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        검색결과 10,754

        61.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 CFRP 그리드의 정착길이에 따른 콘크리트 보의 휨거동을 평가한 실험적 연구를 보고한다. 실험을 위해 폭 250 mm, 높이 125 mm, 길이 2000 mm의 실험체가 제작되었다. 실험변수로 CFRP 그리드의 정착길이(1000 mm, 800 mm, 700 mm, 600 mm, 500 mm, 400 mm, 300 mm, 200 mm)가 고려되었다. 실험체 제작 후 3점 휨실험이 수행되었다. 실험결과 모든 실 험체의 강성은 정착길이에 영향을 받지 않고 유사한 것으로 나타났다. 초기 균열하중은 모든 실험체에서 유사하게 나타났으나, 정착길이가 감소됨에 따라 최대하중, 최대하중 시의 처짐 및 변형률은 감소하는 경향을 나타냈다. 특히 부재 길이에 80% 이상 이 정착된 경우 부재 길이와 동일한 정착길이를 가진 콘크리트 보의 약 90% 이상의 구조성능을 확보할 수 있는 것으로 확인되 었다. 제안된 수치해석 모델은 CFRP 그리드의 정착길이가 감소됨에 따른 극한하중의 저하를 유사하게 예측하였으며, 극한하중 의 오차는 평균 13.1%로 CFRP 그리드의 정착길이에 따른 콘크리트 보의 휨성능을 비교적 정확하게 예측하는 것으로 나타났다.
        4,000원
        62.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 해양공간 통합관리 수단의 지원책으로 활용되는 해양공간 정책 시뮬레이터 기술에 대한 한국, 중국, 일본, 미국, 유럽 등 주요 5개국에 대한 정량분석을 위한 유효특허 1,474건을 도출하고, 연도별, 국가별 특허출원 동향 및 워드 클라우드 분석을 통해 국내 기술 경쟁력 및 국내·외 기술 트렌드를 파악하였다. 분석 결과 해양공간 정책 시뮬레이터 기술의 경우 중국(1,254건, 85.1%) 주도의 특허출원이 활발하게 이루어지고 있으며, 세부 기술별로는 어업환경 변화예측 및 활용 시뮬레이터(AC)가 392건(26.6%)으로 가장 높은 것 으로 나타난다. 핵심 키워드 변화를 통해 최근에는 다중 데이터의 수집과 데이터의 탐지, 예측, 평가 등으로 기술 트렌드가 이루어지고 있 음을 확인하였으며, 중국 주도의 시장 독과점 및 선점에 대비하기 위해 주변 기술에 대한 특허출원 고려 및 표준화 선점 등의 연계 전략 을 통한 대비와 정부 차원의 해양공간 정책 시뮬레이터 기술 연구개발에 대한 적극적인 정책적 지원이 필요함을 진단하였다.
        4,200원
        63.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aerospace and power generation industries have an increasing demand for high-temperature, highstrength materials. However, conventional materials typically lack sufficient fracture toughness and oxidation resistance at high temperatures. This study aims to enhance the high-temperature properties of Nb-Si-Ti alloys through ball milling. To analyze the effects of milling time, the progression of alloying is evaluated on the basis of XRD patterns and the microstructure of alloy powders. Spark plasma sintering (SPS) is employed to produce compacts, with thermodynamic modeling assisting in predicting phase fractions and sintering temperature ranges. The changes in the microstructure and variation in the mechanical properties due to the adjustment of the sintering temperature provide insights into the influence of Nb solid solution, Nb5Si3, and crystallite size within the compacts. By investigating the changes in the mechanical properties through strengthening mechanisms, such as precipitation strengthening, solid solution strengthening, and crystallite refinement, this study aims to verify the applicability of Nb-Si-Ti alloys in advanced material systems.
        4,000원
        64.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Composite-based piezoelectric devices are extensively studied to develop sustainable power supply and selfpowered devices owing to their excellent mechanical durability and output performance. In this study, we design a leadfree piezoelectric nanocomposite utilizing (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 (BCTZ) nanomaterials for realizing highly flexible energy harvesters. To improve the output performance of the devices, we incorporate porous BCTZ nanowires (NWs) into the nanoparticle (NP)-based piezoelectric nanocomposite. BCTZ NPs and NWs are synthesized through the solidstate reaction and sol-gel-based electrospinning, respectively; subsequently, they are dispersed inside a polyimide matrix. The output performance of the energy harvesters is measured using an optimized measurement system during repetitive mechanical deformation by varying the composition of the NPs and NWs. A nanocomposite-based energy harvester with 4:1 weight ratio generates the maximum open-circuit voltage and short-circuit current of 0.83 V and 0.28 A, respectively. In this study, self-powered devices are constructed with enhanced output performance by using piezoelectric energy harvesting for application in flexible and wearable devices.
        4,000원
        65.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A checklist of dietary behavior items for the elderly was developed based on Korean dietary guidelines. First, a literature review was conducted, and 63 preliminary items, including 30 items on food intake, 12 on eating habits, and 21 on dietary culture, were obtained to evaluate the dietary guidelines. The preliminary items were evaluated by experts using Lawshe’s method to verify the content validity. They were then revised, resulting in 52 items: 25, 11, and 16 in the food intake, eating habits, and dietary culture domains, respectively. A face-to-face survey was conducted on 331 people over 65 years of age in the metropolitan area, and their one-day food intake was surveyed using a 24-hour recall method in August 2022. The 48 items, including 24, 11, and 13 items on food intake, eating habits, and dietary culture, respectively, correlated significantly with the evaluation indicators of nutrient intake, such as mean adequacy ratio, dietary diversity score, and nutrient intake density. These items were considered suitable for evaluating the elderly's compliance with dietary guidelines.
        5,100원
        66.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 기존 (불)투과형 사방댐의 부식 및 시공성 등의 문제를 보완하고자 GFRP와 CFRP를 사용하여 내부식성 투과형 사방댐을 설계한 선행연구의 후속 연구로써 FRP로 제작된 격자형 사방 구조물(Grid)을 설계하여 탈부착이 가능한 투과 형 사방댐을 개발하기 위한 기초 연구이다. 이를 위해 탄소산업진흥원(K-Carbon)의 상용 Grid 제원을 인용하였으며, Grid를 구성 하는 띠(Strip)는 41×21개로 총 4000×2000×1.5 mm의 크기로 설계하였다. Grid의 개발을 위한 기초 연구라는 특성상 Grid의 지지 부(Slot)와 충진재는 파괴되지 않는다고 가정하였으며, FRP의 파괴 이론인 Hashin Damage Criteria에 따라 Grid의 설계하중 작용 시의 안전성을 상용 유한요소해석 프로그램인 ABAQUS로 평가하였다. 그 결과, 0.01~0.03sec 내에서 GFRP와 CFRP Grid가 파괴 되었으며, 이는 Grid의 성능이 충분하지 못함을 의미한다. 이에 따라 Grid의 성능 향상을 위해서 GFRP 및 CFRP(면재)와 Balsa Wood(심재)로 구성된 Sandwich Grid를 개발하였으며, 동일 조건에서 해석을 수행한 결과, Grid 대비 Sandwich Grid가 약 126~140 배 뛰어난 성능을 보였다. 결론적으로 Sandwich Grid를 이용한 탈착형 사방댐은 내구성 및 경제성 측면에서 이점이 분명하다 판 단되지만, 이는 일부 가정 사항과 수치 해석을 기반으로 하는 결과이므로 향후 추가 연구가 수행되어야 할 필요가 있다.
        4,000원
        67.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        By developing molds and facilities to horizontally mold the functional part of the dry-cast concrete block, We intend to develop molds and a series of facilities to horizontally mold the functional part of the dry-cast concrete block to increase production per cycle while maintaining existing production methods and major facilities. In order to do so, CAE analysis is first required to develop molds and facilities for horizontally molding the functional part of the drycast concrete block in the horizontal direction. The procedure will be carried out by reviewing the validity of boundary conditions and physical properties, 3D modeling, grid generation, construction of analysis models, model validity, analysis according to frequency changes, and analysis according to physical properties. First, through the comparison of two-point support, three-point support, and two-point and three-point support in the constraint conditions, We would like to compare it with the actual molded product in the horizontal direction. But first of all, it is considered two-point support in the constraint conditions in this paper.
        4,300원
        68.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        세계 각국은 온실가스 배출을 줄이기 위하여 활발한 노력을 하고 있다. 한국도 노후화된 석탄발전을 폐지하고 LNG 발전으로 전환하는 정책을 추진하고 있다. 그러나, 한국은 가스터빈 제작 기술이 국산화되지 않아서 해외 제작사로부터 전량 수입하여 설치하고 있다. 따라서, 본 논고에서는 가스터빈 발전산업에 대한 국내·외 환경을 살펴보고, 이를 기반으로 PEST-SWOT-AHP 방법론을 적용하여 한국형 가스터빈 기술개발 및 보급 확대 추진전략을 제안하였다. 연구결과, 한국형 가스터빈 기술개발과 보급 확대 전략은 1) 가스터빈 기술개발 및 사업화 촉진을 위한 발전공기업의 역할 강화, 2) 온실가스 감축을 위한 LNG 발전 비중 확대, 3) 정부의 적극적인 가스터빈 산업 생태계 조성 노력, 4) LNG 발전소 건설에 대한 국민 공감대 형성 등으로 요약할 수 있다.
        6,300원
        69.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study aimed to develop high-performance concrete repair materials for the cross-sectional repair of deteriorated bridge concrete. METHODS : To derive the optimal mix using the dry shotcrete method, experiments were conducted to develop an appropriate performance in terms of durability and watertightness based on basic experiments on materials. By mixing silica fume, GGBFS, and natural fibers, this study compared the differences in each variable. Each variable was compared using compressive strength, flexural strength, plastic shrinkage, chlorine ion penetration resistance, and freeze-thaw tests. RESULTS : By mixing silica fume and natural fibers, watertightness and durability were secured, and by adding an expansion material and polymer powder, a material that exhibited suitable performance as a repair material was developed. The material demonstrated suitable performance in terms of compressive strength, freeze–thaw resistance, plastic shrinkage crack resistance, and chlorine ion penetration resistance. CONCLUSIONS : The repair material developed in this study has a higher performance than repair mortar, and because it uses a dry shotcrete method, the process and post-processing are simpler than the wet shotcrete method; therefore, it is believed to be more efficient for repair work.
        4,000원
        70.
        2024.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        정책은 정부의 공식적인 기본방침이며 정책목표와 정책수단까지 연결 되어 있다. 특히, 정책은 법률에 기반하여 집행되는데 이러한 목적 및 방 향에 영향이 있는 정책명 및 법률명이 명시되어야 한다는 것이다. 그러 나 우리 사회가 현재 직면하고 있는 인구구조변화와 관련하여 다양한 논 의가 진행되고 있으나 이러한 현상을 설명하는 개념으로서 인구감소와 지방소멸 등을 혼용하고 있는 부분에 대해 비판적 입장이다. 즉, 정책의 정의 및 의의를 기초로하여 볼 때, 인구구조변화에 대해 혼용하는 것이 아닌 일치된 용어가 우선 선행되어야 한다. 본 연구에서는 기본적으로 지방소멸은 지나치게 자극적인 용어의 활용으로 관심을 높이는 데에 급 급한 것으로, 현상의 해결이나 미래지향적인 방향성을 제시하여 정책의 궁극적 목적과 괴리감이 있다. 이러한 비판에 근거로 세 가지를 제시하 였다. 감소와 소멸의 개념에 대한 문법적 차이, 정책의 정의와 연계성, 특별법 우선의 원칙이다. 이러한 근거에 따라 지방소멸이 아닌 인구감소 를 사용하여 적절한 정책과 법률이 활용되어 집행과 평가가 이루어져야 할 것이다.
        8,900원
        71.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In 2022, the domestic production performance of functional cosmetics in South Korea reached 4.6 trillion won, accounting for 33.85% of the total cosmetics production. The number of functional cosmetics reviewed increased by about 7.5% from the previous year, totaling 974 items. Especially with the increasing importance of the skin barrier function due to skin sensitivity caused by various environmental pollutants, domestic cosmetic companies are showing interest in the development of new ingredients and products related to this area. This study aims to analyze academic research trends related to in vitro experiments for the development of cosmetics improving the skin barrier, to provide practical information for the cosmetic industry. The findings are as follows: Academic research mainly focused on the efficacy of natural ingredients in improving the skin barrier, but there is a significant lack of quantitative accumulation of research. For the development of skin barrier-improving cosmetic ingredients, efficacy evaluation indicators were set, including hyaluronic acid production, expression of filaggrin gene, loricrin, formation of cornified envelope (CE), and expression of ceramide synthesis enzyme genes. Moreover, effective cosmetic ingredients for improving the skin barrier included lemongrass and perilla leaf extracts, flavonoids, Lactococcus lactis subsp. lactis, Exosomelike Nanovesicles derived from apple callus, Eleutherococcus sessiliflorus, Acanthopanax sessiliflorus, Eleutherococcus gracilistylus, Acer okamotoanum extracts, Aloe vera adventitious root extract, ethanol extract of Aruncus dioicus, and organic solvent fraction of Dracocephalum argunense.
        4,000원
        72.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study analyzes the body shapes of lower-body obese female adolescents and proposes a slacks pattern suitable for their body type. Lower-body obesity is a prevalent type of teenage obesity, and our proposals aim to improve consumer satisfaction in ready-to-wear clothes across this demographic. We first observe characteristics of obese lower bodies, noting significantly above-average thigh and hip circumference. These figures indicate a high degree of curvature in obese lower bodies, along with a large drop value. Leveraging this data, we develop a novel slacks pattern using 3D avatars in a virtual simulation system. The formulas for the main areas of the pattern are as follows: front waist girth W/4+0.75cm+0.5cm, back waist girth W/4+0.5cm– 0.5cm, front hip girth H/4+1.25cm–0.5cm, back hip girth H/4+2cm+0.5cm, front crotch extension H/16+0.5cm, back crotch extension H/8+1cm. Results from appearance evaluations show that this pattern minimizes strain rate on the waist and hips, and its average score is significantly higher than that of an alternative pattern that was also evaluated. The minimized strain rate and high average score indicate that our pattern assigns a sufficient amount of space to the appropriate areas. Based on these results, we expect our research to inform slacks pattern development and production for obese consumers of all types.
        4,500원
        73.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to merge Picasso’s expressive elements and deconstructive fashion’s formative traits, proposing an upcycle fashion design that fuses artistic and philosophical aspects. The analysis of Picasso’s Cubism identified qualities like liberating revolution, fluidity of vision, geometric reducibility, complex symbolism, and creative imitation. The analysis of Derrida’s deconstructionism revealed expressive traits: uncertainty, intertextuality, différance, and dis-de phenomenon. An upscale fashion design was developed based on six Picasso works featuring women. The design was created using the fashion design software CLO 3D and integrated clothing waste and scrap fabrics as materials.The results are as follows. First, upcycle fashion was viewed from a new perspective based on Picasso and Derrida’s values. This perspective suggested creating better ethical values by upholding environmental protection in novel ways that overcome limitations rather than destroy existing values indiscriminately. Second, upcycle fashion design methodologies were derived from various perspectives utilizing formative features of Picasso’s works and specific expressive features of deconstructed fashion. Third, the direction of mitigating waste and pollution from clothing production and transportation was revealed by making clothes in a virtual space using the CLO 3D program. This study contributed to obtaining various methods for developing upcycle fashion designs using own methods of Picasso and Derrida to diversify the approaches of upcycling, which is relatively stagnant in disassembling.
        5,200원
        74.
        2023.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This article presents the crucial role played by the French underground research laboratory (URL) in initiating the deep geological repository project Cigéo. In January 2023, Andra finalized the license application for the initial construction of Cigéo. Depending on Government’s decision, the construction of Cigéo may be authorized around 2027. Cigéo is the result of a National program, launched in 1991, aiming to safely manage high-level and intermediate level long-lived radioactive wastes. This National program is based on four principles: 1) excellent science and technical knowledge, 2) safety and security as primary goals for waste management, 3) high requirements for environment protection, 4) transparent and openpublic exchanges preceding the democratic decisions and orientations by the Parliament. The research and development (R&D) activities carried out in the URL supported the design and the safety demonstration of the Cigéo project. Moreover, running the URL has provided an opportunity to gain practical experience with regard to the security of underground operations, assessment of environmental impacts, and involvement of the public in the preparation of decisions. The practices implemented have helped gradually build confidence in the Cigéo project.
        4,600원
        75.
        2023.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Concerning the apprehensions about naturally occurring radioactive materials (NORM) residues, the International Atomic Energy Agency (IAEA) and its member nations have acknowledged the imperative to ensure the radiation safety of NORM industries. Residues with elevated radioactivity concentrations are predominantly produced during NORM processing, in the form of scale and sludge, referred to as technically enhanced NORM (TENORM). Substantial quantities of TENORM residues have been released externally due to the dismantling of NORM processing factories. These residues become concentrated and fixed in scale inside scrap pipes. To assess the radioactivity of scales in pipes of various shapes, a Monte Carlo simulation was employed to determine dose rates corresponding to the action level in TENORM regulations for different pipe diameters and thicknesses. Onsite gamma spectrometry was conducted on a scrap iron pipe from the titanium dioxide manufacturing factory. The measured dose rate on the pipe enabled the estimation of NORM concentration in the pipe scale onsite. The derived action level in dose rate can be applied in the NORM regulation procedure for on-site judgments.
        4,000원
        76.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Abstract Purpose : This study sought to identify ways to develop the Korean optometrists to meet the diverse and growing social demand for eye health services. Methods : We analyzed the optometrist qualification system, scope of practice, educational qualifications, and types of qualifications in 38 OECD countries based on the World Health Organization (WHO) and the European Union (EU) national occupational classifications of health care professions, data from World Council of Optometry (WCO) member countries, International Orthoptics Association (IOA), and databases of laws and occupational regulations in each country. Results : The occupational classification of the WHO and EU was classified into optometrists and dispensing opticians systems at the same level as medical personnel. However, the occupational classification in Korea is operating in a lower and monotonous structure. More than 78% of OECD countries operated optometrists system, and more than 67% of optometrists performed Category 3 or higher tasks, including prevention and management of abnormal visual function and primary screening and diagnosis of eye health. The educational level of optometrists was found to have a bachelor's degree or higher education than a bachelor's degree in more than 72% of countries. In addition, major overseas countries appeared to be developing into a system of subdivided qualification types such as orthoptist, advanced optometrist, therapeutic optometrist, independent prescribing optometrist, and ophthalmic medical technicians based on the optometrists system, essential clinical experience, and additional specialized education. Conclusion : The Korean optometrists system should introduce the international level as a national qualification, expand the scope of work to Category 3, and develop more specialized and subdivided qualifications. In conclusion, Korean optometrists need to have a standardized curriculum based on international standards, a bachelor's degree or higher, and certification with required clinical experience. Key words : Korean optometrist, Optometrist, Vision care Authors
        4,200원
        77.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The 4th Industrial Revolution and the continuous development of Science and Technology have also required a speedy business promotion method in the defense industry. Advanced countries including the United States are already boldly innovating the existing high-cost and long-term acquisition system with the highest priority in weapons development to cope with the military rise of Russia and China. The Ministry of National Defense and the Defense Acquisition Program Administration have also recently introduced a quick acquisition system and are applying it to business promotion. In addition, some small-scale projects and weapons systems are being reorganized so that they can be managed by the units demanding them. After an organizational diagnosis of the Project Acquisition Group by the Ministry of National Defense in 2020, it has been reassigned as a subordinate unit of the Army Logistics Command from a direct unit managed by the Army HQ. As a result, problems such as work conflict or redundancy have been identified. In addition, a system has been implemented to shorten the acquisition period by applying a rapid acquisition program in the field of weapons systems by benchmarking the rapid acquisition program of advanced countries. The force support system project process will also need to introduce such a quick acquisition system. In addition, the Ministry of National Defense is considering ways to delegate some weapon systems to each military, which will then carry out tasks ranging from requirements determination to project management. Accordingly, it is now time to expand the organization for the management of the Army's weapons system acquisition project. Therefore, in this paper, the Army Project Acquisition Group was analyzed on its organization, acquisition procedures, and cooperation systems, with presentations of development plans for each field.
        4,000원
        78.
        2023.12 구독 인증기관 무료, 개인회원 유료
        󰡔유몽천자(牖蒙千字)󰡕는 한국개신교선교사 게일(James Scarth Gale(한국명 : 奇一), 1863-1937)과 그의 조사(pundit) 이창직(李昌稙, 1866-1936)이 함께 편찬한 경신 학교와 정신여학교의 교과서이다. 이 책은 총 4권으로 구성된 교재다. 여기에 실린 내용 은 자연과학, 사회과학, 서양의 역사, 서양의 인물, 서양의 문학, 우리의 한문고전에 관한 것 등으로 이루어져 있다. 더불어 개화기에 우리의 어문 생활에 필요하다고 생각한 한자 와 관련 정보, 한자어, 국한문, 한문에 관한 지식을 정식 학교 교육을 받는 학생들에게 알 려 주기 위하여 편찬한 것이다. 본고에서는 이러한 󰡔유몽천자󰡕 전집의 체계와 구성, 전 집을 구성하는 3가지 문체 유형, 그리고 전집에 새겨져 있는 개신교선교사의 문체실험의 역사를 고찰했다.
        4,900원
        79.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, we present a case study of developing MVIS (Machine Vision Inspection System) designed for exterior quality inspection of stamping dies used in the production of automotive exterior components in a small to medium-sized factory. While the primary processes within the factory, including machining, transportation, and loading, have been automated using PLCs, CNC machines, and robots, the final quality inspection process still relies on manual labor. We implement the MVIS with general- purpose industrial cameras and Python-based open-source libraries and frameworks for rapid and low-cost development. The MVIS can play a major role on improving throughput and lead time of stamping dies. Furthermore, the processed inspection images can be leveraged for future process monitoring and improvement by applying deep learning techniques.
        4,000원
        80.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Approximately 40,000 elevators are installed every year in Korea, and they are used as a convenient means of transportation in daily life. However, the continuous increase in elevators has a social problem of increased safety accidents behind the functional aspect of convenience. There is an emerging need to induce preemptive and active elevator safety management by elevator management entities by strengthening the management of poorly managed elevators. Therefore, this study examines domestic research cases related to the evaluation items of the elevator safety quality rating system conducted in previous studies, and develops a statistical model that can examine the effect of elevator maintenance quality as a result of the safety management of the elevator management entity. We review two types: odds ratio analysis and logistic regression analysis models.
        4,000원
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