According to static model balancing, the electrostatic and mechanical forces from an equivalent circuit one can have an analytical solution useful for characterization of a self-reciprocating radioisotope-fueled micro...
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According to static model balancing, the electrostatic and mechanical forces from an equivalent circuit one can have an analytical solution useful for characterization of a self-reciprocating radioisotope-fueled micro power generator. Charge collection efficiency (CCE) a, an empirical coefficient describing the portion of the total emitted current that gets collected by the cantilever, is an important parameter to gauge the usefulness of the cantilever. In this paper, based on MCNP Monte Carlo calculations, an applicable computational method has been proposed for assessment of the CCE in self-reciprocating radioisotope-powered cantilevers. Validity of the proposed method has been confirmed via comparison of the simulation results on CCE with the experimental value for this parameter, namely, 13.59% and 14.2%, respectively, in a previously demonstrated prototype cantilever device. The relative difference between computational and experimental results is within 4%, which confirms that the order of magnitude of the results is very close. Furthermore, suggestions have been proposed and investigated for the enhancement of the CCE in self-reciprocating radioisotope-fueled power generators. Effect of cantilever geometry and material on CCE has been investigated for some material and geometry specifications. The obtained results are indicative of the fact that this method can be used to investigate optimized design parameters in order to improve the total efficiency of the device.
Today, business models are invariably part of complex networks of suppliers, manufacturers and distributors. Uncertainty is recognized as an inevitable characteristic of supply networks and managers need to be aware o...
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Today, business models are invariably part of complex networks of suppliers, manufacturers and distributors. Uncertainty is recognized as an inevitable characteristic of supply networks and managers need to be aware of its specifications and consequences of that. Therefore, understanding, acknowledgment, and moderation of the causes and effect of uncertainty is crucial. Under-controlled uncertainty leads to the improvement of networks' performances and reliable networks. This paper complies with uncertain complex supply networks with their fundamental types. By defining critical routes in PERT networks, a combination of stochastic and mathematical models calculates the delivery time uncertainty in supply networks. This approach can be used as a tool for managers to control and monitor uncertainty in complex networks. (c) 2014 Elsevier Ltd. All rights reserved.
A modified phase-field model is presented to numerically study the dynamics of flowing foam in an obstructed channel. The bubbles are described as smooth deformable fields interacting with one another through a repuls...
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A modified phase-field model is presented to numerically study the dynamics of flowing foam in an obstructed channel. The bubbles are described as smooth deformable fields interacting with one another through a repulsive potential. A strength of the model lies in its ability to simulate foams with wide range of gas fraction. The foam motion, composed of about hundred two-dimensional gas elements, was analyzed for gas fractions ranging from 0.4 to 0.99, that is below and beyond the jamming transition. Simulations are preformed near the quasi-static limit, indicating that the bubble rearrangement in the obstructed channel is primarily driven by the soft collisions and not by the hydrodynamics. Foam compression and relaxation upstream and downstream of the obstacle are reproduced and qualitatively match previous experimental and numerical observations. Striking dynamics, such as bubbles being squeezed by their neighbors in negative flow direction, are also revealed at intermediate gas fractions.
This article presents a computational method for solving a problem with parameter for a system of Fredholm integro-differential equations. Some additional parameters are introduced and the problem under consideration ...
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This article presents a computational method for solving a problem with parameter for a system of Fredholm integro-differential equations. Some additional parameters are introduced and the problem under consideration is reduced to solving a system of linear algebraic equations. The coefficients and right-hand side of the system are calculated by solving the Cauchy problems for ordinary differential equations. We establish a criterion for the unique solvability of the problem under consideration. A numerical algorithm is offered for solving the problem with parameter. The results are illustrated by numerical examples.
One of challenging issues in structural random analysis is to accurately predict the dynamic stresses. It is even important for fatigue life prediction and strength-safe design. This paper proposes an accurate and eff...
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One of challenging issues in structural random analysis is to accurately predict the dynamic stresses. It is even important for fatigue life prediction and strength-safe design. This paper proposes an accurate and efficient computational method to obtain the dynamic stresses of structures under random loading. Firstly, the random loading given by PSD is transferred into harmonic functions. Meanwhile, structural modal stress analysis is conducted. Based on the modal stress superposition and the equivalent treatment for higher modal responses, the dynamic stresses are determined. It consists of two parts: one is from the modal stress superposition, and the other is from the equivalent analysis including the contributions of the ignored higher modes. This new method is verified by the experiment conducted in our laboratory, showing that the dynamic stresses predicted by the new method agree well with the experimental results, and it is of high computational efficiency. The proposed method can be easily applied to dynamic stresses prediction for engineering structures under random loading. (C) 2016 Elsevier Masson SAS. All rights reserved.
This paper reports the development of a computer program for the ultimate analysis of reinforced concrete slab or wall panels based on the Yield Line method. The program is able to generate and search for the most app...
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This paper reports the development of a computer program for the ultimate analysis of reinforced concrete slab or wall panels based on the Yield Line method. The program is able to generate and search for the most appropriate yield line pattern which satisfied the upper bound theorem at ultimate limit state. The basic procedure is to consider the three dimensional geometric compatibility of the collapsed slab elements. The required flexural resistance is determined by the maximisation of the virtual work equation using the Conjugate Gradient iterative method. The overall procedure can also be applied to panels with columns at the corners, or free edges as well as with openings. The proposed method is not suitable for slabs which have reflex internal angles at any corners.
A computational method is developed to calculate the deformation of curved interconnects for stretchable electronics. Similar to finite element method (FEM), the concept for discretization of continuum computational d...
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A computational method is developed to calculate the deformation of curved interconnects for stretchable electronics. Similar to finite element method (FEM), the concept for discretization of continuum computational domain is used in the method, which can be used to compute complex structures. Different from FEM, the method is mesh independent. As case study, the deformation of a serpentine interconnect is respectively calculated by the developed method and commercial FEM software ANSYS with enough elements. By comparison of the predicted results, it shows that developed method is effective and can be used to obtain more accurate deformation of the complex curved slender structures with lower computational cost.
作者:
Koh, Jin MingCheong, Kang HaoSUTD
Sci & Math Cluster 8 Somapah Rd S-487372 Singapore Singapore SUTD
Massachusetts Inst Technol Int Design Ctr 8 Somapah Rd S-487372 Singapore Singapore Singapore Inst Technol
Engn Cluster 10 Dover Dr S-138683 Singapore Singapore
Not all workable spectrometer systems can be represented by an exact analytical field;furthermore, while traditional design methods typically involve approximating known analytical fields with appropriate electrode/ma...
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Not all workable spectrometer systems can be represented by an exact analytical field;furthermore, while traditional design methods typically involve approximating known analytical fields with appropriate electrode/magnet configurations, modern simulation-based approaches do away with analytical representations altogether. Nonetheless, analytical solutions offer several advantages, including the ease of accurately evaluating focusing properties, and the prospect of optimization through mathematical analysis. In this paper, we propose an original and novel data-driven computational method for determining highly-accurate analytical field solutions, applicable to energy analyzers of arbitrary geometry and electrode/magnet configuration. The method encompasses a statistical analysis on a sample numerical field, from which appropriate eigenvalue bases are identified for the construction of an approximate series solution. The proposed method is demonstrated on three instruments-the parallel radial mirror analyzer, radial mirror analyzer, and parallel cylindrical mirror analyzer-illustrating its excellent versatility and accuracy in both the derived analytical fields (< 1% mean error) and relative energy resolution predictions. We also demonstrate the potential application of automated optimization on the analytical fields through an adaptive Levenberg-Marquardt algorithm, exploiting the dimension-reducing properties of the method to aid in efficiency. Our proposed method is general enough to be applied across other fields of applications.
This paper describes the development of a computer-based method for producing chined planing boat hull forms adequate to be applied in concept design. The method is based on a principle where the designer specifies a ...
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This paper describes the development of a computer-based method for producing chined planing boat hull forms adequate to be applied in concept design. The method is based on a principle where the designer specifies a small set of critical parameters he/she wishes obtain or keep preserved and generates a complete hull form, without the traditional skilled recourse of giving stations point by point. From this set of parameters a detailed and faired drawing with offsets is generated very quickly. The method allows, in its execution mode, the flexibility to modify, adjust and enlarge the input set of parameters. The method was created to allow both (1) automated hull form definitions when integrated to an existing computer system and (2) quick but detailed preliminary calculations of stability, lift and drag, volumes and internal space allocations, sea-keeping estimates, etc., all with very reasonable precision. As application examples some planing boat hull forms are generated. Some are typical and others less usual. The later ones are defined to show the method's limits, in order to validate it. (C) 2000 Elsevier Science Ltd. All rights reserved.
A computational method was developed for the prediction of handle value of the bed linen fabrics by using step-wise block regression method. The objective evaluation of fabric hand would contribute in engineering and ...
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A computational method was developed for the prediction of handle value of the bed linen fabrics by using step-wise block regression method. The objective evaluation of fabric hand would contribute in engineering and developing the bed linen fabrics that offers maximum comfort while sleeping. The subjective evaluation of fabric hand restricts the engineering of the high-quality fabrics and the scientific understanding of the fabric properties. The expert's opinion selected the four primary hand properties that are soft feeling, smoothness, fullness, and stiffness influencing the handle of the bed linen fabrics. Primary and total hand equations were developed using the 16 basic mechanical properties. The experimental total hand value was also calculated using existing hand equation for futon's cloth and the statistical approach was followed to investigate the correlation between subjective, experimental, and computational total hand values. An excellent correlation of 0.889 was found between the subjective and computational hand values. The research concludes that the total hand value of the bed linen fabrics can be predicted with tolerable accuracy level.
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