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To the characteristics of large number of sensor nodes, wide area and unbalanced energy consumption in farmland Wireless Sensor Networks, an efficient data collection strategy (GCMS) based on grid clustering and a mobile sink is proposed. Firstly, cluster is divided based on virtual grid, and the cluster head is selected by considering node position and residual energy. Then, an optimal mobile path and residence time allocation mechanism for mobile sink are proposed. Finally, GCMS is simulated and compared with LEACH and GRDG. Simulation results show that GCMS can significantly prolong the network lifetime and increase the amount of data collection, especially suitable for large-scale farmland Wireless Sensor Networks. [ABSTRACT FROM AUTHOR]

Solar energy harvesting has been presented as a key solution to alleviate the lifespan problem of conventional battery-based wireless sensor networks, but it does not address the problem of uneven energy consumption across the network. In conventional sensor networks with a stationary sink node, the nodes around the sink node consume more energy than other nodes, which is known as the hotspot problem. In recent studies, mobile sink technology has been proved to be an effective solution to the problem, where a mobile sink visits sensor nodes and collects data. To reduce the energy consumption of the mobile sink, a subset of sensor nodes are designated as anchor nodes to collect data for a certain period, and the mobile sink visits only such anchor nodes. However, even with these approaches, small hotspots can still be formed near those anchor nodes, hence it is crucial to optimize the selection and management of anchor nodes. This study aims to propose a dual line-based anchor node selection scheme tailored to efficiently solve the hotspot problem in mobile sink-based solar-powered wireless sensor networks. The proposed scheme designates the areas, in which some nodes can be chosen as anchor nodes, in the form of two lines. This dual line-based anchor selection algorithm effectively operates for the best use of the solar energy harvested by each node in a balanced manner. The experimental results confirm that the proposed scheme minimizes hotspots in the network, reduces the blackout time of nodes, and improves the data collection rate. • The proposed scheme is designed for solar powered WSNs operating with a mobile sink. • The proposed scheme can maximize the utilization of harvested energy at each node. • The proposed scheme can alleviate the hotspot problem significantly. • The proposed scheme can reduce the blackout time for solar-powered sensor nodes. • The proposed scheme can improve the quantity and quality of the collected data. [ABSTRACT FROM AUTHOR]

It is difficult to collect data and evaluate the status of NC machine tools automatically because of the diversity of isomeric CNC systems. Aiming at this problem, a general method is designed. First, an energy consumption data collector is designed to collect energy consumption data of NC machine tools' spindle and the data feature is analyzed. Then the standard energy consumption data by NC machining simulation or pre-acquisition during the operation of every NC code program is collected and further a standard energy consumption database is built according to the standard data. Second, to judge the type of work piece and the status of NC machine tools, the time series theory is used to deal with the energy consumption data by compared with the data that of the standard database. Finally, the feasibility and reliability of the proposed method is verified through an example. [ABSTRACT FROM AUTHOR]

The energy hole problem is a major concern in the wireless sensor network (WSN) given the uneven energy depletion of the power-constrained sensor nodes. Recently, several studies have incorporated a mobile data collector (MDC) to collect data from sensor nodes where the MDC reaches a set of data collection points (DCPs) to collect data from nearby nodes. This strategy has resolved the underlying cause of unbalanced energy consumption by avoiding the long chain of multi-hop routing. However, in most of the existing protocols, sensor nodes information is relayed to the Base Station (BS) to nominate MDC sojourn points and travel sequence. Such a centralized approach results in a substantial exchange of messages among sensor nodes causing high energy consumption. Moreover, these approaches perceived a uniform data generation rate at sensor nodes while ignoring the limited buffer cache capacity during the MDC path design. In this context, this paper proposes a distributed MDC sojourn point nomination method that significantly improves the message complexity and energy consumption of the WSN. The selected DCPs information is relayed to the BS where a modified Ant Colony Optimization algorithm is applied to construct the MDC traversal path. The performance of the proposed protocol is extensively analysed with some related existing schemes in terms of network parameters like energy efficiency, network lifetime, packet delivery ratio, and end to end delay. Moreover, the scalability of the proposed scheme is evaluated by varying the number of MDC and sensor nodes in the network. • A distributed Mobile Data Collector (MDC) sojourn point nomination method. • MDC data gathering trajectory simultaneously optimizes the energy and cache memory. • Ant Colony Optimization based data collection traversal sequence of the MDC. • Works with uniform as well as non-uniform data generating sources. [ABSTRACT FROM AUTHOR]

An improved method is developed for urban bus driving cycle construction. Driving condition data are collected on the representative routes which are selected between the major residential areas and commercial or industrial areas according to the traffic flow. The micro-trip is defined as a trip between two bus stops. A driving cycle is then constructed with the randomly selected micro-trips according to the proportion of the driving condition. The representative urban bus driving cycle is selected by the variation of the parameter mean value. The improved method of urban bus driving cycle construction and the synthesized Dalian urban bus driving cycle are both verified with the case study of urban bus in Dalian. Driving cycle by the improved method provides the design references for the measurement of pollution and fuel consumption on the electric vehicles which are developed with the characteristics of urban bus. [ABSTRACT FROM AUTHOR]