• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.12
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• pp.115-121
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• 2008

The communication-based train control (CBTC) technology is a kind of railway signaling technologies and is to control the train operation through communication. A project adopting the CBTC technology is in progress and its object is to develop interoperable and interchangeable subsystems. Thus the purpose of this paper is on how to develop the required subsystems and integrate them successfully without sufficient design information at the system level. Accordingly this project shall require the integration and test at the system level. In order to do so, a top-level system specification shall be needed, which is not available in the current phase of the project. The main objective of the test and evaluation activities is to see whether the developed system meets the system specification. In this paper, we describe how the test and evaluation can be carried out based on the subsystems design specifications, considering the system architecture and the operation concept of the existing system as well.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.2
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• pp.126-130
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• 2006

Programmable Logic Controller(PLC) is the most widely utilized and plays an important role in industrial control system. Sequential Function Chart(SFC) is a graphic language which is suitable for describing a sequential control logic in discrete control system. We can design a distribute control construction and a hierarchical control construction in process control system described by SFC. In hierarchical control structure, we construct each subsystems to synchronize a synchronous signal between subsystems, and the command system gives and takes a synchronous signal with subsystems. Therefore, the system has a low memory efficiency and a low system performance. In this paper, we propose the method that improved the efficiency of memory in hierarchical control construction, and confirm its feasibility through an actual example.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.9
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• pp.81-87
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• 2009

In this paper, remote monitoring system for wind turbine site is developed. This system is a hierarchical reliable monitoring system connected by wireless communication channels between monitoring host computer and modular slave measuring subsystems. The design of this systems; the slave measuring subsystems is placed in meteorological tower and wind turbine, and the supervisory host computer is in the safety zone. The slave measuring subsystems signals are from a meteorological tower, wind turbine generator and tower. For monitoring and command function, the supervisory computer is implemented with a PC using graphic user interface. This system can be transferred the information among host computer and remote computers through the Ethernet. Consequently we can get reliability but economic system. The system has the concept of universality and modularity, so it is simple and easy to implement in wind turbine test sites.

• Coupled systems mechanics
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• v.12 no.1
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• pp.1-20
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• 2023

On the basis of the explicit time-domain method, an investigation is performed on the influence of the rotational stiffness and rotational damping of the vehicle body and front-rear bogies on the dynamic responses of the vehicle-bridge coupled systems. The equation of motion for the vehicle subsystem is derived employing rigid dynamical theories without considering the rotational stiffness and rotational damping of the vehicle body, as well as the front-rear bogies. The explicit expressions for the dynamic responses of the vehicle and bridge subsystems to contact forces are generated utilizing the explicit time-domain method. Due to the compact wheel-rail model, which reflects the compatibility requirement of the two subsystems, the explicit expression of the evolutionary statistical moment for the contact forces may be performed with relative ease. Then, the evolutionary statistical moments for the respective responses of the two subsystems can be determined. The numerical results indicate that the simplification of vehicle model has little effect on the responses of the bridge subsystem and the vehicle body, except for the responses of the rotational degrees of freedom for the vehicle subsystem, regardless of whether deterministic or random analyses are performed.

• The Bulletin of The Korean Astronomical Society
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• v.32 no.2
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• pp.58.1-58.1
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• 2007

• Journal of the Korean Society for information Management
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• v.11 no.1
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• pp.167-187
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• 1994

This project is to design and to implement an cornputenzed acquisition system by structured analysis technique for the Yomi university library. In result of desgmng, we added three subsystems, whlch are accession control, account, and print out system, to DOBIS/E acquisition system because we found that our DOBIS/E acquision system is able to use as we do ordenng and receiving in traditional process. DOBIS/E system and three added subsystems is closely related, and allow acquisition librarians to work more efficiently than before.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.325-328
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• 1997

In this paper the modeling and control of a twin roll strip caster is investigated. Mathematical models for the strip casting process are obtained by analyzing five critical areas such that the molten steel level in the pool, solidification process, roll separating force and torque, roll dynamics including hydraulic actuators, and roll drive system. A two-level control strategy is proposed. At lower level, three local subsystems are independently feedback-controlled by suitable local controllers which perform well to the behaviors of each subsystem. They are a variable structure control of the molten steel level in the pool, an adaptive predictive control of the roll gap which is directly related to the strip thickness, and an $H^{\infty}$ control of the roll drive system. At higher level, all reference signals to the lower level subsystems are generated by an optimal controller in the perspective of regulating the strip thickness and roll separating force. Simulations are provided..

• ETRI Journal
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• v.37 no.1
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• pp.175-185
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• 2015

This paper presents a system-of-systems (SoS) approach to the formal modeling of a cyber-physical system (CPS) for simulation-based analysis. The approach is based on a convergence technology for modeling and simulation of a highly complex system in which SoS modeling methodology, hybrid systems modeling theory, and simulation interoperation technology are merged. The methodology maps each constituent system of a CPS to a disparate model of either continuous or discrete types. The theory employs two formalisms for modeling of the two model types with formal specification of interfaces between them. Finally, the technology adapts a simulation bus called DEVS BUS whose protocol synchronizes time and exchange messages between subsystems simulation. Benefits of the approach include reusability of simulation models and environments, and simulation-based analysis of subsystems of a CPS in an inter-relational manner.

• Smart Structures and Systems
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• v.15 no.2
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• pp.375-393
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• 2015

In this study, local dynamic characteristics of mountable PZT interfaces are numerically analyzed to verify their feasibility on impedance monitoring of the prestress-loss in tendon anchorage subsystems. Firstly, a prestressed tendon-anchorage system with mountable PZT interfaces is described. Two types of mountable interfaces which are different in geometric and boundary conditions are designed for impedance monitoring in the tendon-anchorage subsystems. Secondly, laboratory experiments are performed to evaluate the impedance monitoring via the two mountable PZT interfaces placed on the tendon-anchorage under the variation of prestress forces. Impedance features such as frequency-shifts and root-mean-square-deviations are quantified for the two PZT interfaces. Finally, local dynamic characteristics of the two PZT interfaces are numerically analyzed to verify their performances on impedance monitoring at the tendon-anchorage system. For the two PZT interfaces, the relationships between structural parameters and local vibration responses are examined by modal sensitivity analyses.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.245-248
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• 1998

Until now, to solve the problem, the lack of memory at TDX-10A ESS (Electronic Switching System), we have extended only main memory of the systems. However, this method is useful for only Transitcall Processing Subsystems and, it is not an effective way that is able to apply to all Subsystems of ESS because of the financial aspect. In this paper, we will introduce a new method which uses Non-Resident Program. This method utilizes main memory more effectively. We will also analyze the effectiveness resulting from test of new method applied to TDX-10A ESS.