On Some Unsolved Problems of Mathematica
Journal Title: Engineering, Technology & Applied Science Research - Year 2012, Vol 2, Issue 4
Abstract
In this paper, some unsolved problems of the Mathematica software package are documented. At first, it is shown, using a number of examples, that the processing (simplification) of rational-fractional expressions involving powers in the general form, has been implemented in Maple more carefully than in Mathematica. Then, an error in Mathematica is demonstrated, leading to incorrect results at a change of a function’s body. For each example of symbolic or symbolic-numeric computations, alternate routes for solving the emerged problem are proposed (where possible). An added problem, related to Mathematica’s computing speed is documented, employing examples related to two-dimensional gas dynamics problems. It is shown that Mathematica computes rather slowly (about one thousand times slower) compared to a Fortran code.
Authors and Affiliations
E. V. Vorozhtsov
Gas Turbine Engine Starting Applicated on TV2-117 Turboshaft
The paper presents the examination of two different types of engine starting configurations, applicated on TV2-117A turboshaft, running into the test bench. The first type of starting configuration is a normal starting,...
A Hybrid Data Mining Method for Customer Churn Prediction
The expenses for attracting new customers are much higher compared to the ones needed to maintain old customers due to the increasing competition and business saturation. So customer retention is one of the leading facto...
Simulation of the Optimized Structure of a Laterally Coupled Distributed Feedback (LC-DFB) Semiconductor Laser Above Threshold
In this paper, the laterally coupled distributed feedback semiconductor laser is studied. In the simulations performed, variations of structural parameters such as the grating amplitude a, the ridge width W, the thicknes...
Numerical and Experimental Efficiency Evaluation of a Counter-Rotating Vertical Axis Wind Turbine
This paper investigates the concept of a concentric counter-rotating vertical axis wind turbine (VAWT), consisting of a two stage vertical H-type turbine with three blades on each stage. The model has an inner and an out...
A Simple Electronic Circuit for an Automatic Train Safety Stop System
A particular safety system known as “dead man’s circuit” detects the presence of human command in the conduction of the trains operated by the Brazilian Company of Urban Trains (CBTU) in Recife, Brazil, thus consisting a...