A new approach in chaos shift keying for secure communication

A chaotic sequence for chaos shift keying (CSK) that provides auto- and cross-correlation properties (that are similar to those of random white noise) is used for spread spectrum systems. Due to its bifurcation behavior (depending on the initial condition), the number of chaotic sequences that can be generated by a single formula is not restricted and will not repeat itself. These characteristics provide an increase in system capacity and security performance. The paper presents a study of two different commonly used chaotic logistic maps and a modified chaotic logistic map for CSK spread spectrum system. The newly modified logistic map provides similar bits error rate (BER) performance to the best logistic map. Yet, it also provides an additional chaotic parameter for the control of its dynamic property, hence increasing the system security and capacity

Interrater reliability in visual identification of interictal high-frequency oscillations on electrocorticography and scalp EEG.

High-frequency oscillations (HFOs), including ripples (Rs) and fast ripples (FRs), are promising biomarkers of epileptogenesis, but their clinical utility is limited by the lack of a standardized approach to identification. We set out to determine whether electroencephalographers experienced in HFO analysis can reliably identify and quantify interictal HFOs. Two blinded raters independently reviewed 10 intraoperative electrocorticography (ECoG) samples from epilepsy surgery cases, and 10 scalp EEG samples from epilepsy monitoring unit evaluations. HFOs were visually marked using bandpass filters (R, 80-250 Hz; FR, 250-500 Hz) with a sampling frequency of 2,000 Hz. There was agreement as to the presence or absence of epileptiform discharges (EDs), Rs, and FRs, in 17, 18, and 18 cases, respectively. Interrater reliability (IRR) was favorable with κ = 0.70, 0.80, and 0.80, respectively, and similar for ECoG and scalp electroencephalography (EEG). Furthermore, interclass correlation for rates of Rs (0.99, 95% confidence interval [CI] 0.96-0.99) and FRs (0.77, 95% CI 0.41-0.91) were superior in comparison to EDs (0.37, 95% CI -0.60 to 0.75). Our data suggest that HFO identification and quantification are reliable among experienced electroencephalographers. Our findings support the reliability of utilizing HFO data in both research and clinical arenas

Predicting Flux And Pressure Relationships of Large Scale Filtration with USD Model Inputs: Method and application

Ultra Scale-Down tools have demonstrated the huge benefit for rapid process development with reduced material requirement and better solutions. In this poster, a method was reported to predict the flux and transmembrane pressure relationships of a diafiltration application for a crossflow filtration (CFF) process, based on data generated using an Ultra Scale-Down (USD) device that uses dead-end mode of operation to mimic CFF. A new flux prediction protocol was developed to accurately determine the system resistance of large scale crossflow filtration (CFF) systems, and, to predict CFF performance using USD data. Antibody fragment (Fab’) is expressed in E. coli as an intracellular product and E.coli homogenate was used for scale-up studies and to validate the prediction results. Predicted and actual flux-pressure drop and transmission data showed good agreement. Wall shear rate correlations have been established for both the lab scale cassette and the USD device, and a mimic has been developed by operating both scales at equivalent membrane averaged shear rates

Capital Flows Management During the Post-2007 Global Financial Crisis: The Experiences of SEACEN Economies

Although global financial stability in late 2010 and early 2011 has, in general, improved when compared to the 2008-2009 period of the sub-prime global financial crisis, vulnerabilities remain high. The recent World Economic Outlook of the IMF (WEO, September 2011) underlines the two speed recovery processes taking place in the world economies. In advanced economies, especially those hit hardest by the crisis, firms, government and household sectors continue to be heavily indebted and are likely to spur relatively weak demand. Although the financial markets of these economies have, in most parts, returned to profitability, the overall frail balance sheets reflect the general subdued state of the local economy. In sharp contrast, the emerging economies, including those of the SEACEN region, are posting robust growth rates until the second half of 2011, meeting new challenges associated with strong demand, rapid credit and excess liquidity. Price pressures, including potential asset price bubbles, have been the common themes of policy challenges for the SEACEN economies. Managing macro-financial risks, namely balancing growth, balance sheet soundness of the financial institutions, particularly the banking sector, and keeping a lid on inflationary pressures, have been and will likely be the primary policy challenges for these emerging markets in 2011 and 2012. This paper takes stock of recent trends and developments with regard to capital flows in the SEACEN economies. It elaborates in detail, the breakdowns and compositions of the flows. In particular, the focus of the analyses is on key flows such as the international bank lending activities to the region. The paper also summarises and analyses some of the basic push and pull factors of these flows to understand some of the domestic and external drivers of these flows. Some of the economic consequences of these capital flows and policy dilemma facing the SEACEN economies are also looked at. The paper also examines the policy responses of the central banks/monetary authorities, in particular, to mitigate the negative consequences and maximise the benefits of capital flows.

Application of Digital Corpus Analysis Technologies to address Low English Proficiency' in undergraduates in English Medium Higher Education

Undergraduates with Low English Proficiency (LEP) in faculties that teach exclusively in the English medium would be linguistically ill-prepared to follow an English medium degree. One of the immediate needs created is the need to develop high discipline and course content specific (content related to the undergraduates’ year of study, such as the first year) English proficiency within an extremely limited time [1]. This need could be more acute in first-year LEP students who need to transition to English Medium Instruction (EMI) in higher education. So is the need to develop discipline-specific (content related to the undergraduates’ subjects of study) English proficiency for the first time after completing school education in the local languages [2]. Based on observations gathered through an endeavour to prepare English language assistance course material for English preliminary level undergraduates in EMI, this paper proposes digital Corpus Analysis technology as a feasible tool that can be used as a fast-track method to develop a discipline and course-specific English proficiency in LEP undergraduates.

Ferromagnetic Enhancement of CE-type Spin Ordering in (Pr,Ca)MnO3_3

We present resonant soft X-ray scattering (RSXS) results from small band width manganites (Pr,Ca)MnO$_3$, which show that the CE-type spin ordering (SO) at the phase boundary is stabilized only below the canted antiferromagnetic transition temperature and enhanced by ferromagnetism in the macroscopically insulating state (FM-I). Our results reveal the fragility of the CE-type ordering that underpins the colossal magnetoresistance (CMR) effect in this system, as well as an unexpected cooperative interplay between FM-I and CE-type SO which is in contrast to the competitive interplay between the ferromagnetic metallic (FM-M) state and CE-type ordering.Comment: Accepted for publication in Phys. Rev. Let

MOF Derived Porous ZnO/C Nanocomposites for Efficient Dye Photodegradation

This is the author accepted manuscript. The final version is available from American Chemical Society via the DOI in this recordHomogeneously dispersed crystalline ZnO nanoparticles embedded in a porous carbon matrix were synthesized via a one-step carbonization of porous metal–organic framework MOF-5 at 800 and 1000 °C in different gas atmospheres. The resulting ZnO/C nanocomposites generally retain cubic particle morphology and high specific surface area of the precursor MOF-5. Various characterization techniques, including XRD, SEM, TEM, elemental mapping, Raman, FTIR, and XPS, confirmed that the carbonization of MOF-5 in water vapor atmosphere produced homogeneously dispersed ZnO nanoparticles confined within the functionalized porous carbon matrix. The rich oxygen-containing hydrophilic functional groups on the surface of the nanocomposite, the defects in the carbon-doped ZnO nanostructure, the crystalline ZnO nanoparticles, and the high textural properties resulted in excellent methylene blue adsorption and photodegradation performance under visible light irradiation. This simple and environmentally friendly approach can be further employed to harvest a variety of new homogeneously dispersed functional metal oxide/carbon composites for various environment and energy related applications.Engineering and Physical Sciences Research Council (EPSRC)Deutsche Forschungsgemeinschaft (German Research Council