• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1588-1595
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• 2019

This paper presents the technique on structuring information of the diagram repository for UML diagrams. Because object interactions are the body of object-oriented programming, this paper handles especially the sequence diagrams and class diagrams among UML diagrams. Based on class diagrams, sequence diagrams represent the procedure of object interactions in run-time and then the corresponding codes are generated from the contents of those sequence diagrams. To do this work, this paper presents a method to construct the information repository for generating code from the contents of sequence diagrams. This paper classifies the five message types of sequence diagrams and then extracts the needed information including items and values on the corresponding message types for constructing message repositories. Because sequence diagram is composed of messages included, the final repository is constructed by collecting each of structured repositories on messages sequentially.

• Journal of Satellite, Information and Communications
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• v.12 no.4
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• pp.42-49
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• 2017

Delay- and Disruption-Tolerant Network (DTN) has been considered as a key technology to overcome main challenges in interplanetary communications such as an intermittent connectivity and high bit error rates. The lack of end-to-end connectivity between source and destination results in long and variable delays and data loss, hence the Internet Protocols cannot operate properly in such environments because it requires an end-to-end connectivity. The DTN, which utilizes 'store-and-forward' message passing scheme between nodes, can overcome the lack of end-to-end connectivity in Interplanetary Network (IPN). In this paper, DTN is applied to 3-hop relay IPN, where messages are transmitted from Earth ground station to Lunar lander through Earth satellite and Lunar orbiter. ONE simulator is used to reflect the real environment of IPN and an efficient resource management method are analyzed to guarantee the message delivery by optimizing a message TTL (Time to Live), buffer size and message fragmentation.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.623-626
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• 2017

스마트기기 간 파일을 공유할 경우, 사용자는 파일 공유 프로그램을 설치해 이를 이용하거나 외부저장장치를 이용해 파일을 공유한다. 클라우드 저장소에 파일을 저장해 이를 공유하는 웹 애플리케이션을 사용할 경우, 클라우드 저장소의 제한된 크기로 인해 파일의 크기가 제한되는 경우가 있다. 본 논문에서는 기존 파일 공유 방법의 단점을 해결하기 위해 P2P 파일 공유 웹 애플리케이션을 제시한다. P2P 파일 공유 웹 애플리케이션을 이용하면 기존에 설치된 브라우저만을 이용해 파일 용량 제한 없는 파일 공유가 가능하다. HTML5 표준의 WebRTC를 이용하면 브라우저만을 이용해 연결지향 양방향 P2P 통신이 가능하다. 본 논문에서는 P2P 파일 공유 웹 애플리케이션 구현에 앞서 P2P 파일 공유 프로토콜을 제시한다. 본 논문에서 제시하는 P2P 파일 공유 프로토콜은 JSON 메시지와 메시지 핸들러를 이용한 브라우저 간 비동기적 RPC(Remote Procedure Call) 형태로 설계되었다. 본 논문에서 설계한 프로토콜을 이용해 P2P 파일 공유 웹 애플리케이션을 구현하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9C
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• pp.855-862
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• 2009

The path key establishment phase in the wireless sensor network is vulnerable to Byzantine attack. Huang and Hedhi proposed a Byzantine resilient multi-key establishment scheme using a systematic RS code, which has shortcomings of exposing a part of message symbols and inefficient transmission. In this paper, we propose a new Byzantine resilient multi-path key establishment scheme in which direct message symbols are not exposed to an adversary and are more efficiently transmitted the RS-encoded symbols to the destination node. In the Proposed scheme, a non-systematic RS code is used to transmit a generated indirect secret key and each encoded symbol is relayed through available paths between two sensor nodes. If enough symbols are collected at the destination node, it is possible to reconstruct the secret message through RS decoding.

• ETRI Journal
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• v.10 no.1
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• pp.22-31
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• 1988

TDX-10 교환기에 실현될 CCITT No.7 시스팀 중 MTP 서브시스팀 설계를 위한 예비 연구로서 블럭별 자료구조를 설계하였다. 본고에서는 자료구조 설계방법은 관계형 데이터 베이스 설계 개념을 응용하여 데이터의 조작 및 관리가 용이한 자료구조의 설계 방법을 제시하였으며, 특히 Entity-Relationship 데이터 모델을 이용하여 개념 데이터 모델을 설정하고 이로부터 제3규정형 형태의 관계형 자료구조를 도출하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.139-141
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• 2002

최근 보안에 관한 관심이 높아지면서 IPSec을 이용한 VPN system이 널리 이용되고 있다. IPSec에서 암호화에 사용되는 키를 생성하는 IKE는 IPSec의 핵심 프로토콜이지만다소 복잡하고 메시지 교환도 많아 패킷의 손실이 큰 무선망에는 적합하지 않다. 무선망에서 좀 더 효율적으로 동작하기 위한 인터넷 키 교환 방법 및 공개키 기반구조를 제시하였다.

• Journal of Software Engineering Society
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• v.14 no.1
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• pp.19-29
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• 2001

본 논문은 절차지향 소프트웨어로 재공학하는 과정에서 객체의 안전한 지속성(Safe Persistence)에 대한 결정 방법을 제안한다. 본 논문에서는 지속성 결정을 위해 다섯 단계를 제시하며 각 과정을 통해 객체의 정확한 생성과 소멸 시점을 추출하고, 정제 과정을 거침으로써 객체의 메시지 전달과 생성/소멸 과정에서 안전성과 일관성을 유지할 수 있도록 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.6
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• pp.1114-1116
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• 2015

In this paper, we propose a load distribution scheme in SDN utilizing load redirection, enabling incoming messages to be migrated to another controller. Specifically, when the capacity of a controller reaches a threshold, the controller makes incoming packets be migrated to a less-loaded controller to prevent them from being blocked. Analytical result shows that our scheme has lower blocking probability than the conventional scheme.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.9
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• pp.469-478
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• 2001

It is difficult to test a distributed system because of the task of controlling concurrent events,. Existing works do not propose the test sequence generation algorithm in a formal way and the amount of message is large due to synchronization. In this paper, we propose a formal test sequence generation algorithm using logical clock to control concurrent events. It can solve the control-observation problem and makes the test results reproducible. It also provides a generic solution such that the algorithm can be used for any possible communication paradigm. In distributed test, the number of channels among the testers increases non-linearly with the number of distributed objects. We propose a new remote test architecture for solving this problem. SDL Tool is used to verify the correctness of the proposed algorithm and it is applied to the message exchange for the establishment of Q.2971 point-to-multipoint call/connection as a case study.

• The KIPS Transactions:PartC
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• v.9C no.4
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• pp.551-562
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• 2002

We usually applied PPP CHAP when the visited ISP subscriber accesses to authentication server in own home ISP network and IP Assignment for remote Internet service. But PPP CHAP doesn't support in case of visited ISP subscriber in GPRS network accesses to authentication sorrel in own home ISP network for wireless Internet service. We suggest solution for this problem with PPP CHAP improvement. For this we propose the modified PPP CHAP message format, PCO Message format at MT, and interworking message and format between GGSN and RADIUS in home ISP network for wireless internet service of mobile ISP subscriber at GPRS network in this paper. We also show authentication results when visited mobile ISP subscriber via PPP CHAP at GPRS network accesses the RADIUS server in home ISP network.