• Steel and Composite Structures
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• 제31권6호
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• pp.601-615
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• 2019

In cold-formed steel (CFS) structures, such as trusses, wall frames and columns, the use of back-to-back built-up CFS angle sections are becoming increasingly popular. In such an arrangement, intermediate fasteners are required at discrete points along the length, preventing the angle-sections from buckling independently. Limited research is available in the literature on the axial strength of back-to-back built-up CFS angle sections. The issue is addressed herein. This paper presents the results of 16 experimental tests, conducted on back-to-back built-up CFS screw fastened angle sections under axial compression. A nonlinear finite element model is then described, which includes material non-linearity, geometric imperfections and explicit modelling of the intermediate fasteners. The finite element model was validated against the experimental test results. The validated finite element model was then used for the purpose of a parametric study comprising 66 models. The effect of fastener spacing on axial strength was investigated. Four different cross-sections and two different thicknesses were analyzed in the parametric study, varying the slenderness ratio of the built-up columns from 20 to 120. Axial strengths obtained from the experimental tests and finite element analysis were used to assess the performance of the current design guidelines as per the Direct Strength Method (DSM); obtained comparison showed that the DSM is over-conservative by 13% on average. This paper has therefore proposed improved design rules for the DSM and verified their accuracy against the finite element and test results of back-to-back built-up CFS angle sections under axial compression.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1640-1643
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• 2005

This paper presents analysis of dynamic characteristics of a high-speed milling spindle with a drawbar and a built-in motor. The spindle system with a built-in motor can be used to simplify the structure of machine tools, to improve the machining flexibility of machine tools, and to perform the high speed machining. In this system the shaft is usually assumed as a rigid rotor. In this paper, the modal characteristics of drawbar in high-speed milling spindle system due to supporting stiffness between drawbar and shaft and considering the mass and stiffness effects of the built-in motor's rotor are analyzed by numerical method. The result shows enough stiff supports must be provided between shaft and drawbar to prevent occurring drawbar vibration lower than the natural frequency of 1st bending mode of spindle. And considering the mass and stiffness of built-in motor's rotor is important thing to derive more accurate results.

• 한국가구학회지
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• 제28권3호
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• pp.135-144
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• 2017

The development of human civilization has been accompanied by a corresponding development of storage facilities. In particular, the storage of residential spaces not only performs the storage management function for personal property but also is considered an important prerequisite for a comfortable life. While examining the history of the transformation of built-in furniture, this study emphasizes the social and cultural implications of Korean residences. Therefore, We attempt to uncover the Korean characteristics that can be discovered in the transformation of storage furniture according to the changes that occurred in Korean residential forms following the modern era and to question the problematic issues of the built-in furniture in Korea.

• 한국디지털건축인테리어학회논문집
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• 제11권3호
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• pp.27-34
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• 2011

The DIABUTSU hotel was built first in Korea and we know that the hotel was built in 1888. However, it has many questions. This study was conducted to uncover the truth. Non-text media in the study is useful to take advantage of the media. However, it is not used in Korea. I prefer that study by Non-text Media. The findings, DIABUTSU hotel was built in 1884. It was Japanese-style two-story wooden building. HORI was hospitality there and many foreigners stayed. Underwood, Appenzeller and Carles were this hotel and they recorded about the hotel in 1885. We know that three story building was the first hotel. But this is wrong in fact. The first hotel is Japanese-style wooden building built in 1884.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권1호
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• pp.248-268
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• 2018

The performance of smartphone applications are usually constrained in user interactions due to resource limitation and it promises great opportunities to improve the performance by exploring the smartphone built-in and embedded sensing techniques. However, heterogeneity in techniques, semantic gap between sensor data and usable context, and complexity of contextual situations keep the techniques from seamless integration. Relevant studies mainly focus on feasibility demonstration of emerging sensing techniques, which rarely address both general architectures and comprehensive technical solutions. Based on a proposed functional model, this investigation provides a general architecture to deal with the dynamic context for context-aware automation and decision support. In order to take advantage of the built-in sensors to improve the performance of mobile applications, an ontology-based method is employed for context modelling, linguistic variables are used for heterogeneous context presentation, and semantic distance-based rule matching is employed to customise functions to the contextual situations. A case study on mobile application authentication is conducted with smartphone built-in hardware modules. The results demonstrate the feasibility of the proposed solutions and their effectiveness in improving operational efficiency.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2002년도 추계학술발표대회
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• pp.161-166
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• 2002

Functional ability is an important criterion to predict the capability of older persons to maintain independent living in the community setting. This study focused on the effect of built-environment features to ameliorate declines in functional ability and reduce the likelihood of relocation. Using longitudinal data from the Asset and Health Dynamics Among the Oldest Old (1993, 1995), relocation was analyzed for 6,225 respondents aged 70 or older. Findings are that while functional decline in household activities of daily living among older persons increased their residential moves in the community, functional declines in basic activities of daily living, household activities of daily living, and advanced activities of daily living among them increased their entrance into an institutional care facility However, they were less likely to enter an institutional care facility when their home was equipped with built-environment features such as street level ramps, special railings, modifications to allow someone in a wheelchair, grab bars or shower seat in the bathroom, and special call device or system to get help.

• 한국가구학회지
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• 제17권4호
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• pp.27-48
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• 2006

Most of us spend the greater part of our lives in the kitchen, but of all the man environments it maybe the least well-explored share commitment to a cleaner and healthier environment. It has long been kitchen system belief that the environment is a precious gift. In case of built in kitchen system, because it depend upon the earth's resources to design and manufacture steel hardware products, human beings feel an abiding responsibility to act wisely in the environmental choices we make, large and small, every day. Built in kitchen system, designed and coordinated by study of designer, represents an open, complete, free and 'focused' way of conceiving, furnishing and organizing one's own kitchen. A space rich in technical values and home warmth, where few, simple and carefully designed components distinguish and characterize the various work spaces, from the area, intended for preparing and washing food, to the cooking area, and to a wide range of multivalent pieces of furniture, wood paneled wall units and shelves.

• Structural Engineering and Mechanics
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• 제28권4호
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• pp.443-460
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• 2008

The aim of this paper is to propose a design procedure for predicting the buckling strength of built-up, cold-formed steel columns based on the two well known methods; the effective width method and the Direct Strength Method. Several design approaches, based on different elastic buckling solutions, were considered in this investigation. Traditional hand methods, without interaction effects between the different modes, and a new numerical spline finite strip method were used to predict the buckling stresses. All of the proposed methods were compared with experimental data on plain and lipped, built-up columns. Results have shown that the effective width approaches are more accurate than the Direct Strength Method. However, both methods can be investigated using more experimental data to assess a practical design method for built-up columns.

• Journal of Welding and Joining
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• 제19권2호
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• pp.98-103
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• 2001

Root gap out of standard by welding deformation is frequently produced at butt weld joints of steel bridge. For example although standard root gap is below 6mm at butt weld joints of plates under 15mm thickness. maximum 35mm root opening is produced at the weld field. At this case, the part out of standard is generally built up and the rest part is welded by WPS. Direct welding without built-up welding is preferred in weld field because built-up welding process bring about the cost-up at manufacturing. To apply this direct weld to root gap out of standard, the investigation about mechanical properties and fatigue at weldment is required. Inthisstudy, therefore the verification for direct weld without built up is performed at weldment as root gap. It includes tension, bending. hardness, impact and fatigue test for each welding specimen of 6mm, 25mm, 35mm root gap.

• 한국소음진동공학회논문집
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• 제11권9호
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• pp.462-474
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• 2001

In this paper, Generalized Differential Quadrature Method is applied to the buckling analysis of built-up columns without or with stay plates. numerical analysis using GDQM is carried out for various boundary conditions(simply supported conditions, fixed conditions, fixed-simply supported conditions), dimensionless stiffness parameter and dimensionless inertia moment parameter. The accuracy and convergence of solutions are compared with exact solutions of Gjelsvik to validate the results of GDQM. Results obtained by this method are as follows. 91) This method can yield the accurate numerical solutions using few grid points. (2) The buckling load of built-up column increases as the dimensionless stiffness parameter decreases. (3) The effects of boundary conditions on the buckling load are not considerable as the dimensionless stiffness parameter increases. (4) The buckling load of built-up column increases due to the stay plate.