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Development of acoustic computer simulation for performance spaces: A systematic review and meta-analysis

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Building Simulation 2022年第10期15卷 1729-1745页

作者： Chao Wang jian Kang School of Architecture Tianjin UniversityTianjin 300072China UCL Institute for Environmental Design and Engineering The BartlettUniversity College London(UCL)Central House14 Upper Woburn PlaceLondon WC1H0NNUK

This article aims to review the development of acoustic computer simulation for performance spaces. The databases of Web of Science and Scopus were searched for peer-reviewed journal articles published in English between 1960 and 2021, using the keywords for “simulation”, “acoustic”, “performance space”, “measure”, and their synonyms. The inclusion criteria were as follows: (1) the searched article should be focused on the field of room acoustics (reviews were excluded);(2) a computer simulation algorithm should be used;(3) it should be clearly stated that the simulated object is a performance space;and (4) acoustic measurements should be used for comparison with the simulation. Finally, twenty studies were included. A standardised data extraction form was used to collect the modelling information, software/algorithm, indicators for comparison, and other information. The results revealed that the most used acoustic indicators were early decay time (EDT), reverberation time (T30), strength (G), and definition (D50). The accuracy of these indicators differed greatly. For non-iterative simulation, the simulation accuracies of most indicators were outside their respective just noticeable differences. Although a larger sample size was required for further validation, simulations of T30, EDT, and D50 all showed an increase in accuracy with increasing time from 1979 to 2020, except for G. In terms of frequency, the simulation was generally less accurate at lower frequencies, which occurred at T30, G, D50 and T20. However, EDT accuracy did not exhibit significant frequency sensitivity. The prediction accuracy of inter-aural cross-correlation coefficients (IACC) was even higher at low frequencies than it was at high frequencies. The average value of most indicators showed a clear systematic deviation from zero, providing hints for future algorithm improvements. Limitations and the risks of bias in this review were discussed. Finally, various types of benchmark tests were sug

关键词： acoustic simulation accuracy systematic review performance space iterative simulation

Compositional dependence of thermophysical properties in binary alkaline earth borate melts:Insights from structure in short-range and intermediate-range order

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Journal of Materials Science & Technology 2022年第36期131卷 195-203页

作者： jian Yang Il Sohn Department of Materials Science and Engineering Yonsei UniversitySeoul120749Korea State Key Laboratory of Cemented Carbide Zhuzhou 412000China

In this work,the thermal conductivity of alkaline earth borate melts was measured using hot-wire method from 1323 to 1623 K,and the thermal diffusivity was extrapolated from the thermal conductivity and heat *** compositional dependence of thermophysical properties was interpreted according to the structure in short-range and intermediate-range *** on the Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),and 11B magic-angle spinning nuclear magnetic resonance(MAS-NMR)spectra,modifier cation with higher field strength prefers the formation of non-bridging oxygens(NBOs)for the charge compensation at high BO_(1.5)/MO ratios.A lower amount of covalent bond and greater isolation of large borate groups lead to a lower thermal conductivity in calcium borate melt compared with strontium and barium *** the large size of Ba^(2+)encounters difficulty in fitting around B^[4]-OB^[4]linkages inside the overcrowded large borate groups when BO_(1.5)/BaO=2.5,promoting the formation of NBOs on the edge of borate groups for the charge compensation of modifier cations and leading to the decline in the thermal *** conductivity plays a major role in regulating the thermal diffusivity at a given temperature since the compositional dependence of volumetric heat capacity is relatively weak compared with that of thermal conductivity.

关键词： Thermal conductivity Magic-angle spinning nuclear magnetic resonance(MAS-NMR) X-ray photoelectron spectroscopy(XPS) Raman spectroscopy Thermal diffusivity

Advances in communications using optical vortices

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Photonics Research 2016年第5期4卷 14-28页

作者： jian Wang Wuhan National Laboratory for Optoelectronics School of Optical and Electronic Information Huazhong University of Science and Technology

An optical vortex having an isolated point singularity is associated with the spatial structure of light waves.A polarization vortex(vector beam) with a polarization singularity has spatially variant polarizations. A phase vortex with phase singularity or screw dislocation has a spiral phase front. The optical vortex has recently gained increasing interest in optical trapping, optical tweezers, laser machining, microscopy, quantum information processing, and optical communications. In this paper, we review recent advances in optical communications using optical vortices. First, basic concepts of polarization/phase vortex modulation and multiplexing in communications and key techniques of polarization/phase vortex generation and(de)multiplexing are introduced. Second, free-space and fiber optical communications using optical vortex modulation and optical vortex multiplexing are presented. Finally, key challenges and perspectives of optical communications using optical vortices are discussed. It is expected that optical vortices exploiting the space physical dimension of light waves might find more interesting applications in optical communications and interconnects.

关键词： OAM mode Advances in communications using optical vortices

State of the art in applications of machine learning in steelmaking process modeling

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International Journal of Minerals,Metallurgy and Materials 2023年第11期30卷 2055-2075页

作者： Runhao Zhang jian Yang State Key Laboratory of Advanced Special Steel School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

With the development of automation and informatization in the steelmaking industry,the human brain gradually fails to cope with an increasing amount of data generated during the steelmaking *** learning technology provides a new method other than production experience and metallurgical principles in dealing with large amounts of *** application of machine learning in the steelmaking process has become a research hotspot in recent *** paper provides an overview of the applications of machine learning in the steelmaking process modeling involving hot metal pretreatment,primary steelmaking,secondary refining,and some other *** three most frequently used machine learning algorithms in steelmaking process modeling are the artificial neural network,support vector machine,and case-based reasoning,demonstrating proportions of 56%,14%,and 10%,*** data in the steelmaking plants are frequently ***,data processing,especially data cleaning,is crucially important to the performance of machine learning *** detection of variable importance can be used to optimize the process parameters and guide *** learning is used in hot metal pretreatment modeling mainly for endpoint S content *** predictions of the endpoints of element compositions and the process parameters are widely investigated in primary *** learning is used in secondary refining modeling mainly for ladle furnaces,Ruhrstahl–Heraeus,vacuum degassing,argon oxygen decarburization,and vacuum oxygen decarburization *** development of machine learning in the steelmaking process modeling can be realized through additional efforts in the construction of the data platform,the industrial transformation of the research achievements to the practical steelmaking process,and the improvement of the universality of the machine learning models.

关键词： machine learning steelmaking process modeling artificial neural network support vector machine case-based reasoning data processing

Practical Green’s function for the thermal stress field induced by a heat source in plane thermoelasticity

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Applied Mathematics and Mechanics(English Edition) 2020年第4期41卷 543-550页

作者： jian HUA Ming DAI State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The classical Green’s functions used in the literature for a heat source in a homogeneous elastic medium cannot lead to ?nite remote thermal stresses in the medium,so that they may not work well in practical thermal stress analyses. In this paper, we develop a practical Green’s function for a heat source disposed eccentrically into an elastic disk/cylinder subject to plane deformation. The edge of the disk/cylinder is assumed to be thermally permeable and traction-free. The full thermal stress ?eld induced by the heat source in the disk/cylinder is determined exactly and explicitly via the Cauchy integral techniques. In particular, a very simple formula is obtained to describe the hoop thermal stress on the edge of the disk/cylinder, which may be conveniently useful for analyzing the thermal stresses in microelectronic components.

关键词： heat source Green’s function thermal stress finite matrix

Influence of modeling approaches and structural parameters on impact resistance of the human porous cranium

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Acta Mechanica Sinica 2021年第6期37卷 910-928,I0001页

作者： Qianqian Wu jian Xiong Center for Composite Materials and Structures Harbin Institute of TechnologyHarbin150001China

Failure mechanism and impact resistance of a human porous cranium are studied in detail by means of theoretical and numerical *** is hypothesized that pore distribution of a cranium directly affects cranial energy absorption,and a stretched beam model and a real beam model are taken as the example for the ***,for the purpose of comparison with numerical results,a theoretical model is also proposed for the prediction of residual velocity and contact force of the impactor for an impacted *** with the real beam model,the stretched beam model containing through-thickness pores is easily deformed under the impact,thereby buffering well the external impact *** energy absorption efficiency of both the stretched beam model and real beam model is concerned with the threshold velocity for penetration which is directly related to the size of the structural damage ***,there is good agreement between numerical and theoretical *** addition,the effect of structural geometric parameters(shape and size of the impactor)on the impact resistance of the skull bone is theoretically *** study provides reference for the evaluation of the energy absorption and failure mechanism of the skull under impact loads.

关键词： Skull porous structure Impact resistance Modeling approach Theoretical prediction Influence of structural parameters

Coexistence Theory of Slag Structure and Its Application to Calculation of Oxidizing Capability of Slag Melts

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Journal of Iron and Steel Research International 2003年第1期10卷 1-10页

作者： ZHANG jian University of Science and Technology Beijing

The coexistence theory of slag structure and it's application to calculation of the oxidizing capabilities of slag melts is described. It is shown that the law of mass action can be widely applied to the calculation of oxidizing capabilities of slag melts in combination with the coexistence theory of slag *** slag melts containing basic oxides FeO and MnO, their oxidizing capabilities can be expressed by N Fe tO =N FeO +6N Fe 2O 3 , while for slag melts containing basic oxides CaO, MgO, etc., in addition to FeO and MnO, their oxidizing capabilities can be given as N Fe tO =N FeO +6N Fe 2O 3 +8N Fe 3O 4 .

关键词： oxidizing capability coexistence theory slag structure activity mass action concentration

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Open-loop Phase Synchronization Method of Positive and Negative Sequences for Three-phase Asymmetric Grid

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CSEE Journal of Power and Energy Systems 2023年第5期9卷 1973-1979页

作者： jian He Shanxu Duan State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Currently,a grid-connected inverter is required to inject a dual-sequence current during asymmetric grid sags,which means both positive and negative sequence phases should be *** paper proposes an open-loop phase synchronization(OLS)method of positive and negative sequences for an asymmetric grid based on the moving average filter(MAF),which does not need to separate the positive and negative sequence fundamental components of grid *** a benefit,there is no double-frequency oscillation in the estimated phases at offnominal frequencies since the positive and negative sequence phases are obtained *** proposed method not only has the inherent advantages of OLS,but also further improves the dynamic response since the window length of MAF is only 1/6 of the fundamental *** effectiveness of the proposed OLS is verified by experimental results.

关键词： Asymmetric grid open-loop synchronization positive and negative sequence phases

Dynamics about Neural Array with Simple Lateral Inhibitory Connections

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Chinese Annals of Mathematics,Series B 2011年第2期32卷 161-186页

作者： jian ZHUANG Department of Statistics School of Economics Anhui University of Technology Maanshan 243000 Anhui China

Lateral inhibitory effect is a well-known feature of information processing in neural *** paper presents a neural array model with simple lateral inhibitory *** detailed examining into the dynamics of this kind of neural array,the author gives the sufficient conditions under which the outputs of the network will tend to a special stable pattern called spatial sparse pattern in which if the output of a neuron is 1,then the outputs of the neurons in its neighborhood are *** ability called spatial sparse coding plays an important role in self-coding,self-organization and associative memory for patterns and pattern *** main conclusions about the dynamics of this kind of neural array which is related to spatial sparse coding are introduced.

关键词： Simple lateral inhibitory connections Spatial sparse coding Spatial sparse pattern Neural array