On Dynamic Compromise

What prevents majorities from extracting surplus from minorities in a dynamic legislative process? In this paper we study an infinitely repeated game where legislators determine the division of a surplus each period. A division proposal is made at the beginning of the period by a randomly selected legislator and is then voted on. Proposals that are accepted by a simple majority are implemented, otherwise the status quo allocation prevails. We show existence of a symmetric Markov perfect equilibrium in which more than a minimum winning majority receive a positive allocation for an intermediate range of discount factors. However, the equilibrium outcome is sensitive to initial conditions: compromise is achieved when initial allocations are well distributed, otherwise the equilibrium spirals towards a complete absence of compromise. We find that, contrary to intuition, compromise becomes easier to sustain as the number of legislators increases. Classification-JEL Codes: C73, D74

The design of caring environments and the quality of life of older people

There has been little systematic research into the design of care environments for older people. This article reviews empirical studies from both the architectural and the psychological literature. It outlines the instruments that are currently available for measuring both the environment and the quality of life of older people, and it summarises the evidence on the layout of buildings, the sensory environment and the privacy of residents. The conclusion is drawn that all evidence-based design must be a compromise or dynamic and, as demands on the caring environment change over time, this compromise must be re-visited in the form of post-occupancy evaluation

The Economic Reunification of Korea: A Dynamic General Equilibrium Model

This paper constructs a dynamic specific factors model to examine the impact of the economic reunification of North and South Korea. The model is a compromise between the highly stylized neoclassical models of trade found in the theoretical trade literature, and the highly aggregated models used in dynamic macroeconomics. We find that the policies with the biggest effects on aggregate output are changes in government tax and spending rates, particularly spending on infrastructure. In contrast, we find that both skilled and unskilled wages are much more responsive to the particulars of trade policy, particularly openness to intra-Korea trade and intra-Korea labor mobility. The location of production in a fully integrated Korean economy is determined by the location of infrastructure.factor mobility; dynamic general equilibrium; specific-factors; Korea

Exact Inference Techniques for the Analysis of Bayesian Attack Graphs

Attack graphs are a powerful tool for security risk assessment by analysing network vulnerabilities and the paths attackers can use to compromise network resources. The uncertainty about the attacker's behaviour makes Bayesian networks suitable to model attack graphs to perform static and dynamic analysis. Previous approaches have focused on the formalization of attack graphs into a Bayesian model rather than proposing mechanisms for their analysis. In this paper we propose to use efficient algorithms to make exact inference in Bayesian attack graphs, enabling the static and dynamic network risk assessments. To support the validity of our approach we have performed an extensive experimental evaluation on synthetic Bayesian attack graphs with different topologies, showing the computational advantages in terms of time and memory use of the proposed techniques when compared to existing approaches.Comment: 14 pages, 15 figure

Stabilization of grid frequency through dynamic demand control

Frequency stability in electricity networks is essential to the maintenance of supply quality and security. This paper investigates whether a degree of built-in frequency stability could be provided by incorporating dynamic demand control into certain consumer appliances. Such devices would monitor system frequency (a universally available indicator of supply-demand imbalance) and switch the appliance on or off accordingly, striking a compromise between the needs of the appliance and the grid. A simplified computer model of a power grid was created incorporating aggregate generator inertia, governor action and load-frequency dependence plus refrigerators with dynamic demand controllers. Simulation modelling studies were carried out to investigate the system's response to a sudden loss of generation, and to fluctuating wind power. The studies indicated a significant delay in frequency-fall and a reduced dependence on rapidly deployable backup generation

Optimum estimate of delays and dispersive effects in low-frequency interferometric observations

Modern radio interferometers sensitive to low frequencies will make use of wide-band detectors. For such wide bandwidths, dispersive atmospheric effects introduce variations in the fringe delay which change through the band of the receivers. These undesired dispersive effects must be estimated and calibrated with the highest precision. We studied the achievable precision in the estimate of the ionospheric dispersion and the dynamic range of the correlated fringes for different distributions of sub-bands in low-frequency and wide-band interferometric observations. Our study is focused on the case of sub-bands with a bandwidth much narrower than that of the total covered spectrum (case of LOFAR). We computed the uncertainty of the ionospheric delay, the delay ambiguity, and the dynamic range of the fringes using four different kinds of sub-band distributions: constant spacing between sub-bands, random spacings, spacings based on a power-law distribution, and spacings based on Golomb rulers (sets of integers whose sets of differences have non-repeated elements). For a large number of sub-bands ($> 20$, depending on the delay window) spacings based on Golomb rulers give the most precise estimates of dispersive effects and the highest fringe dynamic ranges. Spacings based on the power-law distribution give similar results, although better than those with the Golomb rulers for smaller number of sub-bands. Random distributions result in large fringe dynamic ranges, but the estimate of dispersive effects is worse. A constant spacing of sub-bands results in very bad fringe dynamic ranges, but good estimates of ionospheric dispersion. Combining all the results, the power-law distribution gives the best compromise between homogeneity in the bandwidth sampling, precision in the estimate of ionospheric effects, dynamic range of the correlated fringes, and group-delay ambiguity.Comment: 8 pages, 7 figures. Accepted for publication in A&

Generating Efficient, Terminating Logic Programs

The objective of control generation in logic programming is to automatically derive a computation rule for a program that is efficient and yet does not compromise program correctness. Progress in solving this important problem has been slow and, to date, only partial solutions have been proposed where the generated programs are either incorrect or inefficient. We show how the control generation problem can be tackled with a simple automatic transformation that relies on information about the depths of derivations. To prove correctness of our transform we introduce the notion of a semi delay recurrent program which generalises previous ideas in the termination literature for reasoning about logic programs with dynamic selection rules