754 research outputs found
Options for International Financing of Climate Change Mitigation in Developing Countries
This paper provides a model-based analysis of the potential macro-economic impacts of different options for international financing of climate change mitigation in developing countries. The model used is the multi-region and multi-sector climate change version of the WorldScan model. Following the outcome of the UNFCCC conference in Copenhagen, it makes no specific assumptions about the future international climate regime. The analysis shows that the environmental prospects systematically improve in a transition from the Clean Development Mechanism projects towards a global carbon market, while the opposite is foreseen for the economic costs. The more of a carbon market we have when moving from the project-based CDM to sectoral crediting mechanisms and internationally linked cap-and-trade, the more finance the carbon market will channel to developing countries.european union eu annex I non-annex I climate conference in Copenhagen climate change mitigation clean development mechanism emission trading system the US brazil china india own participation of developing countries sectoral crediting mechanisms hayden Veenendaal Zarnic
The Erpenbeck high frequency instability theorem for ZND detonations
The rigorous study of spectral stability for strong detonations was begun by
J.J. Erpenbeck in [Er1]. Working with the Zeldovitch-von Neumann-D\"oring (ZND)
model, which assumes a finite reaction rate but ignores effects like viscosity
corresponding to second order derivatives, he used a normal mode analysis to
define a stability function V(\tau,\eps) whose zeros in
correspond to multidimensional perturbations of a steady detonation profile
that grow exponentially in time. Later in a remarkable paper [Er3] he provided
strong evidence, by a combination of formal and rigorous arguments, that for
certain classes of steady ZND profiles, unstable zeros of exist for
perturbations of sufficiently large transverse wavenumber \eps, even when the
von Neumann shock, regarded as a gas dynamical shock, is uniformly stable in
the sense defined (nearly twenty years later) by Majda. In spite of a great
deal of later numerical work devoted to computing the zeros of V(\tau,\eps),
the paper \cite{Er3} remains the only work we know of that presents a detailed
and convincing theoretical argument for detecting them.
The analysis in [Er3] points the way toward, but does not constitute, a
mathematical proof that such unstable zeros exist. In this paper we identify
the mathematical issues left unresolved in [Er3] and provide proofs, together
with certain simplifications and extensions, of the main conclusions about
stability and instability of detonations contained in that paper.
The main mathematical problem, and our principal focus here, is to determine
the precise asymptotic behavior as \eps\to \infty of solutions to a linear
system of ODEs in , depending on \eps and a complex frequency as
parameters, with turning points on the half-line
Ages on weathered Plio-Pleistocene tephra sequences, western North Island, New Zealand
Using the zircon fission-track method, we have obtained five ages on members of two strongly-weathered silicic, Pliocene-Pleistocene tephra sequences, the Kauroa and Hamilton Ash formations, in western North Island, New Zealand. These are the first numerical ages to be obtained directly on these deposits. Of the Kauroa Ash sequence, member K1 (basal unit) was dated at 2.24 ± 0.29 Ma, confirming a previous age of c. 2.25 Ma obtained (via tephrochronology)from K/Ar ages on associated basalt lava. Members K2 and K3 gave indistinguishable ages between 1.68 ± 0.12 and 1.43 ± 0.17 Ma. Member K12, a correlative of Oparau Tephra and probably also Ongatiti Ignimbrite, was dated at 1.28 ± 0.11 Ma, consistent with an age of 1.23 ± 0.02 Ma obtained by various methods on Ongatiti Ignimbrite. Palaeomagnetic measurements indicated that members K13 to K15 (top unit, Waiterimu Ash) are aged between c. 1.2 Ma and 0.78 Ma. Possible sources of the Kauroa Ash Formation include younger volcanic centres in the southern Coromandel Volcanic Zone or older volcanic centres in the Taupo Volcanic Zone, or both. Of the Hamilton Ash sequence, the basal member Ohinewai Ash (HI) was dated at 0.38 ± 0.04 Ma. This age matches those obtained by various methods on Rangitawa Tephra of 0.34-0.35 Ma, supporting correlation with this Whakamaru-caldera derived deposit. The origin of the other Hamilton Ash beds is unknown but various younger volcanic centres in the Taupo Volcanic Zone are possible sources. The topmost member, Tikotiko Ash (H6-H7), is estimated to be aged between c. 0.18 and 0.08 Ma. Various silicic pyroclastic deposits documented in North Island and in marine cores may be co-eval with members of the Kauroa Ash and Hamilton Ash sequences on the basis of their age
Understanding Digital Inequality
Digital inequality is one of the most critical issues in the knowledge economy. Governments, businesses, and the public have devoted tremendous resources to address such inequality, yet the results are inconclusive. Theoretical understanding, complemented with theory-based empirical assessment of the phenomenon, is essential to inform effective policy-making and intervention. The context of our investigation is a city government project known as the LaGrange Internet TV initiative that allowed all city residents to access the Internet via their cable TVs at no additional cost. We examine the residents’ acceptance behavior through the lens of the theory of planned behavior (TPB), which focuses on attitudes, subjective norms, and perceived behavioral control, as explanatory variables of innovation decisions. The theoretical focus of TPB is expanded to include exposure to innovation. Furthermore, we elaborate potential behavioral differences between privileged and underprivileged adopters. The results of the multigroup analysis reveal different behavioral models between the two groups. Enjoyment and confidence in using information and communication technologies (ICT) and accessibility are more influential in shaping ICT innovation decisions for the underprivileged than the privileged. The privileged group has a higher tendency to respond to exposure to innovation and may adopt ICT faster than the underprivileged. Implications are discussed for policy-making and theoretical development
Addressing Digital Inequality for the Socio-economically Disadvantaged through Government Initiatives: Forms for Capital that Affect ICT Utilization
Digital inequality, or unequal access to and use of information and communication technologies (ICT), is a severe problem preventing the socio-economically disadvantaged from participating in a digital society. To understand the critical resources that contribute to digital inequality and to inform public policy for stimulating initial and continued ICT usage by the socio-economically disadvantaged, we drew on capital theories and conducted a field study to investigate: (1) the forms of capital for utilizing ICT and how they differ across potential adopters who are socio-economically disadvantaged (SED) and socio-economically advantaged (SEA); (2) how these forms of capitals are relatively impacted for the SEA and the SED through public policy for ICT access; and (3) how each form of capital influences the SED’s intentions to use initially and to continue to use ICT. The context for our study involved a city in the southeastern United States that offered its citizens free ICT access for Internet connectivity. Our results show that SED potential adopters exhibited lower cultural capital but higher social capital relative to the SEA. Moreover, the SED who participated in the city’s initiative realized greater positive gains in cultural capital, social capital, and habitus than the SEA. In addition, we find that the SED’s initial intention to use ICT was influenced by intrinsic motivation for habitus, self-efficacy for cultural capital, and both important referents’ expectations and support from acquaintances for social capital. Cultural capital and social cultural capital also complemented each other in driving the SED’s initial use intention. The SED’s continued use intention was affected by both intrinsic and extrinsic motivations for habitus and both knowledge and self-efficacy for cultural capital but was not affected by social capital. We also make several recommendations for future research on digital inequality and ICT acceptance to extend and apply the proposed capital framework
Understanding Digital Inequality: Comparing Continued Use Behavioral Models of the Socio-economically Advantaged and Disadvantaged
Digital inequality is one of the most critical issues in the knowledge economy. The private and public sectors have devoted tremendous resources to address such inequality, yet the results are inconclusive. Theoretically grounded empirical research is needed both to expand our understanding of digital inequality and to inform effective policy making and intervention. The context of our investigation is a city government project, known as the LaGrange Internet TV initiative, which allowed all city residents to access the Internet via their cable televisions at no additional cost. We examine the residents’ post-implementation continued use intentions through a decomposed theory of planned behavior perspective, which is elaborated to include personal network exposure. Differences in the behavioral models between socio-economically advantaged and disadvantaged users who have direct usage experience are theorized and empirically tested. The results reveal distinct behavioral models and isolate the key factors that differentially impact the two groups. The advantaged group has a higher tendency to respond to personal network exposure. Enjoyment and confidence in using information and communication technologies, availability, and perceived behavioral control are more powerful in shaping continued ICT use intention for the disadvantaged. Implications for research and practice are discussed
Leverage Points for Addressing Digital Inequalities: Comparing Under-Privileged Adopters and Non-Adopters of High Speed Internet TV
Digital inequality, or the unequal access and use of information communication technologies, inhibits under-privileged people from opportunities in the digital world. Although government and private organizations have devoted considerable resources to address this inequality, issues remain unsolved. A theory-based investigation of the phenomenon is essential for effective policy-making and intervention. The context of the field study is the “Free Internet TV” initiative in LaGrange, Georgia, which provided high-speed Internet to every household via cable at no cost. This research investigates underprivileged residents’ innovation behavior through the lens of Theory of Planned Behavior (TPB). Exposure to Innovation and Trust in Government are included to elaborate the theoretical focus of TPB. The research compares the models that characterize under-privileged adopters and non-adopters’ innovation decisions. The results advance the theoretical understanding of digital inequality, enrich the knowledge of adoption of innovation, and identify leverage points for policymakers devising interventions to address the inequality
Static, Lightweight Includes Resolution for PHP
Dynamic languages include a number of features that are challenging to model properly in static analysis tools. In PHP, one of these features is the include expression, where an arbitrary expression provides the path of the file to include at runtime. In this paper we present two complementary analyses for statically resolving PHP includes, one that works at the level of individual PHP files and one targeting PHP programs, possibly consisting of multiple scripts. To evaluate the effectiveness of these analyses we have applied the first to a corpus of 20 open-source systems, totaling more than 4.5 million lines of PHP, and the second to a number of programs from a subset of these systems. Our results show that, in many cases, includes can be either resolved to a specific file or a small subset of possible files, enabling better IDE features and more advanced program analysis tools for PHP
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