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1

Event-triggered cluster consensus of leader-following linear multi-agent systems

Xu B., He W.

Journal of Artificial Intelligence and Soft Computing Research

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2018

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Vol. 8, No. 4

293--302

EN

This paper is concerned with cluster consensus of linear multi-agent systems via a distributed event-triggered control scheme. Assume that agents can be split into several clusters and a leader is associated with each cluster. Sufficient conditions are derived to guarantee the realization of cluster consensus by a feasible event-triggered controller if the network topology of each cluster has a directed spanning tree and the couplings within each cluster are sufficiently strong. Further, positive inner-event time intervals are ensured for the proposed event-triggered strategy to avoid Zeno behaviors. Finally, a numerical example is given to illustrate the effectiveness of the theoretical results.

2

Numerical Study of the Effect of Furrows on Biosonar Beamforming in Aselliscus Stoliczkanus Bat

He W., Feng J., Gao L., Zhang Z., Lu H.

Archives of Acoustics

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2017

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Vol. 42, No. 3

395--399

EN

The Aselliscus Stoliczkanus bat, studied here, has intricately shaped structures surrounding the nostrils. These structures are hypothesised to have influence on animals’ acoustic radiation patterns. Using micro-tomography scanning technique, a 3D digital model of the noseleaf is reconstructed and biosonar beam pattern is analysed using a finite element method based on the 3D noseleaf model. The present research focuses on the conspicuous furrows in noseleaf, and our analysis allows to conclude the followings: a) structural details in noseleaf of Aselliscus Stoliczkanus bat can produce acoustic effects even if it is not adjacent to the nostrils, b) the furrows possess frequency-selective characteristics, c) the furrows have the function to manipulate the direction and width of the outgoing ultrasound wave.

3

Impact of the Mixture of Hexa(N-hydroxymethyl)amidocyclotriphosphazene and Partially Methylated Melamine Formaldehyde Resin on the Flame Retardancy of Paper

Tang L., Zhao J., Sui X., Song H., He W.

Fibres & Textiles in Eastern Europe

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2016

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Vol. 24, no. 4 (118)

153--160

EN

The flame retardancy of the mixture of hexa(N-hydroxymethyl)amidocyclotriphosphazene and partially methylated melamine formaldehyde resin (HHMATP/PMMM) in paper was proposed by limiting oxygen index measurement (LOI), the vertical burning test and cone calorimetry test (CCT). In our research, the LOI of washed FR-paper could still be up to 33.5%; the after flame time , and burning time were reduced to 4.8 s & 0 s, and the char length was only 12.0 mm. While the results of CCT imply that compared with non-flame retarded paper, the heat release rate (HRR) of FR-paper with HHMAPT/PMMM increases gently; the mass loss becomes significantly slow, and the prolonged maximum heat release rate (PHRR), average heat release rate (MHRR), average effective heat of combustion (MEHC) and total heat release (THR) drop greatly. According to the experimental results, HHMATP/PMMM has not only excellent flame retardancy in paper but also good water resistance, with HHMATP/PMMM playing a flame retardant role mainly by means of the condensed phase mechanism.

PL

Badano zmniejszenie palności papieru stosując mieszaninę hexa(N-hydroxymethyl)amidocyclotriphosphazene i częściowo zmetylowanej żywicy melamine formaldehyde (HHMATP/PMMM) poprzez indeks tlenowy (LOI), test pionowego palenia i test kalorymetru stożkowego (CCT). Eksperymenty wykazały, że HHMATP/PMMM ma nie tylko dobry wpływ na ograniczenie palności papieru, ale również na jego odporność na działanie wody.

4

Impact of Hexaamidocyclotriphosphazene on the Flame Retardancy of Paper

Tang L., Bi W., Ke Y., Song H., He W., Liu Y.

Fibres & Textiles in Eastern Europe

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2016

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Vol. 24, no. 4 (118)

148--152

EN

In this paper, the flame retardancy of hexaamidocyclotriphosphazene (HACTP) in paper was studied by limiting oxygen index measurement, the vertical burning test and cone calorimetry test. Meanwhile the mechanism was discussed by the analysis of residues obtained in the cone calorimeter test. The experimental results revealed that HACTP had excellent flame retardancy in paper.

PL

Badano zmniejszenie palności papieru stosując hexaamidocyklotrifosfazen (HACTP) poprzez indeks tlenowy, test pionowego palenia, i test kalorymetru stożkowego. Badano również mechanizm ograniczenia palności poprzez analizę resztek uzyskanych z testu kalorymetru stożkowego. Eksperymenty wykazały, że HACTP ma wybitny wpływ na zmniejszenie palności papieru.

5

The Preparation of NC Microspheres and BuNENA Modified NC Microspheres by the Breath Figures Method

He L., He W., Luo Y.

Central European Journal of Energetic Materials

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2016

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Vol. 13, no. 3

567--578

EN

The ‘breath figures’ method was used to prepare nitrocellulose (NC) microspheres and N-butyl-N-(2-nitroxyethyl)nitramine (BuNENA) modified NC microspheres (BMNM). By using acetone as the solvent and non-solvent n-hexane as the atmosphere, NC microspheres and BMNM were obtained. The matching of solvents and non-solvents was the key factor influencing the final morphology. TG and DSC were employed to study the thermal decomposition characteristics of BMNM. The results suggested that there were two distinct stages of thermal mass loss from the BMNM: the first was the mass loss associated with partial volatilisation of BuNENA, and its activation energy was 68.54 kJ/mol. The second mass loss was the thermal decomposition of NC and residual BuNENA with a high activation energy (249.53 kJ/mol, calculated by the Kissinger method). According to the thermal decomposition kinetics model, the optimal kinetics model of BMNM was B1-A2. The addition of BuNENA did not influence the thermal decomposition of NC.

6

A Novel Approach To Diagnosis Of Analog Circuit Incipient Faults Based On KECA And OAO LSSVM

Zhang C., He Y., Zuo L., Wang J., He W.

Metrology and Measurement Systems

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2015

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Vol. 22, nr 2

251--262

EN

Correct incipient identification of an analog circuit fault is conducive to the health of the analog circuit, yet very difficult. In this paper, a novel approach to analog circuit incipient fault identification is presented. Time responses are acquired by sampling outputs of the circuits under test, and then the responses are decomposed by the wavelet transform in order to generate energy features. Afterwards, lower-dimensional features are produced through the kernel entropy component analysis as samples for training and testing a one-against-one least squares support vector machine. Simulations of the incipient fault diagnosis for a Sallen-Key band-pass filter and a two-stage four-op-amp bi-quad low-pass filter demonstrate the diagnosing procedure of the proposed approach, and also reveal that the proposed approach has higher diagnosis accuracy than the referenced methods.

7

Automatic calibration system for digital-display vibrometers based on machine vision

He W., Xu G., Rong Z., Li G., Liu M.

Metrology and Measurement Systems

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2014

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Vol. 21, nr 2

317--328

EN

Considering the low efficiency during the process of traditional calibration for digital-display vibrometers, an automatic calibration system for vibrometers based on machine vision is developed. First, an automatic vibration control system is established on the basis of a personal computer, and the output of a vibration exciter on which a digital-display vibrometer to be calibrated is installed, is automatically adjusted to vibrate at a preset vibration level and a preset frequency. Then the display of the vibrometer is captured by a digital camera and identified by means of image recognition. According to the vibration level of the exciter measured by a laser interferometer and the recognized display of the vibrometer, the properties of the vibrometer are calculated and output by the computer. Image recognition algorithms for the display of the vibrometer with a high recognition rate are presented, and the recognition for vibrating digits and alternating digits is especially analyzed in detail. Experimental results on the built-up system show that the prposed image recognition methods are very effective and the system could liberate operators from boring and intense calibration work for digital-display vibrometers.

8

Modelling and Calculation of the Initial Ignition Gas Pressure Flow through a Rigid Porous Medium in a 100 mm Ignition Simulator

Xiao Z., Ying S., He W., Xu F.

Central European Journal of Energetic Materials

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2014

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Vol. 11, no. 4

475--489

EN

To acquire a better understanding of the early ignition phenomena in a 100 mm ignition simulator loaded with a packed propellant bed, a theoretical model of the ignition gas flow through the rigid porous medium was developed. Three pressure gauges were installed in the lateral side of the ignition simulator for post ignition measurement of the chamber pressure. The pseudo-propellant loaded into the chamber was similar in size to the standard 13/19 single-base cylindrical propellant. It was composed of a rigid ceramic composite with low thermal conductivity. It was assumed that the pseudo-propellant bed was rigid in contrast to the assumption of an elastic porous medium. The calculated pressure values were well verified by the experimental data at a low loading density of the pseudo-propellant bed of 0.18 g•cm-3. However, there was still error between the experimental and the calculated results in the early pressure peak position closest to the ignition primer when the loading density of the pseudo-propellant bed was increased to 0.73 and 1.06 g•cm-3. This error is attributed to the change in local permeability of the pseudo-propellant bed at high loading densities, which is assumed, for ease of modelling, to be constant in the model. These calculations may enable a better understanding of the physical processes of ignition gas flow in an ignition simulator loaded with a pseudo-propellant bed.

9

A novel forward problem solver based on meshfree method for electrical impedance tomography

Hu G., Chen M., He W., Zhai J.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 2a

234--237

EN

In this paper the meshfree method is developed to solve the forward problem for electrical impedance tomography. Differing from finite element method and finite volume method, there is no mesh generation in meshfree method, which is easier to realize and more propitious to be developed as an adaptive procedures for image reconstruction. Numerical simulation results are presented and compared with the results of analytical solution. It is observed that the obtained results are consistent with the results of analytical solution.

PL

W artykule zaproponowano nowa metodę tomograficznej analizy impedancji w której nie generuje się oczek jak na przykład w metodzie elementów skończonych. Dzięki temu uzyskuje się łatwiejsza analizę, w tym także metodami adaptacyjnymi.

10

Granular Computing Based on Gaussian Cloud Transformation

Liu Y., Li D., He W., Wang G.

Fundamenta Informaticae

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2013

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Vol. 127, nr 1-4

385--398

EN

Granular computing is one of the important methods for extracting knowledge from data and has got great achievements. However, it is still a puzzle for granular computing researchers to imitate the human cognition process of choosing reasonable granularities automatically for dealing with difficult problems. In this paper, a Gaussian cloud transformation method is proposed to solve this problem, which is based on Gaussian Mixture Model and Gaussian Cloud Model. Gaussian Mixture Model (GMM) is used to transfer an original data set to a sum of Gaussian distributions, and Gaussian Cloud Model (GCM) is used to represent the extension of a concept and measure its confusion degree. Extensive experiments on data clustering and image segmentation have been done to evaluate this method and the results show its performance and validity.

11

Preparation and Performance of a Novel Water Gel Explosive Containing Expired Propellant Grains

Wang P., Xei X., He W.

Central European Journal of Energetic Materials

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2013

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Vol. 10, no. 4

495--507

EN

Novel water gel explosives containing expired single base and double base propellant grains were prepared by using a new gelling agent and a simple process. The shock wave overpressures and underwater output energies of the explosives were measured. The detonation performances of the explosives were also investigated. As the particle size of the propellant was increased, the detonation velocity, peak overpressure and underwater energy of the explosive containing single base propellant (NCP) were gradually reduced. Double base propellant (DBP) had low detonation sensitivity due to its thermoplasticity. When it was mixed with the appropriate quantity of NCP, DBP could also be reused. NCP acted as the sensitizer and energy source in the explosive containing both DBP and NCP. So the detonation velocity, peak overpressure and underwater energy of the explosive increased with the increase in ωNCP. With excellent detonation performance, these two kinds of water gel explosives can be used as opencast blasting agents.

12

How to build a photovoltaic system

Markvart T., Arnold R. J., He W.

Opto-Electronics Review

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2000

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Vol. 8, No. 4

333-338

EN

This paper gives an overview of photovoltaic system engineering. Several issues are discussed that are currently under consideration in the area of grid-connected and stand-alone systems. The regulatory framework for the utility interface of a photovoltaic system is outlined, with examples of criteria which usually need to be satisfied by a grid-connected system before connection to the utility network is permitted. An area that has received considerable attention in the design of stand-alone system is sizing. Several sizing methods are discussed, and a possible a extension of one of the sizing techniques to photovoltaic/wind energy hybrids is also briefly discussed.