11,801 research outputs found

    Free-libre open source software as a public policy choice

    Get PDF
    Free Libre Open Source Software (FLOSS) is characterised by a specific programming and development paradigm. The availability and freedom of use of source code are at the core of this paradigm, and are the prerequisites for FLOSS features. Unfortunately, the fundamental role of code is often ignored among those who decide the software purchases for Canadian public agencies. Source code availability and the connected freedoms are often seen as unrelated and accidental aspects, and the only real advantage acknowledged, which is the absence of royalty fees, becomes paramount. In this paper we discuss some relevant legal issues and explain why public administrations should choose FLOSS for their technological infrastructure. We also present the results of a survey regarding the penetration and awareness of FLOSS usage into the Government of Canada. The data demonstrates that the Government of Canada shows no enforced policy regarding the implementation of a specific technological framework (which has legal, economic, business, and ethical repercussions) in their departments and agencies

    Deep pockets, packets, and harbours

    Get PDF
    Deep Packet Inspection (DPI) is a set of methodologies used for the analysis of data flow over the Internet. It is the intention of this paper to describe technical details of this issue and to show that by using DPI technologies it is possible to understand the content of Transmission Control Protocol/Internet Protocol communications. This communications can carry public available content, private users information, legitimate copyrighted works, as well as infringing copyrighted works. Legislation in many jurisdictions regarding Internet service providers’ liability, or more generally the liability of communication intermediaries, usually contains “safe harbour” provisions. The World Intellectual Property Organization Copyright Treaty of 1996 has a short but significant provision excluding liability for suppliers of physical facilities. The provision is aimed at communication to the public and the facilitation of physical means. Its extensive interpretation to cases of contributory or vicarious liability, in absence of specific national implementation, can prove problematic. Two of the most relevant legislative interventions in the field, the Digital Millennium Copyright Act and the European Directive on Electronic Commerce, regulate extensively the field of intermediary liability. This paper looks at the relationship between existing packet inspection technologies, especially the ‘deep version,’ and the international and national legal and regulatory interventions connected with intellectual property protection and with the correlated liabilities ‘exemptions. In analyzing the referred two main statutes, we will take a comparative look at similar interventions in Australia and Canada that can offer some interesting elements of reflection

    The Miura Map on the Line

    Full text link
    The Miura map (introduced by Miura) is a nonlinear map between function spaces which transforms smooth solutions of the modified Korteweg - de Vries equation (mKdV) to solutions of the Korteweg - de Vries equation (KdV). In this paper we study relations between the Miura map and Schroedinger operators with real-valued distributional potentials (possibly not decaying at infinity) from various spaces. We also investigate mapping properties of the Miura map in these spaces. As an application we prove existence of solutions of the Korteweg - de Vries equation in the negative Sobolev space H^{-1} for the initial data in the range of the Miura map.Comment: 33 page

    Shanghai, Dubai, Mumbai Or Goodbye?

    Get PDF
    Starting in 2007, Sovereign Wealth Funds (SWFs) from Asia and the Middle East have invested billions of dollars in major U.S. financial firms. The primary driving force behind their growth is rising commodity prices, in particular oil. Given that SWFs represent a relatively new, cash-rich investment group, we studied the public policy concerns with their investments, SWFs mode of entry, and how does the market react to the investment. SWFs lack of transparency with regards to their investment motives and governance structure is cause for concern. While taking full opportunity of depressed security prices as a result of the 2007-2008 financial crisis, they are also being prudent by investing mostly in preferred stocks and fixed-income convertible securities of large U.S. corporations that are followed by many analysts and are highly liquid. Despite investing handsomely in U.S. targets and adopting a hands-off approach toward management; the liquidity crisis continues to perpetuate the decline in SWF-targets’ stock price post-investment. Using an event study parameter approach, we found the short-run market reaction to be statistically insignificant in 11 out of 12 announcements of SWF investments; but in the months following the investment, SWF-targets underperform both the S&P500 and the Dow Jones Financial Services Index Fund.Stock Market, Sovereign Wealth Funds (SWFs), SWF-targets’ stock price post-investment

    Wind Damage in Maine Forests: Trends and Vulnerability Assessment

    Get PDF
    The likelihood of windthrow or windsnap occurring in a forest stand includes numerous factors; however, past research suggests that these factors can be grouped into four broad categories: regional climate, topographic exposure, soil properties and stand characteristics (Mitchell, 1995). Of the three categories, stand characteristics are most commonly and easily modified through forest management. Vulnerability to wind damage in Maine may increase in the future because of three trends influencing stand conditions. One, Maine forests contain a considerable amount of balsam fir and red spruce, tree species that are considered particularly susceptible to wind damage. Two, extensive areas regenerated after the 1970\u27s and 1980\u27s era spruce budworm outbreak are maturing. Three, partial removals currently account for over 74 percent of the area harvested annually in the state (McWilliams et al. 2005). Two approaches to augment our understanding of the interaction between forest management and wind damage vulnerability in Maine forests were developed The first approach combined information from the base of scientific wind disturbance literature with more localized information from Maine\u27s forest resource managers. Forest resource professionals were surveyed through phone calls and professional meetings to gather information about wind damage over their careers. The second approach developed a general vulnerability to wind damage model that reflects topographic exposure (distance limited TOPEX (Ruel et al. 1997), restricted rooting depth, elevation, and stand characteristics (height, density, edge, treatment history, and species composition). Results of the first approach reveal serious limitations in information about wind damage statewide. However, numerous patterns and trends were identified. Damage differs by storm type and storms impact the state on a continuum of storm intensity, frequency, and scale. Numerous factors influence the damage potential of these wind events on forests. These factors include topographic exposure, soil conditions and stand characteristics. Damaging storms appear to originate from the southwest most frequently and impact softwoods more severely than hardwoods. Frequent low-intensity winds tend to eliminate softwoods from hardwood dominated stands. The general vulnerability to wind damage model is based on Mitchell\u27s (1998) conceptual windthrow triangle and is built from eight component variables describing stand, soil, and topographic characteristics. The model is built and calibrated from composite variables which combine the component variables into distinct site and stand components. The model was tested on a 40,800 hectare forest area in northern Maine with spatially explicit wind damage records. To avoid problems with spatial autocorrelation ten random samples were drawn from the study area and evaluated individually with a Mann-Whitney non-parametric comparison of means test (alpha 0.05). Results from the ten samples were pooled, and a one sample comparison of means t-test was used to analyze the consistency of the results from the ten individual samples (alpha 0.05). The final model identifies significant and consistent differences between damaged and undamaged areas (p-value 0.000). When evaluated individually, not all model components were significantly different (e.g., density, edge, exposure and species composition). Variables describing thinning, stand height, and elevation had the greatest differences between means of the populations of damaged and undamaged stands in the study area. The general model developed proved useful on the study area and by design should be transferable to diverse regions throughout the state

    Flutter suppression control law synthesis for the Active Flexible Wing model

    Get PDF
    The Active Flexible Wing Project is a collaborative effort between the NASA Langley Research Center and Rockwell International. The objectives are the validation of methodologies associated with mathematical modeling, flutter suppression control law development and digital implementation of the control system for application to flexible aircraft. A flutter suppression control law synthesis for this project is described. The state-space mathematical model used for the synthesis included ten flexible modes, four control surface modes and rational function approximation of the doublet-lattice unsteady aerodynamics. The design steps involved developing the full-order optimal control laws, reducing the order of the control law, and optimizing the reduced-order control law in both the continuous and the discrete domains to minimize stochastic response. System robustness was improved using singular value constraints. An 8th order robust control law was designed to increase the symmetric flutter dynamic pressure by 100 percent. Preliminary results are provided and experiences gained are discussed
    • 

    corecore