• 대한예방의학회:학술대회논문집
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• 2002.10a
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• pp.334-335
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• 2002

• Journal of the Korean Society for Precision Engineering
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• v.29 no.4
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• pp.367-372
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• 2012

The biggest factors that lower the machining accuracy are thermal deformation and chatter vibration. In this article, we introduce the study case of technology that can automatically compensate the errors of these factors of a machine during processing on the machine tool's CNC(Computerized Numerical Controller) in real time. This study is related to the detection and compensation of thermal deformation and chatter vibration that can compensate for faster and produce processed goods with more precision by autonomous compensation. In addition, this study is related to the active control of vibration during machining, monitoring of cutting force and auto recognition of machining axes origin. Thus, we attempt to introduce the related contents of the development we have made in this article.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.1009-1021
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• 1999

This paper describes the design principles and structure of a prototype system for collaborative authoring over a wide area network. The system includes extensive support for commenting and comment review, facilities for document space navigation, and tools for controlling and monitoring work group activity, including document locking and activity recording. The operational prototype provides a testbed for the examination of human computer interaction, group interaction, group support, document structures, and the problem and the history of efforts to address it.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11a
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• pp.77-80
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• 2003

본 논문은 웹 기반의 원격 보수유지 시스템을 구현하기 위한 첫 단계의 일부로서 원격 모니터링을 위한 웹 기반 기술 구축에 관한 것이다. 원격 작업장에 있는 정밀 기계 장비(CNC)를 대상으로 하여 작업장이 아닌 장소에서도 온도, 진동, 소음, 영상 데이터 등을 모니터하고 또한 장비의 상태를 진단할 수 있는 시스템 구축에 대한 것이다. 원격 사용자는 인터넷을 통해 어디에서나 생산 현장에 있는 로칼 서버에 접속하여 해당 장비를 모니터 및 상태 진단이 가능한 시스템을 구현하였다.

• Tunnel and Underground Space
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• v.6 no.4
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• pp.287-297
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• 1996

Input data play an important role in numerical analyses. However, it is difficult to obtain appropriate data for many reasons. In order to overcome those difficulties, an automatic MPBX(Multi-Position Borehole Extensometer) monitoring system is developed. This system can be applied to the analyses of measured data which include evaluation of the stabiliyt, efficiency of construction and the validity of numerical analyses. At first, the MPBX among field measurement tools is considered in this study. Also, 3-dimension finite element analyses are carried out to verify the influence of geological conditions and excavation sequence on the MPBX displacement. The effect of geological conditons on the displacement can be estimated qualitatively qualitavely from the measured data by plotting displacement vs. depth.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.515-517
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• 2004

Although sustainable development of a city should in theory be based on updated spatial information like land cover/use changes, in practice there are no effective tools to get such information. However the development of satellite and sensor technologies has increased the supply of high resolution satellite data, allowing cost-effective, multi-temporal monitoring. Especially KOMPSAT-1(KOrea Multi-Purpose SATellite) acquired a large number of images of the whole Korean peninsula and covering some large cities a number of times. In this study land-use patterns and trends of Daejeon from the year 2000 to the year 2003 will be considered using land use maps which are generated by manual interpretation of multi-temporal KOMPSAT EOC imagery and to show the possibility of using high resolution satellite remote sensing data for urban analysis.

• Tribology and Lubricants
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• v.13 no.4
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• pp.47-52
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• 1997

Friction torques, electrical contact resistances and bearing temperatures were measured on high speed angular contact ball beatings for the spindle of machine tools. The test bearings ran with oil-air lubrication at the thrust loads from 320 N to 1920 N and at the rotational speed of up to 12000 rpm. Electrical contact resistances between balls and races were measured to evaluate the formation of the lubricant film in the contact area. The test results with sufficient lubrication showed that the variations of friction torques were sensitive to the thrust loads and the rotational speeds, and that the friction torques were higher than those with insufficient lubrication. With insufficient lubrication and high thrust loads, the collapse of the lubricant film was detected even at a high rotational speed. It was concluded that these high speed beatings to run in condition of fluid lubrication should require monitoring not only the temperature increase of the bearing but also the lubricant film formation in contact areas resulting from the change in the applied load and the lubricant amount.

• Smart Structures and Systems
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• v.13 no.6
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• pp.959-974
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• 2014

Hand-Arm Vibration Syndrome (HAVS) is a group of diseases caused by exposure of the hands to vibration while operating the hand held power tools such as road breaker, drilling machine, demolition hammer in construction works. In this paper, area-changed capacitive micro-accelerometer is designed to measure the vibration exposure on worker's hand when operating a drilling machine on various blocks such as clay block, paver block and solid cement block. The design process includes mathematical modelling of micro-accelerometer and simulations are done using INTELLISUITE 8.6. Experimental results are taken for various blocks surfaces using conventional and micro-accelerometer. Comparisons show that usage of area-changed micro-accelerometer for Hand-arm vibration monitoring provides better sensitivity, which in turn reduces the risk of HAVS in workers.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1123-1126
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• 2005

This paper introduces the key features of NCS (Network based Control System), which is quite a new concept in the industrial automation market. Two control systems "DCS" and "PLC" have been recognized as control systems used for process and factory automation during the past decades. However, the market requires more complex functionality, such as monitoring and operation, alarm handling and notification from remote locations using the Web or e-mail. Besides enhancing functionality, interoperability between each device and system is highly required since network and engineering tools provided by many vendors do not cooperate with each others, so that lots of conversion, reconfiguration and reprogramming are required when expanding systems. NCS can meet this requirement, installing leading-edged IT technology using international standards for network and engineering environment. NCS, which is a harmony of web functionality, networkability and a reliable control function, enables information integration and responding to the market's requirements with agility and high reliability.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8059-8065
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• 2016

Nasopharyngeal carcinoma (NPC) is a common tumor in southern China and south-eastern Asia. Effective strategies for the prevention or screening of NPC are limited. Exploring effective biomarkers for the early diagnosis and prognosis of NPC continues to be a rigorous challenge. Evidence is accumulating that DNA methylation alterations are involved in the initiation and progression of NPC. Over the past few decades, aberrant DNA methylation in single or multiple tumor suppressor genes (TSGs) in various biologic samples have been described in NPC, which potentially represents useful biomarkers. Recently, large-scale DNA methylation analysis by genome-wide methylation platform provides a new way to identify candidate DNA methylated markers of NPC. This review summarizes the published research on the diagnostic and prognostic potential biomarkers of DNA methylation for NPC and discusses the current knowledge on DNA methylation as a biomarker for the early detection and monitoring of progression of NPC.