A control theoretic model of driver steering behavior

A quantitative description of driver steering behavior such as a mathematical model is presented. The steering task is divided into two levels: (1) the guidance level involving the perception of the instantaneous and future course of the forcing function provided by the forward view of the road, and the response to it in an anticipatory open-loop control mode; (2) the stabilization level whereby any occuring deviations from the forcing function are compensated for in a closed-loop control mode. This concept of the duality of the driver's steering activity led to a newly developed two-level model of driver steering behavior. Its parameters are identified on the basis of data measured in driving simulator experiments. The parameter estimates of both levels of the model show significant dependence on the experimental situation which can be characterized by variables such as vehicle speed and desired path curvature

The international trading order at the crossroads

As economic theory shows and experience underlines, international trade and the specialization associated herewith is one important source of economic growth, employment creation and technological innovation in participating countries. In awareness of this potential for increasing economic prosperity throughout the world, the architects of the international trading system, which was to emerge from the ashes of World War II, envisaged a framework of rules leading to, and securing, open markets. The General Agreement on Tariffs and Trade (GATT), which came into being in 1948, laid down such trade rules, basically the principles of non-discrimination and multilateralism in world trade. The aim was not to establish free trade, without any government intervention. What was meant is liberal trade, in which governments may interfere, but using price measures which are transparent and do not rule out competition (i.e. non-prohibitive tariffs rather than quantitative restrictions or subsidies). Adherence by the member countries to the principles of multilateralism and non-discrimination was expected to give rise to the production of an international public good: stability and predictability of trade rules.

From six to ten and beyond: The European Community at the crossroads

The purpose of this paper is to assess the main factors causing the impasse which the EC has reached. The next section examines the lack of consensus of the member states on the aims of the EC and on the means to achieve them. Subsequently, this is related to the EC enlargement. Finally, recommendations will be made on major policy issues in order to provide a new stimulus to the integration process in Western Europe.

The economic integration of Spain with the E.E.C: Problems and prospects

In 1959/60, there was a radical shift in Spain's economic development strategy from a strongly autarchic to a cautiously outward orientation. A group of neo-liberal technocrats who enterered for the first time since Civil War the governmental administration obviously understood that the establishment of the European Common Market (1957) and the introduction of external convertibility by the highly industrialized countries (1958) would accentuate the economic growth path in Western Europe and, thereby, open new possibilities of rapid economic development for Spain. After all, the Government recognized that economic integration is an important device for promoting economic development. This is particularly true if industrialization is considered as a corner-stone of rapid economic and social progress (as was, and is, the case in Spain). The arguments in favour of more integration are too well known to need a detailed elaboration here. Essentially, they refer to the economies of scale that can be achieved in a wider market than the relatively small national one, to the increase of overall efficiency that will result from the more competitive environment, and to the improvement in the allocation of resources that can take place by arriving at a product-mix according to the country's comparative advantage. Whatever the degree to which Spain was able to reap the benefits of integration, the economic boom, which the country has been experiencing since 1960, and which deserves to be regarded as an outstanding success story in terms of income expansion as well as of growth and structural changes of production and foreign trade proves that the opening of the economy was rewarding thus far.

The domestic resource cost concept: Theory and an empirical application to the case of Spain

The problem of how to make an optimum use of a country's limited productive resources is often a crucial one to the policy makers in less developed countries (LDCs). Not surprisingly, therefore, the various methods of cost-benefit analysis have attracted much attention among professional economists and are finding a wide spread application in evaluating the social profitability of investment projects and in the planning decision-making process as well. Relatively less attention has been paid to yet another criterion of project appraisal in a developing country that has been developed independently of social cost benefit analysis - the so called domestic resource cost (DRC) approach to project appraisals. This approach is properly regarded as the application of the propositions of allocation theory when the project, or the industry in question, produces (or saves) foreign exchange. The DRC concept compares the opportunity costs of domestic resources (primary factors such as labour, capital, land) conmitted to the production of final goods with prices at which these goods can be exported or imported - the latter prices (the foreign exchange gained or saved) being considered as the ensuing benefits from production. The rationale for using the foreign exchange gained (through exports) or saved (through imports) as a standard of reference is that foreign exchange is relatively, and often critically, scarce in many developing countries.

The expansion of manufactured exports in developing countries: An empirical assessment of supply and demand issues

Economist's thinking about the role of international trade in the process of economic development exhibits a cyclical behaviour. The classical thinking, which held sway until the 1930s, emphasized the crucial role of trade in promoting growth through the optimal allocation of resources made possible by the exploitation of international comparative advantage. By the 1950s, after years of frustration and disappointment in attempting to foster development on the basis of primary commodity exports, many economists, particularly those associated with the Latin American experience, rejected the logic of the classical argument, maintaining instead that underdevelopment is a fundamental problem of transforming the structure of an economy and not of merely achieving marginal optimality in the allocation of resources. Furthermore, imperfections of the international trading framework, such as increasing oligopolistic competition, discriminatory pricing on world markets and product differentiation, discredited deeply the idea of an export-led growth for developing countries. The economic consequence of the new viewpoint was a fundamental rejection of the market mechanism in favour of direct intervention and control of economic decision-making. The main tactic of this strategy was to force the substitution of imports with domestic production by controlling investment decisions and protecting the domestic market from international competition. By the mid-1960s, however, this strategy, or at least the tactics employed to pursue it, had proved unsuccessful (in terms of sustained growth, adequate expansion of industrial employment and removal of severe balance of payments constraints), in many instances only exacerbating problems they were designed to cure.

Export liberalization and the outward oriented trade regime

The purpose of this essay is to re-assess the case of outward- oriented trade regimes in the process of economic development. The nature of outward-orientation is briefly explained in the next section. As developing countries usually start their industrialization through import substitution strategies, the shift from an inward- to an outward-oriented trade regime raises questions concerning the set of economic policies to be reshaped, the timing of the policy reform, and the feasibility of such changes, which all are discussed in the third section. The fourth section provides evidence on successful as well as on unsuccessful liberalization attempts undertaken in the seventies and traces the causes for success or failure by relating the country experiences to the policy framework for export liberalization outlined in the previous section. In the fifth section, the revival of export pessimism is evaluated.

Complex networks in climate dynamics - Comparing linear and nonlinear network construction methods

Complex network theory provides a powerful framework to statistically investigate the topology of local and non-local statistical interrelationships, i.e. teleconnections, in the climate system. Climate networks constructed from the same global climatological data set using the linear Pearson correlation coefficient or the nonlinear mutual information as a measure of dynamical similarity between regions, are compared systematically on local, mesoscopic and global topological scales. A high degree of similarity is observed on the local and mesoscopic topological scales for surface air temperature fields taken from AOGCM and reanalysis data sets. We find larger differences on the global scale, particularly in the betweenness centrality field. The global scale view on climate networks obtained using mutual information offers promising new perspectives for detecting network structures based on nonlinear physical processes in the climate system.Comment: 24 pages, 10 figure