Current Mobile Research Articles

The Potential of Battery Electric Taxis in Santiago de Chile

Given the semi-private nature of the mode, the conversion of taxi vehicles to electric requires a feasibility analysis, as it can impact their operations and revenues. In this research, we assess the feasibility of taxi companies in Santiago de Chile operating with battery electric vehicles (BEVs), considering the current electric mobility infrastructure of the city. We used a large database of GPS pulses provided by a taxi app to obtain a complete picture of typical taxi trips and operations in the city. Then, we performed an assessment of the feasibility of the fleet conversion by considering battery capacity, driving range, proximity to recharging stations, and charging power. The results are promising, as the number of completed trips ranges from 87.35% to 94.34%, depending on the BEV driving range. The analysis shows the importance of installing fast charging points in the locations or BEV driving ranges.

OFET Informatics: Observing the impact of organic transistor's design parameters on the device output performance using a machine learning algorithm

AbstractOrganic field effect transistors (OFETs), used in the fabrication of nano‐sensors, are one of the most promising devices in organic electronics because of their lightweight, flexible, and low fabrication cost. However, the numerical modeling of such OFETs is still in an early stage due to the minimal analytical as well as numerical models presented in the literature. This research aims to demonstrate an experimentally verified machine‐learning model by investigating an OFET with polyaniline as a p‐type organic semiconductor. OFET's threshold voltage, on/off current ratio, subthreshold swing, and device mobilities are studied as the primary output chiasmatic parameters. The random‐forest machine learning model has shown the criticality of the doping effect on turning the OFET to depletion mode, with positive threshold voltage, under doping higher than cm−3. Additionally, the study highlights the effectiveness of the gate oxide thickness in controlling the OFET threshold voltage. A 50 nm oxide thickness showed sufficiency to have a non‐depleted OFET operation.

COVID-19 responses restricted abilities and aspirations for mobility and migration: insights from diverse cities in four continents

Research on the impacts of COVID-19 on mobility has focused primarily on the increased health vulnerabilities of involuntary migrant and displaced populations. But virtually all migration flows have been truncated and altered because of reduced economic and mobility opportunities of migrants. Here we use a well-established framework of migration decision-making, whereby individual decisions combine the aspiration and ability to migrate, to explain how public responses to the COVID-19 pandemic alter migration patterns among urban populations across the world. The principal responses to COVID-19 pandemic that affected migration are: 1) through travel restrictions and border closures, 2) by affecting abilities to move through economic and other means, and 3) by affecting aspirations to move. Using in-depth qualitative data collected in six cities in four continents (Accra, Amsterdam, Brussels, Dhaka, Maputo, and Worcester), we explore how populations with diverse levels of education and occupations were affected in their current and future mobility decisions. We use data from interviews with sample of internal and international migrants and non-migrants during the 2020 COVID-19 pandemic outbreak to identify the mechanisms through which the pandemic affected their mobility decisions. The results show common processes across the different geographical contexts: individuals perceived increased risks associated with further migration, which affected their migration aspirations, and had reduced abilities to migrate, all of which affected their migration decision-making processes. The results also reveal stark differences in perceived and experienced migration decision-making across precarious migrant groups compared to high-skilled and formally employed international migrants in all settings. This precarity of place is particularly evident in low-income marginalised populations.

Cellulose acetate-derived ternary-doped hierarchically porous carbons blended perovskite active layers for solar cells and X-ray detectors

Herein, we have synthesized hetero-atoms (nitrogen (N), sulfur (S), phosphorus (P))-doped porous carbons (PCs) which upon dispersion in perovskite precursor solution with different (2–8 wt.%) modify its morphology and improve optoelectronic characteristics of the perovskite active layer (AL) results into enhancing efficiency and stability of perovskite solar cells (PSCs). The results indicate that PCs (6 wt.%) modifies perovskite AL-constructed PSCs and X-ray photodetectors outperform other investigated devices. The excellent PSCs (AL@NSPCPC) demonstrate power conversion efficiency (PCE) of 13.81%, fill factor (FF) 64.77%, current density Jsc (23.518 mA/cm2), and open circuit voltage Voc (0.906 V), which is significantly higher than pristine AL 10.42%, 57.01%, 20.423 mA/cm2, and 0.895 V, respectively. Furthermore, the sample (AL@NSP-CPC) when constructs in the geometry of an X-ray photodetector, shows 15.56 μA/cm2, 4.66 mA/Gy·cm2, 5.26×10−4 cm2/V·s, and 3.58 × 1015 cm−3 of collected charge density (CCD), dark current density (DCD), sensitivity, mobility, and trap density, respectively. Thus, heteroatom-doped PCs modified perovskite layers demonstrate promise for constructing PSCs and X-ray photodetectors opening future research in exploiting these abundant, and inexpensive carbons materials having large mobility and tunable morphology along with surface passivation at perovskite/hole transport layer (HTL) interface to further enhance their photovoltaic parameters.

Crowd cluster data in the USA for analysis of human response to COVID-19 events and policies

We provide data on daily social contact intensity of clusters of people at different types of Points of Interest (POI) by zip code in Florida and California. This data is obtained by aggregating fine-scaled details of interactions of people at the spatial resolution of 10 m, which is then normalized as a social contact index. We also provide the distribution of cluster sizes and average time spent in a cluster by POI type. This data will help researchers perform fine-scaled, privacy-preserving analysis of human interaction patterns to understand the drivers of the COVID-19 epidemic spread and mitigation. Current mobility datasets either provide coarse-level metrics of social distancing, such as radius of gyration at the county or province level, or traffic at a finer scale, neither of which is a direct measure of contacts between people. We use anonymized, de-identified, and privacy-enhanced location-based services (LBS) data from opted-in cell phone apps, suitably reweighted to correct for geographic heterogeneities, and identify clusters of people at non-sensitive public areas to estimate fine-scaled contacts.

Virtual Coupling in Railways: A Comprehensive Review

The current mobility situation is constantly changing as people are increasingly moving to urban areas. Therefore, a flexible mode of transport with high-capacity passenger trains and a high degree of modularity in the trains’ composition is necessary. Virtual coupling (VC) is a promising solution to this problem because it significantly increases the capacity of a line and provides a more flexible mode of operation than conventional signaling systems. This novel review, in which approximately 200 papers were analyzed, identifies the main topics of current railway-related VC research, and represents the first step toward the implementation of VC in future railways. It was found that industry research has mainly focused on the feasibility of VC implementation and operation, whereas in academia, which is coordinated with industry, research has focused on control and communication systems. From a technological perspective, the main challenges for VC were identified with regard to aspects such as safety, control technology, interlocking, vehicle-to-vehicle communication, cooperative train protection and control, and integrated traffic management. The important directions for future research that have been identified for future development include complete dynamic models, real-time controllers, reliable and secure communication, different communication topologies, cybersecurity, intelligent control, reinforcement learning, and Big Data analytics.

Considering the Use of Mobile Medical Containers in the Event of Natural Disasters

Introduction:In recent years, Japan has been hit by a number of natural disasters including the Great East Japan Earthquake, the Kumamoto Earthquake, the heavy rains in western Japan, and the heavy rains in Kumamoto to name a few. In each of these events, a number of hospitals located within the disaster areas were damaged and ceased to function, leading to difficulties in providing regional medical care. This presentation examines the effectiveness of mobile medical containers in handling such situations in the future.Method:This study organizes lessons learned from past disasters as well as the merits of and challenges facing current mobile medical containers while looking into the future.Results:When the Great East Japan Earthquake occurred, assembly-and-installation type temporary health clinics were constructed, but due to the numerous Japanese laws and regulations, it took almost three months for these to be delivered. On the other hand, current mobile medical containers are already in use in countries such as Tonga and Senegal and have the following advantages: (1) High mobility and easy installation, (2) Expandability as necessary, and (3) Durability for long-term use.Conclusion:Despite challenges such as clarification of legal handling, electricity, water supply and drainage, we consider mobile medical containers to be effective alternative medical facilities in the event of disasters.

The contribution of perennial fodder crops to the nitrogen balance of agroecosystems in Western Siberia

The article presents the results of experiments obtained in stationary experiments on the basis of grain-fallow and grain-grass crop rotations on meadow-chernozem soil in the Omsk region. The influence of spring wheat precursors (alfalfa of the 3rd year of life and fallow) on individual elements of soil fertility and crop yield has been established. It was revealed that when cultivating spring wheat by fallow in the grain-fallow crop rotation, the nitrogen balance (-28 kg/ha) is negative with an intensity of 66 %. When sowing wheat in grain-grass crop rotation on a layer of perennial grasses, the nitrogen balance is positive (+21.0 kg/ha) and the intensity is 119 %. The favorable effect of the legume component in the crop rotation on the nitrogen regime of the soil significantly increased the yield of spring wheat by 0.5 t/ha in comparison with wheat cultivated in the field crop rotation by bare fallow. Under similar conditions, studies were carried out on irrigated meadowchernozem soil in an eight-field stationary grain-grass crop rotation. The removal of nitrogen by the yield of various perennial grasses, as well as the responsiveness of alfalfa, bromus and sweet clover with productivity parameters to the level of nitrogenphosphorus nutrition, were studied. The current mobilization of nitrogen under these conditions under the vegetative brome without fertilizers was 76 kg/ha. When optimizing the phosphate regime of the soil, this indicator increased to 99 kg/ha. The removal of nitrogen by alfalfa on similar agricultural backgrounds increases due to symbiotically fixed nitrogen, by 89 and 193 kg/ha, respectively, or 2.2 and 2.9 times. Alfalfa and sweet clover responded positively to the improvement of mineral fertilizing conditions (P60N60-160). In alfalfa of the 1-5 year of life the collection of green mass and fodder units increased to 40.56 and 7.00 t/ha, respectively, or by 86 and 54 % relative to the control without fertilizers, with 82.76 GJ of exchange energy per hectare. The productivity of sweet clover of the 2nd year of life increased up to 30.85 t/ha of green mass and 2.83 t/ha of fodder units or by 37 and 17 % relative to the control.

A transport of one’s own: Women in contemporary Mexico City’s public transport through the lens of photojournalism

This article proposes the use of photojournalism to understand women’s urban mobility practices in contemporary Mexico City. Throughout the analysis, a variety of issues such as economic violence, time poverty and sexual harassment emerge. In general, the article argues that, by analysing the cultural representations that circulate within different media in a specific social and historical context, particular experiences of urban mobilities are made visible, thereby enriching current urban mobility scholarship. Specifically, the article explores how the analysis of material makes visible the various and distinct encounters that women experience when using public transport in Mexico City. The article makes the case that there is already plenty of scholarship within the humanities and cultural studies that could be integrated into existing research on urban mobility practices, enhancing our understanding of how such practices are distinct in particular locations and time periods, and ultimately helping to achieve a more complex and nuanced understanding of them.

Characterisation and application of bismuth ferrite - bismuth vanadate p-n heterojunction in the photoelectrocatalytic degradation of ciprofloxacin in water

Towards the photoelectrocatalytic degradation of ciprofloxacin, BFO/BVO heterojunction was constructed to improve the performance of the individual semiconductors. The enhanced performance of the heterojunction photoanode was attributed to increase in visible light harvesting, greater current mobility leading to higher current density, low charge transfer resistance, and low recombination rate of photogenerated electron and hole. The BFO, BVO and BFO/BVO photoanodes prepared were immobilized on fluorine doped tin oxide coated glass and characterised using x-ray diffractometry, scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy (EIS), UV–vis diffusive reflectance spectroscopy, photocurrent measurement, ultra performance liquid chromatography- mass spectrometry (UPLC-MS). The percentage removal of ciprofloxacin using BFO, BVO and BFO/BVO photoanodes were 56%, 49% and 80.3% respectively. The current density of the heterojunction photoanode were markedly improved when compared to the individual performances of the photoanodes. Also, the BFO/BVO heterojunction photoanode showed stability after repeated usages. Data from UPLC-MS studies was used to propose the degradation pathway, products, and mechanism of the degradation process. .

Motivating change in commuters’ mobility behaviour: Digital nudging for public transportation use

ABSTRACT The urgency of climate change is evident worldwide, but current mobility patterns still cause severe environmental damage . The largest share of these mobility-related problems is caused by everyday private car use, such as commuting. One way to change mobility patterns is through digital nudging in the form of trip recommendations to increase commuters’ public transportation use. To examine the effects of the recommendations, we undertake a choice-based conjoint analysis and determine whether participants choose the recommended trip option more frequently and whether the recommendations influence participants’ public transportation preferences. Our results show differences based on commuters’ travel times and mobility app use. Significant positive effects were observed among commuters with a short travel time who do not usually use mobility apps. This study contributes to the digital nudging and transportation literature, and has practical implications in terms of using recommendations to encourage switching from private cars to public transportation.

A design strategy for Geo AR mobile game sustainable success emphasizing game completeness

Current geolocation-based augmented reality mobile games lost more than 90% of their active users compared to the peak volume, threatening their sustainable success. Calls for making this type of game “complete” have been made in the literature. This paper uses the grounded theory approach to investigate a unique game, Pokémon GO, which attains its sustainable success to find a general pattern. First, key game design changes of Pokémon GO are identified in the nearly five-year history of this game. Second, relationships between various system updates, design components in the game, and the active user level change are identified. Third, a theory of sustainable success is proposed based on the relationships identified. Finally, the “complete game strategy” has been proposed and detailed for game designers’ consideration.

Chirality-dependent electrical transport properties of carbon nanotubes obtained by experimental measurement

Establishing the relationship between the electrical transport properties of single-wall carbon nanotubes (SWCNTs) and their structures is critical for the design of high-performance SWCNT-based electronic and optoelectronic devices. Here, we systematically investigated the effect of the chiral structures of SWCNTs on their electrical transport properties by measuring the performance of thin-film transistors constructed by eleven distinct (n, m) single-chirality SWCNT films. The results show that, even for SWCNTs with the same diameters but different chiral angles, the difference in the on-state current or carrier mobility could reach an order of magnitude. Further analysis indicates that the electrical transport properties of SWCNTs have strong type and family dependence. With increasing chiral angle for the same-family SWCNTs, Type I SWCNTs exhibit increasing on-state current and mobility, while Type II SWCNTs show the reverse trend. The differences in the electrical properties of the same-family SWCNTs with different chiralities can be attributed to their different electronic band structures, which determine the contact barrier between electrodes and SWCNTs, intrinsic resistance and intertube contact resistance. Our present findings provide an important physical basis for performance optimization and application expansion of SWCNT-based devices.

Berlin Pankow: a 15-min city for everyone? A case study combining accessibility, traffic noise, air pollution, and socio-structural data

Cars are dominating urban traffic in cities around the world, even though daily trips in many cities are often realized with active modes of transportation or public transport. Urban transport planning processes need to adapt to this reality and the necessity of climate change mitigation. Against this background, the research project “Mobility Reporting”, a joint undertaking of the district Pankow in Berlin and researchers from TU Berlin and TU Dresden, established a new, goal-driven, and participative planning process. The process identified local mobility as one of the central planning goals. The 15-min city (FMC) was thus adduced as a benchmark to analyze the district’s current mobility system and development potential. We conducted extensive accessibility analyses to examine the status quo concerning the FMC. We calculated travel times to essential destinations in daily life by foot, public transport, and car. This analysis was accompanied by a mixed online and paper–pencil survey conducted to evaluate the perceived accessibility of people in Pankow. The survey results shed light on the question of which walking time thresholds constitute a “very good” or “good” accessibility. Further analyses included environmental and social variables, allowing us to check whether areas with different accessibility levels also differ regarding the socio-economic characteristics of their inhabitants. For example, do socially advantaged neighborhoods have better local accessibility? Is there a trade-off between exposure to environmental pollution and good accessibility? With this contribution, we shed light on what an FMC is and ought to be. Results from the survey support the normative and political vision of the FMC. Pankow generally offers the merits of a walkable city, showing the expected travel time differences between the dense inner city and the outskirts. Socially disadvantaged neighborhoods are not consistently less accessible. However, there seems to be a trade-off between good accessibility (especially PT accessibility) and correlated externalities of transport, namely air pollution and noise.

Origin-Destination Traffic Survey—Case Study: Data Analyse for Bacau Municipality

In order to develop a transport model for the municipality of Bacau, it was necessary to collect data on the current mobility characteristics of people and goods. Traffic data were collected by means of using an origin-destination (O-D) survey. This survey was carried out in the form of a manual traffic census arranged in stations at six points on the entrance sectors of the national roads in the city of Bacau. At the level of the municipality of Bacau, data from a sample of 3040 drivers were used for the origin-destination surveys. The respondents answered 11 questions. The article presents the results obtained from the six control points for seven questions that were considered relevant. The data obtained were initially used to identify, from a percentage and quantitative point of view, the type of traffic specific to the municipality of Bacau. The analysis of the data shows that the majority of vehicles, 78.9%, originate from Bacau County and that 87.2% of those interviewed have Bacau County as their destination. Most vehicles passing through the checkpoints were within the time intervals 7:30–8:30, i.e., 15.55%, and 16:30–17:30, i.e., 16.18%. The highest proportion of registered vehicles were from Romania, 97.99%. Additionally, 40.75% of the respondents were travelling for business purposes, and approximately the same share was found for the number of people in the vehicle; i.e., single occupant vehicles comprised 58.35% of the total vehicles surveyed. Passenger cars accounted for 67.66% of the vehicles. By using the OriginLab software, the aim was to create parallel graphs for each control point in order to identify certain correlations between the data obtained from the questionnaire. At the end of the article, a hierarchical cluster statistical analysis was carried out by using OriginLab, which identified a series of correlations between the analysed parameters.

Green Infrastructure and Slow Tourism: A Methodological Approach for Mining Heritage Accessibility in the Sulcis-Iglesiente Bioregion (Sardinia, Italy)

In European countries many measures are carried out to improve the disadvantaged conditions and socio-economic marginality of rural areas in comparison with central places. These conditions also affect the quality of travel for visitors and tourists. Therefore, in response to a ‘new’ tourist demand, motivated also by the restrictions following the spread of the COVID-19 virus in recent years, the institutions and the different local actors are working more incisively to improve rural areas. The rural tourism services offer, combined with the Green Infrastructure (GI) project, at different scales—from local to regional—interesting territorial development strategies to achieve the Agenda 2030 objectives. This contribution considers the Sulcis-Iglesiente-Guspinese area, in the Sardinia Region (IT), as a case study. In this area, the landscape context is marked by past mining activity, and the project of a path of historical, cultural, and religious values has proven to be an activator of regenerative processes, in environmental, social, and economic terms. The present study proposes a methodological approach to develop an index (FI—feasibility index) to assess the feasibility of the Stop Places (SPs) project along a horse trail to integrate the current slow mobility of bicycles and pedestrians in the bioregion.

How the app designs influence the app use and optimization measures in Chinese internet market

With the rapid expansion of Chinese Internet mobile app market, being conscious of the mobile app success determinants performs a vital aspect for enterprises. To overcome the common strait that many enterprises fail to achieve profitability by exploiting commercial mobile applications on account of few app downloads and low customer utilization rate, this essay mainly focuses on the predicament that application operation is confronted with in the current Chinese mobile app market and interprets three general interfering factors affecting app profitability. With selected data and correlation analyses, it confirms the impact icon's aesthetic design, customer satisfaction and customer loyalty on improving the profitability of mobile applications. According to the research results, some feasible optimization measures are proposed for mobile application developers. The results could help assist entrepreneurs in making profits by improving app user utilization. However, some objective factors and limitations are ignored in the discussion of influencing factors and more in-depth researches are suggested.

Other Radicals

This essay is an introduction to a special section that focuses on the life and work of Anton de Kom, and especially on his seminal 1934 Wij slaven van Suriname. It forms part of a larger project that explores how a Caribbean intellectual tradition can be thought differently if greater attention is paid to the Dutch Caribbean. The essays included in the section demonstrate the shifting role that De Kom and his book have played—from the 1930s and the anxieties they created for the colonial state; to their international impact on other revolutionary movements, such as in Cuba; to their current mobilization by numerous young people of Surinamese descent in the Netherlands as part of an antiracist activism and politics of belonging. Almost ninety years after Wij slaven was first published, it has become a bestseller and De Kom has been named to the Dutch national historical canon. As more than political activism, the guest editors examine Anton de Kom in this Small Axe platform for Caribbean thought with the hope that these essays will stimulate even more scholarship on De Kom’s life and work and on the Dutch Caribbean more broadly, beyond the borders of the Dutch-speaking context.

Mission Critical Communications Support With 5G and Network Slicing

Mission Critical (MC) communications take a pivotal role to achieve effective Public Protection and Disaster Relief (PPDR) actions. Even though 3GPP standards define MC applications and services in an architectural framework compatible with current 5G mobile networks, real-life experiments and applications of these concepts are still at the very beginning. In this paper, we present an architectural study and related experimental activity on network slicing for MC communications. We implemented these services in a fully virtualized environment, and deployed and tested them in a multi-domain network slicing scenario compliant with the ETSI NFV-MANO specifications. Our work aligns with the 5G approach separating control and data planes. The level of automation in service deployment and the slice isolation features are demonstrated, showing the benefits in terms of application performance, management flexibility, scalability, and quality of service differentiation capabilities.

All-Transfer Electrode Interface Engineering Toward Harsh-Environment-Resistant MoS2 Field-Effect Transistors.

Nanoscale electronic devices that can work in harsh environments are in high demand for wearable, automotive, and aerospace electronics. Clean and defect-free interfaces are of vital importance for building nanoscale harsh-environment-resistant devices. However, current nanoscale devices are subject to failure in these environments, especially at defective electrode-channel interfaces. Here, harsh-environment-resistant MoS2 transistors are developed by engineering electrode-channel interfaces with an all-transfer of van der Waals electrodes. The delivered defect-free, graphene-buffered electrodes keep the electrode-channel interfaces intact and robust. As a result, the as-fabricated MoS2 devices have reduced Schottky barrier heights, leading to a very large on-state current and high carrier mobility. More importantly, the defect-free, hydrophobic graphene buffer layer prevents metal diffusion from the electrodes to MoS2 and the intercalation of water molecules at the electrode-MoS2 interfaces. This enables high resistances of MoS2 devices with all-transfer electrodes to various harsh environments, including humid, oxidizing, and high-temperature environments, surpassing the devices with other kinds of electrodes. The work deepens the understanding of the roles of electrode-channel interfaces in nanoscale devices and provides a promising interface engineering strategy to build nanoscale harsh-environment-resistant devices.