• 수산해양기술연구
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• 제43권4호
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• pp.362-369
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• 2007

This paper was studied on the characteristics of acid resistance and thermal shock for epoxy coatings in the strong acidic environment. The exhaust gas system, such as a air preheater, desulfurization equipment, for industrial boiler is damaged by dew point corrosion. To protect the acid corrosion, the coating using nonmetal was applied. The electrochemical polarization test, acid resistance and thermal shock test for epoxy coatings were carried out. And the acid resistance and thermal shock characteristics, aspect, and electrochemical anti-corrosion characteristics for epoxy coatings in the strong acidic environment were considered. The main results are as followings: As the epoxy glass flake coating by acidic thermal shock was damaged to the crack, blistering and elution etc., the current density of epoxy glass flake coating is high. But the damage of epoxy metal complex coating by acidic thermal shock was not occurred. Therefore the characteristics of acid resistance and thermal shock for epoxy metal complex coating is better than those for epoxy glass flake coating.

• 지식경영연구
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• 제20권2호
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• pp.59-86
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• 2019

As the era of the 4th Industrial Revolution evolves, not only private companies but also government agencies and institutions in public sector are adopting cloud computing services converged by new information technologies such as IoT, big data, and artificial intelligence to strengthen competitiveness and create new business values. The purpose of this study is to investigate the relationship between innovation characteristics, innovation resistance, and acceptance of innovative technologies from the perspective of cloud computing services in the public sector. In this study, we collected the survey data from 190 employees of IT division in the public sector, and analyzed the causal relationship between innovation characteristics, technostress, innovation resistance, and intention to adopt the cloud computing service that they perceived. As a result of the analysis, we demonstrated that innovation characteristics, technostress have significant effect on innovation resistance and acceptance intention, and that top executive commitment and innovation resistance also have significant effect on acceptance intention. This study provides meaningful practical implications for the staffs preparing for adoption of cloud computing services and the executives who make the final decision in public sector.

• Smart Structures and Systems
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• 제24권4호
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• pp.435-446
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• 2019

The existing piezoelectric spherical transducers with fixed prescribed dynamic characteristics limit their application in scenarios with multi-frequency or frequency variation requirement. To address this issue, this work proposes an improved design of piezoelectric spherical transducers using the resistance tuning method. Two piezoceramic shells are the functional elements with one for actuation and the other for tuning through the variation of load resistance. The theoretical model of the proposed design is given based on our previous work. The effects of the resistance, the middle surface radius and the thickness of the epoxy adhesive layer on the dynamic characteristics of the transducer are explored by numerical analysis. The numerical results show that the multi-frequency characteristics of the transducer can be obtained by tuning the resistance, and its electromechanical coupling coefficient can be optimized by a matching resistance. The proposed design and derived theoretical solution are validated by comparing with the literature given special examples as well as an experimental study. The present study demonstrates the feasibility of using the proposed design to realize the multi-frequency characteristics, which is helpful to improve the performance of piezoelectric spherical transducers used in underwater acoustic detection, hydrophones, and the spherical smart aggregate (SSA) used in civil structural health monitoring, enhancing their operation at the multiple working frequencies to meet different application requirements.

• 한국초등과학교육학회지:초등과학교육
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• 제33권2호
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• pp.335-351
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• 2014

The 96 elementary school teachers' the degrees of understandings about the characteristics of the currents according to the connection methods of batteries in simple electric circuits were investigated. In this study, the concepts on the characteristics of currents according to the connection methods of batteries were divided 'the learned concepts' and 'the differentiated concepts'. The characteristics of the currents in the region of the larger resistance of load than the internal resistance of a battery were called the learned concepts, they are taught in the science curriculum. While the characteristics of the currents in the region of the smaller resistance of load than the internal resistance of a battery were called the differentiated concepts, they are not exposed clearly in the science curriculum. The results obtained in this study are as follows: The average score related to the learned concepts was relatively high, while the degree of the teachers' cognitions of the internal resistance of a battery and the resistance of wires were low. Also the average score related to the differentiated concepts was very low because it seems so new to the elementary school teachers. It strongly suggests that the elementary school teachers did not understand meaningfully the characteristics of the currents related to the connections of batteries on the ground of the cognitions of the internal resistances of batteries and the resistances of loads in simple electric circuits. Hence, they might experience difficulties due to the problems occurred in relation to the connections of batteries in the elementary school science lessons.

• Smart Structures and Systems
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• 제30권2호
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• pp.183-193
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• 2022

Structural health monitoring and structural vibration control are multidisciplinary and frontier research directions of civil engineering. As intelligent materials that integrate sensing and actuation capabilities, shape memory alloys (SMAs) exhibit multiple excellent characteristics, such as shape memory effect, superelasticity, corrosion resistance, fatigue resistance, and high energy density. Moreover, SMAs possess excellent resistance sensing properties and large deformation ability. Superfine NiTi SMA wires have potential applications in structural health monitoring and micro-drive system. In this study, the mechanical properties and electrical resistance sensing characteristics of superfine NiTi SMA wires were experimentally investigated. The mechanical parameters such as residual strain, hysteretic energy, secant stiffness, and equivalent damping ratio were analyzed at different training strain amplitudes and numbers of loading-unloading cycles. The results demonstrate that the detwinning process shortened with increasing training amplitude, while austenitic mechanical properties were not affected. In addition, superfine SMA wires showed good strain-resistance linear correlation, and the loading rate had little effect on their mechanical properties and electrical resistance sensing characteristics. This study aims to provide an experimental basis for the application of superfine SMA wires in engineering.

• 인터넷정보학회논문지
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• 제18권6호
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• pp.101-112
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• 2017

본 연구는 혁신확산이론과 혁신저항모델을 적용하여 소셜TV 혁신저항과 이용의도에 영향을 미치는 요인을 탐색하였다. 주요 결과를 중심으로 살펴보면, 첫째, 소셜TV 비이용자의 지각된 혁신특성 중 적합성과 복잡성은 혁신저항에 통계적으로 유의한 영향을 미치는 것으로 나타났다. 둘째, 소셜TV 비이용자의 인지된 위험은 혁신저항에 통계적으로 유의한 정적 영향을 미치는 것으로 나타났다. 셋째, 소셜TV 비이용자의 지각된 혁신특성 중 적합성과 복잡성은 이용의도에 통계적으로 유의한 영향을 미치는 것으로 나타났다. 넷째, 소셜TV 비이용자의 인지된 위험은 소셜TV 이용의도에 통계적으로 유의한 영향을 미치지 못한 것으로 나타났다.

• Structural Engineering and Mechanics
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• 제2권4호
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• pp.403-412
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• 1994

The durability of concrete is related to the permeation characteristics of its near surface. An attempt was made to use the permeation characteristics namely, absorptivity, permeability and diffusivity, to predict the freeze/thaw resistance of concrete. Test results indicate that in general, there was a trend that freeze/thaw resistance of concrete was enhanced with improved absorptivity and diffusivity whilst the freeze/thaw resistance of normal concrete was found to have the best relationship with its intrinsic permeability. The latter method is therefore proposed to be adopted to predict freeze/thaw resistance of normal concrete. Since Figg air test is an inexpensive and simple test method that measures indirectly the intrinsic permeability of concrete, it is further proposed that it could be used as a quality control tool to assess, non-destructively, the freeze/thaw durability potential of in-situ concrete.

• Journal of Advanced Marine Engineering and Technology
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• 제22권5호
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• pp.702-711
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• 1998

The characteristics of corrosion resistance for the surface of medium high carbon steels and low alloy steels utilizing as manufacturing the machinery structures and machining tools and treating by plasma/ion nitriding process have been studied in terms of electrochemical polarization behav-iors including corrosion potential(Ecorr) anodic polarization trends and polarization resistance(Rp) The seven base materials showed a clear passivation behavior for the polarization tests in the ASTM standard solution 1N ${H_2){SO_4}$ Although the treated surface by plasma nitriding for the seven test materials showed a significant increase in hardness the treatment gave a detri-mental effect in corrosion resistance. The various characteristics including corrosion potential polarization curves microstructures corrosion current polarization resistance among non-treat-ed nitriding and/or soft-nitriding treated specimens have been investigated and some of the mechanisms discussed.

• 한국콘텐츠학회논문지
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• 제14권8호
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• pp.61-73
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• 2014

기존의 전자책 연구들이 이용과 충족 이론과 기술수용모형 중심으로 이루어졌던 반면, 본 논문은 전자책의 확산을 어렵게 만드는 원인을 혁신저항모형을 토대로 분석하였다. 따라서 본 연구에서는 혁신특성으로 상대적 이점, 적합성, 복잡성을, 사용자특성으로는 혁신에 대한 태도, 기존제품(종이책)에 대한 태도를 변수로 도출하여 연구모형을 설정하였다. 온라인 설문조사를 실시해 각 변수들이 혁신저항에 미치는 영향을 알아보고 혁신저항과 수용의도의 관계를 검증하였다. 연구결과, 복잡성과 기존제품(종이책)에 대한 태도가 혁신저항에 영향을 미치는 결정 요인이었고, 혁신저항은 수용의도에 부정적인 영향을 미쳤다. 따라서 전자책의 구매에서부터 독서 경험 전 과정의 용이성을 높이는 데 주력해야 하며, 종이책의 사용경험과 차별화 되는 전자책 고유의 상호작용적 기능과 특성을 개발하고 부각해야 한다.

• 한국프랜차이즈경영연구
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• 제11권4호
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• pp.7-15
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• 2020

Purpose: The purpose of this study is to clarify the role of decoupling between job characteristics, innovation behavior, and innovation resistance in order to seek ways for companies to survive and grow continuously through innovation activities in various uncertain situations. Research design, data and methodology: A total of 263 valid questionnaires were collected and used for analysis for employees working at the company. For the analysis, simple and multiple regression analysis, and 3-step mediated regression analysis were conducted using SPSS 24.0 and AMOS 24.0. Results: First, it was found that skill variety, task identity, autonomy, and feedback increase decoupling, and decoupling increases innovation resistance. In addition, it was confirmed that decoupling had a mediating effect between job characteristics and innovation resistance excluding task significance. Finally, it was found that task significance and feedback increase innovation behavior, and decoupling and task identity increase innovation resistance, but feedback can alleviate innovation resistance. Conclusions: As a result of the analysis, the fact that job characteristics excluding task importance have a positive effect on decoupling means that there are two sides of job characteristics perceived by employees. In other words, it means that the results of analysis on the jobs that the company assigns to its members may not be effective. In addition, decoupling, a phenomenon that seems to be accepting on the outside, but perceives that it is negative on the inside, means that there is a possibility to reject innovation. Therefore, prior to carrying out innovation activities, companies should give clear job specifications and meanings for the job and give them autonomy when assigning jobs to their members. In order to provide appropriate feedback, the company must design, operate, and provide feedback. It was found that there was a need to review the overall effectiveness. In addition, efforts such as strengthening corporate-level fairness, maintaining psychological contracts, and realizing authentic leadership should be preceded to reduce decoupling.