Pengfei Zhang, Lijun Zhao, Olga Vata and Sriram Rajagopal
This paper aims to examine three of the major issues relating to the welfare of seafarers, including wages, social security benefits and onboard and ashore welfare facilities and…
Abstract
Purpose
This paper aims to examine three of the major issues relating to the welfare of seafarers, including wages, social security benefits and onboard and ashore welfare facilities and services. It is impossible to research all countries here, so this paper selects Greece – which is one of today’s primary shipping countries as for shipowning, as well as for global supply and demand for seafarers – to conduct an empirical case study.
Design/methodology/approach
Based on the existing knowledge and scholarship, and primary data collected in several phases of fieldwork, this paper intends to critically examine three major issues relating to the welfare for Greek seafarers, namely, wages, social security benefits and onboard and ashore welfare facilities and services.
Findings
This paper finds that they face poor labour conditions, which are getting worse due to the depressed world and Greek economies and intense financial pressures on shipping companies. The entry into force of the Maritime Labour Convention 2006 has a significant impact on the world maritime industry.
Research limitations/implications
This paper critically examines the three major issues relating to the welfare of Greek seafarers.
Originality/value
Such issues, which Greece is facing are also common in other countries, so the findings and suggestions revealed from this paper are of importance for the global shipping industry and other states.
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Feifei Bian, Danmei Ren, Ruifeng Li, Peidong Liang, Ke Wang and Lijun Zhao
The purpose of this paper is to enable robots to intelligently adapt their damping characteristics and motions in a reactive fashion toward human inputs and task requirements…
Abstract
Purpose
The purpose of this paper is to enable robots to intelligently adapt their damping characteristics and motions in a reactive fashion toward human inputs and task requirements during physical human–robot interaction.
Design/methodology/approach
This paper exploits a combination of the dynamical system and the admittance model to create robot behaviors. The reference trajectories are generated by dynamical systems while the admittance control enables robots to compliantly follow the reference trajectories. To determine how control is divided between the two models, a collaborative arbitration algorithm is presented to change their contributions to the robot motion based on the contact forces. In addition, the authors investigate to model the robot’s impedance characteristics as a function of the task requirements and build a novel artificial damping field (ADF) to represent the virtual damping at arbitrary robot states.
Findings
The authors evaluate their methods through experiments on an UR10 robot. The result shows promising performances for the robot to achieve complex tasks in collaboration with human partners.
Originality/value
The proposed method extends the dynamical system approach with an admittance control law to allow a robot motion being adjusted in real time. Besides, the authors propose a novel ADF method to model the robot’s impedance characteristics as a function of the task requirements.
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Feifei Bian, Danmei Ren, Ruifeng Li, Peidong Liang, Ke Wang and Lijun Zhao
The purpose of this paper is to present a method which enables a robot to learn both motion skills and stiffness profiles from humans through kinesthetic human-robot cooperation.
Abstract
Purpose
The purpose of this paper is to present a method which enables a robot to learn both motion skills and stiffness profiles from humans through kinesthetic human-robot cooperation.
Design Methodology Approach
Admittance control is applied to allow robot-compliant behaviors when following the reference trajectories. By extending the dynamical movement primitives (DMP) model, a new concept of DMP and stiffness primitives is introduced to encode a kinesthetic demonstration as a combination of trajectories and stiffness profiles, which are subsequently transferred to the robot. Electromyographic signals are extracted from a human’s upper limbs to obtain target stiffness profiles. By monitoring vibrations of the end-effector velocities, a stability observer is developed. The virtual damping coefficient of admittance controller is adjusted accordingly to eliminate the vibrations.
Findings
The performance of the proposed methods is evaluated experimentally. The result shows that the robot can perform tasks in a variable stiffness mode as like the human dose in the teaching phase.
Originality Value
DMP has been widely used as a teaching by demonstration method to represent movements of humans and robots. The proposed method extends the DMP framework to allow a robot to learn not only motion skills but also stiffness profiles. Additionally, the authors proposed a stability observer to eliminate vibrations when the robot is disturbed by environment.
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Jun Zhao and Lijun Chen
This study seeks to examine the relationship between individual's cultural values of individualism, collectivism, selected personality traits and the psychological contracts they…
Abstract
Purpose
This study seeks to examine the relationship between individual's cultural values of individualism, collectivism, selected personality traits and the psychological contracts they tend to form.
Design/methodology/approach
Surveys were used to collect data from China and US sample sets. Multiple regression analyses were conducted to explore the impact of selected cultural values and personality traits on individuals' tendency to form transactional contract or relational contract.
Findings
Personality characteristics of equity sensitivity and external locus of control were found to be positively related to transactional contract type for both samples, and conscientiousness was found to be positively related to relational contract, but the relationship was only found for the Chinese sample. The impact of the individualistic cultural value on the type of psychological contract one forms with the employer is uncertain, but the individualism value was found to have a mediator effect between age and transactional contract type for the Chinese sample.
Practical implications
The study contributes evidence that can help explain why employees who face the same job conditions and employment relationships may develop different psychological contracts with their employers. The finding on the mediating effect of individualism between age and transactional contract highlight challenges faced by managers in China's changing economy in terms of motivating and retaining young employees.
Originality/value
The study contributes to research on personality and psychological contracts. In the domain of personality, the study attempts to explore how personality affects organizational behavior. From the perspective of psychological contract, the paper contributes evidence that can help explain why employees who face the same job conditions and employment relationships may develop different psychological contracts with their employers.
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Lujie Chen, Antonella Moretto, Fu Jia, Federico Caniato and Yu Xiong
Qiuping Huang, Xiande Zhao, Min Zhang, KwanHo Yeung, Lijun Ma and Jeff Hoi-yan Yeung
The purpose of this paper is to empirically investigate the joint effects of lead time, information sharing and the accounts receivable period on reverse factoring (RF) adoption…
Abstract
Purpose
The purpose of this paper is to empirically investigate the joint effects of lead time, information sharing and the accounts receivable period on reverse factoring (RF) adoption from the suppliers’ perspective.
Design/methodology/approach
Supported by one of the largest commercial banks in China, survey data are collected from 424 Chinese manufacturing firms and analyzed using regression methods.
Findings
The results suggest that lead time positively affects suppliers’ RF adoption directly and indirectly through the accounts receivable period. Meanwhile, information sharing has a positive, direct and a negative, indirect influence on suppliers’ RF adoption.
Originality/value
The findings give suppliers and financial institutions a better understanding of how to leverage the benefits of RF.
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Min Zhang, Qiuping Huang, Xiande Zhao and Lijun Ma
In this study, we examine the implementation of purchase order finance (POF) which is an innovative supply chain finance (SCF) solution by an innovative SCF lender (i.e. supply…
Abstract
Purpose
In this study, we examine the implementation of purchase order finance (POF) which is an innovative supply chain finance (SCF) solution by an innovative SCF lender (i.e. supply chain service provider (SCSP)). The effect of information integration between the SCSP (lender) and product designers (borrowers) on the lender's POF decisions and the borrowers' new product launch is investigated.
Design/methodology/approach
We conduct a case study in the Chinese smartphone industry. A mixed methods design is used, and data are collected from both the supply chain service provider (SCSP) and product designers. We first conduct a qualitative study. Hypotheses are developed concerning the relationships between information integration, in terms of social interaction and information system integration, POF and new product launch. We then conduct a quantitative study. The multilevel structural equation modelling method is used to test the hypotheses.
Findings
We find that information system integration is positively associated with POF but has no significant effect on new product launch. Social interaction is negatively associated with POF but positively associated with new product launch. POF is positively associated with new product launch.
Originality/value
This study contributes to the literature by empirically examining the implementation of POF from both the lender's and borrower's perspectives. We find that information system integration and social interaction have different effects on POF and new product launch. The results thus provide insights into how a lender makes POF decisions and reveal the benefits of POF for borrowers.
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Lijun Chen, Wanting Zhao and Zheqing Gong
The traditional VeoVa10-VAc copolymer latex, which prepared via the emulsion polymerization of the mixed monomers of VAc and VeoVa10, has the poor water resistance and thermal…
Abstract
Purpose
The traditional VeoVa10-VAc copolymer latex, which prepared via the emulsion polymerization of the mixed monomers of VAc and VeoVa10, has the poor water resistance and thermal stability because of the migration of the conventional emulsifier molecules and the low bond energy of C-C bond. The purpose of this work is that the fluorinated monomer is used to modify the latex. The film of the resultant latex has the C-F bond with high bond energy and low surface energy, which can effectively improve the heat resistance and water resistance of the resultant film. In addition, the reactive emulsifier is used to replace the conventional emulsifier. The drawbacks of the conventional emulsifier molecules migrate and desorb can be avoided when the polymer latex is stored, thereby also improving the water resistance.
Design/methodology/approach
The modified VAc-VeoVa10 latex has been successfully synthesized via the semi-continuous seeded emulsion polymerization, which VAc and VeoVa10 is used as the main monomers and HFMA was used as the functional monomer. KPS and reactive surfactants of SE-10 were used as the initiator and emulsifier, respectively. The structure of resultant latex film was characterized by Fourier transform infrared spectroscopy (FTIR). The latex films were tested by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle (CA). The particle size and its distribution of the latex were measured by the nano particle size analyzer.
Findings
The factors that had an influence on the properties of the latex and the film were investigated in detail. The stability of the resultant latex is good. The average particles of the latex and its distribution are small and uniform, respectively. In comparison with the conventional latex film, the thermal stability and hydrophobicity of the resultant latex film are improved obviously.
Practical implications
The resultant latex can be used in both the waterborne interior and exterior wall coatings, pickering stabilized waterborne polymer dispersions, polymer powders, environmentally friendly polymer-modified waterproof mortar and other fields, which can be satisfied with the high demand of thermal stability and hydrophobicity.
Originality/value
The modification of poly (VAc-VeoVa10) by reactive surfactant and fluorinated monomer is seldom reported. In this study, the fluorinated poly (VAC-VeoVa) latex is prepared via the reactive surfactants, which VAc and VeoVa10 is used as the main monomers and hexafluorobutyl methacrylate is used as the functional monomer. Potassium persulfate (KPS) and allyl nonyl phenoxy propyl alcohol polyoxyethylene ether ammonium sulfate are used as the initiator and emulsifier, respectively.
Details
Keywords
Lijun Chen, Wanting Zhao and Zheqing Gong
The traditional vinyl ester of neodecanoic acid-vinyl acetate (VeoVa10-VAc) copolymer latex is a linear structure with poor film formation, thus causing solvent resistance and…
Abstract
Purpose
The traditional vinyl ester of neodecanoic acid-vinyl acetate (VeoVa10-VAc) copolymer latex is a linear structure with poor film formation, thus causing solvent resistance and wear resistance of the latex film to be poor. This study aims to investigate the use of cross-linkers in emulsion polymerization to modify the latex. During the course of film formation, the reactive functional groups react to form cross-linkage. The network structure can effectively improve the compactness of the resin, thereby greatly improving the water resistance, solvent resistance and heat resistance of the resultant film. In addition, the reactive emulsifier is used to replace the conventional emulsifier. Thus, the drawbacks of the conventional emulsifier molecules migrate and desorb can be avoided when the polymer latex is stored.
Design/methodology/approach
The cross-linked VAc-VeoVa10 latex has been synthesized with the reactive surfactants, in which VAc and VeoVa10 are used as the main monomers and ethylene glycol dimethacrylate (EGDMA) was used as the cross-linked monomer. Potassium persulfate (KPS) and mixed surfactants of alkyl allyl polyoxyethylene ether ammonium sulfate (JS-20) and allyl nonyl phenol polyoxyethylene ether (ANPEO-10) were used as the initiator and emulsifier, respectively. The structure of resultant latex film was characterized by Fourier transform infrared spectroscopy. The latex films were tested by thermogravimetric analysis, differential scanning calorimetry and contact angle (CA). The particle size and its distribution of the latex were measured by the nano particle size analyzer.
Findings
The factors that had an influence on the properties of the latex and the film were investigated in detail. The stability of the resultant latex is good. The average particles of the latex and its distribution are small and uniform, respectively. In comparison with the conventional latex film, the thermal stability and hydrophobicity of the resultant latex film are improved obviously.
Practical implications
The resultant latex can be used in both the waterborne interior and exterior wall coatings, pickering stabilized waterborne polymer dispersions, polymer powders, environmentally friendly polymer-modified waterproof mortar and other fields, which can be satisfied with the high demand of thermal stability and hydrophobicity.
Originality/value
The modification of poly (VAc-VeoVa10) by reactive emulsifier and cross-linker is seldom reported. In this study, the cross-linked poly (VAC-VeoVa) latex is prepared through the reactive surfactants, with VAc and VeoVa10 used as the main monomers and EGDMA used as the cross-linked monomer. KPS and mixed surfactants of JS-20 and ANPEO-10 are used as the initiator and emulsifier, respectively.