• Title/Summary/Keyword: Tree-Based Network

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A Hierarchical Underwater Acoustic Sensor Network Architecture Utilizing AUVs' Optimal Trajectory Movements (수중 무인기의 최적 궤도 이동을 활용하는 계층적 수중 음향 센서 네트워크 구조)

  • Nguyen, Thi Tham;Yoon, Seokhoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37C no.12
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    • pp.1328-1336
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    • 2012
  • Compared to terrestrial RF communications, underwater acoustic communications have several limitations such as limited bandwidth, high level of fading effects, and a large underwater propagation delay. In this paper, in order to tackle those limitations of underwater communications and to make it possible to form a large underwater monitoring systems, we propose a hierarchical underwater network architecture, which consists of underwater sensors, clusterheads, underwater/surface sink nodes, autonomous underwater vehicles (AUVs). In the proposed architecture, for the maximization of packet delivery ratio and the minimization of underwater sensor's energy consumption, a hybrid routing protocol is used. More specifically, cluster members use Tree based routing to transmit sensing data to clusterheads. AUVs on optimal trajectory movements collect the aggregated data from clusterhead and finally forward the data to the sink node. Also, in order to minimize the maximum travel distance of AUVs, an Integer Linear Programming based algorithm is employed. Performance analysis through simulations shows that the proposed architecture can achieve a higher data delivery ratio and lower energy consumption than existing routing schemes such as gradient based routing and geographical forwarding. Start after striking space key 2 times.

Index based on Constraint Network for Spatio-Temporal Aggregation of Trajectory in Spatial Data Warehouse

  • Li Jing Jing;Lee Dong-Wook;You Byeong-Seob;Oh Young-Hwan;Bae Hae-Young
    • Journal of Korea Multimedia Society
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    • v.9 no.12
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    • pp.1529-1541
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    • 2006
  • Moving objects have been widely employed in traffic and logistic applications. Spatio-temporal aggregations mainly describe the moving object's behavior in the spatial data warehouse. The previous works usually express the object moving in some certain region, but ignore the object often moving along as the trajectory. Other researches focus on aggregation and comparison of trajectories. They divide the spatial region into units which records how many times the trajectories passed in the unit time. It not only makes the storage space quite ineffective, but also can not maintain spatial data property. In this paper, a spatio-temporal aggregation index structure for moving object trajectory in constrained network is proposed. An extended B-tree node contains the information of timestamp and the aggregation values of trajectories with two directions. The network is divided into segments and then the spatial index structure is constructed. There are the leaf node and the non leaf node. The leaf node contains the aggregation values of moving object's trajectory and the pointer to the extended B-tree. And the non leaf node contains the MBR(Minimum Bounding Rectangle), MSAV(Max Segment Aggregation Value) and its segment ID. The proposed technique overcomes previous problems efficiently and makes it practicable finding moving object trajectory in the time interval. It improves the shortcoming of R-tree, and makes some improvement to the spatio-temporal data in query processing and storage.

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A Multi-Chain Based Hierarchical Topology Control Algorithm for Wireless Sensor Networks

  • Tang, Hong;Wang, Hui-Zhu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.9
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    • pp.3468-3495
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    • 2015
  • In this paper, we present a multi-chain based hierarchical topology control algorithm (MCHTC) for wireless sensor networks. In this algorithm, the topology control process using static clustering is divided into sensing layer that is composed by sensor nodes and multi-hop data forwarding layer that is composed by leader nodes. The communication cost and residual energy of nodes are considered to organize nodes into a chain in each cluster, and leader nodes form a tree topology. Leader nodes are elected based on the residual energy and distance between themselves and the base station. Analysis and simulation results show that MCHTC outperforms LEACH, PEGASIS and IEEPB in terms of network lifetime, energy consumption and network energy balance.

Design of Geocasting in MANET using the Improved LBM

  • Lee, Cheol-Seung;Lee, Joon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.2 no.2
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    • pp.99-105
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    • 2007
  • MANET(Mobile Ad-hoc network) have recently attracted a lot of attention in the research community as well as in industry. Although the previous research mainly focused on various of MANET in routing, we consider, in this paper, how to efficiently support applications such as variable geocasting basd on MANET. The goal of a geocasting protocol is deliver data packet to a group of nodes that are located within a specified geocasting region. Previous research that support geocast service in mobilie computing based on MANET have the non-optimization problem of data delivery path, overhead by frequent reconstruction of the geocast tree, and service disruption problem. In this paper, we propose the mobility pattern based geocast technique using variable service range according to the mobility of destination node and resource reservation to solve this problem. The experimental results show that our proposed mechanism has improved performance of Accessibility & Network Overhead than previous research.

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Bit-map-based Spatial Data Transmission Scheme

  • OH, Gi Oug
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.8
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    • pp.137-142
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    • 2019
  • This paper proposed bitmap based spatial data transmission scheme in need of rapid transmission through network in mobile environment that use and creation of data are frequently happen. Former researches that used clustering algorithms, focused on providing service using spatial data can cause delay since it doesn't consider the transmission speed. This paper guaranteed rapid service for user by convert spatial data to bit, leads to more transmission of bit of MTU, the maximum transmission unit. In the experiment, we compared arithmetically default data composed of 16 byte and spatial data converted to bitmap and for simulation, we created virtual data and compared its network transmission speed and conversion time. Virtual data created as standard normal distribution and skewed distribution to compare difference of reading time. The experiment showed that converted bitmap and network transmission are 2.5 and 8 times faster for each.

Two Phase Heuristic Algorithm for Mean Delay constrained Capacitated Minimum Spanning Tree Problem (평균 지연 시간과 트래픽 용량이 제한되는 스패닝 트리 문제의 2단계 휴리스틱 알고리즘)

  • Lee, Yong-Jin
    • The KIPS Transactions:PartC
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    • v.10C no.3
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    • pp.367-376
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    • 2003
  • This study deals with the DCMST (Delay constrained Capacitated Minimum Spanning Tree) problem applied in the topological design of local networks or finding several communication paths from root node. While the traditional CMST problem has only the traffic capacity constraint served by a port of root node, the DCMST problem has the additional mean delay constraint of network. The DCMST problem consists of finding a set of spanning trees to link end-nodes to the root node satisfying the traffic requirements at end-nodes and the required mean delay of network. The objective function of problem is to minimize the total link cost. This paper presents two-phased heuristic algorithm, which consists of node exchange, and node shift algorithm based on the trade-off criterions, and mean delay algorithm. Actual computational experience and performance analysis show that the proposed algorithm can produce better solution than the existing algorithm for the CMST problem to consider the mean delay constraint in terms of cost.

A Design of TNA(Traceback against Network Attacks) Based on Multihop Clustering using the depth of Tree structure on Ad-hoc Networks (애드혹 네트워크 상에 트리구조 깊이를 이용한 다중홉 클러스터링 기반 TNA(Traceback against Network Attacks) 설계)

  • Kim, Ju-Yung;Lee, Byung-Kwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37A no.9
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    • pp.772-779
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    • 2012
  • In the current MANET, DOS or DDOS attacks are increasing, but as MANET has limited bandwidth, computational resources and battery power, the existing traceback mechanisms can not be applied to it. Therefore, in case of traceback techniques being applied to MANET, the resource of each node must be used efficiently. However, in the traceback techniques applied to an existing ad hoc network, as a cluster head which represents all nodes in the cluster area manages the traceback, the overhead of the cluster head shortens each node's life. In addition, in case of multi-hop clustering, as one Cluster head manages more node than one, its problem is getting even worse. This paper proposes TNA(Traceback against Network Attacks) based on multihop clustering using the depth of tree structure in order to reduce the overhead of distributed information management.

Power Saving Algorithm based on Data Reuse in Tree Structured Wireless Sensor Networks (트리 구조 무선 센서 네트워크에서의 데이터 재사용 기반의 전력 절감 기법)

  • Lee, Sang-Hyun;Yoo, Myung-Sik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.7B
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    • pp.649-658
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    • 2009
  • Due to limited size and limited battery lifetime of sensor node, one has to address the power saving issue in wireless sensor network. The existing power saving algorithm based on data reuse was proposed for the cluster structured wireless sensor network. We state the problem of existing power saving algorithm and propose new power saving algorithm for tree structured wireless sensor network. The proposed algorithm reduces power consumption by buffering the sensed data at the selected relay node for its data lifetime. The optimum buffering node is selected so that the power saving gain is maximized and at the same time, power consumption among sensor nodes are equally distributed in the network. With computer simulations, it is shown that the proposed algorithm outperforms the conventional algorithm in terms of power saving gain.

A Layered Network Flow Algorithm for the Tunnel Design Problem in Virtual Private Networks with QoS Guarantee

  • Song, Sang-Hwa;Sung, Chang-Sup
    • Management Science and Financial Engineering
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    • v.12 no.2
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    • pp.37-62
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    • 2006
  • This paper considers the problem of designing logical tunnels in virtual private networks considering QoS guarantee which restricts the number of tunnel hops for each traffic routing. The previous researches focused on the design of logical tunnel itself and Steiner-tree based solution algorithms were proposed. However, we show that for some objective settings it is not sufficient and is necessary to consider both physical and logical connectivity at the same time. Thereupon, the concept of the layered network is applied to the logical tunnel design problem in virtual private networks. The layered network approach considers the design of logical tunnel as well as its physical routing and we propose a modified branch-and-price algorithm which is known to solve layered network design problems effectively. To show the performance of the proposed algorithm, computational experiments have been done and the results show that the proposed algorithm solves the given problem efficiently and effectively.

Assessment of compressive strength of high-performance concrete using soft computing approaches

  • Chukwuemeka Daniel;Jitendra Khatti;Kamaldeep Singh Grover
    • Computers and Concrete
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    • v.33 no.1
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    • pp.55-75
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    • 2024
  • The present study introduces an optimum performance soft computing model for predicting the compressive strength of high-performance concrete (HPC) by comparing models based on conventional (kernel-based, covariance function-based, and tree-based), advanced machine (least square support vector machine-LSSVM and minimax probability machine regressor-MPMR), and deep (artificial neural network-ANN) learning approaches using a common database for the first time. A compressive strength database, having results of 1030 concrete samples, has been compiled from the literature and preprocessed. For the purpose of training, testing, and validation of soft computing models, 803, 101, and 101 data points have been selected arbitrarily from preprocessed data points, i.e., 1005. Thirteen performance metrics, including three new metrics, i.e., a20-index, index of agreement, and index of scatter, have been implemented for each model. The performance comparison reveals that the SVM (kernel-based), ET (tree-based), MPMR (advanced), and ANN (deep) models have achieved higher performance in predicting the compressive strength of HPC. From the overall analysis of performance, accuracy, Taylor plot, accuracy metric, regression error characteristics curve, Anderson-Darling, Wilcoxon, Uncertainty, and reliability, it has been observed that model CS4 based on the ensemble tree has been recognized as an optimum performance model with higher performance, i.e., a correlation coefficient of 0.9352, root mean square error of 5.76 MPa, and mean absolute error of 4.1069 MPa. The present study also reveals that multicollinearity affects the prediction accuracy of Gaussian process regression, decision tree, multilinear regression, and adaptive boosting regressor models, novel research in compressive strength prediction of HPC. The cosine sensitivity analysis reveals that the prediction of compressive strength of HPC is highly affected by cement content, fine aggregate, coarse aggregate, and water content.