• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.431-431
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• 2000

The modeling of 5-bar linkage robot manipulator dynamics by means of a mathematical and neural architecture is presented. Such a model is applicable to the design of a feedforward controller or adjustment of controller parameters. The inverse model consists of two parts: a mathematical part and a compensation part. In the mathematical part, the subsystems of a 5-bar linkage robot manipulator are constructed by applying Kawato's Feedback-Error-Learning method, and trained by given training data. In the compensation part, MLP backpropagation algorithm is used to compensate the unmodeled dynamics. The forward model is realized from the inverse model using the inverse of inertia matrix and the compensation torque is decoupled in the input torque of the forward model. This scheme can use tile mathematical knowledge of the robot manipulator and analogize the robot characteristics. It is shown that the model is reasonable to be used for design and initial gain tuning of a controller.

• Bulletin of the Korean Mathematical Society
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• v.58 no.6
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• pp.1507-1520
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• 2021

Let R be a commutative ring with 1 ≠ 0, n be a positive integer and M be an R-module. In this paper, we introduce the concept of weakly quasi n-absorbing submodule which is a proper generalization of quasi n-absorbing submodule. We define a proper submodule N of M to be a weakly quasi n-absorbing submodule if whenever a ∈ R and x ∈ M with 0 ≠ aⁿ x ∈ N, then aⁿ ∈ (N :_R M) or a^n-1 x ∈ N. We study the basic properties of this notion and establish several characterizations.

• Journal of the Korean School Mathematics Society
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• v.23 no.2
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• pp.179-201
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• 2020

The purpose of this study is to analyze tasks reflected in Korean and US textbooks according to the mathematical modeling perspectives, and then to compare the diversity of learning opportunities given to students from both countries. For this, we analyzed mathematical modeling tasks of textbooks based on three aspects: mathematical modeling process, data, and expression. Results are as follows. First, with respect to modeling process, Korean textbook provides a high percentage of the task at all stages of modeling than US textbook. Second, with respect to data, both countries' textbooks have the highest percentage of matching task. Korean textbooks have a large gap in data characteristics by textbook. Third, with respect to expression, both countries' textbooks have the highest percentage of text and picture. Korean textbooks have a large gap in the type of expression than US textbooks, and some textbooks have no other expression except for text and picture. Fourth, tasks were analyzed by integrating the three features. The three features were not combined in various ways. It is necessary to diversify the integration of the three features.

• IE interfaces
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• v.25 no.3
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• pp.300-308
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• 2012

For convenient business process modeling we propose a mathematical approach to obtain appropriate process structures. In this paper, we define business process structural constraints, on which basis, using Social Network Analysis (SNA), we analyze the frequency of handover occurrences among performers in social network. We here present, therefrom, a new, mathematical approach to business process modeling that proceeds by identifying the social relations among activities.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.1
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• pp.70-76
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• 2002

Unmanned vehicles have to decide their velocities suitable for the paths which should be generated by the vehicles themselves, based on the kinematic and dynamic aspects of vehicles. For this purpose, this paper is to propose a mathematical modeling of tuning trace for the cornering of an unmanned vehicle by using normal-tangent coordinates as well as extracting the characteristics of behavior for car drivers in cornering. In the proposed modeling, the limitations of velocity can be determined based on the knowledge that the handling of drivers means the control of radius of curvature. The proposed modeling can reduce computational load and generate turning angles and velocities suitable for the cornering of unmanned vehicles.

• Journal of Electrical Engineering and Technology
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• v.7 no.6
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• pp.845-851
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• 2012

Power system loads have a significant impact on a system. Although it is difficult to precisely describe loads in a mathematical model, accurately modeling them is important for a system analysis. The traditional load modeling method is based on the load components of a bus. Recently, the load modeling method based on measurements from a system has been introduced and developed by researchers. The two major components of a load modeling problem are determining the mathematical model for the target system and estimating the parameters of the determined model. We use the composite load model, which has both static and dynamic load characteristics. The ZIP model and the induction motor model are used for the static and dynamic load models, respectively. In this work, we propose the measurement-based parameter estimation method for the composite load model. The test system and related measurements are obtained using transient security assessment tool(TSAT) simulation program and PSS/E. The parameter estimation is then verified using these measurements. Cases are tested and verified using the sample system and its related measurements.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.4_1
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• pp.513-519
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• 2022

In this paper, we describe performances of P-PD controllers in the quadrotor system with steady-state error compensation by adding a corrective term to the system input. A decentralized control system using P-PD controllers was successfully implemented on a quadrotor platform. We also presented the results of a mathematical modeling analysis for control the quadrotor and experimental results for each response performance according to the heading reference value in accordance with the mathematical modeling and P-PD controller design. A control experiment with the real system was implemented for the test platform, and the results were evaluated and compared.

• Honam Mathematical Journal
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• v.36 no.1
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• pp.131-139
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• 2014

We present a theoretical study that assesses the persistence of obesity. The basic reproductive number for the model is computed, and its sensitivity on some parameter values is explored. This may be of interest to public health authorities.

• Research in Mathematical Education
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• v.1 no.1
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• pp.87-94
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• 1997

"In computer-assisted learning (CAL), small group problem-solving instruction is efficient. CAL should shift the focus of school mathematics toward goals for problem solving and mathematical modeling. For the shift, the roles and responsibilities for teachers are very important in CAL" (Heid et al. 1990).

• Korean Management Science Review
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• v.11 no.1
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• pp.59-72
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• 1994

In this paper we examine potentials of a spreadsheet program, one of the most widly available software system, as a mathematical optimization modeling tool. For an illustrative example, a shortest path problem is modeled on Lotus-123 for practical use and an implementational framework and a general guide to the spreadsheet modeling of network analysis is provided.