Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002. / Includes bibliographical references (p. 64-67). / by Long Yin Choy. / S.M.

For the finite element (FE) simulation of relatively thin organs under complex dynamic loadings that are relevant in the biomedical engineering field, shell elements, compared to volume elements, have the potential to capture the whole thickness of the organ at once. Shell elements, are also known to feature efficiently large critical time steps, ensuring competitive computational times in dynamic structural analysis projects. As an improvement to the tools available for modelling and analysis, a new general nonlinear thick continuum-based (CB) shell FE embedded in an updated Lagrangian formulation and an explicit time integration scheme was recently developed. It can account for irregular and complex geometries, and hyper-elastic, large, nearly incompressible anisotropic 3D deformations characteristic of soft tissues. The original proof of concept was developed in MATLAB, which despite known advantages, is very slow. As a result, computational times, even for simple problems, have not been competitive. Therefore, the present work focused on re-writing the code in an efficient programming language with execution speed in mind in order to compete with the available elements which, in spite of having inferior capabilities, have better running times. In addition, a programming algorithm was needed to improve running time. Once it was implemented, the running time was reduced in half on a benchmark problem. Optimization was then exploited to introduce workarounds and design improvements that reduced running time further to 95% of its original value. The new version of the code was implemented in C++ and reached the goal of reducing running time while maintaining the expected functionality.

<p>MATLAB to C code translation is of increasing interest for science and industry. In</p><p>detail two MATLAB to C compilers denoted as Matlab to C Synthesis (MCS) and</p><p>Embedded MATLAB C (EMLC) have been studied. Three aspects of automatic code</p><p>generation have been studied; 1) generation of reference code; 2) target code generation;</p><p>3) floating-to-fixed-point conversion. The benchmark code used aimed to cover</p><p>simple up to more complex code by being viewed from a theoretical as well as practical perspective. A fixed-point filter implementation is demonstrated. EMLC and MCS</p><p>offer several fixed-point design tools. MCS provides a better support for C algorithm</p><p>reference generation, by covering a larger set of the MATLAB language as such. More</p><p>suitable for direct target implementation is code generated from EMLC. As a result</p><p>of the need to guarantee that the EMLC generated C-code allocates memory only</p><p>statically, MATLAB becomes more constraint by EMLC. Functional correctness was</p><p>generally achieved for each automatic translation.</p>

With the development of the wireless communication system, the antenna has been widely used as an important tool in data transmission. However, there are many characteristic parameters for antenna need to be calculated by complex calculation. For example the mutual input impedance of dipole antenna, the Directivity coefficient and the Gain coefficient. Therefore, it is quite practically hard to implement by hand, especially for student who was studying on it. In order to solve this problem, this thesis has establishes the calculation procedure for the complex parameters of antenna by using MATLAB software.

MATLAB to C code translation is of increasing interest for science and industry. In detail two MATLAB to C compilers denoted as Matlab to C Synthesis (MCS) and Embedded MATLAB C (EMLC) have been studied. Three aspects of automatic code generation have been studied; 1) generation of reference code; 2) target code generation; 3) floating-to-fixed-point conversion. The benchmark code used aimed to cover simple up to more complex code by being viewed from a theoretical as well as practical perspective. A fixed-point filter implementation is demonstrated. EMLC and MCS offer several fixed-point design tools. MCS provides a better support for C algorithm reference generation, by covering a larger set of the MATLAB language as such. More suitable for direct target implementation is code generated from EMLC. As a result of the need to guarantee that the EMLC generated C-code allocates memory only statically, MATLAB becomes more constraint by EMLC. Functional correctness was generally achieved for each automatic translation.

Mobile devices and their applications are continuing to develop and the more advanced they are, the more they require high data ranges and the more they demand of the available wireless communication networks. At present, LTE (Long Term Evolution) is a good solution as it provides the users of mobile devices with a good throughput and a low latency. In the future, the two most important aspects for end users will be system spectral efficiency and system power controlling. This thesis deals with LTE downlink spectral efficiency and power controlling. The thesis will show how, by using IP multicasting for the LTE downlink, the base station is able to provide the necessary data through a significantly smaller spectrum and, additionally, how cooperative diversity, i.e. the cooperation between several base stations, can improve or even maximise the total network channel capacity, regardless of bandwidth size. A Packet and Resource Plan Scheduling algorithm (PARPS) is used to schedule the transmissions, and the results are calculated in MATLAB. By this means it is possible to analyse the efficiency of the spectrum management, the coverage probability and the power controlling for the different transmitters used for the LTE downlink.The LTE downlink scheme is simulated in Matlab for different numbers of transmitters (2-3). IP multicasting over the LTE downlink manages to transmit the same amount of data using less transmission power (50- 66.6%) with a better system spectral efficiency.

Recent advancement in wireless communications and electronics has enabled the development of sensor networks. With development in technology, wireless sensor network is used more and more in our daily life, because the technology is more flexible and cheaper than the wired sensor network. The objective of this study has been to solve the problem that how closely a group of mobile wireless nodes are clustered. Matlab is used to simulate the various situations of nodes. There are two major parts in this software design. One is the function of detecting the movement of the mouse. Another is the function of estimating the connectivity of the nodes. Some methods will be proposed and evaluated through some realistic scenarios.

Bachelor-Arbeit Univ. St. Gallen, 2007.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: bicgstab, cgs, gmres, NITSOL, Newtons Method, nonlinear systems. Includes bibliographical references (p. 53).

University, Diss., 2002--Kassel. / Lizenzpflichtig.