• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1953-1958
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• 2012

The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with such electric faults, specially short circuit faults. Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB), that is, Residual Current Protective Devices (RCDs) used on low voltage distribution lines cut off earth leakage and overload, but the RCD can not cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied in low voltage distribution panel are prescribed to rated breaking time about 30ms(KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To improve such problem, this paper proposes a prevention apparatus using the line voltage drop of neutral wire and some semiconductor switching devices. Some experimental tests of the proposed apparatus confirm the validity of the analytical results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.876-880
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• 2013

The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The principal factor of the fire is electric arc or spark accompanied with such electric faults. Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB), that is, Residual Current Protective Devices (RCDs) used on low voltage distribution lines cut off earth leakage and overload, but the RCD can not cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied in low voltage distribution panel are prescribed to rated breaking time about 30[ms] (KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To improve such problems, this paper studies on an arc fault circuit interrupter (AFCI) using the distorted voltage wave in electric arc faults. The proposed voltage sensing type AFCI is an electrical fire prevention apparatus of new conception that operates a circuit breaker with sensing the instantaneous voltage drop of line voltage at electrical faults occurrence. The proposed AFCI is composed of control circuit topology using some semiconductor switching devices. Some experimental tests of the proposed AFCI confirm practicality and the validity of the analytical results.

• ETRI Journal
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• v.37 no.3
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• pp.541-550
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• 2015

In this paper, we propose a classification-based approach for hybridizing statistical machine translation and rulebased machine translation. Both the training dataset used in the learning of our proposed classifier and our feature extraction method affect the hybridization quality. To create one such training dataset, a previous approach used auto-evaluation metrics to determine from a set of component machine translation (MT) systems which gave the more accurate translation (by a comparative method). Once this had been determined, the most accurate translation was then labelled in such a way so as to indicate the MT system from which it came. In this previous approach, when the metric evaluation scores were low, there existed a high level of uncertainty as to which of the component MT systems was actually producing the better translation. To relax such uncertainty or error in classification, we propose an alternative approach to such labeling; that is, a cut-off method. In our experiments, using the aforementioned cut-off method in our proposed classifier, we managed to achieve a translation accuracy of 81.5% - a 5.0% improvement over existing methods.

• Journal of the Korean Society of Safety
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• v.36 no.3
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• pp.66-73
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• 2021

This report documents the results of an at-power internal events Level 1 Probabilistic Safety Assessment (PSA) for a Korea research reactor (KRR). The aim of the study is to determine the accident sequences, construct an internal level 1 PSA model, and estimate the core damage frequency (CDF). The accident quantification is performed using the AIMS-PSA software version 1.2c along with a fault tree reliability evaluation expert (FTREX) quantification engine. The KRR PSA model is quantified using a cut-off value of 1.0E-15/yr to eliminate the non-effective minimal cut sets (MCSs). The final result indicates a point estimate of 4.55E-06/yr for the overall CDF attributable to internal initiating events in the core damage state for the KRR. Loss of Electric Power (LOEP) is the predominant contributor to the total CDF via a single initiating event (3.68E-6/yr), providing 80.9% of the CDF. The second largest contributor is the beam tube loss of coolant accident (LOCA), which accounts for 9.9% (4.49E-07/yr) of the CDF.

• YAKHAK HOEJI
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• v.58 no.2
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• pp.112-124
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• 2014

This study aimed to develop a regulation system for off-label drug use to secure the safe use of marketed drugs. We searched governmental documents for national and global regulating systems of off-label drug uses and a body of academic literature to explore current regulating trends. We included European Union, United Kingdom, United States of America, Australia and Japan, and critically reviewed the regulation of off-label drug use in four issues, which were a regulatory structure, safety control before and after off-label use, and information management. The findings of the present investigation called for several measures in off-label drug uses: enhancing prescribers' self-regulation, providing up-to-date information to prescribers for evidence-based practice and to patients for their informed consent, making evidence with scientific rigor, building an official registering process for off-label use in good quality and extending the role of pharmaceutical industry in pharmacovigilance. At last, we proposed a new system so as to regulate and evaluate off-label drug uses both at national and institutional level. In the new system, we suggested a clear-cut definition for clinical evidence that applicants would submit. We newly introduced an official 'Off-Label Drug Use Report' to evaluate the safety and clinical efficacy of a given off-label drug use. In addition, we developed an algorism of the regulation of off-label drug use within an institution to help set up the culture of evidence-based practices in off-label drug uses.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.2
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• pp.125-131
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• 1994

This paper describes a method to measure the distortion level of loudspeaker using a LMS(Least Mean Square) adaptive filter. Conventional technique to measure the distortion level uses a band-pass filter with a sharp cut-off frequency characteristics. However. such the band-pass filter has a bed time response characteristics. On the other hand, the proposed method offers us an easy way to measure the specified harmonic distortion level with a small hardware. Moreover, our method is not affected by noise which has no correlation with the test signal, and the measurement can be carried out in a noisy environment. The effectiveness of the proposed method is confirmed by experiment using a loudspeaker in a noisy room.

• Food Science and Preservation
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• v.6 no.4
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• pp.351-356
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• 1999

To develop and extend the shelf-life of vitamin C enriched fresh-cut apples using CA stored Fuji apples, dipping in 10% L-ascorbic acid and packaging with 0.03 mm LDPE, 0.04 mm PP and 0.08 mm Nylon/PE film(N$_2$displacement) were carried out. The changes of gas concentrations in the packaging and quality attributes of fresh-cut apples were examined during storage at 10$^{\circ}C$. The concentrations of O$_2$was maintained lower in Nylon/PE film than the other film, the level of O$_2$was in the range of 1∼3%. The increase of C$_2$H$_4$ concentrations in Nylon/PE film bag was more suppressed than the others. The vitamin C content of fresh-cut apples was enriched by dipping in L-ascorbic acid solution up to 241 mg$.$100 g-1 f.w., and the loss or that content was retarded differently by the package conditions of lower O$_2$level during storage. Browning in fresh-cut apples was shown after 6 days of storage in LDPE and PP film. but it was not shown by 14 days of storage in Nylon/PE film. Spoilage and off odor in fresh-cut apples were not detected up to 14 days of storage in Nylon/PE film. The results indicated that the vitamin C enriched fresh-cut apples can be processed from the long-term CA stored apples, and maintaining high quality of the products ill be possible in cases of the application of sealing packaging after O$_2$removal with film having low O$_2$permeability.

• Journal of the Korean Institute of Gas
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• v.24 no.4
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• pp.32-38
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• 2020

Based on the cases of fire and explosion accident in the chemical reactor, thr problems of preventive measures installed in the chemical reactor were analyzed. The chemical reactors produce a variety of chemicals and install rupture disk to relieve the pressure that rises sharply in the event of a runaway reaction. In order to maintain the function of the rupture disk, the emissions was allowed to be discharged into the atmosphere, resulting in fire and explosion accidents. As a way to improve this, safety instrumented system based on the safety integrity level(SIL3) was applied as a preventive measures for chemical reactor. Two emergency shur-off valves are installed in series on pipe dropping raw materials for chemical reactor so that the supply of raw materials can be cut off even if only one of the two emergency shut-off valves is operated during the runaway reaction. The automatic on/off valve is installed in parallel in the supply pipe of the reaction inhibitor so that the reaction inhibitor can be injected even if only one valve is opened at the time of the runaway reaction.

• Journal of Nutrition and Health
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• v.47 no.5
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• pp.342-350
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• 2014

Purpose: This study investigated the eating behaviors of Chinese children using the Nutrition Quotient for Children (NQ-C). Methods: The research subjects were 336 students (166 boys and 170 girls) in the 5th and 6th years at two elementary schools in Shandong Province and Jiangsu Province. Results: The average score of the Children's NQ was good, reaching 69.6 points. The factor scores for balance, moderation, diversity, regularity, and practice were 58.8, 84.9, 63.6, 76.1, and 73.6 points, respectively. Compared with the diagnostic cut-off points of the factors, mean balance, moderation, regularity, and practice scores were above the cut-off points, but diversity score did not meet the cut-off points. Fathers' education level showed positive correlation with the balance, regularity, and NQ scores of the students. Mothers' education level also showed positive correlation with the balance and regularity scores and mother's employment showed positive correlation with regularity score. As the exercise hours per day increased, the NQ score also increased. Conclusion: The questionnaire of NQ-C developed in Korea can be used in assessment of nutrition behavior of Chinese elementary students who have similar eating patterns.

• Journal of The Korean Society of Clinical Toxicology
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• v.16 no.2
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• pp.68-74
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• 2018

Purpose: In 2012, a revised guideline for acute acetaminophen overdose was proposed in the UK, recommending that the treatment threshold should be lowered to 100 mcg/ml at 4 hours after ingestion without risk stratification of hepatotoxicity. However, the poison centers in some developing countries do not have laboratory resources to provide serum drug levels in time. The primary aim of the study is to evaluate the cut-off value of reported dose per kilogram to determine when N-acetylcysteine treatment is warranted under the revised guideline. Methods: Data were collected retrospectively from the toxicology registry of an urban emergency medical center between 1st January 2010 and 30th June 2017. Inclusion criteria were single acute overdose of more than 75 mg/kg in 15 hours from ingestion and over 14 years of age. Subgroups were created by 25 mg/kg increments of reported dose, then sensitivity, specificity, positive predictive value and negative predictive value were calculated for the cut-off values of 100 mg/kg, 125 mg/kg, 150 mg/kg and 175 mg/kg for toxic serum level over '100-treatment line'. Results: A total of 99 patients were enrolled in the study; 24 patients showed toxic serum levels (24.2%). Zero of 17 patients with an ingestion dose under 100 mg/kg showed toxic level (0%), and 0 of 15 under 125 mg/kg (0%), 2 of 14 under 150 mg/kg (14.3%), and 4 of 12 under 175 mg/kg (33.3%) had toxic levels. The higher the ingested dose per kilogram of weight, the higher the frequency of the toxic serum concentration on the first test (${\chi}^2$ test for trend, ${\chi}^2=22.66$, p-value<0.001) and the sensitivity of each value was 100%, 100%, 92% and 76%. Conclusion: In acute single acetaminophen intoxication, the ingestion dose of 100 mg/kg of weight will be useful in determining the need for the N-acetylcysteine antidote in the indigent laboratory environment.