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1 – 10 of 38Yong Yin, Jian Zhou, Chaoyong Zhang and Dejun Chen
The purpose of this paper is to discuss an adaptive SLA mechanism for service sharing in virtual environment, which can organize and govern QoS items in terms of service execution…
Abstract
Purpose
The purpose of this paper is to discuss an adaptive SLA mechanism for service sharing in virtual environment, which can organize and govern QoS items in terms of service execution time, reliability, and availability, and provides a common understanding about services, responsibilities, priorities, guarantees and warranties-related virtual cooperative issues.
Design/methodology/approach
The management framework for SLA is introduced, based on which the whole process including SLA contract, adaptive SLA negotiation strategy, SLA deployment and SLA assessment are discussed, and the prototype is implemented in the cloud manufacturing platform.
Findings
A proposed SLA framework for service sharing in virtual environments is given; electronic contracts are designed in the framework for encapsulating measurable aspects of service level agreements so as to provide common understanding about the service; and an improved SLA negotiation strategy with three phases is presented for the dynamicity of the virtual services.
Originality/value
The paper presents a very useful adaptive SLA mechanism for service sharing in virtual environments that can be utilized in concurrent or future advanced manufacturing modes.
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Keywords
Dejun Chen, Zude Zhou, Yingzhe Ma and D.T. Pham
The purpose of this paper is to create a platform framework based on agent for virtual enterprise (VE) with the characteristic of supply chain by adopting multi‐agent technology.
Abstract
Purpose
The purpose of this paper is to create a platform framework based on agent for virtual enterprise (VE) with the characteristic of supply chain by adopting multi‐agent technology.
Design/methodology/approach
According to the system hierarchy theory and the features of VE with the characteristic of supply chain, the conception and organization structure of supply chain‐oriented VE are proposed. Combined with characters of multi‐agent, a platform framework based on agent for VE with the characteristic of supply chain is created. Aiming at complexity of net node of running platform framework, two‐layer architecture mode, which are information alternation layer and basic function layer inside net node based on agent, are designed. The modes are proved to be reasonable in the management of the system and networks resources.
Findings
The theory base of realization of the VE based on agent with the characteristic of supply chain is found.
Research limitations/implications
The reasonable basic function design of various agents are main limitations.
Practical implications
The paper presents a very useful tool for the operation and management of VE.
Originality/value
A new approach and scheme for VE with the characteristic of supply chain is presented. This paper is aimed at researchers and engineers.
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Keywords
Dejun Chen, Zude Zhou and D.T. Pham
The purpose of this paper is to create a model of role‐based access control (RBAC) for virtual enterprise (VE).
Abstract
Purpose
The purpose of this paper is to create a model of role‐based access control (RBAC) for virtual enterprise (VE).
Design/methodology/approach
An access control model for security and management of VE is presented by integrating generic structure of VE and applying the principles of RBAC. In addition, the application of the model to a supply chain oriented VE illustrates that a general access control scheme can ensure the running of VE.
Findings
A theory base of access control for the realization of the VE is found.
Originality/value
The paper provides a very useful new model of access control for VE. This paper is aimed at researchers and engineers.
Details
Keywords
Dejun Chen, Zude Zhou, Yingzhe Ma and D.T. Pham
The purpose of this paper is to create a model of role‐based access control (RBAC) based access control for virtual enterprise (VE).
Abstract
Purpose
The purpose of this paper is to create a model of role‐based access control (RBAC) based access control for virtual enterprise (VE).
Design/methodology/approach
An access control model for security and management of VE is presented by integrating generic structure of VE and applying the principles of RBAC. In addition, the application of the model to a supply chain‐oriented VE illustrates that a general access control scheme can ensure the running of VE.
Findings
A theory base of access control for the realization of the VE is found.
Originality/value
The paper presents a very useful new model of access control for VE. This paper is aimed at researchers and engineers.
Details
Keywords
Dejun Chen, Zude Zhou and Rui Hu
The purpose of this paper is to create the inventory scheduling model for supply chain system.
Abstract
Purpose
The purpose of this paper is to create the inventory scheduling model for supply chain system.
Design/methodology/approach
Aiming at the problems of analysis and modeling of multi‐agent system, an agent‐oriented Petri net (AOPN) model is proposed by introducing the characteristics of agent based on Petri net, and formalization definition of AOPN is presented. Combined with the inventory scheduling in supply chain system, inventory scheduling model based on AOPN is constructed. On the basis of the inventory scheduling model, its program model is designed. Then the reachability of the inventory scheduling model is analyzed and its soundness is verified.
Findings
The AOPN model and inventory scheduling model based on AOPN in supply chain system are found.
Research limitations/implications
The reasonable basic function design of various agents are main limitations.
Practical implications
A very useful tool of analysis for the modeling of inventory scheduling in supply chain system.
Originality/value
The paper presents a new modeling method of inventory scheduling in supply chain system. This paper is aimed at researchers and engineers.
Details
Keywords
The purpose of this paper is to investigate the effects of laser power on the electrochemical corrosion performance in 3.5% NaCl, 0.1 M H2SO4 and 0.1 M NaOH solutions, which…
Abstract
Purpose
The purpose of this paper is to investigate the effects of laser power on the electrochemical corrosion performance in 3.5% NaCl, 0.1 M H2SO4 and 0.1 M NaOH solutions, which provided an experimental basis for the application of Al–Ti–Ni amorphous coating in marine environment.
Design/methodology/approach
Amorphous Al–Ti–Ni coatings were fabricated on S355 structural steel by laser thermal spraying (LTS) at different laser powers. The surface and cross-section morphologies, chemical element distribution, phases and crystallization behaviors of obtained coatings were analyzed using a scanning electron microscope, energy-dispersive X-ray spectroscope, X-ray diffraction and differential scanning calorimetry, respectively. The effects of laser power on the electrochemical corrosion performances of Al–Ti–Ni coatings in 3.5% NaCl, 0.1 M H2SO4 and 0.1 M NaOH solutions were investigated using an electrochemical workstation.
Findings
The crystallization temperature of Al–Ti–Ni coatings fabricated at the laser power of 1,300 and 1,700 W is ∼520°C, whereas that fabricated at the laser power of 1,500 W is ∼310°C. The coatings display excellent corrosion resistance in 3.5% NaCl and 0.1 M NaOH solutions, while a faster dissolution rate in 0.1 M H2SO4 solution. The coatings fabricated at the laser power of 1,300 and 1,700 W present the better electrochemical corrosion resistance in 3.5% NaCl and 0.1 M NaOH solutions, whereas that fabricated at the laser power of 1,500 W exhibits the better electrochemical corrosion resistance in 0.1 M H2SO4 solution.
Originality/value
In this work, Al-wire-cored Ti–Ni powder was first on S355 steel with the laser power of 1,300, 1,500 and 1,700 W, and the effects of laser power on the electrochemical corrosion performance in 3.5% NaCl, 0.1 M H2SO4 and 0.1 M NaOH solutions were investigated using an electrochemical workstation.
Details
Keywords
In this study, an amorphous Al-Ti-Ni coating was fabricated on S355 steel using an arc spraying, and its corrosion behavior immersed in 3.5 per cent NaCl solution for 720 h was…
Abstract
Purpose
In this study, an amorphous Al-Ti-Ni coating was fabricated on S355 steel using an arc spraying, and its corrosion behavior immersed in 3.5 per cent NaCl solution for 720 h was discussed, which provided an experimental basis for the application of arc sprayed Al-Ti-Ni coating on S355 steel on marine platform.
Design/methodology/approach
An amorphous Al-Ti-Ni coating was sprayed on S355 structural steel using an arc spraying. The surface-interface morphologies, chemical element compositions and phases of the obtained Al-Ti-Ni coating were analyzed using a scanning electron microscope, energy dispersive spectrometer and X-ray diffractometer, respectively. The distributions of chemical elements on the coating surface and interface were analyzed using an energy spectrum scanning; the bonding mechanism between the coating and the substrate was also discussed.
Findings
Financial support for this research by the Key Research and Development Project of Jiangsu Province (BE2016052).
Originality/value
In this study, an amorphous Al-Ti-Ni coating was fabricated on S355 steel using an arc spraying, its corrosion behavior immersed in 3.5 per cent 25 NaCl solution for 720 h was discussed.
Details
Keywords
Xiaoyu Wang, Jia Zhai, Dejun Xie and Jingjing Jiang
The purpose of this paper is to investigate the impact of Federal Open Market Committee (FOMC) meetings and the changes of the target rates on stock market uncertainty.
Abstract
Purpose
The purpose of this paper is to investigate the impact of Federal Open Market Committee (FOMC) meetings and the changes of the target rates on stock market uncertainty.
Design/methodology/approach
Multivariate regression analysis is applied to the historical data of VIX, FOMC meetings and target rates. Subtle relations are revealed by further categorizing the FOMC meetings into being scheduled and unscheduled and distinguishing the signs of the changes in VIX and target rates. CPI and the prime rate are used for robustness test.
Findings
The authors first examine the relation between FOMC meetings and target surprises; the results indicate that unscheduled FOMC meetings heavily impact the target surprises. Then, the authors investigate the relation between FOMC meetings and VIX changes; the results show that both unscheduled and scheduled FOMC meetings impact VIX, where the impacts of scheduled FOMC meetings are more substantial. The authors also analyze the responses of VIX to the target surprises, and the results reveal that there is an asymmetric effect of target surprises on VIX, where the influences of the scheduled positive target surprises are more significant. Finally, by examining the relation between the FOMC meeting and the risk-neutral density of the VIX option, the authors conclude that both KURT and SKEW are more affected by unscheduled FOMC meetings.
Originality/value
Deeper dimensions of the relations between VIX, FOMC meetings and target rates are analyzed and more insightful understandings of such relations are gained.
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This paper aims to enhance the corrosive wear and electrochemical corrosion of Ti–6Al–4V alloy.
Abstract
Purpose
This paper aims to enhance the corrosive wear and electrochemical corrosion of Ti–6Al–4V alloy.
Design/methodology/approach
A CoCrAlYTaSi alloy coating was fabricated on Ti–6Al–4V alloy using a laser thermal spraying (LTS). The surface and cross-section morphologies, chemical elements, phases and bonding strength of the obtained coating were analyzed using a scanning electron microscope, energy dispersive spectroscope, X-ray diffraction and scratch test, respectively, The corrosive wear and electrochemical corrosion of CoCrAlYTaSi coating in 3.5 Wt.% NaCl solution were investigated using a wear tester and electrochemical workstation, respectively.
Findings
The average coefficient of frictions (COFs) of CoCrAlYTaSi coating under the wear loads of 2, 4 and 6 N are 1.31, 1.02 and 0.88, respectively; and the corresponding wear rates are 0.66 × 10−4, 1.10 × 10−4 and 1.30 × 10−4 mm3·N–1·m–1, respectively. The wear mechanism under the wear load of 2 N is abrasive wear, while those under the wear loads of 4 and 6 N are adhesive wear and abrasive wear. The charge transfer resistance of CoCrAlYTaSi coating is 5.368 × 105 Ω·cm2, higher than 2.193 × 105 of the substrate.
Originality/value
In this study, a CoCrAlYTaSi coating was firstly fabricated on Ti–6Al–4V alloy using a LTS. Its corrosive wear and electrochemical corrosion in 3.5 Wt.% NaCl solution were investigated, which played a protective role of corrosive wear on Ti–6Al–4V alloy.
Details
Keywords
Yan Baoxu and Kong Dejun
The amorphous Al-Ni-Fe-Gd coatings were fabricated to improve anti-corrosion performance of offshore platforms.
Abstract
Purpose
The amorphous Al-Ni-Fe-Gd coatings were fabricated to improve anti-corrosion performance of offshore platforms.
Design/methodology/approach
The amorphous Al-Ni-Fe-Gd coatings were first fabricated on S355 steel using the laser thermal spraying.
Findings
The amorphous forming capability and corrosion resistance increases with the laser powers increasing.
Research Limitations/implications
The amorphous Al-Ni-Fe-Gd coatings were applied on S355 steel of offshore platforms to increase its long-term heavy and anti-corrosion protection.
Originality/value
The amorphous Al-Ni-Fe-Gd coatings were first fabricated using a laser thermal spraying, improving its anti-corrosion.
Details