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Research Status and Trends of Indoor Positioning and Navigation Technology in China

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Journal of Geodesy and Geoinformation Science 2023年第3期6卷 87-101页

作者： baoguo YU Lu HUANG Yachuan bao Haonan JIA Shuang LI chong chen Academy for Network&Communications of CETC Shijiazhuang 050081China State Key Laboratory of Satellite Navigation System and Equipment Technology Shijiazhuang 050081China

As an essential component of future comprehensive Positioning,Navigation,and Timing(PNT)system,indoor positioning technology has extensive application demands,making it a focal point of attention in both academia and *** article comprehensively reviews the research status of indoor positioning technology in China,with a focus on highlighting representative achievements and application validations from major research institutions in recent *** addresses the challenges and issues faced in promotion and application of large-scale,high-precision indoor ***,a universal and seamless indoor-outdoor positioning system architecture is proposed,along with a technical roadmap and key technologies to achieve this ***,an analysis and outlook on future technological trends are presented.

关键词： indoor positioning location services integrated PNT

Development of quadrilateral spline thin plate elements using the B-net method

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Acta Mechanica Sinica 2013年第4期29卷 567-574页

作者： Juan chen chong-Jun Li School of Mathematics and Quantitative Economics Dongbei University of Finance and Economics School of Mathematical Sciences Dalian University of Technology

The quadrilateral discrete Kirchhoff thin plate bending element DKQ is based on the isoparametric element Q8, however, the accuracy of the isoparametric quadrilateral elements will drop significantly due to mesh distortions. In a previous work, we constructed an 8-node quadrilateral spline element L8 using the triangular area coordinates and the B- net method, which can be insensitive to mesh distortions and possess the second order completeness in the Cartesian co- ordinates. In this paper, a thin plate spline element is devel- oped based on the spline element L8 and the refined tech- nique. Numerical examples show that the present element indeed possesses higher accuracy than the DKQ element for distorted meshes.

关键词： Spline finite element ~ Refined quadrilateral el-ement ~ Discrete Kirchhoff plate element ~ Triangular areacoordinates ~ B-net method

AutoBPS-BIM:A toolkit to transfer BIM to BEM for load calculation and chiller design optimization

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Building Simulation 2023年第7期16卷 1287-1298页

作者： Zhihua chen Zhang Deng Adrian chong Yixing chen College of Civil Engineering Hunan UniversityChangshaHunan 410082China Key Laboratory of Building Safety and Energy Efficiency(Hunan University) Ministry of EducationChina Department of Building National University of Singapore4 Architecture Drive117566Singapore

This study developed a rapid building modeling tool,AutoBPS-BIM,to transfer the building information model(BIM)to the building energy model(BEM)for load calculation and chiller design *** eight-storey office building in Beijing,33.2 m high,67.2 m long and 50.4 m wide,was selected as a case study ***,a module was developed to transfer BIM in IFC format into BEM in *** air volume systems were selected for the air system,while water-cooled chillers and boilers were used for the central *** EnergyPlus model calculated the heating and cooling loads for each space as well as the energy consumption of the central ***,a chiller optimization module was developed to select the optimal chiller design for minimizing energy consumption while maintaining thermal *** available chillers were included,with capacities ranging from 471 kW to 1329 *** results showed that the cooling loads of the spaces ranged from 33 to 100 W/m^(2) with a median of 45 W/m^(2),and the heating load ranged from 37 to 70 W/m^(2) with a median of 52 W/m^(2).The central plant’s total cooling load under variable air volume systems was 1400 *** with the static load calculation method,the dynamic method reduced 33%of the chiller design *** two chillers were used,different chiller combinations’annual cooling energy consumption ranged from 10.41 to 11.88,averaging 11.12 kWh/m^(2).The lowest energy consumption was 10.41 kWh/m^(2) when two chillers with 538 kW and 1076 kW each were *** the proper chiller number with different capacities was critical to achieving lower energy consumption,which achieved 12.6%cooling system energy consumption reduction for the case study *** study demonstrated that AutoBPS-BIM has a large potential in modeling BEM and optimizing chiller design.

关键词： BIM building energy model EnergyPlus chiller design optimization AutoBPS-BIM

Memristor initial-boosted coexisting plane bifurcations and its extreme multi-stability reconstitution in two-memristor-based dynamical system

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Science China(Technological Sciences) 2020年第4期63卷 603-613页

作者： bao Han chen Mo WU HuaGan bao Bocheng School of Information Science and Engineering Changzhou UniversityChangzhou 213164China

Initial-dependent extreme multi-stability and offset-boosted coexisting attractors have been significantly concerned *** paper constructs a novel five-dimensional(5-D)two-memristor-based dynamical system by introducing two memristors with cosine memductance into a three-dimensional(3-D)linear autonomous dissipative *** theoretical analyses and numerical plots,the memristor initial-boosted coexisting plane bifurcations are found and the memristor initial-dependent extreme multi-stability is revealed in such a two-memristor-based dynamical system with plane ***,a dimensionality reduction model with the determined equilibrium is established via an integral transformation method,upon which the memristor initial-dependent extreme multi-stability is reconstituted theoretically and expounded ***,physically circuit-implemented PSIM(power simulation)simulations are carried out to validate the plane offset-boosted coexisting behaviors.

关键词： memristor-based system memristor initial coexisting plane bifurcations extreme multi-stability

CONSTRUCTION OF GEOMETRIC PARTIAL DIFFERENTIAL EQUATIONS FOR LEVEL SETS

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Journal of Computational Mathematics 2010年第1期28卷 105-121页

作者： chong chen Guoliang Xu LSEC ICMSEC Academy of Mathematics and Systems Science Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences Beijing 100190 China LSEC ICMSEC Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China

Geometric partial differential equations of level-set form are usually constructed by a variational method using either Dirac delta function or co-area formula in the energy functional to be minimized. However, the equations derived by these two approaches are not consistent. In this paper, we present a third approach for constructing the level-set form equations. By representing various differential geometry quantities and differential geometry operators in terms of the implicit surface, we are able to reformulate three classes of parametric geometric partial differential equations （second-order, fourth-order and sixth- order） into the level-set forms. The reformulation of the equations is generic and simple, and the resulting equations are consistent with their parametric form counterparts. We further prove that the equations derived using co-area formula are also consistent with the parametric forms. However, these equations are of much complicated forms than these given by the equations we derived.

关键词： Geometric partial differential equations Level set Differential geometry operators.

A 3D pyramid spline element

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Acta Mechanica Sinica 2011年第6期27卷 986-993页

作者： Juan chen chong-Jun Li Wan-Ji chen School of Mathematics and Quantitative Economics Dongbei University of Finance and Economics 116025 Dalian China School of Mathematical Sciences Dalian University of Technology116024 Dalian China Key Laboratory of Liaoning Province for Composite Structural Analysis of Aerocraft and Simulation Shenyang Aerospace University 110136 Shenyang China State Key Laboratory for Structural Analysis of Industrial Equipment Dalian University of Technology 116024 Dalian China

In this paper,a 13-node pyramid spline element is derived by using the tetrahedron volume coordinates and the B-net method,which achieves the second order completeness in Cartesian *** appropriate examples were employed to evaluate the performance of the proposed *** numerical results show that the spline element has much better performance compared with the isoparametric serendipity element Q20 and its degenerate pyramid element P13 especially when mesh is distorted,and it is comparable to the Lagrange element *** has been demonstrated that the spline finite element method is an efficient tool for developing high accuracy elements.

关键词： Spline finite element Pyramid element The second order completeness B-net method

Quantum Curve and Bilinear Fermionic Form for the Orbifold Gromov–Witten Theory of P[r]

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Acta Mathematica Sinica,English Series 2024年第1期40卷 43-80页

作者： chong Yao chen Shuai GUO Mathematics Department Duke UniversityBox 90320DurhamNC 27708-0320USA School of Mathematical Sciences Peking UniversityBeijing 100871P.R.China

We construct the quantum curve for the Baker-Akhiezer function of the orbifold Gromov-Witten theory of the weighted projective line P[r].Furthermore,we deduce the explicit bilinear Fermionic formula for the(stationary... 详细信息

关键词： Quantum curve Free Fermions Gromov-Witten invariants Orbifold P^(1)

Effect of Limited Single Irrigation on Yield of Winter Wheat and Spring Maize Relay Intercropping

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Pedosphere 2007年第4期17卷 529-537页

作者： ZHANG Bu-chong HUANG Gao-bao LI Feng-Min State Key Laboratory of Arid Agroecology Lanzhou University Lanzhou 730000 （China）. Department of Water Resources Engineering Gansu Agricultural University Lanzhou 730070 （China） School of Agronomy Gansu Agricultural University Lanzhou 730070 （China） State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences Yangling 712100 （China）

A field experiment was conducted during the 2002/2003 cropping season of winter wheat （Triticum aestivum） and spring maize （Zea mays） to evaluate the effect of limited single drip irrigation on the yield and water use of both crops under relay intercropping in a semi-arid area of northwestern China. A controlled 35 mm single irrigation, either early or late, was applied to each crop at a certain growth stage. Soil water, leaf area, final grain yield and yield components such as the thousand-grain weight, length of spike, fertile spikelet number, number of grains per spike, and grain weight per spike were measured, and water use efficiency and leaf area index were calculated for the irrigated and non-irrigated relay intercropping treatments and sole cropping controls. The results showed that yield, yield components, water use efficiency, and leaf area index in the relay intercropping treatments were affected by limited single drip irrigation during various growth stages of wheat and maize. The total yields in the relay intercropping treatment irrigated during the heading stage of wheat and the heading and anthesis stage of maize were the highest among all the treatments, followed by that irrigated during the anthesis stage of wheat and silking stage of maize; so was the water use efficiency. Significant differences occurred in most yield components between the irrigated and non-irrigated relay-intercropping treatments. The dynamics of the leaf area index in the relay-intercropped or solely cropped wheat and maize showed a type of single-peak pattern, whereas that of the relay intercropping treatments showed a type of double-peak pattern. Appropriately, limited single irrigation and controlled soil water content level could result in higher total yield, water use efficiency, and leaf area index, and improved yield components in relay intercropping. This practice saved the amount of water used for irrigation and also increased the yield. Therefore, heading stage of whe

关键词： leaf area index limited single irrigation water use efficiency winter wheat and spring maize relay intercropping yield and yield components

Construction of n-sided polygonal spline element using area coordinates and B-net method

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Acta Mechanica Sinica 2010年第5期26卷 685-693页

作者： Juan chen chong-Jun Li Wan-Ji chen School of Mathematical Sciences Dalian University of Technology 116024 Dalian China State Key Laboratory for Structural Analysisof Industrial Equipment Dalian University of Technology116024 Dalian China Institute for Structural Analysis of Aerocraft Shenyang Institute of Aeronautical Engineering110136 Shenyang China

In general, triangular and quadrilateral elements are commonly applied in two-dimensional finite element methods. If they are used to compute polycrystalline materials, the cost of computation can be quite significant. Polygonal elements can do well in simulation of the materials behavior and provide greater flexibility for the meshing of complex geometries. Hence, the study on the polygonal element is a very useful and necessary part in the finite element method. In this paper, an n-sided polygonal element based on quadratic spline interpolant, denoted by PS2 element, is presented using the triangular area coordinates and the B-net method. The PS2 element is conforming and can exactly model the quadratic field. It is valid for both convex and non-convex polygonal element, and insensitive to mesh distortions. In addition, no mapping or coordinate transformation is required and thus no Jacobian matrix and its inverse are evaluated. Some appropriate examples are employed to evaluate the performance of the proposed element.

关键词： Finite element method n-sided polygonalelement - Bivariate spline interpolation The second ordercompleteness