15 research outputs found
Dynamical structure of Carrollian Electrodynamics
We present an action of ultra-relativistic electrodynamics on a flat Carroll
manifold. The model exhibits a couple of physical degrees of freedom per
space-point. We observe that the action of the conformal Carroll algebra on the
phase space is Hamiltonian in 4 space-time dimensions. Moreover the elements of
the algebra give rise to an infinite number of conserved charges and the charge
algebra is an exact realization of the kinematical algebra.Comment: Added few reference
Speed Control of DC Motor using Pid Controller Based on Matlab
This paper is to design PID controller to supervise and control the speed response of the DC motor and MATLAB program is used for calculation and simulation PID controllers are widely used in a industrial plants because of their simplicity and robustness. Industrial processes are subjected to variation in parameters and parameter perturbations. We are choosing PID parameters and discussed Key words: DC motor, PID controller, MATLAB representatio
ESRO: Experience Assisted Service Reliability against Outages
Modern cloud services are prone to failures due to their complex
architecture, making diagnosis a critical process. Site Reliability Engineers
(SREs) spend hours leveraging multiple sources of data, including the alerts,
error logs, and domain expertise through past experiences to locate the root
cause(s). These experiences are documented as natural language text in outage
reports for previous outages. However, utilizing the raw yet rich
semi-structured information in the reports systematically is time-consuming.
Structured information, on the other hand, such as alerts that are often used
during fault diagnosis, is voluminous and requires expert knowledge to discern.
Several strategies have been proposed to use each source of data separately for
root cause analysis. In this work, we build a diagnostic service called ESRO
that recommends root causes and remediation for failures by utilizing
structured as well as semi-structured sources of data systematically. ESRO
constructs a causal graph using alerts and a knowledge graph using outage
reports, and merges them in a novel way to form a unified graph during
training. A retrieval-based mechanism is then used to search the unified graph
and rank the likely root causes and remediation techniques based on the alerts
fired during an outage at inference time. Not only the individual alerts, but
their respective importance in predicting an outage group is taken into account
during recommendation. We evaluated our model on several cloud service outages
of a large SaaS enterprise over the course of ~2 years, and obtained an average
improvement of 27% in rouge scores after comparing the likely root causes
against the ground truth over state-of-the-art baselines. We further establish
the effectiveness of ESRO through qualitative analysis on multiple real outage
examples.Comment: Accepted to 38th IEEE/ACM International Conference on Automated
Software Engineering (ASE 2023
Particle-in-cell simulation study of PCE-gun for different hollow cathode aperture sizes
Pseudospark (PS) discharge is promising source for high brightness and high intensity electron beam pulses. In the present paper, an effort has been made to analyse the temporal behaviour of discharge current, applied voltage, plasma density in the PS discharge based PCE-Gun at different hollow cathode aperture sizes using 3-D particle-in-cell (PIC) simulation code “VORPAL”. The peak discharge current in the PS discharge is a function of hollow cathode dimensions. The plasma generation process by self ionization discharge is examined at different operating conditions. Argon is taken as the background neutral gas. It has been observed that the decrease in the aperture size from 8 mm to 3 mm increases the discharge current, the electron confinement time and the plasma density
Holographic Description of Noncommutative Schwinger Effect
We consider the phenomenon of spontaneous pair production in the presence of an external electric field for noncommutative Yang-Mills theories. Using Maldacena’s holographic conjecture, the threshold electric field for pair production is computed from the quark/antiquark potential for noncommutative theories. As an effect of noncommutativity, the threshold electric field is seen to be smaller than its commutative counterpart. We also estimate the correction to the production rate of quark/antiquark pairs to the first order of the noncommutative deformation parameter. Our result bears resemblance with an earlier related work (based on field-theoretic methods)
Schwinger-Type Pair Production in Non-SUSY AdS/CFT
We study pair production of particles in the presence of an external electric field in a large N non-supersymmetric Yang-Mills theory using the holographic duality. The dual geometry we consider is asymptotically AdS and is effectively parametrized by two parameters, u0 and −5/2<δ≤0, both of which can be related to the effective mass of quark/antiquark for non-supersymmetric theories. We numerically calculate the interquark potential profile and the effective potential to study pair production and analytically find out the threshold electric field beyond which one gets catastrophic pair creation by studying rectangular Wilson loops using the holographic method. We also find out the critical electric field from DBI analysis of a probe brane. Our initial investigations reveal that the critical electric field necessary for spontaneous pair production increases or decreases w.r.t. its non-supersymmetric value depending on the parameter δ. Ultimately, we find out the pair production rate of particles in the presence of an external electric field by evaluating circular Wilson loops using perturbative methods. From the later investigation, we note the resemblance with our earlier prediction. However, we also see that for and below another certain value of the parameter δ, the pair production rate of particle/antiparticle pairs blows up as the external electric field is taken to zero. We thus infer that the vacuum of the non-SUSY gauge theory is unstable for a range of non-supersymmetric parameter δ and that the geometry/non-SUSY field theory under consideration has quite different characteristics than earlier reported
Breakdown Characteristics of Triggered Pseudospark Discharge-Based Multigap Plasma Cathode Electron Source
Particle-in-cell simulation study of PCE-gun for different hollow cathode aperture sizes
225-229Pseudospark (PS)
discharge is promising source for high brightness and high intensity electron
beam pulses. In the present paper, an effort has been made to analyse the
temporal behaviour of discharge current, applied voltage, plasma density in the
PS discharge based PCE-Gun at different hollow cathode aperture sizes using 3-D
particle-in-cell (PIC) simulation code “VORPAL”. The peak discharge current in
the PS discharge is a function of hollow cathode dimensions. The plasma
generation process by self ionization discharge is examined at different
operating conditions. Argon is taken as the background neutral gas. It has been
observed that the decrease in the aperture size from 8 mm to 3 mm increases the
discharge current, the electron confinement time and the plasma density