• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.408-412
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• 2007

Combining the analytical transfer matrix method with supersymmetry algebra, a new quantization condition is suggested. To demonstrate the efficiency of the new quantization condition, the eigenenergies of the Coulomb potential are analytically derived. The scattering-led phase shifts are also determined and they are the same for all Coulomb potential states. It is found that the new quantization condition is mathematically simple and exact.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.137-143
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• 1998

Numerical simulation is conducted to clarify the heat transfer and fluid flow characteristics of traction motor for electric car SIMPLE algorithm based on finite volume method is used to make linear algebra equation. The governing equations are solved by TDMA(TriDiagonal Matrix Algorithm) with line-by-line method and block correction. From the results of simulation, the characteristics of cooling pattern is strongly affected by the size of hole in stator core. In the case of high rotational speed of rotor, temperature difference along the axial direction is more decreased than that of low rotational speed.

• Journal of the Korean Mathematical Society
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• v.58 no.2
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• pp.309-326
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• 2021

In near-ring theory several different types of primitivity exist. These all imply several different types of primeness. In case of near-rings with DCCN most of the types of primeness are known to imply primitivity of a certain kind. We are able to show that also so called 1-prime near-rings imply 1-primitivity. This enables us to classify maximal ideals in near-rings with chain condition with the concept of 1-primeness which leads to further results in the structure theory of near-rings.

• Journal of the Korea Society for Simulation
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• v.19 no.3
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• pp.109-117
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• 2010

In this study, we consider stationary waiting times in a simple fork-and-join type queue which consists of three single-server machines, Machine 1, Machine 2, and Assembly Machine. We assume that the queue has a renewal arrival process and that independent service times at each node are either deterministic or non-overlapping. We also assume that the Machines 1 and 2 have an infinite buffer capacity whereas the Assembly Machine has two finite buffers, one for each machine. Services at each machine are given by FIFO service discipline and a communication blocking policy. We derive the explicit expressions for stationary waiting times at all nodes as a function of finite buffer capacities by using (max,+)-algebra. Various characteristics of stationary waiting times such as mean, higher moments, and tail probability can be computed from these expressions.

• Journal of the Korean Mathematical Society
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• v.31 no.4
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• pp.569-608
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• 1994

The subject matter of this survey has to do with holomorphic maps from a compact Riemann surface to projective space, which are also called algebrac curves; the theory we survey lies at the crossroads of function theory, projective geometry, and commutative algebra (although we should mention that the present survey de-emphasizes the algebraic aspect). Algebraic curves have been vigorously and continuously investigated since the time of Riemann. The reasons for the preoccupation with algebraic curves amongst mathematicians perhaps have to do with-other than the usual usual reason, namely, the herd mentality prompting us to follow the leads of a few great pioneering methematicians in the field-the fact that algebraic curves possess a certain simple unity together with a rich and complex structure. From a differential-topological standpoint algebraic curves are quite simple as they are neatly parameterized by a single discrete invariant, the genus. Even the possible complex structures of a fixed genus curve afford a fairly complete description. Yet there are a multitude of diverse perspectives (algebraic, function theoretic, and geometric) often coalescing to yield a spectacular result.

• Journal for History of Mathematics
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• v.11 no.2
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• pp.35-42
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• 1998

It is an undecidable problem to determine whether a given equation logically follows from a given set of equations. However, it is possible to give the answer to many instances of the problem, even though impossible to answer all the instances, by using rewrite systems and completion procedures. Rewrite systems and completion procedures can be implemented as computer programs. The new equations such a computer program generates are theorems that hold in the given equational theory. For example, a completion procedure applied on the group axioms generates simple theorems about groups. Mathematics students' teaming to know the existence and mechanisms of computer programs that prove simple theorems can be a significant help to promote the interests in abstract algebra and logic, and the motivation for studying.

• Journal of the Korean Mathematical Society
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• v.58 no.6
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• pp.1407-1419
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• 2021

The Iwasawa decomposition NAK of the Lie group G = SO₀(2, 1) with a left invariant metric produces Riemannian submersions G → N\G, G → A\G, G → K\G, and G → NA\G. For each of these, we calculate the curvature of the base space and the lifting of a simple closed curve to the total space G. Especially in the first case, the base space has a constant curvature 0; the holonomy displacement along a (null-homotopic) simple closed curve in the base space is determined only by the Euclidean area of the region surrounded by the curve.

• Communications of Mathematical Education
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• v.28 no.1
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• pp.65-79
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• 2014

The present study seeks to provide an easy path to differential perceptions of students at the upper high school level by applying a story telling method and also, characteristically, to earn some time for class discussion by reducing learning time for simple calculational procedure through Computer Algebra System(CAS) tools. This study offers a clear example of storytelling textbooks through Sage. Hence, the study aims at enabling students who have practiced contents with Sage tools to deal with diverse and complicated calculation problems, if they learn to build up mathematical formulas for those problems.

• Research in Mathematical Education
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• v.23 no.1
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• pp.13-22
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• 2020

The effectiveness of mathematics classroom teaching is directly affected by the teaching language. Comparing the teaching language of a novice teacher in algebra instruction with an expert teacher from the perspective of pragmatics, it comes to a conclusion that: both teachers attach great importance to the use of the teaching language, with the proportion of the teaching language time more than 50%; the novice teacher uses the affirmative language frequently, twice as often as the expert teacher; the declarative language the novice teacher uses in the exploration is mostly to repeat students' answer, which takes up a short time; the novice teacher uses the teaching language too much in the consolidation, which causes fewer opportunities for students to think. Then we get the following revelations: streamline the teaching language and control the time of the teaching language reasonably; make good use of the affirmative language to provide students hints and necessary time for thinking; avoid simple restatement of the student's answer and use the declarative language ingeniously to improve the feedback quality; use the teaching language appropriately to help students accumulate basic experience in mathematics activities.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.8 s.338
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• pp.1-10
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• 2005

In this paper, the explicit low density codes construction from the generalized permutation matrices related to algebra theory is investigated, and we design several Jacket inverse block matrices on the recursive formula and permutation matrices. The results show that the proposed scheme is a simple and fast way to obtain the low density codes, and we also Proved that the structured low density parity check (LDPC) codes, such as the $\pi-rotation$ LDPC codes are the low density Jacket inverse block matrices too.