Spatial Accessibility to Shopping Malls in Nanjing,China:Comparative Analysis with Multiple Transportation Modes

This study attempts to evaluate the rationality of the spatial layout of shopping malls and identify the urban area with poor shopping mall accessibility,as well as to provide a reference and assist decision-making for planning.Using the case of Nanjing,China,this study developed a method to evaluate the accessibility of shopping malls by three transport modes(car traffic,public transit,and bicycle).Specially,we divide the urban space into a regular hexagonal grid and harvest the total travel time from each of 7204 hexagon centroids to each of 129 shopping malls using the Baidu Internet map.The door-to-door travel time approach is used to evaluate all travel stages(walking,waiting,transfer,and transportation)based on travel time calculations.We further divide the shopping malls into two levels(super-regional and regional)based on the Dianping App’s information and develop the indicator of accessibility to shopping malls:the number of shopping malls within tolerance time thresholds and apply the closest facility and cumulative opportunities methods to measure accessibility scores.The results show that the accessibility estimations vary greatly with transport modes.The accessibility of shopping malls presents a concentric ring trend centered on the city center under the car traffic and bicycle modes.And public transit accessibility tends to axially extend due to the topology of bus routes and metro lines.In particular,we observe that the accessibility of shopping malls in Nanjing has an uneven spatial distribution pattern,with high accessibility values in the central urban areas and lots of underserved areas in urban fringe regions.Based on the accessibility measurements,we finally map the poor accessibility area and propose corresponding implications for urban planning.

我国产前诊断机构空间可及性与公平性

目的评价我国产前诊断机构的空间可及性与公平性,以期为优化此类机构的空间规划布局提供参考。方法用两步移动搜索法和空间基尼系数对我国产前诊断机构的空间可及性和公平性进行评价。结果我国中东部地区和各省(自治区、直辖市)中心城市产前诊断服务的空间可及性与公平性均优于西部地区和偏远地区。结论建议适当增加西部地区和偏远地区的产前诊断机构与卫生技术人员数量,以优化我国产前诊断机构的规划布局。

Modelling geographic accessibility to Primary Health Care Facilities:combining open data and geospatial analysis

Ensuring healthy lives and promoting well-being for all ages is the 3rd Sustainable Development Goal(SDG).Inequality in access to health care remains one of the primary challenges in achieving the goal.With the ever-increasing expansion of urban areas and population growth,there is a need to regularly examine the pattern of accessibility of basic amenities across regions,States and urban areas.This study examined geographic access to Primary Health Care Facilities(PHCF)in Nigeria using the combination of open data and geospatial analysis techniques.Thus,showcasing an approach can be replicated across different regions in Sub-Saharan Africa due to issues of information gap.Data on elevation,location of health care facilities,population and network data were utilised.The result shows that PHCF aggregate at certain locations,e.g.major urban agglomerations,and transit route leading to these places.High concentrations are found in the capital city.The average travel time to the nearest PHCF is about 14 min(Standard Deviation±13.30 min)while the maximum is about 2 hours.Pockets of low accessibility areas exist across the Akwa Ibom State in the Niger Delta region of Nigeria.There is an indication that most places have good geographic access.Across the 1787 settlements identified in our dataset,98.3%are with good access(<30 min),27 settlements are located in the poor access class(31–60 min),while two settlements are within the very poor access class(>60 min).Geographic access is not the main limiting factor to health care access in the region.Therefore,computation of access to health care should take into consideration other dimensions of accessibility,to create a robust measure which will support effective and efficient health care planning and delivery.

The study on county accessibility in China： Characteristics and effects on population agglomeration

This paper calculated spatial accessibility of all counties （city,urban district） in China with cost weighted distance method. Region divisions of county accessibility were conducted,and relation of traffic accessibility and population aggregation was discussed in this paper. The results indicated that county accessibility in China had mainly low values and a distribution structure of circle layer and reverse-to-natural gradient. There was an obvious correlation between county accessibility and population density in China. With these analyses,inner mechanisms of population migration in different traffic conditions and region types were revealed,and can provide useful proposals to regional planning,traffic planning and smart distribution of people in China.

分级诊疗制度下的医疗设施可达性研究——以深圳市为例

At present,the hierarchical medical system is widely promoted in China,and the reasonable allocation of medical resources and equal medical services have become important research topics in the field of urban planning.However,it is rare to see studies on the allocation of medical resources from the perspective of spatial accessibility based on the hierarchy of medical facilities and more refined spatial units of population.This research refines the population data from general to residential buildings in urban villages based on census data of buildings.By examining Shenzhen through a 2SFCA(2-step floating catchment area),this research evaluates the accessibility of community and regional medical facilities and the spatial matching at various referral rates by implementing GIS network analysis.The main findings are as follows.(1)The overall development of medical facilities in Shenzhen is currently lagged back among the first-tier cities in China,and there is a discrepancy between administrative districts in terms of the accessibility of medical facilities.(2)Under the current conditions in Shenzhen,the best spatial matching can be achieved only at the referral rate of 70%–80%,indicating weak primary medical resources in Shenzhen.In the future layout and construction of medical facilities,it is necessary to classify and grade the communities and increase the construction of medical facilities in communities with lagging medical standards.In addition,the treatment capacity of community medical services should be improved and the treatment of minor diseases in senior hospitals should be evacuated,so that the referral rate can be controlled at an appropriate level to achieve a balanced allocation and efficient use of medical resources.

Measuring COVID-19 vaccination coverage: an enhanced age-adjusted two-step foating catchment area model

Background:There are only limited studies on access to COVID-19 vaccines and identifying the most appropriate health centres for performing vaccination in metropolitan areas.This study aimed to measure potential spatial access to COVID-19 vaccination centres in Mashhad,the second-most populous city in Iran.Methods:The 2021 age structure of the urban census tracts was integrated into the enhanced two-step foating catchment area model to improve accuracy.The model was developed based on three diferent access scenarios:only public hospitals,only public healthcare centres and both(either hospitals or healthcare centres)as potential vaccination facilities.The weighted decision-matrix and analytic hierarchy process,based on four criteria(i.e.service area,accessibility index,capacity of vaccination centres and distance to main roads),were used to choose potential vaccination centres looking for the highest suitability for residents.Global Moran’s index(GMI)was used to measure the spatial autocorrelation of the accessibility index in diferent scenarios and the proposed model.Results:There were 26 public hospitals and 271 public healthcare centres in the study area.Although the exclusive use of public healthcare centres for vaccination can provide the highest accessibility in the eastern and north-eastern parts of the study area,our fndings indicate that including both public hospitals and public healthcare centres provide high accessibility to vaccination in central urban part.Therefore,a combination of public hospitals and public healthcare centres is recommended for efcient vaccination coverage.The value of GMI for the proposed model(accessibility to selected vaccination centres)was calculated as 0.53(Z=162.42,P<0.01).Both GMI and Z-score values decreased in the proposed model,suggesting an enhancement in accessibility to COVID-19 vaccination services.Conclusions:The periphery and poor areas of the city had the least access to COVID-19 vaccination centres.Measuring spatial access to COVID-19 vaccination centres can provide valuable insights for urban public health decisionmakers.Our model,coupled with geographical information systems,provides more efcient vaccination coverage by identifying the most suitable healthcare centres,which is of special importance when only few centres are available.

Downlink scheduling of multiuser MIMO systems with transmit beamforming

This article deals with downlink scheduling for multiuser multiple-input multiple-output （MIMO） systems, where the base station communicates with multiple users simultaneously through transmit beamforming. Most of the existing transmission schemes for multiuser MIMO systems focus on optimizing sum rate performance of the system. The individual quality of service （QoS） requirements （such as packet delay and minimum transmission rate for the data traffic） are rarely considered. In this article, a novel scheduling strategy is proposed, where we try to optimize the global system performance under individual QoS constraints. By performing scheduling into two steps, namely successive user selection and power allocation, the scheduler can achieve efficient resource utilization while maintaining the QoS requirements of all users. Extensive simulations and analysis are given to show the effectiveness of the proposed scheduler.

A Dedicated MAC Protocol Package for Real-Time Ocean Current Field Estimation Using Distributed Underwater Acoustic Sensor Networks

Distributed underwater acoustic sensor networks(UASNs)are envisioned in real-time ocean current velocity estimation.However,UASNs at present are still dominated by post-processing partially due to the complexity of on-line detection for travel times and lack of dedicated medium access control(MAC)protocols.In this study,we propose a dedicated MAC protocol package for real-time ocean current velocity estimation using distributed UASNs.First,we introduce the process and requirements of ocean current velocity estimation.Then,we present a series of spatial reuse time division multiple access(TDMA)protocols for each phase of real-time ocean current field estimation using distributed UASNs,followed by numerical analysis.We divide UASNs into two categories according to their computing ability:feature-complete and feature-incomplete systems.The feature-complete systems that have abundant computing ability carry out the presented MAC protocol package in three phases,whereas the feature-incomplete ones do not have enough computing ability and the presented MAC protocol package is reduced to two phases plus an additional downloading phase.Numerical analysis shows that feature-complete systems using mini-slot TDMA have the best real-time performance,in comparison with feature-incomplete systems and other feature-complete counterparts.Feature-incomplete systems are more energy-saving than feature-complete ones,owing to the absence of in-network data exchange.

Understanding coupled coordination relationships between social and ecological functions of urban green spaces

Urban Green Spaces(UGSs)can provide social and ecological benefits,and the coordination of these two functions will largely advance human-nature harmony in cities.As such,we proposed a comprehensive framework to evaluate UGSs multifunctionality,i.e.the coupling coordination relationship of ecological connectivity and spatial accessibility of UGSs.Wuhan City in Central China was taken as a case study,and multiple ecosystem service values of green space patches and the disordered use of UGSs multifunctionality were explored.The results demonstrated low-level coupling coordination of UGSs multifunctionality in Wuhan.More than 70%of UGSs were imbalanced,27.91%of which featured small sizes,low connectivity and accessibility.We suggest that planners should optimize UGSs arrangement to improve species reachability,especially for species with dispersal distance less than 4 km,and to create 15-minute community life circles for residents at the same time.Our findings are expected to support the promotion of UGSs multifunctionality and the balance of urban development and habitat conservation.