• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.1
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• pp.55-63
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• 2019

This paper develops an algorithm to determine the batch size of the batch process in real time for improving production and efficient control of production system with multiple processes and batch processes. It is so important to find the batch size of the batch process, because the variability arising from the batch process in the production system affects the capacity of the production. Specifically, batch size could change system efficiency such as throughput, WIP (Work In Process) in production system, batch formation time and so on. In order to improve the system variability and productivity, real time batch size determined by considering the preparation time and batch formation time according to the number of operation of the batch process. The purpose of the study is to control the WIP by applying CONWIP production system method in the production line and implements an algorithm for a real time batch size decision in a batch process that requires long work preparation time and affects system efficiency. In order to verify the efficiency of the developed algorithm that determine the batch size in a real time, an existed production system with fixed the batch size will be implemented first and determines that batch size in real time considering WIP in queue and average lead time in the current system. To comparing the efficiency of a system with a fixed batch size and a system that determines a batch size in real time, the results are analyzed using three evaluation indexes of lead time, throughput, and average WIP of the queue.

• ETRI Journal
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• v.29 no.3
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• pp.270-280
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• 2007

In Linux, real-time tasks are supported by separating real-time task priorities from non-real-time task priorities. However, this separation of priority ranges may not be effective when real-time tasks make the system calls that are taken care of by the kernel threads. Thus, Linux is considered a soft real-time system. Moreover, kernel threads are configured to have static priorities for throughputs. The static assignment of priorities to kernel threads causes trouble for real-time tasks when real-time tasks require kernel threads to be invoked to handle the system calls because kernel threads do not discriminate between real-time and non-real-time tasks. We present a dynamic kernel thread scheduling mechanism with weighted average priority inheritance protocol (PIP), a variation of the PIP. The scheduling algorithm assigns proper priorities to kernel threads at runtime by monitoring the activities of user-level real-time tasks. Experimental results show that the algorithms can greatly improve the unexpected execution latency of real-time tasks.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.10
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• pp.21-30
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• 1994

We discussed the Distributed Control System's design on preface and analyzed time of the real-time communication by using designed system. The DCS proposed in this thesis was implemented to network file system having recovery advantage and shared memory method to access file system of a Remote Station with ease. Also, this system minimized the network delay-time by using the real-time VME147 board. In implemented DCS, the performance analysis of real-time process of a Remote Station was done to get the total time for reak-tune communication from a Remote Station to the Central Station after terminating of process. For the analysis of system performance, we experiented by three steps. Firstly, we measuredthe processing the of LOOP function that real-time CPU convertes to-2,500~10.000 values from the input data of the Analog Interface Card. Secondly, we measured the processing time of the LOGIC function and the LOOP function. Lastly, we measured total processing time for communication from a Remote Station to the Centrol Station.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.4
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• pp.233-239
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• 2015

This paper describes a method that is integrated trace for real-time virtualization environment. This method has solved the problem that the performance trace may not be able to analyze integrated method between heterogeneous operating systems which is consists of real-time operating systems and general-purpose operating system. In order to solve this problem, we have attempted to reuse the performance analysis function in general-purpose operating system, thereby real-time operating systems can be analyzed along with general-operating system. Furthermore, we have implemented a prototype based on ARM Cortex-A15 dual-core processor. By using this integrated trace method, real-time system developers can be improved productivity and reliability of results on real-time virtualization environment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2322-2327
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• 2009

Uncertainty of power system operation increases due to complexity and facilities diversification in the power system. Therefore the importance of SCADA(Supervisory Control and Data Acquisition) system which obtain and manage the actual data in real-time is very important. Accordingly in the studies of power system analysis, the efforts to include real-time power system analysis in simulation and applications are made in many ways. The real-time communication characteristics of SCADA system is considered so as to develop the power system analysis program that matches actual system conditions. The observation and management of SCADA system is realized by Intouch which is mainly used for factory automation and PSS/E(Power System Simulator for Engineers) provides real time system data. SQL DB and Python language is used for real-time communication between the softwares. It is very comfortable to use the various functions in Intouch WindowMaker.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.425-428
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• 2003

Real time monitoring of object position is very important in Customs Free Zone like Incheon Airport and Incheon Harbor because all logistics must be controled spatially for effective management. Real time positioning system using GPS(Global Positioning System) is apt for the monitoring of logistics. In this study, we aims to develope real time monitoring system for logistics using GPS.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1181-1184
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• 2005

In this paper, we proposed small scale real-time operating system for embedded system. Real-time system is characterized by the severe consequences that result if logical as well as timing correctness properties of system are not met. On real-time system, real-time operating system allows real-time applications to be designed and expanded easily. Functions can be added without requiring major changes to the software. We design small scale real-time operating system for preemptive kernel, and design kernel component such as multitasking, scheduler, task priority, semaphore, inter-task communication, clock tick timer, ISR(Interrupt Service Routine) mechanism has low interrupt latency.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.3
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• pp.260-267
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• 2013

A combat system for navy's battleship is a system of systems who supports naval indigenous operations by integrating and inter-operating many different kind of weapon and non-weapon systems, which has characteristics of large-scale complex computing system. This paper considers a characteristics of naval combat system which has been developed by domestic technology and suggests a way to improve future naval combat system in terms of computing architecture by applying commercial real-time operating system technologies. This paper also provides an evaluation criteria for combat system adaptability of real-time operating systems.

• Journal of Multimedia Information System
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• v.1 no.2
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• pp.95-100
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• 2014

Variable message signs (VMS) have the different sizes and a specific type according to the city scene and it has to be displayed by different message on the display panel in real-time. And VMS manufacturers must produce the different products in order to give a customized product to each order. In addition that, they should test and check the correct operation to each VMS product using the different message frame. That is very time and workers consuming and VMS emulator with an automatic variable message generator system is necessary. Also, the automatic message generator system is needed to real-time scheduling in order to display the message on the VMS panel like real world. In this paper, we design and implement the VMS emulator embedded the automatic message frame generator system with real-time scheduling which can set several parameters easily on the windows dialog.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.4
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• pp.320-326
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• 2000

The real-time simulator of a pneumatic actuation system that is composed of differential PWM signal generator, charge solenoid valve, discharge solenoid valve, actuator, load, and rotational potentiometer is developed using a DSP board and a PC. The simulator receives the control signals from the external controller through the A/D converter, updates the state and output variables of the Pneumatic actuation system responding to the input signals every sampling time, and sends out the output signals through the D/A converter in real time. The user can observe the displacements, velocities, pressures, and mass flows representing the operation of pneumatic actuation system through the PC monitor in real time. Also the user can see the moving images between the pistons and rotating arm realistically in real time. The accuracy of the real-time simulator is verified by the good agreement of the real-time simulation results and the experimental results of the pneumatic actuation system.