Drift and Diffusion in Movement Adaptation to Space-Time Constraints

Motor Control ◽  
2013 ◽  
Vol 17 (4) ◽  
pp. 323-339
Author(s):  
Yeou-Teh Liu ◽  
Tsung-Yu Hsieh ◽  
Karl M. Newell
Keyword(s):  
Space Time ◽  
Time Constraints ◽  
And Diffusion

Drift and Diffusion in Practice Dynamics to Space-Time Constraints

2011 ◽  
Author(s):  
Yeou-Teh Liu ◽  
Tsung-Yu Hsieh ◽  
Ru-Han Lin ◽  
Karl M. Newell
Keyword(s):  
Space Time ◽  
Time Constraints ◽  
And Diffusion

Socioeconomic variations and disparity in space–time accessibility in suburban China: A case study of Guangzhou

Urban Studies ◽  
2020 ◽  
pp. 004209802091641
Author(s):  
Zifeng Chen ◽  
Anthony Gar-On Yeh
Keyword(s):  
Structural Equation ◽  
Time Perspective ◽  
Space Time ◽  
Time Constraints ◽  
Service Access ◽  
Service Accessibility ◽  
Home Based ◽  
Household Heads ◽  
And Gender

The concept of conventional place-based accessibility, despite being well researched, tends to ignore people’s space–time constraints arising from mandatory activities (e.g. work and household duties), which confine people’s potential movement and delimit the accessible opportunities. As people with different socioeconomic statuses may have different space–time constraints even while living in similar locations, using the place-based measures could lead to an underestimation of accessibility inequality. This study applies a space–time measure to unravel the disparities in service accessibility in suburban China. Since the late 1970s, suburbanisation in Chinese cities has fostered income inequality and has elevated other dimensions (e.g. institutional status and gender) of disparity within each income class. Within this context, we conduct a case study of suburban neighbourhoods in Guangzhou, based on the activity diary data derived from a home-based questionnaire survey. Findings indicate that the use of a space–time measure effectively captures the disparities in service accessibility among residents in suburban Guangzhou. On the basis of structural equation modelling, we further identify that certain socioeconomic groups (e.g. high-income residents, public sector workers, local hukou holders, male household heads and welfare housing residents) tend to experience fewer space–time constraints from rigid activities, such as work, commuting and household duties, and are thus more advantaged in accessing service facilities. These findings imply that urban planning should address the space–time perspective to promote equal service access for the highly heterogeneous social groups in suburban China and to incorporate time-sensitive policies (e.g. flexitime policies).

scholarly journals Research on Modeling Intrahousehold Interactions from the Perspective of Space-Time Constraints

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Liangpeng Gao ◽  
Yanjie Ji ◽  
Yang Liu ◽  
Baohong He
Keyword(s):  
Structural Equation ◽  
Activity Patterns ◽  
Family Members ◽  
Equation Model ◽  
Space Time ◽  
Time Constraints ◽  
Time Geography ◽  
Activity Restriction ◽  
Travel Decisions ◽  
Household Interaction

Interactions among family members can yield valuable information for interpreting individual travel decisions. Typically, each family member plays a set role and travel decisions are made by considering the combined needs of household members. This study investigates both multiactivity and multiperson interactions in urban nuclear families and proposes the novel concepts of “activity-restriction degree” and “activity-constraint niche” to quantify the degree of space-time constraints within time geography. A structural equation model is employed to analyze intrahousehold interactions based on individual activity-travel patterns during the workday. The results indicate that the links between family members reflect behavioral responses (with constraints) between individuals and other family members. Household interaction constraints not only influence individual travel decisions but also affect the realization of the household activity for everyone. These interactions lead to reasonable adjustments and mutual support and to the identification of efficient activity patterns that meet the demands of the entire household.

Reformulation of elliptic equations for heat transfer and diffusion in solids with space-time algebra

2021 ◽  
Author(s):  
Victor L. Mironov
Keyword(s):  
Heat Transfer ◽  
Elliptic Equations ◽  
Space Time ◽  
Second Order ◽  
Diffusion In Solids ◽  
Heat Flows ◽  
Vector Potentials ◽  
Commutative Space ◽  
The One ◽  
And Diffusion

In this paper, we demonstrate the application of non-commutative space-time algebra of sedeons to generalize the system of equations describing heat transfer and impurity diffusion in solids at finite velocity. It is shown that by analogy with electrodynamics, these transfer processes can be described using a compact second-order sedeonic equation for generalized scalar and vector potentials. On the one hand, this equation is reduced to the system of first-order differential equations for vortex-less mass and heat flows, and on the other hand, it can be transformed to the second-order elliptical equations for the profiles of temperature and impurity concentration. The comparison of peculiarities in transfer within the frames of parabolic and elliptic equations is discussed.

Arm motion planning based on space-time constraints

2004 ◽  
Author(s):  
Dengming Zhu ◽  
Zhaoqi Wang ◽  
He Huang ◽  
Min Shi
Keyword(s):  
Motion Planning ◽  
Space Time ◽  
Time Constraints ◽  
Arm Motion
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