• Communications of the Korean Mathematical Society
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• v.33 no.4
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• pp.1239-1248
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• 2018

Recently, many authors have obtained several hypergeometric identities involving hypergeometric functions of one and multi-variables such as the Appell's functions and Horn's functions. In this paper, we obtain several new transformations suitably by applying the fractional calculus operator to these hypergeometric identities, which was introduced recently by Tremblay.

• Kyungpook Mathematical Journal
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• v.19 no.1
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• pp.119-125
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• 1979

In the present paper we study a new integral transform whose kernel involves the product of two H-functions of two complex variables. Next, we establish an inversion formula for this new transform. On account of very general nature of its kernel, several other integral transforms studies earlier by many research workers viz., Bose (1952), Mukherji (1962), Nigam (1963), Rathie (1965), Singh (1969), Mittal & Goel (1973), and Gupta, Garg & Kalla (1975), follow as its particular cases.

• Kyungpook Mathematical Journal
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• v.20 no.1
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• pp.77-82
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• 1980

There are many definitions of the fractional derivative. It is purpose of this paper to show some results which were got for fractional partial derivative of functions of two variables and to give an application of the fractional partial derivative.

• Kyungpook Mathematical Journal
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• v.28 no.1
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• pp.45-50
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• 1988

Circulant and multiblock circulant matrices have many important applications, and therefore their inverses are of considerable interest. A simple recursive algorithm is presented to compute the inverse of a multiblock circulant matrix. The algorithm only uses complex variables, roots of unity and normal matrix/vector operations.

• The Korean Journal of Ecology
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• v.19 no.5
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• pp.465-476
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• 1996

There are several environmental variables that may be influential to the spatial distribution of forest vegetation. To create a map of forest vegetation zone over southern part of Korean Peninsula, digital map layers were produced for each of environmental variables that include topography, geographic locations, and climate. In addition, an extensive set of field survey data was collected at relatively undisturbed forests and they were introduced into the GIS database with exact coordinates of survey sites. Preliminary statistical analysis on the survey data showed that the environmental variables were significantly different among the previously defined five forest vegetation zones. Classification of the six layers of digital map representing environmental variables was carried out by a supervised classifier using the training statistics from field survey data and by a clustering algorithm. Although the maps from two classifiers were somewhat different due to the classification procedure applied, they showed overall patterns of vertical and horizontal distribution of forest zones. considering the spatial contents of many ecological studies, GIS can be used as an important tool to manage and analyze spatial data. This study discusses more about the generation of digital map and the analysis procedure rather than the outcome map of forest vegetation zone.

• Water for future
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• v.28 no.2
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• pp.137-143
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• 1995

The location and the shape of freshwater-saltwater transition zones in coastal aquifers are affected by many hydraulic variables. To date most work to determine the effects of these variables are limited to qualitative comparison of transition zones. In this work characteristics of transition zones (maximum intrusion length, thickness, and degree of stratification) are quantified, and effects of principal hydraulic variables(velocity and dispersivity) on these characteristics are studied using a numerical model. Dimensional analysis is used to assemble entire model results. Effects of velocity and dispersivity are seen clearly. From this study, increase in velocity is found to cause shrinkage of transition zones. This observation contradicts claims by some that, because dispersion is proportional to velocity, increase in velocity would cause expansion of transition zones.

• International Journal of Contents
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• v.3 no.1
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• pp.1-8
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• 2007

The distributions of the minimum correlated F-variable arises in many applied statistical problems including simultaneous analysis of variance (SANOVA), equality of variance, selection and ranking populations, and reliability analysis. In this paper, negative binomial sampling technique is employed to derive the distributions of the minimum of chi-square variables and hence the distributions of the minimum correlated F-variables. The work presented in this paper is divided in two parts. The first part is devoted to develop some combinatorial identities arised from the negative binomial sampling. These identities are constructed and justified to serve important purpose, when we deal with these distributions or their characteristics. Other important results including cumulants and moments of these distributions are also given in somewhat simple forms. Second, the distributions of minimum, chisquare variable and hence the distribution of the minimum correlated F-variables are then derived within the negative binomial sampling framework. Although, multinomial theory applied to order statistics and standard transformation techniques can be used to derive these distributions, the negative binomial sampling approach provides more information regarding the nature of the relationship between the sampling vehicle and the probability distributions of these functions of chi-square variables. We also provide an algorithm to compute the percentage points of the distributions. The computation methods we adopted are exact and no interpolations are involved.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.2 no.2
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• pp.155-168
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• 1995

Many arthritis patients experience physical and psychological impairment. The influence psychological factors on physical functioning beyond disease & demographic factors has been investigated. Unlike others studied the relationship between just two variables (i. e., depression & helplessness or self-efficacy & depression), the relationships among several variables such as depression, helplessness and self-efficacy were examined altogether. Foully-two patients were examined to identify the relationship between the variables. It was found that ADL is significantly negatively related to depression and helplessness, and positively related to self-efficacy. And ADL was more strongly correlated with self-efficacy and helplessness than depression. Contrary to ADL, pain was significantly negatively related to self-efficacy, and positively related to depression and helplessness. Then stepwise regression analysis was performed to identify the variables to predict ADL. It revealed that helplessness was the only significant predictor of ADL. Finally, it is suggested that the inclusion of the method to increase self-efficacy & to decrease helplessness in any nursing intervention is very important.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1232-1240
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• 2002

Recently, linear motors are applied to many small precision products. Thus high generating power with small size is required of it. In order to increase the motor efficiency, the design variables need to be optimized. In this study, Vector Fields FEM software, OPERA-3d, was used for simulating linear motor. The thrust and magnetic flux density at the air-gap center were simulated and compared with the experimental results. Taguchi method was applied to investigate the effects of each variables. As a result, the thickness of conductor and magnet was important for the thrust but the thickness of the yoke. The temperature of the conductor was determined by finding the thermal conductivity that was determined by experimentation. Correlation equation relating to the thrust and temperature was proposed by Latin square and Least Square method. The optimum design variables were determined by correlation equation, and compared with simulation results. According to this analysis, thrust force of linear motor was improved about 7% comparing with conventional model.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.4
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• pp.273-288
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• 2012

In recent years, smartphone is the most widely used ubiquitous functionality. People do not want to just call other people any more by using a cellular phone; they want to connect to the Internet and use various applications. Hence, cellular phones need to become smart. A smartphone has an operating system and many applications. Specifically the goals of this research are; (1) to suggest theory framework of acceptance about smartphone based on TAM, (2) to examine relationships between exogenous variables. The research model and hypotheses were developed based on the theories of technology acceptance model. Questionnaire was used to collect data. The analysis of this study is designed as individual level to examine the causal relationship among variables. The the reliability and validity of data was tested by explanatory factor analysis, Cronbach's alpha coefficient, confirmatory factor analysis, and correlation analysis. Also, the structural equation model(SEM) analysis was performed to test the usefulness of the model. The analysis results revealed that social norms and individual innovation are major influential variables on the perceived usefulness of smartphone. Also, social norms are influential variables on the perceived enjoyment of smartphone.