• Communications of Mathematical Education
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• v.37 no.3
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• pp.517-544
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• 2023

This study presents the process and outcomes of developing mathematical-informatics linkage·convergence class materials, based on previous research findings that indicate a lack of such materials in high schools despite the increasing need for development of interdisciplinary linkage·convergence class materials In particular, this research provides insights into the discussions of six teachers who participated in the same professional learning community program, aiming to create materials that are suitable for linkage·convergence class materials and highly practical for classroom implementation. Following the material development process, a theme-based design model was applied to create the materials. In alignment with prior research and consensus among teacher learning community members, mathematics and informatics teachers developed instructional materials that can be utilized together during a 100-minute block lesson. The developed materials utilize societal issue contexts to establish links between the two subjects, enabling students to engage in problem-solving through mathematical modeling and coding. To increase the validity and practicality of the developed resources during their field application, CVR verification was conducted involving field teachers. Incorporating the results of the CVR verification, the finalized instructional materials were presented in the form of a teaching guide. Furthermore, we aimed to provide insights into the trial-and-error experiences and deliberations of the developers throughout the material development process, with the intention of offering valuable information that can serve as a foundation for conducting related research by field researchers. These research findings hold value as empirical evidence that can explore the applicability of teaching material development models in fields. The accumulation of such materials is expected to facilitate a cyclical relationship between theoretical teaching models and practical classroom applications.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.11a
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• pp.131-137
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• 2007

본 연구에서는 RLS(Rescursive Least Square) 추정 알고리즘을 이용하여 정전용량형 센서를 사용한 원격 RF 센서 시스템을 구현하고자 한다. IC 칩 형태의 원격 RF 센서 시스템이 가지는 구성의 복잡성 그리고 전력소모 문제를 해결하기 위해 보다 간단한 유도결합모델이 제안된다. 원격 RF 시스템은 페이저법을 이용하여 수학적으로 모델링되며, 모델기반의 RLS 알고리즘을 적용하기위해 시스템의 파라메타를 재배열한다. 오차 제곱합의 수렴특성을 가진 RLS 알고리즘을 이용하여 정전용량 파라메타를 추정한다. 실제 위상차를 측정하기 위해 Exclusive OR를 이용한 위상차 감지 장치를 제안한다. 센서로는 각종 환경 측정-습도, 압력 등-에 실제 활용되고 있는 정전용량형 센서를 채택한다. 잡음을 내포한 측정 데이터에 대한 추정 성능을 확인함으로써 그 유효성을 검증하고자 한다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.3
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• pp.28-36
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• 1982

Petri nets have been used for medeling a wide variety of systems from computer to social systems. This paper disusses Petri nets in the context of mathematical representation and its associated bag theory. The method of modeling systems such as event-condition, computer progranm computer operation and PERT chart is discribed and their Petri net representation are presented. Finally Petri net representation of tunnel diode oscillator circuit and the analysis of the circuit using Petri net are discussed with the program and results.

• Journal of Environmental Science International
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• v.18 no.8
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• pp.911-918
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• 2009

Electromagnetic interference (EMI) is defined as the interaction phenomena of electromagnetic waves scattered from a large structure or complex terrain. In this study, the propagation of linear wave is modeled with ray theory, direct simulation Monte Carlo (DSMC), and some classical theories on flat plates. The wave physics of reflection, refraction, and diffraction are simulated for the investigation of front and back scattering of the one-dimensional plane wave from a tower with ray theory and DSMC, respectively. The effect of rotating disk idealized from the real wind-turbine blades is modeled with a simplified version of the classical electromagnetic theory as well as DSMC based on the ray theory.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.317-320
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• 2000

경계선 추출(edge detection)은 영상처리 및 인식 분야의 여러 응용분야에서 쓰이는 중요한 전처리과정 중 하나이다. 경계선이란 두 영역 사이의 경계에 위치한 점들[12]을 말하며, 경계선 추출은 영상 속에 위치한 이런 경계점들을 찾는 작업을 말한다. 경계선 추출 방법에 대해서는 많은 연구가 진행되어 왔지만 사물의 실제 경계선을 정확히 추출해내는 것은 여전히 어려운 문제로 남아있다. 이에 본 논문에서는 인간의 시각 정보처리 방법을 기존 문헌을 통해 분석하고 이를 기반으로 한 경계선 추출 모형을 제안한다. 제안된 모형은 기존의 수학적인 시각 모형에서 불가피하게 제외되는 시각 특징 및 인간의 시각기관의 특징을 포함할 수 있을 것으로 기대된다.

• School Mathematics
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• v.7 no.4
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• pp.391-402
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• 2005

The purpose of this study is to resolve misunderstanding for centroid of a triangle and to clarify several logical problems in finding the centroid of a Polygon. The conclusions are the followings. For a triangle, the misunderstanding that the centroid of a figure is the intersection of two lines that divide the area of the figure into two equal part is more easily accepted caused by the misinterpretation of a median. Concerning the equilibrium of a triangle, the median of it has the meaning that it makes the torques of both regions it divides to be equal, not the areas. The errors in students' strategies aiming for finding the centroid of a polygon fundamentally lie in the lack of their understanding of the mathematical investigation of physical phenomena. To investigate physical phenomena mathematically, we should abstract some mathematical principals from the phenomena which can provide the appropriate explanations for then. This abstraction is crucial because the development of mathematical theories for physical phenomena begins with those principals. However, the students weren't conscious of this process. Generally, we use the law of lever, the reciprocal proportionality of mass and distance, to explain the equilibrium of an object. But some self-evident principles in symmetry may also be logically sufficient to fix the centroid of a polygon. One of the studies by Archimedes, the famous ancient Greek mathematician, gives a solution to this rather awkward situation. He had developed the general theory of a centroid from a few axioms which concerns symmetry. But it should be noticed that these axioms are achieved from the abstraction of physical phenomena as well.

• Journal of Elementary Mathematics Education in Korea
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• v.11 no.1
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• pp.1-21
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• 2007

The purpose of this study was to propose instructional methods using base-ten blocks in teaching the multiplication of decimal for 5th grade students by analyzing the process of their conceptual comprehension of multiplication of decimal. The students in this study were found to understand various meanings of operations (e.g., repeated addition, bundling, and area) by modeling them with base-ten blocks. They were able to identify the algorithm through the use of base-ten blocks and to understand the principle of calculations by connecting the manipulative activities to each stage of algorithm. The students were also able to determine whether the results of multiplication of decimal might be reasonable using base-ten blocks. This study suggests that appropriate use of base-ten blocks promotes the conceptual understanding of the multiplication of decimal.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.1
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• pp.37-47
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• 2005

This Paper proposes a practical design and implementation methodology for a disturbance rejection controller. In a 2 Degree-Of-Freedom (DOF) structure, disturbance rejection performance can be improved without a high gain in forward-loop controller which might cause unwanted side-effects in conventional controller. But, since design methodology of 2 DOF controller is originally derived from the 2 DOF theory, it is not easy to utilize fer various industrial applications. Disturbance observer is a simple, but very effective 2 DOF controller. In this paper, practical issues are discussed from basic idea of DOB to technical procedure for design and implementation. Additionally, a methods and their examples of experimental modeling are explained. The proposed method is demonstrated by two examples of linear-type motor systems.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.9
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• pp.80-87
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• 2004

Active control of on-orbit spacecraft jitter is a significant problem for future spacecraft mission requiring stringent pointing performance. Jitter is major disturbance source degrading payload pointing performance. Both passive and active jitter isolation techniques have been studied during the last decade. We present active jitter isolation for a model device in this work. The device provides active control capability by 3 degree-of-freedom control of payload in feedback control strategy. Mathematical modeling of the device is pursued which is naturally used for a baseline controller design. Simulation results are used to validate the designed control law.

• Geophysics and Geophysical Exploration
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• v.5 no.3
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• pp.206-216
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• 2002

The finite element method (FEM), a powerful numerical modeling tool for solving various engineering problems, is frequently applied to three-dimensional (3-D) modeling thanks to its capability of discretizing and simulating the shape of model with finite number of elements. Considering the accuracy of the solution and computing time in modeling of engineering problems, it is preferable to construct physical continuity and simplify mesh system. Although there exist systematic mesh generation systems for arbitrary shaped model, it is hard to model a simple cylinder in terms of 3-D coordinate system especially in the vicinity of the central axis. In this study I adopt cylindrical coordinate system for modeling the 3-D model space and define the origin of the coordinates with mathematically clear coordinate transformation. Since we can simulate the whole space with hexahedral elements, the cylindrical coordinate system is effective in handling the 3-D model structure. The 3-D do resistivity modeling scheme developed in this study provides basie principle for borehole-to-surface resistivity survey, which can be a useful tool for the application to environmental problem.