A model composite assessment of the enhancement of Arctic warming by sea ice retreat

Thesis (M.S.) University of Alaska Fairbanks, 2006Five global climate models used in the Arctic Climate Impact Assessment are utilized to estimate the local enhancement of Arctic warming attributable to sea ice retreat in 21st century B2-scenario greenhouse gas (GHG) simulations. The models show a wide range of ice retreat, resulting in a corresponding range in the enhancement of warming. The enhancement is highly seasonal, varying locally from essentially zero in the summer to several degrees CC) in the late autumn and early winter. The composite climate model response to GHG forcing manifests as a nonlinear amplification of seasonally modulated warming enhancement. The magnitude of the warming enhancement increases with the threshold decline in ice concentration used to define retreat because higher thresholds better isolate the warming enhancement signal over ice retreat areas. A threshold of 20% ensures that all models in this study have enough ice retreat area to sample the enhancement because all start with ice concentrations at least that high over substantial northern hemisphere areas. All estimates are lower bounds because they do not account for advective effects

Symbolic Maximum Likelihood Estimation with Mathematica

Mathematica is a symbolic programming language that empowers the user to undertake complicated algebraic tasks. One such task is the derivation of maximum likelihood estimators, demonstrably an important topic in statistics at both the research and expository level. In this paper, a Mathematica package is provided that contains a function entitled SuperLog. This function utilises pattern-matching code that enhances Mathematica's ability to simplify expressions involving the natural logarithm of a product of algebraic terms. This enhancement to Mathematica's functionality can be of particular benefit for maximum likelihood estimation

Stop worrying and love the Ireland/Northern Ireland protocol

Colin Murray (Newcastle Law School) argues that Northern Ireland’s Unionist Parties should rein in their opposition to the Ireland/Northern Ireland Protocol. Brexit has undoubtedly produced many immediate dislocations, but these could be mitigated under the Withdrawal Agreement processes and over time the unique access to the Single Market that Northern Ireland retained will make it an attractive base for companies seeking to trade in both the UK and EU

It’s time for Northern Ireland’s Unionist parties to decide what they actually want to achieve out of the protocol renegotiation

The EU has now announced the compromises it is prepared to make over the Northern Ireland Protocol. Colin Murray writes that Unionist parties face multiple risks if they continue to back the UK Government in its effort to dismantle the Protocol

Salus populi suprema lex: The Development of national security jurisprudence prior to the first world war

This study assesses the changing judicial approach to national security concerns in the half сеntuгу preceding the First World War. This era of jurisprudence has been largely neglected by legal historians, most studies assuming that the modem judicial approach to national security developed only after the first rambles of the guns of August 1914.However, pre-war jurisprudence demonstrates the judiciary's increasing familiarity with national-security concerns, through their exposure to what may be described as 'modem' national-security legislation, from the mid-Victorian era onwards. This study therefore considers the judicial approach to such ill-considered statutes as the Foreign Enlistment Act 1819 and its successor the Foreign Enlistment Act 1870, and the Defence Acts 1842-73 (and related enactments). This thesis also examines the judicial response to the application of aspects of nineteenth-century commercial, contract and customs law to protect security concerns. Through detailed examination of each of these areas of law, this study will ascertain the degree of influence that national-security concerns exerted upon judicial interpretation in the years 1860-1914.It is contended that the cumulative weight of this jurisprudence indicates that the First World War was not the turning point in judicial attitude that it has been widely proclaimed to be, and that the supine approach to national-security concerns characteristic of the twentieth-century jurisprudence can be traced into the Victorian era. Superficial variations in jurispradence, including shifts from positivist to normative "packaging" of security concerns should not disguise the judiciary's adoption, long prior to the First World War, of a functionalist interpretative approach to national-security arguments

The Northern Ireland Protocol is currently caught between an untrusting Brussels and an unrealistic London

While a number of issues in the Northern Ireland protocol require technical and legal fixes, at this point there seems to be very little point in discussing them, writes Colin Murray. This is because the key actors are talking at such cross-purposes that the most contentious issues cannot be resolved

Internal agent states : experiments using the swarm leader concept

In recent years, an understanding of the operating principles and stability of natural swarms has proven to be a useful tool for the design and control of artificial robotic agents. Many robotic systems, whose design or control principals are inspired by behavioural aspects of real biological systems such as leader-follower relationship, have been developed. We introduced an algorithm which successfully enhances the navigation performance of a swarm of robots using the swarm leader concept. This paper presents some applications based on that work using the simulations and experimental implementation using a swarming behaviour test-bed at the University of Strathclyde. Experimental and simulation results match closely in a way that confirms the efficiency of the algorithm as well as its applicability