ISSN:0253-3839    

DOI:10.1080/02533839.1994.9677644

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The following study presents a newly developed approach for modeling perforated muffler components, such as partially perforated extended inlet/outlet elements. After evaluating the transfer matrices of all sub‐elements, the transfer matrices product is obtained by multiplication of partially perforated extended inlet/outlet elements. For acoustic impedance in the linear regime, a closed form solution of the partially perforated intruding tube muffler transmission loss was first obtained. In the case of zero mean flow, the predicted results for the various muffler configurations strongly corresponds to the measured values within the limitations of the one‐dimensional theory. By tuning the lengths and associated physical parameters to the in‐situ case of various tubular elements, one can achieve rapid and economical modeling of frequently used commercial reactive mufflers as well as mufflers for other industrial applications can be achieved. This aeroacoustic modeling ability is very useful for vehicular muffler designer especiallly during the preliminary design stages.

ISSN:0253-3839    

DOI:10.1080/02533839.1994.9677645

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Mandarin Chinese is a tonal language, in which every syllable is assigned a tone that has a lexical meaning. Therefore tone recognition is very important for Mandarin speech. This paper presents a method for continuous speech tone recognition. Context‐dependent discrete hidden Markov models (HMM's) are used taking into account the tones of the syllables on both sides, and special efforts were made in selecting the minimum number of key context‐dependent models considering the characteristics of the tones. The results indicate that a total of 23 context‐dependent models have very good potential to describe the complicated tone behavior for all 175 possible tone concatenation conditions in continuous speech, such that the required training data can be reduced to a minimum and the recognition process can be simplified significantly. The best achievable recognition rate is 83.55 %.

ISSN:0253-3839    

DOI:10.1080/02533839.1994.9677646

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

For industrial constrained manipulators, the interactive motion and force dynamics between the end effector and the constrained environment occur at both the normal space and the tangent space to the constraint manifold. In order to characterize such interactive behaviors, it is advantageous to develop a specific coordinate frame to facilitate the formulation of such constrained dynamics. Most previous approaches solved the problem from the algebraic viewpoint. This paper, on the other hand, develops a systematic method to construct a geometric constraint frame from the perspective of integral manifold theory. A constraint frame, distinct from previous orthogonal moving frames, behaves as a partially orthogonal coordinate system and is endowed with intrinsic geometric implications which are beneficial to the dynamic analysis and the controller design. The algebraic and geometric points of view concerning the constrained systems are compared and discussed. An illustrative example for constrained manipulators will be demonstrated.

ISSN:0253-3839    

DOI:10.1080/02533839.1994.9677647

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper investigates the hydraulic head distribution of a pumping well located in the river wedge under steady state conditions. Adopting polar coordinates and using the principle of image well and superposition, we develop a new solution and establish some general formulas. The results can be used both in the field of ground water hydrogeology and the petroleum engineering.

ISSN:0253-3839    

DOI:10.1080/02533839.1994.9677648

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A new boundary element method is developed for the analysis of multi‐layered elastic media. This approach is based on the integral transform method, displacement potential theory and principle of superposition. The Kelvin's solution, the solution expressed by the displacement potentials due to the interface loadings, combined with the initial conditions are superposed to determine the solution within a layer.

ISSN:0253-3839    

DOI:10.1080/02533839.1994.9677649

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The viscosities of pig hemoglobin solutions and liposome encapsulated pig hemoglobin (LEH) suspensions were systematically measured as a function of shear rates, temperature, hematocrits of LEH suspensions, concentrations of hemoglobin solutions and hemoglobin contents in LEH suspensions. Newtonian flow behavior of hemoglobin solution is observed. Moreover, the viscosity values of the solutions linearly decrease as the solution warms from 4°C to 37°C, but non‐linearly increase with an increase in the concentration of hemoglobin in solutions. In contrast to hemoglobin solutions, LEH suspensions show non‐Newtonian flow behavior at all tested shear rates. The viscosity values of LEH suspensions non‐linearly decrease as the solution warms from 4°C to 37°C, but increase with an increase of hematocrit and hemoglobin content of solutions. The above mentioned non‐linear flow behavior of LEH suspensions is strongly dependent on the hemoglobin contents in suspensions. Moreover, LEH suspensions with hemoglobin contents of 7.2 g/dl is Theologically the most suitable suspensions for further applications.

ISSN:0253-3839    

DOI:10.1080/02533839.1994.9677650

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Blow forming is a commonly used production method to deform superplastic sheets. Several papers have appeared to analytically predict the pressurization sequence needed to control the inflation process at a desired strain rate. Some of them, however, are based on an over‐simplified assumption of uniform thickness reduction during the inflation, which often leads to non‐conservative prediction of pressure‐time path. Others have been more rigorous in the formulation, which on the other hand, results in more extensive equations requiring iterative method with a computer program. This paper presents a modified approach. Ignoring the assumption of uniform thinning, a set of physically sound yet easy‐to‐use equations for obtaining pressure‐time curves, heights of the deforming dome, and thickness variations both in space and time, are derived. The analytical results compare favorably with the experimental data and more elaborate finite element solutions.

ISSN:0253-3839    

DOI:10.1080/02533839.1994.9677651

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

With the countercurrent electromigration method, the ionic mobility differences of Li+and K+in molten binary electrolyte LiCl‐KCl have been measured over a widely concentration and temperature range. Except at a region of high concentration of LiCl, the mobility of the large cation,K+(bk), is greater than that of the smaller Li+(bu) cation. The crossing points of the isotherm mobility shifts with the temperature with a higher concentration of LiCl. When the Coulombic attraction force is expected to be the dominant factor for ruling the cation mobilities, bothbuandbKhave been found to be well expressed by the empirical equationb = [A/(V— Vo) ]exp(—E/RT), whereA, VoandEare characteristic constants of the cation,Vis the molar volume of mixtures, andRis the gas constant.

ISSN:0253-3839    

DOI:10.1080/02533839.1994.9677652

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Based on reflection arrangement, two antenna polarization measurement techniques, the absolute polarization measurement method and the polarization‐transfer measurement method are presented with experimental results. In the absolute polarization measurement method or the system calibration, the polarization characteristics of transmitting and receiving dual‐polarization antennas used in the measurement system are determined using the two polarization‐isolated scattering calibrators. In the polarization‐transfer measurement method, the antenna being tested operates in either transmitting mode or receiving mode. Since the transmitting and receiving antennas are located side by side in the measurement system, the phase reference signal between two antennas can be implemented with a short cable.

ISSN:0253-3839    

DOI:10.1080/02533839.1994.9677653

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor