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Number of results: 8
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Abstract

This article deals with the problem of the knowledge’s utility. This issue is considered from three perspectives. The dualistic perspective is based on the two-component structure: knowledge–reality; the subject–the object. In this regard, the knowledge’s utility is measured by the measure of the power that can be obtained over the world. From the monistic perspective knowledge is useful if it allows the internal improvement of the bearer of the knowledge. Knowledge in terms of the emergent system arises in the fluid cognitive relationship between components of changing system. Relations between the system (whole) and units (part of ) are variable and undetermined by the specificity of the individual components which are also reciprocal and mutually forming.
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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

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 iron ore mine owned by the state concern of Luossavaara – Kiirunavaara AB-LKAB state concern has several mining skip shaft hoists for drawing iron ore. Despite using modern systems to secure the travel of these hoists in line with the Swedish regulations, units intended for the emergency breaking of vessels must be used in the so-called free travel paths in the tower and in the shaft sump. The paper discusses the main requirements that, in accordance with the Swedish regulations as regards the operational use of mining shaft hoists, must be met by devices of this type and a solution was proposed for a structure design of the braking unit for the mining shaft hoist installed in the B-1 shaft in the Kiruna mine. The frictional braking system in the form of moving bumping beams was decided to be used in the said hoist, developed in the Cable Transport Department in the University of Science and Technology in Krakow. The action of moving bumping beams consists in these beams, placed at the beginning of free travel paths, not only braking the rushing hoist vessels but also (with the integrated units for vessel capture) performing the function of grips. They secure the vessels against falling down into the shaft after the finished braking process. The advantage of such a solution is that the structural elements: the guiding shank of the tower, the head of the vessel and the bumping beams, transfer many times lower values of dynamic forces at the time of the strike of the vessel against the moving bumping beams when compared with dynamic forces arising at the time of the hit of the vessel against the fixed bumping beams. In the process of designing moving bumping beams, braking simulation is an important stage conducted with a computer program developed in KTL AGH. This program enables the modelling of load-bearing and balance ropes as flexible elements with elastic and suppressing properties. The results of these simulations, especially in the scope of the achieved braking deceleration of the vessels, the values of braking distances and forces in the load-bearing ropes are crucial in confirming the correctness of the assumed concept of the emergency braking system. The braking units in the form of moving bumping beams have been executed by the Polish company Coal-Bud Sp. z o.o. and are now being integrated in the tower and in the shaft sump of the B-1 shaft of the Kiruna mine in Sweden.
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Abstract

The aim of this paper is to discuss energy certification systems and multi-criteria certification schemes – both the assessment tools focusing on the level of the single building and on the urban level. The role of certification systems and the emerging technologies as a means of reducing energy consumption and achieving the high energy quality of the built environment is investigated.
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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

High voltage direct current (HVDC) emergency control can significantly improve the transient stability of an AC/DC interconnected power grid, and is an important measure to reduce the amount of generator and load shedding when the system fails. For the AC/DC interconnected power grid, according to the location of failure, disturbances can be classified into two categories: 1) interconnected system tie-line faults, which will cause the power unbalance at both ends of the AC system, as a result of the generator rotor acceleration at the sending-end grid and the generator rotor deceleration at the receiving-end grid; 2) AC system internal faults, due to the isolation effect of the DC system, only the rotor of the generator in the disturbed area changes, which has little impact on the other end of the grid. In view of the above two different locations of disturbance, auxiliary power and frequency combination control as well as a switch strategy, are proposed in this paper. A four-machine two-area transmission system and a multi-machine AC/DC parallel transmission system were built on the PSCAD platform. The simulation results verify the effectiveness of the proposed control strategy.
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