Principle Based Semantics for HPSG

The paper presents a constraint based semantic formalism for HPSG. The advantages of the formlism are shown with respect to a grammar for a fragment of German that deals with (i) quantifier scope ambiguities triggered by scrambling and/or movement and (ii) ambiguities that arise from the collective/distributive distinction of plural NPs. The syntax-semantics interface directly implements syntactic conditions on quantifier scoping and distributivity. The construction of semantic representations is guided by general principles governing the interaction between syntax and semantics. Each of these principles acts as a constraint to narrow down the set of possible interpretations of a sentence. Meanings of ambiguous sentences are represented by single partial representations (so-called U(nderspecified) D(iscourse) R(epresentation) S(tructure)s) to which further constraints can be added monotonically to gain more information about the content of a sentence. There is no need to build up a large number of alternative representations of the sentence which are then filtered by subsequent discourse and world knowledge. The advantage of UDRSs is not only that they allow for monotonic incremental interpretation but also that they are equipped with truth conditions and a proof theory that allows for inferences to be drawn directly on structures where quantifier scope is not resolved

Discrimination and nepotism: the efficiency of the anonymity rule.

The paper considers two categories of discrimination: 'discrimination against' and 'discrimination in favor', which Becker coins 'nepotism'. The paper develops an experimental test to distinguish between these two types of discrimination. The experiment compares the behavior towards individuals of different groups with the behavior towards anonymous individuals (those having no clear group affiliation). We illustrate the two attitudes by considering two segmented societies: Belgian society, with its linguistic segmentation between the Flemish and the Walloons, and Israeli society, where we focus on religious versus secular segmentation. In Belgium, we find evidence of discrimination against. Both the Walloons and the Flemish treat people of their own group in the same way as anonymous individuals while discriminating against individuals of the other group. In contrast, the behavior of ultra-orthodox religious Jews in Israel can be categorized as nepotism: they favor members of their own group while treating anonymous individuals in the same way as secular individuals. The distinction between the different types of discrimination is important in evaluating the effectiveness and the efficiency consequences of anti-discriminatory legislations.Discrimination; Efficiency; Effectiveness; Legislation;

Chromium silicide formation by ion mixing

The formation of CrSi_2 by ion mixing was studied as a function of temperature, silicide thickness and irradiated interface. Samples were prepared by annealing evaporated couples of Cr on Si and Si on Cr at 450°C for short times to form Si/CrSi_2/Cr sandwiches. Xenon beams with energies up to 300 keV and fluences up to 8 X 10^15 cm^(-2) were used for mixing at temperatures between 20 and 300°C. Penetrating only the Cr/CrSi_2 interface at temperatures above 150°C induces further growth of the silicide as a uniform stoichiometric layer. The growth rate does not depend on the thickness of the initially formed silicide at least up to a thickness of 150 nm. The amount of growth depends linearly on the density of energy deposited at the interface. The growth is temperature dependent with an apparent activation energy of 0.2 eV. Irradiating only through the Si/CrSi_2 interface does not induce silicide growth. We conclude that the formation of CrSi_2 by ion beam mixing is an interface-limited process and that the limiting reaction occurs at the Cr/CrSi_2 interface

Sharing Geographic Data: How to Update Distributed or Replicated Data

Geographic data is expensive to collect and maintain and sharing data is crucial for its effective use in urban planning at all levels. For a few hardly ever changing themes the simple distribution of copies of data is feasible, but for other data, access to “live” data and updating, sometimes even distributed updating, of the data is necessary. The organization of sharing data can be separated into three sets of issues: (1) Interpretation: how to understand the data, (2) Authorization: is a user permitted to use the data, and (3) Access: how to achieve effective and non-disturbing use and updating of data by several users? Solutions must take threats into account: hackers may try to steal or disturb the use of data, and the revelations of Snowden's documents only emphasize the danger of others reading data not intended for their eyes. Effective sharing geographic data without conflicts requires integrating results from different areas of computer science research, including at least: cryptography, computer security, database management, and computer networking

Why Is Cartographic Generalization So Hard?

I remember first presentations about cartographic generalizations (Spiess 1971), where tools for generalization were shown, but the conclusions stated, more or less clearly, that fully automated cartographic generalization was not possible. There has been an impressive stream of research documenting methods to generalize maps. The consensus today seems to be that automated tools under control of a cartographer are the most effective means (Buttenfield et al. 1991; Weibel 1995). In this contribution some fundamental aspects of map making, including generalizations are analyzed. Map generalization is studied by most map producers, especially the National Mapping Agencies, because they have to maintain maps at different scale and it appears economical to derive a map at smaller from a map of a larger scale by an automated process. Equally important is the production of maps at arbitrary scales for the illustration of web pages. These tasks are the backdrop for the following abstract analysis

Strong coupling of a qubit to shot noise

We perform a nonperturbative analysis of a charge qubit in a double quantum dot structure coupled to its detector. We show that strong detector-dot interaction tends to slow down and halt coherent oscillations. The transitions to a classical and a low-temperature quantum overdamping (Zeno) regime are studied. In the latter, the physics of the dissipative phase transition competes with the effective shot noise.Comment: 5 pages, 4 figure

Electrochemistry of Dihalogenated Nicotonic Acids in Aqueous and Aprotic Media

The electrochemical reduction of several 2,5- and 5,6- dihalonicotinic acids have been studied in dimethyl sulfoxide as well as in aqueous buffers of different pH. The polarographic half-wave potentials for the reduction of these compounds in both media are reported here. The compounds appear to reduce at the carboxyl group. The presence of halogen atoms on the pyridine ring facilitates reduction