• Journal of the Korea Society of Computer and Information
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• v.15 no.4
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• pp.99-106
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• 2010

In this paper, we propose an industrial fluid monitoring system which performs the flow control function and monitors fluid pressure transmitted from MFC(Mass Flow Controller) unit. This system consists of MFC unit, channel device, and monitoring management software. MFC unit transmits the measured data of the fluid pressure to the channel device which would provide the input/output interface between management software, monitoring and MFC unit. The monitoring and management software control and analyze by monitoring real time measurements of fluid pressure from each channel of MFC unit. This software can process 20 channels and 0.1 monitoring cycle which gives 200 data measurement per second (i.e., 720,000 data/hour). At this time, the storage space increases in proportion to the rise of input data. This growth of data and storage space makes loss of data access efficiency. Therefore, it demands the implementation by sensing scheme of change scope and data, which can effectively manage the data.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.234-242
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• 2002

In this research, a transmission control unit was developed for a wheel loader on the basis of 16-bit microcontroller system. The TCU has the basic functions which include shifting control algorithm, actuation of six proportional solenoid valves, signal conditioning for four speed sensors, remote data monitoring capability with RF-module and duty cycle identification system which could identify the duty cycles from PWM signals. In order to design the control system, the overall transmission structure of the wheel loader was investigated and its characteristics of shifting were analyzed in advance. For the purpose of identifying the existing control algorithm and acquire some information about the shifting performance, the shifting experiments were performed for various shifting conditions with the conventional TCU. From the previous work on the conventional TCU, the shifting scheme was designed with the open-loop control which is based on the experimental data only to verify the feasibility of the developing TCU's shilling capability. The experimental results show comparable shifting characteristics to that of conventional TCU though the tests were performed at restricted shilling conditions. Hence, we could have the confidence for the development of the wheel loader automatic transmission TCU and its shifting quality could be improved with the adoption of appropriate feedback control scheme.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.47
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• pp.211-218
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• 1998

In start-up process control applications it may be necessary to limit the sample size to one measurement. A control chart for individual measurements is used whenever it is desirable to examine each individual value from the process immediately. A possible option would be to use an exponential weighted moving(EWM), using modifying statistics with individual measurement, chart for monitoring the process center, and using a moving range (MR) chart for monitoring process variability. In this paper it is shown that there is scheme in using the EWM procedure based on average run length. An expression for the ARL is given in terms of an integral equation, approximated using numerical quadrature. In this case, where it is reasonable to assume normality and negligible autocorrelation in the observations, provide graphs that simplify the design of EWM-MR chart and taking method of exponential smoothing constant(λ) and constant(K) are suggested. The charts suggested above evaluate using the conditional probability.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.5
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• pp.481-486
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• 2007

Wireless Sensor Network(WSNs) consists of small sensor nodes with sensing, computation, and wireless communication capabilities. The large number of sensor nodes in a WSN means that there will often be some nodes which give erroneous sensor data owing to several reasons such as power shortage and transmission error. Generally, these sensor data are gathered by a sink node to monitor and diagnose the current environment. Therefore, this can make it difficult to get an effective monitoring and diagnosis. In this paper, to overcome the aforementioned problems, intelligent sensor data validation method based on PCA(Principle Component Analysis) is utilized. Furthermore, a practical implementation using embedded system is given to show the feasibility of the proposed scheme.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.136-139
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• 2000

Controller refinement scheme to improve the performance of a conventional system automatically in frequency domain is proposed. The controller automatic tuning method features using experimental frequency responses of the conventional closed-loop system, the conventional controller, and the improved closed-Imp system; instead of poorly modeled plant due to non-linearities and disturbances. The improved closed-loop system characteristics is automatically acquired by the conventional closed-loop system characteristics and the proposed performance index in system bandwidth. And the proper controller is realized by least squares approximation in frequency domain. To testify the usefulness of the approach, experimental results of robot path-tracking control applied with various controllers is used, and then is analyzed with respect to a equivalent proportional controller. Experimental results and analytic results are well-matched.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1662-1664
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• 2007

As the logistic environment of digital contents is rapidly changing, the protection of the digital rights for digital content has been recognized as one of critical issues. Digital Right Management(DRM) has taken much interest Internet Service Provider(ISP), authors and publishers of digital content as an interested approach to create a trusted environment for access and use of digital resources. This paper propose an interested digital rights protection scheme using license agent to address problems facing contemporary DRM approached : static digital rights management, and limited application to on-line environment. We introduce a dynamic mission control technology to realize dynamic digital rights management. And we incorporate license agent to on- and off-line monitoring and tracking. The proposed system prevent illegal access and use by using PKI security method, real time action monitoring for user, data security for itself.

• Journal of Korea Multimedia Society
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• v.25 no.8
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• pp.1085-1096
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• 2022

The manufacturing industry is continuously pursuing advanced technology and smartization as it converges with innovative technology. Improvement of manufacturing productivity is achieved by monitoring, analyzing, and controlling the facilities and processes of the manufacturing site in real time through a network. In this paper, we proposed a new OPC-UA based digital twin model for smart factory facilities. A testbed system for USB flash drive packaging facility was implemented based on the proposed digital twin model and OPC-UA data communication scheme. Through OPC-UA based digital twin model, equipment and process status information is transmitted and received from PLC to monitoring and control 3D digital models and physical models in real time. The usefulness of the developed digital twin testbed system was evaluated through usability test.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.817-819
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• 2012

This paper propose an interested digital rights protection scheme to address problems facing contemporary DRM approached : static digital rights management, and limited application to on-line environment. We introduce a dynamic mission control technology to realize dynamic digital rights management. And we incorporate license agent to on- and off-line monitoring and tracking. The proposed system prevent illegal access and use by using PKI security method, real time action monitoring for user, data security for itself.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.215-218
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• 2004

The pseudolites are ground-based transmitters that can be configured to emit GPS-like signals with the purpose of enhancing the GPS by providing increased accuracy, integrity, and availability. Although the use of the pseudolites offers many potentially significant benefits, a number of technical issues must also be addressed. One is the pseudolite signal power level which is related with near-far problem, and other issues include deployment requirements, signal data rate, signal integrity monitoring, and user antenna location and sensitivity. In order to solve the near-far problem, the frequency offset or the pulsing schemes is implemented in most the pseudolites. However, in the case of the previous pulsing scheme with the fixed code pattern, the near-far problem still remains. This paper aims to design a sequential pulsing scheme to avoid the near-far problem. A pulse mode pseudolite has less interference than the continuous mode.

• IE interfaces
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• v.12 no.2
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• pp.254-265
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• 1999

This study presents a ready-to-use production planning and control (PP&C) system for the plastic extrusion industry of this country. From the view point of production management, the problems of the industry which are composed of small to midium size manufactures can be summarized as i) poor field data gathering ii) absence of systematic factory management. This study first attempts to devise a simple but useful field monitoring system. Then it presents a PP&C scheme that utilizes the special characteristics of plastic extrusion factory. Various algorithms for the scheme are devised. The resulting system is now realized and ready to implement.