• Structural Engineering and Mechanics
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• 제83권5호
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• pp.681-692
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• 2022

The vibrational response of the two bones in a Volleyball player's arm under ball impact is conducted. The two bones in hand, Ulna and Radius, are modeled as two cylindrical shells. The formulations associated with the shells' vibration are obtained using the energy method. Then, the results are extracted with the aid of the two-dimensional form of DQM in conjunction with Runge-Kutta. The results are validated by means of a published paper. Lastly, the role of parameters in determining vibrational frequency as well as deflection is explored through parametric studies. It was shown that the impactor speed and the time of the impact could be essential factors in determining the vibration behavior of the bones. This work can be used in the further investigation of the behavior of bones and physiological structures.

• 한국공간구조학회논문집
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• 제6권3호
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• pp.43-50
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• 2006

This paper is concerned with the natural periods of ambient vibration and eigenvalue analysis. Ambient vibration tests were conducted to four bearing-wall reinforced concrete buildings ranging from twelve to nineteen stories. The performance of modeling in eigenvalue analysis was investigated using consideration of rigidity out of the plane in the slab and the non-structural bearing wall. Measured natural period was also compared with the value by the KBC2005. Natural period of the short direction in eigenvalue analysis is well fitted with the measured one. In the other hand, Natural period of the long direction in eigenvalue analysis is slightly more overestimated than the measured one. Natural period of the long direction in eigenvalue analysis was found to be enhanced by considering the effect of the stiffness out of the plane of the slab and non-structural wall in the structural modeling.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.635-639
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• 2004

In this paper, we present a novel approach for the structure of Fuzzy Neural Network(FNN) based on wavelet function and apply this network structure to the modeling of chaotic nonlinear systems. Generally, the wavelet fuzzy model(WFM) has the advantage of the wavelet transform by constituting the fuzzy basis function(FBF) and the conclusion part to equalize the linear combination of FBF with the linear combination of wavelet functions. However, it is very difficult to identify the fuzzy rules and to tune the membership functions of the fuzzy reasoning mechanism. Neural networks, on the other hand, utilize their learning capability for automatic identification and tuning. Therefore, we design a wavelet based FNN structure(WFNN) that merges these advantages of neural network, fuzzy model and wavelet transform. The basic idea of our wavelet based FNN is to realize the process of fuzzy reasoning of wavelet fuzzy system by the structure of a neural network and to make the parameters of fuzzy reasoning be expressed by the connection weights of a neural network. And our network can automatically identify the fuzzy rules by modifying the connection weights of the networks via the gradient descent scheme. To verify the efficiency of our network structure, we evaluate the modeling performance for chaotic nonlinear systems and compare it with those of the FNN and the WFM.

• 지구물리와물리탐사
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• 제7권3호
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• pp.197-206
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• 2004

지하수 과잉양수에 의해 충적층 지반의 미세한 변위가 나타나는 경우는 대상지역 소유역내의 물수지 불균형이 주요한 원인으로, 이러한 미세변위를 효과적으로 계측하기 위해서는 대상지역내 지반의 대표적인 지점들에서 물수지 측정과 연계된 침하량의 장기 모니터링 방법이 효율적이다. 이 연구에서는 롬층과 모래층으로 구성된 지반에 대하여 시추조사를 이용한 3차원 토양단면도를 작성한 후, 2차원 전기비저항 탐사로부터 얻어진 수리지질구조를 이용하여 개념모델을 구성하였다. 이러한 개념모델과 다양한 수리지질조사 결과를 기초로 지하수 유동모델링과 지반침하 모델링을 수행하여 개념모델의 정확성을 검증한 결과, 롬층과 모래층으로 구성된 지반에서 미세 지반변형과 연관된 수리지질 구조를 해석하는 경우에는 hand auger를 이용한 시추조사와 전극간격을 짧게 한 2차원 전기비저항 탐사법을 함께 적용하는 것이 유용함을 확인하였다.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제8권1호
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• pp.39-58
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• 2004

The School of Mathematical Sciences at University Sains Malaysia has offered a laboratory course on the integration of hand-held technology into the teaching and learning of mathematics since the beginning of the 2001/2002 academic year. This inquiry-based course highlights the explorations and application of mathematics in a data rich modeling environment. In addition, the course addresses several issues related to the effective integration of such technology into the mathematics curriculum. This paper discusses the appropriate use of graphing technology to present mathematical concepts and to support student's understanding in a student-centered learning environment, shares knowledge on the new mathematics that was made possible by hand-held technology, and summarizes student reactions to this innovative learning mode.

• 한국물환경학회지
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• 제23권4호
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• pp.535-542
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• 2007

The Geumho river watershed located in the middle of the Nakdong river has been threatened by high population growth and urbanization. Of concern specifically is the potential impact of future developments in the watershed on the reduction of base flow and the consequent risk of degradation of ecological habitats in Geumho river. Anticipated increase in imperviousness, on the other hand, is expected to elevate flood risk and the associated environmental damage. A watershed hydrology based modeling study is initiated in this study to assist in planning for sustainable future development in the Geumho river watershed. The Soil and Water Assessment Tool (SWAT) is selected to model the impact of urbanization in the Geumho river watershed on the hydrologic response thereof. The modeling results show that in general the likelihood that the watershed will experience high and low stream flows will increase in view of the urbanization so far achieved.

• 한국정보과학회논문지:소프트웨어및응용
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• 제33권1호
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• pp.17-31
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• 2006

소프트웨어 아키텍쳐는 소프트웨어 시스템의 상위 수준 모델이다. 이러한 소프트웨어 아키텍쳐는 명료하고 엄밀한 표현을 위해 아키텍쳐 기술 언어(ADL)를 사용하여 기술된다. 하지만 대부분의 ADL들은 C2 스타일 ADL(C2SADL)처럼 소프트웨어 시스템의 개발에 필요한 요소들 중에서 특정한 관점만을 고려하여 정의되었거나 별도의 표기형식으로 배워야 하는 부담이 있기 때문에 아키텍쳐를 명세하는 언어로서 정착되지 못하였다. 반면 UML은 범용 모델링 언어로서 소프트웨어 개발의 전 과정에 일관된 표기형식과 폭넓은 지원도구들을 제공하고 있으므로 소프트웨어 개발을 위한 사실상의 표준 언어로 자리잡았다. 그러나 UML은 소프트웨어 아키텍쳐를 표현하도록 설계된 것은 아니기 때문에 UML을 사용하여 아키텍쳐를 표현하기 위해서는 UML을 확장, 변경하여야 한다. 본 논문에서는 UML2.0에 기반한 C2 아키텍쳐 모델링 언어 프로파일을 정의하였다. 정의된 C2 아키텍쳐 모델링 언어는 식당 예약 시스템을 모델링 하는데 사용되었다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제33권2호
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• pp.167-185
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• 2006

소프트웨어 시스템의 상위 수준 모델인 소프트웨어 아키텍쳐는 아키텍쳐 기술 언어(ADL)를 사용하여 표현된다. 하지만 ACME와 같은 대부분의 ADL들은 별도의 표기형식으로 배워야 하는 부담이 있기 때문에 아키텍쳐를 명세하는 언어로서 정착되지 못하였다. 반면 VML은 범용 모델링 언어로써 소프트웨어 개발의 전 과정에 일관된 표기형식과 폭넓은 지원도구들을 제공하고 있으므로 소프트웨어 개발을 위한 사실상의 표준 언어로 자리잡았다. 그러나 UML은 소프트웨어 아키텍쳐를 표현하도록 설계된 것은 아니기 때문에 UML을 사용하여 아키텍쳐를 표현하기 위해서는 UML을 확장, 변경하여야 한다. 지금까지 아키텍쳐 모델링에 UML을 이용하기 위한 많은 연구가 진행되어 왔다. 하지만 지금까지의 이러한 연구의 대부분은 아키텍쳐의 핵심 개념들의 표현이 미흡했던 UML1.x에 기반하고 있으며 곧 발표될 UML2.0에서는 이전 버전에서 미흡했던 아키텍쳐 모델링에 유용한 개념들이 많이 추가되었다. 본 논문에서는 UML2.0에 기반한 아키텍쳐 모델링 언어를 정의하였다. UML2.0을 확장하여 Generic ADL을 정의하였으며 정의된 아키텍쳐 모델링 언어는 식당 예약 시스템을 모델링 하는데 사용되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1948-1953
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• 2005

The Teakwondo is composed of the breaking, competition and poomsea. In the hand breaking, the breaking impact of human is affected by the breaking posture. In this paper, impact analysis of the human model for breaking posture is carried out. The LifeMOD is used in breaking modeling and simulation. The simulation model createsthe human model to hit and to grasp a pine board. For the breaking, the poomsea motion of the hand joint inputs the splines pass condition. As the results, the reaction of human joint is presented

• Structural Engineering and Mechanics
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• 제69권5호
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• pp.499-509
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• 2019

While the wheel flat is an asymmetrical phenomenon in the railway, majority of researches have used two-dimensional models in the investigation of the effect of wheel flat on the wheel rail forces. This is due to the considerably low computational costs of two dimensional (2D) models although their reliability is questionable. This leaves us with the question of "what is the optimum modeling technique?". It is addressed in this research. For this purpose, two and three dimensional numerical models of railway vehicle/track interaction were developed. The three dimensional (3D) model was validated by comparisons of its results with those obtained from a comprehensive field tests carried out in this research and then, the results obtained from the 2D and 3D models were compared. The results obtained indicate that there are considerable differences between wheel/rail forces obtained from the 2D and 3D models in the conditions of medium to large wheel-flats. On the other hand, it was shown that the results of the 2D models are reliable for particular ranges of vehicle speed, railway track stiffness and wheel-fats lengths and depths. The results were used to draw a diagram, which presents the optimum modeling technique, compromising between the costs and accuracy of the obtained results.