• Nuclear Engineering and Technology
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• v.53 no.11
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• pp.3505-3516
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• 2021

During nuclear facility decommissioning, workers are continuously exposed to high-level radiation. Hence, adequate path planning is critical to protect workers from unnecessary radiation exposure. This work discusses recent development in radioactive path planning and the algorithms recommended for the task. Specifically, we review the conventional methods for nuclear decommissioning path planning, analyze the techniques utilized in developing algorithms, and enumerate the decision factors that should be considered to optimize path planning algorithms. As a major contribution, we present the quantitative performance comparison of different algorithms utilized in solving path planning problems in nuclear decommissioning and highlight their merits and drawbacks. Also, we discuss techniques and critical consideration necessary for efficient application of robots and robotic path planning algorithms in nuclear facility decommissioning. Moreover, we analyze the influence of obstacles and the environmental/radioactive source dynamics on algorithms' efficiency. Finally, we recommend future research focus and highlight critical improvements required for the existing approaches towards a safer and cost-effective nuclear-decommissioning project.

• Journal of Korean Society on Water Environment
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• v.33 no.5
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• pp.511-524
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• 2017

This study was carried out for the purpose of creating a restoration plan to improve the ecological quality of the Changwon and Nam streams. Based upon the results of comprehensive diagnostic assessment, restoration priority was given to the upstream reach, where conservation status is relatively superior. Restoration level was usually determined to practice active restoration as conservation, and the states of both Changwon and Nam streams were not so good. Restoration plans, by reach, were classified into "upstream", "midstream", and "downstream" were suggested in both terms of horizontal section frame and vegetation-based on the result of diagnostic assessment and the reference information. "Upstream", "mid-stream" and the "downstream" of Changwon and Nam streams were classified into "small-gravel- mountainous", "small-sand-plain", and "small-clay-plain streams" respectively (based on scale, and substrate and slope of river bed). The spatial arrangement of vegetation was laid out in diagram form by reflecting micro-topography and the water level of the horizontal section of river. Information regarding species composition was recommended as dominant species, which appear frequently in three vegetation zones composed of herbaceous plants, shrubs and trees and sub-tree- dominated zones divided by reflecting disturbance regime, depending on position on the horizontal section of river. Moreover, there have been prepared not only plans to improve the terrestrial ecosystems around the streams but also plans to create ecological networks, which can serve to improve the ecologic quality of the whole regional environment by serving to connect streams and terrestrial ecosystems, a process probably necessary and definitely recommended to realize true (genuine) restoration. Plans for ecological parks and networks were prepared by mimicking the species composition of Alnus japanica community, Zelkova serrata community, Carpinus laxiflora community, Quercus aliena community, and Q. serrata community.

• Journal of the Korean Society of Safety
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• v.36 no.4
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• pp.47-53
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• 2021

The fatality rate is used to estimate each country's risk level. However, the fatality rate is calculated using the number of fatal accidents and workers, which is collected differently across countries. It is therefore problematic to use these numbers in an equivalent way. This study proposes a new approach for calculating the number of full-time equivalent workers when evaluating individual countries' fatality rate by suggesting an equivalent condition for the calculation of the number of full-time equivalent workers. This study proceeds in three steps: (i) analysis of the fatality rate among various countries; (ii) fatality rate calculation using the full-time equivalent workers; and (iii) comparison of the fatality rate among various countries. The study found that for the fatality rate based on national data, the fatality rate in South Korea (1.72‱) is 10 times higher than that in United Kingdom (0.17‱). However, according to the number of full-time equivalent workers, the fatality rate in South Korea (1.86‱) was three times higher than that in the United Kingdom (0.56‱). These findings reveal a difference in the fatality rate depending on the method used to calculate the number of full-time equivalent workers. Therefore, the number of full-time equivalent workers must be calculated for each country to accurately compare the fatality rate. Ultimately, the study's results highlight the need for clearer standards in the assessment of the fatality rate by country in international organizations such as the ILO.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.1
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• pp.29-39
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• 2012

Currently, environment-friendly and sustainable fisheries are one of the major issues among fisheries authorities. A variety of alternative management policies and projects are going on to enhance fisheries management systems and fishery resources such as a TAC management program and a VDS (Vessel Day Scheme) management scheme for distant water fishing nations in Western and Central Pacific Fisheries Commission (WCPFC) convention area. These kinds of efforts among fisheries management authorities are aimed at limiting fishing capacity or fishing power. In terms of fisheries management, Fishing capacity and fishing power have increased the importance of the impact on a fishery and level of the resources. Increased fishing capacity and fishing power have caused not only depletion of fisheries resource, but also additional fishing cost. therefore, there is a clear need for authorities to manage fishing capacity and fishing power. It is also help ensure the conservation and sustainability of the fishery resources. Because of lack of data, absolute fishing power is difficulty to measure. The notion of relative fishing power is frequently used. In this study, relative fishing power was assessed using Mastuda (1991) method for fishing power index. The raw data for assessment was based on fishermen's logbook data from sampled fishing vessels in coastal snow crab gillnet fishery. Data Envelopment Analysis (DEA) method was used to assess fishing capacity. DEA is a linear programming methodology to measure the efficiency of a set of entities called Decision-Making Units (DMUs). It was recommended by FAO for assessing capacity in fisheries.

• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.353-363
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• 2020

Purpose: The purpose of this study is to verify the effects of assessment and compensation system, information technology, knowledge quality, and knowledge management activities on the earthquake disaster management job performance. Method: Questionnaire survey was performed for the fire officials, and the multi-regression analysis for surveyed data was statistically performed by using SPSS 25.0 program. Result: Information technology, knowledge quality and knowledge management activities among the factors of the knowledge management system related to earthquake disasters have had significant positive effects on the earthquake disaster management job performance, but assessment and compensation system are found to have no significant effects on the earthquake disaster management job performance. Conclusion: It was confirmed that the higher the level of information technology, knowledge quality and knowledge management activities related to earthquake disasters, the higher the disaster management job performance.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.1
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• pp.77-88
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• 2017

The concern on the greenhouse gas emissions is increasing globally. Especially, the greenhouse gas emission from fisheries is an important issue due to Cancun Agreements Mexico in 1992 and the Kyoto protocol in 2005. Furthermore, the Korean government has a plan to reduce the GHG emissions as 5.2% compared to the BAU in fisheries until 2020. However, the investigation on the GHG emissions from Korean fisheries has not been executed much. Therefore, the quantitative analysis of GHG emissions from Korean fishery industry is needed as the first step to find a relevant way to reduce GHG emissions from fisheries. The purpose of this research is to investigate which degree of GHG emitted from the major coastal fisheries such as coastal gillnet fishery, coastal dual purpose fishery, coastal pots fishery and coastal small scale stow net fishery. Here, we calculated the GHG emission from the fisheries using the LCA (Life Cycle Assessment) method. The system boundary and input parameters for each process level are defined for LCA analysis. The fuel use coefficients of the fisheries are also calculated according to the fuel type. The GHG emissions from sea activities by the fisheries will be dealt with. Furthermore, the GHG emissions for the unit weight of fishes are also calculated with consideration to the different consuming areas. The results will be helpful to understand the circumstances of GHG emissions from Korean fisheries.

• Clean Technology
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• v.17 no.4
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• pp.406-411
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• 2011

A detailed database of waste heat is built to propose energy exchange networks to recover waste energy in Pohang Steel Industrial Complex. A visualized technique is used to figure out the status of waste heat energy and to suggest potential energy exchange networks. Several energy networks are proposed in terms of temperature level, the amount of available energy, distance, and construction cost. A simple economical assessment is applied to the energy exchange networks which have higher economic potential. Their average payback period is estimated to be 2.8 years. The total amount of energy saving by constructing the proposed energy exchange networks is 4,778 TOE per year. It corresponds to 11,160 ton $CO_2$ reduction with the assumption that the recycled waste energy replaces the use of LNG in energy-demanding companies.

• Nuclear Engineering and Technology
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• v.21 no.2
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• pp.73-88
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• 1989

Ten methods of the total two-phase pressure drop prediction based on five existing models and correlations have been examined for their accuracy and applicability to pressurized water reactor conditions. These methods were tested against 209 experimental data of local and bulk boiling conditions : Each correlations were evaluated for different ranges of pressure, mass velocity and Quality, and best performing models were identified for each data subsets. A computer code entitled 'K-TWOPD' has been developed to calculate the total two-phase pressure drop using the best performing existing correlations for a specific property range and a correction factor to compensate for the predicted error of the selected correlations. Assessment of this code shows that the present method fits all the available data within $\pm$11% at a 95% confidence level compared with $\pm$25%, for the existing correlations.

• Journal of Animal Science and Technology
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• v.63 no.2
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• pp.248-261
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• 2021

Attributable to their major function in pathogen recognition, the use of bovine leukocyte antigens (BoLA) as disease markers in immunological traits in cattle is well established. However, limited report exists on polymorphism of the BoLA gene in zebu cattle breeds by high resolution typing methods. Thus, we used a polymerase chain reaction sequence-based typing (PCR-SBT) method to sequence exon 2 of the BoLA class II DRB3 gene from 100 animals (Boran, n = 13; Sheko, n = 20; Fogera, n = 16; Horro, n = 19), Hanwoo cattle (n = 18) and Bangladesh Red Chittagong zebu (n = 14). Out of the 59 detected alleles, 43 were already deposited under the Immuno Polymorphism Database for major histocompatibility complex (IPD-MHC) while 16 were unique to this study. Assessment of the level of genetic variability at the population and sequence levels with genetic distance in the breeds considered in this study showed that Zebu breeds had a gene diversity score greater than 0.752, nucleotide diversity score greater than 0.152, and mean number of pairwise differences higher than 14, being very comparable to those investigated for other cattle breeds. Regarding neutrality tests analyzed, we investigated that all the breeds except Hanwoo had an excess number of alleles and could be expected from a recent population expansion or genetic hitchhiking. Howbeit, the observed heterozygosity was not significantly (p < 0.05) higher than the expected heterozygosity. The Hardy Weinberg equilibrium (HWE) analysis revealed non-significant excess of heterozygote animals, indicative of plausible over-dominant selection. The pairwise FST values suggested a low genetic variation among all the breeds (FST = 0.056; p < 0.05), besides the rooting from the evolutionary or domestication history of the cattle. No detached clade was observed in the evolutionary divergence study of the BoLA-DRB3 gene, inferred from the phylogenetic tree based on the maximum likelihood model. The investigation herein indicated the clear differences in BoLA-DRB3 gene variability between African and Asian cattle breeds.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.2
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• pp.281-293
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• 2023

Industrial control systems (ICS) are increasingly targeted by security incidents as attackers' knowledge of ICS characteristics grows and their connectivity to information technology expands. Vulnerabilities related to ICS are growing rapidly, but patching all vulnerabilities in a timely manner is challenging. The common vulnerability assessment system used to patch vulnerabilities has limitations as it does not consider weaponization after discovery. To address this, this study defines criteria for classifying attacker skill levels based on open information including operating technology and vulnerability information in ICS. The study also proposes a method to evaluate vulnerability severity that reflects actual risk and urgency by incorporating the corresponding attribute in the existing severity score calculation. Case studies based on actual accidents involving vulnerabilities were conducted to confirm the effectiveness of the evaluation method in the ICS environment.