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1 – 10 of over 14000Mingjie Hao, Yiming Bie, Le Zhang and Chengyuan Mao
The purpose of this paper is to develop a dynamic control method to improve bus schedule adherence under connected bus system.
Abstract
Purpose
The purpose of this paper is to develop a dynamic control method to improve bus schedule adherence under connected bus system.
Design/methodology/approach
The authors developed a dynamic programming model that optimally schedules the bus operating speed at road sections and multiple signal timing plans at intersections to improve bus schedule adherence. First, the bus route was partitioned into three types of sections: stop, road and intersection. Then, transit agencies can control buses in real time based on all collected information; i.e. control bus operating speed on road sections and adjust the signal timing plans through signal controllers to improve the schedule adherence in connected bus environment. Finally, bus punctuality at the downstream stop and the saturation degree deviations of intersections were selected as the evaluation criteria in optimizing signal control plans and bus speeds jointly.
Findings
An illustrative case study by using a bus rapid transit line in Jinan city was performed to verify the proposed model. It revealed that based on the proposed strategy, the objective value could be reduced by 73.7%, which indicated that the punctuality was highly improved but not to incur excessive congestion for other vehicular traffic.
Originality/value
In this paper, the authors applied speed guidance and the adjustment of the signal control plans for multiple cycles in advance to improve the scheduled stability; furthermore, the proposed control strategy can reduce the effect on private traffics to the utmost extend.
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Hien Thu Thi Nguyen, Long Thanh Giang and Toan Ngoc Pham
The purpose of this study was to evaluate how higher tax on tobacco would influence output and employment in Vietnam.
Abstract
Purpose
The purpose of this study was to evaluate how higher tax on tobacco would influence output and employment in Vietnam.
Design/methodology/approach
The authors used micro-simulation techniques proposed by Walbeeck (2010). Both national data (from Input–Output Table) and household data (Vietnam Household Living Standard Survey) were utilized.
Findings
The results showed that any increase in the excise tax for tobacco would have positive net impacts on both national output and employment. The tobacco industry would not be significantly affected due to its small contribution to national economy and employment. More importantly, money released from reduced tobacco consumption would be reallocated to other goods and services, and thus outputs and jobs in nontobacco sectors would increase.
Research limitations/implications
The key limitation of this study was due to unavailability of updated data, especially Input–Output Table as well as household living standard survey.
Practical implications
This study concluded that government should increase tax on cigarette along with a well-planned roadmap to avoid unexpected consequences on income and employment of laborers in this sector.
Originality/value
This study replicated a popular approach in order to verify an important government policy (i.e. effect of tax on tobacco on output and employment) under Vietnamese context.
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Cong Li, YunFeng Xie, Gang Wang, XianFeng Zeng and Hui Jing
This paper studies the lateral stability regulation of intelligent electric vehicle (EV) based on model predictive control (MPC) algorithm.
Abstract
Purpose
This paper studies the lateral stability regulation of intelligent electric vehicle (EV) based on model predictive control (MPC) algorithm.
Design/methodology/approach
Firstly, the bicycle model is adopted in the system modelling process. To improve the accuracy, the lateral stiffness of front and rear tire is estimated using the real-time yaw rate acceleration and lateral acceleration of the vehicle based on the vehicle dynamics. Then the constraint of input and output in the model predictive controller is designed. Soft constraints on the lateral speed of the vehicle are designed to guarantee the solved persistent feasibility and enforce the vehicle’s sideslip angle within a safety range.
Findings
The simulation results show that the proposed lateral stability controller based on the MPC algorithm can improve the handling and stability performance of the vehicle under complex working conditions.
Originality/value
The MPC schema and the objective function are established. The integrated active front steering/direct yaw moments control strategy is simultaneously adopted in the model. The vehicle’s sideslip angle is chosen as the constraint and is controlled in stable range. The online estimation of tire stiffness is performed. The vehicle’s lateral acceleration and the yaw rate acceleration are modelled into the two-degree-of-freedom equation to solve the tire cornering stiffness in real time. This can ensure the accuracy of model.
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Solomon O. Obadimu and Kyriakos I. Kourousis
The material extrusion (ME) process induces variations in the final part’s microscopic and macroscopic structural characteristics. This viewpoint article aims to uncover the…
Abstract
Purpose
The material extrusion (ME) process induces variations in the final part’s microscopic and macroscopic structural characteristics. This viewpoint article aims to uncover the relation between ME fabrication parameters and the microstructural and mesostructural characteristics of the ME BASF Ultrafuse Steel 316L metal parts. These characteristics can affect the structural integrity of the produced parts and components used in various engineering applications.
Design/methodology/approach
Recent studies on the ME BASF Ultrafuse Steel 316L are reviewed, with a focus on those which report microstructural and mesostructural characteristics that may affect structural integrity.
Findings
A relationship between ME fabrication parameters and subsequent microstructural and mesostructural characteristics is discussed. Common microstructural and mesostructural/macrostructural defects are also highlighted and discussed.
Originality/value
This viewpoint article attempts to bridge the existing gap in the literature, highlighting the influence of ME fabrication parameters on Steel 316L parts fabricated via this additive manufacturing method. Moreover, this article identifies and discusses important considerations for the purposes of selecting and optimising the structural integrity of ME-fabricated Steel 316L parts.
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Samaan Al‐Msallam and Amal Abdelhadi
This paper examines factors that lead consumers to engage in unethical consumer behaviour (UECB) to develop a framework for understanding this phenomenon.
Abstract
Purpose
This paper examines factors that lead consumers to engage in unethical consumer behaviour (UECB) to develop a framework for understanding this phenomenon.
Design/methodology/approach
The study data were collected using the qualitative approach by conducting personal interviews with 27 marketers in two Arab countries, Libya and Syria.
Findings
The findings indicate that previous models of UECB are applicable to Arab consumers. However, the effects of the examined factors on UECB adoption are influenced by the local environment. Also, the paper explored some newly factors that clearly affect UECB.
Practical implications
This study provides a model of UECB for Arab consumers to help companies to understand Arab consumers’ behaviour. This model determines the influencing factors on this behaviour that companies can use to build their marketing strategies directed at the Libyan and Syrian markets during the reconstruction phase. Moreover, the research results help companies avoid and control UECB.
Originality/value
Almost all studies of UECB have been conducted in Western countries; the present study attempts to address this gap in the ethical decision-making literature, as well as marketing literature, and examine the UECB in Arab countries. Furthermore, previous studies of UECB mostly look at one typical form of UECB; this study provides a broader contribution to the literature on UECB by using a set of scenarios; shoplifting, software piracy and pilfering from hotel rooms.
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Jamie Stone and Shahin Rahimifard
Resilience in agri-food supply chains (AFSCs) is an area of significant importance due to growing supply chain volatility. While the majority of research exploring supply chain…
Abstract
Purpose
Resilience in agri-food supply chains (AFSCs) is an area of significant importance due to growing supply chain volatility. While the majority of research exploring supply chain resilience has originated from a supply chain management perspective, many other disciplines (such as environmental systems science and the social sciences) have also explored the topic. As complex social, economic and environmental constructs, the priority of resilience in AFSCs goes far beyond the company specific focus of supply chain management works and would conceivably benefit from including more diverse academic disciplines. However, this is hindered by inconsistencies in terminology and the conceptual components of resilience across different disciplines. The purpose of this study is to use a systematic literature review to identify which multidisciplinary aspects of resilience are applicable to AFSCs and to generate a novel AFSC resilience framework.
Design/methodology/approach
This paper uses a structured and multidisciplinary review of 137 articles in the resilience literature followed by critical analysis and synthesis of findings to generate new knowledge in the form of a novel AFSC resilience framework.
Findings
Findings indicate that the complexity of AFSCs and subsequent exposure to almost constant external interference means that disruptions cannot be seen as a one-off event; thus, resilience must concern the ability to not only maintain core function but also adapt to changing conditions.
Practical implications
A number of resilience elements can be used to enhance resilience, but their selection and implementation must be carefully matched to relevant phases of disruption and assessed on their broader supply chain impacts. In particular, the focus must be on overall impact on the ability of the supply chain as a whole to provide food security rather than to boost individual company performance.
Originality/value
The research novelty lies in the utilisation of wider understandings of resilience from various research fields to propose a rigorous and food-specific resilience framework with end consumer food security as its main focus.
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Ellen Ernst Kossek, Brenda A. Lautsch, Matthew B. Perrigino, Jeffrey H. Greenhaus and Tarani J. Merriweather
Work-life flexibility policies (e.g., flextime, telework, part-time, right-to-disconnect, and leaves) are increasingly important to employers as productivity and well-being…
Abstract
Work-life flexibility policies (e.g., flextime, telework, part-time, right-to-disconnect, and leaves) are increasingly important to employers as productivity and well-being strategies. However, policies have not lived up to their potential. In this chapter, the authors argue for increased research attention to implementation and work-life intersectionality considerations influencing effectiveness. Drawing on a typology that conceptualizes flexibility policies as offering employees control across five dimensions of the work role boundary (temporal, spatial, size, permeability, and continuity), the authors develop a model identifying the multilevel moderators and mechanisms of boundary control shaping relationships between using flexibility and work and home performance. Next, the authors review this model with an intersectional lens. The authors direct scholars’ attention to growing workforce diversity and increased variation in flexibility policy experiences, particularly for individuals with higher work-life intersectionality, which is defined as having multiple intersecting identities (e.g., gender, caregiving, and race), that are stigmatized, and link to having less access to and/or benefits from societal resources to support managing the work-life interface in a social context. Such an intersectional focus would address the important need to shift work-life and flexibility research from variable to person-centered approaches. The authors identify six research considerations on work-life intersectionality in order to illuminate how traditionally assumed work-life relationships need to be revisited to address growing variation in: access, needs, and preferences for work-life flexibility; work and nonwork experiences; and benefits from using flexibility policies. The authors hope that this chapter will spur a conversation on how the work-life interface and flexibility policy processes and outcomes may increasingly differ for individuals with higher work-life intersectionality compared to those with lower work-life intersectionality in the context of organizational and social systems that may perpetuate growing work-life and job inequality.
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Klara Granheimer, Tina Karrbom Gustavsson and Per Erik Eriksson
Prior research has emphasised the importance of the early phases of construction projects, as well as the difficulties of procuring engineering services – especially due to the…
Abstract
Purpose
Prior research has emphasised the importance of the early phases of construction projects, as well as the difficulties of procuring engineering services – especially due to the uncertainties. Despite that, studies on the public procurement of engineering services are scarce. Although scholars have shown that uncertainty may affect the choice of control modes, the level of uncertainty that characterises services is not addressed by the two task characteristics: knowledge of the transformation process and output measurability. The purpose is to investigate organisational control in public procurement of engineering services.
Design/methodology/approach
The existing control model was adjusted in this study by conceptually adding uncertainty as a third aspect to the two task characteristics. A single case study of the Swedish Transport Administration was used. The empirical data, comprising 14 interviews with managers from the client and engineering consulting companies, were analysed using flexible pattern matching and visual mapping approaches and then illustrated using the model.
Findings
The public client did not base its choice of control modes on uncertainty, but rather on the other two task characteristics. Consequently, the service providers argued that the chosen control modes reduced their creativity, increased their financial risks and caused unclear responsibilities. This study therefore shows that uncertainty is an important factor to consider in the choice of control modes, both from a theoretical perspective and from the service providers' point of view. The developed model may therefore be useful for researchers as well as practitioners.
Originality/value
This study is the first attempt to add uncertainty as a task characteristic when choosing control modes. The results contribute to the scarce control literature regarding the procurement of engineering services for construction projects and the procurement of other services with high uncertainty.
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