• Journal of The Korean Association For Science Education
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• v.28 no.8
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• pp.796-813
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• 2008

A good understanding of how gifted science students understand physics is important to developing and delivering effective curriculum for gifted science students. This dissertation reports on a systematic investigation of gifted science students' reasoning model in learning physics. An analysis of videotaped class work, written work and interviews indicate that I will discuss the framework to characterize student reasoning. There are three main groups of students. The first group of gifted science students holds several different understandings of a single concept and apply them inconsistently to the tasks related to that concept. Most of these students hold the Aristotelian Model about Newton's second law. In this case, I define this reasoning model as the manifold model. The second group of gifted science students hold a unitary understanding of a single concept and apply it consistently to several tasks. Most of these students hold a Newtonian Model about Newton's second law. In this case, I define this reasoning model as the coherence model. Finally, some gifted science students have a manifold model with several different perceptions of a single concept and apply them inconsistently to tasks related to the concept. Most of these students hold the Aristotelian Model about Newton's second law. In this case, I define this reasoning model as the coherence model.

• Journal of Korean Philosophical Society
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• v.148
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• pp.157-181
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• 2018

The aim of this essay is to identify elements of methodologies to investigate the development of Newtonian dynamics. This methodology involves the transformation and synthesis of preceding theories. My essay attempts to confirm my assertion by analyzing historical case of Newton's discovery of his dynamics. While discovering his mechanistic theory, Newton reconstructed theoretical concepts and structures of intellectual predecessors, such as Aristotle, Descartes, Galileo, and Kepler. Newton's synthesis was possible only after carefully reconstructing the appropriate and useful ideas of previous natural philosophers' ideas. As a result, Newtonian dynamics are completed with these modified and integrated concepts incorporated into Newton's law of motion and space-time concepts. This study consists of two parts. First, Lakatos' research program has been applied in order to analyze the structure of Newtonian dynamics. Second, the aforementioned methodologies of discovery are distilled from the case study.

• International Journal of Automotive Technology
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• v.8 no.6
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• pp.731-744
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• 2007

A method for dynamic analysis and design calculation of a Powertrain Mounting System(PMS) including Hydraulic Engine Mounts(HEM) is developed with the aim of controlling powertrain motion and reducing low-frequency vibration in pitch and bounce modes. Here the pitch mode of the powertrain is defined as the mode rotating around the crankshaft of an engine for a transversely mounted powertrain. The powertrain is modeled as a rigid body connected to rigid ground by rubber mounts and/or HEMs. A mount is simplified as a three-dimensional spring with damping elements in its Local Coordinate System(LCS). The relation between force and displacement of each mount in its LCS is usually nonlinear and is simplified as piecewise linear in five ranges in this paper. An equation for estimating displacements of the powertrain center of gravity(C.G.) under static or quasi-static load is developed using Newton's second law, and an iterative algorithm is presented to calculate the displacements. Also an equation for analyzing the dynamic response of the powertrain under ground and engine shake excitations is derived using Newton's second law. Formulae for calculating reaction forces and displacements at each mount are presented. A generic PMS with four rubber mounts or two rubber mounts and two HEMs are used to validate the dynamic analysis and design calculation methods. Calculated displacements of the powertrain C.G. under static or quasi-static loads show that a powertrain motion can meet the displacement limits by properly selecting the stiffness and coordinates of the tuning points of each mount in its LCS using the calculation methods developed in this paper. Simulation results of the dynamic responses of a powertrain C.G. and the reaction forces at mounts demonstrate that resonance peaks can be reduced effectively with HEMs designed on the basis of the proposed methods.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1765_1766
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• 2009

In this paper, we propose the mathematical model for the vehicle system and the observer for adhesion force. To model the dynamic properties of vehicle system, we have considered two fundamental parts. The first part is the motion equations for vehicle based on Newton's second law. The second part is the torque dynamics of the traction motor. These parts are affected by outer conditions such as adhesive coefficient, running resistance and gradient resistance. The each parts are presented by the numerical formula. From two equations, we get the observer on adhesion force. Simulation results show that the proposed observer have the good performance compared with the normal observer.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.1955-1961
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• 2007

In this paper, we propose the mathematical model for the vehicle system including running characteristics. The well defined model for a system is necessary to study and to enhance system performance. To model the dynamic properties of vehicle system, we have considered two fundamental parts. The first part is the motion equations for vehicle based on Newton's second law. The second part is the torque dynamics of the traction motor. These parts are affected by outer conditions such as adhesive coefficient, running resistance and gradient resistance. The each parts are presented by the numerical formula. To test the driving characteristics of the developed model, we performed the simulations by dynamic system simulation software, "SIMULINK" and the results are given for several conditions.

• IE interfaces
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• v.22 no.3
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• pp.205-213
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• 2009

Warfare information system is a core factor of future combat operation under NCW(Network centric Warfare) environment. In this paper, we proposed a new MOE(Measure of Effectiveness) that can assess the combat power synergistic effect of warfare information system in the theater-level joint fire operation. This new MOE uses the rule of Newton's second law($F=(m{\Delta}{\upsilon})/{\Delta}t{\Rightarrow}(M{\upsilon}I)/T$). Four factors considered in combat power evaluation are network power(M), movement velocity(v), information superiority(I), command and control time(T). We applied this new MOE to the JFOS-K(Joint Fire Operating System-Korea) to assess its combat power effect and compared with other's effects obtained from different MOE.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.104-112
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• 2008

In modern war information system development makes battlefield materialize, and combat factors can maximize combat power exhibition as that apply synchronization. Information system is the core of combat power operation under NCW(Network centric Warfare). This paper proposed a new MOE(Measure of Effectiveness) that can assess the combat power synergistic effect of information system at the theater joint fire operation in NCW environment. This methodology applied the rule of Newton's second law $F=(m{\Delta}{\upsilon})/t{\Rightarrow}(M{\upsilon}I)/T$) Details factor in combat power evaluation is as following. (1) M : Network power; (2) v : Movement velocity; (3) I : Information superiority; (4) T : C2(command and control) time. We applied this methodology to the "JFOS-K(Joint Fire Operating System-Korea) in Joint Chief of Staff" in the real military affair section.

• Structural Engineering and Mechanics
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• v.35 no.4
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• pp.387-407
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• 2010

In this paper, using perturbation and Galerkin method, the response of a resonant viscoelastic microbeam to an electric actuation is obtained. The microbeam is under axial load and electrical load. It is assumed that midplane is stretched, when the beam is deflected. The equation of motion is derived using the Newton's second law. The viscoelastic model is taken to be the Kelvin-Voigt model. In the first section, the static deflection is obtained using the Galerkin method. Exact linear symmetric mode shape of a straight beam and its deflection function under constant transverse load are used as admissible functions. So, an analytical expression that describes the static deflection at all points is obtained. Comparing the result with previous research show that using deflection function as admissible function decreases the computation errors and previous calculations volume. In the second section, the response of a microbeam resonator system under primary and secondary resonance excitation has been obtained by analytical multiple scale perturbation method combined with the Galerkin method. It is shown, that a small amount of viscoelastic damping has an important effect and causes to decrease the maximum amplitude of response, and to shift the resonance frequency. Also, it shown, that an increase of the DC voltage, ratio of the air gap to the microbeam thickness, tensile axial load, would increase the effect of viscoelastic damping, and an increase of the compressive axial load would decrease the effect of viscoelastic damping.

• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.851-866
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• 2016

The purpose of this study is to investigate pre-service elementary teachers' views of the law of action-reaction by examining their degrees of understanding and Typically-Perceived-Situations (TPS). Data were collected from 177 Grade 3 pre-service elementary teachers. The results of analyzing these data show: First, the participants did not sufficiently understand about the law of action-reaction, and their degrees of understanding were different depending on the situation provided in the questionnaire. Second, in relation to the TPSs of the law of action-reaction, the participants thought of irrelevant situations to the law of action-reaction such as "a situation generated by inertia" as well as commonly relevant ones such as "a person pushing a wall", and had somewhat biased TPSs in terms of 'action type' and 'result motion type' of action-reaction. Finally, several suggestions on the science education for promotion of understanding about the law of action-reaction were given.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.175-178
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• 1997

This study was carried out to obtain an analytical expression for the specifications of the Stewart Platform that minimize the maximum force acting on the hydraulic cylinder. The position and orientation of the platform were calculated by means of the inverse kinematic analysis. The maximum force to be exerted on a cylinder was calculated using the Newton's second law for the case when the platform is moved along a horizontal axis with 0.6 g, the maximum translational acceleration possible. This paper suggests a mathematical model to minimize the maximum actuating force using radius and angle ratios as design variables. Finally, a fuzzy set for the minimum actuating force is proposed for this dynamic optimal design problem.