• International Journal of Computer Science & Network Security
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• v.21 no.11
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• pp.165-170
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• 2021

Discrete event systems interact with the external environment to decide which action plan is adequate. Some of these interactions are not predictable in the modelling phase and require consequently an adaptation of the system to the metamorphosed behavior of the environment. One of the challenging issues is to guarantee safety behavior when failures tend to derive the system from normal status. In this paper we propose a framework to combine diagnose technique with adaptive control to avoid unsafe sate an maintain the normal behavior as long as possible.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.671-678
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• 2009

Recently, there have been some researches in the equipment fault detection based on shock and vibration information. Most research of them is based on shock and vibration monitoring to determine the equipment fault or not. Different with engine fault detection based on shock and vibration information we focus on detection of engine for boat and system control. First, it use the duplicated-checking method for shock and vibration information to determine the engine fault or not. If there is a fault happened, we use the integral to determine the error engine shock wave width and detect the fault area. On the other hand, we use the engine trend analysis and standard of safety engine to implement the shock and vibration information database. Our simulation results show that the probability of engine fault determination is 98% and the probability of engine fault detection is 72%

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.405-410
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• 2016

Elevator industry is a field that is mechanical, electrical and electronic technology and constantly requires inspection and maintenance considering various applications and various types. Recently, various elevator control and monitoring technologies with IT are developing for elevators on land. But technologies with IT have been hardly done in marine elevator that is consistently assured safety and reliability of life cycle for its parts in poor environment. In this paper, we implemented embedded main controller, floor controller and car controller that meet the requirements and use NMEA network protocol by analyzing home and abroad integrated elevator operation and management systems. Especially, we secured reliability of maintenance by real-time fault diagnosis and control that was implemented with limit switch, gyro sensor, temperature/humidity/barometric pressure sensor and fire detection sensor thinking over the environmental conditions of terrestrial and marine elevator.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2192-2197
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• 2005

This paper describes how to diagnose SBR plant equipment using time-series data mining. It shows the equipment diagnostics based upon vibration signals that are acquired from each device for process control. Data transform techniques including two data preprocessing skills and data mining methods were employed in the data analysis. The proposed method is not only suitable for SBR equipment, but is also suitable for other industrial devices. The experimental results performed on a lab-scale SBR plant show a good equipment-management performance.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.11-16
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• 2003

The 3-level converter/inverter system is very efficient in the ac motor drives of high voltage and high power application. This paper proposed a simple method to diagnose faults using change of current vector pattern in space vector diagram when the faults occurrence in the 3-level inverter and a control method that can protect system from unbalance of the neutral point voltage according to faults. The validity of the proposed method is demonstrated by the simulation results.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.956-958
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• 1995

This paper presents the automatic construction of fuzzy rule-based systems for diagnosing the faults of complex systems. Generally, fuzzy systems work well when we can use expert's experience to articulate fuzzy IF-THEN rules and memberships for fuzzy sets. When we cannot do this, we should generate the fuzzy rules and membership functions for fuzzy sets directly from experimental data. In this paper, we propose a new method on how to extract fuzzy sets and fuzzy rules. We also introduce an efficient fine-tunning algorithm of the parameters of membership functions.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.307-312
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• 2020

This paper proposed intelligent motor control system that replaced smart motor devices, such as motor protection relays, smart circuit breakers and variable speed drives, with one integrated module to perform efficient motor control at industrial sites. The proposed intelligent motor control system provides easy monitoring of critical data for each motor or load connected to an intelligent motor control system over a CIP(Common Industrial Protocol)-based network, which enables accurate process control at all times, real-time access to fault information and records to simplify diagnosis and minimize equipment downtime.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.6
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• pp.57-69
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• 2001

Expert system is one of AI area. It simulates the human's way of thinking to give solutions of problem in many applications. Most expert system consists of many components such as inference engine, knowledge base, and so on. Especially the performance of expert system depend on the control of efficiency of inference engine. Inference engine has to get features; first, if possible to minimize restrictions when it constructed the knowledge base. second, it has to serve various kinds of inferencing methods. In this paper we propose knowledge scheme for representing domain knowledge in ease, knowledge implementation technique for inferencing, and integrated knowledge-base engine with blackboard and inference engine. And we describe a expert system prototype that implemented in this paper using proposed methods, it perform diagnose about heavy industrial device. The fault diagnosis system prototype has been studied in this paper will be practical foundation in the research area of knowledge based system.

• Nuclear Engineering and Technology
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• v.52 no.9
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• pp.1998-2008
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• 2020

Solenoid operated valves (SOV) play important roles in industrial process to control the flow of fluids. Solenoid valves can be found in so many industries as well as the nuclear plant. The ability to be able to detect the presence of faults and predicting the remaining useful life (RUL) of the SOV is important in maintenance planning and also prevent unexpected interruptions in the flow of process fluids. This paper proposes a fault diagnosis method for the alternating current (AC) powered SOV. Previous research work have been focused on direct current (DC) powered SOV where the current waveform or vibrations are monitored. There are many features hidden in the AC waveform that require further signal analysis. The analysis of the AC powered SOV waveform was done in the time and frequency domain. A total of sixteen features were obtained and these were used to classify the different operating modes of the SOV by applying a machine learning technique for classification. Also, a deep neural network (DNN) was developed for the prediction of RUL based on the failure modes of the SOV. The results of this paper can be used to improve on the condition based monitoring of the SOV.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.233-236
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• 1989

This paper deals with the expert system using network configuration and input information composed of protective relays and tripped circuit breakers. This system has knowlegebase independent on network dimension because network representation consists of the type of the matrix. Therefore, the knowlege of network representation is simplified, the space of knowlege is reduced, the addition of facts to the knowlege is easy and the expansion of facts is possible. In this paper, the network representation is defined to system matrix. This expert system based on the system matrix diagnoses normal, abnormal operations of protective devices as well as possible fault sections. The brach and bound search technique is used: breadth first technique mixed with depth first technique of primitive PROLOG search technique. This system will be used for real time operations. This expert system obtaines the solution using the pattern matching in working memory without no listing approach for rule control. This paper is written in PROLOG, the A.I. language.