• IEMEK Journal of Embedded Systems and Applications
• /
• v.11 no.5
• /
• pp.259-265
• /
• 2016

In this paper, we present an architecture for the fault isolation by applying virtualization-based multi-stack technologies. We propose the simultaneous sharing and switching mechanism using virtualied serial communications. Each guest OS has its own virtual serial device. The distribution module provides communications between the guest OS's through the virtual serial devices and simultaneously detect the liveness of the guest OS. The suggested mechanism has been implemented in VirtualBox and shows satisfactory performance in transmission speed and data sharing capability with virtual RS232.

• International Journal of Contents
• /
• v.8 no.4
• /
• pp.1-6
• /
• 2012

Mutual Exclusion is one of the most studied topics in distributed systems where processes communicate by asynchronous message passing. It is often necessary for multiple processes at different sites to access a shared resource or data called a critical section (CS) in distributed systems. A number of algorithms have been proposed to solve the mutual exclusion problem in distributed systems. In this paper, we propose the new algorithm which is modified from Garg's algorithm[1] thus works properly in a fault-tolerant system. In our algorithm, after electing the token generator, the elected process generates a new token based on the information of the myreqlist which is kept by every process and the reqdone which is received during election. Consequently, proposed algorithm tolerates any number of process failures and also does even when only one process is alive.

• Proceedings of the Korean Information Science Society Conference
• /
• 1999.10c
• /
• pp.360-362
• /
• 1999

이동 에이전트 시스템은 인터넷에서 증가하고 있으며 전자 상거래 분야에 있어서 기반이 되는 개념이다. 전자상거래뿐만 아니라 다른 많은 분야에서 보안은 중요한 문제이다. 기존의 보안 기법을 이동 에이전트 시스템에 적용하기에는 많은 어려움이 있으므로 이동 에이전트 시스템에 적합한 새로운 보안 프로토콜을 필요로 하고 이에 대한 많은 연구가 진행중에 있다. 기존 시스템과 프로토콜은 서버나 클라이언트 중 한 쪽만 보호하는 단방향 인증을 제공하고 에이전트의 중요 정보를 공개하고 수명(liveness)을 보장하지 못하는 한계점을 지니고 있다. 본 논문에서 제시하는 시스템과 인증 프로토콜은 기존의 한계점을 해결하기 위한 방안을 제시하고 에이전트 서버간 상호 익명성을 보장하며 서버의 결함을 허용하는 융통성도 제공한다. 상호 인증 프로토콜을 제공함으로서 불법적인 에이전트와 서버의 침입을 막을 수 있다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2012.06b
• /
• pp.220-222
• /
• 2012

SaaS 어플리케이션 개발시 비즈니스 프로세스 자동화를 위한 과정에 검증 기능을 추가함으로써 보다 안전한 SaaS 어플리케이션을 개발 할 수 있는 방법을 제안하였다. 이를 활용하면 SaaS 어플리케이션에서 발생하는 프로세스들간 실행에서 deadlock, safety, liveness 등을 보장받을 수 있고, 비즈니스 프로세스들의 여러 버전들간의 일관성 및 어플리케이션 개발자가 개발한 결과물과 테넌트 관리자가 수정한 결과물에 대한 일관성을 보장받음으로써 신뢰할 수 있는 SaaS 어플리케이션을 개발 할 수 있다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.04a
• /
• pp.45-47
• /
• 2000

본 연구는 심볼릭 모델 체커 중의 하나인 SMV(Symbolic Model Verifier)를 이용하여 한국전자통신연구원(ETRI)에서 개발한 CCA(Cache Coherent Agent) 보드를 위한 I-Link Bus(Inside Bus)의 몇 가지 특성(property)들을 검증하여 I-Link Bus의 요구사항(requirement)이 만족됨을 보인다. 이 검증에서는 I-Link Bus의 모델을 SMV 입력 언어로 명세하며, 검증할 특성들을 시제 논리(temporal logic)를 이용하여 나타낸다. 검증을 통해서 I-Link Bus와 PIF(Processor Interface), DC(Directory Controller), RC(Remote access cache Controller)모듈들이 중재기 우선 순위, send 우선 순위, 중재 요청 신호의 관리, liveness등의 특성들을 만족한다라는 것을 검증하였다.

• Journal of Communications and Networks
• /
• v.16 no.4
• /
• pp.385-396
• /
• 2014

In this paper, we present a formal method for modeling and checking an enhanced version of the carrier sense multiple access with collision avoidance protocol related to the IEEE 802.11 MAC layer, which has been proposed as the standard protocol for wireless local area networks. We deal mainly with the distributed coordination function (DCF) procedure of this protocol throughout a sequence of transformation steps. First, we use the unified modeling language state machines to thoroughly capture the behavior of wireless stations implementing a DCF, and then translate them into the input language of the UPPAAL model checking tool, which is a network of communicating timed automata. Finally, we proceed by checking of some of the safety and liveness properties, such as deadlock-freedom, using this tool.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.581-586
• /
• 2003

As a very important part in development of the protocol, verification and conformance test for protocol specification are complementary techniques that are used to increase the level of confidence in the system functions. as prescribed by their specifications. In this paper, we verify the safety and liveness properties of rail signal control protocol type 1 specified in LTS(Labeled Transition System) with model checking method, and experimentally prove that it is possible to check for the deadlock, livelock and rechability of the states and actions on LTS. We also propose a formal method on generation of conformance test cases using the concept of UIO sequences from verified protocol specification.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.10
• /
• pp.2740-2751
• /
• 1999

Critical to more widespread use of Internet telephony are the smooth interoperability with the existing telephone network and the improved quality of voice connections. Of these requirements, this interoperability comes through the use of Internet Telephony Gateway's which perform protocol translation between an IP network and the Public Switched Telephone Network. In this paper, we have focused on the necessity and possibility of interoperability, and furthermore derives the necessary requirements for interoperability between IP networks and PSTN. For this purpose, we have analyzed the signaling protocols for gateway system. Then, we have modelled the inter-working part using the Petri-Net model. Through reachability trees of the Petri-Net model, we have confirmed that interoperability is possible, and that characteristics of deadlock, liveness, and boundness are satisfied.

• Journal of Korea Society of Industrial Information Systems
• /
• v.4 no.1
• /
• pp.1-6
• /
• 1999

This paper is on the analysis for the real-time software requirement. This method can be used for TNPN(Timed Numerical Peri Net) as a easy communication means with real-users. It is based on the RTTL(Real Time Temporal Logic) for correctness the system. TNPN is used to represent a behavior specification language, the validity of specified behaviors in TNPN is expressed in RTTL, and analyzed through the teachability graph. Thus, the requirement between user and system is satisfied Using the example of shared track, the validity of the property of real-time(safetiness, responsiveness, liveness, priority) is verified. Also this framework if given to connection with a object, natually.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2014.04a
• /
• pp.223-224
• /
• 2014

애드-혹 무선 네트워크를 구성하고 유지하기 위해서는 네트워크 내에 생존하고 있는 노드에 대한 정보가 공유되어야 한다. 본 논문에서는 영공간(null-space)을 활용하여 효율적이면서 보안을 유지할 수 있는 생존정보 전달 프로토콜을 제안한다. 이론적인 분석에서 제안하는 프로토콜은 생존 정보를 누적함으로써 전송횟수를 최소한으로 줄일 수 있고 도청과 오염 공격에 대해 강건함을 확인하였다.