13,955 research outputs found
Dynamic concentration of the triangle-free process
The triangle-free process begins with an empty graph on n vertices and
iteratively adds edges chosen uniformly at random subject to the constraint
that no triangle is formed. We determine the asymptotic number of edges in the
maximal triangle-free graph at which the triangle-free process terminates. We
also bound the independence number of this graph, which gives an improved lower
bound on the Ramsey numbers R(3,t): we show R(3,t) > (1-o(1)) t^2 / (4 log t),
which is within a 4+o(1) factor of the best known upper bound. Our improvement
on previous analyses of this process exploits the self-correcting nature of key
statistics of the process. Furthermore, we determine which bounded size
subgraphs are likely to appear in the maximal triangle-free graph produced by
the triangle-free process: they are precisely those triangle-free graphs with
density at most 2.Comment: 75 pages, 1 figur
Independently Parameterised Momenta Variables and Monte Carlo IR Subtraction
We introduce a system of parameters for the Monte Carlo generation of Lorentz
invariant phase space that is particularly well-suited to the treatment of the
infrared divergences that occur in the most singular, Born-like configurations
of QCD processes. A key feature is that particle momenta are generated
independently of one another, leading to a simple parameterisation of all such
IR limits. We exemplify the use of these variables in conjunction with the
projection to Born subtraction technique at next-to-next-to-leading order. The
geometric origins of this parameterisation lie in a coordinate chart on a
Grassmannian manifold.Comment: 16 pages; v2: version published in JHE
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Profiting from Socially Beneficial Green Investment in an Era of Global Warming
Monetizing the value of socially beneficial green investment is complex and will play an important role in the transformation currently sweeping through the industry. A common or agreed-to approach has yet to be developed, and options under consideration have numerous barriers, the most difficult being political ones
Sharing Global Governance: The Role of Civil Society Organizations
This report explores the multiple roles and potential of CSOs in international policymaking and examines the strengths and weaknesses of CSOs and state-based organizations in global governance. It looks particularly closely at the resources, access, skills and experience that each group of actors brings to the table. It concludes that the infrastructure used to incorporate CSOs into the United Nations and other multilaterals must be strengthened and expanded if more integrated and effective forms of collaboration are to be developed and outlines policy recommendations how this goal can be accomplished
The Meaning of Collective Terrorist Threat: Understanding the Subjective Causes of Terrorism Reduces Its Negative Psychological Impact
This article hypothesized that the possibility to construct intellectual meaning of a terrorist attack (i.e., whether participants can cognitively understand why the perpetrators did their crime) reduces the negative psychological consequences typically associated with increased terrorist threat. Concretely, the authors investigated the effect of intellectual meaning (induced by providing additional information about potential economic, cultural, and historical reasons for the terrorist attack) on perceived terrorist threat and associated emotional well-being. Study 1 revealed that pictures of terrorist attacks elicited less experienced terrorist threat when they were presented with background information about the terrorists’ motives (meaning provided) rather than without additional background information (no meaning provided). Study 2 replicated this effect with a different manipulation of terrorist threat (i.e., newspaper article) and clarified the underlying psychological process: Participants in the high terror salience condition with meaning provided experienced less terrorist threat and thus more emotional well-being in the face of crisis than participants in the high terror salience condition without meaning provided. Theoretical and practical implications in the context of psychological health and mass media effects are discussed
Chaining Test Cases for Reactive System Testing (extended version)
Testing of synchronous reactive systems is challenging because long input
sequences are often needed to drive them into a state at which a desired
feature can be tested. This is particularly problematic in on-target testing,
where a system is tested in its real-life application environment and the time
required for resetting is high. This paper presents an approach to discovering
a test case chain---a single software execution that covers a group of test
goals and minimises overall test execution time. Our technique targets the
scenario in which test goals for the requirements are given as safety
properties. We give conditions for the existence and minimality of a single
test case chain and minimise the number of test chains if a single test chain
is infeasible. We report experimental results with a prototype tool for C code
generated from Simulink models and compare it to state-of-the-art test suite
generators.Comment: extended version of paper published at ICTSS'1
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