• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.5-14
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• 1999

Free vibration characteristics of a cantilevered laminated composite beam with multiple non-propagating transverse open cracks are investigated. In the present analysis a special ply-angle distribution referred to as asymmetric stiffness configuration inducing the elastic coupling between chord-wise bending and extension is considered. The multiple open cracks are modelled as equivalent rotational springs whose spring constants are calculated based on the fracture mechanics of composite material structures. Governing equations of a composite beam with open cracks are derived via Hamilton's Principle and Timoshenko beam theory encompassing transverse shear and rotary inertia effect is adopted. The effects of various parameters such as the ply angle, fiber volume fraction, crack numbers, crack positions and crack depthes on the free vibration characteristics of the beam with multiple cracks are highlighted. The numerical results show that the existence of the multiple cracks in an anisotropic composite beam affects the free vibration characteristics in a more complex fashion compared with the beam with a single crack.

• Korean Journal of Human Ecology
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• v.17 no.1
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• pp.13-26
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• 2008

The purposes of this study was to examine the effects of undergraduate's optimism and family-control on their awareness of caregiving for the elderly. The subjects for this study were 374 undergraduates from 4 universities in G city. The collected data were analyzed with SPSS WIN(ver. 12.0) program, and frequency and percentile, mean and standard deviation, t-test, correlation analysis, multiple regression, and path analysis were utilized. The main findings of the study were as follows. The undergraduate's degree of optimism and family-control, and their awareness of caregiving for the elderly were slightly higher than the average. In addition, the undergraduate's optimism and family-control were differed according to their 'existence and/or nonexistence of religion', and their awareness of caregiving for the elderly was significantly different depending on 'existence and/or nonexistence of religion', and 'existence and/or nonexistence of living together with their grandparents'. It was also found that the undergraduate's awareness of caregiving for the elderly was directly influenced by their family-control, whereas their awareness of caregiving for the elderly was indirectly influenced by their optimism via family-control.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.523-530
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• 2020

The efficient market hypothesis explains the random walk hypothesis suggesting that stock prices are independent of each other, hence, it is impossible to earn abnormal profits. The positive effect of a well-functioning and highly efficient stock market on the performance of an economy motivated the Philippine Stock Exchange to pursue massive modernization initiatives. This research provides evidence of the existence of random walk in the Philippine stock market employing the Augmented Dickey-Fuller (1981) and Phillips-Perron (1988) unit root tests, the Lo-MacKinlay's (1988) conventional variance ratio test, and Chow-Denning's (1993) simple multiple variance ratio test. Results of the ADF and PP unit root tests confirm the necessary condition for a random walk. The Chow-Denning (1993) maximum /z/ statistic and the Wald test statistic as in Richardson and Smith (1991) for the joint hypotheses and the Lo and MacKinlay (1988) individual statistics variance ratio test generally accepted the null hypothesis of a random walk. That is, the unit root and variance ratio tests consistently indicate that the null hypothesis of random walk cannot be rejected. The existence of a random walk in weak-form efficiency can be attributed to market liquidity as a result of continuous development and modernization of the Philippine equity market.

• Korean Institute of Interior Design Journal
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• v.19 no.1
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• pp.27-36
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• 2010

The purpose of this study is to define concept and characteristics of "Unphenomenon", the design concept conceived by Shiro Kuramata who is a world renowned Japanese interior designer and to explore how his ideas were materialized in his works. This study 1) examines his experience during his childhood reflected in his essay The scenery of the Unphenomenon' and training in Kuwazawa Design Institute that made Shiro Kuramata a true interior designer, and also considers how his design philosophy had been built up and realized under the unique social situation at the time. 2) defines the concept and characteristics of "Unphenomenon" as substance of his design philosophy by surveying remarks in his books and comments made by people around him in press interviews. 3) concludes his own design method and uniqueness by analyzing his works based on them. As a result, the study has founded that 1) transparency as recognitive realization of existence and non-existence: non-existence of physical property, connotation, ambiguity 2) expression of uncommonness by correcting and reinterpreting common prejudices: flotation, distortion of scale and shape 3) realization of insubstantiality by removing and replacing material and shape: replacement into light, removal of the structure, multiple layers of meaning.

• Journal of Korean Institute of Industrial Engineers
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• v.15 no.2
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• pp.23-31
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• 1989

From the supplier's point of view, we examine the existence of a Pareto superior pricing schedule for one wholesaler with multiple retailers. In the case of multiple retailers, an order quantity pricing schedule should depends on the retailer's underlying characteristics. But identification of each retailer's characteristics may be impossible; rather, the wholesaler knows only the probability distribution of each retailer's characteristics. Perfect price discrimination is impossible because a separate pricing schedule cannot be tailored for each retailer. Some degree of discrimination is possible only by using a non-linear pricing schedule. From this analysis based on the non-linear pricing, we conclude that there is no Pareto superior pricing schedule for the case of multiple retailers.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.305-310
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• 1991

In industrial multivariable plants, it is often the case that the plant outputs are detected in a similar components not simultaneously but serially. In this paper, the problem of estimating the state vector of the plant based on the data obtained from such a detecting scheme is considered, and a special type of observer (referred to as a "multiple serial-sampling" type observer) which renews its internal states whenever a new group of data is obtained is proposed. It is proved that such an observer can be constructed for almost every sampling period if the plant is observable as a continuous-time multivariable system, and that the poles of the closed-loop system using the serial-sampling type observer consist of the poles of the observer and those of the state feedback system. The behaviors of the observer and the closed-loop system are studied by simulation. The results of simulation indicate that a multiple serial-sampling type observer can estimate the state of the plant more accurately than the ordinary type observers and improve the closed-loop performance, especially, in the existence of dectecting noise.ing noise.

• Communications for Statistical Applications and Methods
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• v.24 no.2
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• pp.115-127
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• 2017

This paper proposes a Bayesian test for the equivalence of survival functions in multiple groups. Proposed Bayesian test use the model of Cox's regression with time-varying coefficients. B-spline expansions are used for the time-varying coefficients, and the proposed test use only the partial likelihood, which provides easier computations. Various simulations of the proposed test and typical tests such as log-rank and Fleming and Harrington tests were conducted. This result shows that the proposed test is consistent as data size increase. Specifically, the power of the proposed test is high despite the existence of crossing hazards. The proposed test is based on a Bayesian approach, which is more flexible when used in multiple tests. The proposed test can therefore perform various tests simultaneously. Real data analysis of Larynx Cancer Data was conducted to assess applicability.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.2
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• pp.217-227
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• 2002

Theoretical and experimental free vibration characteristics of cantilevered laminated composite beams with single or multiple transverse non-propagating open cracks are investigated. The presence of intrinsic cracks in beams modifies the flexibility and in turn free vibration characteristics of the structures, and the existence of the multiple cracks in an anisotropic composite beam affects the free vibration characteristics in a more complex fashion compared with the beam with a single crack. Also the experimental results are well coincide with the numerical results in the decrease of natural frequencies and the transformation of mode shapes because of intrinsic cracks in the composite or aluminum beams. It is revealed that non-destructive crack detection(NDT) or vibration based inspection(VBI) is possible by analyzing the free vibration responses of cracked composite beams.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.319-324
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• 2006

In this paper, we propose Bayesian procedure for the multiple change points analysis in a sequence of fractions nonconforming. We first compute the Bayes factor for detecting the existence of no change, a single change or multiple changes. The Gibbs sampler with the Metropolis-Hastings subchain is run to estimate parameters of the change point model, once the number of change points is identified. Finally, we apply the results developed in this paper to both a real and simulated data.

• Journal of applied mathematics & informatics
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• v.27 no.1_2
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• pp.79-87
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• 2009

This paper deals with the multipoint boundary value problem for one dimensional p-Laplacian $({\phi}_p(u'))'(t)$ + f(t,u(t)) = 0, $t{\in}$ (0, 1), subject to the boundary value conditions: u'(0) - $\sum\limits^n_{i=1}{\alpha_i}u({\xi}_i)$ = 0, u'(1) + $\sum\limits^n_{i=1}{\alpha_i}u({\eta}_i)$ = 0. Using a fixed point theorem for operators on a cone, we provide sufficient conditions for the existence of multiple (at least three) positive solutions to the above boundary value problem.