• Smart Structures and Systems
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• 제6권5_6호
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• pp.579-593
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• 2010

Low-power radio frequency (RF) chip transceiver technology and the associated structural health monitoring platforms have matured recently to enable high-rate, lossless transmission of measurement data across large-scale sensor networks. The intrinsic value of these advanced capabilities is the allowance for high-quality, rapid operational modal analysis of in-service structures using distributed accelerometers to experimentally characterize the dynamic response. From the analysis afforded through these dynamic data sets, structural identification techniques can then be utilized to develop a well calibrated finite element (FE) model of the structure for baseline development, extended analytical structural evaluation, and load response assessment. This paper presents a case study in which operational modal analysis is performed on a three-span prestressed reinforced concrete bridge using a wireless sensor network. The low-power wireless platform deployed supported a high-rate, lossless transmission protocol enabling real-time remote acquisition of the vibration response as recorded by twenty-nine accelerometers at a 256 Sps sampling rate. Several instrumentation layouts were utilized to assess the global multi-span response using a stationary sensor array as well as the spatially refined response of a single span using roving sensors and reference-based techniques. Subsequent structural identification using FE modeling and iterative updating through comparison with the experimental analysis is then documented to demonstrate the inherent value in dynamic response measurement across structural systems using high-rate wireless sensor networks.

• 한국시뮬레이션학회논문지
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• 제25권4호
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• pp.93-108
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• 2016

전기차 카셰어링은 친환경차량인 전기차를 여러 사용자들이 함께 이용함으로써 교통부문의 온실가스 발생량을 감소시키고, 동시에 자가용 증가로 인한 공간 및 환경문제를 해결할 수 있는 방안으로 주목받고 있다. 그러나 아직 도입단계에 불과하기 때문에 전기차 카셰어링 시스템의 효율성이나 사업가능성에 대한 연구나 분석이 필요한 실정이다. 이러한 배경하에 본 연구에서는 전기차 카셰어링 시스템의 운영상태와 결과를 분석이 가능한 모형을 개발하였으며, 현재 실시되고 있는 시범사업 내용을 반영하여 시뮬레이션을 실시하였다. 시뮬레이션 결과 전기차 카셰어링 시스템 운영과 관련된 변수들 사이의 관계와 운영효율을 최대화 할 수 있는 최적용량 등을 분석하였다. 시뮬레이션 분석에서는 차량대수와 충전기수가 증가할수록 서비스 제공율은 계속 증가하다가 일정수준에 도달하면 증가폭과 그 효율이 감소하는 것으로 나타났다. 또한 카셰어링 시스템 운영에 따른 수익과 비용을 분석하여 연간 운영 이익을 최대화 할 수 있는 최적 차량대수 및 최적 충전기 수를 도출하였다.

• STI Policy Review
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• 제8권2호
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• pp.75-93
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• 2017

Recently, global competition in the manufacturing sector is driving firms in the manufacturing sector to conduct product innovation projects to maintain their competitive edge. The key points of product innovation projects are 1) what the purpose of the project is and 2) what expected results in the target market can be achieved by implementing the innovation. Therefore, this study focuses on the performance of innovation projects with a business viewpoint. In this respect, this study proposes the "achievement rate" of product innovation projects as a measurement of project performance. Then, this study finds the best strategies from various innovation activities to optimize the achievement rate of product innovation projects. There are three major innovation activities for the projects, including three types of R&D activities: Internal, joint and external R&D, and five types of non-R&D activities - acquisition of machines, equipment and software, purchasing external knowledge, job education and training, market research and design. This study applies decision tree modeling, a kind of data-mining methodology, to explore effective innovation activities. This study employs the data from the 'Korean Innovation Survey (KIS) 2014: Manufacturing Sector.' The KIS 2014 gathered information about innovation activities in the manufacturing sector over three years (2011-2013). This study gives some practical implication for managing the activities. First, innovation activities that increased the achievement rate of product diversification projects included a combination of market research, new product design, and job training. Second, our results show that a combination of internal R&D, job training and training, and market research increases the project achievement most for the replacement of outdated products. Third, new market creation or extension of market share indicates that launching replacement products and continuously upgrading products are most important.

• 한국의류산업학회지
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• 제23권4호
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• pp.458-468
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• 2021

In the context of Sustainable development, China, the world's second-largest apparel market, is also concerned about the environmental impact of fiber waste. Currently, there is a great interest in sustainable fashion in both supply and demand in China. Based on the theory of planned behavior(TPB), the determinants of sustainable fashion consumption(SFC) of Chinese consumers were evaluated in this study: man-nature orientation(MNO) and environmental knowledge(EK) as motivation and perceived online-store accessibility(POA) and perceived money availability(PMA) as barriers. Wenjuanxing, a Chinese professional survey collection agency, conducted an online survey of millennials in Shanghai, China. The final sample size for the survey was 215. Partial least squares structural equation modeling was employed to test the proposed hypotheses. The results indicated that attitudes, subjective norms, and perceived behavioral control significantly affected the purchase intention towards sustainable fashion products. MNO and EK influenced the attitude, whereas EK, POA, and PMA influenced perceived behavioral control. This study contributes to the TPB literature through the examination of four antecedents: MNO, EK, POA, and PMA. The findings provide valuable insights for retailers and markets based on the identification of the motivations and barriers that enhance the purchasing intention of Chinese millennials toward SFC.

• 융합정보논문지
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• 제11권10호
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• pp.1-9
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• 2021

팬더믹의 영향으로 메타버스에 대한 관심이 증가하고 있으나, 지속성 있는 메타버스 운영을 위한 흥미 요인에 대한 이해는 부족한 실정이다. 따라서 본 연구는 사용자 커뮤니티 담화를 분석하여 메타버스 서비스의 흥미 요인을 밝히고자 한다. 이를 위해 게임 기반 메타버스의 대표 사례인 <모여봐요 동물의 숲>의 사용자 커뮤니티 담화를 수집해, Latent Dirichlet Allocation (LDA)를 활용해 토픽모델링을 실시했다. 추출된 토픽은 크래프팅과 성장을 위한 허들, 현실 연계 콘텐츠의 정보, 채집 활동과 수집 기록, 소셜라이징, 사용자 생성 콘텐츠와 자기표현, 시즈널 이벤트의 수행도, 캐릭터 상호작용과 슬롯 제한으로 나타났다. 게임 기반 메타버스의 흥미 요인은 성장과 확인 가능한 지표, 다양한 층위의 상호작용, 자기표현과 자유도, 현실세계와의 연결로 정리되고, 이를 통해 시간 기반 콘텐츠 운영, 운과 확률의 활용, 제약의 활용이라는 게임 기반 메타버스의 콘텐츠 기획 방향성을 도출했다. 본 연구는 실증적 담화 데이터를 활용해 흥미 요인을 도출했다는 것에 의의가 있다.

• 한국측량학회지
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• 제39권5호
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• pp.343-349
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• 2021

In The process from design to construction in the existing construction work was less efficient due to the contradictory approach of identifying the 3D state in the plan view and the repeated generation of surveys, floor plans, drawings. Accurate 3D design data is essential for smart construction. However, most of the existing related studies have focused on explaining the development method and main functions of equipment or improving the productivity of smart construction. Therefore, in this study, the utility of 3D design model generation for smart construction and construction survey using 3D laser scanner was evaluated. Plane and vertical road alignment were created using the specifications of the road. The generated road alignment was created as a three-dimensional corridor design using cross-sections at intervals of 20m. In addition, it was possible to create a DTM (Digital Terrain Model) using a digital map and effectively create a 3D design model for the study area through overlapping. Construction survey using a 3D laser scanner showed accuracy within 10cm as a result of the accuracy evaluation. These results proved that construction surveying using a 3D laser scanner is possible because it satisfies the acceptable accuracy of the relevant regulations modeling of target areas using 3D design and construction survey using 3D laser scanner can be a way to address shortcomings of existing GNSS (Global Navigation Satellite System) methods. And accurate 3D data will be used as essential data as basic data for smart construction.

• Journal of Preventive Medicine and Public Health
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• 제54권3호
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• pp.161-165
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• 2021

Objectives: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads heterogeneously, disproportionately impacting poor and minority communities. The relationship between poverty and race is complex, with a diverse set of structural and systemic factors driving higher rates of poverty among minority populations. The factors that specifically contribute to the disproportionate rates of SARS-CoV-2 infection, however, are not clearly understood. Methods: We evaluated SARS-CoV-2 test results from community-based testing sites in Los Angeles, California, between June and December, 2020. We used tester zip code data to link those results with United States Census report data on average annual household income, rates of healthcare coverage, and employment status by zip code. Results: We analyzed 2 141 127 SARS-CoV-2 test results, of which 245 154 (11.4%) were positive. Multivariable modeling showed a higher likelihood of SARS-CoV-2 test positivity among Hispanic communities than among other races. We found an increased risk for SARS-CoV-2 positivity among individuals from zip codes with an average annual household income

• 지식경영연구
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• 제20권2호
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• pp.25-42
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• 2019

AI speakers which are wireless speakers with smart features have released from many manufacturers and adopted by many customers. Though smart features including voice recognition, controlling connected devices and providing information are embedded in many mobile phones, AI speakers are sitting in home and has a role of the central en-tertainment and information provider. Many surveys have investigated the important factors to adopt AI speakers and influ-encing factors on satisfaction. Though most surveys on AI speakers are cross sectional, we can track customer attitude toward AI speakers longitudinally by analyzing customer reviews on AI speakers. However, there is not much research on the change of customer attitude toward AI speaker. Therefore, in this study, we try to grasp how the attitude of AI speaker changes with time by applying text mining-based analysis. We collected the customer reviews on Amazon Echo which has the highest share of AI speakers in the global market from Amazon.com. Since Amazon Echo already have two generations, we can analyze the characteristics of reviews and compare the attitude ac-cording to the adoption time. We identified all sub topics of customer reviews and specified the topics for smart features. And we analyzed how the share of topics varied with time and analyzed diverse meta data for comparisons. The proportions of the topics for general satisfaction and satisfaction on music were increasing while the proportions of the topics for music quality, speakers and wireless speakers were decreasing over time. Though the proportions of topics for smart fea-tures were similar according to time, the share of the topics in positive reviews and importance metrics were reduced in the 2nd generation of Amazon Echo. Even though smart features were mentioned similarly in the reviews, the influential effect on satisfac-tion were reduced over time and especially in the 2nd generation of Amazon Echo.

• 기술혁신학회지
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• 제22권3호
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• pp.340-361
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• 2019

본 연구는 특허 데이터를 활용하여 인공지능 기술의 구조를 파악하고 주요 글로벌 IT 기업들의 인공지능 기술역량을 분석한다. 2007년부터 2017년까지 미국 특허청에 등록된 2,589개의 인공지능 특허를 바탕으로 LDA 토픽모델링을 수행하여 인공지능 분야의 20개의 기술 토픽을 도출하였다. 인공지능 기술 분야 중 언어이해, 음성처리보다는 시각이해, 데이터분석, 동작제어, 그리고 기계학습 분야의 연구개발이 최근 활발한 것으로 나타났다. 또한 기업별 인공지능 기술 역량을 분석하여 인공지능 기술 분야별로 우수 역량을 보유한 기업을 도출하고, 기업별로 강점을 가지고 있는 세부 기술 분야를 도출하였다. 본 연구 결과는 인공지능 기업들의 기술기획 및 전략 수립에 유용하게 활용될 수 있을 것으로 기대된다.

• 한국정보시스템학회지:정보시스템연구
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• 제28권3호
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• pp.1-23
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• 2019

Purpose This study examines the role of corporate image and privacy concerns in intention to use of online travel services using data from Vietnam. Design/methodology/approach The data collection was implemented to a student sample at the Foreign Trade University in Hanoi, which has a high concentration of young people who are interested in online travel in Vietnam. The paper based questionnaire was directly delivered to the respondents. After sorting to eliminate unfit samples, the number of responses was 541, which exceeds 500, the minimum number typically required. To test the hypotheses, we applied structural equation modeling (SEM) and Confirmatory Factor Analysis (CFA) was used to evaluate the reliability and validity of constructs in the model. We also used direct, indirect and total effect coefficient to evaluate the total impact of factors on the intention to use online services. Findings This study found that corporate image is positively associated to intention to use online services. It found a link between corporate image and privacy concerns, which suggests another way for firms to address their customers' privacy concerns; corporate image, which has received great attention in traditional offline sales channels, but not in online services, should receive higher attention in IS research. Online travel businesses, besides increasing ease of use, perceived usefulness and trust in their services, should focus on build a reliable corporate image, which can not only promote the service use but also help to eliminate users' the privacy concerns.