Ad-hoc wireless networking for supporting on-site communication

Ad-hoc networks are self-organized wireless networks. They have the potential to be widely used in emergency salvation, construction sites, and military fields. However, the research about the efficient usage of ad-hoc networking in engineering applications is still limited. In this research, a new approach for investigating problems related to deploying ad-hoc wireless networks for supporting on-site communication and collaboration is proposed. Several modes of communication which are common in on-site applications are considered including location information, text messaging, voice and video communications, and file transmission. A prototype system is implemented for testing these modes based on available ad-hoc network protocols and using mobile devices. In addition, in order to verify our proposed approach, several tests are designed and implemented to demonstrate the usefulness of the prototype system. The results from the tests showed that our prototype system is applicable for ad-hoc wireless networks. Furthermore, a new protocol based on clustering to improve data accessibility in ad-hoc networks is tested using a simulation tool to study its performance under different scenarios. The simulation results showed the impact of the area size, wireless range, number of nodes, and node speed on data accessibility

Exploring the Spatially Heterogeneous Effects of the Built Environment on Bike-Sharing Usage During the COVID-19 Pandemic

Bike-sharing holds promise for available and healthy mobility services during COVID-19 where bike sharing users can make trips with lower health concerns due to social distancing compared to the restricted transportation modes such as public transit and ridesharing services. Leveraging the trip data of the Divvy bike-sharing system in Chicago, this study explores spatially heterogeneous effects of built environment on bike-sharing usage under the pandemic. Results show that the average weekly ridership declined by 52.04%. To account for the spatially heterogeneous relationship between the built environment and the ridership, the geographically weighted regression (GWR) model and the semiparametric GWR (S-GWR) model are constructed. We find that the S-GWR model outperforms the GWR and the multiple linear regression models. The results of the S-GWR model indicate that education employment density, distance to subway, COVID-19 cases, and ridership before COVID-19 are global variables. The effects between ridership and the built environment factors (i.e., household density, office employment density, and the ridership) vary across space. The results of this study could provide a useful reference to transportation planners and bike-sharing operators to determine the high bike-sharing demand area under the pandemic, thus adjusting station locations, capacity, and rebalancing schemes accordingly

Revealing the real-world CO2 emission reduction of ridesplitting and its determinants based on machine learning

Ridesplitting, which is a form of pooled ridesourcing service, has great potential to alleviate the negative impacts of ridesourcing on the environment. However, most existing studies only explored its theoretical environmental benefits based on optimization models and simulations. To put into practice, this study aims to reveal the real-world emission reduction of ridesplitting and its determinants based on the observed data of ridesourcing in Chengdu, China. Integrating the trip data with the COPERT model, this study calculates the CO2 emissions of shared rides (ridesplitting) and their substituted single rides (regular ridesourcing) to estimate the CO2 emission reduction of each ridesplitting trip. The results show that not all ridesplitting trips reduce emissions from ridesourcing in the real world. The CO2 emission reduction rate of ridesplitting varies from trip to trip, averaging at 43.15g/km. Then, the interpretable machine learning models, gradient boosting machines, are applied to explore the relationship between the CO2 emission reduction rate of ridesplitting and its determinants. Based on the SHapley Additive exPlanations method, the overlap rate and detour rate of shared rides are identified to be the most important factors that determine the CO2 emission reduction rate of ridesplitting. Increasing the overlap rate, the number of shared rides, average speed, and ride distance ratio and decreasing the detour rate, actual trip distance, ride distance gap can increase the CO2 emission reduction rate of ridesplitting. In addition, nonlinear effects and interactions of several key factors are examined through the partial dependence plots. This study provides a scientific method for the government and ridesourcing companies to better assess and optimize the environmental benefits of ridesplitting.Comment: 33 pages, 12 figure

From Functional Space to Experience Space:Applying space syntax analysis to a museum in China

Space syntax starts from the ontology of space to quantify the space and uses mathematical logic to reveal and describe the logic of the space structure.However, the application of space syntax analysis to museums in China has rarely been explored. In light of this, this study employs space syntax to analyse the Gulangyu Organ Museum (Xiamen, China) and uses the topological depth, visual graph analysis, and agent simulation to describe the structure of the museum space. Accordingly, several suggestions are proposed,including rearranging the layout of the museum’s functions and transforming the museum from functional space to experience space. This study can serve as a valuable reference for the application of space syntax in the design and optimization of space design and functional layout. We believe that the findings of this study can also be applied to other cultural institutions (e.g.,galleries) with similar characteristics

Locale-varying relationships between tourism development and retail property prices in a shopping destination

Existing literature has inadequately examined the nexus between tourism and property prices. Additionally, it mainly focuses on hotels and housing, thereby overlooking other property categories (e.g., retail properties). The relationship between tourism development and retail property prices in shopping destinations (e.g., Hong Kong and Singapore) may hinge on the locale. More specifically, the relationship may be different in the tourist precinct or popular tourism shopping area (PTSA) and the unpopular tourism shopping area (UTSA). This study examines locale-varying relationships between tourism development (measured by tourist volume and tourism expenditure) and retail property prices from 2002Q1 to 2014Q4 in Hong Kong using standard and error-correction-model-based (ECM-based) Granger causality tests. Results of standard Granger causality tests indicate that tourism development Granger causes the increase in retail property prices in the PTSA but not in the UTSA. Moreover, results of ECM-based Granger causality tests further verify the robustness and plausibility of the tourism-led growth (in retail property prices) hypothesis in the PTSA. In other words, we find that tourism development measures can be used to better predict changes in retail property prices in the PTSA than simply referring to the price history

Willing to pay more for high-quality schools?: A hedonic pricing and propensity score matching approach

Principally, the enrolment of elementary school in China is solely based on residential location. Due to the scarcity of prestigious schools, the household registration (or hukou in Chinese) and the territorial-based school admission policy, a feasible approach for parents to provide the children with good education is to purchase the house in the attendance zone of a high-quality school (or xuequfang in Chinese). The supply-demand imbalance gives rise to the xuequfang phenomenon (much higher prices of xuequfang relative to non xuequfang). Based on 1250 housing samples in 286 multi- or high-storey residential districts, this paper firstly develops two basic and four Box-Cox transformed hedonic price models to estimate the effect of high-quality schools on residential property prices. The consistency of six models greatly enhances the credibility of this study. Moreover, complementary, the propensity score matching technique is used to estimate the treatment effect. The two methods consistently suggest that residential property values are affected by top-tier schools. They reveal that xuequfang exhibit values that are between 9.3% and 12.1% higher than non-xuequfang, ceteris paribus. The negative influences of the xuequfang phenomenon and several countermeasures (gradually reforming household registration system, optimizing resource distribution to balance the quality of education, highlighting family education and children’s all-round development) are discussed

Review of Associations between Built Environment Characteristics and Severe Acute Respiratory Syndrome Coronavirus 2 Infection Risk.

The coronavirus disease 2019 pandemic has stimulated intensive research interest in its transmission pathways and infection factors, e.g., socioeconomic and demographic characteristics, climatology, baseline health conditions or pre-existing diseases, and government policies. Meanwhile, some empirical studies suggested that built environment attributes may be associated with the transmission mechanism and infection risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, no review has been conducted to explore the effect of built environment characteristics on the infection risk. This research gap prevents government officials and urban planners from creating effective urban design guidelines to contain SARS-CoV-2 infections and face future pandemic challenges. This review summarizes evidence from 25 empirical studies and provides an overview of the effect of built environment on SARS-CoV-2 infection risk. Virus infection risk was positively associated with the density of commercial facilities, roads, and schools and with public transit accessibility, whereas it was negatively associated with the availability of green spaces. This review recommends several directions for future studies, namely using longitudinal research design and individual-level data, considering multilevel factors and extending to diversified geographic areas

The Effectiveness of Pay-It-Forward in Addressing HPV Vaccine Delay and Increasing Uptake Among 15–18-Year-Old Adolescent Girls Compared to User-Paid Vaccination: A Study Protocol for a Two-Arm Randomized Controlled Trial in China

Background Human papillomavirus (HPV) vaccination could prevent cervical and other HPV-associated cancers attributable to vaccine-associated HPV types. However, HPV vaccination coverage among women aged 9–18 years old is low in China. Common barriers include poor financial affordability, minimal public engagement, and low confidence in domestically produced HPV vaccines. Pay-it-forward offers an individual a free or subsidized service then an opportunity to voluntarily donate and/or create a postcard message to support future people. This study aims to assess the effectiveness of pay-it-forward as compared to standard-of-care self-paid vaccination to improve HPV vaccine uptake among adolescent girls aged 15–18 years, who are left out in the current pilot free HPV vaccination task force in some parts of China. Methods This is a two-arm randomized controlled trial in Chengdu, China. Eligible adolescent girls (via caregivers) will be randomly selected and recruited through four community health centers (one in the most developed urban areas, one in higher middle-income and one in lower middle-income suburban areas, and one in the least developed rural areas) using the resident registration list. A total of 320 participants will be randomized into two study arms (user-paid versus pay-it-forward vaccination) in a 1:1 ratio. The intervention assignment will be blinded to recruiters and participants using envelop concealment until the research assistants open the envelop to determine which treatment to deliver to each individual. The primary outcome of the study will be HPV vaccine uptake by administrative data. Secondary outcomes include costs, vaccine hesitancy, and the completion rates of the 3-dose HPV vaccination series. Discussion This study will investigate an innovative pay-it-forward strategy’s effectiveness and economic costs to improve HPV vaccination among 15–18-year-old adolescent girls. Study findings will have implications for increasing HPV vaccine uptake in places where HPV vaccines are provided for a fee

The effectiveness of pay-it-forward in addressing HPV vaccine delay and increasing uptake among 15-18-year-old adolescent girls compared to user-paid vaccination: a study protocol for a two-arm randomized controlled trial in China

BACKGROUND: Human papillomavirus (HPV) vaccination could prevent cervical and other HPV-associated cancers attributable to vaccine-associated HPV types. However, HPV vaccination coverage among women aged 9-18 years old is low in China. Common barriers include poor financial affordability, minimal public engagement, and low confidence in domestically produced HPV vaccines. Pay-it-forward offers an individual a free or subsidized service then an opportunity to voluntarily donate and/or create a postcard message to support future people. This study aims to assess the effectiveness of pay-it-forward as compared to standard-of-care self-paid vaccination to improve HPV vaccine uptake among adolescent girls aged 15-18 years, who are left out in the current pilot free HPV vaccination task force in some parts of China. METHODS: This is a two-arm randomized controlled trial in Chengdu, China. Eligible adolescent girls (via caregivers) will be randomly selected and recruited through four community health centers (one in the most developed urban areas, one in higher middle-income and one in lower middle-income suburban areas, and one in the least developed rural areas) using the resident registration list. A total of 320 participants will be randomized into two study arms (user-paid versus pay-it-forward vaccination) in a 1:1 ratio. The intervention assignment will be blinded to recruiters and participants using envelop concealment until the research assistants open the envelop to determine which treatment to deliver to each individual. The primary outcome of the study will be HPV vaccine uptake by administrative data. Secondary outcomes include costs, vaccine hesitancy, and the completion rates of the 3-dose HPV vaccination series. DISCUSSION: This study will investigate an innovative pay-it-forward strategy's effectiveness and economic costs to improve HPV vaccination among 15-18-year-old adolescent girls. Study findings will have implications for increasing HPV vaccine uptake in places where HPV vaccines are provided for a fee. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR), ChiCTR2200055542. Registered on 11 January 2022