• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.419-419
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• 2000

This paper describes a requirement analysis for automotive engine design using a computer aided systems engineering tool RDD-100. Because the engine is a complex system with many subsystems, there are many needs of stakeholder throughout the life-cycle of the engine. The originating requirements have been derived from the needs and decomposed into leaf-node requirements with the tool. Many requirement errors have been detected during the decomposition process and resolved by modifying the requirements. Inconsistency problems have been also resolved with the tool, Analysis of engine requirements using RDD-100 brings clarity to engine design early in the development process.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.208-216
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• 2020

With the spread of smart manufacturing, one of the key topics of the 4th industrial revolution, manufacturing systems are moving beyond automation to smartization using artificial intelligence. In particular, in the existing automatic machining, a number of machining defects and non-processing occur due to tool damage or severe wear, resulting in a decrease in productivity and an increase in quality defect rates. Therefore, it is important to measure and predict tool life. In this paper, ν-ASVR (ν-Asymmetric Support Vector Regression), which considers the asymmetry of ⲉ-tube and the asymmetry of penalties for data out of ⲉ-tube, was proposed and applied to the tool wear prediction problem. In the case of tool wear, if the predicted value of the tool wear amount is smaller than the actual value (under-estimation), product failure may occur due to tool damage or wear. Therefore, it can be said that ν-ASVR is suitable because it is necessary to overestimate. It is shown that even when adjusting the asymmetry of ⲉ-tube and the asymmetry of penalties for data out of ⲉ-tube, the ratio of the number of data belonging to ⲉ-tube can be adjusted with ν. Experiments are performed to compare the accuracy of various kernel functions such as linear, polynomial. RBF (radialbasis function), sigmoid, The best result isthe use of the RBF kernel in all cases

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.853-856
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• 1993

In this paper, we describe a chaos simulator as a developing tool for applications of chaos engineering. This simulator is composed of three modules, such as generation module of chaotic signals by deterministic rules, determination module whether observed time series is chaos or not, and nonlinear system identification module by self generating Neuro Fuzzy Model.

• Industrial Engineering and Management Systems
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• v.14 no.2
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• pp.175-182
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• 2015

The recent manufacturing industry in Japan has found it difficult to transfer skills from trained workers to inexperienced workers because the former ages and then retires. This is a particular problem for lathe process, as this operation requires explicit and tacit knowledge, and defining the skills clearly in a manual is difficult. This study aims to develop a training system for lathe operation by using a simulator; this includes formulas that help define the relationship between the speed of tool feed and cutting sound/shape of chips which were proposed in the preceding study. The developed training system is verified the effectiveness.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.200-207
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• 2003

Presented in this paper is a new fast and robust algorithm generating NC tool path for 2D pockets with islands. The input shapes are composed of line segments and cricular arcs. The algorithm has two steps: creation of successive offset loops and linking the loops to tool path. A modified pair-wise technique is developed in order to speed up and stabilize the offset process, and the linking algorithm is focused on minimizing tool retractions and preventing thin-wall rotting The proposed algorithm has been implemented In C++ and some illustrative examples are presented to show the practical strength of the algorithm.

• Journal of the Korean Society of Systems Engineering
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• v.16 no.1
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• pp.18-24
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• 2020

The KSLV-II project with high difficulties technically requires thorough technical management during long-term life cycle more than 10 years for launching into space. The TRL is a quantitative indicator developed by NASA widely used all over the world to measure technology maturity of a system development objectively and consistently. The TRL is also used to make sure technology level and to establish a future direction in the KSLV-II project. The TRL has advantage enable to identify a technology level through quantitative indicators. However, it takes a lot of efforts such as trials and errors, time and cost to apply it to the project considering the project environments, and stakeholder needs. These include not only to establish TRL management plan from ideal, conceptual and abstractive standards/guidelines such as NASA's, but also to construct TRL management environment enable to apply and manage harmoniously. In the KSLV-II project, it is required to figure out current technology level and technology development trend in the future, to access conveniently, to share related data in real time, and to update periodically for the comprehensive TRL management. From the reason above, the TRL management environment was built by using the systems engineering tool already has been used for other system management data such as requirements in the project. It also could be accomplished a practical management basis of systems engineering from the traceability among system management data including TRL. In this paper, case study results are introduced to manage the TRL for the space launch vehicle using the systems engineering tool in the KSLV-II project.

• Journal of the Korean Society of Systems Engineering
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• v.7 no.1
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• pp.53-56
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• 2011

Configuration management plays a key role in systems engineering process for any project from earlier stage of development. It consists of five major activities, ie., configuration management planing, configuration identification, configuration control, configuration status accounting and configuration verification and audit, and is essential to control system design, development and operation throughout entire life cycle of the system development. And it is directly associated with other part of systems engineering management process, ie., technical data management which provides traceability of important decisions and changes during development. In this paper, we describe how to apply CASE(Computer-aided Systems Engineering) tool-Cradle for the configuration management to achieve effectiveness of Technical Management process.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.30
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• pp.167-175
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• 1994

Generally, queueing networks, networks, chains and simulation techniques are among the most widely used evaluation tools to study computer systems, manufacturing systems etc. But, these tools have some assumptions and difficulties. So, this thesis presents a method for manufacturing system using Petri nets. Petri nets are a graphical and mathmatical modeling tool and are promising tool for describing and studying systems that are characterized as being concurrent asychronous, dynamic, distributed and parrallel. It designs Petri net model for processing time of manufacturing system And it applied to a job shop system composed of 8 machines and 4 different job types.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.208.1-212
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• 1997

In this paper, a computer simulation tool for evaluting integrated engine/transmission control system using MATLAB/SIMULINK is investigated. Since a modular programming technique based upon the object-oriented programming is used in the paper, the simulation tool developed reduces the burden of model complexity by dividing engine/transmission systems into hierarchical subsystem. Furthermore, it also provides user -friendly, reusable, and upgradable characteristics of the system. The simulation tool could be useful to the automotive engineers who frequently change models and develop new systems in the automotive powertrain and control area.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.10
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• pp.836-843
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• 2003

The automatic train control (ATC) system development project for the Automated Guideway Transit (AGT) system has high technical risk because the system is unmanned train control system using wireless technology which was unprecedented in train control industry of Korea. To overcome the technical risk during concept design phase of the ATC system development project, the integrated product team(IPT) carried out a reverse and reengineering process using a systems engineering design model. The generic systems engineering process is incorporated in the both reverse and reengineering process. As a result of the systems engineering effort, the IPT has built top layer systems engineering design model of the ATC subsystem. The purpose of this paper is to deliver the reverse and reengineering process which was used to develop the systems engineering design model of ATC system using a computer aided systems engineering tool. This study also shows that the model based reverse and reengineering process can reduce the technical risk by identifying the differences of requirement, functional and physical architecture between a reference system and a target system.