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Open Access
Article
Publication date: 18 April 2024

Changhai Tian and Shoushuai Zhang

The design goal for the tracking interval of high-speed railway trains in China is 3 min, but it is difficult to achieve, and it is widely believed that it is mainly limited by…

Abstract

Purpose

The design goal for the tracking interval of high-speed railway trains in China is 3 min, but it is difficult to achieve, and it is widely believed that it is mainly limited by the tracking interval of train arrivals. If the train arrival tracking interval can be compressed, it will be beneficial for China's high-speed railway to achieve a 3-min train tracking interval. The goal of this article is to study how to compress the train arrival tracking interval.

Design/methodology/approach

By simulating the process of dense train groups arriving at the station and stopping, the headway between train arrivals at the station was calculated, and the pattern of train arrival headway was obtained, changing the traditional understanding that the train arrival headway is considered the main factor limiting the headway of trains.

Findings

When the running speed of trains is high, the headway between trains is short, the length of the station approach throat area is considerable and frequent train arrivals at the station, the arrival headway for the first group or several groups of trains will exceed the headway, but the subsequent sets of trains will have a headway equal to the arrival headway. This convergence characteristic is obtained by appropriately increasing the running time.

Originality/value

According to this pattern, there is no need to overly emphasize the impact of train arrival headway on the headway. This plays an important role in compressing train headway and improving high-speed railway capacity.

Details

Railway Sciences, vol. 3 no. 3
Type: Research Article
ISSN: 2755-0907

Keywords

Open Access
Article
Publication date: 3 May 2022

Bo Jiang, Changhai Tian, Jiehang Deng and Zitong Zhu

This study aims to analyze the development direction of train speed, density and weight in China.

2276

Abstract

Purpose

This study aims to analyze the development direction of train speed, density and weight in China.

Design/methodology/approach

The development of China's railway in the past 40 years can be divided into 3 stages. At the stage of potential tapping and capacity expansion, it is important to improve the train weight and density by upgrading the existing lines, and improving transportation capacity rapidly. At the stage of railway speed increase, the first priority is to increase train speed, reduce the travel time of passenger train, and synchronously take into account the increase of train density and weight. At the stage of developing high-speed railway, train speed, density and weight are co-developing on demand.

Findings

The train speed of high-speed railway will be 400 km h−1, the interval time of train tracking will be 3 min, and the traffic density will be more than 190 pairs per day. The running speed of high-speed freight EMU will reach 200 km h−1 and above. The maximum speed of passenger train on mixed passenger and freight railway can reach 200 km h−1. The minimum interval time of train tracking can be compressed to 5 min. The freight train weight of 850 m series arrival-departure track railway can be increased to 4,500–5,000 t and that of 1,050 m series to 5,500–6,400 t. EMU trains should gradually replace ordinary passenger trains to improve the quality of railway passenger service. Small formation trains will operate more in intercity railway, suburban railway and short-distance passenger transportation.

Originality/value

The research can provide new connotations and requirements of railway train speed, density and weight in the new railway stage.

Details

Railway Sciences, vol. 1 no. 1
Type: Research Article
ISSN: 2755-0907

Keywords

Open Access
Article
Publication date: 28 July 2023

Guido Veronese, Anas Ismail, Fayez Mahamid, Basel El-Khodary, Dana Bdier and Marwan Diab

This study aims to explore the effect of mental health in terms of depression, anxiety, stress, fear of COVID-19 and quality of life (QoL) on the reluctance to be vaccinated in a…

Abstract

Purpose

This study aims to explore the effect of mental health in terms of depression, anxiety, stress, fear of COVID-19 and quality of life (QoL) on the reluctance to be vaccinated in a population of Palestinian adults living in occupied Palestinian territories and Israel.

Design/methodology/approach

The authors recruited 1,122 Palestinian adults who consented to participate in the study; 722 were females, and the mean age of the sample was 40.83 (SD 8.8). Depression, anxiety, and stress scale (DASS), World Health Organization QoL-BREF, FCov-19 and reluctance to the vaccine scale were administered; hierarchical regression analysis was applied to test vaccine reluctance as a dependent variable, and mental health, fear of COVID-19 and QoL as independent variables. This study hypothesized influence of such variables on the vaccine choice with differences due to the participants’ geographical locations.

Findings

Findings showed an effect of mental health, particularly depression, QoL and fear of COVID on vaccine reluctance, with depression and fear of COVID in the West Bank and Gaza, while in Israel, QoL played a role in vaccination choices.

Research limitations/implications

The future needs to be comprehended more thoroughly to discover mutations and fluctuations over time in vaccine hesitancy and the increasing role of psychological distress, diminished QoL and fear of Covid-19. Online recruitment might not have allowed the study to include the most disadvantaged strips of the Palestinian population.

Practical implications

Human rights perspectives must be considered in public health and public mental health policies to ensure the QoL and well-being for the Palestinian population during and following the pandemic.

Social implications

The crumbling of the Palestinian health-care system exacerbated the sense of dread among the population and made them less likely to vaccinate. The pandemic-like spread of Covid-19 prompts a plea for the global community to actively advocate for the urgent re-establishment of equity, autonomy and durability of the medical infrastructure in the occupied territories and equal entitlements for the Palestinians in Israel.

Originality/value

The results demonstrated the importance for public mental health to consider the multiple levels implied in the vaccine refusal in Palestine and Israel among the Palestinian population.

Details

Journal of Public Mental Health, vol. 22 no. 4
Type: Research Article
ISSN: 1746-5729

Keywords

Open Access
Article
Publication date: 9 December 2021

S. Pragati, R. Shanthi Priya, Prashanthini Rajagopal and C. Pradeepa

The coronavirus disease 2019 (COVID-19) pandemic has been reported to have a major impact on the mental health of an individual. Healing the mental stress, anxiety, depression and…

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Abstract

Purpose

The coronavirus disease 2019 (COVID-19) pandemic has been reported to have a major impact on the mental health of an individual. Healing the mental stress, anxiety, depression and insomnia of an individual's immediate surroundings play a major role. Therefore, this study reviews how the built environment impacts the healing of an individual's state of mind.

Design/methodology/approach

Various works of literature on healing environments were analysed to create frameworks that can facilitate psychological healing through architectural elements. Articles were selected from various journals like SAGE, PubMed, Journal of Applied and Computational Mechanics (JACM), Routledge Taylor and Francis, Journal of Contemporary Urban Affairs (JCUA), ScienceDirect, and Emerald databases, news articles, official web pages, and magazines that have been referred.

Findings

Indicators (spatial, sensory comfort, safety, security, privacy and social comfort) are linked to sub-indicators (access, distractions and views) and design characteristics (indoor climate, interior view, outside view, privacy, communication, noise, daylighting, temperature) which help in better connection of the built environment with individual's mental health. From the above indicators, sub-indicators and design characteristics, the authors have come to a conclusion that a view to the outside with better social interaction has an in-depth effect on an individual's mental health.

Research limitations/implications

This study predominantly talks about healing in hospitals but quarantining of COVID-19 patients happens in residences too. So, it is important to find the healing characteristics in residences and in which typology the recovery process is high.

Originality/value

This paper has been written completely by the author and the co-authors and has not been copied from any other sources.

Details

Frontiers in Engineering and Built Environment, vol. 2 no. 1
Type: Research Article
ISSN: 2634-2499

Keywords

Open Access
Article
Publication date: 12 July 2022

Nianfei Gan, Miaomiao Zhang, Bing Zhou, Tian Chai, Xiaojian Wu and Yougang Bian

The purpose of this paper is to develop a real-time trajectory planner with optimal maneuver for autonomous vehicles to deal with dynamic obstacles during parallel parking.

Abstract

Purpose

The purpose of this paper is to develop a real-time trajectory planner with optimal maneuver for autonomous vehicles to deal with dynamic obstacles during parallel parking.

Design/methodology/approach

To deal with dynamic obstacles for autonomous vehicles during parking, a long- and short-term mixed trajectory planning algorithm is proposed in this paper. In long term, considering obstacle behavior, A-star algorithm was improved by RS curve and potential function via spatio-temporal map to obtain a safe and efficient initial trajectory. In short term, this paper proposes a nonlinear model predictive control trajectory optimizer to smooth and adjust the trajectory online based on the vehicle kinematic model. Moreover, the proposed method is simulated and verified in four common dynamic parking scenarios by ACADO Toolkit and QPOASE solver.

Findings

Compared with the spline optimization method, the results show that the proposed method can generate efficient obstacle avoidance strategies, safe parking trajectories and control parameters such as the front wheel angle and velocity in high-efficient central processing units.

Originality/value

It is aimed at improving the robustness of automatic parking system and providing a reference for decision-making in a dynamic environment.

Details

Journal of Intelligent and Connected Vehicles, vol. 5 no. 3
Type: Research Article
ISSN: 2399-9802

Keywords

Open Access
Article
Publication date: 19 March 2024

Chun Tian, Gengwei Zhai, Mengling Wu, Jiajun Zhou and Yaojie Li

In response to the problem of insufficient traction/braking adhesion force caused by the existence of the third-body medium on the rail surface, this study aims to analyze the…

Abstract

Purpose

In response to the problem of insufficient traction/braking adhesion force caused by the existence of the third-body medium on the rail surface, this study aims to analyze the utilization of wheel-rail adhesion coefficient under different medium conditions and propose relevant measures for reasonable and optimized utilization of adhesion to ensure the traction/braking performance and operation safety of trains.

Design/methodology/approach

Based on the PLS-160 wheel-rail adhesion simulation test rig, the study investigates the variation patterns of maximum utilized adhesion characteristics on the rail surface under different conditions of small creepage and large slip. Through statistical analysis of multiple sets of experimental data, the statistical distribution patterns of maximum utilized adhesion on the rail surface are obtained, and a method for analyzing wheel-rail adhesion redundancy based on normal distribution is proposed. The study analyzes the utilization of traction/braking adhesion, as well as adhesion redundancy, for different medium under small creepage and large slip conditions. Based on these findings, relevant measures for the reasonable and optimized utilization of adhesion are derived.

Findings

When the third-body medium exists on the rail surface, the train should adopt the low-level service braking to avoid the braking skidding by extending the braking distance. Compared with the current adhesion control strategy of small creepage, adopting appropriate strategies to control the train’s adhesion coefficient near the second peak point of the adhesion coefficient-slip ratio curve in large slip can effectively improve the traction/braking adhesion redundancy and the upper limit of adhesion utilization, thereby ensuring the traction/braking performance and operation safety of the train.

Originality/value

Most existing studies focus on the wheel-rail adhesion coefficient values and variation patterns under different medium conditions, without considering whether the rail surface with different medium can provide sufficient traction/braking utilized adhesion coefficient for the train. Therefore, there is a risk of traction overspeeding/braking skidding. This study analyzes whether the rail surface with different medium can provide sufficient traction/braking utilized adhesion coefficient for the train and whether there is redundancy. Based on these findings, relevant measures for the reasonable and optimized utilization of adhesion are derived to further ensure operation safety of the train.

Open Access
Article
Publication date: 30 September 2022

Ye Shen, Bo Li, Wei Tian, Jinjun Duan and Mingxuan Liu

With the increasing requirements for intelligence in the field of aviation manufacturing, manual assembly can hardly adapt to the trend of future production. The purpose of this…

Abstract

Purpose

With the increasing requirements for intelligence in the field of aviation manufacturing, manual assembly can hardly adapt to the trend of future production. The purpose of this study is to realize the semi-automatic assembly of the movable airfoil by proposing a human-robot collaborative assembly strategy based on adaptive admittance control.

Design/methodology/approach

A logical judgment system for operating intentions is introduced in terms of different situations of the movements; hence, a human cognition-based adaptive admittance control method is developed to curb the damage of inertia; then virtual limit walls are raised on the periphery of the control model to ensure safety; finally, simulated and experimental comparisons with other admittance control methods are conducted to validate the proposed method.

Findings

The proposed method can save at least 28.8% of the time in the stopping phase which effectively compensates for inertia during the assembly process and has high robustness concerning data disturbances.

Originality/value

Due to the human-robot collaboration to achieve compliant assembly of movable airfoils can preserve human subjectivity while overcoming the physical limits of humans, which is of great significance to the investigation of intelligent aircraft assembly, the proposed method that reflects the user's naturalness and intuitiveness can not only enhance the stability and the flexibility of the manipulation, but also contribute to applications of industrial robots in the field of human-robot collaboration.

Details

Journal of Intelligent Manufacturing and Special Equipment, vol. 3 no. 2
Type: Research Article
ISSN: 2633-6596

Keywords

Open Access
Article
Publication date: 23 May 2022

Yangsheng Ye, Degou Cai, Lin Geng, Hongye Yan, Junkai Yao and Feng Chen

This study aims to propose a semiempirical and semitheoretical cyclic compaction constitutive model of coarse-grained soil filler for the high-speed railway (HSR) subgrade under…

Abstract

Purpose

This study aims to propose a semiempirical and semitheoretical cyclic compaction constitutive model of coarse-grained soil filler for the high-speed railway (HSR) subgrade under cyclic load.

Design/methodology/approach

According to the basic framework of critical state soil mechanics and in view of the characteristics of the coarse-grained soil filler for the HSR subgrade to bear the train vibration load repeatedly for a long time, the hyperbolic empirical relationship between particle breakage and plastic work was derived. Considering the influence of cyclic vibration time and stress ratio, the particle breakage correction function of coarse-grained soil filler for the HSR subgrade under cyclic load was proposed. According to the classical theory of plastic mechanics, the shearing dilatation equation of the coarse-grained soil filler for the HSR subgrade considering particle breakage was modified and obtained. A semiempirical and semitheoretical cyclic compaction constitutive model of coarse-grained soil filler for the HSR subgrade under cyclic load was further established. The backward Euler method was used to discretize the constitutive equation, build a numerical algorithm of “elastic prediction and plastic modification” and make a secondary development of the program to solve the cyclic compaction model.

Findings

Through the comparison with the result of laboratory triaxial test under the cyclic loading of coarse-grained soil filler for the HSR subgrade, the accuracy and applicability of the cyclic compaction model were verified. Results show that the model can accurately predict the cumulative deformation characteristics of coarse-grained soil filler for the HSR subgrade under the train vibration loading repeatedly for a long time. It considers the effects of particle breakage and stress ratio, which can be used to calculate and analyze the stress and deformation evolution law of the subgrade structure for HSR.

Originality/value

The research can provide a simple and practical method for calculating deformation of railway under cyclic loading.

Open Access
Article
Publication date: 14 August 2021

Susan Danissa Calderón Urbina, Antonios Stamatogiannakis and Dilney Goncalves

This study aims to introduce the duration of uniqueness, an important dimension of unique products. It studies how choices between products with long versus short duration of…

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Abstract

Purpose

This study aims to introduce the duration of uniqueness, an important dimension of unique products. It studies how choices between products with long versus short duration of uniqueness are influenced by the interaction between pressure and consumers’ need for uniqueness (NFU).

Design/methodology/approach

This research uses a multi-method study approach. A pilot field-study tested the novelty and importance of the research by asking retail professionals to predict the choice of a hypothetical consumer. A retrospective study assessed the importance of duration of uniqueness in unique product choices, by asking consumers about a real and recent unique product purchase. Four additional experimental studies directly tested hypotheses by manipulating pressure and by measuring or manipulating uniqueness motivations.

Findings

The pilot field-study showed the novelty and relevance of this research for professionals. Study 1 revealed that, retrospectively, uniqueness duration was considered important for the choice of unique products, by high-NFU consumers under pressure. Studies 2 and 3 demonstrated that pressure increases the tendency of high-NFU, but not low-NFU, consumers to choose products with long over short uniqueness duration. Study 4 provided initial evidence for the process behind the effect. Study 5 showed that considerations of uniqueness duration when choosing mediated the effects.

Research limitations/implications

The results of the pilot field-study and retrospective study might be affected by recall bias or lay theories. The findings need to be replicated with other sources of pressure and uniqueness. This calls for further research.

Practical implications

Results are important for companies marketing unique products and they suggest that pressure-based marketing appeals can be used strategically to increase sales of products with long uniqueness duration but decrease sales of products with short uniqueness duration. Although the research provides these guidelines, managers should consider the ethical implications of pressure strategies.

Originality/value

This is the first attempt to empirically investigate the duration of uniqueness. Although extant research has examined choices between products with different degrees of uniqueness, this research studies choice of products with similar degrees of uniqueness, but different uniqueness duration. Thus, this research adds to the scarce literature studying the duration of symbolic benefits. Moreover, although pressure and NFU frequently co-exist in uniqueness consumption settings, this study is the first to study their joint effects.

Details

European Journal of Marketing, vol. 55 no. 13
Type: Research Article
ISSN: 0309-0566

Keywords

Open Access
Article
Publication date: 22 June 2021

Truong Thi Thuy Duong and Nguyen Xuan Thao

The paper aims to propose a practical model for market segment selection and evaluation. The paper carries out a technique of order preference similarity to the ideal solution…

1451

Abstract

Purpose

The paper aims to propose a practical model for market segment selection and evaluation. The paper carries out a technique of order preference similarity to the ideal solution (TOPSIS) approach to make an operation systematic dealing with multi-criteria decision- making problem.

Design/methodology/approach

Introducing a multi-criteria decision-making problem based on TOPSIS approach. A new entropy and new similarity measure under neutrosopic environment are proposed to evaluate the weights of criteria and the relative closeness coefficient in TOPSIS model.

Findings

The outcomes show that the TOPSIS model based on new entropy and similarity measure is effective for evaluation and selection market segment. Profitability, growth of the market, the likelihood of sustainable differential advantages are the most important insights of criteria.

Originality/value

This paper put forward an effective multi-criteria decision-making dealing with uncertain information.

Details

Asian Journal of Economics and Banking, vol. 5 no. 2
Type: Research Article
ISSN: 2615-9821

Keywords

1 – 10 of 246