• 한국멀티미디어학회논문지
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• 제18권11호
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• pp.1375-1382
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• 2015

This paper aims to introduce the numerical methods for solving the optimal control theory to model bufferbloat problem. Mathematical tools are useful to provide insight for system engineers and users to understand better about what we are facing right now while experiment in a large-scale testbed can encourage us to implement in realistic scenario. In this paper, we introduce a survey of the numerical methods for solving the optimal control problem. We propose the dynamic optimization sweeping algorithm for optimal control of the active queue management. Simulation results in network simulator ns2 demonstrate that our proposed algorithm can obtain the stability faster than the others while still maintain a short queue length (≈10 packets) and low delay experience for arriving packets (0.4 seconds).

• Coupled systems mechanics
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• 제1권1호
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• pp.99-113
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• 2012

We present a monolithic semi-implicit algorithm for solving fluid-structure interaction problem at small structural displacements. The algorithm uses one global mesh for the fluid-structure domain obtained by gluing the fluid and structure meshes which are matching on the interface. The continuity of velocity at the interface is automatically satisfied and the continuity of stress does not appear explicitly in the global weak form due to the action and reaction principle. At each time step, we have to solve a monolithic system of unknowns velocity and pressure defined on the global fluid-structure domain. Numerical results are presented.

• 한국수학사학회지
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• 제26권5_6호
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• pp.389-400
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• 2013

The article makes a discussion to conceptualize a histo-genetic principle in the real historical view point. The classical histo-genetic principle appeared in 19th century was founded by the recapitulation law suggested by biologist Haeckel, but recently it was shown that the theory on it is no longer true. To establish the alternative rationale, several metaphoric characterizations from the history of mathematics are suggested: among them, problem solving, transition of conceptual knowledge to procedural knowledge, generalization, abstraction, circulation from phenomenon to substance, encapsulation to algebraic representation, change of epistemological view, formation of algorithm, conjecture-proof-refutation, swing between theory and application, and so on.

• 반도체디스플레이기술학회지
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• 제22권2호
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• pp.133-137
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• 2023

This study the problem of deposition uniformity observed during Mist-CVD deposition experiments. The TRIZ's ADRIGE algorithm, a problem-solving technique, is utilized to systematically analyze the issue and propose solutions. Through problem and resource analysis, technical contradictions are identified regarding the precursor's volume and its path when it encounters the substrate. To resolve these contradictions, the concept of applying the principle of dimensional change to transform the precursor's three-dimensional path into a one-dimensional path is suggested. The chosen solution involves the design of an enhanced Mist-CVD system, which is evaluated for feasibility and analyzed using computational fluid dynamics. The analysis confirms that the deposition uniformity consistently follows a pattern and demonstrates an improvement in uniformity. The improved Mist-CVD equipment is validated through analysis, providing evidence of its feasibility and yielding satisfactory results.

• 한국정보교육학회:학술대회논문집
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• 한국정보교육학회 2010년도 하계학술대회
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• pp.235-241
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• 2010

본 논문은 빠르게 변하고 있는 지식 정보화 사회에서 문제해결능력 및 창의성의 향상을 위한 알고리즘 교육방법에 대하여 연구하였다. 특히 컴퓨터 정보 교육의 알고리즘은 학생들의 논리적 사고력과 문제를 해결하기 위해 최선의 해결책을 찾는데 있어 효과적인 학습 내용으로 매우 중요하다. 하지만 알고리즘 교육은 주로 컴퓨터와 언어를 이용하여 정적으로 이루어진다는 것을 고려했을 때 초등학생들의 인지 구조와 수준에 맞게 가르치는 것이 필요하다. 본 연구에서는 알고리즘의 원리를 컴퓨터가 없이 놀이를 통하여 습득하게 함으로 학습자들로 하여금 알고리즘의 원리를 익히게 하고 문제 해결력과 창의력을 기르게 하는데 목적이 있다.

• Journal of Multimedia Information System
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• 제4권4호
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• pp.219-224
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• 2017

This paper is to introduce an application of face recognition algorithm in parallel. We have experiments of 25 images with different motions and simulated the image recognitions; grouping of the image vectors, image normalization, calculating average image vectors, etc. We also discuss an analysis of the related eigen-image vectors and a parallel algorithm. To develop the parallel algorithm, we propose a new type of initial matrices for eigenvalue problem. If A is a symmetric matrix, initial matrices for eigen value problem are investigated: the "optimal" one, which minimize ${\parallel}C-A{\parallel}_F$ and the "super optimal", which minimize ${\parallel}I-C^{-1}A{\parallel}_F$. In this paper, we present a general new approach to the design of an initial matrices to solving eigenvalue problem based on the new optimal investigating C with preserving the characteristic of the given matrix A. Fast all resulting can be inverted via fast transform algorithms with O(N log N) operations.

• Earthquakes and Structures
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• 제24권2호
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• pp.111-126
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• 2023

Highly reliable and versatile methods artificial intelligence (AI) have found multiple application in the different fields of science, engineering and health care system. In the present study, we aim to utilize AI method to investigated vibrations in the human leg bone. In this regard, the bone geometry is simplified as a thick cylindrical shell structure. The deep neural network (DNN) is selected for prediction of natural frequency and critical buckling load of the bone cylindrical model. Training of the network is conducted with results of the numerical solution of the governing equations of the bone structure. A suitable optimization algorithm is selected for minimizing the loss function of the DNN. Generalized differential quadrature method (GDQM), and Hamilton's principle are used for solving and obtaining the governing equations of the system. As well as this, in the results section, with the aid of AI some predictions for improving the behaviors of the various sport systems will be given in detail.

• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.175-180
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• 2022

To develop computational thinking skills, university students are learning how to solve problems with algorithms, program commands and grammar, and program writing. Because non-computer majors have difficulty with computer programming-related content, they need a learning method to acquire coding knowledge from the process of understanding, interpreting, changing, and improving source codes by themselves. This study explored clone coding, refactoring coding, and coding methods using reconstruction tools, which are practical and effective learning methods for improving coding skills for students who are accustomed to coding. A coding learning process with the code reconstruction principle was designed to help non-computer majors use it to understand coding technology and develop their problem-solving ability and applied the coding technology learning method used in programmer education.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1780-1783
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• 2002

A problem of signal transmitted and received in OFDM systems is considered. In particular, an efficient solution to the problem of blind channel estimation based on Maximum Likelihood (ML) principle has been investigated. The paper proposes a new upper-bound cost, used in conjunction with a standard branch and bound integer programming technique for solving the ML problem. The tighter upper-bound cost exploits a finite-alphabet property of the transmitted signal. The proposed upper-bound cost was found to greatly speed up the ML algorithm, thus reducing computational complexity. Experimental results and discussion are included.

• Structural Engineering and Mechanics
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• 제85권3호
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• pp.393-406
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• 2023

Smart structures are those structure that could adopt some behavior to prevent instability in their responses. The recognition of stability deterioration has been performed through rigid mathematical formulations in control theory and unpredicted results could not be addressed in control systems since they are able to only work under their predefined condition. On the other hand, incorporating all affecting parameters could result in high computational cost and delay time in the response of the systems. Artificial intelligence (AI) method has shown to be a promising methodology not only in the computer science by at everyday life and in engineering problems. In the present study, we exploit the capabilities of artificial intelligence method to obtain frequency response of a smart structure. In this regard, a comprehensive development of equations is presented using Hamilton' principle and first order shear deformation theory. The equations were solved by numerical methods and the results are used to train an artificial neural network (ANN). It is demonstrated that ANN modeling could provide accurate results in comparison to the numerical solutions and it take less time than numerical solution.