• 제어로봇시스템학회논문지
• /
• 제13권9호
• /
• pp.920-926
• /
• 2007

Establishing a fixed path for the message delivery through a wireless network is impossible due to the mobility. Among the number of routing protocols that have been proposed for wireless ad-hoc networks, the AODV(Ad-hoc On-demand Distance Vector) algorithm is suitable in the case of highly dynamic topology changes, along with ZigBee Routing(ZBR), with the exception of route maintenance. Accordingly, this paper introduces a routing scheme focusing on the energy efficiency and route discovery time for wireless alarm systems using IEEE 802.15.4-based ZigBee. Essentially, the proposed routing algorithm utilizes a cluster structure and applies ZBR within a cluster and DSR (Dynamic Source Routing) between clusters. The proposed algorithm does not require a routing table for the cluster heads, as the inter-cluster routing is performed using DSR. The performance of the proposed algorithm is evaluated and compared with ZBR using an NS2 simulator. The results confirm that the proposed Cluster-based AODV (CAODV) algorithm is more efficient than ZBR in terms of the route discovery time and energy consumption.

• 정보처리학회논문지C
• /
• 제18C권2호
• /
• pp.119-126
• /
• 2011

일반적으로 센서 네트워크에서는 라우팅 트리를 구축한 후에 시간 동기화 작업을 따로 진행하였다. 그 때문에 패킷교환의 횟수가 늘어나고 전력의 소모를 유발한다. 본 논문에서는 라우팅 트리 구축과정에서 교환하는 정방향과 역방향의 패킷에 LTS(Lightweight Time Synchronization) 알고리즘 연산에 필요한 정보를 추가하여 플러딩 라우팅 트리 구축 알고리즘과 시간 동기화 과정을 결합한 알고리즘을 제안한다. 또한, 일정한 라운드 시간을 사용하여 클럭 휨으로 인한 시간 오류를 보정하였다. 제안하는 알고리즘이 TSRA(Time Synchronization Routing Algorithm) 방식보다 센서 노드들 간의 시간을 더욱 정교하게 동기화한다는 것을 NS2 시뮬레이터를 통해서 증명하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제16권5호
• /
• pp.1708-1734
• /
• 2022

In the development of logistics system, the breakthrough of important technologies such as technology platform for logistics information management and control is the key content of the study. Based on Javascript and JQuery, the logistics system realizes real-time monitoring, collection of historical status data, statistical analysis and display, intelligent recommendation and other functions. In order to strengthen the cooperation of warehouse storage, enhance the utilization rate of resources, and achieve the purpose of real-time and visual supervision of transportation equipment and cargo tracking, this paper studies the VNF dynamic deployment and SFC routing problem in the network load change scenario based on the logistics system. The BIP model is used to model the VNF dynamic deployment and routing problem. The optimization objective is to minimize the total cost overhead generated by each SFCR. Furthermore, the application of the SFC mapping algorithm in the routing topology solving problem is proposed. Based on the concept of relative cost and the idea of topology transformation, the SFC-map algorithm can efficiently complete the dynamic deployment of VNF and the routing calculation of SFC by using multi-layer graph. In the simulation platform based on the logistics system, the proposed algorithm is compared with VNF-DRA algorithm and Provision Traffic algorithm in the network receiving rate, throughput, path end-to-end delay, deployment number, running time and utilization rate. According to the test results, it is verified that the test results of the optimization algorithm in this paper are obviously improved compared with the comparison method, and it has higher practical application and promotion value.

• Journal of Communications and Networks
• /
• 제17권4호
• /
• pp.384-393
• /
• 2015

This paper proposes an insect behavior-inspired routing algorithm for large-scale wireless mesh networks. The proposed algorithm is adapted from the behavior of an insect called Bombyx mori, a male silkmoth. Its unique behavior is its flying technique to find the source of pheromones. The algorithm consists of two steps: the shortest-path algorithm and the zigzag-path algorithm. First, the shortest-path algorithm is employed to transmit data. After half of the total hops, the zigzag-path algorithm, which is based on the movement of the male B. mori, is applied. In order to adapt the biological behavior to large-scale wireless mesh networks, we use a mesh topology for implementing the algorithm. Simulation results show that the total energy used and the decision time for routing of the proposed algorithm are improved under certain conditions.

• IEIE Transactions on Smart Processing and Computing
• /
• 제4권2호
• /
• pp.115-125
• /
• 2015

This paper presents a Cuckoo search algorithm to secure adversaries misdirecting multi-hop routing in Mobile ad hoc networks (MANETs) using a robust Trust Predicated Routing Framework with an optimized cluster head selection. The clustering technique designed in this framework leads to efficient routing in MANETs. The heavy work load in the node causes an energy drop in cluster head, which leads to re-clustering of the group, and another cluster head is selected to avoid packet loss during data transmission. The problem in the re-clustering process is that the overall efficiency of the routing process is reduced and the processing time is increased. A Cuckoo search based optimization algorithm is proposed to solve the problem of re-clustering by selecting the secondary cluster head within the initially formed cluster group and eliminating the reclustering process. The proposed framework enables a node to select a reliable and secure route for MANET and the performance can be evaluated by comparing the simulated results with the AODV routing protocol, which shows that the performance of the proposed routing protocol are improved significantly.

• 정보처리학회논문지C
• /
• 제18C권1호
• /
• pp.15-22
• /
• 2011

일반적으로 센서 네트워크는 라우팅 트리를 구축한 후에 시간 동기화를 수행한다. 이로 인하여 시간 동기화가 늦어지고 교환하는 패킷이 증가하여 에너지를 많이 소모하는 문제를 유발한다. 본 논문에서는 한 번의 플러딩 과정으로 라우팅 트리를 구축하고 이와 동시에 시간 동기화를 수행하는 TSRA (Time Synchronization Routing Algorithm) 알고리즘을 제안한다. 라우팅 패킷에 패킷 수신 시간과 패킷 전송시간을 추가하여 두 노드간 시간 차이를 구하고, 시간 차이를 전송함으로써 노드들 간의 시간 동기화를 구현한다. 시뮬레이션에 의하여 제안하는 알고리즘은 기존의 동기화 알고리즘인 TPSN과 동등한 수준의 정확도를 보이면서 동기화 속도 및 에너지 소모 면에서 우수하다는 것을 입증하였다.

• 한국경영과학회지
• /
• 제35권2호
• /
• pp.53-69
• /
• 2010

This paper proposes an ant-based routing algorithm, Ant System-Routing in wireless Senor Networks(AS-RSN), for wireless sensor networks. Using a transition rule in Ant System, sensors can spread data traffic over the whole network to achieve energy balance, and consequently, maximize the lifetime of sensor networks. The transition rule advances one of the original Ant System by re-defining link cost which is a metric devised to consider energy-sufficiency as well as energy-efficiency. This metric gives rise to the design of the AS-RSN algorithm devised to balance the data traffic of sensor networks in a decentralized manner and consequently prolong the lifetime of the networks. Therefore, AS-RSN is scalable in the number of sensors and also robust to the variations in the dynamics of event generation. We demonstrate the effectiveness of the proposed algorithm by comparing three existing routing algorithms: Direct Communication Approach, Minimum Transmission Energy, and Self-Organized Routing and find that energy balance should be considered to extend lifetime of sensor network and increase robustness of sensor network for diverse event generation patterns.

• 한국시뮬레이션학회논문지
• /
• 제14권4호
• /
• pp.95-106
• /
• 2005

Recent advances in wireless sensor networks have led to many routing protocols designed for energy-efficiency in wireless sensor networks. Despite that many routing protocols have been proposed in wireless sensor networks, a single routing protocol cannot be energy-efficient if the environment of the sensor network varies. This paper presents a fuzzy logic based Adaptive Routing (FAR) algorithm that provides energy-efficiency by dynamically changing protocols installed at the sensor nodes. The algorithm changes protocols based on the output of the fuzzy logic which is the fitness level of the protocols for the environment. A simulation is performed to show the usefulness of the proposed algorithm.

• 융합신호처리학회논문지
• /
• 제4권1호
• /
• pp.64-70
• /
• 2003

최근 VLSI 회로 설계는 자동 레이아웃(automatic layout) 들을 사용하여 효과적으로 이루어지고 있다. 자동 레이아웃은 VLSI 칩 상에 모듈들의 위치를 결정하는 배치와 각 모듈간을 상호 연결하는 배선 두 가지의 중요한 기능으로 구성되어 있다. VLSI 칩의 성능과 면적은 이 두 가지의 기능을 수행하는 알고리즘의 성능에 따라 크게 좌우된다. 채널 배선은 VLSI 설계 과정중의 하나로, 글로벌 배선을 수행한 후 각 배선 영역에 할당된 네트들을 트랙에 할당하여 구체적인 네트들의 위치를 결정하는 문제이며, 네트들이 할당된 트랙의 수를 최소화하는 문제이다. 본 논문에서는 4-레이어 채널 배선 문제를 해결하기 위한 네트리스트 분할 문제에 대하여 유전자 알고리즘(genetic algorithm; GA)을 이용한 해 공간 탐색(solution space search) 방식을 제안하였으며, 제안한 방식을 여러 문제들에 대해 시뮬레이티드 어닐링 알고리즘과 비교, 분석한 결과 최적, 최악 및 평균비용 측면에서 더 좋은 결과를 얻을 수 있었다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2005년도 추계종합학술대회
• /
• pp.109-112
• /
• 2005

In this paper, we propose an improved delay-constrained unicast routing (I-DCUR) algorithm for real-time networks which is based on the delay-constrained unicast routing (DCUR) algorithm. Our I-DCUR algorithm is quite different from DCUR algorithm, because the node will choose the link between the active node and the previous node, and it will replace the original loop path when it detects a loop. Thus, firstly consider to choose the link between the active node and the previous node to replace the original loop path when a node detects a loop. So our algorithm can make the construction of path more efficiently, as compared to DCUR algorithm. We could see that the performance of I-DCUR algorithm is much better than DCUR algorithm in the experimental results. There were over 40% improvement in 100 nodes, 60% in 200 nodes, and 9% reduction of costs.