Abstract
The rhombus inverted nine-spot well pattern is often adopted in low permeability oilfield development, which has the advantage of high oil production rate and flexible adjustment. Due to the strong heterogeneity of the low permeability reservoirs, the oil wells along the fracture direction are heavily water-flooded and the water cut rises quickly, and the oil wells on both sides of fractures have no response to water injection. Hence, deep profile control is an effective way to solve this kind of plane contradiction, and is widely applied in the low permeability oilfield development. However, because of the asymmetry of the rhombus inverted nine-spot well pattern and the heterogeneity of the low permeability reservoirs, there are differences in the response characteristics of oil wells at different locations after deep profile control. In this paper, combined with physical experiments and numerical simulations, we analyzed oil increment, the distribution of streamlines and slugs of wells at different locations before and after deep profile control, and evaluated the response characteristics of oil wells of rhombus inverted nine-spot well pattern after deep profile control in low permeability fractured reservoirs. It is concluded that the effect of increasing oil production of the side wells is better than that of the angle wells after deep profile control, and the response sequence is side well, angle well in short axis, and angle well in long axis, which is also verified by the practical results of deep profile control in Daqing Oilfield.
1 Introduction
The development of low permeability fractured reservoirs using the rhombus inverted nine-spot well pattern is often confronted with the problem of uneven water flooding [1, 2, 3]. The general performance of water flooding is that the injected water flows along the fracture direction, and the water cuts of corresponding oil wells on fractures rise quickly, such that the water cuts of oil wells and effect of water flooding are apparently controlled by the fracture direction [4, 5, 6, 7]. Once the fractures open, the injection pressure of the water well will be reduced, and the water absorption capacity of the reservoir will be enhanced and the ineffective circulation of water injection will become serious [8, 9, 10]. Deep profile control is an effective method to solve this kind of plane contradiction, and is widely applied in the low permeability oilfield development [11]. However, due to the asymmetry of the rhombus inverted nine-spot well pattern and the heterogeneity of the low permeability fractured reservoirs, there are significant differences in the response characteristics of oil wells at different locations after deep profile control [12]. In the process of oil and gas development, the macroscopic phenomenon is often the appearance, but the law of oil and gas seepage is the fundamental [13, 14, 15, 16, 17]. Therefore, it is of great significance to analyze the response characteristics of the rhombus inverted nine-spot well pattern by using the seepage mechanics method, in order to improve the effect of deep profile control. Nevertheless, at present, there are few researches on the percolation mechanism of deep profile control in the rhombus inverted nine-spot well pattern, and most of them are mainly focused on the timing of water breakthrough [18], the sweep coefficient of water injection [19], and the calculation of fracturing productivity [20, 21]. Furthermore, because the deep profile control is mostly applied to heterogeneous formations with severe injection water channeling, conventional research method of seepage mechanics often fails to analyze the percolation mechanism of deep profile control in the rhombus inverted nine-spot well pattern.
Scholars from all over the world have tried to find out the reasons for the differences in the response characteristics of oil wells at different locations after deep profile control through the method of seepage simulation. Dawe [22] and Liang [23] studied the principle of deep profile control by using micro model and Berea sandstone core experiment, respectively. It was considered that the fundamental reason for the difference in permeability between oil and water after plugging is the separation of oil-water flow channels. Seright [24] used tracer technology to study the effects of permeability, water injection rate after plugging, lithology, and gel properties on the plugging performance of the plugging agent. It found that strong gel can reduce the plugging rate of Berea core with different permeabilities to the same value. For weak gel, the higher the permeability is, the greater the plugging rate is; the residual resistance coefficient after plugging decreases with the increase of water injection speed. Fan [25] and Li [26] employed streamline numerical simulator to analyze the distribution characteristics of streamlines before and after deep profile control, and qualitatively explained the effect of deep profile control on streamlines. In addition, from different perspectives Islam, Rossen and Balan, et al. [27, 28, 29, 30, 31] have also proposed several numerical simulation methods such as empirical / semi-empirical model, total balance model, percolation model, and diversion model to simulate the seepage of deep profile control. But there is a lack of targeted research on the rhombus inverted nine-spot well pattern. Furthermore, there is no detailed discussion on the response characteristics and production dynamic change laws of oil wells at different locations (angle wells and side wells) in rhombus inverted nine-spot well pattern after deep profile control.
In this paper, a two-dimensional heterogeneous cementation model was used to study the variation of oil production and water cut of oil wells at different locations of rhombus inverted nine-spot well pattern after deep profile control, and the response characteristics of reducing water production and increasing oil production of oil wells at different locations were also analyzed based on the physical model. In addition, by establishing the numerical simulation model of rhombus inverted nine-spot well pattern considering ground stress, the oil increment, and the variation law of streamline field before and after deep profile control were studied. The response characteristics of different wells in the rhombus inverted nine-spot well pattern were also obtained.
2 Materials and methods
2.1 Physical simulation experiment
2.1.1 Model preparation and experimental fluid
In order to characterize the percolation characteristics of low permeability fractured reservoirs, a heterogeneous flat cementation model was adopted, which was made of epoxy resin and quartz sand. In the model, a high permeability strip was added to the long-axis injection-production well direction to characterize the direction of fracture development. Nine wells were arranged in the model, where I1 is the injection well (water well), P1- P8 are the production wells (oil wells P1 and P5 are the angle wells in the long axis, P3 and P7 are the angle wells in the short axis, and P2, P4, P6, and P8 are the side wells), and the layout of specific well locations are shown in Figure 1. The model size is 0.4 m × 0.3 m × 0.03 m, the average porosity of this model is 13.1%, the matrix permeability is 0.69 × 10−3 um2, and the permeability in high permeability area is about 200 ×10−3 um2.

Sketch map of well location
The experimental fluids include the crude oil with viscosity of 30 mpa·s, water with viscosity of 0.5 mpa·s, and gel plugging agent. Gel plugging agent is composed of Polyacrylamide (PAM) with concentration of 0.9% and Phenolic resin crosslinking agent with concentration of 1.0%[32, 33, 34]. The performance evaluation indicators of gel plugging agents are shown in Table 1.
Performance evaluation index of gel plugging agent
Viscosity | Gelation time | Molecular Weight of | Residual | Inaccessible pore | Maximum adsorption |
---|---|---|---|---|---|
(mPa·s) | (h) | PAM | resistance factor | volume | capacity (kg/kg) |
20 | 48 | 6000000 | 170 | 0.15 | 0.00012 |
2.1.2 Experimental device and process
The physical simulation experimental device mainly consists of ISCO pump, drug tank, flat cementation core, and output-end oil-water metering device, as shown in Figure 2. The ISCO pump and the drug tank are connected to the water well, which are used for water injection and plugging agent injection, respectively. Each oil well is connected with an oil-water metering device for recording fluid production and water cut change in different wells.

Physical simulation experimental device
In order to simulate the actual reservoir development process, the oil wells in mainstreams (i.e. P1 and P5) were flooded first and had a water content of 98%, which is to simulate the process of water channeling in water injection development. Then the plugging agent was injected into the water well, simulating the deep profile control of the injection well [35]. The specific experimental steps are as follows:
1) First, the model was saturated with water. Then, the crude oil was injected to saturate the model. Finally the model was aged for 7 days.
2) The second water injection was carried out until the water content of the two oil wells (i.e. P1 and P5) reached 98%, and the liquid production and water content data of different oil wells were recorded.
3) The plugging agent was injected into water well.
4) The water injection was repeated to simulate the subsequent water-flooding stage and recorded the fluid production and water cut-off data of the wells at different positions.
2.2 Numerical simulation
2.2.1 Numerical simulation model for deep profile control
According to the physical model shown in Figure 1, a numerical simulation model as shown in Figure 3 is established [36, 37]. In Figure 3, I1 is the injection well, and p1- p8 is the production well. A horizontal fracture runs through P1, I1 and P5. Parameters of geology, fluid, and well pattern are found in Table 2.

Streamline distribution before deep profile control of rhombus inverted nine-spot well pattern
Parameter list of numerical model
Parameters | Value | Parameters | Value |
---|---|---|---|
Permeability (10−3µm2) | 0.69 | Saturation pressure (MPa) | 6.91 |
Porosity (%) | 13.1 | Formation volume factor | 1.206 |
Oil viscosity (mPa·s) Formation pressure | 30 | Well pattern | rhombus inverted nine-spot well pattern |
(MPa) | 9.79 | Grid number | 200×150×15 |
Grid spacing (m) Fracture permeability | 0.002×0.002×0.002 | Development direction of fracture | the direction is parallel to the long axis |
(10−3µm2) | 200 |
3 Results and discussion
3.1 Physical experiment data
The oil productions and the oil increments of 8 production wells at different locations were recorded and calculated, respectively. The specific parameters of oil production are shown in the Table ??.
Table 3 shows that the two angle wells (P1 and P5) located on the mainstreams have the smallest single-well increase in oil production, and have an average oil increment of 0.85 cm3. The single-well oil increment of two angle wells (P3 and P7) perpendicular to the high permeability strip is significantly higher than those of P1 and P5, whose average oil increment is 1.3 cm3. And the single-well oil increase of four side wells (P2, P4, P6, and P8) is the largest, whose average oil increase reaches 4.48 cm3.
Statistical data of oil increment in single well
Well number | Oil production before deep profile control (cm3) | Oil production after deep profile control (cm3) | Oil increment (cm3) |
---|---|---|---|
P1 | 8.9 | 9.7 | 0.8 |
P2 | 2.2 | 6.6 | 4.4 |
P3 | 4.5 | 5.7 | 1.2 |
P4 | 2.3 | 6.7 | 4.4 |
P5 | 8.6 | 9.5 | 0.9 |
P6 | 2.2 | 6.7 | 4.5 |
P7 | 4.4 | 5.8 | 1.4 |
P8 | 2.3 | 6.9 | 4.6 |
3.2 Numerical simulation analysis
During the development of rhombus inverted nine-spot well pattern, serious flooding occurs along the direction of principal stress and is not effective in the direction of vertical principal stress. The shape of streamline before and after profile control is analyzed by means of numerical simulation, as shown in Figure 3. Before deep profile control, because the conductivity of the fracture is higher than that of the matrix, the streamlines are dense along the fracture direction (I1 - P1, I1 - P5), and the streamlines along the vertical fracture direction are relatively sparse. A large amount of injected water flows along the fracture direction, resulting in rapid flooding of the angle wells (P1, P5).
Plugging measures are conducted to the injection well I1, and the distribution of streamlines after plugging is shown in Figure 4. As can be seen from Figure 4, the plugging agent forms a block plug along the direction of the fracture, which indicates that the plugging agent mainly seepage along the fracture zone (i.e. I1 - P1, I1 - P5). After plugging, the injected water needs to bypass the plugging section and sweep outward, and there is no streamline through the slug area, thus enlarging the sweep area of injection water between the side wells (P2, P4, P6, and P8) and the angle well (P3, P7), and displacing the dead oil in this area in large quantities.

Diagram of streamline and slug distribution after deep profile control of rhombus inverted nine-spot well pattern
Based on the results of numerical simulation, the field data of accumulated oil production before and after deep profile control are first derived. Then, the two oil increment data before and after profile control of each grid are subtracted into excel to calculate, so the oil increment data of each grid are obtained. Finally, the field data of the oil increment is introduced into eclipse, and the distribution field of the oil increase after the deep profile control is obtained, as shown in Figure 5. It can be concluded from Figure 5 that the oil increasing area is mainly concentrated in the area between the side wells (P2, P4, P6, and P8) and the angle well (P3, P7), but the effect of increasing oil production is not obvious for the area near the angle wells along fracture direction (P1, P5). The results of the numerical simulation coincide with the physical experiment data well.

Field diagram of oil increment distribution after deep profile control of rhombus inverted nine-spot well pattern
4 Case verification
Daqing Oilfield (Dq) employs the rhombus inverted nine-spot well pattern of 150 m × 500 m to develop, and has the formation permeability of 0.67 × 10−3 µm2, the average effective porosity is 10.14%. The reservoir plane permeability difference is great, and the heterogeneity is strong. Dq Oilfield has the current oil recovery factor of 10.4% and the total water cut of 57%, and has a clear direction of horizontal water channeling. From 2008 to 2012, the deep profile control was carried out in Dq Oilfield. The oil increase after the profile control is counted and the results are shown in Table 4.
The effect of deep profile control in Dq Oilfield
Well group number | Oil increment of angle well in long axis (t) | Oil increment of angle well in short axis (t) | Oil increment of side well (t) |
---|---|---|---|
P34-21 | 0 | 105 | 398 |
P34-27 | 0 | 118 | 258 |
P34-31 | 7 | 49 | 443 |
P40-25 | 0 | 57 | 142 |
P73-08 | 0 | 26 | 119 |
X32-12 | 0 | 34 | 138 |
X34-15 | 0 | 16 | 109 |
X24-110 | 2 | 69 | 587 |
X24-108 | 0 | 47 | 121 |
According to the oil increment effect of deep profile control on actual block (Table 4), it can be seen that after the deep profile control in rhombus inverted nine-spot well pattern, the oil increment of most long-axis angle wells is 0, and only two of them have less than 10 tons of oil increment,which is significantly less than the oil increase of the side wells and the angle wells in short axis. The increase in oil production of side wells is the highest and exceeds 100 t. The effect of deep profile control in real blocks is consistent with the characteristics described in the previous physical model and mathematical model.
5 Conclusions
In this paper, taking the actual block as an example, the heterogeneous cementation physical model and the numerical simulation model of streamline are established. By analyzing the oil increment and distribution characteristics of streamline before and after profile control, it is considered that the streamlines do not pass through the plugging area and spread outward through bypassing the plugging slug, which results in the increase in the swept coefficient of water flooding and the reduction of dead oil area. By comparing and analyzing the oil increasing field before and after deep profile control, the oil increasing area of deep profile control in rhombus inverted nine-spot well pattern is mainly concentrated in the area between the side wells and the short-axis angle wells. However, there is no obvious oil increasing effect in the area near the long-axis angle wells. Moreover, the results of the physical experiment and the numerical simulation agree well with the actual oil field production. Therefore, it is suggested that side wells and angle wells should be arranged in the remaining oil enrichment area in the later period of well pattern adjustment, the oil recovery thus can be improved to the maximum.
Acknowledgement
We gratefully acknowledge the financial supports from Shandong Provincial Natural Science Foundation, China(ZR2018BA024), the National Science and Technology Major Project (2017ZX05013-001) and the Project of Shandong Province Higher Educational Science and Technology Program (No. J17KB069).
Conflicts of Interest: The authors declare no conflict of interest.
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- 3-D Electromagnetic field analysis of wireless power transfer system using K computer
- Simplified simulation technique of rotating, induction heated, calender rolls for study of temperature field control
- Design, fabrication and testing of electroadhesive interdigital electrodes
- A method to reduce partial discharges in motor windings fed by PWM inverter
- Reluctance network lumped mechanical & thermal models for the modeling and predesign of concentrated flux synchronous machine
- Special Issue Applications of Nonlinear Dynamics
- Study on dynamic characteristics of silo-stock-foundation interaction system under seismic load
- Microblog topic evolution computing based on LDA algorithm
- Modeling the creep damage effect on the creep crack growth behavior of rotor steel
- Neighborhood condition for all fractional (g, f, n′, m)-critical deleted graphs
- Chinese open information extraction based on DBMCSS in the field of national information resources
- 10.1515/phys-2018-0079
- CPW-fed circularly-polarized antenna array with high front-to-back ratio and low-profile
- Intelligent Monitoring Network Construction based on the utilization of the Internet of things (IoT) in the Metallurgical Coking Process
- Temperature detection technology of power equipment based on Fiber Bragg Grating
- Research on a rotational speed control strategy of the mandrel in a rotary steering system
- Dynamic load balancing algorithm for large data flow in distributed complex networks
- Super-structured photonic crystal fiber Bragg grating biosensor image model based on sparse matrix
- Fractal-based techniques for physiological time series: An updated approach
- Analysis of the Imaging Characteristics of the KB and KBA X-ray Microscopes at Non-coaxial Grazing Incidence
- Application of modified culture Kalman filter in bearing fault diagnosis
- Exact solutions and conservation laws for the modified equal width-Burgers equation
- On topological properties of block shift and hierarchical hypercube networks
- Elastic properties and plane acoustic velocity of cubic Sr2CaMoO6 and Sr2CaWO6 from first-principles calculations
- A note on the transmission feasibility problem in networks
- Ontology learning algorithm using weak functions
- Diagnosis of the power frequency vacuum arc shape based on 2D-PIV
- Parametric simulation analysis and reliability of escalator truss
- A new algorithm for real economy benefit evaluation based on big data analysis
- Synergy analysis of agricultural economic cycle fluctuation based on ant colony algorithm
- Multi-level encryption algorithm for user-related information across social networks
- Multi-target tracking algorithm in intelligent transportation based on wireless sensor network
- Fast recognition method of moving video images based on BP neural networks
- Compressed sensing image restoration algorithm based on improved SURF operator
- Design of load optimal control algorithm for smart grid based on demand response in different scenarios
- Face recognition method based on GA-BP neural network algorithm
- Optimal path selection algorithm for mobile beacons in sensor network under non-dense distribution
- Localization and recognition algorithm for fuzzy anomaly data in big data networks
- Urban road traffic flow control under incidental congestion as a function of accident duration
- Optimization design of reconfiguration algorithm for high voltage power distribution network based on ant colony algorithm
- Feasibility simulation of aseismic structure design for long-span bridges
- Construction of renewable energy supply chain model based on LCA
- The tribological properties study of carbon fabric/ epoxy composites reinforced by nano-TiO2 and MWNTs
- A text-Image feature mapping algorithm based on transfer learning
- Fast recognition algorithm for static traffic sign information
- Topical Issue: Clean Energy: Materials, Processes and Energy Generation
- An investigation of the melting process of RT-35 filled circular thermal energy storage system
- Numerical analysis on the dynamic response of a plate-and-frame membrane humidifier for PEMFC vehicles under various operating conditions
- Energy converting layers for thin-film flexible photovoltaic structures
- Effect of convection heat transfer on thermal energy storage unit
Articles in the same Issue
- Regular Articles
- A modified Fermi-Walker derivative for inextensible flows of binormal spherical image
- Algebraic aspects of evolution partial differential equation arising in the study of constant elasticity of variance model from financial mathematics
- Three-dimensional atom localization via probe absorption in a cascade four-level atomic system
- Determination of the energy transitions and half-lives of Rubidium nuclei
- Three phase heat and mass transfer model for unsaturated soil freezing process: Part 1 - model development
- Three phase heat and mass transfer model for unsaturated soil freezing process: Part 2 - model validation
- Mathematical model for thermal and entropy analysis of thermal solar collectors by using Maxwell nanofluids with slip conditions, thermal radiation and variable thermal conductivity
- Constructing analytic solutions on the Tricomi equation
- Feynman diagrams and rooted maps
- New type of chaos synchronization in discrete-time systems: the F-M synchronization
- Unsteady flow of fractional Oldroyd-B fluids through rotating annulus
- A note on the uniqueness of 2D elastostatic problems formulated by different types of potential functions
- On the conservation laws and solutions of a (2+1) dimensional KdV-mKdV equation of mathematical physics
- Computational methods and traveling wave solutions for the fourth-order nonlinear Ablowitz-Kaup-Newell-Segur water wave dynamical equation via two methods and its applications
- Siewert solutions of transcendental equations, generalized Lambert functions and physical applications
- Numerical solution of mixed convection flow of an MHD Jeffery fluid over an exponentially stretching sheet in the presence of thermal radiation and chemical reaction
- A new three-dimensional chaotic flow with one stable equilibrium: dynamical properties and complexity analysis
- Dynamics of a dry-rebounding drop: observations, simulations, and modeling
- Modeling the initial mechanical response and yielding behavior of gelled crude oil
- Lie symmetry analysis and conservation laws for the time fractional simplified modified Kawahara equation
- Solitary wave solutions of two KdV-type equations
- Applying industrial tomography to control and optimization flow systems
- Reconstructing time series into a complex network to assess the evolution dynamics of the correlations among energy prices
- An optimal solution for software testing case generation based on particle swarm optimization
- Optimal system, nonlinear self-adjointness and conservation laws for generalized shallow water wave equation
- Alternative methods for solving nonlinear two-point boundary value problems
- Global model simulation of OH production in pulsed-DC atmospheric pressure helium-air plasma jets
- Experimental investigation on optical vortex tweezers for microbubble trapping
- Joint measurements of optical parameters by irradiance scintillation and angle-of-arrival fluctuations
- M-polynomials and topological indices of hex-derived networks
- Generalized convergence analysis of the fractional order systems
- Porous flow characteristics of solution-gas drive in tight oil reservoirs
- Complementary wave solutions for the long-short wave resonance model via the extended trial equation method and the generalized Kudryashov method
- A Note on Koide’s Doubly Special Parametrization of Quark Masses
- On right-angled spherical Artin monoid of type Dn
- Gas flow regimes judgement in nanoporous media by digital core analysis
- 4 + n-dimensional water and waves on four and eleven-dimensional manifolds
- Stabilization and Analytic Approximate Solutions of an Optimal Control Problem
- On the equations of electrodynamics in a flat or curved spacetime and a possible interaction energy
- New prediction method for transient productivity of fractured five-spot patterns in low permeability reservoirs at high water cut stages
- The collinear equilibrium points in the restricted three body problem with triaxial primaries
- Detection of the damage threshold of fused silica components and morphologies of repaired damage sites based on the beam deflection method
- On the bivariate spectral quasi-linearization method for solving the two-dimensional Bratu problem
- Ion acoustic quasi-soliton in an electron-positron-ion plasma with superthermal electrons and positrons
- Analysis of projectile motion in view of conformable derivative
- Computing multiple ABC index and multiple GA index of some grid graphs
- Terahertz pulse imaging: A novel denoising method by combing the ant colony algorithm with the compressive sensing
- Characteristics of microscopic pore-throat structure of tight oil reservoirs in Sichuan Basin measured by rate-controlled mercury injection
- An activity window model for social interaction structure on Twitter
- Transient thermal regime trough the constitutive matrix applied to asynchronous electrical machine using the cell method
- On the zagreb polynomials of benzenoid systems
- Integrability analysis of the partial differential equation describing the classical bond-pricing model of mathematical finance
- The Greek parameters of a continuous arithmetic Asian option pricing model via Laplace Adomian decomposition method
- Quantifying the global solar radiation received in Pietermaritzburg, KwaZulu-Natal to motivate the consumption of solar technologies
- Sturm-Liouville difference equations having Bessel and hydrogen atom potential type
- Study on the response characteristics of oil wells after deep profile control in low permeability fractured reservoirs
- Depiction and analysis of a modified theta shaped double negative metamaterial for satellite application
- An attempt to geometrize electromagnetism
- Structure of traveling wave solutions for some nonlinear models via modified mathematical method
- Thermo-convective instability in a rotating ferromagnetic fluid layer with temperature modulation
- Construction of new solitary wave solutions of generalized Zakharov-Kuznetsov-Benjamin-Bona-Mahony and simplified modified form of Camassa-Holm equations
- Effect of magnetic field and heat source on Upper-convected-maxwell fluid in a porous channel
- Physical cues of biomaterials guide stem cell fate of differentiation: The effect of elasticity of cell culture biomaterials
- Shooting method analysis in wire coating withdrawing from a bath of Oldroyd 8-constant fluid with temperature dependent viscosity
- Rank correlation between centrality metrics in complex networks: an empirical study
- Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering
- Modeling of electric and heat processes in spot resistance welding of cross-wire steel bars
- Dynamic characteristics of triaxial active control magnetic bearing with asymmetric structure
- Design optimization of an axial-field eddy-current magnetic coupling based on magneto-thermal analytical model
- Thermal constitutive matrix applied to asynchronous electrical machine using the cell method
- Temperature distribution around thin electroconductive layers created on composite textile substrates
- Model of the multipolar engine with decreased cogging torque by asymmetrical distribution of the magnets
- Analysis of spatial thermal field in a magnetic bearing
- Use of the mathematical model of the ignition system to analyze the spark discharge, including the destruction of spark plug electrodes
- Assessment of short/long term electric field strength measurements for a pilot district
- Simulation study and experimental results for detection and classification of the transient capacitor inrush current using discrete wavelet transform and artificial intelligence
- Magnetic transmission gear finite element simulation with iron pole hysteresis
- Pulsed excitation terahertz tomography – multiparametric approach
- Low and high frequency model of three phase transformer by frequency response analysis measurement
- Multivariable polynomial fitting of controlled single-phase nonlinear load of input current total harmonic distortion
- Optimal design of a for middle-low-speed maglev trains
- Eddy current modeling in linear and nonlinear multifilamentary composite materials
- The visual attention saliency map for movie retrospection
- AC/DC current ratio in a current superimposition variable flux reluctance machine
- Influence of material uncertainties on the RLC parameters of wound inductors modeled using the finite element method
- Cogging force reduction in linear tubular flux switching permanent-magnet machines
- Modeling hysteresis curves of La(FeCoSi)13 compound near the transition point with the GRUCAD model
- Electro-magneto-hydrodynamic lubrication
- 3-D Electromagnetic field analysis of wireless power transfer system using K computer
- Simplified simulation technique of rotating, induction heated, calender rolls for study of temperature field control
- Design, fabrication and testing of electroadhesive interdigital electrodes
- A method to reduce partial discharges in motor windings fed by PWM inverter
- Reluctance network lumped mechanical & thermal models for the modeling and predesign of concentrated flux synchronous machine
- Special Issue Applications of Nonlinear Dynamics
- Study on dynamic characteristics of silo-stock-foundation interaction system under seismic load
- Microblog topic evolution computing based on LDA algorithm
- Modeling the creep damage effect on the creep crack growth behavior of rotor steel
- Neighborhood condition for all fractional (g, f, n′, m)-critical deleted graphs
- Chinese open information extraction based on DBMCSS in the field of national information resources
- 10.1515/phys-2018-0079
- CPW-fed circularly-polarized antenna array with high front-to-back ratio and low-profile
- Intelligent Monitoring Network Construction based on the utilization of the Internet of things (IoT) in the Metallurgical Coking Process
- Temperature detection technology of power equipment based on Fiber Bragg Grating
- Research on a rotational speed control strategy of the mandrel in a rotary steering system
- Dynamic load balancing algorithm for large data flow in distributed complex networks
- Super-structured photonic crystal fiber Bragg grating biosensor image model based on sparse matrix
- Fractal-based techniques for physiological time series: An updated approach
- Analysis of the Imaging Characteristics of the KB and KBA X-ray Microscopes at Non-coaxial Grazing Incidence
- Application of modified culture Kalman filter in bearing fault diagnosis
- Exact solutions and conservation laws for the modified equal width-Burgers equation
- On topological properties of block shift and hierarchical hypercube networks
- Elastic properties and plane acoustic velocity of cubic Sr2CaMoO6 and Sr2CaWO6 from first-principles calculations
- A note on the transmission feasibility problem in networks
- Ontology learning algorithm using weak functions
- Diagnosis of the power frequency vacuum arc shape based on 2D-PIV
- Parametric simulation analysis and reliability of escalator truss
- A new algorithm for real economy benefit evaluation based on big data analysis
- Synergy analysis of agricultural economic cycle fluctuation based on ant colony algorithm
- Multi-level encryption algorithm for user-related information across social networks
- Multi-target tracking algorithm in intelligent transportation based on wireless sensor network
- Fast recognition method of moving video images based on BP neural networks
- Compressed sensing image restoration algorithm based on improved SURF operator
- Design of load optimal control algorithm for smart grid based on demand response in different scenarios
- Face recognition method based on GA-BP neural network algorithm
- Optimal path selection algorithm for mobile beacons in sensor network under non-dense distribution
- Localization and recognition algorithm for fuzzy anomaly data in big data networks
- Urban road traffic flow control under incidental congestion as a function of accident duration
- Optimization design of reconfiguration algorithm for high voltage power distribution network based on ant colony algorithm
- Feasibility simulation of aseismic structure design for long-span bridges
- Construction of renewable energy supply chain model based on LCA
- The tribological properties study of carbon fabric/ epoxy composites reinforced by nano-TiO2 and MWNTs
- A text-Image feature mapping algorithm based on transfer learning
- Fast recognition algorithm for static traffic sign information
- Topical Issue: Clean Energy: Materials, Processes and Energy Generation
- An investigation of the melting process of RT-35 filled circular thermal energy storage system
- Numerical analysis on the dynamic response of a plate-and-frame membrane humidifier for PEMFC vehicles under various operating conditions
- Energy converting layers for thin-film flexible photovoltaic structures
- Effect of convection heat transfer on thermal energy storage unit