• 한국수학교육학회지시리즈E:수학교육논문집
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• 제37권2호
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• pp.213-231
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• 2023

이분모분수의 덧셈과 뺄셈은 약분과 통분을 활용하여 분수의 값을 변형시키는 과정을 요구하는 복잡한 과정이다. 따라서 약분과 통분 및 이분모분수의 덧셈과 뺄셈은 필연적으로 밀접한 관련이 있다. 이에 2015 개정 교육과정이 반영된 초등 수학 교과서 국정 1종 및 검정 10종 중 약분과 통분 및 이분모분수의 덧셈과 뺄셈 단원을 대상으로 차시 흐름 및 시각적 표현을 분석하여 교수학적 시사점을 도출하고자 하였다. 분석 결과, 약분과 통분 및 이분모분수의 덧셈과 뺄셈 단원의 차시 흐름은 출판사별 차이가 크지 않고 유사하게 구성되어 있었으나 주요 활동 및 교과서 구성에서 차이가 나타났다. 또한, 각 교과서의 특성에 따라 시각적 표현의 종류 및 개수가 다양하게 나타났으며 이에 따른 장단점을 고려하여 수업 방향 및 내용을 구성할 필요가 있다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.177-180
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• 2009

Tube hydroforming provides a number of advantages over the conventional stamping process, including fewer secondary operations, weight reduction, assembly simplification, adaptability to forming of complex structural components and improved structural strength and stiffness. A hydroformed vehicle body component has an attachment flange or the like-formed as an integral part of the hydroforming process. For a given flange shape, a parting plane for the dies is established relative to which the various surfaces of the flange shape, in cross section, have no significant reverse curvature. This study shows analysis results that form the flanged tubular parts in the hydroforming. The thickness variations and defects during the hydroforming for flange forming could be analyzed by FE analysis. FE analysis was performed by LS-DYNA/Dynaform 5.5.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.184-189
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• 2008

In this study, an artificial wheel load generation method is proposed to assist practical engineers performing dynamic analysis with simple procedure. To generate an artificial wheel loads from running vehicle, PSD(Power Spectrum Density) profiles of actual wheel load were sampled in terms of various road roughnesses. A detailed truck and bridge models were used for sampling actual wheel load to represent the real motion of moving vehicle. These wheel load profiles were simplified for the artificial wheel load. The simplification of actual wheel load profiles was performed by regression analysis. The result showed that the artificial wheel load well represents the real profiles of wheel load.

• 대한의용생체공학회:의공학회지
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• 제21권6호
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• pp.559-566
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• 2000

Methodology for finite element analysis of vertebral column and pedicle screw system, which circumvents the tremendous difficulties in geometric, material, and structural modeling, is proposed. The simplification is focused on the modeling of the cancellous bone in vertebral body the intervertebral disc. and the instrumented internal fixation devices. Each proposed modeling technique is justified to result in reasonable accuracy. These methods are believed to be suitable for the development of pedicle screw systems, not only because modeling itself is much simpler. but also because reliable empirical data for disc stiffness may be incorporated with little additional effort, and presumably frequent design change may be easily reflected on the analysis.

• 소성∙가공
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• 제11권5호
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• pp.414-422
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• 2002

Most of numerical analyses for injection molding have been based on the Hele Shaw's approximation: two-dimensional flow analysis. In some cases, that approximation causes significant errors due to loss of geometrical information as well as simplification of the flow characteristics along the thickness direction. The present work covers numerical analyses of injection molding using three-dimensional solid elements. The accuracy of the analysis results has been verified through some numerical examples in comparison with the classical shell-based approach. The Proposed approach is then applied to predict product defects and to improve flow characteristics for a precision electronics part. In addition, design of experiment has been utilized in order to find the optimal process conditions for better product quality.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 금형가공 심포지엄
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• pp.68-75
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• 2002

Most of numerical analyses for injection molding have been based on the Hele Shaw's approximation: two-dimensional flow analysis. In some cases, that approximation causes significant errors due to loss of geometrical information as well as simplification of the flow characteristics along the thickness direction. The present work covers numerical analyses of injection molding using three-dimensional solid elements. The accuracy of the analysis results has been verified through some numerical examples in comparison with the classical shell-based approach. The proposed approach are then applied to predict product defects and to improve flow characteristics for a precision electronics part. In addition, design of experiment has been utilized in order to find the optimal process conditions for better product quality.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(3)
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• pp.59-62
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• 2001

This paper discusses a data mining technique for time series analysis of traffic data, which provides useful knowledge for network configuration management. Commonly, a network designer must employ a combination of heuristic algorithms and analysis in an interactive manner until satisfactory solutions are obtained. The problem of heuristic algorithms is that it is difficult to deal with large networks and simplification or assumptions have to be made to make them solvable. Various data mining techniques are studied to gain valuable knowledge in large and complex telecommunication networks. In this paper, we propose a traffic pattern association technique among network nodes, which produces association rules of traffic fluctuation patterns among network nodes. Discovered rules can be utilized for improving network topologies and dynamic routing performance.

• 한국연소학회지
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• 제17권2호
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• pp.17-23
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• 2012

In this study, thermoacoustic analysis model was developed in order to predict both eigenfrequencies and initial growth rate of combustion instabilities for lean premixed gas turbine combustors. As a first step, a model combustor and nozzle were selected and analytical linear equations for thermoacoustic waves were derived for a given combustion system. Then, methods showing how the equations can be used for analysis of the combustion instability were suggested. It was found that the prediction results showed a good agreement with the measurements. However, there were some limitation in growth rate predictions, which were related with over-simplification of flame structure, acoustic boundary conditions, and temperature distribution in the combustor.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1308-1311
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• 1996

We propose a new linearized model which can be used very efficiently for the design and analysis of the autopilot of aerodynamically controlled skid-to-turn missiles. Proposed model is based on the linearized equations of the missile dynamics derived in the aerodynamic frame where xz plane contains the missile longitudinal axis and velocity vector. However, to take the effect due to the small perturbation of the missile body into consideration, we introduce a new frame which is identical to the aerodynamic frame in the trim state but after small perturbation it moves fixed with the missile body, and finally, the proposed model is set up in this frame. It is shown by nonlinear simulations and stability analysis of a numerical example that the new model describes the missile motion better than the conventional one linearized in the body frame with a certain amount of simplification.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.485-492
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• 2000

Current design practice for the prediction of tunnelling-induced ground movements depends on empirical methods, which are based on many assumptions and simplification of the modeling. Some discrepancies between the predictions and the measurements of ground movements regarding adjacent structures are inevitable. In order to investigate tunnel-induced ground movements affect on the settlement of existing structures as well as existing structures affect tunnel-induced ground movement, 2-D elasto-plastic finite element analysis are performed. The following influencing factors such as load of the structures, the width of structures, its bending and axial stiffness, its position relative to the tunnel are considered in the numerical analysis.