Marcin Stępniak

Where the grass is greener: social segregation in three major Polish cities at the beginning of the 21st century

In Europe a range of segregation studies can be found in the North, West and South, but hardly any in Central Eastern Europe – a region where the major economic and political changes induced by the demise of socialism in 1989 contributed to new social divisions and related spatial patterns. However, these changes have not been uniform and have resulted in context-specific outcomes. Relying on data on the socio-occupational structure of the population from the National Census 2002 at the census tract scale, this article explores the levels and patterns of social segregation in three major Polish cities: Łódź, Cracow and Warsaw, urban areas that reflect divergent paths of more and less successful post-socialist transformations. This contribution concludes that, more than a decade after the demise of socialism, census tracts still generally contained populations that were heterogeneous with regard to socio-occupational status and that socioeconomic transformations in Poland and the social toll these processes involved have not yet been fully translated into intra-urban spaces.

PARADOXES OF (POST)SOCIALIST SEGREGATION: METROPOLITAN SOCIOSPATIAL DIVISIONS UNDER SOCIALISM AND AFTER IN POLAND

The state of the art in research on residential segregation and concentration in Central and Eastern Europe (CEE) largely focuses on process description (e.g., the multitude of works on gentrification and suburbanization). Even though major advances in the conceptualization and measurement of segregation have been made, works that scrutinize the patterns of segregation and/or concentration in CEE are rare, while studies that simultaneously explore and link segregation patterns under socialism and after are virtually nonexistent. Relying on Polish census-tract level data on the educational structure of population in 1978, 1988, and 2002, this study explores the patterns of social segregation and concentration in the three major Polish cities (Warsaw, Cracow, and Łódź), representing different paths of development under socialism and after. The results show that the population of the three major Polish cities was still socially heterogeneous at the census tract level in 2002. The results also reveal that the level of social residential segregation in the three cities has been decreasing steadily since 1978, irrespective of the prevailing economic system. [Key words: Residential segregation, concentration, socialist city, post-socialist city, Poland.]

The impact of selected planned motorways and expressways on the potential accessibility of the Polish-Slovak borderland with respect to tourism development

Abstract Further tourism development in the Polish-Slovak borderland, as well as its overall economic development, depends on the construction of a motorway and expressway network. This paper analyses the impact of selected planned motorways and expressways (D1, A4, D3/S69, R1/R3/S7, and R4/S19) on the potential accessibility of the Polish-Slovak borderland with respect to the development of tourism. The most important investment project in Slovakia is the completion of the (started) D1 motorway. The R4/S19 and the R1/R3/S7 expressways and the D3 motorway/S69 expressway are expected to contribute to improved cross-border connections.

Reducing the uncertainty induced by spatial aggregation in accessibility and spatial interaction applications

Analyses of spatial interaction are to some degree plagued by uncertainty regarding the impact of spatially dispersed interaction masses within zones on travel times. In this paper, interaction-weighted travel times are computed from a matrix between regularly distributed points at fine resolution, and used together with secondary data to improve estimates of interaction weighted travel time based on commonly applied methods. The paper proposes a method for computing intra-zonal, interaction weighted travel times that is considerably less sensitive to spatial aggregation than existing approaches, and demonstrates that population-weighted centroids are to be preferred over geographically-weighted centroids.

Spatio-Temporal Variation of Accessibility by Public Transport—The Equity Perspective

The growth of large, open datasets coupled with an acceleration of technical developments, including GIS solutions, opens the door to new challenges in transport research. One of the emerging fields of research is the temporal dynamics of accessibility. The increase in availability of General Transit Feed Specification (GTFS) data permits the inclusion of very detailed, schedule-based travel time information. In the study presented we focus on the spatial and temporal variation in accessibility by public transport in the city of Szczecin (Poland). This paper advocates the necessity of incorporating a temporal component in accessibility analysis. We conducted a full day analysis for 1 day using averaged 15-min-long time periods at a very detailed spatial scale (enumeration districts). Based on the calculated origin-destination matrix in 96 time-profiles we calculated the potential accessibility indicator. Then we investigated spatial disparities and their variability during the day-long observation. Apart from the well-known spatial disparities in accessibility level, our findings underline the uncertainty of the accessibility pattern. Moreover, the results show that less accessible areas are also more affected by the daily variation in accessibility level. The findings provide a more realistic insight into accessibility patterns which will be useful for transport planners and policy makers.

The Impact of Data Aggregation on Potential Accessibility Values

The paper focuses on an investigation of the Modified Areal Unit Problem (MAUP) in a potential accessibility case study of the Mazovia region. Three different potential accessibility models were prepared based on the same theoretical background and coherent spatial data: a municipal model, a grid model and a population-weighted average travel time model. We concentrated on two main issues: the differences in the results produced by the three different models, and the impact of different methods of calculation of self-potential on these differences. The results show significant differences in accessibility values produced by the three models tested. The municipal model produced underestimated values of potential accessibility indicator in all spatial units. The differences are first of all a consequence of taking into consideration the densely populated peripheral districts of Warsaw that are ‘visible’ in grid-based models, but ‘not visible’ (i.e. averaged) in the central-location oriented municipal model. As a consequence, the total travel time between the average (population-weighted) origin-destination grid nodes is shorter than that calculated at the municipal level and the potential accessibility values are higher in both grid-based models. However, in general, the main cause of the differences of accessibility values observed is not the self-potential but rather the complexity of transportation and land use relations between neighbouring municipalities.

The SOA paradigm and e-service architecture reconsidered from the e-business perspective

A business service has well founded structure where its operations (corresponding to request-quote, order-contract, invoice-payment) are related to each other. These relations cannot be expressed in WSDL. The request-quote operation corresponds to SLA negotiations and can be performed in a universal description language such as OWL that can also express all the relations between service operations mentioned above. Generally, from the e-business perspective the following notions are important: (1) Service architecture. (2) Communication protocols in e-business processes. These notions are crucial for providing standards necessary for creating open, heterogeneous and scalable systems for realizing complex e-business processes. These notions are discussed in the paper.

SO-MRS: A Multi-robot System Architecture Based on the SOA Paradigm and Ontology.

A generic architecture for a class of distributed robotic systems is presented. The architecture supports openness and heterogeneity, i.e. heterogeneous components may be joined and removed from the systems without affecting its basic functionality. The architecture is based on the paradigm of Service Oriented Architecture (SOA), and a generic representation (ontology) of the environment. A device (e.g. robot) is seen as a collection of its capabilities exposed as services. Generic protocols for publishing, discovering, arranging services are proposed for creating composite services that can accomplish complex tasks in an automatic way. Also generic protocols for execution of composite services are proposed along with simple protocols for monitoring the executions, and for recovery from failures. A software platform built on a multi-robot system (according to the proposed architecture) is a multi-agent system.

Fault Tolerant Automated Task Execution in a Multi-robot System

In multi-robot systems unexpected situations occur frequently, and cause failures of robots performing tasks. Mechanisms for automation of failure handling and recovery (if possible) are proposed. They are based on general protocols similar to the well known standard WS-TX for business transactions. The protocols and mechanisms are implemented in the prototype Autero system as a software platform for accomplishing complex tasks in open and heterogeneous multi-robot systems.

Transaction Protocol and Mechanisms for Adaptive Management of Long-Running Tasks

Execution of real-world services can lead to many unexpected events that need to be handled. So that failures of tasks composed of such services frequently occur. Mechanisms for automated task accomplishment and failure handling in open and heterogeneous systems are proposed. They are based on general protocols derived from the well known OASIS Web Services Transaction standard WS-TX for business transactions. The protocols and mechanisms are implemented in the prototype Autero multi-robot system in which the robots cooperate so as to accomplish complex tasks.