Percolation properties of the classic Sierpinski carpet and sponge

Iterative construction of a Sierpinski carpet or sponge is regarded as a critical phenomenon analogous to uncorrelated percolation. Critical exponents are derived or calculated that are related by equations identical to those obtained from percolation theory. Finite-size scaling then gives accurate values for the conductivity of the carpet or sponge at any stage of iteration

How Much Sunlight Does it Take to Disinfect a Boardroom? A Short History of Executive Compensation Regulation

This paper reviews the history of executive compensation disclosure and other government policies affecting CEO pay, and as well surveys the literature on the effects of these policies. Disclosure has increased nearly uniformly since 1933. A number of other regulations, including special taxes on CEO pay and rules regarding votes on some pay packages have also been introduced, particularly in the last 20 years. However, there is little solid evidence that any of these policies have had any substantial impact on pay. Policy changes have likely helped drive the move towards more use of stock options, but there is no conclusive evidence on how policy has otherwise affected the level or composition of pay. I also review evidence from overseas on “Say on Pay,” recently proposed in the US, which would allow nonbinding shareholder votes on CEO compensation. The experiences of other countries have been positive, with tighter linkages between pay and performance and improved communication with investors. Mandatory say on pay would be beneficial in the US.

Semantic keyword search for expert witness discovery

In the last few years, there has been an increase in the amount of information stored in semantically enriched knowledge bases, represented in RDF format. These improve the accuracy of search results when the queries are semantically formal. However framing such queries is inappropriate for inexperience users because they require specialist knowledge of ontology and syntax. In this paper, we explore an approach that automates the process of converting a conventional keyword search into a semantically formal query in order to find an expert on a semantically enriched knowledge base. A case study on expert witness discovery for the resolution of a legal dispute is chosen as the domain of interest and a system named SKengine is implemented to illustrate the approach. As well as providing an easy user interface, our experiment shows that SKengine can retrieve expert witness information with higher precision and higher recall, compared with the other system, with the same interface, implemented by a vector model approach

The integration of grid and peer-to-peer to support scientific collaboration

There have been a number of e-Science projects which address the issues of collaboration within and between scientific communities. Most effort to date focussed on the building of the Grid infrastructure to enable the sharing of huge volume of computational and data resources. The ‘portal’ approach has been used by some to bring the power of grid computing to the desk top of individual researchers. However, collaborative activities within a scientific community are not only confined to the sharing of data or computational intensive resources. There are other forms of sharing which can be better supported by other forms of architecture. In order to provide a more holistic support to a scientific community, this paper proposes a hybrid architecture, which integrates Grid and peer-to-peer technologies using Service Oriented Architecture. This platform will then be used for a semantic architecture which captures characteristics of the data, functional and process requirements for a range of collaborative activities. A combustion chemistry research community is being used as a case study

Importance of mutual benefits in online knowledge sharing communities

The sustainability of knowledge sharing e-communities is a major issue at present. A hypothesis was proposed at the outset in the paper that the provision of mutual benefits among participants will lead to positive participation. Drawing from the economic and social theories, a framework for analysis was developed and tested in an empirical study. The preliminary results demonstrated a direct relationship between mutual benefits and the level of participation, and hence supported the hypothesis

Market response to economic policies: a stumbling block for policymakers

Rational expectations (Economic theory) ; Economic policy ; Econometric models

Enabling e-Research in combustion research community

Abstract This paper proposes an application of the Collaborative e-Science Architecture (CeSA) to enable e-Research in combustion research community. A major problem of the community is that data required for constructing modelling might already exist but scattered and improperly evaluated. That makes the collection of data for constructing models difficult and time-consuming. The decentralised P2P collaborative environment of the CeSA is well suited to solve this distributed problem. It opens up access to scattered data and turns them to valuable resources. Other issues of the community addressed here are the needs for computational resources, storages and interoperability amongst different data formats can also be addressed by the use of Grid environment in the CeSA

Why did Europe’s productivity catch-up sputter out? a tale of tigers and tortoises

This paper takes a different approach to examining the sharp turnaround in EU relative to U. S. labor productivity growth since 1995. The vast majority of the literature focuses on the American growth revival. But close to half of the turnaround was caused by a European retardation. What caused that retardation? Our paper shows that none of the consensus explanations of the American revival provide any help at all in explaining the European retardation. It is sui generis and therein lies a tale that has not previously been told. ; Europe has faltered across the board. The deceleration of its productivity growth is not explained at all by ICT production and only to a small degree by retailing/wholesaling. Rather, the big European countries have failed in nearly every dimension. The retardation of Europe is illuminated by dividing up the EU-15 countries into Tigers, a Middle group, and Tortoises. ; Our first surprise in examining the data is to find that the EU-US turnaround in labor productivity growth was not just a reflection of an equivalent turnaround in total factor productivity growth. Capital deepening also faltered in Europe, indicting all the macroeconomic determinants of economy-wide investment as part of Europe’s problem. ; The most striking aspect of our results is that the failing of the Tortoise countries is widespread, spanning industries as diverse as agriculture, wholesale trade, mining, chemicals, construction, fabricated metals, and clothing. Our explanation is that Europe’s previous catch-up to the U. S. productivity level before 1995 was artificial – by making labor expensive, Europe raised its average product. But after 1995 as labor market reforms have helped to make labor cheaper, so the average product of labor has been pushed down and its growth rate has faltered. The falling behind of Europe is quite simple to explain; European regulations defied the laws of labor market equilibrium for decades, and a slight leak in the dam holding back market forces has already led to faster growth in European employment and slower growth in productivity.

Collaborative e-science architecture for Reaction Kinetics research community

This paper presents a novel collaborative e-science architecture (CeSA) to address two challenging issues in e-science that arise from the management of heterogeneous distributed environments: (i) how to provide individual scientists an integrated environment to collaborate with each other in distributed, loosely coupled research communities where each member might be using a disparate range of tools; and (ii) how to provide easy access to a range of computationally intensive resources from a desktop. The Reaction Kinetics research community was used to capture the requirements and in the evaluation of the proposed architecture. The result demonstrated the feasibility of the approach and the potential benefits of the CeSA