• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.385-392
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• 2001

Time-dependent frequency and energy of free vibration of the Spagetti problem, that is the axially moving continuum with time-varying length, are investigated. Exact expressions for the natural frequency and time-varying vibration energy are derived by dealing with traveling waves. When the string length is increased, the vibration period increases, but the free vibration energy varies as a function of both translating velocity and boundary velocity of the continuum. However, when the string undergoes retraction, the vibration energy increases with time, String tension together with non-zero instantaneous velocity at the moving boundary results in energy variation.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.4
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• pp.272-279
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• 2002

The time-dependent frequency and energy of free vibration of the spagetti problem, that is the axially moving continuum with time-varying length, are investigated. Exact expressions for the natural frequency and time-varying vibration energy are derived by dealing with traveling waves. The vibration period increases with increasing length, but the free vibration energy decreases. When the string undergoes retraction, the vibration energy increases with time. The free response of the time-varying string is represented by superposing two traveling waves.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.73-78
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• 2023

The dining philosophers problem(DPP) is that five philosophers sit around a round table and eat spaghetti(or noodles) together, where they must have a pair of chopsticks(two) on both sides of them to eat, and if all philosophers have one chopstick on the right, no one can eat because the deadlock occurs. Deadlocks are a problem that frequently occur in parallel systems, and most current operating systems(OS) cannot prevent it. This paper proposes a silver bullet that causes no deadlock in an OS where all processors of 2≤n≤∞ have multiple parallel processing capabilities. The proposed method is a group round-robin method in which ⌊n/2⌋ odd processors form a group and perform simultaneously, and shift right to the next processor when execution ends. The proposed method is to perform two times for even processors, three times for odd processors per one round-robin. If the proposed method is performed n times, even-numbered processors perform n/2 times and odd-numbered processors perform (n-1)/2-times.

• Journal of the Korean School Mathematics Society
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• v.16 no.4
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• pp.745-770
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• 2013

In the knowledge-based society today, most knowledge is the integrated one which is difficult to be classified into subjects rather than the knowledge of a single subject. Thus, integrated thinking, which integrated knowledge is preferentially acquired first and then can be also associated with imagination and artistic sensitivity, is simultaneously required in order that we have a problem-solving capability in our daily life. STEAM education(science, technology, engineering, arts and mathematics) is one of the educational methods to improve this problem-solving capability as well as integrated thinking. This research developed materials for STEAM education which can be applied to the 6th grade curriculum of elementary school mathematics, then input it, and analyzed how it impacts with students' attitudes toward mathematics. Unit 3 'Prism' and Pyramid' were restructured and replaced by classes such as 'Spaghetti Project' or 'Paper Craft'. Unit 4 'Several Solid Figure' was taught as a class of 'EDUCUBE'. Unit 6 'Proportional Graph' was taught as a class of 'Creating my own bracelet'. After having this class, we found that mathematics class applied STEAM also has a positive effect on the mathematical attitude of students. Many students said that math is fun and gets more interesting after having math class applied STEAM and we come to know that they have positive awareness of mathematics.