• Computers and Concrete
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• 제2권3호
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• pp.177-188
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• 2005

This paper presents a numerical model developed to evaluate the load-deflection and moment-curvature relationship for concrete beams strengthened externally with four different Fiber Reinforced Polymer (FRP) composite systems. The developed model considers the inelastic behavior of concrete section subjected to a combined axial force and bending moment. The model accounts for tensile strength of concrete as defined by the modulus of rupture of concrete. Based on the adopted material constitutive relations, the model evaluates the sectional curvature as a function of the applied axial load and bending moment. Deflections along the beam are evaluated using a finite difference technique taking into account support conditions. The developed numerical technique has been tested on a cantilever beam with a transverse load applied at its end. A study of the behavior of the beam with tension reinforcement compared to that with FRP areas giving an equivalent ultimate moment has been carried out. Moreover, cracking of the section in the tensile region at ultimate load has also been considered. The results indicated that beams reinforced with FRP systems possess more ductility than those reinforced with steel. This ductility, however, can be tuned by increasing the area of FRP or by combining different FRP layers.

• 복식문화연구
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• 제28권4호
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• pp.508-526
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• 2020

This study has established a fashion illustration education plan using the contour drawing that fosters observational ability and enables creative drawing. This study developed two illustration curriculum proposals consisting of 15 weeks, combining literature and case studies. The researchers organized a step-by-step teaching plan that utilizes contour drawing according to the three stages of fashion illustration classes: foundation courses, general courses, and intensive courses. When the contour drawing is used at the beginning stage of the foundation courses of fashion illustration, it can be used as a technique to reduce the fear of students about practical skills, induce interest in illustration, and cultivate observation ability about objects. In general process, it is combined with various tools and coloring materials to strengthen expression power, and it is possible to produce detailed expressions and illustrations about human body and clothing. In intensive courses, it is expanded to the production of creative works with new aesthetics through digital techniques and mixed materials. As such, the contour drawing is expanded in various ways according to the learning contents and goals of each step, and is flexibly adjusted according to the learning content. Contour drawing has the effect of acquiring observation and expression ability, and it is analyzed as a technique that enables the production of creative illustration of students.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권5호
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• pp.583-595
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• 2018

Stiffened panels are widely used in naval architecture and ocean engineering, and knowledge about their dynamic behaviour represents important issue in the design procedure. Ordinary vibration analysis consists of natural frequencies and mode shapes determination and can be extended to forced response assessment, while the Structural Intensity (SI) analysis, assessing magnitude and direction of vibrational energy flow provides information on dominant transmission paths and energy distribution including sink positions. In this paper, vibrational energy flow in stiffened panels under harmonic loading is analyzed by the SI technique employing the finite element method. Structural intensity formulation for plate and beam element is outlined, and developed system combining in-house code and general finite element tool is described. As confirmed within numerical examples, the developed tool enables separation of SI components, enabling generation of novel SI patterns and providing deeper insight in the vibrational energy flow in stiffened panels, comparing to existing works.

• Smart Structures and Systems
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• 제22권5호
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• pp.587-609
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• 2018

There is greater significance in identifying the incipient damages in structures at the time of their initiation as timely rectification of these minor incipient cracks can save huge maintenance cost. However, the change in the global dynamic characteristics of a structure due to these subtle damages are insignificant enough to detect using the majority of the current damage diagnostic techniques. Keeping this in view, we propose a hybrid damage diagnostic technique for detection of minor incipient damages in the structures. In the proposed automated hybrid algorithm, the raw dynamic signatures obtained from the structure are decomposed to uni-modal signals and the dynamic signature are reconstructed by identifying and combining only the uni-modal signals altered by the minor incipient damage. We use these reconstructed signals for damage diagnostics using ARMAX model. Numerical simulation studies are carried out to investigate and evaluate the proposed hybrid damage diagnostic algorithm and their capability in identifying minor/incipient damage with noisy measurements. Finally, experimental studies on a beam are also presented to compliment the numerical simulations in order to demonstrate the practical application of the proposed algorithm.

• 대한전자공학회논문지SD
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• 제39권2호
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• pp.39-45
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• 2002

본 논문에서는 PDP 시스템에서의 새로운 EMI(전자파) 예측 방법을 제시한다. AC PDP 시스템을 정확하게 기술할 수 있는 새로운 AC PDP 셀 회로 모델을 개발하였다. 개발한 모델과 Hertzian 다이폴 안테나 모델을 결합하여 PDP 시스템에서 방출되는 EMI를 정량적으로 계산하였다. 시뮬레이션 결과는 테스트 패널을 이용한 실험을 통하여 검증되었다. AC PDP 시스템은 CISPR 13에 준거하여 반 무반향실에서 30㎒∼300㎒의 주파수 대역에서 측정하였다. 따라서 제시된 EMI 예측방법은 EMI와 관련한 PDP 시스템 설계에 유용하게 사용될 수 있다.

• 한국게임학회 논문지
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• 제9권4호
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• pp.57-66
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• 2009

퀘스트(Quest) 시스템은 MMORPG에서 콘텐츠를 제공하는 핵심 시스템 중 하나이다. 퀘스트디자인 업무에서 퀘스트 보상 설정은 게임 내 작용하는 여러 구성 요소의 높은 조합 복잡도로 인해 적절한 보상 수준을 산출하기가 어려운 문제에 속한다. 본 논문에는 퀘스트 보상 문제를 순회 판매원 문제(Traveling Salesman Problem, TSP)로 모델링하여 해결함으로써 적절한 보상수치를 자동적으로 산출해 낼 수 있는 기법을 제안하였다. 이를 통해 퀘스트 디자인 단계에서 퀘스트 보상 수치 확정을 위한 강도 높은 테스트 부담을 줄이고 정확한 보상 수치를 산출하는데 도움이 될 것이다.

• 천문학회보
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• 제38권2호
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• pp.50.2-50.2
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• 2013

Galaxy clusters, the largest gravitationally bound systems, are an important means to place constraints on cosmological models. Moreover, they are excellent places to test galaxy evolution models in connection to the environments. To this day, massive clusters have been found unexpectedly at high redshfit (Kang & Im 2009, Durret et al. 2011, Tashikawa et al. 2012), and evolution of galaxies in cluster has not been fully understood. Finding galaxy cluster candidates at z > 1 in wide, deep imaging survey data will enable us to solve such issues of modern extragalactic astronomy. We report new candidates of galaxy clusters in the wide and deep survey fields, European Large Area ISO Survey North1(ELAIS-N1) and North2(ELAIS-N2) fields, covering sky area of $8.75deg^2$ and $4.85deg^2$ each. We also suggest a new useful colour-colour selection technique to separate 1 < z < 2 galaxies from low-z galaxies by combining multi-wavelength data from the UKIRT Infrared Deep Sky Survey Deep Extragalactic Survey (UKIDSS DXS, JK bands), Spitzer Wise-area InfraRed Extragalactic survey (SWIRE, Optical-Infrared bands), Canada France Hawaii Telescope (CFHT, z band) and Infrared Medium-deep Survey(IMS, J band).

• Journal of electromagnetic engineering and science
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• 제9권3호
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• pp.152-158
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• 2009

We have developed a novel digital feedback predistortion(DFBPD) linearization based on RF feedback PD for the wide bandwidth modulated signals. The wideband PD operation is carried out by combining the DFBPD and memory lookup table(LUT). To experimentally demonstrate the linearization performance of the proposed PD technique for wideband signal, a class-AB amplifier using an LDMOSFET MRF6S23140 with 140-W peak envelope power is employed at 2.345 GHz. For a forward-link 2FA wideband code-division multiple-access signal with 10 MHz carrier spacing, the proposed DFBPD with memory LUT delivers the adjacent channel leakage ratio at an 10 MHz offset of -56.8 dBc, while those of the amplifier with and without DFBPD are -43.2 dBc and -41.9 dBc, respectively, at an average output power of 40 dBm. The experimental result shows that the new DFBPD with memory LUT provides a good linearization performance for the signal with wide bandwidth.

• 대한기계학회논문집B
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• 제31권8호
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• pp.663-671
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• 2007

In this work, shape optimization of a wire-wrapped fuel assembly in a liquid metal reactor has been carried out by combining a three-dimensional Reynolds-averaged Navier-Stokes analysis with the radial basis neural network method, a well known surrogate modeling technique for optimization. Sequential Quadratic Programming is used to search the optimal point from the constructed surrogate. Two geometric design variables are selected for the optimization and design space is sampled using Latin Hypercube Sampling. The optimization problem has been defined as a maximization of the objective function, which is as a linear combination of heat transfer and friction loss related terms with a weighing factor. The objective function value is more sensitive to the ratio of the wire spacer diameter to the fuel rod diameter than to the ratio of the wire wrap pitch to the fuel rod diameter. The optimal values of the design variables are obtained by varying the weighting factor.

• 한국생산제조학회지
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• 제18권3호
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• pp.248-254
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• 2009

The worn crater wear geometry of coated tools after machining has been configured by using Confocal Laser Scanning Microscopy(CLSM) and the Wavelet-based filtering technique. The CLSM can be well suited to construct the three-dimensional crater wear on the rake surfaces of coated tips. However, The raw heightness data of HEI(height encoded image) acquired by CLSM must be filtered due to the electronic and imaging noise occurring in constructing the crater image. So the Wavelet-based filtering algorithm is necessary to denoise the shape features in a micro scales so as to realize accurate crater wear topography analysis. The crater wear patterns filtered enable us to predict the crater wear shape in order to study the tool wear evolution. The study shows that the technique by combining the CLSM and Wavelet-based filtering is an excellent one to obtain the geometries of worn tool rake surfaces over a wide range of surface resolution in a micro scale.