Journal articles: 'Mobility metrics'

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Calderbank, David M. J., Vladimir S. Matveev, and Stefan Rosemann. "Curvature and the c-projective mobility of Kähler metrics with hamiltonian 2-forms." Compositio Mathematica 152, no. 8 (April 26, 2016): 1555–75. http://dx.doi.org/10.1112/s0010437x16007302.

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The mobility of a Kähler metric is the dimension of the space of metrics with which it is c-projectively equivalent. The mobility is at least two if and only if the Kähler metric admits a nontrivial hamiltonian 2-form. After summarizing this relationship, we present necessary conditions for a Kähler metric to have mobility at least three: its curvature must have nontrivial nullity at every point. Using the local classification of Kähler metrics with hamiltonian 2-forms, we describe explicitly the Kähler metrics with mobility at least three and hence show that the nullity condition on the curvature is also sufficient, up to some degenerate exceptions. In an appendix, we explain how the classification may be related, generically, to the holonomy of a complex cone metric.

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Ibadah, Nisrine, Khalid Minaoui, Mohammed Rziza, Mohammed Oumsis, and César Benavente-Peces. "Deep Validation of Spatial Temporal Features of Synthetic Mobility Models." Computers 7, no. 4 (December 16, 2018): 71. http://dx.doi.org/10.3390/computers7040071.

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This paper analyzes the most relevant spatial-temporal stochastic properties of benchmark synthetic mobility models. Each pattern suffers from various mobility flaws, as will be shown by the models’ validation. A set of metrics is used to describe mobility features, such as the speed decay problem, the density wave phenomenon, the spatial node distribution, and the average neighbor percentage. These metrics have already been validated for the random waypoint mobility model (RWPMM), but they have not yet been verified for other mobility patterns that are most frequently used. For this reason, this investigation attempts to deeply validate those metrics for other mobility models, namely the Manhattan Grid mobility, the Reference Point Group mobility, the Nomadic Community mobility, the Self-Similar Least Action Walk, and SMOOTH models. Moreover, we propose a novel mobility metric named the “node neighbors range”. The relevance of this new metric is that it proves at once the set of outcomes of previous metrics. It offers a global view of the overall range of mobile neighbors during the experimental time. The current research aims to more rigorously understand mobility features in order to conduct a precise assessment of each mobility flaw, given that this fact further impacts the performance of the whole network. These validations aim to summarize several parameters into 18,126 different scenarios with an average of 486 validated files. An exhaustive analysis with details like those found in this paper leads to a good understanding of the accurate behaviors of mobility models by displaying the ability of every pattern to deal with certain topology changes, as well as to ensure network performances. Validation results confirm the effectiveness and robustness of our novel metric.

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Manno, Gianni, and Andreas Vollmer. "Benenti Tensors: A useful tool in Projective Differential Geometry." Complex Manifolds 5, no. 1 (May 18, 2018): 111–21. http://dx.doi.org/10.1515/coma-2018-0006.

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AbstractTwo metrics are said to be projectively equivalent if they share the same geodesics (viewed as unparametrized curves). The degree of mobility of a metric g is the dimension of the space of the metrics projectively equivalent to g. For any pair of metrics (g, ḡ) on the same manifold one can construct a (1, 1)- tensor L(g, ḡ) called the Benenti tensor. In this paper we discuss some geometrical properties of Benenti tensors when (g, ḡ) are projectively equivalent, particularly in the case of degree of mobility equal to 2.

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Wong, J. Y., P. Jayakumar, E. Toma, and J. Preston-Thomas. "A review of mobility metrics for next generation vehicle mobility models." Journal of Terramechanics 87 (February 2020): 11–20. http://dx.doi.org/10.1016/j.jterra.2019.10.003.

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Spohn, Marco Aurélio, and Matheus Henrique Trichez. "An Analysis of a Real Mobility Trace Based on Standard Mobility Metrics." Revista de Informática Teórica e Aplicada 26, no. 1 (April 14, 2019): 26. http://dx.doi.org/10.22456/2175-2745.84330.

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Better understanding mobility, being it from pedestrians or any other moving object, is practical and insightful. Practical due to its applications to the fundamentals of communication, with special attention to wireless communication. Insightful because it might pinpoint the pros and cons of how we are moving, or being moved, around. There are plenty of studies focused on mobility in mobile wireless networks, including the proposals of several synthetic mobility models. Getting real mobility traces is not an easy task, but there has been some efforts to provide traces to the public through repositories. Synthetic mobility models are usually analyzed through mobility metrics, which are designed to capture mobility subtleties. This work research on the applicability of some representative mobility metrics for real traces analysis. To achieve that goal, a case study is accomplished with a dataset of mobility traces of taxi cabs in the city of Rome/Italy. The results suggest that the mobility metrics under consideration are capable of capturing mobility properties which would otherwise require more sophisticated analytical approaches.

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SHU, Xiao. "Relations among Mobility Metrics in Wireless Networks." Int'l J. of Communications, Network and System Sciences 01, no. 03 (2008): 246–53. http://dx.doi.org/10.4236/ijcns.2008.13030.

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Matveev, Vladimir S., and Stefan Rosemann. "The degree of mobility of Einstein metrics." Journal of Geometry and Physics 99 (January 2016): 42–56. http://dx.doi.org/10.1016/j.geomphys.2015.09.008.

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Evangeline, C. Suganthi, and S. Appu. "An Efficient Data Transmission in VANET Using Clustering Method." International Journal of Electronics and Telecommunications 63, no. 3 (August 28, 2017): 309–13. http://dx.doi.org/10.1515/eletel-2017-0045.

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Abstract A special type of Mobile Ad-hoc Networks (MANETs) which has frequent changes of topology and higher mobility is known as Vehicular Ad-hoc Networks (VANETs). In order to divide the network into groups of mobile vehicles and improve routing, data gathering, clustering is applied in VANETs. A stable clustering scheme based on adaptive multiple metric combining both the features of static and dynamic clustering methods is proposed in this work. Based on a new multiple metric method, a cluster head is selected among the cluster members which is taken from the mobility metrics such as position and time to leave the road segment, relative speed and Quality of Service metrics which includes neighborhood degree, link quality of the RSU and bandwidth. A higher QoS and cluster stability are achieved through the adaptive multiple metric. The results are simulated using NS2 and shows that this technique provides more stable cluster structured with the other methods.

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Gao, Xuesong, Hui Wang, and Lun Liu. "Profiling Residents’ Mobility with Grid-Aggregated Mobile Phone Trace Data Using Chengdu as the Case." Sustainability 13, no. 24 (December 12, 2021): 13713. http://dx.doi.org/10.3390/su132413713.

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People’s movement trace harvested from mobile phone signals has become an important new data source for studying human behavior and related socioeconomic topics in social science. With growing concern about privacy leakage of big data, mobile phone data holders now tend to provide aggregate-level mobility data instead of individual-level data. However, most algorithms for measuring mobility are based on individual-level data—how the existing mobility algorithms can be properly transformed to apply on aggregate-level data remains undiscussed. This paper explores the transformation of individual data-based mobility metrics to fit with grid-aggregate data. Fifteen candidate metrics measuring five indicators of mobility are proposed and the most suitable one for each indicator is selected. Future research about aggregate-level mobility data may refer to our analysis to assist in the selection of suitable mobility metrics.

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Xu, Gang, Leigh Sturges, Michael Chapman, Chris Albrecht, Dave Bergner, and Xianming Shi. "Snow Removal Performance Metrics: Past, Present, and Future." Transportation Research Record: Journal of the Transportation Research Board 2613, no. 1 (January 2017): 61–70. http://dx.doi.org/10.3141/2613-08.

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Snow and ice maintenance operations are among the most critical functions of state transportation agencies and municipalities in cold regions. The use of snow removal performance metrics is of increasing interest to transportation practitioners and academics. For this paper, a comprehensive literature review and a survey were conducted to gather information on the performance metrics used in winter highway maintenance activities by different transportation agencies. Performance goals for snow and ice control were identified in the survey, with average rankings as follows (in descending order): safety, mobility, economy, essential functions, environment, infrastructure, and livability. The survey results were also tabulated and analyzed to identify best practices and future trends in the agencies. Restoring safety and mobility consistently remains a priority of nearly all agencies. At present, the time taken to reach an established level of service is the most commonly used metric of different agencies. Because of the relatively high effectiveness, reliability, and timeliness of outcome-based and severity index–based performance metrics, more agencies are moving toward these types of metrics. Performance measurement by geographic area was also investigated but no clear trend was found.

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Kumar, Santosh, S. C. Sharma, and Bhupendra Suman. "Mobility Metrics Based Classification & Analysis of Mobility Model for Tactical Network." International Journal of Next-Generation Networks 2, no. 3 (September 30, 2010): 39–51. http://dx.doi.org/10.5121/ijngn.2010.2305.

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Amine, Khalil. "An energy-degree evaluation metric for clustering purposes in mobile ad hoc networks." International Journal of Modeling, Simulation, and Scientific Computing 10, no. 02 (April 2019): 1950005. http://dx.doi.org/10.1142/s1793962319500053.

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Network clustering is the process of partitioning a network into a number of virtual entities mastered by certain nodes, called cluster centers that are responsible for collecting and maintaining topology information and managing the routing processes. In ad hoc networking, clustering has been introduced to deal with the dynamic topology by providing a temporarily stable network core. Clustering process mainly depends on the metric upon which the selection of cluster centers is performed. A wide range of clustering metrics were introduced in the literature based on network issues including mobility and connectivity degree, giving rise to a variety of clustering schemes. Although clustering provides energy consumption reduction, residual energy has not received enough attention and few studies have addressed the clustering on the basis of this feature. This paper discusses the current clustering metrics and proposes an energy-degree evaluation metric with mobility consideration taking into account the nodes residual energy and the network connectivity as two main keys of clustering.

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Chung, Jane, Joseph Boyle, and David Wheeler. "CORRELATIONS OF GPS-BASED COMMUNITY MOBILITY METRICS BETWEEN PERSONS WITH DEMENTIA AND FAMILY CAREGIVERS." Innovation in Aging 6, Supplement_1 (November 1, 2022): 453. http://dx.doi.org/10.1093/geroni/igac059.1767.

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Abstract Currently, the majority of dementia care is provided at home by informal caregivers. Most informal caregivers share a routine with their loved ones and change their activity patterns to adapt to a new routine of persons with dementia (PWDs). Given the dementia caregiving context, caregivers’ mobility behaviors and PWDs’ mobility may be positively associated. This study aimed to characterize patterns of GPS-derived community mobility in dementia dyads and examine relationships between PWDs’ and caregivers’ mobility patterns. Six dyads wore a GPS data logger inside and outside the home for 8-11 days. Twelve participants generated valid GPS track files (N=110). Four temporal and spatial mobility metrics were derived from GPS data (total distance, time use, median speed, and convex hull area). Then we calculated Pearson correlation coefficients between PWDs and their caregivers over all tracks. All dyads made active out-of-home trips, indicated by mean daily distance (range: 6,198 - 115,592m for PWDs; 5,125 - 108,857m for caregivers). Median speed of movement ranged from 0.09 to 1.29 km/hour for PWDs, and from 0.21 to 0.97 km/hour for caregivers. The mean size of convex hull over the monitoring period indicates a limited space usage level in both PWDs and caregivers, meaning restricted community mobility despite relatively large distance trips. The correlation coefficient was positive and significant for each metric (r = 0.70-0.97, p < .001). These results suggest substantial agreement in the mobility metrics between PWD and their caregivers, indicating a high level of dyadic effects of a partner’s experience of community mobility.

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Jeong, Kyungsoo, Venu Garikapati, Yi Hou, Alicia Birky, and Kevin Walkowicz. "Comprehensive Approach to Measure the Mobility Energy Productivity of Freight Transport." Transportation Research Record: Journal of the Transportation Research Board 2674, no. 7 (June 2, 2020): 29–43. http://dx.doi.org/10.1177/0361198120920879.

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Freight travel accounts for a major share of the energy consumed in the transportation sector in any country, and the United States is no exception. Understanding and modeling freight movement are critical, particularly in the context of capturing the impact of emerging technologies on freight travel and its externalities. The domain of freight modeling and forecasting has been gaining pace in recent years, but advancement in comprehensive freight performance metrics is still lagging. Conventional freight performance metrics such as truck-miles, ton-miles, or value-miles are unidimensional and aggregate in nature, making them unsuitable to accurately capture the impact of emerging transportation trends on the performance or productivity of freight systems. Addressing the research need, this paper presents the “Freight Mobility Energy Productivity” metric to quantify freight productivity of current as well as future freight systems, accounting for various costs associated with freight transport. The proposed metric was implemented using data from the Freight Analysis Framework along with other published sources, and shows intuitive results in quantifying freight productivity. Further, a scenario analysis exercise was conducted to test the capability of the metric in tracking improvements in system-level freight productivity as a result of vehicle electrification. The relative differences in Freight Mobility Energy Productivity scores help identify which zones benefit from the vehicle powertrain technology improvement. The results of the scenario analysis reinforce confidence that the proposed metric can be used as a decision support tool in assessing the productivity of existing as well as future freight trends and technologies.

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Buchman, Aron S., Robert J. Dawe, Sue E. Leurgans, Thomas A. Curran, Timothy Truty, Lei Yu, Lisa L. Barnes, Jeffrey M. Hausdorff, and David A. Bennett. "Different Combinations of Mobility Metrics Derived From a Wearable Sensor Are Associated With Distinct Health Outcomes in Older Adults." Journals of Gerontology: Series A 75, no. 6 (June 27, 2019): 1176–83. http://dx.doi.org/10.1093/gerona/glz160.

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Abstract Background Gait speed is a robust nonspecific predictor of health outcomes. We examined if combinations of gait speed and other mobility metrics are associated with specific health outcomes. Methods A sensor (triaxial accelerometer and gyroscope) placed on the lower back, measured mobility in the homes of 1,249 older adults (77% female; 80.0, SD = 7.72 years). Twelve gait scores were extracted from five performances, including (a) walking, (b) transition from sit to stand, (c) transition from stand to sit, (d) turning, and (e) standing posture. Using separate Cox proportional hazards models, we examined which metrics were associated with time to mortality, incident activities of daily living disability, mobility disability, mild cognitive impairment, and Alzheimer’s disease dementia. We used a single integrated analytic framework to determine which gait scores survived to predict each outcome. Results During 3.6 years of follow-up, 10 of the 12 gait scores predicted one or more of the five health outcomes. In further analyses, different combinations of 2–3 gait scores survived backward elimination and were associated with the five outcomes. Sway was one of the three scores that predicted activities of daily living disability but was not included in the final models for other outcomes. Gait speed was included along with other metrics in the final models predicting mortality and activities of daily living disability but not for other outcomes. Conclusions When analyzing multiple mobility metrics together, different combinations of mobility metrics are related to specific adverse health outcomes. Digital technology enhances our understanding of impaired mobility and may provide mobility biomarkers that predict distinct health outcomes.

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Barcelo, Marc, Alejandro Correa, Jose Lopez Vicario, Antoni Morell, and Xavier Vilajosana. "Addressing Mobility in RPL With Position Assisted Metrics." IEEE Sensors Journal 16, no. 7 (April 2016): 2151–61. http://dx.doi.org/10.1109/jsen.2015.2500916.

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Maldonado, Peter, Angie Peng, Derek Ouyang, Jenny Suckale, and Daniel E. Ho. "Science Translation During the COVID-19 Pandemic: An Academic-Public Health Partnership to Assess Capacity Limits in California." American Journal of Public Health 112, no. 2 (February 2022): 308–15. http://dx.doi.org/10.2105/ajph.2021.306576.

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On the basis of an extensive academic–public health partnership around COVID-19 response, we illustrate the challenge of science-policy translation by examining one of the most common nonpharmaceutical interventions: capacity limits. We study the implementation of a 20% capacity limit in retail facilities in the California Bay Area. Through a difference-in-differences analysis, we show that the intervention caused no material reduction in visits, using the same large-scale mobile device data on human movements (mobility data) originally used in the academic literature to support such limits. We show that the lack of effectiveness stems from a mismatch between the academic metric of capacity relative to peak visits and the policy metric of capacity relative to building code. The disconnect in metrics is amplified by mobility data losing predictive power after the early months of the pandemic, weakening the policy relevance of mobility-based interventions. Nonetheless, the data suggest that a better-grounded rationale for capacity limits is to reduce risk specifically during peak hours. To enhance the connection between science, policy, and public health in future times of crisis, we spell out 3 strategies: living models, coproduction, and shared metrics. (Am J Public Health. 2022;112(2):308–315. https://doi.org/10.2105/AJPH.2021.306576 )

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Shi, Yan, Long Hao Zou, and Shan Zhi Chen. "A Mobility Pattern Aware Clustering Mechanism for Mobile Vehicular Networks." Applied Mechanics and Materials 130-134 (October 2011): 317–20. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.317.

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Clustering is one of the promising technologies for group mobility in mobile vehicular networks. MPAC (Mobility Pattern Aware Clustering) mechanism is proposed in this paper. MPAC aims at improving the stability of the cluster depending on GR (Group Relation), which is derived from some basic mobility metrics such as speed, direction, acceleration and vehicle location. The cluster formation and cluster maintenance operation based on the above mobility metrics are defined. Simulation results show that MPAC has obvious performance advantages in cluster stability, which is illustrated by the mean number of cluster reconfiguration and the mean life time of cluster heads.

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Scherler, Dirk, and Wolfgang Schwanghart. "Drainage divide networks – Part 2: Response to perturbations." Earth Surface Dynamics 8, no. 2 (April 20, 2020): 261–74. http://dx.doi.org/10.5194/esurf-8-261-2020.

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Abstract. Drainage divides are organized into tree-like networks that may record information about drainage divide mobility. However, views diverge about how to best assess divide mobility. Here, we apply a new approach of automatically extracting and ordering drainage divide networks from digital elevation models to results from landscape evolution model experiments. We compared landscapes perturbed by strike-slip faulting and spatiotemporal variations in erodibility to a reference model to assess which topographic metrics (hillslope relief, flow distance, and χ) are diagnostic of divide mobility. Results show that divide segments that are a minimum distance of ∼5 km from river confluences strive to attain constant values of hillslope relief and flow distance to the nearest stream. Disruptions of such patterns can be related to mobile divides that are lower than stable divides, closer to streams, and often asymmetric in shape. In general, we observe that drainage divides high up in the network, i.e., at great distances from river confluences, are more susceptible to disruptions than divides closer to these confluences and are thus more likely to record disturbance for a longer time period. We found that across-divide differences in hillslope relief proved more useful for assessing divide migration than other tested metrics. However, even stable drainage divide networks exhibit across-divide differences in any of the studied topographic metrics. Finally, we propose a new metric to quantify the connectivity of divide junctions.

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Li, Z., L. Sun, and E. C. Ifeachor. "GPS-free mobility metrics for mobile ad hoc networks." IET Communications 1, no. 5 (2007): 970. http://dx.doi.org/10.1049/iet-com:20060289.

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Wickert, Andrew D., John M. Martin, Michal Tal, Wonsuck Kim, Ben Sheets, and Chris Paola. "River channel lateral mobility: metrics, time scales, and controls." Journal of Geophysical Research: Earth Surface 118, no. 2 (April 15, 2013): 396–412. http://dx.doi.org/10.1029/2012jf002386.

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Pop, M. D., and O. Proștean. "Identification of significant metrics and indicators for smart mobility." IOP Conference Series: Materials Science and Engineering 477 (February 18, 2019): 012017. http://dx.doi.org/10.1088/1757-899x/477/1/012017.

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Kiosak, V. A., V. S. Matveev, J. Mikeš, and I. G. Shandra. "On the degree of geodesic mobility for Riemannian metrics." Mathematical Notes 87, no. 3-4 (April 2010): 586–87. http://dx.doi.org/10.1134/s0001434610030375.

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Gao, Zhenxiang, Yan Shi, and Shanzhi Chen. "Measures of node centrality in mobile social networks." International Journal of Modern Physics C 26, no. 09 (June 22, 2015): 1550107. http://dx.doi.org/10.1142/s0129183115501077.

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Mobile social networks exploit human mobility and consequent device-to-device contact to opportunistically create data paths over time. While links in mobile social networks are time-varied and strongly impacted by human mobility, discovering influential nodes is one of the important issues for efficient information propagation in mobile social networks. Although traditional centrality definitions give metrics to identify the nodes with central positions in static binary networks, they cannot effectively identify the influential nodes for information propagation in mobile social networks. In this paper, we address the problems of discovering the influential nodes in mobile social networks. We first use the temporal evolution graph model which can more accurately capture the topology dynamics of the mobile social network over time. Based on the model, we explore human social relations and mobility patterns to redefine three common centrality metrics: degree centrality, closeness centrality and betweenness centrality. We then employ empirical traces to evaluate the benefits of the proposed centrality metrics, and discuss the predictability of nodes' global centrality ranking by nodes' local centrality ranking. Results demonstrate the efficiency of the proposed centrality metrics.

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Saad, Amna, Husna Osman, and Mufind Mukaz Ebedon. "Review of Ad Hoc Networks scenarios and challenges in years 2015-2019." International journal of electrical and computer engineering systems 12 (November 2, 2021): 39–50. http://dx.doi.org/10.32985/ijeces.12.si.5.

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A Mobile Ad-hoc Network (MANET) protocol performance analysis depends on the type of simulation tools, mobility models, and metrics used. These parameters' choice is crucial to researchers because it may produce an inaccurate result if it is not well chosen. The challenges researcher is facing are on the choice of these four parameters. Our survey shows an inclination to used Ad-hoc On-Demand Distance Vector routing (AODV) for performance comparison and enhancement of it by the researcher. Network simulation 2 (NS2) was the most selected tool, but we observe a decline in its utilization in recent years. Random Waypoint Mobility model (RWPM) was the most used mobility model. We have found a high percentage of the published article did not mention the mobility models use; this will make the result difficult for performance comparison with other works. Packet Delivery Ratio (PDR), End to End Delay (E2ED) were the most used metrics. Some authors have self-developed their simulation tools; the authors have also used new metrics and protocols to get a particular result based on their research objective. However, some criteria of choosing a protocol, metrics, mobility model, and simulation tool were not described, decreasing the credibility of their papers' results. Improvement needs to be done in the Ad-hoc network in terms of benchmark, acceptable scenario parameters. This survey will give the best practice to be used and some recommendations to the Ad-hoc network community.

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Laqtib, Safaa, Khalid El Yassini, and Moulay Lahcen Hasnaoui. "Link-state QoS routing protocol under various mobility models." Indonesian Journal of Electrical Engineering and Computer Science 16, no. 2 (November 1, 2019): 906. http://dx.doi.org/10.11591/ijeecs.v16.i2.pp906-916.

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<p>Mobile Ad Hoc Network (MANET) consists of a group of mobile or wireless nodes that are placed randomly and dynamically that causes the continual change between nodes. A mobility model attempts to mimic the movement of real mobile nodes that change the speed and direction with time. The mobility model that accurately represents the characteristics of the mobile nodes in an ad hoc network is the key to examine whether a given protocol. The aim of this paper is to compare the performance of four different mobility models (i.e. Random Waypoint, Random Direction, Random walk, and Steady-State Random Waypoint) in MANET. These models were configured with Optimized Link State Routing (OLSR) protocol under three QoS (Quality of Service) <a title="Learn more about Metrics" href="https://www.sciencedirect.com/topics/engineering/metrics">metrics</a> such as the Packet Delivery Ratio (PDR), Throughput, End-to-End delay. The simulation results show the effectiveness of Steady-State Random Waypoint Mobility Models and encourage further investigations to extend it in order to guarantee other QoS requirements.</p>

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Wu, Fang-jing, Ying-Jun Chen, and Sok-Ian Sou. "CoCo." ACM Transactions on Internet of Things 2, no. 3 (July 2021): 1–22. http://dx.doi.org/10.1145/3457139.

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As mobility is an important key to many applications, this work proposes a location-less model to represent mobility that is used to quantify correlations between mobility traces collected by built-in sensors on smartphones. We analyze the mobility correlations from two aspects: co-direction relationship and co-movement relationship . The former is to quantify the similarity of macroscopic moving directions between mobility traces, whereas the latter is to quantify the similarity of their microscopic vibrations. To verify the merits of the two proposed metrics, an exemplary use case, termed co-mobility detection , is considered to determine if two mobile devices share the same journey on the same mobile entity (e.g., carried by the same person). Comprehensive experiments with diverse combinations of mobility traces are conducted in three different environments with different density of Wi-Fi networks. The experimental results indicate that the proposed metrics can effectively evaluate both the coarse-grained similarity of moving directions and the fine-grained similarity of movement variations along mobility traces. The accuracy of the co-mobility detection algorithm can achieve 90% on average for mobility traces with a duration of 70 s.

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Silva-Batista, Carla, Graham Harker, Rodrigo Vitorio, Fay B. Horak, Patricia Carlson-Kuhta, Sean Pearson, Jess VanDerwalker, Mahmoud El-Gohary, and Martina Mancini. "Feasibility of a Novel Therapist-Assisted Feedback System for Gait Training in Parkinson’s Disease." Sensors 23, no. 1 (December 23, 2022): 128. http://dx.doi.org/10.3390/s23010128.

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We tested the feasibility of one session of treadmill training using a novel physical therapist assisted system (Mobility Rehab) using wearable sensors on the upper and lower limbs of 10 people with Parkinson’s disease (PD). Participants performed a 2-min walk overground before and after 15 min of treadmill training with Mobility Rehab, which included an electronic tablet (to visualize gait metrics) and five Opal sensors placed on both the wrists and feet and on the sternum area to measure gait and provide feedback on six gait metrics (foot-strike angle, trunk coronal range-of-motion (ROM), arm swing ROM, double-support duration, gait-cycle duration, and step asymmetry). The physical therapist used Mobility Rehab to select one or two gait metrics (from the six) to focus on during the treadmill training. Foot-strike angle (effect size (ES) = 0.56, 95% Confidence Interval (CI) = 0.14 to 0.97), trunk coronal RoM (ES = 1.39, 95% CI = 0.73 to 2.06), and arm swing RoM (ES = 1.64, 95% CI = 0.71 to 2.58) during overground walking showed significant and moderate-to-large ES following treadmill training with Mobility Rehab. Participants perceived moderate (60%) and excellent (30%) effects of Mobility Rehab on their gait. No adverse events were reported. One session of treadmill training with Mobility Rehab is feasible for people with mild-to-moderate PD.

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Quintana, Rafael, and Richard Correnti. "The Concept of Academic Mobility: Normative and Methodological Considerations." American Educational Research Journal 57, no. 4 (September 27, 2019): 1625–64. http://dx.doi.org/10.3102/0002831219876935.

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Most of the literature on the development of educational inequality has operated under the achievement gaps paradigm, often assuming that the underlying normative and methodological foundations related to equality and justice in education are a settled matter. In this article, we argue that important normative dimensions are overlooked with traditional mean-based measures, and that metrics that capture students’ academic mobility as they progress through school can provide the informational base needed to describe and evaluate these policy and socially relevant aspects. We discuss some key normative principles and methodological dimensions related to academic mobility and provide an empirical example of the mobility metrics presented using a nationally representative data set.

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Cana, Erion. "Comparative Performance Simulation of DSDV AODV and DSR MANET Protocols in NS2." International Journal of Business & Technology 2, no. 1 (May 2013): 24–31. http://dx.doi.org/10.33107/ijbte.2013.2.1.4.

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Mobile Ad hoc Networks (MANET) are self-configured and infrastructure less networks with autonomous mobile nodes. Due to the high flexibility, these kind of networks are heavily used in rescue operations, military missions etc. Many routing protocols for this kind of networks exist. This article presents a comparative and quantitative performance study of DSDV, AODV and DSR routing protocols using different simulation models in NS2. Performance metrics like PDR, E2E Delay and Throughput are analyzed under varying network, traffic and mobility parameters like number of nodes, traffic flows, mobility speed and pause time. Results show that AODV outperforms DSDV and DSR in all the performance metrics. DSDV performs better than DSR in terms of PDR and E2E delay. DSR gives 20-30 higher Throughput than DSDV. Performance metrics are highly influenced by network topology parameters like number of nodes and number of traffic flow connections. Mobility parameters like speed and pause time have slight impact on performance.

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Gargiulo, Paolo, Kyle Joseph Edmunds, Magnús K. Gíslason, Chase Latour, Þröstur Hermannsson, Luca Esposito, Paolo Bifulco, et al. "Patient-specific mobility assessment to monitor recovery after total hip arthroplasty." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 232, no. 10 (September 7, 2018): 1048–59. http://dx.doi.org/10.1177/0954411918797971.

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Total hip arthroplasty is a ubiquitously successful orthopedic surgical procedure, whose prevalence is rising worldwide. While many investigations focus on characterizing periprosthetic pathophysiology, the objective of our research is to develop and describe multi-metric assemblies as a first step toward creating a patient-specific mobility index that rehabilitators and orthopedic surgeons can utilize for prescribing their respective procedures. In total, 48 total hip arthroplasty patients (both cemented and uncemented) undergoing unilateral, primary surgery went through computed tomographic scans and gait analysis measurements both before and 1 year following their surgery. Altogether, the reported quantitative metrics include 11 spatial and temporal gait parameters, muscle density, and electromyography signals from the rectus femoris, vastus lateralis, and vastus medialis, and bone mineral density values from bioimage analysis around the implant stem. We found that measured parameters from a subgroup were sensitive to changes observed during patient recovery, implicating the predictive sensitivity of these patient conditions. Most post-operative gait parameters changed significantly, while electromyography data indicated few significant differences. Moreover, results from bioimage analyses indicate a general reduction of periprosthetic bone mineral density after 1 year, in association with increasing density of the quadriceps muscles. Furthermore, this work identifies which quantitative metrics undergo the greatest variation after total hip arthroplasty and demonstrates the clinical feasibility of a multimodal approach to mobility assessment that may ultimately support decision-making for post-surgical rehabilitation protocols.

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De Vincentis, Rosita, Federico Karagulian, Carlo Liberto, Marialisa Nigro, Vincenza Rosati, and Gaetano Valenti. "A Data-Driven Approach to Analyze Mobility Patterns and the Built Environment: Evidence from Brescia, Catania, and Salerno (Italy)." Sustainability 14, no. 21 (November 3, 2022): 14378. http://dx.doi.org/10.3390/su142114378.

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Investigating the correlation between urban mobility patterns and the built environment is crucial to support an integrated approach to transportation and land-use planning in modern cities. In this study, we aim to conduct a data-driven analysis of these two interrelated parts of the urban environment through the estimation of a set of metrics to assist city planners in making well-informed strategic decisions. Metrics are computed by aggregating and correlating different types of data sources. Floating Car Data (FCD) are used to compute metrics on mobility demand and traffic patterns. The built environment metrics are mainly derived from population and housing census data, as well as by investigating the topology and the functional classification adopted in the OpenStreetMap Repository to describe the importance and the role of each street in the overall network. Thanks to this set of metrics, accessibility indexes are then estimated to capture and explain the interaction between traffic patterns and the built environment in three Italian cities: Brescia, Catania, and Salerno. The results confirm that the proposed data-driven approach can extract valuable information to support decisions leading to more sustainable urban mobility volumes and patterns. More specifically, the application results show how the physical shape of each city and the related street network characteristics affect the accessibility profiles of different city zones and, consequently, the associated traffic patterns and travel delays. In particular, the combined analysis of city layouts, street network distributions, and floating car profiles suggests that cities such as Brescia, which is characterized by a homogeneously distributed radial street system, exhibit a more balanced spread of activities and efficient mobility behaviors.

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DeFelice, Jeffrey, and Jane E. G. Lipson. "Different metrics for connecting mobility and glassiness in thin films." Soft Matter 15, no. 7 (2019): 1651–57. http://dx.doi.org/10.1039/c8sm02355g.

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Ackers, Louise. "Internationalisation, Mobility and Metrics: A New Form of Indirect Discrimination?" Minerva 46, no. 4 (December 2008): 411–35. http://dx.doi.org/10.1007/s11024-008-9110-2.

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Alsuhli, Ghada H., Ahmed Khattab, and Yasmine A. Fahmy. "Double-Head Clustering for Resilient VANETs." Wireless Communications and Mobile Computing 2019 (March 3, 2019): 1–17. http://dx.doi.org/10.1155/2019/2917238.

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Scalability and the highly dynamic topology of Vehicular Ad Hoc Networks (VANETs) are the biggest challenges that slow the roll-out of such a promising technology. Adopting an effective VANET clustering algorithm can tackle these issues in addition to benefiting routing, security and media access management. In this paper, we propose a general-purpose resilient double-head clustering (DHC) algorithm for VANET. Our proposed approach is a mobility-based clustering algorithm that exploits the most relevant mobility metrics such as vehicle speed, position, and direction, in addition to other metrics related to the communication link quality such as the link expiration time (LET) and the signal-to-noise ratio (SNR). The proposed algorithm has enhanced performance and stability features, especially during the cluster maintenance phase, through a set of procedures developed to achieve these objectives. An extensive evaluation methodology is followed to validate DHC and compare its performance with another algorithm using different existing and newly proposed evaluation metrics. These metrics are analyzed under various mobility scenarios, vehicle densities, and radio channel models such as log-normal shadowing and two-ray ground loss with and without Nakagami-m fading model. The proposed algorithm DHC has proven its ability to be more stable and efficient under different simulation scenarios.

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Crane, Breanna, Kyle Moored, Andrea Rosso, and Michelle Carlson. "Methods and Rationale for Using GPS-Derived Objective Technologies to Examine Community Mobility in Older Adults." Innovation in Aging 5, Supplement_1 (December 1, 2021): 563. http://dx.doi.org/10.1093/geroni/igab046.2162.

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Abstract Objective measures of community mobility are advantageous for capturing life-space activity. In contrast to subjective, self-reported approaches, GPS-derived objective measures leverage passive, real-time data collection techniques to mitigate recall bias and minimize participant burden. We present methods to quantify community mobility among a sample of 164 community-dwelling older adults (Mean age=77.3±6.5) from a physical therapy intervention aimed at improving walking ability. We characterized community mobility using activity space metrics (e.g., standard deviation ellipse (SDE) area), timing (e.g., time outside home), and shape (e.g., SDE compactness). We will discuss challenges and solutions to generating these metrics as well as their associations with physical and cognitive performance. Time outside of home and SDE area, but not SDE compactness, were correlated with better performance on the 6-Minute Walking Test and Trail-Making Test (Part B) (ρ=.20-.23, p’s<.05). These findings will aid in understanding which community mobility measures are associated with functional capacity.

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Santosh Kumar and Sharma Bhupendra Suman. "Classification and Evaluation of Mobility Metrics for Mobility Model Movement Patterns in Mobile Ad-Hoc Networks." International Journal on Applications of Graph Theory In wireless Ad Hoc Networks And sensor Networks 3, no. 3 (September 30, 2011): 25–38. http://dx.doi.org/10.5121/jgraphoc.2011.3303.

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ElDessouki, Wael M. "Development of a Neighborhood Mobility Index for Assessing Mobility Disparities in Developing Countries with Application to the Greater Cairo Area, Egypt." Sustainability 14, no. 23 (November 28, 2022): 15846. http://dx.doi.org/10.3390/su142315846.

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Most urban planners emphasize sustainability’s environmental and economic aspects and overlook the social equity dimension. Assessment of the current mobility situation is a prerequisite for developing socially sustainable urban mobility plans. However, current metrics for mobility assessment are data intensive and sometimes require the development of a detailed transportation model for the urban area, which is difficult to achieve in developing nations. In this study, we have created an index for assessing mobility for neighborhoods in a metropolitan area that requires minimal land-use information and utilizes online third-party travel-time data. The proposed index merges the fundamental principles of the traditional transportation planning process and congestion metrics to assess the mobility status of different neighborhoods in an urban area for a single mode of transportation. The developed neighborhood mobility index (NMI) was evaluated in the Greater Cairo Area (GCA), and the results were validated by conducting a one-dimensional ANOVA. The validation results showed that the results obtained using the developed NMI were reliable with a good degree of confidence. The case study demonstrated the capabilities of the NMI in detecting disparities between neighborhoods in a city and showed how planners and decision-makers could use it in preparing sustainable mobility plans.

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Berke, Alex, Ronan Doorley, Luis Alonso, Vanesa Arroyo, Marc Pons, and Kent Larson. "Using mobile phone data to estimate dynamic population changes and improve the understanding of a pandemic: A case study in Andorra." PLOS ONE 17, no. 4 (April 26, 2022): e0264860. http://dx.doi.org/10.1371/journal.pone.0264860.

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Compartmental models are often used to understand and predict the progression of an infectious disease such as COVID-19. The most basic of these models consider the total population of a region to be closed. Many incorporate human mobility into their transmission dynamics, usually based on static and aggregated data. However, mobility can change dramatically during a global pandemic as seen with COVID-19, making static data unsuitable. Recently, large mobility datasets derived from mobile devices have been used, along with COVID-19 infections data, to better understand the relationship between mobility and COVID-19. However, studies to date have relied on data that represent only a fraction of their target populations, and the data from mobile devices have been used for measuring mobility within the study region, without considering changes to the population as people enter and leave the region. This work presents a unique case study in Andorra, with comprehensive datasets that include telecoms data covering 100% of mobile subscribers in the country, and results from a serology testing program that more than 90% of the population voluntarily participated in. We use the telecoms data to both measure mobility within the country and to provide a real-time census of people entering, leaving and remaining in the country. We develop multiple SEIR (compartmental) models parameterized on these metrics and show how dynamic population metrics can improve the models. We find that total daily trips did not have predictive value in the SEIR models while country entrances did. As a secondary contribution of this work, we show how Andorra’s serology testing program was likely impacted by people leaving the country. Overall, this case study suggests how using mobile phone data to measure dynamic population changes could improve studies that rely on more commonly used mobility metrics and the overall understanding of a pandemic.

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Berke, Alex, Ronan Doorley, Luis Alonso, Vanesa Arroyo, Marc Pons, and Kent Larson. "Using mobile phone data to estimate dynamic population changes and improve the understanding of a pandemic: A case study in Andorra." PLOS ONE 17, no. 4 (April 26, 2022): e0264860. http://dx.doi.org/10.1371/journal.pone.0264860.

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Compartmental models are often used to understand and predict the progression of an infectious disease such as COVID-19. The most basic of these models consider the total population of a region to be closed. Many incorporate human mobility into their transmission dynamics, usually based on static and aggregated data. However, mobility can change dramatically during a global pandemic as seen with COVID-19, making static data unsuitable. Recently, large mobility datasets derived from mobile devices have been used, along with COVID-19 infections data, to better understand the relationship between mobility and COVID-19. However, studies to date have relied on data that represent only a fraction of their target populations, and the data from mobile devices have been used for measuring mobility within the study region, without considering changes to the population as people enter and leave the region. This work presents a unique case study in Andorra, with comprehensive datasets that include telecoms data covering 100% of mobile subscribers in the country, and results from a serology testing program that more than 90% of the population voluntarily participated in. We use the telecoms data to both measure mobility within the country and to provide a real-time census of people entering, leaving and remaining in the country. We develop multiple SEIR (compartmental) models parameterized on these metrics and show how dynamic population metrics can improve the models. We find that total daily trips did not have predictive value in the SEIR models while country entrances did. As a secondary contribution of this work, we show how Andorra’s serology testing program was likely impacted by people leaving the country. Overall, this case study suggests how using mobile phone data to measure dynamic population changes could improve studies that rely on more commonly used mobility metrics and the overall understanding of a pandemic.

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Yan, An, and Bill Howe. "Fairness-Aware Demand Prediction for New Mobility." Proceedings of the AAAI Conference on Artificial Intelligence 34, no. 01 (April 3, 2020): 1079–87. http://dx.doi.org/10.1609/aaai.v34i01.5458.

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Emerging transportation modes, including car-sharing, bike-sharing, and ride-hailing, are transforming urban mobility yet have been shown to reinforce socioeconomic inequity. These services rely on accurate demand prediction, but the demand data on which these models are trained reflect biases around demographics, socioeconomic conditions, and entrenched geographic patterns. To address these biases and improve fairness, we present FairST, a fairness-aware demand prediction model for spatiotemporal urban applications, with emphasis on new mobility. We use 1D (time-varying, space-constant), 2D (space-varying, time-constant) and 3D (both time- and space-varying) convolutional branches to integrate heterogeneous features, while including fairness metrics as a form of regularization to improve equity across demographic groups. We propose two spatiotemporal fairness metrics, region-based fairness gap (RFG), applicable when demographic information is provided as a constant for a region, and individual-based fairness gap (IFG), applicable when a continuous distribution of demographic information is available. Experimental results on bike share and ride share datasets show that FairST can reduce inequity in demand prediction for multiple sensitive attributes (i.e. race, age, and education level), while achieving better accuracy than even state-of-the-art fairness-oblivious methods.

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Ahmad, Muqeet, Tianrui Li, Zahid Khan, Faisal Khurshid, and Mushtaq Ahmad. "A Novel Connectivity-Based LEACH-MEEC Routing Protocol for Mobile Wireless Sensor Network." Sensors 18, no. 12 (December 5, 2018): 4278. http://dx.doi.org/10.3390/s18124278.

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In mobile wireless sensor network (MWSN), the lifetime of the network largely depends on energy efficient routing protocol. In the literature, cluster leader (CL) is selected based on remaining energy of mobile sensor nodes to enhance sensor network lifetime. In this study, a novel connectivity-based Low-Energy Adaptive Clustering Hierarchy-Mobile Energy Efficient and Connected (LEACH-MEEC) routing protocol was proposed, where CL is selected based on connectivity among neighboring nodes and the remaining energy of mobile sensor nodes. Consequently, it improves data delivery, network lifetime and balances the energy consumption. We studied various performance metrics including the number of alive nodes (NAN), remaining energy (RE) and packet delivery ratio (PDR). Our proposed LEACH-MEEC outperforms all other algorithms due to the connectivity metric. Moreover, the performance of mobility models was investigated through graphical and statistically tabulated results. The results show that Reference Point Group Mobility model (RPGM) is better than other mobility models.

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Doci, Arta, and Fatos Xhafa. "WIT: A Wireless Integrated Traffic Model." Mobile Information Systems 4, no. 3 (2008): 219–35. http://dx.doi.org/10.1155/2008/341498.

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Simulation is a common approach for designing ad hoc network applications, due to the slow deployment of these networks. The main building blocks of ad hoc network applications are the routing protocols, mobility, and traffic models. Several studies, which use synthetic models, show that mobility and traffic have a significant effect on protocol performance. Synthetic models do not realistically reflect the environment where the ad hoc networks will be deployed. In addition, mobility and traffic tools are designed independently of each other, however real trace data challenge that assumption. Indeed, recent protocol performance evaluation using real testbeds show that performance evaluations under real testbeds and simulations that use synthetic models differ significantly. In this paper we consider jointly both real mobility and traffic for protocol performance evaluation. The contributions of this work are as follows: (1) demonstrates that real mobility and traffic are interconnected; (2) announces the design and implementation of WIT –Wireless Integrated Traffic–, which includes the design of a real traffic generator; (3) shows that under real mobility and integrated traffic the performance metrics need to be re-thought, thus we propose availability as a new ad hoc network protocol performance metric; and, finally, (4) evaluates protocol performance under synthetic and real mobility models with integrated traffic. We believe that the results of our work constitute a step forward toward benchmarking of ad hoc network performance evaluations.

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Tripp-Barba, Carolina, Aníbal Zaldívar-Colado, Luis Urquiza-Aguiar, and José Alfonso Aguilar-Calderón. "Survey on Routing Protocols for Vehicular Ad Hoc Networks Based on Multimetrics." Electronics 8, no. 10 (October 17, 2019): 1177. http://dx.doi.org/10.3390/electronics8101177.

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In the last few years, many routing protocols have been proposed for vehicular ad hoc networks (VANETs) because of their specific characteristics. Protocols that use several metrics have been shown to be the most adequate to VANETs due to their effectiveness in dealing with dynamic environment changes due to vehicle mobility. Metrics such as distance, density, link stability, speed, and position were selected by the authors for the best proposal. Several surveys of routing proposals have been generated to categorize contributions and their application scenarios, but none of them focused on multimetric approaches. In this paper, we present a review of the routing protocols based on more than one metric to select the best route in a VANET. The main objective of this research was to present the contemporary most frequently used metrics in the different proposals and their application scenarios. This review helps in the selection protocols or the creation of metrics when a new protocol is designed.This survey of multimetric VANET routing protocols employed systematic literature-review (SLR) methodology in four well-knownown databases that allowed to analyze current state-of-the-art proposals. In addition, this paper provides a description of these multimetric routing protocols. Our findings indicate that distance and speed are the most popular and versatile metrics. Finally, we define some possible directions for future research related to the use of this class of protocols.

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Horak, Fay B., Martina Mancini, Patricia Carlson-Kuhta, John G. Nutt, and Arash Salarian. "Balance and Gait Represent Independent Domains of Mobility in Parkinson Disease." Physical Therapy 96, no. 9 (September 1, 2016): 1364–71. http://dx.doi.org/10.2522/ptj.20150580.

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Abstract Background The Instrumented Stand and Walk (ISAW) test, which includes 30 seconds of stance, step initiation, gait, and turning, results in many objective balance and gait metrics from body-worn inertial sensors. However, it is not clear which metrics provide independent information about mobility. Objective It was hypothesized that balance and gait represent several independent domains of mobility and that not all domains would be abnormal in individuals with Parkinson disease (PD) or would change with levodopa therapy. Design This was a cross-sectional study. Methods A factor analysis approach was used to identify independent measures of mobility extracted from the ISAW in 100 participants with PD and 21 control participants. First, a covariance analysis showed that postural sway measures were independent of gait measures. Then, the factor analysis revealed 6 independent factors (mobility domains: sway area, sway frequency, arm swing asymmetry, trunk motion during gait, gait speed, and cadence) that accounted for 87% of the variance of performance across participants. Results Sway area, gait speed, and trunk motion differed between the PD group in the off-levodopa state and the control group, but sway frequency (but not sway area) differed between the PD group in the off-levodopa state and the control group. Four of the 6 factors changed significantly with levodopa (off to on): sway area, sway frequency, trunk motion during gait, and cadence. When participants were on levodopa, the sway area increased compared with off levodopa, becoming more abnormal, whereas the other 3 significant metrics moved toward, but did not reach, the healthy control values. Limitations Exploratory factor analysis was limited to the PD population. Conclusions The different sensitivity various balance and gait domains to PD and to levodopa also support neural control of at least 6 independent mobility domains, each of which warrants clinical assessment for impairments in mobility.

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Ganz, Natalie, Eran Gazit, Nir Giladi, Robert J. Dawe, Anat Mirelman, Aron S. Buchman, and Jeffrey M. Hausdorff. "Automatic Quantification of Tandem Walking Using a Wearable Device: New Insights Into Dynamic Balance and Mobility in Older Adults." Journals of Gerontology: Series A 76, no. 1 (September 15, 2020): 101–7. http://dx.doi.org/10.1093/gerona/glaa235.

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Abstract Background Wearable sensors are increasingly employed to quantify diverse aspects of mobility. We developed novel tandem walking (TW) metrics, validated these measures using data from community-dwelling older adults, and evaluated their association with mobility disability and measures of gait and postural control. Methods Six hundred ninety-three community-dwelling older adults (age: 78.69 ± 7.12 years) wore a 3D accelerometer on their lower back while performing 3 tasks: TW, usual-walking, and quiet standing. Six new measures of TW were extracted from the sensor data along with the clinician’s conventional assessment of TW missteps (ie, trip other loss of balance in which recovery occurred to prevent a fall) and duration. Principal component analysis transformed the 6 new TW measures into 2 summary TW composite factors. Logistic regression models evaluated whether these TW factors were independently associated with mobility disability. Results Both TW factors were moderately related to the TW conventional measures (r < 0.454, p < .001) and were mildly correlated with usual-walking (r < 0.195, p < .001) and standing, postural control (r < 0.119, p < .001). The TW frequency composite factor (p = .008), but not TW complexity composite factor (p = .246), was independently associated with mobility disability in a model controlling for age, sex, body mass index, race, conventional measures of TW, and other measures of gait and postural control. Conclusions Sensor-derived TW metrics expand the characterization of gait and postural control and suggest that they reflect a relatively independent domain of mobility. Further work is needed to determine if these metrics improve risk stratification for other adverse outcomes (eg, falls and incident disability) in older adults.

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Kmuar, Santosh, and S. C. Sharma S.C.Sharma. "Evaluation of Direct and Derived Mobility Metrics of Mobility Models and Its Impact on Reactive Routing Protocols." International Journal of Computer Applications 48, no. 21 (June 30, 2012): 40–49. http://dx.doi.org/10.5120/7484-0590.

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Safa Sadiq, Ali, Norsheila Binti Fisal, Kayhan Zrar Ghafoor, and Jaime Lloret. "An Adaptive Handover Prediction Scheme for Seamless Mobility Based Wireless Networks." Scientific World Journal 2014 (2014): 1–17. http://dx.doi.org/10.1155/2014/610652.

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We propose an adaptive handover prediction (AHP) scheme for seamless mobility based wireless networks. That is, the AHP scheme incorporates fuzzy logic with AP prediction process in order to lend cognitive capability to handover decision making. Selection metrics, including received signal strength, mobile node relative direction towards the access points in the vicinity, and access point load, are collected and considered inputs of the fuzzy decision making system in order to select the best preferable AP around WLANs. The obtained handover decision which is based on the calculated quality cost using fuzzy inference system is also based on adaptable coefficients instead of fixed coefficients. In other words, the mean and the standard deviation of the normalized network prediction metrics of fuzzy inference system, which are collected from available WLANs are obtained adaptively. Accordingly, they are applied as statistical information to adjust or adapt the coefficients of membership functions. In addition, we propose an adjustable weight vector concept for input metrics in order to cope with the continuous, unpredictable variation in their membership degrees. Furthermore, handover decisions are performed in each MN independently after knowing RSS, direction toward APs, and AP load. Finally, performance evaluation of the proposed scheme shows its superiority compared with representatives of the prediction approaches.

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Sassolas-Serrayet, Timothée, Rodolphe Cattin, Matthieu Ferry, Vincent Godard, and Martine Simoes. "Estimating the disequilibrium in denudation rates due to divide migration at the scale of river basins." Earth Surface Dynamics 7, no. 4 (November 29, 2019): 1041–57. http://dx.doi.org/10.5194/esurf-7-1041-2019.

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Abstract. Basin-averaged denudation rates may locally exhibit a wide dispersion, even in areas where the topographic steady state is supposedly achieved regionally. This dispersion is often attributed to the accuracy of the data or to some degree of natural variability of local erosion rates which can be related to stochastic processes such as landsliding. Another physical explanation of this dispersion is local and transient disequilibrium between tectonic forcing and erosion at the scale of catchments. Recent studies have shown that basin divide migration can potentially induce such perturbations, and they propose metrics to assess divide mobility based on cross-divide contrasts in headwater topographic features. Here, we use a set of landscape evolution models assuming spatially uniform uplift, rock strength and rainfall to assess the effect of divide mobility on basin-wide denudation rates. We propose using basin-averaged aggressivity metrics based on cross-divide contrasts (1) in channel χ, an integral function of position in the channel network; (2) in channel local gradient; and (3) in channel height, measured at a reference drainage area. From our simulations, we show that the metric based on differences in χ is the most reliable to diagnose local disequilibrium. The other metrics are more suitable for relatively active tectonic regions such as mountain belts, where contrasts in local gradient and elevation are more important. We find that the ratio of basin denudation associated with drainage migration to uplift can reach a factor of 2, regardless of the imposed uplift rate, erodibility, diffusivity coefficient or critical hillslope gradient. A comparison with field observations in the Great Smoky Mountains (southern Appalachians, USA) underlines the difficulty of using the metric based on χ, which depends on the – poorly constrained – elevation of the outlet of the investigated catchment. Regardless of the considered metrics, we show that observed dispersion is controlled by catchment size: a smaller basin may be more sensitive to divide migration and hence to disequilibrium. Our results thus highlight the relevance of divide stability analysis from digital elevation models as a fundamental preliminary step for basin-wide denudation rate studies based on cosmogenic radionuclide concentrations.

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Site, Aditi, Saigopal Vasudevan, Samuel Olaiya Afolaranmi, Jose L. Martinez Lastra, Jari Nurmi, and Elena Simona Lohan. "A Machine-Learning-Based Analysis of the Relationships between Loneliness Metrics and Mobility Patterns for Elderly." Sensors 22, no. 13 (June 30, 2022): 4946. http://dx.doi.org/10.3390/s22134946.

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Loneliness and social isolation are subjective measures associated with the feeling of discomfort and distress. Various factors associated with the feeling of loneliness or social isolation are: the built environment, long-term illnesses, the presence of disabilities or health problems, etc. One of the most important aspect which could impact feelings of loneliness is mobility. In this paper, we present a machine-learning based approach to classify the user loneliness levels using their indoor and outdoor mobility patterns. User mobility data has been collected based on indoor and outdoor sensors carried on by volunteers frequenting an elderly nursing house in Tampere region, Finland. The data was collected using Pozyx sensor for indoor data and Pico minifinder sensor for outdoor data. Mobility patterns such as the distance traveled indoors and outdoors, indoor and outdoor estimated speed, and frequently visited clusters were the most relevant features for classifying the user’s perceived loneliness levels.Three types of data used for classification task were indoor data, outdoor data and combined indoor-outdoor data. Indoor data consisted of indoor mobility data and statistical features from accelerometer data, outdoor data consisted of outdoor mobility data and other parameters such as speed recorded from sensors and course of a person whereas combined indoor-outdoor data had common mobility features from both indoor and outdoor data. We found that the machine-learning model based on XGBoost algorithm achieved the highest performance with accuracy between 90% and 98% for indoor, outdoor, and combined indoor-outdoor data. We also found that Lubben-scale based labelling of perceived loneliness works better for both indoor and outdoor data, whereas UCLA scale-based labelling works better with combined indoor-outdoor data.

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Journal articles on the topic 'Mobility metrics'

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