Switching-Cell Arrays - An Alternative Design Approach in Power Conversion

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThe conventional design of voltage-source power converters is based on a two-level half-bridge configuration and the selection of power devices designed to meet the full application specifications (voltage, current, etc.). This leads to the need to design and optimize a large number of different devices and their ancillary circuitry and prevents taking advantage from scale economies. This paper proposes a paradigm shift in the design of power converters through the use of a novel configurable device consisting on a matrix arrangement of highly-optimized switching cells at a single voltage class. Each switching cell consists of a controlled switch with antiparallel diode together with a self-powered gate driver. By properly interconnecting the switching cells, the switching cell array (SCA) can be configured as a multilevel active-clamped leg with different number of levels. Thus, the SCA presents adjustable voltage and current ratings, according to the selected configuration. For maximum compactness, the SCA can be conceived to be only configurable by the device manufacturer upon the customer needs. For minimum cost, it can also be conceived to be configurable by the customer, leading to field-configurable SCAs. Experimental results of a 6x3 field-configurable SCA are provided to illustrate and validate this design approach.Peer ReviewedPostprint (author's final draft

Access to Credit and the Effect of Credit Constraints on Costa Rican Manufacturing Firms

This paper examines the finances and the effect of credit limitations on the behavior and performance of firms in Costa Rica. The study is based on a survey of manufacturing firms conducted by the authors during 2001. The paper characterizes the profile firms’ finances, examines the determinants of firms’ access to banking credit and tries to assess the effect of credit constraints on the behavior and performance of firms. The paper finds that while banks are the main source of credit for larger firms, non-banking credit (trade plus informal credit) remains the leading source of funds for smaller firms. Moreover, own funds and informal credit is a leading form of credit for newly created firms. It is also found that the probability of having banking credit and the fraction of banking credit/total debt is mostly affected by (if anything) characteristics of the firm and not by those of their owners. Indeed, the firm’s value and age, and whether it keeps formal accounting procedures appear as the most relevant determinants of access to banking credit. With respect to the starting up finances of firms, the data is not conclusive on the determinants of banking credit, yet it suggests a negative relationship with the previous entrepreneurship experience of the owner. The paper discusses different explanations, all of which highlight the importance of credit constraints. Adopting ideas from the econometric literature on treatment effects, the paper explores the effect of banking credit on the behavior and performance of firms. Two different methods are used to correct for selection biases: a parametric two-step point method and a non-parametric method that estimates upper and lower bounds for the effects. While the results are not statistically conclusive, both methods do suggest that having access to banking credit positively affects firms’ performance.

Productive Development Policies in Costa Rica: Market Failures, Government Failures, and Policy Outcomes

This paper analyzes five Productive Development Policies (PDPs) implemented in Costa Rica, finding that they are not optimally addressing market failures. Moreover, government failures rather than market failures represent the main justification for PDPs. Even in the presence of market failures, the policy instruments applied are not necessarily the most economically efficient but rather the most politically feasible options. In addition, the lack of policy evaluation and monitoring prevents adjustments and corrections of such policies. Addressing the arguments for policy intervention and incorporating the results of evaluation into policy design and reform are necessary conditions for success. In spite of positive policy outcomes, limitations to enhance competitiveness and create the conditions for productivity growth are still present. An umbrella approach in the case of those PDPs that reinforce each other is necessary for productivity growth.Policy Analysis, Policy Making, Industrial Policy, Costa Rica

Enforcement, Contract Design, and Default: Exploring the Financial Markets of Costa Rica

This paper examines the institutional determinants of incentives to repay in Costa Rica and their effects on defaults and the design of financial contracts. Enforcement mechanisms help to determine how much is paid back to creditors and how much shareholders receive as dividends. Theoretically, however, the most important effects will be on the observable characteristics of contracts, as rational agents foresee the incentives of other parties. As courts enforce contracts and punish defaulters, they determine the form contracts take and the magnitude and direction of investments. The paper contains findings on the practices of financial intermediaries that are discussed in the context of contract theory, with a focus on the formal financial intermediaries that are scattered throughout the country. Much of the information comes from primary sources, including a sample of almost 1,700 civil trials and a detailed survey on the credit policies of 31 intermediaries. This paper reviews the creditor-borrower relationship at all stages—ex ante, interim, and ex post. The evidence supports the importance of collateral and other ex post repayment incentives. The evidence also suggests that, contrary to the common view, banks are not passive lenders. They remain alert to how well projects perform and rely on previous experience and a rather sophisticated informational network in granting credit.

La propuesta de directiva comunitaria relativa a la aplicación de los derechos de los pacientes en la asistencia sanitaria transfronteriza

La Comisión Europea adoptó el pasado 2 de julio una propuesta de directiva sobre la aplicación de los derechos de los pacientes en materia de asistencia sanitaria transfronteriza. Dicha propuesta forma parte de la Agenda Social Renovada y establece un marco comunitario para la asistencia sanitaria transfronteriza. Este marco se estructura en torno a tres ámbitos diferentes: Los principios comunes a todos los sistemas de salud de la UE, estableciendo qué Estado miembro será responsable de velar por los principios comunes de la asistencia sanitaria y cuáles son sus responsabilidades. Un marco especifico para la asistencia sanitaria transfronteriza: se aclararán los derechos de los pacientes a recibir asistencia sanitaria en otro Estado miembro, incluidos los límites que los Estados miembros pueden imponer a esta asistencia sanitaria en el extranjero, y el nivel de la cobertura financiera prevista para la asistencia sanitaria transfronteriza. La cooperación europea en materia de asistencia sanitaria: colaboración entre los países de la UE en las regiones fronterizas, el reconocimiento de las recetas emitidas en otros países, las redes europeas de referencia, la evaluación de las tecnologías sanitarias, la recopilación de datos, la calidad y la seguridad.The Commission’s proposal for a directive on services in the internal market at the start of 2004 included provisions codifying the rulings of the Court of Justice in applying free movement principles to heath services. This approach, however, was not considered appropriate by Parliament and Council, which invited the Commission to develop specific proposals in this area. On 2 July 2008, part of the Renewed Social Agenda, the Commission adopted a draft Directive on the application of patients’ rights in to cross-border healthcare, which provides a Community framework for safe, high quality an efficient cross-border healthcare, by reinforcing cooperation between Member States and providing legal certainty over the rights of patinglésients to seek healthcare in another Member State

Bailouts in Costa Rica as a Result of Government Centralization and Discretionary Transfers

This paper investigates the inter-relation between the central government and the municipalities in Costa Rica. It examines episodes in which the central government has bailed out the local governments from their obligations. We employ empirical and descriptive methods to show how discretionary grants relate to the degree of fiscal discipline of the municipality to produce hidden bailouts. Political, demographic, and economic variables explain the allocation of these discretionary transfers. We illustrate the effects of the high concentration of decision-making of the central government on the fiscal performance of the municipalities. The municipalities play a limited role and its functioning largely depends upon the central government. We argue that the national administration would face a high political cost if it did not bail out the local government in several of the episodes studied. Using panel data from 1982-1997 on 81 cantones, we find that the fiscal effort of the local government is reduced by the presence of discretionary grants. The local governments finance local expenses with these discretionary transfers according to our empirical results. As expected from the centralization issue, political variables such as the affiliation of the local administration have significant effects on the resources received by the municipalities.

José Luis Monge Recalde (AP). Discurso de investidura: Sesión Plenaria número 19, celebrada el día 7 de Abril de 1984

[spa] El sistema de investidura del candidato, en caso de que ninguno no obtenga la mayoría absoluta.[cat] El sistema d'investidura del candidat, en el cas que cap d'ells obtengui la majoria absoluta.[spa] José Luis Monge Recalde no fue investido candidato a la Presidencia de la Comunidad Autónoma de Navarra. Sólo obtuvo 21 votos a favor y 23 en contra del Parlamento de Navarra en las sesiones del 7 al 14 de abril de 1984.[cat] José Luis Monge Recalde no fou investit candidat a la Presidència de la Comunitat Autònoma de Navarra. Només va obtenir 21 vots a favor i 23 en contra del Parlament de Navarra a les sessions del 7 al 14 d'abril de 1984

Global CO2 emissions and global temperatures: Are they related

This paper deals with the analysis of the relationship between CO2 emissions and temperatures. For this purpose, global CO2 emissions and four measures of global temperatures (land, land and ocean, northern and southern temperatures) are used. We used techniques based on fractional integration and cointegration. The results indicate first that the orders of integration differ in the two variables. Thus, while emissions are I(1) or I(d) with d higher than 1, temperatures display orders of integration strictly smaller than 1 and thus invalidating the hypothesis of cointegration between the two variables. Due to this, another approach is conducted where we suppose that the emissions are weakly exogenous in relation to the temperatures. The results using this approach show a significantly positive relationship between the two variables with a long memory pattern.pre-print303 K

Water prices: persistence, mean reversion and trends.

Time series referring to water prices at different regions all over the world are examined in this paper by using fractionally integrated methods. We look at series corresponding to the following regions: Asia Pacific and Russia, Europe, United States and Latin America as well as global data. The results indicate large degrees of persistence, with the values of the differencing parameter being close to one in all cases and higher under the assumption of uncorrelated errors. If autocorrelation is permitted, a small degree of mean reversion is found in all except the Latin American series. The possibility of structural breaks is also investigated and the results indicate the presence of multiple breaks in the data: three in the case of Latin America and global data; four in Europe and USA and five for the Asian Pacific and Russia. Nevertheless, we do not observe a significant change in the degree of persistence across subsamples and once more mean reversion is found if autocorrelation is permitted.post-print353 K