• Journal of the Korean Home Economics Association
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• v.49 no.1
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• pp.17-25
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• 2011

This study examined the impact of academic achievement and maternal differential treatment on academic self-concept among adolescent siblings. The sample consisted of 438 students attending middle schools in Seoul (M = 15.2 yrs.), who had a sibling. Data were analyzed using Structural Equation Modeling. Academic achievement compared with a sibling and maternal differential treatment had direct effects on academic self-concept, indicating that children with higher academic achievement scores than their sibling and with perceived maternal differential treatment reported a significantly higher academic self-concept. Also, the relationship between academic achievement as compared with a sibling and academic self-concept was mediated by maternal differential treatment. These findings could be used in educational settings as a basis for improving the academic self-concept of early adolescents.

• Communications of Mathematical Education
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• v.29 no.1
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• pp.131-155
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• 2015

The purpose of this study is to investigate if top-ranked high school students do integrated understanding about the concept of a differential coefficient. For here, the meaning of integrated understanding about the concept of a differential coefficient is whether students understand tangent and velocity problems, which are occurrence contexts of a differential coefficient, by connecting with the concept of a differential coefficient and organically understand the concept, algebraic and geometrical expression of a differential coefficient and applied situations about a differential coefficient. For this, 38 top-ranked high school students, who are attending S high school, located in Cheongju, were selected as subjects of this analysis. The test was developed with high-school math II textbooks and various other books and revised and supplemented by practising teachers and experts. It is composed of 11 questions. Question 1 and 2-(1) are about the connection between the concept of a differential coefficient and algebraic and geometrical expression, question 2-(2) and 4 are about the connection between occurrence context of the concept and the concept itself, question 3 and 10 are about the connection between the expression with algebra and geometry. Question 5 to 9 are about applied situations. Question 6 is about the connection between the concept and application of a differential coefficient, question 8 is about the connection between application of a differential coefficient and expression with algebra, question 5 and 7 are about the connection between application of a differential coefficient, used besides math, and expression with geometry and question 9 is about the connection between application of a differential coefficient, used within math, and expression with geometry. The research shows the high rate of students, who organizationally understand the concept of a differential coefficient and algebraic and geometrical expression. However, for other connections, the rates of students are nearly half of it or lower than half.

• Research in Mathematical Education
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• v.12 no.3
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• pp.193-200
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• 2008

In this study, an innovative computer support has been suggested to improve differential perception of the students. Research has been conducted on a calculus class which has 35 students. A semi-structured interview has been reported in the study. By this interview, it was tried to make differential concept more understandable by using Micro Soft Excel component of the well-known MS Office software. By this aim, students have been asked to integrate a simple function by using MS Excel. At the end of the study, it was observed that differential concept made more sense in students' minds than previous.

• Journal of Educational Research in Mathematics
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• v.8 no.2
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• pp.495-507
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• 1998

This article intends to review what problems the terms in calculus have and how those problems are caused. For this purpose We make examinations on the considerations in the analysis of mathematical terminology, which includes the problems of general and technical terms, the meaning and the boundary of words, their consistency, the name and meaning, concept and their concept images, translations and qwerty effects. And in chapter 3, We analyse the textbook which are currently used, through which I was able to find out that the terms in calculus have some problems, In other words, the key terms such as "differentiable", "differential coefficient", "differential" have their roots in the term "differential" but the term "derived function" is very distinct from other terms and thus obstructs the consistency of terms. And the central term "differential" is being used without clear definition. In particular, the fact that "differential", when used in its arbitrary definition, has the image of "splitting minutely" can be an obstacle to understanding the exact concepts of calculus. In chapter 4, We make a review on the history of calculus and the term "differential" currently used in modern mathematics so that I can identify the origin of the problem connected with the usage of the term "differential". We should recognize the specified problems and its causes and keep their instructional implications in mind. Furthermore, following researches and discussions should be made on whether the terminology system of calculus should be reestablished and how the reestablishment should be made.e terminology system of calculus should be reestablished and how the reestablishment should be made.

• Journal of the Chungcheong Mathematical Society
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• v.28 no.2
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• pp.269-286
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• 2015

In this paper, we extend the concept of the pseudo differential operators in the usual Schwartz's distribution spaces to the one of the generalized pseudo differential operators in the Beurling's generalized distribution spaces. And we shall investigate some properties of the generalized pseudo differential operators including the generalized pseudo local property. Finally, we will study the smoothness and properly supported property of these operators.

• Korean Journal of Psychosomatic Medicine
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• v.4 no.2
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• pp.254-261
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• 1996

Somatoform disorders are a group of syndromes in which patients focus on and complain of physical symptoms when there is no demonstrable underlying organic pathology or when complaints are in excess of what is expected. The author reviewed concept, sociocultural etiology, differential diagnosis and methods of evaluation of somatoform disorder. The symptoms of Korean culture-specific somatizing cluster, so called Wha-Byung, are discussed.

• The Pure and Applied Mathematics
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• v.16 no.1
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• pp.155-165
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• 2009

We investigate the growth of solutions of complex linear differential equations in the unit disc. We obtain properties of solutions of differential equations with entire coefficients. We use the concept of the hyper order to estimate the growth of solutions.

• Korean Institute of Interior Design Journal
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• v.19 no.4
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• pp.58-65
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• 2010

The purpose of this study is to be applied with the basic data for the design method in the housing space which is differential. So, we analyzed the expression method and the application characteristic to materials of units in housing complex. To that, we researched on the condition of finishing material about the kind of material, color, texture and pattern for components in living room space. The results of this study are as follows : First, at the present time, the Object concept is expressed by 'mixing' and 'juxtaposition' of material, texture and pattern of finishing materials in housing space. But, we could find that the Object concept was used restrictively in housing space. So, we have to find different expression methods to be the effective and differential design by being applied Object concept for the housing space. Second, the 'mixing' which is the method to express the Object concept is showed in only 'art wall'. so, we can estimate that the method is the limited method to plan the varied housing. It is needed various expression methods to design components for the housing space. Third, it showed that the 'mixing' was a passive expression method using a little differential for design of housing space. We could estimate that similar methods were applied to the housing design. By results of this study, we can think that the develop study is needed to find design methods for expression of the Object in housing space.

• Magazine of the Korean Society of Agricultural Engineers
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• v.34 no.4
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• pp.97-105
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• 1992

The main purpose of this paper is to present the buckling loads of tapered columns due to dynamic concept. The ordinary differential equation governing the bucking loads for tapered columns is derived on the basis of dynamic concept. Three kinds of cross sectional shape are considered in the governing equation. The Improved Euler method and Determinant Search method are used to perform the integration of the differential equation and to determine the buckling loads, respectively. The hinged-hinged, hinged-clamped, clamped-clamped and free-clamped end constraints are applied in numerical examples. The buckling loads are reported as the function of section ratio, and the effects of cross-sectional shapes are investigated. The buckling load equation, which are fitted by numerical data, are proposed as a function of section ratio. It is expected that these equations can be utilized in structural engineering field.

• The Journal of Korea Robotics Society
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• v.10 no.4
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• pp.230-244
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• 2015

Continuous-path motion control such as resolved motion rate control requires online solving of the inverse differential kinematics for a robot. However, the solution space of the inverse differential kinematics related to Jacobian J is not well-established. In this paper, the solution space of inverse differential kinematics is analyzed through categorization of mapping conditions between joint velocities and end-effector velocity of a robot. If end-effector velocity is within the column space of J, the solution or the minimum norm solution is obtained. If it is not within the column space of J, an approximate solution by least-squares is obtained. Moreover, this paper introduces an improved mapping diagram showing orthogonality and mapping clearly between subspaces, and concrete examples numerically showing the concept of several subspaces. Finally, a solver and graphics user interface (GUI) for inverse differential kinematics are developed using MATLAB, and the solution of inverse differential kinematics using the GUI is demonstrated for a vertically articulated robot.