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Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a design approach for a class of rotationally invariant 2D filters of finite impulse response (FIR) type, which may form circular filter banks with imposed specifications. The design is conducted analytically in the frequency domain and starts from a maximally flat low-pass prototype based on a trapezoidal function with specified width and slope. Its trigonometric approximation is derived using the Fourier series expressed analytically, truncated to a number of terms depending on the imposed accuracy. The chosen trapezoidal function leads to significantly smaller ringing oscillations compared to the approximation of an ideal square characteristic. By shifting the LP prototype to various frequencies, the desired filter bank is generated, where the component filters have a specified bandwidth, steepness, and overlap. The 2D circular filter bank results by applying a specific frequency mapping to the factored frequency response of the prototype filter. Thus, the frequency responses of the 2D filter bank components will also result in factored form, which is an advantage in implementation. The circular filter bank is designed in two versions, a uniform and a non-uniform (dyadic) filter bank. The designed filter banks have accurate shapes and relatively low order for the specified parameters. These filter banks are then used in a sub-band image decomposition application. Finally, an efficient implementation of these filters at the system level is proposed based on polyphase decomposition and the block filtering technique with a high degree of parallelism, resulting in a lower computational complexity. [ABSTRACT FROM AUTHOR]

This work proposes an analytical design procedure for a particular class of 2D filters, namely anisotropic Gaussian FIR filters. The design is achieved in the frequency domain and starts from a low-pass Gaussian 1D prototype with imposed specifications, whose frequency response is efficiently approximated by a factored trigonometric polynomial using the Chebyshev series. Then, using specific 1D to 2D frequency mappings applied to the prototype, the frequency response for a 2D anisotropic filter with a specified orientation angle is directly derived in two versions, namely with a straight or elliptical shape in the frequency plane. The resulting filters have an accurate shape with low distortion. Several design examples for specified parameters (angle and selectivity) are provided. Then, simulations of directional filtering on various test images are given, which show their capability of extracting oriented lines or other various oriented objects from synthetic or real-life images. Finally, a computationally efficient implementation at the system level is proposed, based on a polyphase decomposition and block-filtering approach, which yields a 2D filter with a high degree of parallelism and low arithmetic complexity. [ABSTRACT FROM AUTHOR]

This letter from the guest editors introduces Vol. 26(1) of the Nexus Network Journal: Architecture and Mathematics. This special issue, with the theme 'Analytical Design in Architecture: New Developments', presents a convergence of historical and contemporary computational methodologies in architecture. The eleven contributions to this issue harness the power of diverse forms of analytical knowledge to create new, intuitive planning platforms and offer designers constructive feedback on novel design methodologies. The topics presented in this issue range from pragmatic design algorithms to the intuitive understanding of traditional architecture, and from the abstract space to experience-oriented education. [ABSTRACT FROM AUTHOR]

This research reports the results of implementation of composite materials and the complete redesign of a tipping silo semi-trailer. The conventional semi-trailer, used for comparison, was designed based on a Feldbinder commercial model, while the innovative one has the same overall dimensions but a new geometry, while maintaining the same performance in terms of deflection and safety factor. The research involves sizing and verification of the results obtained using finite element software (Solidworks Simulation®) with different loading conditions. The main result is that the optimised solution has the lowest weight, with a reduction of about 28 % considering the same equipment and accessories mounted on the two solutions. The last part of the research concerns an estimate of economic investment containing the return on the initial investment and the reduction in fuel consumption by comparing the two solutions. Considering that the vehicle always carries the maximum (payload = 27,500 kg) and the overall weight reduction of about 1800 kg, there is a reduction in fuel consumption for the proposed solution. The return on investment for the new solution occurs between three/four years depending on the number of kilometres driven annually. Finally, the purpose of this paper is to create an example of a procedure for reducing the carbon footprint and the fuel consumption of vehicles by replace and redesign entire mechanical components, in this case industrial vehicles, that would be useful to follow and replicate for any specific case study and increase the eco-sustainability of industrial manufacturers.

This paper proposes an analytical design procedure for 2D FIR circular filter banks and also a novel, computationally efficient implementation of the designed filter bank based on a polyphase structure and a block filtering approach. The component filters of the bank are designed in the frequency domain using a specific frequency transformation applied to a low-pass, band-pass and high-pass 1D prototype with a specified Gaussian shape and imposed specifications (peak frequency, bandwidth). The 1D prototype filter frequency response is derived in a closed form as a trigonometric polynomial with a specified order using Fourier series, and then it is factored. Since the design starts from a 1D prototype with a factored transfer function, the frequency response of the designed 2D filter bank components also results directly in a factored form. The designed filters have an accurate shape, with negligible distortions at a relatively low order. We present the design of two types of circular filter banks: uniform and non-uniform (dyadic). An example of image analysis with the uniform filter bank is also provided, showing that the original image can be accurately reconstructed from the sub-band images. The proposed implementation is presented for a simpler case, namely for a smaller size of the filter kernel and of the input image. Using the polyphase and block filtering approach, a convenient implementation at the system level is obtained for the designed 2D FIR filter, with a relatively low computational complexity. [ABSTRACT FROM AUTHOR]

In this paper, using the critical angle theorem and creating in-phase conditions, an inhomogeneous medium is designed to radiate plane wavefront in different directions. Each side of the antenna is considered a flat dielectric lens by considering the regular k-sided structures as directional beam antennas. Finally, a closed-form formula for the dielectric constant of the sides is obtained. In comparison with polygonal DBAs designed based on other methods, the presented DBAs designed have thinner dielectric slabs (d/D). The designed lenses have been simulated in Comsol Multiphysics software that showing good performances. [ABSTRACT FROM AUTHOR]

This article presents an argument for the enhanced utilisation of urban morphology in urban design, drawing inspiration from space syntax theory and methodologies, advocating for the integration of social, economic, and cultural considerations alongside physical structures. This perspective shift entails transitioning from descriptive analysis to quantitative inquiries for the prediction and assessment of urban dynamics. By incorporating spatial analysis and socio-economic factors, urban morphology offers a competent understanding of the complexities inherent to urban environments. This comprehension supports the development of evidence-based designs and predictive models that enable such an approach in urban design. To operationalise this approach, the article introduces a methodology that interlinks urban morphology and design through a cyclic process encompassing analysis, design, evaluation, and further design development. This framework is illustrated through the case study of Jilin City, where an assessment of the public transport system led to a comprehensive urban design strategy. The study demonstrates how urban morphology insights, supported by analytical investigations enabled by space syntax methodology, can actively influence urban design and planning practices. By effectively embedding this morphological approach, urban designers and planners acquire the tools needed to navigate the evolving urban systems while respecting the interplay between physical structures and human existence. The article concludes by highlighting the need for an ongoing evolution of this approach to maintain relevance in shaping future urban settings. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study about the effect of the ratio between the area of Basalt Fiber Reinforced Polymer (BFRP) bars to the total area of steel and BFRP bars (Af/At) on the behavior of Reinforced Concrete Box (RCB) girders. Also, it displays the effectiveness of the mixed steel and BFRP (MSBFRP) bars as the main reinforcement to enhance the behavior of RCB girders in flexure. Moreover, the ultimate flexural capacity of the tested girders was evaluated analytically. The experimental program consisted of five RCB girders. The first two girders were reinforced in the tension side with either steel or BFRP bars, while the other three ones were reinforced with both steel and BFRP bars with different Af/At ratios. The effect of Af/At ratio on the initiation and propagation of cracks, mode of failure, ultimate and cracking loads, the corresponding deflection, and ductility was investigated. It was found that increasing the Af/At ratio improved both the ultimate load and the deflection at failure, while the ductility index decreased. Comparing the obtained RCB test results with those found in the literature of the ordinary beams revealed that the behavior is almost identical. The Af/At ratio of about 50% to 70% is recommended in the design of hybrid RCB girders as it provides enough post elastic strength and stiffness for meeting the ductility requirement.

In this study, the analytical design and electromagnetic performance comparison of a squirrel-cage induction motor (SCIM) and a wound-field flux switching motor (WFFSM) for high-speed brushless industrial motor drives is undertaken for the first time. The study uses analytical sizing techniques and finite element analysis (FEA) to model and predict the performance of both motors at a 7.5 kW output power. This study includes detailed equations and algorithms for sizing and modeling of both types of motors, as well as performance calculations that aid in motor selection, design optimization, and system integration. The main findings show that the SCIM has superior torque performance for starting and overload conditions, while the WFFSM offers advantages in power factor, efficiency over a wide operating range, and potential for higher peak power output. To this end, the WFFSM is capable of high-speed and high-efficiency operation while the SCIM is suitable for applications requiring variable speed operation. The validation study shows good agreement between analytical and FEA calculations for both motors. The results provide insights into the design and performance characteristics of both motors, enabling researchers to explore innovative approaches for improving their efficiency, reliability, and overall performance. [ABSTRACT FROM AUTHOR]

This paper presents the flexural behavior of reinforced concrete box (RCB) girders reinforced with both steel and fiber-reinforced polymer (FRP). An experimental study was conducted on five RCB girders. The first two girders were reinforced in the tension side with either steel or basalt FRP (BFRP) bars, while the other three ones were reinforced with both steel and BFRP bars with various BFRP-to-total reinforcement ratios (Af/At). The RCB girders were tested under four-point monotonic static loading and the main fundamental characteristics of the proposed reinforcement were investigated. The experimental results showed that increasing the Af/At ratio improved both the ultimate load and the deflection at failure, while the ductility index decreased. Comparing the obtained RCB test results with those found in the literature of the ordinary beams revealed that the behavior is almost identical. With the range of the experimental investigations conducted in this study, a value of about 50% to 70% for Af/At ratio is recommended in the design of hybrid RCB girders as it provides enough post elastic strength and stiffness for meeting the ductility requirement. Ultimately, the application of the analytical structural approach available in the literature was adopted to predict the flexural capacity of mixed RCB girders and good agreement with the experimental results was proved. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Engineering Research & Development (IJERAD) is the property of International Journal of Engineering Research & Development and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This work proposes an efficient analytical design procedure for elliptical and circular 2D digital filters with an adjustable response. The design relies on a 1D low-pass prototype filter with a specified bandwidth, to which a particular frequency mapping is applied. The prototype can be scaled in frequency, having adjustable selectivity. This analytical procedure yields 2D filters with accurate shape even near the frequency plane margins, very low distortions and steep transition at a relatively low order, thus being very efficient. The elliptical filters can be tuned to a desired orientation angle and can be used as directional filters. Also an uniform circular filter bank with a specified number of bands is designed. The frequency response results directly factored, and the corresponding filter matrices result as a convolution of small size matrices, which simplifies implementation and allows for a sequential filtering, in several steps. The proposed method is based entirely on accurate approximations and frequency mappings, without using any numerical optimization algorithms. Several examples of filtering on various test images are provided, to illustrate the capabilities of this class of filters. [ABSTRACT FROM AUTHOR]

A vacuum system is one of the crucial components of the Electron Beam-Powder Bed Fusion Process (EB-PBF). It ensures the generation of a high-intensity electron beam. This paper presents a vacuum system design for the EB-PBF process. The work chamber and EB gun chamber have been designed and verified using ANSYS workbench for stress, strain, and deformation limits and found satisfactory. The analytical calculations have been performed for all the pumps, considering the various gas loads during the process. After the design, the vacuum system has been fabricated and tested for its stability, ultimate vacuum, and leak rate. The helium leak test results show that all the joints have a leak rate better than 1 × 10−8 mbar l/s. Further, the analytical results of each pump have been compared with experimental results and found almost in line with the theoretical results. The results show that a pressure lower than 1 × 10−5 mbar and 5 × 10−6 mbar can be achieved in the work chamber and EB gun chamber in less than 23 min and 10 min respectively. The chamber was evacuated multiple times and found that the chamber could still hold pressure better than 1 × 10−2 mbar after 48 h. • The design was verified using ANSYS for its stress, strain, and deformation limits. • The experimental results are almost in line with the analytical calculations. • The system has a leak rate (He) better than 1 × 10−8 mbar l/s at all joint locations. • The chamber can hold a vacuum of 1 × 10−2 mbar even after 48 h of evacuation. • The total pump downtime of the EB-PBF system is less than 23 min. [ABSTRACT FROM AUTHOR]

This article presents an argument for the enhanced utilisation of urban morphology in urban design, drawing inspiration from space syntax theory and methodologies, advocating for the integration of social, economic, and cultural considerations alongside physical structures. This perspective shift entails transitioning from descriptive analysis to quantitative inquiries for the prediction and assessment of urban dynamics. By incorporating spatial analysis and socio-economic factors, urban morphology offers a competent understanding of the complexities inherent to urban environments. This comprehension supports the development of evidence-based designs and predictive models that enable such an approach in urban design. To operationalise this approach, the article introduces a methodology that interlinks urban morphology and design through a cyclic process encompassing analysis, design, evaluation, and further design development. This framework is illustrated through the case study of Jilin City, where an assessment of the public transport system led to a comprehensive urban design strategy. The study demonstrates how urban morphology insights, supported by analytical investigations enabled by space syntax methodology, can actively influence urban design and planning practices. By effectively embedding this morphological approach, urban designers and planners acquire the tools needed to navigate the evolving urban systems while respecting the interplay between physical structures and human existence. The article concludes by highlighting the need for an ongoing evolution of this approach to maintain relevance in shaping future urban settings.

In this study, a simplified reduced-order modeling scheme is developed to determine the resonant frequency of a doubly clamped beam microelectromechanical system (MEMS) resonator with square release-etch holes. New formulations of the effective bending and shear stiffnesses are proposed and applied to the Timoshenko beam equations. The model is validated by comparison with finite element analysis results. The results show that the model can achieve high accuracy for a wide range of dimensions. In conclusion, the developed model is expected to contribute to reduced-order modeling of MEMSs devices. [ABSTRACT FROM AUTHOR]

This paper is based on fuzzy clustering algorithm on financial data, design of financial data mining system and analysis of financial data, analysis of financial data on the financial decision-making mechanism, from financial data how to enhance the information base of the forecast, financial data how to improve the pertinence of decision-making, financial data how to build a new competitive advantage, financial data how to promote the dynamic decision-making of four, through the analysis of data in financial decision-making specific implementation cases, focusing on the real-life problems faced by the management and the effect of financial data platform to solve problems; finally, through this paper, we hope to provide reference and reference for other similar enterprises to apply financial data for financial decision-making. This paper first describes the theory of financial data, analyzes the mechanism of financial data and financial decision-making, how financial data enhance the information base of forecasting, how financial data improve the pertinence of decision-making, how financial data build a new competitive advantage, how financial data promote dynamic decision-making four dimensions to summarize. [ABSTRACT FROM AUTHOR]

This research reports the results of both the implementation of innovative materials, such as composite material, and the application of the prestressing technique through appropriate tie-rods, for crane construction. The novelty lies in the introduction of both factors in order to reduce and limit the vertical deflection, while also reducing the cross section, which is the main constraint at the machine design phase. In this way, to limit the load-induced deflection of the crane, a constant external action is applied that induces a deflection opposite to that induced by the load. In particular, the object of this research is a jib crane with dimensions 4000x5000 (height and length in mm) with a load capacity of 4905 N. The research involves analytical dimensioning followed by verification of the results obtained using finite elements software (Ansys®). The parameters adopted for sizing, both the boom and the column, are the maximum displacements and safety coefficients concerning both maximum stresses and buckling phenomena. The main result is that the composite crane has the lowest weight: approximately 29 % and 21 % of the weight of the corresponding non-prestressed steel crane, for non-prestressed and prestressed composite configurations, respectively. The last part of the research concerns the construction methods for building cranes, in particular the implementation of the composite solution. [ABSTRACT FROM AUTHOR]

Space-time-modulated metasurfaces can manipulate electromagnetic waves in space and frequency domains simultaneously. In this article, an analytical design of space-time-modulated metasurfaces with modulation elements composed of two paths, In-phase (I) and Quadrature (Q), is proposed. The model is derived analytically, the space-/frequency-domain manipulations are achieved by designing the dimension and time sequence of I and Q paths. In the specular reflection direction, an objective frequency shift of the reflected first-order harmonic can be obtained. While, in other directions, the opposite first-order harmonic can be easily controlled by changing the dimension of I/Q paths, and the objective first-order harmonic remains unchanged. Furthermore, with a small dimension of I/Q paths, the first-order harmonic can be used for beam scanning by predesigning the start time of the modulation element. To realize the space-time-modulated metasurface with the required periodically time-varying responses, 2 bit unit cells loaded with dynamically switchable pin diodes are used as I/Q modulation. Both the analytical and numerical results demonstrate that space- and frequency-domain manipulations of the reflected fields by the first-order harmonics can be simultaneously obtained. The proposed designs have potential applications in wireless communications, radar camouflaging, and cloaking. [ABSTRACT FROM AUTHOR]

In this study we focus on the H ∞ optimization of a tuned mass damper inerter (TMDI), which is implemented on an harmonically forced structure of a single degree of freedom in the presence of stiffness uncertainty. Posed as a min-max optimization problem, its closed-form solutions are analytically derived via an algebraic approach that was newly developed in this work, and ready-to-use formulae of tuning parameters are provided herein for the optimal TMDI (referred to as the TMD). The accuracy of the derived solutions are examined by comparing them with the existing literature and with numerically solved solutions in both deterministic and uncertain scenarios. Our numerical investigation suggested that compared to the classic design, the proposed tuning strategy could effectively reduce the peak vibration amplitude of the host structure in the worst-case scenario. Moreover, its peak vibration amplitude decreases monotonically as the total amount of the tuned mass and inertance increases. Therefore, the incorporation of a grounded inerter in a traditional TMD could render the deteriorated performance of vibration control less important, thereby protecting the primary system against the detuning effect more effectively. Finally, the effectiveness of the proposed design under random excitation is also underlined. [ABSTRACT FROM AUTHOR]

This research study presents an approach for analysis of pico hydro waterwheels by both experimental and numerical methods. The purpose of this research is to harness the energy efficiently from flowing water of irrigation channels and other shallow water sources in rural areas because the electrification of rural areas through connection to grid electricity is very costly. The novelty of this research work lies in testing of the waterwheel as a high-speed device, which is not usually explored. The review of existing literature reveals that pico waterwheels have been extensively studied but without changing the blade profile immersed in the water stream ot the inclination angle of the water stream. In this study, a pico scale waterwheel was tested with three different types of blade profiles, namely a C-shape blade, V-shape blade and straight blade, through computational fluid dynamics (CFD) simulations for different tip speed ratios (TSR), varying the immersed depth of the blade in the stream and changing the angle of the water conduit while keeping the number of blades and the diameter of the wheel constant. The numerical and experimental results were validated for the C-shape blade profile. A substantial improvement in performance is observed with a C-shape blade profile at a TSR of 0.88. The results show that by varying the angle of the water conduit, the maximum performance is achieved at inclination φ = 45°, with an overall improvement of 4.87% in the efficiency. [ABSTRACT FROM AUTHOR]

This work presents an analytical methodology to design a permanent magnet transverse flux generator using a reluctance circuit. Unlike other research, it fully indicates the details to design the rotor, stator, and the air gap of the machine, with all its geometry. In the design section, special considerations to determine the outer diameter of the rotor, and the accompanying pole pitch for the U-cores and I-cores are presented. The proposal of an iterative algorithm using a reluctance circuit to calculate the turns of the armature winding and curved trajectories of flux tubes to model the leakage flux that will allow the synchronous inductance calculation also is presented. The proposed methodology allows determining the performance and the lumped parameters of the generator. Furthermore, it provides evidence that with this design it is possible to select the values of standard voltage for electric generators of this topology. The analytical results of the magnetic flux densities, magnetic flux, lumped parameters, electromotive force, terminal voltage, armature current, power factor, and efficiency are compared with 3D finite element method. Analyzing these results, it is possible to verify the good agreement between them.

This paper focuses on step by step design of fractional order proportional-integral controller for the stability and robust performance of second order plus time delay plant. Analytically obtained equations are generalized and can be used for mentioned plants. Main aim of the method is to flatten the phase curve of the Bode plot between phase and gain crossover frequencies. Thus, robustness to gain variations is provided. Besides, stability of the whole system is ensured. In contrast to existing studies in the literature, not only the gain crossover frequency, both gain and phase crossover frequencies are considered in the design procedure. Also, the phase flattening is not achieved by equalizing the phase derivative to zero. The paper brings a different point of view to the problem. Two different controllers are calculated. The first one achieves desired gain crossover frequency and phase margin properties. Second one ensures the phase crossover frequency and the gain margin. Then, these controllers are connected and there obtained an only controller satisfying both conditions. Proposed equations are applied on two different models from the literature and the results are given graphically. [ABSTRACT FROM AUTHOR]

This paper presents a design and optimization procedure for a dual-stator machine with a diametrically magnetized PM to improve the electromagnetic performance. First, analytical design equations are presented based on MEC analysis; they are used to design a basic dual-stator machine. Then, by applying an artificial intelligence algorithm, the machine is optimized to achieve high efficiency and torque density as well as low pulsating torque for direct-drive applications. A quantitative comparison is performed between the optimized new machine and conventional dual-stator machines to evaluate the performances and improvements of the understudy machine. The machine performances including air-gap flux density distribution, back electromotive force, electromagnetic torque, cogging torque, and torque ripple are analyzed using the finite element method. The analysis results have demonstrated that benefiting from its topology, the optimized dual-stator machine with a diametrically magnetized PM has comprehensively better performance, including higher torque density, higher efficiency, and lower torque ripple and cogging torque compared to conventional dual-stator machines. [ABSTRACT FROM AUTHOR]

This paper describes an analytical design technique in the frequency domain for a particular class of two-dimensional zero-phase anisotropic filters, namely with an elliptical or circular frequency response. These filters may be low-pass, if their response contains the origin of the frequency plane, or band-pass. The elliptical filters are specified by their orientation angle and the lengths of its axes. Their synthesis begins from a Gaussian low-pass prototype with a given selectivity, its frequency response being a ratio of two factored, even order polynomials. A specific frequency transformation is next determined, which is applied to the 1D prototype, leading to the desired 2D elliptically-shaped filter. The frequency response of the obtained filter results in a factored, matrix form and it explicitly contains the imposed specifications. Thus the filter is parametric, it can be adjusted or tuned for various specifications, without the need to resume every time from the start the design procedure. The filters designed through this analytical method are accurate in shape and efficient, of relatively low order, and their frequency response results in a factored form, convenient for implementation. Some relevant examples of design using the proposed method and also some filtering tasks on various test images are provided, to show their capabilities in image processing applications. [ABSTRACT FROM AUTHOR]

This article presents a ring motor that is wrapped around the outer diameter of a propeller for electric rotorcraft. The approach is motivated by the greater aerodynamic efficiency afforded by larger diameter propellers with lower rotational speeds, ultimately minimizing battery energy requirements in electric rotorcraft. Lower rotational blade speeds are mismatched with electric machines that derive power density from high-speed operation, thus a machine design with very high torque density is proposed to allow lower speed operation without the aid of gearing. By wrapping the machine around the outer diameter of the blades, the innate lever arm drastically increases the torque density of the machine without the need for liquid cooling. An analytical design approach is used to characterize the machine design space and design outcomes are verified with finite-element analysis. The final prototype design targets the “heavy-lift” drone space and was tested to verify performance. Measurements of back electromotive force and max torque per amp, along with unloaded and loaded (propeller) testing, benchmark the design and highlight the relative impacts among the various loss mechanisms. The measured specific torque density of the air-cooled design is 6.25 N·m/kg – total mass, 11.1 N·m/kg – active mass only. Key areas for improvement, such as bearing drag reduction and winding fault tolerance, are identified. [ABSTRACT FROM AUTHOR]

In this study we focus on the H∞ optimization of a tuned mass damper inerter (TMDI), which is implemented on an harmonically forced structure of a single degree of freedom in the presence of stiffness uncertainty. Posed as a min-max optimization problem, its closed-form solutions are analytically derived via an algebraic approach that was newly developed in this work, and ready-to-use formulae of tuning parameters are provided herein for the optimal TMDI (referred to as the TMD). The accuracy of the derived solutions are examined by comparing them with the existing literature and with numerically solved solutions in both deterministic and uncertain scenarios. Our numerical investigation suggested that compared to the classic design, the proposed tuning strategy could effectively reduce the peak vibration amplitude of the host structure in the worst-case scenario. Moreover, its peak vibration amplitude decreases monotonically as the total amount of the tuned mass and inertance increases. Therefore, the incorporation of a grounded inerter in a traditional TMD could render the deteriorated performance of vibration control less important, thereby protecting the primary system against the detuning effect more effectively. Finally, the effectiveness of the proposed design under random excitation is also underlined.

This paper deals with analytical design, electromagnetic field analysis and parametric sensitivity analysis of an external rotor permanent magnet-assisted synchronous reluctance motor (PMASynRM). In this work, parametric sensitivity analysis of rotor geometry is performed to obtaining the minimum torque ripple and maximum electromagnetic torque with employing numerical analysis based on two-dimensional finite element method (FEM). In order to determine the optimum operation effect of geometry parameters like the q axis insulation ratio and the flux barrier arm angle for the proposed machine with three barriers is investigated and sensitivity of structure for rotor geometrical variation is presented. The studied machine in this work is a three phase, six pole, external rotor PMASynRM, which is designed by analytical approach and analyzed to obtain the maximum torque and minimum torque ripple based on a parametric sensitivity analysis approach. The obtained results from the FEM-based sensitive analysis and electromagnetic field analysis confirm the analytical design procedure for the proposed PMASynRM. [ABSTRACT FROM AUTHOR]

Transverse flux motors (TFMs) are being investigated to be used in vehicle traction applications due to their high torque density. In this paper, a two-phase axial-gap transverse flux motor is designed for an electric scooter, proposing a novel analytical design method. First, the dimensioning equations of the motor are obtained based on the vehicle requirements, and the stationary dq model is calculated. Then, the motor is optimized using a multiobjective genetic algorithm, and finally a 3D-FEM verification is made. Both the motor structure and the design method aim to have a low complexity, in order to favor the sizing and manufacturing processes through a low computation time and simple core shapes. This approach has not yet been explored in axial-gap TFMs.

This article studied the interference between two channels of a tunable diplexer and proposed a feasible solution to alleviate the effect. A novel approach to synthesize the channel filter with the first element replicating the other channel’s effect is first developed. It led a set of simple formulae for fixed frequency diplexer design. After that, a framework incorporating a redundant coupling path to generate cancellation effect is derived using the coupling matrix theory. The proposed theories are demonstrated and verified using a combline diplexer design. The simulated and measured results suggest that the interference of the two channels can be greatly mitigated. [ABSTRACT FROM AUTHOR]

This paper reported an analytical formulation for the optimum geometry of a uniform pressure coil used in electromagnetic forming and welding. To characterize the energy efficiency of the coil, we defined the objective function as the ratio between the produced magnetic pressure and the required magnetic energy. We then deduced an analytical formulation of the objective function in terms of the geometry and electromagnetic parameters. Based on the analytical formulation, we finally deduced the optimum configuration of the coil geometry in analytical form. To validate the proposed analytical formulation, we analytically and numerically analyzed a uniform pressure coil fabricated in our laboratory, showing that the proposed analytical formulation can well reproduce the numerical results over a broad range of geometric parameters. In addition, it was found that the uniform pressure coil exhibits an optimum channel height, which can be analytically expressed in terms of the coil geometry. In summary, the present study provides an efficient method for designing a uniform pressure coil. [ABSTRACT FROM AUTHOR]

This paper presents an analytical design basedhierarchical control method for non-square MIMO wood-chip refining process, whose design procedure of the control scheme contains two layers. Firstly, the lower layer loop controller with PID structure is designed separately for the mutually independent lower layer device plant, and then generalized non-square process is obtained on the basis of lower layer closed-loop system and non-square MIMO refining process. Secondly, the upper layer setting controller with the centralized PID structure is designed by the multivariable decoupling control and internal model control (IMC), and an analytical designed method for the lower layer loop controller and the upper layer setting controller is developed using the maximum sensitivity (M s) specification. Finally, Simulation results demonstrate the effectiveness of the proposed method for control and optimal operation of the non-square MIMO refining process. • This paper proposes a hierarchical control method for wood-chip refining process. • Loop controller at lower layer is designed for the independent device plant. • The static decoupling is used for the generalized non-square operational process. • Setting controller at upper layer is designed by the multivariable decoupling IMC. • An analytical design method for the controllers with PID structure is developed. [ABSTRACT FROM AUTHOR]

This work presents the suggestion of a model for the prediction of the reliability of type III gas storage vessel under pressure, considering the geometrical and mechanical uncertainties using the Monte Carlo method. Using the hoop stress for each ply, the Monte Carlo method was used to predict the distribution function of the mechanical response. The random design variables of the aluminum liner; which is overwrapped by a composite manufactured by filament winding. Nine random design variables with uncertainties were selected, namely: elastic constants of metallic and composite materials, ply angles, thickness, and finally the mechanical loading (pressure). To ensure the accuracy of the obtained results, we have performed 105 simulations. The obtained results showed that the elastic properties of the composite materials have no significant influence on the security of the composite vessels type III in relation to the manufacturing parameters: which are thickness, winding angle, and the loading pressure. The probability of failure increased significantly when all the random variables were considered simultaneously. [ABSTRACT FROM AUTHOR]

This article proposes a mathematical model of an axial flux induction motor (AFIM) with one stator and one rotor. The model is based on the expression for the electromagnetic torque, which presents a function of two independent variables: the axial length of the stator core and the flux density in the air gap. This allows calculating the main dimensions of the motor with the highest possible torque density. Thus, developed model is suitable for designing the motor of specified volume with maximum torque, and solving the inverse problem of minimizing the machine volume with the specified torque. The detailed output of the model and the results of the calculations for the low-power engine powered by voltage of 7.35 V (RMS) are given. The results are validated using FEM in ANSYS software: with the outer motor diameter of 0.11 m, the flux density in it reaches 1.2 T.

Simplification of the design of Mechanically Stabilized Earth wall structures (MSE wall or MSEW) is now an important factor that helps us not only to save a time and costs, but also to achieve the desired results more reliably. It is quite common way in practice, that the designer of a section of motorway or railway line gives order for design to a supplier of geosynthetics materials. However, supplier company has experience and skills, but a general designer does not review the safety level of design and its efficiency, and is simply incorporating into the overall design of the construction project. Actually, large number of analytical computational methods for analysis and design of MSE walls or similar structures are known. The problem of these analytical methods is the verification of deformations and global stability of structure. The article aims to clarify two methods of calculating the internal stability of MSE wall and their comparison with FEM numerical model. Comparison of design approaches allows us to draft an effective retaining wall and tells us about the appropriateness of using a reinforcing element.

A comparative optimal design of fluid-saturated prismatic cellular metal honeycombs (PCMHs) having different cell shapes is presented for thermal management applications. Based on the periodic topology of each PCMH, a unit cell (UC) for thermal transport analysis was selected to calculate its effective thermal conductivity. Without introducing any empirical coefficient, we modified and extended the analytical model of parallel–series thermal–electric network to a wider porosity range (0.7∼0.98) by considering the effects of two-dimensional local heat conduction in solid ligaments inside each UC. Good agreement was achieved between analytical predictions and numerical simulations based on the method of finite volume. The concept of ligament heat conduction efficiency (LTCE) was proposed to physically explain the mechanisms underlying the effects of ligament configuration on effective thermal conductivity (ETC). Based upon the proposed theory, a construct strategy was developed for designing the ETC by altering the equivalent interaction angle with the direction of heat flow: relatively small average interaction angle for thermal conduction and relatively large one for thermal insulation.

Abstract To determine the overall trustworthiness of a complex Cyber Physical System (CPS), it is critical to consider several methods of engineering design. Traditionally, translating a customer needs into requirements, through physical realization and into an operation leans on processes that are largely dependent upon functional requirements. There are, however, no strict rules in design that dictate the use of functionality as the fundamental approach. Since no strict rules exist, non-functional requirements will be used contrary to the traditional use of functional requirements. In particular, trustworthiness is a relatively defined term relying on face-validity methods from a multitude of non-functional requirements identified in related research. A limited-design method with Analytical Hierarchy Process (AHP), Axiomatic Design (AD) and Design of Experiments (DOE) is tested using this nonfunctional requirement of trustworthiness. The aggregated measurement is used to determine where it is best to focus design efforts in the concept stage. [ABSTRACT FROM AUTHOR]

In this study, low speed and high torque permanent magnet synchronous motors (PMSM) used in elevator applications are investigated. Better motor design solutions are proposed by using the analytical calculations, the finite element method based simulations. Firstly, a permanent magnet synchronous motor having 60 slots 16 poles (already in the market) for an eight- person elevator which is operating at a speed of one meter per second is analyzed by using the simulation and experimental results. The simulations of the motors having 48 and 54 slots are performed as the next step. Different types of motors have been analyzed in terms of current, voltage, harmonic components, moment and efficiency characteristics. In the view of these results, the most suitable motor is prototyped considering the cost and the relevant standards for the elevator applications. The proposed new motor with 54 slots shows a better performance due to its simulation and test results by increased efficiency and decreased the size, volume and weight. This is valid even though better permanent magnets are preferred. In addition, the stack length of the new motor is reduced by 20% and this output is very important especially for elevator applications. [ABSTRACT FROM AUTHOR]