• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.5
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• pp.160-168
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• 2011

As importance of the field of maintenance and management come to the fore because of collapses of the Seongsu bridge and the Sampoong department store, "Special Act for the Safety Control of Public Structures" was established in 1995 and the major maintenance and management system began taking effect "Detailed inspection and Precision safety diagnosis". However, a technical standard of "Detailed inspection and Precision safety diagnosis" was low because its history was not long, and also the results of research were not enough so anxiety for "Insufficient Detailed inspection and Precision safety diagnosis" was continuously left. While its evaluation system introduced in 2002, the ratio of "Insufficient Detailed inspection and Precision safety diagnosis" has been getting lower. However, according to the evaluation result after carrying out "Detailed inspection and Precision safety diagnosis" recently, it seems difficult to become lower for the ratio of "Insufficient Detailed inspection and Precision safety diagnosis" in future. Therefore, it is considered of questionary survey of the concerned organization and the mechanism side in connection with "Insufficient Detailed inspection and Precision safety diagnosis". So it is arranged the fundamental problems caused by an "Insufficient Detailed inspection and Precision safety diagnosis" that is to show the improving direction of the existing evaluation system in a based on this.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.37-38
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1319-1322
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• 2004

In this paper, a fault diagnosis system for ram in PHWR plant is developed. The developed diagnosis system can detect the ram stuck phenomena due to increased ball wear and damage in ball nut using discrete wavelet transform before the ram is stuck. The validity of developed diagnosis system is shown via experiments using ball nut characteristic test equipment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1249-1250
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• 2012

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.455-456
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• 2002

Wear is one of the main factors causing breakdown and fault of machine, so ferrography technique analyzing wear particles can be an effective way for condition monitoring and fault diagnosis. On the base of the forward multilayer neural network, a nodes self-deleting neural network model is provided in this paper. This network can itself deletes the nodes to optimize its construction. On the basis of the nodes self-deleting neural network, an intelligent ferrography diagnosis expert system (IFDES) for wear particles recognition and wear diagnosis is described. This intelligent expert system can automatically slim lip knowledge by learning from samples and realize basically the entirely automatic processing from wear particles recognition to wear diagnosis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.1005-1010
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• 2000

Internet service has widely used in office automation such as, manufacturing management purchase, and material resource. Nowadays, factory automation and shop floor control system including CAD/CAM department need a web based monitoring and diagnosis to achieve global collaboration and tole-service. This raper deal with design of web based remote monitoring and diagnosis system which concerned with open architecture controller for machine tool.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.643-646
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• 2000

As many industrial systems become more complex, it becomes extremely difficult to diagnose the cause of failures. This paper presents a failure diagnosis approach based on discrete event system theory. In particular, the approach is a hybrid of event-based and state-based ones leading to a simpler failure diagnoser with supervisory control capability. The design procedure is presented along with a pump-valve system as an example.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.575-576
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• 2006

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.183-192
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• 2022

Function and performance degradation in tunnel structure can cause road's function loss, proactive maintenance is needed to prevent the initial damage from progressing to intensified damage. Inspection and diagnosis are implemented in accordance with regulations, but it does not fully reflect maintenance processes such as inspection and diagnosis, planning rehabilitation and carrying out. It was carried out for 5,540 cases inspection and diagnosis result in 1,728 tunnels was analyzed to suggest rational maintenance plan in this study.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.233-238
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• 2000

CNC machine tool is assembled by central processor, PLC(Programmable Logic Controller), and actuator. The sequential control of machine generally controlled by a PLC. The main fault occured at PLC in 3 control parts. In LC faults, operational fault is charged over 70%. This paper describes diagnosis model and data processing for remote monitoring and diagnosis system in machine tools with open architecture controller. Two diagnostic models based on the ladder diagram. Logical Diagnosis Model(LDM), Sequential Diagnosis Model(SDM), are proposed. Data processing structure is proposed ST(Structured Text) based on IEC1131-3. The faults from CNC are received message form open architecture controller and faults from PLC are gathered by sequential data.. To do this, CNC and PLC's logical and sequential data is constructed database.