Optimal Deployment of Solar Insecticidal Lamps over Constrained Locations in Mixed-Crop Farmlands

Solar Insecticidal Lamps (SILs) play a vital role in green prevention and control of pests. By embedding SILs in Wireless Sensor Networks (WSNs), we establish a novel agricultural Internet of Things (IoT), referred to as the SILIoTs. In practice, the deployment of SIL nodes is determined by the geographical characteristics of an actual farmland, the constraints on the locations of SIL nodes, and the radio-wave propagation in complex agricultural environment. In this paper, we mainly focus on the constrained SIL Deployment Problem (cSILDP) in a mixed-crop farmland, where the locations used to deploy SIL nodes are a limited set of candidates located on the ridges. We formulate the cSILDP in this scenario as a Connected Set Cover (CSC) problem, and propose a Hole Aware Node Deployment Method (HANDM) based on the greedy algorithm to solve the constrained optimization problem. The HANDM is a two-phase method. In the first phase, a novel deployment strategy is utilised to guarantee only a single coverage hole in each iteration, based on which a set of suboptimal locations is found for the deployment of SIL nodes. In the second phase, according to the operations of deletion and fusion, the optimal locations are obtained to meet the requirements on complete coverage and connectivity. Experimental results show that our proposed method achieves better performance than the peer algorithms, specifically in terms of deployment cost

Innovative Supplier Selection from Collaboration Perspective with a Hybrid MCDM Model: A Case Study Based on NEVs Manufacturer

In the context of Chinese innovation-driven strategy, the role of suppliers has been attracting much attention. Since not every supplier can contribute to the buyer’s innovation, scientifically selecting an innovative supplier is highly valued by decision-makers from the new energy vehicle (NEV) manufacturers. This paper focuses on proposing a novel decision framework in the context of collaborative innovation, which helps NEV manufacturers to select an innovative supplier who can work hand in hand with them to enhance their innovation performance. First, a novel capability-willingness-risk (C-W-R) evaluation indicator system is established, considering supply risk from a multi-proximity perspective which is tightly tied to collaborative innovation performance, only considered from geographical proximity in previous supplier selection research. Then a hybrid fuzzy-symmetrical multicriteria decision-making (MCDM) model is proposed that integrates fuzzy linguistic sets, best–worst method (BWM), prospect theory (PT) and VIKOR. With this approach, a final ranking is obtained for innovative supplier selection by NEV manufacturers in China. Moreover, sensitivity analysis and comparison analysis illustrate the proposed decision framework’s effectiveness and reliability and dig deep into the buyer−supplier collaborative innovation. Finally, some managerial suggestions are given for supplier selection from the standpoint of NEV manufacturers

Innovative Supplier Selection from Collaboration Perspective with a Hybrid MCDM Model: A Case Study Based on NEVs Manufacturer

In the context of Chinese innovation-driven strategy, the role of suppliers has been attracting much attention. Since not every supplier can contribute to the buyer’s innovation, scientifically selecting an innovative supplier is highly valued by decision-makers from the new energy vehicle (NEV) manufacturers. This paper focuses on proposing a novel decision framework in the context of collaborative innovation, which helps NEV manufacturers to select an innovative supplier who can work hand in hand with them to enhance their innovation performance. First, a novel capability-willingness-risk (C-W-R) evaluation indicator system is established, considering supply risk from a multi-proximity perspective which is tightly tied to collaborative innovation performance, only considered from geographical proximity in previous supplier selection research. Then a hybrid fuzzy-symmetrical multicriteria decision-making (MCDM) model is proposed that integrates fuzzy linguistic sets, best–worst method (BWM), prospect theory (PT) and VIKOR. With this approach, a final ranking is obtained for innovative supplier selection by NEV manufacturers in China. Moreover, sensitivity analysis and comparison analysis illustrate the proposed decision framework’s effectiveness and reliability and dig deep into the buyer−supplier collaborative innovation. Finally, some managerial suggestions are given for supplier selection from the standpoint of NEV manufacturers

Quantitative estimation and influencing factors of ecosystem soil conservation in Shangri-La, China

Shangri-La is one of the regions with fragile ecological environment in China. It is also a key ecological protection area in northwestern Yunnan. Evaluation of soil conservation capability plays an important role in maintaining the ecosystem safety and sustainable development of the area. This study uses remote sensing image data, meteorological data, soil types data and DEM (Digital Elevation Model) to estimate the soil conservation capacity in different land use types, different grades of slopes, different vegetation coverage, different precipitation, and different soil types through the USLE (Universal Soil Loss Equation).The result shows that soil conservation capacity is the comprehensive influence of factors such as topography, soil types,vegetation coverage and precipitation condition,and the areas with forest, gentle slopes and above gentle slope, high vegetation coverage, precipitation of 500 mm to 600 mm, and dark brown soil, where the quantity of soil conservation is relatively large. It provides a basis for Shangri-La to carry out water and soil conservation, and to achieve ecological governance

Optimization design of multistage pump impeller based on response surface methodology

The central composite design of the response surface methodology is applied to optimize ge- ometrical parameters of a multistage pump impeller in this paper, and a relevant experiment was conducted. The maximum head difference is 5.6%, and the maximum efficiency differ- ence is 0.73%, which can ensure the accuracy of the investigation. Meanwhile, 30 groups of test schemes are obtained based on the software Design Expert, and the numerical calcula- tion of each scheme is conducted. According to the calculation results and variance analysis, it is found that the effect of response variables of the primary terms blade number, impeller outlet diameter, blade outlet width, and the quadratic terms between the blade number and impeller outlet diameter, blade number and blade wrap angle, impeller outlet diameter and blade outlet width on the head are significant. However, the primary term blade wrap an- gle, the quadratic terms between the blade number and blade outlet width, impeller outlet diameter and blade wrap angle, blade wrap angle and blade outlet width have no significant effect on the head. Furthermore, a response surface regression model of the single-stage im- peller head of a multistage pump was established after removing insignificant factors, and the deviation of the response surface regression model is only 2.4%. The significant sequence of the influence of response variables on the head is the blade number, impeller diameter, blade outlet width, and blade wrap angle. Finally, the optimal geometrical parameters of the impeller are obtained: the number of blades is 6, the diameter of the impeller is 254 mm, the blade wrap angle is 119◦, the outlet width of the blade is 4.3 mm, and the predicted value of the head is 189.19 m. Therefore, the influence rule of impeller geometrical parameters on the head was obtained, which can provide theoretical references for the optimization design of the multistage pump impeller

Investigation on the Transient Characteristics of Self-Priming Pumps with Different Hub Radii

Self-priming pumps, important fluid equipment, are widely used in the disaster relief and emergency fields. Meanwhile, the impeller is the only rotational unit of the self-priming pump, which plays an essential part in the power capability of the pump. In this paper, impellers with different hub radii are proposed; by comparing the internal flow characteristics, blade surface load, pressure pulsation characteristics, and radial force distribution of each scheme, the relationship between transient characteristics and hub radius is obtained. The results present that the impeller with a large hub radius can not only weaken the pressure pulsation, blade surface load, and radial force distribution, but also improve the ability of the blade to work on the internal flow field. Finally, the relevant hydraulic experiment is conducted, with the difference between the experiment and calculation below 3%, which ensures the accuracy of the calculation results

Preparation of size-selective Mn<inf>3</inf>O<inf>4</inf> hexagonal nanoplates with superior electrochemical properties for pseudocapacitors

Porous Mn3O4 hexagonal nanoplates were synthesized through annealing the hydrohausmannite precursor obtained by a one-pot hydrothermal process and by precisely controlling the concentrations of potassium hydroxide and glucose. The effect of potassium hydroxide and glucose on the growth of hexagonal nanoplates was investigated, and a growth mechanism was also proposed. Due to its abundant pores, the pure Mn3O4-based electrode exhibits excellent cycling stability with 100% capacity retention after 5000 cycles. The asymmetric supercapacitor exhibited high performance with an energy density of 17.276 W h kg-1 at a power density of 207.3 W kg-1 in a wide potential window of 1.5 V

Graphene Nanoscrolls with Confined Silicon Nanoparticles as a Durable Anode for Lithium-Ion Batteries

Graphene Nanoscrolls with Confined Silicon Nanoparticles as a Durable Anode for Lithium-Ion Batterie

A Node Location Algorithm Based on Node Movement Prediction in Underwater Acoustic Sensor Networks

Aiming at the problems of the low mobility, low location accuracy, high communication overhead, and high energy consumption of sensor nodes in underwater acoustic sensor networks, the MPL (movement prediction location) algorithm is proposed in this article. The algorithm is divided into two stages: mobile prediction and node location. In the node location phase, a TOA (time of arrival)-based ranging strategy is first proposed to reduce communication overhead and energy consumption. Then, after dimension reduction processing, the grey wolf optimizer (GWO) is used to find the optimal location of the secondary nodes with low location accuracy. Finally, the node location is obtained and the node movement prediction stage is entered. In coastal areas, the tidal phenomenon is the main factor leading to node movement; thus, a more practical node movement model is constructed by combining the tidal model with node stress. Therefore, in the movement prediction stage, the velocity and position of each time point in the prediction window are predicted according to the node movement model, and underwater location is then completed. Finally, the proposed MPL algorithm is simulated and analyzed; the simulation results show that the proposed MPL algorithm has higher localization performance compared with the LSLS, SLMP, and GA-SLMP algorithms. Additionally, the proposed MPL algorithm not only effectively reduces the network communication overhead and energy consumption, but also improves the network location coverage and node location accuracy.The work was supported in part by the National Key Research and Development Program under Grant 2018YFC0407900, in part by the National Natural Science Foundation of China under Grant 61971206, in part by the Open Fund of State Key Laboratory of Acoustics under Grant SKLA201901, in part by the China Academy of Military Sciences Fund (2019), in part by the Liaoning BaiQianWan Talents Program (2016), and in part by the Natural Science Foundation of Liaoning Province Project under Grant 20170540793