• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.5
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• pp.562-567
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• 2006

Model Predictive Control(MPC) system uses the current input which minimizes the difference between the desired output and the estimated output in the receding horizon scheme. In many cases (for example, system with constraints or nonlinear system), however, it is not easy to find the optimal solution to the above problem. In this paper, we show that real number coding genetic algorithm can be used to solve the optimal problem for MPC effectively. Also, we show by simulation that the real coding algorithm is mote natural and advantageous than the digital coding one.

• Journal for History of Mathematics
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• v.33 no.6
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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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• v.14 no.2
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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.

• Journal of East-West Nursing Research
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• v.14 no.2
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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.

• Proceedings of the KSR Conference
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• 2009.05a
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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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• v.14 no.3
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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.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.5
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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.

• Communications of the Korean Mathematical Society
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• v.9 no.4
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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.

• School Mathematics
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• v.3 no.2
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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.

• Journal for History of Mathematics
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• v.25 no.3
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• pp.53-75
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• 2012

When imaginary numbers were first encountered in the 16th century, mathematicians were able to calculate the imaginary numbers the same as they are today. However, it required 200 years to mathematically acknowledge the existence of imaginary numbers. The new mathematical situation that arose with a development in mathematics required a harmony of real numbers and imaginary numbers. As a result, the concept of complex number became clear. A history behind the development of complex numbers involved a process of determining a comprehensive perspective that ties real numbers and imaginary numbers in a single category, complex numbers. This came after a resolution of conflict between real numbers and imaginary numbers. This study identified the new perspective and way of mathematical thinking emerging from resolving the conflicts. Also educational implications of the analysis were discussed.