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Published in Suzanne K. Kearns, Fundamentals of International Aviation, 2021
Entering the deployment phase, SESAR activities focus on large-scale production and implementation of a variety of infrastructure, equipment, and technologies (including Galileo, the European GNSS). A few examples of initiatives include moving to a 4D trajectory management approach, allowing for flight paths to be adjusted in real time based on predicted demand. (4D refers to the three physical dimensions plus time.) A 4D management approach provides flights with a specific arrival time, and in compensation for accepting the timeslot, aircraft are routed directly without deviations. Data have shown a 100 percent reduction in holding, a 6 percent reduction in total distance flown, a 68 percent reduction in conflicts, and 11 percent less fuel burnt;providing advanced air traffic services through traffic synchronization to improve arrival and departure management, through optimal traffic sequencing;improving ATM network services through better information-sharing within a common operational environment; andintegrating airports into ATM to support collaborative decision-making and improving runway throughput and surface movement management [14].
Three-Dimensional Layout Planning in the Context of Zimbabwe's Planning Profession
Published in Charles Chavunduka, Walter Timo de Vries, Pamela Durán-Díaz, Sustainable and Smart Spatial Planning in Africa, 2022
Dimensions are the different values that are required to locate points on a shape. The first stage of understanding what 3D is about is looking at the dimensions that are in existence. The starting position is a point which in general gives a position and has no dimensions. The next is connecting two points and creating a line (Couprie and Bertrand, 2008). A line has just one dimension known as the length. From the line, there is a plane. Planes have two dimensions that are the length and width. A 3D shape is a solid shape that has a length, width and height. This is how people view things. The fourth dimension is 4D, which is the time component to the 3D shapes (Hu et al., 2000). For general sketches of the dimensions (Figure 18.1).
Three-dimensional ultrasound
Published in Peter R Hoskins, Kevin Martin, Abigail Thrush, Diagnostic Ultrasound, 2019
Peter R Hoskins, Tom MacGillivray
The terms ‘1D’, ‘2D’, ‘3D’ and ‘4D’ are used. The ‘D’ in every case refers to ‘dimension’. ‘1D’ is one spatial dimension, in other words a line; for example a 1D transducer consists of a line of elements. ‘2D’ is two spatial dimensions, which is an area. A 2D transducer consists of a matrix of elements. ‘3D’ is three spatial dimensions, in other words a volume. 3D scanning refers to the collection of 3D volume data. ‘4D’ is three spatial dimensions and one time dimension. 4D scanning refers to the collection of several 3D volumes over a period of time. Examples include the visualisation of the heart during the cardiac cycle, or of the fetus during fetal movement. Table 12.1 summarizes this terminology.
Advanced 4D-bioprinting technologies for brain tissue modeling and study
Published in International Journal of Smart and Nano Materials, 2019
Timothy J. Esworthy, Shida Miao, Se-Jun Lee, Xuan Zhou, Haitao Cui, Yi Y. Zuo, Lijie Grace Zhang
4D bioprinting is a cutting-edge additive manufacturing technology which has an intrinsic capability to fabricate de novo living tissue constructs which can be made to change in various mechanical or physio-spatial aspects when subjected to predetermined stimuli or trigger sources [44]. Moreover, 4D-bioprinting techniques can be used to place both living cells and growth factors in highly ordered, biomimetic motifs which can undergo physiologically relevant transformations which accurately simulate developmental processes, such as tissue stretching, compressing, or the shifting of the biomaterial’s modulus. In this context, the fourth dimension in ‘4D bioprinting’ refers to the element of time which one or more of a 3D printed object’s physical attributes are functionally dependent upon. Put another way, a 4D-bioprinted construct’s conformation or physical characteristics vary through time as a consequence of a given triggering mechanism or stimulus. In this way, these complex 4D objects can be designed in such a manner which they exhibit an inherent ‘self-assembly’ attribute, whereby a construct will change in shape, conformation, or consistency immediately following the printing process. The feature of self-assembly that some 4D-bioprinted objects display arises from physically based information or modular cues which are directly incorporated into the construct’s design and the formulation of the printing material. Wherein these internally based cues guide the construct through the dynamic transformation process once the printing is completed and an external stimulus is enacted [36].
3D-4D visualisation of IoT data from Singapore’s National Science Experiment
Published in Journal of Spatial Science, 2022
Francisco Benita, Jan Perhac, Bige Tunçer, Remo Burkhard, Simon Schubiger
The findings of the user studies in Bleisch et al. (2008), Seipel and Carvalho (2012) or Bleisch and Dykes (2015) have characterised several stylised facts about data visualisation literacy. The participants involved during the experiments were equally fast and accurate when using both the 2D and 3D visualisations. Participants felt more confident (with respect to their own performance to complete tasks) when they used 3D bars visualisations instead of 2D bars visualisations. The key difference between the 3D and 2D settings is in task completion time (efficiency) rather than effectiveness, among many other benefits. With 4D visualisations, this is 3D in time, users can interact in a more friendly way with the temporal dimension of the space-time datasets.
Analysis of barriers of sustainable 4D printing using Grey TOPSIS approach
Published in International Journal of Sustainable Engineering, 2023
Vishal Ashok Wankhede, S. Vinodh
3D printing technology was first discovered in 1987, and it has since attracted governments, researchers and enterprises to use it to produce distinct products from 3D models utilising computer-aided design (CAD) software (Nugroho et al. 2021). This initiative is prompted by many benefits based on 3D printing when compared to conventional production processes like injection moulding and extrusion. Such a method can construct a 3D structure with complicated geometry, which is extremely difficult to create with traditional injection moulding (Jian et al. 2022; Nugroho et al. 2021). Furthermore, it is centred on additive manufacturing technology, which constructs an item by applying raw materials layer by layer to reduce waste (Ameta et al. 2022; Maraveas, Bayer, and Bartzanas 2022). Subtractive manufacturing, for instance computer numerical control (CNC) machining, on the other hand, produces a component by reducing the quantity of material used. However, 3D printing cannot completely replace traditional production due to challenges with surface smoothness, printing speed and mechanical qualities of printed items. Because the fabrication process of this technique is slower than that of injection moulding and extrusion, it may not be suited for large-scale manufacturing (Mallakpour, Tabesh, and Hussain 2021). The generated items from 3D printing often have a rough surface due to the staircase effect (Nugroho et al. 2021; Trenfield et al. 2019). 3D printing with programming, stimuli, time and smart materials may be converted into 4D printing. The term time in this context does not refer to the time it takes to manufacture items. Skylar Tibbits demonstrated how alterations in a static produced item occur over time at the MIT TED conference in 2012. The term ‘electronic commerce’ implies to the auction of goods and services over the internet. This resulted in a new printing age encompassing a new dimension in 3D printing, namely, time, and this was given its own name, 4D printing technology. The fourth dimension is time, which can be inferred as 4D printing is time as an additional dimension of 3D printing (Demoly et al. 2021; Kumar et al. 2021; Mallakpour, Tabesh, and Hussain 2021).