• Archives of Pharmacal Research
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• 제13권4호
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• pp.385-387
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• 1990

3-[(1-Methyl-1H-tetrazol-5-y)thiomethyl] is one of the most important side chains in cephaloporins. This side chain which occures in numerous antibacterial agents, suc as cefamandole, latamoxef, cefoperazone, and cefmenoxime, contributes remarkable potency and broad spectrum. For the continuous work of study on the development of broad spectrum cephalosporins, we become interested in the effect of structural modification of the substituent at the N-1 position of mercaptoterazole toward biological activity because our recent work had demonstraated that the arylsubstituted mercaptotetrazoles (Fig. 1) had favorable effect on the activity against gram-positive bacteria. The main focus of this report was to investigate the relationship between activity and functional groups in the mercaptotetrazole.

• Perspectives in Nursing Science
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• 제8권1호
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• pp.10-19
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• 2011

Purpose: This article was proposed to describe and summarize the following 1) the structural hierarchy of nursing knowledge and 2) the four different methods of concept analysis and concept development, which are used most frequently in nursing literature, and 3) to demonstrate a qualitative data synthesis of situation-specific theories in Korea in order to provide an venue for developing Korean-contextualized nursing theory. Methods: A literature review and a meta-synthesis were used. An interpretive integration method for the meta-synthesis was used to incorporate incorporating the results of ten qualitative studies in Korea. Results: The normative and extended concept of the self was one of the three foremost concepts. The experiences of being detached from a group and of being unlike others were perceived with distress to Korean participants. Lastly, as a coping method, complying with a higher flow or power was used. Conclusion: Based on the three concepts elicited in this article, a substantive theory which withholds Korean nursing concepts and essences is hoped to be developed in future.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.599-604
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• 2002

Substructures position is considered as design parameter to obtain optimal structural changes to raise its dynamic characteristics. In conventional SDM (structural dynamics modification) method, the layout of modifying substructures position is first fixed and at that condition the structural optimization is performed by using the substructures size and/or material property as design parameters. But in this paper as a design variable substructures global translational and rotational position is treated. For effective structural modification the eigenvalue sensitivity with respect to that design parameter is derived based on measured frequency response function. The optimal structural modification is calculated by combining eigenvalue sensitivities and eigenvalue reanalysis technique iteratively. Numerical examples are presented to the case of beam stiffener optimization to raise the natural frequency of plate.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.666-669
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• 2004

Substructures position is considered as design parameter to obtain optimal structural changes to raise its dynamic characteristics. In conventional SDM (structural dynamics modification) method, the layout of modifying substructures position is first fixed and at that condition the structural optimization is performed by using the substructures size and/or material property as design parameters. But in this paper as a design variable substructures global translational and rotational position is treated. For effective structural modification the eigenvalue sensitivity with respect to that design parameter is derived based on measured frequency response function. The optimal structural modification is calculated by combining eigenvalue sensitivities and eigenvalue reanalysis technique iteratively. Numerical examples are presented to the case of beam stiffener optimization to raise the natural frequency of plate.

• Journal of Mechanical Science and Technology
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• 제18권9호
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• pp.1529-1536
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• 2004

A structure is broken down into a number of substructures by means of the finite element method and the substructures are synthesized for the complete structure. The divided substructures take two types: fixed-free and free-free elements. The flexibility and stiffness matrices of the free-free elements are the Moore-Penrose inverse of each other. Thus, it is not easy to determine the equilibrium equations of the complete structure composed of two mixed types of substructures. This study provides the general form of equilibrium equation of the entire structure through the process of assembling the equilibrium equations of substructures with end conditions of mixed types. Applications demonstrate that the proposed method is effective in the structural analysis of geometrically complicated structures.

• Structural Engineering and Mechanics
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• 제10권1호
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• pp.81-92
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• 2000

This study is an investigation of the effect of cracks on the dynamical characteristics of a cantilever beam, having multiple open-edge transverse cracks. The flexibilities due to crack have been identified for several crack depths and locations. In the study the finite element method and component mode synthesis methods are used. Coupling the components is performed by a flexibility matrix taking into account the interaction forces. Each component is modelled by cantilever beam finite elements with two nodes and three degrees of freedom at each node. The results obtained lead to conclusion that, by using the drop in the natural frequencies and the change in the mode shapes, the presence and nature of cracks in a structure can be detected. There is some counter-evidence, however, that the effects due to multiple cracks may interact to make detection more difficult than for isolated cracks.

• 소음진동
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• 제10권4호
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• pp.575-583
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• 2000

In this paper, we design a vibration control system that includes a 3-D.O.F. mass-spring-damper structure for the analytical model of a building that is excited at the base of this structure by an external dynamic force, and one Active Mass Damper(AMD) on the top of this structure to generate control forces fro attenuation of the structural response. Two robust controllers based on $\mu$-synthesis and H$\infty$ optimal control are designed for the structural system to show that the performance of a control system can be degraded by some parameter uncertainties such as mass, stiffness coefficients, and/or damping coefficients. The performance of the two controllers are compared in terms of nominal performance, robust stability and robust performance by simulations.

• Structural Engineering and Mechanics
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• 제65권4호
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• pp.359-368
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• 2018

Dynamic analysis of complex and large structures may be costly from a numerical point of view. For coupled vibroacoustic finite element models, the importance of reducing the size becomes obvious because the fluid degrees of freedom must be added to the structural ones. In this paper, a component mode synthesis method is proposed for large vibroacoustic interaction problems. This method couples fluid subdomains and dynamical substructuring of Craig and Bampton type. The acoustic formulation is written in terms of the velocity potential, which implies several advantages: coupled algebraic systems remain symmetric, and a potential formulation allows a direct extension of Craig and Bampton's method to acoustics. Those properties make the proposed method easy to implement in an existing finite element code because the local numerical treatment of substructures and fluid subdomains is undifferentiated. Test cases are then presented for axisymmetric geometries. Numerical results tend to prove the validity and the efficiency of the proposed method.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.597-602
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• 2007

It is proposed to analyze the vibration of slab with MTMD and vibration-induced noise. Substructure synthesis is introduced to develope the interaction between the slab and MTMD which are defined in different space and acoustic power is obtained from the velocity field of slab. Numerical analysis is performed to show that the vibration and noise of slab can be reduced by MTMD. A living room of wall type apartment including the wall and MTMD is modeled and analyzed by FEM program Numerical analysis shows that the vibration and noise control effect is different depending on the location and mass ratio of MTMD. Futhermore, noise is more effectively reduced when the vibration of higher modes of slab are reduced rather than lower modes.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.852-855
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• 2005

Structural Dynamic Modification(SDM) is a technique to improve structure's dynamic characteristics by adding and removing substructures or changing material properties and shape of structures. This paper describes SDM techniques applied to a large structure with too many DOFs. The goal of this SDM technique is to modify a targe structure efficiently for its natural frequencies to avoid excitation frequencies. In this case, models reduced by Component Mode Synthesis(CMS) method that is a coupling technique are used to analyze a large structure efficiently. This paper considers a helicopter deck model with 55,000 DOFs as an application.