scholarly journals Challenges in Application of Petri Nets in Manufacturing Systems

Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2305
Author(s):  
Iwona Grobelna ◽  
Andrei Karatkevich
Keyword(s):  
Petri Nets ◽  
Control Systems ◽  
Manufacturing Systems ◽  
State Of The Art ◽  
Deadlock Prevention ◽  
Current State ◽  
Verification Methods ◽  
Challenges And Opportunities ◽  
University Level ◽  
Made In

Petri nets are a useful mathematical formalism for specification of manufacturing systems, supported by various analysis and verification methods. The progress made in automating control systems and the widespread use of Industry 4.0 pose a number of challenges to their application, starting from the education at university level and ending with modelling of real case studies. The paper aims to present and analyse the most relevant challenges and opportunities related to the use of Petri nets as a modelling technique of manufacturing systems. The review of the literature is primarily based on the years 2019–2020 to reflect the current state of the art. The newest approaches to deadlock prevention and recovering, but also other important analysis problems and difficulties in modelling real industrial processes are discussed. Trends for the future are also identified.

Developments in Rechargeable Mno2Electrodes for Lithium Batteries

1988 ◽  
Vol 135 ◽  
Author(s):  
Michael M Thackeray
Keyword(s):  
Lithium Batteries ◽  
Lithium Battery ◽  
Electrode Materials ◽  
State Of The Art ◽  
Structural Features ◽  
Rechargeable Batteries ◽  
Current State ◽  
Alternative Systems ◽  
Battery Technology ◽  
Made In

AbstractConsiderable efforts are in progress to develop rechargeable batteries as alternative systems to the nickel-cadmium battery. In this regard, several advances have been made in ambient-temperature lithium battery technology, and specifically in the engineering of rechargeable lithium/manganese dioxide cells. This paper reviews the current state of the art in rechargeable Li/MnO2battery technology; particular attention is paid to the structural features of various MnO2electrode materials which influence their electrochemical and cycling behaviour in lithium cells.

Optimal Passive Damper Positioning Techniques

2013 ◽  
pp. 85-111 ◽  
Author(s):  
Arun M. Puthanpurayil ◽  
Rajesh P Dhakal ◽  
Athol J. Carr
Keyword(s):  
Seismic Event ◽  
State Of The Art ◽  
Sensitivity Study ◽  
Optimal Distribution ◽  
Comparative Sensitivity ◽  
Numerical Studies ◽  
Current State ◽  
Passive Damper ◽  
Damping Model ◽  
Made In

A consolidated review of the current-state-of-the-art on optimal damper positioning techniques is presented in this chapter. The inherent assumptions made in previous research are discussed and substantiated with numerical studies. Earlier studies have shown that optimal distribution of dampers is sensitive to in-structure damping. In this chapter the significance of optimal distribution of dampers coupled with the necessity for the use of a more realistic in-structure damping model is qualitatively illustrated using a comparative sensitivity study. The effect of inherent assumption of linearity of the parent frame on the ‘optimality’ is also investigated. It is shown that linearity assumption imposed on the parent frame in a major seismic event may not be justified; thereby raising doubts on the scope of optimality techniques proposed in literature.

Petri Net Based Deadlock Prevention Approach for Flexible Manufacturing Systems

2011 ◽  
pp. 416-433 ◽  
Author(s):  
Chunfu Zhong ◽  
Zhiwu Li
Keyword(s):  
Petri Nets ◽  
Petri Net ◽  
Flexible Manufacturing ◽  
Mixed Integer Linear Programming ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Iteration Step ◽  
Mixed Integer ◽  
Deadlock Prevention ◽  
Prevention Approach

In flexible manufacturing systems, deadlocks usually occur due to the limited resources. To cope with deadlock problems, Petri nets are widely used to model these systems. This chapter focuses on deadlock prevention for flexible manufacturing systems that are modeled with S4R nets, a subclass of generalized Petri nets. The analysis of S4R leads us to derive an iterative deadlock prevention approach. At each iteration step, a non-max-controlled siphon is derived by solving a mixed integer linear programming. A monitor is constructed for the siphon such that it is max-controlled. Finally, a liveness-enforcing Petri net supervisor can be derived without enumerating all the strict minimal siphons.

scholarly journals Progress in Cooling Nanoelectronic Devices to Ultra-Low Temperatures

2020 ◽  
Vol 201 (5-6) ◽  
pp. 772-802 ◽  
Author(s):  
A. T. Jones ◽  
C. P. Scheller ◽  
J. R. Prance ◽  
Y. B. Kalyoncu ◽  
D. M. Zumbühl ◽  
...  
Keyword(s):  
State Of The Art ◽  
Electronic Devices ◽  
Bulk Materials ◽  
Nanoelectronic Devices ◽  
Current State ◽  
Physical Effects ◽  
On Chip ◽  
Nanoscale Physics ◽  
A Current ◽  
Made In

AbstractHere we review recent progress in cooling micro-/nanoelectronic devices significantly below 10 mK. A number of groups worldwide are working to produce sub-millikelvin on-chip electron temperatures, motivated by the possibility of observing new physical effects and improving the performance of quantum technologies, sensors and metrological standards. The challenge is a longstanding one, with the lowest reported on-chip electron temperature having remained around 4 mK for more than 15 years. This is despite the fact that microkelvin temperatures have been accessible in bulk materials since the mid-twentieth century. In this review, we describe progress made in the last 5 years using new cooling techniques. Developments have been driven by improvements in the understanding of nanoscale physics, material properties and heat flow in electronic devices at ultralow temperatures and have involved collaboration between universities and institutes, physicists and engineers. We hope that this review will serve as a summary of the current state of the art and provide a roadmap for future developments. We focus on techniques that have shown, in experiment, the potential to reach sub-millikelvin electron temperatures. In particular, we focus on on-chip demagnetisation refrigeration. Multiple groups have used this technique to reach temperatures around 1 mK, with a current lowest temperature below 0.5 mK.

scholarly journals Insight and psychosis: the next 30 years

2019 ◽  
Vol 217 (3) ◽  
pp. 521-523 ◽  
Author(s):  
Anthony S. David
Keyword(s):  
Conceptual Development ◽  
State Of The Art ◽  
Involuntary Treatment ◽  
The Past ◽  
Current State ◽  
Decision Making Capacity ◽  
Cognitive Neurosciences ◽  
Clinical Associations ◽  
The Relationship ◽  
Made In

Academic interest in the concept of insight in psychosis has increased markedly over the past 30 years, prompting this selective appraisal of the current state of the art. Considerable progress has been made in terms of measurement and confirming a number of clinical associations. More recently, the relationship between insight and involuntary treatment has been scrutinised more closely alongside the link between decision-making capacity and insight. Advances in the clinical and cognitive neurosciences have influenced conceptual development, particularly the field of ‘metacognition’. New therapies, including those that are psychologically and neurophysiologically based, are being tested as ways to enhance insight.

scholarly journals Biohorology and biomarkers of aging: Current state-of-the-art, challenges and opportunities

2020 ◽  
Vol 60 ◽  
pp. 101050 ◽  
Author(s):  
Fedor Galkin ◽  
Polina Mamoshina ◽  
Alex Aliper ◽  
João Pedro de Magalhães ◽  
Vadim N. Gladyshev ◽  
...  
Keyword(s):  
State Of The Art ◽  
Biomarkers Of Aging ◽  
Current State ◽  
Challenges And Opportunities

Synthesis and applications of CdSe nano-tetrapods in hybrid photovoltaic devices

2012 ◽  
Vol 84 (12) ◽  
pp. 2549-2558 ◽  
Author(s):  
Lijuan Zhao ◽  
Linfeng Hu
Keyword(s):  
State Of The Art ◽  
Chloroform Solution ◽  
Photovoltaic Devices ◽  
Direct Band Gap ◽  
Field Emitters ◽  
Current State ◽  
Photovoltaic Applications ◽  
Direct Band ◽  
Remarkable Progress ◽  
Made In

Tetrapod-shaped nanocrystals have attracted increasing interest for optoelectronic applications in recent years due to their rich morphologies. With unique properties such as a direct band-gap and excellent photoelectrical characteristics, CdSe nano-tetrapods are promising nanostructures for applications in such fields as photodetectors, field emitters, and photovoltaic devices. This review mainly describes the remarkable progress made in synthesis and hybrid photovoltaic applications of CdSe nano-tetrapods over the last few years. In particular, the “blinking” effect observed from these nano-tetrapods in chloroform solution is highlighted. This overview covers the current state of the art as well as an outlook on possibilities and limitations.

Sign in / Sign up

Export Citation Format

Share Document