• 한국기계가공학회지
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• 제20권2호
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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.

• 한국산업융합학회 논문집
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• 제22권6호
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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.

• 한국IT서비스학회지
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• 제16권1호
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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.

• 융합정보논문지
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• 제11권12호
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• pp.244-253
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• 2021

본 연구는 화재 발생 시 스마트폰 네비게이션 어플리케이션을 이용한 화재 대피 유도 서비스 시스템이 화재대피 시간에 어떤 영향을 미치는지 살펴보고자 하는 연구이다. 컴퓨터 시나리오 시뮬레이션에서 네비게이션 어플리케이션을 사용하였을 때 대피시간이 22초 단축되었고 실증시뮬레이션 또한 네비게이션 어플리케이션을 사용하였을 때 대피시간이 40초 감소되어 화재 발생 시 피난 시간 단축에 효과적이라는 점을 알 수 있다. 실증 시나리오 시뮬레이션을 한 결과는 피난유도를 실시한 경우가 실시하지 않은 경우보다 피난 종료까지 시간이 39초 더 빠르게 나타났다. 실증 시나리오 시뮬레이션은 피난 경로에 병목현상이 발생하지 않았고 이로인해 컴퓨터 시나리오 시뮬레이션과 실증 시나리오 시뮬레이션의 대피 완료 소요시간의 차이가 발생하였다. 추후 시나리오 시뮬레이션에 학생실습 연구에 기여할 것이다.

• 한국IT서비스학회지
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• 제22권5호
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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.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2022년도 춘계학술대회
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• pp.207-208
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• 2022

최근 디지털 기술이 발전하면서 조선해양분야에 새롭게 도입되는 도입하는 연구사례가 늘고 있으며 업계에서도 관련 장비 및 서비스가 개발되고 있다. 새로운 장비가 개발되고 출시하기 이전에 우선 검증과정을 거쳐야한다. 조선해양분야에서는 우선 육상에서 시뮬레이션 시험 또는 환경시험을 통해 장비를 검증하고 있다. 하지만 육상시험만 진행하면 실운용환경에서의 검증데이터가 부족하다. 본 논문에서는 실운용 환경에서의 검증을 위한 실증시나리오 개발에 있어 고려할 수 있는 사항에 대해 기술한다.

• Journal of Astronomy and Space Sciences
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• 제32권4호
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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.

• 문화기술의 융합
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• 제7권3호
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• pp.415-424
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• 2021

본 연구는 성인 여성들을 대상으로 온라인 태권도 시범 공연으로 인한 플로우(Flow) 경험이 관여도 및 재관람 의도에 미치는 영향을 파악하고, 온라인 태권도 시범 공연의 활성화 및 관람객 증진, 성인 태권도 수련생 증진을 위한 실질적 자료를 제공하고자 한다. 이에 국기원 태권도 시범단이 공연한 '하이킥' 온라인 태권도 시범 공연을 관람한 관람객 들을 모집단으로 선정하였고, 결과와 논의를 통한 결론은 다음과 같다. 첫째, 여성 관람객들의 태권도 경험 유무로 인한 플로우, 관여도, 재관람의도의 차이는 플로우 하위요인 중 즐거움 요인을 제외한 주변의식, 시간왜곡, 관여도. 재관람의도 요인에서 차이가 있는 것으로 나타났다. 둘째, 온라인 태권도 시범 공연의 플로우(Flow) 요인 중 주의집중, 즐거움, 시간왜곡 요인은 관여도에 긍정적인 영향을 미친 것으로 나타났다. 셋째, 온라인 태권도 시범 공연의 플로우(Flow) 요인은 재관람의도에 긍정적인 영향을 미치는 것으로 나타났다. 넷째, 온라인 태권도 시범 공연의 관여도는 재관람의도에 긍정적인 영향을 미치는 것으로 나타났다.

• ETRI Journal
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• 제35권5호
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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.

• 청정기술
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• 제29권4호
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• pp.297-304
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• 2023

첨단 전자 제품 산업의 비약적인 발전은 환경적 측면에서 고농도 암모니아 폐수의 증가를 초래했다. 고농도 암모니아 폐수를 안정적으로 처리하기 위해 다양한 방법의 기술이 시도되고 있으나, 지금까지 성공적인 기술이 개발되어 적용되지는 못하고 있다. 본 연구에서는 첨단 전자산업에서 발생하는 고농도 암모니아 함유 폐수에 대하여 밀폐(closed) 순환형 대향류 충전탑 형식의 실증설비를 이용하여 온도, 공기부하율 그리고 폐수부하율 변화에 따른 암모니아성 질소의 제거효율과 제거 특성을 평가하였다. 폐수량 20.8 m³ h^-1, 공기량 18,000 Nm³ h^-1의 운전 조건에서 온도를 45, 50, 55 그리고 60℃로 변경하여 운전한 결과, 암모니아성 질소(NH₃-N)의 제거율은 각각 87.5, 93.4, 96.8 및 98.7%로 온도가 제거율에 미치는 가장 큰 영향 인자임을 알 수 있었다. 공기부하율을 증가시키면 제거율도 증가하나, 흡수탑의 액적(droplet)이 탈기탑으로 유입되어 제거율 증가는 크지 않았다. 폐수 부하율이 변경되어도 제거율은 크게 변하지 않았는데, 이는 제거율에 영향이 없는 것이 아니라, 상대적으로 높은 공기부하율에 기인한 것으로 판단된다. 실증연구를 통해 암모니아 탈기법은 첨단 전자산업에서 발생하는 고농도 암모니아 폐수를 안정적으로 처리할 수 있는 적정한 공법임을 확인할 수 있었다.