• Smart Structures and Systems
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• 제26권1호
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• pp.103-115
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• 2020

The cold-formed steel storage racks are extensively employed in various industries applications such as storing products in reliable places and storehouses before distribution to the market. Racking systems lose their stability under lateral loads, such as seismic actions due to the slenderness of elements and low ductility. This justifies a need for more investigation on methods to improve their behavior and increase their capacity to survive medium to severe loads. A standardized connection could be obtained through investigation on the moment resistance, value of original rotational stiffness, ductility, and failure mode of the connection. A total of six monotonic tests were carried out to determine the behavior of the connection of straight 2.0 mm, and 2.6 mm thickness connects to 5 lug end connectors. Then, the obtained results are benched mark as the original data. Furthermore, an extreme learning machine (ELM) technique has been employed to verify and predict both moment and rotation results. Out of 4 connections, increase the ultimate moment resistance of connection by 13% and 18% for 2.0 mm and 2.6 mm upright connection, respectively.

• Structural Engineering and Mechanics
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• 제35권4호
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• pp.431-457
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• 2010

This article provides a discussion of the mathematic modeling of connections for designing and qualifying structures, systems, and components subject to monotonic or cyclic loading. To characterize the force-deformation behavior of connections under monotonic loading, a review of the Ramberg-Osgood, Richard-Abbott, and Menegotto-Pinto models is conducted, and it is shown that these nonlinear functions can be mathematically derived by scaling up or down a linear force-deformation function. A generalized four-parameter model for simulating connection behavior is investigated to facilitate nonlinear regression analysis. In order to perform seismic analysis of frameworks, a hysteretic model accounting for loading, unloading, and reloading is described using the established monotonic model. For preliminary analysis, a method is provided to quickly determine the model parameters that fit approximately with the observed data. To reach more accurate values of the parameters, the methods of nonlinear regression analysis are investigated and the modified Levenberg-Marquardt and separable nonlinear least-square algorithms are applied in determining the model parameters. Example case studies illustrate the procedure for the computation through the use of experimental/analytical data taken form the literature. Transformation of connection curves from the three-parameter model to the four-parameter model for structural analysis is conducted based on the modeling of connections subject to fire.

• 한국보육지원학회지
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• 제15권3호
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• pp.83-113
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• 2019

Objective: This study aimed to develop and apply the home connection program for promoting the mathematical interaction of parents of 3-year-olds. Methods: We surveyed questionnaires for 36 parents and interviewed 3 parents of 3-year-olds for the development of the program. Twenty-one 3-year-olds were selected as participants in the program. Quantitative data from a checklist for parent's mathematical interaction were analyzed using repeated measures ANOVA. Qualitative data from self-evaluation of teachers and parents were categorized and analyzed in terms of meaning. Results: Based on the home connection program, the session were provided in the following order [educare center activities ${\rightarrow}$ home-linked activities ${\rightarrow}$ home+educare integrated activities] and in each session, the three-step course [sharing of thinking ${\rightarrow}$ gathering of thinking ${\rightarrow}$ broadening of thinking] was applied. Implementation of this program led to promoting parental mathematical interaction. Conclusion/Implications: This study will lead to follow-up studies that reveal positive effects of our program.

• 한국강구조학회 논문집
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• 제26권1호
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• pp.1-10
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• 2014

본 연구에서는 원전 구조물 내 철근 콘크리트 구조와 강판 콘크리트 구조가 이질접합된 경우를 모사하기 위하여, 상하부 표면강판 간에 타이바를, 상하부 리브재 간에 타이형강을 구성한 보형 실험체를 제작하여 실험체의 면외 휨 거동특성을 확인하고자 하였다. 실험결과, 실험체의 연성거동을 검증하였으며, 타이바와 타이형강이 콘크리트 및 강판의 분리를 방지함으로써 접합부의 취성파괴를 막아주고 있음을 확인하였다. 또한, #14 주철근으로 구성한 강판 콘크리트 구조 접합부에 대하여 두 가지 형태의 기계적 정착이음 방식에 따른 인장실험을 수행함으로써 본 방식의 설계 적정성을 평가하였다. 실험결과, 두 실험체 모두 주철근이 항복에 도달할 때까지 철근의 정착 및 연결 기능을 탄성한도 내에서 건전히 수행하고 있음을 확인하였다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제20권1호
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• pp.45-55
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• 2014

Purpose: The purpose of this study is to provide data on the basis for architectural planning of floor plan type and spatial composition by analysing standard mental health centers in Seoul. Methods: Data were collected through literature research, field surveys, and expert interviews to 22 standard mental health centers in Seoul. Results: The results of this study could be summarized as follows; Firstly, Mental Health Center is divided into five types according to the location. Location types of mental health center were 'Director type', 'Health center connection type', 'Public facilities connection type', 'Complex center connection type' and 'Commercial Facilities connection type'. Secondly, Depending on the type of management a mental health center is divided into two types. Types are 'Complex type' and 'Independent type'. Average area of 'Complex type' is $192.99m^2$ and 'Independent type' is $266.87m^2$. This difference affects the various spaces. Implications: It is necessary to give and architectural suggestion of mental health center in response to the proposal of the system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.551-556
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• 2004

The Korean Train eXpress(KTX) which started in last April has got many complaints of passengers. This is caused by weak connections between KTX and traditional trains. This paper shows the methods to increase the connection in 3 points of view; business, operation and rolling stocks. For the flexible business, it is necessary that the connecting trains must be multi-purposefully for the satisfaction of KTX transferring passengers and existing commuting passengers. And the expanding of free class is needed. A free class is the base of business flexibility. In an operation point of view, I show the method that can decrease pains for getting transfer. Finally, for the effective using of rolling stocks, I propose that TC(trailer with control) car is added to existing locomotive and passenger coach set. In concluding, KTX needs strong connections with traditional trains. This will bring more competitive power with other transportation systems. And that method must get flexible and various service, in addition to effective and minimizing investment.

• 품질경영학회지
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• 제39권2호
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• pp.305-312
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• 2011

Kano model has been widely used to identify and classify customer attributes of a product or a service. The first step of Kano model application is the derivation of customer attributes, and brainstorming has been used conventionally for the purpose. A typical advantage of brainstorming is to get many ideas in a relatively short period, but the practicability of the derived ideas are known to be not so good. The derivation of good and practical ideas is important for the successful use of Kano model. Wish list, bug list and forced connection method as well as brainstorming were applied to PMP(Portable Multimedia Player) in order to derive customer attributes. To compare the idea generation methods, the derived attributes are classified and compared using Kano model.

• 콘크리트학회논문집
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• 제21권5호
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• pp.549-556
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• 2009

이 연구에서는 프리캐스트 콘크리트 구조시스템에서 기존에 사용되고 있는 벽체의 수직접합부의 시공 및 문제점을 최소화하기 위해 접합부의 폭을 100 mm에서 150 mm로 증가시키고 연결방식을 3가지로 하여 구조적 성능 및 적용성에 대해 분석하였다. 또한, 해석적으로 구조적 성능을 파악하기 위해 비선형 유한 요소 해석법으로 분석하였다. 분석 결과, 광폭형 연결부를 가진 접합부를 적용하였을 때, PC벽체에 가해지는 하중을 더 효율적으로 철근이 분담하여 내력이 증가하고 연성적인 거동을 하는 것으로 나타났다. 또한, 접합부 루프근의 단면적이 커질수록 그리고 철근 개수가 증가할수록 최대내력이 증가하며 광폭형 접합부 형식 중에 용접형-링형-C형의 순서로 내력이 큰 것으로 나타났다. 용접형의 경우 현장조건에 따른 변화가 발생할 수 있으므로 광폭형 연결 부위를 링형 접합부로 하는 것이 안정적인 거동을 하며 현장 용접의 철저한 품질관리가 필요하다.

• International Journal of Clinical Preventive Dentistry
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• 제14권4호
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• pp.247-255
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• 2018

Objective: Osseointegration is essential process for successful implants and effects to implant in long term, therefore, passive fitness of good prosthesis is necessary. To make a good prosthesis, at first it should be done a sectioned casting and then joined method of sectioned casting body is recommended. Methods: In this study, to provide the fundamental data on stable connection method for successful implants, the author tested fitness of casting body, and compared difference between gas soldering technique and laser welding technique. Results: In fitness test of 2 abutment (test A, C), gas soldering group's fitness in the opposite part of connection was worse than laser welding group. In fitness test of 3 abutment (test B, D), gap distance was increased both in gas soldering technique and laser welding technique. Gap distance at the connecting part and the opposite part of the abutment in gas soldering technique was worse than laser welding technique and the more additional abutment, the worse gap distance in gas soldering technique. In fitness test of 3 abutment (test B, D), there's little variation in No. 2 abutment when connecting soldering process was done and there's little influence on already soldered connection part when the additional soldering connection was done. Conclusion: On weak loading condition and the part which is needed an accuracy, laser welding technique is more effective and on long-span prosthesis and frequent chewing loading part, laser welding technique is recommended first and applying additional gas soldering technique would be better for making much more successful prosthesis.

• 한국건설순환자원학회논문집
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• 제11권4호
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• pp.517-526
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• 2023

현장에서 재사용율이 높은 시스템 동바리를 대상으로 임의 설계와 과도한 가재새 보강을 지양하고자 성능평가를 근거로한 시스템 동바리의 수직재와 수평재의 연결부에 대한 연결 조건을 제시하고자 하였다. 이를 위하여 국내에 가설현장에 널리 사용되는 대표적인 연결재 유형인 디스크형과 포켓형을 대상을 하중방향(수직, 수평)과 가력방법(단조, 반복)에 대하여 회전강성을 평가하였다. 평가결과 현행 설계기준에서 연결재에 대하여 회전강성을 "0"으로 규정한 것과 달리 모든 시편에서 회전강성 값을 확인할 수 있었으며, 최대 회전강성은 디스크형 연결재를 사용하여 수직방향으로 반복 가력한 시편에서 회전강성값이 19.624 kNm/rad로 확인되었다.