Cuckoo bees behave similarly to the well-known birds, cuckoos - they lay eggs in the nests of other bees. Proposed thesis charts the evolution of host specialization within the strictly cuckoo genus Sphecodes. According to the classical view based on the Red Queen hypothesis, parasites should gradually specialize during evolution to keep pace in the "arms race" with their hosts. Specialization is also perceived as an evolutionary dead end - narrow adaptation prevents change of host. To test these hypotheses phylogeny of tribus Sphecodini based on the partial sequences of five genes was constructed. For each ancestor has been by two methods of mapping ancestral characters (Bayesian method, Maximum Parsimony) specified, whether it was specialist or generalist and which kind of host or hosts it had. The results show that the original strategy of genus Sphecodes is specialization and generalists originated from specialized ancestors only recently. The results also show that the jumps between the hosts are common. These findings are inconsistent with the Red Queen hypothesis as well as with the view that specialization is an evolutionary dead end. Falsity of these hypotheses within the genus Sphecodes established also likelihood ratio test, in which the likelihood of model allowing two-way transition...

The main goal of a scheduling process is to decide when and how to execute each of the project’s activities. Despite large variety of researched scheduling problems, the majority of them can be described as generalisations of the resource-constrained project scheduling problem (RCPSP). Because of wide applicability and challenging difficulty, RCPSP has attracted vast amount of attention in the research community and great variety of heuristics have been adapted for solving it. Even though these heuristics are structurally different and operate according to diverse principles, they are designed to obtain only one solution at a time. In the recent researches on RCPSPs, it was proven that these kind of problems have complex multimodal fitness landscapes, which are characterised by a wide solution search spaces and presence of multiple local and global optima. The main goal of this thesis is twofold. Firstly, it presents a variation of the RCPSP that considers optimisation of projects in an uncertain environment where resources are modelled to adapt to their environment and, as the result of this, improve their efficiency. Secondly, modification of a novel evolutionary computation method Cuckoo Search (CS) is proposed, which has been adapted for solving combinatorial optimisation problems and modified to obtain multiple solutions. To test the proposed methodology, two sets of experiments are carried out. Firstly, the developed algorithm is applied to a real-life software development project. Secondly, the performance of the algorithm is tested on universal benchmark instances for scheduling problems which were modified to take into account specifics of the proposed optimisation model. The results of both experiments demonstrate that the proposed methodology achieves competitive level of performance and is capable of finding multiple global solutions, as well as prove its applicability in real-life projects.

Yes / An Improved Discrete Cuckoo Search (IDCS) is proposed in this paper to solve resource-constrained project scheduling problems (RCPSPs). The original Cuckoo Search (CS) was inspired by the breeding behaviour of some cuckoo species and was designed specifically for application in continuous optimisation problems, in which the algorithm had been demonstrated to be effective. The proposed IDCS aims to improve the original CS for solving discrete scheduling problems by reinterpreting its key elements: solution representation scheme, Lévy flight and solution improvement operators. An event list solution representation scheme has been used to present projects and a novel event movement and an event recombination operator has been developed to ensure better quality of received results and improve the efficiency of the algorithm. Numerical results have demonstrated that the proposed IDCS can achieve a competitive level of performance compared to other state-of-the-art metaheuristics in solving a set of benchmark instances from a well-known PSPLIB library, especially in solving complex benchmark instances. / Partially funded by the Innovate UK project HARNET – Harmonised Antennas, Radios and Networks under contract no. 100004607.

Authentication in digital systems is still prominently done through passwords. These passwords should simultaneously be easy to remember, unique, and change over time. Humans, however, have a limited ability to remember complex passwords. To make this easier, users often adopt schemes where a base word is only modified slightly. While such schemes can easily fulfil basic password requirements based on length or the symbols used, they can leave users vulnerable. Leaked passwords, even expired ones, can be exploited by malicious actors and a single compromised account can cascade to multiple services.  We propose a v-gram based approach to detect similarity with a set of passwords, which could be used to improve user password habits. The proposed scheme utilizes a Cuckoo Filter, which allows for inherent obfuscation of the stored passwords and the integration of encryption techniques natively. The system could for example be embedded in a password manager to inform users when they are using a password that is too similar to a previous password. This work comprises an analysis of several aspects of the system in order to assess its suitability.  A Cuckoo Filter using a single byte fingerprint for each v-gram can achieve load factors exceeding 95%, while maintaining a false positivity rate of less than 3%. The computational cost of guessing a password based on the information stored within the filter is relatively low. While the false positivity rate of the filter and the size of the alphabet have an impact, they are only logarithmically proportional to the cost, and the attack is considered a significant vulnerability. Nevertheless, the proposed system can be a viable alternative for detecting similarity between passwords — if configured correctly — and could be used to guide user behaviour to more secure password habits.

Obligate brood parasites lay their eggs in nests of other species, relying on these host parents to care for their offspring. This phenomenon has been a curiosity amongst researchers since its first description and has become a model study system for testing such ideas as coevolution and species recognition. This thesis examines a few of the many questions that arise from this breeding system. The New Zealand Grey Warbler (Gerygone igata) and its brood parasite, the Shining Cuckoo (Chrysococcyx lucidus) are used as the main study species, although research on the eviction behaviour of Common Cuckoos (Cuculus canorus) has also been conducted. First, the current state of knowledge and recent discoveries regarding nestling rejection abilities of hosts is reviewed in chapter one. Second, a comparative study of New Zealand passerine begging calls has been conducted to test for begging call similarity between a brood parasite and its host, as well as developing a new technique for detecting the mode of coevolution that may be occurring in the parasite – host relationship. Parent-offspring communication in Grey Warblers is also examined to test for both parental and nestlings Parents use both alarm calls to warn offspring of potential danger, and also parental feeding calls to elicit a begging response from nestlings. By contrast, nestlings are able to signal both age and short term levels of need to parents through the acoustic structure of the begging call. The evolutionary costs and benefits of egg eviction behaviour in the Common Cuckoo are also tested. An experimental approach showed that egg eviction had a growth cost, but this cost was temporary and restricted to during and immediately after the egg eviction phase. A pattern of compensatory growth was observed after the eviction period, so that during the later nestling stages there was no difference in mass, and no difference in fledging age. Finally, variation in the Grey Warbler breeding biology and Shining Cuckoo parasitism rates are examined through both time and across latitudes. This research has shown a counterintuitive pattern of breeding phenology across latitudes. These patterns have implications for Shining Cuckoos both in terms of timing of available nests and host selection. Keywords: Begging call, breeding phenology, brood parasitism, coevolution, Common Cuckoo, eviction, Grey Warbler, parent-offspring communication, Shining Cuckoo.

This thesis deals with design and implementation of mapping of match action tables from P4 language to FPGA technology. Goal of the thesis was to describe key principles, which need to be understood in order to design such a mapping and function of algorithms needed, apply these principles by implementing them and analyze the speed and memory requirements of such an implementation. Outcome provides configurable hardware unit capable of classifying packets and connection between the unit and match action tables from P4 language. The implementation is based on DCFL algorithm and requires less memory compared to HiCuts and HyperCuts algorithms while being comparably fast at worst-case scenarios.

Brood parasitism is a breeding strategy which imposes significant selection pressure upon the host as well as the parasite. Consequently, specific adaptations were formed on both sides. One of the adaptations could be vocal behaviour of brood parasite juveniles. Several conducted studies suggested that juveniles of the common cuckoo (Cuculus canorus) adapt the form of their begging calls according to the host species they parasitize on. However, the outcomes of these studies were ambiguous. Therefore one of my tasks was to verify those findings. Two reed warblers - the great reed warbler (Acrocephalus arundinaceus) and the reed warbler (Acrocephalus scirpaceus) - living in sympatry were selected as the hosts. The structure of begging calls of common cuckoo juveniles raised by these two host species did not differ in any of the measured parameters (syllable duration, minimum and maximum frequency, peak frequency, frequency bandwidth and calling rate). On the contrary the structure of begging calls of own host juveniles varied significantly among the individual species. Moreover, a considerable individual variability was detected in both groups of cuckoo juveniles. Recent studies have revealed that juveniles already perceive sound and acquire knowledge of their parents' voices in the process of...

No description available.

Currently, smart mobile devices are used for more than just calling and texting. They can run complex applications such as GPS, antivirus, and photo editor applications. Smart devices today offer mobility, flexibility, and portability, but they have limited resources and a relatively weak battery. As companies began creating mobile resource intensive and power intensive applications, they have realized that cloud computing was one of the solutions that they could utilize to overcome smart device constraints. Cloud computing helps decrease memory usage and improve battery life. Mobile cloud computing is a current and expanding research area focusing on methods that allow smart mobile devices to take full advantage of cloud computing. Code offloading is one of the techniques employed in cloud computing with mobile devices. This research compares two dynamic offloading frameworks to determine which one is better in terms of execution time and battery life improvement.

Economic dispatch is an important optimization challenge in power systems. It helps to find the optimal output power of a number of generating units that satisfy the system load demand at the cheapest cost, considering equality and inequality constraints. Many nature inspired algorithms have been broadly applied to tackle it such as particle swarm optimization. In this dissertation, two improved particle swarm optimization techniques are proposed to solve economic dispatch problems. The first is a hybrid technique with Bat algorithm. Particle swarm optimization as the main optimizer integrates bat algorithm in order to boost its velocity and to adjust the improved solution. The second proposed approach is based on Cuckoo operations. Cuckoo search algorithm is a robust and powerful technique to solve optimization problems. The study investigates the effect of levy flight and random search operation in Cuckoo search in order to ameliorate the performance of the particle swarm optimization algorithm. The two improved particle swarm algorithms are firstly tested on a range of 10 standard benchmark functions and then applied to five different cases of economic dispatch problems comprising 6, 13, 15, 40 and 140 generating units. / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)