Evaluating the Impact of Data Transfer Time and Mobility Patterns in Opportunistic Networks

Author(s):  
Jorge Herrera-Tapia ◽  
Enrique Hernandez-Orallo ◽  
Pietro Manzoni ◽  
Andres Tomas ◽  
Carlos Tavares Calafate ◽  
...  
2015 ◽  
Vol 19 (10) ◽  
pp. 1814-1817 ◽  
Author(s):  
Enrique Hernandez-Orallo ◽  
Jorge Herrera-Tapia ◽  
Juan-Carlos Cano ◽  
Carlos T. Calafate ◽  
Pietro Manzoni

2021 ◽  
Vol 7 (4) ◽  
pp. 1-24
Author(s):  
Douglas Do Couto Teixeira ◽  
Aline Carneiro Viana ◽  
Jussara M. Almeida ◽  
Mrio S. Alvim

Predicting mobility-related behavior is an important yet challenging task. On the one hand, factors such as one’s routine or preferences for a few favorite locations may help in predicting their mobility. On the other hand, several contextual factors, such as variations in individual preferences, weather, traffic, or even a person’s social contacts, can affect mobility patterns and make its modeling significantly more challenging. A fundamental approach to study mobility-related behavior is to assess how predictable such behavior is, deriving theoretical limits on the accuracy that a prediction model can achieve given a specific dataset. This approach focuses on the inherent nature and fundamental patterns of human behavior captured in that dataset, filtering out factors that depend on the specificities of the prediction method adopted. However, the current state-of-the-art method to estimate predictability in human mobility suffers from two major limitations: low interpretability and hardness to incorporate external factors that are known to help mobility prediction (i.e., contextual information). In this article, we revisit this state-of-the-art method, aiming at tackling these limitations. Specifically, we conduct a thorough analysis of how this widely used method works by looking into two different metrics that are easier to understand and, at the same time, capture reasonably well the effects of the original technique. We evaluate these metrics in the context of two different mobility prediction tasks, notably, next cell and next distinct cell prediction, which have different degrees of difficulty. Additionally, we propose alternative strategies to incorporate different types of contextual information into the existing technique. Our evaluation of these strategies offer quantitative measures of the impact of adding context to the predictability estimate, revealing the challenges associated with doing so in practical scenarios.


2021 ◽  
Author(s):  
Lerato E Magosi ◽  
Yinfeng Zhang ◽  
Tanya Golubchick ◽  
Victor De Gruttola ◽  
Eric J Tchetgen Tchetgen ◽  
...  

Mathematical models predict that community–wide access to HIV testing–and–treatment can rapidly and substantially reduce new HIV infections. Yet several large universal test–and–treat HIV prevention trials in high–prevalence epidemics demonstrated variable reduction in population–level incidence. To elucidate patterns of HIV spread in universal test–and–treat trials we quantified the contribution of geographic–location, gender, age and randomized–HIV–intervention to HIV transmissions in the 30–community Ya Tsie trial in Botswana (estimated trial population: 175,664). Deep–sequence phylogenetic analysis revealed that most inferred HIV transmissions within the trial occurred within the same or between neighboring communities, and between similarly–aged partners. Transmissions into intervention communities from control communities were more common than the reverse post–baseline (30% [12.2 – 56.7] versus 3% [0.1 – 27.3]) than at baseline (7% [1.5 – 25.3] versus 5% [0.9 – 22.9]) compatible with a benefit from treatment–as–prevention. Our findings suggest that population mobility patterns are fundamental to HIV transmission dynamics and to the impact of HIV control strategies.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Harry E. R. Shepherd ◽  
Florence S. Atherden ◽  
Ho Man Theophilus Chan ◽  
Alexandra Loveridge ◽  
Andrew J. Tatem

Abstract Background Since early March 2020, the COVID-19 epidemic across the United Kingdom has led to a range of social distancing policies, which resulted in changes to mobility across different regions. An understanding of how these policies impacted travel patterns over time and at different spatial scales is important for designing effective strategies, future pandemic planning and in providing broader insights on the population geography of the country. Crowd level data on mobile phone usage can be used as a proxy for population mobility patterns and provide a way of quantifying in near-real time the impact of social distancing measures on changes in mobility. Methods Here we explore patterns of change in densities, domestic and international flows and co-location of Facebook users in the UK from March 2020 to March 2021. Results We find substantial heterogeneities across time and region, with large changes observed compared to pre-pademic patterns. The impacts of periods of lockdown on distances travelled and flow volumes are evident, with each showing variations, but some significant reductions in co-location rates. Clear differences in multiple metrics of mobility are seen in central London compared to the rest of the UK, with each of Scotland, Wales and Northern Ireland showing significant deviations from England at times. Moreover, the impacts of rapid changes in rules on international travel to and from the UK are seen in substantial fluctuations in traveller volumes by destination. Conclusions While questions remain about the representativeness of the Facebook data, previous studies have shown strong correspondence with census-based data and alternative mobility measures, suggesting that findings here are valuable for guiding strategies.


2007 ◽  
Vol 2007 ◽  
pp. 1-9 ◽  
Author(s):  
Peter Počta ◽  
Peter Kortiš ◽  
Martin Vaculík

This paper describes measurements of the impact of background traffic on speech quality in an environment of WLANs (IEEE 802.11). The simulated background traffic consists of three types of current traffics in telecommunication networks such as data transfer service, multimedia streaming service, and Web service. The background traffic was generated by means of the accomplished Distributed Internet Traffic Generator (D-ITG). The impact of these types of traffic and traffic load on speech quality using the test sequence and speech sequences is the aim of this paper. The assessment of speech quality is carried out by means of the accomplished Perceptual Evaluation of Speech Quality (PESQ) algorithm. The proposal of a new method for improved detection of the critical conditions in wireless telecommunication networks from the speech quality point of view is presented in this paper. Conclusion implies the next application of the method of improved detection of critical conditions for the purpose of algorithms for link adaptation from the speech quality point of view in an environment of WLANs. The primary goal of these algorithms is improving speech quality in the VoWLAN connections, which are established in the competent link.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Tzu-Ching Wu ◽  
Navdeep Sangha ◽  
Feryal N Elorr ◽  
Edgar Olivas ◽  
Christy M Ankrom ◽  
...  

Background: The transfer process for patients with large vessel occlusions from a community hospital to an intra-arterial therapy (IAT)-capable center often involves multiple teams of physicians and administrative personnel, leading to delays in care. Objective We compared time metrics for spoke drip-and-ship telemedicine (TM) patients transferred for IAT to comprehensive stroke centers (CSC) in two different health systems: Kaiser Permanente (KP) with an integrated health care system of spokes and a 50 mile range using ambulances for transfer vs UTHealth (UTH), where patients are transferred by helicopter from varying health systems ranging up to 200 miles from the hub. Methods: We retrospectively identified patients in the KP and UTH networks transferred from TM spokes to the CSC (KP—6 spokes and UTH -17 spokes). From 9/15 to 4/16, a total of 79 TM patients (KP-28 patients, UTH-51 patients) were transferred to the respective hubs for evaluation of IAT. Baseline clinical data, transfer, and IAT metrics were abstracted. Results: On average, it takes ~90 minutes for a TM patient to arrive at the CSC hub once accepted by the transfer center. Patients in the KP Network arrive at the hub faster than UTH patients, but IAT metrics/outcomes are comparable. Over 50% of the patients did not undergo IAT on hub arrival mostly due to lack of clot on CTA (20/45) or symptom improvement (9/45). Conclusion: In two large, yet different TM networks, the transfer time from spoke to hub needs to be shortened. Areas for improvement include spoke arrival to transfer acceptance and transfer acceptance to hub arrival. A prospective study is underway to develop best practice time parameters for this complex process of identifying and transferring patients eligible for IAT.


STORIA URBANA ◽  
2009 ◽  
pp. 21-48
Author(s):  
Banales José Luis Onyňn

- The article focuses on the relationship between tramway networks and urban structure in Spain during the period 1900-1936. It states that this relationship should be studied after considering the use of transport and the mobility patterns of different classes, specially the working class. Once these factors have been studied it is possible to assert the impact of the tramway netmark on urban growth. The impact of the tramways on major Spanish cities did not take the form of a transport revolution that would radically changed the urban pattern. Tramways did not direct urban growth until use of tramway lines by the working class became general. This did not happen until World War I. Since then, skilled and some unskilled workers did change their mobility patterns and tramway use experienced a cycle of growth that continued until the late 1950s.


1999 ◽  
Vol 23 (1B) ◽  
pp. 117-127
Author(s):  
R. Lykins ◽  
M. Ramalingam ◽  
B. Donovan ◽  
E. Durkin ◽  
J. Beam

A computerized analytical program is being developed to help investigate the impact of power system requirements on aircraft performance. The program has an user interface that operates in MS-EXCEL, linking several subsystems analysis programs for execution and data transfer in the power systems analysis. The program presently includes an encoded propulsion engine cycle code, which allows the inspection of power extraction effects on engine performance. To validate the results of the encoded engine program, a study was conducted to investigate the separate effects of shaft power extraction and pneumatic bleed. The selected engine cycle was that for a standard tactical fighter, with a flight condition of varied altitude (sea level to 40,000 ft) and constant Mach Number (0.9). As expected the resultant data showed that the engine performance was more sensitive to pneumatic bleed than to shaft power extraction. The paper’s efficiency comparisons between shaft power and bleed air power helps indicate the higher efficiency for the power system of a more-electric type aircraft. Present efforts on the analytical interface are to incorporate a fuel thermal management analysis capability.


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