Sustainable living neighbourhoods:Measuring public space quality and walking environment in Lisbon

Obesity and global warming are two major challengesthat affect communities’health and quality of life.Providing good walking environments,with appropriate pedestrian infrastructure,green areas and access to commercial retail and transport hubs favour liveable,healthy,and sustainable cities.The Lisbon City Hall has implemented an intervention program in the public space as a strategy to improve environmental quality and mitigate the effects of climate change.The program“A square in each neighbourhood”intends not only to reinforce the economic base of Lisbon,namely tourism,restaurants,commerce,and creative activities but also to promote physical activity and improve the quality of living of all citizens.For studying the impact of the public space quality on the walking environment,Campolide,a typical Lisbon neighbourhood,Portugal,which includes one of the requalified squares,was selected.A two-step methodology based on spatial modelling is proposed.In the first step,the public space quality was evaluated based on a set of 13 urban quality attributes.Attributes,intended for the street level,were collected from open data platforms and complemented with a field survey.Then,through spatial analysis,these attributes were used to build the Pedestrian Environment Quality Indicator and the Priority Intervention Indicator.Using these indicators,walking-friendly streets were mapped and the most critical sites that require priority intervention were identified to prepare for the requalification planning process.The street with the highest quality in the study area according to the dimensions evaluated-connectivity,convenience,comfort,cleanliness,and conviviality-has a great offer of trees,bus stops,commercial establishments,commercial diversity,crossings,paper bins/eco points and esplanades.On the opposite side of the rank,the street with the lowest quality has no trees or green areas,transport stops,benches and tables,or commercial activity.The urban quality indicators constitute a helpful tool for city planners and policymakers when planning sustainable living neighbourhoods.

Estimating walking access area for rail transit station based on discrete choice model

The discrete choice model is used to estimate the walking access area of rail transit stations while considering the influence of existing competition from other traffic modes. The acceptable walking access area is determined according to the willingness of passengers to walk who prefer rail transit compared with bus and automobile. Empirical studies were conducted using the survey data of six stations from the rail transit in Nanjing, China. The results indicate that the rail transit is more preferable compared with bus and private automobile in this case when excluding the influence of individual and environmental factors. It is found that passengers tend to underestimate their willingness to walk. The acceptable walking access area of every rail transit station is different from each other. Suburban stations generally have a larger walking access area than downtown stations. In addition, a better walking environment and a scarcer surrounding traffic environment can also lead to a larger walking area. The model was confirmed to be effective and reasonable according to the model validation. This study can be of benefit to the passenger transportation demand estimation in the location planning and evaluation of rail transit stations.

ON MARKOV CHAINS IN SPACE-TIME RANDOM ENVIRONMENTS

In Section 1, the authors establish the models of two kinds of Markov chains in space-time random environments (MCSTRE and MCSTRE(+)) with abstract state space. In Section 2, the authors construct a MCSTRE and a MCSTRE(+) by an initial distribution Φ and a random Markov kernel (RMK) p(γ). In Section 3, the authors es-tablish several equivalence theorems on MCSTRE and MCSTRE(+). Finally, the authors give two very important examples of MCMSTRE, the random walk in spce-time random environment and the Markov br...

Some Probability Properties of Random Walk in Time-Random Environment

A general formulation of the stochastic model for random walk in time-random environment and an equivalent definition is established in this paper. Moreover, some basic probability relations similar to the classical case which are very useful in the corresponding research of fractal properties are given. At the end, a typical example is provided to show the recurrence and transience. Key words random environment - random walk in timerandom environment - skew product Markov chain CLC number O 211.6 Foudation item: Supported by the National Natural Science Foundation of China (10371092) and Foundation of Wuhan University.Biography: Zhang Xiao-min (1977-), male, Ph. D candidate, research direction: stochastic processes and random fractal.

RENEWAL THEOREM FOR(L,1)-RANDOM WALK IN RANDOM ENVIRONMENT

We consider a random walk on Z in random environment with possible jumps {-L,…, -1, 1}, in the case that the environment {ωi ： i ∈ Z} are i.i.d.. We establish the renewal theorem for the Markov chain of ＂the environment viewed from the particle＂ in both annealed probability and quenched probability, which generalize partially the results of Kesten （1977） and Lalley （1986） for the nearest random walk in random environment on Z, respectively. Our method is based on （L, 1）-RWRE formulated in Hong and Wang the intrinsic branching structure within the （2013）.

THE DIMENSIONS OF THE RANGE OF RANDOM WALKS IN TIME-RANDOM ENVIRONMENTS

Suppose {Xn} is a random walk in time-random environment with state space Z^d, ｜Xn｜ approaches infinity, then under some reasonable conditions of stability, the upper bound of the discrete Packing dimension of the range of {Xn} is any stability index α. Moreover, if the environment is stationary, a similar result for the lower bound of the discrete Hausdorff dimension is derived. Thus, the range is a fractal set for almost every environment.

A random walk with a branching system in random environments

We consider a branching random walk in random environments, where the particles are reproduced as a branching process with a random environment (in time), and move independently as a random walk on ? with a random environment (in locations). We obtain the asymptotic properties on the position of the rightmost particle at time n, revealing a phase transition phenomenon of the system.

Large Deviations for Hitting Times of a Random Walk in Random Environment on a Strip

We consider a random walk in random environment on a strip, which is transient to the right. The random environment is stationary and ergodic. By the constructed enlarged random environment which was first introduced by Goldsheid （2008）, we obtain the large deviations conditioned on the environment （in the quenched case） for the hitting times of the random walk.

Age-dependent branching processes in random environments

We consider an age-dependent branching process in random environments. The environments are represented by a stationary and ergodic sequence ξ = (ξ 0, ξ 1,…) of random variables. Given an environment ξ, the process is a non-homogenous Galton-Watson process, whose particles in n-th generation have a life length distribution G(ξ n ) on ?+, and reproduce independently new particles according to a probability law p(ξ n ) on ?. Let Z(t) be the number of particles alive at time t. We first find a characterization of the conditional probability generating function of Z(t) (given the environment ξ) via a functional equation, and obtain a criterion for almost certain extinction of the process by comparing it with an embedded Galton-Watson process. We then get expressions of the conditional mean E ξ Z(t) and the global mean EZ(t), and show their exponential growth rates by studying a renewal equation in random environments.

Asymptotic Behavior for Random Walks in Time-Random Environment on Z^1

In this paper, we give a general model of random walks in time-random environment in any countable space. Moreover, when the environment is independently identically distributed, a recurrence-transience criterion and the law of large numbers are derived in the nearest-neighbor case on Z^1. At last, under regularity conditions, we prove that the RWIRE {Xn} on Z^1 satisfies a central limit theorem, which is similar to the corresponding results in the case of classical random walks.