Experimental Analysis Research Papers - Academia.edu (original) (raw)

In this Letter we present an experimental analysis of the acoustic transmission of a two-dimensional periodic array of rigid cylinders in air with two different geometrical configurations: square and triangular. In both configurations,... more

In this Letter we present an experimental analysis of the acoustic transmission of a two-dimensional periodic array of rigid cylinders in air with two different geometrical configurations: square and triangular. In both configurations, and above a certain filling fraction, we observe an overlap, in the range of the audible frequencies, between the attenuation peaks measured along the two high-symmetry directions of the Brillouin zone. This effect is considered as the fingerprint of the existence of a full acoustic gap. Nevertheless, the comparison with our calculation of band structures shows that the triangular lattice has band states in that frequency range. We call them deaf bands. This contradictory result is explained by looking at the symmetry of the deaf bands; they cannot be excited by experiments of sound transmission.

This paper forwards a new way of accounting for the experimental evidence related to the Ultimatum Game. We argue that players in this game have reasons to be both fair and self-interested, but the balance between these two considerations... more

This paper forwards a new way of accounting for the experimental evidence related to the Ultimatum Game. We argue that players in this game have reasons to be both fair and self-interested, but the balance between these two considerations cannot be expressed in terms of a tradeoff. We test our thesis by perturbing the Ultimatum Game in a way that emphasizes the force of self-interest considerations; the evidence we collected provides support for our thesis.

This study describes an experimental analysis of a five-fold plant-insect interaction, with the primary aim of determining the net effect of insect-insect interactions on the host plant. The participlants are the extrafloral... more

This study describes an experimental analysis of a five-fold plant-insect interaction, with the primary aim of determining the net effect of insect-insect interactions on the host plant. The participlants are the extrafloral nectary-bearing host plant Acacia decurrens; the resident sap-sucking membracid treehopper Sextius virescens; the ant Iridomyrmex sp. which attends both EFN and treehoppers; external herbivores including grasshoppers and gall wasps; and predators and parasitoids of the membracids. The main results are as follows. 1. The membracids alone decrease plant growth and seed set. 2. In the absence of membracids, the ants defend the plant against external herbivores, and their presence increases plant growth and seed set. 3. The interaction between ants and membracids exerts an overall negative effect on plant growth and seed set. This has not been demonstrated for any system previously and is the main result of the study. 4. Ant attendance does not increase membracid populations or feeding rates significantly, or reduce mid-season mortality. 5. Ant attendance decreases late-season membracid mortality significantly. This has been shown previously for Lepidoptera and nymphal Homoptera only. 6. The mechanism of the interactive effect in (3) is apparently that the honeydewsecreting membracids attract the ants away from the EFN and decrease the efficacy of the plant's ant defence.

Introduced in the late eighties for margining certain accounts of brokers, the risk- based approach to m argining portfolios with equity derivatives has yielded substan­ tially lower margin requirements in comparison with the... more

Introduced in the late eighties for margining certain accounts of brokers, the risk- based approach to m argining portfolios with equity derivatives has yielded substan­ tially lower margin requirements in comparison with the strategy-based approach that has been used for margining customer accounts for more than four decades. For this reason, after the approvals of the pilot program on July 14, 2005, and its extensions on December 12, 2006, and July 19, 2007, the final approval of using the risk-based approach to margining customer accounts by the SEC on July 29, 2008, at the time of the global financial crisis, appeared to be one of the most radical and puzzling steps in the history of margin regulations. This paper presents the results of a novel mathematical and experimental analysis of both approaches which sup­ port the thesis that the pilot program could have influenced or even triggered the equity market crash in October 2008. It also provides recommendations on ways to set ...

This paper presents a theoretical and experimental analysis of multi-frequency radar systems for monitoring vital signs. The main advantage of using a multi-frequency architecture is the possibility to improve the detection sensitivity of... more

This paper presents a theoretical and experimental analysis of multi-frequency radar systems for monitoring vital signs. The main advantage of using a multi-frequency architecture is the possibility to improve the detection sensitivity of heart beats and breathing rate while cancelling the body movement with signal processing. Simulations were carried out using ADS software for three systems operating at 5.8, 24

We present a basic model of supercapacitor based on a theoretical analysis discussing the frequency dependence of the electric permittivity. Directly from the Maxwell’s theory, an equivalent parallel capacitance and conductance is deduced... more

We present a basic model of supercapacitor based on a theoretical analysis discussing the frequency dependence of the electric permittivity. Directly from the Maxwell’s theory, an equivalent parallel capacitance and conductance is deduced having frequency dependence. Dynamic behavior is assessed in the frequency range up to 20Hz which is typical for hybrid vehicle applications. In order to investigate the equivalent

Numerical simulation of manufacturing processes has become in the last years an important tool to improve these processes reducing lead times and try out, and providing products free of defects and with controlled mechanical properties.... more

Numerical simulation of manufacturing processes has become in the last years an important tool to improve these processes reducing lead times and try out, and providing products free of defects and with controlled mechanical properties. Finite Element Method (FEM) is one of the most important methods to simulate metal forming. In tube drawing with fixed plug both the outer diameter and the inner diameter of the tube are properly defined if correct process conditions are chosen for the die angle, drawing speed, lubrication and area reduction per pass. These conditions have great influence on drawing loads and residual stresses present in the product. In this work, the cold drawing of tubes with fixed plug was simulated by FEM with the commercial software MSC.Superform to find the best geometry of die and plug to reduce the drawing force. The numerical analysis supplied results for the reactions of the die and plug and the stresses in the tube, the drawing force and the final dimensions of the product. Those results are compared with results obtained from analytic models, and used tooling design. Experimental tests with a laboratory drawing bench were carried out with three different lubricants and two different lubrication conditions.