• Smart Structures and Systems
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• 제29권3호
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• pp.499-512
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• 2022

This work proposes a novel contactless vibration damping and thermal isolation tripod platform based on Superconducting Magnetic Levitation (SML). This prototype is suitable for cryogenic environments, where classical passive, semi active and active vibration isolation techniques may present tribological problems due to the low temperatures and/or cannot guarantee an enough thermal isolation. The levitating platform consists of a Superconducting Magnetic Levitation (SML) with inherent passive static stabilization. In addition, the use of Operational Modal Analysis (OMA) technique is proposed to characterize the transmissibility function from the baseplate to the platform. The OMA is based on the Stochastic Subspace Identification (SSI) by using the Expectation Maximization (EM) algorithm. This paper contributes to the use of SSI-EM for SML applications by proposing a step-by-step experimental methodology to process the measured data, which are obtained with different unknown excitations: ambient excitation and impulse excitation. Thus, the performance of SSI-EM for SML applications can be improved, providing a good estimation of the natural frequency and damping ratio without any controlled excitation, which is the main obstacle to use an experimental modal analysis in cryogenic environments. The dynamic response of the 510 g levitating platform has been characterized by means of OMA in a cryogenic, 77 K, and high vacuum, 1E-5 mbar, environment. The measured vertical and radial stiffness are 9872.4 N/m and 21329 N/m, respectively, whilst the measured vertical and radial damping values are 0.5278 Nm/s and 0.8938 Nm/s. The first natural frequency in vertical direction has been identified to be 27.39 Hz, whilst a value of 40.26 Hz was identified for the radial direction. The determined damping values for both modes are 0.46% and 0.53%, respectively.

• 한국콘텐츠학회논문지
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• 제20권6호
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• pp.279-292
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• 2020

본 연구에서는 멀티플랫폼 환경에서 지상파TV의 채널브랜드자산이 시청자들의 지상파 콘텐츠 선택과 이용에 미치는 영향을 점검하였다. 연구결과, 지상파TV 채널브랜드자산이 멀티플랫폼 상 지상파TV 콘텐츠 이용 정도에 미치는 영향은 SBS인지도만이 지상파TV 콘텐츠 이용 정도에 유의미한 영향을 미치는 것으로 나타났다. 지상파TV 채널브랜드자산이 지상파 콘텐츠 시청 매체의 다양성에 미치는 영향은 어떤 채널에서도 유의미하지 않은 것으로 나타났으며, 지상파 콘텐츠 시청 플랫폼 유형별 이용에 미치는 영향은 지상파TV 채널별로 플랫폼 유형에 따라 차이를 보이는 것으로 나타났다. 더불어, 지상파TV 채널브랜드자산이 지상파 콘텐츠 이용 장르의 다양성에 미치는 영향은 KBS인지도와 SBS인지도만이 지상파TV 콘텐츠 이용 장르의 다양성에 유의미한 영향을 미치는 것으로 나타났다. 마지막으로, 지상파 채널브랜드자산이 지상파TV 콘텐츠 장르 유형별 이용에 미치는 영향은 각 채널별로 특정 장르유형을 중심으로 다르게 나타났다. 본 연구의 결과는 채널브랜드자산이 멀티플랫폼 상에서 시청자들의 지상파TV 콘텐츠 선택 및 이용에 부분적이나마 영향을 미친다는 것을 제시해주며, 이는 경쟁적인 매체환경에서 방송채널의 경쟁력 강화를 위해 의미있는 시사점을 제공해 준다.

• 사물인터넷융복합논문지
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• 제7권3호
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• pp.81-90
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• 2021

본 연구에서는 블록체인 기반 금융 플랫폼의 이용자 특성과 기술적 특성이 금융 소비자의 사용 의도에 미치는 영향을 분석하였다. 또한 이러한 영향 관계에서 상대적 이점과 인지된 위험이 사용 의도에 어떠한 인과 관계가 있는지를 분석하였다. 2021년 6월 1일부터 7월 30일까지 블록체인 기술이 접목된 금융 플랫폼을 사용한 경험이 있는 대상자를 표본으로 비대면 자기기입식 온라인 설문조사를 실시하였고, 187부로 연구를 진행하였다. 통계처리는 SPSS 21.0 프로그램을 이용하여 빈도 분석, 탐색적 요인 분석, 신뢰도 분석, 상관관계 분석, 다중 회귀분석, 3단계 매개 회귀분석을 실시하였다. 통계값의 유의 수준은 95% 미만으로 하였다. 연구 결과는 다음과 같다. 첫째, 이용자 특성에서 혁신성과 유용성이 사용 의도에 영향을 미치는 것으로 나타났다. 둘째, 기술적 특성에서 적합성과 신뢰성이 사용 의도에 영향을 미치는 것으로 나타났다. 셋째, 이용자 특성과 사용 의도의 관계에서 상대적 이점과 인지된 위험은 부분매개 역할을 하는 것으로 나타났다. 넷째, 기술적 특성과 사용 의도의 관계에서 상대적 이점과 인지된 위험은 부분매개 역할을 하는 것으로 나타났다. 다섯째, 인증서 사용 경험에 따라 이용자 특성의 편재성, 기술적 특성의 적합성, 사용 의도에서 차이가 있는 것으로 나타났다. 이러한 연구의 결과가 사물인터넷을 기반으로 한 금융 플랫폼 발전에 기여할 수 있을 것이다.

• 한국의류산업학회지
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• 제24권4호
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• pp.386-398
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• 2022

This study was conducted to corroborate the factors that influence consumer characteristics and technology acceptance on online luxury platforms, which are rapidly emerging as distribution channels for luxury brands. To this end, the relationship between the degree of technology acceptance and behavioral intention of fashion consumers on online luxury platforms and the effect on specific factors such as age and gender was investigated to see if there was a difference in behavior and use behavior. A survey was conducted on Korean consumers between the age of 20 and 40 who have used online luxury platforms and then, a statistical analysis was conducted. As a result of the study, performance expectancy and facilitating conditions, hedonic motivation, price value, and habit were found to have a significant effect on platform behavioral intention, but effort expectancy and social influence did not have a significant effect. Additionally, both facilitating conditions and habit were found to have a directly significant effect on the platform use behavior, and it was confirmed that the platform behavior intention also had a significant effect on the use behavior. As a result of confirming the moderating effect of gender and age, there was no difference based on gender, but only the relationship between price value and behavioral intention was found to have a moderating effect. It is hoped that domestic online luxury platforms will grow into channels with distinct characteristics and continue to develop in the luxury market by utilizing specific affect factors of this study.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1863-1866
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• 2005

In this paper we propose a platform that is applicable to low altitude remote sensing. Basic idea of the platform is based on the model helicopter. On big difference from the conventional model helicopter is that our platform has four main rotors. Furthermore, vision control strategy is introduced so that operator can use the platform without any specialized intensive knowledge

• Journal of Information Technology Applications and Management
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• 제27권2호
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• pp.51-71
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• 2020

Technological innovation can be both an opportunity and a crisis to take the initiative in the ecosystem, and companies are constantly competing to lead the platform within the ecosystem, including innovation in new products and services, absorption or integration of related industries. To cope with this rapid change in the environment today, it is essential to define the corporate ecosystem and platform business, and to understand the role and characteristics of users. This study seeks to conduct research on the usefulness, enjoyment, technicality, facilitation conditions, and causes of social impact on platform service loyalty to users of Kakao services. And this study will enable platform service providers through apps to use them as the basis for building business strategies in the service introduction phase.

• Smart Structures and Systems
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• 제11권2호
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• pp.135-161
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• 2013

This work presents a test platform for the assessment and benchmarking of modern actuators which have been specifically developed for the new field and service robotics applications. This versatile platform has been designed for the comparative analysis of actuators of dissimilar technology and operating conditions. It combines a modular design to adapt to linear and rotational actuators of different sizes, shapes and functions, as well as those with different load capacities, power and displacement. This test platform emulates the kinematics of robotic joints while an adaptive antagonist-load actuator allows reproducing the variable dynamic loads that actuators used in real robotics applications will be subjected to. A data acquisition system is used for monitoring and analyzing test actuator performance. The test platform combines hardware and software in the loop to allow actuator performance characterization. The use of the proposed test platform is demonstrated through the characterization and benchmarking of three controllable impedance actuators recently being incorporated into modern robotics.

• East Asian mathematical journal
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• 제39권2호
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• pp.167-181
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• 2023

The purpose of this study is to confirm the possibility of whether learning using a math learning platform can be used to expand students' conceptual structure and to consider how to use it. To this end, first-year middle school students studied using a math learning platform. Then, the concept map created was compared and analyzed with the concept map created before learning to examine the change in the concept structure. The results of analyzing the concept map are as follows. First, the change in the hierarchical structure of the concept appeared as the division of the upper concept was subdivided. However, it has also been changed to comprehensively integrate and simplify higher concepts. The term-centered concept structure has changed to content-centered superordinate and subordinate concepts. In the concept structure, subordinate concepts linked to one higher concept were expanded and differentiated. Second, changes in the integrated structure did not form a linkage structure. The expansion of the integrated structure of concepts through learning using the learning platform was influenced by the composition of the learning contents designed in the learning platform.

• 디지털콘텐츠학회 논문지
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• 제19권6호
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• pp.1151-1160
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• 2018

본 연구는 클라우드 기반 공통협업플랫폼의 사용행동을 알아보고자 실증 분석하여 결과를 도출하였다. 클라우드 기반 플랫폼의 독립변수들로 유연성, 신뢰성, 범용성, 보안성, 상호작용을 선정하였으며, UTAUT이론을 활용하여 사용의도를 매개변수로 최종적으로 사용행동을 종속변수로 선정 하였다. 조절변수로는 회사유형을 활용하였다. 가설검증은 AMOS 23.0과 SPSS 23.0 통계 프로그램을 사용하였으며, 클라우드 기반 공통협업플랫폼을 사용하는 사용자들을 대상으로 설문지를 배포하여 총 180부를 분석에 사용하였다. 분석결과, 신뢰성, 보안성, 상호작용은 사용의도에 긍정적인 영향을 미치는 것으로 나타났으며, 유연성, 범용성은 사용의도에 긍정적인 영향을 미치지 못하는 것으로 나타났다. 최종적으로 사용의도는 사용행동에 긍정적인 영향을 미치는 것으로 검증이 되었다. 마지막으로 회사유형에 따른 조절효과가 있는 것으로 나타났다.

• 대한물리의학회지
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• 제14권2호
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• pp.21-28
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• 2019

PURPOSE: This study was conducted to compare different standing postures with the use of standing aids for lumbar spine posture and muscle activity, and to identify the most desirable standing posture. METHODS: The lumbopelvic angle was assessed based on static radiographic measurement on the sagittal plane. Lumbar lordosis, lumbosacral lordosis, and the intervertebral joint angle at L1/L5 and L5/S1 were measured using radiography in three standing postures (standing on level ground, standing with one foot on a platform, and standing on a sloped surface). In addition, muscle activity was measured using surface electromyography to examine the co-contraction of the lumbar and hip muscles. RESULTS: Lumbar lordosis, lumbosacral lordosis, and L5/S1 intervertebral joint flexion occurred with one foot on the platform. No significant differences were found between standing on a sloped surface and standing on level ground. However, muscle co-contraction was reduced with the use of standing aids. CONCLUSION: This study demonstrated that standing with a foot on a platform induced lumbar lordosis, but that there was no significant difference between standing on a sloped surface and standing on level ground. However, muscle co-contraction was reduced with the use of standing aids. Based on the motor control pattern as a predictor of LBP, the use of standing aids would help workers during prolonged standing.