A note on selecting maximals in finite spaces

Given a choice problem, the maximization rule may select many alternatives. In such cases, it is common practice to interpret that the final choice will end up being made by some random procedure, assigning to any maximal alternative the same probability of being chosen. However, there may be reasons based on the same original preferences for which it is suitable to select certain maximal alternatives over others. This paper introduces two choice criteria induced by the original preferences such that maximizing with respect to each of them may give a finer selection of alternatives than maximizing with respect to the original preferences. Those criteria are built by means of several preference relations induced by the original preferences, namely, two (weak) dominance relations, two indirect preference relations and the dominance relations defined with the help of those indirect preferences. It is remarkable that as the original preferences approach being complete and transitive, those criteria become both simpler and closer to such preferences. In particular, they coincide with the original preferences when these are complete and transitive, in which case they provide the same solution as those preference

A characterization of some families of Cohen--Macaulay, Gorenstein and/or Buchsbaum rings

We provide algorithmic methods to check the Cohen--Macaulayness, Buchsbaumness and/or Gorensteiness of some families of semigroup rings that are constructed from the dilation of bounded convex polyhedrons of $\R^3_{\geq}$. Some families of semigroup rings are given satifying these properties

Teaching-innovation experience in competitiveness and innovation in business

The aim of this paper is to contrast the students’ opinions about the teaching innovation experience carried out in the subject “Competitividad en Innovación en la Empresa” (Competitiveness and Innovation in Business). The procedure will start with the subject’s profile, going through the main objectives and teaching methodology, to finish with evaluation and assessment, as suggested in the subject’s syllabus for the academic year 2007/08. Taking this as a starting point and, due to the fact that the number of students in the control group is not very high, we suggest changing both the teaching methodology and the evaluation. These changes will be contrasted with the students’ acceptance and involvement.PROCEEDINGS C

Technocracy inside the rule of law : challenges in the foundations of legal norms

Technocracy is usually opposed to democracy. Here, another perspective is taken: technocracy is countered with the rule of law. In trying to understand the contemporary dynamics of the rule of law, two main types of legal systems (in a broad sense) have to be distinguished: firstly, the legal norm, studied by the science of law; secondly, the scientific laws (which includes the legalities of the different sciences and communities). They both contain normative prescriptions. But their differ in their subjects‘ source: while legal norms are the will’s expression of the normative authority, technical prescriptions can be derived from scientific laws, which are grounded over the commonly supposed objectivity of the scientific knowledge about reality. They both impose sanctions too, but in the legal norm they refer to what is established by the norm itself, while in the scientific legality they consist in the reward or the punishment derived from the efficacy or inefficacy to reach the end pursued by the action. The way of legitimation also differs: while legal norms have to have followed the formal procedures and must not have contravened any fundamental right, technical norms‘ validity depend on its theoretical foundations or on its efficacy. Nowadays, scientific knowledge has become and important feature in policy-making. Contradictions can arise between these legal systems. These conflicts are specially grave when the recognition or exercise of fundamental rights is instrumentally used, or when they are violated in order to increase the policies‘ efficacy. A political system is technocratic, when, in case of contradiction, the scientific law finally prevails

A non-proposition-wise variant of majority voting for aggregating judgments

Majority voting is commonly used in aggregating judgments. The literature to date on judgment aggregation (JA) has focused primarily on proposition-wise majority voting (PMV). Given a set of issues on which a group is trying to make collective judgments, PMV aggregates individual judgments issue by issue, and satisfies a salient property of JA rules—independence. This paper introduces a variant of majority voting called holistic majority voting (HMV). This new variant also meets the condition of independence. However, instead of aggregating judgments issue by issue, it aggregates individual judgments en bloc. A salient and straightforward feature of HMV is that it guarantees the logical consistency of the propositions expressing collective judgments, provided that the individual points of view are consistent. This feature contrasts with the known inability of PMV to guarantee the consistency of the collective outcome. Analogously, while PMV may present a set of judgments that have been rejected by everyone in the group as collectively accepted, the collective judgments returned by HMV have been accepted by a majority of individuals in the group and, therefore, rejected by a minority of them at most. In addition, HMV satisfies a large set of appealing properties, as PMV also does. However, HMV may not return any complete proposition expressing the judgments of the group on all the issues at stake, even in cases where PMV does. Moreover, demanding completeness from HMV leads to impossibility results similar to the known impossibilities on PMV and on proposition-wise JA rules in genera

Detecting the gravitational wave background from primordial black hole dark matter

The black hole merging rates inferred after the gravitational-wave detection by Advanced LIGO/VIRGO and the relatively high mass of the progenitors are consistent with models of dark matter made of massive primordial black holes (PBH). PBH binaries emit gravitational waves in a broad range of frequencies that will be probed by future space interferometers (LISA) and pulsar timing arrays (PTA). The amplitude of the stochastic gravitational-wave background expected for PBH dark matter is calculated taking into account various effects such as initial eccentricity of binaries, PBH velocities, mass distribution and clustering. It allows a detection by the LISA space interferometer, and possibly by the PTA of the SKA radio-telescope. Interestingly, one can distinguish this background from the one of non-primordial massive binaries through a specific frequency dependence, resulting from the maximal impact parameter of binaries formed by PBH capture, depending on the PBH velocity distribution and their clustering properties. Moreover, we find that the gravitational wave spectrum is boosted by the width of PBH mass distribution, compared with that of the monochromatic spectrum. The current PTA constraints already rule out broad-mass PBH models covering more than three decades of masses, but evading the microlensing and CMB constraints due to clustering.Comment: 12 pages, 4 figure

Cosmic troublemakers: the Cold Spot, the Eridanus Supervoid, and the Great Walls

The alignment of the CMB Cold Spot and the Eridanus supervoid suggests a physical connection between these two relatively rare objects. We use galaxy cata\-logues with photometric (2MPZ) and spectroscopic (6dF) redshift measurements, supplemented by low-redshift compilations of cosmic voids, in order to improve the 3D mapping of the matter density in the Eridanus constellation. We find evidence for a supervoid with a significant elongation in the line-of-sight, effectively spanning the total redshift range $z<0.3$. Our tomographic imaging reveals important substructure in the Eridanus supervoid, with a potential interpretation of a long, fully connected system of voids. We improve the analysis by extending the line-of-sight measurements into the antipodal direction that interestingly crosses the Northern Local Supervoid at the lowest redshifts. Then it intersects very rich superclusters like Hercules and Corona Borealis, in the region of the Coma and Sloan Great Walls, as a possible compensation for the large-scale matter deficit of Eridanus. We find that large-scale structure measurements are consistent with a central matter underdensity $\delta_0 \approx -0.25$, projected transverse radius $r_{0}^{\perp}\approx 195$ Mpc/h with an extra deepening in the centre, and line-of-sight radius $r_{0}^{\parallel}\approx500$ Mpc/h, i.e. an ellipsoidal supervoid. The expected integrated Sachs-Wolfe imprint of such an elongated supervoid is at the $\Delta T_{\rm ISW} \approx -40 \mu K$ level, thus inappropriate to accounting for the Cold Spot pattern in the CMB.Comment: 13 pages, 9 figures. Accepted by MNRAS in this for

Automated Functional Testing based on the Navigation of Web Applications

Web applications are becoming more and more complex. Testing such applications is an intricate hard and time-consuming activity. Therefore, testing is often poorly performed or skipped by practitioners. Test automation can help to avoid this situation. Hence, this paper presents a novel approach to perform automated software testing for web applications based on its navigation. On the one hand, web navigation is the process of traversing a web application using a browser. On the other hand, functional requirements are actions that an application must do. Therefore, the evaluation of the correct navigation of web applications results in the assessment of the specified functional requirements. The proposed method to perform the automation is done in four levels: test case generation, test data derivation, test case execution, and test case reporting. This method is driven by three kinds of inputs: i) UML models; ii) Selenium scripts; iii) XML files. We have implemented our approach in an open-source testing framework named Automatic Testing Platform. The validation of this work has been carried out by means of a case study, in which the target is a real invoice management system developed using a model-driven approach.Comment: In Proceedings WWV 2011, arXiv:1108.208