbo hot spring waters tourists. The SEM with several factors mentioned above as exogenous variables shows that they have complex and strong relationships. As results of a SEM, it was shown that variables influencing in pleasance are surrounding scenery, clean condition inside hot springs and congestion for use in satisfaction level most. Secondly, in case of kindness, attitudes of employees influence in satisfaction level most, followed by attitudes of residents and kindness of employees. Thirdly, in case of information, it was shown guidance on internal roads influencing in satisfaction level most, followed by guidance on owner drivers, guidance on surrounding tourist attractions and guidance on public transportation. Finally, a variable influencing in accessibility most is satisfaction level of public transportation.

• Nuclear Engineering and Technology
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• v.36 no.1
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• pp.83-103
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• 2004

The methodological framework of the Level 2 PSA appears to be currently standardized in a formalized fashion, but there have been different opinions on the way the sources of uncertainty are characterized and treated. This is primarily because the Level 2 PSA deals with complex phenomenological processes that are deterministic in nature rather than random processes, and there are no probabilistic models characterizing them clearly. As a result, the probabilistic quantification of the Level 2 PSA CET / APET is often subjected to two sources of uncertainty: (a) incomplete modeling of accident pathways or different predictions for the behavior of phenomenological events and (b) expert-to-expert variation in estimating the occurrence probability of phenomenological events. While a clear definition of the two sources of uncertainty involved in the Level 2 PSA makes it possible to treat an uncertainty in a consistent manner, careless application of these different sources of uncertainty may produce different conclusions in the decision-making process. The primary purpose of this paper is to characterize typical sources of uncertainty that would often be addressed in the Level 2 PSA and to provide a formal guidance for quantifying their impacts on the PSA Level 2 risk results. An additional purpose of this paper is to give a formal approach on how to combine random uncertainties addressed in the Level 1 PSA with subjectivistic uncertainties addressed in the Level 2 PSA.

• Journal of Navigation and Port Research
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• v.41 no.5
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• pp.277-286
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• 2017

IMO introduced e-Navigation concept to improve the efficiency of ship operation, port operation, and ship navigation technology. IMO proposed sixteen MSPs (Maritime Service Portfolio) applicable to the ships and onshore in case of e-Navigation implementation. In order to meet the demands of the international society, the system implementation work for the Korean e-Navigation has been specified. The Korean e-Navigation system has five service categories: the S2 service category, which is a ship anomaly monitoring service, is a service that classifies emergency levels according to the degree of abnormal condition when a ship has an abnormality in ship operation, and provides guidance for emergency situations. The navigation safety module is a sub-module of the S2 service that determines the emergency level in case of navigation equipment malfunctioning, engine or steering gear failure during navigation. It provides emergency response guidance based on emergency level to the abnormal ship. If an abnormal condition occurs during the ship operation, first, the ship shall determine the emergency level, according to the degree of abnormality of the ship. Second, an emergency response guidance is generated based on the determined emergency level, and the guidance is transmitted to the ship, which helps the navigators prevent accidents and not to spread. In this study, the operational concept for the implementation of the Korean e-Navigation system is designed and the concept is focused on the navigation safety module of S2 service.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.3
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• pp.119-129
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• 2016

This paper presents an integrated navigation system for accurate navigation solution-based safety and convenience services in the vehicular augmented reality (AR)-head up display (HUD) system. For lane-level guidance service, especially, an accurate navigation system is essential. To achieve this, an inertial navigation system (INS)/global positioning system (GPS)/vision/digital map (IGVM) integrated navigation system has been developing. In this paper, the concept of the integrated navigation system is introduced and is implemented based on a multi-model switching filter and vehicle status decided by using the GPS data and inertial measurement unit (IMU) measurements. The performance of the implemented navigation system is verified experimentally.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.256-257
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• 2018

This paper deals with the path-following control for marine surface vehicles with underactuated characteristics. In consideration of practical limitations of actuators, an improved DVS(dynamic virtual ship) guidance algorithm is proposed with the multi-level DVS optionally selected to be tracked. To address the output-feedback control issue, an adaptive FLS(fuzzy logical systems) is devised to online approximate the kinematic states. Based on that observing framework, the path-following control law is thereafter derived. Simulations testify effectiveness of the proposed scheme

• Journal of Korean Elementary Science Education
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• v.37 no.3
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• pp.254-266
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• 2018

The aim of this study is to analyze STEAM lessons focused on the learner's learning. This study was conducted on 4th-graders in Y city, Kyung-gi province. The lessons were based on a joint teaching plan for students through the teacher learning community (TLC) with three teachers from the same school. Each of the three classes that conducted the class was selected and analyzed as the main center of observation by three students. The conclusions from this study are as follows: First, we identified that different levels of learners are learning in STEAM lessons through a learner-centered class analysis. Some students arrived on their own by taking the initiative in class, others by consulting with a group of friends, and others needed active teacher guidance to learn. Second, Depending on the level and characteristics of the students, some learning criteria were not reached. Some students need guidance at a glance level, and others need individually instructed or guided activities. Teachers need to keep an eye out for students and give them an appropriate level of guidance during class. In STEAM lessons, it appears that students of different levels and characteristics can immerse themselves in their own way, as well as the clear guidance of activity for their students.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.9
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• pp.922-929
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• 2009

This paper deals with the State-Dependent Riccati Equation (SDRE) Technique for the design of helicopter nonlinear waypoint guidance controller. To generate the flight guidance through multiple waypoints, we use the trigonometric spline. The controller design and its validation is based upon a level 2 simulation helicopter model and the designed SDRE controller is applied to the trajectory tracking problems. To validate the designed SDRE controller, the simulation environment of high fidelity helicopter model is developed using three independent computers. This paper focuses on the validation the present SDRE controller through the helicopter waypoint guidance simulation.

• International Journal of Aeronautical and Space Sciences
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• v.10 no.2
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• pp.12-22
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• 2009

This paper deals with the State-Dependent Riccati Equation (SDRE) Technique for the design of rotorcraft waypoint guidance. To generate the flight trajectory through multiple waypoints, we use the trigonometric spline. The controller design and its validation is based upon a level 2 simulation rotorcraft model and the designed SDRE controller is applied to the trajectory tracking problems. To verify the designed guidance law, the simulation environment of high fidelity rotorcraft model is developed using three independent PCs. This paper focuses on the validation of rotorcraft waypoint guidance law which is designed by using SDRE Controller.

• Korean Medical Education Review
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• v.26 no.1
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• pp.5-18
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• 2024

The author recommends the creation of a nationwide career guidance program at the national level through the establishment of a long-term cohort, involving collaboration among medical schools nationwide. This cohort would be constructed for the purpose of analyzing correlations from admission to medical school to post-graduate education, facilitating the development of a career guidance program. This will aid in career development through students' self-analysis and competency building. Each medical school should operate a systematic career guidance program. Career guidance for post-graduate major selection should be included in the regular curriculum. Schools are advised to operate student counseling rooms for various career guidance services. For example, medical schools can operate 1:1 career counseling, academic counseling, career guidance surveys, psychological tests, and counseling. It is advisable to establish a mentor-professor system, connect mentor professors, and build a network of experts related to majors to provide immediate support according to students' needs. Professional mentor training should be provided to mentor professors. To provide opportunities for students to experience their career paths in advance, early clinical exposure, long-term integrated clinical practice, community-based clinical practice, participation in student research programs, career fairs, and student internship programs are recommended. In South Korea, it is necessary to systematically operate the internship system and make improvements to facilitate optical career choices. Additionally, considering the significant influence of social factors on students' career choices in South Korea, efforts should be made to identify and address the issues related to these social factors.