• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.1
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• pp.68-75
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• 2023

In an automotive plant, an automated storage and retrieval system (ASRS) synchronizes material handling flows from a part production line to an auto-assembly line. The part production line transfers parts on small-/large-sized pallets. The products on pallets are temporarily stored on the ASRS, and the ASRS retrieves the products upon request from the auto-assembly line. Each ASRS aisle is equipped with narrow-/wide-width racks for two pallet sizes. An ASRS aisle with narrow-/wide-width racks improves both storage space utilization and crane utilization while requiring delicate ASRS aisle design, i.e., the locations of the narrow-/wide-width racks in an ASRS aisle, and proper operation policies affect the ASRS performance over demand fluctuations. We focus on operation policies involving a common storage zone using wide-width racks for two pallet sizes and a storage-retrieval job-change for a crane based on assembly-line batch size. We model a discrete-event simulation model and conduct extensive experiments to evaluate operation policies. The simulation results address the best ASRS aisle design and suggest the most effective operation policies for the aisle design.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.3
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• pp.267-273
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• 2023

As the impacts of global climate change become increasingly apparent, the reduction of carbon emissions has emerged as a critical subject of discussion. Nuclear power has garnered attention as a potential carbon-free energy source; however, the rapidity of load following in nuclear power generation poses challenges in comparison to fossil-fueled methods. Consequently, power-to-gas systems, which integrate nuclear power and hydrogen, have attracted growing interest. This study presents a preliminary design of a very high temperature reactor (VHTR) integrated blue hydrogen production process utilizing DWSIM, an open-source process simulator. The blue hydrogen production process is estimated to supply the necessary calorific value for carbon capture through tail gas combustion heat. Moreover, a thermodynamic assessment of the main recuperator is performed as a function of the helium flow rate from the VHTR system to the blue hydrogen production system.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.275-275
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• 2022

Tsunamis triggered by undersea earthquakes have the characteristic of longer wavelengths and can propagate a very long distance. Although the occurrence frequency of tsunami is low, it can cause casualties and properties. Historically, tsunamis that occurred on the western coast of Japan attacked the eastern coast of the Korean Peninsula and damaged the property and the loss of human life in 1983 and 1993. By tsunami in 1983 especially, 2 people were killed, and more than 200 casualties occurred. In addition, it caused 2 million dollars in property damage at Imwon Port. In 2011, The eastern cities of Japan: Iwate, Miyagi, Ibaraki, and Fukushima were damaged by a tsunami that occurred near onshore along the Pacific ocean and caused more than 300 billion dollars in property damage, and 20,000 casualties occurred. Moreover, those provoked nuclear power plant meltdown at Fukushima. In this study, it was carried out a relationship between maximum tsunami heights and fault parameters of earthquake: strike angle, dip angle, and slip angle at Imwon port. Those fault parameters are known that it does not relate to the magnitude of earthquake directly. Virtual tsunamis, which could be triggered by probable undersea earthquakes in the future, were investigated and mutual information based on probability and information theory was introduced to figure out the relationship between maximum tsunami height and fault parameters. Fault parameters were evaluated according to the strong relationship with maximum tsunami heights finally.

• ETRI Journal
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• v.45 no.4
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• pp.636-649
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• 2023

Renewable energy generation cannot be consistently predicted or controlled. Therefore, it is currently not widely used in the electricity market, which requires dependable production. In this study, reliability- and variance-based controls of energy storage strategies are proposed to utilize renewable energy as a steady contributor to the electricity market. For reliability-based control, photovoltaic (PV) generation is assumed to be registered in the power generation plan. PV generation yields a reliable output using energy storage units to compensate for PV prediction errors. We also propose a runtime state-ofcharge management method for sustainable operations. With variance-based controls, changes in rapid power generation are limited through ramp rate control. This study introduces new reliability and variance indices as indicators for evaluating these strategies. The reliability index quantifies the degree to which the actual generation realizes the plan, and the variance index quantifies the degree of power change. The two strategies are verified based on simulations and experiments. The reliability index improved by 3.1 times on average over 21 days at a real power plant.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.3
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• pp.101-108
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• 2023

Although the proportion of coal-fired power generation is decreasing, efficient operating technology is needed to continuously invest in facilities and reduce maintenance costs until it is abolished. Boilers, one of the main facilities of power plants, operate for a long time in harsh environments of high temperature and high pressure. In addition, damage due to deterioration is likely to occur depending on the fuel and tube material used. It is very important to judge soundness because damage caused by deterioration adversely affects facility operation. Previously, replication method was used to analyze the progress of deterioration. In the replication method, pre-treatment such as chemical treatment is performed on the boiler tube in the field, the area is reproduced by attaching a film, and the replicated film is determined by an expert in the laboratory with an expensive microscope. However, this method involves substantial costs and time requirements, as well as the possibility of human errors. To address these issues, we developed a mobile health assessment system in this research. Since it is detachable and takes images in real time, this system enables swift evaluations across a broad range and facilitates the assessment of preprocessing quality. In addition, it was intended to reduce existing human mistakes by developing a degradation classification algorithm using the merger cluster method.

• Architectural research
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• v.25 no.4
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• pp.73-84
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• 2023

Indoor thermal conditions greatly affect the health and comfort of humans who occupy the space in it. The purpose of this research is to analyze the influence of water and vegetation elements as a microclimate modifier in buildings to obtain thermal comfort through the study of thermal environment models. This research covers two objects, namely public buildings and housing in Makassar City, South Sulawesi Prov-ince - Indonesia. Quantitative methods through field surveys and measurements based on thermal and personal variables. Data analysis based on ASHRAE 55 2020 standard. The data was processed with a parametric statistical approach and then simulated with the Computational Fluid Dynamics (CFD) simulation method to find a thermal prediction model. The model was made by increasing the ventilation area by 2.0 m2, adding 10% vegetation with shade plant characteristics, moving water features in the form of fountains and increasing the pool area by 15% to obtain PMV + 0.23, PPD + 8%, TSV-1 - +0, Ta_25.7℃, and relative humidity 63.5 - 66%. The evaluation shows that the operating temperature can analyze the visitor's comfort temperature range of >80% and comply with the ASHRAE 55-2020 standard. It is concluded that water elements and indoor vegetation can be microclimate modifiers in buildings to create desired comfort conditions and adaptive con-trols in buildings such as the arrangement of water elements and vegetation and ventilation systems to provide passive cooling effects in buildings.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.10
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• pp.2701-2717
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• 2023

In this paper, a hybrid fuzzy-based method is suggested for determining India's best system for power generation. This suggested approach was created using a fuzzy-based combination of the Giza Pyramids Construction (GPC) and Recalling-Enhanced Recurrent Neural Network (RERNN). GPC is a meta-heuristic algorithm that deals with solutions for many groups of problems, whereas RERNN has selective memory properties. The evaluation of the current load requirements and production profile information system is the main objective of the suggested method. The Central Electricity Authority database, the Indian National Load Dispatch Centre, regional load dispatching centers, and annual reports of India were some of the sources used to compile the data regarding profiles of electricity loads, capacity factors, power plant generation, and transmission limits. The RERNN approach makes advantage of the ability to analyze the ideal power generation from energy data, however the optimization of RERNN factor necessitates the employment of a GPC technique. The proposed method was tested using MATLAB, and the findings indicate that it is effective in terms of accuracy, feasibility, and computing efficiency. The suggested hybrid system outperformed conventional models, achieving the top result of 93% accuracy with a shorter computation time of 6814 seconds.

• Journal of Fashion Business
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• v.27 no.5
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• pp.13-25
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• 2023

The implementation of ESG practices in the fashion industry has been accelerating, and its significance has been growing across all industries. This paper aims to examine the strategies for ESG implementation in domestic fashion brands and analyze how ESG principles are applied in the context of domestic conscious fashion. To analyze conscious fashion as a means of ESG implementation, the evaluation criteria of ESG from the Textile Fashion Policy Research Institute were utilized as analytical tools. As a result, five categories of domestic conscious fashion emerged: animal-free vegan fashion, eco-friendly plant-based vegan materials, upcycled fashion, regenerated fiber fashion utilizing waste materials, and fair trade fashion. The characteristics of these ESG practices in conscious fashion were identified with four key features. Firstly, the adoption of environmentally friendly materials demonstrates a tendency towards resource conservation, minimizing environmental degradation, and protecting ecosystems. Secondly, technology-driven circular practices are predominant in vegan and upcycled types, evident in the development of fashion materials and secondhand content. Thirdly, design practices based on scarcity incorporate characteristics of upcycling and fair trade. Lastly, the practices of social and ethical values underlie the philosophies of three types of conscious fashion. With the acceleration of ESG practices in the fashion industry and the increasing importance thereof, it is expected that domestic conscious fashion in South Korea will diversify in the future.

• Korea Trade Review
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• v.45 no.6
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• pp.99-112
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• 2020

It is no exaggeration to say that today's world economy is dependent on international trade, which is the result of inter-state transactions. As the vast majority of international goods transport is transported by international shipping, interest in the seaborne transport field is natural in international and trade studies. In particular, in the case of international shipping, as it is the basis of typical international transportation, changes in international shipping due to the innovation of technology may have an effect on international trade norms. In this study, as a result of evaluating port preference in a hypothetical scenario by using the Design of Experiments method, bunkering as well as port service, which is traditionally important, was identified as a major competitive factor of future ports. It has been revealed that, above all, the port to respond to the future is the continued importance of port services and the supply of ship fuel. Therefore, port authorities are providing implications that LNG bunkering infrastructure suitable for international environmental regulations is important.

• Corrosion Science and Technology
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• v.22 no.5
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• pp.314-321
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• 2023

The aim of the present study was to investigate the effect of thymus extract on corrosion inhibition of aluminum 5083 alloy in a 0.1 M NaCl medium prepared using a mixture of ethylene glycol and water using potentiodynamic and electrochemical impedance spectroscopy (EIS) techniques. The potentiodynamic electrochemical technique showed an increase in corrosion inhibition efficiency starting from 49.63% at a concentration of 0.25 g/L to 92.71% at a maximum concentration of 1.25 g/L of the extract. These results were consistent with those obtained via EIS analysis. Spectral characterization of the tested plant extract using the Fourier-transform infrared spectroscopy (FTIR) technique confirmed the presence of organic compounds having different oxygen and aromatic functionalities in the extract that could help enhance the adsorption of these compounds on the aluminum surface. This study reveals possible adsorption isotherm of the thymus extract on the aluminum surface, supporting a Langmuir isotherm for the adsorption of inhibitor molecules on this surface.