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1 – 10 of over 9000Juan Du, Yan Xue, Vijayan Sugumaran, Min Hu and Peng Dong
For prefabricated building construction, improper handling of the production scheduling for prefabricated components is one of the main reasons that affect project performance…
Abstract
Purpose
For prefabricated building construction, improper handling of the production scheduling for prefabricated components is one of the main reasons that affect project performance, which causes overspending, schedule overdue and quality issues. Prior research on prefabricated components production schedule has shown that optimizing the flow shop scheduling problem (FSSP) is the basis for solving this issue. However, some key resources and the behavior of the participants in the context of actual prefabricated components production are not considered comprehensively.
Design/methodology/approach
This paper characterizes the production scheduling of the prefabricated components problem into a permutation flow shop scheduling problem (PFSSP) with multi-optimization objectives, and limitation on mold and buffers size. The lean construction principles of value-based management (VBM) and just-in-time (JIT) are incorporated into the production process of precast components. Furthermore, this paper applies biogeography-based optimization (BBO) to the production scheduling problem of prefabricated components combined with some improvement measures.
Findings
This paper focuses on two specific scenarios: production planning and production rescheduling. In the production planning stage, based on the production factor, this study establishes a multi-constrained and multi-objective prefabricated component production scheduling mathematical model and uses the improved BBO for prefabricated component production scheduling. In the production rescheduling stage, the proposed model allows real-time production plan adjustments based on uncertain events. An actual case has been used to verify the effectiveness of the proposed model and the improved BBO.
Research limitations/implications
With respect to limitations, only linear weighted transformations are used for objective optimization. In regards to research implications, this paper considers the production of prefabricated components in an environment where all parties in the supply chain of prefabricated components participate to solve the production scheduling problem. In addition, this paper creatively applies the improved BBO to the production scheduling problem of prefabricated components. Compared to other algorithms, the results show that the improved BBO show optimized result.
Practical implications
The proposed approach helps prefabricated component manufacturers consider complex requirements which could be used to formulate a more scientific and reasonable production plan. The proposed plan could ensure the construction project schedule and balance the reasonable requirements of all parties. In addition, improving the ability of prefabricated component production enterprises to deal with uncertain events. According to actual production conditions (such as the occupation of mold resources and storage resources of completed components), prefabricated component manufacturers could adjust production plans to reduce the cost and improve the efficiency of the whole prefabricated construction project.
Originality/value
The value of this article is to provide details of the procedures and resource constraints from the perspective of the precast components supply chain, which is closer to the actual production process of prefabricated components. In addition, developing the production scheduling for lean production will be in line with the concept of sustainable development. The proposed lean production scheduling could establish relationships between prefabricated component factory manufacturers, transportation companies, on-site contractors and production workers to reduce the adverse effects of emergencies on the prefabricated component production process, and promote the smooth and efficient operation of construction projects.
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Gang Yu, Zhiqiang Li, Ruochen Zeng, Yucong Jin, Min Hu and Vijayan Sugumaran
Accurate prediction of the structural condition of urban critical infrastructure is crucial for predictive maintenance. However, the existing prediction methods lack precision due…
Abstract
Purpose
Accurate prediction of the structural condition of urban critical infrastructure is crucial for predictive maintenance. However, the existing prediction methods lack precision due to limitations in utilizing heterogeneous sensing data and domain knowledge as well as insufficient generalizability resulting from limited data samples. This paper integrates implicit and qualitative expert knowledge into quantifiable values in tunnel condition assessment and proposes a tunnel structure prediction algorithm that augments a state-of-the-art attention-based long short-term memory (LSTM) model with expert rating knowledge to achieve robust prediction results to reasonably allocate maintenance resources.
Design/methodology/approach
Through formalizing domain experts' knowledge into quantitative tunnel condition index (TCI) with analytic hierarchy process (AHP), a fusion approach using sequence smoothing and sliding time window techniques is applied to the TCI and time-series sensing data. By incorporating both sensing data and expert ratings, an attention-based LSTM model is developed to improve prediction accuracy and reduce the uncertainty of structural influencing factors.
Findings
The empirical experiment in Dalian Road Tunnel in Shanghai, China showcases the effectiveness of the proposed method, which can comprehensively evaluate the tunnel structure condition and significantly improve prediction performance.
Originality/value
This study proposes a novel structure condition prediction algorithm that augments a state-of-the-art attention-based LSTM model with expert rating knowledge for robust prediction of structure condition of complex projects.
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Li Fan, Min Hu and Mingqi Yang
The purpose of this paper is to develop a theoretical design for the attitude control of electromagnetic formation flying (EMFF) satellites, present a nonlinear controller for the…
Abstract
Purpose
The purpose of this paper is to develop a theoretical design for the attitude control of electromagnetic formation flying (EMFF) satellites, present a nonlinear controller for the relative translational control of EMFF satellites and propose a novel method for the allocation of electromagnetic dipoles.
Design/methodology/approach
The feedback attitude control law, magnetic unloading algorithm and large angle manoeuvre algorithm are presented. Then, a terminal sliding mode controller for the relative translation control is put forward and the convergence is proved. Finally, the control allocation problem of electromagnetic dipoles is formulated as an optimization issue, and a hybrid particle swarm optimization (PSO) – sequential quadratic programming (SQP) algorithm to optimize the free dipoles. Three numerical simulations are carried out and results are compared.
Findings
The proposed attitude controller is effective for the sun-tracking process of EMFF satellites, and the magnetic unloading algorithm is valid. The formation-keeping scenario simulation demonstrates the effectiveness of the terminal sliding model controller and electromagnetic dipole calculation method.
Practical implications
The proposed method can be applied to solve the attitude and relative translation control problem of EMFF satellites in low earth orbits.
Originality/value
The paper analyses the attitude control problem of EMFF satellites systematically and proposes an innovative way for relative translational control and electromagnetic dipole allocation.
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N Jayakumar, S Subramanian, S Ganesan and E. B. Elanchezhian
The combined heat and power dispatch (CHPD) aims to optimize the outputs of online units in a power plant consisting thermal generators, co-generators and heat-only units…
Abstract
Purpose
The combined heat and power dispatch (CHPD) aims to optimize the outputs of online units in a power plant consisting thermal generators, co-generators and heat-only units. Identifying the operating point of a co-generator within its feasible operating region (FOR) is difficult. This paper aims to solve the CHPD problem in static and dynamic environments.
Design/methodology/approach
The CHPD plant operation is formulated as an optimization problem under static and dynamic load conditions with the objectives of minimizations of cost and emissions subject to various system and operational constraints. A novel bio-inspired search technique, grey wolf optimization (GWO) algorithm is used as an optimization tool.
Findings
The GWO-based algorithm has been developed to determine the preeminent power and heat dispatch of operating units within the FOR region. The proposed methodology provides fuel cost savings and lesser pollutant emissions than those in earlier reports. Particularly, the GWO always keeps the co-generator’s operating point within the FOR, whereas most of the existing methods fail.
Originality/value
The GWO is applied for the first time to solve the CHPD problems. New dispatch schedules are reported for 7-unit system with the objectives of total fuel cost and emission minimizations, 24-unit system for economic operation and 11-unit system in dynamic environment. The simulation experiments reveal that GWO converges quickly, consistent and the statistical performance clears its applicability to CHPD problems.
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Cuicui Feng, Ming Yi, Min Hu and Fuchuan Mo
The environment in which users acquire medical and health information has changed dramatically, with online health communities (OHCs) emerging as an essential means for accessing…
Abstract
Purpose
The environment in which users acquire medical and health information has changed dramatically, with online health communities (OHCs) emerging as an essential means for accessing health information. It is imperative to comprehend the factors that shape the users' compliance willingness (UCW) to health information in OHCs.
Design/methodology/approach
This study adopted the information adoption model (IAM) and theory of planned behavior (TPB) to investigate the influence of argument quality (AQ), source credibility (SC) and subjective norms (SN) on UCW while considering the two types of online health information – mature and emerging treatments. The authors conducted an explanatory-predictive study based on a 2 (treatment types: mature vs. emerging) * 2 (AQ: high vs. low) * 2 (SC: high vs. low) scenario-based experiment, using the partial least squares structural equation modeling (PLS-SEM).
Findings
SC positively influences AQ. AQ, SC and SN contribute to information usefulness (IU). These factors positively affect UCW through the mediation of IU. SN were found to improve UCW directly. Moreover, the moderating effect of SC on AQ and IU was more substantial for emerging treatments.
Originality/value
The research model integrates IAM and TPB, considering information types as an additional variable. The approach and findings provide a valuable explanation for UCW to health information in OHCs.
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Abdulkhaliq Alazzawie and Noureldin Mohamed Abdelaal
Adopting the split complementizer phrase (CP) hypothesis, the paper aims at providing an account for object cliticization in Standard Arabic (SA) as an instance of object…
Abstract
Purpose
Adopting the split complementizer phrase (CP) hypothesis, the paper aims at providing an account for object cliticization in Standard Arabic (SA) as an instance of object displacement. Kayne's proposal on cliticization is adopted here to account for the type of displacement in SA that objects clitics in SA, like full determiner phrases (DPs), obligatorily move from their base position as independent complements of the verb to the specifier of Foc first before attaching to the verb under the tense node.
Design/methodology/approach
This research adopts a qualitative interpretive research design (Creswell, 2007, 2010). The majority of the samples chosen for the study involve dependent pronominal objects obligatorily attached to the verb. The samples were judged to be grammatical based on the author's judgment as an native speaker of Arabic. Moreover, all the examples were checked for grammaticality by two full professors of Arabic grammar who are native speakers.
Findings
The analysis proposed that, like lexical DP's, pronominal objects originate as separate maximal projection (XP) constituents and move from their base position as verbal complements to the focus position [Spec, Foc]. In other words, both are able to move out of VP, targeting the same specifier position of a functional projection. This movement is focus-driven, that is, triggered by the edge feature on Foc. Pronominal objects at a later phase crucially higher than V0 (possibly in phonetic form (PF)) get cliticized to the verb which has adjoined to T.
Originality/value
Unlike displaced lexical DP objects in SA syntax, displaced pronominal objects, however, have received less critical attention especially within Rizzi's (1997, 2004) left periphery theory and, therefore, some areas of these constructions remain poorly understood.
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Yaw A. Debrah and Ian G. Smith
Presents over sixty abstracts summarising the 1999 Employment Research Unit annual conference held at the University of Cardiff. Explores the multiple impacts of globalization on…
Abstract
Presents over sixty abstracts summarising the 1999 Employment Research Unit annual conference held at the University of Cardiff. Explores the multiple impacts of globalization on work and employment in contemporary organizations. Covers the human resource management implications of organizational responses to globalization. Examines the theoretical, methodological, empirical and comparative issues pertaining to competitiveness and the management of human resources, the impact of organisational strategies and international production on the workplace, the organization of labour markets, human resource development, cultural change in organisations, trade union responses, and trans‐national corporations. Cites many case studies showing how globalization has brought a lot of opportunities together with much change both to the employee and the employer. Considers the threats to existing cultures, structures and systems.
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In this paper, we study partial identification of the distribution of treatment effects of a binary treatment for ideal randomized experiments, ideal randomized experiments with a…
Abstract
In this paper, we study partial identification of the distribution of treatment effects of a binary treatment for ideal randomized experiments, ideal randomized experiments with a known value of a dependence measure, and for data satisfying the selection-on-observables assumption, respectively. For ideal randomized experiments, (i) we propose nonparametric estimators of the sharp bounds on the distribution of treatment effects and construct asymptotically valid confidence sets for the distribution of treatment effects; (ii) we propose bias-corrected estimators of the sharp bounds on the distribution of treatment effects; and (iii) we investigate finite sample performances of the proposed confidence sets and the bias-corrected estimators via simulation.
The question of responsibility is not new to labour law. The earliest developments in labour law and social law sprang from a “legal revolution” to borrow the words of Georges…
Abstract
The question of responsibility is not new to labour law. The earliest developments in labour law and social law sprang from a “legal revolution” to borrow the words of Georges Scelle, considering the concept of responsibility that prevailed in common law. Civil responsibility which was originally based on fault could now be based on the risk inherent to a socially useful activity so as to ensure that the responsibility for damages that might result from it be equitably shared. This development took place under the generalization of the industrial production mode, first within the frame work of laws respecting compensation for industrial accidents.
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Dezhong Liu and Brian H. Kleiner
Historically, it was taken for granted that public services would be delivered by a staff of career civil service employees, working within the structure of centralised public…
Abstract
Historically, it was taken for granted that public services would be delivered by a staff of career civil service employees, working within the structure of centralised public agencies budgeted with appropriated funds. Today, none of these are true‐public programmes are more than likely performed by alternative organisations or mechanisms rather than by public agencies (International City Management Association, 1989); and when public agencies are used, they are more likely to be staffed by contingent workers hired through flexible employment mechanisms rather than permanent employees protected by civil service regulations and collective bargaining agreements (Kilbom, 1995).
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