Chuang Cheng, Hui Zhang, Hui Peng, Zhiqian Zhou, Bailiang Chen, Zhiwen Zeng and Huimin Lu
When the mobile manipulator is traveling on an unconstructed terrain, the external disturbance is generated. The load on the end of the mobile manipulator will be affected…
Abstract
Purpose
When the mobile manipulator is traveling on an unconstructed terrain, the external disturbance is generated. The load on the end of the mobile manipulator will be affected strictly by the disturbance. The purpose of this paper is to reject the disturbance and keep the end effector in a stable pose all the time, a control method is proposed for the onboard manipulator.
Design/methodology/approach
In this paper, the kinematics and dynamics models of the end pose stability control system for the tracked robot are built. Through the guidance of this model information, the control framework based on active disturbance rejection control (ADRC) is designed, which keeps the attitude of the end of the manipulator stable in the pitch, roll and yaw direction. Meanwhile, the control algorithm is operated with cloud computing because the research object, the rescue robot, aims to be lightweight and execute work with remote manipulation.
Findings
The challenging simulation experiments demonstrate that the methodology can achieve valid stability control performance in the challenging terrain road in terms of robustness and real-time.
Originality/value
This research facilitates the stable posture control of the end-effector of the mobile manipulator and maintains it in a suitable stable operating environment. The entire system can normally work even in dynamic disturbance scenarios and uncertain nonlinear modeling. Furthermore, an example is given to guide the parameter tuning of ADRC by using model information and estimate the unknown internal modeling uncertainty, which is difficult to be modeled or identified.
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Hui Yuen Peng and Fong Kwong Yam
In general, lighting application, white light emitting diode (LED) usually exposed to an extreme operating temperature of above 90°C. It is well-known that luminous efficacy and…
Abstract
Purpose
In general, lighting application, white light emitting diode (LED) usually exposed to an extreme operating temperature of above 90°C. It is well-known that luminous efficacy and spectral characteristic of white LED are dependent on the temperature, causing thermal effects on luminous efficacy and color shift of white LED become a critical application checkpoint to be addressed by white LED manufactures. Thus, the purpose of this paper is to minimize the thermal stability issue affecting white LED luminescence during operation by introducing phosphor sedimentation process.
Design/methodology/approach
The LED samples were assembled and sent for centrifugation with 0, 5 and 10 revolutions per second (rps), respectively, during phosphor sedimentation process. Luminescence properties of these LED samples were then characterized at a varying temperature to investigate the effect of phosphor sedimentation on the luminescence stability of LED samples. The LED samples were also cross-sectioned and analyzed to understand the phosphor sedimentation mechanism. Computational fluid dynamics (CFD) was applied to study the temperature distribution of the non-phosphor sediment (NPS) and phosphor sediment (PS) LED during operation to validate the hypotheses based on experimental data.
Findings
Experimental results show that the luminous intensity of PS LED samples degrades less significant at high temperature. The experimental results also show that the color coordinate for PS LED samples is more stable and is less blue-shifted than NPS LED samples as the temperature increased. These are because the heat generated by phosphor particles during operation can be dissipated effectively throughout a high thermal conductivity substrate after phosphor sedimentation. Thus, the phosphor temperature of PS LED is lower than NPS LED during operation as validated with the thermal simulation.
Practical implications
The study of this paper is applicable as a reference for industries who intend to resolve the thermal stability of white LED during operation. The luminescence properties changes as a function of the temperature study in this paper can be used to predict the application performances of white LED accurately. Apart from that, the analysis method of temperature distribution using CFD simulations can be extended by other CFD users in the future.
Originality/value
Implementation of phosphor sedimentation to reduce thermal instability issue of white LED has yet to be reported on previous studies. Most literature just studied the thermal instability issue of either assembled LED or raw material, without suggesting any solution to tackle the issue.
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Umair Akram, Peng Hui, Muhammad Kaleem Khan, Yasir Tanveer, Khalid Mehmood and Wasim Ahmad
The purpose of this paper is to investigate the impact of website quality on online impulse buying behavior (OIBB) in China, and assess the moderating roles of sales promotion and…
Abstract
Purpose
The purpose of this paper is to investigate the impact of website quality on online impulse buying behavior (OIBB) in China, and assess the moderating roles of sales promotion and credit card use.
Design/methodology/approach
An online and personal survey from 1,161 online shoppers belonging to three big cities of China – Beijing, Shanghai, and Nanjing – was conducted. A random sampling technique was utilized for data collection. Data were analyzed using validity and reliability tests, confirmatory factor analysis, and structural equation modeling.
Findings
Three major findings discovered are: first, the website quality positively affects the OIBB; second, the sales promotion significantly influences OIBB and acts as a strong moderator on the relationship between website quality and online impulse buying; and third, the online impulse purchases are positively influenced by use of credit card, and the use of credit card enhances the relationship between website quality and online impulse buying.
Research limitations/implications
First, the website quality positively affects the OIBB; second, the sales promotion significantly influences OIBB and acts as a strong moderator in the relationship between website quality and online impulse buying; and third, online impulse purchases are positively influenced by credit card use. Moreover, credit card use enhances the relationship between website quality and online impulse buying.
Originality/value
This research is the first to investigate the relationship between website quality and OIBB in China, with sales promotion and credit card use as moderators.
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Keywords
Muhammad Sohaib, Umair Akram, Peng Hui, Hassan Rasool, Zohaib Razzaq and Muhammad Kaleem Khan
The purpose of this paper is to investigate the electronic word-of-mouth (eWOM) motivations of regulatory-focused customers with positive and negative consumption experiences.
Abstract
Purpose
The purpose of this paper is to investigate the electronic word-of-mouth (eWOM) motivations of regulatory-focused customers with positive and negative consumption experiences.
Design/methodology/approach
An online survey is conducted in Beijing and Shanghai. A random sampling technique is used to collect data from 854 respondents. Two scenarios of eWOM communication – positive and negative consumption experiences – are randomly assigned to each respondent. This study employs the structural equation modeling and confirmatory factor analysis techniques. However, it uses ordinary least squares and logistic regression to analyze 137 participants in the experimental study.
Findings
Promotion-focused customers that aim for self-enhancement and obtaining social benefits are motivated to spread positive eWOM on social networking sites. However, prevention-focused customers are driven by vengeance and anxiety, revealing higher intentions to post negative eWOM on review sites. eWOM generation is subject to gender, as promotion-focused male customers spread it more than both prevention-focused and promotion-focused female customers. Moreover, platform assistance (PA) has a significant positive impact upon regulatory-focused customers and eWOM (positive vs negative) relationships.
Practical implications
This study provides a deeper understanding of motivational factors of eWOM communication. Specifically, in case of product or service failure, negative consumption experiences drive prevention-focused customers to generate negative eWOM. Thus, using various tactics, marketers need to shift customers from focusing on prevention to focusing on promotion. For example, redeemable free coupons can shift customer attention and generate positive eWOM.
Originality/value
This study provides unique insights about eWOM motivation across genders. It examines regulatory focus, positive vs negative consumption experiences and moderation of PA.
Details
Keywords
Petr Vrchota, Ales Prachar, Shia-Hui Peng, Magnus Tormalm and Peter Eliasson
In the European project AFLoNext, active flow control (AFC) measures were adopted in the wing tip extension leading edge to suppress flow separation. It is expected that the…
Abstract
Purpose
In the European project AFLoNext, active flow control (AFC) measures were adopted in the wing tip extension leading edge to suppress flow separation. It is expected that the designed wing tip extension may improve aerodynamic efficiency by about 2 per cent in terms of fuel consumption and emissions. As the leading edge of the wing tip is not protected with high-lift device, flow separation occurs earlier than over the inboard wing in the take-off/landing configuration. The aim of this study is the adoption of AFC to delay wing tip stall and to improve lift-to-drag ratio.
Design/methodology/approach
Several actuator locations and AFC strategies were tested with computational fluid dynamics. The first approach was “standard” one with physical modeling of the actuators, and the second one was focused on the volume forcing method. The actuators location and the forcing plane close to separation line of the reference configuration were chose to enhance the flow with steady and pulsed jet blowing. Dependence of the lift-to-drag benefit with respect to injected mass flow is investigated.
Findings
The mechanism of flow separation onset is identified as the interaction of slat-end and wing tip vortices. These vortices moving toward each other with increasing angle of attack (AoA) interact and cause the flow separation. AFC is applied to control the slat-end vortex and the inboard movement of the wing tip vortex to suppress their interaction. The separation onset has been postponed by about 2° of AoA; the value of ift-to-drag (L/D) was improved up to 22 per cent for the most beneficial cases.
Practical implications
The AFC using the steady or pulsed blowing (PB) was proved to be an effective tool for delaying the flow separation. Although better values of L/D have been reached using steady blowing, it is also shown that PB case with a duty cycle of 0.5 needs only one half of the mass flow.
Originality/value
Two approaches of different levels of complexity are studied and compared. The first is based on physical modeling of actuator cavities, while the second relies on volume forcing method which does not require detailed actuator modeling. Both approaches give consistent results.
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Keywords
Haya Aldaghlas, Felix Kin Peng Hui and Colin Fraser Duffield
The initiation phase of capital projects is critical as this is where the highest number of options exist for modifying the project with minimal expenditure. Government and large…
Abstract
Purpose
The initiation phase of capital projects is critical as this is where the highest number of options exist for modifying the project with minimal expenditure. Government and large organisations frequently involved in major capital projects have extensive procedures for this phase, yet organisations having an operational focus (like major container terminal stevedores), that only occasionally undertake capital projects face the dilemma of the trade-off between project planning and the management of operations. This research reported in this paper investigated the impact of industry operational considerations on the initiation of capital projects.
Design/methodology/approach
In addition to an extensive literature review, a living research investigation of real projects initiated by a stevedoring company operating in Australia has been observed; the primary author of this paper spent six months as a participant/observer and witnessed the initiation of 12 capital projects. The collected data was qualitatively analysed using a four-step coding method.
Findings
The findings confirm that project initiation is a challenge for organisations who only spasmodically undertake capital projects and available project management frameworks do not necessarily consider the impact of such an organisation's culture. Issues identified that may have a negative impact on the initiation phase include lack of workplace trust, high individualism, ineffective interdepartmental communication, lack of resources and engineering and safety complexity.
Originality/value
The study investigated an underexplored industry within the context of project initiation, using the Australian stevedoring as a case study. This initial investigation suggests that a tailored project management framework is needed for the initiation phase of projects to reflect the unique nature of the stevedoring industry and by inference other industries that have a strong operational focus.
Details
Keywords
Ali Mohammed Saeed, Colin Duffield and Felix Kin Peng Hui
A study of the current practices for evaluating the ex-post performance of public-private partnership (PPP) school projects in Australia via literature review and qualitative case…
Abstract
Purpose
A study of the current practices for evaluating the ex-post performance of public-private partnership (PPP) school projects in Australia via literature review and qualitative case studies has found that no consistent approach exists for evaluating operational performance. A detailed critique of international PPP audits and practices has identified existing gaps in ex-post performance evaluation. Through a process of comparative analysis and industry confirmation, a performance analysis technique aligned with international practice has been developed that can be utilised by the educational departments across Australia to evaluate the ex-post performance of PPP projects (PPPs). The paper aims to discuss these issues.
Design/methodology/approach
This paper opted for qualitative archival analysis of case studies using pattern matching, explanation building, time series, and comparative analysis. The data used for document analysis included value reports, project summaries, and contract documents, as well as local and international audit guidelines.
Findings
This paper reviewed current practices, identified a range of processes, and reported the best practices. However, consideration of the approaches taken in the UK and Australia for evaluating operational performance indicates that current techniques lack consistency.
Research limitations/implications
The developed ex-post performance measurement framework is limited to Australian PPP school projects and, at this stage, cannot be generalised to other social PPP projects.
Practical implications
The paper includes implications for the development of better performance evaluation practices and audits.
Social implications
An enhanced framework for measuring operational performance will increase the accountability of taxpayers in the content of their utilisation by the government.
Originality/value
This paper presents an enhanced ex-post performance measurement framework for education departments across Australia.
Details
Keywords
Abbas Rajabifard, Masoud Kahalimoghadam, Elisa Lumantarna, Nilupa Herath, Felix Kin Peng Hui and Zahra Assarkhaniki
The achievement of the sustainable development goals (SDGs) for all communities and jurisdictions require a comprehensive roadmap that encompasses all dimensions of data…
Abstract
Purpose
The achievement of the sustainable development goals (SDGs) for all communities and jurisdictions require a comprehensive roadmap that encompasses all dimensions of data infrastructure, social, economic, environmental and governance ecosystems. With this in mind, this paper aims to establish the link between the curriculum and intended learning outcomes of undergraduate and postgraduate subjects offered by the University and sustainability. This study is a part of a wider university strategy to embed sustainability knowledge and values in the university curricula. The 17 SDGs developed as a part of the 2030 Agenda for Sustainability Development was used as tool to measure and map how the subjects are linked with sustainability.
Design/methodology/approach
To incorporate sustainability into the curriculum, this paper developed an interdisciplinary approach for analysing the interconnection between the SDGs, the expected subject learning points and the relevant aspects of sustainability (geospatial information, the legal, policies and institutional components). As part of the approach, in the first phase of the study, qualitative data were collected through a review of published information on the SDGs and the content of the subjects available in the subject handbook. Subject codes were assigned to the keywords and key phrases extracted from the SDGs and the subject content, and then compared and matched to establish the link between the subjects and the SDGs. Six university schools offering over 2,157 subjects were investigated. In the second phase, a survey was conducted involving subject coordinators with the purpose of validating the findings of the first phase and determining the strength of the linkages between the subjects and the SDGs. In the third phase, a plugin was designed to be used in the digital twin platform developed in the UoM, allowing visualisation of the research outcomes.
Findings
Based on the interim findings, it was found that some subjects within the schools are linked to more than one SDG. However, not all of the subjects within the schools can be linked to the SDGs. There is a scope of improvement for embedding sustainability in more subjects within the schools. Some of the schools were also found to have weak linkages with sustainability, which demonstrate the challenge in technical subjects in linking their subject contents with sustainability.
Originality/value
This study provides a methodology which enables the integration of sustainability into current state of the curricula at the university to be established. Further, with the advancement of geospatial technology and new visualisation opportunities through the use of the digital twin platform provides capabilities to communicate the outcomes of sustainability and involvement of each faculties and departments more effectively to the university community and wider stakeholders.
Details
Keywords
Jiehao Li, Junzheng Wang, Shoukun Wang, Hui Peng, Bomeng Wang, Wen Qi, Longbin Zhang and Hang Su
This paper aims on the trajectory tracking of the developed six wheel-legged robot with heavy load conditions under uncertain physical interaction. The accuracy of trajectory…
Abstract
Purpose
This paper aims on the trajectory tracking of the developed six wheel-legged robot with heavy load conditions under uncertain physical interaction. The accuracy of trajectory tracking and stable operation with heavy load are the main challenges of parallel mechanism for wheel-legged robots, especially in complex road conditions. To guarantee the tracking performance in an uncertain environment, the disturbances, including the internal friction, external environment interaction, should be considered in the practical robot system.
Design/methodology/approach
In this paper, a fuzzy approximation-based model predictive tracking scheme (FMPC) for reliable tracking control is developed to the six wheel-legged robot, in which the fuzzy logic approximation is applied to estimate the uncertain physical interaction and external dynamics of the robot system. Meanwhile, the advanced parallel mechanism of the electric six wheel-legged robot (BIT-NAZA) is presented.
Findings
Co-simulation and comparative experimental results using the BIT-NAZA robot derived from the developed hybrid control scheme indicate that the methodology can achieve satisfactory tracking performance in terms of accuracy and stability.
Originality/value
This research can provide theoretical and engineering guidance for lateral stability of intelligent robots under unknown disturbances and uncertain nonlinearities and facilitate the control performance of the mobile robots in a practical system.
Details
Keywords
Sari Wahyuni, Alif Azadi Taufik and Felix Kin Peng Hui
This study aims to understand the factors and problems that relate to Indonesian port competitiveness and the problems that need to be addressed by major actors such as the…
Abstract
Purpose
This study aims to understand the factors and problems that relate to Indonesian port competitiveness and the problems that need to be addressed by major actors such as the government and port corporations.
Design/methodology/approach
It combines quantitative analysis from 59 survey respondents and qualitative analysis from focus-group discussions and in-depth interviews with port experts, financial bodies, port corporations and government officials on the condition of Indonesian port planning, development and financing.
Findings
An Indonesian port competitiveness model was developed, comprising government support, business support and operational performance. The authors found a gap between policy expectation and realization of port facilitation, caused by inefficient government bureaucracy, customs clearance and strategic decision-making. The government's consistency and commitment need work to encourage investor interest. Road connectivity, intermodal transportation, and energy infrastructure should be enhanced to increase operational performance. These problems are caused by a lack of feasibility analysis, consideration of local economic developments, and late adoption of standard technology. The maritime-sector workforce should be trained to be more professional with foreign players, more innovative and more open towards foreign assistance.
Practical implications
Port competitiveness includes government-related variables. The government’s initiatives are welcomed but are not enough. Adequate attention to both micro and macro port is necessary to increase port competitiveness. Future research should develop more comprehensive solutions to increase port competitiveness in Indonesia using problems and factors outlined here.
Originality/value
The study investigated the unique factors and problems that relate to Indonesian port competitiveness. It uses a national scope and rich expert data involved in Indonesia's port industry.