Continuous Connectivity Research Articles

Rewriting the Journey of the Mantua-Peschiera Railway: A Moving Experience

The research presented in this article is embedded in the context of the on-going doctoral thesis titled The Mantua-Peschiera Railway: A Case Study for the Historical Analysis and Design Methodology of a Regeneration Project. The research focuses on the decommissioned railway that once connected the city of Mantua to Peschiera del Garda in the north of Italy and questions its possible future. Nowadays, the railway is not perceived as it was, because, without any specific or recognizable appearence, its few remains, such as the passenger stations, are in ruins. The historical data helped to reshape the original project of the line and its deep interdependence with its environment showing peculiar and original characters as a branch line. The author's research aims to create a possible scenario in which the former railway guarantees a continuous connection between the object and its territory within its new function as a Cultural Route.

Study on Crack Development and Micro-Pore Mechanism of Expansive Soil Improved by Coal Gangue under Drying-Wetting Cycles.

Expansive soil is prone to cracks under a drying–wetting cycle environment, which brings many disasters to road engineering. The main purpose of this study is use coal gangue powder to improve expansive soil, in order to reduce its cracks and further explore its micro-pore mechanism. The drying–wetting cycles test is carried out on the soil sample, and the crack parameters of the soil sample are obtained by Matlab and Image J software. The roughness and micro-pore characteristics of the soil samples are revealed by means of the Laser confocal 3D microscope and Mercury intrusion meter. The results show that coal gangue powder reduces the crack area ratio of expansive soil by 48.9%, and the crack initiation time is delayed by at least 60 min. Coal gangue powder can increase the internal roughness of expansive soil. The greater the roughness of the soil, the less cracks in the soil. After six drying–wetting cycles, the porosity and average pore diameter of the improved and expanded soil are reduced by 37% and 30%, respectively, as compared to the plain expansive soil. By analyzing the cumulative pore volume and cumulative pore density parameters of soil samples, it is found that the macro-cracks are caused by the continuous connection and fusion of micro-voids in soil. Coal gangue powder can significantly reduce the proportion of micro-voids, cumulative pore volume, and cumulative pore density in expansive soil, so as to reduce the macro-cracks.

Problems of teaching Russian as a foreign language for special purposes: analysis of students' opinions

Introduction. For foreign students of Russian universities, the Russian language serves as a means of obtaining higher professional education. In this regard, one of the priority tasks of improving the quality of training specialists for foreign countries is the language training of foreign citizens in the Russian language for special purposes. Materials and methods. 126 foreign students of the first year of technical specialties of Peter the Great St. Petersburg Polytechnic University participated in the survey. The results of the study. The survey made it possible to identify the difficulties that foreign students have in the process of learning the language of their specialty and communicating in Russian in the educational environment of the university of the Russian Federation. Among the main difficulties affecting successful communication, foreign students noted communication with teachers of specialized disciplines (46.1%) and with employees of the dean's office (40.4%). The greatest difficulties in the training sessions are caused by understanding the lecture material (49.4%) and understanding the tasks for laboratory work (46.1%). Among the difficulties directly related to the study of the Russian language of the future specialty, the following types of tasks were noted: forming sentences (43.85%), grammar tasks (42.7%), writing dictations (36%). Discussion of the results. The results of the survey allow us to place methodological accents in the preparation of curricula, the creation of modern textbooks and tutorials; to take into account the communicative needs of foreign students who are starting to study on higher professional education programs in Russian technical universities; to implement the principle of continuity and interdisciplinary connections in the formation of the educational route of foreign students. Conclusion. Effective organization of teaching foreign students in the Russian language for special purposes contributes to improving the quality of training of highly qualified competitive specialists for foreign countries and the growth of the international authority of Russian higher professional education.

Influence of seasonal vegetation dynamics on hydrological connectivity in tropical drylands

AbstractSeasonally dry forests in tropical regions show over 300% inter‐annual biomass variability that directly affects the runoff and erosion dynamics. However, biomass fluctuation is mostly overlooked in hydrosedimentological analysis, including in connectivity analysis. The aim of this paper is to understand how the dryland vegetation seasonality in Brazilian drylands affects the potential runoff and sediment connectivity using the Index of Connectivity (stream and outlet targets). Two main analytical steps were used to identify the influence of dry forest biomass fluctuation on connectivity: Creation of vegetation scenarios based on the relationship between rainfall patterns and NDVI fluctuations (Landsat images); Identification of the effect of the vegetation scenarios on Index of Connectivity. The method was applied to a 90 km2 watershed in NE Brazil, creating a daily vegetation classification using five vegetation scenarios related to rainfall parameters, with average NDVI values from 0.18 during very dry scenarios (<20 mm of antecedent rainfall) to 0.62 in very wet scenario (>500 mm of antecedent rainfall). The primary connectivity behaviour is controlled by a continuous connectivity decrease, reaching 32%, related to increase of humidity and vegetation biomass. At the same time, due to rainfall irregularity, high magnitude rainfall events can occur even during very dry scenarios, when the watershed shows very high potential connectivity. It indicates that connectivity in runoff‐dominated regions is temporally variable due to the highly seasonal vegetation and variable incidence of intense rainstorms.

A Laser Link From Lunar Surface Employing Line-of-Sight MIMO

Future exploration of our planetary system relies on the Moon as a base and stepping stone to other planets. A high-rate data connection to this celestial body is, therefore, imperative. Free-space optical (FSO) communications will enable continuous broadband connectivity to Earth. Currently pursued concepts incorporate data relay satellites orbiting the Moon, where each individual satellite terminal has to overcome the lunar distance facing restraints on telescope apertures and on beam pointing and tracking accuracies. We propose a concept of one dedicated link originating from a robotic telescope station installed on the lunar surface. We study the conceptual architecture of such an FSO ground node at the lunar surface with a spotlight on the link design at the physical layer. In particular, we increase the FSO channel capacity through multiple transmission- and receiving-apertures. Our findings encourage the application of the Line-of-Sight (LOS) multiple-input multiple-output (MIMO) technology to FSO communications at large link distances typically coming along with space missions, as thereby the maximum MIMO capacity can be achieved. Directing our study on the link geometry such connections seem technically feasible at relatively low system complexity with the receivers located at a single site and the transmitters only few meters apart.

Requirements Analysis in Disruptive Engineering Solutions Using the Paradigm of Living Systems

A particular characteristic of disruptive products is in reengineering advanced technologies for addressing the needs of low-end consumers and/or non-consumers, to transform them into new consumers. This requires a lean co-creative analysis of requirements with all stakeholders involved. Even if a theory encourages the continuous connection of designers and users throughout the design lifecycle for agile adaptation of requirements to the new experiences of users by intersecting them with various versions of the prototype, the rigid budget and time allocated to the design project require novel approaches to clarify the right vectors of product-evolution from the very early design stages of the project lifecycle—allowing agile approaches to fine-tune the set of requirements. In this context, an analysis process of requirements that uses a constructor inspired by living systems is introduced in this paper. This constructor identifies gaps in requirement formulation and indicates areas where improvements must be undertaken. The method is applied in the case of a new cybersecurity software solution that targets micro and small companies.

Shape-adjustable developable generalized blended trigonometric B\xe9zier surfaces and their applications

Developable surfaces have a vital part in geometric modeling, architectural design, and material manufacturing. Developable Bézier surfaces are the important tools in the construction of developable surfaces, but due to polynomial depiction and having no shape parameter, they cannot describe conics exactly and can only handle a few shapes. To tackle these issues, two straightforward techniques are proposed to the computer-aided design of developable generalized blended trigonometric Bézier surfaces (for short, developable GBT-Bézier surfaces) with shape parameters. A developable GBT-Bézier surface is established by making a collection of control planes with generalized blended trigonometric Bernstein-like (for short, GBTB) basis functions on duality principle among points and planes in 4D projective space. By changing the values of shape parameters, a group of developable GBT-Bézier surfaces that preserves the features of the developable GBT-Bézier surfaces can be generated. Furthermore, for a continuous connection among these developable GBT-Bézier surfaces, the necessary and sufficient G^{1} and G^{2} (Farin–Boehm and beta) continuity conditions are also defined. Some geometric designs of developable GBT-Bézier surfaces are illustrated to show that the suggested scheme can settle the shape and position adjustment problem of developable Bézier surfaces in a better way than other existing schemes. Hence, the suggested scheme has not only all geometric features of current curve design schemes but surpasses their imperfections which are usually faced in engineering.

Analysis of Vehicle-to-Vehicle Basic Safety Message Communication Using Connectivity Characteristic Matrix

<p class='IJASEITAbtract'>This work investigates vehicular mobility and the main factors that impact Vehicle-to-Vehicle (V2V) connectivity using Basic Safety Message (BSM). MATLAB simulation used for Vehicular mobility and connectivity characterization under specific road traffic conditions. The simulation covers connectivity between traveling vehicles and a selected target vehicle to monitor communication interaction and establish an envelope within which reliable communication and BSM messages can occur. Another objective of this work is to use BSM exchanges to indicate the level of connectivity used to estimate traffic density, thus enabling congestion prediction. The obtained data contain information describing many vehicles, distance, connectivity time, and traffic density. The simulation results indicate an increase in the number of connected vehicles (connectivity level) as a function of both traffic density and communication range. Extending communication over fixed duration showed increased connectivity levels, allowing more vehicles to interact and exchange BSMs. The rate of change of connectivity per communication range is an indication of the state of traffic. Continuous connectivity proved to be less than general connectivity as vehicles exits through ramps and move from one cluster of vehicles to another. Varying duration per fixed communication range produced evidence of spatial domain change, and cluster variation as threshold values separate vehicles clusters in time and space. This work presented a model to help analyze the impact of vehicular mobility as a function of BSM communication range variation and connectivity duration variation correlated to traffic density.

Characteristics of Statistical Investigations Tasks Created by Preservice Teachers

ABSTRACT This study focused on statistical investigation tasks designed by preservice teachers. Participants designed a statistical investigation task as a culminating summative assessment after completing modules on teaching and learning statistics. Our study examined the designed tasks to identify their strengths as well as areas of needed improvement. Strengths of the designed tasks include the use of large and multivariate datasets, continual connection to context, and the expectation that their students would engage In multiple parts of the statistical investigation cycle and use multiple data representations in a sophisticated way. Noted areas for improvement include issues related to the statistical content of the tasks such as taking a mathematical approach rather than a statistical approach, as well as pedagogical issues such as unclear questions or a focus on numerical computations. Implications regarding preparing preservice teachers to teach statistics are provided.

9.4 TEEN QUARANTINE: HIGH SCHOOL STUDENT EMPOWERMENT THROUGH COVID-19

This presentation will review the wide spectrum of experiences that adolescents faced during a challenging 2020-2021 school year, through a developmental, social, and emotional learning lens. Typical adolescent experiences were drastically altered, due to virtual and hybrid learning, requiring adaptations for continued growth, connection, learning, and exploration. Despite hardship, challenge, and injustice, development proceeds and the question of best supporting our youth and families during a tumultuous time are explored, with an emphasis on how the youth themselves may be the catalyst for a healthier and safer future.

Dynamic properties and fracture damage characteristics of granite under impact load

The goal of this research is to study the dynamic properties and fracture damage laws of granite at the meso-scale under impact load. The quasi-static and dynamic mechanical properties of granite were studied through laboratory tests (Uniaxial compression, split Hopkinson pressure bar). The establishment of three-dimensional coupled numerical model of rock specimen and split Hopkinson pressure bar was realized by new coupling technology of PFC-FLAC. Three wave superposition and end stress distribution were discussed to determine the stress balance of the specimen during the loading process. The dynamic compression mechanics response characteristics and crack growth laws of granite under different strain rates were studied. The results indicated that PFC-FLAC coupling technology can solve the problems of tedious modeling process and long calculation time in the past three-dimensional discrete element model, and can better describe the dynamic mechanical behaviour of rock. There is obvious rate dependency in the dynamic strength of rock material, and the dynamic compressive strength of rock increases with the increase of strain rate. The macro fracture of rock mass is the result of the continuous development, expansion, aggregation and connection of the internal microcracks. With the increase of strain rate, the increase and cross propagation of cracks lead transformation of rock from intact to crushing destruction. Under dynamic loading, the failure process of rock is crack initiation, propagation, crossing, transfixion and rupture.

Micromechanical Landscape of Three-Dimensional Disordered Graphene Networks

Disordered carbons can be considered under the modeling framework of disordered graphene networks (DGNs) due to the continuous three-dimensional connectivity and high graphitization. Correlating microstructures and mechanical behaviors of DGNs to their topology is pivotal to revealing more intrinsic features hidden by disorder. Herein, starting from basic deformations and topology, we investigate DGNs with various densities to explore their micromechanical landscape. Both the tension and shear of DGNs exhibit prolonged plastic platforms through local tearing of microstructures. However, compression displays special plastic damages of forming kinklike puckers and sp3-bonded carbon, resulting in a tension-compression asymmetry of DGNs. Out-of-plane topological defects contribute to the main negative-curvature topology in deformed DGNs. Moreover, there are novel scaling laws where both the Young's modulus and strength (logarithms) follow an inversely proportional scaling with respect to average angular defects. Ashby charts demonstrate that the mechanical properties of DGNs can reach the theoretical limit region, surpassing those of most conventional materials.

A step towards SDMs: A “couple‐and‐weigh” framework based on accessible data for biodiversity conservation and landscape planning

AbstractAimThe ongoing global change makes landscape planning and management of ecological corridors crucial to preserve biodiversity. We propose a workflow optimizing the use of different data sources to convert ecological niche models (ENMs) into landscape‐focused species distribution models (SDMs), using these latter to compute ecological corridors. We infer corridors connecting present occurrence localities to future climatic refugia as well as to localities where extinct populations occurred. Also, a continuous connectivity change index is proposed to assess current–future differences. Finally, we discuss possible applications of our workflow to conservation, assessing the capability of established protected areas to preserve ecological corridors.LocationEurope.MethodsAs case study to illustrate our framework, we use a database comprising occurrence localities of Vipera ursinii, one of the most endangered European reptiles. We obtain weighted SDMs for each of the four V. ursinii subspecies by coupling climate‐based ENMs with standardized occurrence frequencies along land use and altitude gradients through weighted averaging in GIS. We calculate current and future landscape connectivity for each subspecies based on the corresponding weighted SDM. We compare predictive performance of “traditional” ENMs, including climate, land use and topography as predictors and weighted SDMs.ResultsWeighted SDMs outperform ENMs, according to Boyce index. SDMs are used to infer connectivity, predicted to decrease in all future scenarios for V. ursinii, and assess where connections may favour movements of individuals to, for example, future suitable areas. Generally, protected areas are predicted to cover low‐connectivity territories.Main conclusionsThe proposed “couple‐and‐weigh” approach could represent a helpful tool to investigate biogeography, conservation and landscape planning topics, as it permits to capitalize on occurrence records and accessible environmental predictors by narrowing the target species’ potential distribution, estimated within “traditional” ENMs, to the realized one through post‐modelling GIS analyses, which in turn improves estimation of friction maps used to infer connectivity.

Genomic differentiation with gene flow in a widespread Amazonian floodplain‐specialist bird species

AbstractAimEcological, climatic and palaeogeographical processes drive biological diversification. However, the evolutionary outcomes of those mechanisms are complex and difficult to discriminate. Here, we test how alternative drivers affected connectivity along the Amazonian floodplains generating current patterns of population structure and diversity within the Striped Woodcreeper, a widespread bird species tied to forests seasonally flooded by Amazonian rivers.LocationAmazonian floodplains.TaxonXiphorhynchus obsoletus (Aves, Furnariidae).MethodsWe sequenced 2213 loci of ultraconserved elements (UCEs) and 20 exons to investigate patterns of genetic structure and connectivity across the Striped Woodcreeper distribution, using a set of spatially explicit methods. Population genetics statistics were calculated for each sampled drainage and within each identified cluster. We tested alternative evolutionary scenarios and estimated past and current demographic parameters implementing a simulation‐based framework.ResultsThree genetic clusters with high admixture proportions were identified. These clusters are distributed in the western, central and eastern parts of the Amazon Basin and are not correlated with different river water types representing ecological gradients along the floodplains. Instead, migration rates indicate two putative historical barriers along the main channel of the Amazonas‐Solimões River. Demographic model tests suggest a process of sequential differentiation, partitioned across the Amazon Basin, with stable population sizes and continuous gene flow.Main conclusionOur results support the hypothesis that late Quaternary changes in connectivity between the eastern and western Amazonian drainages were responsible for driving genetic differentiation in the Striped Woodcreeper. Genomic differentiation occurred in the presence of long‐term gene flow throughout the X. obsoletus distribution, suggesting some degree of continuous historical connectivity across Amazonian floodplains. Compared to previous studies, our results suggest that although connectivity among populations of Amazonian bird species specialized in floodplain habitats varies in response to the same abiotic mechanisms, species‐specific differences in habitat use may be a strong predictor of population divergence.

Non-use of Digital Health Consultations Among Swedish Elderly Living in the Countryside

Digital health consultations in primary care have the advantage of offering equal healthcare for people residing in the countryside. While it is gaining acceptance among young- and middle-aged people, the elderly are reluctant to use it. The aim of this study was hence to identify reasons for non-use among elderly in the countryside and describe perceived possible challenges and opportunities with digital health consultations. Semi-structured interviews were conducted with 13 persons over 65 years old residing in the Swedish countryside. There was a mistrust for services offered by private companies and their public funding, a lack of knowledge of available services, and a lack of perceived usefulness. Personal interaction and continuity was more important than time or travel conveniences, although these advantages were recognized. To prevent digital exclusion, caregivers need to offer information, encouragement, or tools for the elderly. Digital primary care also needs to offer familiarity, with continuity and personal connections.

Digital communication, health & wellbeing in universities: a double-edged sword

ABSTRACT We explore how digital communication relates to worker health and wellbeing within Australian universities prior to COVID-19. To investigate effects of digital communication we sought perspectives of senior Human Resource and wellbeing personnel for semi-structured interviews. Analyses revealed that digital communication creates both negative and positive aspects of work, leading to differing effects and outcomes of health and wellbeing. Themes that emerged included flexibility, collaboration and access to resources, a sense of continual accessibility and connectivity to work, information overload and interpersonal relationships. Depending on how digital communication is managed, we found each aspect has the capacity to be simultaneously positive (i.e., resourceful) or negative (e.g., demanding). Drawing on organisational theory, we propose new ways to conceptualise workplace digital communication and propose practical management approaches. Future research should continue to unpack the relationship between digital communication and work practices, while considering potential management and policy strategies to protect worker health and safety.

Numerical study on bending resistance of cold‐formed steel back‐to‐back built‐up elements

AbstractCold‐formed steel back‐to‐back built‐up beams are efficient and very attractive structural elements which can also offer excellent efficiency in production, both in capacity and material savings. The connection between such built‐up steel components can be easily obtained by screws or bolts, but the developments in the welding processes also lead to other solutions like continuous (laser or MIG brazing) or discrete (spot welding). This paper presents a parametric numerical study on such elements where various shapes and cross‐section geometries will be analysed, using different types of connection between the built‐up steel elements. The results from the evaluation of local and global buckling behaviour of such beams will serve as a base for planning future experimental work. Based on the numerical model, the paper presents the influence of several parameters i.e., the type of the channel section (lipped or plain channels), length of the beam, continuous and discrete connections between channels, the number and the distance between discrete connections along the beam axis and along the beam height. From the parametric study, it is concluded that capacity of the cold‐formed steel back‐to‐back built‐up steel beams is highly affected by the type of connections.

Dynamic Relay Selection and Positioning for Cooperative UAV Networks

In this letter, we are interested in resource reservation for networking purposes in drone teams deployed for search and rescue missions. We build on a well-known static relay positioning technique that minimizes the number of drones and propose a positioning and trajectory planning algorithm for relay nodes to provide connectivity to drones that are out in the air for a search mission. Our results show that by reserving a portion of the available drones for relay purposes only, gains as high as 50% can be achieved in mission times, while providing continuous connectivity from the search drones to BS.

Lessons From the COVID-19 Pandemic on the Nature of Work Among Those With Mental Illness.

Workers with mental illness may be uniquely affected by the labor market impacts of the pandemic. The authors used data from the National Health Interview Survey (2016-2018) to categorize workers by employment in essential or nonessential industries and by the feasibility of working remotely. Workers with psychological distress prepandemic were less likely than those without psychological distress to have occupations where remote work was feasible. These individuals may face higher risk of exposure to the virus and, if they are nonessential workers, higher risk of unemployment. Efforts that facilitate safe, continued connection to the workforce may be of value to workers with preexisting mental illnesses.

Design, Simulation and Optimization of an Electrical Drive-Train

Today, design engineers engaged in the development of a high-performance electrical drive-train are challenged by the multitude of possible topological choices and numerous mutually interconnected physical phenomena. Development teams around the globe struggle with this challenge; usually they employ several tools for simulation and topology optimization and transfer multiple versions of their product models in a mainly manual process. The research presented in this paper aims to explore a holistic possibility to realize a sensible analysis-synthesis cycle that takes into consideration current developments in design, simulation and optimization processes. This kind of process can enhance the transparency of design decisions, can reduce the risk of design and process flaws and can support the approach toward a holistic optimum. The investigation starts with the development of the topological concept of the drive-train and continues over the interconnected simulation of several decisive properties of the drive-train. Obviously, these properties concern several domains (mechanical, electrical, thermal and the control domain). The optimization of the drive-train takes into consideration the main requirement—in the investigated example, which is a formula student drive-train—the lap time. The result is a holistic concept for a design, simulation and optimization approach that considers topological variety, interconnected multi-domain simulation and a continuous connection to the decisive requirements.