• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.2
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• pp.107-119
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• 2021

The cross-flow turbine is one of the most famous and widely used hydraulic power systems for a long time. The cross-flow turbine is especially popular in many countries and remote regions where off-grided because of its many benefits such as low cost, high efficiency at low head, simple structure, and easy maintenance. However, most modern turbines, including the cross-flow turbine, are unsuitable for the ultra-low head situation, known as less than 3m water head or zero head with over 0.5m/s flow velocity. In this study, we demonstrated a 20kW class inverted-type cross-flow turbine's performance. First, we reevaluated our previous studies and introduced how to design the inverted-type cross-flow turbine. Secondly, we fabricated the 20kW class inverted-type cross-flow turbine for the performance test. And then, we designed a testbed and installed the turbine system in the demonstration facility. In the end, we compare the demonstration with its previous CFD results. The comparing result shows that both CFD and real model fitted on guide vane angle at 10 degrees. At the demonstration, we achieved 42% turbine efficiency at runner speed 125 RPM.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.729-737
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• 2019

The world is now going through the era of the Fourth Industrial Revolution. Major global economies, including the United States, Germany, Japan and China, are fostering industries related to the fourth industrial revolution with policies and investments. South Korea is also setting up its fourth industrial revolution committee under the president, expanding policies and investment to foster industries related to the fourth industrial revolution, and increasing investment in research and development. Accordingly, government and private investment in industries and technologies related to the Fourth Industrial Revolution is made extensively around the world, and many related industries and technologies are being developed. In this paper, we will look into the status and problems of Advanced Concept Technology Demonstration projects that can quickly and easily introduce technologies related to the fourth industrial revolution in the private sector where many developments are taking place, and present the direction of development.

• Journal of Information Technology Services
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• v.16 no.1
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• pp.83-98
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• 2017

Broadcasting telecommunication convergence service means a service where broadcasting and telecommunication converge. Recently with the advancement of technology, broadcasting telecommunication convergence service has been evolving to provide multimedia contents through various devices including wired and wireless network environment. Up to now, IPTV and smartphone-based convergence services have been dominant, but more developed and evolved technology and media will appear in the future. In order to derive the next generation broadcasting telecommunication convergence service supporting model, this study derives an evaluation model of broadcasting telecommunication convergence service and presents a case of evaluation of 30 demonstration projects supported by the Korean government from 2010 to 2014. In this study, we derive an evaluation model and evaluate the demonstration projects by reflecting the position of the main stake holders of service such as users, experts, and related organizational institutions, away from the existing simple service evaluation method. Expert questionnaire used AHP (Analytic Hierarchy Process) method, and the evaluation results were divided into upper and lower groups to provide key implications by a gap analysis. From this analysis this study suggests guidelines for next generation broadcasting telecommunication service support projects. The next generation broadcasting convergence service business should be based on open platform type in terms of service type. In terms of service media, it should be centered on open devices such as smart phones and smart TVs. In terms of types of business responsibilities, it should be led by public organizations and it is necessary to increase the fund matching ratio by at least 62% when the private sector participates.

• Journal of Convergence for Information Technology
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• v.11 no.12
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• pp.244-253
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• 2021

This study examined how the fire evacuation induction service system using a smartphone navigation application in the event of a fire affects the fire evacuation time, and the following conclusions were drawn. 1. The evacuation time was reduced by 22 seconds when the navigation application was used in computer scenario simulation. Even in the demonstration simulation, the evacuation time was reduced by 40 seconds when the navigation application was used. This indicates that the navigation application is effective in shortening the evacuation time in case of fire. 2. As a result of the demonstration scenario simulation, the time until the end of evacuation was 39 seconds faster in the case of evacuation guidance than in the case where it was not conducted. 3. No bottlenecks occurred in the evacuation route during the demonstration scenario simulation. As a result, there was a difference in the time required to complete the evacuation between the computer scenario simulation and the demonstration scenario simulation.

• Journal of Information Technology Services
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• v.22 no.5
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• pp.109-124
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• 2023

This study aims to apply the concept of regulatory stringency to the regulatory sandbox with a fresh perspective. The regulatory sandbox is a system that gives opportunities under certain conditions to new technologies or businesses that have not been launched due to inadequacy or insufficiency in legal systems. Previous research on regulatory sandboxes has mainly focused on discussions about their impact on specific technologies or business domains. This study attention to the results according to the evaluations. Among them, whether special cases for demonstration can evolve into official permission has garnered significant attention. For this study, among the cases that passed the regulatory sandbox evaluation from February, 2019, to December, 2022, 162 cases in the field of ICT convergence were selected. The evaluation results were classified into three groups 'positive interpretation (Fast Track)', 'temporary permission', and 'special case for demonstration.' Each case was assigned to one of the three groups. Through the comparative analysis, the common characteristics and differences were summarized. Then, this study explored improvement measures to pass a less restrictive regulatory sandbox. The analysis of the cases revealed that the differences in each evaluation result were attributed to variations in the technological characteristics and user protection features. Considering these differences, as well as the higher weight and importance of the preparation stage for sandbox application, this study suggested a three-step approach to prepare for temporary permission and positive interpretation rather than special case for demonstration. In addition, this thesis discussed the policy limitations of the regulatory sandbox mechanism in South Korea and the limitations of the current study. Hopefully, the results of this study would be beneficial to individuals and companies, particularly venture companies and startups seeking to develop new technologies or businesses and utilize regulatory sandboxes.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.207-208
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• 2022

Recently, with the development of digital technology, new research cases which applied new technology were increased. Also, the related equipment and services are being developed in the industry. Before new equipment is developed and released, it must go through a verification process. In the maritime industry, equipment is verified through simulation tests or environmental tests on land. However, if only the test on land is conducted, verification data in the actual operating environment might be insufficient. In this paper, considerations are described in the development of an onboard demonstration scenario for verification in the operating environment.

• Journal of Astronomy and Space Sciences
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• v.32 no.4
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• pp.419-425
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• 2015

In this study, a new idea for developing a space scale for measuring mass in a microgravity environment was proposed by using the inertial force properties of an object to measure its mass. The space scale detected the momentum change of the specimen and reference masses by using a load-cell sensor as the force transducer based on Newton's laws of motion. In addition, the space scale calculated the specimen mass by comparing the inertial forces of the specimen and reference masses in the same acceleration field. By using this concept, a space scale with a capacity of 3 kg based on the law of momentum conservation was implemented and demonstrated under microgravity conditions onboard International Space Station (ISS) with an accuracy of ${\pm}1g$. By the performance analysis on the space scale, it was verified that an instrument with a compact size could be implemented and be quickly measured with a reasonable accuracy under microgravity conditions.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.415-424
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• 2021

This study aims to identify the impact of flow experience on participation and re-view of online taekwondo demonstrations on adult women, and provide practical data to revitalize online taekwondo demonstration performances, promote visitors, and promote adult taekwondo trainees. Visitors who watched the "High Kick" online taekwondo demonstration performance performed by the Kukkiwon Taekwondo Demonstration Team were selected as a population, and a total of 248 copies of the data were finally used by distributing online questionnaires. First, the difference in flow, involvement, and re-visibility due to female visitors' experiences in taekwondo is the perception, time distortion, and involvement except pleasure factors among flow sub-factors. There is a difference in the factors of re-viewing. Second, among the flow factors of online taekwondo demonstration performances, the factors of attention, pleasure, and time distortion were found to have had a positive impact on involvement. Third, the flow factor of online taekwondo demonstration shows a positive effect on the intention of re-watching. Fourth, the level of participation in online taekwondo demonstrations has a positive effect on the intention of re-watching. The results of this study suggest changes in attitudes and behavior, such as increased involvement of female visitors and intention of re-viewing, and it is believed that online performances will help establish a new non-face-to-face cultural performance system.

• ETRI Journal
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• v.35 no.5
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• pp.911-914
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• 2013

This letter presents Progression-Preserving Projection, a dimension reduction technique that finds a linear projection that maps a high-dimensional sensor dataset into a two- or three-dimensional subspace with a particularly useful property for visual exploration. As a demonstration of its effectiveness as a visual exploration and diagnostic means, we empirically evaluate the proposed technique over a dataset acquired from our own virtual-reality-enhanced ball-intercepting training system designed to promote the upper extremity movement skills of individuals recovering from stroke-related hemiparesis.

• Clean Technology
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• v.29 no.4
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• pp.297-304
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• 2023

The rapid advancement of the high-tech electronics industry has led to a significant increase in high-concentration ammonia wastewater. Various methods have been attempted to reliably treat wastewater containing high concentrations of ammonia, but no successful technology has yet been developed and applied. In this study, the removal efficiency and characteristics of ammonia nitrogen was evaluated according to changes in temperature, air loading rate, and liquid loading rate using a closed circulation countercurrent packed tower type demonstration facility for wastewater containing high concentrations of ammonia generated in the high-tech electronics industry. The temperature was varied while maintaining operating conditions of a wastewater flowrate of 20.8 m³ h^-1 and an air flow rate of 18,000 Nm³ h^-1. The results showed that at temperatures of 45,50,55, and 60℃, the removal efficiencies of ammonia nitrogen (NH₃-N) were 87.5%, 93.4%, 96.8%, and 98.7%, respectively. It was observed that temperature had the most significant impact on the removal efficiency of NH₃-N under these conditions. As the air loading rate increases, the removal rate also increases, but the increase in removal efficiency is not significant because droplets from the absorption tower flow into the stripping tower. Even if the liquid loading rate was changed by ±30%, the removal rate did not change significantly. This does not mean that the removal rate was unaffected, but was believed to be due to the relatively high air load rate. Through demonstration research, it was confirmed that ammonia stripping is a reliable technology that can stably treat high-concentration ammonia wastewater generated in the high-tech electronics industry.