Multiple Discharges Before Leader Inception in Long Air Gaps Under Positive Switching Impulses

There are multiple corona bursts before leader inception when the rising rate of the applied voltage or electric field is not sufficiently high enough in long positive sparks. In existing studies, no attention has been paid to whether these corona bursts occur in the same location, and they are mostly considered directly as belonging to the same discharge. However, this paper presents that in a typical rod-plate long air gap, the multiple corona bursts before leader inception are distributed in at least two different locations, and the highest probability of three discharges occurs. Also, the discharge occurs with the highest probability in the time sequence ‘tip-tip-side-tip-other side’ of the electrode in the first five corona bursts. For each discharge, the first corona current is a single, double exponential pulse, while the following corona currents are mostly a superposition of multiple pulses. The above findings are mainly based on experiments in a 1.4 m air gap under positive switching impulses, in which the voltage, current, and high-speed images were recorded simultaneously. Finally, based on the experimental results, this paper discusses the effects brought by ignoring the multiple discharges on key parameters of leader inception and makes some suggestions to optimise long spark experiments

Multiple Discharges Before Leader Inception in Long Air Gaps Under Positive Switching Impulses

There are multiple corona bursts before leader inception when the rising rate of the applied voltage or electric field is not sufficiently high enough in long positive sparks. In existing studies, no attention has been paid to whether these corona bursts occur in the same location, and they are mostly considered directly as belonging to the same discharge. However, this paper presents that in a typical rod-plate long air gap, the multiple corona bursts before leader inception are distributed in at least two different locations, and the highest probability of three discharges occurs. Also, the discharge occurs with the highest probability in the time sequence ‘tip-tip-side-tip-other side’ of the electrode in the first five corona bursts. For each discharge, the first corona current is a single, double exponential pulse, while the following corona currents are mostly a superposition of multiple pulses. The above findings are mainly based on experiments in a 1.4 m air gap under positive switching impulses, in which the voltage, current, and high-speed images were recorded simultaneously. Finally, based on the experimental results, this paper discusses the effects brought by ignoring the multiple discharges on key parameters of leader inception and makes some suggestions to optimise long spark experiments

Schlieren Techniques for Observations of Long Positive Sparks: Review and Application

Understanding the mechanism of positive leader discharge is important in lightning protection engineering and the external insulation design in high voltage power transmission systems. During the propagation of a positive leader, some processes without light-emitting, for example, the insulation recovery process after the breakdown, cannot be observed by optical photography techniques. With the combination of the digital high-speed imaging system, the conventional Schlieren techniques offer new vistas in the long air gap discharge observation. The important features of high spatial resolution, high sensitivity, and easy arrangement make Schlieren techniques powerful and effective tools for characterising the discharge processes without light-emitting. This work presents a brief review of current Schlieren techniques and discusses the design of the Schlieren optics system for long spark observations. Several interesting phenomena discovered at different phases of long sparks with high-speed Schlieren techniques are also presented

NEOLAF, an LLM-powered neural-symbolic cognitive architecture

This paper presents the Never Ending Open Learning Adaptive Framework (NEOLAF), an integrated neural-symbolic cognitive architecture that models and constructs intelligent agents. The NEOLAF framework is a superior approach to constructing intelligent agents than both the pure connectionist and pure symbolic approaches due to its explainability, incremental learning, efficiency, collaborative and distributed learning, human-in-the-loop enablement, and self-improvement. The paper further presents a compelling experiment where a NEOLAF agent, built as a problem-solving agent, is fed with complex math problems from the open-source MATH dataset. The results demonstrate NEOLAF's superior learning capability and its potential to revolutionize the field of cognitive architectures and self-improving adaptive instructional systems

NewtonianTalk: Integration of physics playground and AutoTutor using GIFT

Despite the popularity of games, there has been limited peerreviewed literature published on game-based learning for science. This paper will describe a project that combined an Intelligent Tutoring System (AutoTutor) with a physics game called Physics Playground. As part of this integration we used the Generalized Intelligent Framework for Tutoring (GIFT) to manage communication between the two technologies. We will also discuss the design of a study comparing two versions of the integration. This study is taking place over Spring of 2015 and will be studying the effects of integrating different levels of tutoring into a gamebased learning system

Intelligent tutoring system trends 2006-2018: A literature review

This research examined the longitudinal trends of intelligent tutoring systems (ITS) research using text mining techniques in a more comprehensive manner. Two hundred and thirty-one (231) refereed journal articles were retrieved and analyzed from the Web of Science database from the top six major educational technology-based journals, which are based on the Google Scholar metrics and Baidu Scholar in the period from January 2006 to December 2018. Content analysis was implemented for further analysis based on (a) category of research purpose, (b) disciplines domains, (c) sample group, (d) context utilization, (e) research design, (f) category of learning, (g) learning outcome, (h) periodic journal, (i) country, (j) publisher. This review research of ITS presented findings, which could be a layover platform and guidance for researchers, educators, policymakers or even journal publisher for the future research or reference in the realm of ITS regarding the latest trends