• 한국수소및신에너지학회논문집
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• 제34권6호
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• pp.641-649
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• 2023

This study analyzes the cool-down process of liquid hydrogen storage tanks, which have advantages in terms of large-capacity transfer, storage, and utilization as hydrogen demand increases. A hydrogen liquefaction plant is selected for analysis and an efficient tank cooling method is sought by comparing the time required for the cool-down process with the gas consumption in connection with the gassing-up process required for the operation of the liquid hydrogen storage tank. The results of this study can be referred to in the operation process after the initial start-up and maintenance of the hydrogen liquefaction plant.

• 한국컴퓨터정보학회논문지
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• 제29권7호
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• pp.221-229
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• 2024

경제발전 수준이 높아짐에 따라 인적자본에 대한 관심은 더욱 높아지고 있다. 본 연구는 중국의 31개 지역을 대상으로 2002-2019년 기간 지역별 혁신적 인적자본을 추계 비교하고 있다. 본 연구의 혁신적 인적자본은 학력형 인적자본, 논문형 인적자본 그리고 특허형 인적자본으로 구성된다. 특히 본 연구는 기존 연구와 달리 특허형 인적자본과 논문형 인적자본의 가중치를 학력형 인적자본보다 높게 가정하고 있다. 왜냐하면 단순한 학력보다는 특허와 논문이 지역의 혁신역량에 상대적으로 더욱 큰 영향을 초래할 것이기 때문이다. 본 논문의 분석결과는 세 가지로 요약할 수 있다. 첫째, 중국의 지역별 혁신적 인적자본이 지역별 격차를 나타내고 있다. 지역경제발전 수준이 높은 지역일수록 혁신적 인적자본의 수준도 높다. 둘째, 지역별 혁신적 인적자본이 동태적으로 변하고 있다. 셋째, 북경시, 상해시, 광동성, 강소성을 중심으로 지역별 집중 현상이 더욱 가속화되고 있다. 따라서 본 연구결과는 지역경제발전에서 혁신적 인적자본의 역할이 중요함을 강조하고 있다.

• Structural Engineering and Mechanics
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• 제66권3호
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• pp.399-409
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• 2018

This paper demonstrates the potential application of machine learning algorithms for approximate prediction of the load and deflection capacities of the novel type of Laced Steel Concrete-Composite (LSCC) beams proposed by Anandavalli et al. (Engineering Structures 2012). Initially, global and local responses measured on LSCC beam specimen in an experiment are used to validate nonlinear FE model of the LSCC beams. The data for the machine learning algorithms is then generated using validated FE model for a range of values of the identified sensitive parameters. The performance of four well-known machine learning algorithms, viz., Support Vector Regression (SVR), Minimax Probability Machine Regression (MPMR), Relevance Vector Machine (RVM) and Multigene Genetic Programing (MGGP) for the approximate estimation of the load and deflection capacities are compared in terms of well-defined error indices. Through relative comparison of the estimated values, it is demonstrated that the algorithms explored in the present study provide a good alternative to expensive experimental testing and sophisticated numerical simulation of the response of LSCC beams. The load carrying and displacement capacity of the LSCC was predicted well by MGGP and MPMR, respectively.

• Steel and Composite Structures
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• 제21권3호
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• pp.537-551
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• 2016

A new type of composite beam which consists of a wide flange steel shape beam and an innovative type of composite slab was introduced. The composite slab is composed of concrete slab and normal flat steel plates, which are connected by perfobond shear connectors (PBL shear connectors). This paper describes experiments of two large-scale specimens of that composite beam. Both specimens were loaded at two symmetric points for 4-point loading status, and mechanical behaviors under hogging and sagging bending moments were investigated respectively. During the experiments, the crack patterns, failure modes, failure mechanism and ultimate bending capacity of composite beam specimens were investigated, and the strains of concrete and flat steel plate as well as steel shapes were measured and recorded. As shown from the experimental results, composite actions were fully developed between the steel shape and the composite slab, this new type of composite beams was found to have good mechanical performance both under hogging and sagging bending moment with high bending capacity, substantial flexure rigidity and good ductility. It was further shown that the plane-section assumption was verified. Moreover, a design procedure including calculation methods of bending capacity of this new type of composite beam was studied and proposed based on the experimental results, and the calculation methods based on the plane-section assumption and plastic theories were also verified by comparisons of the calculated results and experimental results, which were agreed with each other.

• Structural Engineering and Mechanics
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• 제83권4호
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• pp.415-433
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• 2022

Eighteen (18) (120×300×2200 mm) beams were prepared and tested to evaluate the shear strength of Glass Fiber Reinforced Concrete (GFRC) beams with no shear reinforcement, and evaluate the effectiveness of various innovative strengthening systems to increase the shear capacity of the GFRC beams. The test variables are the amount of discrete glass fiber (0.0, 0.6, and 1.2% by volume of concrete) and the type of longitudinal reinforcement bars (steel or GFRP), the strengthening systems (externally bonded (EB) sheet, side near-surface mounted (SNSM) bars, or the two together), strengthening material (GFRP or steel) links, different configurations of NSM GFRP bars (side bonded links, full wrapped stirrups, side C-shaped stirrups, and side bent bars), link spacing, link inclination angle, and the number of bent bars. The experimental results showed that adding the discrete glass fiber to the concrete by 0.6%, and 1.2% enhanced the shear strength by 18.5% and 28%, respectively in addition to enhancing the ductility. The results testified the efficiency of different strengthening systems, where it is enhanced the shear capacity by a ratio of 28.4% to 120%, and that is a significant improvement. Providing SNSM bent bars with strips as a new strengthening technique exhibited better shear performance in terms of crack propagation, and improved shear capacity and ductility compared to other strengthening techniques. Based on the experimental shear behavior, an analytical study, which allows the estimation of the shear capacity of the strengthened beams, was proposed, the results of the experimental and analytical study were comparable by a ratio of 0.91 to 1.15.

• 한국벤처창업학회:학술대회논문집
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• 한국벤처창업학회 2007년도 춘계학술대회
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• pp.35-64
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• 2007

중소기업의 기술혁신 역량을 강화하기 위한 각종 정부 정책과 투자의 지속적인 확대에도 불구하고 우리나라의 산학연 협력 수준은 선진국에 비해 아직도 상당히 미홉한 것으로 평가되고 있다. 또한 기술혁신성과에 영향을 미치는 기업 내부요인에 대해 다양한 요인이 제시되고 있지만, 산학연 기술협력과 기술혁신성과 간의 관계에 대한 기존 연구에서는 산학연 기술협력과 성과 간의 직접적인 영향(상관)관계만을 고려하고 있으며, 기업 내부요인들에 의해 그 효과가 어떻게 달라지는지는 분석하고 있지 않다. 따라서 본 연구에서는 산학연 기술협력이 중소기업의 기술혁신 성과를 높이기 위해서 어떤 중소기업을 지원해야 하며, 증소기업들이 어떤 내부적인 노력을 해야 하는가를 우리나라 증소제조업을 대상으로한 실증분석을 통해 규명하고자 한다. 분석 결과, 산학연 기술협력과 흡수 능력 중 혁신적 인적자원관리 시스템이 기술혁신성과에 정(+)의 영향을 끼쳤다. 또한 산학연 기술협력과 혁신적 인적자원관리 시스템 간에 정(+)의 상호작용 효과가 존재하는 것으로 나타났다. 이 연구는 정책적으로 산학연 기술지원을 할 때 기업의 기술개발강도만을 갖고 판단할 것이 아니라 기업 내부적으로 혁신 창출을 위한 노력, 즉 혁신적 인적자윈관리 시스템이 갖추어져 있는지 고려해 볼 필요가 있음을 시사한다. 경영 측면에서는 중소기업에 내부 자원과 능력의 한계가 존재하므로 외부자원을 충분히 활용함으로써 기술혁신성과를 높이는 것이 중요하다는 시사점을 제공한다.

• International Journal of Concrete Structures and Materials
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• 제3권2호
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• pp.119-126
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• 2009

This paper provides a brief summary of the performance of an innovative slip hardening twisted steel fiber in comparison with other fibers including straight steel smooth fiber, high strength steel hooked fiber, SPECTRA (high molecular weight polyethylene) fiber and PVA fiber. First the pull-out of a single fiber is compared under static loading conditions, and slip rate-sensitivity is evaluated. The unique large slip capacity of T-fiber during pullout is based on its untwisting fiber pullout mechanism, which leads to high equivalent bond strength and composites with high ductility. Due to this large slip capacity a smaller amount of T-fibers is needed to obtain strain hardening tensile behavior of fiber reinforced cementitious composites. Second, the performance of different composites using T-fibers and other fibers subjected to tensile and flexural loadings is described and compared. Third, strain rate effect on the behavior of composites reinforced with different types and amounts of fibers is presented to clarify the potential application of HPFRCC for seismic, impact and blast loadings.

• World Technopolis Review
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• 제4권3호
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• pp.157-167
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• 2015

Innovation system is a framework concept that can be classified in many ways, namely-national, regional, sectoral and technological. Regardless of classification, all these systems have some common features and characteristics as a system. Before the innovation system concept, Mongolia developed and implemented a system to maintain nation's capacity to acquire, absorb and disseminate technologies like other countries. There were two important practices in the system development. Firstly, Mongolia modified and implemented a system "ShBOS" (meant "Invention and Innovative Idea System") that met its unique features to create innovative culture in the nation. Secondly, newly emerged ICT sector was quickly scaled up to be able to export technological products. The main objective of this article is to study modern experience of developing the national innovation system in Mongolia, assess current state of the system, innovation awareness and readiness, and carry out recommendations on its improvement with particular focus on the capacity of ICT sector as a pilot sector. The paper suggests that the above mentioned two achievements can be applied for developing the national innovation system through technological innovation system approach.

• Steel and Composite Structures
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• 제35권4호
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• pp.509-525
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• 2020

Steel-concrete composite slabs with profiled steel sheeting are widely used in the execution of floors in steel and composite buildings. The rapid construction process, the elimination of conventional replaceable shuttering and the reduction of temporary support are, in general, considered the main advantages of this structural system. In slabs with the spans currently used, the longitudinal shear resistance commonly provided by the embossments along the steel sheet tends to be the governing design mode. This paper presents an innovative reinforcing system that increases the longitudinal shear capacity of composite slabs. The system is constituted by a set of transversal reinforcing bars crossing longitudinal stiffeners executed along the upper flanges of the steel sheet profiles. This type of reinforcement takes advantage of the high bending resistance of the composite slabs and increases the slab's ductility. Two experimental programmes were carried out: a small-scale test programme - to study the resistance provided by the reinforcing system in detail - and a full-scale test programme to test simply supported and continuous composite slabs - to assess the efficacy of the proposed reinforcing system on the global behaviour of the slabs. Based on the results of the small-scale tests, an equation to predict the resistance provided by the proposed reinforcing system was established. The present study concludes that the resistance and the ductility of composite slabs using the reinforcing system proposed here are significantly increased.

• 디지털융복합연구
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• 제8권2호
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• pp.29-42
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• 2010

그동안 정부는 R&D투자의 성과 제고를 위해 R&D 시스템 내의 구조와 프로세스를 개선하는데 많은 노력을 기울여 왔다. 그러나 대내외 기술 환경이 급변하고 투자규모가 지속적으로 증가함에 따라, 정부 R&D 또한 다양한 외부자원의 활용을 통해서 규모의 수확을 이룰 수 있는 혁신적인 접근방법이 필요한 상황이다. 이러한 관점에서 '개방형 혁신'은 외부자원에 대한 흡수능력 (absorptive capacity)을 향상시키고, 다양한 혁신주체 간 협력과 참여를 제고시킬 수 있다는 점에서 '정부실패'의 가능성을 최소화 시킬 수 있다. 본 논문은 정부 R&D투자의 성과에 관한 선행연구와 정부정책을 평가하고, 개방형 혁신이 정부 R&D투자의 성과 제고에 기여할 수 있는 연계성을 보여주고 있다.