An ideal observability subspace expression is stated for bilinear abstract system with bounded operator in Hilbert spaces. The case of finite dimentional space is also treated. However, it’s noticed that the state ideal observability can never be fulfilled within an infinite dimensional phase space in the case of scalar output. The case of bilinear discrete-time system with delays in observation is also described. To illustrate this work some examples are presented.
One of the main problems of electrical power quality is to ensure a constant power ?ux from the supply system to the receiver, keeping in the same time the undisturbed wave form of the current and voltage signals. Distortion of signals are caused by nonlinear or time varying receivers, voltage changes or power losses in a supply system. The wave-form of the voltage of the source may also be deformed. This study seeks the optimal current and voltage wave-form by means of an optimization criteria. The optimization problem is de?ned in Hilbert space and the special functionals are minimized. The source inner impedance operator is linear and time-varying. Some examples of calculations are presented.
The aim of this paper is to look at the quantitative dimension of public space resources in Polish cities, a comparative analysis of these resources, determining the share of public space in the urban spatial structure and referring this structure to European cities. The concept of ‘public space resources’ has been introduced, and is defined as those areas in the city that fulfill or can fulfill the functions of public space. This concept, and then the proposal of its operationalization, aimed to draw attention to the spatial and physical aspects of public space, which would allow to broaden and supplement social approaches in the study of public space. The quantitative approach to public space proposed in the paper also enabled a comparative research to assess the role of public space in the structure of Polish cities in a more objective manner and refer it to European cities.
The following article presents a selection of the most interesting examples of transformations of public space in towns and cities of varying sizes in Lesser Poland which were aided by European grants obtained from the pool of EU funds, with special attention to the Lesser Poland Regional Operational Programme (ROP) an also the Rural Development Programme (RDP) in the years 2007-2013. The presented findings are of a preliminary nature and are phase in the wider studies being conducted by the Author covering the multifaceted transformations of public space that have taken place and are taking place in Poland with the aid of European funding. The aim of these studies is an overall evaluation of how, in specific planning periods, the joining of the European Union and the possibility of taking advantage of Western experience, as well as financial support, influenced and influence today the transformations of public space in Polish towns and cities, and their influence on people’s thoughts and perceptions of such space.
This paper brings up elementary problems related to the creation of friendly public spaces in residential complexes as the main places of social integration. Contemporary social transformations are reflected in a new, intensified usage of public spaces which – offering more and more possibilities of satisfying human needs in the field of social contact, knowledge, recreation, stimulation etc. – provoke people and their activities to transfer “life” from a private space to a public space.
In this paper, the authors study the 3D propagation of sound waves between two closed spaces. The separation element between the two rooms is considered to include either a small opening or a homogeneous lightweight panel, coupling the two spaces. A numerical study of this configuration is performed, trying to understand the influence of the position and geometry of this opening in the sound pressure level reduction curve at low and midfrequencies. Additionally, the coupling effect between the two acoustic spaces is analyzed, in order to better understand its importance when determining the sound pressure level reduction. Different boundary conditions are ascribed to the walls of these rooms, simulating both the completely reflecting and partially absorbing surfaces.
The numerical modelling was performed using a multi-domain formulation of the Method of Fundamental Solutions (MFS). The system is composed of two coupled rooms, limited by rigid or by absorbing walls, and separated by a thin wall (tending to null thickness) with a small opening. An experimental validation of the proposed model is presented, comparing its results with those found experimentally for a reduced-scale model. It is important to note that, for such a configuration, a traditional single-domain approach using methods like the MFS or the BEM would lead to undetermined equation systems, and thus the proposed model makes use of a domain decomposition technique.
The article concerns problems with shaping contemporary housing estates. By analyzing housing structures designed in recent years, the aim was to demonstrate the importance of creating the continuity of public spaces in order to achieve places seen as attractive and presenting features of high quality urban space. Essential for the research is the question about the conditions which should be fulfi lled when creating the ideal residential place which then leads to a series of answers. These included indicating a good location with functional and aesthetic urban/architectural solutions. Environmental issues are important as well. Regardless of whether it is a multi-family dwelling or a single family house, a good neighborhood and its location in a well-connected place with necessary basic services within walking range are important. It is also signifi cant how the public space was shaped and whether a natural network was created. Due to factors such as the specifi city of the structure’s location in the city and diff erent surfaces of designed estates, as well as the variety of residential buildings being constructed, it is often diffi cult to assess them unambiguously. Importantly, this assessment also includes social and economic aspects as well as technical issues. However, by using multi-directional research it can be noted that the forms of public spaces within housing complexes play an important role in the creation of high-quality structures, perceived as attractive not only by the residents.
The main objective of the article is an attempt to indicate factors which determine the image of a city as a good place to live as well as to reveal the ways in which they affect the citizens’ quality of life. In order to do so, the author selected the city of Gdynia which is perceived as the best city to live in by its citizens. Among the most important factors determining the quality of life in general there are: the scale of a city, local identity, public spaces, symbolic places, housing environment, perception of a place, personal satisfaction of a place where a particular person lives, urban policies as well as presence and activeness of local leaders. The article presents the results of a social study carried out by the author herself during two periods of time – in 2004 and 2014 as well as the results of the Social Diagnosis 2015.
The article is an attempt to collate and present the existing works of Polish geographers who focused on public space in cities, taking two main theoretical and methodological approaches – objective and subjective – under consideration. The article discusses different definitions of the analysed term in an interdisciplinary context as well as indicates main aspects and research directions in geographical studies along with the scholars representing them. Moreover, the authors make an attempt to evaluate the existing state of the art and try to set future perspectives for geographical studies on public space in cities. The article finishes with the authors’ conclusions regarding the necessity to continue the research on public space and the role Polish geographers shall play in it.
The article is an attempt to analyze the spatio-pedagogical discourse of the German social pedagogy. It represents only a fragment of reflection on the turns in paradigm of place/ space (spatial turn), as pedagogical terms. & e authors seek to answer the question what is the space and place, and what concepts in the field of reflection on the place/space run in the German social pedagogy. The text introduces, inter alia, the relational concept of space developed by Martina Löw, duality of space and the concept of spacing. Active creation of urban space, the spatial dimension of the relationship and its dynamics are subjected to discussion. The article presents critical approach to the notion of transdisciplinary space, and space-oriented social work. Finally, it provides the incentive for in-depth, international analyzes of spatio-pedagogical theories.
In this paper a small time local controllability, naturally defined in a configuration space, is transferred into a task-space. It was given its analytical characterization and practical implications. A special attention was put on singular configurations. Theoretical considerations were illustrated with two calculation examples. An extensive comparison of the proposed construction with the controllability defined in an endogenous configuration space approach was presented pointing out to their advantages and disadvantages.
The subject of this paper is the study of the specificity of the transformation of the urban public spaces of the Western world and the problem of the multi form nature of this phenomenon. The Author uses such concepts as that of the "hybrid" and of "hybridization" borrowed from the field of natural sciences and explains the reasons for their introduction within this specific scope of research in a broad manner.
Commercial functions are very important to the process of urban revitalization. Various commercial forms of trade, such as markets, marketplaces, cloth halls have enriched the public spaces of cities over the centuries. Over the last 25 years of the free market in Poland, we have observed deformations within the urban structure caused by new types of commercial functions. The attractive functions of urban malls and shopping centers, which are usually placed inside, cause the degradation he streets located outside. Shopping centers, spread within the city and isolated by parking areas from pedestrian networks, contribute to the growth of inner peripheries. The fluctuations of the global economy should lead us however, to the delimitation of commercial functions, especially the largest ones. The proper relations between these commercial areas and the beautiful landscape of the city can be used as an element of building the city's image. Ventures within the historical city centers require the development of new instruments which would allow us to protect existing values.
A meadow, a flowery meadow, a clearing, a lawn – smoothly trimmed, flat and recessed, a grassy pathway – these are elements of gardens that have been known for centuries, used in different styles and different types of gardens, including in public spaces. Pratum commune, commons or grassy mounds are the landmarks of the landscape of many a city, both currently and throughout history. Decorative grasses, such as pampas, Miscanthus or Pennisestum started to be used in garden compositions in XIX-century England. Initially more so due to their peculiarity than beauty. However, it was naturalism that gave rise to the wider use of grasses in gardens and parks in various places of the world and gained many propagators, including W. Robinson, J. Jensen K. Foerster and P. Oudolf.Grasses are currently often designed by landscape architects in urbanised spaces. They are employed both in geometric and freeform compositions. Their texture and delicate colour create a background for more expressive plants. They often constitute the key element of naturalist layouts, and the use of domestic species aids in preserving biodiversity and recreating the domestic landscape. Many of these current projects have been discussed in magazines and subject literature and have received awards in competitions. This review article is devoted to this subject.
The article describes the relationship between the local community and the primary school considered as “place” within the meaning derived from the book by yi-Fu Tuan “Space and place: The perspective of experience”. The article compares the cases of two schools in the city of bielsko-biała (the city has a population of 175 thousands inhabitants). One school is overcrowded, yet its future existence has been secured. The second school, however, was first transferred to another location and it eventually went into liquidation in 2012. The article demonstrates then underlying reasons and consequences of losing the school as place. Moreover, it indicates potential problems emerging in such cases altogether with a set of possible solutions.