Intelligent Monitoring System for Home Based on FRBF Neural Network

Dezhong Zheng,Yang Wang,Yan Wang 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.2

In accordance with the requirements for home security and safe guard, a new type of intelligent monitoring system is researched and developed. The system is established with CAN bus and wireless as the foundation. Multi-sensor technology is used to improve the alarm algorithm of the system, a new fuzzy neural network is put forward as the classifier. There are four layers in the network, and the input signals are temperature and the concentration of CO, smoke and CO2, the output signal is the fire probability. Radial basis function (RBF) is used as the fuzzy membership function. The principal component analysis (PCA) is used to extract the information of sensors and an observation window is used to extract the necessary information for neural network. Experiments show that the system can provide accurate detection results in a short time.

Confining polymerization at emulsion interface by surface-initiated atom transfer radical polymerization on reactive Pickering stabilizer

Dezhong Yin,Wangchang Geng,Qiuyu Zhang,Baoliang Zhang 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.31 No.-

In this paper, surface-initiated atom transfer radical polymerization (SI-ATRP) on surface of Pickeringstabilizer for microencapsulation was investigated. By SI-ATRP on initiator-immobilized SiO2 particles,emulsion droplets were involved into microcapsules. The density of PMMA chains on SiO2 surfacereached 1.31 chain nm 2 and the initiator efficiency was estimated to be 28%. The results confirmed thatpolymerization was confined successfully at the interface of emulsion and 80% of polymer chains wereformed via SI-ATRP on Pickering stabilizer. This covalent between SiO2 and polymer endowed theprepared microcapsules with good durability and thermal reliability in phase change materialsapplication.

An Energy Efficient Localized Topology Control Algorithm for Wireless Multihop Networks

Dezhong Shang,Baoxian Zhang,Zheng Yao,Cheng Li 한국통신학회 2014 Journal of communications and networks Vol.16 No.4

Localized topology control is attractive for obtaining reducednetwork graphs with desirable features such as sparser connectivityand reduced transmit powers. In this paper, we focus onstudying how to prolong network lifetime in the context of localizedtopology control for wireless multi-hop networks. For this purpose,we propose an energy efficient localized topology control algorithm. In our algorithm, each node is required to maintain its one-hopneighborhood topology. In order to achieve long network lifetime,we introduce a new metric for characterizing the energy criticalitystatus of each link in the network. Each node independentlybuilds a local energy-efficient spanning tree for finding a reducedneighbor set while maximally avoiding using energy-critical linksin its neighborhood for the local spanning tree construction. Wepresent the detailed design description of our algorithm. The computationalcomplexity of the proposed algorithm is deduced to beO(mlog n), where m and n represent the number of links andnodes in a node’s one-hop neighborhood, respectively. Simulationresults show that our algorithm significantly outperforms existingwork in terms of network lifetime.

Effect of Water Stress Induced by PEG on Growth of Bunching Onion

Dezhong Dong,Riyuan Chen,Guangwen Sun,Houcheng Liu 한국원예학회 2008 한국원예학회 기타간행물 Vol.- No.-

An Energy Efficient Localized Topology Control Algorithm for Wireless Multihop Networks

Shang, Dezhong,Zhang, Baoxian,Yao, Zheng,Li, Cheng The Korea Institute of Information and Commucation 2014 Journal of communications and networks Vol.16 No.4

Localized topology control is attractive for obtaining reduced network graphs with desirable features such as sparser connectivity and reduced transmit powers. In this paper, we focus on studying how to prolong network lifetime in the context of localized topology control for wireless multi-hop networks. For this purpose, we propose an energy efficient localized topology control algorithm. In our algorithm, each node is required to maintain its one-hop neighborhood topology. In order to achieve long network lifetime, we introduce a new metric for characterizing the energy criticality status of each link in the network. Each node independently builds a local energy-efficient spanning tree for finding a reduced neighbor set while maximally avoiding using energy-critical links in its neighborhood for the local spanning tree construction. We present the detailed design description of our algorithm. The computational complexity of the proposed algorithm is deduced to be O(mlog n), where m and n represent the number of links and nodes in a node's one-hop neighborhood, respectively. Simulation results show that our algorithm significantly outperforms existing work in terms of network lifetime.

Method Based on Sparse Signal Decomposition for Harmonic and Inter-harmonic Analysis of Power System

Lei Chen,Dezhong Zheng,Shuang Chen,Baoru Han 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

Harmonic/inter-harmonic detection and analysis is an important issue in power system signal processing. This paper proposes a fast algorithm based on matching pursuit (MP) sparse signal decomposition, which can be employed to extract the harmonic or inter-harmonic components of a distorted electric voltage/current signal. In the MP iterations, the method extracts harmonic/interharmonic components in order according to the spectrum peak. The Fast Fourier Transform (FFT) and nonlinear optimization techniques are used in the decomposition to realize fast and accurate estimation of the parameters. First, the frequency estimation value corresponding to the maxim spectrum peak in the present residual is obtained, and the phase corresponding to this frequency is searched in discrete sinusoids dictionary. Then the frequency and phase estimations are taken as initial values of the unknown parameters for Nelder-Mead to acquire the optimized parameters. Finally, the duration time of the disturbance is determined by comparing the inner products, and the amplitude is achieved according to the matching expression of the harmonic or inter-harmonic. Simulations and actual signal tests are performed to illustrate the effectiveness and feasibility of the proposed method.

The Effect of Different Inflows on the Unsteady Hydrodynamic Characteristics of a Mixed Flow Pump

Yun, Long,Dezhong, Wang,Junlian, Yin,Youlin, Cai,Chao, Feng Korean Society for Fluid machinery 2017 International journal of fluid machinery and syste Vol.10 No.2

The problem of non-uniform inflow exists in many practical engineering applications, such as the elbow suction pipe of waterjet pump and, the channel head of steam generator which is directly connect with reactor coolant pump. Generally, pumps are identical designs and are selected based on performance under uniform inflow with the straight pipe, but actually non-uniform suction flow is induced by upstream equipment. In this paper, CFD approach was employed to analyze unsteady hydrodynamic characteristics of reactor coolant pumps with different inflows. The Reynolds-averaged Naiver-Stokes equations with the $k-{\varepsilon}$ turbulence model were solved by the computational fluid dynamics software CFX to conduct the steady and unsteady numerical simulation. The numerical results of the straight pipe and channel head were validated with experimental data for the heads at different flow coefficients. In the nominal flow rate, the head of the pump with the channel head decreases by 1.19% when compared to the straight pipe. The complicated structure of channel head induces the inlet flow non-uniform. The non-uniformity of the inflow induces the difference of vorticity distribution at the outlet of the pump. The variation law of blade to blade velocity at different flow rate and the difference of blade to blade velocity with different inflow are researched. The effects of non-uniform inflow on radial forces are absolutely different from the uniform inflow. For the radial forces at the frequency $f_R$, the corresponding amplitude of channel head are higher than the straight pipe at $1.0{\Phi}_d$ and $1.2{\Phi}_d$ flow rates, and the corresponding amplitude of channel head are lower than the straight pipe at $0.8{\Phi}_d$ flow rates.

The Effect of Different Inflows on the Unsteady Hydrodynamic Characteristics of a Mixed Flow Pump

Long Yun,Wang Dezhong,Yin Junlian,Cai Youlin,Feng Chao 한국유체기계학회 2017 International journal of fluid machinery and syste Vol.10 No.2

The problem of non-uniform inflow exists in many practical engineering applications, such as the elbow suction pipe of waterjet pump and, the channel head of steam generator which is directly connect with reactor coolant pump. Generally, pumps are identical designs and are selected based on performance under uniform inflow with the straight pipe, but actually non-uniform suction flow is induced by upstream equipment. In this paper, CFD approach was employed to analyze unsteady hydrodynamic characteristics of reactor coolant pumps with different inflows. The Reynolds-averaged Naiver-Stokes equations with the k-ε turbulence model were solved by the computational fluid dynamics software CFX to conduct the steady and unsteady numerical simulation. The numerical results of the straight pipe and channel head were validated with experimental data for the heads at different flow coefficients. In the nominal flow rate, the head of the pump with the channel head decreases by 1.19% when compared to the straight pipe. The complicated structure of channel head induces the inlet flow non-uniform. The non-uniformity of the inflow induces the difference of vorticity distribution at the outlet of the pump. The variation law of blade to blade velocity at different flow rate and the difference of blade to blade velocity with different inflow are researched. The effects of non-uniform inflow on radial forces are absolutely different from the uniform inflow. For the radial forces at the frequency fR, the corresponding amplitude of channel head are higher than the straight pipe at 1.0Фd and 1.2Фd flow rates, and the corresponding amplitude of channel head are lower than the straight pipe at 0.8Фd flow rates.

Method Based on Sparse Signal Decomposition for Harmonic and Inter-harmonic Analysis of Power System

Chen, Lei,Zheng, Dezhong,Chen, Shuang,Han, Baoru The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

Harmonic/inter-harmonic detection and analysis is an important issue in power system signal processing. This paper proposes a fast algorithm based on matching pursuit (MP) sparse signal decomposition, which can be employed to extract the harmonic or inter-harmonic components of a distorted electric voltage/current signal. In the MP iterations, the method extracts harmonic/inter-harmonic components in order according to the spectrum peak. The Fast Fourier Transform (FFT) and nonlinear optimization techniques are used in the decomposition to realize fast and accurate estimation of the parameters. First, the frequency estimation value corresponding to the maxim spectrum peak in the present residual is obtained, and the phase corresponding to this frequency is searched in discrete sinusoids dictionary. Then the frequency and phase estimations are taken as initial values of the unknown parameters for Nelder-Mead to acquire the optimized parameters. Finally, the duration time of the disturbance is determined by comparing the inner products, and the amplitude is achieved according to the matching expression of the harmonic or inter-harmonic. Simulations and actual signal tests are performed to illustrate the effectiveness and feasibility of the proposed method.

A cavitation performance prediction method for pumps PART1-Proposal and feasibility

Yun, Long,Rongsheng, Zhu,Dezhong, Wang Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.11

Pumps are essential machinery in the various industries. With the development of high-speed and large-scale pumps, especially high energy density, high requirements have been imposed on the vibration and noise performance of pumps, and cavitation is an important source of vibration and noise excitation in pumps, so it is necessary to improve pumps cavitation performance. The modern pump optimization design method mainly adopts parameterization and artificial intelligence coupling optimization, which requires direct correlation between geometric parameters and pump performance. The existing cavitation performance calculation method is difficult to be integrated into multi-objective automatic coupling optimization. Therefore, a fast prediction method for pump cavitation performance is urgently needed. This paper proposes a novel cavitation prediction method based on impeller pressure isosurface at single-phase media. When the cavitation occurs, the area of pressure isosurface S_iso increases linearly with the NPSH_a decrease. This demonstrates that with the development of cavitation, the variation law of the head with the NPSH_a and the variation law of the head with the area of pressure isosurface are consistent. Therefore, the area of pressure isosurface S_iso can be used to predict cavitation performance. For a certain impeller blade, since the area ratio R_s is proportional to the area of pressure isosurface S_iso, the cavitation performance can be predicted by the R_s. In this paper, a new cavitation performance prediction method is proposed, and the feasibility of this method is demonstrated in combination with experiments, which will greatly accelerate the pump hydraulic optimization design.