• Journal of the Institute of Convergence Signal Processing
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• v.12 no.2
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• pp.133-138
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• 2011

In IP-based wireless sensor networks (WSNs), it might be necessary to distribute application updates to the sensor nodes in order to fix bugs or add new functionality. However, physical access to nodes is in many cases extremely limited following deployment. Therefore, network reprogramming protocols have recently emerged as a way to distribute application updates without requiring physical access to sensor nodes. In order to solve the network reprogramming problem over the air interface, this thesis presents a new scheme for new update code propagation using fragmentation scheme and network coding. The proposed code propagation method roughly shows reduced performance improvement in terms of the number of data exchange compared with the previously proposed pipelining scheme. Further, It is shows enhanced reliability for update code propagation and reduced overhead in terms of the number of data exchange. As a result, we can efficiently perform the software update from the viewpoint of speed, energy, and network congestion when the proposed code propagation system is applied. In addition, the proposed system solves overhearing problems of network coding such as the loss of original messages and decoding error using the predefined message. Therefore, our system allows a software update system to exchange reliable data in wireless sensor networks.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.862-864
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• 2015

최근 몇 년 사이 FREAK, POODLE, HEARTBLEED, CRIME등등 TLS와 관련된 많은 취약점이 발생하였다. 이러한 취약점들은 해당 TLS버전을 사용하지 않거나 업데이트를 함으로서 예방할 수 있다. 하지만 오래된 서버를 사용하거나 낮은 버전의 TLS만을 지원하여 업데이트를 못하는 경우가 있고, 이러한 서버들은 취약점에 무방비상태로 노출되어있다. 그래서 이러한 서버들에게 TLS관련 취약점을 미리 알려주기 위해 Snort라는 툴을 사용하여 연구를 하였다.

• Journal of the Korea Society of Computer and Information
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• v.9 no.3
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• pp.171-175
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• 2004

This paper proposes a seamless handoff scheme that enables a mobile node to continue a session when moving to an overlapping area. During handoff due to the weakness of signaling, mobile node makes new Care-of Addresses using signals received from access router when MN reaches the edge of its area in addition to its current CoA, and it sends temporary binding update messages to Mobility Anchor Point which manage the area covering MN. MAP receives that binding update messages from MN, and temporarily stores new binding informations from them to its binding cache besides existing binding information for MN. This scheme ensures a seamlessly handoff using multicasting until MN enter a new access router area and sends a confirmed binding update message to MAP.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7B
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• pp.694-702
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• 2009

Geographical routing protocol, where nodes only need local information exchange to make routing decisions, is a very efficient routing scheme for wireless sensor networks in scalability. However, pure geographical routing does not take account of wireless link condition. If wireless link condition is not considered, when the routing table is updated, the nodes with bad link conditions are updated in the routing table and can be chosen as the next hop. This brings out the retransmissions because of received packet's errors. Also, because of these retransmissions, additional power is consumed. In this paper, we propose geographical routing scheme considering wireless link condition, where reliable data transmission is made and the consumed energy is minimized.

• Journal of KIISE:Information Networking
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• v.35 no.5
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• pp.395-401
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• 2008

In order to determine path(s) satisfied with bandwidth-guaranteed in the Internet, routers should have information on network topology and link state. The information is stored in Link State Database (LSDB) located in each router and managed. If link states information is changed, routers inform their neighbor of link state information changed by sending Link State Update (LSU) messages. However, there is trade-off between reflection of actual link state information on LSDB and cost of sending LSU messages. To find a bandwidth-guaranteed path effectively, it is important to decide whether LSU messages are sent or not for the change of link sate. In this paper, we propose a threshold-based LSU algorithm using statistic to effectively decide for sending LSU messages and evaluates its performance by intensive simulations. Simulation results show that the performance of proposed scheme is superior to the existing LSU schemes.

• Digital Contents
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• no.7 s.86
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• pp.18-29
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• 2000

하루가 다르게 새로운 바이러스가 발견되고 컴퓨터 사용자들은 늘 바이러스에 노출된 상태다. 새로운 바이러스가 발견될 때마다 백신프로그램도 계속 업데이트 되어야 한다. 기 발견된 바이러스를 토대로 바이러스 캘린더를 소개함으로써 안전한 PC이용에 도움이 되었으면 한다. 컴퓨터 바이러스는 월별로 활동하는 것과 특정일에 활동하는 것 등 다양하다. 또한 개인과 기업의 바이러스 예장 수칙을 소개한다.

• Journal of IKEEE
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• v.25 no.4
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• pp.762-765
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• 2021

In this paper, an automotive ECU (electronic control unit) with Kalman filter accelerator is designed and implemented. RISC-V is exploited as a processor core. Accelerator for Kalman filter matrix operation, CAN (controller area network) controller for in-vehicle network, and LIN (local interconnect network) controller are designed and embedded. Kalman filter operation consists of time update process and measurement update process. Current state variable and its error covariance are estimated in time update process. Final values are corrected from input measurement data and Kalman gain in measurement update process. Usually floating-point multiplication is exploited in software implementation, but fixed-point multiplier considering accuracy analysis is exploited in this paper to reduce hardware area. In 28nm silicon fabrication, its operating frequency, area, and gate counts are 100MHz, 0.37mm², and 760k gates, respectively.

• KSCI Review
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• v.14 no.2
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• pp.235-244
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• 2006

This paper attacked the unknown DoS which mixed a DoS attack, Worm and the Trojan horse which used IP Source Address Spoofing and Smurf through the SYN Flooding way that UDP, ICMP, Echo, TCP Syn packet operated. the applications that used TCP/UDP in VoIP service networks. Define necessity of a Dynamic Update Engine for a prevention, and measure Miss traffic at RT statistics of inbound and outbound parts in case of designs of an engine at IPS regarding an Self-learning module and a statistical attack spread. and design a logic engine module. Three engines judge attack grades (Attack Suspicious, Normal), and keep the most suitable filtering engine state through AND or OR algorithms at Footprint Lookup modules. A Real-Time Dynamic Engine and Filter updated protected VoIP service from DoS attacks, and strengthened Ubiquitous Security anger, and were turned out to be.

• Journal of the Korea Society of Computer and Information
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• v.11 no.6 s.44
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• pp.165-174
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• 2006

This paper attacked the unknown DoS which mixed a DoS attack, Worm and the Trojan horse which used IP Source Address Spoofing and Smurf through the SYN Flooding way that UDP, ICMP, Echo, TCP Syn packet operated, the applications that used TCP/UDP in VoIP service networks. Define necessity of a Dynamic Update Engine for a prevention, and measure Miss traffic at RT statistics of inbound and outbound parts in case of designs of an engine at IPS regarding an Self-learning module and a statistical attack spread, and design a logic engine module. Three engines judge attack grades (Attack, Suspicious, Normal), and keep the most suitable filtering engine state through AND or OR algorithms at Footprint Lookup modules. A Real-Time Dynamic Engine and Filter updated protected VoIP service from DoS attacks, and strengthened Ubiquitous Security anger, and were turned out to be.

• Journal of Broadcast Engineering
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• v.11 no.1 s.30
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• pp.66-79
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• 2006

As constant development of digital broadcasting and data broadcasting system, new technology will be introduced to digital broadcasting and new broadcasting service will be appeared. These services need to be changed and processed to suit each services and the software of the receiver need to be upgraded. Though, generally the digital broadcasting receivers are not getting updated once it's delivered to home for long time and it need to be done by hand or collected each one of them with trouble. Therefore this paper suggests a way to overcome these difficulties via broadcasting stream. This research is to describe how three modules-namely (1) Downloader, downloads new software from data carrousel stream, (2) Update Loader, installs the software received by downloader; and (3) Recoverer, recovers the former version of the software if some serious problem has been occurred during downloading and installing the software. This paper tries to realize the accommodation of terrestrial STB based on the new technique and service following ATSC A-97 agreement.