Zhang P.,Hunan City University |
Zhang P.,Hunan University |
She S.,Powerchina Zhongnan Engineering Co.
International Journal of Online Engineering | Year: 2017
Wireless sensor networks as an emerging technology have garnered a lot of attention recently. With the development of wireless sensor networks, some problems such as data delay, information loss, and others have gradually appeared. In order to cope with these problems, evaluating the service quality in wireless sensor networks is crucial. However, how to evaluate the service quality in wireless sensor networks and especially how to accurately portray the preferences of a decision maker exactly are often difficult. To deal with this challenge, firstly, an evaluation system of attributes related to the service quality in wireless sensor networks is constructed based on the existing studies. Then, the probabilistic linguistic method including the definition of probabilistic linguistic term sets, the operators of probabilistic linguistic term sets, and the ranking order of probabilistic linguistic term sets are introduced. Probabilistic term sets used to denote the preferences of a decision maker are considered as more appropriate expressions than classical linguistic term sets, 2-tuple linguistic term sets, and portion linguistic term sets in the process of evaluating the service quality in wireless sensor networks. Finally, the probabilistic linguistic method is applied in the constructed service quality in wireless sensor networks so as to demonstrate its validity and applicability and further to help the decision maker find the problems in the service quality in wireless sensor networks and improve them.
Liu X.,Hunan Institute of Engineering |
Li W.,Powerchina Zhongnan Engineering Co Ltd.
International Journal of Online Engineering | Year: 2017
At present, wireless sensor networks (WSN) technology is a field of much research interest in the area of information technology. The application of wireless sensor networks is expected to be very broad. With the development of communication protocol and their corresponding components, wireless sensor networks technology plays an increasingly important role in the power industry. The analysis and forecast of electric power data is essential to the construction and operation of the power network. Through the wireless sensor networks, we can obtain comprehensive power data. Then we can better forecast the power load through the data we obtain from the wireless sensor networks. In this paper, we propose an improved LSSVM method. We collect the power data by the wireless sensor networks and use the improved LSSVM method to forecast the power load. Experimental results demonstrate the effectiveness of the proposed method.
She S.,Powerchina Zhongnan Engineering Co Ltd.
International Journal of Online Engineering | Year: 2017
In this paper, regarding the complexity of polluted water, through analyzing the water environment and its surrounding factors, a water quality monitoring system architecture based on wireless sensor networks is proposed. Firstly, the water quality parameters collected by the sensor are processed by the signal conditioning circuit and then transmitted to the sensor nodes so as to realize the data acquisition of the water quality parameters. Afterwards, through the function analysis of each node in the ZigBee network, the hardware design and software program design of the network coordinator node and the routing node are completed. After joint debugging of the hardware and software, point-to-point communication and system networking of the ZigBee network are achieved. Finally, the results of experiments show that the system can realize the data acquisition and wireless transmission of the temperature and PH parameters of different solutions. Furthermore, each node realizes its own function and meets the design requirements of the system.
Yuan J.,Changsha University of Science and Technology |
He Y.,Powerchina Zhongnan Engineering Corporation Ltd |
Liu J.,Changsha University of Science and Technology
Journal of Performance of Constructed Facilities | Year: 2016
Red clay is a common roadbed filler in China. In southern China, because of the high natural moisture content, it is hard to make enough compact clay in the process of roadbed filling construction, and it shrinks and cracks when dehydrated. This article compares the domestic regional soil properties of red clay in China, analyzing its physical properties, composition, chemical properties, and water characteristics, and the filler used in the construction of the Dongxin expressway. Swelling of the red clay packing was also observed. According to laboratory tests, field test analyses, and settlement observation tests, when using red clay as road filler, the use of a smooth bump grinding wheel and rolling of subgrade compaction works best for controlling moisture content, with the wet compaction test method within the range of ±5% of optimum moisture content. This method can ensure the strength and stability of the subgrade to provide guidance for the use of red clay in construction. © 2015 American Society of Civil Engineers.
Zhou Y.,Wuhan Naval University of Engineering |
Li H.,Wuhan Naval University of Engineering |
Wang W.,Power China Zhongnan Engineering Corporation Ltd |
Cao Q.,Wuhan Naval University of Engineering |
Zhou S.,Wuhan Naval University of Engineering
Journal of Electrical Engineering and Technology | Year: 2015
This paper presented an improved analytical method for calculating the open-circuit magnetic field in the surface-mounted permanent magnet machines accounting for slots and eccentric magnet pole. Magnetic field produced by radial and parallel permanent magnet is equivalent to that produced by surface current according to equivalent surface-current method of permanent magnet. The model is divided into two types of subdomains. The field solution of each subdomain is obtained by applying the interface and boundary conditions. The magnet field produced by equivalent surface current is superposed according to superposition principle of vector potential. The investigation shows harmonic contents of radial flux density can be reduced a lot by changing eccentric distance of eccentric magnet poles compared with conventional surface-mounted permanent-magnet machines with concentric magnet poles. The FE(finite element) results confirm the validity of the analytical results with the proposed model. © The Korean Institute of Electrical Engineers
Zhou M.,PowerChina ZhongNan Engineering Corporation Ltd |
Dai G.-L.,Central South University
Tiedao Xuebao/Journal of the China Railway Society | Year: 2015
A finite element analysis model was established on the stability of longitudinally connected ballastless slab track on simply-supported beam bridges of high speed railway. In this model, solid finite elements were used to simulate track structure; contact elements were applied to simulate the contact constraint relationship between adjacent layers; compression bar elements were used to simulate the support of bridges to the track; nonlinear spring elements were applied to simulate the constraint of pigeonhole type lateral chock blocks on track structure. The correctness of the model was verified through theoretical calculation. On the basis of this, constraints between layers, section stiffness of mortar layer and the layout of pigeonhole type lateral chock blocks on the stability of longitudinal connected ballastless slab track were compared. The research showed that the basic assumptions of traditional stability calculating methods did not match the practical conditions, and the caculating results tended to be unsafe. The nonlinear constraint relations between layers must be calculated during the stability analysis of the track structure. The weaker the constraint between the layers was, the worse the stability of the track structure. The track structure lost its stability when the temperature of the longitudinally connected ballastless slab track rose to 18.9℃ if pigeonhole type lateral blocks were not installed. The spacing between adjacent blocks should not be more than 18.3m when the maximum permissible temperature of track structure was 30℃. The stability of track structure can be effectively improved by improving the quality of mortar layers and reducing the spacing between adjacent blocks. ©, 2015, Science Press. All right reserved.
Zhou J.,Huazhong University of Science and Technology |
Lu Y.,Power China Zhongnan Engineering Corporation Ltd |
Li C.,Huazhong University of Science and Technology
Energy Conversion and Management | Year: 2015
In the manuscript "Comment on 'A hybrid multi-objective cultural algorithm for short-term environmental/economic hydrothermal scheduling' by Youlin Lu et al. [Energy Convers. Manage. 52 (2011) 2121-2134]", Abdollah Ahmad et al. reported that there were some inaccuracies made by Youlin Lu et al. in the paper [Energy Convers. Manage. 52 (2011) 2121-2134] while presenting the solutions. By detailed analysis and checking, the different results in the two papers are caused by taking the storage volume at different moments of one period during hydro generation calculation. Abdollah Ahmad et al. take the final storage volume of the period when doing the calculating, while Youlin Lu et al. take the initial storage volume of the period. The checking results indicate that the schemes in the two papers are correct and reasonable only they are obtained by taking different storage volumes. These schemes have less fuel cost and emission while satisfying various constraints. Moreover, the key references cited in the original paper also take the initial storage volume of the period to calculate hydro generation, which are suitable for the comparison of the optimal results. Finally, few inaccurate expressions in the original paper [Energy Convers. Manage. 52 (2011) 2121-2134] are modified. © 2015 Elsevier Ltd. All rights reserved.
Xu G.,Tianjin University |
Meng Q.,Powerchina Zhongnan Engineering Corporation Ltd |
Yuan X.,Tianjin University
Shuikexue Jinzhan/Advances in Water Science | Year: 2016
In order to study the motion law of salt water when the levees break with storm surge in the delta estuary, one-dimensional and two-dimensional coupled salinity numerical models are developed to simulate the salt water movement when the levees break with storm surge. The impact of buildings in flood plains on the salt water movement and the gradient development process of the dyke breach are considered. The water levels and salinity calculated by the river networks model are tested with the measured data of multiple survey stations in 2008. The model is applied to simulate the salt water movement of an offshore dyke on the Pearl River Delta when the levees break with storm surge, and the maximum salinity isosurface diagram is mapped. The results show that the salinity of levee-breach flood in most of the breaches is over 4psu. Therefore, the impact of the high salinity ponding of levee breaches flood cannot be ignored. By comparing the drainage salinity calculated in the cases of “levee breaches” and “non-levee breaches”, it is found that the levee breaches shunt of upstream enhances the storage capacity of tidal water, increases the flood tidal volume, raises the trace-back risk of salt water intrusion of downstream river network and weakens the suppressing effect of the upstream flow on salt water intrusion. © 2016, Editorial Board of Advances in Water Science. All right reserved.
Chen X.,Powerchina Zhongnan Engineering Corporation Ltd |
Zhang D.,Powerchina Zhongnan Engineering Corporation Ltd
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2015
Installed capacity is an important indicator of a hydropower station, its scale directly related to the energy efficiency, efficiency of water resources use, and rational utilization of equipments and investment etc. The factors of installed capacity are not the same for hydropower stations of different regulation performances. This paper divides hydropower stations into two types, good regulation performance and limited regulation performance. A general procedure and the existing issues in the practical work of making choices for the stations of different performances are discussed, proceeding from the factors influencing the choices of installed capacity. Through the analysis of examples, confirmed the correctness of the factors in this paper, which provided a reference for the choices of installed capacity. Last, this paper suggests that it is necessary to expand the installed capacity of the existing hydropower stations timely but this should depend on the timing. ©, 2014, 10031243 Tsinghua University Press. All right reserved.
Shi H.-X.,Power China Zhongnan Engineering Corporation Ltd |
Hu Y.-L.,Power China Zhongnan Engineering Corporation Ltd |
Chang S.-S.,Power China Zhongnan Engineering Corporation Ltd
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2016
The geological condition of the upper reservoir for Liyang Pumped Storage Power Station is complex. Because the thickness of filled landfill at the bottom of the reservoir varies rapidly and the differential settlement is large, the HDPE geomembrane is adopted as the material of reservoir bottom seepage prevention system owing to its flexibility to unequal transformation, which reduces the seepage loss and make the construction be easier. The design and application of geomembrane seepage prevention system are introduced, including selection and design of materials for seepage prevention layer, surrounding connection design of geomembrane, construction method of geomembrane etc. © 2016, Chinese Society of Civil Engineering. All right reserved.