5,352 research outputs found
Heterogeneity and Vulnerability in the Urban Informal Economy
The focus of this paper is on the low-value urban informal economy in sub-Saharan Africa. The paper presents a case study from Uganda, with the focus on secondary cities where much of the urban population growth is expected in the next decade. There is also good evidence that informality will persist within both dynamic and in slow urban economies in sub-Saharan Africa. Analysis of the results from fieldwork is presented in support of the basic argument that, as the informal economy is likely to persist there is need for a more conducive policy approach to ensure its positive contribution to the urban economic development; seen as a mainstay of Africaâs future economic development. Currently, the informal economy is considered ephemeral, with little institutional engagement, with the focus on restrictive
measures.
The paper explores the range of theoretical perspectives on the urban informal economy leading to its re-conceptualizing as part of a continuum of activities in which both formal and informal elements are interlinked. Given the need to improve productivity of activities of different constituent groups along the continuum, the aim of this paper is to develop a conceptual framework that would enable the systematic analyses and identification of the internal diversities within the informal economy. It could be used in future policy research to identify diagnostic groups for entry points. The findings from the fieldwork carried out in the cities of Mbale and Mbarara, show that there are several viable options for sustainable livelihoods, particularly in a dynamic urban center. However, while women dominate in numbers, men remain the main actors. This calls for an inclusive, gender-mainstreamed, pro-poor development policy to complement an enterprise-based approach
Implementation of a Deutsch-like quantum algorithm utilizing entanglement at the two-qubit level, on an NMR quantum information processor
We describe the experimental implementation of a recently proposed quantum
algorithm involving quantum entanglement at the level of two qubits using NMR.
The algorithm solves a generalisation of the Deutsch problem and distinguishes
between even and odd functions using fewer function calls than is possible
classically. The manipulation of entangled states of the two qubits is
essential here, unlike the Deutsch-Jozsa algorithm and the Grover's search
algorithm for two bits.Comment: 4 pages, two eps figure
A Systematic Examination of the 2013 ACC/AHA Pooled Cohort Risk Assessment Tool for Atherosclerotic Cardiovascular Disease
AbstractBackgroundThe 2013 American College of Cardiology/American Heart Association updated cholesterol guidelines recommend the use of Pooled Cohort Equations to estimate 10-year absolute risk for atherosclerotic cardiovascular disease (ASCVD) in primary prevention.ObjectivesThis study sought to systematically examine the Pooled Cohort Equations to determine risk factor levels required to exceed risk thresholds outlined in new cholesterol guidelines.MethodsWe entered continuous risk factor levels in isolation and in specified combinations with the risk tool, and we observed predicted risk output patterns. We used the 10-year ASCVD risk threshold of â„7.5% as a clinically relevant risk threshold.ResultsWe demonstrated that a hypothetical man or woman can reach clinically relevant risk thresholds throughout the eligible age spectrum of 40 to 79 years of age, depending on the associated risk factor burden in all race-sex groups. Age continues to be a major determinant of 10-year ASCVD risk for both men and women. Compared with the previous risk assessment tool used in cholesterol guidelines, the inclusion of a stroke endpoint and use of race-specific coefficients permit identification of at-risk African Americans and non-Hispanic white women at much younger ages and lower risk factor levels.ConclusionsThese data provide context of specific risk factor levels and groups of individuals who are likely to have 10-year ASCVD risk estimates â„7.5%. Age continues to be a major driver of risk, which highlights the importance of the clinician-patient discussion before statin therapy is initiated
A Buffer Stocks Model for Stabilizing Price of Staple Food with Considering the Expectation of Non Speculative Wholesaler
This paper is a study of price stabilization in the
staple food distribution system. All stakeholders experience
market risks due to some possibility causes of price volatility.
Many models of price stabilization had been developed by
employing several approaches such as floor-ceiling prices,
buffer funds, export or import taxes, and subsidies. In the
previous researches, the models were expanded to increase the
purchasing price for producer and decrease the selling price
for consumer. Therefore, the policy can influence the losses for
non-speculative wholesaler that is reflected by the descending
of selling quantity and ascending of the stocks. The objective of
this model is not only to keep the expectation of both producer
and consumer, but also to protect non-speculative wholesaler
from the undesirable result of the stabilization policy. A
nonlinear programming model was addressed to determine the
instruments of intervention program. Moreover, the result
shows that the wholesaler behavior affects the intervention
costs.
Index Terms Buffer stocks, Price stabilization, Nonlinear
programming, Wholesaler behavior
Universal simulation of Hamiltonian dynamics for qudits
What interactions are sufficient to simulate arbitrary quantum dynamics in a
composite quantum system? Dodd et al. (quant-ph/0106064) provided a partial
solution to this problem in the form of an efficient algorithm to simulate any
desired two-body Hamiltonian evolution using any fixed two-body entangling
N-qubit Hamiltonian, and local unitaries. We extend this result to the case
where the component systems have D dimensions. As a consequence we explain how
universal quantum computation can be performed with any fixed two-body
entangling N-qudit Hamiltonian, and local unitaries.Comment: 13 pages, an error in the "Pauli-Euclid-Gottesman Lemma" fixed, main
results unchange
Proof Relevant Corecursive Resolution
Resolution lies at the foundation of both logic programming and type class
context reduction in functional languages. Terminating derivations by
resolution have well-defined inductive meaning, whereas some non-terminating
derivations can be understood coinductively. Cycle detection is a popular
method to capture a small subset of such derivations. We show that in fact
cycle detection is a restricted form of coinductive proof, in which the atomic
formula forming the cycle plays the role of coinductive hypothesis.
This paper introduces a heuristic method for obtaining richer coinductive
hypotheses in the form of Horn formulas. Our approach subsumes cycle detection
and gives coinductive meaning to a larger class of derivations. For this
purpose we extend resolution with Horn formula resolvents and corecursive
evidence generation. We illustrate our method on non-terminating type class
resolution problems.Comment: 23 pages, with appendices in FLOPS 201
Quantum entanglement in the NMR implementation of the Deutsch-Jozsa algorithm
A scheme to execute an n-bit Deutsch-Jozsa (D-J) algorithm using n qubits has
been implemented for up to three qubits on an NMR quantum computer. For the one
and two bit Deutsch problem, the qubits do not get entangled, hence the NMR
implementation is achieved without using spin-spin interactions. It is for the
three bit case, that the manipulation of entangled states becomes essential.
The interactions through scalar J-couplings in NMR spin systems have been
exploited to implement entangling transformations required for the three bit
D-J algorithm.Comment: 4-pages in revtex with 5 eps figure included using psfi
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