• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.8 s.179
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• pp.2091-2099
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• 2000

The object of the present study is to present an adaptive wavelet-Galerkin method for the analysis of thin-walled box beam. Due to good localization properties of wavelets, wavelet methods emerge as alternative efficient solution methods to finite element methods. Most structural applications of wavelets thus far are limited in fixed-scale, non-adaptive frameworks, but this is not an appropriate use of wavelets. On the other hand, the present work appears the first attempt of an adaptive wavelet-based Galerkin method in structural problems. To handle boundary conditions, a fictitous domain method with penalty terms is employed. The limitation of the fictitious domain method is also addressed.

• Nuclear Engineering and Technology
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• v.50 no.4
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• pp.619-626
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• 2018

Most publications confirm that an ecological interface is a very efficient tool to supporting operators in recognition of complex and unusual situations and in decision-making. The present article describes the experience of implementation of an ecological interface concept for visualization of material balance in a drum separator of RBMK-type NPPs. Functional analysis of the domain area was carried out and revealed main factors and contributors to the balance. The proposed ecological display was designed to facilitate execution of the most complicated cognitive operations, such as comparison, summarizing, prediction, etc. The experimental series carried out at NPPs demonstrated considerable reduction of operators' mental load, time of reaction, and error rate.

• Smart Structures and Systems
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• v.8 no.2
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• pp.157-172
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• 2011

A new method for both local damage(s) identification and input excitation force identification of beam structures is presented using the dynamic response sensitivity-based finite element model updating method. The state-space approach is used to calculate both the structural dynamic responses and the responses sensitivities with respect to structural physical parameters such as elemental flexural rigidity and with respect to the force parameters as well. The sensitivities of displacement and acceleration responses with respect to structural physical parameters are calculated in time domain and compared to those by using Newmark method in the forward analysis. In the inverse analysis, both the input excitation force and the local damage are identified from only several acceleration measurements. Local damages and the input excitation force are identified in a gradient-based model updating method based on dynamic response sensitivity. Both computation simulations and the laboratory work illustrate the effectiveness and robustness of the proposed method.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2294-2296
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• 2005

Multilayer microstrip lines are an integral part of an MMIC. This paper presents an analysis of multilayer GaAs-MMIC microstrip line using a spectral domain method(SDM) taking into account the effect of the variation in the thickness of various layers of substrates on the characteristic impedance and the effective dielectric constant of the line. This work is expected to be useful in GaAs foundries for accurate CAD modelling of the microstrip lines up to 40GHz.

• Earthquakes and Structures
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• v.3 no.3_4
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• pp.297-313
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• 2012

This paper is intended to show the robustness and capabilities of a coupled boundary element-finite element technique for the analysis of vibrations generated by high-speed trains under different geometrical, mechanical and operation conditions. The approach has been developed by the authors and some results have already been presented. Nevertheless, a more comprehensive study is presented in this paper to show the relevance and robustness of the method which is able to predict vibrations due to train passage at the vehicle, the track, the free-field and any structure close to the track. Local soil discontinuities, underground constructions such as underpasses, and coupling with nearby structures that break the uniformity of the geometry along the track line can be represented by the model. Non-linear behaviour of the structures can be also considered. Results concerning the excitation mechanisms, track behaviour and sub-Rayleigh and super-Rayleigh train speed are summarized in this work.

• Asia-Pacific Journal of Business
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• v.9 no.4
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• pp.1-11
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• 2018

Retiring from work is a major personal and professional transition and has a major influence on one's life. Tourism researchers have been aware of the importance of seniors' tourism and leisure activities to enhance their well-being. The study examines the effect of tourism experience on leisure life domain, which in turn influences overall quality of life. Moreover, the moderating effect of travel patterns is also tested. A final sample of 328 was used for data analysis including Structural equation modeling (SEM) and multi-group analysis to test the hypotheses. The findings revealed that tourism experience positively influences satisfaction with leisure life domain and overall quality of life. Findings also indicated that there are moderating effects of the travel patterns on the relationship between satisfaction with leisure life domains and overall quality of life. The study also provided managerial implications for tourism marketers and destination managers.

• Earthquakes and Structures
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• v.17 no.2
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• pp.143-162
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• 2019

Motivated by a simpler and more compact hybrid active tuned mass damper (ATMD) system with wide frequency spacing (i.e., high robustness) but not reducing the effectiveness using the least number of ATMD units, the active tuned tandem mass dampers (ATTMD) have been proposed to attenuate undesirable oscillations of structures under the ground acceleration. Likewise, it is expected that the frequency spacing of the ATTMD is comparable to that of the active multiple tuned mass dampers (AMTMD) or the multiple tuned mass dampers (MTMD). In accordance with the mode generalised system in the specific vibration mode being controlled (simply referred herein to as the structure), the closed-form expression of the dimensionless displacement variances has been derived for the structure with the attached ATTMD. The criterion for the optimum searching may then be determined as minimization of the dimensionless displacement variances. Employing the gradient-based optimization technique, the effects of varying key parameters on the performance of the ATTMD have been scrutinized in order to probe into its superiority. Meanwhile, for the purpose of a systematic comparison, the optimum results of two active tuned mass dampers (two ATMDs), two tuned mass dampers (two TMDs) without the linking damper, and the TTMD are included into consideration. Subsequent to work in the frequency domain, a real-time Simulink implementation of dynamic analysis of the structure with the ATTMD under earthquakes is carried out to verify the findings of effectiveness and stroke in the frequency domain. Results clearly show that the findings in the time domain support the ones in the frequency domain. The whole work demonstrates that ATTMD outperforms two ATMDs, two TMDs, and TTMD. Thereinto, a wide frequency spacing feature of the ATTMD is its highlight, thus deeming it a high robustness control device. Furthermore, the ATTMD system only needs the linking dashpot, thus embodying its simplicity.

• The Mathematical Education
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• v.41 no.3
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• pp.233-256
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• 2002

This study investigated school mathematics curriculum of England, newly revised in 1998, focused on the 'number and algebra' domain among three major domains of the English curriculum. On the basis of its understanding, this domain was compared and analyzed with school mathematics curriculum of Korea. In doing so, this study explored its plans and procedures and established a frame of comparison for the curriculums between the two countries. The structure of the National Curriculum in England is composed of programmes of study and attainment targets. The former sets out what should be taught in mathematics at key stages 1, 2, 3, and 4 and provides the basis for planning schemes of work, and the latter sets out the knowledge, skills, and understanding that pupils of different abilities and matures are expected to have by the end of each key stage. Attainment targets are composed of eight levels and an additional level of increasing difficulty. According to the results of the present study, Korea focuses on the formal and systematic mathematical knowledge on the basis of sound understanding of certain mathematical terms or concepts. On the other hand, England tends to deal with numbers more flexibly and naturally through the aquisition of mental methods, calculator use methods, etc, and emphasizes that mathematics be realistic and useful in solving a diverse number of problems confronted in everyday life.

• The Korean Journal of Health Service Management
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• v.10 no.1
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• pp.67-77
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• 2016

Objectives : This study was to test the influencing effects of calling, work value, and organizational commitment on turnover intention in hospital nurses. Methods : Two-hundred sixty hospital nurses were recruited in B city, South Korea. They were asked to complete a questionnaire, and 251 data sets were included in the multiple regression analysis. Results : Subjects had more extrinsic work value rather than intrinsic and a low calling level. There were significant correlations among transcendent summons, purpose/meaningfulness, pro-social intentions, intrinsic work value, and organizational commitment. Influencing factors of turnover intention were purpose/meaningfulness (t=-2.170, p=.031) and organizational commitment (t=-7.824, p<.001). The model was statistically significant explaining 27.8% of the variance (F=47.550, p<.001). Conclusions : Nurses showed a weak sense of calling and their work value leaned towards the extrinsic domain. Therefore, nurse managers should support a plan that enhances the calling and intrinsic work value of nurses to get them to commit to their organization and subsequently, reduce the turnover rate.

• Journal of KIISE:Information Networking
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• v.32 no.5
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• pp.625-632
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• 2005

Recently, real time services have been demanding a lot and the number of mobile devices is increasing extremely. Many researchers are focusing on decreasing handoff or signaling cost, produced when mobile devices are moving around. With these efforts, HMIPv6(Hierarchical Mobile Internet Protocol Version 6) was proposed. Mobile nodes do not need to register their locations to Home Agents whenever crossing over subnets within a MAP domain. In HMIPv6, mobile nodes choose the farthest MAP without considering node mobility pattern. However, a large MAP domain is not always efficient for a slow moving node and required additional work to choose a MAP in HMIPv6. Hence, this paper proposes 'Performance Analysis of HMIPv6 applying adaptive MAP Domain Site'.