• East Asian Economic Review
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• 제28권1호
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• pp.3-35
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• 2024

This paper utilizes social network analysis to examine the structural characteristics and trade dynamics of the renewable energy (hydropower, wind energy, and solar energy) trade network within the RCEP region from 2011 to 2020. The findings reveal: (1) The renewable energy trade network within the RCEP exhibits dynamism, heterogeneity, and an uneven development. The solar energy network is the most balanced and stable, while the wind energy network lags and shows marked fluctuations, with the hydropower network falling between these two. This demonstrates the diversity of energy trade within the region. (2) China, Singapore, and Japan are identified as the key exporting and importing countries, with Vietnam showing substantial growth potential. Individual analyses shed light on the stark disparities in trade status among nations, reflecting the diverse roles and future potential of member countries. (3) The QAP regression analysis reveals a significant influence of environmental pressure, particularly carbon dioxide emissions, on the renewable energy trade network. This study contributes to promoting environmental sustainability and energy security in the RCEP region and provides empirical evidence for global renewable energy trade strategies.

• 센서학회지
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• 제33권4호
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• pp.196-202
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• 2024

Path-planning, a critical component of mobile robot navigation, comprises both local and global planning. Previous studies primarily focused on enhancing the individual performance of these planners, avoiding obstacles, and computing an optimal global path from a starting position to a target position. In this study, we introduce a practical path-planning framework that employs a target planner to bridge the local and global planners; this enables mobile robots to navigate seamlessly and efficiently toward a global target position. The proposed target planner assesses the visibility of waypoints along the global path, and it selects a reachable navigation target, which can then be used to generate efficient control commands for the local planners. A visibility-based target planner can handle situations, wherein the current, target waypoint is occupied by unknown obstacles. Real-world experiments demonstrated that the proposed pathplanning framework with the visibility-based target planner allowed the robot to navigate to the final target position along a more efficient path than the framework without a target planner.

• 한국가정과교육학회지
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• 제32권3호
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• pp.111-133
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• 2020

이 연구의 목적은 2015 개정 가정과 교과서를 중심으로 세계시민교육에 대한 내용을 분석하여 가정과에서의 세계시민교육과의 관련성을 살펴보는데 있다. 이를 위하여 병행 삼각 설계(concurrent triangulation design)의 절차에 따라 세계시민교육의 기준틀(UNESCO의 TLO)의 관점에서 2015 개정 중학교 가정과 교과서에 나타난 세계시민교육의 내용을 추출하여 분석하였다. TLO의 9가지 주제에 대해 빈도를 조사한 결과 세계시민교육 내용은 2015 개정 가정과 12종 교과서 전체에서 세계시민교육 관련 주제가 다뤄진 비율 중 사회·정서적 영역은 54.6% 정도를 차지하였다. 특히, TLO 4가 가장 높은 비율을 보였고 TLO 5, TLO 1의 순으로 나타났다. 중학교 12종 가정과 교과서에서 추출된 세계시민교육 학습 주제를 가정과 학습 영역별로 분류해 본 결과 아동·가족생활 영역(94개)은 모든 학습 주제와 가장 큰 관련성을 보였으며, 식생활(13개), 의생활(13개), 주생활(15개), 소비생활(14개)은 비슷한 분포로 학습 주제를 나타내었다. 아동·가족생활 영역은 청소년기 발달과 특징, 가족 관계, 성폭력과 가정 폭력 예방, 변화하는 가족과 건강가정, 저출산·고령사회와 일·가정 양립, 생애 설계와 진로 탐색에서, 식생활 영역은 청소년기의 영양과 식행동, 식품의 선택과 안전한 조리에서, 의생활 영역은 의복 관리와 재활용에서, 주생활 영역은 주생활 문화와 주거 공간 활용, 주거생활과 안전에서, 소비생활 영역은 청소년기의 소비생활 내용 요소가 세계시민교육의 학습 주제와 관련성이 있었다. 이처럼 세계시민교육 학습 주제와 가정과 모든 학습 영역별 학습 내용 요소와의 관련성이 높게 나타났다. 이에 가정과에서는 세계시민교육과 가정교과와의 관련성을 이해하여 어떻게 적용될지 파악하여 앞으로 세계시민교육과 관련된 프로그램 개발과 수업 개선 및 교과서 개발의 방향 설정이 필요할 것이다.

• Journal of applied mathematics & informatics
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• 제7권2호
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• pp.409-438
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• 2000

In this paper we develop a new procedure to control stepsize for Runge- Kutta methods applied to both ordinary differential equations and semi-explicit index 1 differential-algebraic equation In contrast to the standard approach, the error control mechanism presented here is based on monitoring and controlling both the local and global errors of Runge- Kutta formulas. As a result, Runge-Kutta methods with the local-global stepsize control solve differential of differential-algebraic equations with any prescribe accuracy (up to round-off errors)

• 대한수학회지
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• 제44권5호
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• pp.1065-1078
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• 2007

We consider initial value problems for the semirelativistic Hartree type equations with cubic convolution nonlinearity $F(u)=(V*{\mid}u{\mid}^2)u$. Here V is a sum of two Coulomb type potentials. Under a specified decay condition and a symmetric condition for the potential V we show the global existence and scattering of solutions.

• Kyungpook Mathematical Journal
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• 제59권4호
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• pp.631-649
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• 2019

In this paper, we prove the global nonexistence of solutions for a quasilinear wave equation with time delay and acoustic boundary conditions. Further, we establish the blow up result under suitable conditions.

• The Korean Journal of Ecology
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• 제19권1호
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• pp.65-70
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• 1996

The daily photosynthetic photon flux density incident on a horizontal surface was estimated with sunshine duration through daily global radiation at Taegu in Korea. The constant and coefficient of $\AA$ngstrom equation for global radiation were calculated as 0.1763 and 0.5012, respectively. The conversion factor from daily global radiation to daily photosynthetic photon flux density was determined as 2.2359.

• 한국사회복지학회:학술대회논문집
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• 한국사회복지학회 2002년도 국제학술대회 자료집
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• pp.205-224
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• 2002

This paper addresses to the emerging issues for regional/global welfare issues, with special focus on the potentials and influences of the transnational advocacy activism for human and welfare rights. Part One of the paper outlines the emergence of transnational (cyber-)activism for global welfare. It is followed by a discussion of the incompatibility between economic globalization and regional/local deprivation, as well as the potentials for welfare promotion and empowerment. Part Four critically examines the contours and complexity of informational society. The last two parts delineate, respectively, the barriers against and prospects of global welfare activism.

• Journal of applied mathematics & informatics
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• 제34권1_2호
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• pp.157-165
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• 2016

In this paper, we develop a new hybridization conjugate gradient method for solving the unconstrained optimization problem. Under mild assumptions, we get the sufficient descent property of the given method. The global convergence of the given method is also presented under the Wolfe-type line search and the general Wolfe line search. The numerical results show that the method is also efficient.

• Journal of applied mathematics & informatics
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• 제26권1_2호
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• pp.275-282
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• 2008

Our aim in this paper is to investigate the global attractivity of the recursive sequence $x_{n+1}$ = $\frac{\alpha-{\beta}x_{n-1}}{\gamma+g(x_n)}$ under specified conditions. We show that the positive (or zero for $\alpha$ = 0) equilibrium point of the equation is a global attractor with a basin that depends on certain conditions posed on the coefficients and the function g(x).