• Journal of Industrial Technology
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• v.20 no.A
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• pp.73-82
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• 2000

This study was implemented to find an optimal model for wastewater treatment processes using PHOENICS(Parabolic, hyperbolic or Elliptic Numerical Integration Code Series) and ASM(Activated Sludge Model). PHOENICS is a general software based upon the laws of physics and chemistry which govern the motion of fluids, the stresses and strains in solids, heat flow, diffusion, and chemical reaction. The wastewater flow and removal efficiency of particle in two phase system of a grit chamber in wastewater treatment plant were analyzed to inquire the predictive aspect of the operational model. ASM was developed for a biokinetic model based upon material balance in complex activated sludge systems, which can demonstrate dynamic and spatial behavior of biological treatment system. This model was applied to aeration tank and settling chamber in Choonchun city, and the modeling result shows dynamic transport in aeration tank. PHOENCS and ASM could be contributed for the optimal operation of wastewater treatment plant.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.162-163
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• 2011

This paper presents the system dynamics methodology for modeling and control the production/inventory system. Under system dynamics point of view, we can apply some production/inventory policies as if we use the control laws for dynamics systems, then the behavior of system is analyzed and evaluated to improve the performance of production/inventory system. We also utilize the hybrid modeling method for the dynamic of production system with the combination of Matlab/Simulink and Matlab/Sateflow. Finally, the numerical simulation results are carried out in Matlab/Simulink environment and compare with the results from other works. It is shown that our approach can obtain some good performances (such as operational cost, stability of inventory, customer service level).

• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.1
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• pp.122-129
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• 2020

Korea's HEMS are mainly operated during the week, but they are pushing for 24-hour operations. This study has made an overall comparison and review of helicopter safety management that should be accompanied to this end. For research purposes, helicopter regulations and helicopter accident statistics were analyzed, with a high accident rate associated with pilot error and night flight. It was proposed that future preparations would require reinforcement of laws and regulations, reinforcement of pilots' night training, and introduction of training and preflight risk assessments. This study will provide a direction for future helicopter safety. This study will provide for future direction of helicopter safety research.

• Journal of Korea Port Economic Association
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• v.21 no.3
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• pp.191-217
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• 2005

Ninety percent of an average Chinese manufacturer's time spent is on logistics. Therefore, logistics presents the greatest challenge for multinational companies conducting businesses in China. Although more than 18,000 registered logistics companies exist in China, 85 percent of their revenues are generated from basic trucking and storage services. These facts indicate that China will need increasing presence of high-quality foreign 3PL providers, who are able to provide sophisticated IT systems, industry/operational expertise, standardized operating processes, and international networks, compared to their Chinese counterparts. However, they are facing complicated array of laws and regulations as well as difficulty of finding qualified people to fulfill these needs. There are a number of foreign 3PL providers engaged in China's logistics sector to reap a huge opportunity. Nevertheless, many 3PL foreign providers are still cautious about making large investments. Thus they arelooking for alliances that can provide complementarities instead. Another salient feature of strategy is to take over the transportation assets and warehousing of major Chinese manufacturers and distributors.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.3
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• pp.434-440
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• 2010

In this paper, we define generalized induced linguistic aggregation operator called generalized induced linguistic ordered weighted harmonic mean(GILOWHM) operator. Each object processed by this operator consists of three components, where the first component represents the importance degree or character of the second component, and the second component isused to induce an ordering, through the first component, over the third components which are linguistic variables and then aggregated. It is shown that the induced linguistic ordered weighted harmonic mean(ILOWHM) operator and linguistic ordered weighted harmonic mean(LOWHM) operator are the special cases of the GILOWHM operator. Based on the GILOWHM and LWHM operators, we develop an approach to group decision making with linguistic preference relations. Finally, a numerical example is used to illustrate the applicability of the proposed approach.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.2
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• pp.100-105
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• 2021

The purpose of this study is to provide in-flight security in situations where aviation security is constantly threatened by the increase in illegal interference in aircraft and the threat of terrorism that still exists. It is to identify legal operational problems such as education and qualification of the original system and to propose improvement measures. To this end, the need for revision based on relevant laws and guidelines such as "Operation Guidelines for In-Flight Security Officers" is to be discussed based on international standards such as ICAO and Federal Air Marshal. The research method was based on interviews with SEMs such as cabin managers, which focused on ensuring the legal status of In-Flight Security Officer, establishing relationships with captains, and improving education and training.

• Journal of applied mathematics & informatics
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• v.41 no.5
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• pp.973-988
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• 2023

In real-life scenarios, we may have to deal with real numbers or numbers in intervals or a combination of both to solve multi-criteria decision-making (MCDM) problems. Also, we may come across a situation where we must combine this interval and actual number membership values into a single real number. The most significant factor in combining these membership values into a single value is by using aggregation operators or scoring algorithms. To overcome such a situation, we suggest the cubic hypersoft set (CHSS) concept as a workaround. Ultimately, this makes it simple for the decision-maker to obtain information without misconceptions. The primary aim of this study is to establish some operational laws for the cubic hypersoft set, present the fundamental properties of aggregation operators and propose an algorithm by using the technique of order of preference by similarity to the ideal solution (TOPSIS) technique based on correlation coefficients to analyze the stress-coping skills of workers.

• Journal of Korean Society of Rural Planning
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• v.19 no.4
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• pp.73-79
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• 2013

As facilities performing the production, processing, preservation, and shipment of agricultural products; agricultural facilities are categorized into planting facilities and livestock facilities based on the management target. Agricultural facilities are set in farmlands, and facility users mainly complain about the legal or institutional restrictions on farm rather than their own facilities itself. From 2009 to 2012, the Ministry of Agriculture Food and Rural Affairs (MAFRA) published the "Casebook of farmer Complaints on Farmlands" in order to help answer farmers' questions and support public workers' workloads. However, contents related to agricultural facility installed in farmland are currently not dealt with in particular. Among agricultural facilities, demands of property rights with livestock facilities have risen due to construction permissions, operational restrictions, and high initial investment costs; and relevant laws were revised and are now being executed. However, for planting facilities such as mushroom facilities, ginseng facilities, and greenhouses; farmer complaints related to property rights are constantly increasing because revisions to relevant laws are not being made despite the rising diversity of construction materials through technical developments as well as the rising scale of assets-i.e. mechanization, automation, and the application of New Regeneration Energies according to capital influx. In this study, the current state of relevant agricultural facility legislation were organized and their drawbacks deduced in order to propose improvements of Agricultural Facility Legislation. The result of interviewing with public workers and farmers show that agricultural facilities should be regarded as extensions of farmlands rather than as facilities built in land where development actions were being taken. Alternatives able to reflect these opinions were suggested through expert consultation.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3409-3416
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• 2023

Licensing the next-generation of nuclear reactor designs requires extensive use of Modeling and Simulation (M&S) to investigate system response to many operational conditions, identify possible accidental scenarios and predict their evolution to undesirable consequences that are to be prevented or mitigated via the deployment of adequate safety barriers. Deep Learning (DL) and Artificial Intelligence (AI) can support M&S computationally by providing surrogates of the complex multi-physics high-fidelity models used for design. However, DL and AI are, generally, low-fidelity 'black-box' models that do not assure any structure based on physical laws and constraints, and may, thus, lack interpretability and accuracy of the results. This poses limitations on their credibility and doubts about their adoption for the safety assessment and licensing of novel reactor designs. In this regard, Physics Informed Neural Networks (PINNs) are receiving growing attention for their ability to integrate fundamental physics laws and domain knowledge in the neural networks, thus assuring credible generalization capabilities and credible predictions. This paper presents the use of PINNs as surrogate models for accidental scenarios simulation in Nuclear Power Plants (NPPs). A case study of a Loss of Heat Sink (LOHS) accidental scenario in a Nuclear Battery (NB), a unique class of transportable, plug-and-play microreactors, is considered. A PINN is developed and compared with a Deep Neural Network (DNN). The results show the advantages of PINNs in providing accurate solutions, avoiding overfitting, underfitting and intrinsically ensuring physics-consistent results.

• Strategy21
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• s.42
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• pp.258-292
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• 2017

This paper is designed to make a national strategic concept for the ROK's maritime security and to explore cooperation directions for the ROK Navy and Coast Guard in order to implement the newly-made maritime security strategic concept. As strategy is composed of three main categories(goals, ways, means), the goal of the ROK's maritime security strategy is 'Safe and Affluent Sea' and the way to realize the goal is the principle of cooperative leverage, and the means as tasks to implement the strategic concept are maritime safety, maritime security, and maritime stewardship. The concept of national fleet as used in the US is applied to promoting the cooperation between the ROK Navy and Coast Guard. Thus, under the newly-established maritime security strategic concept along with the national fleet model, followings are suggested as policy proposals for facilitating mutual cooperation between the ROK Navy and Coast Guard in dealing with not only traditional threats but also non-traditional treats at sea and from the sea as well. First, the ROK Navy and Coast Guard has been making efforts to enhance interoperability between the two sea services. However, the mutual cooperations have been focused mainly on areas on operational level rather than policy level. Therefore, the two sea services are recommended to enlarge exchanges and cooperation in policy areas. Second, there are still demands for further cooperation areas between the two sea services in command and communications. The interoperability in C2 between the two needs to be upgraded even to the areas of anti-terrorist activities ar sea, ASUW, ASW, maritime interdiction, etc. Third, mutual comparability between the two needs to be reflected in the maritime forces development to ensure the comparability in UNREP and other logistics areas. Fourth, the standardization of logistical materials and equipments is needed as a way of sustaining operational capability and logistical capacity for the ROK Navy and Coast Guard as well. Fifth, the ROK Navy and Coast Guard are recommended to participate more actively in international maritime cooperation activities such as PASSEX. Sixth, Complementary laws and regulations need further to be revised and to be newly made for collectively managing swiftly maritime accidents and natural disasters at sea.