1,264 research outputs found
Best Practices for Disaster Coverage: an Analysis of How the Herald Newspaper and WLOX-TV Covered Hurricane Katrina
A substantial amount of research has been done on Hurricane Katrina and its effects on New Orleans, Louisiana. However, few studies have focused on how the Mississippi Gulf Coast was affected by the hurricane. The purpose of this study is to bring attention to the reporting efforts of WLOX-TV and The Herald newspaper to cover Hurricane Katrina. This case study analyzes the practices WLOX and The Herald used to cover the hurricane and to explore which practices could be implemented in other newsrooms in the future. A total of four interviews were conducted with members from the newsrooms who had major roles in the hurricane coverage. The individuals who were intervieprovided first-hand accounts of the practices used to cover the hurricane. The data revealed that both newsrooms implemented storm plans, which helped tremendously in covering the news in the days and weeks following the hurricane
Complementary Symmetry Nanowire Logic Circuits: Experimental Demonstrations and in Silico Optimizations
Complementary symmetry (CS) Boolean logic utilizes both p- and n-type field-effect transistors (FETs) so that an input logic voltage signal will turn one or more p- or n-type FETs on, while turning an equal number of n- or p-type FETs off. The voltage powering the circuit is prevented from having a direct pathway to ground, making the circuit energy efficient. CS circuits are thus attractive for nanowire logic, although they are challenging to implement. CS logic requires a relatively large number of FETs per logic gate, the output logic levels must be fully restored to the input logic voltage level, and the logic gates must exhibit high gain and robust noise margins. We report on CS logic circuits constructed from arrays of 16 nm wide silicon nanowires. Gates up to a complexity of an XOR gate (6 p-FETs and 6 n-FETs) containing multiple nanowires per transistor exhibit signal restoration and can drive other logic gates, implying that large scale logic can be implemented using nanowires. In silico modeling of CS inverters, using experimentally derived look-up tables of individual FET properties, is utilized to provide feedback for optimizing the device fabrication process. Based upon this feedback, CS inverters with a gain approaching 50 and robust noise margins are demonstrated. Single nanowire-based logic gates are also demonstrated, but are found to exhibit significant device-to-device fluctuations
Silicon p-FETs from Ultrahigh Density Nanowire Arrays
Statistical numbers of field-effect transistors (FETs) were fabricated from a circuit of 17-nm-wide, 34-nm-pitch Si nanowires boron doped at a level of 10^(18) cm^(-3). Top-gated 4-μm-wide Si nanowire p-FETs yielded low off-currents (∼10^(-12) A), high on/off ratios (10^5−10^6), good on current values (30 μA/μm), high mobilities (∼100 cm^2/V−s), and low subthreshold swing values (∼80 mV/decade between 10^(-12) and 10^(-10) A increasing to 200 mV/decade between 10^(-10)−10^(-8) A)
A bottom-up definition of self-sufficiency: Voices from low-income jobseekers.
Self-sufficiency (SS) is the epitome of America’s ‘reluctant’welfare state. It is generally accepted in social welfare policycircles as a concept related to independence and financialstability. Nevertheless, SS is not a term agreed upon inpractice by policymakers, researchers, or service providersand is frequently used without a clear common definition.In this sense, the purpose of this study is to explore the extentto which the top-down definition of ‘economic’ SS as thesocial policy goal is consistent with how the clients of job training programs perceive the term. Using a groundedtheory approach, a bottom-up definition of SS was derivedfrom a focus group of low-income jobseekers. The focusgroup was transcribed for a content analysis from which a client-centered definition of SS was drawn. Findings suggestthat SS is a process of developing psychological strength properties and a goal-oriented progression toward realistic financial outcomes.Implications for evidence-based community interventions for client empowerment and workforce development are suggested
Spiers Memorial Lecture: Molecular mechanics and molecular electronics
We describe our research into building integrated molecular electronics circuitry for a diverse set of functions, and with a focus on the fundamental scientific issues that surround this project. In particular, we discuss experiments aimed at understanding the function of bistable [2]rotaxane molecular electronic switches by correlating the switching kinetics and ground state thermodynamic properties of those switches in various environments, ranging from the solution phase to a Langmuir monolayer of the switching molecules sandwiched between two electrodes. We discuss various devices, low bit-density memory circuits, and ultra-high density memory circuits that utilize the electrochemical switching characteristics of these molecules in conjunction with novel patterning methods. We also discuss interconnect schemes that are capable of bridging the micrometre to submicrometre length scales of conventional patterning approaches to the near-molecular length scales of the ultra-dense memory circuits. Finally, we discuss some of the challenges associated with fabricated ultra-dense molecular electronic integrated circuits
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Development of a Knowledge Management System Integrated with Local Communication Channels and Knowledge Management Initiatives for Kenyan Rural Farming Communities
yesThis paper presents an innovative application of wireless, mobile and ubiquitous technologies to support informal and collaborative learning in Kenyan rural farming communities. Such an approach is achieved by the development of a knowledge management system (KMS) integrated with existing local community communication channels, together with experimental knowledge management (KM) initiatives employing the VeSeL (Village e-Science for Life) distributed resource kits (DRKs). The initiatives support illiterate and semi-literate farming community groups, in learning new agriculture practices, and also enable the use of advanced digital technology to improve their agricultural practices and literacy levels. Results of a recent field trip to Kenya are presented and an application sketch is developed. The process of applying wireless and Internet technologies for the education of local farming communities, using irrigation and water management as the application, concludes the paper.EPSR
Catch rate of juveniles Ethamatosa fimbriata, Sardinella maderensis, and Brachydeuterus auritus fishing in Freetown Peninsular
We investigated the incidences of juvenile fishing according to fishing practices in Freetown peninsular. The industrial trawl fishing sector, despite its technology is not fully selective to avoid bycatch of juvenile fish, and artisanal fishing is so less for economic reasons. Ineffective enforcement of fishing regulations is a major cause to the catch of both targeted and non-targeted juvenile fish. We collected data on the quantity of juvenile fish and the daily duration of fishing trips in four landing sites over a two-week period Bernoulli random variables and properties of uniform distribution were used to analyze the data. Catch rates of juveniles Ethamatosa fimbriata, Sardinella maderensis, and Brachydeuterus auritus around the Freetown peninsular were 170.8, 212.4 and 194.60 kg per hour per day, respectively. This rate revealed that the current trend of juvenile fish landings is a threat to the sustainability of fishery capital, revenue, and biodiversity.Key words: High juvenile, landing, national problem, Sierra Leone, by-catch juvenile
Spectrum sensing in cognitive radio using multitaper method based on MIMO-OFDM techniques
The current inefficient utilization of frequency spectrum has alerted regulatory bodies to streamline improvements. Cognitive radio (CR) has recently received considerable attention and is widely perceived as a promising improvement tool in estimating, or equivalently sensing, the frequency spectrum for wireless communication systems. The cognitive cycle in CR systems is capable of recognizing and processing better spectrum estimation (SE) and hence promotes the efficiency of spectrum utilization. Among different SE methods, the multi-taper method (MTM) shows encouraging results. Further performance improvement in the SE for CR can be achieved by applying multiple antennas and combining techniques. This paper proposes a constructive development of SE using MTM, abbreviated as MTSE, and by employing multiple-input multiple-output (MIMO), parsed into separate parallel channels using singular value decomposition (SVD), and maximum ratio combining (MRC) configurations. Deviating from these improvements, however, multicarrier systems such as orthogonal frequency division multiplexing (OFDM) show inferior sensing performances due to the noise multiplicity generated and combined from all subcarrier channels. By means of the quadrature matrix form, the probabilities for such integrated settings of SE have been derived to reach at their approximate asymptotes. Numerical simulations revealed specific better performances stemmed from coupling the fashionable MTSE and MIMO technologies
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