• Journal of KIISE:Computer Systems and Theory
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• v.35 no.9_10
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• pp.421-428
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• 2008

A. Ghafoor proposed Even networks as a class of fault-tolerant multiprocessor networks in [1] and analyzed so many useful properties include node disjoint paths. By introducing node disjoint paths in [1], fault diameter of Even networks is d+2(d=odd) and d+3(d=even). But the lengths of node disjoint paths proved in [1] are not the shortest. In this paper, we show that Even network Ed is node symmetric. We also propose the shortest lengths of node disjoint paths using cyclic permutation, and fault diameter of Even networks is d+1.

• The KIPS Transactions:PartA
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• v.17A no.3
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• pp.113-120
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• 2010

Even networks were introduced as a class of fault-tolerant multiprocessor networks and analyzed so many useful properties and algorithms such as simple routing algorithms, maximal fault tolerance, node disjoint path. Introduced routing algorithms and node disjoint path algorithms are proven to be optimal. However, it has not been introduced to constructing scheme for edge-disjoint spanning trees in even networks. The design of edge-disjoint spanning trees is a useful scheme to analyze for measuring the efficiency of fault tolerant of interconnection network and effective broadcasting. Introduced routing algorithm or node disjoint path algorithm are for the purpose of routing or node disjoint path hence they are not applicable to constitute edge disjoint spanning tree. In this paper, we show a construction algorithm of edge-disjoint spanning trees in even network $E_d$.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.718-720
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• 2001

본 논문에서는 하이퍼큐브보다 망 비용이 개선된 상호연결망 HCN(n,n)의 임의의 두 노드간에 노드중복하지 않는 n+1개의 병렬경로를 구성하는 방법을 제시하고, 그 결과를 통하여 HCN(n,n)의 고장지름이 dia(HCN(n,n))+4 이하임을 보인다. 이러한 병렬경로는 노드간에 메시지를 전송하는 시간을 줄일 수 있으며, HCN(n,n)의 노드 몇 개가 고장이 발생해도 통신지연시간이 발생하지 않음을 의미한다.

• The KIPS Transactions:PartA
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• v.17A no.1
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• pp.1-8
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• 2010

The fault diameter is one of the important measures for transmission rate and reliability of interconnection network. H.-O. Lee et al.[Parallel paths in folded hyper-star graph, Journal of KIPS, Vol.6, No.7, pp.1756-1769, 1999] suggested the node-disjoint paths of FHS (2n,n), and proved that the fault diameter of FHS(2n,n) is less than 2n-1. In this paper, we suggest an advanced node-disjoint paths of FHS(2n,n). We also prove that the wide diameter of FHS(2n,n) is dist(U,V)+4, and the fault diameter of FHS(2n,n) is less than n+2.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.5
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• pp.429-436
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• 2009

Odd network was introduced as one model of graph theory. In [1], it was introduced as a class of fault-tolerant multiprocessor networks and analyzed so many useful properties such as simple routing algorithms, maximal fault tolerance, node axsjoint path, etc. In this paper, we sauw a construction algorithm of edge-axsjoint spanning trees in Odd network $O_d$. Also, we prove that edge-disjoint spanning tree generated by our algorithm is optimal edge-disjoint spanning tree.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.263-266
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• 2001

상호 연결망에서 임의의 두 노드 사이에 존재하는 노드 중복 없는 경로들의 집합을 Container라고 하는데, 본 논문에서는 계층적 하이퍼큐브 연결망의 Container가 n+1임을 보이고, 그 결과를 통하여 계층적 하이퍼큐브 연결망의 고장지름이 dia(HCN(n,n))+4 이하임을 보인다. 이러한 Container는 노드간에 메시지를 전송하는 시간을 줄일 수 있으며, 연결망의 노드 몇 개가 고장이 발생해도 통신지연시간이 발생하지 않음을 의미한다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.436-438
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• 2003

Ad hoc Network에서 효율적인 데이터 트래픽의 전송을 위하여 AODV 라우팅 알고리즘을 보안한 DM-AODV(Disjoint Multipath AODV)와 이를 활용하여 Qos율 높인 트래픽 분산 알고리즘인 TPA(Traffic Partitioning Algorithm)을 제안한다. 첫째, dynamic한 Ad hoc network환경에서 사용될 수 있는 DM-AODV을 사용하여 중복 노드가 없는 multipath들과 그 경로 각각의 최소 대역폭(bandwidth)을 구하고 둘째, 소스 노드에 들어오는 트래픽의 요구 대역폭과 TPA을 사용하여, 네트워크가 정상 일 때 전달 될 main path들과 네트워크 장애 시 할당 될 alternative path들에 들어오는 트래픽을 dynamic하게 분산시킴으로써 어플리케이션이 요구하는 높은 대역폭의 트래픽 수용 가능성을 높이고, 들어오는 트래픽의 안정적인 대역폭 보장과 속도의 향상, 폭주(congestion)의 감소 효과를 나타낸다. 또한 Main path에 장애 발생시, 미리 계산된 alternative Path에 트래픽을 전송함으로서 들어오는 패킷의 손실을 최소한으로 한다. 본 논문에서는 Ad hoc network에서의 QoS를 높이는 두 알고리즘을 소개하고, 동작 원리를 알아본다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.12C
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• pp.208-217
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• 2001

In mobile Internet environment, providing multicast requires much more complex mechanism comparing with the unicast Mobile IP routing protocol. This is because multicast datagrams are sent to a group address that do not belong to a specific network. The IETF Mobile IP suggested two approaches for mobile multicasting, namely remote subscription and hi-directional tunneling. In remote subscription, a mobile node may join a group via a local multicast router on the visited subnet. Therefore remote subscription may cause much datagram loss while reconstructing the delivery tee. In bi-directional tunneling, a mobile node may join a group via a hi-directional tunnel to its home agent. Bi-directional tunneling may suffer from inefficient routing. In this paper, we proposed a new mobile multicasting protocol, Mobile If Multicast using Local Broadcast(MIMLB) which can receive multicast datagrams as fast as possible and optimize routing path for multicast delivery. The MIMLB protocol uses hi-directional tunneling to receive multicast datagrams. And the MIMLB protocol can resolve datagram duplicated problem and optimize routing path by using local broadcast. Simulation results show that MIMLB reduces delivery path length and optimizes multicast routing path when a mobile nod? moves into a foreign network.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5559-5564
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• 2015

A variety of routing protocols targeted specifically at mobile ad-hoc network environments have been developed. Mobile ad-hoc network is a self-organizing temporary network, operating without the aid of any established wired infrastructure. The proposed protocol supports seamless communication services between the mobile hosts within a mobile ad-hoc network environments. In particular, our protocol makes faster route re-establishment possible by maintaining multiple paths in each mobile host, and also, the protocol provides reliable communication environments. We compare the performance of RWP model with that of LW model. This paper shows delivery ratio with single path and non-disjoint multiple path according to mobility model and node numbers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11A
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• pp.903-911
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• 2011

In this paper we proposed an energy adaptive data aggregation and transmission mechanism to solve the problem of energy limitation in wireless sensor networks (WSNs). Hierarchical structure methods are wildly used in WSNs to improve the energy efficiency. LEACH and TEEN protocols are the typical techniques. In these methods, all nodes, including nodes who have sensed data to transmit and nodes who haven't, are set frame timeslots in every round. MNs (member nodes) without sensed data keep active all the time, too. These strategies caused energy waste. Furthermore, if data collection in MNs is same to the previous transmission, it increases energy consumption. Most hierarchical structure protocols are developed based on LEACH. To solve the above problems, this paper proposed a method in which only MNs with sensed data can obtain allocated frame to transmit data. Moreover, if the MNs have same sensed data with previous, MNs turn to sleep mode. By this way redundant data transmission is avoided and aggregation in CH is lightened, too.