Introducing Dynamic Behavior in Amalgamated Knowledge Bases

The problem of integrating knowledge from multiple and heterogeneous sources is a fundamental issue in current information systems. In order to cope with this problem, the concept of mediator has been introduced as a software component providing intermediate services, linking data resources and application programs, and making transparent the heterogeneity of the underlying systems. In designing a mediator architecture, we believe that an important aspect is the definition of a formal framework by which one is able to model integration according to a declarative style. To this purpose, the use of a logical approach seems very promising. Another important aspect is the ability to model both static integration aspects, concerning query execution, and dynamic ones, concerning data updates and their propagation among the various data sources. Unfortunately, as far as we know, no formal proposals for logically modeling mediator architectures both from a static and dynamic point of view have already been developed. In this paper, we extend the framework for amalgamated knowledge bases, presented by Subrahmanian, to deal with dynamic aspects. The language we propose is based on the Active U-Datalog language, and extends it with annotated logic and amalgamation concepts. We model the sources of information and the mediator (also called supervisor) as Active U-Datalog deductive databases, thus modeling queries, transactions, and active rules, interpreted according to the PARK semantics. By using active rules, the system can efficiently perform update propagation among different databases. The result is a logical environment, integrating active and deductive rules, to perform queries and update propagation in an heterogeneous mediated framework.Comment: Other Keywords: Deductive databases; Heterogeneous databases; Active rules; Update

Insuring Canada’s Exports: The Case for Reform at Export Development Canada

Export Development Canada competes with private companies in providing trade credit insurance. Is it time to rethink the Crown agency's mandate?trade credit insurance

Russian Financial Transition: The Development of Institutions and Markets for Growth

A well-developed financial intermediation industry increases domestic savings, efficiently allocates investment resources to the most productive uses in the economy and increases the rate of economic growth. In the Soviet economy the banking system served as a means of collecting household savings and a means of distributing centrally determined capital grants to enterprises. Banks then audited enterprise financial activities to ensure compliance to the financial plan. After a decade the transition from the Soviet banking system to a market oriented banking system is incomplete and fraught with uncertainty. While the number of financial institutions has increased dramatically, the state sector still dominates financial sector activity, the legal and regulatory framework is incomplete, information necessary for risk management is of poor quality and policy makers and regulators have been slow to act to improve intermediation services. While significant progress has been made, the commonly recognized characteristics of a sound financial system are not yet met.http://deepblue.lib.umich.edu/bitstream/2027.42/39839/3/wp455.pd

Classifications of innovations: Survey and future directions

The purpose of this paper is to focus on similarity and/or heterogeneity of taxonomies of innovation present in the economic fields to show as the economic literature uses different names to indicate the same type of technical change and innovation, and the same name for different types of innovation. This ambiguity of classification makes it impossible to compare the various studies; moreover the numerous typologies existing in the economics of innovation, technometrics, economics of technical change, management of technology, etc., have hindered the development of knowledge in these fields. The research presents also new directions on the classification of innovation that try to overcome these problems.Classifications, Taxonomy, Technical change, Product, Innovation Patterns, Management of Technology, Economics of innovation

Do UK Institutional Shareholders Monitor their Investee Firms?

As institutional investors are the largest shareholders in most listed UK firms, one expects them to monitor the firms they invest in. However, there is mounting empirical evidence which suggests that they do not perform any monitoring. This paper provides a new test on whether UK institutional investors engage in monitoring. The test consists of an event study on directors’ trades. If institutional shareholders act as monitors, their monitoring activities convey new information about a firm’s future value to other outside shareholders and reduce the informational asymmetry between the managers and the market. As a result, directors’ trades convey less information to the market, and the stock price reaction is weaker. However, our results show that institutional shareholders do not have any significant impact on the stock price reaction which stands in marked contrast with the impact that families, individuals and other firms have on stock prices.Insider trading;institutional investor monitoring;shareholder activism;corporate governance;ownership and control

Possible technological determinants and primary energy resources of future long waves

The purpose of this paper is to conjecture the possible underlying technological determinants of future long waves, based on prominent studies of scholars and leading forecasting companies; in particular, this research assumes the converging of nano-bio-info-cogno technologies to be the foundation of 5th and 6th economic cycles, whereas the future technological revolution that may underpin the 7th long wave is assumed to be Faster-Than-Light technologies. The positive effects of these future technological revolutions on worldwide economic system are a high increase of productivity, employment rate, consumption and economic growth that lead to longer, happier, and healthier living as well as general well-being.Long Waves, Technological Revolution, Forecasting, Foresight

Measuring Intersectoral Knowledge Spillovers: an Application of Sensitivity Analysis to Italy

R&D spillovers are unanimously considered as one of the main driving forces of technical change, innovation and economic growth. This paper aims at measuring inter-industrial R&D spillovers, as a useful information for policy-makers. We apply an “uncertainty-sensitivity analysis” to the Italian input-output table of intermediate goods split into 31 economic sectors for the year 2000. The value added of using this methodology is the opportunity of distinguishing (separately) between spillover effects induced by productive linkages (the Leontiev forward multipliers) and those activated by R&D investments, capturing also the uncertain and non-linear nature of the relations between spillovers and factors affecting them.R&D spillovers, Input-output models, Sensitivity analysis, Monte Carlo simulations

Market Piracy in the Design-Based Industry : Economics and Policy regulation

Market piracy in the design-based industry is an expanding worldwide phenomenon (Grossman and Shapiro, 1988a,b; Chaudhry and Walsh, 1996; Schultz II and Saprito, 1996). It deserves a great deal of attention both because of its impressive international dimension (Verma, 1996) and its intrinsic illegality, ambiguity and powerfull potential links with criminal organizations (Andreano and Sigfried, 1980; Fiorentini and Peltzman, 1995). The aim of this paper is to develop theoretical arguments about economic agents' behavior and to shed some light on the main regulatory issues of illegal markets. At a first sight the room for rational incentives to commercial piracy is self-evident. On one hand, an original backpack by the Italian stylist Prada costs, for instance, $510 in Manhattan, New York, and a bootleg copy costs$ 70 in Rome, just in front of Castel Sant'Angelo. On the other hand, the number of units sold can be impressive: as an example Louis Vuitton sells 3.5 millions units per year. Market piracy is usually noticed in sectors such as luxury goods or fashion, but piracy can also be observed in more traditional sectors such as car manufacturers, "bureautic" industry, cooking utensils, aircraft-parts and so on.

Costs and Technology of Public Transit Systems in Italy:Some Insights to Face Inefficiency

This study provides fresh evidence about the characteristics of technology and cost structure of public transit systems in Italy. The aim is to suggest useful guidelines for facing detected inefficiencies. The analysis is carried out through the estimation of a translog variable cost function. The sample includes 45 Italian public companies. Firms are observed in the years 1996, 1997 and 1998, and operate both in the urban and extra-urban compartments. Results support previous evidence on the existence of natural monopoly at local level and stress the importance of the average speed of vehicles in explaining cost differences between companies. We conclude that cost benefits can be achieved by promoting mergers between firms (whenever possible), introducing some forms of "competition-for-the-market" (e.g., competitive tendering for the single license) and taking more care of the local traffic regulation.