• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.795-801
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• 2008

An experimental study has been performed on the single phase flow and convective heat transfer in trapezoidal microchannels. The microchannel was about $270{\mu}m$ wide, $800{\mu}m$ deep. and 7 mm long, which might ensure hydrodynamically fully-developed laminar flow at a low Reynolds number. The experiments were conducted with R1l3 and water, with the Reynolds number ranging from approximately 30 to 5000 for friction factor and 30 to 700 for the Nusselt number. Friction factors in laminar are found to be in good agreement with the predictions of existing correlation suggesting that a conventional analysis approach can be employed in predicting flow friction behavior in microchannels. However turbulent friction factors are hardly predictable by the existing correlations. The experimental results show that the Nusselt number is not a constant but increases almost linearly with the Reynolds number even the flow is fully developed (Re < 100). The dependence of the Nusslet number on the Reynolds number is contradictory to the conventional theory. At a Reynolds number greater than 100, the Nusselt number increases slowly with the Reynolds number, where thennally developing flow is responsible for the increase of the Nusselt number with the Reynolds number.

• Steel and Composite Structures
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• v.26 no.4
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• pp.473-484
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• 2018

Free vibration of cross-ply laminated plates using a higher-order shear deformation theory is studied. The arbitrary number of layers is oriented in symmetric and anti-symmetric manners. The plate kinematics are based on higher-order shear deformation theory (HSDT) and the vibrational behaviour of multi-layered plates are analysed under simply supported boundary conditions. The differential equations are obtained in terms of displacement and rotational functions by substituting the stress-strain relations and strain-displacement relations in the governing equations and separable method is adopted for these functions to get a set of ordinary differential equations in term of single variable, which are coupled. These displacement and rotational functions are approximated using cubic and quantic splines which results in to the system of algebraic equations with unknown spline coefficients. Incurring the boundary conditions with the algebraic equations, a generalized eigen value problem is obtained. This eigen value problem is solved numerically to find the eigen frequency parameter and associated eigenvectors which are the spline coefficients.The material properties of Kevlar-49/epoxy, Graphite/Epoxy and E-glass epoxy are used to show the parametric effects of the plates aspect ratio, side-to-thickness ratio, stacking sequence, number of lamina and ply orientations on the frequency parameter of the plate. The current results are verified with those results obtained in the previous work and the new results are presented in tables and graphs.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.4 no.2
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• pp.211-223
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• 2009

Objectives : The aim of this research is to analyze the current trend of the studies about eridian muscle and to provide background for further studies. Methods : Reviewing 33 domestic oriental medical studies about meridian muscle, and comparative analysis was made. These studies were classified by method, theme and subtitle. Results : 1. According to the classification by study method, number of literary studies are 22(67%), which is more than half, number of experimental studies are 5(15%) and clinical studies are 6(18%). 2. According to the classification by study theme in literary study, percentage of 'Structure amp; Movement of Meridian Muscle' took 64%, Theory study of Meridian Muscle' took 14%, 'Application of Concept of Meridian Muscle' took 14%, 'Treatment of Meridian Muscle disorder' took 9% arranged in order. 3. In 'Theory study of Meridian Muscle', there were not only literary approaches but also Deficiency-Excessiveness(虛實) and historical approaches. Study about 'Structure & Movement of Meridian Muscle' includes analysis of muscle and Myofascial pain syndrome. On this background, it is necessary to recognize the linkage and motion analysis of Meridian Muscle. Therefore, studies were changed into interpretation about Anatomy trains, analysis of motion. The study about 'Treatment of Meridian Muscle disorder' provided the various treatment method-Acupuncture, Manual therapy, Ashi(阿是)-point therapy, CHUNA therapy etc.- in literary study. The study about the 'Application of Concept of Meridian Muscle' has been performed in relation to Embedding Therapy, Kyungkuen chuna, Ki-gong therapy. 4. Experimental Studies were all Anatomical Studies. Studies were done in trial of discovering the actual existence, but revealed problem in interpretating the meaning of Meridian Muscle. 5. Clinical Studies based on Ashi(阿是)-point therapy CHUNA Muscles Along Meridians Release Therapy etc, were performed. Experimental studies about Meridian Muscle were assessed as low grade according to Jadad Scale. There were no studies which were based on well-organized Meridian Muscle theory. Conclusions : There needs to be more discussion about concept of Meridian Muscle and proceed more reliable experimental studies with organized Meridian Muscle theory. Further objective studies about treatment of Meridian Muscle should be done.

• Steel and Composite Structures
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• v.25 no.6
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• pp.693-704
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• 2017

In this research, a simple hyperbolic shear deformation theory is developed and applied for the bending, vibration and buckling of powerly graded material (PGM) sandwich plate with various boundary conditions. The displacement field of the present model is selected based on a hyperbolic variation in the in-plane displacements across the plate's thickness. By splitting the deflection into the bending and shear parts, the number of unknowns and equations of motion of the present formulation is reduced and hence makes them simple to use. Equations of motion are obtained from Hamilton's principle. Numerical results for the natural frequencies, deflections and critical buckling loads of several types of powerly graded sandwich plates under various boundary conditions are presented. The accuracy of the present formulation is demonstrated by comparing the computed results with those available in the literature. As conclusion, this theory is as accurate as other theories available in the literature and so it becomes more attractive due to smaller number of unknowns.

• Journal of Distribution Research
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• v.16 no.3
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• pp.33-75
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• 2011

The ownership structure of a franchise system is determined by the franchisor's strategic choice. A close look at the extant theories and perspectives in economics and management such as resource scarcity theory, agency theory, transaction cost analysis, and mixed ownership theory reveals that firms choose their ownership structure for the sake of economic efficiency, profit potentials, the chance of survival, and other strategic concerns. The present study, on the basis of strategic choice perspective, reviews the divergent theories of a franchise system's ownership structure and its determinants, thus providing a theoretical framework for comparing the contradictory arguments along the several critical dimensions. We also developed and tested the conflicting hypotheses regarding key determinants of ownership structure including firm's age, size, transaction-specific investments, uncertainty, and risk-sharing propensity. Using a FDD (Franchise Disclosure Document) data set of 543 Korean franchisors, we found that the years in business, the total number of employees, days of training, the inverse of the years of franchising, and the requirement of royalty payment have positive relationships with the proportion of company-owned outlets to total number of outlets. On the other hand, the proportion of company-owned outlets was found to have negative relationships with the total number of outlets and the extent of geographic dispersion of outlets, but to have no significant relationships with the initial investment required and the inverse of contract length. Based on the findings, we provide several theoretical and managerial implications for studying ownership structure of franchise systems.

• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.353-359
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• 2000

This study was carried out to introduce the fuzzy theory to standardize recipe of Korean foods, such as Pibimbab, Deonjang chigae (soybean stew), and Kimchi chigae (Kimchi stew). That is recipe of Pibimbab using fuzzy theory. Before this recipe was introduced, it thoroughly analyzed a number of data on Korean food such as materials used by cook book, commercial food, restaurants, food service operation recipes, and home recipes. And then the recipe of Korean food, Pibimbab will be possible to be standardized by fuzzy theory. The theory of fuzzy set is a theory of graded concept. The theory has matured into a wide ranging collection of concepts and techniques for dealing with complex phenomena. It defined a Membership function of fuzzy set by analyzed four sorts of data on Korean food, Pibimbab, and it established the fuzzy model using the quantity of materials as input and sensory test scores as output. This study will contribute to develop standard recipe for Korean foods and expert system of recipes using computer system.

• Earthquakes and Structures
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• v.14 no.2
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• pp.103-115
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• 2018

In this work, a simple but accurate hyperbolic plate theory for the free vibration analysis of functionally graded material (FGM) sandwich plates is developed. The significant feature of this formulation is that, in addition to including the shear deformation effect, it deals with only 3 unknowns as the classical plate theory (CPT), instead of 5 as in the well-known first shear deformation theory (FSDT) and higher-order shear deformation theory (HSDT). A shear correction factor is, therefore, not required. Two common types of FGM sandwich plates are considered, namely, the sandwich with the FGM face sheet and the homogeneous core and the sandwich with the homogeneous face sheet and the FGM core. The equation of motion for the FGM sandwich plates is obtained based on Hamilton's principle. The closed form solutions are obtained by using the Navier technique. The fundamental frequencies are found by solving the eigenvalue problems. Numerical results of the present theory are compared with the CPT, FSDT, order shear deformation theories (HSDTs), and 3D solutions. Verification studies show that the proposed theory is not only accurate and simple in solving the free vibration behaviour of FGM sandwich plates, but also comparable with the higher-order shear deformation theories which contain more number of unknowns.

• The Journal of Korean Society for School & Community Health Education
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• v.6
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• pp.117-126
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• 2005

This study attempted to extract a suggestive point to help the design of a program, which is used to promote physical activities, by applying a social cognitive theory based on literature review on the physical activity based on a social cognitive theory. This study considers 10 journal articles that used a social cognitive theory, physical activity, and exercise as the major variable using the EBSCOhost Academic Search Premier and Educator's Reference Desk (ERIC). The type of papers was analyzed using a certain criterion, which can be configured according to the number of each year's papers, characteristics of research subjects, application type of a social cognitive theory, and classification of the application of objects in a social cognitive theory. The characteristics of each year's papers presented no specific characteristics for each year's papers, but the study in 2004 especially presented a high level. The characteristics of research subjects presented four highest cases in the case of the college student, and there were zero cases for children. The application type of studies on physical activities using a social cognitive theory can be largely classified as three types. The results of the measurement using a sectional investigation for SCT objects were 2 cases, the application of SCT for promoting physical activities was 1 case, and the demonstration of evaluation for the effect of SCT objects presented 8 highest cases. Although the social cognitive theory in the characteristics of the classification of object applications can be classified as 10 objects, there were no cases that used 10 all objects, partial applications of the object were measured in 8 studies, and two cases presented no detailed considerations on the object. Most of studies used a part of the object where the application of self-efficacy were measured by 8 highest cases. In addition, there were no measurements on the situation, observation learning, answer and response, and self-management. The elements of attitude, cognitive activity, self-efficacy, and handicaps among the SCT object were commonly used, and studies that the self-efficacy largely affects on the promotion of physical activities presented the main current.

• Steel and Composite Structures
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• v.25 no.6
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• pp.717-726
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• 2017

In this paper, a new simple shear deformation theory for bending analysis of functionally graded plates is developed. The present theory involves only three unknown and three governing equation as in the classical plate theory, but it is capable of accurately capturing shear deformation effects, instead of five as in the well-known first shear deformation theory and higher-order shear deformation theory. A shear correction factor is, therefore, not required. The material properties of the functionally graded plates are assumed to vary continuously through the thickness, according to a simple power law distribution of the volume fraction of the constituents. Equations of motion are obtained by utilizing the principle of virtual displacements and solved via Navier's procedure. The elastic foundation is modeled as two parameter elastic foundation. The results are verified with the known results in the literature. The influences played by transversal shear deformation, plate aspect ratio, side-to-thickness ratio, elastic foundation, and volume fraction distributions are studied. Verification studies show that the proposed theory is not only accurate and simple in solving the bending behaviour of functionally graded plates, but also comparable with the other higher-order shear deformation theories which contain more number of unknowns.

• Journal of Korean Society of Forest Science
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• v.89 no.5
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• pp.634-644
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• 2000

Sterba's theory that stem number maintaining maximum basal area per ha is maximum stem number of a stand, had been applied to data from 103 temporary plots in even-aged Pinus densiflora stands in Kangwon province, Korea and a maximum stem number and mortality model was prepared. DBH growth model which estimates dbh with the independent variables of stem number per ha and dominant height shows the good statistical performance, and explains well differences in dbh growth that would be caused by stem number per ha and dominant height. Basal area model derived from dbh growth model also explains well differences in basal area according to stem number per ha and dominant height. The maximum stem number curve, which is derived from stem number per ha at maximum basal area for dominant height and dbh, represents well the upper range of stem number per ha observed. And maximum stand density index derived from the maximum stem number model for dbh could be used for the index of maximum potential density of a stand. The maximum stem number model and maximum stand density index in this study were not based on stand data with maximum density but based on the temporary data from stands with various density. This maximum stem number model can be applied to the estimation of mortality and maximum potential volume.