• 한국정보교육학회:학술대회논문집
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• 2021.08a
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• pp.45-50
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• 2021

In order for SW education to be established in the era of non-face-to-face caused by COVID-19, research on the efficiency of SW education according to face-to-face and non-face classes is needed. Therefore, this study classified the operation status of the curriculum of 30 SW gifted classes nationwide in 2020 according to the class method(face-to-face, non-face, and blended). Subsequently, the results of class time and production per person were compared and analyzed through quantitative analysis. According to the study, the type of classes that performed the most classes compared to the planned number of hours was non-face-to-face(90.9%), followed by face-to-face(84.2%) and the least was blended(80.5%). The average number of products per student was the highest in the face-to-face class(0.504), while the blended class(0.421) and non-face-to-face class(0.42). Based on the results of this study, the non-face-to-face approach is advantageous in securing the number of hours, but various measures should be prepared to solve this problem because teachers and students find it difficult to guide the output.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.817-823
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• 2023

Manufacturing plants face the challenge of reducing energy use in response to climate change. Reducing energy consumption can be seen as one of the most important issues, such as reducing production costs and improving efficiency. Among manufacturing industries, the increase in energy consumption in the food industry is gradually increasing along with the improvement of the standard of living and the increase in population. In order to save energy in food processing plants, it is important to identify and analyze energy consumption characteristics in energy-consuming processes. Prior to this, it is necessary to monitor and analyze existing energy consumption to derive reduction measures. In this study, a small and medium-sized food processing plant producing processed meat products was used as a case study to identify and analyze the energy consumption structure at typical cycle/stage level of the batch heating process. From this, we tried to establish realistic and quantitative goals that can be obtained under individual process operating conditions. The results of this study will be used as basic data for the development of diffusion and pervasive energy saving FEMS technology for common core processes of food factories of small and medium-sized enterprises in the future.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.789-795
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• 2023

Digital-Twin are recognized as an important core technology for the realization of Smart Factories by simulating and optimizing the monitoring and predictive maintenance of manufacturing equipment and the operation of production lines in a digital space. To implement this system, we adopt the IEC62541-based OPC-UA (Open Platform Communications Unified-Architecture) Protocol, which has strengths in interoperability and connectivity between heterogeneous platforms. Therefore, In this paper, We designed and implemented an IIoT(Industry Internet of Things) system that connects heterogeneous platforms, and developed an OPC-UA simulator based on IEC 62541. We will present whether the data will be applied to the Digital-Twin Platform and whether it will work, and proceed with performance tests and evaluations. We evaluate the operation performance and OPC-UA performance of the Digital-Twin platform lightened by the proposed device, and present the optimal IEC62514-based simulator system. We proceeded with the performance evaluation of sending and receiving data with OPC-UA wrapping with the proposed simulator, and found that a lightweight Digital-Twin platform can be operated. This research can apply the OPC-UA protocol for implementing smart factory and meta-factory in the manufacturing shop floor with limited resources, avoiding the waste of time and space on the shop floor through the OPC-UA simulator. We expect that this will contribute to a significant improvement in efficiency by minimizing.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.3
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• pp.161-168
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• 2023

Converter slag is a by-product generated by refining the pig iron produced into molten steel in the blast furnace, occupying about 15 % of the weight of steel production. It has a high free-CaO content that can generate expansion cracks when used for concrete aggregate. This is the main reason to make it difficult to recycle. To solve this problem, government guideline requires that converter slag has to be aged in an open yard for 90 days. However, aging can not be perfectly performed because it entails time and cost. In this study, we tried to investigate the applicability of converter slag as a cementitious material rather than an aggregate by mixing converter slag with mortar formulations. According to the EDS results of the converter slag in the experiment, we found that screening in the aggregate phase was more effective than that in the powder phase. When the particles separated by a magnet in the aggregate state were pulverized and used for concrete up to a 15 % replacement ratio, various engineering characteristics, such as flow, length change, and compressive strength, showed engineering characteristics similar to those of the control mix.

• Journal of Practical Engineering Education
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• v.14 no.3
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• pp.543-553
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• 2022

A collaborative robot(Cobot) is one of the production systems presented in the 4th industrial revolution and are systems that can maximize efficiency by combining the exquisite hand skills of workers and the ability of simple repetitive tasks of robots. Also, research on the development of an efficient interface method between the worker and the robot is continuously progressing along with the solution to the safety problem arising from the sharing of the workspace. In this study, a method for controlling the robot by recognizing the worker's hand signal was presented to enhance the convenience and concentration of the worker, and the safety of the worker was secured by introducing the concept of a safety zone. Various technologies such as robot control, PLC, image processing, machine learning, and ROS were used to implement this. In addition, the roles and interface methods of the proposed technologies were defined and presented for using educational media. Students can build and adjust the educational media system by linking the introduced various technologies. Therefore, there is an excellent advantage in recognizing the necessity of the technology required in the field and inducing in-depth learning about it. In addition, presenting a problem and then seeking a way to solve it on their own can lead to self-directed learning. Through this, students can learn key technologies of the 4th industrial revolution and improve their ability to solve various problems.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.5
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• pp.196-201
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• 2023

In order to improve the efficiency of the water splitting system for hydrogen energy production, the high overvoltage in the electrochemical reaction caused by the catalyst in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) must be reduced. Among them, transition metal-based compounds (hydroxide, sulfide, etc.) are attracting attention as catalyst materials to replace currently used precious metals such as platinum. In this study, Ni foam, an inexpensive metal porous material, was used as a support and β-Ni(OH)₂ microcrystals were synthesized through a hydrothermal synthesis process. In addition, changes in the crystal morphology, crystal structure, and water splitting characteristics of β-Ni(OH)₂ microcrystals synthesized by doping Fe to improve electrochemical properties were observed, and applicability as a catalyst in a commercial water electrolysis system was examined.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.9
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• pp.263-272
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• 2023

Industrial Internet of Things (IIoT) is an important factor in increasing production efficiency in industrial sectors, along with data collection, exchange and analysis through large-scale connectivity. However, as traffic increases explosively due to the recent spread of IIoT, an allocation method that can efficiently process traffic is required. In this thesis, I propose a two-stage task offloading decision method to increase successful task throughput in an IIoT environment. In addition, I consider a hybrid offloading system that can offload compute-intensive tasks to a mobile edge computing server via a cellular link or to a nearby IIoT device via a Device to Device (D2D) link. The first stage is to design an incentive mechanism to prevent devices participating in task offloading from acting selfishly and giving difficulties in improving task throughput. Among the mechanism design, McAfee's mechanism is used to control the selfish behavior of the devices that process the task and to increase the overall system throughput. After that, in stage 2, I propose a multi-armed bandit (MAB)-based task offloading decision method in a non-stationary environment by considering the irregular movement of the IIoT device. Experimental results show that the proposed method can obtain better performance in terms of overall system throughput, communication failure rate and regret compared to other existing methods.

• Journal of Intelligence and Information Systems
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• v.29 no.4
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• pp.375-393
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• 2023

The demand for Less than Container Load (LCL) has been on the rise due to the growing need for various small-scale production items and the expansion of the e-commerce market. Consequently, more companies in the International Freight Forwarder are now handling LCL. Given the variety in cargo sizes and the diverse interests of stakeholders, there's a growing need for a container loading algorithm that optimizes space efficiency. However, due to the nature of the current situation in which a cargo loading plan is established in advance and delivered to the Container Freight Station (CFS), there is a limitation that variables that can be identified at industrial sites cannot be reflected in the loading plan. Therefore, this study proposes a container loading methodology that makes it easy to modify the loading plan at industrial sites. By allowing the characteristics of cargo and the status of the container to be considered, the requirements of the industrial site were reflected, and the three-dimensional space was manipulated into a two-dimensional planar layer to establish a loading plan to reduce time complexity. Through the methodology presented in this study, it is possible to increase the consistency of the quality of the container loading methodology and contribute to the automation of the loading plan.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.1
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• pp.82-93
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• 2024

Since the cement industry generates more than 60 % of CO₂ during the clinker production process, supplementary cementitious materials are used worldwide to reduce CO₂ efficiently. Mainly used supplementary cementitious materials such as blast furnace slag and fly ash, which are used in various industries including the cement industry, concrete admixtures, and ground solidification materials. However, since their availability is expected to decrease in the future according to the carbon neutrality strategy of each industry, new supplementary cementitious materials should be used to achieve the cement industry's goal for increasing the additive content of Portland cement. Limestone is a material that already has a large amount in the cement industry and has the advantage of high grinding efficiency, so overseas developed countries established Portland limestone cement standards and succeeded in commercialization. This study was an experimental study conducted to evaluate the possibility of utilizing domestic PLC, the effect of fineness and replacement ratio on the physical properties of cement was investigated, and the environmental impact of cement was evaluated by analyzing CO₂ emissions.

• BMB Reports
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• v.57 no.1
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• pp.60-65
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• 2024

The CRISPR-Cas9 system has significantly advanced regenerative medicine research by enabling genome editing in stem cells. Due to their desirable properties, mesenchymal stem cells (MSCs) have recently emerged as highly promising therapeutic agents, which properties include differentiation ability and cytokine production. While CRISPR-Cas9 technology is applied to develop MSC-based therapeutics, MSCs exhibit inefficient genome editing, and susceptibility to plasmid DNA. In this study, we compared and optimized plasmid DNA and RNP approaches for efficient genome engineering in MSCs. The RNP-mediated approach enabled genome editing with high indel frequency and low cytotoxicity in MSCs. By utilizing Cas9 RNPs, we successfully generated B2M-knockout MSCs, which reduced T-cell differentiation, and improved MSC survival. Furthermore, this approach enhanced the immunomodulatory effect of IFN-r priming. These findings indicate that the RNP-mediated engineering of MSC genomes can achieve high efficiency, and engineered MSCs offer potential as a promising therapeutic strategy.