• 한국초등과학교육학회지:초등과학교육
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• 제33권1호
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• pp.172-180
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• 2014

The first purpose of this study is to distinguish difficult chapters in 'Speed of objects' chapter and find the factors which give difficulty to the teachers and students. Also, it attempts to compare the students' assessment scores with the degree of difficulty in teaching and also with the degree of difficulty in learning. This report is expected to help science teachers develop their PCK(Pedagogical Content Knowledge) for teaching the chapter professionally. 15 teachers who had taught the 'Speed of Objects' chapter and their 386 students took part in the survey to acquire information about the difficulties in teaching and learning. 386 students also received a test to examine their understandings of the chapter. The results of this study are as follow; First, the degree of teachers' and students' difficulty is only affected by the contents, and the degree of onerousness felt by teachers is higher than that of students. Second, The topics caused higher difficulty to teachers were 'Understanding the meaning of motion(2nd lesson)', 'Understanding the meaning and unit of speed(5th lesson)', 'Changing unit of speed(6th lesson)', 'Drawing a distance-time graph(7th lesson)', and 'Understanding the relative motion(10th). The topics that led higher difficulty to students were the contents of 5th, 6th, and 7th lessons. Third, the 'Speed of Objects' chapter can be divided into 4 types of difficulty according to the degree of teaching and learning; 'Strong difficulty', 'Learning difficulty', 'Weak difficulty', and 'Teaching difficulty'. Last, students showed low achievement to the tasks that were related with 'Strong difficulty' and 'Teaching difficulty'.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제14권3호
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• pp.195-209
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• 2010

Utilizing a structure of operations known as Dissection-Motion-Operations (DMO), a set of mathematics propositions or area-formulas in school mathematics will be introduced through shape-to-shape transforms. The underlying theme for DMO is problem-solving through visual reasoning and proving manipulatively or electronically vs. rote learning and memorization. Visual reasoning is the focus here where two operations that constitute DMO are utilized. One operation is known as Dissection (or Decomposition) operation that operates on a given region in 2D or 3D and dissects it into a number of subregions. The second operation is known as Motion (or Composition) operation applied on the resultant sub-regions to form a distinct area (or volume)-equivalent region. In 2D for example, DMO can transform a given polygon into a variety of new and distinct polygons each of which is area-equivalent to the original polygon (cf [Rahim, M. H. & Sawada, D. (1986). Revitalizing school geometry through Dissection-Motion Operations. Sch. Sci. Math. 86(3), 235-246] and [Rahim, M. H. & Sawada, D. (1990). The duality of qualitative and quantitative knowing in school geometry, International Journal of Mathematical Education in Science and Technology 21(2), 303-308]).

• 한국운동역학회지
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• 제14권3호
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• pp.301-311
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• 2004

The purpose of this study was to verify the usefulness of the Mathcad program as a tool for the studying and teaching the sport biomechanics. A projectile motion was analyzed because it is the one of the most popular motion in sports activities. A 3 dimensional CG data for the high jump bar clear phase was used to calculate the initial velocity vector of the CG. Linear regression function and other functions such as cubic spline and derivative of Mathcad were used to calculate this vector. Finally, the approach angle to the bar and peak jump height was calculated. Programming in Mathcad was relatively easy compare to traditional computer language such as Fortran and C, because of the unique documentation method of Mathcad. Additionally the 2 and 3 dimensional graph function was very easy and useful to describe the mechanical data. If the use of Mathcad program is more popular in the field of sport biomechanics, it could greatly contribute to overcome the limit of research caused by the lack of proper programming ability.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.311-312
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• 2011

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1621-1623
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• 1997

Use of teaching pendant is the most widespread and economical way to teach desired motion to robots. It is also very primitive,time consuming and ineffective way of teaching which has not changed since the early days of robot. In order to reduce the teaching effor, a new efficient form of teaching is needed. Also, the recent robotics research trend into service robots such as home robot, nurse robot and medical robot calls for a new teaching method which is both easy and inexpensive. In this paper, the design and operation principle of a low cost force/moment sensor is presented. The proposed sensor architecture is so simple and inexpensive that it opens the prospect for a new paradigm of robot teaching which is easy and efficinet. Other prospective areas of application are tele-manipulation of robots wher it can be used in master arm, and virtual environment where it can be used as an user input device.

• 공학교육연구
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• 제15권5호
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• pp.36-41
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• 2012

Student members from The University of Tokushima worked voluntarily at the science school for elementary school children and high school students under the support of Japan Science and Technology Agency. The teaching classes for the science school were held in 2010 as follows: (1) Science handicraft class for children on "Wonder in light, sound, temperature and force", (2) Family Science School for children and parents on "Measurement of length, temperature, weight and energy", (3) "Tatara steel making" for high school students, (4) "Wave motion in strings" for high school students. This paper describes how the students prepared the teaching materials and what they obtained from the teaching activities.

• 한국과학교육학회지
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• 제41권2호
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• pp.155-169
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• 2021

이 연구는 초등 과학교과 전담을 맡고 있는 한 경력 교사의 과학교수지향(sceience teaching orientation)의 특징과 과학 교수지향이 다른 PCK 요소들과 어떤 관련이 맺고 있는지를 탐색한 사례연구이다. 이를 위해 Magnusson, Krajcik, & Borko(1999)의 PCK 모델을 적용하였으며, 특히 과학 교수지향과 관련하여 Friedrichsen, Driel, & Abell(2011)의 정의를 이용하였다. 과학수업에 전문성이 있다고 인정받는 한 명의 초등교사를 연구 참여자로 선정하고 그의 과학수업 21차시를 관찰하였다(물체의 운동 단원 10차시, 빛과 렌즈 단원 11차시). 교사 면담과 참여 교사의 PCK를 명시적으로 파악할 수 있는 CoRe(content representation) 응답지를 수집하여 함께 분석하였다. 먼저 사전 면담 자료를 통해 참여 교사의 과학 교수지향을 귀납적으로 분석하였다. Friedrichsen, Driel, & Abell(2011)이 제안한 과학 교수지향의 세 측면(과학 교수의 목적과 목표에 관한 신념, 과학의 본성에 관한 신념, 과학 교수학습에 관한 신념)을 가장 잘 표현할 수 있는 어구를 찾고, 이를 상위 범주로 분류하여 이에 이름을 붙이는 범주화 작업을 하였다. 과학 교수지향을 제외한 다른 PCK 요소들의 특징은 CoRe 응답지와 수업 관찰 자료를 Magnusson, Krajcik, & Borko 1999)의 PCK 모델에 따라 연역적으로 분석하였다. 연구 결과, 과학교수지향의 세 측면과 관련하여 그는 각각 '과학과 일상생활과의 관계와 과학 개념의 습득', '앎에 이르는 방법으로서의 과학', '학생 중심수업' 신념을 가지고 있었다. 이러한 세 측면은 다중적이고 복합적으로 얽혀 있었으나 '과학 탐구'라는 하나의 과학 교수지향으로 수렴됨을 확인할 수 있었다. 또한 교사가 다른 PCK 요소의 선정과 조직에 관련하여 의사결정을 내릴 때 더 주요하게 영향을 미치는 신념이 있음을 관찰할 수 있었다. 과학수업 전문성을 가지고 있다고 인정받는 초등교사의 과학 교수지향의 특징, 과학 교수지향과 다른 PCK 요소들과의 관련성을 탐색한 이 연구의 결과는 초등교사의 과학수업 실천을 이해하는데 있어 과학 교수지향의 역할과 의미에 시사점을 줄 수 있을 것이다.

• Journal of Trauma and Injury
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• 제36권1호
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• pp.65-69
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• 2023

The surgical approach for humeral implant failure can be challenging due to neurovascular anatomy and the possible necessity of osteosynthesis removal. We present a rare case of humeral nail bending after secondary trauma in a patient with preexistent nonunion of the humerus after intramedullary nailing. During revision surgery, the nail was sawed in half and the distal part was removed, followed by plate osteosynthesis with cable fixation to achieve absolute stability. The patient regained a full range of motion 1 year after surgery, and complete healing of the fracture was seen on imaging.

• 한국컴퓨터정보학회논문지
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• 제23권8호
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• pp.17-23
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• 2018

In this paper, we implemented a flight posture simulator that intuitively understands aircraft flight posture and visualizes the principle of motion. The proposed system operates the 6 - axis motion platform according to the change of the navigation information and transmits the flight attitude to the simulator using the gyro sensor. A gyro sensor and an acceleration sensor are used together to analyze the attitude of the aircraft. The reason is that the gyro sensor has a cumulative error in the integration process. And the accelerometer sensor was compensated by using the complementary filter because noise was serious due to short term vibration. Using the compensated sensor information, the motion platform is operated by calculating the angle to be transmitted to the 6-axis motor. And visualization result is implemented using OpenGL. The results of this study can be used as teaching materials for students related to aviation in the future.

• Advances in Computational Design
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• 제4권3호
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• pp.197-210
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• 2019

Motion generation of a four-bar linkage is a type of mechanism synthesis that has a wide range of applications such as a pick-and-place operation in manufacturing. In this research, the use of meta-heuristics for motion generation of a four-bar linkage is demonstrated. Three problems of motion generation were posed as a constrained optimization probably using the weighted sum technique to handle two types of tracking errors. A simple penalty function technique was used to deal with design constraints while three meta-heuristics including differential evolution (DE), self-adaptive differential evolution (JADE) and teaching learning based optimization (TLBO) were employed to solve the problems. Comparative results and the effect of the constraint handling technique are illustrated and discussed.