• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2166-2171
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• 2007

In this paper, we proposed a Sequential Download System(SDS) to provide high steaming QoS in p2p network. SDS is able to receive a media file simultaneously from multiple source peer by download manager and deal with unexpected leave of source peer. Also It can provide stable streaming services with minimum buffering delay and manage request of other peer by memory map in process of downloading.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1354-1360
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• 2013

In transmission system, reclosing scheme is very useful method to improve continuity of power supply and reliability of system. Especially, high speed reclosing which is used generally in transmission systems has a benefit improving transient stability. However, the reclosing can jeopardize the stability under the condition having high difference of voltage phase angle between both ends. Thus, this paper proposes optimal sequential reclosing scheme to improve transient stability due to reclosing operation. The optimal sequential reclosing is that each phase is closed sequentially considering transient energy. In this paper, 345kV and 154kV transmission system is modeled using EMTP (ElectroMagnetic Transient Program) to verify the performance and effectiveness of optimal sequential reclosing on transient stability. Also, Integral Square Error(ISE) method is used to assess the transient stability.

• Journal of Ocean Engineering and Technology
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• v.15 no.4
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• pp.108-114
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• 2001

Petri nets have been introduced as a powerful analyzing and design tool for the discrete systems such as sequential control systems. However, one of the important problems in its applications is that the model can be analyzed hardly when we deal with large scale systems because of increase of the number of Petri net components. To overcome this problem, some methods for dividing or reducing of Petri net have been suggested. In this paper, an approach for hierarchical expression of Petri net based on Sequential function Chart(SFC) and Bottom Up oriented Mehodology(BUM) is proposed. Especially, some definitions and rules are defined in order to divide and compose sub Petri nets. A measuring tank system will be described as a typical kind of discrete systems and modeled by some sub Petri nets based on the SFC and BUM by the proposed method in this paper.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.26-31
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• 2001

Petri nets(PN) have been introduced as a poweful analyzing and design tool for the discrete systems such as sequential control systems. However, one of the important problems in its applications is that the model can not be analyzed easily when we deal with large scale systems because of increase of the number of components of the systems. To overcome this problem, some methods for dividing or reducing of PN have been suggested. In this paper, an approach for hierarchical expression of PN based on Sequential Function Chart(SFC) and Bottom Up oriented Mehodology(BUM) is proposed. Especially, some definition and rules are defined in order to divide and compose sub PN. A measuring tank system will be described as a typical kind of discrete systems and modeled by some sub PN based on the SFC and BUM by the proposed method in this paper.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.6
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• pp.379-387
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• 1986

The architecture and design of a highperformance general-purpose microprogrammable sequential controller are presented. Conventional sequential controllrs are limited by speed, memory requirement, flexibility and programming ease. The proposed controller solves those limitations. it has a fixed hardware and is microprogrammable throutgh firmware modification. It is especially designed for complex high-speed sequential controllers requiring large I/O capabilities, such as industrial process ocntroller or power electronic conversion controller.

• Journal of information and communication convergence engineering
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• v.9 no.2
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• pp.224-229
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• 2011

Cellular Automata is a discrete dynamical system that can be completely described in terms of local relation. For any given image, the system can save its features as well as increase or decrease the brightness of it locally through consideration of optimized transition in succession. These transitions in succession satisfy the function "Lyapunov" and have sequential movements. This study suggests the way of noise reduction for each image with the use of the Sequential Cellular Automata system. The mentioned transition in succession gives stable results with high-convergence performance to random noises and PSNR (Peak Signal-to-Noise Ratio) using histograms and MSE (Mean Square Error) for verification of effectiveness.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.2
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• pp.202-210
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• 2011

The fabrication method of aspheric lens is changed from machining to press molding so as to improve the productivity. In the case of the press molding method, the temperature control of the molding die is most important, because the temperature of each molding die determines the quality of lens. But any practical method for direct measuring of the lens temperature and the die internal temperature is yet unknown. Besides, in the case of the press molding system in which the heating and pressing and cooing of a die is done at separate work stations, the lens productivity of the system for small lens is yet too low. The paper shows an improved structure of convective sequential system, the lens productivity of which is three times as many as the conventional convective system. To know the die internal temperature, numerical results are given using ANSYS. A new convective sequential system is developed and tested. Finally, the Taguchi method is applied in order to optimize the setting conditions of individual work station of the system.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.2
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• pp.292-300
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• 1987

This paper, realizes the design of the sequential controller of a reinforced warehousing-delivery and unmanned transportation system for automated warehouse system. The system is composed of ware housing delivery adn transportation system using two unmanned vehicles with hierachical structure. It is described by GRAFCET and realized by programmed logic with microprocessor. Being described by GRAFCET, the system is able to divide it into subsystems and to synchronize them. Defining the concept of program module, one can easily program the system with the microprocessor instruction language.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.5023-5038
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• 2017

Big data is an emerging technology which deals with wide range of data sets with sizes beyond the ability to work with software tools which is commonly used for processing of data. When we consider a huge network, we have to process a large amount of network information generated, which consists of both normal and abnormal activity logs in large volume of multi-dimensional data. Intrusion Detection System (IDS) is required to monitor the network and to detect the malicious nodes and activities in the network. Massive amount of data makes it difficult to detect threats and attacks. Sequential Pattern mining may be used to identify the patterns of malicious activities which have been an emerging popular trend due to the consideration of quantities, profits and time orders of item. Here we propose a sequential pattern mining algorithm with fuzzy logic feature selection and fuzzy weighted support for huge volumes of network logs to be implemented in Apache Hadoop YARN, which solves the problem of speed and time constraints. Fuzzy logic feature selection selects important features from the feature set. Fuzzy weighted supports provide weights to the inputs and avoid multiple scans. In our simulation we use the attack log from NS-2 MANET environment and compare the proposed algorithm with the state-of-the-art sequential Pattern Mining algorithm, SPADE and Support Vector Machine with Hadoop environment.

• Journal of Digital Contents Society
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• v.5 no.1
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• pp.73-78
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• 2004

In this paper we implemented a field-sequential stereoscopic endoscope system that can generate stereoscopic images with different perspective depth using LCD shutter. The stereoscopic image is generated form stereoscopic adapter that has LCD shutter. We have compared the stereoscopic depth of a field-sequential stereoscopic endoscope system with that of the conventional endoscope system. And the implemented system is verified by evaluation the field-sequential stereoscopic image on a Monitor. This system will be use to medical instruments in time.