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