Ideal Walk Research Articles

Optimal Walking Strategies and Optimal Design of Walking Assistive System

Walking includes many variations among humans, from one step to another. Understanding what kind of walking variations exist is therefore important to determine how normal gait behavior is. Ideal walking characteristics by considering human dynamics can be found by using optimization. For this purpose, a multibody dynamic model of human walking was developed. After creating multibody dynamic model, the motion patterns were optimized by minimizing total joint energy and moment during one gait cycle. To define the joint angle characteristics during one gait cycle, many design variable should be considered. However, the number of required design variables were reduced significantly by using singular value decomposition. After obtaining optimal walking patterns, a passive walking assistive system was proposed to reduce joint power and moment. The stiffness and location of passive walking assistive system was optimized to reduce joint moment and power further.

Walking duration in daily travel: an analysis among males and females using a hazard-based model

This study examines how various travel/built environmental and individual/household characteristics influence the walking durations of males and females in the city of Rasht, Iran, using data from the 2007 Rasht Household Travel Survey (RHTS). Accelerated hazard (AH) modelling, as a new approach in walking-related studies, was used to predict walking durations. The survival curve analysis showed that the ideal walking time was five minutes, but walking up to ten minutes was also acceptable. The AH models indicated that the walking duration of males and females varied under different conditions and contexts. For example, female workers were likely to walk longer trips relative to non-workers; however, this was the opposite among males. Household characteristics such as car ownership were found with greater negative effect on walking duration of males than females. Furthermore, zones with higher land use mix and higher connectivity led to shorter walking duration in both models.

Control Method Based on Sensor Data for Stable Walking of a Biped Robot under Port Environment

Jing, C.L., You, X.F., and Xia, T., 2020. Control method based on sensor data for stable walking of a biped robot under port environment. In: Guido Aldana, P.A. and Kantamaneni, K. (eds.), Advances in Water Resources, Coastal Management, and Marine Science Technology. Journal of Coastal Research, Special Issue No. 104, pp. 271–275. Coconut Creek (Florida), ISSN 0749-0208.In spite of great improvement of walking ability after the merging of various walking techniques, there still exists a large gap between a biped robot and a person. In particular, under some complex environments such as port, the development and perfection of the control theory based on the detected sensor data are of great significance to achieving ideal walking ability for the robot. In this study, the detected sensor data are merged into the established dynamic model, and then, both the force and the moment of the connecting rod are accurately calculated for programming actual ZMP trajectory. Further, the data are sent to the slave computer for robot control, thereby enhancing the walking stability. The present simulation results prove that the biped robot can successfully realize stable walking.

A Study on the Calculation of Platform Sizes of Urban Rail Hub Stations Based on Passenger Behavior Characteristics

The Chinese national rail transit design specification decides the size of urban rail transit platforms in China. This suggested method treats passengers as homogeneous individuals when calculating the walking area within a platform. However, the heterogeneity of passenger behavior in a rail hub station has not been considered. It is not reasonable to see passengers as homogeneous individuals. In this study, by observing passenger behavior characteristics at rail hub platforms, two parameters were obtained, walking speed and luggage size. Passengers were then accordingly put into different groups, and dynamic spatial demands for each passenger group were calculated by parameter fitting functions. Based on the theory of spatiotemporal consumption, the nonlinear constraint model was constructed to determine the space-time consumption of each passenger group, and finally the area demands of different types of passengers were obtained for different time and passenger flows. An application was made to Beikezhan Station on Xi’an Metro line 2. The calculation results show the area demands ranges of four passenger groups with distinct characteristics, and their space-time consumption varied. The study can calculate the space demands for all passenger varieties within a rail hub transit platform and provide suggestions for the determination of the ideal walking area size of rail transit platforms.

Design and Speed-Adaptive Control of a Powered Geared Five-Bar Prosthetic Knee Using BP Neural Network Gait Recognition.

To improve the multi-speed adaptability of the powered prosthetic knee, this paper presented a speed-adaptive neural network control based on a powered geared five-bar (GFB) prosthetic knee. The GFB prosthetic knee is actuated via a cylindrical cam-based nonlinear series elastic actuator that can provide the desired actuation for level-ground walking, and its attitude measurement is realized by two inertial sensors and one load cell on the prosthetic knee. To improve the performance of the control system, the motor control and the attitude measurement of the GFB prosthetic knee are run in parallel. The BP neural network uses input data from only the GFB prosthetic knee, and is trained by natural and artificially modified various gait patterns of different able-bodied subjects. To realize the speed-adaptive control, the prosthetic knee speed and gait cycle percentage are identified by the Gaussian mixture model-based gait classifier. Specific knee motion control instructions are generated by matching the neural network predicted gait percentage with the ideal walking gait. Habitual and variable speed level-ground walking experiments are conducted via an able-bodied subject, and the experimental results show that the neural network control system can handle both self-selected walking and variable speed walking with high adaptability.

Holographic gauged NJL model: The conformal window and ideal walking

We study the holographic Dynamic AdS/QCD description of a SU($N_c$) non-abelian gauge theory with $N_f$ fermions in the fundamental representation which also have Nambu-Jona-Lasinio interactions included using Witten's multi-trace prescription. In particular here we study aspects of the dynamics in and near the conformal window of the gauge theory as described by the two loop running of the gauge theory. If the number of flavours is such that the IR fixed point lies with the anomalous dimension, $\gamma$, of the quark bilinear above one then chiral symmetry breaking occurs. Here we display a spiral in the mass - quark condensate plane describing a sequence of unstable excited states of the vacuum. An attractive NJL operator enhances the vacuum condensate but only an infinitely repulsive NJL interaction switches off the condensation completely. When $N_f$ changes so that the IR fixed point falls below one (the conformal window region) there is a numerical discontinuity in the phase structure with condensation only occurring with a super critical NJL interaction. In the conformal window, the running of $\gamma$ to a non-trivial IR fixed point is similar to walking dynamics, although chiral symmetry breaking is not triggered. In the "Ideal Walking" scenario, chiral symmetry is broken in that IR conformal regime by the NJL interaction, but the change in $\gamma$ enhances the UV condensate. That enhancement of the condensate is shown in an analytic model with a sharp change in $\gamma$ and we show equivalent numerical results for the case of the two loop running. In the model the $\sigma$ becomes massless as the gauge theory running becomes near conformal and we show it is possible to realize a light higgs-like state in Ideal Walking models.

Ideal walking dynamics via a gauged NJL model

According to the Ideal Walking Technicolor paradigm large mass anomalous dimensions arise in gauged Nambu--Jona-Lasinio (NJL) models when the four-fermion coupling is sufficiently strong to induce spontaneous symmetry breaking in an otherwise conformal gauge theory. We therefore study the $SU(2)$ gauged NJL model with two adjoint fermions using lattice simulations. The model is in an infrared conformal phase at small NJL coupling while it displays a chirally broken phase at large NJL couplings. In the infrared conformal phase we find that the mass anomalous dimension varies with the NJL coupling reaching $\gamma_m \sim 1$ close to the chiral symmetry breaking transition, de facto making the present model the first explicit realization of the Ideal Walking scenario.

Use of formative research and social network theory to develop a group walking intervention: Sumter County on the Move!

Although social support is a frequently cited enabler of physical activity, few studies have examined how to harness social support in interventions. This paper describes community-based formative research to design a walking program for mobilizing naturally occurring social networks to support increases in walking behavior. Focus group methods were used to engage community members in discussions about desired walking program features. The research was conducted with underserved communities in Sumter County, South Carolina. The majority of focus group participants were women (76%) and African American (92%). Several important themes emerged from the focus group results regarding attitudes toward walking, facilitators of and barriers to walking, ideal walking program characteristics, and strategies for encouraging community members to walk. Most noteably, the role of existing social networks as a supportive influence on physical activity was a recurring theme in our formative research and a gap in the existing evidence base. The resulting walking program focused on strategies for mobilizing, supporting and reinforcing existing social networks as mechanisms for increasing walking. Our approach to linking theory, empirical evidence and community-based formative research for the development of a walking intervention offers an example for practitioners developing intervention strategies for a wide range of behaviors.

Kinematics of Migration of Individual Fibroblasts in Vitro: Faster in a Group, but More Target-Oriented Alone

During repair of localized damage in a monolayer of cells, migrating NIH3T3 fibroblasts exhibit certain kinematic traits that are influenced directly by factors in their environment such as temperature, pH, and particularly the numbers and distributions of neighboring cells. The present study measures the velocity and direction of individual fibroblasts cultured in a monolayer during migration into a damaged region. Specifically, a parameter termed ＂percent ideal walk＂ was defined for evaluating the efficiency of the migrating cells, which were divided into two distinct groups based on migration behavior, namely those migrating alone or with up to four cells and those migrating in a large group (more than six cells). The results show significantly lower velocities for cells that migrated alone or in a group of up to four cells, compared to the velocity of the cells that migrated in a group of more than seven cells (p ＜ 0.05). Interestingly, cells that migrated alone or in small groups showed a trend of more efficient directional migration, which was on the edge of statistical significance (p = 0.056). This may be attributed to the abundance of mechanical and chemical stimuli that migrating cells generate and sense in a larger group.

Pedestrians' perceptions of walkability and safety in relation to the built environment in Cali, Colombia, 2009–10

ObjectiveTo assess pedestrians' perceptions of the walkability of the urban environment and pedestrian safety in Cali, Colombia.DesignStandardised intercept interviews were conducted of 400 pedestrians walking in 20 randomly selected urban...

Conformal window of gauge theories with four-fermion interactions and ideal walking technicolor

We investigate the effects of four-fermion interactions on the phase diagram of strongly interacting theories for any representation as function of the number of colors and flavors. We show that the conformal window, for any representation, shrinks with respect to the case in which the four-fermion interactions are neglected. The anomalous dimension of the mass increases beyond the unity value at the lower boundary of the new conformal window. We plot the new phase diagram which can be used, together with the information about the anomalous dimension, to propose ideal models of walking technicolor. We discover that when the extended technicolor sector, responsible for giving masses to the standard model fermions, is sufficiently strongly coupled the technicolor theory, in isolation, must have an infrared fixed point for the full model to be phenomenologically viable. Using the new phase diagram we show that the simplest one family and minimal walking technicolor models are the archetypes of models of dynamical electroweak symmetry breaking. Our predictions can be verified via first principle lattice simulations.

Investigating Adequacy of Existing and Proposed Active Green Spaces in Kahramanmaras City

In this study, the adequacy of the active green spaces in Kahramanmaras city were investigated in terms of square meter per person, parcel widths of the green areas and possibility for access by walking to the parcels by comparing proposals in urban development plans and existing applications. The results displayed that 386.6 ha urban area was planned as active green spaces in the urban development plan, and 7.1 m 2 per capita was anticipated according to population projection of the development plan. However, existing active urban green spaces covered 45.2 ha area, and the per capita ratio is 1.4 m 2 according to actual urban population. Almost all the proposed and existing parcels' widths of active urban green spaces are below the ideal dimensions. Of the study area, 68% is in the ideal walking distance to proposed active green spaces, while this ratio is 48% for existing parcels. These results showed that active green spaces do not make a sufficient contribution to urban life due to their small areas and disproportionate distributions across the urban.

Collective preferences, obligations, and rational choice

Can teams and other collectivities have preferences of their own, preferences that are not in some way reducible to the personal preferences of their members? In short, are collective preferences possible? In everyday life people speak easily of what we prefer, where what is at issue seems to be a collective preference. This is suggested by the acceptability of such remarks as ‘My ideal walk would be . . . along rougher and less well-marked paths than we prefer as a family’. One can imagine, indeed, that each member of a given family prefers something other than what the family prefers. What, then, do the collective preferences of everyday understanding amount to?