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This study aims to develop a four-dimensional (4D) textile composite that self-forms upon thermal stimulation while eliminating thermomechanical programming steps by using fused deposition modeling (FDM) 3D printing technology, and tries to refine the product development path for this composite.

Polylactic acid (PLA) printing filaments were deposited on prestretched Lycra-knitted fabric using desktop-level FDM 3D printing technology to construct a three-layer structure of thermally responsive 4D textiles. Subsequently, the effects of different PLA thicknesses and Lycra knit fabric relative elongation on the permanent shape of thermally responsive 4D textiles were studied. Finally, a simulation program was written, and a case in this study demonstrates the usage of thermally responsive 4D textiles and the simulation program to design a wrist support product.

The constructed three-layer structure of PLA and Lycra knitted fabric can self-form under thermal stimulation. The material can also achieve reversible transformation between a permanent shape and multiple temporary shapes. Thinner PLA deposition and higher relative elongation of the Lycra-knitted fabric result in the greater curvature of the permanent shape of the thermally responsive 4D textile. The simulation program accurately predicted the permanent form of multiple basic shapes.

The proposed method enables 4D textiles to directly self-form upon thermal, which helps to improve the manufacturing efficiency of 4D textiles. The thermal responsiveness of the composite also contributes to building an intelligent human–material–environment interaction system.

Several studies have addressed the use of four-dimensional (4D) building information modeling (BIM) for construction management. However, the automation of the processes for generating 4D models and their integrated use with Location-Based Planning and the Last Planner® System is not well discussed. Therefore, this paper aims to develop a method for automating the generation and use of 4D BIM models integrated with Location-Based Planning and Last Planner® System supporting project control cycles.

The research strategy adopted was Design Science Research. The automated method for using the 4D models was developed and refined in two residential building projects in Brazil, along with 31 meetings and involving 11 direct users. The assessment of the proposed method focuses on four constructs: the impact of process automation, the impact on the identification and assessment of site progress and the planning process, ease of adoption and utility of the proposed method.

The results of this paper indicated increased adherence between planned and executed through an automated method for using the 4D models. The established routines enabled automating the link between the planning levels and the three-dimensional (3D) model, providing a more agile and updated data source and achieving 92.8% of user satisfaction regarding the deadline and frequency of delivery of the 4D model reports. Moreover, this study identified the relationships between the processes of the method proposed and Digital Models.

The primary scientific value achieved in this study is creating a method for automating processes and simplifying steps for the generation and use of 4D BIM models in the production planning and control cycles during the construction phase.

The current air traffic management (ATM) operational approach is changing; “time” is now integrated as an additional fourth dimension on trajectories. This notion will impose on aircraft the compliance of accurate arrival times over designated checkpoints (CPs), called time windows (TWs). This paper aims to clarify the basic requirements and foundations for the practical implementation of this functional framework.

This paper reviews the operational deployment of 4D trajectories, by defining its relationship with other concepts and systems of the future ATM and communications, navigation and surveillance (CNS) context. This allows to establish the main tools that should be considered to ease the application of the 4D-trajectories approach. This paper appraises how 4D trajectories must be managed and planned (negotiation, synchronization, modification and verification processes). Then, based on the evolution of a simulated 4D trajectory, the necessary corrective measures by evaluating the degradation tolerances and conditions are described and introduced.

The proposed TWs model can control the time tolerance within less than 100 s along the passing CPs of a generic trajectory, which is in line with the expected future ATM time-performance requirements.

The main contribution of this work is the provision of a holistic vision of the systems and concepts that will be necessary to implement the new 4D-trajectory concept efficiently, thus enhancing performance. It also proposes tolerance windows for trajectory degradation, to understand both when an update is necessary and what are the conditions required for pilots and air traffic controllers to provide this update.

This paper aims to provide a review of four-dimensional (4D) printing using fused-deposition modeling (FDM). 4D printing is an emerging innovation in (three-dimensional) 3D printing that encompasses active materials in the printing process to create not only a 3D object but also a 3D object that can perform an active function. FDM is the most accessible form of 3D printing. By providing a review of 4D printing with FDM, this paper has the potential in educating the many FDM 3D printers in an additional capability with 4D printing.

This is a review paper. The approach was to search for and review peer-reviewed papers and works concerning 4D printing using FDM. With this discussion of the shape memory effect, shape memory polymers and FDM were also made.

4D printing has become a burgeoning area in addivitive manufacturing research with many papers being produced within the past 3-5 years. This is especially true for 4D printing using FDM. The key findings from this review show the materials and material composites used for 4D printing with FDM and the limitations with 4D printing with FDM.

Limitations to this paper are with the availability of papers for review. 4D printing is an emerging area of additive manufacturing research. While FDM is a predominant method of 3D printing, it is not a predominant method for 4D printing. This is because of the limitations of FDM, which can only print with thermoplastics. With the popularity of FDM and the emergence of 4D printing, however, this review paper will provide key resources for reference for users that may be interested in 4D printing and have access to a FDM printer.

Practically, FDM is the most popular method for 3D printing. Review of 4D printing using FDM will provide a necessary resource for FDM 3D printing users and researchers with a potential avenue for design, printing, training and actuation of active parts and mechanisms.

Continuing with the popularity of FDM among 3D printing methods, a review paper like this can provide an initial and simple step into 4D printing for researchers. From continued research, the potential to engage general audiences becomes more likely, especially a general audience that has FDM printers. An increase in 4D printing could potentially lead to more designs and applications of 4D printed devices in impactful fields, such as biomedical, aerospace and sustainable engineering. Overall, the change and inclusion of technology from 4D printing could have a potential social impact that encourages the design and manufacture of such devices and the treatment of said devices to the public.

There are other 4D printing review papers available, but this paper is the only one that focuses specifically on FDM. Other review papers provide brief commentary on the different processes of 4D printing including FDM. With the specialization of 4D printing using FDM, a more in-depth commentary results in this paper. This will provide many FDM 3D printing users with additional knowledge that can spur more creative research in 4D printing. Further, this paper can provide the impetus for the practical use of 4D printing in more general and educational settings.

The current uptake of 4D planning in industry is slow and there is a need to demonstrate its value over traditional planning technologies. The aim of this research study is to develop a novel approach to establish the value of a 4D tool in the construction industry.

The exploratory research strategy draws on several social science research methods to collect information from human subjects. This exploratory research work has used literature review, open‐ended questionnaire, surveys, semi‐structured interviews and historical site records. These have been analysed in order to identify, develop and quantify 4D‐based key performance indicators.

The paper identifies and quantifies 4D‐based key performance indicators. Analysis of the planning efficiency (hit rate percentages) measure on three projects shows that, on an average, a 17 per cent increase in the average industry hit rate was achieved by the use of 4D technology. Also the quantification of communication efficiency measure has shown that on average 30 per cent of meeting time was saved by the use of 4D planning.

The complexity and rapidly paced development of today's projects are challenging the industry to find new innovative approaches to deliver projects. 4D is emerging as a construction‐planning technology to address some of these challenges. 4D planning has the potential to improve visualisation of building design and construction, but its implementation in the industry has yet to reach maturity. This technology enables clients, contractors, planners and sub‐contractors to visualise and understand design and scheduling issues at the early stages of the project.

This paper proposes to apply the lean philosophy principle of minimizing or eliminating non-value adding activities combined with 4D building information modeling (BIM) simulations to reduce transportation waste in construction production processes.

This study adopts design science research (DSR) because of its prescriptive character to produce innovative constructions (artifacts) to solve real-world problems. The artifact proposed is a set of constructs for evaluating the utility of 4D BIM simulations for transportation waste reduction. The authors performed two learning cycles using empirical studies in projects A, B and C. The construction process of cast-in-place (CIP) reinforcement concrete (RC) was selected to demonstrate and evaluate 4D BIM's utility. The empirical studies focused on understanding the current transportation waste, collecting actual performance data during job site visits and demonstrating the usage of 4D BIM.

In the first cycle, 4D BIM successfully allowed users to understand the CIP-RC process's transportation activities, which were modeled. In the second cycle, 4D BIM enabled better decision-making processes concerning the definitions of strategies for placing reusable formworks for CIP concrete walls by planning transportation activities.

In Cycle 2, three different scenarios were simulated to identify the most suitable formwork assembly planning, and the results were compared to the real situations identified during the job site visits. The scenario chosen demonstrated that the 4D BIM simulation yielded an 18.75% cycle time reduction. In addition, the simulation contributed to a decrease in transportation waste that was previously identified.

The original contribution of this paper is the use of 4D BIM simulation for managing non-value adding activities to reduce transportation waste. The utility of 4D BIM for the reduction of those conflicts considered three constructs: (1) the capacity to improve transportation activity efficiency, (2) the capacity to improve construction production efficiency and (3) the capacity to reduce transportation waste consequences.

Despite its benefits, the uptake of 4D planning in the construction industry is slow and therefore there is a need to demonstrate its value over traditional planning technologies. The aim of this paper is to develop a novel approach that demonstrates the value of 4D tools to the construction industry.

The research strategy utilised draws on several social science research methods. The data collection methods employed included a literature review, an open‐ended questionnaire, surveys, semi‐structured interviews and the analysis of historical site records. The data collected were analysed using qualitative and quantitative techniques in order to identify, develop and quantify 4D‐based key performance indicators.

This paper identifies and quantifies 4D‐based key performance indicators using case study analysis. In the case studies it was found that, on average, a 17 per cent increase in planning efficiency were achieved by the use of 4D technology, while the communication efficiency measure illustrated that, on average, a 30 per cent reduction in the time used for meetings was achieved by the use of 4D planning.

The complexity and rapid pace of development in today's construction projects are challenging the industry to find new innovative approaches to delivering projects. 4D tools are emerging as a construction planning technology that addresses some of these challenges. 4D planning has the potential to improve the visualisation of building design and construction, but its implementation in the industry has yet to reach maturity.

The paper highlights technology that enables clients, contractors, planners and sub‐contractors to visualise and understand design and scheduling issues at the early stages of a project.

The rapid development of the construction industry requires effective ways to monitor and control the project, and the use of 4D BIM is found to be very efficient. The purpose of this paper is to consider development, application and evaluation of 4D Bridge Information Modelling (BrIM) models for an ongoing bridge project.

An ethnographic action-based case study research methodology is adopted in this study. An ongoing bridge construction project in India is chosen and the 4D BrIM application is evaluated both quantitatively and qualitatively using planned percentage complete (PPC) measurements and semi-structured interviews, respectively.

The evaluation of the case study shows an increase in PPC values from 26.5 to 56.4 per cent after implementation of 4D BrIM in the project. The application of 4D BrIM in the construction phase benefits the project team in material delivery planning, project monitoring and control, construction schedule improvement, documentation and coordination.

The developed models are practically applied to the ongoing project and the positive benefits are observed. It is shown that 4D BrIM has the potential to improve the construction of bridge projects.

Studies have contributed towards the development and implementation of 3D BrIM models for bridge projects. Limited efforts have been taken to analyse how 4D BrIM models help in the overall management of bridge projects. This study adds value to the existing literature through development, implementation and systematic qualitative and quantitative evaluation of 4D BrIM models.

The 4D CAD model has been accepted for better conceptualizing and comprehending the sequences and spatial constraints in a construction schedule. The purpose of this paper is to identify the deficiencies of the visualization of the 4D CAD model and to propose improvements.

The presentation abilities of the existing 4D CAD model are analyzed and compared with the other conventional methods, namely Gantt chart, network diagram, and the calendar. Four aspects of the visualization are addressed, namely the overview of a schedule, the duration of an activity, the relationship of an activity, and the project progress tracking. The proposed improvements employed different visual properties of 3D CAD objects such as color, line weight, and line type to represent the different activities' performing statuses. A prototype of the 4D CAD model with enhanced visualization was developed on a construction project case.

The model evaluation showed that this development could enhance the visualization of the 4D CAD model and provide a more informative construction schedule.

It is anticipated that the 4D CAD model with these enhancements can substitute for conventional presentation methods of construction schedules.

British construction industry KPI data collected over recent years shows a trend in projects exceeding their time schedules. In 2013, the UK Government set a target for projects timeframes to reduce by 50 per cent. Proposed interventions included more rapid project delivery processes, and consistent improvements to construction delivery predictions, deployed within the framework of 4D Building Information Modelling (BIM). The purpose of this paper is to use Rogers’ Innovation Diffusion theory as a basis to investigate how this adoption has taken place.

In total, 97 construction planning practitioners were surveyed to measure 4D BIM innovation take-up over time. Classic innovation diffusion research methods were adopted.

Results indicated an increasing rate of 4D BIM adoption and reveal a time lag between awareness and first use that is characteristic of this type of innovation.

Use of a non-probability sampling strategy prevents the results being generalisable to the wider construction population. Future research directions and methods are suggested, including qualitative investigations into decision-making processes around 4D BIM, and case studies exploring the consequences of 4D BIM adoption.

Recommendations of how to facilitate the adoption of 4D BIM innovation are proposed, which identify the critical aspects of system compatibility and safe trialling of the innovation.

This paper reinforces 4D BIM as an innovation and records its actual UK industry adoption rate using an accepted diffusion research method. By focusing on UK industry-wide diffusion the work also stands apart from more typical research efforts that limit innovation diffusion exploration to individual organisations.