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The development of mega container ships and operational pressures puts forward higher requirements on the operational ability of the container terminal. Accordingly, the purpose of this paper is to propose an effective method for quay crane (QC) scheduling of multiple hatches vessel considering double-cycling strategy to improve the operation efficiency and reduce the risk of delay.

A mixed integer programming model, which covers the main operational constraints in a container terminal, is formulated to solve the quay crane scheduling problem (QCSP) with a novel objective.

A case study is presented and a number of numerical experiments are conducted to validate the effectiveness of the proposed model. Meanwhile, management insights are proposed. The results demonstrate that the proposed method can efficiently solve QCSP in a container terminal, and an interesting finding is that reducing the stack layers on the vessel can improve the operation efficiency of QC.

A new mathematical model is proposed for QC scheduling at the operational level, which considers the constraints of double-cycling strategy, multiple hatches and hatch covers. The proposed model also provides methods to research the QC double-cycling problem considering the balance between energy cost and operation efficiency.

This paper aims to contrastively investigate the antioxidant behavior and tribological performance of a novel multifunctional additive (PBT) and dialkyldithiophosphate (ZDDP) in complex lithium grease (CLG).

PBT was successfully synthesized through esterification reaction. The antioxidant behavior of PBT and ZDDP was investigated by thermal analysis, and meanwhile, their tribological performance was evaluated by Optimol SRV-IV oscillating reciprocating friction and wear tester (SRV-IV test) and MRS-1J four-ball tester (Four-ball test). Furthermore, their anticorrosion ability was determined by copper strip corrosion test.

Four-ball tests showed that the extreme pressure property of PBT was a little inferior to that of ZDDP. Besides, all the other results demonstrated that PBT showed more superior antioxidation stability, friction-reduction and antiwear ability, as well as anticorrosion performance than ZDDP.

This work provides a study of hindered phenol derivative as a multifunctional additive in lubricant grease, which can contribute to the development of substitution of ZDDP.

Compared with traditional industrial processing technologies of sulfurized isobutylene, the one-step synthesis method involving high pressure is more environment-friendly and leads to better product performance. However, products from various sources perform differently because of the difference in the contents of their components. Therefore, the purpose of this study was to investigate the relationships between sulfide components of high-pressure sulfurized isobutylene and load carrying capacities.

A typical high-pressure sulfurized isobutylene was chosen, and the structure and contents of its sulfide components were characterized using gas chromatography-mass spectrometry and gas chromatography (GC). Extreme-pressure properties of the sample at different concentrations were evaluated using a four-ball tribometer.

A multiple regression equation model was established, and tert-butyl trisulfide made the greatest contribution to the extreme-pressure properties according to the equation coefficient, while tert-butyl tetrasulfide had no effect. The results can be attributed to the fact that the structure of a sulfurized additive having an impact is application-specific.

A precise and fast way to predict weld load values of high-pressure sulfurized isobutylene by using GC and the established equation model were successfully developed. Moreover, the empirical equation shows the relationships between sulfide component concentrations and load carrying capacities.

How to make accurate action decisions based on visual information is one of the important research directions of industrial robots. The purpose of this paper is to design a highly optimized hand-eye coordination model of the robot to improve the robots’ on-site decision-making ability.

The combination of inverse reinforcement learning (IRL) algorithm and generative adversarial network can effectively reduce the dependence on expert samples and robots can obtain the decision-making performance that the degree of optimization is not lower than or even higher than that of expert samples.

The performance of the proposed model is verified in the simulation environment and real scene. By monitoring the reward distribution of the reward function and the trajectory of the robot, the proposed model is compared with other existing methods. The experimental results show that the proposed model has better decision-making performance in the case of less expert data.

A robot hand-eye cooperation model based on improved IRL is proposed and verified. Empirical investigations on real experiments reveal that overall, the proposed approach tends to improve the real efficiency by more than 10% when compared to alternative hand-eye cooperation methods.

Potentially harmful elements (PHEs) in the soil at gold mining sites can endanger the health and sustainability of the local community. We examined the potential health risks associated with the presence of PHEs (Al, Cd, Cu, Fe, Hg, Mn, Pb, Sb, Se and Ti) in the soils of active, closed/abandoned/former and profile gold mine sites in Ghana.

We collected 102 soil samples from these mine sites, analysed them for their total element contents and calculated the geo-accumulation index, enrichment factor, contamination factor and pollution load index (PLI) (Igeo). We calculated the risks to human health by utilizing the hazard index (HI) and hazard quotient (HQ) for adult males, adult females and children who may ingest contaminated soil particles.

The average total Cd concentration in the soils was above the global average of 0.2 mg/kg for abandoned (2.86 mg/kg), active (3.93 mg/kg) and profile (4.04 mg/kg) areas. Mercury was detected at elevated concentrations in the soil of active mines (0.92 mg/kg), profiles (0.89 mg/kg) and abandoned mines (0.87 mg/kg). In the active, abandoned and profile soils, titanium concentrations were 14.18, 6.74 and 4.82 mg/kg, respectively, in several folds above the global average of 0.57 mg/kg. The majority of the sites were contaminated with Cd, Hg and Ti based on the calculated PLI values (active = 2.04, abandoned = 1.77 and profile = 2.7). Cadmium, mercury, lead and titanium in mine spoils were found to be correlated with aluminium, iron, manganese, pH, total carbon, clay content and phosphorus in a multivariate analysis using correlation and principal component analysis.

Both natural and anthropogenic processes contributed to the elevated metal contents in the mining sites, as indicated by the investigation’s results. The children’s hazard index values exceeded the threshold of 1.0, indicating the presence of non-carcinogenic risks.

Green space technology (e.g. revegetation) may thus be critical for preserving public health and reviving the ecological integrity of the contaminated sites.

This study highlights health risks to local communities in southwest Ghana by investigating the presence of potentially harmful elements in soils from gold mining sites for the first time. It assesses non-carcinogenic and carcinogenic health risks using a methodology recommended by the US Environmental Protection Agency for soil-to-human health risk assessment, especially for children. The study highlights how contamination has been found, making green space technology essential for preserving ecological integrity and protecting public health. The inclusion of geospatial distribution mapping of PTEs offers a visual depiction of the spread of contamination at both active and closed mining sites.

Brand storytelling is an effective marketing tool. However, when choosing whether to tell more or tell less, it remains unclear which of these two narrative styles is most effective. This study aims to examine whether blank-leaving(less) leads to favourable brand attitudes and compares its effects on consumers’ story immersion, to non-blank-leaving(more).

Two experiments were conducted to test the hypotheses. In Study 1, a single-factorial design was used with 252 participants assigned at random to one of two narrative conditions: blank-leaving or non-blank-leaving. Study 2 replicated Study 1 and investigated the moderating role of implicit mindsets.

The results show that a blank-leaving narrative style increases favourable brand attitudes. Consumers present deeper immersion in the brand story that uses blank-leaving, as compared to non-blank-leaving, leading to a more favourable brand attitude. Furthermore, this effect is stronger for individuals with growth mindsets.

Telling the brand story using a blank-leaving narrative style is more effective in catching consumers’ attention than non-blank-leaving. In particular, a blank-leaving narrative is a good approach for targeting consumers who have a growth mindset.

To the best of the authors’ knowledge, this research is the first to investigate and compare the effects of blank-leaving and non-blank-leaving narrative styles on brand attitudes in the context of storytelling marketing.

The hosts' third-party certifications in the sharing accommodation platforms have largely overlooked how the provision of such certification information could facilitate the trust-building process and subsequently influence consumers' purchase intention. Adopting an institution-based trust perspective, the authors differentiate various types of hosts' certification information (i.e. financial certification and social certification) and examine their role in the trust-building process between the hosts and the customers on sharing accommodation platforms.

This study uses the property-month level data of Airbnb Beijing from January 2019 to June 2020. Econometric analyses are adopted to evaluate the impact of institution-based trust on consumers' purchase intention. Specifically, the ordinary least square is used to testify the relationship between institution-based trust and purchase intention.

The empirical results show that the information on institution-based trust increases the likelihood that customers would reach purchase decisions. More importantly, results show that both financial certification and social certification affect consumers' purchase intention. The results further show that listings' attributes moderate the relationship between institution-based trust and customer purchase intention. Moreover, the authors find that “Superhost” and “Experience” positively moderate such relationships.

This paper confirms that the host certification fosters institution-based trust and reveals the impact of hosts' certification on consumers' purchase intentions. This study is among one of the first studies to incorporate institution-based trust into the trust formation on the sharing economy platform, which can improve the understanding of trust in the sharing economy context. The authors emphasize the importance of trust types on sharing economy platforms.

This paper aims to build a moderate mediation model to delineate when and how employee with perceived overqualification will exert extra effort and therefore engage in more altruistic helping behavior.

The research hypotheses were empirically tested using multitime and multisource survey data. Given the nested nature of data (i.e. 52 immediate supervisors rated 143 subordinates), multilevel structural equation modeling analyses within Mplus were conducted to test the proposed model.

The results support the proposed moderated mediation effect and indicate that perceived overqualification is positively related to extra effort on a condition that there is either strong desire for higher workplace status or more developmental job opportunities. The extra effort will subsequently lead to more altruistic helping behavior.

Based on the findings of this paper, human resource managers should consider the job applicant’s desire for workplace status and the organizational context the employer can provide when hiring overqualified employees. Second, organizations should carefully conduct job design to improve overqualified employees’ on-the-job developmental experiences. Third, training programs should be conducted to help satisfy needs and improve workplace status of overqualified employees, so that they can exert extra job effort and engage in pro-organizational behaviors.

Drawing on motivation–opportunity–ability theory, this paper extends the limited understanding of important boundary conditions under which perceived overqualification can be beneficial. The findings add to the knowledge on extant literature by identifying altruistic helping behavior as a new outcome of perceived overqualification.

The purpose of this paper is to build a moderate mediation model to delineate the effects of leader humility on employee constructive voice behavior based on conservation of resources theory and crossover of resources model. Specifically, when a leader behaves with humility, the followers will be more likely to feel they receive psychological resources from their interactions with the leader (i.e. relational energy), and thus engage in more constructive voice behavior. In addition, this energizing effect only occurs when the leader is perceived as having higher apparent sincerity by their subordinates.

The research hypotheses of this study were empirically tested using multi-timepoint and multi-source (i.e. supervisors and subordinates) survey data in China. Study 1, based on data from 449 subordinates and 88 immediate supervisors, was conducted to test the proposed mediation effect. Study 2, based on data from 185 subordinates and 50 immediate supervisors, was conducted to replicate the findings of Study 1 and test the integrated model.

The results of Study 1 support the proposed mediation effect that leader humility positively predicts followers’ constructive voice behavior via boosting followers’ relational energy. The results of Study 2 replicate the findings of Study 1 and further indicate that leader humility is only positively related to perceived relational energy when a leader is perceived as having higher apparent sincerity by their subordinates.

This paper provides detailed instructions for business practitioners. First, given that employee constructive voice behavior is related to employee relational energy and is beneficial to organizations, leaders are encouraged to behave with humility when interacting with their subordinates. Second, from the perspective of human resource management, well-designed training programs can be used to help leaders to develop leader humility. Third, the findings of this paper call attention to a potential risk for humble leaders. Organizations should educate leaders on the potential negative consequences of false humility and encourage leader humility that will appear in leaders’ sincerity.

Overall, drawing on conservation of resources theory and crossover of resources model, this paper reveals that boosting relational energy is a mechanism via which humble leaders can shape employees’ voice behavior. Second, by examining the moderation effect of apparent sincerity of leaders from followers’ perspective, this paper suggests an actor–recipient perspective to identify the boundaries of the energizing mechanism. Third, the findings of this paper add to the knowledge on voice research by highlighting an additional source of energy for employee constructive voice behavior.

With the development of a new generation of digital technologies, digital transformation (DT) has become an inevitable trend for enterprises to achieve development in various industries. Nevertheless, the contradiction between the “fragmented” use of digital technologies and the “systematic” transformation of the industry leads to the underperformance of DT in the construction industry. Whilst previous studies have examined why DT is needed and how separate digital technologies can be used in construction projects, they failed to specify effective tools that can help enterprises identify key resources that facilitate DT from the organisational perspective.

This study established an objective assessment framework for evaluating the digital transformation capability (DTC) of construction enterprises in identifying limitations in their transformation efforts. This study also established a management entropy quantitative model and a comprehensive capability evaluation model of DT to analyse the DT performance of construction enterprises from the internal and external perspectives. Data were collected from 95 listed enterprises in China’s construction industry in 2020 as a case study.

This study concluded that enterprise profitability provides a strong endogenous driving force for DT. Research and development capabilities and DT proficiency of enterprises are the most critical factors in facilitating DT. In addition, China’s construction enterprises' DT was characterised by uneven development and low orderliness. The lack of a unified digital integration platform is key to cracking the dilemma.

This paper systematically identified key DTC in construction enterprises and proposed an objective framework for measuring DTC to enhance the DT performance of these enterprises.