• Advances in Computational Design
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• 제2권3호
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• pp.195-210
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• 2017

Simultaneous optimization of trusses which concurrently takes into account design variables related to the size, shape and topology of the structure is recognized as highly complex optimization problems. In this class of optimization problems, it is possible to encounter several unstable mechanisms throughout the solution process. However, to obtain a feasible solution, these unstable mechanisms somehow should be rejected from the set of candidate solutions. This study proposes triangular unit based method (TUBM) instead of ground structure method, which is conventionally used in the topology optimization, to decrease the complexity of search space of simultaneous optimization of the planar truss structures. TUBM considers stability of the triangular units for 2 dimensional truss systems. In addition, integrated particle swarm optimizer (iPSO) strengthened with robust technique so called improved fly-back mechanism is employed as the optimizer tool to obtain the solution for these class of problems. The results obtained in this study show the applicability and efficiency of the TUBM combined with iPSO for the simultaneous optimization of planar truss structures.

• 전력전자학회논문지
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• 제16권6호
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• pp.554-560
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• 2011

단일 주파수로 유도가열에 의한 표면 경화 열처리 공정에서 생기는 설비의 이중 투자 문제 및 열처리 공정시간을 단축할 수 있도록 하기 위해 하나의 공정에서 두가지 공정을 동시에 처리할 수 있도록 해주는 동시 이중 주파수(Simultaneous dual frequency: SDF) 구동기법 기술에 대해 설명한다. 본 논문에서는 듀얼 방식의 인버터를 제안하여 이중 주파수(Dual frequency) 구동기법을 구현하였으며 시뮬레이션과 실험을 통해 제안된 인버터의 이중 주파수제어 및 전력제어를 검증하였다.

• International Journal of Contents
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• 제16권1호
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• pp.44-56
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• 2020

The purpose of this study was to examine how the presentation mode (sequential- vs. simultaneous-mode) of information influences its evaluation. Three experiments revealed the interaction effect between the presentation mode and the valence of the product information. When respondents read about the positive aspects of the product, the evaluation was higher in the simultaneous presentation mode than in the sequential presentation mode. For negative product information, respondents' evaluation was higher in the sequential presentation mode than in the simultaneous presentation mode. The simultaneous presentation mode intensified the impact of the information valence on evaluation. This study proposed that the sequential and the simultaneous presentation modes prime high and low construal levels, respectively. The mediation analysis provides support for such a prediction. Finally, the mediating effect of construal levels in evaluation was shown to disappear when respondents focused on the product information for a longer duration, while the mediation effect remained when the response time was short.

• Journal of applied mathematics & informatics
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• 제39권3_4호
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• pp.437-442
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• 2021

In this paper, we study the characterizations of two-sided best simultaneous approximations for ℓ-tuple subset from a closed convex subset of ℝ^m with ℓ^m₁(w)-norm. Main fact is, k^* is a two-sided best simultaneous approximation to F from K if and only if there exist f₁, …, f_p in F, for any k ∈ K $${\mid}{\sum\limits_{i=1}^{m}}sgn(f_{ji}-k^*_i)k_iw_i{\mid}{\leq}\;{\sum\limits_{i{\in}Z(f_j-k^*)}}\;{\mid}k_i{\mid}w_i$$ for each j = 1, …, p and 𝐰 ∈ W.

• 충청수학회지
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• 제23권4호
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• pp.705-710
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• 2010

Let $C_1(X)$ be a normed linear space over ${\mathbb{R}}^m$, and S be an n-dimensional subspace of $C_1(X)$ with spaned by {$s_1,{\cdots},s_n$}. For each ${\ell}$- tuple vectors F in $C_1(X)$, the two-sided best simultaneous approximation problem is $$\min_{s{\in}S}\;\max\limits_{i=1}^\ell\{{\parallel}f_i-s{\parallel}_1\}$$. A $s{\in}S$ attaining the above minimum is called a two-sided best simultaneous approximation or a Chebyshev center for $F=\{f_1,{\cdots},f_{\ell}\}$ from S. This paper is concerned with algorithm for calculating two-sided best simultaneous approximation, in the case of continuous functions.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권2호
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• pp.126-131
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• 2010

Objectives: This study is aimed to determine any differences in the postoperative stability between absorbable and titanium plate systems for fixation in orthognathic surgery with simultaneous maxillomandibular procedures especially including maxillary posterior impaction and advancement. Study Design: Forty patients with dentofacial deformities were randomly assigned into titanium (4 males and 6 females) and absorbable (17 males and 13 females) fixation group. All patients had undergone surgical alterations of maxilla with posterior impaction and advancement. A comparison study of the change in the maxillary position after the simultaneous surgery was performed with 1-day, 6-months postoperative lateral cephalograms compared to preoperative lateral cephalogram by tracing. Wilcoxon rank sum test was used for statistical analysis. Result: The position of the maxilla was stable after surgery and was not changed significantly from 1 day to 6 month after the simultaneous maxillomandibular surgery both in the experimental (absorbable plates) and control (titanium plates). Conclusion: This study suggests that application of absorable plating system in the fixation of maxillary segment in the simultaneous maxillomandibular procedures, leads to a predictable short-term postoperative skeletal stability comparable to the titanium plating system. Long term follow-up and further studies will be needed.

• Pediatric Infection and Vaccine
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• 제22권2호
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• pp.69-74
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• 2015

목적: 예방접종을 시행하는 의사들에게 설문지를 이용해 동시접종 시행 여부와 안전에 대한 염려가 없는가를 조사하여, 동시접종 시행 시 문제점을 파악하고자 하였다. 방법: 조사자가 부산 6개 행정구 내에 있는 국가필수예방접종 사업 등록기관을 방문하여 의사들에게 설문을 실시하였다. 결과: 응답자 155명 중 144명(93%)이 동시접종을 시행하고 있었으며, 141명(91%)이 동시접종에 긍정적인 반응을 보였다. 동시접종을 시행하고 있는 144명 중 67명(47%)은 동시접종의 안전성에 대해서 확신을 가지지 못한 채 접종을 시행 중이었으며, 동시접종 시행 중 부작용을 경험한 86명 중 35명(41%)은 동시접종이 단독접종보다 부작용 빈도가 높을 수 있다고 생각하는 것으로 나타났다. 결론: 동시접종은 높은 비율로 시행 중인 것으로 나타났지만, 동시접종을 시행하는 의사들 중 안전성에 대해 확신을 가지지 못하는 비율이 높게 나타났다. 원활한 접종 시행을 위해 이런 의문을 해소할 수 있는 근거를 제시할 필요가 있다.

• 한국지능시스템학회논문지
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• 제17권4호
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• pp.506-510
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• 2007

전자나침반(DMC)은 실내의 전자기적 요소나 강한 자성체 건물구조에서는 쉽게 방해를 받던 나침반보다 실내에서 간섭에 강한 특징을 가지고 있다. 그리고 초음파 센서는 물체와의 거리를 계산해 줄뿐만 아니라 값싼 센서로서 경제적인 이점을 가지고 있어 Simultaneous Localization and Mapping(SLAM)에서 많이 사용하고 있다. 본 논문에서는 자율 이동 로봇의 구동에서 전자나침반과 초음파 센서를 이용한 SLAM의 구현에 대해 연구하였다. 로봇의 특성상 한정된 센싱 데이터만으로 방향과 위치를 파악하고 그 데이터 값으로 가능한 빠르게 위치 측정을 하여야 한다. 그러므로 자율 이동 로봇에서의 SLAM 적용함으로 위치측정의 구현과 지도 작성을 수행한다. 그리고 SLAM 구현상의 주된 연구 중의 하나인 Kid Napping 문제에 중점을 두고 연구한다. 특히, 위치 측정의 구현을 수행하기 위한 데이터의 센싱 방법으로 초음파 센서를 사용하였고 비슷한 위치의 데이터 값이 주어지거나 사전 정보 없는 상태에서는 로봇의 상태를 파악하기 위해서 전자 나침반을 사용하였다. 그래서 자율 이동 로봇의 위치를 정확하게 측정하기 위해서 활용하였다.

• 산업경영시스템학회지
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• 제35권1호
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• pp.24-31
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• 2012

This study is designed to predict the overall electric power load, to apply the method of time sharing and to reduce simultaneous load factor of electric power when authorized by user entering demand plans and using schedules into the user's interface for a certain period of time. This is about smart grid, which reduces electric power load through simultaneous load factor of electric power reduction system supervision agent. Also, this study has the following characteristics. First, it is the user interface which enables authorized users to enter and send/receive such data as demand plan and using schedule for a certain period of time. Second, it is the database server, which collects, classifies, analyzes, saves and manages demand forecast data for a certain period of time. Third, is the simultaneous load factor of electric power control agent, which controls usage of electric power by getting control signal, which is intended to reduce the simultaneous load factor of electric power by the use of the time sharing control system, form the user interface, which also integrate and compare the data which were gained from the interface and the demand forecast data of the certain period of time.

• 대한구순구개열학회지
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• 제5권2호
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• pp.85-93
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• 2002

Simultaneous implant installation with bone graft was performed in 15 cases. Four cases were cleft alveolus patients. 56 implants were placed immediately with block bone grafts. 2 cases were cranial bone grafts and the others were iliac bone grafts. Three of 56 implants were lost(94.6% Survival rate). One of three was cleft alveolus case. The cleft alveolus patients with simultaneous implants installation showed functional and esthetic results without infraocclusion and positional changes. Bergland index was considered to be type I after 12 months later. Immediate implant installation with bone graft is one of choice of treatment in closing cleft alveolus hoping simultaneous implant installation could be related with function which might result in less resorption of graft. Functional and esthetic results are satisfaction ; there was no infraocclusion and positional changes.