• Journal of applied mathematics & informatics
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• 제27권5_6호
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• pp.981-1000
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• 2009

This paper considers asset liability management problems when their deterministic equivalent formulations are general nonlinear optimization problems. The presented approach uses a nonmonotone trust region strategy for solving a sequence of unconstrained subproblems parameterized by a scalar parameter. The objective function of each unconstrained subproblem is an augmented penalty-barrier function that involves both primal and dual variables. Each subproblem is solved approximately. The algorithm does not restrict a monotonic decrease of the objective function value at each iteration. If a trial step is not accepted, the algorithm performs a non monotone line search to find a new acceptable point instead of resolving the subproblem. We prove that the algorithm globally converges to a point satisfying the second-order necessary optimality conditions.

• 드라이브 ㆍ 컨트롤
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• 제15권3호
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• pp.29-35
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• 2018

This paper presents the design of attachments for dual arms of disaster responding heavy machine. The heavy machine handles a variety of tasks such as cutting, shredding, picking and moving in unstructured environment. Despite the need for rapid response, the heavy machine has difficulty in repeatedly replacing the attachment depending on the task. Thus, we propose a method to solve this physical and functional contradiction relation by using TRIZ separation principles. Above all, the existing equipment and the required working scenarios were surveyed and summarized in order to separate the attachments functionally for right-handed, left-handed and two-handed operation. Then, we proposed the design directions and conceptual design as following: multi function type attachment A, for precise operation and various operations; grab type attachment B, for grasping irregular objects and auxiliary device for both arms to handle bulky objects.

• Structural Engineering and Mechanics
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• 제29권2호
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• pp.117-134
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• 2008

A new adaptive dual reciprocity boundary element method for dynamic analysis of 3-D structures is presented in this paper. It is based on finding the best approximation function of a radial basis function (RBF) group $f=r^n+c$ which minimize the error of displacement field expansion. Also, the effects of some parameters such as the existence of internal points, number of RBF functions and position of collocation nodes in discontinuous elements are investigated in this adaptive procedure. Three numerical examples show improvement in dynamic response of structures with adaptive RBF in dual reciprocity with respect to ordinary BEM.

• 산업융합연구
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• 제21권12호
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• pp.101-111
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• 2023

본 연구는 국내 경도인지장애 환자의 인지기능을 위한 이중과제 프로그램의 효과를 분석하기 위해 체계적 문헌고찰 및 메타분석을 시행하였다. 8개의 데이터베이스를 사용하여 검색하였으며, 검색어는 경도인지장애, 인지, 이중과제였다. 2013년 1월부터 2023년 7월까지 출간된 문헌 중 무작위 및 비무작위 대조군 실험설계를 분석하였다. 총 682편의 문헌이 검색되어 포함 및 배제 기준을 충족한 8편의 문헌을 최종 분석하였다. 문헌의 질 평가는 RoB와 RoBANS를 사용하였다. 메타분석은 CMA 4.0 ver.을 사용하였다. 분석 결과 이중과제 프로그램의 전체 효과 크기는 중간 효과 크기였다. 결과변수에 따른 효과 크기는 지남력, 실행기능은 큰 효과 크기이며, 전반적 인지기능, 시공간기능, 기억기능, 주의기능은 중간 효과 크기였다. 중재 기간에 따른 분석 결과 적용 기간은 4~8주 적용이 효과가 더 크게 나타났으며, 총 회기에서는 24~30회기 적용의 효과 크기가 더 크게 나타났다. 본 연구는 경도인지장애 환자의 인지기능 증진을 위해 적용된 이중과제 프로그램의 효과 및 적용 방법에 대한 임상적 근거를 제시하였다.

• 대한전자공학회논문지TC
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• 제48권8호
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• pp.1-6
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• 2011

본 논문에서는 이중 홉 증폭 후 전달(AF: Amplify-and-Forward) 릴레이 시스템에 대한 새로운 성능 분석 기법을 레일리 페이딩 채널에 대하여 제안한다. 기존의 분석 기법들에서는 S-R-D(Source-Relay-Destination) 링크의 수신 신호 대 잡음비(SNR: Signal-to-Noise Ratio)에 대한 누적 분포 함수(CDF: Cumulative Distribution Function) 혹은 확률 밀도 함수 (PDF: Probability Density Function)로부터 모멘트 발생 함수(MGF: Moment Generating Function)를 유도한 후 평균 심벌 오류율을 유도된 MGF를 이용하여 표현하였다. 본 논문에서는 기존의 분석과 다른 새로운 접근법을 제안한다. 즉, S-R(Source-Relay) 링크 및 R-D(Relay-Destination) 링크의 PDF들로부터 S-R-D 링크에 대한 MGF를 직접 유도한다. 그리고 새롭게 유도된 MGF을 기존의 연구들에서 제시한 형태와 비교 분석한다. 또한 제안된 성능분석 기법의 정확성은 모의실험을 통하여 검증한다. 이를 통하여 제안된 분석 기법이 이중 홉 증폭 후 전달 릴레이 시스템에 대한 새로운 해를 제시함을 확인한다.

• 한국보육지원학회지
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• 제17권6호
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• pp.109-132
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• 2021

Objective: This study examined the relationships among attention deficits/hyper activities problems(ADHD problems), executive function difficulties, and social capital inside the family, especially with the mediating effect of social capital inside the family, in children from dual-income households. Methods: The participants were 401 children from dual-income households from the eighth wave of the Panel Study on Korean Children. They belonged into lower and higher ADHD problems groups that showed below 25% or more than 75% of ADHD screening items' total score. The data were analyzed by t-test, correlation analysis and mediating effect test by PROCESS macro 3.5.3.. Results: Children's executive function difficulties and social capital inside the family were significantly different between the two lower and higher ADHD problems groups. A mediating effect was found based on the negative relationships between the social capital inside the family including mother's warm childrearing behavior and positive coparenting, and children's executive function difficulties. Children's ADHD problems had a negative influence on each of the two social capital variables and each of the two variables had a negative influence on the executive function difficulties. Conclusion/Implications: These results emphasize the meaningful role of social capital inside the family in the development of first graders with ADHD problems from dual-income households.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.97-100
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• 2006

Accelerating ability is one of the most important performance of the vehicle. Unlike conventional internal combustion vehicles and power-assist hybrid vehicles, the maximized acceleration of dual mode hybrid vehicles is not simply. achieved by maximizing engine or motor torque Because of the dynamic stability of planetary gear, speeds and torques control of engine, motor 1 and motor 2 is essential and according to control value, acceleration performance is changed There are two control values which are velocity and torque for each component totalling six. These six values can be variables for an objective function. However, because three velocity variables can be regarded as only one variable speed ratio and the remaining three torque variables can be solved analytically, without complicated numerical algorithm the solution for the objective function can be obtained. This optimized solution shows the best performance possible to the specified dual mode system.

• 호남수학학술지
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• 제36권4호
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• pp.921-932
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• 2014

The aim of this paper is to define hyperholomorphic functions with dual sedenion variables on $\mathcal{S}{\times}\mathcal{S}$, where $$\mathcal{S}{\sim_=}\mathbb{C}^8$$. By the condition of harmonicity, we research properties of hyperholomorphic functions of dual sedenion variables in Clifford analysis.

• East Asian mathematical journal
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• 제29권3호
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• pp.293-302
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• 2013

We research properties of ternary numbers and hyperholomorphic functions with values in $\mathbb{C}$(2). We represent reduced quaternion numbers and obtain some propertries in dual reduced quaternion systems in view of Clifford analysis. Moreover, we obtain Cauchy theorems with respect to dual reduced quaternions.

• Journal of Advanced Marine Engineering and Technology
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• 제28권5호
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• pp.801-810
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• 2004

The Primal-Dual Interior-Point (PDIP) method is currently one of the fastest emerging topics in optimization. This method has become an effective solution algorithm for large scale nonlinear optimization problems. such as the electric Optimal Power Flow (OPF) and natural gas and electricity OPF. This study describes major theoretical developments of the PDIP method as well as practical issues related to implementation of the method. A simple quadratic problem with linear equality and inequality constraints