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A produção dos números escolares (1871-1931): contribuições para uma abordagem crítica das fontes estatísticas em História da Educação; The production of school numbers (1871-1931): contributions to a critical approach to statistical sources in History of Education

GIL, Natália de Lacerda
Fonte: Associação Nacional de História - ANPUH Publicador: Associação Nacional de História - ANPUH
Tipo: article; editorial; publishedversion
Português
Relevância na Pesquisa
65.87%
O presente artigo pretende contribuir para a reflexão acerca das estatísticas educacionais como fonte para as pesquisas em História da Educação. Buscou-se aqui, principalmente, desvelar a maneira pela qual foram produzidas, no âmbito central, as estatísticas educacionais referentes ao período de 1871 a 1931. Foram analisados relatórios oficiais - da Diretoria Geral de Estatística - e repertórios estatísticos editados por aquela repartição, onde se buscou localizar as recomendações e definições para a realização dos trabalhos. Pretendeu-se, problematizando as fontes documentais de estatística educacional e suas interpretações mais comuns, diminuir o desconhecimento sobre a origem de números escolares, que, eventualmente, são utilizados em pesquisas atuais sem o conveniente exame crítico.; Abstract This article intends to contribute to the reflection on the Educational Statistics as being source for the researches on History of Education. The main concern was to reveal the way Educational Statistics related to the period from 1871 to 1931 were produced, in central government. Official reports - from the General Statistics Directory - and Statistics yearbooks released by that department were analyzed and, on this analysis...

The production of school numbers (1871-1931): contributions to a critical approach to statistical sources in History of Education

GIL, Natalia de Lacerda
Fonte: ASSOC NAC HISTORIA-ANPUH Publicador: ASSOC NAC HISTORIA-ANPUH
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
65.89%
This article intends to contribute to the reflection on the Educational Statistics as being source for the researches on History of Education. The main concern was to reveal the way Educational Statistics related to the period from 1871 to 1931 were produced, in central government. Official reports - from the General Statistics Directory - and Statistics yearbooks released by that department were analyzed and, on this analysis, recommendations and definitions to perform the works were sought. By rending problematic to the documental issues on Educational Statistics and their usual interpretations, the intention was to reduce the ignorance about the origin of the school numbers, which are occasionally used in current researches without the convenient critical exam.

"Contando crimes e criminosos em São Paulo: uma sociologia das estatísticas produzidas e utilizadas entre 1871 e 2000"; "Making Crime and Offenders Count: a history of the São Paulo, Brazil"

Lima, Renato Sérgio de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/10/2005 Português
Relevância na Pesquisa
55.75%
Esta tese investiga os papéis políticos assumidos pela produção e o uso de estatísticas sobre crimes e criminosos na história recente das instituições que compõem o chamado sistema de justiça criminal brasileiro (polícias Civil e Militar, Ministério Público, Poder Judiciário e Estabelecimentos Carcerários), em São Paulo. Por meio da análise de documentos e formulários de coleta de dados, defende-se que, mesmo após a redemocratização e as pressões para a estruturação de procedimentos de controle público das agências estatais de pacificação social, o segredo permanece como modus-operandi desse sistema, no qual dados são produzidos, mas não há coordenação entre produtores e usuários; entre oferta e demanda da informação. Dessa forma, não havendo consenso sobre os papéis das estatísticas criminais disponíveis, há um movimento simultâneo de crescimento dos estoques de dados gerados como subproduto da adoção de modernas ferramentas de informática, de um lado, e, paradoxalmente, há o reforço da opacidade e da ?experiência? institucional das práticas burocráticas no desenho e operação de políticas públicas de pacifi cação social, de outro. O resultado alcançado reforça a manutenção dos mecanismos de reprodução de verdades profissionais e institucionais nos modelos vigentes de segurança pública e justiça criminal...

A dimensão da educação nacional: um estudo sócio-histórico sobre as estatísticas oficiais da escola brasileira; The Dimension of the National Education: a socialhistorical study of the Brazilian school official statistics

Gil, Natália de Lacerda
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 09/04/2007 Português
Relevância na Pesquisa
65.91%
Esta tese é resultado de um estudo sócio-histórico que teve por objetivo compreender como se configuraram as relações entre educação e estatística no Brasil no período de 1871 até a década de 1940. A partir da análise de documentos de Estado - publicados pela Diretoria Geral de Estatística, pelo Ministério da Educação e Saúde, pelo Serviço de Estatística de Educação e Saúde, pelo INEP e pelo IBGE - foi possível identificar como se consolidou a legitimidade que usufruem as estatísticas educacionais para a condução de decisões políticas e de que maneira estas estatísticas colaboraram na formulação de representações sobre a escola primária brasileira. Procedeu-se, inicialmente, ao relato das iniciativas do poder público no sentido de criar e aperfeiçoar um aparato capaz de elaborar informações numéricas consideradas confiáveis. Foi, também, descrita a maneira pela qual eram produzidas as estatísticas educacionais, localizando as fontes de informação e explicando os procedimentos para coleta dos dados. Pretendeu-se, por essa iniciativa, diminuir o desconhecimento acerca da origem de números escolares que, eventualmente, são utilizados em pesquisas atuais sem o conveniente exame crítico. Foram indicadas...

Percepção de risco e comportamento em saúde de usuários com história pessoal de neoplasias em uma unidade de saúde da família; Risk perception and health behavior of users with personal history of neoplasm in a family health unit.

Alvarenga, Larissa de Melo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: dissertação de mestrado Formato: application/pdf
Publicado em 27/01/2011 Português
Relevância na Pesquisa
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As neoplasias malignas figuram como a segunda causa de morte por doença no mundo todo, no Brasil, e no município de Ribeirão Preto. Políticas têm sido propostas na arena da saúde pública para o enfrentamento da problemática do câncer no país. De acordo com a Política Nacional de Atenção Oncológica, é no contexto da Atenção Básica à Saúde que ações no âmbito individual e coletivo precisam ser realizadas, visando à prevenção, o diagnóstico precoce e o combate ao câncer. Para que o cuidado ministrado às famílias brasileiras com história pessoal e/ou familiar de câncer, no contexto da Estratégia Saúde da Família, seja efetivo, é essencial conhecer como os usuários percebem seu risco para essa doença, quais são os comportamentos em saúde por eles adotados e se esses sujeitos têm interesse em serviços e testes genéticos para avaliação de risco para predisposição hereditária ao câncer. Logo, os objetivos desse estudo foram descrever o perfil sócio demográfico de usuários de uma unidade de saúde da família com história pessoal de neoplasias malignas; conhecer sua percepção de risco e opinião sobre as causas do câncer; mapear a realização de exames preventivos e do acesso às informações sobre os mesmos; descrever o interesse em serviços de genética do câncer e associar comportamentos adotados para prevenção de tumores e história familiar de malignidades. Trata-se de um estudo descritivo...

Historical hand-atlas, illustrated, containing large scale copper plate maps of each state and territory of the United States, and the provinces of Canada, together with a complete reference map of the world, topographical and railroad map of the United States, thirteen comprehensive maps of bible geography ... : nine farm maps and history of Wells County, Indiana, illustrated, containing a condensed history of the county, biographical sketches, general statistics, miscellaneous matters, &c.

H.H. Hardesty (Firm)
Fonte: Chicago : H.H. Hardesty & Co Publicador: Chicago : H.H. Hardesty & Co
Tipo: image; map; cartographic
Publicado em //1881 Português
Relevância na Pesquisa
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LeGear. Atlases of the United States, 4583; Includes indexes, brief history of Wells County, and brief biographies of early Wells County residents.

Historical hand-atlas, illustrated, containing large scale copper plate maps of each state and territory of the United States, and the provinces of Canada, together with a complete reference map of the world, topographical and railroad map of the United States, thirteen comprehensive maps of bible geography ... : outline maps and histories of Wood and Pleasants Counties, West Virginia, illustrated, containing a condensed history of the county, biographical sketches, general statistics, miscellaneous matters, &c.

H.H. Hardesty (Firm)
Fonte: Chicago : H.H. Hardesty & Co Publicador: Chicago : H.H. Hardesty & Co
Tipo: image; map; cartographic; maps.
Publicado em //1882 Português
Relevância na Pesquisa
45.65%
Phillips, 11040; LeGear. Atlases of the United States, 6413; Includes indexes, brief histories of Wood and Pleasants County, and brief biographies of early Wood and Pleasants County residents.

The county of Bay, Michigan : maps, history, illustrations and statistics.

D.A. Bullock & Co.
Fonte: Bay City, Mich. : D.A. Bullock & Co Publicador: Bay City, Mich. : D.A. Bullock & Co
Tipo: image; map; cartographic; maps.
Publicado em //1896 Português
Relevância na Pesquisa
45.74%
LeGear. Atlases of the United States, 4962; Includes indexes, brief history of Bay County, and brief biographies and portraits of early Bay County residents.; LC copy imperfect: Liquid staining to lower portion of all pages. Ill. pasted on p. [3] and county statistics pasted on p. [5]. DLC

Likelihoods From Summary Statistics: Recent Divergence Between Species

Leman, Scotland C.; Chen, Yuguo; Stajich, Jason E.; Noor, Mohamed A. F.; Uyenoyama, Marcy K.
Fonte: Copyright © 2005 by the Genetics Society of America Publicador: Copyright © 2005 by the Genetics Society of America
Tipo: text
Publicado em /11/2005 Português
Relevância na Pesquisa
45.83%
We describe an importance-sampling method for approximating likelihoods of population parameters based on multiple summary statistics. In this first application, we address the demographic history of closely related members of the Drosophila pseudoobscura group. We base the maximum-likelihood estimation of the time since speciation and the effective population sizes of the extant and ancestral populations on the pattern of nucleotide variation at DPS2002, a noncoding region tightly linked to a paracentric inversion that strongly contributes to reproductive isolation. Consideration of summary statistics rather than entire nucleotide sequences permits a compact description of the genealogy of the sample. We use importance sampling first to propose a genealogical and mutational history consistent with the observed array of summary statistics and then to correct the likelihood with the exact probability of the history determined from a system of recursions. Analysis of a subset of the data, for which recursive computation of the exact likelihood was feasible, indicated close agreement between the approximate and exact likelihoods. Our results for the complete data set also compare well with those obtained through Metropolis-Hastings sampling of fully resolved genealogies of entire nucleotide sequences.

Generalization of Motor Learning Depends on the History of Prior Action

Krakauer, John W; Mazzoni, Pietro; Ghazizadeh, Ali; Ravindran, Roshni; Shadmehr, Reza
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: text
Português
Relevância na Pesquisa
55.74%
Generalization of motor learning refers to our ability to apply what has been learned in one context to other contexts. When generalization is beneficial, it is termed transfer, and when it is detrimental, it is termed interference. Insight into the mechanism of generalization may be acquired from understanding why training transfers in some contexts but not others. However, identifying relevant contextual cues has proven surprisingly difficult, perhaps because the search has mainly been for cues that are explicit. We hypothesized instead that a relevant contextual cue is an implicit memory of action with a particular body part. To test this hypothesis we considered a task in which participants learned to control motion of a cursor under visuomotor rotation in two contexts: by moving their hand through motion of their shoulder and elbow, or through motion of their wrist. Use of these contextual cues led to three observations: First, in naive participants, learning in the wrist context was much faster than in the arm context. Second, generalization was asymmetric so that arm training benefited subsequent wrist training, but not vice versa. Third, in people who had prior wrist training, generalization from the arm to the wrist was blocked. That is...

History of medical screening: from concepts to action

Morabia, A; Zhang, F
Fonte: BMJ Group Publicador: BMJ Group
Tipo: text
Publicado em /08/2004 Português
Relevância na Pesquisa
65.65%
The objective of medical screening is to identify disease in its preclinical, and therefore hopefully still curable, phase. This may have been an old quest in medicine but it became historically possible when at least four conditions were met: the availability of simple, valid and acceptable forms of tests, the discovery of effective treatments, the establishment of a theory of screening, and the wide access to health care. Five selected examples that illustrate the history of medical screening are reviewed: screening for psychiatric disorders in the United States army as it is one of the oldest screening programmes; screening for syphilis as it used one of the earliest screening tests; screening for diabetes as one of the first modern forms of mass screening; screening for cervical cancer using the Pap test as one of the greatest successes of screening; and screening for breast cancer by mammography as this offers a good opportunity to discuss the development of modern evaluation of screening programmes. The evaluation of the impact of screening on human health slowly progressed, from obvious changes in the vital statistics such as the decline in incidence of syphilis, to less obvious changes such as the decline in mortality of cancer of the uterus...

The medical history as a diagnostic technology

Summerton, Nick
Fonte: Royal College of General Practitioners Publicador: Royal College of General Practitioners
Tipo: text
Publicado em 01/04/2008 Português
Relevância na Pesquisa
45.7%
The medical history is a powerful diagnostic technology. However, in seeking to establish an appropriate balance between the history and the other diagnostic modalities more explicit consideration must be given to the performance characteristics of the medical history. Building on recent work undertaken in the UK and elsewhere in Europe it is now feasible to develop a library of setting-specific likelihood ratios and ? statistics for key elements of the medical history. Of particular importance to those working in primary care, statistically adjusted combinations of information from the medical history can be generated; furnishing clinicians with likelihood ratios of significant magnitudes. It is suggested that developing a more rational approach to the use of the medical history could lead to improvements in diagnostic efficiency and effectiveness, with benefits for individual patient care in addition to the overall NHS budget. When diagnosis is viewed as a processing pathway founded on a robust medical history, it becomes clear than in some situations investigations may become unnecessary and, in other circumstances, their impact will be enhanced.

Improvements in Ability to Detect Undiagnosed Diabetes by Using Information on Family History Among Adults in the United States

Yang, Quanhe; Liu, Tiebin; Valdez, Rodolfo; Moonesinghe, Ramal; Khoury, Muin J.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: text
Português
Relevância na Pesquisa
45.67%
Family history is an independent risk factor for diabetes, but it is not clear how much adding family history to other known risk factors would improve detection of undiagnosed diabetes in a population. Using the National Health and Nutrition Examination Survey for 1999?2004, the authors compared logistic regression models with established risk factors (model 1) with a model (model 2) that also included familial risk of diabetes (average, moderate, and high). Adjusted odds ratios for undiagnosed diabetes, using average familial risk as referent, were 1.7 (95% confidence interval (CI): 1.2, 2.5) and 3.8 (95% CI: 2.2, 6.3) for those with moderate and high familial risk, respectively. Model 2 was superior to model 1 in detecting undiagnosed diabetes, as reflected by several significant improvements, including weighted C statistics of 0.826 versus 0.842 (bootstrap P = 0.001) and integrated discrimination improvement of 0.012 (95% CI: 0.004, 0.030). With a risk threshold of 7.3% (sensitivity of 40% based on model 1), adding family history would identify an additional 620,000 (95% CI: 221,100, 1,020,000) cases without a significant change in false-positive fraction. Study findings suggest that adding family history of diabetes can provide significant improvements in detecting undiagnosed diabetes in the US population. Further research is needed to validate the authors’ findings.

Likelihood-Free Inference of Population Structure and Local Adaptation in a Bayesian Hierarchical Model

Bazin, Eric; Dawson, Kevin J.; Beaumont, Mark A.
Fonte: Genetics Society of America Publicador: Genetics Society of America
Tipo: text
Publicado em /06/2010 Português
Relevância na Pesquisa
45.69%
We address the problem of finding evidence of natural selection from genetic data, accounting for the confounding effects of demographic history. In the absence of natural selection, gene genealogies should all be sampled from the same underlying distribution, often approximated by a coalescent model. Selection at a particular locus will lead to a modified genealogy, and this motivates a number of recent approaches for detecting the effects of natural selection in the genome as “outliers” under some models. The demographic history of a population affects the sampling distribution of genealogies, and therefore the observed genotypes and the classification of outliers. Since we cannot see genealogies directly, we have to infer them from the observed data under some model of mutation and demography. Thus the accuracy of an outlier-based approach depends to a greater or a lesser extent on the uncertainty about the demographic and mutational model. A natural modeling framework for this type of problem is provided by Bayesian hierarchical models, in which parameters, such as mutation rates and selection coefficients, are allowed to vary across loci. It has proved quite difficult computationally to implement fully probabilistic genealogical models with complex demographies...

History-Dependent Excitability as a Single-Cell Substrate of Transient Memory for Information Discrimination

Baroni, Fabiano; Torres, Joaquín J.; Varona, Pablo
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: text
Publicado em 28/12/2010 Português
Relevância na Pesquisa
45.76%
Neurons react differently to incoming stimuli depending upon their previous history of stimulation. This property can be considered as a single-cell substrate for transient memory, or context-dependent information processing: depending upon the current context that the neuron “sees” through the subset of the network impinging on it in the immediate past, the same synaptic event can evoke a postsynaptic spike or just a subthreshold depolarization. We propose a formal definition of History-Dependent Excitability (HDE) as a measure of the propensity to firing in any moment in time, linking the subthreshold history-dependent dynamics with spike generation. This definition allows the quantitative assessment of the intrinsic memory for different single-neuron dynamics and input statistics. We illustrate the concept of HDE by considering two general dynamical mechanisms: the passive behavior of an Integrate and Fire (IF) neuron, and the inductive behavior of a Generalized Integrate and Fire (GIF) neuron with subthreshold damped oscillations. This framework allows us to characterize the sensitivity of different model neurons to the detailed temporal structure of incoming stimuli. While a neuron with intrinsic oscillations discriminates equally well between input trains with the same or different frequency...

Genetic Study of Population Mixture and Its Role in Human History

Moorjani, Priya
Tipo: thesis or dissertation
Português
Relevância na Pesquisa
45.71%
Mixture between populations is an evolutionary process that shapes genetic variation. Intermixing between groups of distinct ancestries creates mosaics of chromosomal segments inherited from multiple ancestral populations. Studying populations of mixed ancestry (admixed populations) is of special interest in population genetics as it not only provides insights into the history of admixed groups but also affords an opportunity to reconstruct the history of the ancestral populations, some of whom may no longer exist in unmixed form. Furthermore, it improves our understanding of the impact of population migrations and helps us discover links between genetic and phenotypic variation in structured populations. The majority of research on admixed populations has focused on African Americans and Latinos where the mixture is recent, having occurred within the past 500 years. In this dissertation, I describe several studies that I have led that expand the scope of admixed studies to West Eurasians and South Asians where the mixture is older, and data from ancestral groups is mostly unavailable. First, I introduce a novel method that studies admixture linkage disequilibrium (LD) to infer the time of mixture. I analyze genomewide data from 40 West Eurasian populations and show that all Southern European...

Development, Calibration and Performance of an HIV Transmission Model Incorporating Natural History and Behavioral Patterns: Application in South Africa

McCormick, Alethea W.; Abuelezam, Nadia N.; Rhode, Erin R.; Hou, Taige; Walensky, Rochelle P.; Pei, Pamela P.; Becker, Jessica E.; DiLorenzo, Madeline A.; Losina, Elena; Freedberg, Kenneth A.; Lipsitch, Marc; Seage, George R.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
45.74%
Understanding HIV transmission dynamics is critical to estimating the potential population-wide impact of HIV prevention and treatment interventions. We developed an individual-based simulation model of the heterosexual HIV epidemic in South Africa and linked it to the previously published Cost-Effectiveness of Preventing AIDS Complications (CEPAC) International Model, which simulates the natural history and treatment of HIV. In this new model, the CEPAC Dynamic Model (CDM), the probability of HIV transmission per sexual encounter between short-term, long-term and commercial sex worker partners depends upon the HIV RNA and disease stage of the infected partner, condom use, and the circumcision status of the uninfected male partner. We included behavioral, demographic and biological values in the CDM and calibrated to HIV prevalence in South Africa pre-antiretroviral therapy. Using a multi-step fitting procedure based on Bayesian melding methodology, we performed 264,225 simulations of the HIV epidemic in South Africa and identified 3,750 parameter sets that created an epidemic and had behavioral characteristics representative of a South African population pre-ART. Of these parameter sets, 564 contributed 90% of the likelihood weight to the fit...

Heterogeneity in the Frequency and Characteristics of Homologous Recombination in Pneumococcal Evolution

Mostowy, Rafal; Croucher, Nicholas J.; Hanage, William P.; Harris, Simon R.; Bentley, Stephen; Fraser, Christophe
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
55.5%
The bacterium Streptococcus pneumoniae (pneumococcus) is one of the most important human bacterial pathogens, and a leading cause of morbidity and mortality worldwide. The pneumococcus is also known for undergoing extensive homologous recombination via transformation with exogenous DNA. It has been shown that recombination has a major impact on the evolution of the pathogen, including acquisition of antibiotic resistance and serotype-switching. Nevertheless, the mechanism and the rates of recombination in an epidemiological context remain poorly understood. Here, we proposed several mathematical models to describe the rate and size of recombination in the evolutionary history of two very distinct pneumococcal lineages, PMEN1 and CC180. We found that, in both lineages, the process of homologous recombination was best described by a heterogeneous model of recombination with single, short, frequent replacements, which we call micro-recombinations, and rarer, multi-fragment, saltational replacements, which we call macro-recombinations. Macro-recombination was associated with major phenotypic changes, including serotype-switching events, and thus was a major driver of the diversification of the pathogen. We critically evaluate biological and epidemiological processes that could give rise to the micro-recombination and macro-recombination processes.

Effectiveness of Insecticide Spraying and Culling of Dogs on the Incidence of Leishmania infantum Infection in Humans: A Cluster Randomized Trial in Teresina, Brazil

Werneck, Guilherme L.; Costa, Carlos H. N.; de Carvalho, Fernando Aécio Amorim; Pires e Cruz, Maria do Socorro; Maguire, James H.; Castro, Marcia C.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
55.5%
Background: To evaluate the effect of insecticide spraying for vector control and elimination of infected dogs on the incidence of human infection with L. infantum, a randomized community intervention trial was carried out in the city of Teresina, Brazil. Methods/Principal Findings Within each of ten localities in the city, four blocks were selected and randomized to 4 interventions: 1) spraying houses and animal pens with insecticide; 2) eliminating infected dogs; 3) combination of spraying and eliminating dogs, and 4) nothing. The main outcome is the incidence of infection assessed by the conversion of the Montenegro skin test (MST) after 18 months of follow-up in residents aged ?1 year with no previous history of visceral leishmaniasis (VL). Reactions were measured at 48–72 h, induration of ?5 mm considered positive. Interventions were executed after the baseline interview and repeated 6 and 12 months later. The effects of each type of intervention scheme on the incidence of infection were assessed by calculating relative risks and 95% confidence intervals using Poisson population-averaged regression models with robust variance. Among the 1105 participants, 408 (37%) were MST positive at baseline. Of the 697 negatives, only 423 (61%) were reexamined at the end of the follow-up; 151 (36%) of them converted to a positive MST. Only dog culling had some statistically significant effect on reducing the incidence of infection...

Discovering user context with mobile devices : location and time

Song, Ning, M. Eng. Massachusetts Institute of Technology
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: thesis Formato: 62 leaves
Português
Relevância na Pesquisa
55.5%
Life for many people is based on a set of daily routines, such as home, work, and leisure. If the activities in life occur in recurring patterns, then the context in which they occur should also follow a pattern. In this thesis, we explore using cell phones for learning recurring locations using only a timestamped history of the cell tower the device is connected to. We base our approach on an existing graph-based online algorithm, but modify it to compute additional statistics for offline analysis to obtain better results. We then further refine the offline algorithm to include time-partitioned nodes to resolve some observed shortcomings. Finally, we evaluate all three algorithms on a dataset of GSM readings over a one month period, and show how our successive modifications improved the locations found.; by Ning Song.; Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.; Includes bibliographical references (leaves 59-62).