• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.4
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• pp.351-363
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• 2004

Equation of motion of non conservative system considering mass matrix, elastic stiffness matrix, load correction stiffness matrix by circulatory force's direction change and Winkler and Pasternak foundation stiffness matrix is derived. Also stability analysis due to the divergence and flutter loads is performed. And the influence of internal and external damping coefficient on flutter load is investigated applying the quadratic eigen problem solution. Additionally the influence of non-conservative force's direction parameter, internal and external damping and Winkler and Pasternak foundation on the critical load of Beck's and Leipholz's and Hauger's columns are investigated.

• Structural Engineering and Mechanics
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• v.70 no.1
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• pp.55-66
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• 2019

This work deals with the size-dependent wave propagation analysis of functionally graded (FG) anisotropic nanoplates based on a nonlocal strain gradient refined plate model. The present model incorporates two scale coefficients to examine wave dispersion relations more accurately. Material properties of FG anisotropic nanoplates are exponentially varying in the z-direction. In order to solve the governing equations for bulk waves, an analytical method is performed and wave frequencies and phase velocities are obtained as a function of wave number. The influences of several important parameters such as material graduation exponent, geometry, Winkler-Pasternak foundation parameters and wave number on the wave propagation of FG anisotropic nanoplates resting on the elastic foundation are investigated and discussed in detail. It is concluded that these parameters play significant roles on the wave propagation behavior of the nanoplates. From the best knowledge of authors, it is the first time that FG nanoplate made of anisotropic materials is investigated, so, presented numerical results can serve as benchmarks for future analysis of such structures.

• Journal of Distribution Science
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• v.20 no.6
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• pp.11-19
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• 2022

Purpose: This study aims at exploring and understanding the effect of four independent variables related to dairy retail marketing and distribution (deep freezers, promotions, company support and distributor-retailer relationship) and one moderating variable Covid-19 lockdown on sales of dairy product during the Covid 19 pandemic situation. Research design and methodology: Personal interviews and door-to-door surveys and promotional tools were designed to publicise and collect data from the retailers. The sale data before, during and after promotion activity were all recorded and evaluated to draw an inferential conclusion. Factor analysis and multiple regression methods were adopted to analyses the data collected. Results: The research shows that four out of the five factors studied was found having significant impact on dairy retail sales. The highest impact on sales was contributed by promotions, secondly by the deep freezer impact followed by distributor-retailer relationship during the study period and lastly but not the least due to influence of Covid-19 lockdown. Conclusions: The study contributes to the body of knowledge in cold chain distribution process through utilization of right mix of tools and tactics for effective marketing and distribution of dairy products in developing countries especially during a pandemic situation.

• Steel and Composite Structures
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• v.23 no.3
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• pp.317-330
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• 2017

This paper presents a free vibration analysis of plates made of functionally graded materials and resting on two-layer elastic foundations by proposing a non-polynomial four variable refined plate theory. Undetermined integral terms are introduced in the proposed displacement field and unlike the conventional higher shear deformation theory (HSDT), the present one contains only four unknowns. Equations of motion are derived via the Hamilton's principles and solved using Navier's procedure. Accuracy of the present theory is demonstrated by comparing the results of numerical examples with the ones available in literature.

• Geomechanics and Engineering
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• v.22 no.1
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• pp.65-80
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• 2020

This paper presents a theoretical investigation on the response of the thermo-mechanical bending of FG plate on variable elastic foundation. A quasi-3D higher shear deformation theory is used that contains undetermined integral forms and involves only four unknowns to derive. The FG plates are supposed simply supported with temperature-dependent material properties and subjected to nonlinear temperature rise. Various homogenization models are used to estimate the effective material properties such as temperature-dependent thermoelastic properties. Equations of motion are derived from the principle of virtual displacements and Navier's solution is used to solve the problem of simply supported plates. Numerical results for deflections and stresses of FG plate with temperature-dependent material properties are investigated. It can be concluded that the proposed theory is accurate and simple in solving the thermoelastic bending behavior of FG thick plates.

• Computers and Concrete
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• v.25 no.3
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• pp.215-224
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• 2020

In the present study, according to the important of porosity in low specific weight in comparison of high stiffness of carbon nanotubes reinforced composite, buckling and free vibration analysis of sandwich composite beam in two configurations, of laminates using differential quadrature method (DQM) is studied. Also, the effects of porosity coefficient and three types of porosity distribution on critical buckling load and natural frequency are discussed. It is shown the buckling loads and natural frequencies of laminate 1 are significantly larger than the results of laminate 2. When configuration 2 (the core is made of FRC) and laminate 1 ([0/90/0/45/90]_s) are used, the first natural frequency rises noticeably. It is also demonstrated that the influence of the core height in the case of lower carbon volume fractions is negligible. Even though, when volume fraction of fiber increases, the critical buckling load enhances smoothly. It should be noticed the amount of decline has inverse relationship with the beam aspect ratio. Investigating three porosity patterns, beam with the distribution of porosity Type 2 has the maximum critical buckling load and first natural frequency. Among three elastic foundations (constant, linear and parabolic), buckling load and natural frequency in linear variation has the least amount. For all kind of elastic foundations, when the porosity coefficient increases, critical buckling load and natural frequency decline significantly.

• Structural Engineering and Mechanics
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• v.55 no.1
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• pp.47-64
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• 2015

This paper presents the effect of hybridization material on variation of critical buckling load with different cross-ply laminates plate resting on elastic foundations of Winkler and Pasternak types subjected to combine uniaxial and biaxial loading by using two variable refined plate theories. Governing equations are derived from the principle of virtual displacement; the formulation is based on a new trigonometric shape function of displacement taking into account transverse shear deformation effects vary parabolically across the thickness satisfying shear stress free surface conditions. These equations are solved analytically using the Navier solution of a simply supported. The influence of the various parameters geometric and material, the thickness ratio, and the number of layers symmetric and antisymmetric hybrid laminates material has been investigated to find the critical buckling loads. The numerical results obtained through the present study with several examples are presented to verify and compared with other models with the ones available in the literature.

• Journal of Society of Preventive Korean Medicine
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• v.12 no.2
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• pp.115-130
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• 2008

It is very important problem that exactly distinguish constitution, in Sasang constitutional Medicine. But, it is careless that discuss the propriety of 'Sasang constitution unchangeability theory(四象體質 不變論)'. The foundation of Sasang constitution unchangeability theory is the sentence in DongUi SuSae BoWon Sa-dan theory(東醫壽世保元 四端論) : "The Organ system of Taeyang(太陽), Taeum(太陰), Soyang (少陽) and Soeum(少陰) is the variation of YinYang(陰陽), is firm nature and is unnecessary agreement. (太少陰陽之臟局 陰陽之變化也 天稟之已定 固無可論)". But, the foundation of Sasang constitution unchangeability theory contradict the theory that Organ system(臟腑) is made by deviation of emotions(joy, anger, sorrow and pleasure :喜怒哀樂) or temperament(性情). Because these emotions is revealed after birth(後天), the deviation of Organs system made by deviation of emotions is not innate, is acquired after birth. Therefore, it is necessary to discuss the opinion that Sasang constitution is variable after birth. The conclusion of our study is that Sasang constitution can be variable after birth.

• The Korean Journal of Franchise Management
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• v.3 no.1
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• pp.92-110
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• 2012

Due to the social problems including recent economic crisis and unemployment rate increase, the demand of business foundation market has been increased and, in the meantime, on the basis of the business foundation support policy of the government including youth foundation support policy and Small & Medium Business Administration foundation planning, business foundation market has been showing steady growth trend. With this enlargement of foundation market, as the accompanied increase of franchise market is expected, it is considered that the importance of more realistic and concrete research about franchise market be larger than before. This study considered brand image, main office support, foundation cost, information search activity as the advanced variable of effect on brand selection and established the cause of effect on brand selection by improving the existing advanced research, and its result is as follows. First, according to foundation business kind, age, sex, yes or no of marriage, there is some difference III the thought about brand image and foundation possibility. Second, Second, the most important factor of franchise contract intention is economical specificity. It is difficult to consider brand image, franchise support and information search activity as the property having a big effect on preliminary founder, and it was shown that the cost for franchise management(Consistency with initial foundation cost and self-capital, promotion cost, management fund, facility/equipment reinvestment, etc.) is an important property. Specially, it was shown that consistency with initial foundation cost and self-capital is the most important factor for preliminary founder.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.8
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• pp.357-363
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• 2001

This paper presents the application of the technique Q( differential transformation to the vibration analysis of beams resting on variable two-parameter elastic foundations. The closed form series solutions for beams are obtained for various boundary conditions. Numerical calculations are carried out and compared with previously published results. The results obtained by the present method agree very well with those reported in the previous works. The present analysis shows the usefulness and validity of differential transformation in solving nonlinear problem of the free vibration.