Hybrid Analytical Model Research Articles

The Spatial Modeling and Analysis of Ancient Sites of Khonj County Using Hybrid AND-GIS Analysis

In the new thinking of the scientific and academic community of Iran, applying science and guiding it to meet the fundamental needs of human society is one of the most important tasks. The identification of these phenomena with the help of GIS theoretical spatial sciences leads to the identification of how each of the human phenomena has been established in the past. Spatial modeling for spatial analysis and scattering of archeological sites in Khonj County is the main purpose of the present research. In terms of purpose and terms of methodology, this research is applied and descriptive-analytical, based on the library, model, and spatial studies. The selected indicators were collected in two stages by studying the records (research projects, statistics, books), using the viewpoints of the experts (taking advantage of Delphi's method and extracting the opinions of academic theorists and managers of related organizations), and they were integrated using the Delphi method. In this section, 14 indicators were identified, and then the ANP-Dematle hybrid analytical model was used to identify the effect of indicators and criteria on each other and ranking. Finally, they were overlapped by GIS software using fuzzy analysis. Research results show: the latitude variable (a3) has the highest impressment (0.120) and then variables of the gradient (c3) and height (b1) with impressment of 0.118 and 0.117 are in the next ranks, respectively. The results of the analysis of fourteener indicators in the ArcGis software environment, which are effective in determining the spatial scattering of 93 archaeological sites show that distance and proximity to water, good soil, and high altitude are some of the reasons for the formation of settlements in this county. The most important reasons that influence the settlement patterns of this region are dependence on three important characteristics: water, good soil for agriculture as well as suitable height.

Rational Hybrid Analytical Model for Steel Pipe Rack Quantification in Oil & Gas Industries

The objective of this work is to develop an analytical model to overcome the shortfalls in current engineering practices that are being used to estimate the pipe rack steel quantities during the pre-bid engineering phase in Oil & Gas industries. The research methodology consists of performing data analysis of past projects and devising a new system by developing suitable structure formulation techniques, loading system creation, structural stability analysis and LRFD design calculations, along with steel quantification procedures, which are completed in a single run. Then this rational hybrid analytical model is applied to examine a real-time project pipe rack structure module. As research findings, the results of the analytical model are compared with the outcome of both the conventional methods as well as the bench mark detailed engineering calculations. It is found that the quantity obtained using the new method is extremely close to the detailed engineering quantity with the least time consuming. Hence, this novel analytical model has proved to be a boon to structural engineers working in Oil and Gas industries since the crux of pre-bid engineering is to process voluminous data and calculate the quantities more precisely within a shorter time frame to be a successful bidder.

Enhancing the Performance of 802.15.4-Based Wireless Sensor Networks With NB-IoT

Multihop low-power wireless communication is a key feature of wireless sensor networks (WSNs). Although with a lot of efforts, the performance of multihop WSNs in practical deployment could still be unpredictable and unsatisfactory, such as high packet transmission latency and short network lifetime. Narrowband Internet of Things (NB-IoT) is an emerging cellular technology for providing wide-area coverage. In this article, we investigate the possibilities of deploying 802.15.4 and NB-IoT equipped sink nodes (i.e., gateways ) into existing WSNs to achieve the predictable and improved performance in terms of end-to-end reliability , end-to-end latency , and network lifetime . To calculate these key network-wide metrics, we propose a hybrid analytical model for 802.15.4 and NB-IoT traffic, taking the new features of NB-IoT into account. Based on the established model, we formally consider two types of fundamental problems, i.e., the minimum gateway deployment and the optimal $\kappa $ -gateway deployment. We implement our framework and extensively evaluate it in the realistic as well as synthetic WSNs. Results demonstrate that our approach can provide significant performance gains, e.g., the network lifetime can be extended by 37.4%–80.3% by deploying only one sink node. Compared with a state-of-the-art method, our approach improves the network lifetime by 12.6%–31.8%.

Developing a hybrid analytics approach to measure the efficiency of deposit banks

This study aims at analyzing the efficiency of deposit banks using contemporary analytics-based decision-making techniques within a fuzzy environment. Specifically, a hybrid analytic model drawing on a fuzzy analytical network process and data envelopment analysis was developed and applied to the assessment of Turkish deposit banks quoted on Borsa Istanbul. The findings revealed that; (i) the efficiency results for banking activity vary for competitiveness and for the adoption of new technologies before and after the financial recession; (ii) the majority of deposit banks operating primarily with non-interest based factors found to be less-efficient; (iii) the ownership and capital structure of banks do not significantly contribute to their banking performance, as they were technically inefficient during the same period; and (iv) the inputs of the banking activities could be reduced while a constant level of output is maintained by adopting and properly using the most efficient technology to boost the technical efficiency.

A new hybrid analytical model based on winding function theory for analysis of surface mounted permanent magnet motors

PurposeThe purpose of this paper is to present an improved winding function theory (IWFT) for performance analysis of surface mounted permanent magnet (SMPM) motors, which can precisely and simultaneously consider the impacts of stator slotting, the winding distribution, the magnetic flux density within PMs because of the armature reaction, the PM magnetization angle and the magnetic saturation,.Design/methodology/approachTo obtain this improved analytical model, the conformal mappings (CMs) are introduced to calculate the relative complex permeance of slotted air-gap, which is used to obtain the function of slotted air-gap length. The equivalent magnetizing current model is used to extract the equivalent winding function for each PM pole. For retaining the basic assumption of WFT, the magnetic saturation is also considered by a proper increase in the air-gap length in the front of the stator teeth.FindingsA new hybrid analytical model (HAM) based on WFT is presented in this paper, which can simultaneously and accurately consider the effects of slotting, the magnetic saturation, the variation of PM operating point and the winding distribution. In fact, IWFT removes all the drawbacks of the conventional WFT. Moreover, IWFT is more user-friendly and faster than other analytical and numerical techniques.Practical implicationsThe obtained HAM can be used for design, optimization and fault diagnosis in electric machines.Originality/valueThis paper presents a new HAM for accurate modeling the SMPM motors, which includes different considerations of electromagnetic modeling. This new HAM can also be used for modeling the other electric motors.

Development of a Hybrid Analytical Model for a Fast Computation of Magnetic Losses and Optimization of Coaxial Magnetic Gears

This paper focuses on a two-dimensional (2-D) analytical model for a fast computation of magnetic losses due to eddy currents in the permanent magnets as well as iron losses in the ferromagnetic parts within coaxial magnetic gears. The magnetic field distribution is computed in yokes and permanent magnets by solving both Maxwell's equations, whereas for pole pieces, the magnetic field is computed by coupling the previous analytical model with a reluctance network model. Both the eddy current losses and iron losses are determined from this hybrid analytical model. The iron loss model takes into account the temporal and spatial variations of flux density. The eddy current loss model takes into account the magnet splitting. Results of this magnetostatic eddy current loss model are then compared to the results obtained with a 2-D magnetodynamic finite element model. A verification of validity limits is also proposed. The final function of this analytical model is to ensure integration into a set of models in the aim of a global mechatronic optimization of magnetic gears, for their insertion into multimegawatt wind turbines. A preliminary bi-objective, mass-efficiency optimization protocol is subsequently proposed along with an analysis of the computation time reduction via the presented models.

Testing analytical tidal propagation models of the one-dimensional hydrodynamic equations in Morocco's estuaries

ABSTRACTIn this paper, we tested two analytical models for tidal propagation in two estuaries, i.e. Sebou and Loukkos (Morocco): (1) is a hybrid analytical model, based on new approximation of the friction term in the momentum equation, tidal damping expression and river discharge effect; and (2) is a analytical model for the closed channel, i.e. with a closed landward boundary. For given topography, friction, and tidal amplitude at the seaward boundary, the velocity amplitude, the wave celerity, the tidal damping, and the phase lag along the estuaries axis are calculated. These models were calibrated and validated using observed data. A good-fit between models and measurements is obtained, as verified by statistical performance tests, which suggests that the predictive models can be used to obtain a first-order estimation of tidal dynamics and reflected wave along the estuaries axis.

Hybrid Analytical Modeling of Saturated Linear and Rotary Electrical Machines: Integration of Fourier Modeling and Magnetic Equivalent Circuits

This paper presents a 2-D hybrid analytical modeling method for the analysis of the magnetostatic field distribution with the capability of including nonlinear materials. The model combines Fourier modeling, which is accurate and fast, with meshed magnetic equivalent circuits that have unique permeability in mesh elements and, therefore, can model local saturation. To present the diverse applicability of the proposed method, it is applied to a linear machine with permanent magnet excitation and a rotary machine with current excitation. Magnetic field calculations are compared with finite-element analysis (FEA) with good agreement.

Hybrid analytical model for composite heat transfer in a spiral pile ground heat exchanger

A spiral pile ground heat exchanger (PGHE) is a recently developed type of ground heat exchanger (GHE) used in ground-coupled heat pump system. Existing analytical models are not applicable to a spiral PGHE when the pile has thermal properties that are different from those of the soil. A novel hybrid analytical model to represent this situation was developed in the present study. The proposed model utilizes a decomposition algorithm to solve the problem of a coil line source embedded in a composite cylinder. The decomposition algorithm uses a composite cylindrical surface source solution to deal with the composite heat conduction along the radius and a coil line source solution to deal with the heat conduction between tube loops in depth direction. An assumption of homogeneity enables the solution of the hybrid model with only a slight error. The error of the hybrid model was investigated with respect to thermal properties and geometries of a spiral PGHE and compared with those of existing models. The error under normal cases was found to be acceptable for engineering applications. The proposed hybrid model is superior to existing analytical models, enabling simultaneous and reasonably accurate evaluations of the effects of the thermal properties of the pile and the coil pitch.

Hybrid analytical model of switched reluctance machine for real‐time hardware‐in‐the‐loop simulation

Applications of switched reluctance machine (SRM) are increasing in the industry due to their many desirable features. This study proposes a hybrid analytical model (HAM) of the SRM for the hardware-in-the-loop (HIL) simulation. To obtain satisfactory accuracy, the phase flux linkage is solved by the magnetic equivalent circuit (MEC) method when the stator and rotor poles overlap, and by the space harmonic method (SHM) when the poles do not overlap. The backward Euler and Newton–Raphson methods are used to calculate the exciting current, while the Gaussian quadrature is used to compute the electromagnetic torque in the HIL simulation. The digital hardware implementation of computation components are developed on the field-programmable gate array by exploiting the parallel hardware architecture and fully pipelined arithmetic processing. To highlight the performance of the HAM, the captured real-time results are compared with the off-line transient solution obtained through the co-simulation of Ansys Maxwell®, Ansys Simplorer®, and Simulink®, which model the SRM, drive circuit, and control system, respectively.

Hybrid analytical model of switched reluctance machine for real-time hardware-in-the-loop simulation

Hybrid analytical model of switched reluctance machine for real-time hardware-in-the-loop simulation

Optimal design of supply chain network under uncertainty environment using hybrid analytical and simulation modeling approach

Models that aim to optimize the design of supply chain networks have gained more interest in the supply chain literature. Mixed-integer linear programming and discrete-event simulation are widely used for such an optimization problem. We present a hybrid approach to support decisions for supply chain network design using a combination of analytical and discrete-event simulation models. The proposed approach is based on iterative procedures until the difference between subsequent solutions satisfies the pre-determined termination criteria. The effectiveness of proposed approach is illustrated by an example, which shows closer to optimal results with much faster solving time than the results obtained from the conventional simulation-based optimization model. The efficacy of this proposed hybrid approach is promising and can be applied as a powerful tool in designing a real supply chain network. It also provides the possibility to model and solve more realistic problems, which incorporate dynamism and uncertainty.

A hybrid analytical model for open-circuit field calculation of multilayer interior permanent magnet machines

Due to the complicated rotor structure and nonlinear saturation of rotor bridges, it is difficult to build a fast and accurate analytical field calculation model for multilayer interior permanent magnet (IPM) machines. In this paper, a hybrid analytical model suitable for the open-circuit field calculation of multilayer IPM machines is proposed by coupling the magnetic equivalent circuit (MEC) method and the subdomain technique. In the proposed analytical model, the rotor magnetic field is calculated by the MEC method based on the Kirchhoff’s law, while the field in the stator slot, slot opening and air-gap is calculated by subdomain technique based on the Maxwell’s equation. To solve the whole field distribution of the multilayer IPM machines, the coupled boundary conditions on the rotor surface are deduced for the coupling of the rotor MEC and the analytical field distribution of the stator slot, slot opening and air-gap. The hybrid analytical model can be used to calculate the open-circuit air-gap field distribution, back electromotive force (EMF) and cogging torque of multilayer IPM machines. Compared with finite element analysis (FEA), it has the advantages of faster modeling, less computation source occupying and shorter time consuming, and meanwhile achieves the approximate accuracy. The analytical model is helpful and applicable for the open-circuit field calculation of multilayer IPM machines with any size and pole/slot number combination.

Cogging Force Analysis of Linear Permanent Magnet Machines Using a Hybrid Analytical Model

The aim of this paper is, first, to extend the application of the hybrid analytical modeling (HAM) approach for the analysis of tubular linear machines (TLPM), something that has never been reported yet in the scientific literature. The HAM consists of a strong coupling between the reluctance network and the Fourier series solution of magnetic scalar potential. In order to assess the merits and capabilities of the HAM, it is applied to the study of the cogging force in linear machines and compared with finite element analyses (FEA). The cogging force is a global quantity, which is very sensitive to magnetic field computation accuracy and constitutes, therefore, a good measure of the accuracy of the HAM as compared with FEA. The HAM should require less computation time as compared with FEA, and is then more suitable for predesign stage. Three different structures are analyzed: a flat linear machine, a TLPM with internal mobile armature, and, finally, a TLPM with external mobile armature. The analyses are conducted, considering the effect of magnetic saturation.

Comparison of hybrid analytical modelling and reluctance network modelling for pre-design purposes

The aim of this paper is to compare two modelling approaches, used for the pre-design of electrical machines. A new hybrid analytical modelling (HAM) approach, based on a direct coupling of analytical solution of Maxwell’s equations with reluctance networks (RN), is compared to mesh-based generated reluctance networks modelling, in terms of computation time and results quality. In order to assess the quality of results obtained from both models, both approaches are compared to finite element simulations. A permanent magnet linear structure is chosen as a case study. It is shown that the new hybrid analytical model allows to combine advantages of analytical and reluctance networks modelling. As compared to RN, the new approach helps reduce calculation time and gives good results.

Performance analysis of a radial flux PM machine using a hybrid analytical model and a MBG reluctance network model

Performance analysis of a radial flux PM machine using a hybrid analytical model and a MBG reluctance network model

A fuzzy-hybrid analytic model to assess investors' perceptions for industry selection

The 2008–2009 global financial crisis and its subsequent ramifications on capital markets have led to an increasing attention on the importance of cognitive and behavioral issues in finance. The purpose of this study is to determine the ranking of the industry alternatives for portfolio investments based on individual investors' perceptions. Accordingly, a hybrid analytic multi-criteria decision model (MCDM)—based on the Fuzzy Analytic Hierarchy Process (FAHP) and the Fuzzy Technique for the Order of Preference by Similarity to Ideal Solution (FTOPSIS) methods along with sensitivity analysis—is developed to identify and rank-order the best performing industry options. The proposed model is applied to Borsa Istanbul Stock Exchange 100 Index (BIST 100) in Turkey. The results indicate that (i) the investors' perceptions on market conditions and global financial situation influence their industry selection on company stocks; (ii) the investors' perceptions on portfolio investments rely heavily on performance and risk levels of individual asset/stocks, and (iii) traded stocks of financial industry (along with its sub-industries) have greater performance expectations than those of the ones in other industries such as technology, services and tourism.

A hybrid analytical model of sterilization effect on marine bacteria using microbubbles interacting with shock wave

The present paper reports on a hybrid analytical model consisting of a biological probability model and a physical impact model proposed to predict the cell viability ratio of a sterilization method for marine bacteria using microbubbles interacting with a shock wave. The physical impact model of interaction between a microbubble and a shock wave is developed on the basis of the bubble motion analysis with experimental pressure data and a one-dimensional numerical simulation. An underwater shock wave produced by microbubble motion is simulated using a second-order finite differential scheme by means of bubble surface velocity variation obtained from Herring’s bubble motion equation, and the radius of the sterilized space around a microbubble is estimated by the critical pressure that just causes cell wall damage of marine bacteria. The sterilization effect predicted by the present hybrid analysis shows a good agreement with the bio-experimental result.

3-D Hybrid Analytical Modeling: 3-D Fourier Modeling Combined With Mesh-Based 3-D Magnetic Equivalent Circuits

This paper presents a novel 3-D hybrid analytical modeling (HAM) method that integrates a mesh-based 3-D magnetic equivalent circuit model into 3-D Fourier modeling. This HAM is capable of predicting the electromagnetic field distributions for Cartesian 3-D structures. A generalized approach of the hybrid-modeling concept is presented. The modeling technique is applicable to a wide range of electromagnetic devices, such as linear and planar actuators. In only a fraction of the calculation times of 3-D finite-element approaches, the 3-D HAM calculates the magnet field distributions and forces with approximately 90% accuracy.

A General Framework Based on a Hybrid Analytical Model for the Analysis and Design of Permanent Magnet Machines

In highly concurrential markets the time to market is reduced, which implies a need of design tools having relatively high accuracy to computation time ratio. It is to address this problematic that the presented modelling approach has been developed. A general framework for the analysis and design of electromagnetic devices is presented. This framework is based on a new hybrid analytical model (HAM) [1]-[4]. The HAM can be applied to different electric machines types (synchronous and asynchronous) and structures (rotating with radial field or axial field, linear flat or tubular structures, or multi-degree-of-freedom structures). It is based on a direct coupling of analytical solution of Maxwell's equations (AM) with reluctance networks (RN). This new technique allows to combine advantages of both methods and should help reduce computation time as compared to finite elements method [3]. This modeling approach is relatively simple and allows the accurate prediction of performances of electromagnetic devices.