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Number of results: 56
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Abstract

This paper presents a set of concepts aiming at the reconstruction of mechanisms of economic space development. These concepts are ordered in the way that consecutive concepts add new pieces of knowledge increasing the degree of cognition of the mechanisms of the economic space. This set includes among others: a shift from one steady-state to the next steady-states, self-organization and the development far from equilibrium, multiple equilibrium, punctuated equilibrium, innovation in the phase transition, a pulsative course of the development process, an emergence of complex spatial systems, a development code of the system of regions.
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Abstract

The numerical algorithm of thermal phenomena is based on the solution of the heat conduction equations in Petrov-Galerkin’s formula using the finite element method. In the modeling of phase transformation in the solid state, the models based on the diagrams of continuous heating and continuous cooling (CHT and CCT). In the modeling of mechanical phenomena, equations of equilibrium and constitutive relationships were adopted in the rate form. It was assumed that the hardened material is elastic-plastic, and the plasticizing can be characterized by isotropic, kinematic or mixed strengthening. In the model of mechanical phenomena besides thermal, plastic and structural strains, the transformations plasticity was taken into account. Thermo-physical size occurring in the constitutive relationship, such as Young’s modulus and tangential modulus, while yield point depend on temperature and phase composition of the material. The modified Leblond model was used to determine transformation plasticity. This model was supplemented by an algorithm of modified plane strain state, advantageous in application to the modeling of mechanical phenomena in slender objects. The problem of thermoelasticity and plasticity was solved by the FEM. In order to evaluate the quality and usefulness of the presented numerical models, numerical analysis of temperature fields, phase fractions, stresses and strains was performed, i.e. the basic phenomena accompanying surface layer of progressive-hardening with a movable heat source of slender elements made of tool steel for cold work.
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Abstract

This paper is an attempt to explain the concept of emergence of spatial systems. It indicates basic features of this concept, such as: coevolution, selforganization, patterns, sudden changes, hierarchy. The emergence of complex systems is very fruitful approach to the theoretical reconstruction of the processes of space economy. It should be included in the discussion on evolutionary economics and geography. Recently, in both disciplines creative research is carried out on this subject matter.
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Abstract

The Complexity of Economic Space. Two notions should be distinguished: complication and complexity. The first, is conceived as the quantitative escalation of what is theoretically reducible, e.g. one directional hierarchical structure and circular action. The second, are systems formed by great number of elements combined in a nonlinear way in interactions with many other elements. Then, such systems cannot by reduced to simple elements, like atoms in chemical matter. Examples are: human individuals, brains, ecosystems, economy, cities and regions. Complex systems are characterized a.o. by the following features: intensive interactions, feedbacks, nonlinearities, fluctuation, self-reinforcing, accumulation, emergence, alternate hierarchical systems, path dependence, coevolution. Some of them are presented in this paper.
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Abstract

Equilibrium, disequilibrium and adaptation. The inspirations for spatial economics. This paper is a part of author’s long-term research project related to dynamics and evolution of space economy. In the attempts of theoretical reconstruction of these processes the notion of equilibrium plays an important role, as well as related notions: disequilibrium and adaptation. In the analysis of equilibrium the author drew on the concepts elaborated by the neoclassical school of economics. In the analysis of disequilibrium the concept of physics turned out to be fertilizing, namely the concept of dissipative structures and self-organisation. The concept of adaptation is elaborated in depth in biology. These three concepts have been applied in spatial economics long since. Further research is necessary however, to make these application more relevant to spatial economics, and in this way more fruitful.
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Abstract

This paper presents a set of concepts aiming at the reconstruction of mechanisms of the development of economic space. These concepts are ordered in the way that consecutive concepts add new pieces of knowledge increasing the degree of cognition of the mechanisms of economic space. This set includes among others: shift from one steady-state to the next steady-states, selforganization and the development out of equilibrium, multiple equilibrium, punctuated equilibrium, innovation in the phase transition, pulsative course of development process, emergence of complex spatial systems, development code of the system of regions.
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Abstract

Regional differentiation of economic growth in Poland between 1995 and 2015. The paper explores the regional differentiation of economic growth in Poland between 1995 and 2015 in terms of GDP per capita. The historically lagging-behind regions of eastern Poland has shown relatively high dynamics and reduced the gap vis-à-vis Western European regions. At the same time, they have not been catching up with the fastest growing metropolitan areas, which leads to increased inter-regional disparities in the country. The lowest rate of growth is characteristic of northern regions and western borderland, which is related to their social and cultural features, including poor human capital, and limited internal market. There is moderate correlation between regional economic growth and the quality of life. The least favourable situation in both respects is found in the German borderland.
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Abstract

The resistance parameters of timber structures decrease with time. It depends on the type of load and timber classes. Strength reduction effects, referred to as creep-rupture effects, due to long term loading at high stress ratio levels are known for many materials. Timber materials are highly affected by this reduction in strength with duration of load. Characteristic values of load duration and load duration factors are calibrated by means of using probabilistic methods. Three damage accumulation models are considered, that is Gerhard [1] model, Barret, Foschi[2] and Foshi Yao [3] models. The reliability is estimated by means of using representative short- and long-term limit states. Time variant reliability aspects are taken into account using a simple representative limit state with time variant strength and simulation of whole life time load processes. The parameters in these models are fitted by the Maximum Likelihood Methods using the data relevant for Polish structural timber. Based on Polish snow data over 45 years from mountain zone in: Zakopane – Tatra, Świeradów – Karkonosze, Lesko – Bieszczady, the snow load process parameters have been estimated. The reliability is evaluated using representative short – and long –term limit states, load duration factor kmod is obtained using the probabilistic model.
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