Multi-Dimensional Inheritance

In this paper, we present an alternative approach to multiple inheritance for typed feature structures. In our approach, a feature structure can be associated with several types coming from different hierarchies (dimensions). In case of multiple inheritance, a type has supertypes from different hierarchies. We contrast this approach with approaches based on a single type hierarchy where a feature structure has only one unique most general type, and multiple inheritance involves computation of greatest lower bounds in the hierarchy. The proposed approach supports current linguistic analyses in constraint-based formalisms like HPSG, inheritance in the lexicon, and knowledge representation for NLP systems. Finally, we show that multi-dimensional inheritance hierarchies can be compiled into a Prolog term representation, which allows to compute the conjunction of two types efficiently by Prolog term unification.Comment: 9 pages, styles: a4,figfont,eepic,eps

How has the macroeconomic imbalances procedure worked in practice to improve the resilience of the euro area? March 24 2020

This paper shows how the Macroeconomic Imbalances Procedure (MIP) could be streamlined and its underlying conceptual framework clarified. Implementation of the country-specific recommendations is low; their internal consistency is sometimes missing; despite past reforms, the MIP remains largely a countryby-country approach running the risk of aggravating the deflationary bias in the euro area. We recommend to streamline the scoreboard around a few meaningful indicators, involve national macro-prudential and productivity councils, better connect the various recommendations, simplify the language and further involve the Commission into national policy discussions. This document was prepared for the Economic Governance Support Unit at the request of the ECON Committee

What lies behind the "Too-Small-To-Survive" banks

It is a common place that during financial crises, like the one started in 2007, authorities provide substantial financial support to some problem banks, whilst at the same time let several others to go bankrupt. Is this happening because some particular banks are considered important and big enough to save, whereas some others are perceived as being ‘Too-Small-To-Survive’? Is the size of banks the fundamental factor that makes authorities to treat them differently, or it is also that some banks perform poorly and are not capable of withstanding some considerable shocks whatsoever? Our study provides concrete answers to these questions thus filling part of the void in the existing literature. A short- and a long-run positive relationship between size and performance is documented regardless of the level of bank soundness (healthy vs. failed and assisted banks) under scrutiny. Importantly, we pose and lend support to the ‘Too-Small-To-Survive’ hypothesis according to which the impact of bank performance on failure probability strongly depends on size. Evidence shows that authorities tend not to save banks whose size is below some specific threshold

Quantifying knowledge exchange in R&D networks: A data-driven model

We propose a model that reflects two important processes in R&D activities of firms, the formation of R&D alliances and the exchange of knowledge as a result of these collaborations. In a data-driven approach, we analyze two large-scale data sets extracting unique information about 7500 R&D alliances and 5200 patent portfolios of firms. This data is used to calibrate the model parameters for network formation and knowledge exchange. We obtain probabilities for incumbent and newcomer firms to link to other incumbents or newcomers which are able to reproduce the topology of the empirical R&D network. The position of firms in a knowledge space is obtained from their patents using two different classification schemes, IPC in 8 dimensions and ISI-OST-INPI in 35 dimensions. Our dynamics of knowledge exchange assumes that collaborating firms approach each other in knowledge space at a rate $\mu$ for an alliance duration $\tau$. Both parameters are obtained in two different ways, by comparing knowledge distances from simulations and empirics and by analyzing the collaboration efficiency $\mathcal{\hat{C}}_{n}$. This is a new measure, that takes also in account the effort of firms to maintain concurrent alliances, and is evaluated via extensive computer simulations. We find that R&D alliances have a duration of around two years and that the subsequent knowledge exchange occurs at a very low rate. Hence, a firm's position in the knowledge space is rather a determinant than a consequence of its R&D alliances. From our data-driven approach we also find model configurations that can be both realistic and optimized with respect to the collaboration efficiency $\mathcal{\hat{C}}_{n}$. Effective policies, as suggested by our model, would incentivize shorter R&D alliances and higher knowledge exchange rates.Comment: 35 pages, 10 figure

Sustainability in Software Engineering

The intersection between software engineering re- search and the problems related to sustainability and green IT has been the subject of increasing attention. In spite of that, we observe that sustainability is still not clearly defined, or understood, in the field of software engineering. This lack of clarity leads to confusion about e.g. what is relevant to measure or the research implications over time or space. This paper provides an overview of how the research so far has defined sustainability, and how this definition has been used to guide which research areas. To this end, we carried out a systematic mapping study for selecting, classifying and analyzing relevant publications. In this study, we investigate which knowledge areas and which time scope of sustainability effects are mostly targeted in scientific research. Our analysis shows research trends and discusses gaps to be filled

Assessing the potential for knowledge-based development in transition countries. Bruegel Working Paper 2010/01, May 2010

This Working Paper by Bruegel Senior Fellow Reinhilde Veugelers examines the potential for a knowledge-based growth path in transition countries of central and eastern Europe, the Caucasus and Central Asia. The paper looks closely at how total-factor productivity, a residual growth factor commonly interpreted as reflecting technological progress, drives growth rates in these economies which exhibit a much lower GDP per capita compared to the EU15 or the United States. By analysing the prerequisites for knowledge-based growth, the author explains why transition countries are at a systemic disadvantage relative to the EU15, US and Japan and have limited potential for knowledge-based growth

Willman 1 - a probable dwarf galaxy with an irregular kinematic distribution

We investigate the kinematic properties and stellar population of the Galactic satellite Willman 1 (Wil 1) by combining Keck/DEIMOS spectroscopy with KPNO mosaic camera imaging. Wil 1 is an ultra-low luminosity Milky Way companion. This object lies in a region of size-luminosity space (M_V ~ -2 mag, d ~ 38 kpc, r_half ~ 20 pc) also occupied by the Galactic satellites Bo\"otes II and Segue 1 and 2, but no other known old stellar system. We use kinematic and color-magnitude criteria to identify 45 stars as possible members of Wil 1. With a systemic velocity of v_helio = -12.8 +/- 1.0 km/s, Wil 1 stars have velocities similar to those of foreground Milky Way stars. Informed by Monte-Carlo simulations, we identify 5 of the 45 candidate member stars as likely foreground contaminants. We confirm a significant spread in the abundances of the likely Wil 1 red giant branch members ([Fe/H] = -1.73 +/- 0.12 and -2.65 +/- 0.12, [Ca/Fe] = -0.4 +/- 0.18 and +0.13 +/- 0.28). This spread supports the scenario that Wil 1 is an ultra-low luminosity dwarf galaxy rather than a star cluster. Wil 1's innermost stars move with radial velocities offset by 8 km/s from its outer stars and have a velocity dispersion consistent with 0 km/s, suggesting that Wil 1 may not be in dynamical equilibrium. The combination of the foreground contamination and unusual kinematic distribution make it difficult to robustly determine the dark matter mass of Wil 1. As a result, X-ray or gamma-ray observations of Wil 1 that attempt to constrain models of particle dark matter using an equilibrium mass model are strongly affected by the systematics in the observations presented here. We conclude that, despite the unusual features in the Wil 1 kinematic distribution, evidence indicates that this object is, or at least once was, a dwarf galaxy.Comment: AJ accepted version. The primary improvements are a detailed investigation of the membership probability (Section 3.4 and new Figures 6, 7 and 8) and the revised spectroscopic [Fe/H] and [Ca/Fe] measurements of the two brightest member stars. Conclusions are unchanged from the submitted versio

Resolving systemic financial crisis : policies and institutions

The authors analyze the role of institutions in resolving systemic banking crises for a broad sample of countries. Banking crises are fiscally costly, especially when policies like substantial liquidity support, explicit government guarantees on financial institutions’ liabilities, and forbearance from prudential regulations are used. Higher fiscal outlays do not, however, accelerate the recovery from a crisis. Better institutions—less corruption, improved law and order, legal system, and bureaucracy—do. The authors find these results to be relatively robust to estimation techniques, including controlling for the effects of a poor institutional environment on the likelihood of financial crisis and the size of fiscal costs. Their results suggest that countries should use strict policies to resolve a crisis and use the crisis as an opportunity to implement medium-term structural reforms, which will also help avoid future systemic crises.Payment Systems&Infrastructure,Labor Policies,Fiscal&Monetary Policy,Financial Crisis Management&Restructuring,Banks&Banking Reform,Financial Crisis Management&Restructuring,Governance Indicators,National Governance,Banks&Banking Reform,Economic Conditions and Volatility

A New 95 GHz Methanol Maser Catalog: I. Data

The Purple Mountain Observatory 13.7 m radio telescope has been used to search for 95 GHz (8$_0$--7$_1$A$^+$) class I methanol masers towards 1020 Bolocam Galactic Plane Survey (BGPS) sources, leading to 213 detections. We have compared the line width of the methanol and HCO$^+$ thermal emission in all of the methanol detections and on that basis we find 205 of the 213 detections are very likely to be masers. This corresponds to an overall detection rate of 95 GHz methanol masers towards our BGPS sample of 20%. Of the 205 detected masers 144 (70%) are new discoveries. Combining our results with those of previous 95 GHz methanol masers searches, a total of four hundred and eighty-one 95 GHz methanol masers are now known, we have compiled a catalog listing the locations and properties of all known 95 GHz methanol masers.Comment: 18 pages, 7 figures, 8 tables, accepted for publication in ApJ