• 한국수학사학회지
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• 제27권2호
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• pp.139-152
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• 2014

This paper aims to compare and contrast Kierkegaard and Turing, whose birth dates were one hundred years apart, analyzing them from the perspective of the limit. The model of analysis is two concentric circles and movement in them and on the boundary of outer circle. In the model, Kierkegaard's existential stages have 1:1 correspondences: aesthetic stage, ethical stage, religious stage A and religious stage B correspond to inside of the inner circle, outside of the inner circle, the boundary of the outer circle and the outside of the outer circle, respectively. This paper claims that Turing belongs to inside of the outer circle and moves to the center while Kierkegaard belongs to outside of the outer circle and moves to the infinity. Both of them have movement of potential infinity but their directions are opposite.

• Nuclear Engineering and Technology
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• 제56권8호
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• pp.3139-3143
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• 2024

Stratified flow in horizontal tubes is frequently observed in gas-liquid two-phase flow system. In the two-fluid modeling, it is important to define the interface shape in solving the balance equations to determine the key parameters such as the interfacial transfer terms, void fraction, and pressure drop. A double-circle model is usually introduced to depict the concave-down interface in a horizontal circular tube under the stratified-wavy flow condition. However, calculation of the central angle in the double-circle model, which represents the interfacial curvature, requires an appropriate iterative numerical root-finding scheme to solve the implicit transcendental equation. In this study, an explicit approximate equation has been proposed without requirement of the iterative scheme and numerical instability, which is expected to improve the coding process and computation efficiency in the analysis code with the two-fluid model.

• 수산해양기술연구
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• 제59권4호
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• pp.336-343
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• 2023

The aging fishery training vessels from the past have mostly been decommissioned, and many universities are introducing state-of-the-art large fishery training vessels. The purpose of these training vessels is to train marine professionals and above all, safety to prevent marine accidents should be of utmost priority as many students embark on the vessel. This study estimated the impact of the hydrodynamic interaction forces acting on the model vessel (fishery training vessel) from the bank when the vessel pass near the semi-circle bank wall in various conditions through the numerical calculation, especially concerning maneuvering motions of the vessel. For estimation, variables were mainly set as the size of the semi-circle shape, the lateral distance between the bank and the model vessel, and the depth near the bank. As a result, it was estimated that, in order for the model vessel to safely pass the semi-circle bank wall at a speed of 4 knots, the water depth to the vessel draft ratio should be 1.5 or more (approximately 8 m of water depth), and the lateral distance from the semi-circle bank wall should be 0.4 times the model vessel's length (L_pp) or more (a distance of 34 m or more). Under these conditions, it was expected that the model vessel would pass without significantly being affected by the bank wall.

• 한국인터넷방송통신학회논문지
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• 제18권3호
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• pp.83-92
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• 2018

본 논문은 빠르게 확대되고 있는 산업으로 각광 받고 있는 드론을 활용하여 특정 신호를 발생하는 목표물의 위치를 추정하고자 Apollonius Circle 기법을 활용하였다. 기존의 방향탐지 방법은 지상에서 차량을 통해 실시하거나 높은 위치에 안테나를 설치하여 목표물의 위치를 탐지했지만 기존의 방향탐지 방법은 LOS 신호 수신 환경을 구성하기 어렵고 또한 장비의 무게와 크기 때문에 이동 측정이 어렵다. 그러나 드론을 활용한 방향탐지는 높은 고도에서 비행하는 드론을 이용해 LOS 신호 수신 환경을 구성 및 이동 측정이 쉽다. 본 연구에서는 지상 방향탐지의 측정데이터를 이용하여 드론의 신호 수신환경을 3차원 800MHz Path-Loss Model를 활용하여 신호를 재구성하여 드론 수신 Power로 재구성하였으며 목표물의 위치를 추정하고자Apollonius Circle 기법을 활용하여 목표물의 위치를 추정하는 시뮬레이션을 구성하였다. 시뮬레이션은 지상 방향탐지와 드론 방향탐지를 구성하여 목표물의 위치추정 성능을 분석하였다.

• Journal of Information Processing Systems
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• 제15권6호
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• pp.1422-1437
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• 2019

With the rapid development of the Internet and the Mobile Internet, social communication based on the network has become a life style for many people. WeChat is an online social platform, for about one billion users, therefore, it is meaningful to study the spreading and evolution mechanism of the rumor on the WeChat social circle. The Rumor was injected into the WeChat social circle by certain individuals, and the communication and the evolution occur among the nodes within the circle; after the refuting-rumor-information injected into the circle, subsequently,the density of four types of nodes, including the Susceptible, the Latent, the Infective, and the Recovery changes, which results in evolving the WeChat social circle system. In the study, the evolution characteristics of the four node types are analyzed, through construction of the evolution equation. The evolution process of the rumor injection and the refuting-rumor-information injection is simulated through the structure of the virtual social network, and the evolution laws of the four states are depicted by figures. The significant results from this study suggest that the spreading and evolving of the rumors are closely related to the nodes degree on the WeChat social circle.

• 대한수학교육학회지:수학교육학연구
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• 제17권2호
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• pp.111-125
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• 2007

본 논문에서는 컴퓨터와 수학교육의 관계를 구성주의 관점에서 바라보는 '컴퓨터와 수학교육'에 대한 논의와 그에 대한 구체적 사례를 다룬다. 먼저 대표적인 '컴퓨터와 수학교육' 환경인 Logo와 DGS에 대해 각각의 특징을 살펴보고, 두 환경의 통합 필요성을 제기하고 통합할 수 있는 공통된 관점에 대해 논의한다. 나아가 이 공통된 관점을 적용하여 두 환경을 연결할 수 있는 매개 모델(Circle model)을 만들어 보고 표현들 사이의 수학적 관계를 논의한다. 특별히 여기에서는 원, 타원, Cardioid등의 평면 곡선을 여러 표현으로 구성하고 탐구해본다. 또한 곡선 둘레의 길이에 관한 오류 사례에서 매개 모델의 역할과 의미를 논의한다.

• 한국지구과학회지
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• 제24권7호
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• pp.595-603
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• 2003

이 연구는 서울 지역 소재 3개 초등학교 103명의 4학년 학생들을 대상으로 사회적 구성주의 교수학습모형을 적용한 후 학생들이 가지는 개념의 변화를 분석하였다. 특히, 사회적 구성주의 교수학습모형의 개념원도 활용 수업 전후 학생들의 개념 변화를 지필고사로 평가, 조사하였다. 103명을 대상으로 개념원도를 도입한 수업을 1개월 동안 실시한 전후 지필고사를 실시하였다. 연구결과에 따르면, 개념원도를 적용한 수업은 유의미하게 학생들의 개념을 신장시킨 것으로 나타났다. 결론적으로, 개념원도를 적용한 사회적 구성주의 교수-학습모형은 진단평가, 형성평가에 도입할 가치가있는 것으로 고찰되었다.

• 산업경영시스템학회지
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• 제28권2호
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• pp.36-45
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• 2005

This paper aims to investigate and analyze the process solving problems with activities of Quality Control Circle, carried out on a small scale, among various activities of industrial fields. Then this paper intends to provide and integrated model through integrating each process into one. In addition, this paper also aims to enhance the efficiency of the suggested model by realizing the model through support system.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 추계 학술발표회
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• pp.490-496
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• 2006

In order to design accurately plastic board drain (PBB) method, it is important to determine the equivalent circle of PBD. In this paper, a series of numerical analyses on soft ground improved by PBD were carried out, in order to investigate the resonable equivalent circle of PBD considering consolidation behavior of improved soft ground by PBD. The applicability of numerical analyses, in which an elasto-viscoplastic three-dimensional consolidation finite element method was applied, could be confirmed comparing with results of a series of model tests on consolidation behaviors of soft ground improved by PBD. And, through the results of the numerical analyses, consolidation behaviors of soft ground during consolidation was elucidated, together with the equivalent circle of PBD considering consolidation behaviors.

• 한국생산제조학회지
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• 제9권1호
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• pp.68-74
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• 2000

The STL file format is an approximation of 3-D model with triangular facets. STL is a standard input file format of Rapid Prototyping(RP) equipment In computer graphics a circle has been approximated with an inscribed polygon which causes an error between the real and approximated circles. In this study an intersecting polygon has been used to approximate the circle and applied to produce more accurate RP part. The newly proposed method shows it's excellence in part accuracy.