• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
• /
• pp.1432-1435
• /
• 1996

This paper obtains maximum allowable delay bounds for stability of network-based control systems and presents a network scheduling method which makes the network-induced delay be less than the maximum allowable delay bound. The maximum allowable delay bounds are obtained using the Lyapunov theorem. Using the network scheduling method, the bandwidth of a network can be allocated to each node and the sampling period of each sensor and controller can be determined. The presented method can handle three kinds of data (periodic, real-time asynchronous, and non real-time asynchronous data) and guarantee real-time transmissions of real-time synchronous data and periodic data, and possible transmissions of non real-time asynchronous data. The proposed method is shown to be useful by examples in two types of network protocols such as the token control and the central control.

• Journal of Power Electronics
• /
• 제9권5호
• /
• pp.800-808
• /
• 2009

This paper presents a practical method of pressure control for a hydraulic oil-pump system using an SR (Switched Reluctance) drive. For a 6Mpa grade hydraulic oil-pump, a 2.6kW SR drive is developed. In order to get high performance pressure dynamics in actual applications, a data based PID control scheme is proposed. The look-up table from a pre-measured data base produces an approximate current reference based on motor speed and oil-pressure. A PID controller can compensate for the pressure error. With the combination of the two references, the proposed control scheme can achieve fast dynamics and stable operation. Furthermore, a suitable current controller considering the nonlinear characteristics of an SRM (Switched Reluctance Motor) and practical test methods for data measuring are presented. The proposed control scheme is verified by experimental tests.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제53권10호
• /
• pp.678-689
• /
• 2004

The major concern of networked control system is network uncertainties such as time delay and data loss. Because these uncertainties may degrade the performance of networked control system and destabilize the entire system. Therefore, the performance and the stability variation of networked control system due to network uncertainties must be considered first in designing networked control system. In particular, the stability analysis of networked control system is most important issue since time delay and data loss can make the overall systems unstable. In this paper, we present a new stability analysis method of networked control system with time delay and data loss, which is impossible in previous works. The proposed method can determine maximum time delay and allowable transmission rate that preserve stability performance of networked control system. The results of the simulation validate effectiveness of our stability analysis method.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제13권3호
• /
• pp.1523-1545
• /
• 2019

Cloud computing is now a widespread and economical option when data owners need to outsource or share their data. Designing secure and efficient data access control mechanism is one of the most challenging issues in cloud storage service. Anonymous broadcast encryption is a promising solution for its advantages in the respects of computation cost and communication overload. We bring forward an efficient anonymous identity-based broadcast encryption construction combined its application to the data access control mechanism in cloud storage service. The lengths for public parameters, user private key and ciphertext in the proposed scheme are all constant. Compared with the existing schemes, in terms of encrypting and decrypting computation cost, the construction of our scheme is more efficient. Furthermore, the proposed scheme is proved to achieve adaptive security against chosen-ciphertext attack adversaries in the standard model. Therefore, the proposed scheme is feasible for the system of data access control in cloud storage service.

• 제어로봇시스템학회논문지
• /
• 제18권10호
• /
• pp.912-920
• /
• 2012

In this paper, we propose a new and cost-effective RCP (Rapid Control Prototyping) system based on Matlab/Simulink and a DAQ (Data Acquisition) unit with the high speed USB communication interface. The proposed RCP system has a feature that a computer on which Simulink is running acts as a realtime controller and a DAQ unit performs data acquisition, transmission of the data to and from a computer, and the application of control data received from the computer. For its implementation, we develop 10 communication blocks each of which is constructed by using S-function. In order to increase the data communication speed and thus to reduce the sampling period of the overall control system, we propose to use a batch transfer strategy through the USB interface. The proposed RCP system has several advantages over existing methods such as good maintainability, portability due to the USB interface, low cost, and no necessity for C-code generation even though it can only be applied to control systems with moderate sampling rates. It is expected that the proposed RCP system can be useful in teaching control-related topics to undergraduate and graduate students.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2002년도 ICCAS
• /
• pp.54.1-54
• /
• 2002

1. Introduction 2. Related Work 3. Secure Data Transmission on web-based monitoring and control System 3.1 Requirement facts with the Security for the Secure Data Transmission 3.2 Architecture for the Secure Data Transmission 4. Conclusions and Further Research

• Toxicological Research
• /
• 제17권2호
• /
• pp.83-90
• /
• 2001

The background control data were compiled from rat developmental toxicity studies con-ducted at Toxicology Research Center, KRICT during the 1993-1999 period. These data were assembled in order to provide background in formation for the maternal and fetal data collected in 13 developmental toxicity studies using Sprague-Dawley rats. A total of 325 mated females were used in these studies during the seven-year period and overall pregnancy rate of these females was 93.8%. The present background control data included body weights, food consumption, hematological values, and organ weights of pregnant females, caesarean section data, and fetal examination data. These data can be used not only as a historical database for the meaningful interpretation of data from reproductive and developmental toxicity studies, but also as a contribution to biological characterization oj Sprague-Dawley rats.

• Journal of the Korean Data and Information Science Society
• /
• 제13권2호
• /
• pp.147-156
• /
• 2002

In this paper, we propose EWMA control charts using the life time data for the system with the constant failure rate, which were drawn from the fixed sampling interval without replacement(with replacement), and investigate the power of detection of EWMA by comparing ARL of EWMA control charts with one of Shewhart control charts.

• 산업경영시스템학회지
• /
• 제12권19호
• /
• pp.89-98
• /
• 1989

This research addresses the most sophisticated level of complexity of current electronic data processing(EDP) technology realtime, distributed data base(DDB) system. The major objective is to develop guidelines for the control and audit of these sophisticated system, since the control and audit philosophies, control features, and audit techniques applicable to traditional EDP systems are no longer fully appropriate for, or relevant to, these stat-of-art systems. An attempt is made to develop an internally consistent audit and control Conceptual Framework summarizing and integrating the material developed in this research, which then leads into the analysis of the control and audit model.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
• /
• pp.203-206
• /
• 1996

The purpose of this paper is to find how to determine the parameters of the basic control system design such as hinge moment coefficients and to display the controllability of the ChangCong-91. Since the estimation from the flight test of real aircraft is the most reliable, we performed the flight test of ChangGong-91 to get the various parameters such as velocity, height, control force, control surface deflection, 3 axis acceleration, 3 axis angular rate, pitch angle, angle of attack temperature and so on. We recorded the flight test data in VHS tapes and stored them to personal computer using A/D(analog to digital) converter. Flight test was done in various conditions, and the acquired data was processed with parameter identification method such as least square method. These data will be utilized for the development of Autopilot System design and Control Loading System design.