Optimal Memoryless Encoding for Low Power Off-Chip Data Buses

Off-chip buses account for a significant portion of the total system power consumed in embedded systems. Bus encoding schemes have been proposed to minimize power dissipation, but none has been demonstrated to be optimal with respect to any measure. In this paper, we give the first provably optimal and explicit (polynomial-time constructible) families of memoryless codes for minimizing bit transitions in off-chip buses. Our results imply that having access to a clock does not make a memoryless encoding scheme that minimizes bit transitions more powerful.Comment: Proceedings of the 2006 IEEE/ACM international Conference on Computer-Aided Design (San Jose, California, November 05 - 09, 2006). ICCAD '06. ACM, New York, NY, 369-37

It's politics, stupid! A political analysis of the HIV/AIDS Trust Fund in Uganda

The role of trust funds in the practice of and the policy discourse on the sustainable financing for health and HIV is growing. However, there is a paucity of political analyses on implementing trust fund arrangements. Drawing on a novel meta-framework – connecting multiple streams and advocacy coalition frameworks to policy cycle models of analysis – to politically analyse HIV financing policy design, adoption and implementation as well as insights from public finance literature, this article critically analyses the politics of the AIDS Trust Fund (ATF) in Uganda. We find that politics was the most fundamental driver for the establishment of the ATF. Whereas HIV financing is inherently both technical and political, enacting the ATF was largely a geopolitical positioning policy instrument that entailed navigating political economy challenges in managing multiple stakeholder groups’ politics. With the mandated tax revenues earmarked to capitalise the ATF covering only 0.5% of the annual resource needs, we find a very insignificant potential to contribute to financial sustainability of the national HIV response per se. As good ideas and evidence alone often do not necessarily produce desired results, we conclude that systematic and continuous political analysis can bring meaningful insights to our understanding of political economy dimensions of the ATF as an innovative financing policy instrument, thereby helping drive technically sound health financing policy proposals into practice more effectively. For Uganda, while proponents have invested a considerable amount of hope in the ATF as a source of sustainable domestic funding for the HIV response, substantial work remains to be done to address a number of questions that continue to beguile the current ATF architecture. Regarding global health financing policy, the findings suggest the need to pay attention to the position, power and interests of stakeholders as a powerful lever in health financing policy reforms

Anti-Pasch optimal packings with triples

It is shown that for v ≠ 6, 7, 10, 11, 12, 13, there exists an optimal packing with triples on v points that contains no Pasch configurations. Furthermore, for all v ≡ 5 (mod 6), there exists a pairwise balanced design of order v, whose blocks are all triples apart from a single quintuple, and that has no Pasch configurations amongst its triples

Evaluation of 'TRY': an algorithm for neonatal continuous positive airways pressure in low-income settings

BACKGROUND: Non-invasive respiratory support using bubble continuous positive airway pressure (bCPAP) is useful in treating babies with respiratory distress syndrome. Despite its proven clinical and cost-effectiveness, implementation is hampered by the inappropriate administration of bCPAP in low-resource settings. A clinical algorithm-'TRY' (based on Tone: good; Respiratory distress; Yes, heart rate above 100 beats/min)-has been developed to correctly identify which newborns would benefit most from bCPAP in a teaching hospital in Malawi. OBJECTIVE: To evaluate the reliability, sensitivity and specificity of TRY when employed by nurses in a Malawian district hospital. METHODS: Nursing staff in a Malawian district hospital baby unit were asked, over a 2-month period, to complete TRY assessments for every newly admitted baby with the following inclusion criteria: clinical evidence of respiratory distress and/or birth weight less than 1.3 kg. A visiting paediatrician, blinded to nurses' assessments, concurrently assessed each baby, providing both a TRY assessment and a clinical decision regarding the need for CPAP administration. Inter-rater reliability was calculated comparing nursing and paediatrician TRY assessment outcomes. Sensitivity and specificity were estimated comparing nurse TRY assessments against the paediatrician's clinical decision. RESULTS: Two hundred and eighty-seven infants were admitted during the study period; 145 (51%) of these met the inclusion criteria, and of these 57 (39%) received joint assessments. The inter-rater reliability was high (kappa 0.822). Sensitivity and specificity were 92% and 96%, respectively. CONCLUSIONS: District hospital nurses, using the TRY-CPAP algorithm, reliably identified babies that might benefit from bCPAP and thus improved its effective implementation

Community-linked maternal death review (CLMDR) to measure and prevent maternal mortality: a pilot study in rural Malawi.

In Malawi, maternal mortality remains high. Existing maternal death reviews fail to adequately review most deaths, or capture those that occur outside the health system. We assessed the value of community involvement to improve capture and response to community maternal deaths

Covering Arrays for Equivalence Classes of Words

Covering arrays for words of length $t$ over a $d$ letter alphabet are $k \times n$ arrays with entries from the alphabet so that for each choice of $t$ columns, each of the $d^t$ $t$-letter words appears at least once among the rows of the selected columns. We study two schemes in which all words are not considered to be different. In the first case words are equivalent if they induce the same partition of a $t$ element set. In the second case, words of the same weight are equivalent. In both cases we produce logarithmic upper bounds on the minimum size $k=k(n)$ of a covering array. Definitive results for $t=2,3,4$, as well as general results, are provided.Comment: 17 page

Set-Codes with Small Intersections and Small Discrepancies

We are concerned with the problem of designing large families of subsets over a common labeled ground set that have small pairwise intersections and the property that the maximum discrepancy of the label values within each of the sets is less than or equal to one. Our results, based on transversal designs, factorizations of packings and Latin rectangles, show that by jointly constructing the sets and labeling scheme, one can achieve optimal family sizes for many parameter choices. Probabilistic arguments akin to those used for pseudorandom generators lead to significantly suboptimal results when compared to the proposed combinatorial methods. The design problem considered is motivated by applications in molecular data storage and theoretical computer science