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Linear Systems
Published in Jeffery J. Leader, Numerical Analysis and Scientific Computation, 2022
In fact, many programming languages will allow you to run multiple processes on a single processor via threading (also called multi-threading). This is somewhat analogous to having multiple cores, but instead of sending different tasks to different processors a single processor is given multiple tasks, each of which is called a thread. For example, in computing Ax we might spawn two threads, one of which computes the dot products for odd-numbered rows of A and the other for even-numbered rows. When there is a lull in the computation of R1·x, perhaps because only part of R1 could be brought nearer the CPU, the second thread can run at least part of the computation of R2·x rather than simply standing idle while waiting. It's possible to outsmart oneself when using threads, but when done well this can really speed up a computation.
A countless variant simulation-based toolkit for remote learning and evaluation
Published in Cogent Engineering, 2023
Felipe Romero, Gerardo Bandera, Javier Romero, Luis F. Romero
Module 5: Input/Output and Operating Systems: a) Preemptive multitasking and time quanta: A microscopic view of how the operating system deals with multitasking using time slicing. Any process can be blocked due to interrupts (Figure 2). b) Interruptions and Daisy Chain: Three devices can set external interrupts, which may be masked individually or globally. The acknowledged response to interruptions is managed by a daisy–chain module.c) Wator: A population dynamics simulation of a toroidal ocean, using multi–threading and high-intensive CPU usage, combined with the process explorer of the system to teach preemption and multitasking.
Optimization of dimensional accuracy in threading process using solid-lubricant embedded textured tools
Published in Materials and Manufacturing Processes, 2022
Salman Khani, Seyedhamidreza Shahabi Haghighi, Mohammad Reza Razfar, Masoud Farahnakian
According to the developed model, predicted maximum deflection in optimal microtexture condition for T1, T-MoS2, and T-CNT were 32.5, 29.5, 28.0 µm, respectively. Also, T0 traditional tool produced 46.8 µm in threading process. Therefore, δmax reduction for T1, T-MoS2, and T-CNT tools are 30.6%, 36.9%, and 40.2%, respectively. The application of the MoS2 and CNT solid lubricants in the cutting process reduces cutting force. The shear strength (τc) of both MoS2 and CNT solid lubricants is much lower than metal shear strength. Therefore, according to Eq. (4), maximum deflection during machining with textured tools embedded with solid lubricant reduces more in comparison with the textured and traditional tools.
Manufacturing a telescopic tube screw using a hydroforming process
Published in Materials and Manufacturing Processes, 2019
Hui Seok Jeong, Jae Hyun Ra, Sang Wook Han, Young Hoon Moon
The proposed hydroforming process for fabricating a telescopic tube screw, with internal thread on the outer tube and outer thread on the inner tube, was successfully implemented and validated in this study.The application of different loading paths in the hydroforming process is useful for creating a small gap to enhance the threading rotation of the tube screws. The small gap originates from different elastic recoveries between the inner and outer tubes.The flexural modulus, peak load, absorbed energy, and loading efficiency of the combined threaded tubes are superior to those of the as-received double-layered circular tubes. The structural strength of tube screw strongly confirms the reliability and applicability of the telescopic tube screws fabricated by the proposed method.The telescopic tube screw, which can provide an adjustable length feature without any restrictions, exhibits strong potential to be used for a wide variety of applications that allow for a secure and perfect fit.