413 research outputs found
Introduction to probabilistic concurrent systems
No full textThe first part of the paper is an introduction to the theory of probabilistic
concurrent systems under a partial order semantics. Key definitions and results
are given and illustrated on examples. The second part includes contributions.
We introduce deterministic concurrent systems as a subclass of concurrent
systems. Deterministic concurrent system are "locally commutative'" concurrent
systems. We prove that irreducible and deterministic concurrent systems have a
unique probabilistic dynamics, and we characterize these systems by means of
their combinatorial properties.Comment: Extended version of the Petri Net 2021 conference paper
arXiv:2008.07233 "Deterministic concurrent systems" by the same author. 32
pages, 9 figures, 17 reference
Análisis de escenarios de financiamiento para fortalecer la liquidez de la cooperativa de ahorro y crédito Sumak Samy Ltda.
No full textLas cooperativas de ahorro y crédito se ven afectadas por la insuficiencia de liquidez, lo que genera una inestabilidad financiera y pérdidas derivadas de eventos que obstaculizan el cumplimiento de los compromisos financieros adquiridos por la entidad. El objetivo del estudio es encontrar escenarios de financiamiento para mejorar la liquidez de la Cooperativa de Ahorro y Crédito Sumak Samy Ltda. La investigación se llevó a cabo con un diseño no experimental y un enfoque mixto transversal, utilizando los métodos analítico-sintético e hipotético-deductivo. Los resultados del estudio indican que la falta de estrategias de financiamiento está generando problemas de liquidez en la institución, lo que impide el desarrollo normal de sus actividades y dificulta su crecimiento institucional. En el ámbito financiero, el índice de liquidez es un pilar fundamental para el crecimiento y fortalecimiento de la institución, a medida que tiene como fin diagnosticar la capacidad de una entidad para generar suficiente dinero en efectivo
Relative returns to policy reform - evidence from controlled cross-country regressions
No full textThe authors aim at contributing to understand the dispersion of returns from policy reforms using cross-country regressions. The authors compare the"before reform"with"after reform"GDP growth outcome of countries that undertook import-liberalization and fiscal policy reforms. They survey a large sample (about 54) of developing countries over the period 1980-99. The benefits of openness to trade and fiscal prudence have been extensively identified in the growth literature, but the evidence from simple cross-section analysis can sometimes be inconclusive and remains vulnerable to criticism on estimation techniques, such as identification, endogeneity, multi-colinearity, and the quality of the data. The authors use a different analytical framework that establishes additional controls. First, they construct a counterfactual control group. These are countries that-under specific thresholds-did not introduce policy reforms under scrutiny. Second, the authors also try to use the most appropriate variable of policy reform, for example, exogenous changes in import-tariffs instead of the endogenous sum of all trade flows. Third, the authors try to base the before-after reform comparison on the most accurate date for the beginning of a policy reform period (instead of comparing averages over fixed intervals of time). Once these controls are set, they explain the difference between average GDP growth rates during the country-specific post and the pre-reform periods, relative to the average GDP growth of the relevant control group. The explanatory variables in the regressions include the standard growth-regression controls. The results are the following: 1) With a better measurement and timing of the policy reforms, the growth effect (the"returns on reform") is generally smaller than in previous papers. 2) There is evidence of contingent relationships between policy and growth, corresponding to the country's size, its export profile, and its governance. 2) Within the group of policy reformers, some countries have exhibited a relatively weaker growth response. Overall, the findings suggest that more accurate measurement and definition of the timing of reforms does not strengthen the significance of the effects of reforms on GDP growth. In fact, the effects are weaker than indicated in most cross-section studies. This suggests that the policy implications to be derived from these relationships should be treated with even more caution than previously thought.Environmental Economics&Policies,Trade Policy,Public Health Promotion,Economic Theory&Research,Health Monitoring&Evaluation,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Economic Theory&Research,Achieving Shared Growth,Environmental Economics&Policies,Trade and Regional Integration
Análisis de escenarios de financiamiento para fortalecer la liquidez de la Cooperativa de Ahorro y Crédito Sumak Samy Ltda.
No full textSavings and credit cooperatives are affected by insufficient liquidity, which generates financial instability and losses derived from events that hinder the fulfillment of the financial commitments acquired by the entity. The objective of the study is to find financing scenarios to improve the credit union's liquidity. Through the application of strategies that allow having sufficient resources. The research was carried out with a non-experimental design and a mixed transversal approach, using the analytical-synthetic and hypothetical-deductive methods. The results of the study indicate that the lack of financing strategies is generating liquidity problems in the institution, which prevents the normal development of its activities and hinders its institutional growth. In the financial field, the liquidity index is a fundamental pillar for the growth and strengthening of the institution, as its purpose is to diagnose the capacity of an entity to generate sufficient cash.Las cooperativas de ahorro y crédito se ven afectadas por la insuficiencia de liquidez, lo que genera una inestabilidad financiera y pérdidas derivadas de eventos que obstaculizan el cumplimiento de los compromisos financieros adquiridos por la entidad. El objetivo del estudio es encontrar escenarios de financiamiento para mejorar la liquidez de la Cooperativa de Ahorro y Crédito Sumak Samy Ltda. La investigación se llevó a cabo con un diseño no experimental y un enfoque mixto transversal, utilizando los métodos analítico-sintético e hipotético-deductivo. Los resultados del estudio indican que la falta de estrategias de financiamiento está generando problemas de liquidez en la institución, lo que impide el desarrollo normal de sus actividades y dificulta su crecimiento institucional. En el ámbito financiero, el índice de liquidez es un pilar fundamental para el crecimiento y fortalecimiento de la institución, a medida que tiene como fin diagnosticar la capacidad de una entidad para generar suficiente dinero en efectivo
The Africa Growth and Opportunity Act and its rules of origin : generosity undermined?
No full textThe African Growth and Opportunity Act (AGOA), signed into American law on May 18, 2000, is a major plank of U.S. initiatives toward the African continent. The Act aims broadly at improving economic policymaking in Africa, enabling countries to embrace globalization, and securing durable political and economic stability. As an incentive for Africa to adopt the necessary policy reform, AGOA offers increased preferential access for African exports to the United States. This paper describes the provisions of AGOA and assesses its quantitative impact on African exports, particularly in the apparel sector. Its main conclusions are: 1) AGOA will provide real opportunities to Africa. Even on conservative estimates about Africa's supply response, Africa's non-oil exports could be increased by about 8-11 percent. 2) However, the medium-term gains could have been much greater if AGOA had not imposed certain conditions and not excluded certain items from its coverage. The most important condition is the stringent rule-of-origin, that is, the requirement that exporters source certain inputs from within Africa or the United States. Estimates suggest that the absence of these conditions would have magnified the impact nearly five-fold, resulting in an overall increase in non-oil exports of US100-US$140 million increase that is expected in the presence of these restrictions. These restrictions, particularly on apparel, will come at a particularly inopportune time, as Africa will be exposed to competition from other developing countries when the quotas maintained on the latters'exports under the Multi-Fiber Arrangement (MFA) are eliminated. Africa's apparel exports will be lower by over 30 percent with the dismantling of the MFA. If, on the other hand, AGOA had provided unrestricted access, the negative impact of the dismantling could be nearly fully offset.Export Competitiveness,Economic Theory&Research,Trade Policy,Environmental Economics&Policies,Agribusiness&Markets,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Economic Theory&Research,Environmental Economics&Policies,Export Competitiveness,Trade Policy
Production of hydrogen from water using a thermochemical copper-chlorine cycle
No full textA system for producing hydrogen gas from water decomposition using a thermochemical CuCl cycle, the improvement comprising the use of an insulated hydrogen production reactor comprising a reaction chamber and a separation chamber; the reaction chamber having a hydrogen chloride gas inlet and a solid copper inlet; one or more levels provided in the reaction chamber, the number of which is dependant on production scale and pressure drop; each level comprising a perforated plate with associated filter media, the perforations of the plate and media being of decreasing size from top to bottom of the reaction chamber, and being sized to permit downward flow of the hydrogen gas and molten CuCl products, as well as the HCL gas reactant, and to prevent entrainment of solid copper in the molten CuCl; the separation chamber being located below the reaction chamber and being of greater cross section than the reaction chamber and comprising a first hydrogen removal and entrained copper removal zone and a second molten CuCl removal zone; removal of the reaction products being controlled so as to substantially decrease the amount of entrained copper in the molten CuCl; and the first zone having outlets for removal of hydrogen gas and entrained copper particles, with the second zone having an outlet for removal of molten CuCl
Macroeconomics effects of private sector participation in Latin America's infrastructure
No full textThe authors provide empirical evidence on the impact that private participation in infrastructure has had on key macroeconomic variables in a sample of 21 Latin American countries from 1985-98. Specifically, they look at the effects on GDP per capita, current public expenditures, public investment, and private investment, controlling for country effects and institutional factors. The authors also investigate the relevance of the specific contractual form of private participation contracts on these variables and show differentiated effects according to contract types. The results suggest that: 1) Private sector involvement in utilities and transport have some, but not impressive, positive effects on GDP per capita. 2) There is some degree of crowding-out of private investment resulting from greenfield projects in utilities, and delayed crowding-in from concessions in transport. 3) There is crowding-in of public investment by private participation in utilities, while there is crowding-out by increased private investment in transport. 4) Private participation in utilities decreases recurrent expenditures, while in transport it results in an increase. The net effect on the public sector account is uncertain, but this uncertainty is a major risk. The revelation of this risk may be the main contribution of this paper since it is inconsistent with the fiscal gains expected by many policymakers as they engage in infrastructure privatization programs.Decentralization,Environmental Economics&Policies,Labor Policies,Health Economics&Finance,ICT Policy and Strategies,Health Economics&Finance,Environmental Economics&Policies,ICT Policy and Strategies,Scientific Research&Science Parks,Science Education
Ensaios sobre o poder judiciário no Brasil
No full textThis thesis is a collection of empirical essays on the institut ional features of the justice system in Brazil, focused on state district courts of the first degree. It relies on econometric methods and insights from microeconomic theory, which are essential towards understanding and modeling micro - level data (case dat a). The first chapter investigates another important feature of judicial behavior: whether judges exhibit any sort of systematic bias towards poor litigants. Many surveys have shown that in the process of decision - making, judges in Brazil tend to put signi ficant weight on the social consequences of their decisions, in detriment of strict observance of the law. Survey results must be confronted with patterns revealed by actual case data, which justifies the study. The statistical analysis is based on an orig inal database, constructed by the author based on the collection of millions of civil cases for the State Justice of Paraná . Relying on a discrete choice model, the paper estimates the winning chances of poor litigants relative to non - poor litigants, contr olling for all case and jurisdiction characteristics. The main conclusion of the study is that poor litigants are less likely to win a case than non - poor counterparts. These results consider the mechanisms through which poverty conditions may affect case o utcomes: i) when poverty condition is a substantive fact of the case and part of the legal reasoning (which typically occurs in family cases); ii) selection of disputes: poverty condition implies changes in fee - shifting schemes, with a direct impact on the expected value of the dispute; iii) selection and incentives of attorneys: poor litigants may face selection and incentive problems with respect to attorneys, thereby reducing their chances of victory in court. After taking into account such mechanisms, t he study finds no evidence that judges tend to favor poor litigants. In particular, the comparison between poor and non - poor plaintiffs suggest the occurrence of opportunistic behavior, related to the abuse of indigent assistance benefits, which eliminates fee - shifting and, as result, all the downside associated to the law suit. The second chapter is an attempt to test whether there exists a trade - off between procedural fairness and judicial efficiency. Put another way, the fact that a case is resolved faster is potentially compromising to the quality of the sentence. Again, conv entional wisdom has been supportive of that dilemma, on the grounds that expeditiousness is detrimental of the compliance to the right to legal due process. The study presents an empirical framework to test the hypothesis that such a dilemma exists in the Brazilian justice system. The model relies on the basic premise that the quality of the judicial decision is inversely related to its chances of being reversed by the court of appeals ( Tribunal de Justiça ). The database is constructed by the author, this t ime based on information available for thousands of cases in district courts of Minas Gerais . The data comprises various civil cases and their respective appeals. Based on a linear probability model, results suggest that the dilemma isn't corroborated by the data. On the contrary, they are suggestive of a complementary relation between expeditiou sness and quality: cases that are tried faster are associated with 'better' sentences, in the sense that they are less likely to be reversed at the court of appeals. The empirical model includes all case characteristics, and discusses the possibility of se lection bias on the sample. The last chapter is a study on the decision patterns of courts of appeals in criminal cases. The main objective is to measure the impact of judicial backgrounds on appellate decisions, based on jurisprudence from the State Supr eme Court of Santa Catarina , Brazil. The study exploits a particular feature of the judicial selection process in Brazil: the Federal Constitution reserves 10% of the seats in State Supreme Courts to attorneys affiliated to the Brazilian Bar Association (O AB), and 10% to public prosecutors ( Ministerio Publico ). The remainder of the Court seats are to be filled by career Judges from district courts. Those three backgrounds provide a clear - cut distinction on ideological cleavages. Specifically, under the null hypothesis, we expect, in criminal cases, that former attorneys adopt a pro - defendant stance whereas former prosecutors adopt a pro - plaintiff stance. Based on a large sample of criminal appeals in Santa Catarina , this study takes advantage that cases are randomly assigned to judges, to identify the causal effects of legal backgrounds on judicial decision - making. Results suggest that former prosecutors are 20% more likely to decide against defendants than career judges. On the other hand, former attorneys a re 6% more likely to do so. Considering a sample of procedural cases only, we find much stronger effects: former prosecutors are 50% more likely and former attorneys are 50% less likely to decide against defendants. The strong background effects, found on procedural matters, reveal that former attorneys (prosecutors) tend to regard procedural rights much more (less) seriously than former judges.Esta tese apresenta três artigos – organizados em três capítulos – sobre os padrões decisórios dos magistrados no Brasil. O primeiro artigo avalia uma questão importante a respeito de comportamentos judiciais qual seja a da possibilidade da existência de um viés favorável ao pobre em ações judiciais. Diversas pesquisas de opinião realizadas no Brasil têm mostrado que os magistrados tem uma preocupação com a desigualdade social e que por isso, levam em consideração as consequências sociais de suas decisões judiciais, além da pura e simples observância das leis. Este cenário confere relevância à questão de se, em termos práticos, os magistrados apresentam algum tipo de viés judicial, notadamente em relação a cidadãos menos favorecidos. Assim, este artigo busca testar a presença de viés judicial. Em termos de um modelo estatístico, configura-se uma situação de viés favorável ao pobre quando este possui chances maiores de vitória na ação judicial, comparado com não pobres. O artigo discute diversos mecanismos teóricos através dos quais a condição de hipossuficiência da parte influencia o resultado judicial. Os testes estatísticos se baseiam em uma base de dados construída a partir dos links de acompanhamento processual do sítio de internet do tribunal de Justiça do Paraná. Os resultados não corroboram a hipótese de que existe viés judicial favorável aos pobres. O segundo artigo tem como objetivo apresentar um teste estatístico para a hipótese de que “a justiça tarda, mas não falha”. Esta hipótese traduz-se em um dilema entre celeridade processual e a qualidade da sentença. O método de pesquisa consiste em um teste estatístico para a hipótese de que a duração do processo eleva a chances de reforma em instância superior, isto é, reduz a qualidade da sentença. A partir de uma grande amostra aleatória de processos cíveis da justiça comum do primeiro grau de Minas Gerais, estima-se a probabilidade de reforma de uma decisão judicial do primeiro grau, em função da duração do processo. Visando contornar problemas de viés de variável omitida e viés de seleção, o modelo inclui diversas variáveis de controle, incluindo: características do processo originário, tais como classe, complexidade e valor da causa, além do número de advogados e tipos de partes; e efeitos fixos de jurisdição originária e de órgão julgador. Os resultados não só refutam a existência de um dilema entre duração e qualidade, como sugerem que a morosidade processual eleva a probabilidade de reforma de uma decisão judicial. Dito de outra forma, a qualidade das decisões judiciais varia diretamente com o grau de celeridade processual. Nesse sentido, a necessidade de se atingir uma justiça imparcial e equilibrada não deveria servir como justificativa para a morosidade judicial. No último artigo, analise-se o papel da formação profissional dos magistrados sobre suas decisões. O artigo apresenta quantificações acerca dos efeitos da formação profissional e jurídica dos magistrados sobre suas decisões judiciais. Especificamente, busca-se analisar em que medida as diferenças nas origens de carreira dos desembargadores (que podem ser oriundos da carreira de juiz, do Ministério Público ou da advocacia), têm efeito sobre o resultado de apelações e incidentes criminais. Utiliza-se a base de dados de jurisprudência do tribunal de Justiça de Santa Catarina, construída especificamente para esta pesquisa. A hipótese nula da pesquisa se divide em duas partes: primeiro, os desembargadores oriundos da advocacia são sistematicamente mais propensos a decidir favoravelmente ao réu, comparados àqueles oriundos da carreira de juiz. Segundo, os desembargadores oriundos do Ministério Público são sistematicamente mais propensos a decidir contrariamente ao réu, relativamente aqueles oriundos da carreira. Os resultados empíricos sugerem a presença de efeitos de origem bastante significativos, particularmente quando se consideram incidentes recursais - o que corrobora a noção de que a formação jurídica do magistrado é relevante para explicar a prevalência do "garantismo processual", especialmente na área criminal
Puglia with Open Arms
No full textThis tale is a love story, a Valentine, to the Puglia region of Italy. Suffused with Mediterranean warmth and geniality, it follows the adventures of Samy Ben Meddah, of North African origin, as he meets Italian counterparts from the north shore of the Mediterranean. Behind the southern warmth of Puglia there lurks a serious subject, the problematic of immigration and culture shocks in a transcultural world. The author presents a wide spectrum of immigrations: geographical, temporal, and artistic. But the whole is leavened by wit and the Southern joie de vivre. As Samy leaves Puglia, he summarizes its manifold attractions:
It is simple... natural... welcoming... convivial... seductive... generous... affectionate... Then it will be forever part of my journey... for to return here is to find again an old friend... with whom I lived an unprecedented love... It is also to leave again for new horizons... for so many encounters... so many communions..
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