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1.
J. E. J. 《技术计量学》2013,55(4):502-503
This article demonstrates advantages of using nonorthogonal resolution IV designs for running small screening experiments when the primary goal is identification of important main effects (MEs) with a secondary goal of entertaining a small number of potentially important second-order interactions. This is accomplished by evaluating the structure and performance of designs obtained by folding over small efficient nonorthogonal resolution III designs and comparing them with more commonly used orthogonal resolution III designs of comparable size, such as fractional factorials and Plackett–Burman designs. The folded-over designs are available for a wider class of run sizes and perform as well as or better than resolution III competitors in selecting the correct model when a few active two-factor interactions are present and significantly outperform resolution III competitors in terms of correctly identifying MEs. A simple two-step procedure is proposed for analyzing data from such designs that separates the goals and is well suited for sorting through likely models quickly.  相似文献   

2.
Theoretical analyses and designs of high-Q, quartz thin film resonators are presented. The resonators operate at an ultra-high frequency of 3.4 GHz for application to high-frequency timing devices such as cesium chip-scale atomic clocks. The frequency spectra for the 3.4-GHz thin film quartz resonators, which serve as design aids in selecting the resonator dimensions/configurations for simple electrodes, and ring electrode mesa designs are presented here for the first time. The thin film aluminum electrodes are found to play a major role in the resonators because the electrodes are onlyone third the thickness and mass of the active areas of the plate resonator. Hence, in addition to the material properties of quartz, the elastic, viscoelastic, and thermal properties of the electrodes are included in the models. The frequency-temperature behavior is obtained for the best resonator designs. To improve the frequency-temperature behavior of the resonators, new quartz cuts are proposed to compensate for the thermal stresses caused by the aluminum electrodes and the mounting supports. Frequency response analyses are performed to determine the Q-factor, motional resistance, capacitance ratio, and other figures of merit. The resonators have Q's of about 3800, resistance of about 1300 to 1400 ohms, and capacitance ratios of 1100 to 2800.  相似文献   

3.
Serkan M  Kirkici H 《Applied optics》2008,47(2):230-241
We present two optical system designs using aspherical lenses for beam circularization, collimation, and expansion of semiconductor lasers for possible application in lidar systems. Two different optical lens systems are investigated; namely, two aspherical lens and single aspherical lens systems. Software package programs of ZEMAX and MATLAB to simulate the optical designs are used. The beam reshaping results are presented for one specific laser beam output.  相似文献   

4.
Serkan M  Kirkici H  Cetinkaya H 《Applied optics》2007,46(22):5489-5499
In this paper, we present two optical system design methods for beam circularization, collimation, and expansion of semiconductor laser output beam for possible application in LIDAR systems. Two different optical mirror systems are investigated: an off-axis hyperbolic/parabolic mirror system and an off-axis parabolic mirror system. Equations specific to these mirror systems are derived and computer package programs such as ZEMAX and MATLAB are used to simulate the optical designs. The beam reshaping results are presented.  相似文献   

5.
New materials of the trigonal 32 class have received much attention recently, due to their quartz-like temperature behavior and the promise of higher electromechanical coupling coefficients. The magnitude and phase of the reflection coefficient of the metal strips that form the SAW transducers and reflector structures is a critical parameter that allows proper device designs and optimal material surface orientation. This paper describes an investigation of the magnitude and phase of the SAW metal strip reflectivity in some new materials and along now orientations. The materials are langanite, langasite, and gallium phosphate. The results are presented as contour plots of the magnitude and phase of the reflection coefficient. In addition, the phase velocity, temperature coefficient of delay, electromechanical coupling coefficient, and power flow angle are given, thus allowing proper orientation selection for SAW device designs. The results presented highlight the reflection coefficient calculations in the selection of natural single-phase unidirectional transducer orientations (NSPUDT) for these new materials. The orientation regions suggested in this paper for the new materials are thus very promising for low-loss, high-performance consumer and communications SAW designs, such as NSPUDT filters, resonator-based filters, and other devices that can benefit from a high metal strip reflectivity  相似文献   

6.
Some novel new resonator designs based on the distributed Bragg reflector are presented. The resonators implement a TE011 resonance in a cylindrical sapphire dielectric, which is confined by the addition of rutile and sapphire dielectric reflectors at the end faces. Finite element calculations are utilized to optimize the dimensions to obtain the highest Q-factors and zero frequency-temperature coefficient for a resonator operating near 0°C. We show that a Q-factor of 70,000 and 65,000 can be achieved with and without the condition of zero frequency-temperature coefficients, respectively  相似文献   

7.
This article describes an implementation of a particular design of experiment (DoE) plan based upon optimal Latin hypercubes that have certain space-filling and uniformity properties with the goal of maximizing the information gained. The feature emphasized here is the concept of simultaneous model building and model validation plans whose union contains the same properties as the component sets. Two Latin hypercube DoE are constructed simultaneously for use in a meta-modelling context for model building and model validation. The goal is to optimize the uniformity of both sets with respect to space-filling properties of the designs whilst satisfying the key concept that the merged DoE, comprising the union of build and validation sets, has similar space-filling properties. This represents a development of an optimal sampling approach for the first iteration—the initial model building and validation where most information is gained to take the full advantage of parallel computing. A permutation genetic algorithm using several genetic operator strategies is implemented in which fitness evaluation is based upon the Audze-Eglais potential energy function, and an example is presented based upon the well-known six-hump camel back function. The relative efficiency of the strategies and the associated computational aspects are discussed with respect to the quality of the designs obtained. The requirement for such design approaches arises from the need for multiple calls to traditionally expensive system and discipline analyses within iterative multi-disciplinary optimisation frameworks.  相似文献   

8.
The ability to store as much energy as possible for the least weight, defined by the rotor's energy density (U/m~J/g), is of paramount importance to the pulsed power supply of electromagnetic guns. This paper extends the work presented in a complementary paper in which the shape factors, Fs, for a representative number of rotating machines were derived and compared. The effects of shape factor, maximum allowable operational stress σ&thetas;max, and effective rotor density ρeff (determined by the addition of electrical conductors to the rotor for power extraction) on rotor energy density and tip speed are presented in this paper. A comparison between two candidate composite designs for electromagnetic pulsed power generation-a laminated disk (LD) and a rim rotor (RR)-is performed. Our analyses have determined that the true discriminator between the LD and the RR designs is the allowable stress each can operate at since they both have the same shape factor and about the same composite density. The LD design is limited by the interlaminar shear strength of the epoxy bond to hoop stresses in the range of 150 ksi(1.0·109 N/m2), while the RR design is able to take full advantage of the strength limit of the composite fiber and operate at hoop stresses as high as 350 ksi (3.1·109 N/m2)  相似文献   

9.
可重构制造系统是面向客户定制的一种新的制造模式.先阐述了可重构制造系统的概念及其特点,并对目前关于可重构制造系统的设计研究进行了总结.然后,以快速响应市场变化为目标,提出了基于公理设计理论的设计方法及设计步骤,对可重构制造系统进行设计,降低了设计的复杂性.层次化设计和分解方法保证了在设计过程中以适当的顺序做出合理决策.最后给出了可重构制造系统的工作流程图.  相似文献   

10.
The treatment-design portion of fractionated two-level split-plot designs is associated with a subset of the 2 nk fractional factorial designs. The concept of aberration is then extended to these splitplot designs to compare designs. Two methods are presented for constructing two-level minimumaberration split-plot designs, along with examples. An extensive catalog of such designs is tabulated. Extensions to prime-level designs and relations to inner-outer arrays are also presented.  相似文献   

11.
Abstract

In this article, we propose a new method for constructing supersaturated designs that is based on the Kronecker product of two carefully chosen matrices. The construction method leads to a partitioning of the factors of the design such that the factors within a group are correlated to the others within the same group, but are orthogonal to any factor in any other group. We refer to the resulting designs as group-orthogonal supersaturated designs. We leverage this group structure to obtain an unbiased estimate of the error variance, and to develop an effective, design-based model selection procedure. Simulation results show that the use of these designs, in conjunction with our model selection procedure enables the identification of larger numbers of active main effects than have previously been reported for supersaturated designs. The designs can also be used in group screening; however, unlike previous group-screening procedures, with our designs, main effects in a group are not confounded. Supplementary materials for this article are available online.  相似文献   

12.
The vibrations originating from badly distributed load inside the drum are in this paper channeled into cost functions which are used as objectives for optimization. The defined kinematic cost function deals with performance of tub motion and can ensure margins to collision of parts inside the washing machine or constitute a step in the process to increase the machine capacity. The dynamic cost function measures transmitted vertical force to the hosting structure. Forces which cause noise and vibration impact on the surroundings. Two different cost functions for stability of a washing machine in the sense of walking avoidance are also presented. The difference between these formulations is studied with an example, which shows that although it is costly to evaluate the second formulation it will give more freedom to find good washing machine designs. Three different applied problems which aim to optimize different suspension designs for new and existing washing machines are presented. For effective numerical computation of the complex multiobjective optimization problems a multistep approach for washing machine structural optimization is presented. With the help of parallel calculation of the response of dynamic models implemented in Adams?View, the approach has been used to solve the presented problems. Results derived from the solution to the optimization problems have been used in development of new washing machines which afterwards have been put on the market.  相似文献   

13.
The block-transitive point-imprimitive 2-(729,8,1) designs are classified. They all have full automorphism group of order 729.13 which is an extension of a groupN of order 729, acting regularly on points, by a group of order 13. There are, up to isomorphism, 27 designs withN elementary abelian, 13 designs withN=Z 9 3 and 427 designs withN the relatively free 3-generator, exponent 3, nilpotency class 2 group, a total of 467 designs. This classification completes the classification of block-transitive, point-imprimitive 2-(, k, 1) designs satisfying , which is the Delandtsheer-Doyen upper bound for the number of points of such designs. The only examples of block-transitive, point-imprimitive 2-(, k, 1) designs with are the 2-(729, 8, 1) designs constructed in this paper.The first three authors acknowledge the support of an Australian European Awards Program scholarship, a Deutsche Akademische Austauschdienst scholarship, and an Australian Research Council Research Fellowship, respectivelyThe authors wish to thank Brendan McKay for his independent verification of the non-isomorphism of the classes of designs found, and of their automorphism groups, using different, nauty techniques [6].  相似文献   

14.
In this paper, the performances of microchannel evaporators with different manifold structures are experimentally investigated. Eight evaporator samples with 7 different designs of the I/O manifold and 5 different designs of the return manifold are made for this study. The performances of the evaporator samples are tested on a psychometric calorimeter test bench with the refrigerant 134A at a real automotive AC condition. The results on the variations of the cooling capacity and air temperature distribution of the evaporator due to the deflector designs in the I/O manifold and flow hole arrangements in the return manifold are presented and analyzed. By studying the KPI’s for the performance of an evaporator, the design trade-off for an evaporator designer is summarized and discussed.  相似文献   

15.
The minimum deflection and weight designs of laminated composite plates are given. The finite element method using Mindlin plate theory is used in conjunction with optimisation routines in order to obtain the optimal designs. Various boundary conditions are considered and results are given for varying aspect ratios and for different loading types. Comparative results are presented for minimum weight priority design as an alternative to minimum deflection/minimum weight priority design to investigate the effect of priority on the deflection and weight.  相似文献   

16.
This study focuses on the topology optimization framework for the design of multimaterial dissipative systems at finite strains. The overall goal is to combine a soft viscoelastic material with a stiff hyperelastic material for realizing optimal structural designs with tailored damping and stiffness characteristics. To this end, several challenges associated with incorporating finite-deformation viscoelastic-hyperelastic materials in a multimaterial design framework are addressed. This includes consideration of a thermodynamically consistent finite-strain viscoelasticity model for simulating energy dissipation together with F-bar finite elements for handling material incompressibility. Moreover, an effective multimaterial interpolation scheme is proposed, which preserves the physics of material mixtures in the context of density-based topology optimization. A numerically accurate analytical design sensitivity calculation is also presented using a path-dependent adjoint method. Furthermore, both prescribed-load and prescribed-displacement boundary conditions are considered in the optimization formulations, together with various strategies for controlling stiffness. As demonstrated by the numerical examples, the use of the stiffer hyperelastic material phase in a design not only improves stiffness but also increases energy dissipation capacity. Moreover, with the finite-deformation theory, the effect of the loading magnitude on the optimized designs can be observed.  相似文献   

17.
Efficient estimation of response variables in a process is an important problem that requires experimental designs appropriated for each specific situation. When we have a system involving control and noise variables, we are often interested in the simultaneous optimization of the prediction variance of the mean (PVM) and the prediction variance of the slope (PVS). The goal of this simultaneous optimization is to construct designs that will result in the efficient estimation of important parameters. We construct new computer‐generated designs using a desirability function by transforming PVM and PVS into one desirability value that can be optimized using a genetic algorithm. Fraction of design space (FDS) plots are used to evaluate the new designs and six cases are discussed to illustrate the procedure. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

18.
The structure of a QAM radio system is explained. Some novel designs that demonstrate the current status of spectral shaping SAW (surface acoustic wave) filters are presented. Compensation of second-order effects is discussed. Experimental results for a filter for a 140-Mb/s 16 QAM cochannel system with a roll-off factor of 0.19 are shown. Two other examples of filters for a 140-Mb/s, 64 QAM system with a 35% relative bandwidth are also presented  相似文献   

19.
It is pointed out that the construction of large particle accelerators and storage rings requires the design and fabrication of large numbers of bending, focusing, and correction magnets. Normal conducting iron yoke magnets are standard for low fields. Two designs representing efforts for manufacturing cost reduction are discussed. Emphasis is placed on superconducting magnets necessary for high fields. Many details of the well-established cos&thetas; one or two layer coil design using NbTi superconductor are presented. Peculiarities in the use of Nb3Sn superconducting material are mentioned. Examples of alternative superconducting magnet designs are given. Finally, the performance of HERA (Hadron-Electron Ring Accelerator) magnets produced in quantity by industry is presented  相似文献   

20.
Cojocaru E 《Applied optics》1994,33(13):2678-2682
An analysis is given of the designs of thin-film coatings on totally reflecting boundaries that produce half-wave, quarter-wave, and half-quarter-wave phase retardations. Particular single-layer, doublelayer, and symmetrical triple-layer coatings that contain only one non-quarter-wave layer are considered. Simple quadratic equations are presented for the non-quarter-wave-layer phase thickness. Useful diagrams of the solution zones for layer refractive indices are obtained.  相似文献   

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