A monomial-based method for solving systems of non-linear algebraic equations

A monomial-based method for solving systems of algebraic non-linear equations is presented. The method uses the arithmetic-geometric mean inequality to construct a system of monomial equations that approximates the system of non-linear equations. A change of variables transforms the monomial system into a system of linear equations, which is readily solved. Special properties of the monomial method are identified and their significance is discussed. Invariance properties of the monomial method produce a built-in, self-adjusting scaling of the variables and equilibration of the equations of the linear system. Other special properties can lead to useful bounds on, and invariances of, the conditioning of the linear system. An invariance to uniform scaling is responsible for extremely rapid convergence to the equation surfaces in the initial iterations. An invariance to multiplication of the algebraic equations by a certain class of functions leads to a useful insensitivity to form of the algebraic system. Insensitivity of the monomial method to solutions with negative components avoids meaningless solutiuons of the algebraic system that appear as undesirable by-products of the formulation. A practical engineering design problem is solved to demonstrate the special properties of the monomial method.     

Subjective evaluation of join cost and smoothing methods for unit selection speech synthesis

In unit selection-based concatenative speech synthesis, join cost (also known as concatenation cost), which measures how well two units can be joined together, is one of the main criteria for selecting appropriate units from the inventory. Usually, some form of local parameter smoothing is also needed to disguise the remaining discontinuities. This paper presents a subjective evaluation of three join cost functions and three smoothing methods. We also describe the design and performance of a listening test. The three join cost functions were taken from our previous study, where we proposed join cost functions derived from spectral distances, which have good correlations with perceptual scores obtained for a range of concatenation discontinuities. This evaluation allows us to further validate their ability to predict concatenation discontinuities. The units for synthesis stimuli are obtained from a state-of-the-art unit selection text-to-speech system: rVoice from Rhetorical Systems Ltd. In this paper, we report listeners' preferences for each join cost in combination with each smoothing method.     

Fatigue crack propagation properties from small sized rod specimens

Mechanical properties characterization is needed in many industrial applications yet sufficient amount of material for fabricating standard-sized testing specimens is often not available. Techniques for testing miniaturized specimen must be adopted. Much effort has been made to develop techniques for impact, fracture toughness and tensile properties of sub-sized specimens. Work on the testing of fatigue properties is more limited. In this study, fatigue crack propagation behavior is evaluated from the growth of surface crack in a cylindrical rod under tension. Rods of various lengths and diameters were tested. As the size of the rod specimen is reduced, the fatigue crack growth rate tends to increase when correlated using the stress intensity factor range. This increase is explained largely by the decrease in the degree of premature crack closure in the small specimens. Valid fatigue crack growth data can be obtained among the specimens examined except on the crack growth on the surface of the smallest specimen, which has a length of 26 mm and diameter of 8 mm. Even so, valid data can still be elucidated on the latter specimen if the interior growth is considered. The dimensions of the latter specimen allow fatigue properties to be evaluated using broken remnants from impact or other test specimens.     

Phase equilibria in the system Al-Rh

Methods of differential thermal analysis, x-ray diffraction, microstructural analysis and electron probe microanalysis are used to study alloys of the Al-Rh system over the whole concentration range. It is established that the phase of equiatomic composition AlRh melts congruently at 2060°C and it has an extended range of homogeneity (45.1–54.2 at.% Rh). The solubility of aluminum in rhodium reaches 9 at.%, decreasing to 6 at.% at 850°C. Coordinates are determined for the eutectic point l ⇆ AlRh + 〈Rh〉 as 70 at.% Rh and 1715°C. The existence of intermediate phases, their crystal structure, and also the method of forming phases in the field of composition rich in aluminum given in publications are confirmed. __________ Translated from Poroshkovaya Metallurgiya, Nos. 5–6(449), pp. 48–56, May–June, 2006.     

Measurements of frequencies and spatial correlations of coherent structures in rod bundle flows

Cross-wire anemometry was used to identify and characterize coherent flow pulsations in isothermal air flow near the gap regions of a five-rod bundle with a design pitch-to-diameter ratio of 1.149 and contained in a quasi-trapezoidal duct. It was confirmed that such pulsations are quasi-periodic and contribute significantly to the velocity fluctuations across the gap. The frequency of pulsations was found to decrease with diminishing rod–wall gap size in the range between 0.015D and 0.250D, where D is the rod diameter. The pulsations in a rod–wall gap and an adjacent rod–rod gap were strongly coupled and occurred at the same frequency as one rod was displaced towards the duct wall.     

Anwendung des Programms COMO III bei OR-Untersuchungen auf dem Gebiet Luftverteidigung/Flugabwehr

Zusammenfassung Das Programm COMO III, das seit 1975 bei der IABG in zahlreichen OR-Untersuchungen auf den Gebieten der Luftverteidigung und Flugabwehr verwendet wird, hat sich für derartige Untersuchungen als sehr gut geeignet erwiesen. Hervorzuheben sind insbesondere die benutzerfreundliche und flexible Dateneingabe für die Simulationsläufe sowie der modulare Aufbau des Modells, der es ermöglicht, die Abbildung der zu untersuchenden Systeme beliebig zu verfeinern oder zu aggregieren. COMO III sieht außerdem standardmäßig eine benutzerorientierte Datenausgabe vor, die für die meisten Untersuchungszwecke ausreicht und keinen zusätzlichen Programmaufwand erfordert.

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Summary The COMO III program has been used by IABG since 1975 for a great number of OR studies on air defence problems. The program has proved to be very well qualified for this purpose. In particular, the user-friendly and flexible data input for simulation runs should be stressed as well as the modular structure of the program which allows an optionally refined or aggregated modelling of the systems to be studied. Besides this, COMO III provides a standardised user-oriented data output which is sufficient for most study purposes and needs no additional programming effort.

     

External heat transfer in infiltrated granular beds. Experimental study

Experimental data was obtained on external heat transfer in infiltrated granular beds of coarse particles. It was determined that calcualtions with the proposed model agree satisfactorily with the experimental results.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 53, No. 6, pp. 919–923, December, 1988.     

Calcium and phosphorus levels as indices of textured milk proteins being substituted for meat proteins

Textured milk proteins were tested in a meat model system with an exchange level of 34-87% of the meat proteins. The correlation between the substitution index and the calcium and phosphorus content was statistically significant.     

Integrated fluid handling system for biomolecular interaction analysis.

An integrated fluid handling system used for multichannel biomolecular interaction analysis is described. Reactions between biological molecules are monitored in real time by measuring changes in the angular position where surface plasmon resonance occurs at a biospecific active surface. The adsorption efficiency of the analyte onto the biospecific active surface is up to approximately 3%, due to the low channel height, 50 microns, in the flow cell. When a large part of the total biospecific active surface for surface plasmon resonance probing (approximately 0.15 mm2) is used, the sensitivity is high. Sample sizes in the order of 1-50 microL can be injected. The sample zone dispersion is minimized by the low dead volume in the system (approximately 0.4 microL) accomplished by using integrated sample loops and thin conduits. An asset of this integration is the low reagent consumption. The sensor chip with the biospecific active surface is reusable and easily exchanged. Experimental results obtained with a theophylline monoclonal antibody as the analyte are compared with a theoretical model. The standard deviation for the repeatability is approximately 5% typically with 50 microL of 250 pM analyte, and the assay time is 10 min. The detection limit is approximately 10 pg of the analyte on the probed spot of the surface. Possible improvements of the sensitivity and detection limit are discussed.