• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.124-126
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• 2003

인스펙션은 소프트웨어 개발 프로세스에서 작성된 산출물에 대한 품질 보증 활동의 하나이다. 산출물에서 결함을 찾을 수 있는 가장 정형적. 효율적, 경제적인 방범이 인스펙션이라고 알려져 있다［1］. 인스펙션은 테스트 전에 결함을 검출하여 소프트웨어의 품질을 높이고, 테스트 후에 발견되는 결함을 줄임으로써 유지보수에 드는 시간과 비용을 절감시킨다. 본 논문에서는 인스펙션 중에서도 코드에 관련된 인스펙션을 연구하고자 한다. 현재의 개발 패러다임은 CBD(Component Based Development)로 가고 있다. 소프트웨어 개발이 많아지고 규모가 커짐에 따라 재사용성이 뛰어난 컴포넌트로 개발들이 이루어지고 수행되고 있다. 컴포넌트를 개발할 때에도 품질은 중요한 문제이기 때문에 연구가 필요하다. 기존의 패러다임에서는 품질을 위한 인스펙션에 관한 많은 연구들이 있었고 진행되었다. 하지만 CBD에서의 품질을 위한 인스펙션에 관한 연구는 많이 이루어지지 않고 있다. 본 논문에서는 이러한 문제점을 알아보고 EJB(Enterprise Java Beans) 컴포넌트에 대한 코드 인스펙션을 통해 결함을 줄이고 품질을 향상시키기 위한 컴포넌트 인스펙션 프로세스(Component Inspection Process)를 실시한다. 프로세스의 각 단계에서는 UML 다이어그램. EJB의 콜백 메소드 흐름 다이어그램, 그리고 체크리스트를 사용한다. CIP 사용함으로써 CBD에서의 많은 결함을 줄이고 품질을 향상시킬 수 있게 될 것이다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.6
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• pp.71-77
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• 1999

Monitoring of Cutting tool wear is a critical issue in automated machining system and has been extensively studied for many years. An austempered ductile iron(ADI) exhibits the excellent mechanical properties and the wear resistance. ADI has generally the poor machinability due to the characteristic. This paper presents the in-process detection of flank wear of cutting tools using the acoustic emission sensor and the digital oscilloscope. The amplitude level of AE signal(AErms) is mainly affected by cutting speed and it is proportional to cutting speed. There have been the relationship of direct proportion between the amplitude level of AE signals and the flank wear width of cutting tool. The flank wear with corresponding to the tool life is successfully detected with the monitor-ing system used in this study.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.3
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• pp.55-60
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• 2001

A technique on the detection of tool wear based on the ultrasonic pulse-echo method in turning process is presented. The change in amount of the reflected energy from nose and flank of the tool can be related to the level of tool wear and mechanical integrity of the tool, that is, there exists an excellent correlation between the ultrasonic measurement and tool wear. As a results, the method is very useful for the prediction of cutting tool life and the determination of tool exchange period.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.115-115
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• 2009

아연코팅강판의 레이저 용접시 발생하는 용접결함은 이미 널리 알려진 이슈이다. 그러나 대부분의 연구가 박판을 중심으로 이루어지고 있어서, 후판을 중심으로 한 조선산업에서의 아연코팅 강판의 연구는 매우 미진한 실정이다. 이중 후판 아연코팅강판의 결함검출연구는 그 연구가 거의 전무한 실정으로, 본 연구에서는 후판 아연코팅강판의 레이저 겹치기용접시의 결함검출을 중심으로 실험을 실시하였다. 실험은 Fig. 1에서와 같이 광신호와 음향신호의 RMS를 통하여 raw signal에서 잘 나타나지 않았던 신호의 패턴을 확인함으로써 실제 신호와 비드와를 대응을 가능하게 하였다. 또한 결함 발생시의 RMS값을 건전한 상태와 비교분석하여 실제 결함검출의 가능성도 확인할 수 있었다.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.11
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• pp.25-31
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• 1996

In this paper, three different types of commercial tools -P20, NC123K and ceramic- have been used to cut austempered ductile iron(ADI). In the austempered condition the materials are hard, strong and difficult to machine. Thus, we selected a optimum tool material among three different types of used tools in machining of austempered ductile iron. It was used acoustic emission (AE) to know cutting characteristic for selected tool and investigate characteristic of AE signal according to cutting condition and relationship between AE signal and flank wear land of the ceramic tool. The obtained results are as follows ; (1) The ceramic tool among three different types of tools is the best in machining austempered ductile iron. (2) In case of ceramic tool, the amplitude level of AE signal(AErms) is mainly affected by cutting condition and it is proportional to cutting speed. (3)There have been the relationship of direct proportion between the amplitude level of AE signal and flank wear land of the tool. (4) It was observed that the value of AErms was only affected by cutting speed. Therefore it is possible to in-process detec- tion of ceraic tool's wear in case the initial value of AErms at each cutting speed decided.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.852-856
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• 1997

This paper describes a ultrasonic method for direct measurement of tool wear in turning operations. An integrated single ultrasonic transducer operating at a frequency of 10MHz is placed in contact with the insert tip. The change in amount of the reflected energy form the nose and flanks of the tool can be related to the level of tool wear and thr mechanical integrity of the tool. As a results, a correlation exists between the untrasonic measurement and tool wear and that it is tool dependent.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.3
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• pp.117-121
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• 1992

There have been many studies on chatter vibration in machining but there seems to be no regulations to decide the commencing point of chatter objectively. The development of an objective method which can estimate and detect chatter commencement is very much in need for automatic manufacturing systems, dynamic performance tests for machine tools, and so on. In this study, an approach for in-process monitoring and for deciding commencing point of the chatter vibration using the frequency band-energy method was proposed. From this method, in-process monitoring system for detection the chatter vibration was developed, and investigated its practical possibility. As a result, it is shown by experiments that the chatter vibtation can be detected accurately. Since the changing pattern of the signal energy in certain frequency band during chattering is seldom affected by the variation of cutting conditions, if adequate pre-measures are taken, this method can be widely used in most machining processes.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.3
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• pp.73-81
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• 1991

There have been many studies on chatter vibration in machining but there seems to be no regulations to decide the commencing point of chatter objectively. The development of an objective method which can estimate and detect chatter commencement is very much in need for automatic manufacturing systems, dynamic performance tests for machine tools, so on. In this study, therefore, the estimation and the in-process detection of chatter have been experi- mentally investigated for the turning process. As a result, the commencing point of chatter can be decided from the behavior of the maximum amplitude of the dynamic component of cutting force, where the maximum amplitude is suddenly increasing with the chatter commencement. Then the commencing point of chatter can be estimated practically by this method before the occurrence of excessive vibration. Also, it is possible to detect the occurence of chatter vibration through the in-process measurement, by monitoring the maximum amplitude of the dynamic component of cutting force.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.10
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• pp.50-56
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• 1995

Chatter Vibration is an unwanted phenomenon in metal cutting and it always affects surface finish, tool life, machine life and the productivity of machining process. The real-time detection of the chatter vibration is is necessarily required to automation system. In this study, we constructed the multi-sensing system using Tool Dynamometer, Accelermeter and AE sensor. Especially, Acoustic Emission(AE) generated during turning was investigated the possibility for real-time detection of chatter vibration. Turning experiments were performed using carbide insert tip under realistic cutting conditions and tapered workpiece of SM45C. Consquently, the real-time detection using multi-sensing system can be used for Inprocess monitoring of chatter vibration.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.344-348
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• 1992

This paper presents a new methodology for on-line tool breakage detection by sensor fusion concept of an acoustic-emission (AE) sensor. A built-in piezoelectric force sensor was used to measure cutting force instead of a tool dynamometer to preserve the machine tool dynamics. he sensor was inserted in the tool turret housing of an NC lathe. FEM analysis was carried out to locate the most sensitive position for the sensor. When a tool is broken, the explicit changes of signals' pattern take place. A burst-type AE signal increases abruptly. Followingly, a cutting force drops significantly. Therefore a burst of AE signal is used as a triggering signal to inspect the following cutting force. Significant drop of cutting force is utilized to detect tool breakage. The algorithm was implemented in a DSP board for in-process tool breakage detection. The proposed monitoring system was capable of a good applicable tool breakage detection.