Structural Changes in the Iranian Economy: An Empirical Analysis with Endogenously Determined Breaks

This paper employs annual time series data (1960-2003) and the ZA (Zivot and Andrews, 1992) and the LP (Lumsdaine and Papell, 1997) approaches to determine endogenously the more likely time of major structural breaks in various macroeconomic variables of the Iranian economy. We have considered the presence of one and two unknown structural breaks in the data. The results obtained from these two approaches are consistent in that the time of one structural break in eight out of the ten variables examined in the paper is the same. The resulting structural breaks coincide with important phenomena in the economy such as the 1974 oil shock, the 1979 Islamic revolution, the Iraqi war or the implementation of the exchange rate unification policy in 1993 in the case of the official exchange rate.structural break, unit root test, Iranian economy

Semiparametric Estimation of Structural Functions in Nonseparable Triangular Models

Triangular systems with nonadditively separable unobserved heterogeneity provide a theoretically appealing framework for the modelling of complex structural relationships. However, they are not commonly used in practice due to the need for exogenous variables with large support for identification, the curse of dimensionality in estimation, and the lack of inferential tools. This paper introduces two classes of semiparametric nonseparable triangular models that address these limitations. They are based on distribution and quantile regression modelling of the reduced form conditional distributions of the endogenous variables. We show that average, distribution and quantile structural functions are identified in these systems through a control function approach that does not require a large support condition. We propose a computationally attractive three-stage procedure to estimate the structural functions where the first two stages consist of quantile or distribution regressions. We provide asymptotic theory and uniform inference methods for each stage. In particular, we derive functional central limit theorems and bootstrap functional central limit theorems for the distribution regression estimators of the structural functions. These results establish the validity of the bootstrap for three-stage estimators of structural functions, and lead to simple inference algorithms. We illustrate the implementation and applicability of all our methods with numerical simulations and an empirical application to demand analysis.Comment: 45 pages, 4 figures, 1 table, we have added grant funding acknowledgement to v

Integrated control-structure design

A new approach for the design and control of flexible space structures is described. The approach integrates the structure and controller design processes thereby providing extra opportunities for avoiding some of the disastrous effects of control-structures interaction and for discovering new, unexpected avenues of future structural design. A control formulation based on Boyd's implementation of Youla parameterization is employed. Control design parameters are coupled with structural design variables to produce a set of integrated-design variables which are selected through optimization-based methodology. A performance index reflecting spacecraft mission goals and constraints is formulated and optimized with respect to the integrated design variables. Initial studies have been concerned with achieving mission requirements with a lighter, more flexible space structure. Details of the formulation of the integrated-design approach are presented and results are given from a study involving the integrated redesign of a flexible geostationary platform

Challenges in macro-finance modeling

This article discusses various challenges in the specification and implementation of "macro-finance" models in which macroeconomic variables and term structure variables are modeled together in a no-arbitrage framework. The author classifies macro-finance models into pure latent-factor models ("internal basis models") and models that have observed macroeconomic variables as state variables ("external basis models") and examines the underlying assumptions behind these models. Particular attention is paid to the issue of unspanned short-run fluctuations in macroeconomic variables and their potentially adverse effect on the specification of external basis models. The author also discusses the challenge of addressing features such as structural breaks and time-varying inflation uncertainty. Empirical difficulties in the estimation and evaluation of macro-finance models are also discussed in detail.Econometric models ; Macroeconomics

Design sensitivity analysis with Applicon IFAD using the adjoint variable method

A numerical method is presented to implement structural design sensitivity analysis using the versatility and convenience of existing finite element structural analysis program and the theoretical foundation in structural design sensitivity analysis. Conventional design variables, such as thickness and cross-sectional areas, are considered. Structural performance functionals considered include compliance, displacement, and stress. It is shown that calculations can be carried out outside existing finite element codes, using postprocessing data only. That is, design sensitivity analysis software does not have to be imbedded in an existing finite element code. The finite element structural analysis program used in the implementation presented is IFAD. Feasibility of the method is shown through analysis of several problems, including built-up structures. Accurate design sensitivity results are obtained without the uncertainty of numerical accuracy associated with selection of a finite difference perturbation

Comparing the influence of structural funds programmes on regional development approaches in Western Scotland and Silesia : adaptation or assimilation?

The implementation of EU Structural Funds (SF) programmes is credited with influencing the focus and content of domestic regional development activities, enhancing coordination of national and sub-national levels tasked with regional development and strengthening partnerships between public, private and voluntary actors. However, the influence of programmes is uneven. Analyses, based on the Europeanization literature, present a complex relationship between EU and domestic factors. A range of variables has been identified to explain this differential influence. The paper contends that, when considering New Member States (NMS) from Central and Eastern Europe (CEE), this approach requires reorientation. In the face of strategically weak and under-resourced domestic approaches, programmes are driving, rather than attempting to adjust, the domestic regional development agendas. To support this, the paper takes a comparative approach, assessing the influence of programmes in cases from opposite ends of the SF implementation spectrum: the UK (Western Scotland) and Poland (Silesia)

The organizational implementation of information systems: towards a new theory

This dissertation provides fundamental conceptual building blocks for a new theory of IS implementation. The main argument presented is for a new perspective to supplement and complement the main existing perspectives on IS implementation: the technological determinist perspective, the managerial imperative perspective, and the socio-technical interactionist perspective. in this the research seeks to overcomes identified shortcomings of these existing approaches to understanding IS implementation. The research methodology emphasizes multidisciplinary theory-building, based on the resource-based approach to strategy, using autopoiesis as the key organizational epistemology. The research explores the concept of organizational climate dimensions as the shapers of organizational contexts, and relates these to information systems research in implementation. The new perspective developed emphasizes managerial action and organizational contexts as a mid-level approach, bridging the gap between top-down, rationalist methods and bottom-up, emergent approaches. Based on this conceptual framework, the context for IS corporate governance is operationalized and presented as a causal model with five independent variables - IS Intent, Discipline, Trust, Support and Structural IS-related factors and one independent variable. IS-Organizational Learning. Data collection is carried out in large Portuguese companies by means of a postal questionnaire. The empirical data is supplemented by five short case studies. The key conclusions of the thesis are: (1) The duality managerial action - organizational contexts opens up whole new possibilities for research and practice of IS implementation. (2) The use of the notion of organizational contexts dimensions as a research tool allows the analysis to go deeper than the vague generalization about organizations found in most current literature. (3) The use of quantitative methods to investigate IS-related organizational contexts is not suitable, except for descriptive purposes; semi-structured interviews and in-depth case studies are recommended. (4) Two specific dimensions of IS-related contexts are suggested as topics for further investigation: IS Intent and IS structural factors

Metallic nanoparticles meet Metadynamics

We show how standard Metadynamics coupled with classical Molecular Dynamics can be successfully ap- plied to sample the configurational and free energy space of metallic and bimetallic nanopclusters via the implementation of collective variables related to the pair distance distribution function of the nanoparticle itself. As paradigmatic examples we show an application of our methodology to Ag147, Pt147 and their alloy AgshellPtcore at 1:1 and 2:1 chemical compositions. The proposed scheme is not only able to reproduce known structural transformation pathways, as the five and the six square-diamond mechanisms both in pure and core-shell nanoparticles but also to predict a new route connecting icosahedron to anti-cuboctahedron.Comment: 7 pages, 8 figure