Accessible Capacity of Secondary Users

A new problem formulation is presented for the Gaussian interference channels (GIFC) with two pairs of users, which are distinguished as primary users and secondary users, respectively. The primary users employ a pair of encoder and decoder that were originally designed to satisfy a given error performance requirement under the assumption that no interference exists from other users. In the scenario when the secondary users attempt to access the same medium, we are interested in the maximum transmission rate (defined as {\em accessible capacity}) at which secondary users can communicate reliably without affecting the error performance requirement by the primary users under the constraint that the primary encoder (not the decoder) is kept unchanged. By modeling the primary encoder as a generalized trellis code (GTC), we are then able to treat the secondary link and the cross link from the secondary transmitter to the primary receiver as finite state channels (FSCs). Based on this, upper and lower bounds on the accessible capacity are derived. The impact of the error performance requirement by the primary users on the accessible capacity is analyzed by using the concept of interference margin. In the case of non-trivial interference margin, the secondary message is split into common and private parts and then encoded by superposition coding, which delivers a lower bound on the accessible capacity. For some special cases, these bounds can be computed numerically by using the BCJR algorithm. Numerical results are also provided to gain insight into the impacts of the GTC and the error performance requirement on the accessible capacity.Comment: 42 pages, 12 figures, 2 tables; Submitted to IEEE Transactions on Information Theory on December, 2010, Revised on November, 201

Newsgroups Float Into Safe Harbor, and Copyright Holders Are Sunk

Usenet newsgroups are swiftly becoming a popular vehicle for pirating digital music, movies, books, and other copyrighted works. Meanwhile, courts ignore Usenet’s tremendous potential for copyright infringement. In Ellison v. Robertson, the Ninth Circuit Court of Appeals found that America Online’s Usenet service might qualify for safe harbor under the Digital Millennium Copyright Act. According to the district court below, safe harbor would preclude a finding of secondary copyright infringement against America Online. However, the courts misinterpreted the safe harbor provisions. One safe harbor provision was misapplied and another was ignored altogether. This iBrief critiques the Ellison opinions and analyzes the application of the safe harbor provisions to Usenet operators

Healthcare professionals' perspectives on mental health service provision : a pilot focus group study in six European countries

Background: The mental healthcare treatment gap (mhcGAP) in adult populations has been substantiated across Europe. This study formed part of MentALLY, a research project funded by the European Commission, which aimed to gather qualitative empirical evidence to support the provision of European mental healthcare that provides effective treatment to all adults who need it. Methods: Seven focus groups were conducted with 49 health professionals (HPs), including psychologists, psychiatrists, social workers, general practitioners, and psychiatric nurses who worked in health services in Belgium, Cyprus, Greece, the Netherlands, Norway and Sweden. The focus group discussions centered on the barriers and facilitators to providing quality care to people with mild, medium, and severe mental health problems. Analyses included deductively and inductively driven coding procedures. Cross-country consensus was obtained by summarizing findings in the form of a fact sheet which was shared for triangulation by all the MentALLY partners. Results: The results converged into two overarching themes: (1) Minding the treatment gap: the availability and accessibility of Mental Health Services (MHS). The mhcGAP gap identified is composed of different elements that constitute the barriers to care, including bridging divides in care provision, obstacles in facilitating access via referrals and creating a collaborative 'chain of care'. (2) Making therapeutic practice relevant by providing a broad-spectrum of integrated and comprehensive services that value person-centered care comprised of authenticity, flexibility and congruence. Conclusions: The mhcGAP is comprised of the following barriers: a lack of funding, insufficient capacity of human resources, inaccessibility to comprehensive services and a lack of availability of relevant treatments. The facilitators to the provision of MHC include using collaborative models of primary, secondary and prevention-oriented mental healthcare. Teamwork in providing care was considered to be a more effective and efficient use of resources. HPs believe that the use of e-mental health and emerging digital technologies can enhance care provision. Facilitating access to a relevant continuum of community-based care that is responsive coordinated and in line with people's needs throughout their lives is an essential aspect of optimal care provision

Report to the Childhood Development Initiative on Archiving of C.D.I. Data

This report presents the ethical and legal issues involved in depositing data-sets of research for secondary use in Ireland

The impact of broadband in schools

The report reviews evidence for the impact of broadband in English schools, exploring; Variations in provision in level of broadband connectivity; Links between the level of broadband activity and nationally accessible performance data; Aspects of broadband connectivity and the school environment that contribute to better outcomes for pupils and teachers; Academic and motivational benefits associated with educational uses of this technology

InfoInternet for Education in the Global South: A Study of Applications Enabled by Free Information-only Internet Access in Technologically Disadvantaged Areas (authors' version)

This paper summarises our work on studying educational applications enabled by the introduction of a new information layer called InfoInternet. This is an initiative to facilitate affordable access to internet based information in communities with network scarcity or economic problems from the Global South. InfoInternet develops both networking solutions as well as business and social models, together with actors like mobile operators and government organisations. In this paper we identify and describe characteristics of educational applications, their specific users, and learning environment. We are interested in applications that make the adoption of Internet faster, cheaper, and wider in such communities. When developing new applications (or adopting existing ones) for such constrained environments, this work acts as initial guidelines prior to field studies.Comment: 16 pages, 1 figure, under review for a journal since March 201

Unlocking the Treasure Chest of Labor Market Information: Crucial Information for Job Seekers, Educators, and Employers in a Tough Economy

Quality labor market data and analysis is critical to developing effective market-driven workforce and economic strategies in states, regions, and localities. Such information can be complex, intimidating, and overwhelming to many users, however. This issue brief offers a framework for understanding workforce information, including a summary of the different types of consumers of information and their need for comprehensive data and analysis about the labor market. It identifies the publicly available information sources that produce the data and provides suggestions on how to identify and address the gaps between user needs and the availability of reliable and timely data and analytical capacity to enable effective and informed decision-making by data consumers. Finally, it recommends ways in which states and local areas can make workforce information more readily available to consumers who must make important decisions