• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.2
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• pp.116-122
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• 2002

Electro Explosive Devices can be susceptible to electromagnetic interference. When these components are exposed to external electromagnetic fields, it may cause to induce sufficient current to generate enough heat for an inadvertent detonation. It is almost impossible to monitor the event of firing throughout the electromagnetic environment test. The survivability of EED for hazards of electromagnetic radiation is investigated. A fiber optic sensor is installed near the bridge wire after removing explosive material in order to measure the induced current on the bridge wire. The length of lead-wire of the EED fabricated is around 15 cm.

• Radiation Oncology Journal
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• v.31 no.2
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• pp.88-96
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• 2013

Purpose: This study identifies accident sequences from the past accidents in order to help the risk analysis application to the external radiotherapy. Materials and Methods: This study reviews 59 accidental cases in two retrospective safety analyses that have collected the incidents in the external radiotherapy extensively. Two accident analysis reports that accumulated past incidents are investigated to identify accident sequences including initiating events, failure of safety measures, and consequences. This study classifies the accidents by the treatments stages and sources of errors for initiating events, types of failures in the safety measures, and types of undesirable consequences and the number of affected patients. Then, the accident sequences are grouped into several categories on the basis of similarity of progression. As a result, these cases can be categorized into 14 groups of accident sequence. Results: The result indicates that risk analysis needs to pay attention to not only the planning stage, but also the calibration stage that is committed prior to the main treatment process. It also shows that human error is the largest contributor to initiating events as well as to the failure of safety measures. This study also illustrates an event tree analysis for an accident sequence initiated in the calibration. Conclusion: This study is expected to provide sights into the accident sequences for the prospective risk analysis through the review of experiences.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2606-2613
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• 2022

Spent resin often exceeds radiation limits for safe disposal, creating a need for commercial-scale treatment techniques to reduce resin radioactivity. In this study, the radiological safety of a commercialized spent resin treatment device with a treatment capacity of 1 ton/day was evaluated. The results confirm that the device is radiologically safe in the event of an accident. This device desorbs ¹⁴C from the spent resin, allowing disposal as low-level waste instead of intermediate-level waste. The device also reduces overall waste by recycling the extracted ¹⁴C. Potential accident scenarios were explored to enable dose assessments for both internal and external exposure while preventing further spillage of the device and processing the spilled resin. The scenarios involved the development of a surface fracture on the resin mixture separator and microwave systems, which were operated under pressure and temperature of 0-6 bar and 0-150 ℃, respectively. In the case of accidents with separator and microwave device, the maximum allowable working time of worker were derived, respectively, considering external and internal exposures. When wearing the respirator corresponding to APF 50, in the case of the microwave device accident scenario, the radiological safety was confirmed when the maximum worker worked within 132.1 h.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.24 no.2
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• pp.71-77
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• 2013

Psychological resilience in children preventing them from being overwhelmed by traumatic events and nurture their healthy development is universal and powerful. Movies about fairy tales provide children with the notion of the existence of the power and various manifestations. Even though the traumatic event affects the development of the child, with a good supporting system and by providing healthy internal and external factors to reconstruct the event, the traumatized child may accept the event objectively, develop the healthier part of the ego, and even sublimate the traumatic events. As the children participate in movies or plays, several protectors can be devised. The child prepares the role under a "promise" of virtual reality, performs the role recognizing that the traumatic event is not real, and returns to real life as the role or play ends. When these protectors are provided, it is considered that resilience can function properly and the role does not have a negative influence on the development of a child.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.27-33
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• 2017

This study is intended to identify issues on the basis of investigating the actual state of laboratory environment and outlet circuit, and derive end states by expressing sequences from the initiating event of disaster to accident in leakage current, poor contact and overload through ETA(event tree analysis). To this end, this study investigated the actual state of electric equipment of laboratory at universities in all parts of country. And it is shown that most of them are failure in electric work and user negligence in the investigation of actual state. It is found that there is earth fault and defect in wire diameter in the failure of electric work and the problem of partial disconnection due to wire bundling and poor contact in user negligence. Outlet-related component, failure rate and initiating events are composed of a total of 41 initiating events, i.e., 30 internal initiating events and 11 external initiating events. And end states are composed of a total of 15 parts, i.e., 3 electric power parts and 12 safety parts. Earthing class 3 is the most important safety device against leakage current (initiating event). And in case of poor contact, it is necessary for manager to check thoroughly because there is no safety device. In case of overload/overcurrent, when high-capacity equipment is connected, a molded case circuit breaker, safety device, worked. However, in most cases, it is verified that this doesn't work. This study can be utilized as electric equipment safety guide for laboratory safety manager and managers.

• Journal of Radiation Protection and Research
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• v.45 no.2
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• pp.53-68
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• 2020

Background: International organizations such as the World Health Organization (WHO) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reported public exposure doses due to radionuclides released in the Fukushima nuclear accident a few years after the event. However, the reported doses were generally overestimated due to conservative assumptions such as a longer stay in deliberate areas designated for evacuation than the actual stay. After these reports had been published, more realistic dose values were reported by Japanese scientists. Materials and Methods: The present paper reviews those reports, including the most recently published articles; and summarizes estimated effective doses (external and internal) and issues related to their estimation. Results and Discussion: External dose estimation can be categorized as taking two approaches-estimation from ambient dose rate and peoples' behavior patterns-and measurements using personal dosimeters. The former approach was useful for estimating external doses in an early stage after the accident. The first 4-month doses were less than 2 mSv for most (94%) study subjects. Later on, individual doses came to be monitored by personal dosimeter measurements. On the basis of these measurements, the estimated median annual external dose was reported to be < 1 mSv in 2011 for 22 municipalities of Fukushima Prefecture. Internal dose estimation also can be categorized as taking two approaches: estimation from whole-body counting and estimation from monitoring of environmental samples such as radioactivity concentrations in food and drinking water. According to results by the former approach, committed effective dose due to ¹³⁴Cs and ¹³⁷Cs could be less than 0.1 mSv for most residents including those from evacuated areas. Conclusion: Realistic doses estimated by Japanese scientists indicated that the doses reported by WHO and UNSCEAR were generally overestimated. Average values for the first-year effective doses for residents in two affected areas (Namie Town and Iitate Village) were not likely to reach 10 mSv, the lower end of the doses estimated by WHO.

• Cross-Cultural Studies
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• v.50
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• pp.313-346
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• 2018

It is noted that generally speaking, the expressing of actualization or non-actualization of events is not the main role of possibility for the utilization of expressions. In spite of this fact, it is possible to see many examples in which possibility expressions represent actual events, and impossibility expressions represent a type of non-actualization in relation to events. This effect can be described as a semantic extension, by which the participant-internal possibility is extended to actualization due to participant-internal factors, and the participant-external possibility is extended to the actualization due to participant-external factors. When the related possibility expressions are used in this extended sense, they express the dynamic evaluative meaning of 'desirability' of the realized event, while it is determined that when the impossibility expressions are used in this extended sense, they are seen to express the evaluative meaning of 'regretfulness' about the non-actualization of the event. In Modern Japanese, it is noted that there are a few expressions of ability and possibility. They can be largely divided into four types of expressions, according to their origins or uses of expression, which are 'ability verbs', affixes '-れる/られる(-reru/rareru)', '-できる(-dekiru)', and '-得る(-eru)'. They can all express participant-internal possibility and participant-external non-deontic possibility. While 'ability verbs', affixes '-れる/られる' and '-できる' can express participant-external deontic possibility, '-得る' cannot. However, '-得る' is the only possible element to designate the event of a epistemic possibility. Also, the four types of expressions have the usage of conveying 'actualization/non-actualization,' as is the case of the Korean language. However in Japanese, in fact adjectives cannot be associated with 'ability verbs' or 'ability affixes.' Thus the expressions of 'regrets' should in that case depend on the use contexts, unlike the expression 'adj+-지 못하다' as noted in Korean. The ability and possibility in Modern Chinese are mainly expressed by means of the four auxiliary verbs '能($n{\acute{e}}ng$)', '会(huì)', '可以(kěyǐ)' and '可能 ($k{\check{e}}n{\acute{e}}ng$)'. '能' and '会' along with '可以' can all convey participant-internal possibility. In this way '能' and '可以' can express participant-external possibility. Only '会' and '可能' can express epistemic possibility. As for 'actualization,' among the four auxiliary verbs, only '能' can represent actualization. Also, among the negatives of the four auxiliary verbs, only '沒能' can represent non-actualization.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.2
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• pp.87-98
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• 2015

Safety assessments of geological radioactive waste disposal systems, need to consider the abnormal scenario in which a system is impacted by external events in addition to a reference scenario. In this study, the characterization and prediction of an earthquake as an external event which will impact disposal systems were conducted probabilistically and statistically for the safety assessment. The domestic earthquake data were analyzed, and the prediction methodologies of the earthquake were suggested with a computational example. From the results, the earthquake occurrence rates in Korea ranged from 0.4 /yr to 36.2 /yr depending on the data set and the completeness magnitude. From a conservative point of view, the earthquake occurrence rate in the disposal system was suggested as 5.4×10^-4 /yr considering the area of the disposal system. At that time, the completeness magnitude of an earthquake was 2.3. This study will be followed by an appraisal of impacts associated with external events on the geological disposal system, and it will contribute to improvements in reliability of the safety assessment.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.89-96
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• 2020

Solar lamp systems may not operate normally in the event of some system or controller failure due to internal or external factors, in which case secondary problems occur, which may cost the system recovery. Thus, when these errors occur, a technology is needed to recover to the state it was in before the failure occurred and to enable re-execution. This paper designs and implements a system that can recover the state of the system to the state prior to the time of the error by using the Watchdog Timer within the controller if a software error has occurred inside the system, and it also proposes a technology to reset and re-execution the system through a separate reset circuit in the event of hardware failure. The proposed system provides stable operation, maintenance cost reduction and reliability of the solar lamp system by enabling the system to operate semi-permanently without external support by utilizing the automatic recovery and automatic reset function for errors that occur in the operation of the solar lamp system. In addition, it can be applied to maintain the system's constancy by utilizing the self-operation, diagnosis and recovery functions required in various high reliability applications.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.4
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• pp.303-308
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• 2011

Vehicle black boxes that have similar functions as airplane black boxes are currently being used due to the loss of many lives and properties arising from vehicle accidents. Both black-box products and Event Data Recorder(EDR) systems are currently available in the market. Most of the existing in-vehicle black boxes, however, record only external videos and images and cannot show the vehicle's driving status, whereas EDR products record only the driving status and not external videos. To address the problem of black boxes that can record only videos and images and that of EDR systems that can record only driving data, an integrated vehicle state and video recording system that uses MOST(Media-oriented System Transport) and OBD-II(Onboard Diagnostics II) and CAM (camera) and GPS (global positioning system).