Modeling and Analysis

Abstract: - This paper describes a fully integrated acoustic sensor that combines high sensitivity, wide frequency range and low cost of batch processed miniaturized silicon components. A sputtered piezoelectric ZnO layer transforms the mechanical deflection of ...

In this paper, simultaneous laser transmission welding process is systematically investigated via process modeling, using an FEM and RSM combined approach. The objective of the present research is to study the effects of process parameters on the temperature field and weld bead dimensions. The thermal field is simulated by solving a three dimensional transient heat diffusion equation with temperature dependent material properties using the ANSYS® multi-physics. Response surface methodology is then applied for developing mathematical models based on simulation results. The second order equations developed by RSM can predict the values of the responses with significant accuracy. The effect of parameters and their interactions on the responses are studied using the developed response surface models. The mathematical models are further used in search of the optimal process window for obtaining an acceptable weld. The graphical optimization results into a couple of overlay contours plots, which allow quick visual inspection of the area of feasible response values in the factor space to choose the favorable welding parameter combination.►FEM along with RSM is employed to study the simultaneous laser transmission welding process. ► The numerical simulation is performed using the commercial FE package ANSYS®. ► The temperature distribution and shape and size of the molten pool are computed. ► RSM is used to analyze the responses and to determine the mathematical models with best fits. ► The effect of parameters and their interactions on the responses are studied and discussed.

We survey some results of social network modeling and analysis relevant for telephone call networks and illustrate these results over the call logs of major Hungarian telephone companies. Our unique data sets include millions of users, long time range, and sufficiently strong sociodemographic information on the users. We explore properties that give stronger intuition on how contacts within real social networks arise, and suggest properties unexplained by current network evolution models.

An Expeditionary Strike Group (ESG) is a new capability mix that combines the combat power of three surface combatants and one submarine with an Amphibious Readiness Group/ Marine Expeditionary Unit (Special Operations Capable) (ARG/MEU(SOC)). ESGs provide Combatant Commanders with more flexible, robust, and distributed offensive combat capability and enhance Naval expeditionary force survivability. Beginning in 2002, the Navy and Marine Corps began an experiment to explore the offensive and defensive capabilities of the ESG as well as different command structure options. This paper describes the initial effort by the Adaptive Architectures for Command and Control research program to support the analysis and design of ESG-1 command structures through modeling and analysis.

Laser communications systems offer a significant advantage over traditional radio frequency systems due to the shorter wavelength of laser light. Data can be sent at higher rates for less power with proportionally smaller transmitters and receivers. A laser communications system has never been demonstrated in a moon to Earth link at MBps data rates This paper presents a model of a laser downlink from the moon, developed to rapidly explore various system architectures. Modeling and analysis shows that the target data rates of above 2 Mb/s are possible with 300 mW of transmitter power using a 3.5 mm aperture, a 1.5 m receiver diameter and a minimum gimbal resolution (maximum step size) of 78 μrad. 19.89 Mb/s data rates are possible using a 1 cm transmit aperture but with a much stricter minimum gimbal resolution (maximum step size) of 27 μrad.

Transport in Porous Media 43: 3–28, 2001. c 2001 Kluwer Academic Publishers. Printed in the Netherlands. ... Modeling and Analysis of Seawater Intrusion in the ... Coastal Aquifer of Eastern Cap-Bon, Tunisia ... CLAUDIO PANICONI1, IHSEN KHLAIFI2, GIUDITTA LECCA1, ...

This paper describes an attempt to predict the response of shear-critical ECC members that exhibit strong anisotropic stress and strain fields. The ECC members investigated include pre-cracked ECC plates under stress field rotation, orthogonally-reinforced ECC (R/ECC) panel under pure shear, and shear-critical R/ECC beams under reversed cyclic loading. To achieve a simple yet accurate prediction, the mechanics of the ECC are represented by smeared models using a fixed crack approach. The applicability of these models is demonstrated through a simulation of ECC plates and R/ECC panel responses. This demonstrates the importance of an appropriate shear transfer model in representing essential behaviors of ECC in an anisotropic field. Predictions of these models were then compared against experimental results of shear-critical R/ECC beams with a M/Vd ratio of 1.0 and 0.5. For beams with a M/Vd ratio of 1.0, a good agreement is observed in terms of hysteretic response, crack pattern, and failure mechanisms. For beams with a 0.5 M/Vd ratio, the analysis somewhat underestimates the beam capacity, although it does predict a correct failure mechanism. Overall, this paper demonstrates that practical application of nonlinear finite-element analysis to ECC structural members is possible.

A schematic representation of optical feedback between two resonator mirrors undergoing a phase shift each round trip as a function of the separation of the mirrors is studied. A transfer function modeling of the extrinsic Fabry–Perot interferometer (EFPI) is presented. Nyquist ...