M-grid: Using Ubiquitous Web Technologies to create a Computational Grid

There are many potential users and uses for grid computing. However, the concept of sharing computing resources excites security concerns and, whilst being powerful and flexible, at least for novices, existing systems are complex to install and use. Together these represent a significant barrier to potential users who are interested to see what grid computing can do. This paper describes m-grid, a system for building a computational grid which can accept tasks from any user with access to a web browser and distribute them to almost any machine with access to the internet and manages to do this without the installation of additional software or interfering with existing security arrangements

AN ECONOMIC ANALYSIS OF THE EMISSION REDUCTION MARKET SYSTEM IN CHICAGO

A mixed-integer programming model is used to investigate economic impacts of the permit trading market in Chicago and determine the equilibrium price. Unlike previous studies, the model determines unit pollution abatement cost endogenously depending on firms' technology adoption decisions. A sequential trading process is used to simulate firms' behavior under incomplete information. The results show that average shadow prices, a counterpart of conventional shadow prices in discrete problems, slightly underestimate the equilibrium prices. Moreover, the model predicts an over-supply of permits for the first two trading seasons.mixed-integer programming, ERMS, average shadow price, pollution permit, Environmental Economics and Policy,

Adaptive Filters Revisited - RFI Mitigation in pulsar observations

Pulsar detection and timing experiments are applications where adaptive filters seem eminently suitable tools for radio-frequency-interference (RFI) mitigation. We describe a novel variant which works well in field trials of pulsar observations centred on an observing frequency of 675 MHz, a bandwidth of 64 MHz and with 2-bit sampling. Adaptive filters have generally received bad press for RFI mitigation in radio astronomical observations with their most serious drawback being a spectral echo of the RFI embedded in the filtered signals. Pulsar observations are intrinsically less sensitive to this as they operate in the (pulsar period) time domain. The field trials have allowed us to identify those issues which limit the effectiveness of the adaptive filter. We conclude that adaptive filters can significantly improve pulsar observations in the presence of RFI.Comment: Accepted for publication in Radio Scienc

Greening Historic DC: Challenges and Opportunities to Incorporate Historic Preservation into the District\u27s Drive for Sustainable Development

This paper focuses primarily on the District of Columbia, a city with a robust past and a bold agenda for a sustainable future. However, it may not be obvious why historic preservation - a movement typically concerned with aesthetics - can play an integral role in a city\u27s sustainability initiative. Therefore, this paper first sets forth the basic argument why historic preservation can be a tool to promote sustainable development. Part II examines the scientific data indicating that historic preservation is a green building practice. Next, Part III posits that investment in historic districts is an investment in sustainability. Then, Part IV gives an overview of the recent efforts by the National Trust for Historic Preservation to bolster this argument, including the National Trust\u27s collaboration with the U.S. Green Building Council, which has yielded significant changes to the LEED rating system. The remainder of this paper focuses on the efforts of the District. This paper identifies challenges and opportunities for the city\u27s historic preservation program as the city commits to a sustainable future

Time-resolved photometric and spectroscopic analysis of a luminous Ap star HD103498

We present the results on the photometric and spectroscopic monitoring of a luminous Ap star HD103498. The time-series photometric observations were carried out on 17 nights using three-channel fast photometer attached to the 1.04-m optical telescope at ARIES, Nainital. The photometric data of five nights of year 2007 show clear signature of 15-min periodicity. However, the follow-up observations during 2007--2009 could not repeated any such periodicity. To confirm the photometric light variations, the time-series spectroscopic observations were carried out with the 2.56-m Nordic Optical Telescope (NOT) at La Palma on February 2, 2009. Any radial velocity variations were absent in this data set which is in full agreement with the photometric observations taken near the same night. Model atmosphere and abundance analysis of HD103498 show that the star is evolved from the Main Sequence and its atmospheric abundances are similar to two other evolved Ap stars HD133792 and HD204411: large overabundances of Si, Cr, and Fe and moderate overabundances of the rare-earth elements. These chemical properties and a higher effective temperature distinguish HD103498 from any known roAp star.Comment: 8 Figures, 2 Tables, 9 Pages, Accepted for publication in MNRA

The Use of Hosted Enterprise Applications by SMEs: A User Perspective

This paper seeks to deepen our understanding of the engagement of small to medium-sized enterprises (SMEs) in hosted enterprise applications (high complexity e-business applications) in the UK by investigating the relevance of organisational and technical factors through conducting interviews with SME users of hosted applications. The emergence and development of the application service provider (ASP) sector has attracted much interest and highly optimistic forecasts for revenues. Of particular interest in this paper is the emergence of service offerings targeted specifically at SMEs. The paper starts by considering information technology (IT) adoption by SMEs in general before reviewing the provision of hosted enterprise applications in the US and UK. The empirical data collected from SME users of hosted enterprise applications is then analysed in order to produce the key findings and conclusions. From an SME user perspective the key findings to emerge from the study include: i) confirmation that ICT infrastructure was no longer a barrier to adoption, ii) the pragmatic approach taken to security issues, iii) the use of both multiple information systems (hosted and resident) and service providers, iv) the attractiveness of the rental cost model and v) the intention to continue or extend their use of hosted applications within the enterprise. The early promise of the ASP sector appears not to have been generally realised for SMEs in the UK. This study explores the experience of early adopters of this new IT related innovation and identifies some significant business gains experienced by SME users. It also highlights the opportunity for gaining competitive advantage by using hosted enterprise applications to reduce costs. There are very few empirical studies of hosted applications which take a deliberately SME user perspective and this paper make an important contribution in this emerging field

The Use of Hosted Enterprise Applications by SMEs: A Dual Market and User Perspective

YesThis deliberately dual perspective paper seeks to deepen our understanding of the engagement of SMEs in hosted enterprise applications in the UK. The emergence and development of the ASP sector has attracted much interest and highly optimistic forecasts for revenues. The paper starts by considering ICT adoption by SMEs in general before reviewing the provision of hosted enterprise applications in the US and UK (market perspective). The study is extended by qualitative empirical data collected by semi-structured interviews with SME users of hosted enterprise applications (user perspective) and subsequent analysis in order to develop the key findings and conclusions. From an SME user perspective the key findings to emerge from the study include: i) confirmation that ICT infrastructure was no longer a barrier to adoption, ii) the pragmatic approach taken to security issues, iii) the use of both multiple information systems and multiple service providers, iv) the financial attractiveness of the rental model and v) the intention to continue or extend the use of hosted applications. It also highlights the opportunity for gaining competitive advantage by using hosted enterprise applications to reduce costs. There are very few empirical studies of hosted applications which take deliberately market and SME user perspectives - this paper makes an important contribution in this emerging field