Dynamic stability of space vehicles. Volume 8 - Atmospheric disturbances that affect flight control analysis

Space vehicle and control system dynamic response to atmospheric disturbance

An interactive multi-block grid generation system

A grid generation procedure combining interactive and batch grid generation programs was put together to generate multi-block grids for complex aircraft configurations. The interactive section provides the tools for 3D geometry manipulation, surface grid extraction, boundary domain construction for 3D volume grid generation, and block-block relationships and boundary conditions for flow solvers. The procedure improves the flexibility and quality of grid generation to meet the design/analysis requirements

The size of the largest fluctuations in a market model with Markovian switching

This paper considers the size of the large fluctuations of a stochastic differential equation with Markovian switching. We concentrate on processes which obey the Law of the Iterated Logarithm, or obey upper and lower iterated logarithm growth bounds on their almost sure partial maxima. The results are applied to financial market models which are subject to random regime shifts. We prove that the security exhibits the same long-run growth properties and deviations from the trend rate of growth as conventional geometric Brownian motion, and also that the returns, which are non-Gaussian, still exhibit the same growth rate in their almost sure large deviations as stationary continuous-time Gaussian processes

Color structure for soft gluon resummation - a general recipe

A strategy for calculating the color structure needed for soft gluon resummation for processes with any number of colored partons is introduced using a N_c --> infinity inspired basis. In this basis a general formalism can be found at the same time as the calculations are simplified. The advantages are illustrated by recalculating the soft anomalous dimension matrix for the processes gg --> gg, q\qbar --> q \qbar g and q\qbar --> ggg.Comment: 16 page

Long quantum channels for high-quality entanglement transfer

High-quality quantum-state and entanglement transfer can be achieved in an unmodulated spin bus operating in the ballistic regime, which occurs when the endpoint qubits A and B are coupled to the chain by an exchange interaction $j_0$ comparable with the intrachain exchange. Indeed, the transition amplitude characterizing the transfer quality exhibits a maximum for a finite optimal value $j_0^{opt}(N)$, where $N$ is the channel length. We show that $j_0^{opt}(N)$ scales as $N^{-1/6}$ for large $N$ and that it ensures a high-quality entanglement transfer even in the limit of arbitrarily long channels, almost independently of the channel initialization. For instance, the average quantum-state transmission fidelity exceeds 90% for any chain length. We emphasize that, taking the reverse point of view, should $j_0$ be experimentally constrained, high-quality transfer can still be obtained by adjusting the channel length to its optimal value.Comment: 12 pages, 9 figure

Aspects of power corrections in hadron-hadron collisions

The program of understanding inverse-power law corrections to event shapes and energy flow observables in e+ e- annihilation to two jets and DIS (1+1) jets has been a significant success of QCD phenomenology over the last decade. The important extension of this program to similar observables in hadron collisions is not straightforward, being obscured by both conceptual and technical issues. In this paper we shed light on some of these issues by providing an estimate of power corrections to the inter-jet E_t flow distribution in hadron collisions using the techniques that were employed in the e+ e- annihilation and DIS cases.Comment: 15 pages, 1 figure, uses JHEP3.cl

Jet vetoing and Herwig++

We investigate the simulation of events with gaps between jets with a veto on additional radiation in the gap in Herwig++. We discover that the currently-used random treatment of radiation in the parton shower is generating some unphysical behaviour for wide-angle gluon emission in QCD 2 to 2 scatterings. We explore this behaviour quantitatively by making the same assumptions as the parton shower in the analytical calculation. We then modify the parton shower algorithm in order to correct the simulation of QCD radiation.Comment: 18 pages, 11 figure

Plenty More Fish in the Sea? A working paper on the legal issues related to fishing beyond maximum sustainable yield: A UK case study

Maximum Sustainable Yield (MSY) is about to become a centre stage issue. The EU now has a commitment that fishing will progressively be managed at levels that correspond to MSY, and setting of quotas will respect scientific advice. Where possible, this is to be attained by 2015, and all fish stocks will be managed at MSY by 2020 at the latest. What the term ‘maximum sustainable yield’ means will dominate the next seven years of fisheries discussions. MSY has two different interpretations. Scientists use the term to mean the ability of a fish stock to support a sustainable fishing industry. Lawyers use it when assessing the obligations of a country in respect of its sovereign fishing rights. This report focuses on the legal interpretation of MSY. The report’s findings are particularly important as the EU has consistently over-allocated quota and ignored scientific advice, with the result that 75% of EU fish stocks are overfished. The starting point of a thorough investigation of MSY is the nature of fishing rights themselves. Fisheries were traditionally open access and seen as being inexhaustible. The origins of this approach date at least as far back as the era of the Roman Empire, but even then interpretation by the Roman courts created some perverse outcomes. The principle of open access became established for the English fishery in the 12th century. Before then, it is likely that all viable tidal fisheries were granted by the Crown into private hands following the Norman conquest. Indeed, some of these private tidal fisheries still persist today. In the seventeenth century, the mare liberum (freedom of the seas) debate confirmed open access on the high seas, but the position for territorial waters (within the 3 mile limit) was more complex. Under the common law, fishers operated under the public right to fish which permitted open access and has come to be interpreted as being based on the principle of inexhaustibility of the stock. Where this myth of inexhaustibility has come from is difficult to tell. It is often attributed to the Victorian scientist Thomas Huxley because of his pronouncement on the fecundity of some fish species, but Huxley himself highlights fisheries which were vulnerable to over-fishing and recognises that, on the high seas, no regulatory mechanisms were available, so this aspect of his findings was theoretical. Moreover, the negative impacts of some fisheries were known to the legislators at least since the Middle Ages and it is tempting to posit that public authorities, in whatever form they manifested themselves, have always been aware that some fishing methods can cause significant harm. As it stands, the basic principle the courts still adhere to is that the right to fish is untrammelled, but whether this principle would withstand direct judicial scrutiny is questionable. The United Nations Convention on the Laws of the Sea (UNCLOS) changed everything. Coastal states now enjoy sovereign rights over a far larger area of sea than they did previously. UK territorial waters now extend to 12 nautical miles and its exclusive economic zone (EEZ) extends up to 200 nautical miles. UNCLOS recognises sovereign rights for fisheries but also imposes duties on coastal states to restore stocks to levels which can produce MSY within their EEZs. Sovereign fishing rights are not untrammelled; they are qualified by a duty to restore stocks and to preserve the marine environment. Similar obligations are contained in the Convention on Biodiversity (with a target for 2020) and by virtue of the World Summit for Sustainable Development (with a target of 2015 for depleted stocks). Increasingly, international obligations of this nature are being enforced through the domestic courts. Many countries (including the UK itself for its Crown Dependencies and overseas territories) vest their fishing rights in an identifiable legal entity which then not just regulates the fishery, but also acts as an owner in the way it disposes of the fishery to commercial operators. Unfortunately, for the waters immediately adjacent to the UK, it is not clear in what Crown entity the UK’s fishing rights actually vest. The UK fishery is clearly some form of public asset and it is likely that there is a Crown trust in existence. The terms of this trust would place similar duties to maintain and restore fish stocks as those contained within UNCLOS. Despite a first instance decision to the contrary, it is possible that the terms of that trust are enforceable by third parties. There is a well-established principle in English law of nemo dat quod non habet (you cannot dispose of something you don’t own). The fact that the UK’s sovereign rights are qualified to MSY mean that the UK cannot grant to its fishers (or fishers of other Member States operating in UK waters) untrammelled rights which it does not possess itself. The same principle applies to the EU Common Fisheries Policy; the UK cannot confer on the EU greater fishing rights than those acknowledged by UNCLOS. The scientific origins of the term MSY were in the work of Beverton and Holt and related to a theoretical maximum, where a capture fishery will sustain itself. The legal meaning of the term gives discretion to fisheries managers to establish a management system which uses the best available science to determine what actions needs to be taken. The legal interpretation of MSY is therefore much broader than the scientific one and has the following features: • it is constantly evolving relating to the best available science of the time; • it defines the limits of a coastal state’s sovereign rights; • it may relate to the setting of fishing quota (where calculations of scientific MSY are particularly predominant), but many obligations for the attainment of MSY may also be satisfied by the imposition of technical or area-based management techniques such as marine protected areas; • it provides the framework in which fisheries should be managed; and • it can be used to show where stocks or areas of sea are not being properly managed, and thus direct where management resources should be targeted. The introduction of the ecosystem approach to fisheries management means that legal MSY can now take into consideration a much wider range of services provided by the fishery in the calculation and management of that fishery. UNCLOS itself permits taking into consideration relevant environmental and economic factors, including the economic needs of coastal fishing communities, but the ecosystem approach takes that a stage further by assessing all the services provided by the fishery. This shifts the focus away from simply treating the fishery as a commercial resource, to ensure that management benefits a much broader constituency. In 2008, the environmental non-governmental organisation (NGO), WWF tried to take the European Commission to the European Court of Justice for failing to allocate cod quota according to scientific advice. However, WWF was unable to access the European court system because the ECJ refused access to NGOs; ECJ rules at the time did not grant an NGO the right to be heard in court. Those rules are under scrutiny once again because they seem incompatible with the Aarhus Convention, so this position may change shortly. There are also other legal forums for testing the point. The UK courts do not have the same access restrictions as the ECJ, so a case launched in the UK courts concerning UK fishing rights or the voting patterns of the UK Minister in the EU could come to trial. The former President of the International Tribunal for the Laws of the Sea (ITLOS), Rüdiger Wolfrum, recommended ITLOS as having suitable jurisdiction to ensure compliance with MSY requirements The legal regime has dramatically moved away from the impossibility of mare liberum and open access fisheries to the possibility of effective regulation. Clearer sovereignty over the sea and better technology informing enforceable law means the legal context of fisheries have changed fundamentally for the better. There is an understanding that fisheries are held on trust for future generations. Fishing to MSY and trusteeship amount to the same thing; the legal interpretation of coastal states’ rights and responsibilities under MSY and the obligations of a Crown trust are the same. The ecosystem approach provides the matrix to understand who the beneficiaries of that trust are and where management effort needs to be directed. All these pieces are now in place and the hard law is there at the edges to ensure that reform remains on track. In short there are two key points to be drawn from this report: • It is illegal for coastal states to permit fishing beyond MSY; and • It is highly likely that this law is enforceable through the court system.Waterloo Foundatio

SIC~POVMs and Clifford groups in prime dimensions

We show that in prime dimensions not equal to three, each group covariant symmetric informationally complete positive operator valued measure (SIC~POVM) is covariant with respect to a unique Heisenberg--Weyl (HW) group. Moreover, the symmetry group of the SIC~POVM is a subgroup of the Clifford group. Hence, two SIC~POVMs covariant with respect to the HW group are unitarily or antiunitarily equivalent if and only if they are on the same orbit of the extended Clifford group. In dimension three, each group covariant SIC~POVM may be covariant with respect to three or nine HW groups, and the symmetry group of the SIC~POVM is a subgroup of at least one of the Clifford groups of these HW groups respectively. There may exist two or three orbits of equivalent SIC~POVMs for each group covariant SIC~POVM, depending on the order of its symmetry group. We then establish a complete equivalence relation among group covariant SIC~POVMs in dimension three, and classify inequivalent ones according to the geometric phases associated with fiducial vectors. Finally, we uncover additional SIC~POVMs by regrouping of the fiducial vectors from different SIC~POVMs which may or may not be on the same orbit of the extended Clifford group.Comment: 30 pages, 1 figure, section 4 revised and extended, published in J. Phys. A: Math. Theor. 43, 305305 (2010

The Challenges of Pluralism: Locating Religion in a World of Diversity

This is a postprint (author's final draft) version of an article published in the journal Social Compass in 2010. The final version of this article may be found at http://dx.doi.org/10.1177/0037768610362406 (login may be required). The version made available in OpenBU was supplied by the author.The author argues that religious pluralism is the normal state of affairs. Religion itself is multi-dimensional, and the several dimensions of religious and spiritual experience can be combined in myriad ways across individual lives. Preliminary findings from new research are presented, detailing modes of spiritual discourse that include mystery, majesty, meaning, moral compassion, and social connection. These dimensions find expression across multiple social institutions. In addition, religion is multi-traditional and organized by plural producers of the goods and services and events that embody and transform religious tradition. Finally, it is argued that religious pluralism must be studied in terms of the structures of power and privilege that allow some religious ideas to be given free voice, but limit the practice of other religious rituals or the gathering of dissident religious communities