The Spatial Variability of Vehicle Densities as Determinant of Urban Network Capacity

Due to the complexity of the traffic flow dynamics in urban road networks, most quantitative descriptions of city traffic so far are based on computer simulations. This contribution pursues a macroscopic (fluid-dynamic) simulation approach, which facilitates a simple simulation of congestion spreading in cities. First, we show that a quantization of the macroscopic turning flows into units of single vehicles is necessary to obtain realistic fluctuations in the traffic variables, and how this can be implemented in a fluid-dynamic model. Then, we propose a new method to simulate destination flows without the requirement of individual route assignments. Combining both methods allows us to study a variety of different simulation scenarios. These reveal fundamental relationships between the average flow, the average density, and the variability of the vehicle densities. Considering the inhomogeneity of traffic as an independent variable can eliminate the scattering of congested flow measurements. The variability also turns out to be a key variable of urban traffic performance. Our results can be explained through the number of full links of the road network, and approximated by a simple analytical formula

Gestione informatizzata dei dati archeologici e dei sistemi GIS. Applicazione al sito di Hierapolis di Frigia

The system used for organizing the data from the excavation at Hierapolis, a sample site for this research project, represents an example of the application of the methodology of GIS to a stratigraphically excavated site. The use of this methodology, based on the logical structuring of data in independent layers, makes it possible to reconstruct the micro-dynamics typical of a stratigraphic excavation. Once the archaeological layers are separated, divided and organized according to their geographic position, they are treated as a series of divisible and superimposable layers which can be used in order to create the floor plans of single monuments and, more in general, maps showing the different phases of the city. This type of data management makes it easier to understand the spatial organization and transformation of a city over time

Characterizing cycling traffic fluency using big mobile activity tracking data

Mobile activity tracking data, i.e. data collected by mobile applications that enable activity tracking based on the use of the Global Navigation Satellite Systems (GNSS), contains information on cycling in urban areas at an un-precedented spatial and temporal extent and resolution. It can be a valuable source of information about the quality of bicycling in the city. Required is a notion of quality that is derivable from plain GNSS trajectories. In this article, we quantify urban cycling quality by esti-mating the fluency of cycling traffic using a large set of GNSS trajectories recorded with a mobile tracking appli-cation. Earlier studies have shown that cyclists prefer to travel continuously and without halting, i.e. fluently. Our method extracts trajectory properties that describe the stopping behaviour and dynamics of cyclists. It aggre-gates these properties to segments of a street network and combines them in a descriptive index. The suitability of the data to describe the cyclists' behaviour with street-level detail is evaluated by comparison with various data from independent sources. Our approach to characterizing cycling traffic fluency offers a novel view on the cyclability of a city that could be valuable for urban planners, application providers, and cyclists alike. We find clear indications for the data's ability to estimate characteristics of city cycling quality correctly, despite behaviour patterns of cyclists not caused by external circumstances and the data's inher-ent bias. The proposed quality measure is adaptable for different applications, e.g. as an infrastructure quality measure or as a routing criterion

Constructive Aggression? Multiple Roles of Aggressive Content in Political Discourse on Russian YouTube

Abstract Today, aggressive verbal behavior is generally perceived as a threat to integrity and democratic quality of public discussions, including those online. However, we argue that, in more restrictive political regimes, communicative aggression may play constructive roles in both discussion dynamics and empowerment of political groups. This might be especially true for restrictive political and legal environments like Russia, where obscene speech is prohibited by law in registered media and the political environment does not give much space for voicing discontent. Taking Russian YouTube as an example, we explore the roles of two under-researched types of communicative aggression—obscene speech and politically motivated hate speech—within the publics of video commenters. For that, we use the case of the Moscow protests of 2019 against non-admission of independent and oppositional candidates to run for the Moscow city parliament. The sample of over 77,000 comments for 13 videos of more than 100,000 views has undergone pre-processing and vocabulary-based detection of aggression. To assess the impact of hate speech upon the dynamics of the discussions, we have used Granger tests and assessment of discussion histograms; we have also assessed the selected groups of posts in an exploratory manner. Our findings demonstrate that communicative aggression helps to express immediate support and solidarity. It also contextualizes the criticism towards both the authorities and regime challengers, as well as demarcates the counter-public

RELATIONSHIP BETWEEN URBANIZATION AND DENGUE HAEMORRHAGIC FEVER INCIDENCE IN SEMARANG CITY

Unplanned urbanization can cause unhealthy urban environment, which in turn increases the population of mosquitoes carrying the dengue vector. Consequently, this would reduce the urban life quality because public health is an important aspect of it. The increasing incidence of Dengue Haemorrhagic Fever (DHF) in Semarang City has been alarming. In 2013, the incidence was 2,364 cases, which increased up to 89.11% from the 1,250 cases of 2012. So, it is necessary to study about what relationship is there between the level of urbanization and the incidence of DHF in Semarang. This study used quantitative and spatial approach. The unit of analysis is sub-district with time series data from 2006 to 2013. The analysis technique is spatial analysis through image interpretation, regression, and descriptive analysis. The level of urbanization has been measured through the variables of population growth, population density, land use change, and building density. The results have shown that there is no significant correlation between the level of urbanization and the incidence of dengue fever. The urbanization is acknowledged as influencing only about 28% of the DHF incidence in the city, while the other 72% has been influenced by other factors