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1. A chunk-based slicer for cooperative 3D printing

   https://doi.org/10.1108/rpj-07-2017-0150  

   McPherson, Jace ; Zhou, Wenchao ( November 2018 , Rapid Prototyping Journal)

   null (Ed.)

   Purpose The purpose of this research is to develop a new slicing scheme for the emerging cooperative three-dimensional (3D) printing platform that has multiple mobile 3D printers working together on one print job. Design/methodology/approach Because the traditional lay-based slicing scheme does not work for cooperative 3D printing, a chunk-based slicing scheme is proposed to split the print job into chunks so that different mobile printers can print different chunks simultaneously without interfering with each other. Findings A chunk-based slicer is developed for two mobile 3D printers to work together cooperatively. A simulator environment is developed to validate the developed slicer, which shows the chunk-based slicer working effectively, and demonstrates the promise of cooperative 3D printing. Research limitations/implications For simplicity, this research only considered the case of two mobile 3D printers working together. Future research is needed for a slicing and scheduling scheme that can work with thousands of mobile 3D printers. Practical implications The research findings in this work demonstrate a new approach to 3D printing. By enabling multiple mobile 3D printers working together, the printing speed can be significantly increased and the printing capability (for multiple materials and multiple components) can be greatly enhanced. Social implications The chunk-based slicing algorithm is critical to the success of cooperative 3D printing, which may enable an autonomous factory equipped with a swarm of autonomous mobile 3D printers and mobile robots for autonomous manufacturing and assembly. Originality/value This work presents a new approach to 3D printing. Instead of printing layer by layer, each mobile 3D printer will print one chunk at a time, which provides the much-needed scalability for 3D printing to print large-sized object and increase the printing speed. The chunk-based approach keeps the 3D printing local and avoids the large temperature gradient and associated internal stress as the size of the print increases. 

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2. Towards Efficiently Provisioning 5G Core Network Slice Based on Resource and Topology Attributes

   https://doi.org/10.3390/app9204361  

   Li, Xin ; Guo, Chengcheng ; Xu, Jun ; Gupta, Lav ; Jain, Raj ( October 2019 , Applied Sciences)

   null (Ed.)

   Efficient provisioning of 5G network slices is a major challenge for 5G network slicing technology. Previous slice provisioning methods have only considered network resource attributes and ignored network topology attributes. These methods may result in a decrease in the slice acceptance ratio and the slice provisioning revenue. To address these issues, we propose a two-stage heuristic slice provisioning algorithm, called RT-CSP, for the 5G core network by jointly considering network resource attributes and topology attributes in this paper. The first stage of our method is called the slice node provisioning stage, in which we propose an approach to scoring and ranking nodes using network resource attributes (i.e., CPU capacity and bandwidth) and topology attributes (i.e., degree centrality and closeness centrality). Slice nodes are then provisioned according to the node ranking results. In the second stage, called the slice link provisioning stage, the k-shortest path algorithm is implemented to provision slice links. To further improve the performance of RT-CSP, we propose RT-CSP+, which uses our designed strategy, called minMaxBWUtilHops, to select the best physical path to host the slice link. The strategy minimizes the product of the maximum link bandwidth utilization of the candidate physical path and the number of hops in it to avoid creating bottlenecks in the physical path and reduce the bandwidth cost. Using extensive simulations, we compared our results with those of the state-of-the-art algorithms. The experimental results show that our algorithms increase slice acceptance ratio and improve the provisioning revenue-to-cost ratio. 

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3. A hybrid adjacency and time-based data structure for analysis of temporal networks

   https://doi.org/10.1007/s41109-022-00489-5  

   Hilsabeck, Tanner ; Arastuie, Makan ; Xu, Kevin S. ( July 2022 , Applied Network Science)

   Dynamic or temporal networks enable representation of time-varying edges between nodes. Conventional adjacency-based data structures used for storing networks such as adjacency lists were designed without incorporating time and can thus quickly retrieve all edges between two sets of nodes (anode-based slice) but cannot quickly retrieve all edges that occur within a given time interval (atime-based slice). We propose a hybrid data structure for storing temporal networks that stores edges in both an adjacency dictionary, enabling rapid node-based slices, and an interval tree, enabling rapid time-based slices. Our hybrid structure also enablescompound slices, where one needs to slice both over nodes and time, either by slicing first over nodes or slicing first over time. We further propose an approach for predictive compound slicing, which attempts to predict whether a node-based or time-based compound slice is more efficient. We evaluate our hybrid data structure on many real temporal network data sets and find that they achieve much faster slice times than existing data structures with only a modest increase in creation time and memory usage.

    

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4. Architecting the Cooperative 3D Printing System

   https://doi.org/10.1115/DETC2020-22711  

   Poudel, Laxmi ; Marques, Lucas Galvan ; Williams, Robert Austin ; Hyden, Zachary ; Guerra, Pablo ; Fowler, Oliver Luke ; Moquin, Stephen Joe ; Sha, Zhenghui ; Zhou, Wenchao ( August 2020 , 40th Computers and Information in Engineering Conference (CIE))

   null (Ed.)

   Cooperative 3D printing (C3DP) is a novel approach to additive manufacturing, where multiple mobile 3D printing robots work together cooperatively to print the desired part. At the core of C3DP lies the chunk-based printing strategy. This strategy splits the desired part into smaller chunks, and then the chunks are assigned and scheduled to be printed by individual printing robots. In our previous work, we presented various hardware and software components of C3DP, such as mobile 3D printers, chunk-based slicing, scheduling, and simulation. In this study, we present a fully integrated and functional C3DP platform with all necessary components, including chunker, slicer, scheduler, printing robots, build floor, and outline how they work in unison from a system-level perspective. To realize C3DP, new developments of both hardware and software are presented, including new chunking approaches, scalable scheduler for multiple robots, SCARA-based printing robots, a mobile platform for transporting printing robots, modular floor tiles, and a charging station for the mobile platform. Finally, we demonstrate the capability of the system using two case studies. In these demonstrations, a CAD model of a part is fed to the chunker, divided into smaller chunks, passed to the scheduler, and assigned and scheduled to be printed by the scheduler with a given number of robots. The slicer generates G-code for each of the chunks and combines G-code into one file for each robot. The simulator then uses the G-code generated by the slicer to generate animations for visualization purposes.

    

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5. Bench-Scale Testing of Grouts for Geo-Slice Peels

   https://doi.org/10.1061/9780784483428.033  

   Yost, K.M. ( January 2021 , Proc. International Foundations Congress and Equipment Exposition (IFCEE 2021))

   Geo-slicing is a novel in situ sampling technique developed in Japan to identify evidence of paleoseismicity in soil deposits not conducive to trenching. To preserve and enhance the stratigraphic features of the geo-slice sample, a “peel” is created from the vertical slice of the soil profile by laying a reinforcing cloth and a grout or adhesive over the slice. After the adhesive dries, the cloth is removed from the slice. A thin layer of soil remains attached to the cloth, creating the peel. The peel can then be examined for paleoliquefaction features such as dikes and sills of sand that are generally devoid of bedding structures. Previous geo-slicing studies used a highly toxic Japanese grout. To conform to modern environmental regulations, it is necessary to identify a less-hazardous grout that still produces a satisfactory peel. A bench-scale study of multiple adhesives for creating geo-slice peels was performed. Adhesives are evaluated for their efficacy in creating a relief that enhances the bedding structures of the soil slice and for other properties such as flexibility and hazard level. Of the eleven adhesives evaluated herein, flex seal liquid was identified as most suitable for creating geo-slice peels. 

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