• 한국정밀공학회지
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• 제22권6호
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• pp.135-143
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• 2005

The shoes process management monitoring system for supporting SCM is developed in this study. This system consists of a monitoring program, a conveyer system, a pneumatic unit, a controller, an USB camera, and a server and a client computer. To operate the developed system easily, the monitoring program using LabVIEW in the Windows environment is developed. This program consists of 5 modules: production management, inventory control, media management, defective management, and communication management. The developed system has several advantages: reduced time for managing process work, decreased labor costs, effective operation, and continuous work without an operator. Nowadays advanced manufacturing companies are trying to find a way to check the performance of their production equipments and plants from remote sites. Thus, to manage the developed system from remote sites, communication network is constructed. In order to evaluate the performance of the monitoring system, experiments were performed. The experimental results showed that the developed system provided a reliable performance and a stable communication.

• 정보처리학회논문지D
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• 제13D권4호
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• pp.613-618
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• 2006

임베디드 소프트웨어의 적용범위가 넓어짐에 따라 소프트웨어의 개발시간을 줄이기 위한 많은 개발도구가 개발되었다. 하지만, 기존 도구들은 특정 플랫폼 적용을 목적으로 개발되었기 때문에 적용 가능한 범위가 제한된다. 이러한 문제 해결을 위하여 다양한 통신 환경을 지원함으로써 플랫폼 제약을 제거한 임베디드 모니터링 시스템을 개발하였다. 임베디드 모니터링 시스템은 코드 인라인 기법을 통하여 모니터링 과정을 진행한다. 하지만, 코드 인라인 기법은 모니터링 센서의 수행에 대한 부하문제를 가지고 있기 때문에 모니터링 센서의 최적화에 대한 고려가 필요하다. 이에 본 논문에서는 모니터링 과정 초기화 방안과 모니터링 센서 최적화를 위한 비트마스킹 기법을 제안한다. 개발된 임베디드 모니터링 시스템은 임베디드 시스템을 사용하는 모든 분야에 적용가능하다.

• 제어로봇시스템학회논문지
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• 제6권12호
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• pp.1113-1119
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• 2000

To operate a process plant safely and economically, process monitoring is very important. Process monitoring is the task to identify the state of the system from sensor data. Process monitoring includes data acquisition, regulatory control, data reconciliation, fault detection, etc. This research focuses on the data recon-ciliation using scale-space filtering and fault detection using functional-link associative neural networks. Scale-space filtering is a multi-resolution signal analysis method. Scale-space filtering can extract highest frequency factors(noise) effectively. But scale-space filtering has too large calculation costs and end effect problems. This research reduces the calculation cost of scale-space filtering by applying the minimum limit to the gaussian kernel. And the end-effect that occurs at the end of the signal of the scale-space filtering is overcome by using extrapolation related with the clustering change detection method. Nonlinear principal component analysis methods using neural network have been reviewed and the separately expanded functional-link associative neural network is proposed for chemical process monitoring. The separately expanded functional-link associative neural network has better learning capabilities, generalization abilities and short learning time than the exiting-neural networks. Separately expanded functional-link associative neural network can express a statistical model similar to real process by expanding the input data separately. Combining the proposed methods-modified scale-space filtering and fault detection method using the separately expanded functional-link associative neural network-a process monitoring system is proposed in this research. the usefulness of the proposed method is proven by its application a boiler water supply unit.

• 한국기계가공학회지
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• 제11권5호
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• pp.142-147
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• 2012

Machining tool conditions directly affect to quality of product and productivity of manufacturing. Many researches performed for tool condition monitoring in machining process to improve quality and productivity. Conventional methods use characteristics of signal for cutting force, motor current consumption, vibration of machine tools and machining sound. Recently, diameter of machining tool is become smaller for minimizing of mechanical parts. Tool condition monitoring using conventional methods are relatively difficult because micro machining using small diameter tool has low machining load and high cutting speed. These days, the direct monitoring for tool conditions using vision system is performed actively. But, vision system is affected by external conditions such as back ground of image and illumination. In this study, minimizing technology of external conditions using distribution analysis of image data are developed in micro machining using small diameter drill and tap. The image data is gathered from vision system. Several sets of experiment results are performed to verify the characteristics of the proposed machining technology.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.313-317
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• 1996

This work deals with description of gas purifing system to product high pure helium gas using low temperature absorption. The system controls temperature of heaters, open/close of solenoid valves and levels of liquid nitrogen to purify a raw gas and continuously products purified gas with perfoming alternatively purification and regeneration. We develop the monitoring and control program to monitor the gas purification process on real-time and control the process time with checking the impurities in purified gas. From the result of system operation, the developed monitoring and control system continuously products high pure helium gas with reducing impurities in raw gas to permitted limits(less than 0.01 ~ 0.05 ppm)

• International Journal of Precision Engineering and Manufacturing-Green Technology
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• 제5권5호
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• pp.571-581
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• 2018

In the present study, monitoring of elliptical vibration cutting process by utilizing internal data in the ultrasonic elliptical vibration device without external sensors such as a dynamometer and displacement sensor is investigated. The internal data utilized here is the change of excitation frequency, i.e. resonant frequency of the device, voltages applied to the piezoelectric actuators composing the device, and electric currents flowing through the actuators. These internal data change automatically in the elliptical vibration control system in order to keep a constant elliptical vibration against the change of the cutting process. Correlativity between the process and the internal data is described by using a vibration model of ultrasonic elliptical vibration cutting and verified by several experiments, i.e. planing and mirror surface finishing of hardened die steel carried out with single crystalline diamond tools. As a result, it is proved that it is possible to estimate the elements of elliptical vibration cutting process, e.g. tool wear and machining load, which are important for stable cutting in such precision machining.

• Structural Monitoring and Maintenance
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• 제10권3호
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• pp.261-281
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• 2023

Magnetic flux sensors are commonly used in monitoring the cable force, but the application of the sensors in large diameter non-closed Galfan cables, as those adopted in Yueqing Gymnasium which is located in Yueqing City, Zhejiang Province, China and is the largest span hybrid space structure in the world, is seldom done in engineering. Based on the construction of Yueqing Gymnasium, this paper studies the cable tension monitoring using the magnetic flux method across two stages, namely, the pre-calibration stage before the cable leaves the rigging factory and the field tension formation stage of the cable system. In the pre-calibration stage in the cable factory, a series of 1:1 full-scale comparative tests were carried out to study the feasibility and relability of this kind of monitoring method, and the influence on the monitoring results of charging and discharging voltage, sensor location, cable diameter and fitting method were also studied. Some meaningful conclusions were obtained. On this basis, the real-time cable tension monitoring system of the structure based on the magnetic flux method is established. During the construction process, the monitoring results of the cables are in good agreement with the data of the on-site pressure gauge.The work of this paper will provide a useful reference for cable force monitoring in the construction process of long-span spatial structures.

• 산업공학
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• 제24권1호
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• pp.8-14
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• 2011

Principal Component Analysis (PCA) reduces the dimensionality of the process by creating a new set of variables, Principal components (PCs), which attempt to reflect the true underlying process dimension. However, for highly nonlinear processes, this form of monitoring may not be efficient since the process dimensionality can't be represented by a small number of PCs. Examples include the process of semiconductors, pharmaceuticals and chemicals. Nonlinear correlated process variables can be reduced to a set of nonlinear principal components, through the application of Kernel Principal Component Analysis (KPCA). Support Vector Data Description (SVDD) which has roots in a supervised learning theory is a training algorithm based on structural risk minimization. Its control limit does not depend on the distribution, but adapts to the real data. So, in this paper proposes a non-linear process monitoring technique based on supervised learning methods and KPCA. Through simulated examples, it has been shown that the proposed monitoring chart is more effective than $T^2$ chart for nonlinear processes.

• 대한기계학회논문집A
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• 제34권10호
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• pp.1513-1519
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• 2010

최근 고품질 제품 생산을 위한 방법으로 센서를 이용한 사출공정모니터링 시스템이 적용되고 있다. 그러나 마이크로 금형, 광학용 금형 및 구조가 복잡한 금형에는 센서 설치가 어렵기 때문에, 공정 모니터링 시스템이 적용되기 어려운 단점이 있다. 본 연구에서는 금형과 사출성형기 노즐의 압력 을 측정하여 공정 모니터링 데이터의 정량적 지수를 정의하고, 성형품 중량에 대한 상관분석을 수행하여 노즐에 설치된 압력센서의 공정모니터링 적용성을 알아보았다. 또한 공정모니터링 데이터를 분석하여 다단사출속도, 보압 및 제한 사출 압력의 영향에 따른 사출성형기의 공정 제어 특성도 알아보았다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.781-788
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• 2003

It is an essential process to predict behaviors of ground and structure to seek economical efficiency and stability on the given environment. Predictions are conducted through analysis process of ground and structure. For these analyses, exact and quick acquisition of measuring data is required. But we face many difficulties in data acquisition stages due to the conditions of construction site. Therefore development of a powerful and effective monitoring system that can manage the integration of database and the implementation of measuring process in real time is strongly desired. This article shows an actual example of application of internet based monitoring system compared with the conventional monitoring system.