Estudaremos a teoria de bases de Gröbner em anéis de polinômios comutativos com coeficientes em uma nelnoetheriano e em anéis de operadores diferencias. Apresentaremos, em ambos casos, uma generalização do algoritmo da divisão, do S-polinômio e do algoritmo de Buchberger para calcular bases de Gröbner. / We study the theory of Gröbner bases for commutative polynomials rings over a noetherian ring and of rings of differential operators. In both cases we exhibit a generalization of the division algorithm, the S -polynomial and the Buchberger algorithm for computing Gröbner bases.

O objetivo desta dissertação é retomar a controvérsia em torno dos efeitos da liberalização comercial sobre o mercado de trabalho brasileiro, em especial os diferenciais de salários entre trabalhadores qualificados e não qualificados na indústria de transformação em 1995 e 1999. Após uma adaptação da decomposição de Oaxaca-Blinder (OB), encontramos evidências, para o Brasil como um todo e para a região metropolitana de São Paulo, de que o diferencial de salário aumentou, em benefício dos trabalhadores qualificados. Considerando a hipótese de que o Brasil é um país com abundância de trabalho não qualificado e intensivo neste fator, este resultado é oposto à premissa teórica do modelo Heckscher-Ohlin e Stolper-Samuelson (HOS) e suas variantes, de que a abertura de um país em desenvolvimento, ou intensivo em trabalho não qualificado, tende a diminuir a desigualdade. Do outro lado, encontramos evidências para a região metropolitana de Recife, de que o diferencial salarial entre trabalhadores qualificados e não qualificados diminuiu após a liberalização comercial, corroborando com a premissa teórica do modelo HOS e suas variantes. Entretanto, este resultado não deve, evidentemente, ser estendido para o Brasil, ilustrando assim diferenças regionais e estruturais não negligenciáveis do mercado de trabalho por região da Federação. / The objective of this MA Dissertation was to take up again the controversy of the effects of trade liberalization in Brazilian labor market, specially the wage differentials between skilled and unskilled workers in the industry in 1995 and 1999. After an adaptation of Oaxaca-Blinder decomposition (OB), it was found evidence in Brazil as a whole and in Sao Paulo metropolitan area, that wage differential increased for the benefit of skilled workers. On one hand, supposing that Brazil is an economy characterized by unskilled workers abundance which are intensively used, this result is contrary to the premise theory of Heckscher-Ohlin and Stolper-Samuelson (HOS) model and their variants that defends that trade liberalization in developing country, or unskilled worker intensive countries, has a tendency to reduce inequality. On the other hand, it was found evidence in Recife metropolitan area that wage differential between skilled and unskilled workers has reduced after trade liberalization, corroborating with the theory premise of HOS model and their variants. However, this result cannot be extended to Brazil, illustrating, therefore, its labor markets regional and structural differences.

Estudaremos a teoria de bases de Gröbner em anéis de polinômios comutativos com coeficientes em uma nelnoetheriano e em anéis de operadores diferencias. Apresentaremos, em ambos casos, uma generalização do algoritmo da divisão, do S-polinômio e do algoritmo de Buchberger para calcular bases de Gröbner. / We study the theory of Gröbner bases for commutative polynomials rings over a noetherian ring and of rings of differential operators. In both cases we exhibit a generalization of the division algorithm, the S -polynomial and the Buchberger algorithm for computing Gröbner bases.

Trata-se de um estudo ecológico exploratório tipo comparação de múltiplos grupos. Objetivo: descrever o padrão de mortalidade da população a partir de estratos homogêneos de vulnerabilidade social dos municípios no Estado de São Paulo de 2003 a 2005. Método: Construção de estratos homogêneos, através de indicador composto por variáveis socioeconômicas e demográficas e comparação dos padrões de mortalidade através de taxas padronizadas. Resultados: Construção de cinco estratos homogêneos de vulnerabilidade social (Muito Fraca, Fraca, Intermediária, Intensa e Muito Intensa). Estimativas de risco mais elevadas para mortes maternas (27,82 a 56,22 %000 nascidos vivos), mortes infantis (12,48 a 16,20%0 nascidos vivos) e acidentes de transporte (14,68 a 24,06%000 hab.) foram mostradas nos estratos de maior vulnerabilidade declinando para os de menor vulnerabilidade. Para as Neoplasias (80,85 a 104,96 %000 hab.) e D. Infecciosas e Parasitárias (23,21 a 27,52 a %000 hab.) as mais elevadas ocorreram nos estratos de menor vulnerabilidade, declinando para os de maior vulnerabilidade. Para Diabetes Mellitus (17,36 a 23,57%000 hab.), D. Circulatórias (174,03 a 206,87%000 hab.), Homicídios (11,50 a 21,24%000 hab.) e, D. Respiratórias (62,58 a 75,54 %000 hab.), as mais elevadas situaram-se no estrato de vulnerabilidade social intermediária, declinando para os de maior vulnerabilidade, à exceção da Diabetes Mellitus. Conclusões: Foram evidenciadas desigualdades de mortalidade, apontando para grupos humanos com maiores necessidades de saúde, estratificação do risco epidemiológico e identificação de áreas críticas que indicam para a necessidade do desenvolvimento de políticas de saúde mais equitativas. / This is an ecologic exploratory study employing multiple group comparison. Objective: to describe mortality patterns of the population from homogeneous social vulnerable strata of the cities in the State of São Paulo, from 2003 to 2005. Method: Construction of homogeneous strata employing an indicator composed of socioeconomic and demographic variables and comparison of mortality patters through standardized rates. Results: Construction of five homogeneous social vulnerability strata (Very Weak, Weak, Intermediate, Intense and Very Intense). Risk estimates higher for maternal deaths (27,82 to 56,22 %000 live births), children deaths (12,48 to 16,20%0 live births) and transportation accidents (14,68 to 24,06%000 inhabitants) were shown in the strata of higher vulnerability, declining for those in lower vulnerability. For Neoplasias (80,85 to 104,96 %000 inhabitants) and Infectious and Parasitic diseases (23,21 a 27,52 a %000 inhabitants) higher rates corresponded to lower vulnerability strata, declining for those in higher vulnerability. Diabetes Mellitus (17,36 a 23,57%000 inhabitants), Homicides (11,50 a 21,24%000 inhabitants) and Respiratory Diseases (62,58 a 75,54 %000 inhabitants) higher rates were found at the intermediate social vulnerability stratum, declining for those in higher vulnerability, except for Diabetes Mellitus. Conclusions: Mortality inequalities became evident, pointing to human groups in higher health needs, stratification of the epidemiologic risk and identification of critical areas that show the need to develop more equitable health policies.

Diss. Stockholm : Handelshögskolan, 1993

This paper uses co-integration method and error-correction model to re-examine the relationship between real exchange rate and expected interest rate differentials, including cumulated current account balance, over floating exchange rate periods. As indicated by the dynamic model, I find that there is a long run relationship among the variables using Johansen co-integration method. Final conclusion is that the empirical evidence is provided to show that our error-correction model leads to a good real exchange rate forecast.

The aim of this study is to examine whether, and to what extent, the differences in wages between women and men can be explained by discrimination against women in the labour market.The first part of the analysis is a cross-sectional analysis. Firstly, a model is estimated with wages as the dependent variable and with sex, individuals' qualifications, personal characteristics, occupation and the branch of industry in which they are employed as the independent variables. The results of this regression reveal that the hourly wage for a woman is about nine SEK lower than for a man. Separate wage functions for women and men show that women obtain a lower return from both education and work experience. A breakdown of the difference in wages reveals that most of the dissimilarity is explained by discrimination against women and very little by differences in men's and women's productivity. In the absence of discrimination, women's relative pay would be between 16 and 25 percent higher. The stability of the findings is checked by means of reverse regression. This resulted in discrimination against men in some cases and against women in others. Thus, different conclusions can be drawn from the two methods. In certain special cases the results produced by reverse regression are correct, whereas, in more general cases, the direct method shows itself to be more satisfactory. The study ends with an analysis of the effects of various laws and agreements on the development of women's wages and employment in Swedish industry. The introduction of equal pay, the removal of the ban on night work for women in industry and the wage solidarity policy have had a positive influence on the relative demand for women workers. The study's conclusions are, firstly, that the differences in pay between the sexes can partly be explained by discrimination against women. Secondly, within industry, wage discrimination against women has declined as a result of changes leading in an anti-discrimination direction. / digitalisering@umu

The three chapters of my dissertation examine immigrant assimilation in the Canadian labour market. Through three levels of analysis, which are distinguished by the sample restrictions that are employed, I investigate immigrant labour force and job dynamics, immigrant propensity for self-employment, and immigrant wage assimilation, respectively. In the first chapter, I exploit recently-introduced immigrant identifiers in the Canadian Labour Force Survey (LFS) and the longitudinal dimension of these data to compare the labor force and job dynamics of Canada's native-born and immigrant populations. I am particularly interested in the role of job, as opposed to worker, heterogeneity in driving immigrant wage disparities and in how the paths into and out of jobs of varying quality compares between immigrants and the native-born. The main finding is that the disparity in immigrant job quality, which does not appear to diminish with years since arrival, reflects a combination of relatively low transitions into high-wage jobs and high transitions out of these jobs. The former result appears about equally due to difficulties obtaining high-wage jobs directly out of unemployment and in using low-wage jobs as stepping-stones. I find little or no evidence, however, that immigrant jobseekers face barriers to low-wage jobs. We interpret these findings as emphasizing the empirical importance of the quintessential immigrant anecdote of a low-quality "survival job" becoming a "dead-end job". The second chapter analyzes immigrant choice of self-employment versus paid employment. Using the Canadian Census public use microdata files from 1981 to 2006, I update the Canadian literature on immigrant self-employment by examining changes in the likelihood of self-employment across arrival cohorts of immigrants and how self-employment rates evolve in the years following migration to Canada. This study finds that new immigrants, who arrived between 1996 and 2005, turned to self-employment at a faster rate than the earlier cohorts and that immigrants become increasingly likely to be self-employed as they spend more time in Canada. More important, I examine immigrant earnings outcomes relative to the native-born, instead of within, sectors and thus explore the extent to which a comparative advantage in self-employment, captured by the difference in potential earnings between the self- and paid-employment sectors, can explain the tremendous shift toward self-employment in the immigrant population. The results show that the earnings advantage between the self- and the paid-employment sectors accounts for the higher likelihood of self-employment for traditional immigrants in the years following migration. However, the potential earnings difference cannot explain the reason that non-traditional immigrants are more likely to be self-employed as they consistently lose an earnings advantage in the self-employment sector relative to the paid-employment sector. My paper suggests that immigrants may face barriers to accessing paid-employment, or immigrants are attracted to self-employment by non-monetary benefits. Lastly, in the third chapter, studies which estimate separate returns to foreign and host-country sources of human capital have burgeoned in the immigration literature in recent years. In estimating separate returns, analysts are typically forced to make strong assumptions about the timing and exogeneity of human capital investments. Using a particularly rich longitudinal Canadian data source, I consider to what extent the findings of the Canadian literature may be driven by biases arising from errors in measuring foreign and host-country sources of human capital and the endogeneity of post-migration schooling and work experience. The main finding is that the results of the current literature by and large do not appear to be driven by the assumptions needed to estimate separate returns using the standard data sources available.

<p>This paper uses co-integration method and error-correction model to re-examine the relationship between real exchange rate and expected interest rate differentials, including cumulated current account balance, over floating exchange rate periods. As indicated by the dynamic model, I find that there is a long run relationship among the variables using Johansen co-integration method. Final conclusion is that the empirical evidence is provided to show that our error-correction model leads to a good real exchange rate forecast.</p>

Thesis (Ph. D.)--University of California, San Diego, 2003. / Vita. Includes bibliographical references.