Node Selection Method Research Articles

A Study on Transmission Characteristics of Large Scale Multi-hop Wireless LAN using L2 Routing

Transmission characteristics of multi-hop wireless LAN (IEEE 802.11g) are degraded according to the number of hops due to the nature of multiple access control. To decrease the number of hops in the multi-hop network, a connecting node selection method according to the depth of hop is evaluated. To prevent packet congestion due to the flooding packet using the L3 routing method, L2 routing method using only data link layer information such as received power is also evaluated. The maximum number of hops, which indicates the minimum throughput and maximum response time in the multi-hop network, is effectively decreased even under the condition of high repeater-node density by using the number of hops together with the received power as the metrics, in comparison with the conventional metric of received power only.

Faster MIP solutions via new node selection rules

When a branch and bound method is used to solve a linear mixed integer program (MIP), the order in which the nodes of the branch and bound tree are explored significantly affects how quickly the MIP is solved. In this paper, new methods are presented that exploit correlation and distribution characteristics of branch and bound trees to trigger backtracking and to choose the next node to solve when backtracking. A new method is also presented that determines when the cost of using a node selection method outweighs its benefit, in which case it is abandoned in favor of a simpler method. Empirical experiments show that these proposed methods outperform the current state of the art.

Branch-and-Cut Algorithmic Framework for 0−1 Mixed-Integer Convex Nonlinear Programs

With widespread use of mixed-integer modeling for continuous and discontinuous nonlinear chemical processes, a robust mixed-integer nonlinear optimization algorithm is strongly demanded for the design and operation of chemical processes that achieve greater profits and also satisfy environmental and safety constraints. In this article, an extensive evaluation of a branch-and-cut algorithmic framework for 0−1 mixed-integer convex nonlinear programs, called MINO for Mixed-Integer Nonlinear Optimizer, is presented. The numerical performances of MINO are tested against four sets of medium-sized practical application problems from the fields of operations research and chemical engineering. The effects of the nonlinear programming (NLP) solvers, the cut generating and maintaining strategy, the node selection method, and the frequency of cut generation are examined, in order to handle MINLP problem with different mathematical structures. Preliminary computational results show that MINO exhibits a capability for handling practical MINLP problems that is comparable to that of the commercial solvers SBB and DICOPT, and it shows better performance for some problems for which either commercial solver encounters convergence problem within a CPU time limit of 6 h.

A Novel Semidistributed Localization Via Multinode TOA–DOA Fusion

This paper presents a 2-D semi-distributed localization technique, which is based on the fusion of the positioning data estimated by multiple mobile nodes. The fusion is implemented in the local coordinate of one of the nodes (reference node) and improves the positioning performance of the desired node in the coordinate of the reference node. This paper introduces the proposed localization fusion technique. The fusion weights and positioning error are theoretically derived, and the efficiency of a suboptimal reference node selection method, the positioning error, and the position update rate are evaluated via simulations.

Weighted Distance Based Sensor Selection for Target Tracking in Wireless Sensor Networks

A novel weighted distance based node selection method for bearings-only sensors in wireless sensor networks (WSN) is proposed. Weighted distance is involved as information utility in sensor management of WSN. Based on the probability distribution function of predicted target state and the bearing error of a sensor itself, the sensor with the minimum weighted distance is activated in the tracking mission. Compared with entropy based method, the proposed method saves much computational cost by avoiding the estimation of the posteriori distribution. Simulation results demonstrated that the proposed method can achieve competitive tracking accuracy comparing to the existing representative methods.

Local node selection for localization in a distributed sensor network

This paper discusses a new localized resource manager for a wireless sensor network of bearings-only sensors. Specifically, each node uses knowledge of the target under surveillance to determine whether it should actively collect measurements and how far to disseminate the data in order for the sensor network to maintain track of the target. At each node, the resource manager requires only knowledge of the relative location to the target for itself and the active nodes from the previous snapshot. The decentralized strategy represents a modification to the global node selection (GNS) method that exploits knowledge of the location of all nodes in the network. Simulations show that despite the lack of global network knowledge, the new localized management method is almost as effective as GNS in terms of balancing the tradeoff between energy usage and localization accuracy.

Age and cognitive ability as predictors of computerized information retrieval

Abstract This paper presents an empirical investigation of age and cognitive ability as predictors of computerized information retrieval. Upon the basis of age-related changes in cognitive ability, hypotheses were generated relating to the effects of database structure (linear, hierarchical, or network) and node selection method (explicit or embedded menu). In keeping with previous research in other areas of human-computer interaction, there was a significant main effect of age, with older subjects performing more slowly. However, interactive effects of ‘question block’ indicated that older subjects were at a particular disadvantage in the early stages of task performance. Age differences in processing speed and/or psychomotor skill appeared to be a particularly important factor. Whilst the effects of cognitive ability were generally weak, spatial memory and logical reasoning scores were negatively correlated with information retrieval response times. Although interactions were not significant, trends in ...