Wyniki wyszukiwania - BazTech

1

Measuring ship collision risk in a dense traffic environment

Huang Y., Van Gelder P. H. A. J. M.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2019

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Vol. 13. no. 4

737--744

EN

Collision risk measurement is an essential topic for ship collision prevention. Many risk measures, i.e. DCPA/TCPA, etc., decouple the ship traffic into several pairs of ships and then evaluate the risk in each pair. This kind of measurement loses some information of the entire traffic and might include some biases in risk measurement, especially in multiple-ship scenarios. In this article, Imminent Collision Risk Assessment (ICRA) is extended, which formulates collision risk as a ratio of reachable maneuvers leading to a collision and all reachable maneuvers (velocities). Two groups of scenarios have been simulated to show the ICRA is suitable for assessing the collision risk in multiple-ship scenarios. Moreover, two improvements have been introduced: (1) a generalized velocity obstacle algorithm is introduced to collect the maneuvers leading to collisions, which considers ship dynamics; (2) the constraints of forces are considered in the formulation of reachable maneuvers. As a result, the proposed measurement helps one ship assess the risk of approaching obstacles which are difficult to avoid the collision in terms of own-ship’s dynamics and kinetic constraints.

2

The surface features of activated stibnite surface with copper or lead ion

Cao Q., Huang Y., Zou H., Wen S.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 3

763--770

EN

Cu2+ and Pb2+ are widely used as activators for the flotation of stibnite. In this work, by the treatment of Cu2+ or Pb2+, the activation product and the thickness of activation layer on the stibnite surface were both investigated. Based on the flotation results, zeta potential analysis and X-ray photoelectron spectroscopy (XPS) study, it was found that Cu2+ was reduced to Cu+ at the stibnite surface and a layer of Cu2S was formed at the surface. While, a PbS layer presenting at the stibnite surface is responsible for the activation flotation of stibnite with Pb2+. Time of flight secondary ion mass spectrometry (TOF-SIMS) analysis further implies that, when stibnite was activated with 5×10-5 mol/dm3 of CuSO4 or Pb(NO3)2, the thickness of Cu2S layer on the Cu-activated surface was close to 2.7 nm, while the thickness of PbS layer was about 1.8 nm on the Pb-activated surface.

3

Manipulation of the supercontinuum energy distribution based on the positive chirp in photonic crystal fiber

Yang H., Tong X., Zhao S., Huang Y.

Optica Applicata

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2018

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Vol. 48, nr 1

75--85

EN

The effect of initial frequency chirp is numerically investigated to obtain high-efficient supercontinuum radiation in photonic crystal fibers with two closely spaced zero-dispersion wavelengths. Our results show that the positive chirp can significantly improve the probability of energy transferred from the soliton to the dispersive wave. And with the increase of the chirp, the energy increases obviously. At the same time, the intensity of the dispersive wave is proportional to the chirp value. Especially, solitons will not appear when the chirp value exceeds 3.9. Therefore, choosing an appropriate positive chirp, we can regulate the energy of the dispersive wave and solitons in photonic crystal fibers.

4

Effects of Holding Conditions on Microstructure of Al-5Ti-1B and Its Refining Efficiency on Al-Cu Alloy

Huang Y., Shao H., Xiao Z., Ren X.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 2

647--652

EN

A series of Al-5Ti-1B master alloys were obtained via fluoride salt process by holding them between 780°C and 880°C for 10-90 min. The influence of holding temperature and time during preparation on the microstructure and its refining performance were investigated by X-ray diffractometer, optical microscopy and scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. The results indicated both the morphology and the distribution of TiB22and Al3Ti were seriously affected by holding conditions. Inadequate TiB2 particles were generated when holding time was short. However, Fe-containing impurity particles that aggregated along the matrix grain boundaries were found after the prolonged holding time. The refining and microhardness test results revealed that Al-5Ti-1B, the one held at 820°C for 30 min showed the optimum refining efficiency on Al-Cu alloy.

5

Analysis of recent coastline evolution due to marine reclamation projects in the Qinzhou Bay

Yan Y., Zhang Z., Wang C., Zhang L., Huang Y., Zhang J.

Polish Maritime Research

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2017

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S 2

188--194

EN

Intense marine reclamation activities bring obvious benefits, meanwhile, these activities also influence the coastal natural formation, hydrodynamic processes and water environment etc. In order to investigate the exact influence in the Qinzhou Bay brought by marine reclamation behaviors in recent years, based on the remote sensing image data in the Qinzhou Bay in 2006, 2008, 2009, 2012 and 2014, with the help of GIS and RS software, the thesis interprets Qinzhou Bay coastline and artificial reclamation by man-machine interaction and makes quantitative analysis in the Qinzhou Bay coast evolution recently. The results show: (1) Qinzhou Bay coastal morphology change degree was strong in 2006 - 2012 and the coastline changed greatly. Originally part of the natural shore segments which had twists and turns were gradually filled into artificial coast, the coast constantly advanced to the sea, coastline became regular and straight; (2) The change degree of coastline was relatively small in 2006-2008, the average artificial coastline increased 8.86 km/a, the average artificial reclamation area was 20.79 km2 /a; in 2008-2012, the change range of coastline was the greatest, coastline changed most severely, the average artificial coastline increased 16.07 km/a, the average artificial reclamation area was 58.52 km2 /a; however, in 2012-2014, coastline change degree relatively slowed, the average artificial coastline increased 4.04 km per year, the average artificial reclamation area was 3.464 km2 /a. (3) Compared to the studies of predecessors, the innovation of this paper is that it is the first to carry out the detailed research on coastline evolution caused by reclamation engineerings of the Qinzhou Bay, then formed the change results on coastline that caused by intense human activities in the Qinzhou Bay, provided the area of the marine environment protection with full and accurate data.

6

Adsorption behavior of Zn(II) onto natural minerals in wastewater. A comparative study of bentonite and kaolinite

Chai W., Huang Y., Su S., Han G., Liu J., Cao Y.

Physicochemical Problems of Mineral Processing

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2017

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Vol. 53, iss. 1

264--278

EN

In order to remove the harmful metal ions in lead-zinc mineral processing wastewater, two natural clay minerals (bentonite and kaolin) were used as adsorbents and Zn(II) ions were the emphasis in this work. The adsorption behaviors including kinetics and isotherms were investigated by batch experiments. In addition, the adsorption mechanisms were studied by means of zeta potential testing, optical microscope and XRD analysis. The results show that the adsorption process can be best described as the pseudo-second order kinetic model. The adsorption equilibrium data of bentonite and kaolinite can be respectively fitted best by Langmuir and Freundlich models. Thermodynamic studies display that the adsorption of Zn(II) onto clays is non-spontaneous and endothermic. The maximum capacity of Zn(II) adsorbed on bentonite and kaolinite respectively reaches to 79.2 mg·g-1 and 6.35 mg·g-1 at 25 °C. The structural differences of bentonite and kaolinite result in the differences in adsorption behavior and mechanism. The interaction mechanisms of Zn(II) with bentonite and kaolinite involve electrostatic attraction, cation exchange, surface complex and precipitation. Bentonite as adsorbent has the potential to remove Zn2+ better than kaolinite.

7

Effect of overlying water pH, dissolved oxygen and temperature on heavy metal release from river sediments under laboratory conditions

Huang Y., Zhang D., Xu Z., Yuan S., Li Y., Wang L.

Archives of Environmental Protection

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2017

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Vol. 43, no. 2

28--36

EN

The heavy metal release experiments were conducted in the laboratory to examine the effects of 3 factors - pH, dissolved oxygen (DO), and temperature on the metal release from sediments taken from the Huangpu River. The metal concentrations in the dry sediments ranged from 0.030 to 0.296 mg g-1 for Cr, 0.021 to 0.097 mg g-1 for Ni, 0.014 to 0.219 mg g-1 for Cu, 0.035 mg to 0.521 mg g-1 for Zn, 0.0002 to 0.001 mg g-1 for Cd and 0.023 to 0.089 mg g-1 for Pb. Most of the metals found in the sediments were in the form of residual fraction, the exchangeable fraction consisted of only a small portion of total metals. The average dissolved metal concentrations in the overlying water during the 13-day period under different conditions were ranging from 0.82 to 1.93 μg L-1 for Cr, 1.08 to 4.19 μg L-1 for Ni, 40.79 to 82.28 μg L-1 for Cu, 20.30 to 29.96 μg L-1 for Zn, 1.57 to 4.07 μg L-1 for Cd, and 22.26 to 75.50 μg L-1 for Pb, respectively. Statistical interpretation of the data indicated that pH (7, 8, 9), dissolved oxygen DO (1.0 and 5.0 mg L-1) and temperature (4, 16, 25°C) had no significant effects on the heavy metal release under the studied conditions. Cu and Pb had the highest release flux, while Cd, Pb and Cu had higher mobility. The main factors controlling the metals release might be the inherent characters of metals and sediments.

8

A Fast Method of Feature Extraction for Lowering Vehicle Pass-By Noise Based on Nonnegative Tucker3 Decomposition

Wang H., Cheng G., Deng G., Li X., Li H., Huang Y.

Archives of Acoustics

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2017

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Vol. 42, No. 4

619--629

EN

Usually, the judgement of one type fault of vehicle pass-by noise is difficult for engineers, especially when some significant features are disturbed by other interference noise, such as the squealing noise is almost simultaneous with the whistle in the exhaust system. In order to cope with this problem, a new method, with the antinoise ability of the algorithm on the condition by which the features are entangled, is developed to extract clear features for the fault analysis. In the proposed method, the nonnegative Tucker3 decomposition (NTD) with fast updating algorithm, signed as NTD_FUP, can find out the natural frequency of the parts/components from the exhaust system. Not only does the NTD_FUP extract clear features from the confused noise, but also it is superior to the traditional methods in practice. Then, an aluminium-foil alloy material, which is used for the heat shield for its lower noise radiation, replaces the aluminium alloy alone. Extensive experiments show that the sound pressure level of the vehicle pass-by noise is reduced 0.9 dB(A) by the improved heat shield, which is also considered as a more lightweight design for the exhaust system of an automobile.

9

Research on community garden practice - taking ‘the Kid’s Garden’ in Hunan Agricultural University as an example

Zhou Z., Huang Y., Zhou C.

Architektura Krajobrazu

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2017

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nr 3

34--43

EN

As a form of urban green space, community gardens have provided urban residents with various environments, to satisfy their social, economic and health interests. For the purposes of creating public, open and shared spaces, this article summarizes and contrasts the history of the community garden development in Europe and America, while analyzing the development situation of China as well. Taking “the Kid’s Garden” in Hunan Agricultural University as an example, the authors discuss the whole practice process in three aspects: the layout design, the construction process, and the operation and maintenance plan. Finally, the conclusion of the article presents a community garden building model, which is supported by universities with the goals to reward the society, as well as to provide a win-win result between practice and teaching. This experience is hoped to popularize community gardens and to make a contribution towards a harmonious society.

10

Two-stage classification approach for human detection in camera video in bulk ports

Mi C., Zhang Z., He X., Huang Y., Mi W.

Polish Maritime Research

|

2015

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S 1

163--170

EN

With the development of automation in ports, the video surveillance systems with automated human detection begun to be applied in open-air handling operation areas for safety and security. The accuracy of traditional human detection based on the video camera is not high enough to meet the requirements of operation surveillance. One of the key reasons is that Histograms of Oriented Gradients (HOG) features of the human body will show great different between front & back standing (F&B) and side standing (Side) human body. Therefore, the final training for classifier will only gain a few useful specific features which have contribution to classification and are insufficient to support effective classification, while using the HOG features directly extracted by the samples from different human postures. This paper proposes a two-stage classification method to improve the accuracy of human detection. In the first stage, during preprocessing classification, images is mainly divided into possible F&B human body and not F&B human body, and then they were put into the second-stage classification among side human and non-human recognition. The experimental results in Tianjin port show that the two-stage classifier can improve the classification accuracy of human detection obviously.

11

A new design of a photonic crystal fiber with a beam shaping effect and flexible management of dispersion and confinement loss

Huang Y., Jiang P, Yang H., Yu M.

Optica Applicata

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2014

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Vol. 44, nr 3

375--387

EN

A new design of a guiding-index photonic crystal fiber which possesses a beam shaping effect and flexible control of dispersion has been proposed in this paper. It can shape a Gaussian beam into a circular hollow beam with certain dimension, which can be used in optical communication systems with a Cassegrain antenna to improve transmission efficiency by avoiding the loss of energy caused by the subreflector center reflection. In addition, its dispersion and confinement loss can be changed in a broad range by slightly adjusting structural parameters under condition that the hollow beam dimension remains about the same. Fairly practical properties, zero dispersion or flattened dispersion, can be obtained when structural parameters are set appropriately. A series of models with different parameters are analyzed and compared. Results of numerical simulation show that the ultra-low dispersion of 1.802 ps/km/nm can be obtained when λ = 1.31 μm. Several modest design parameters are given as well.

12

Synthesis of V2O3/C composites with different morphologies by a facile route and phase transition properties of the compounds

Zhang Y., Wang N., Huang Y., Huang C., Mei X, Meng G.

Materials Science Poland

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2014

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Vol. 32, No. 2

236--242

EN

V2O3 and amorphous carbon composites (V2O3/C composites) with different morphologies (e.g. nanospheres, nanorods and nanosheets) were, for the first time, successfully synthesized by a facile hydrothermal route and subsequent calcination. The as-obtained samples were characterized by X-ray powder diffraction (XRD), energy dispersive spectrometery (EDS), elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The morphology of V2O3/C composites could be easily controlled by varying the reaction time, and, as a result, V2O3/C composites with nanospheres, nanorods and nanosheets were selectively synthesized. Furthermore, the phase transition property of V2O3/C composites was measured by differential scanning calorimetry (DSC), suggesting that V2O3/C composites exhibit the phase transition similar to V2O3, which could expand the potential applications of materials related to V2O3 in the future.

13

A visualization system for oil spills IN Qinzhou Bay based on Google Earth

Dong Y., Hu B., Xie Z., Huang Y., Zhang S.

Journal of Power Technologies

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2014

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Vol. 94, nr 1

79--83

EN

This paper mainly aims to solve the visualization problem of oil spill. Combined with conditions on the ground of target research area Qinzhou Bay, important access to the sea for southwest China, the paper propose a model to construct the visualization system of oil spill, which relatively reveals as many as impact factors of oil spill and also is suitable for this region. The rich image resources of satellite remote sensing Google Earth is selected as the client during constructing the system. It combines Oracle which is suitable for storing large amounts of data as a backend database. This paper solves data exchange and data storage of KML between the Google Earth and Oracle by connecting them, which realizes the visualization of oil spill system in Qinzhou Bay.

14

Suppression method of partial-discharge interference signal based on the combination of morphological filters and complex wavelet transform

Wang Y., Zhang D., Lu G., Huang Y.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 4

123-128

EN

Solving the periodic narrowband interference and suppression of white noise during the actual detection of partial discharge (PD) are difficult. In this paper, a method of suppressing the interference signal method based on the combination of morphological filters and complex wavelet transform is proposed. Generalized morphological filters based on the principle of mathematical morphology were structured and set as a pre-filter unit to realize pre-treatment of the original PD signals, and complex wavelet transform was then employed to process the PD signals. Finally, denoised PD signals were obtained. Applying this method to deal with the noise in the simulation and acquisition of PD signals, the results showed that the method can restrain effectively the PD periodic narrowband interference and white noise. Compared with the same wavelet base of the wavelet and the complex wavelet denoising methods, this method reduces energy loss and retains well the PD signals characteristics.

PL

W artykule opisano metodę tłumienia zakłóceń (zakłócenia wąskopasmowe, biały szum) w sygnałach, w przypadku wykrycia wyładowań niezupełnych. W rozwiązaniu wykorzystano kombinację filtrów morfologicznych, działających jako pre-filtr i złożoną transformatę falkową do dalszej obróbki sygnałów. Wykonano badania symulacyjne, potwierdzające skuteczność filtracji.

15

Power Supply & Storage Capability Index of Smart Grid and its Application

Liao H., Liu D., Yu W., Huang Y.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 3a

109--114

EN

In distribution network, the interconnection of distributed energy storage system (DESS) provides network with supply & storage capability which is conducive to regulate peak load and solve intermittency of intermittent energy source. DESS power supply & storage capability index is proposed to quantitatively describe the time-varied maximum power supply and storage capability of DESS, considering the effect caused by interconnection of DESS and the constraint of electrical network and DESS. The supply & storage capability index’s effectiveness is verified under the context of DESS optimal economic scheduling.

PL

W artykule przedstawiono zagadnienie oceny zdolności wytwarzania i gromadzenia energii elektrycznej w systemach typu DES (ang. Distributed Energy Storage). W tym celu zaproponowano indeks, określający wielkości maksymalne wymienionych czynników, uwzględniający możliwość łączenia DES między sobą i z siecią. Opisano sposób weryfikacji otrzymanego parametru.

16

EHL simulation of the effects of the rod surface on hydraulic rod seal operation

Salant R. F., Huang Y.

Hydraulika i Pneumatyka

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2013

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nr 3

23--26

17

Speech Emotion Recognition Using Hybrid Generative and Discriminative Models

Huang Y., Zhang G., Dong F., Li Y., Da F.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 3b

105-108

EN

In this paper, we use Sequential Forward Selection to select 8 dimensional frame-level features from the total 69 dimensional features, and we reduce the dimensions of utterance-level eigenvectors from 63 to 12 by fisher discriminant. Then, two kinds of GMM multidimensional likelihoods are proposed for hybrid generative and discriminative models. Experimental results on Berlin emotional speech databases show that the GMM-MAP/SVM series hybrid model is the optimal Hybrid Generative and Discriminative Models, with the recognition rate up to 85.1%.

PL

W artykule zaprezentowano system wykrywania emocji w głosie na podstawie modelu dyskryminacyjnego. Zaprezentowano badania skuteczności system na przykładzie bazy danych Berlin.

18

Rotor Displacement Estimation for MB Sensorless Control

Zhu Z., Sun Y., Huang Y., Ji X.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 1b

141-145

EN

This paper presents an on-line recursive least squares support vector machine(O-RLS-SVM)-based displacement estimator for magnetic bearings (MBs). The basic premise of the method is that an O-RLS-SVM forms an efficient mapping structure for a nonlinear MB. Through the measurement of phase flux linkages and currents, the O-RLS-SVM is able to estimate the rotor displacement; thereby it facilitates the elimination of the rotor displacement sensor. Simulation results show that the estimator has high estimation precision and favourable operation efficiency.

PL

W artykule przedstawiono system estymacji położenia wirniku w maszynach z poduszką magnetyczną. System nie wymaga czujników – miarą położenia wirnika są przesunięcia fazowe prądu i strumienia magnetycznego.

19

Distribution Networks State Estimation Based on Topological Contraction and Quality Tag

Huang Y., Liu D., Xu W., Yu W.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 5b

1-6

EN

By processing a set of raw measurement data, it provides a real-time system state solution which is the basis of the advanced applications. Currently, the incomplete and poor quality of measurement data is the key factor to impacting state estimation of distribution network. With the help of decision tree theory, the bad data identification method which combines the historical data and remote data from IDP (Integrated Data Platform) and a data processing method is proposed. Algorithm uses the laws of the distribution network data logic to determine the logic of the distribution network. With the help of the theoretical framework of decision tree we can establish the data quality assessment system and fix those bad data so as to increase the quality of the input data. On the basis of data evaluation and fixing, by collecting grid-based data of distribution network and using topology analysis and contracting technology, we can contract the actual network to the state estimation calculation network which meets the observation demand. Quality labels are used to modify the weight of the least squares state estimation algorithm to improve the accuracy of state estimation. Based on the status of data in city distribution network, a proper measurement data detecting and fixing method as well as topology contracting method is proposed. Two real cases of certain central power supply area in Shanghai have verified the effectiveness and feasibility of the method.

PL

W artykule zaproponowano metody badania stanu sieci dystrybucyjnej w czasie rzeczywistym. Metodę zilustrowano na przykładzie dwóch obszarów sieci zasilającej w Szanghaju.

20

Displacement Self-sensing of Bearingless Switched Reluctance Motors Based on LS-SVM

Zhu Z., Sun Y., Huang Y., Ji X.

Przegląd Elektrotechniczny

|

2012

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R. 88, nr 12a

310-313

EN

To achieve the rotor radial displacement self-sensing for a bearingless switched reluctance motor (BSRM), a new displacement estimation method using least squares support vector machine (LS-SVM) was proposed. Firstly, the working principle and mathematic of a 3-phase 12/8 pole BSRM was introduced in brief. Then taking advantage of LS-SVM with better solution for small-sample learning problem and strong generalization ability, two LS-SVMs were trained off-line to obtain two efficient nonlinear mapping structures to express the dynamic behavior of BSRM. The LSSVM training data set is comprised of representative experimental data with current {i | i = (isa1, isa2, ima)} and rotor position θ as inputs and the corresponding displacements {D | D=(α , β )}as outputs. As well as giving a detailed explanation of the new method, simulation and experimental results were presented. It shows that the proposed LS-SVM-based displacement self-sensing method has high precision and operation efficiency.

PL

W artykule przedstawiono uczący się estymator przesunięcia dla bezłożyskowego silnika o przełączanej reluktancji (BSRM), wykorzystujący metodę LS-SVM (ang. Least Square Support Vector Machines). Opisano zasadę działania i model matematyczny silnika BSRM 3- fazowego 12/8 biegunowego. W celu uzyskania efektywnej struktury mapowania nieliniowego do określenia stanów dynamicznych, zastosowano dwa algorytmy, które zostały nauczone offline. Estymator poddano weryfikacji symulacyjnej i eksperymentalnej.