When designing or reviewing control systems, it is important to understand the limitations of the system's design. Many systems today are designed using numerical methods. Although the numerical model may be controllable, stabilizable, or stable, small perturbations of the system parameters can result in the loss of these properties. In this thesis, we investigate these issues for finite element approximations of a thermal convection loop. / Master of Science

People rely on the ability to transmit information over channels of communication that aresubject to noise and interference. This makes the ability to detect and recover from errorsextremely important. Coding theory addresses this need for reliability. A fundamentalquestion of coding theory is whether and how we can correct the errors in a message thathas been subjected to interference. One answer comes from structures known as errorcorrecting codes.A well studied parameter associated with a code is its covering radius. The coveringradius of a code is the smallest radius such that every vector in the Hamming space of thecode is contained in a ball of that radius centered around some codeword. Covering radiusrelates to an important decoding strategy known as nearest neighbor decoding.The multicovering radius is a generalization of the covering radius that was proposed byKlapper [11] in the course of studying stream ciphers. In this work we develop techniques forfinding the multicovering radius of specific codes. In particular, we study the even weightcode, the 2-error correcting BCH code, and linear codes with covering radius one.We also study questions involving the complexity of finding the multicovering radius ofcodes. We show: Lower bounding the m-covering radius of an arbitrary binary code is NPcompletewhen m is polynomial in the length of the code. Lower bounding the m-coveringradius of a linear code is Σp2-complete when m is polynomial in the length of the code. IfP is not equal to NP, then the m-covering radius of an arbitrary binary code cannot beapproximated within a constant factor or within a factor nϵ, where n is the length of thecode and ϵ andlt; 1, in polynomial time. Note that the case when m = 1 was also previouslyunknown. If NP is not equal to Σp2, then the m-covering radius of a linear code cannot beapproximated within a constant factor or within a factor nϵ, where n is the length of thecode and ϵ andlt; 1, in polynomial time.

MMed (Orthopaedic Surgery), Faculty of Health Sciences, University of the Witwatersrand / Intramedullary nail insertion into a fractured bone allows stabilisation of the fracture with minimal intervention through the zone of injured tissue. This study aimed to assess whether intramedullary nailing of the forearm bones (radius and/or ulna) is a safe and effective form of management of these often complex fractures. A prospective case series was followed from presentation to fracture union. Between April 2006 and February 2008, 21 patients were enrolled in the study. The fracture union rate was high and complication rate was low. There was no increased risk of sepsis. The use of intramedullary nailing for diaphyseal fractures was successful but metaphyseal fractures, particularly with shortening, may be problematic. The use of intramedullary nailing for radius/ulna fractures is safe and effective, however the widespread use of this technique may be limited by the cost of the implant.

Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Major Telecomunicações). Faculdade de Engenharia. Universidade do Porto. 2009

Untersuchung von 35 Patientin nach Osteosynthese von Unterarmschaftfrakturen mittels Verriegelungsnagel zur Wiederherstellung des radialen Bogens. / Examination of 35 patients after interlocking forearm nailing for reconstruction of the radial bow.

The flourishing development of internet moves the human technology into another new epoch and the rising of the wireless LAN presents the fact which people are freer and more convenient from the unlimited-space using the internet. More and more equipments can support the mobile device of WLAN. By reducing the cost and its good points of easy-building. Lots of hotspots, for instance, caf顦s, airports, train stations, schools and companies are widely deployed and positive to construct WLAN. How to provide people a simple, easy, and quality environment of WLAN becomes an important issue from the viewpoints of user. When WLAN had been discussed, it was only a simple LAN environment. Before it has been promoted by the manufacture, the mobility and security were not been measured and instituted. All the products from different suppliers and the promotion of wireless internet in school are difficult to be united. By the fact of this, in order to make the resource of internet more flexible and expandable and make internet can be used in wide-ranging and more convenient way, this article draw up a plan and structure of Cross-Domain Roaming System and security control. Besides, our system can support and integration of heterogeneous authentication platforms on the WLAN.

Thèse de doctorat : Sciences de l'ingénieur : Paris Est : 2008. / Titre provenant de l'écran-titre. Bibliogr. : 150 réf.

Thesis (M. Phil.)--University of Hong Kong, 2002. / Includes bibliographical references.

No description available.

Thesis (M. Med. Sc.)--University of Hong Kong, 2007.