This thesis investigates using an approach based on the Actors paradigm for implementing a discrete event simulation system and comparing the results with more traditional approaches. The goal of this work is to determine if using Actors for sequential programming is viable. If Actors are viable for this type of programming, then it follows that they would be usable for general programming. One potential advantage of using Actors instead of traditional paradigms for general programming would be the elimination of a distinction between designing for a sequential environment and a concurrent/distributed one. Using Actors for general programming may also allow for a single implementation that can be deployed on both single core and multiple core systems. Most of the existing discussions about the Actors model focus on its strengths in distributed environments and its ability to scale with the amount of available computing resources. The chosen system for implementation is intentionally sequential to allow for examination of the behaviour of existing Actors implementations where managing concurrency complexity is not the primary task. Multiple implementations of the simulation system were built using different languages (C++, Erlang, and Java) and different paradigms, including traditional ones and Actors. These different implementations were compared quantitatively, based on their execution time, memory usage, and code complexity. The analysis of these comparisons indicates that for certain existing development environments, Erlang/OTP, following the Actors paradigm, produces a comparable or better implementation than traditional paradigms. Further research is suggested to solidify the validity of the results presented in this research and to extend their applicability.

Práce pojednává o vlastnostech plazmonických antén v infračervené a viditelné oblasti. Práce zahrnuje výrobu, měření a numerické modelování optických vlastností antén. Infračervené plazmonické antény na absorbujícím substrátu (SRON) jsou studovány pro jejich rezonanční a absorpční vlastnosti. Byla nalezena geometrie antény, která poskytuje maximální účinnost absorpce ve SRON vrstvě. Dále je studována možnost zesílení daného vibračního módu substrátu (obsahujícího 3-4 materiálové rezonance) pomocí plazmonické rezonance antény. Nakonec jsou prezentována měření katodoluminiscenčních spekter antén ve viditelném spektru.

In this dissertation, we provide necessary conditions for an asymptotically stable equilibrium solution of a nonlinear ordinary differential equation be globally stable. An essential condition is a generalization of the criteria of Bendixson and Dulac for towdimensional differential equations which is used to ensure the absence of periodic orbits, we call this Bendixson criterion. We provide a new Bendixson criterion robust under C1 local perturbations, which together with the Global Stability Principle, ensure the global stability of an asymptotically stable equilibrium. We use this criterion in the study of asymptotic behavior of an epidemiological model called SEIRS / Nesta dissertação, forneceremos condições necessárias para que umasolução de equilíbrio assintoticamente estável de uma equação diferencial ordinária autônoma e não linear seja globalmente estável. Uma das condições essenciais consiste numa generalização dos critérios de Bendixson e Dulac para equações diferenciais bidimensionais que é usada para garantir a inexistência de órbitas periódicas, o qual denominamos critério de Bendixson. Forneceremos um novo critério de Bendixson robusto sobre uma C1 perturbação local, o qual juntamente como Princípio da EstabilidadeGlobal, garante a estabilidade global deum equilíbrio assintoticamente estável. Usaremos este critério no estudo do comportamento assintótico de um modelo epidemiológico intitulado SEIRS.