• Advances in materials Research
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• v.6 no.3
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• pp.257-278
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• 2017

A simple closed-form solution to calculate the interfacial shear and normal stresses of retrofitted concrete beam strengthened with thin composite plate under mechanical loads including the creep and shrinkage effect has been presented in this paper. In such plated beams, tensile forces develop in the bonded plate, and these have to be transferred to the original beam via interfacial shear and normal stresses. Consequently, debonding failure may occur at the plate ends due to a combination of high shear and normal interfacial stresses. These stresses between a beam and a soffit plate, within the linear elastic range, have been addressed by numerous analytical investigations. Surprisingly, none of these investigations has examined interfacial stresses while taking the creep and shrinkage effect into account. In the present theoretical analysis for the interfacial stresses between reinforced concrete beam and a thin composite plate bonded to its soffit, the influence of creep and shrinkage effect relative to the time of the casting, and the time of the loading of the beams is taken into account. Numerical results from the present analysis are presented both to demonstrate the advantages of the present solution over existing ones and to illustrate the main characteristics of interfacial stress distributions.

• Advances in materials Research
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• v.7 no.2
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• pp.119-136
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• 2018

In this paper, static and vibration analysis for anti-symmetric cross-ply and angle- ply carbon/glass hybrid laminates rectangular composite plate are presented. In this analysis, the equations of motion for simply supported thick laminated hybrid rectangular plates are derived and obtained through the use of Hamilton's principle. The closed-form solutions of anti-symmetric cross-ply and angle- ply laminates are obtained using Navier solution. The effects of side-to-thickness ratio, aspect ratio, and lamination schemes on the fundamental frequencies loads are investigated. The study concludes that shear deformation laminate theories accurately predict the behavior of composite laminates, whereas the classical laminate theory over predicts natural frequencies. The excellent accuracy of the present analytical solution is confirmed by making some comparisons of the present results with those available in the literature. It can be concluded that the proposed theory is accurate and simple in solving the free vibration behaviors of anti-symmetric cross-ply and angle- ply hybrid laminated composite plates.

• Steel and Composite Structures
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• v.42 no.1
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• pp.59-74
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• 2022

This study introduces a general reliability-based, performance-based design framework to design frames regarding their uncertainties and user-defined design goals. The Iterative-R method extracted from the main framework can designate a proper R (i.e., response modification factor) satisfying the design goal regarding target reliability index and pre-defined probability of collapse. The proposed methodology is based on FEMA P-695 and can be used for all systems that FEMA P-695 applies. To exemplify the method, multiple three-dimensional, four-story steel special moment-resisting frames are considered. Closed-form relationships are fitted between frames' responses and the modeling parameters. Those fits are used to construct limit state functions to apply reliability analysis methods for design safety assessment and the selection of proper R. The frameworks' unique feature is to consider arbitrarily defined probability density functions of frames' modeling parameters with an insignificant analysis burden. This characteristic enables the alteration in those parameters' distributions to meet the design goal. Furthermore, with sensitivity analysis, the most impactful parameters are identifiable for possible improvements to meet the design goal. In the studied examples, it is revealed that a proper R for frames with different levels of uncertainties could be significantly different from suggested values in design codes, alarming the importance of considering the stochastic behavior of elements' nonlinear behavior.

• Korean Institute of Interior Design Journal
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• v.25 no.6
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• pp.127-138
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• 2016

As the dark side of society, Idle spaces, which occurred with the paradigm change due to rapid modernization and industralization, has been existing as a severed part in cities. But with the periodic change, interest in the existing place and regional regeneration, and the necessity of reconsidering about the idle spaces values of space, city environment, socio-culture, and economy was proposed. I estimated that the change of relational aesthetics aspect of modern arts resulted in the consideration of recognizing 'place' of art, through the study, it was revealed that the form of modern arts and change of enjoyment were related to space, and the fact that this had a relation with the rise of artistic regeneration of idle spaces. mutually communicative relationship formation and practical form of arts was deducted through the interpretation of relational aesthetics, Idle spaces and artistic regeneration space can be categorized into forms of experiential space, creative space, and cultural space, depending on the formation of relationship between author-art-audience. Through the comprehensive analysis, Artistic regeneration space by relationship formation is Vitalization of various forms of art and participation program eliminates the boundary between creation and enjoyment, and the space itself can be said to contain extensive, integral, and nonterritorialization meaning as a place of experiencing art. In other words, Artistic regeneration space of idle spaces forms a close relationship with the local society, and is placed within the context of daily domain as an open space, straying off from the existing separative and closed artistic space configuration. and artistic changeover of idle spaces is not only the appearance of space that simply fulfills function according to transfiguration of modern art, but signifies that art is coexisting with space as an indivisible relationship, and can be said to be the foothold of new relationship creation as the practical 'place' of art.

• Journal of East-West Nursing Research
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• v.10 no.1
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• pp.86-94
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• 2004

This study has verified Family Functioning, Communication and Spiritual Wellbeing, to increase the family functioning in Adult Women. 236 adult women were chosen as the samples for the study, they are now currently registered in the church adult women in Seoul. The instruments used for this study were the Family functioning scale by Olson, the communication scale by David H. Olson and Howard L. Barnes and spiritual wellbing Scale by Palautzian and Ellison Folkman. Data collection were form March to April, 2003. To get the descriptive statistics, SPSS Program, Pearson Correlation Coefficients and stepwise multiple regression were used for analyzing data. The results were as following: 1. Represents the degree of family functioning, communication and spiritual wellbeing, on subjects. Means scores of this study are following: spiritual wellbeing 67.92, lower level of cohesive(5.19) and adaptive(3.93), communication 58.14, lower level of open(5.15) and closed(4.71) and family functioning 95.58, lower level of religious(7.70) and existential(7.63). All each lower level of family functioning, communication and spiritual wellbeing, on subjects were derived significantly different(p.05). There were significant correlation among the variables of subjects. The cohesive family functioning score was significant related to the adapted(r=.588). Especially, the closed communication score showed inverse correlations open family functioning(r=-.424) and open communication score(r=-.680). The existential spiritual wellbeing score also was significant related to the cohesive(p<.001) and adaptive(p<.05) family functioning, open communication(p<.05). Especially, the closed communication score showed inverse correlations existential spiritual wellbeing (r=-.202). The existential spiritual wellbeing score also was significant related to the religious(r=.815, p<.001). These results will not only emphasis the need of family functioning to elevate and decrease the Closed family communication but suggest the important points of gathering various data and analysis about economic, education and marital status. Finally, related to mental health nursing, a community can get the utmost out of these results to keep offering education and practice of family mental health for adult women.

• Smart Structures and Systems
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• v.26 no.4
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• pp.481-493
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• 2020

The negative stiffness spring and inerter are both characterized by the negative stiffness effect in the force-displacement relationship, potentially yielding an amplifying mechanism for dashpot deformation by being incorporated with a series tuning spring. However, resisting forces of the two mechanical elements are dominant in different frequency domains, thus leading to necessary complementarity in terms of vibration control and the amplifying benefit. Inspired by this, this study proposes a Negative Stiffness Inerter System (NSIS) as an earthquake protection system and developed analytical design formulae by fully utilizing its advantageous features. The NSIS is composed of a sub-configuration of a negative stiffness spring and an inerter in parallel, connected to a tuning spring in series. First, closed-form displacement responses are derived for the NSIS structure, and a stability analysis is conducted to limit the feasible domains of NSIS parameters. Then, the dual advantageous features of displacement reduction and the dashpot deformation amplification effect are revealed and clarified in a parametric analysis, stimulating the establishment of a displacement-based optimal design framework, correspondingly yielding the design formulae in analytical form. Finally, a series of examples are illustrated to validate the derived formulae. In this study, it is confirmed that the synergistic incorporation of the negative stiffness spring and the inerter has significant energy dissipation efficiency in a wide frequency band and an enhanced control effect in terms of the displacement and shear force responses. The developed displacement-based design strategy is suitable to utilize the dual benefits of the NSIS, which can be accurately implemented by the analytical design formulae to satisfy the target vibration control with increased energy dissipation efficiency.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.1-8
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• 2010

Wireless multimedia service through the access to mobile telephone network or data network is a vital part of contemporary life, and the demand for frequency spectrum for new services is expected to explode as the ubiquitous computing proliferate. Cognitive radio is a technology, which automatically recognizes and searches for temporally and spatially unused frequency spectrum, then actively determines the communication method, bandwidth, etc. according to the environment, thus utilizing the limited spectrum resources efficiently. In this paper, we investigate the effects of imperfect sensing, misdetection and false alarm, on the primary and secondary users' spectrum usage through the analysis of continuous time Markov Chain. We analyzed the effects of the parameters such as sensing error, offered load on the system performance.

• Journal of Power Electronics
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• v.13 no.2
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• pp.275-286
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• 2013

An explicit frequency-domain circuit model for the conventional coupled magnetic resonance system (CMRS) is newly proposed in this paper. Detail circuit parameters such as the leakage inductances, magnetizing inductances, turn-ratios, internal coil resistances, and source/load resistances are explicitly included in the model. Accurate overall system efficiency, DC gain, and key design parameters are deduced from the model in closed form equations, which were not available in previous works. It has been found that the CMRS can be simply described by an equivalent voltage source, resistances, and ideal transformers when it is resonated to a specified frequency in the steady state. It has been identified that the voltage gain of the CMRS was saturated to a specific value although the source side or the load side coils were strongly coupled. The phase differences between adjacent coils were ${\pi}/2$, which should be considered for the EMF cancellations. The analysis results were verified by simulations and experiments. A detailed circuit-parameter-based model was verified by experiments for 500 kHz by using a new experimental kit with a class-E inverter. The experiments showed a transfer of 1.38 W and a 40 % coil to coil efficiency.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.2
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• pp.68-74
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• 2010

In this paper, we analyze and simulate the channel capacity of a spread spectrum watermarking (SSW) technique in wireless fading channel to apply ITS system. Channel capacity analysis causing minimum effect to existing system is required necessary to apply SSW technique. We derive the channel capacity as a closed-form approximation formula in Rayleigh and Rician fading channel model. The numerical results are demonstrated and good approximated results are reported.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3585-3601
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• 2016

The error rate performance of circularly distributed antenna system is studied over Nakagami-m fading channels, where a dual-channel receiver is employed for the quadrature phase shift keying signals detection. To mitigate the Co-Channel Interference (CCI) caused by the adjacent cells and to save the transmit power, this work presents remote antenna unit selection transmission based on the best channel quality and the maximized path-loss, respectively. The commonly used Gaussian and Q-function approximation method in which the CCI and the noise are assumed to be Gaussian distributed fails to depict the precise system performance according to the central limit theory. To this end, this work treats the CCI as a random variable with random variance. Since the in-phase and the quadrature components of the CCI are correlated over Nakagami-m fading channels, the dependency between the in-phase and the quadrature components is also considered for the error rate analysis. For the special case of Rayleigh fading in which the dependency between the in-phase and the quadrature components can be ignored, the closed-form error rate expressions are derived. Numerical results validate the accuracy of the theoretical analysis, and a comparison among different transmission schemes is also performed.