DRAFT Report:Community Systems Strengthening Toward a Research Agenda

Communities have a long history of acting to preserve and promote the health of their members. Public health researchers, programmers, and funders are increasingly recognizing that community involvement is essential to improving health, especially among populations that are disproportionately affected by HIV. The Global Fund to fight AIDS, Tuberculosis and Malaria, together with civil society organizations and other development partners, created the Community Systems Strengthening (CSS) Framework to help Global Fund applicants frame, define, and quantify efforts to strengthen community contributions engagement (Global Fund 2011). Although the use of a CSS approach in health programming implementation shows promise, it lacks a theoretical framework to guide collaborations with communities. Additionally, it suffers from a paucity of program designs and evaluation practices, an incomplete evidence-based rationale for investing in CSS, and imprecise definitions (e.g., what is meant by “community” and “CSS”).The purpose of this paper is to highlight promising areas for future research related to CSS. Toward this objective, we propose to lay a foundation for a CSS research agenda by using theories and approaches relevant to CSS, reinforced with evidence from projects that employ similar approaches

Complete characterization of sink-strengths for 1D to 3D mobilities of defect clusters.II. Bridging between limiting cases with effective sink-strengths calculations

In a companion paper, we proposed new analytical expressions of cluster sink-strengths (CSS) indispensable to any complete parameterization of rate equations cluster dynamics accounting for reaction between defect clusters populations having a 1D-mobility. In this second paper, we first establish simulation setup rules for truly converged estimates of effective CSS by Kinetic Monte-Carlo, and then we grid on a wide set of radii, rotation energies, diffusion coefficients and concentrations of both reaction partners. Symmetric roles of some parameters are used to infer a generic form for a semi-analytical expression of CSS depending on all these interaction parameters: it is composed of the various analytical limiting cases established and fitted transition functions that allow a gradual switching between them. The analysis of the residuals shows that the overall agreement is reasonably good: it is only in the transition zones that discrepancies are located and this is due to the asymmetry of the actual transition functions. The expression can be easily extended to temperatures at least a few hundred degrees around the reference. But further extending the CSS evaluations to much smaller diffusion coefficients ratios, we see that the domain for 1D-1D mobility is very extended: for a $10^{-3}$ ratio the computed CSS is still not correctly described by the 1D-CSS with respect to a fixed sink (1D-0), but rather by the established 1D-1D expression. For our typical sets of conditions, it is only when approaching a ratio of $10^{-6}$ that the 1D-0 CSS starts to become more relevant. This highlights the counter-intuitive fact that the growth kinetics of moderately trapped 1D mobile loops, whose effective mobility is greatly reduced, may not be described by 1D-0 kinetics but rather by appropriately corrected 1D-1D CSS which have completely different order of magnitude and kinetic orders.Comment: 21 pages, 12 figure

Cooperative sensing of spectrum opportunities

Reliability and availability of sensing information gathered from local spectrum sensing (LSS) by a single Cognitive Radio is strongly affected by the propagation conditions, period of sensing, and geographical position of the device. For this reason, cooperative spectrum sensing (CSS) was largely proposed in order to improve LSS performance by using cooperation between Secondary Users (SUs). The goal of this chapter is to provide a general analysis on CSS for cognitive radio networks (CRNs). Firstly, the theoretical system model for centralized CSS is introduced, together with a preliminary discussion on several fusion rules and operative modes. Moreover, three main aspects of CSS that substantially differentiate the theoretical model from realistic application scenarios are analyzed: (i) the presence of spatiotemporal correlation between decisions by different SUs; (ii) the possible mobility of SUs; and (iii) the nonideality of the control channel between the SUs and the Fusion Center (FC). For each aspect, a possible practical solution for network organization is presented, showing that, in particular for the first two aspects, cluster-based CSS, in which sensing SUs are properly chosen, could mitigate the impact of such realistic assumptions

Compact Stellar Systems around NGC 1399

We have obtained spectroscopic redshifts of colour-selected point sources in four wide area VLT-FLAMES fields around the Fornax Cluster giant elliptical galaxy NGC 1399, identifying as cluster members 30 previously unknown faint (-10.5<M_g'<-8.8) compact stellar systems (CSS), and improving redshift accuracy for 23 previously catalogued CSS. By amalgamating our results with CSS from previous 2dF observations and excluding CSS dynamically associated with prominent (non-dwarf) galaxies surrounding NGC 1399, we have isolated 80 `unbound' systems that are either part of NGC 1399's globular cluster (GC) system or intracluster GCs. For these unbound systems, we find (i) they are mostly located off the main stellar locus in colour-colour space; (ii) their projected distribution about NGC 1399 is anisotropic, following the Fornax Cluster galaxy distribution, and there is weak evidence for group rotation about NGC 1399; (iii) their completeness-adjusted radial surface density profile has a slope similar to that of NGC 1399's inner GC system; (iv) their mean heliocentric recessional velocity is between that of NGC 1399's inner GCs and that of the surrounding dwarf galaxies, but their velocity dispersion is significantly lower; (v) bright CSS (M_V<-11) are slightly redder than the fainter systems, suggesting they have higher metallicity; (vi) CSS show no significant trend in $g' - i'$ colour index with radial distance from NGC 1399.Comment: 13 pages (including supplementary table), 13 figures, 5 tables. Accepted for publication in MNRA

Byzantine Attack and Defense in Cognitive Radio Networks: A Survey

The Byzantine attack in cooperative spectrum sensing (CSS), also known as the spectrum sensing data falsification (SSDF) attack in the literature, is one of the key adversaries to the success of cognitive radio networks (CRNs). In the past couple of years, the research on the Byzantine attack and defense strategies has gained worldwide increasing attention. In this paper, we provide a comprehensive survey and tutorial on the recent advances in the Byzantine attack and defense for CSS in CRNs. Specifically, we first briefly present the preliminaries of CSS for general readers, including signal detection techniques, hypothesis testing, and data fusion. Second, we analyze the spear and shield relation between Byzantine attack and defense from three aspects: the vulnerability of CSS to attack, the obstacles in CSS to defense, and the games between attack and defense. Then, we propose a taxonomy of the existing Byzantine attack behaviors and elaborate on the corresponding attack parameters, which determine where, who, how, and when to launch attacks. Next, from the perspectives of homogeneous or heterogeneous scenarios, we classify the existing defense algorithms, and provide an in-depth tutorial on the state-of-the-art Byzantine defense schemes, commonly known as robust or secure CSS in the literature. Furthermore, we highlight the unsolved research challenges and depict the future research directions.Comment: Accepted by IEEE Communications Surveys and Tutoiral

Role of the nonperturbative input in QCD resummed Drell-Yan QTQ_T-distributions

We analyze the role of the nonperturbative input in the Collins, Soper, and Sterman (CSS)'s $b$-space QCD resummation formalism for Drell-Yan transverse momentum ($Q_T$) distributions, and investigate the predictive power of the CSS formalism. We find that the predictive power of the CSS formalism has a strong dependence on the collision energy $\sqrt{S}$ in addition to its well-known $Q^2$ dependence, and the $\sqrt{S}$ dependence improves the predictive power at collider energies. We show that a reliable extrapolation from perturbatively resummed $b$-space distributions to the nonperturbative large $b$ region is necessary to ensure the correct $Q_T$ distributions. By adding power corrections to the renormalization group equations in the CSS formalism, we derive a new extrapolation formalism. We demonstrate that at collider energies, the CSS resummation formalism plus our extrapolation has an excellent predictive power for $W$ and $Z$ production at all transverse momenta $Q_T\le Q$. We also show that the $b$-space resummed $Q_T$ distributions provide a good description of Drell-Yan data at fixed target energies.Comment: Latex, 43 pages including 15 figures; typos were correcte

Simple Rate-1/3 Convolutional and Tail-Biting Quantum Error-Correcting Codes

Simple rate-1/3 single-error-correcting unrestricted and CSS-type quantum convolutional codes are constructed from classical self-orthogonal \F_4-linear and \F_2-linear convolutional codes, respectively. These quantum convolutional codes have higher rate than comparable quantum block codes or previous quantum convolutional codes, and are simple to decode. A block single-error-correcting [9, 3, 3] tail-biting code is derived from the unrestricted convolutional code, and similarly a [15, 5, 3] CSS-type block code from the CSS-type convolutional code.Comment: 5 pages; to appear in Proceedings of 2005 IEEE International Symposium on Information Theor

Generation of large-amplitude coherent-state superposition via ancilla-assisted photon-subtraction

We propose and demonstrate a novel method to generate a large-amplitude coherent-state superposition (CSS) via ancilla-assisted photon-subtraction. The ancillary mode induces quantum interference of indistinguishable processes, widening the controllability of quantum superposition at the conditional output. We demonstrate the concept in the time domain, by a simple time-separated two-photon subtraction from cw squeezed light. We observe the largest CSS ever reported without any corrections, which will enable various quantum information applications with CSS states.Comment: 5 pages, 4 figures; the revised versio

Generation of Optical Coherent State Superpositions by Number-Resolved Photon Subtraction from Squeezed Vacuum

We have created heralded coherent state superpositions (CSS), by subtracting up to three photons from a pulse of squeezed vacuum light. To produce such CSSs at a sufficient rate, we used our high-efficiency photon-number-resolving transition edge sensor to detect the subtracted photons. This is the first experiment enabled by and utilizing the full photon-number-resolving capabilities of this detector. The CSS produced by three-photon subtraction had a mean photon number of 2.75 -0.24/+0.06 and a fidelity of 0.59 -0.14/+0.04 with an ideal CSS. This confirms that subtracting more photons results in higher-amplitude CSSs.Comment: Main manuscript and supplementary materia