Macroeconomic adjustment to oil shocks and fiscal reform : simulations for Zimbabwe, 1988-1995

The authors develop and apply a macroeconomic general equilibrium model for Zimbabwe. The model integrates a behavioral estimated model structure, taken from a companion paper, with the relevant budget constraints for a six-sector disaggregation into a comprehensive framework. Starting with 1988 as a base year, the authorssent simulations for a base scenario covering the period 1988-1995. From the different macroeconomic issues and reform requirements identified in the companion paper as relevant for Zimbabwe today, they select two for performing alternative scenario simulations here: a continuation of the current oil shock and strong fiscal stabilization. The oil shock is shown to reduce growth, increase inflation, depreciate the real exchange rate, and reduce private investment in Zimbabwe, a country heavily dependent on imported oil. Fiscal adjustment is a major challenge for stabilization and growth faced by Zimbabwe's policy-makers today. The paper's simulations show that deep fiscal reform will significantly help Zimbabwe achieve a sustainable debt path, a decline in interest rates paid on public debt, and a recovery of private consumption and investment.Economic Theory&Research,Environmental Economics&Policies,Banks&Banking Reform,Economic Stabilization,International Terrorism&Counterterrorism

Classifier ensemble for uncertain data stream classification

Currently available algorithms for data stream classification are all designed to handle precise data, while data with uncertainty or imperfection is quite natural and widely seen in real-life applications. Uncertainty can arise in attribute values as well as in class values. In this paper, we focus on the classification of streaming data that has different degrees of uncertainty within class values. We propose two types of ensemble based algorithms, Static Classifier Ensemble (SCE) and Dynamic Classifier Ensemble (DCE) for mining uncertain data streams. Experiments on both synthetic and real-life data set are made to compare and contrast our proposed algorithms. The experimental results reveal that DCE algorithm outperforms SCE algorithm

Leon Trotsky: Three Aspects

This thesis examines three aspects of Leon Trotsky (1879-1940). Chapter One analyses Trotsky's most famous, and most written about, 'theory of permanent revolution'. Defining theory as explanation, it is argued that one cannot talk of a specific 'theory of permanent revolution'. Trotsky introduced laws of uneven and combined development, and it was these that acted as the explanation of the component parts of 'permanent revolution' - (i) the Russian proletariat could seize power before the Russian bourgeoisie; (ii) that once in command the Russian proletariat would introduce socialist measures; (iii) that world revolution would be necessary for full socialism to be constructed. This does not mean that the notion of 'permanent revolution' has to be abandoned. It can be retained, but as a political programme

Limit analysis of conical and parabolic domes based on semi-analytical solution

The evaluation of limit loads of masonry domes has received increasing interest especially due to the importance of historical buildings where domes mainly are one of the most relevant structures. The limit design is used to obtain the safety assessment and the design guidance for restoration and transformation toward preservation and reuse of historical heritage. In the following paper, we present a formulation of the limit analysis based on the semi-analytical approach that starts on Melan's theorem. The self-equilibrated Melan's residual is obtained through the discretization of the analytical form of the equilibrium equation of the spherical dome. The procedure provides a finite-dimensional map of the eigenstress of the structure. Furthermore, the superimposition of the elastic solution to actual loads, obtained by finite element calculation, completes the admissible stress evaluation. Such amissible stress is introduced into the maximization algorithm, based on the lower bound theorem, which results in the collapse load. The same approach is used to get the safety assessment under prescribed load that allows checking the safety of prescribed load pattern and geometry

Macroeconomic framework for an oil-based economy : the case of Bahrain

Bahrain's economy is characterized by producer and consumer subsidies and, possibly misaligned currency. These subsidies have resulted in lower savings rates than would be consistent with the country's endowment in oil and gas. In addition, the misaligned real exchange rate has encouraged imports, at the same time creating incentives biased against the non-oil tradable sectors. So, Bahrain's economy remains largely dependent on a rapidly depleting hydrocarbon resource base. The authors espouse a macroeconomic consistency framework to focus on the behavior of Bahrain's economy along two paths. Part one is based on the assumption that the government's present macroeconomic policy will continue. In that case, the solution exhibits bubbles - fiscal and current account imbalances that would be unsustainable over time. Meanwhile, real appreciation of the dinar would suppress non-oil exports. As a result, the need for foreign borrowing would be more pressing. In an attempt to restore the equilibrium, the government would need to contain aggregate demand by compressing imports and investment, thereby worsening the economic situation. Path two is based on a reform strategy that includes policies to raise the domestic savings rate, improve the fiscal situation (by rationalizing expenditures and introducing income taxes and cost recovery measures), and correct the misaligned exchange rate. The results show that the expenditure-switching effect of the exchange rate alignment would shift resources in favor of the tradable sectors. Non-oil GDP and exports would register high growth rates while economic diversification, in the context of a growing and more dynamic economy, would foster investment efficiency. This would help Bahrainis maintain a high standard of living as the oil income dries up, without too much loss of consumption for the present generation.Economic Stabilization,Economic Theory&Research,Environmental Economics&Policies,Banks&Banking Reform,Macroeconomic Management

Adiabatikus kontroll a kvantumoptikában és a kvantuminformatikában = Adiabatic control in quantum optics and in quantum informatics

Kiterjesztettük a STIRAP eljárást impulzusmomentum-állapotokból álló sokszintes degenerált kvantumrendszerekre, továbbá eljárást dolgoztunk ki állapotuk rekonstruálására. Alapvető kvantumkapu műveleteket implementáltunk a STIRAP módszer felhasználásával félvezető nanostruktúrákban. Disszipatív rendszerekben alkalmazható robusztus eljárást mutattunk be tetszőleges kevert állapot előállítására, mely kvantumbitek preparálására is használható. A kvantumtrajektória megközelítést felhasználva hatékony módszereket dolgoztunk ki az időfejlesztő operátor valamint kétidős korrelációs függvények meghatározására. Módszert javasoltunk fény nemlineáris frekvenciakonverziójára fáziskoherens közegekben. Bebizonyítottuk, hogy a fáziskoherens közegben modellezett hullámkatasztrófákra jellemző logaritmikus fázisszingularitásnál a fáziskitevő valós része egész vagy félegész szám. Megmutattuk, hogy Bose-Einstein kondenzátumban kvázi-egydimenziós áramlásnál az analóg Hawking-sugárzás hőmérséklete csak a csapdázó potenciáltól függhet. Összefonódott állapot létrehozására alkalmas algoritmust fejlesztettünk ki a STIRAP módszer alkalmazásával. Eljárást dolgoztunk ki összefonódott kvantumállapotok preparálására spin-láncokban. Numerikus optimalizációt végeztünk a végesen korrelált állapotok körében a végtelen, transzlációinvariáns spin-láncban a legközelebbi szomszéd összefonódottság maximumának meghatározására. | We have extended the STIRAP (Stimulated Raman Adiabatic Passage) method to degenerate systems consisting of angular momentum states. Moreover, we have developed a reconstruction scheme to retrieve their quantum state. We have applied our quantum state control schemes to nanostructures for implementing basic quantum logic gates. We have developed a robust method to prepare pure and mixed states in dissipative systems. We have developed efficient methods using the quantum trajectory approach for numerically determining two-time correlation functions and the time-evolution operator in open quantum systems. We have developed a method for efficient nonlinear frequency conversion in phase coherent media. We have proved that by logarithmic phase singularities, modeled in phase coherent media, at wave catastrophes the wave amplitude grows with a half-integer power. In a quasi one dimensional flow of Bose-Einstein condensed atoms the Hawking temperature is entirely determined by the curvature of the trapping potential. We have developed a method based on the STIRAP scheme for creating entangled states in compound systems. We have proposed a scheme to create entangled states in spin-chains. We have performed a numerical optimization to determine the maximum nearest neighbor entanglement in a translationally invariant infinite qubit chain based on finitely correlated states