• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.821-826
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• 2001

Out of all metal-cutting processes, the hole-making process is the most widely used. It is estimated to be more than 30% of the total metal-cutting process. It is therefore desirable to monitor and detect drill wear during the hole-drilling process. One important aspect in controlling the drilling process is monitoring drill wear status. Accordingly, this paper deals with Basic system and Online system. Basic system comprised of spindle rotational speed, feed rates, thrust, torque and flank wear measured tool microscope. Online system comprised of spindle rotational speed, feed rates, AE signal, flank wear area measured computer vision. On-line monitoring system does not need to stop the process to inspect drill wear. Backpropagation neural networks (BPNs) were used for on-line detection of drill wear. This paper deals with an on-line drill wear monitoring system to fit the detection of the abnormal tool state.

• 소성∙가공
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• 제16권1호
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• pp.54-60
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• 2007

Optimum injection molding condition for a box mold was searched by the Response Surface Analysis(RSA) with the aid of process monitoring system(PMS). Process variables on the control panel of the injection molding machine such as barrel temperatures, screw speed profile, holding pressures, etc. cannot guarantee the uniformity of the material variables directly related with the state of the product in the mold cavity. In order to make sure the state of the resin in the cavity, pressures and temperatures in the cavity, runner and nozzle were monitored in the experiment with the PMS. To accomplish the consistency of the molding process, dependent variables such as the switchover point and holding time were searched with the PMS. With a proper objective function about deflection of the box-type product, the optimum injection molding condition was obtained.

• 한국지능시스템학회논문지
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• 제18권6호
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• pp.737-745
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• 2008

최근 공정 및 계측기술이 발전함에 따라 밀링, 그라인딩, 브로칭 등 공정작업의 온라인 모니터링에 대한 관심이 높아지고 있다. 온라인 모니터링 시스템은 공구의 마모나 파손 등과 같은 공정변화를 가급적 조기에 발견함으로써 설비를 보호하고 불필요한 비용의 발생을 억제하는 데 그 목적을 두고 있다 본 논문에서는 온라인 공정관측 데이터가 프로파일로 주어질 때 웨이블릿변환을 이용한 $T^2$-검정과 신경회로망의 모니터링 성능에 대해 고찰한다. 2006년 Axinte가 제시한 절삭력 데이터를 이용하여 수치실험을 수행한 결과, 웨이블릿기반 $T^2$는 양호한 검출력을 나타냈지만 그 검사특성은 자기상관에 매우 민감하게 반응하였다. 반면, 자기상관의 존재 하에서도 신경회로망은 $T^2$-검정에 비해 매우 안정적인 검사특성을 갖는 것으로 나타났다. 이는 웨이블릿기반 $T^2$-검정에 노이즈분석을 위한 적응적인 요소가 필요하다는 점을 시사한다

• 한국정밀공학회지
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• 제17권12호
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• pp.94-100
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• 2000

This paper presents a methodology for In-Process monitoring of tool wear by using ultrasonic sensor in turning operation. An integrated single ultrasonic transducer operation at a frequency of 10MHz is placed in contact with the insert tip. The change in amount of the reflected energy from the nose and flank of the tool can be related to the level of tool wear and the mechanical integrity of the tool. As the results, the tool wear monitoring system based on the ultrasonic pulse-echo method was proposed, it is useful to determine a tool life and tool change time.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.41-44
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• 2002

The Semiconductor Industrial are developed after 1940. It was called “Rice of Industrial”. It needs great effect in Electronics. It was developed highly in recent several years with semiconductor manufacturing equipments. Semiconductor manufacturing devices are developed “In-line” type in the first stage. But It was non-effective in modem many type process. Because this reason, Cluster type manufacturing equipments are proposed. Cluster have ability of many-type-process and effective-scheduling by circular type process chamber In this paper. we propose a real-time 3D monitoring and simulation of this semiconductor manufacturing equipments. By proposed monitoring method, we have capability real visual maintanance & virtual simulation. This effective visual 3D monitoring could apply another dangerous environment in entire industrial.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1069-1074
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• 2008

Tool condition monitoring (TCM) is crucial for improvement of productivity in manufacturing process. However, TCM techniques have not been applied to monitor tool failure in an industrial gear shaving application. Therefore, this work studied a statistical TCM method for monitoring gear shaving tool condition. The method modeled the shaving process using beta probability distribution in order to extract the effective features. Modeling includes rectifying for converting a bi-modal distribution into a unimodal distribution, estimating parameters of beta probability distribution based on method of moments. The usefulness of features obtained from the proposed method was evaluated and discussed.

• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1191-1200
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• 2008

Recently classroom monitoring is becoming important since the lecture is being held in the classroom and academic institutions are interested in the quality assurance. Some institutions have adopted ISO 9000 systems and constructed monitoring system through measurement, analysis and improvement. In this study quality assurance problems in academic institutions and the requirements of ISO 9001:2000 will be briefly discussed. Next we will investigate how to monitor the lecture in the classroom(in-class) using statistical process control techniques such as control charts. Then case study will be given to illustrate the technique to use appropriate statistics. Finally how to monitor the learning process during in-class and after-class will be proposed.

• Smart Structures and Systems
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• 제14권2호
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• pp.129-144
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• 2014

In this paper, a fuzzy inference system and an analytical hierarchy process-based online evaluation technique is developed to monitor the condition of the 32-km Donghai Bridge in Shanghai. The system has 478 sensors distributed along eight segments selected from the whole bridge. An online evaluation subsystem is realized, which uses raw data and extracted features or indices to give a set of hierarchically organized condition evaluations. The thresholds of each index were set to an initial value obtained from a structure damage and performance evolution analysis of the bridge. After one year of baseline monitoring, the initial threshold system was updated from the collected data. The results show that the techniques described are valid and reliable. The online method fulfills long-term infrastructure health monitoring requirements for the Donghai Bridge.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.250-252
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• 2002

The goals of environmental monitoring are to locate and quantify the significant contamination, estimate the fate and transport, estimate the potential exposure and risks to humans and the environment, and track the performance of various remedial technologies. In this study, ceramic gas sensor system is proposed to enhance the effectiveness of soil vapor extraction (SVE) process by monitoring the effluent gas. SVE is a technique that is widely used to remediate unsaturated soils contaminated with volatile organic contaminants. The sensor response for benzene, toluene, and xylene, the representative effluent gas compositions of SVE process, was evaluated using the proposed sensor system. As a result, it was verified that the response of sensor was increased or decreased very sensitively according to the change of the effluent gas concentration. Besides, the sensor could detect the difference over a wide range of concentration and it was more sensitive in order of xylene, toluene, and benzene. It is expected that this VOC analysis method results in field monitoring costs saying and appropriate immediate action for process control. More detailed experiments are being conducted in our research group.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.101-104
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• 1995

A acoustic emission (AE) sensor has been used to monitor tool were during milling process. The relation between tool wear and AE RMS (Root mean Square) signal was investigated experimentally. A avaliable monitoring index for monitoring toolwear was newly extracted form AE RMS. And on-line monitoring program was developed. The proposed monitoring system has verified experimentally by roughing end milling titanium alloy with TIN coated HSS tool.