• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.9
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• pp.1007-1013
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• 2011

Because of their high flexibility and durability, multilayer bellows are manufactured for use in commercial vehicles, while single-layer bellows are manufactured for use in passenger vehicles. A study based on the finite element method (FEM) and shape optimization for the single-layer bellows has been actively performed; however, until now, a study based on the FEM has rarely been performed for the multilayer bellows with gaps between the layers. This paper presents a finite-element modeling scheme for the multilayer bellows to improve simulation reliability during the evaluation of stress and flexibility. For performing shape optimization for the multilayer bellows, DOE (design of experiment) and the Kriging metamodel followed by the D-optimal method are used.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.160.2-160.2
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• 2005

• The Journal of the Acoustical Society of Korea
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• v.19 no.1
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• pp.54-60
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• 2000

There are many works to analyze a simple expansion chamber involving higher order modes. These works are classified to mode matching method, velocity potential method and finite element method. Among these methods, mode matching method has good performance at analyzing a concentric expansion chamber. Generally inlet/outlet pipe cross section area is smaller than middle chamber cross section area. So the number of higher order modes of inlet/outlet pipe can be fewer than that of middle chamber. But mode matching method must use the same number of higher order modes at inlet pipe, middle chamber and outlet pipe. Therefore the redundant modes of inlet/outlet pipe makes the computation time of mode matching method longer. In this paper, the new method, which can select number of each higher order modes of inlet pipe, middle chamber and outlet pipe, was suggested. And this method was compared to conventional mode matching method and finite element method in order to demonstrate the accuracy of the new method and to show that the new method can reduce a calculating time.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.3
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• pp.245-252
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• 2016

In this study, an alternative bend design is proposed to overcome the aging problem in piping bends. In this design, the foam pad is not included. Finite element analysis was performed based on the total pipe diameter. From this analysis, the shape of the Shear Control Ring (SCR) was determined. Temperature, stress, and other data of the proposed reinforced pipe were acquired and analyzed after the test was performed. The value of the thermal stress for the reinforced steel pipe satisfied the required standard without the foam pad based on the manufacturing of the reinforced fitting and construction site of the test. The reinforcement provided a shear strength level for the foam pad that resulted in maximum shear stress less than stress based on the original foam pad applied at the pipe bend. Additionally, an increasing factor of safety effect for the reinforced fitting application was discovered.

• Journal of Korean Society of Archives and Records Management
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• v.16 no.1
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• pp.9-40
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• 2016

The space designated for kindergarten and elementary school students, who accounted for half of all users of the presidential archives, is now lacking, with the archives' programs focusing on exhibitions and field trips. With this, an experience exhibition is seen as the most effective way to communicate the value of presidential records and archives based on the theory of cognitive development. Therefore, this study proposes an experiential exhibition program for children about presidential archives based on the experience economy under theories that are recently getting attention. The Presidential Archives through the Experiential Exhibition program for children proposed by this study will become a place for the cultural communication of all generations.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.30 no.4
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• pp.235-254
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• 2019

According to the development of information technology, the paradigm of the archives is shifting from preservation management of past records to use-oriented services. In this regard, this study is conducted an empirical study on the effect of internal marketing factors of university archives on the customer orientation of employees in order to improve organizational satisfaction for users of records information service. Based on the previous research, the delegation of authority, internal communication, management support, and training are established as factors of internal marketing, and the parameters for this are job satisfaction, organizational commitment, customer orientation as dependent variables, and We set up hypothesis between research variables and attempted an analysis through statistical system. In summary, each element of internal marketing showed significant results on job satisfaction and organizational commitment, and management support was most closely related to job satisfaction, organizational commitment, and customer orientation of university archive staff.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4A
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• pp.353-359
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• 2010

Cementitious matrix based composites are vulnerable to the drying shrinkage crack during the curing process. In this study, the drying shrinkage induced fracture behavior of the fiber reinforced concrete is simulated and the effects of the fiber reinforcement conditions on the fracture characteristics are analysed. The numerical model is composed of conduit elements and rigid-body-spring elements on the identical irregular lattice topology, where the drying shrinkage is presented by the coupling of nonmechanical-mechanical behaviors handled by those respective element types. Semi-discrete fiber elements are applied within the rigid-body-spring network to model the fiber reinforcement. The shrinkage parameters are calibrated through the KS F 2424 free drying shrinkage test simulation and comparison of the time-shrinkage strain curves. Next, the KS F 2595 restrained drying shrinkage test is simulated for various fiber volume fractions and the numerical model is verified by comparison of the crack initiating time with the previous experimental results. In addition, the drying shrinkage cracking phenomenon is analysed with change in the length and the surface shape of the fibers, the measurement of the maximum crack width in the numerical experiment indicates the judgement of the crack controlling effect.

• 한국과학교육학회:학술대회논문집
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• 2008.08a
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• pp.103.1-103.1
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• 2008

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2018.10a
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• pp.67-67
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• 2018

• Proceedings of KHEA Conference
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• 2007.06a
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• pp.48-48
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• 2007