Walk In Space Research Articles

Relevance of Pedestrian Circulation in Urban Design: A Study of M.P. Nagar, Bhopal

Walking is one of the vital components in designing cities. It makes cities safe, accessible, and visually more appealing. The research is looking into creating a city that allows pedestrians to use the space as safely as possible, making the space easy to walk through, and invitingly friendly. (Southworth, 2005). A good city would be environmentally conscious, inclusive to all, and a better place to live generally. The study discusses core issues in developing walkable cities, such as the ability to easily move about, safety for pedestrians, and the connection between places. At the same time, it can be seen that integrating walking spaces with public transportation makes cities perform better. For instance, one of the emerging ideas is using streets shared with both cars and people, thus reducing traffic volumes and designing a flexible space in line with change to meet new needs. This focus involves designing cities that are responsive to climate and making public spaces more accessible for walking. (URBAN, 2021/22). The paper has used examples from places like Delhi, Ahmedabad, and Barcelona to demonstrate how pedestrian-friendly ideas have worked in real life. The research also discusses the challenges that cities in developing countries face, which include crowded places, informal business, and scarce money for huge projects. Last but not least, the study provides a guideline to city planners and policymakers on prioritizing walking in urban design to make cities easy to live and move around in. The study encourages a paradigm shift toward better cities for walkers, which eventually leads to sustainable and vibrant cities. Key Words: Walkability, Pedestrian Safety, Urban Design, Public Space Accessibility, Sustainable Cities, Integrated transport.

Multiplicative SHE limit of random walks in space–time random environments

Multiplicative SHE limit of random walks in space–time random environments

Investigating Effects of Future Path Visualisation on Path Choices During Collision Encounters

Safe navigation choices made in walkable spaces highly depend on how a traveller perceives and understands the threat from surrounding travellers’ movements. Hence, if a visual medium like an AR headset provides an augmented view where future paths of others are already shown virtually, this could influence the way a person decides to avoid a potential collision. In this work, taking walking conflicts as an example, we first propose different ways of showing the future path in AR and then investigate whether people decide to walk more safety-consciously when seeing AR information. For this, we conducted a web-based user study (n =27), in which participants sketched a walking path that they preferred when avoiding collisions in different crossing scenes. Each scene in the study contained another person walking and crossing the participant’s expected path, while the prediction of the another person’s future walking path was either not visualised or augmented with a virtual arrow. Participants were then expected to sketch a path to their destination while not colliding with the person in the scene. By applying a sketch transformation pipeline, the participants’ drawings were transformed to trajectories of the preferred walking paths, which where then simulated to estimate the conflict severity using the Post Encroachment Time (PET) metric. The study verified that people choose to adapt their walking paths when seeing the future path information, and also react differently to different types of 3D arrow visualisations that represent the same future path.

Survey and Research on Accessible Slow Walking Space in Fayuan Temple Historical Neighborhood of Xicheng District, Beijing, China

As society progresses and civilization develops, the construction of accessible environments is increasingly receiving widespread public attention. As an important part of urban space, optimizing the accessibility of slow-moving spaces to provide a more convenient, safe and comfortable travel environment for groups such as the elderly and people with travel disabilities has become an important initiative to promote friendly and inclusive development for the whole society. However, the barrier-free transformation of slow-moving spaces in historic districts faces multiple challenges, such as traffic congestion, spatial limitations, and landscape coordination. In order to analyze and identify the problems, and to better balance the protection of historic districts and modern accessibility construction, this project takes the Fayuan Temple Historic District in Xicheng District of Beijing as a case study, and comprehensively evaluates the accessibility environment of the district through various research methods such as experiential surveys, on-site surveys, in-depth interviews, and so on. The study found that: 1) the roads in the historic district are generally narrow and uneven; 2) there is a lack of necessary barrier-free facilities and parking spaces at the entrances and exits of the buildings; 3) there is a scarcity of barrier-free service facilities and they are not in harmony with the neighborhood's style; and 4) the willingness of the people with mobility impairments to travel is affected by the physical environment. This paper puts forward the corresponding policy suggestions for the above problems to provide useful references for the relevant government departments and related designs.

Are different TOD circles oriented towards sustainability amidst urban shrinkage? Evidence from urban areas to suburbs in the Tokyo metropolitan area

Transit-Oriented Development (TOD) is a prominent urban development approach aimed at maximizing the number of residential, commercial, and walkable spaces within the catchment area of public transportation. Despite its widespread discussion, the definition of the TOD catchment area remains ambiguous. This study expands the research scope of TOD catchment areas by introducing the concept of three TOD circles and examines their relevance within the context of urban shrinkage in the Tokyo Metropolitan Area over time. Focusing on the Den-en-toshi Line, which spans Tokyo and Kanagawa Prefecture, as a case study, we developed a sustainable TOD assessment model based on the node-place-ecology (NPE) framework. This model was used to analyze the dynamic changes in different TOD circles from 2011 to 2019. The results indicate a positive sustainable development trend in the first and second circles, while the third circle shows a slight decline. Moreover, a comparison between urban and suburban areas further supports the notion that the monopolization trend of core stations in Tokyo is intensifying. We believe that the model framework developed in this study has great adaptability and can be widely applied globally to help researchers and urban planners conduct more accurate sustainability assessments of TOD stations.

Control of probability flow in Markov chain Monte Carlo-Nonreversibility and lifting.

The Markov chain Monte Carlo (MCMC) method is widely used in various fields as a powerful numerical integration technique for systems with many degrees of freedom. In MCMC methods, probabilistic state transitions can be considered as a random walk in state space, and random walks allow for sampling from complex distributions. However, paradoxically, it is necessary to carefully suppress the randomness of the random walk to improve computational efficiency. By breaking detailed balance, we can create a probability flow in the state space and perform more efficient sampling along this flow. Motivated by this idea, practical and efficient nonreversible MCMC methods have been developed over the past ten years. In particular, the lifting technique, which introduces probability flows in an extended state space, has been applied to various systems and has proven more efficient than conventional reversible updates. We review and discuss several practical approaches to implementing nonreversible MCMC methods, including the shift method in the cumulative distribution and the directed-worm algorithm.

Metodologia para Avaliação da Caminhabilidade em Centros Urbanos

Rapid urbanization has turned urban mobility into one of the biggest challenges for modern cities. Intense competition for public spaces in downtown areas of medium and large cities leads to accidents, congestion, increased costs and travel time, and environmental pollution caused by individual motorized and public transport. Searching for a contribution to social, economic, and environmental sustainability this work, considering walking as an essential form of mobility in an urban center of developing countries, proposes a methodology for supporting citizens who arrive at the downtown public bus terminal to select the best walking route to reach essential public services places in the city. Three macro indicators are considered in determining the best walking route: The ambiance indicator results from six sub-indicators, representing physical characteristics of the walking space; the Comfort indicator results from two sub-indicators, representing the visual attractiveness and local comfort; and the Safety indicator results from four sub-indicators; representing public and personal sensations of safety. The proposed methodology is based on two steps: the first reduces the twelve sub-indicators of each route segment to three main indicators. In the second step, a multi-objective optimization problem is formulated to determine the best route from the origin point (public urban terminals) to the citizen interest point. The identification of the most suitable downtown walkability areas can assist local authorities in developing improvement strategies for their ambiance, safety, and comfort standards, actions that will contribute to environmental sustainability and providing urban areas with walking spaces that meet the citizen's expectations.

A Study on the Effect of Urban Form on the Street Interface Rhythm Based on Multisource Data and Waveform Classification

Good-quality urban street space is crucial for improving walkability. Frequency and amplitude are the main spatial characteristics of the street interface rhythm, known as a “virtual–real” relation. Exploring the mechanism influencing the urban street interface rhythm can help grasp the movement trend. In this study, the correlation between frequency and urban form is explored through a Pearson correlation analysis with multisource data, and the factors influencing the urban street interface rhythm are presented. The results indicate that frequency has a moderate negative correlation with the block scale and a moderate positive correlation with the number of pedestrian access entrances (PAE-n); the PAE-n also has a strong negative correlation with the block scale. Some spatial characteristics of outstanding streets from different countries are analyzed and discussed based on waveform classification. The regularities of interface rhythm that exist within multiple streets are found: multiple gaps on the street interface exist, acting as a “beat”, which regularly integrates or separates the street interface rhythm. The frequency and amplitude of the “beat” significantly affect streets’ walkability, and the amplitude is generally low and uniform, with good visual accessibility in all directions. A “Small Block and Dense Grid” becomes a key factor in improving walkability. Basic knowledge of the street interface rhythm in urban walking space research is supplemented by this study. Furthermore, theoretical guidance and parametric evidence are provided to improve walkability and promote the continuation of the traditional context.

A study on landscape feature and emotional perception evaluation of waterfront greenway

Waterfront greenway is important spatial carriers for urban residents to engage in walking tours and fitness activities. Improving the quality of its walking spaces can have a positive impact on the mental well-being of pedestrians. This enhancement is a crucial aspect of building healthy cities. This study focused on urban waterfront greenway landscapes. Field surveys combined with questionnaire scales were used to assess pedestrians’ emotional perceptions, while concurrently collecting image data of waterfront greenway walking spaces. Semantic segmentation was employed to identify elements, and landscape metrics were calculated using relevant formulas. Correlation analysis was used to investigate the relationship between landscape metric features and emotional perceptions. And established a multiple regression model of pedestrian spatial perception on waterfront greenways to investigate the influence mechanisms of emotional perception and landscape metrics. The study indicates that greenness, proportion of water area, and vegetation diversity positively impact emotional perception of waterfront leisure greenway walking spaces, whereas path width negatively affects emotional perception. Specifically, the magnitude of influence is ranked as follows: greenness (0.491), proportion of water area (0.356), proportion of trails (−0.272), and vegetation diversity (0.130). The design guidelines for urban waterfront greenway spaces were proposed, guided by quantitative studies on landscape elements of waterfront greenway spaces and based on the measurement features of these elements. Moreover, the environmental experience of the waterfront green walking spaces was further enhanced, satisfying the public’s visual perception and psychological needs. The contribution of this study is to lay the foundation for the development of spatial control items for urban waterfront greenway.

Robotic technologies for in-orbit assembly of a large aperture space telescope: A review

Space telescopes have been instrumental in enlightening our understanding of the universe, from the iconic Hubble Space Telescope to specialized instruments like Chandra and Kepler. Pushing the frontiers of cosmic exploration, the future of space exploration hinges on modular Large Aperture Space Telescopes (LAST), much larger than the recently launched 6.5 m James Webb Space Telescope, necessitating robotic assembly in orbit. This paper introduces a paradigm shift in astronomical observation by featuring robotic in-orbit assembly of a large aperture space telescope. This review paper starts by tracing the evolution of telescopes and presents a comprehensive overview of the state-of-the-art space telescopes. This paper then reinforces the need for LAST to address the constant clamour for higher-resolution astronomy. While current semi-autonomous robotic manipulators operate from the International Space Station, their limited walking capabilities constrain their workspace, making them unsuitable for the LAST mission. This paper presents a detailed trade-off analysis of the challenges associated with the in-orbit assembly of LAST using candidate robots to understand the technological gaps. Further, the evolution of space robotic manipulators is presented, highlighting design features, advantages, and drawbacks for in-orbit spacecraft servicing and assembly missions. To tackle design and modelling challenges for robotic systems in space, amidst the various perturbations in the extreme space environment, linear and non-linear control systems necessary for achieving ultra-high precision performance are also discussed. This paper advances the walking space manipulator technology by introducing the next generation of walking space manipulators – the End-Over-End Walking Robot (E-Walker). The dexterous and modular design of the E-Walker makes it an ideal candidate for missions involving assembly, manufacturing, servicing, and maintenance.

The intelligibility of mobile trajectories: walking in public space

This paper deals with practices of personal mobility in public space, such as walking, passing-by and queuing, and their intelligible, recognizable and intersubjectively coordinated character. People co-exist in public places without having to explain their conduct in so-many-words; they smoothly navigate by coordinating their bodies and mobile trajectories without collisions; they queue without any instructions and differentiate between who joins the queue and who projects to butt in the queue. This article addresses the intelligibility of walking trajectories in public space, how they are bodily achieved and visibly interpreted. It reflects on mobility by relying on the notion of public in two different but complementary perspectives: a) by reference to mobility in the context of public places such as parks, squares, and streets; b) by reference to the public intelligibility and recognizability of mobile actions in social interaction. The convergence between these two notions of public enables us to investigate how mobile social actions are formed (made recognizable) and how they are ascribed (actually recognized) by co-present unacquainted persons in public space. The analysis draws on video recordings of mobile trajectories in streets, pathways, and squares.

Exploring thermal comfort and pleasure in outdoor shaded spaces: Inspiration for improving thermal index models

Engaging in outdoor activities offers numerous benefits for physical and mental well-being, highlighting the importance of prioritizing outdoor comfort and safety. Shaded spaces are sought after during hot summers due to their lower surface temperatures and improved thermal comfort. This study conducted group walking experiments in both overhead layers and tree-shaded areas to investigate variations in thermal comfort based on different thermal environments and activity levels. The findings reveal significant differences in the thermal environment between the two areas, with tree shading reducing mean radiant temperature by approximately 3 °C and wind speed by about 1 m/s. Regardless of the walking space, the lowest thermal pleasure and comfort are experienced at a speed of 1.80 m/s. Moreover, the study demonstrates that thermal pleasure (Tp) is influenced by both the objective thermal environment and the human body's thermoregulatory mechanisms. It is also affected by subjective psychological expectations, reflecting the combined outcome of metabolic heat production, external thermal stimuli, and psychological emotions. Thus, pedestrians experienced different levels of thermal pleasure based on their walking speeds and the type of shaded space. These findings underscore the importance of integrating physiological and psychological factors into thermal index models to accurately evaluate outdoor thermal comfort conditions. The study contributes to developing improved thermal index models by enhancing their correlation with the perceived thermal sensations and considering the emotional aspect of thermal pleasure. The implications of this research can guide urban planning efforts to provide more comfortable and enjoyable outdoor shaded spaces.

Virtual walks and phase transitions in the two-dimensional Biswas-Chatterjee-Sen model with extreme switches.

In kinetic exchange models of opinion formation, one considers pairwise interactions to update the states of the agents. We have studied a kinetic exchange model with three opinion states 0,±1, by considering a walk in a one-dimensional virtual space which evolves according to the dynamical states of the agents. The model involves two noise parameters p and q; p represents the fraction of negative interactions and q corresponds to the probability of a stronger interaction with the other agent, which may result in extreme switches (change of state from +1 to -1 or vice versa). The nature of the walks can indicate where the phase transitions occur in the p-q plane; these results are corroborated with those obtained using finite-size scaling method. The criticality is found to be Ising-like, even when extreme switches are allowed. A new critical exponent associated with the probability distribution of the displacements in the virtual space is also obtained independent of the values of the critical parameters. The nature of the walks is compared to similar virtual walks studied earlier.

MULTI-AGENT SIMULATION MODEL OF INFECTIOUS DISEASE SPREAD

The aim of the research is to develop a multi-agent simulation model for predicting the spread of infectious diseases, particularly COVID-19. In the context of the COVID-19 pandemic, there emerged an urgent need to create tools for forecasting and analyzing the dynamics of epidemics, as well as for evaluating the effectiveness of management decisions. The use of mathematical models in this process allows for an adequate description of the infection spread dynamics, which is essential for making informed decisions. The article discusses traditional approaches to epidemic modeling, such as the predator-prey model and the compartmental SIR (Susceptible-Infectious-Recovered) model. The predator-prey model describes the interaction between two species in an ecosystem using differential equations, which allows for modeling population dynamics. The compartmental SIR model divides the population into three groups: susceptible, infected, and recovered, which enables the analysis of the spread of infectious diseases. However, these models have limitations, particularly due to assumptions about population homogeneity and constant parameters. To more accurately model complex epidemic processes, a multi-agent simulation model was developed. In this model, agents interact within a defined area, mimicking real conditions of infection spread. Agents are divided into three classes: healthy, infected, and recovered. The movement of agents is modeled using random walk in a two-dimensional space, taking into account the possibility of contact between them, which can lead to infection. Infected agents transition to the recovered class after a certain period of illness and can no longer be infected. Modeling results showed that the multi-agent model allows for more accurate prediction of infection spread dynamics. Numerous experiments were conducted, demonstrating the model's adequacy in replicating the infection process, peak infection rates, and recovery periods. The influence of various parameters, such as the duration of illness, on the epidemic dynamics was investigated. The obtained results confirm that considering individual characteristics and behavioral traits of agents improves the accuracy of modeling. This allows the multi-agent simulation model to be used for developing effective control strategies and predicting the spread of infectious diseases, which can be useful for making management decisions in real pandemic conditions.

Digital Gait Outcomes for Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS): Discriminative, Convergent, and Ecological Validity in a Multicenter Study (PROSPAX).

With treatment trials on the horizon, this study aimed to identify candidate digital-motor gait outcomes for autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), capturable by wearable sensors with multicenter validity, and ideally also ecological validity during free walking outside laboratory settings. Cross-sectional multicenter study (four centers), with gait assessments in 36 subjects (18 ARSACS patients; 18 controls) using three body-worn sensors (Opal, APDM) in laboratory settings and free walking in public spaces. Sensor gait measures were analyzed for discriminative validity from controls, and for convergent (ie, clinical and patient relevance) validity by correlations with SPRSmobility (primary outcome) and Scale for the Assessment and Rating of Ataxia (SARA), Spastic Paraplegia Rating Scale (SPRS), and activities of daily living subscore of the Friedreich Ataxia Rating Scale (FARS-ADL) (exploratory outcomes). Of 30 hypothesis-based digital gait measures, 14 measures discriminated ARSACS patients from controls with large effect sizes (|Cliff's δ| > 0.8) in laboratory settings, with strongest discrimination by measures of spatiotemporal variability Lateral Step Deviation (δ = 0.98), SPcmp (δ = 0.94), and Swing CV (δ = 0.93). Large correlations with the SPRSmobility were observed for Swing CV (Spearman's ρ = 0.84), Speed (ρ = -0.63), and Harmonic Ratio V (ρ = -0.62). During supervised free walking in a public space, 11/30 gait measures discriminated ARSACS from controls with large effect sizes. Large correlations with SPRSmobility were here observed for Swing CV (ρ = 0.78) and Speed (ρ = -0.69), without reductions in effect sizes compared with laboratory settings. We identified a promising set of digital-motor candidate gait outcomes for ARSACS, applicable in multicenter settings, correlating with patient-relevant health aspects, and with high validity also outside laboratory settings, thus simulating real-life walking with higher ecological validity. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Developing a city-specific walkability index through a participatory approach

Abstract. The extent to which the built environment encourages people to walk in public spaces, hence the quality of being walkable or ‘walkability’ has long been associated with positive outcomes on people’s health. While various studies have developed indices to assess walkability, limited attention has been given to indices that reflect the influence of specific city characteristics on walkability. This study showcases the development of a city-specific walkability index through a participatory approach using Amsterdam as a case study. It explores the viewpoints of urban designers and policy-makers who work or reside in Amsterdam on what constitutes a walkable street and identifies the most significant walkability factors for Amsterdam. These factors are then quantified based on open-access datasets and integrated into a street-level weighted walkability index. The resulting walkability index underscores the importance of factors such as traffic and crime safety, quality of the pedestrian infrastructure, and proximity to public amenities in shaping residents’ decisions to walk in specific public spaces. Finally, this research underscores the importance of involving individuals through participatory methods, considering subjective perspectives, and acknowledging shared experiences within particular groups and spaces when assessing walkability.

Exploring the differences between landscape colour and perceptive colour when walking through urban green space in summer

Landscape colour influences people’s visual behaviour and preferences. Insufficient exploration has been conducted on people’s colour perception when walking through urban green spaces (UGSs) dominated by green in summer. This study used eye-tracking technology to explore the differences between the visual attention colour (VAC) and space colour (SC), and the effect of spatial form on VAC. Participants were asked to view six walking spaces in two UGSs in Nanjing, China. The results indicated that SC and VAC had correlations in hue variance (yellow), saturation mean, and value variance, but weak correlations in hue mean (green), hue variance (green), and value mean. Additionally, the higher the spatial openness, the more reduction in brightness of the VAC compared to SC. The findings suggest that landscape visual perception studies need to consider the interaction between landscape colour, spatial form, and human top-down visual behaviour to support the design of UGSs.

Graph theory based estimation of probable CO2 plume spreading in siliciclastic reservoirs with lithological heterogeneity

Estimating plume spreading in geological CO2 storage reservoirs is critical for several reasons including the assessment of pore space utilization efficiency, preferential CO2 migration pathways and trapping. However, plume spreading critically depends on lithological heterogeneity of the reservoir and CO2 injection rate. It might require numerous high fidelity full physics numerical simulations to constrain the uncertainty in plume spreading for a given reservoir. This might not always be practical due to computational limitations. Hence, reduced physics approaches, such as invasion-percolation method and machine learning, could be useful to answer certain questions on plume spreading in the subsurface. This study presents a new reduced physics approach based on graph theory for estimating probable CO2 plume migration under very low and very high injection rates. The two end-member scenarios are assessed by performing random walk in the 3D reservoir space to constrain 20,000 possible paths of CO2 flow away from the injection well. The resistance to CO2 flow associated with each path is computed for viscous, capillary and gravity forces. The resistances are then transformed into the likelihood of CO2 migration along the path. The algorithm was applied to 45 reservoir models with varying degrees of lithological heterogeneity and the results were compared to those from full physics and invasion percolation simulations. The graph theory results showed a close match with the results from full physics approach for both flow regimes and with results from invasion-percolation approach for capillary-gravity dominated flow regime. The algorithm was further applied to answer key questions on reservoir screening such as pore space utilization potential. The graph theory approach was also integrated with machine learning to predict CO2 saturation. Testing suggested that the graph theory approach can be as much as 50 and 20 times faster than the full physics numerical simulations and invasion-percolation simulations, respectively.

Random feedback alignment algorithms to train neural networks: why do they align?

Feedback alignment algorithms are an alternative to backpropagation to train neural networks, whereby some of the partial derivatives that are required to compute the gradient are replaced by random terms. This essentially transforms the update rule into a random walk in weight space. Surprisingly, learning still works with those algorithms, including training of deep neural networks. The performance of FA is generally attributed to an alignment of the update of the random walker with the true gradient—the eponymous gradient alignment—which drives an approximate gradient descent. The mechanism that leads to this alignment remains unclear, however. In this paper, we use mathematical reasoning and simulations to investigate gradient alignment. We observe that the feedback alignment update rule has fixed points, which correspond to extrema of the loss function. We show that gradient alignment is a stability criterion for those fixed points. It is only a necessary criterion for algorithm performance. Experimentally, we demonstrate that high levels of gradient alignment can lead to poor algorithm performance and that the alignment is not always driving the gradient descent.

Different smartphone tasks and traffic complexity affect pedestrian awareness of co-existing road objects and cerebral oxygenation during shared space walking

Distraction, primarily owing to the widespread use of cell phones and mobile devices while walking, is a contributing factor to pedestrian injuries. Pedestrians distracted by smartphones exhibit decreased situational awareness, influenced by the nature of concurrent tasks. However, little is known about the neural correlations between smartphone use and pedestrian responses to safety–critical events in a walking environment. This study recruited 30 young adults to investigate pedestrians’ ability to selectively respond to road objects while using smartphones (texting and reading) while walking in an immersive virtual environment system. The level of traffic complexity for the road conditions was manipulated by varying the number of safety–critical road objects coexisting in the environment at any given time and the number of required responses to the number of objects. During each 7-min task condition, cerebral oxygenation was measured using functional near-infrared spectroscopy. Furthermore, smartphone task performance, response times to road objects, and perceived workload were also measured. The participants exhibited reduced texting speed and reading performance when responding sequentially to coexisting road objects. Compared with other road conditions, those requiring two responses to four objects resulted in an increased workload and longer object response times. Participants perceived a higher workload in conditions involving tasks with smartphones than those without smartphones. More importantly, increased concentrations of oxygenated hemoglobin in the prefrontal cortex were observed when participants were concurrently performing smartphone and pedestrian tasks. Compared to smartphone reading, smartphone texting induced greater cerebral oxygenation in the bilateral frontopolar cortex. These results suggest that continuously texting while walking may demand additional cognitive resources for executive function. The findings of this study represent an initial step towards elucidating the cognitive mechanisms underlying attentional impairments experienced during smartphone distraction and working towards a viable solution to mitigate pedestrian risk.