• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.4
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• pp.385-392
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• 2009

Maritime safety management needs active public participations because the sea is too wide for a government to respond to all unexpected accidents with limited resources. Marine rescue volunteer organizations of US, UK, Japan and Korea were compared one another on the base of disaster management governance theory, and recommendations for the development of marine rescue volunteer organization of Korea were proposed. The advanced organizations commonly have tradition of marine rescue voluntaryism in the advanced maritime countries. They have nation-wide networks and self-governing structures. Their main activities include public maritime safety education and fundraising programs as well as marine rescue operations. They have cooperative relationships with government agencies in charge of national maritime safety management, which are usually guaranteed by legislations or institutional systems. Donations from the public are major source of their finances. Members mainly consist of civil volunteers, and get basic compensations for their expenses. For the advancement of marine rescue volunteer organization of Korea, efforts are needed to strengthen the membership of civil rescue fleet, to activate public education and fundraising programs, and to amend the related law for institutional support.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.969-975
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• 2015

In this paper, we review the regulations relating to railway safety and station workers interviewed, eight urban rail accidents decreased operating agencies through the prevention research currently being conducted into the (Seoul Metropolitan Rapid Transit Corporation City, Seoul Metro, Incheon traffic mortality, etc.) the root cause for the lack of aggressive prevention measures performed on the difficulties related regulations, organizational culture and work environment, prevention of negative operating authority derived in three improvements were obtained through this direction. First proposed urban railway safety ever buy Conduct production, utilization and operating agencies college safety assistant suggests directions for safety training, organizational culture and work environment improvements in senior management. Finally, active accident prevention campaigns, and provide direction to increase the educational participation of guests. Improvement for such accidents would decrease is thought to play a role in the prevention of future operating agency established when the guidelines.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.61-73
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• 2020

Real-time location-sensing technology using location information collected from IoT devices is being applied for safety management purposes in many industries, such as ports. On the other hand, positional error is always present owing to the characteristics of GPS. Therefore, accident-risk detection algorithms must consider positional error. This paper proposes an methodology of calibration for falling object accident-risk-zone approach detection algorithm considering GPS errors. A probability density function was estimated, with positional error data collected from IoT devices as a probability variable. As a result of the verification, the algorithm showed a detection accuracy of 93% and 77%. Overall, the analysis results derived according to the GPS error level will be an important criterion for upgrading algorithms and real-time risk managements in the future.

• Journal of Advanced Navigation Technology
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• v.26 no.3
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• pp.125-135
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• 2022

UAM is emerging as the biggest issue in the aviation industry and which is attracting a lot of attention not only domestically but also internationally. In Korea, active research is being conducted centered on the government and industry-university research institutes, such as the establishment of a future K-UAM concept of operation. Therefore, in this study applies the SORA (Specific Operation Risk Assessment) model established by the European JARUS (Joint Authorities for Rulemaking on Unmanned Systems) to apply the K-UAM operation environment and specific corridor for the purpose of cargo transportation that will be operated in the future that the government is promoting. We intend to suggest policy and technical measures for risk mitigation in the initial operating environment by evaluating the level of risk and analyzing the results.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.749-765
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• 2010

There are on-going efforts to utilize guided waves for structural damage detection. Active sensing devices such as lead zirconate titanate (PZT) have been widely used for guided wave generation and sensing. In addition, there has been increasing interest in adopting wireless sensing to structural health monitoring (SHM) applications. One of major challenges in wireless SHM is to secure power necessary to operate the wireless sensors. However, because active sensing devices demand relatively high electric power compared to conventional passive sensors such as accelerometers and strain gauges, existing battery technologies may not be suitable for long-term operation of the active sensing devices. To tackle this problem, a new wireless power transmission paradigm has been developed in this study. The proposed technique wirelessly transmits power necessary for PZT-based guided wave generation using laser and optoelectronic devices. First, a desired waveform is generated and the intensity of the laser source is modulated accordingly using an electro-optic modulator (EOM). Next, the modulated laser is wirelessly transmitted to a photodiode connected to a PZT. Then, the photodiode converts the transmitted light into an electric signal and excites the PZT to generate guided waves on the structure where the PZT is attached to. Finally, the corresponding response from the sensing PZT is measured. The feasibility of the proposed method for wireless guided wave generation has been experimentally demonstrated.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.8
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• pp.718-724
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• 2013

In today's automotive industry, there exist several systems that help drivers reduce the possibility of accidents, such as the ADAS (Advanced Driver Assistance System). The ADAS helps drivers make correct and quick decisions during dangerous situations. This study analyzed the performance of the IMM (Interacting Multiple Model) method based on multiple Kalman filters using the data acquired from a driving simulator. An IMM algorithm is developed to identify the current discrete state of neighboring vehicles using the sensor data and the vehicle dynamics. In particular, the driving modes of the neighboring vehicles are classified by the cruising and maneuvering modes, and the transition between the states is modeled using a Markovian switching coefficient. The performance of the IMM algorithm is analyzed through realistic simulations where a target vehicle executes sudden lane change or acceleration maneuver.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2003.11a
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• pp.359-368
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• 2003

In the early stage of 21th century, international nuclear society was on the active look out for new direction, and had a common recognition on the necessity of innovative reactor system. To achieve this purpose effectively, several international projects have been initiated for development of new nuclear energy systems that secure stable energy supply and have improved public acceptance, safety, and cost-effectiveness. In this study, status of international projects on future innovative nuclear energy systems and technology goals of future nuclear energy systems were surveyed, and the technological features of Generation IV nuclear energy system were described.

• Journal of the Korean Solar Energy Society
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• v.26 no.4
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• pp.17-23
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• 2006

This paper proposes a novel active frequency drift (AFD) method for the islanding prevention of grid-connected photovoltaic inverter. To detect the islanding phenomenon of grid-connected photovoltaic (PV) inverters concerning about the safety hazards and the damage to other electric equipments, many kinds of anti-islanding methods have been presented. Among them, AFD method using chopping fraction enables the islanding detection to drift up (or down) the frequency of the voltage during the islanding situation. In this paper, injecting the periodic zero current into the basic AFD method is proposed. This proposed method shows the analytical design value of cf to meet the test procedure of IEEE Std. 1547 with various load conditions. Detection of islanding is verified using simulation tool PSIM.

• Journal of Power Electronics
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• v.19 no.6
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• pp.1467-1476
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• 2019

Grid unbalanced faults can cause core saturation of power transformer and produce lower-order harmonics. These issues increase the electrical stress of power electronic devices and can cause a tripping of an entire HVDC system. In this paper, based on the positive-sequence and negative-sequence impedance model of a VSC-HVDC system as seen from the point of common connection (PCC), the resonance problem is analyzed and the factors determining the resonant frequency are obtained. Furthermore, to suppress over-voltage and over-current during resonance, a novel method using a virtual harmonic resistor is proposed. The virtual harmonic resistor emulates the role of a resistor connected in series with the commutating inductor without influencing the active and reactive power control. Simulation results in PSCAD/EMTDC show that the proposed control strategy can suppress resonant over-voltage and over-current. In addition, it can be seen that the proposed strategy improves the safety of the VSC-HVDC system under unbalanced faults.

• The Korean Journal of Emergency Medical Services
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• v.25 no.1
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• pp.135-146
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• 2021

Purpose: This study aimed to evaluate the Citizen-Corps-Active-In-Disaster (CAIND) according to a new viewpoint based on changes in basic theoretical concepts and establish a development plan. Methods: A documentary survey was administered, and the study followed the technical approach method. Detailed information on CAIND was taken from scholarly monographs, specialty publications, and previous studies, including master and doctorate dissertations. Results: CAIND may be defined as legal auxiliary organizations composed of local residents who volunteer to prepare for "all kinds of disasters as well as prevention activities" and instill the ideology of "leading service organizations of safety as a form of community involvement," "resident-friendly organizational activities based on autonomous operation," and "performing activities which supplement their demands according to the realization of social welfare and regional conditions." Conclusion: The newly established basic theoretical concept included the concepts of "professionalism and possibilities," "social expandability," "voluntary participation," and "the realization and complementation of social welfare"