mode change
Recently Published Documents


TOTAL DOCUMENTS

187
(FIVE YEARS 31)

H-INDEX

16
(FIVE YEARS 2)

This study discussed English student teachers’ growth in employability as a driving consequence of the transition to emergency remote learning in light of COVID-19 pandemic. The authors focused on senior students reaching graduation during this critical time. The learning mode change was believed to have a significant impact on graduates’ employability capital, thus influencing their post-study career plans. This quantitative research followed Tomlinson’s (2017) graduate employability framework, covering five forms of capital explores their perceptions of employability capital and measures how perceptions vary between groups of backgrounds. Specifically, they sought to develop a comprehensive understanding of how the transition to remote learning has challenged students’ employability capital, which then affected their career-related decision-making following graduation. The findings suggested, besides implications and limitation, five clustered forms of capital and explain why they perceived differently.


2021 ◽  
Author(s):  
Subhendu Sengupta ◽  
Vincent Goveas

Abstract This paper is based on successful implementation of procedural automation of Ethane (C2) recovery - rejection mode change using Yokogawa's Exapilot software, wherein ADNONC Gas Processing Habshan 5 & Sulphur management approved the implementation based on similar success of the Sulphur Recover Unit start-up/shutdown procedural automation & company's drive for digitalisation. Scope was to develop modules for automating C2 Recovery /Rejection change over procedure in NGL unit using M/s Yokogawa Exapilot software. These automated procedures aimed to standardize said mode change over operations by incorporating the operating know how and the expertise of skilled-experienced operators into the Exapilot system as a set of Standard Operating Procedures (SOPs) that are executed in right operating sequence for enhanced operating efficiency. Two main procedures & associated modules were designed, engineered and built using Exapilot to enable single-click change over automation for NGL units. Those were validated with operation and deployed in the Exapilot Server and were integrated with the Operator Consoles (HIS) for access, and was supplemented with operator training. Ethane Recovery to Rejection Mode Change Ethane Rejection to Recovery Mode Change Besides standardization and reduced change over time, this improved the critical asset integrity and lifespan of NGL section equipment by advocating systematic operations. Following benefits including major take away from this project: ➢ Standardized the mode change-over procedures & minimized human error by the digitalization of paper documentation procedures into electronic workflow process. Procedural Automation like Exapilot is powerful tool for digital transformation of batch/discrete operation like unit/equipment start-up/shutdown or grade/mode change over. ➢ Reduced inherent delay due to manual change over. Hence, minimizing the loss-opportunities & operating cost. Besides this tool can be used as training tool (when used in offline mode) which help operator succession plan & effective knowledge transfer ➢ Automated critical operation such as temperature/flow ramping, improved equipment integrity and prolonged equipment life. Procedural Automation using Exapilot thus can improve operation efficiency, asset integrity, equipment or material life span This paper presents a success story of procedural automation of batch operation in continuation of similar success in SRU start-up & shutdown automation. This tool along with proper integration work with DCS, has opened door for automation/digitalization in batch operation in continuous process not only in other sites of ADNOC Gas Processing and other ADNOC Group Companies but also in other industries that helps companies to enhance efficiency and fulfil their digitalization journey. Though Exapilot software belongs to M/s Yokogawa, however other DCS systems have similar software such as Honeywell DCS EPKS has E-procedure for procedural automation.


Actuators ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 213
Author(s):  
Ming Yu ◽  
Haotian Lu ◽  
Hai Wang ◽  
Chenyu Xiao ◽  
Dun Lan ◽  
...  

In this article, a fast krill herd algorithm is developed for prognosis of hybrid mechatronic system using the improved Wiener degradation process. First, the diagnostic hybrid bond graph is used to model the hybrid mechatronic system and derive global analytical redundancy relations. Based on the global analytical redundancy relations, the fault signature matrix and mode change signature matrix for fault and mode change isolation can be obtained. Second, in order to determine the true faults from the suspected fault candidates after fault isolation, a fault estimation method based on adaptive square root cubature Kalman filter is proposed when the noise distributions are unknown. Then, the improved Wiener process incorporating nonlinear term is developed to build the degradation model of incipient fault based on the fault estimation results. For prognosis, the fast krill herd algorithm is proposed to estimate unknown degradation model coefficients. After that, the probability density function of remaining useful life is derived using the identified degradation model. Finally, the proposed methods are validated by simulations.


2021 ◽  
Vol 11 (16) ◽  
pp. 7295
Author(s):  
Sung-Yoon Jung ◽  
Seung-Gi Kim ◽  
Joo-Hyung Kim ◽  
Se-Hoon Park

Commercial multi-degrees-of-freedom (multi-DOF) myoelectric hand prostheses can perform various hand gestures and grip motions using multiple DOFs. However, as most upper limb amputees have less than two electromyogram (EMG) signals generated at the amputation site, it is difficult to control various hand gestures and grip motions using multi-DOF myoelectric hand prostheses. This paper proposes a multifunctional myoelectric hand prosthesis system that uses only two EMG sensors while improving the convenience of upper limb amputees in everyday life. The proposed system comprises a six-DOF myoelectric hand prosthesis and an easy and effective control algorithm that enables upper limb amputees to perform various hand gestures and grip motions. More specifically, the hand prosthesis has a multi-DOF five-finger mechanism and a small controller that can be mounted inside the hand, allowing it to perform various hand gestures and grip motions. The control algorithm facilitates four grip motions and four gesture motions using the adduction and abduction positions of the thumb, the flexion and extension state of the thumb, and three EMG signals (co-contraction, flexion, and extension) generated using the two EMG sensors. Experimental results indicate that the proposed system is a versatile, flexible, and effective hand prosthesis system for upper limb amputees.


2021 ◽  
Vol 503 (1) ◽  
pp. 152-161 ◽  
Author(s):  
S E Motta ◽  
J J E Kajava ◽  
M Giustini ◽  
D R A Williams ◽  
M Del Santo ◽  
...  

ABSTRACT The Galactic black hole transient GRS 1915+105 is famous for its markedly variable X-ray and radio behaviour, and for being the archetypal galactic source of relativistic jets. It entered an X-ray outburst in 1992 and has been active ever since. Since 2018 GRS 1915+105 has declined into an extended low-flux X-ray plateau, occasionally interrupted by multiwavelength flares. Here, we report the radio and X-ray properties of GRS 1915+105 collected in this new phase, and compare the recent data to historic observations. We find that while the X-ray emission remained unprecedentedly low for most of the time following the decline in 2018, the radio emission shows a clear mode change half way through the extended X-ray plateau in 2019 June: from low flux (∼3 mJy) and limited variability, to marked flaring with fluxes two orders of magnitude larger. GRS 1915+105 appears to have entered a low-luminosity canonical hard state, and then transitioned to an unusual accretion phase, characterized by heavy X-ray absorption/obscuration. Hence, we argue that a local absorber hides from the observer the accretion processes feeding the variable jet responsible for the radio flaring. The radio–X-ray correlation suggests that the current low X-ray flux state may be a signature of a super-Eddington state akin to the X-ray binaries SS433 or V404 Cyg.


Vestnik MEI ◽  
2021 ◽  
pp. 20-30
Author(s):  
Natalya L. Batseva ◽  
◽  
Vasiliy A. Sukhorukov ◽  

The aim of the study is to develop a technique for searching an adaptive gradual load increase trajectory for power grids with a chain structure and to test this technique on the monitored 500 kV backbone grid sections. The technique for searching an adaptive gradual load increase trajectory was developed proceeding from the theoretical data about the chain structures of power grids and about the specific features of their operation modes. The voltage levels at the 500 kV backbone grid nodes and normalized phase angles across the ties included in the studied section and in the adjacent monitored sections are adopted as criteria for monitoring loss of small-signal aperiodic stability in the section under study. Special attention is paid to active power flows through the monitored adjacent sections with respect to the section under study. The proposed technique was tested on two monitored sections of the backbone 500 kV grid. The numerical analysis results have shown that under certain grid configuration and mode conditions, the marginal active power flow determined according to the proposed technique is either higher than the marginal active power flow determined using the mode change vector with the difference between the values from 54 MW to 319 MW, or lower than the marginal flow, with the difference between the values from 121 MW to 228 MW. It has been established that the difference between the values is caused by higher or lower loading of the monitored adjacent sections with respect to the section under study. Grid configuration and mode conditions has also been found in which the marginal active power flows determined according to the proposed technique and the mode change vector are almost identical with one another with the difference making about 15 MW. The subsequent algorithmic implementation of the procedure and development of the relevant software will make it possible to apply it to a larger number of monitored sections and to study various grid configuration and mode conditions for accumulating statistical data. If the software operation speed requirements in a close-to-real-time mode are satisfied, the software will be adapted to the Stability Margin Monitoring System software package. On the whole, the testing of the proposed technique for chain-shaped grids allowed us to conclude that the procedure can be used for searching an adaptive gradual loading trajectory and determining marginal active power flows in regard of small-signal aperiodic stability using the power system analysis model corresponding to the current grid configuration and mode conditions.


Sign in / Sign up

Export Citation Format

Share Document