458 research outputs found
Rapid heartbeat, but dry palms: reactions of heart rate and skin conductance levels to social rejection
Background: Social rejection elicits negative mood, emotional distress and neural activity in networks that are associated with physical pain. However, studies assessing physiological reactions to social rejection are rare and results of these studies were found to be ambiguous. Therefore, the present study aimed to examine and specify physiological effects of social rejection.Methods: Participants (N = 50) were assigned to either a social exclusion or inclusion condition of a virtual ball-tossing game (Cyberball). Immediate and delayed physiological (skin conductance level and heart rate) reactions were recorded. In addition, subjects reported levels of affect, emotional states and fundamental needs.Results: Subjects who were socially rejected showed increased heart rates. However, social rejection had no effect on subjects’ skin conductance levels. Both conditions showed heightened arousal on this measurement. Furthermore, psychological consequences of social rejection indicated the validity of the paradigm.Conclusions: Our results reveal that social rejection evokes an immediate physiological reaction. Accelerated heart rates indicate that behavior activation rather than inhibition is associated with socially threatening events. In addition, results revealed gender-specific response patterns suggesting that sample characteristics such as differences in gender may account for ambiguous findings of physiological reactions to social rejection
Algorithm for efficient symbolic analysis of large analogue circuits
An algorithm is presented that generates simplified symbolic expressions for the small-signal characteristics of large analogue circuits. The expressions are approximated while they are computed, so that only the most significant terms are generated which remain in the final expression. This principle leads to dramatic savings in CPU time and memory compared to existing techniques, significantly increasing the maximum size of circuits that can be analysed. By taking into account a range for the value of a circuit parameter rather than one single number the generated symbolic expressions are also generally valid
Mediterranean Morphologies in Hot Summer Conditions: Learning from France’s “Glorious Thirty” Holiday Housing:
Climate change and rising temperatures lead to an air-conditioning proliferation in summertime of the Mediterranean regions. This study links urban morphology to the microclimate. It claims that a lesson can be drawn from holiday housing morphologies designed with an additive approach during the “Glorious Thirty” French coastal development (1946-75). It is based on a morphological analysis of four case studies, with on the one hand re-drawing and site visiting, on the other hand, assessment of environmental performance through key parameters: Absolute Rugosity, Compactness Ratio, Building Density, Mineralization, Sky View Factor (SVF) and Height/Width (H/W) Ratio. Compared to literature reference values of a traditional courtyard morphology, the case studies are less compact and with a lower H/W Ratio (higher SVF), but they are less mineral than a historic medieval city centre. This research contributes to the search for semi-collective alternatives (for example additive morphologies) to individual housing in peri-urban areas, with high environmental performance in the summertime.
Efficient symbolic computation of approximated small-signal characteristics of analog integrated circuits
A symbolic analysis tool is presented that generates simplified symbolic expressions for the small-signal characteristics of large analog integrated circuits. The expressions are approximated while they are computed, so that only those terms are generated which remain in the final expression. This principle causes drastic savings in CPU time and memory, compared with previous symbolic analysis tools. In this way, the maximum size of circuits that can be analyzed, is largely increased. By taking into account a range for the value of a circuit parameter rather than one single number, the generated expressions are also more generally valid. Mismatch handling is explicitly taken into account in the algorithm. The capabilities of the new tool are illustrated with several experimental result
A Family of matroid intersection algorithms for the computation of approximated symbolic network functions
In recent years, the technique of simplification during generation has turned out to be very promising for the efficient computation of approximate symbolic network functions for large transistor circuits. In this paper it is shown how symbolic network functions can be simplified during their generation with any well-known symbolic network analysis method. The underlying algorithm for the different techniques is always a matroid intersection algorithm. It is shown that the most efficient technique is the two-graph method. An implementation of the simplification during generation technique with the two-graph method illustrates its benefits for the symbolic analysis of large analog circuits
Accessibility versus air pollution : a geography of externalities in the Brussels agglomeration
This paper proposes a novel approach to investigate the geography of accessibility and air pollution and tests it on the case of the Brussels Capital Region. First, we find a strong positive correlation between accessibility and air pollution, highlighting a trade-off that exists between two emblematic but antithetical externalities of agglomerations. Next, we focus on the outliers that escape this trade-off and we develop a methodology to combine their respective levels of accessibility and air pollution into a 'desirability' indicator. Finally, we analyse the distribution of the most and the least desirable neighbourhoods across the city: while we observe flagrant patterns of inequality, these do not reflect the socio-economic structure of the region, in apparent contrast with the literature on transport justice and environmental justice. The results show how positive and negative socio-ecological externalities can be two sides of the same agglomeration coin. The methodology proves to be relevant to further comparative research and policy making concerned with promoting a balanced progress of social, economic and environmental priorities
Populatiegrenzen van polycentrische regio's op basis van het spoorgebonden OV-netwerk
In deze paper vertrekken we van het academische debat over de optimale omvang van de stad, waarbij zowel economische agglomeratievoordelen als veronderstelde leefbaarheidsproblemen in rekening worden genomen. Vervolgens passen we de uit de literatuur afkomstige drempelwaarden toe op de polycentrische stedelijke agglomeratie van de ‘Vlaamse Ruit’. Een traditionele manier om de grenzen van een grote monocentrische agglomeratie, en het onderscheid tussen de stedelijke kern en peri-urbane gebieden te visualiseren, is door middel van een afstand-verval-functie (1) op basis van bevolkingsdichtheid (2), met als oorsprong het stadscentrum (CBD). Echter, dit type cartografische oefening is minder geschikt om inzicht te verwerven in het functioneren van polycentrische stedelijke agglomeraties, omdat deze bestaan uit meerdere potentieel interagerende en overlappende centra die elk op zich als centrum van een af te bakenen stedelijke agglomeratie zouden kunnen worden beschouwd. Om op een zinvolle manier polycentrischer en monocentrische agglomeraties met elkaar te kunnen vergelijken, stellen we een visualisatie van de grenzen van deze agglomeraties voor op basis van verschillende bevolkingsdrempels. In plaats van gebruik te maken van de traditionele isochronen, visualiseren we in onze cartografische oefening het cumulatieve aantal inwoners met aflopende bereikbaarheid naar de vier grote kernen binnen de Vlaamse Ruit (Brussel, Antwerpen, Gent en Leuven). Vanuit de ruimtelijke beleidsplanning voor het Vlaamse gewest is er vandaag een toenemende interesse voor stedelijke consolidatie en verdichting in de nabijheid van openbaar vervoerknooppunten. De GIS-gebaseerde methode die we voorstellen steunt daarom sterk op duurzame vervoerwijzen (trein, metro, tram en wandelen), en is daarmee de facto op de spoornetten (inclusief metro, tram en lightrail) geënt. We presenteren twee kaarten: de eerste analyse visualiseert de bevolkingsmassa binnen de Vlaamse Ruit via het toewijzen van gemiddelde ‘theoretische’ snelheden per vervoersmodus. De tweede analyse is gebaseerd op de werkelijke dienstregeling van het openbaar vervoer, en maakt daarmee onderscheid tussen primaire, secundaire en tertiaire transportroutes. De resulterende kaarten kunnen de ontwikkeling van een meer duurzame verstedelijkingsstrategie ondersteunen via het opsporen van locaties voor stedelijke verdichting die bijdragen aan de ontwikkeling van de kritische massa die nodig is om het metropolitane functioneren van de Vlaamse Ruit te verzekeren
Symbolic analysis of large analog integrated circuits by approximation during expression generation
A novel algorithm is presented that generates approximate symbolic expressions for small-signal characteristics of large analog integrated circuits. The method is based upon the approximation of an expression while it is being computed. The CPU time and memory requirements are reduced drastically with regard to previous approaches, as only those terms are calculated which will remain in the final expression. As a consequence, the maximum circuit size amenable to symbolic analysis has largely increased. The simplification procedure explicitly takes into account variation ranges of the symbolic parameters to avoid inaccuracies of conventional approaches which use a single value. The new approach is also able to take into account mismatches between the symbolic parameters
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