• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.1
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• pp.7-13
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• 2015

This paper presents mathematical models for high speed permanent-magnet synchronous machine. The mathematical method with two successive steps is used to estimate design parameter as well as the output power. At first, mathematical model for a linkage flux problem is employed to calculate the number of winding turns and stack length of armature core. The magnetic circuit model for an induced voltage and the electric circuit model for a current are modeled. The output powers of the electrical generator were evaluated by the mathematical techniques. The results of this mathematical methods predict the specifications of the machine and can be applied in the design stage of the electrical machine.

• Communications of the Korean Mathematical Society
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• v.16 no.4
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• pp.659-666
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• 2001

The aim of this paper is to derive the analytical so-lution of the queue: H$_{r}$/M/c/k/N for machine interference with balking and reneging, and FIFO (first in, first out) service disci-pline.e.

• Journal of the Korea Society of Computer and Information
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• v.24 no.1
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• pp.257-263
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• 2019

This paper is a study on mathematical aspects that can be basic for understanding and applying the contents of machine learning. If you are familiar with mathematics in the field of computer science, you can create algorithms that can diversify researches and implement them faster, so you can implement many real-life ideas. There is no curriculum standard for mathematics in the field of machine learning, and there are many absolutely lacking mathematical contents that are taught in the curriculum presented at existing universities. Machine learning now includes speech recognition systems, search engines, automatic driving systems, process automation, object recognition, and more. Many applications that you want to implement combine a large amount of data with many variables into the components that the programmer generates. In this course, the mathematical areas required for computer engineer (CS) practitioners and computer engineering educators have become diverse and complex. It is important to analyze the mathematical content required by engineers and educators and the mathematics required in the field. This paper attempts to present an effective range design for the essential processes from the basic education content to the deepening education content for the development of many researches.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.991-994
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• 1995

Recent trend in machine tools is pursuing the high precision and high speed facility and its architecture is being more complicated. With this tendency, it is required the more precise dynamic analysis of electro-mechanical system in machine tools. In this paper, the exact mathematical model of feed and spindle system of a typical machine tools was induced. The feed system is modeled as 7-mass system including the workpiece and the spindle system as 4-mass system. The simulation results show that the induced model depicts the characteristics of real system very well. The effects of each mechanical element to dynamic motion of a machine are analyzed by simulation with the induced model. It ia anticipated that the induced model can be used in the analysis of various machine architectures and in the design stage of new machine tools.

• Korean Management Science Review
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• v.24 no.1
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• pp.91-111
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• 2007

In this paper an effective two-phase approach adopting modified p-median mathematical model is proposed for grouping machines and parts in cellular manufacturing(CM). Unlike the conventional methods allowing machines and parts to be improperly assigned to cells and families, the proposed approach seeks to find the proper block diagonal solution where all the machines and parts are properly assigned to their most associated cells and families in term of the actual machine processing and part moves. Phase 1 uses the modified p-median formulation adopting new inter-machine similarity coefficient based on the non-binary production data-based part-machine incidence matrix(PMIM) that reflects both the operation sequences and production volumes for the parts to find machine cells. Phase 2 apollos iterative reassignment procedure to minimize inter-cell part moves and maximize within-cell machine utilization by reassigning improperly assigned machines and parts to their most associated cells and families. Computational experience with the data sets available on literature shows the proposed approach yields good-quality proper block diagonal solution.

• Communications of Mathematical Education
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• v.37 no.1
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• pp.21-45
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• 2023

This study presents a machine learning program designed to identify impactful papers in the field of mathematics education. To achieve this objective, we examined the impact of papers from a scientific econometrics perspective, developed a mathematics education research network, and defined the impact of mathematics education research using PageRank, a network centrality index. We developed a machine learning model to determine the impact of mathematics education research and identified the journals with the highest percentage of impactful articles to be the Journal for Research in Mathematics Education (25.66%), Educational Studies in Mathematics (22.12%), Zentralblatt für Didaktik der Mathematik (8.46%), Journal of Mathematics Teacher Education (5.8%), and Journal of Mathematical Behaviour (5.51%). The results of the machine learning program were similar to the findings of previous studies that were read and evaluated qualitatively by experts in mathematics education. Significantly, the AI-assisted impact evaluation of mathematics education research, which typically requires significant human resources and time, was carried out efficiently in this study.

• East Asian mathematical journal
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• v.19 no.1
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• pp.17-26
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• 2003

This paper demonstrates the CAS technique of analyzing the nature and the structure of the numerical error for education and research purposes. This also illustrates the CAS approach in experimenting with the numerical operations in an arbitrary computer number system and also in doing error analysis in a visual manner.

• Journal of the Chungcheong Mathematical Society
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• v.34 no.2
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• pp.157-168
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• 2021

This study uses the benchmark interest rate of the Federal Open Market Committee (FOMC) to predict gold futures prices. For the predictions, we used the support vector machine (SVM) (a machine-learning model) and the long short-term memory (LSTM) deep-learning model. We found that the LSTM method is more accurate than the SVM method. Moreover, we applied the Boruta algorithm to demonstrate that the FOMC benchmark interest rates correlate with gold futures.

• IE interfaces
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• v.12 no.1
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• pp.10-18
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• 1999

Job shop manufacturing environments are using the concept of cellular manufacturing systems(CMS) which has several advantages in reducing production lead times, setup times, work-in-process, etc. Utilizing the similarities between cell-machine, part-machine, and the shape/size of parts, CMS can group machines and parts resulting in improved efficiency of this system. However, when grouping machines and parts in machine cells, there inevitably occurs exceptional elements(EEs), which can not operate in the same machine cell. Minimizing these EEs in CMS is a critical point that improving production efficiency. Constraints in machine duplication cost, machining process technology, machining capability, and factory space limitations are main problems that prevent achiving the goal of maintaining an ideal CMS environment. This paper presents an algorithm that minimizes EEs under the constraints of machine duplication cost and factory space limitation. Developing exceptional operation similarity(EOS) by cell-machine incidence matrix and part-machine incidence matrix, it brings the machine cells that operate the parts or not. A mathematical model to minimize machine duplication is developed by EOS, followed by a heuristic algorithm in order to reflect dynamic situation resulting from minimizing exceptional elements process and the mathematical model. A numerical example is provided to illustrate the algorithm.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.37-47
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• 1998

This study discusses the feed dog feeding mechanism of an industrial lock stitch sewing machine, which is a good example to study a machine kinematics. The feed dog feeding mechanism makes the fabrics directly be fed by an elliptic motion of the feed dog that is moved by a rotation of the top shaft and controlled by the feeding control mechanism. This study makes mathematical expressions of machine's motion in the feed dog feeding mechanism. Thus, the motions of this mechanism are characterized, namely how an elliptic motion of the feed dog is affected by the feeding control mechanism. Therefore, the above mathematical expressions may be a basis for the new design of the feed dog feeding mechanism and may be adapted to analysis. Development of the similar feed dog feeding mechanism can be applied to other type sewing machine.