• Advances in aircraft and spacecraft science
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• 제4권1호
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• pp.1-19
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• 2017

Fatigue life prediction of a multi-row countersunk riveted lap joint was performed numerically. The stress and strain conditions in a highly stressed substructure of the joint were analysed using a global/local finite element (FE) model coupling approach. After validation of the FE models using experimental strain measurements, the stress/strain condition in the local three-dimensional (3D) FE model was simulated under a fatigue loading condition. This local model involved multiple load cases with nonlinearity in material properties, geometric deformation, and contact boundary conditions. The resulting stresses and strains were used in the Smith-Watson-Topper (SWT) strain life equation to assess the fatigue "initiation life", defined as the life to a 0.5 mm deep crack. Effects of the rivet-hole clearance and rivet head deformation on the predicted fatigue life were identified, and good agreement in the fatigue life was obtained between the experimental and the numerical results. Further crack growth from a 0.5 mm crack to the first linkup of two adjacent cracks was evaluated using the NRC in-house tool, CanGROW. Good correlation in the fatigue life was also obtained between the experimental result and the crack growth analysis. The study shows that the selected methodology is promising for assessing the fatigue life for the lap joint, which is expected to improve research efficiency by reducing test quantity and cost.

• 한국광학회지
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• 제30권4호
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• pp.167-173
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• 2019

본 논문에서는 고출력 광섬유 레이저의 유도 브릴루앙 산란 억제 특성을 분석하기 위하여, 구형파, 사인파, 임의파 조건의 온도구배 기구부를 설계 및 제작하였다. 또한 전광섬유 MOPA (master oscillator power amplifier) 구조의 이터븀 첨가 편광유지 광섬유 증폭기를 제작하였으며, 온도구배 조건별 역반사 스펙트럼 및 출력을 측정하였다. 구형파 조건의 온도구배에 의해 유도 브릴루앙 산란이 가장 효과적으로 억제되었으며, PRBS (pseudo-random binary sequence) 위상변조 조건과 온도구배 간의 유도 브릴루앙 산란 특성에 끼치는 상호 영향성을 분석하였다.

• 문화기술의 융합
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• 제1권3호
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• pp.47-68
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• 2015

본 연구는 중년여성들이 현재까지 자신들의 삶을 어떻게 살아왔고, 현재시점에서 그들의 삶을 어떻게 바라보고 있는지, 그 경험의 의미와 구조는 무엇인지를 알아보고자 하였다. 이를 위해 50세에서 59세 사이의 중년여성 7명을 대상으로 총 3회에 걸친 인터뷰를 실시하였다. 인터뷰 자료는 현상학적 연구방법인 Giorgi 방법을 이용하여 분석과 해석의 과정을 거쳐서 진행하였으며, 그 결과 의미단위 358개를 도출하고, 다시 하위구성요소 26개로 묶은 후 최종 구성요소로 7개의 범주로 나누었다. 분석 결과, 중년여성들의 삶에 대한 조명은 "어려운 가정 형편", "원가족(family-of origin)의 의미", "역동적인 사회 경험", "결혼", "애달픔", "점점 느껴지는 노화"와 "삶의 초점"으로 구성되었다. 이상과 같은 의미를 바탕으로 중년 여성들의 삶에 대한 조명의 구조는 결론적으로, 어려운 가정형편을 더욱 절실하게 느낀 참여자들이 전문직종에 종사하게 되었으며, 역동적인 사회경험, 결혼, 자식에 대한 애달픔을 경험하면서 노화를 영성을 통하여 긍정적으로 바라보고 있었다. 이에 따라 본 연구에서는 중년여성들에게 통합적이고 바람직한 노후를 맞이하게 하기 위한 올바른 영성 프로그램의 제공을 제언한다.

• ETRI Journal
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• 제42권4호
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• pp.549-561
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• 2020

We developed a 0.1-㎛ metamorphic high electron mobility transistor and fabricated a W-band monolithic microwave integrated circuit chipset with our in-house technology to verify the performance and usability of the developed technology. The DC characteristics were a drain current density of 747 mA/mm and a maximum transconductance of 1.354 S/mm; the RF characteristics were a cutoff frequency of 210 GHz and a maximum oscillation frequency of 252 GHz. A frequency multiplier was developed to increase the frequency of the input signal. The fabricated multiplier showed high output values (more than 0 dBm) in the 94 GHz-108 GHz band and achieved excellent spurious suppression. A low-noise amplifier (LNA) with a four-stage single-ended architecture using a common-source stage was also developed. This LNA achieved a gain of 20 dB in a band between 83 GHz and 110 GHz and a noise figure lower than 3.8 dB with a frequency of 94 GHz. A W-band image-rejection mixer (IRM) with an external off-chip coupler was also designed. The IRM provided a conversion gain of 13 dB-17 dB for RF frequencies of 80 GHz-110 GHz and image-rejection ratios of 17 dB-19 dB for RF frequencies of 93 GHz-100 GHz.

• International Journal of Advanced Culture Technology
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• 제8권1호
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• pp.89-97
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• 2020

There are remains of Japanese gardens in Korea which were built during Japanese occupation in 1910-1945. However, systematic database has not been established for location, quantity, nor types of remaining gardens. This study is aimed at defining current status of Japanese gardens built in Korea. By categorizing types of remaining these Japanese gardens, we also aimed to build a systematic data base for Japanese gardens in Korea. This study was co-conducted by researchers from Korea and Japan. The team identified 17 Japanese gardens remaining in South Korea and categorized them into 4 groups; 1) Japanese garden built by Japanese in modern Japanese house in South Korea, 2) Japanese garden built by Korean in traditional Korean garden and 3) Garden built by Japanese in temples in Korea. (at request by Koreans). This categorization reveals information about the inflow of Japanese gardening culture into Korea and deserves to be an important part of modern gardening History. And the rest are 4) Japanese gardens built at Korean residence, but with much damage and alternation. In this paper, we present the findings to serve as preliminary data for defining Korean traditional gardens and for utilizing Japanese gardens in Korea as historical and cultural infrastructure.

• 한국산업융합학회 논문집
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• 제26권4_2호
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• pp.599-603
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• 2023

Analyzed in the NFDS, The average number of fires in vinyl temporary buildings is more than 1,000 in annually. And the number of deaths and injuries was around 30 people in every year. According to the National Fire Agency, There are 142,386 vinyl temporary buildings for Agriculture and Fishery, of which 4,720 are residential vinyl temporary buildings in illegally. Model house is subject to regulation in fire-related law. But, even though it's the same temporary building, Vinyl temporary building is not subject to regulation. For this reason, Vinyl temporary buildings are left in the blind spot of fire safety. Therefore, In this study, We propose that amend of Act on installation and management of firefighting systems, make of temporary fire safety controller, develop and apply of alarm system that is connected to a single-alarm smoke dretector, organize and operate volunteer fire brigade of the crop group to prevent and extinguish the fire.

• The Journal of Asian Finance, Economics and Business
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• 제8권2호
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• pp.583-593
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• 2021

The purpose of this study was to examine the relationship between transformational leadership and organizational performance with readiness to change and empower knowledge sharing quality as mediating variables. The survey was conducted by collecting the respondents' data by filling up forms which were designed using the google form application and collecting it using WhatsApp. This was performed on 400 respondents, encompassing employees from the National Agency of Drug and Food Control in Indonesia. The research model adopted was validated using Structural Equation Modeling technique with AMOS tool. The findings showed transformational leadership as a significant predictor of readiness to change and it proved relevant in empowering knowledge sharing quality, which in turn affects organizational performance. Furthermore, the effects of both two mediating variables was also examined, and only readiness to change significantly influenced the relationship between predictors of transformational leadership and organizational performance. The findings of this study showed the need for transformational leaders as the research focused on understanding the differences in employee character. This is required to encourage better performance by empowering quality knowledge dissemination mechanisms, with continuous in-house training activities. Therefore, the model adopted in this research and the hypotheses prove the direct effect of transformational leadership on organizational performance, achievable through the mediating role of readiness to change.

• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.855-861
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• 2012

A pioneering version of an on-line management system for high-energy molecules (MS-HEMs) was developed by the ADD and BMDRC in Korea. The current system can manage the physicochemical and explosive properties of virtual and existing HEMs. The on-line MS-HEMs consist of three main routines: management, calculation, and search. The management routine contains a user-friendly interface to store and manage molecular structures and other properties of the new HEMs. The calculation routine automatically calculates a number of compositional and topological molecular descriptors when a new HEM is stored in the MS-HEMs. Physical properties, such as the heat of formation and density, can also be calculated using group additivity methods. In addition, the calculation routine for the impact sensitivity can be used to obtain the safety nature of new HEMs. The impact sensitivity was estimated in a knowledge-based manner using in-house neural network code. The search routine enables general users to find an exact HEM and its properties by sketching a 2D chemical structure, or to retrieve HEMs and their properties by giving a range of properties. These on-line MS-HEMs are expected be powerful tool for deriving novel promising HEMs.

• International Journal of Advanced Culture Technology
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• 제8권3호
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• pp.90-100
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• 2020

Our overall society circulates in line with the economical situations characterized by production and consumption and companies play the role of providing products and services, thus taking very significant responsibilities for the socioeconomical and cultural aspects in society. Therefore, when designers attempt to think of a way to enable companies and society to share their values and propose specific concepts and visualize outcomes, it is very critical to be able to understand economical philosophy and management strategies that interconnect companies with society and seek out proper design approaches. Recently, the world's enterprise and management culture tend to connect products and services provided by companies through chains of social values. Based on the abovementioned shift in the management paradigm, the researcher investigates and analyzes actual cases of attempts by Samsung Electronics to achieve its social impacts and studies actual roles and approaches of in-house designers with creativity and insights of humanity with regard to these attempts. Each case is selected from various fields such as the company's products and service development, business systems, culture, and external strategies and the ultimate goal is to learn about actual insights and approaches of designers to make contributions to the company's management with social impacts. Especially, humanity and creative thinking of many designers working in the manufacturing industry can have significant contributions to achieving its management with social impacts and effects of sustainable management.

• International Journal of Advanced Culture Technology
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• 제8권2호
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• pp.58-67
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• 2020

In this paper, the maintenance training manual of EV vehicle was produced by utilizing digital twin technology and various sensors such as IR-based light house tracking and head tracker. In addition, through digital twin technology and VR to provide high immersiveness to users, sensory content creation technology was secured through animation and effect realization suitable for EV vehicle maintenance situation. EV vehicle maintenance training manual is 3D engine programming and real-time creation of 3D objects and minimization of screen obstacles and selection of specific menus in virtual space in the form of training simulation. In addition, automatic output from the Head Mount Display (HUD), EV vehicle maintenance and inspection, etc., user can easily operate content was produced. This technology development can enhance immersion to users through implementation of detailed scenarios for maintenance / inspection of EV vehicles" and 3D parts display by procedure, realization of animations and effects for maintenance situations. Through this study, familiarity with improving the quality of education and safety accidents and correct maintenance process and the experienced person was very helpful in learning how to use equipment naturally and how to maintain EV vehicles.