• Journal of the Korea Society of Computer and Information
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• v.26 no.10
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• pp.93-100
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• 2021

In this paper, the possibility of a UE (User Equipment) incarceration attack using RRCRejecet and RRCRelease in 5G SNPN (Standalone Non-Public Network) is analyzed based on the 3GPP standard document. First, the cell selection and reselection procedures of the UE are analyzed, and then the processing process of the false base station and the UE before and after transmission of RRCReject and RRCRelease is analyzed. As a result of the analysis, it is possible that the false base station that transmits a strong signal causes the victim UE to establish an RRC connection to the false base station itself. In addition, if the false base station transmits an RRCReject message without integrity protection in response to the victim UE's attempt to establish an RRC connection, it is determined that the victim UE can continue to stay in the RRC connection attempt process. On the other hand, it is determined that it is impossible to incarcerate the victim UE by inducing an attempt to establish an RRC connection to another false base station using RRCRelease.

• Journal of the Korea Society of Computer and Information
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• v.26 no.9
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• pp.81-88
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• 2021

In this paper, we analyze the possibility of deregistration attack in 5G SNPN (Standalone Non-Public Network) based on 3GPP standard document. In the deregistraion attack, the attacker pretends to be a UE that is normally registered with AMF (Access and Mobility Management Function) and attempts to establish a spoofed RRC (Radio Resource Control) connection, causing AMF to deregister the existing UE. The existing deregistration attack attempts a spoofed RRC connection to the AMF in which the UE is registered. In addition, this paper analyzes whether deregistration attack is possible even when an attacker attempts to establish a spoofed RRC connection to a new AMF that is different from the registered AMF. When the 5G mobile communication network system is implemented by faithfully complying with the 3GPP standard, it is determined that a deregistration attack of a UE is impossible.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.8
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• pp.71-80
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• 2007

In this study, an inspection system for valve seal of automotive parts using standalone vision has been developed and presented. The system is comprised of eight CCD cameras, and mechanism that loads the automotive parts to the system for the inspection. An image processing algorithm for detecting two different types of defects of valve seals are developed and the effectiveness of the algorithm is experimentally verified. Inspection process is completed in 0.7 second with acceptable accuracy condition. It is envisaged that this inspection system will have a wide application in the automotive part manufacturing industry in the future.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.9
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• pp.1239-1248
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• 2018

This paper proposes a fault tolerant and high efficiency operation algorithm for a 4 LEG DC/DC converter for a battery energy storage system(BESS) forming a main power source in a standalone DC micro grid. The BESS for the main power supply in the stand-alone DC micro-grid is required to operate at high speed according to fault tolerant control and load by operating at all times. Fault-tolerance control changes the short-circuit fault to an open-circuit fault by using a fuse in case of leg fault in 4 legs, and operates stably through phase shift control. In addition, considering the loss of the power semiconductor, the number of LEG operation is adjusted to operate at high efficiency in the full load region. In this paper, fault tolerant control and high efficiency operation algorithm of DC/DC converter for BESS in standalone DC micro grid is presented and it is proved through simulation and experiment.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.12
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• pp.1-9
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• 2013

A standalone LED lighting system in using solar energy has been used usually less than 70W of lighting power because of a troublesome installation and maintenance. In this system, as more and more LED lighting power increases, the capacity of photovoltaic panel does proportionally, and to improve the charging efficiency of solar energy, MPPT(Maximum Power Point Tracking) techniques is used frequently, but the solar tracker is not. In this paper, a solar tracker which traces the light of the sun in varying hour to hour is studied to apply to the standalone LED lighting system. This solar tracker consists of twin axis for tracing the azimuth and altitude respectively, and it has a robust structure with safe mode to stand a strong wind. As a result of analysis, generating efficiency of the traced type has improved on the fixed one 28.84% on average.

• Proceedings of the Korea Society for Simulation Conference
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• 2004.05a
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• pp.101-108
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• 2004

KEPRI has developed an Nuclear Steam Supply System(NSSS) thermal-hydraulics simulation program (called ARTS-KORI), based on the best-estimate system code, RETRAN, as a part of the development project for the KORI unit 1 Nuclear Power Plant Simulator. A number of code modifications, such as simplifications and removing of discontinuities of the physical correlations, were made in order to change the RETRAN code as an nuclear Steam Supply System thermal-hydraulics engine in the simulator. Some simplified models and a backup system were also developed. This paper briefly presents the results of non-integrated standalone test of ARTS-KORI.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.357-361
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• 2005

As flash technology is a widely used in Web pages, it tends to load a S/W flash player in mobile phones and PDAs to play flash contents on diverse H/W platforms currently. In this paper, we design and implement a linux-based standalone flash player which can be used in various fields like animation, game and advertizing. We also implement an web-based manager which user can effectively manage flash players anywhere.

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.297-303
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• 2009

Automatic Identification System (AIS) is a VHF radio broadcasting system where transmits packets of data via VHF data link. It enables vessels and coastal-based station that equipped with AIS equipment to send and receive useful information. This information can be help in situational awareness and provide a means to assist in collision avoidance. In addition, AIS can be use as Aid-To-Navigation, by providing the location and additional information on buoys and lights. Besides, it can also contain details information in meteorological status of a particular ship location. This paper presents the standalone AIS system that able to receive and report own ship location, meteorological data collection and broadcast safety related information if necessary. With the unique ship's MMSI number, all the information of that particular ship can be monitor by using AIS program written in C++ programming language.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.125-134
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• 2006

QFD(Quality Function Deployment) is a system for translating specific customer needs into detailed product requirements which are deployed throughout design, production, marketing and support operations. QFD is a team tool. However, most of commercial QFD softwares are standalone and therefore offer limited support for teamwork. In this paper, we developed a web-based QFD software to overcome many of the limitations that standalone systems suffer from. That is, this software was developed for synchronizing collaboration between team members distributed not only geographically but also over time. This software was developed by using Visual studio.NET and Microsoft COM+(CBD) technique and can be implemented on the web browser.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.72-75
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• 2009

In this paper, lithium-ion-polymer battery based standalone photovoltaic energy storage is presented. conventional system was difficult to choose hi-directional DC-DC converter because of unbalanced voltage of batteries. The other side, lithium-ion-polymer battery hardly contains unbalanced voltage between each batteries. And Lithium Polymer Battery is clean battery because is doesn't contain heavy metals such as Nickel, Cadmium. We analyzed validity of algorithms according to load pattern for the system through the simulation and experimental results.