Shuang Han, Jing Zhang, Quanyue Yang, Zijian Yuan, Shubin Li, Fengying Cui, Chuntang Zhang and Tao Wang
The performance of the classical car-following system is easily affected by external disturbances. To enhance the performance of the classical car-following model under sudden…
Abstract
Purpose
The performance of the classical car-following system is easily affected by external disturbances. To enhance the performance of the classical car-following model under sudden external disturbances, a novel car-following model is established to smooth traffic flow.
Design/methodology/approach
This paper proposed a Proportion Integration Differentiation (PID) control strategy based on classical control theory and developed a novel car-following model. The linear system theory and Laplace transform are used to derive a closed-loop transfer function. Then, the stability condition is obtained by using the Routh stability criterion and the small gain theorem. Finally, the validity and feasibility of the PID control strategy is proved by numerical simulations.
Findings
The analytic results and the numerical simulation results show that both the integration part and the differential part have the positive effect to suppress traffic oscillation efficiently; the collaboration of these two parts has more power to improve the stability of traffic flow. It means that the proposed model integrated with the PID control strategy has the ability of anti-interference and smooth traffic compared with the classical car-following model.
Originality/value
This paper introduces the PID control strategy into the classical car-following system, which enhances the stability of the system and also provides an efficient method for optimizing the traffic flow system.
Details
Keywords
Many instruments have been developed to measure the perceived luxuriousness of brands, but one of the most frequently used scales is the “brand luxury index” (BLI) from Vigneron…
Abstract
Purpose
Many instruments have been developed to measure the perceived luxuriousness of brands, but one of the most frequently used scales is the “brand luxury index” (BLI) from Vigneron and Johnson (2004) that distinguishes between high- and low-luxury brands. Despite its popularity and widespread use in academic research, the scale's psychometric properties and equivalence across cultures have been questioned. Recently, modified versions of the scale have been developed to strengthen the quality of the measurement. However, the performance and the measurement invariance of the modified version have not yet been investigated. The current paper aims to test the model fit of the modified BLI scale and the measurement invariance across gender, age and country groups using nine datasets from a total of three different countries.
Design/methodology/approach
This paper conducts a multi-group CFA to examine the measurement invariance of the BLI scale. Nine datasets were used in this study. The data were collected across three countries, the United States (5 datasets), China (2 datasets) and India (2 datasets) from 2016 to 2018.
Findings
The results of this analysis suggest that the modified BLI scale has an acceptable model fit and can be interpreted equivalently across gender and age groups. Metric invariance was found among the US, China and India. However, scalar measurement invariance was established only across two countries: the US and India. A follow-up analysis shows that partial scalar invariance can be established across the US, China and India when removing constraints on the parameters of three items: exclusive, precious and sophisticated.
Originality/value
This study is the first study to test the model fit of the modified BLI scale. The findings of this paper contribute to both the academia and industry. The authors recommend scholars and marketers to use a modified 19-item BLI scale to measure the perceived luxuriousness of brands in future research. First, the modified BLI scale tested in the current study offers very good performance with model fit values of a quality that has rarely been seen in prior research. The original scale of Vigneron and Johnson (2004) has been criticized for its poor model fit (Christodoulides et al., 2009). The modified scale of Doss and Robinson (2013) also has problems with the fit value. Second, the modified 19-item scale also shows adequate measurement invariance across different gender, age and countries. For scholars and marketers, the establishment of the metric invariance of the modified 19-item BLI scale implies that the scale can be used across gender, age and countries (the US, China and India) if the purpose of the study is to understand the relationship between some variables and perceived luxuriousness of a brand.
Details
Keywords
Shubin Yu, Liselot Hudders and Verolien Cauberghe
Behavioral targeting has become a popular marketing strategy among brands as it enables advertisers to display ads to consumers based on their previous surfing behaviors. The…
Abstract
Purpose
Behavioral targeting has become a popular marketing strategy among brands as it enables advertisers to display ads to consumers based on their previous surfing behaviors. The purpose of this paper is to investigate the effectiveness of behaviorally targeted ads for luxury brands and to explore how and when behavioral targeting works.
Design/methodology/approach
A 2 (targeted vs non-targeted ads) ×2 (culture: China vs the Netherlands) between-subjects factorial design is conducted to test the hypothesis.
Findings
The result reveals that as for luxury brands, behavioral targeting can shorten the psychological distance and in turn lead to a more positive attitude toward the ad. However, the effect of behavioral targeting depends on the culture. In the Netherlands, behavioral targeting can enhance the attitude toward the ad by lowering the psychological distance. However, in China, these effects are mitigated.
Practical implications
This study contributes to the research of online luxury marketing. First, luxury brands should adapt their marketing strategy to different regional markets. In addition, luxury marketers should not worry about a shorter distance with consumers caused by the use of internet. A shorter distance does not mean to reduce an aura of mystery, but to build up a closer relationship with consumers. Luxury brands are not necessary to be aloof and supercilious like an indifferent robot. A closer relationship with consumers brings more positive effects.
Originality/value
The current research makes important contributions both to the scientific literature and to the luxury industry. First, this research reveals the effectiveness and underlying mechanisms of behavioral targeting for luxury brands and also compares the effectiveness of behavioral targeting in two cultures, which contributes to the current cross-cultural studies and international marketing research. Second, this study also helps luxury marketers to realize the importance of behavioral targeting and to know how and when they can use this new marketing strategy in a global environment.
Details
Keywords
Wenliang Zhu, Wenjian Zhu, Shubin Zheng and Na Wu
The purpose of this paper is to develop an improved adhesion model to better reproduce the low adhesion condition of the anti-skid control for rail vehicles under braking…
Abstract
Purpose
The purpose of this paper is to develop an improved adhesion model to better reproduce the low adhesion condition of the anti-skid control for rail vehicles under braking condition.
Design/methodology/approach
In view of the low adhesion characteristics for rail vehicles under braking conditions, the Polach adhesion model was improved based on the sliding power and sliding energy. The wheel–rail low adhesion model suitable for braking condition was given. The analysis of braking anti-skid control under emergency braking condition was carried out through the co-simulation, and compared with the test data; the effectiveness and practicability of the improved low adhesion model were verified.
Findings
The results showed that the improved adhesion model is simple and efficient and the parameters involved are less, and it can be directly applied to the real-time simulation of anti-skid control in the process of train braking.
Originality/value
This paper can provide a theoretical reference for the reasons of change and improvement of adhesion between wheel and rail caused by the adjustment of braking force under anti-skid control, which can fulfill a need to the study of sliding energy on the contact surface, the removal effect of pollutants on the wheel–rail surface and the improvement and recovery of adhesion caused.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0244/
Details
Keywords
Óscar Carpintero, Ivan Murray and José Bellver
The aim of this paper is to analyse the recent changes in the role played by Africa as a traditional natural resources supplier for the world economy in a multipolar context. We…
Abstract
The aim of this paper is to analyse the recent changes in the role played by Africa as a traditional natural resources supplier for the world economy in a multipolar context. We highlight, on the one hand, how Africa remains a prominent supplier of critical minerals needed for information and communication technologies (ICT), including platinum, vanadium, coltan, chromium, manganese, zirconium, etc., and how the boomerang effect results in Africa also importing electronic waste. On the other hand, we show how the BRICS’ growth model, based on a very intensive use of natural resources acquired through international trade, is now being fuelled by Africa too. BRICS countries (especially China and India) are making foreign direct investments in Africa using their state companies to ensure the supply of natural resources under favourable economic terms. Thus, Africa appears as a disputed territory between the old domination of the advanced capitalist countries and emerging powers like the BRICS. However, this should not mask the fact that the European Union and North America are still the dominant foreign powers in the continent. Finally, we discuss which scenarios are open to further this multipolar moment, particularly in the wake of the great crisis.
Details
Keywords
Paulo Sampaio, André M. Carvalho, Pedro Domingues and Pedro Saraiva
Shubin Si, Josu Takala and Yang Liu
The purpose of this paper is to study the operational competitiveness and identify the development route of Chinese high‐tech manufacturing companies by comparing with other…
Abstract
Purpose
The purpose of this paper is to study the operational competitiveness and identify the development route of Chinese high‐tech manufacturing companies by comparing with other similar international manufacturing companies of global manufacturing strategies database.
Design/methodology/approach
The preliminary analytical models for competitiveness analysis are used to analyze the operational competitiveness strategies in three different types of Chinese high‐tech manufacturing companies based on the weights of the multi‐criteria manufacturing strategies, which are calculated using analytic hierarchy process method. Benchmarking between case companies and leading companies of prospector, analyzer and defender groups is applied to evaluate the manufacturing strategies further.
Findings
As a result of the case studies, it is possible to understand operational competitiveness manufacturing strategies for the case companies, to show one development route for Chinese high‐tech manufacturing companies to be competitive in their markets.
Practical implications
Chinese high‐tech manufacturing companies have their own operational strategies in different development phase. The different weights of important factors such as quality, cost, time and flexibility make the case companies to have some advantages in prospector, analyzer and defender. The preliminary analytical models are effective for Chinese high‐tech manufacturing companies to calculate their operational competitiveness under the influence of Chinese culture and macro‐control.
Originality/value
Benchmarking of operational competitiveness is presented to evaluate the manufacturing strategies in this paper. One development route of Chinese high‐tech manufacturing companies, which is under the influence of Chinese culture and macro‐control, is promoted.
Details
Keywords
Vishal M. and Satyanarayanan K.S.
This paper delineates a literature review on fire-induced progressive collapse on structures and the effect of high temperature on structures and elements. After the occurrences…
Abstract
Purpose
This paper delineates a literature review on fire-induced progressive collapse on structures and the effect of high temperature on structures and elements. After the occurrences of fire in the World Trade Center in the USA, the researchers started concentrating on the progressive collapse that happens due to high temperature. Currently, most of the researchers are working on fire-induced progressive collapse on structures using high-temperature behavior on materials which are used for construction. The researchers have been doing an intensive study to find a better strategy to prevent the building from structural fire damage or collapse with available codes and guidelines throughout the world. This paper aims to provide a better understanding and analytical solutions on the basis of the recent works done by researchers in fire-induced progressive collapse and methods adopted to find the collapse mechanism.
Design/methodology/approach
This paper is written by studying different literature papers of 109 related to progressive collapse on structures and fire-induced progressive collapse.
Findings
The behavior of structures due to high temperature and collapse conditions due to fire in different scenarios is identified.
Originality/value
This paper fulfills an identified need to study how the structure can withstand high-temperature conditions in our day-to-day lives.
Details
Keywords
Ming-Lang Tseng, Chih-Cheng Chen, Kuo-Jui Wu and Raymond Tan
This study integrates economic/ecology (eco)-attributes and performance to build a sustainable service supply chain management (SSCM) model.
Abstract
Purpose
This study integrates economic/ecology (eco)-attributes and performance to build a sustainable service supply chain management (SSCM) model.
Design/methodology/approach
This study proposes the use of the fuzzy Delphi method to screen for the less important attributes and applies a network data envelopment analysis to explore the hierarchical and eco-efficient network interrelationships. The causality and hierarchal eco-efficient model is acquired using a fuzzy decision-making trial and evaluation laboratory analysis
Findings
The findings are as follows: (1) the information and technology management process is derived by enhancing sustainable customer and supplier relationship management, and (2) the eco-efficient model is improved based on long-term relationships with suppliers – that is, synergistic suppliers improve the service chain quality and provide services in an appropriate and timely manner – and research and development coordination. The theoretical and managerial implications are discussed.
Research limitations/implications
The eco-efficient model reveals that the sustainable customer relationship management process, sustainable supplier relationship management process and information and technology management process are the major causal attributes in the model.
Practical implications
The eco-efficient model must be based on (1) long-term relationships with suppliers, (2) synergistic suppliers to improve service chain quality, (3) the provision of services in a timely manner and (4) research and development coordination.
Originality/value
Prior studies neglect to build an ecological economy model using the efficiency causality model of hierarchical interrelationships. Traditional SSCM fails to involve the triple bottom line performance toward sustainability.
Details
Keywords
A.S. Zymaris, D.I. Papadimitriou, E.M. Papoutsis‐Kiachagias, K.C. Giannakoglou and C. Othmer
The purpose of this paper is to propose the use of the continuous adjoint method as a tool to identify the appropriate location and “type” (suction or blowing) of steady jets used…
Abstract
Purpose
The purpose of this paper is to propose the use of the continuous adjoint method as a tool to identify the appropriate location and “type” (suction or blowing) of steady jets used in active flow control systems.
Design/methodology/approach
The method is based on continuous adjoint and covers both internal and external aerodynamics. The adjoint equations, including the adjoint to the SpalartAllmaras turbulence model and their boundary conditions are formulated. At the cost of solving the flow and adjoint equations just once, the sensitivity derivatives of the objective function with respect to hypothetical (normal) jet velocities at all wall nodes are computed. Comparisons of the computed sensitivities with finite differences and parametric studies to assess the present method are included.
Findings
Though the sensitivities are computed for zero jet velocities, they adequately support decision making on: the recommended location of jet(s), at boundary nodes with high absolute valued sensitivities; and the selection between suction or blowing jets, based on the sign of the computed sensitivities. Regarding adjoint methods, two important findings of this work are: the role of the adjoint pressure which proves to be an excellent sensor in flow control problems; and the prediction accuracy of the proposed adjoint method compared to the commonly made assumption of “frozen turbulence”.
Originality/value
First use of the continuous adjoint method using full differentiation of the turbulence model, in flow control optimization. A low‐cost design tool for recommending some of the most important jet characteristics.