Cost-Aware Green Cellular Networks with Energy and Communication Cooperation

Energy cost of cellular networks is ever-increasing to match the surge of wireless data traffic, and the saving of this cost is important to reduce the operational expenditure (OPEX) of wireless operators in future. The recent advancements of renewable energy integration and two-way energy flow in smart grid provide potential new solutions to save the cost. However, they also impose challenges, especially on how to use the stochastically and spatially distributed renewable energy harvested at cellular base stations (BSs) to reliably supply time- and space-varying wireless traffic over cellular networks. To overcome these challenges, in this article we present three approaches, namely, {\emph{energy cooperation, communication cooperation, and joint energy and communication cooperation}}, in which different BSs bidirectionally trade or share energy via the aggregator in smart grid, and/or share wireless resources and shift loads with each other to reduce the total energy cost.Comment: Submitted for possible publicatio

The discourse of disease : the representation of SARS - the China daily and the South China Morning Post

This thesis is a case study on newspaper discourse representation of SARS. The study uses two representative English newspapers in Asia – the China Daily (“CD”) and the South China Morning Post (“SCMP”). By comparing the discursive construction of the same event – the outbreak of SARS - in the two newspapers, it aims to reveal that the practice of news follows institutional, cultural and political assumptions, and also make visible the two newspapers’ embedded attitudes and ideological positions. The methodology is a critical corpus linguistics (CCL) approach, especially using KWIC format (Key Word in context), word frequency, collocation, and concordance data, which is analyzed according to transitivity systems of systemic functional grammar (SFG). The main approach of the study is achieved by a computer-assisted corpus analysis with the help of software “Wordsmith 3.0” (on line version). Results indicate that through the comparison of the newspapers’ corpora, there are statistically significant differences between the two newspapers’ word patterns. First, in the context of SARS, the CD corpus and the SCMP corpus shows different word choice and words frequency in occupying disease-relevant and human-relevant words. Second, when SARS is situated as the node word, the collocation results discuss the observation that the CD tends to treat the SARS epidemic from a national struggle perspective, while the standpoint of the SCMP is more based on the human health and safety, and its social role as the fourth estate. Moreover, the collocation of the three selected keywords is summarized for finding out the general patterns of their concordance lines. Third, according to further concordancing analysis, the study investigates to what extent critical corpus linguistics and transitivity systems of systemic functional grammar can be mutually reinforced and interpreted within the disease discourse context, textually, culturally and ideologically. In particular, a power hierarchy model is established and used in the transitivity analysis. Results show that the two selected newspapers discursively constructed the SARS-issue in a different way, and these differences help to understand how the ideologies work in both newspapers

Computing the elliptic genus of higher rank E-strings from genus 0 GW invariants

We show that the elliptic genus of the higher rank E-strings can be computed based solely on the genus 0 Gromov-Witten invariants of the corresponding elliptic geometry. To set up our computation, we study the structure of the topological string free energy on elliptically fibered Calabi-Yau manifolds both in the unrefined and the refined case, determining the maximal amount of the modular structure of the partition function that can be salvaged. In the case of fibrations exhibiting only isolated fibral curves, we show that the principal parts of the topological string partition function at given base-wrapping can be computed from the knowledge of the genus 0 Gromov-Witten invariants at this base-wrapping, and the partition function at lower base-wrappings. For the class of geometries leading to the higher rank E-strings, this leads to the result stated in the opening sentence.Comment: 40 page