• 한국지능시스템학회논문지
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• 제16권5호
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• pp.562-567
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• 2006

모델 예측 제어 시스템은 이동 제어 구간에서 원하는 출력과 예측된 출력의 차이를 최소화하는 현재의 제어 입력을 적용하는 방식을 사용한다. 제약조건이 있는 경우이거나 비선형 시스템 문제의 경우는 주어진 함수를 최소화하는 최적화 문제를 풀기가 힘들다. 본 논문에서는 모델 예측 제어 시스템의 최적화 문제를 실수 코딩 유전 알고리즘을 이용하여 효율적으로 구할 수 있음을 보인다. 또한 실수코딩 유전알고리즘이 여러 가지 면에서 디지털코딩 유전알고리즘보다 더 자연스럽고 유리함을 모의실험을 통해 보인다.

• 한국수학사학회지
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• 제33권6호
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• pp.327-343
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• 2020

This study investigate philosophical discussions related to the Zeno's paradoxes in order to derive the mathematics educational implications. The paradox of Zeno's motion is sometimes explained by the calculus theories. However, various philosophical discussions show that the resolution of Zeno's paradox by calculus is not a real solution, and the concept of a continuum which is composed of points and the real number continuum may not coincide with the physical space and time. This is supported by the fact that the hyperreal number system of nonstandard analysis could be another model of a straight line or time and that an alternative explanation of Zeno's paradox was possible by the hyperreal number system. The existence of two different theories of the continuum suggests that teachers and students may not have the same view of the continuum. It is also suggested that the real world model used in school mathematics may not necessarily match the student's intuition or mathematical practice, and that the real world application of mathematics theory should be emphasized in education as a kind of 'correspondence.'

• Journal of information and communication convergence engineering
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• 제14권2호
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• pp.84-88
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• 2016

As good example of potential application-specific requirement, (m,k)-firm real-time streams have been recently introduced to deliver multimedia data efficiently in wireless sensor networks. In addition to stream model, communication protocols to meet specific (m,k)-firm real-time streams have been newly developed or extended from existing protocols. However, since the existing schemes for an (m,k)-firm stream have been proposed under typical flat architecture, the scalability problem remains unsolved when the number of real-time flows increases in the networks. To solve this problem, in this paper, we propose a new clustering scheme for an (m,k)-firm stream. The two different clustering algorithms are performed according to either the (m,k)-firm requirement or the deadline. Simulation results are presented to demonstrate the suitability of the proposed scheme under hierarchical architecture by showing that its performance is acceptable irrespective of the increase in the number of flows.

• 동서간호학연구지
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• 제14권2호
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• pp.54-59
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• 2008

Purpose: To investigate self-esteem according to differences between real and ideal Body Mass Index (BMI) in female college students. Methods: Subjects were 587 female students in Korea. Data was collected by using a developed questionnaire through pretesting. Results: Actual number (46.7%) and actual number (5.1%) of participants were defined as being underweight and overweight, respectively. Nearly all participants expression high dissatisfaction with their body shape. Averages of 1.02, 2.97, 7.81 were revealed for underweight, normal weight and overweight group differences between real and ideal BMI. Those who were defined as overweight exhibited significantly self-esteem than those who were defined as underweight. Conclusions: The belief that body shape is heavier than actually the case may be prevalent among female college students in Korea. This difference between the real and ideal BMI negatively influences self-esteem. Programs aimed at improving body image awareness an self-esteem among female college students are needed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.574-580
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• 2009

This study is investigate the bending behavior of real size RC beams strengthened with carbon fiber sheets. For experimental study, 1 control beam and 8 strengthened beams of real size(4 NU-beams and 4 U-beams) are tested and compared. NU-beam has not a V-shaped band and V-beam has a V-shaped band. The variables of experiment are composed of the number of carbon fiber sheets, the existence of U-shaped band, and four point loading, etc. The experimental results showed that the strengthening system with U-shaped band controls the premature debonding and provides a more ductile failure mode than the strengthening system without V-shaped band. It can be found from the load-deflection curves that as the number of fiber sheets is increased, the maximum strength and the flexural rigidity is increased. For the strengthening method with carbon fiber sheets of the real size RC beams, it is required the finding a solution to the bonding problem.

• Journal of Information Technology Applications and Management
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• 제14권3호
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• pp.227-236
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• 2007

Students in cyber universities can take every course because there are no physical constraints such as class rooms. On the other hand. cyber universities should take a heavy burden to schedule real-time exams in a designated time period. Any two courses a student takes must not be simultaneously allocated to a time slot in such a schedule. It is well known that the complexity of this kind of scheduling problem increases exponentially as the number of courses does. This research provides a heuristic method to make on-line real-time exam timetables with minimal exam time span. It considers the constraint of not allocating courses a student takes to simultaneous exam time and prioritizes courses by the number of students.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권5호
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• pp.309-314
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• 2004

In the established virtual-reality system, although it is possible to transact a faculty of sensation and graphic in a single PC, virtual object forcibly treated with rigid body for the reason of the huge amount of calculation, and the number of polygon is restricted. Furthermore, there is some difficulty in the financial aspect and a program field, because the existing virtual-reality system needs at least two workstations or super computers. In this study, the new force-reflecting algorithm called as "Proxy" and a finite element method of Hyperion are applied to this system in order to transact in real-time. Consequently, though the number of polygon, which brings about an obstacle is increased in the real-time graphic transaction, this system makes it possible to transact in the real-time, not being influenced by the size of the virtual object.

• 대한수학회논문집
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• 제9권4호
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• pp.825-830
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• 1994

This paper is concerned with the zeros of successive derivatives of real entire functions. In order to state our results, we introduce the following notations : An entire function which assumes only real values on the real axis is said to be a real entire function. Thus, if a complex number is a zero of a real entire function, then its conjugate is also a zero of the same function.

• 대한수학교육학회지:학교수학
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• 제3권2호
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• pp.267-279
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• 2001

The aim of this study is to examine the number concept of middle school student at grade 9. The research problems of this study are "Can the students classify the various number correctly\ulcorner", "How do the students understand the proposition related to the number concept\ulcorner", and "How do the students know the definition of rational number, irrational number, and real number\ulcorner". In order to examine these problems, we analyze the students' responses about the questions related to the number concept. The result of this examination is that the number concept of students is very insufficient and lacking.

• 한국수학사학회지
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• 제25권3호
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• pp.53-75
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• 2012

본 논문은 복소수 개념이 정당화되는 과정에서 실수와 허수 사이의 관계가 어떻게 변화했는지를 살펴보았다. 허수가 처음 등장한 16세기에 수학자들은 현재와 동일하게 허수를 계산할 수 있었지만 허수를 수학적 대상으로 인정하기까지는 200여년의 시간이 필요했다. 수학이 발달하면서 나타나는 새로운 문제 상황이 실수와 허수의 조화를 요구하였고, 그 결과 복소수의 개념이 점차 명확해졌다. 복소수 개념 발달의 역사는 실수와 허수의 대립이 해소되어 실수와 허수를 복소수로 포괄할 수 있는 관점을 찾아가는 과정이었다. 실수와 허수가 어떤 점에서 대립을 하였고, 수학자들은 이러한 대립에 어떻게 대처하였는가에 분석의 초점을 두고, 실수와 허수의 관계를 정립하는 과정에서 나타난 새로운 사고방식이나 관점을 확인하고 그 영향을 살펴본다. 그리고 이러한 분석결과가 보여주는 교육적 함의를 기술하였다.