Improvement of composite wood properties made from wood waste chips

Producing composite wood such as particleboard is a great way to recycle wood waste produced from the industrial activities. Particleboard is widely used due to its low cost and controllable specification. Therefore, improving the properties of the particleboard is an important task in order to extend the potential of particleboard for greater performance and more diversity of applications. The aim of this study is t o improve the mechanical and physical properties of particleboard by using surface coating. The surface coatings chosen for the project are polyurethane wood varnish, gloss paint, lacquer paint, and wood veneer. Surface coatings were used on the particlebo ard to achieve improvements on modulus of elasticity, modulus of rupture, moisture absorption and thickness swelling. Test results obtained were analyzed to determine the effectiveness of each surface coating to improve the particleboards. Result obtained from the tests showed that wood veneer could effectively improve the mechanical properties of the particleboard while polyurethane wood varnish was excellent in enhancing the physical properties of particleboard. Nevertheless, each surface coating has diff erent characteristics and properties which can improve the particleboard in its unique way. The data on the improvements achieved by each surface coating could become useful reference for manufacturers and users to select suitable coatings for particleboar ds with specific application

Response-based methods to measure road surface irregularity: a state-of-the-art review

"jats:sec" "jats:title"Purpose"/jats:title" "jats:p"With the development of smart technologies, Internet of Things and inexpensive onboard sensors, many response-based methods to evaluate road surface conditions have emerged in the recent decade. Various techniques and systems have been developed to measure road profiles and detect road anomalies for multiple purposes such as expedient maintenance of pavements and adaptive control of vehicle dynamics to improve ride comfort and ride handling. A holistic review of studies into modern response-based techniques for road pavement applications is found to be lacking. Herein, the focus of this article is threefold: to provide an overview of the state-of-the-art response-based methods, to highlight key differences between methods and thereby to propose key focus areas for future research."/jats:p" "/jats:sec" "jats:sec" "jats:title"Methods"/jats:title" "jats:p"Available articles regarding response-based methods to measure road surface condition were collected mainly from “Scopus” database and partially from “Google Scholar”. The search period is limited to the recent 15 years. Among the 130 reviewed documents, 37% are for road profile reconstruction, 39% for pothole detection and the remaining 24% for roughness index estimation."/jats:p" "/jats:sec" "jats:sec" "jats:title"Results"/jats:title" "jats:p"The results show that machine-learning techniques/data-driven methods have been used intensively with promising results but the disadvantages on data dependence have limited its application in some instances as compared to analytical/data processing methods. Recent algorithms to reconstruct/estimate road profiles are based mainly on passive suspension and quarter-vehicle-model, utilise fewer key parameters, being independent on speed variation and less computation for real-time/online applications. On the other hand, algorithms for pothole detection and road roughness index estimation are increasingly focusing on GPS accuracy, data aggregation and crowdsourcing platform for large-scale application. However, a novel and comprehensive system that is comparable to existing International Roughness Index and conventional Pavement Management System is still lacking."/jats:p" "/jats:sec Document type: Articl

Life duration of bike sharing systems

Many factors have been advanced to predicate the sustainability of bike sharing system (BSS) and bike sharing usage, such as fleet size, number of docking stations, payment type and financial support, but there have been few studies that examine survival duration of BSS’ operation. Therefore, this study investigates the determinants of BSS’ duration, using bike sharing monitoring map and respective annual report data from 106 cities around the world. Three categories of independent variables, namely infrastructural factors, social factors and economic factors are included in the generalised linear model (GLM). The findings indicate that coverage area, system capacity and payment type will affect the sustainability of bike sharing operation. Moreover, financial support and purchasing power parity (PPP) per capital are the distinctive factors that seem to influence the likelihood of success of a BSS. Payment method affects the survivability of a BSS after the system is stable

COOR-PLT: A hierarchical control model for coordinating adaptive platoons of connected and autonomous vehicles at signal-free intersections based on deep reinforcement learning

Platooning and coordination are two implementation strategies that are frequently proposed for traffic control of connected and autonomous vehicles (CAVs) at signal-free intersections instead of using conventional traffic signals. However, few studies have attempted to integrate both strategies to better facilitate the CAV control at signal-free intersections. To this end, this study proposes a hierarchical control model, named COOR-PLT, to coordinate adaptive CAV platoons at a signal-free intersection based on deep reinforcement learning (DRL). COOR-PLT has a two-layer framework. The first layer uses a centralized control strategy to form adaptive platoons. The optimal size of each platoon is determined by considering multiple objectives (i.e., efficiency, fairness and energy saving). The second layer employs a decentralized control strategy to coordinate multiple platoons passing through the intersection. Each platoon is labeled with coordinated status or independent status, upon which its passing priority is determined. As an efficient DRL algorithm, Deep Q-network (DQN) is adopted to determine platoon sizes and passing priorities respectively in the two layers. The model is validated and examined on the simulator Simulation of Urban Mobility (SUMO). The simulation results demonstrate that the model is able to: (1) achieve satisfactory convergence performances; (2) adaptively determine platoon size in response to varying traffic conditions; and (3) completely avoid deadlocks at the intersection. By comparison with other control methods, the model manifests its superiority of adopting adaptive platooning and DRL-based coordination strategies. Also, the model outperforms several state-of-the-art methods on reducing travel time and fuel consumption in different traffic conditions.Comment: This paper has been submitted to Transportation Research Part C: Emerging Technologies and is currently under revie

Social Thinking and Risk Between Road Users: The Case of the Pedestrian in Two Cultural Contexts

Interactions between motorized and non-motorized road users constitute situations of risk for the latter. Improving the safety of pedestrians, who are the most vulnerable users, is a challenge for public health in society. The aims of this study concern the social representation of the pedestrian and the impact of the cultural variable in the construction of this knowledge; a field in which there exists little research. In this perspective, the discourse of two groups of students, one from a French city (N=85) and one from Singapore (N=124) are compared. The use of free associations and specific analyses makes it possible to isolate the words or expressions most frequently associated with pedestrians and those that discriminate the two populations. This study reveals that the pedestrian is associated with risk in both cultural environments. Nevertheless the French express more fear and apprehension and the Singaporeans’ representation is both more descriptive and personified. These results are discussed in relation to the cultural contexts

Which factors affect willingness-to-pay for automated vehicle services? Evidence from public road deployment in Stockholm, Sweden

"jats:title"Introduction"/jats:title" "jats:p"Travel demand and travel satisfaction of a transport service are affected by user perceptions of the service quality attributes, and such perceptions should be included in studying user willingness-to-pay (WTP) for automated vehicle (AV) services. This study applied structural equation modelling with service quality attribute perceptions as latent variables affecting WTP."/jats:p" "/jats:sec""jats:sec" "jats:title"Objectives"/jats:title" "jats:p"We investigated how WTP AV services are affected by socio-demographic characteristics, knowledge and experiences with AV, existing travel modes and particularly, perceptions of the associated service quality attributes. The AV services are: 1) "jats:italic"on-demand personalised AV (PAV) service"/jats:italic", 2) "jats:italic"demand responsive shared AV (SAV) service"/jats:italic", and 3) "jats:italic"first−/last-mile automated bus (AB) service"/jats:italic"."/jats:p" "/jats:sec""jats:sec" "jats:title"Methods"/jats:title" "jats:p"The data were collected from 584 potential users of a first−/last-mile AB service trial operated in Kista, Stockholm."/jats:p" "/jats:sec""jats:sec" "jats:title"Results"/jats:title" "jats:p"Results show people hold different expectations towards each type of AV service. These expectations act as the minimum requirements for people to pay for the AV services. Respondents are found to be willing to pay more for PAV service if it is safe, provides good ride comfort, and is competitively priced relative to the price travelling by metro and train over a same distance. Other than service quality attribute perceptions, income level, existing travel modes for daily trips, familiarity with automated driving technology and AB ride experience are important factors affecting WTP for the AV services."/jats:p" "/jats:sec""jats:sec" "jats:title"Conclusion"/jats:title" "jats:p"The developed model can be applied to understand expectations of potential users towards a new AV service, and to identify user groups who are willing to pay the service. New AV services can thus be designed sensibly according to users’ actual needs."/jats:p" "/jats:sec Document type: Articl

Dynamic interactions between commuter's mode choice behaviour and integrated traveller information

A commuter’s mode choice decision in response to provided traveller information is directly dependent on the temporal and spatial interactions between the available travel modes, the network performance and control schemes, and the supplied traveller information. A self-developed simulation model – Intelligent Network Simulation Model (INSIM) – was employed to simulate travel scenarios in a multimodal transportation network. A set of experiments was designed to analyse and evaluate the influence of traffic information on commuter’s mode choice, using a medium-sized area in Singapore. Simulation results showed that the private-to-public mode switch propensity bears a strong and direct relation with amount of disseminated integrated multimodal traveller information (IMTI) as well as timeliness of information update. Other influential factors include degrees of accessibility and compliance to IMTI, and congestion-related events such as accidents