Shadow Places: Patterns of Spatial Concentration and Incorporation of Irregular Immigrants in the Netherlands

Summary: In Western countries, irregular immigrants constitute a sizeable segment of the population. By combining quantitative and qualitative research methods, this article describes and explains irregular immigrants’ patterns of spatial concentration and incorporation in the Netherlands. So far these spatial patterns have not been described and explained systematically, neither in the Netherlands nor elsewhere. The article shows that illegal residence is selectively embedded in the (urban) social structure in various ways. The authors argue that irregular immigrants are likely to be spatially concentrated and incorporated in similar ways in other Western countries; now and in the foreseeable future

Driving stability of a vehicle with high centre of gravity during road tests on a circular path and single lane-change

Issues of driving stability of special-purpose vehicles result from engineering compromise between need of fulfilment of operational requirements and traction correctness of a vehicle. Especially, it concerns a motion in dynamic conditions with presence of high transverse accelerations. The paper comprises description and analysis of motion stability test results of a special-purpose two-axis vehicle with kerb mass of above 12 ton, with 4WD drive system, on a circular path drive and single line-change. One described methodology of the testing, used testing-measuring instrumentation, and distribution of the instrumentation in tested vehicle. It have been included a brief descriptions of the implemented instrumentation and method of acquisition and processing of the measurement data. One has tested a vehicle with highly located and considerably moved rearward centre of gravity. Such distribution of axle loads resulted from necessity of fulfilment of operational requirements of the vehicle. In the paper are presented test results performed for nominal and reduced with 20% tyre pressure. There were analyzed runs of lateral accelerations and axle slip angles in assumed condition of motion. One formulated general conclusions on stability characteristics for such type of vehicles

Koncepcja doboru przełożeń między silnikiem spalinowym a maszyną elektryczną w hybrydowych układach napędowych

Modern vehicles with hybrid combustion-electric drive systems are an important element in the strategy for reducing fuel consumption and emissions of exhaust gas components. Determinant of the use and development is to achieve substantial benefits in terms of classical powertrain vehicles equipped with internal combustion engines. This paper presents the concept of kinematic ratio selection between the engine and the electric machine. This concept is based on the analysis of the internal combustion engine load caused by the resistances of motion and the best possible assessment of the additional load caused by the operation of the generator. It is proposed that the energy transferred to the generator was taken in a most preferred area of the engine performance characteristics and generator by changing kinematic ratio between the engine and the generator. The described concept can also be used for the recovery of vehicles braking energy.Współczesne pojazdy o hybrydowych spalinowo-elektrycznych układach napędowych są istotnym ogniwem w strategii zmniejszania zużycia paliwa i emisji składników spalin. Determinantą ich stosowania i rozwoju jest uzyskanie istotnych korzyści w odniesieniu do klasycznych układów napędowych pojazdów wyposażonych w tłokowe silniki spalinowe. W prezentowanej publikacji przedstawiono koncepcję doboru przełożenia kinematycznego między silnikiem spalinowym a maszyną elektryczną. Koncepcja ta opiera się na analizie obciążenia silnika spalinowego oporami ruchu i ocenie najkorzystniejszego dodatkowego obciążenia generatorem. Proponuje się, aby energia przekazywana do generatora była pobierana w najkorzystniejszym obszarze charakterystyki sprawności silnika spalinowego i generatora przez zmiany przełożenia kinematycznego między silnikiem spalinowym a generatorem. Opisana koncepcja może być również wykorzystywana przy odzyskiwaniu energii podczas hamowania pojazdu

The proposition of utilisation the vehicle in 1:5 scale to construction and testing of an autonomous vehicle

In the near future, vehicles will be moving autonomously with little participation or completely without the driver affecting on the vehicle move. Task of driver will be limited to identify the end point of the vehicle route. Vehicles, to meet this challenge, must be equipped with the control systems and supervising the movement of the vehicle, reacting onto the movement of pedestrians and other vehicles, road signs, time of day and weather conditions. The movement of the vehicle will be controlled and driven by a system on board a vehicle, but will also be required to tracking the vehicles position and its movement parameters using of the vehicle satellite navigation systems. In addition, the motion trajectory of the vehicle will be determined and any deviation from the target track will be corrected. The article presents a proposal for determining the trajectory of the vehicle based on the control points specified by the coordinates of the location of the vehicle and ways of correcting the trajectory of the vehicle. For this purpose was utilized the vehicle in scale

Jedna z możliwości kształtowania charakterystyki rozpraszania energii w konstrukcji samochodu

The importance of safety among all the factors that are taken into account by customers when planning to buy a car has been highlighted. The main factors concerning the shaping of passive safety of a motor vehicle have been described and guidelines on the assessment methods to be employed at the research work in this field have been given. The energy dissipation vs. vehicle body deformation curves that may be observed at frontal collisions have been discussed. The curve shapes that may represent favourable or adverse impact of the energy dissipation characteristics on vehicle occupants. chances to survive inside the vehicle body have been indicated. To obtain favourable energy dissipation characteristics, the authors have proposed their own engineering solution in the design of longitudinal vehicle bodywork beams. The energy dissipation process was improved by reinforcing the longitudinal beam models with special elements welded to beam walls. An assumption was simultaneously made that the shape of the energy dissipation curve might be controlled by the type and arrangement of individual welds. The beam models were actually made and used as specimens tested on a strengthtesting machine at a certified laboratory at the BOSMAL Automotive Research and Development Institute in Bielsko-Biała. Energy dissipation curves determined for test specimens without and with the reinforcements have been presented herein. The test results obtained have been compared with each other and assessed in both qualitative and quantitative terms. The publication has been based on a student.s graduation work done by Michał Szuberla under the supervision of Kazimierz M. Romaniszyn.W publikacji opisano jak ważną rolę w wyborze samochodu przez klienta stanowi czynnik bezpieczeństwa. Opisano również główne czynniki dotyczące kształtowania bezpieczeństwa biernego samochodu i wytyczne badawcze dotyczące metod tej oceny. Omówiono spotykane przebiegi rozpraszania energii w zależności od przebiegu zgniotu nadwozia przy uderzeniu czołowym. Wskazano na przebiegi o charakterze korzystnym i niekorzystnym dla przeżycia ludzi wewnątrz nadwozia. Dla ukształtowania korzystnej charakterystyki rozpraszania energii zaproponowano własne rozwiązanie konstrukcyjne belki podłużnej w konstrukcji nadwozia. Poprawę przebiegu rozpraszania energii uzyskano przez wzmocnienie wykonanych próbek podłużnic specjalnymi elementami przyspawanymi do ścianek podłużnic. Założono przy tym, że przez rodzaj spoiny można wpływać na krzywą rozpraszania energii. Wykonano próbki i poddano je badaniom na maszynie wytrzymałościowej w certyfikowanym laboratorium Instytutu Badań i Rozwoju Motoryzacji BOSMAL w Bielsku Białej. Zaprezentowano przebiegi rozpraszania energii dla próbki bez wzmocnień i ze wzmocnieniami. Porównano i oceniono uzyskane wyniki zarówno pod względem jakościowym i ilościowym. Publikacja powstała na bazie pracy dyplomowej studenta M. Szuberli, promotor; K.M. Romaniszyn

Modelling of the influence of tire characteristics on stability of motion with using vehicle at a scale

The use of physical models of vehicles, at a scale allows them to be used when measuring the behavior of the full-size vehicles. The characteristics of the various systems and their impact on the dynamics of motion of the vehicle can be determined during stand tests or simulation and confirmed during testing of vehicles on test tracks. Testing vehicles built in small series, oversized or performed individually are conducted infrequently or not at all. In such cases, the alternative may be conducting tests of vehicles carried out at a scale. Research may be conducted in the boundary conditions (which could lead to loss of stability or overturning of the vehicle) impossible to achieve during testing of actual vehicles. They are particularly useful for assessing the stability of vehicles, the impact of the solutions or actions of a driver assistance system. Conducting research vehicles at a scale for the assessment of full-size vehicle must meet the criteria of similarity in the study of physical models of vehicles. One of the major issues is interaction of wheels and road. This article describes the results of wheels interaction with the road for tires with different characteristics used in the mobile model of the car and on the actual vehicle. The aim of the study was to prepare reference material to determine the correlation between the characteristics of the tire model and the full-scale tires. This will allow for made adjustment resulting from the impact of the characteristics of the tires on the motion dynamics of comparable cars especially in the curvilinear motion

Methods of testing of vehicles lateral stability based on the study of physical models

W pracy przedstawiono metodykę pozwalająca na wykorzystanie modeli fizycznych pojazdów w skali do analizy stateczności rzeczywistych pojazdów. Parametry geometryczne modelu oraz kinematykę i dynamikę ruchu określono wykorzystując teorię podobieństwa i analizę wymiarową. Omówiono problemy związane z konstruowaniem modeli i ich zespołów oraz zagadnienia związane ze sterowaniem modelu z uwzględnieniem skali podobieństwa. Zagadnienia dotyczące konstrukcji dotyczyły nie tylko parametrów wynikających z teorii podobieństwa ale również i podobieństwo konstrukcyjnego układów przeniesienia napędu, zawieszeń, układu kierowniczego i opon. Dodatkowy problem stanowi zwiększenie wymagań dotyczących sterowania modelu. Na podstawie przeprowadzonych badań opracowano algorytm postępowania dla badań stateczności poprzecznej w dynamicznych warunkach ruchu mobilnego modelu odwzorowującego dynamikę samochodu rzeczywistego.The paper presents a methodology that allows the use of vehicles physical models on scale to analyze the stability of real vehicles. The geometric parameters of the model and the kinematics and dynamics of motion were determined using the theory of similarity and dimensional analysis. The problems related to the construction of models and their parts and to the steering system, taking into account the scale of similarity. Issues concerning the construction were not only the parameters derived from the theory of similarity but also the structural similarity of powertrain, suspension, steering system and tires. An additional problem is the increasing requirements for the control model. Assessed the performed studies was developed algorithm for testing vehicle lateral stability on the study of the physical model in dynamic traffic conditions to allow the representation of the full size vehicle dynamics

Movable model of a car to dynamic testing

W pracy przedstawiono opis zdalnie sterowanego modelu samochodu ciężarowego, który przystosowano do badań dynamiki ruchu. Konstrukcja pojazdu odzwierciedla wszystkie ważniejsze zespoły układu przeniesienia napędu, zawieszeń i układu kierowniczego. Dzięki odpowiedniej budowie można ustalać położenie środka masy. Model wyposażono w czujniki przyspieszeń x-y, których wskazania są przesyłane telemetrycznie do przenośnego komputera. W publikacji przedstawiono wyniki badań gwałtownego skrętu na płaszczyźnie i jazdy po okręgu na płaskiej nawierzchni o stałym nachyleniu.A remote controlled model of a car is described in the paper. The model can be used to preliminary simulating investigations of the car movement. The vehicle model simulates all the most important components of the transmission, suspension and steering system. Owing to a suitable structure it is possible to change the position of the vehicle mass center. The model is equipped with the indicator of the danger of overturning and the sensors of the longitudinal and transverse accelerations, whose read-outs are transmitted telemetrically to a portable computer. It was fixed that the indicator begins its function when the established margin of accelerations is crossed. The modulation of acoustic and optical indicator signals increases with approaching to the limit of overturn of the vehicle. Authors analyze the matter of possible faults of registered movement parameters of the car as can mainly appear from the lack of the similarity of the stiffness of tires, suspensions and the bearing constructions of the vehicle. However, because of very high investigation costs of real car the model investigation can be applied instead of preliminary investigations of real object. Investigations of the indicator of exceeding the limiting lateral accelerations worked out by authors are introduced in the paper. The crossing of acceleration limit can cause the overturning the vehicle. The paper presents test results of sharp turn on the horizontal plane and on circular path drive on a flat surface with constant slope. It was showed in the paper that one can lead functional dynamic investigations on the mobile car model in the range of preliminary investigations

Agency, networks and policy: the case of Poles in Greece

This article is based on fieldwork conducted with Polish migrants in Athens, as well as key informants and policy makers as a case study for a larger project on Immigrants, Policies and Migration Systems. An Ethnographic Comparative Approach (MIGSYS). The article aims to provide a first reflective account of the trajectory of the group under study and how migration patterns have been shaped and affected by existing migration policies based on a pilot study of a small sample of first generation migrants and policy makers. Key themes such as the process of migration, structural factors involved, migrant agency and networks are discussed in identifying the nodal points and the relevant policies that may affect the migrants' decision at each nodal point. The article presents the main patterns of settlement of the group and highlights the most important discrepancies between policies, migrant plans and their implementation. Finally, a discussion of the overall results of the pilot study aims to provide suggestions for further research