• Smart Structures and Systems
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• v.31 no.5
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• pp.531-543
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• 2023

Base isolation is one of the most widely implemented and well-known technique to reduce structural vibration and damages during an earthquake. However, while the base-isolated structure reduces storey drift significantly, it also increases the base drifts causing many practical problems. This study proposes the use of Shape Memory Alloys (SMA) wires for the reduction in base drift while controlling the overall structure vibrations. A multi-degree-of-freedom (MDOF) structure along with base isolators and Shape-Memory-Alloys (SMA) wires in diagonal is tested experimentally and analytically. The isolation bearing considered in this study consists of laminates of steel and silicon rubber. The performance of the proposed structure is evaluated and studied under different loadings including harmonic loading and seismic excitation. To assess the seismic performance of the proposed structure, shake table tests are conducted on base-isolated MDOF frame structure incorporating SMA wires, which is subjected to incremental harmonic and historic seismic loadings. Root mean square acceleration, displacement and drift are analyzed and discussed in detail for each story. To better understand the structure response, the percentage reduction of displacement is also determined for each story. The result shows that the reduction in the response of the proposed structure is much better than conventional base-isolated structure.

• Journal of Family Resource Management and Policy Review
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• v.5 no.2
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• pp.69-85
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• 2001

The purpose of this study was to explore the effect of performance of living proprieties on family adaptability and self-esteem, centering on the married men and women residing in the city of Seoul. 220 respondents were randomly selected in July 2000 for the present research. The results of this study were as follows : First, the performance of living proprieties revealed a relatively high level and was shown a significant difference by sex, age, family type, religion, the number of children, experience of propriety education, value orientation, and the degree of communication. Second, family adaptability revealed a relatively high level and was shown a significant difference by family type, experience of propriety education, and the degree of communication. Self-esteem was shown a significant difference by the number of children and degree of communication. Third, background variable (age), the performance of living proprieties (communication manner, family decorum, social etiquette), and family adaptability had a significant effect on self-esteem. This implies that the performance of living proprieties rather than socio-demographic variables has a positive effect on self-esteem.

• Near Infrared Analysis
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• v.2 no.1
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• pp.29-36
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• 2001

This review paper outlines modern pretreatment methods used in NIR spectroscopy. The pretreatment methods can be divided into four categories. One method in is noise reduction. Smoothing is a representative method for the noise reduction. Another is baseline correction. The second derivative and multiplicative scatter correction (MSC) are most frequently employed for baseline correction. The third is centering and normalization and the last is resolution enhancement. Difference spectra, mean centering and second derivative are used in NIR spectroscopy as resolution enhancement methods. In this paper advantages and drawbacks of pretreatment methods currently used in NIR spectroscopy are discussed with many examples of NIR spectra.

• Tribology and Lubricants
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• v.21 no.1
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• pp.27-32
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• 2005

This paper shows a performance analysis for step type and conical type sealess cylinders. 2 dimensional Reynolds equation and finite difference numerical techniques are utilized for the performance analysis and the piston design. Centering forces of conical pistons are higher than those of step ones. Also, leakage flows of conical pistons are lower than those of step ones. But, the step type piston is practically suggested to apply for sealess cylinders because it is difficult that conical portion is precisely manufactured.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2004.11a
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• pp.149-152
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• 2004

Currently, with the development of an advanced industrial form, attention to human life has risen gradually. On the basis of aboves, Oriental medical industry has been achieved revolutionarily, and moreover the new word 'Well-being' has been born due to the value of life and attention to health. All who live in the 21-century have worried about problem with health and well-being, and the substitute medical science centering around the Oriental medicine has come up as the major concern, not to speak of the Oriental the West. Domestically, Research and attention to the Oriental medicine has increased, and its importance has appeared. At the moment, locally self-governing groups have taken an active step to study the genetic resources centering around locally- breedy wild medicinal herbfor their economy growth. Accordingly, in the historic view, to discover our medicinal herb's essence and to supply professional, systemical infomation of herb genetic, the necessity of professional exhibition museum can come up. under the above circumstances, I propose the public information museum in local area.

• Journal of Korean Society of Steel Construction
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• v.22 no.6
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• pp.553-561
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• 2010

The purpose of this paper is to analytically find the approximate supplement damping ratio of the viscous damper installed in self-centering (SC) single-degree-of-freedom (SDOF) systems with maximum displacements that are similar to those of elasto-plastic (EP) SDOF systems. The behavior of an SC SDOF system under harmonic cyclic loading was first described. Then an analytical model that can capture the behavior of the viscously damped SC SDOF system was introduced. Analysis parameters that characterize the hysteresis of the EP and SC SDOF systems were chosen, and nonlinear time-history analyses were performed using 20 historical accelerograms. Most of the SC SDOF systems with viscous dampers with approximately 10-15% damping ratios presented mean maximum displacement values that were similar to those of the EP SDOF systems. To investigate in detail the seismic performance of both systems, three EP SDOF systems and six corresponding SC SDOF systems were selected. The analyses showed that all the SC SDOF systems eliminated the residual displacements after the end of their shaking, and that the SC SDOF systems with 15% damping ratios performed better than the EP SDOF systems in terms of maximum displacement and acceleration response.

• The Journal of the Korea Contents Association
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• v.20 no.3
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• pp.49-58
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• 2020

The study was conducted on 492 social workers in Seoul and Gyeonggi Province to find out the impact of self-leadership on job satisfaction by social workers, centering on the mediated effect of self-efficacy. First, in the self-leadership of social workers, we confirmed that behavior-oriented and constructive thinking have a positive effect on job satisfaction, and the natural compensation has no effect. Second, in the self-leadership of social workers, we confirmed that behavior-oriented and constructive thinking have a positive effect on self-efficacy, and the natural compensation has no effect. Third, the self-efficacy of social workers was found to have a positive effect on job satisfaction. Fourth, the behavior-oriented and constructive thinking of the social worker who has self-leadership were found to have a positive effect on job satisfaction by mediating self-efficacy. Based on such research, some suggestions for social welfare practice and future research tasks are proposed.

• Smart Structures and Systems
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• v.25 no.2
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• pp.241-254
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• 2020

Using confined shape memory alloy (SMA) bar or plate, this study proposes an innovative self-centering damper. The damper is essentially properly machined SMA core, i.e., bar or plate, that encased in buckling-restrained device. To prove the design concept, cyclic loading tests were carried out. According to the test results, the damper exhibited desired flag-shape hysteretic behaviors upon both tension and compression actions, although asymmetric behavior is noted. Based on the experimental data, the hysteretic parameters that interested by seismic applications, such as the strength, stiffness, equivalent damping ratio and recentering capacity, are quantified. Processed in the Matlab/Simulink environment, a preliminary evaluation of the seismic control effect for this damper was conducted. The proposed damper was placed at the first story of a multi-story frame and then the original and controlled structures were subjected to earthquake excitations. The numerical outcome indicated the damper is effective in controlling seismic deformation demands. Besides, a companion SMA damper which represents a popular type in previous studies is also introduced in the analysis to further reveal the seismic control characteristics of the newly proposed damper. In current case, it was found that although the current SMA damper shows asymmetric tension-compression behavior, it successfully contributes comparable seismic control effect as those having symmetrical cyclic behavior. Additionally, the proposed damper even shows better global performance in controlling acceleration demands. Thus, this paper reduces the concern of using SMA dampers with asymmetric cyclic behavior to a certain degree.

• International Journal of High-Rise Buildings
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• v.3 no.1
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• pp.21-33
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• 2014

The tied braced frame (TBF) system was developed to achieve uniform seismic inelastic demand along the height of multi-storey eccentrically braced steel frames. A modular tied braced frame (M-TBF) configuration has been recently proposed to reach the same objective while reducing the large axial force demand imposed on the vertical tie members connecting the link beams together in TBFs. M-TBFs may however experience variations in storey drifts at levels where the ties have been removed to form the modules. In this paper, the possibility of reducing the discontinuity in displacement response of a 16-storey M-TBF structure by introducing energy dissipating (ED) devices between the modules is examined. Two M-TBF configurations are investigated: an M-TBF with two 8-storey modules and an M-TBF with four 4-storey modules. Three types of ED devices are studied: friction dampers (FD), buckling restrained bracing (BRB) members and self-centering energy dissipative (SCED) members. The ED devices were sized such that no additional force demand was imposed on the discontinuous tie members. Nonlinear response history analysis showed that all three ED systems can be used to reduce discontinuities in storey drifts of M-TBFs. The BRB members experienced the smallest peak deformations whereas minimum residual deformations were obtained with the SCED devices.

• Steel and Composite Structures
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• v.20 no.5
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• pp.1155-1171
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• 2016

Post-tensioned (PT) steel moment resisting frames (MRFs) with semi-rigid connections (SRC) can be used to control the hysteretic energy demands and to reduce the maximum inter-story drift (${\gamma}$). In this study the seismic behavior of steel MRFs with PT connections is estimated by incremental nonlinear dynamic analysis in terms of dissipated hysteretic energy ($E_H$) demands. For this aim, five PT steel MRFs are subjected to 30 long duration earthquake ground motions recorded on soft soil sites. To assess the energy dissipated in the frames with PT connections, a new expression is proposed for the hysteretic behavior of semi-rigid connections validated by experimental tests. The performance was estimated not only for the global $E_H$ demands in the steel frames; but also for, the distribution and demands of hysteretic energy in beams, columns and connections considering several levels of deformation. The results show that $E_H$ varies with ${\gamma}$, and that most of $E_H$ is dissipated by the connections. It is observed in all the cases a log-normal distribution of $E_H$ through the building height. The largest demand of $E_H$ occurs between 0.25 and 0.5 of the height. Finally, an equation is proposed to calculate the distribution of $E_H$ in terms of the normalized height of the stories (h/H) and the inter-story drift.