• 한국산업융합학회 논문집
• /
• 제25권2_1호
• /
• pp.141-148
• /
• 2022

In this paper, the evaluation equations proposed by Tange et al. and Ando et al. were used to evaluate the threshold stress intensity factor ∆K^R_th(s) and fatigue limit ∆𝜎^R_wc, according to the small crack of offshore structural steel F690. Despite the differences in concept and shape of the two equations, the ∆K^R_th(s) and ∆𝜎^R_wc proved completely consistent. It is possible to use these equations to evaluate the dependence of the crack length on the ∆K^R_th(s) and ∆𝜎^R_wc of structures made of all steel grades. With these equations, the characteristics of microcracks can be quantitatively evaluated, and the safety and reliability of the structure can be secured.

• Nuclear Engineering and Technology
• /
• 제54권2호
• /
• pp.601-607
• /
• 2022

In recent years, monitoring of spent nuclear fuel inside dry cask storage has become an important area of national security. Muon tomography is a useful method for monitoring spent nuclear fuel because it uses high energy muons that penetrate deep into the target material and provides a 3-D structure of the inner materials. We designed a muon tomography system consisting of four 2-D position sensitive detector and characterized and optimized the system parameters. Each detector, measuring 200 × 200 cm², consists of a plastic scintillator, wavelength shifting (WLS) fibers and, SiPMs. The reconstructed image is obtained by extracting the intersection of the incoming and outgoing muon tracks using a Point-of-Closest-Approach (PoCA) algorithm. The Geant4 simulation was used to evaluate the performance of the muon tomography system and to optimize the design parameters including the pixel size of the muon detector, the field of view (FOV), and the distance between detectors. Based on the optimized design parameters, the spent fuel assemblies were modeled and the line profile was analyzed to conduct a feasibility study. Line profile analysis confirmed that muon tomography system can monitor nuclear spent fuel in dry storage container.

• 한국산업융합학회 논문집
• /
• 제25권5호
• /
• pp.783-789
• /
• 2022

In this study, STS316L rolled at five rolling degrees were treated with two types of subzero temperatures for 10, 30, and 60 minutes, respectively, and the dominant frequencies of elastic waves was investigated. The dominant frequency was higher as the subzero temperature was lower and the subzero treatment time was longer at each rolling degree. On the other hand, the dominant frequency was higher as the elongation decreased. In the time-frequency analysis for subzero temperature and time of the specimen with a rolling degree of 33%, the dominant frequency was higher at a subzero temperature of -196℃ than -50℃ regardless of subzero treatment time.

• 한국수학교육학회지시리즈C:초등수학교육
• /
• 제20권3호
• /
• pp.237-252
• /
• 2017

4차 산업혁명시대는 수학교육의 방향도 크게 흔들어 놓고 있다. 특히 수학이 다양한 영역에 어떻게 적용되고, 활용될 수 있는지 인식하는 융합 역량이 중요한 시점이다. 이에 본 연구에서는 융합에 대한 관점을 고찰하고, 수학교실에서 활용 가능한 융합 프로그램의 개발을 위한 수학적 탐색을 연구 목적으로 한다. 구체적으로 고대 이슬람 건축물에 사용된 기리 타일을 수학적 관점에서 분석하고, 이를 바탕으로 수학과 다자인 융합 교육을 위한 수학적 탐색을 실시한다. Roger Penrose 보다 500년이나 앞서 만든 기리 타일링의 수학적 분석을 통해 디자인에 대한 이해 및 수학의 활용성과 수학을 통한 타학문의 융합 가능성에 대한 이해의 폭이 넓어지기를 기대한다.

• Bulletin of the Korean Chemical Society
• /
• 제34권1호
• /
• pp.79-88
• /
• 2013

$LiFePO_4$ is a promising active material (AM) suitable for use in high performance lithium-ion batteries used in automotive applications that require high current capabilities and a high degree of safety and reliability. In this study, an optimization of the electrode design parameters was performed to produce high capacity lithium-ion batteries based on $LiFePO_4$/graphite electrodes. The electrode thickness and porosity (AM density) are the two most important design parameters influencing the cell capacity. We quantified the effects of cathode thickness and porosity ($LiFePO_4$ electrode) on cell performance using a detailed one-dimensional electrochemical model. In addition, the effects of those parameters were experimentally studied through various coin cell tests. Based on the numerical and experimental results, the optimal ranges for the electrode thickness and porosity were determined to maximize the cell capacity of the $LiFePO_4$/graphite lithium-ion batteries.

• 한국융합학회논문지
• /
• 제9권12호
• /
• pp.251-258
• /
• 2018

최근 들어 대학들은 학사구조의 다변화를 추구하고 있으며, 다전공 과정(연계전공, 융합전공, 자율전공, 자기설계전공 등) 도입으로 전공 및 학과 간 상호연계를 기반으로 융합인재양성에 노력을 기울이고 있다. 본 연구는 충청권 4개 대학이 연합으로 추진한 '글로벌 창의융합전공'의 설계 운영과정의 단계별 주요요소를 도출하고, 주요특징을 바탕으로 운영모델과 시사점을 제시하고 있다. 융합전공 운영모델은 대학 간 특화영역 연계를 통한 교육체계(인재상, 교육목표, 역량요소, 교육과정)의 구성하고, 역량요소(창의역량, 융합역량, 문제해결역량, 글로벌역량)를 기반으로 교과 및 비교과프로그램의 연계를 설계하였다. 융합전공 운영모델은 과정 및 단계에 따라 주요활동을 체계화함으로써 운영되고 있으며, 프로젝트 기반의 성과중심 지원프로세스를 구축함으로써 국내외 대회 참가, 국제발명대회 참가, 글로벌 역량강화를 지원하여 창의융합 인재양성에 기여하고 있다.

• 한국분말재료학회지
• /
• 제22권3호
• /
• pp.197-202
• /
• 2015

In this study, porous stainless steel (STS316L) sintered body was fabricated by powder metallurgy method and its properties such as porosity, compressive yield strength, hardness, and permeability were evaluated. 67.5Fe-17Cr- 13Ni-2.5Mo (wt%) powder was produced by a water atomization. The atomized powder was classified into size with under $45{\mu}m$ and over $180{\mu}m$, and then they were compacted with various pressures and sintered at $1210^{\circ}C$ for 1 h in a vacuum atmosphere. The porosities of sintered bodies could be obtained in range of 20~53% by controlling the compaction pressure. Compressive yield strength and hardness were achieved up to 268 MPa and 94 Shore D, respectively. Air permeability was obtained up to $79l/min{\cdot}cm^2$. As a result, mechanical properties and air permeability of the optimized porous body having a porosity of 25~40% were very superior to that of Al alloy.

• 한국융합학회논문지
• /
• 제10권4호
• /
• pp.209-217
• /
• 2019

본 연구의 목적은 그로테스크의 개념과 특징을 고찰하고 그로테스크의 회화적 역사를 살펴 본 후 시대별 회화 작품을 응용한 바디페인팅 융합 디자인 작품을 제시함으로써 창의적이고 독창적인 바디페인팅 디자인의 기초자료를 제시하는데 있다. 연구 방법은 관련 서적과 선행 연구 및 인터넷 자료 등을 토대로 그로테스크와 바디페인팅의 개념 및 특징, 표현기법 등을 이론적으로 고찰하고 시대별로 그로테스크 회화 작품의 이미지를 분석한 후 이를 바탕으로 융합 디자인하여 바디페인팅 작품을 제작하였다. 연구 결과, 바디페인팅 작품 제작을 통해 그로테스크를 비롯한 회화 작품들이 바디페인팅 작가들에게 무한한 상상력과 다양한 주제를 제시할 수 있다는 것을 알 수 있었다. 이러한 결과는 향 후 바디페인팅 작품을 디자인하는데 미술작품의 역할이 크게 작용할 수 있음을 시사하는 바이다. 또한 이를 좀 더 학문적이고 체계적으로 연구하고자 하는 이들에게 융합 디자인의 영감을 제시하여 예술 작품으로서의 바디페인팅이 하나의 독자적 영역을 공고히 하는데 도움이 되기를 기대한다.

• 유통과학연구
• /
• 제10권11호
• /
• pp.89-99
• /
• 2012

Purpose - Mobile devices, especially mobile terminals capable of telecommunication and wireless connectivity, are leading the advancements in consumer electronics. Digital convergence drives the functions of various devices, such as cellular phones, MP3 players, personal digital assistants, and gaming, into a single device. This trend would continue and applications such as digital audio and video streaming (including personalized content delivery mechanisms) would soon be on a handheld device. As customers want mobile convergence devices, manufacturers are driving new initiatives in the emerging mobile device market. Given the roles played by device design and service content in user satisfaction of a mobile convergence device, this study focuses on identifying and measuring the constructs for the process by which user satisfaction is achieved. This study synthesizes the expectation-disconfirmation paradigm with empirical theories in user satisfaction. Device and service levels are separated, and nine key constructs for user satisfaction of mobile convergence devices are proposed. Insight into this process could help web-based businesses to improve user satisfaction, thus enhancing the effectiveness of e-commerce for sellers and buyers. Research design, data, methodology - This study draws on three users of mobile convergence devices as examples. To test there search model and hypotheses, survey questionnaires were sent to 607 mobile device users. Mobile device users were initially identified from several members, and subjects were randomly drawn. Data from 577 survey responses were finally analyzed. The unit of measurement and analysis in this research study is at a personal level. Results - The measurements for the constructs were developed and tested in a two-phase study. In the first phase, the device and service dimensions were identified, and instruments for measuring them were developed and tested. In the second phase, using the salient dimensions of the device and service as the formulating first-order factors, instruments were developed and empirically tested to measure satisfaction of the device and service. In measuring satisfaction of mobile convergence devices, the critical tasks are to identify the key constructs of such user satisfaction and to develop validated instruments to measure them. Hence, the results of this study have immediate implications for businesses and for research in user satisfaction of mobile convergence devices. Conclusions - This study provides reliable instruments for operationalizing key constructs in the analysis of user satisfaction of mobile convergence devices within the expectation-disconfirmation paradigm. Hence, convergence device makers will be able to examine whether their websites meet their customers' expectations by examining the device aspect of the mobile convergence device customers, and the service aspect expectations and disconfirmation. Moreover, the introduction of expectation and disconfirmation constructs brings the marketing aspect of convergence devices into focus for such retailers, an aspect crucial to the effective design of websites for online businesses. In addition,this study provides the metrics required to initiate future studies on user satisfaction of mobile convergence devices.

• 한국산업융합학회 논문집
• /
• 제14권4호
• /
• pp.167-172
• /
• 2011

This paper investigated optimal design for slim wall mount arm for flat TV. Recently the number of flat TV sets in use went on increasing in TV market. As the flat TV sets are getting common, consumers came to need another requirements like aesthetic factor besides display performances. As the new TV sets tend to be slimmer due to aesthetic design, Wall mount also requires to be slimmer for aesthetic balance. Slim structures, however, are vulnerable to structural rigidity. In this study, slim wall mount arm has been designed by 3D CAD and DOE (Design of Experiments) and finite element analysis for optimal structural design were carried out to determine the design variables for minimize working stress of wall mount arm. Finally two optimal design conditions were selected through DOE and FEM and one of those was chosen under constraint of minimizing blanking developed length.