An evaluation of the artisanal fisheries resources of the Cross River State of Nigeria

The Cross River State (Nigeria) marine and freshwater artisanal capture fisheries are divided into 4 categories according to the type of resources being exploited. Schaefer's production model is applied to each of the fisheries to estimate the maximum sustainable yields (Ymax). The total potential yield for all the fisheries in natural waters is 178,650 tonnes/year. This potential is unlikely to be achieved as more fishermen are abandoning the occupation due to the scarcity of boats, outboard engines and nets. Even if the full potentials were realized the production would still be short of what the State should produce by about 30.5%. Investment opportunities which, if effected can help to narrow the gap between the available and the desired level of production are enumerate

Relating Knowledge and Coordinated Action: The Knowledge of Preconditions Principle

The Knowledge of Preconditions principle (KoP) is proposed as a widely applicable connection between knowledge and action in multi-agent systems. Roughly speaking, it asserts that if some condition is a necessary condition for performing a given action A, then knowing that this condition holds is also a necessary condition for performing A. Since the specifications of tasks often involve necessary conditions for actions, the KoP principle shows that such specifications induce knowledge preconditions for the actions. Distributed protocols or multi-agent plans that satisfy the specifications must ensure that this knowledge be attained, and that it is detected by the agents as a condition for action. The knowledge of preconditions principle is formalised in the runs and systems framework, and is proven to hold in a wide class of settings. Well-known connections between knowledge and coordinated action are extended and shown to derive directly from the KoP principle: a "common knowledge of preconditions" principle is established showing that common knowledge is a necessary condition for performing simultaneous actions, and a "nested knowledge of preconditions" principle is proven, showing that coordinating actions to be performed in linear temporal order requires a corresponding form of nested knowledge.Comment: In Proceedings TARK 2015, arXiv:1606.0729

The commercial and technical evolution of the ferry industry 1948-1987

The thesis sets out the political, economic and social forces and the parallel institutional and technical factors that shaped the development of the ferry sector between 1948 and 1987. It provides as full an account as the available record permits of an important shipping industry sector that previously has received little serious historical consideration. Most of the ferry industry, dominated by its railway industry parent and ravaged by war losses, came into public ownership in 1948 as a consequence of railway nationalisation followed by a decade of under-investment. The period ended with a loss of supremacy for the railway-owned shipping sector, privatisation, increased competition, the 1987 Herald of Free Enterprise disaster – in no small part exacerbated by the drive through vehicle deck which had done so much to facilitate the ease of passenger car and freight movement - and the certainty of the Channel Tunnel, which spelt the end of sea transport primacy on its most important routes. The era saw ferries transformed in terms of design and capability from being largely tied to rail-connected passenger traffic, there came the innovation of roll-on, roll-off and the hovercraft, with ports undergoing change scarcely less extensive. The thesis examines the basic structural changes that affected the industry, specifically the process that resulted in the establishment of privately-owned firms in situ, the bureaucratic problems that beset British Railways and which hampered its formulation of a coherent response to the varied challenges it faced in the Fifties and Sixties. It shows how the growth in private motor car ownership proved a catalyst for change in a conservative industry and explores the way in which the introduction of newcomers and the hovercraft drove the development of competition, transforming the ferry business but ultimately leading to the government decision to construct a fixed link between the United Kingdom and France. The thesis concludes that the drive and entrepreneurial flair of three private ferry operators, Townsend, Bustard and Thoresen, was largely responsible for the transformation of the industry and argues that the new and growing market created by motor transport would not have been exploited at such a rate or with the same degree of forethought and innovation without their involvement

Designing Costumes for \u3cem\u3eVolpone\u3c/em\u3e by Ben Jonson

This poster presentation showcases my unrealized designs for Volpone by Ben Jonson, completed for the Linfield College Theatre Program’s Costume Design course taught by Laurel Peterson during the 2016 fall semester. The play focuses on Volpone, an old miser who delights in tricking wealthy acquaintances by pretending to be an invalid and attaining more money in doing so. Along with Volpone (meaning fox in Italian), many of the other characters have names pertaining to specific animals such as Mosca (the fly), Voltore (the vulture), and Peregrine. These names point to unflattering personality traits and make it easier for the audience to understand Ben Jonson’s social commentary about European society in 1605. My design concept combined animalistic or classic characterizations of the characters’ personalities with a Victorian Venetian setting. In keeping with the dark undertones and somewhat Dickensian plot of the play, I chose to set it during a time strife with poverty, greedy merchants, constraining gender norms, and strict social morals unheeded by those who dared. In my costume designs, I adhered closely to the early Victorian period while also trying to convey the true nature of each character whether good or evil

Scaling laws for soliton pulse compression by cascaded quadratic nonlinearities

We present a detailed study of soliton compression of ultra-short pulses based on phase-mismatched second-harmonic generation (\textit{i.e.}, the cascaded quadratic nonlinearity) in bulk quadratic nonlinear media. The single-cycle propagation equations in the temporal domain including higher-order nonlinear terms are presented. The balance between the quadratic (SHG) and the cubic (Kerr) nonlinearity plays a crucial role: we define an effective soliton number -- related to the difference between the SHG and the Kerr soliton numbers -- and show that it has to be larger than unity for successful pulse compression to take place. This requires that the phase mismatch be below a critical level, which is high in a material where the quadratic nonlinearity dominates over the cubic Kerr nonlinearity. Through extensive numerical simulations we find dimensionless scaling laws, expressed through the effective soliton number, which control the behaviour of the compressed pulses. These laws hold in the stationary regime, in which group-velocity mismatch effects are small, and they are similar to the ones observed for fiber soliton compressors. The numerical simulations indicate that clean compressed pulses below two optical cycles can be achieved in a $\beta$-barium borate crystal at appropriate wavelengths, even for picosecond input pulses.Comment: 11 pages, 8 figures, resubmitted version, to appear in October issue of J. Opt. Soc. Am. B. Substantially revised, updated mode

Formulating Consciousness: A Comparative Analysis of Searle’s and Dennett’s Theory of Consciousness

This research will argue about which theory of mind between Searle’s and Dennett’s can better explain human consciousness. Initially, distinctions between dualism and materialism will be discussed ranging from substance dualism, property dualism, physicalism, and functionalism. In this part, the main issue that is tackled in various theories of mind is revealed. It is the missing connection between input stimulus (neuronal reactions) and behavioral disposition: consciousness. Then, the discussion will be more specific on Searle’s biological naturalism and Dennett’s multiple drafts model as the two attempted to answer the issue. The differences between them will be highlighted and will be analyzed according to their relation to their roots: dualism and materialism. The two theories will be examined on how each answer the questions on consciousness