• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.237-240
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• 2005

본 본문은 Chus's 방정식과 Lorenz 방정식을 이용한 카오스 회로를 이동 로봇에 내장하여 카오스 이동 로봇을 구성하고 이 카오스 이동 로봇이 어느 임의 평면을 카오스 궤적을 가지고 주행 또는 탐색하다가 상호 연동 제어 명령이 내려지면 2개 또는 여러 개의 로봇이 서로 연동되어 동기화 되는 방법을 제시하고 그 결과를 검증하였다. 카오스 로봇 동기화에서는 장애물이 있는 경우와 은닉 장애물이 있는 경우에서 2개의 로봇이 서로 연동되어 움직이는지를 확인하였으며 만족할 만한 결과를 얻었다.

• Journal of Educational Research in Mathematics
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• v.25 no.4
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• pp.525-547
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• 2015

This study analyzed the written texts of textbook and the teacher's discourse explaining 'the relationship between quadratic functions and quadratic equations' in the 9th grade high school mathematics class. Data consisted of the lecture recordings and the textbooks were analyzed based on the Halliday's systemic functional linguistics. According to the results, the written texts of the textbook used lexico-grammatical strategies such as generalization using hyponomy of meanings, mathematical objectification through nominalization and materialization of meaning through change in themes to compose mathematical concepts. The textbook generalized from an example in the description of formulating mathematical concepts, and in this process the organizational interactions of discourse-semantic level and lexico-grammartical level appeared. On the other hand, the teacher's doscourse appeared the change in transitivity and the addition of the reasons and the process. Also the teacher used explanation process of formulating the relationship between quadratic functions and quadratic equations. The linguistic characteristics of the teacher were linguistic implication and omission of lexemes due to contextual ommission. And there was no use of structural lexico-grammatical resources that influence the discourse-semantic level. This results provide a new framework for analyzing mathematical discourse, and suggest the lexico-grammatical strategies that can be used to explain mathematical concepts by teachers in math classrooms.

• Communications of Mathematical Education
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• v.21 no.3
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• pp.451-466
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• 2007

Geometry in school mathematics is the field that has the possibility of diverse approach such as Synthetic Geometry and Analytic Geometry. Synthetic Geometry is handled in middle schools and Analytic Geometry in the first year of high schools. Therefore, this research show for the possibility of using Synthetic Geometry in high schools which was learned already in middle schools and the way of integrating both of them concretely. This is expected to help students understand the mathematical meaning of figures a lot.

• Journal of Digital Convergence
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• v.14 no.4
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• pp.209-220
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• 2016

Although organizations are providing information security policy, education and support to guide their employees in security policy compliance, accidents by non-compliance is still a never ending problem to organizations. This study investigates the factors that influence employees' information security policy compliance behavior using elements of Triandis model. We analyzed the relationships among Triandis model's factors using PLS(Partial Least Squares). The result of the hypothesis tests shows that organization can induce individual's information security policy compliance intention and behavior by information security policy and facilitating conditions that support it, and proves the importance of members' expected value, habit and affect about information security compliance. This study is significant in a way that it applies Triandis model in the field of information security, and presents direction for members' information security behavior, and will be able to provide measures to establish organization's information security policy and increase members' compliance behavior.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.233-236
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• 2005

본 본문은 Chus's 방정식을 이용한 카오스 회로를 이동 로봇에 내장하여 카오스 이동 로봇을 구성하고 이 카오스 이동 로봇이 어느 임의 평면을 카오스 궤적을 가지고 주행 또는 탐색하다가 동기화 제어 명령이 내려지면 2개 또는 여러 개의 로봇이 서로 동기화 되는 방법을 제시하고 그 결과를 검증하였다. 카오스 로봇 동기화에서는 장애물이 없는 경우와 은닉 장애물이 있는 경우에서 2개의 로봇이 서로 동기화를 이루는지를 확인하였으며 만족할 만한 결과를 얻었다.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.8
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• pp.1240-1251
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• 2007

The purpose of this study was to examine the relationship between weight of fabrics and texture and sensibility and preference of consumers for F/W women's jacket fabrics. Structural Equation Model(SEM) using AMOS program was conducted to analyze the relationships. Then, this study aimed to provide useful information in planning designing fabrics through predicting the subjective characteristics analyzed. The main survey was developed the 7-point semantic differential scale of subjective texture, sensibility and preference. Fifty trained female panelists of 20-30 years old were participated and questionnaire method was used with 20 kind of fabric. The evaluation methods such as by the sense of sight & touch were used when fabrics were estimated subjectively. When evaluated by the sense of sight & touch, fabric's weight did not have effect directly on preference, but had effect indirectly on preference through the texture and the sensibility..

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.6
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• pp.39-48
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• 2017

In this study, combustion modeling of ZPP and $BKNO_3$ mainly used in the PMD industries has been performed. Saint Robert's law, energy conservation equation, and the Noble-Abel equation of the state have been used for governing equations. The results of pressure obtained from established combustion models and actual CBT have been compared. In the case of ZPP, the model has predicted a pressure curve similar to that of the experimental results, but $BKNO_3$ has showed that the maximum pressure of the model is greater than the experiment at small chamber volume. For these gaps, the probability of $BKNO_3$ unburning has been considered.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.6
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• pp.217-222
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• 2017

Any object located in the earth's gravitational field experiences a force in the direction of the center of the earth. In order to describe the motion of objects in the field, the solutions to a system of simultaneous vector kinematic equations need to be obtained. In the analysis of freely-falling objects, the reference direction +y is usually defined to be the downward direction. In the analysis of the motion of objects thrown upward, the reference direction +y is usually defined to be the upward direction. In the analysis of the motion of objects thrown downward, the reference direction +y is usually defined to be the downward direction. In this paper, we show that the choice of reference axis in either upward or direction gives the same results by adopting a scalar product of two vectors in solving the vector kinematic equations. It is rare to find other examples of using a scalar product of two vectors in solving vector kinematic equations describing the motion of objects. An application of this study is that we can arbitrarily choose the reference direction for objects moving in a horizontal direction, including projectile motions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1543-1549
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• 2012

This study focuses on the state space model and the design of a state observer for the slip dynamics between rolls in STS cold cluster mills. First, a mathematical model of the roll slip is given as a nonlinear differential equation. Then, by using a Taylor series expansion, it is linearized as a state space model. Next, by using Gopinath's algorithm, a minimal-order state observer based on the state space model is designed to estimate the angular speed of all idle rolls except for an actuated roll that is measureable. Finally, a computer simulation is used to validate that the proposed state space model very well describes slip dynamics between, and moreover, the state observer very well estimates the angular speed of the idle roll.

• Korean Journal of Materials Research
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• v.27 no.1
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• pp.19-24
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• 2017

This paper is concerned with a test method that can be used to investigate the parameters of the Johnson-Cook constitutive model. These parameters are essential for accurately analyzing material behavior under impact loading conditions in numerical simulation. Ti-6Al-4V alloy (HCP crytal structure) was used as a specimen for the experiments. In the $10^{-3}-10^3/s$ strain rate range, three types of experimental methods (convention, compression and tension) were employed to compare the differences using MTS-810, SHPB and SHTB. Finite element analysis results when applying these parameters were displayed along with the experiment results.