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Open Access
Article
Publication date: 6 September 2021

Yujie Li, Tiantian Chen, Sikai Chen and Samuel Labi

The anticipated benefits of connected and autonomous vehicles (CAVs) include safety and mobility enhancement. Small headways between successive vehicles, on one hand, can cause…

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Abstract

Purpose

The anticipated benefits of connected and autonomous vehicles (CAVs) include safety and mobility enhancement. Small headways between successive vehicles, on one hand, can cause increased capacity and throughput and thereby improve overall mobility. On the other hand, small headways can cause vehicle occupant discomfort and unsafety. Therefore, in a CAV environment, it is important to determine appropriate headways that offer a good balance between mobility and user safety/comfort.

Design/methodology/approach

In addressing this research question, this study carried out a pilot experiment using a driving simulator equipped with a Level-3 automated driving system, to measure the threshold headways. The Method of Constant Stimuli (MCS) procedure was modified to enable the estimation of two comfort thresholds. The participants (drivers) were placed in three categories (“Cautious,” “Neutral” and “Confident”) and 250 driving tests were carried out for each category. Probit analysis was then used to estimate the threshold headways that differentiate drivers' discomfort and their intention to re-engage the driving tasks.

Findings

The results indicate that “Cautious” drivers tend to be more sensitive to the decrease in headways, and therefore exhibit greater propensity to deactivate the automated driving mode under a longer headway relative to other driver groups. Also, there seems to exist no driver discomfort when the CAV maintains headway up to 5%–9% shorter than the headways they typically adopt. Further reduction in headways tends to cause discomfort to drivers and trigger take over control maneuver.

Research limitations/implications

In future studies, the number of observations could be increased further.

Practical implications

The study findings can help guide specification of user-friendly headways specified in the algorithms used for CAV control, by vehicle manufacturers and technology companies. By measuring and learning from a human driver's perception, AV manufacturers can produce personalized AVs to suit the user's preferences regarding headway. Also, the identified headway thresholds could be applied by practitioners and researchers to update highway lane capacities and passenger-car-equivalents in the autonomous mobility era.

Originality/value

The study represents a pioneering effort and preliminary pilot driving simulator experiment to assess the tradeoffs between comfortable headways versus mobility-enhancing headways in an automated driving environment.

Details

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

Keywords

Open Access
Article
Publication date: 13 July 2022

Jiqian Dong, Sikai Chen, Mohammad Miralinaghi, Tiantian Chen and Samuel Labi

Perception has been identified as the main cause underlying most autonomous vehicle related accidents. As the key technology in perception, deep learning (DL) based computer…

Abstract

Purpose

Perception has been identified as the main cause underlying most autonomous vehicle related accidents. As the key technology in perception, deep learning (DL) based computer vision models are generally considered to be black boxes due to poor interpretability. These have exacerbated user distrust and further forestalled their widespread deployment in practical usage. This paper aims to develop explainable DL models for autonomous driving by jointly predicting potential driving actions with corresponding explanations. The explainable DL models can not only boost user trust in autonomy but also serve as a diagnostic approach to identify any model deficiencies or limitations during the system development phase.

Design/methodology/approach

This paper proposes an explainable end-to-end autonomous driving system based on “Transformer,” a state-of-the-art self-attention (SA) based model. The model maps visual features from images collected by onboard cameras to guide potential driving actions with corresponding explanations, and aims to achieve soft attention over the image’s global features.

Findings

The results demonstrate the efficacy of the proposed model as it exhibits superior performance (in terms of correct prediction of actions and explanations) compared to the benchmark model by a significant margin with much lower computational cost on a public data set (BDD-OIA). From the ablation studies, the proposed SA module also outperforms other attention mechanisms in feature fusion and can generate meaningful representations for downstream prediction.

Originality/value

In the contexts of situational awareness and driver assistance, the proposed model can perform as a driving alarm system for both human-driven vehicles and autonomous vehicles because it is capable of quickly understanding/characterizing the environment and identifying any infeasible driving actions. In addition, the extra explanation head of the proposed model provides an extra channel for sanity checks to guarantee that the model learns the ideal causal relationships. This provision is critical in the development of autonomous systems.

Details

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

Keywords

Article
Publication date: 7 July 2021

Xiaohua Xin, Xiaoming Miao, Qian Chen and Tiantian Shang

Despite the fact that user participation (UP) has been highlighted as an important aspect in innovation, previous findings on its relationship with service innovation performance…

Abstract

Purpose

Despite the fact that user participation (UP) has been highlighted as an important aspect in innovation, previous findings on its relationship with service innovation performance (SIP) are inconsistent. This study aims to investigate the relationships among UP, knowledge management capability (KMC) and SIP, especially in the digital age, inspired by the theories of knowledge-based and absorptive capacity.

Design/methodology/approach

Based on a sample of 252 Chinese e-commerce enterprises, this study adopts a hierarchical regression analysis and bootstrap method to test the theoretical framework and research hypotheses.

Findings

UP and KMC have positive effects on SIP, respectively. KMC plays a mediating role in the effect of UP on SIP. Furthermore, the intermediary role of KMC varies in different sub-paths between UP and SIP.

Originality/value

First, this study provides some explanations for inconsistent arguments on the relationship between UP and service innovation. Second, with the consideration of specific dimensions of UP and SIP, the mediation role of KMC varies in different sub-paths has been recognized, which provides a deeper understanding of the relationship between UP and SIP. Third, this study opens the discussion about how to realize SIP more effectively in the digital age, advancing theoretical and practical developments on service innovation.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 34 no. 4
Type: Research Article
ISSN: 1355-5855

Keywords

Article
Publication date: 19 January 2024

Yaowei Zhang, Tiantian Cao, Siqi Liu and Shuqi Chen

The inconsistent results shown in previous group faultline research have created a need for investigating the underlying mechanisms of the faultline's effects. This study focuses…

Abstract

Purpose

The inconsistent results shown in previous group faultline research have created a need for investigating the underlying mechanisms of the faultline's effects. This study focuses on clarifying the competing mediating roles of information diversity and team conflict in the nonlinear relationship between board faultlines (BF) and decision quality.

Design/methodology/approach

This study is empirically tested with the questionnaire data from 105 Chinese listed companies.

Findings

This study finds: (1) an inverted U-shaped curve relationship between BF and board decision quality and (2) that the joint mediating effect of team conflict and information diversity leads to the inverted U-shaped curve relationship between BF and decision quality. Specifically, BF shows a U-shaped curve relationship with team conflict and an inverted U-shaped curve relationship with information diversity. Either too weak or too strong faultlines will inhibit the positive effects of information diversity and amplify the negative effects of team conflicts, leading to low-quality decisions.

Originality/value

This study contributes to the research on: (1) board governance as it clarifies the effect of BF on the board decision-making process and its quality, which helps to open the black box of board decision-making and (2) group faultlines as it reveals how information diversity and team conflict can play a joint mediating role in the functioning of team faultlines.

Details

American Journal of Business, vol. 39 no. 2
Type: Research Article
ISSN: 1935-5181

Keywords

Article
Publication date: 7 August 2017

Du-Xin Liu, Xinyu Wu, Wenbin Du, Can Wang, Chunjie Chen and Tiantian Xu

The purpose of this paper is to model and predict suitable gait trajectories of lower-limb exoskeleton for wearer during rehabilitation walking. Lower-limb exoskeleton is widely…

Abstract

Purpose

The purpose of this paper is to model and predict suitable gait trajectories of lower-limb exoskeleton for wearer during rehabilitation walking. Lower-limb exoskeleton is widely used for assisting walk in rehabilitation field. One key problem for exoskeleton control is to model and predict suitable gait trajectories for wearer.

Design/methodology/approach

In this paper, the authors propose a Deep Spatial-Temporal Model (DSTM) for generating knee joint trajectory of lower-limb exoskeleton, which first leverages Long-Short Term Memory framework to learn the inherent spatial-temporal correlations of gait features.

Findings

With DSTM, the pathological knee joint trajectories can be predicted based on subject’s other joints. The energy expenditure is adopted for verifying the effectiveness of new recovery gait pattern by monitoring dynamic heart rate. The experimental results demonstrate that the subjects have less energy expenditure in new recovery gait pattern than in others’ normal gait patterns, which also means the new recovery gait is more suitable for subject.

Originality/value

Long-Short Term Memory framework is first used for modeling rehabilitation gait, and the deep spatial–temporal relationships between joints of gait data can obtained successfully.

Details

Assembly Automation, vol. 37 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 9 January 2024

Juelin Leng, Quan Xu, Tiantian Liu, Yang Yang and Peng Zheng

The purpose of this paper is to present an automatic approach for mesh sizing field generation of complicated  computer-aided design (CAD) models.

Abstract

Purpose

The purpose of this paper is to present an automatic approach for mesh sizing field generation of complicated  computer-aided design (CAD) models.

Design/methodology/approach

In this paper, the authors present an automatic approach for mesh sizing field generation. First, a source point extraction algorithm is applied to capture curvature and proximity features of CAD models. Second, according to the distribution of feature source points, an octree background mesh is constructed for storing element size value. Third, mesh size value on each node of background mesh is calculated by interpolating the local feature size of the nearby source points, and then, an initial mesh sizing field is obtained. Finally, a theoretically guaranteed smoothing algorithm is developed to restrict the gradient of the mesh sizing field.

Findings

To achieve high performance, the proposed approach has been implemented in multithreaded parallel using OpenMP. Numerical results demonstrate that the proposed approach is remarkably efficient to construct reasonable mesh sizing field for complicated CAD models and applicable for generating geometrically adaptive triangle/tetrahedral meshes. Moreover, since the mesh sizing field is defined on an octree background mesh, high-efficiency query of local size value could be achieved in the following mesh generation procedure.

Originality/value

How to determine a reasonable mesh size for complicated CAD models is often a bottleneck of mesh generation. For the complicated models with thousands or even ten thousands of geometric entities, it is time-consuming to construct an appropriate mesh sizing field for generating high-quality mesh. A parallel algorithm of mesh sizing field generation with low computational complexity is presented in this paper, and its usability and efficiency have been verified.

Details

Engineering Computations, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 23 May 2024

Tiantian Gu, Enyang Hao and Lei Zhang

Smart community construction (SCC) and efficiency require resident participation. This paper aims to explore the determinants of residents’ participation intention (RPI) in the…

Abstract

Purpose

Smart community construction (SCC) and efficiency require resident participation. This paper aims to explore the determinants of residents’ participation intention (RPI) in the SCC.

Design/methodology/approach

Based on the theory of planned behavior (TPB), this study proposed an extended conceptual model to deeply analyze the RPI in the SCC. The relationship between all constructs was verified by processing and analyzing online survey data using confirmatory factor analysis (CFA), structural equation model (SEM), and bootstrapping method.

Findings

Participation attitude, perceived behavioral control, subjective norm, and perceived usefulness significantly and positively affected the RPI. Furthermore, intermediary effects in the extended conceptual model had been confirmed.

Originality/value

To fill the critical gap in the research on the determinants of the RPI in the SCC context, this study developed a novel conceptual model by extending the TPB to analyze the effects of self-driven and externally-driven factors on the RPI from the perspectives of residents’ psychology and external environment. The findings not only clarify the complex process of forming the RPI in the SCC but also provide a theoretical foundation for studying the RPI in similar community construction projects. Additionally, several strategies have been proposed to encourage residents’ participation in the SCC and promote the development of smart communities, such as clarifying residents’ participation obligations, improving the convenience services of smart communities, and diversifying residents’ participation approaches.

Details

Engineering, Construction and Architectural Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 7 December 2023

Tiantian Tang and Liyan Yang

This study investigates the influence of social trust on the attainment of corporate environmental, social and governance (ESG) objectives.

1994

Abstract

Purpose

This study investigates the influence of social trust on the attainment of corporate environmental, social and governance (ESG) objectives.

Design/methodology/approach

This study conducts panel regression analysis on a distinctive dataset for 2009–2017 on Chinese firms.

Findings

The analysis reveals a significant positive association between social trust and firm-level ESG practices. Moreover, the impact of social trust on shaping ESG outcomes is further amplified by factors such as economic growth, corporate governance standards and institutional quality. This relationship remains statistically positive when the authors employ alternative measures and methodologies, such as the instrumental variables, propensity score matching and difference-in-differences approaches. Notably, the results of heterogeneity tests indicate that the Trust–ESG nexus is more prominent for state-owned enterprises and firms with substantial market capitalization, superior profitability and higher leverage.

Originality/value

This study expands the comprehension of the determinants of ESG and underscores the influential role of social trust as an informal institution in enhancing a firm's ESG performance.

Details

China Finance Review International, vol. 14 no. 1
Type: Research Article
ISSN: 2044-1398

Keywords

Article
Publication date: 15 June 2021

Tiantian Yang, Feng Yang and Jinqi Men

This study investigates how Danmu (danmaku) technological features (DTFs) of recommendation vlogs (rec-vlogs) impact consumer experiences and decisions.

2171

Abstract

Purpose

This study investigates how Danmu (danmaku) technological features (DTFs) of recommendation vlogs (rec-vlogs) impact consumer experiences and decisions.

Design/methodology/approach

The authors adopt the partial least squares structural equation modeling (PLS-SEM) technique with a sample of 422 viewers of Danmu-enabled rec-vlogs to examine the proposed model.

Findings

The DTFs positively affect consumer loyalty intentions through the mediation of social presence and immersion. Also, vlogger-product congruency significantly moderates the relationship between social presence and immersion.

Originality/value

With the increasing popularity of vlogs, retailers have adopted the vlog as a new marketing channel to connect with consumers. Although a growing body of studies focuses on this phenomenon, little is known about how DTFs help to increase consumer loyalty toward using rec-vlogs as product information sources. Anchored on the stimulus–organism–response framework, this study investigates how pseudo-synchronicity, Danmu-content congruency and parallelism, three DTFs used in rec-vlogs, impact consumer experiences of social presence and immersion, eventually influence the consumers' loyalty intentions toward rec-vlogs. The authors also examine whether the effect of social presence on immersion is contingent on vlogger-product congruency. These findings have implications for both researchers and practitioners to understand the effect of DTFs in the context of rec-vlogs.

Details

Information Technology & People, vol. 35 no. 4
Type: Research Article
ISSN: 0959-3845

Keywords

Article
Publication date: 3 April 2019

Tiantian Shang, Xiaoming Miao and Waheed Abdul

The purpose of this paper is to demonstrate visually the knowledge structure and evolution of disruptive innovation. The paper used CiteSpace III to analyze 1,570 disruptive…

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Abstract

Purpose

The purpose of this paper is to demonstrate visually the knowledge structure and evolution of disruptive innovation. The paper used CiteSpace III to analyze 1,570 disruptive innovation records from the Web of Science database between 1997 and 2016.

Design/methodology/approach

Initially, this paper offers a comprehensive overview of papers, countries, journals, scholars and application areas. Subsequently, a time zone view of high-frequency keywords is presented, emphasizing the course of evolution of the study hotspots. Finally, a visualization map of cited references and co-citation analysis are provided to detect the knowledge base at the forefront of disruptive innovation.

Findings

The findings are as follows: the number of papers shows exponential growth. The USA has the largest contribution and the strongest center. The Netherlands shows the largest burst, followed by Japan. Journal of Production Innovation Management and Research Policy is the most important journals. Hang CC has the largest number of articles. Walsh ST is identified as a high-yielding scholar. Christensen CM is the most authoritative scholar. Engineering electrical electronic is the most widely used research category, followed by management and business. The evolutionary course of the study hotspots is divided into five stages, namely, start, burst, aggregation, dispersion and not yet formed. Eight key streams in the literature are extracted to summarize the knowledge base at the forefront of disruptive innovation.

Originality/value

This paper explores the whole picture of disruptive innovation research and demonstrates a visual knowledge structure and the evolution of disruptive innovation. It provides an important reference for scholars to capture the current situation and influential trends in this field.

Details

International Journal of Innovation Science, vol. 11 no. 2
Type: Research Article
ISSN: 1757-2223

Keywords

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