9,931 research outputs found
A Geometric Approach to Covariance Matrix Estimation and its Applications to Radar Problems
A new class of disturbance covariance matrix estimators for radar signal
processing applications is introduced following a geometric paradigm. Each
estimator is associated with a given unitary invariant norm and performs the
sample covariance matrix projection into a specific set of structured
covariance matrices. Regardless of the considered norm, an efficient solution
technique to handle the resulting constrained optimization problem is
developed. Specifically, it is shown that the new family of distribution-free
estimators shares a shrinkagetype form; besides, the eigenvalues estimate just
requires the solution of a one-dimensional convex problem whose objective
function depends on the considered unitary norm. For the two most common norm
instances, i.e., Frobenius and spectral, very efficient algorithms are
developed to solve the aforementioned one-dimensional optimization leading to
almost closed form covariance estimates. At the analysis stage, the performance
of the new estimators is assessed in terms of achievable Signal to Interference
plus Noise Ratio (SINR) both for a spatial and a Doppler processing assuming
different data statistical characterizations. The results show that interesting
SINR improvements with respect to some counterparts available in the open
literature can be achieved especially in training starved regimes.Comment: submitted for journal publicatio
Gapped Two-Body Hamiltonian for continuous-variable quantum computation
We introduce a family of Hamiltonian systems for measurement-based quantum
computation with continuous variables. The Hamiltonians (i) are quadratic, and
therefore two body, (ii) are of short range, (iii) are frustration-free, and
(iv) possess a constant energy gap proportional to the squared inverse of the
squeezing. Their ground states are the celebrated Gaussian graph states, which
are universal resources for quantum computation in the limit of infinite
squeezing. These Hamiltonians constitute the basic ingredient for the adiabatic
preparation of graph states and thus open new venues for the physical
realization of continuous-variable quantum computing beyond the standard
optical approaches. We characterize the correlations in these systems at
thermal equilibrium. In particular, we prove that the correlations across any
multipartition are contained exactly in its boundary, automatically yielding a
correlation area law.Comment: 4 pages, one figure. New version: typos corrected, one reference
added. To appear in PR
Health, human capital and economic growth in Brazil
The main objective of the research is to analyze the relationship between population health status, and processes of economic growth and social development in Brazil by exploring the use of the population's nutritional and health variables to assess the quality of human capital and the mechanisms through which these variables may impact the country’s economic performance in terms of human capital formation, long-term economic growth, and social development. This research includes considerations on recent advances in the economic growth theory that contains the relationship between health, human capital, and long-term economic growth, as well as empirical evidence obtained from the analysis of an important Brazilian database, the Living Standards Measurement Survey, (Pesquisa de Padrao de Vida - PPV), a household survey conducted between 1996 and 1997 in both the Southeast and Northeast Regions of Brazil. The first part of the study focuses on information from individuals belonging to the group of economically active population (people between 19 and 59 years-old, both genders) to analyze the connection of individuals' health variables, such as height and health status, with socioeconomic variables, like income and educational attainment, controlling by area of residence (rural vs urban) and region (Northeast vs Southeast) The second part of the study focuses on information from individuals belonging to the group of economically active population (19 to 59 years-old both genders) with at least one child to support (2 to 21 years-old, both genders) in order to evaluate the intergenerational transmission of human capital, that is, analyzing the relations among parents data on health and nutritional status, income and educational attainment and the investment he/she is providing to the formation of human capital of his/her own child, controlling by area of residence (rural vs urban) and region (Northeast vs Southeast). Results lead to the conclusion that improvements generated through human capital investments made in one individual by the family do not finish at the individual himself, but are propagated to the next generations, independently from mechanisms of income. That is, relevant investments in human capital development, as educational attainment, nutrition, and health, create better opportunities to the individual in terms of employment and income. However, beyond these primary effects, there are secondary effects, mainly based on the transmission of human capital formation through generations, that result in population lifestyle changes, economic growth and development.
Indigeneity and political economy: class and ethnicity of the Guarani-Kaiowa
Ontological and identitary questions affecting indigenous peoples are discussed through an assessment of the socio-spatial trajectory of the Guarani-Kaiowa of South America, employing an analytical framework centred around land, labour and ethnicity. These enhanced politico-economic categories provide important entry points for understanding the violence and exploitation perpetrated against indigenous groups, as well as their capacity to reclaim ancestral territory lost to development. Evidence indicates that ethnicity is integral to class-based processes, given that the advance of capitalist relations both presumes and produces difference and subordination. The case study in the Brazilian state of Mato Grosso do Sul demonstrates that the Guarani-Kaiowa became refugees in their own land due to ethnic differences, but at the same time their labour has underpinned the regional economy to a considerable extent through interrelated mechanisms of peasantification and proleterianisation. Trends of exploitation and alienation have intensified in recent decades due to racism and socio-spatial segregation, but the action/reaction of subordinate groups has also been reinforced through references to their ethnicity
Source localization and denoising: a perspective from the TDOA space
In this manuscript, we formulate the problem of denoising Time Differences of
Arrival (TDOAs) in the TDOA space, i.e. the Euclidean space spanned by TDOA
measurements. The method consists of pre-processing the TDOAs with the purpose
of reducing the measurement noise. The complete set of TDOAs (i.e., TDOAs
computed at all microphone pairs) is known to form a redundant set, which lies
on a linear subspace in the TDOA space. Noise, however, prevents TDOAs from
lying exactly on this subspace. We therefore show that TDOA denoising can be
seen as a projection operation that suppresses the component of the noise that
is orthogonal to that linear subspace. We then generalize the projection
operator also to the cases where the set of TDOAs is incomplete. We
analytically show that this operator improves the localization accuracy, and we
further confirm that via simulation.Comment: 25 pages, 9 figure
A case study of inland fisheries management in the Lucheringo-Rovuma- Messinge river systems, northern Niassa, Mozambique : from open access to common property?
Thesis (M.Env.Dev.)-University of Natal, Pietermaritzburg, 2000.There is growing realisation world wide that the attainment of environmental sustainability is contingent upon reinstatement of community authority over management of natural resources. In acknowledgement of this imperative the government of Mozambique has formulated policies and enacted legislation to promote Community-Based Natural Resource Management. The research reported here considers the prospects for achieving CBNRM in a fishery located in a remote part of the country on the border between Mozambique and Tanzania. The central hypothesis addressed is that the fishery in historical terms was operated under a common property regime and that, under a number of forces , this has changed to an open access regime. The challenge facing government is to return the fishery to a common property regime. A conceptual framework which illustrates transformation of the fishery was developed. This was used to structure the research. Central question posed includes: what evidence is there that the fishery may have operated as common property system? what evidence is there that it now operates as an open access system? • what forces promoted such change, if indeed change has occurred? The findings are that the fishery has changed and now has the characteristics of the prospects for a return to CBNRM. Three issues are considered: who is the community? • what are the resources? and what are the management issues? It is concluded that definition of the 'community' is difficult because of historical precedents of access and use. The resource is shown to be complex including fish, water, land and plants; it also varies in tenure and space. Quite different rights of tenure issues accompany different resources. And management is complicated by international issues and apparent weaknesses in organisational structures, legislation and resources (human and financial). Evidence indicates that the people involved in the fishery are concerned about the state of the fishery and the lack of controls. They express a need for CBNRM. This study exposes the very complex nature of the fishery and suggests that failure to appreciate and understand this complexity encourages simplistic approaches to introduction of CBNRM. These are likely to fail. It is recommended that in light of the complexity elucidated by this research, the government should engage a strategic planning process with the intention of designing and implementing a process for introducing CBNRM which is constructed in the context of what is a very complex system
Molecular Identification of Anisakis larvae (Nematode: Anisakidae) from marine fishes collected from three Korean sea waters
Anisakis infects humans who eat raw seafood such as squid, mackerel, and conger, which is considered as one of the parasitic diseases in Korea. Molecular study for Anisakis L3 larvae was performed to identify the species of Anisakis. Molecular analysis for Anisakis L3 larvae was performed to identify the species of Anisakis and by using the DNA alignment tool to identify the DNA sequence relation. Total 98 Anisakis type I L3 larvae were collected from 63 fishes among three kinds of fish species (mackerel (Scomberomorus japonicus), anago (Conger myriaster), and yellow croaker (Larimichthys polyactis)) that came from different location near sea areas (Namhae-gun, Uljin-gun, Daecheon-si, Pohang-si and Seoul). DNA were extracted from Anisakis and ITS gene (forward primer: Nc5 (5’-GTAGGTGAACCTGCGGAAGGATCATT-3’); reverse primer: Nc2 (5’-TTAGTTTCTTTTCCTCCGCT-3’)) was amplified using PCR and sequenced. By using some method that considered for the species identification strategies, such as: Sequence analysing (Anisakis pegreffi (GGCAGAGTC) => C/C allele and Anisakis simplex (GGCAGAGTT) => T/T allele) and the strategy to find the rest total of unidentified in the first strategy by using nucleotide identity percentage: A. pegreffi (AB277823), A. simplex (AB277822), P. decipiens (AB277824) and H. aduncum (AB277826). It was found that Anisakis pegreffi was the most predominant Anisakis species from all fish species and in all Korean locations with 67 as a result of the total. And in the result of nucleotide identity percentage for analyzed the rest 31 samples that not identified during the sequence procedure, based on matched result, 1 were more matched to A. simplex, 25 to A. pegreffi and 5 to H. aduncum.open석
LAND PARCELING AND NEIGHBORHOOD IMPACTS IN BRAZIL
The proposal and implementation of parceling real estate into smaller lots in Brazil is done according to legal and technical formalities. However, these instruments have proved inefficient in reducing the resulting environmental impacts. The ambiguities of the federal, state and municipal laws and regulations have limited the effectiveness of the actions of urban administrators. Law 10257/2001 emerged as an alternative to overcome these difficulties, proposing the adoption of neighborhood impact studies as an instrument to evaluate new proposals of urban occupation for purposes of environmental licensing. Thus, the purpose of this law is to provide the foundations for municipal public authorities to establish criteria for the assessment, mitigation and compensation of impacts resulting from new occupations. However, the very vagueness of the generic nature of this federal law and its incorrect application in the municipal sphere has posed the greatest obstacles to the good use of this instrument of urban environmental management. These deficiencies are classified herein in the categories of philosophical, technical and operational problems. The problems of a philosophical nature lead to technical difficulties, which in turn trigger operational deficiencies. This article discusses these deficiencies and points out ways to reduce them
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