2,549 research outputs found
Evolution of Controllers for the Speed Control in Thyristor Fed Induction Motor Drive
Induction Motors (IMs) are now becoming the pillar of almost all the motoring applications related to the industry and household. The practical applications of IMs usually require constant motoring speed. As a result, different types of control systems for IM's speed controlling have been shaped. One of the important techniques is the utilization of thyristor fed drive. Although, the thyristor fed induction motor drive (TFIMD) offers stable speed performance, the practical speed control demand is much more precise. Hence, this drive system utilizes additional controllers to attain precise speed for practical applications. This paper offers a detailed review of the controllers utilized with the thyristor fed IM drive in the past few decades to achieve good speed control performance. The clear intent of the paper is to provide a comprehensible frame of the pros and cons of the existing controllers developed for the TFIMD speed control requirements.
Keywords: Thyristor Fed Drives, Induction Motors, Speed Controller, Conventional Controllers, and Soft Computing Techniques
Financial Management Strategies for Sustainable Farming Practices
This paper delves into the multifaceted realm of sustainable farming, offering a holistic view of its definition, significance, and the manifold benefits it brings to the agricultural landscape. Sustainable farming represents a paradigm shift in agriculture, emphasizing environmental responsibility, societal well-being, and economic viability. The benefits it offers span across the realms of environmental conservation, social equity, and financial sustainability, making it a compelling and pressing approach for modern farmers. The financial fundamentals of sustainable farming are explored, covering crucial aspects such as budgeting, cash flow management, and the integration of sustainable technologies. Sound financial management is pivotal for ensuring that eco-friendly practices align with economic stability and long-term prosperity. Risk management is another cornerstone, with a focus on identifying and mitigating potential threats, as well as the role of insurance and hedging in safeguarding farming operations. Access to capital is addressed from both traditional and alternative sources, highlighting the significance of financial support for the adoption of sustainable practices. Record-keeping and financial analysis are essential tools for farmers, facilitating informed decision-making, performance tracking, and the adaptability of strategies to achieve maximum sustainability benefits. Study underscores the pivotal role of government support, encapsulating policies, incentives, and tax benefits designed to encourage sustainable farming practices and compliance with regulatory standards. By adhering to these guidelines, farmers not only contribute to environmental conservation but also secure their economic future
Smart Lock using Image Recognition
In the 21st century, for a digital lifestyle in a smart city, security is one of the core ingredients to ensure digital continuity. The existing smart security technologies use a smartphone, card, and fingerprint that need additional devices to carry or can spread out infectious diseases. Now it is high time to think about an additional device free and more timeconsuming technique. So, an intelligent system is proposed in this paper to secure our doors with face authentication. The human face is a unique and easy identifying feature of a human. The registered user2019;s image is saved in the device as a dataset to train the lock. The system recognizes the registered faces very fast and controls the hardware part to be unlocked. The system is capable of detecting and recognizing human faces from a real-time video. It is usable in the door lock, car lock, hutch, and many more security purposes
Tate Form and Weak Coupling Limits in F-theory
We consider the weak coupling limit of F-theory in the presence of
non-Abelian gauge groups implemented using the traditional ansatz coming from
Tate's algorithm. We classify the types of singularities that could appear in
the weak coupling limit and explain their resolution. In particular, the weak
coupling limit of SU(n) gauge groups leads to an orientifold theory which
suffers from conifold singulaties that do not admit a crepant resolution
compatible with the orientifold involution. We present a simple resolution to
this problem by introducing a new weak coupling regime that admits
singularities compatible with both a crepant resolution and an orientifold
symmetry. We also comment on possible applications of the new limit to model
building. We finally discuss other unexpected phenomena as for example the
existence of several non-equivalent directions to flow from strong to weak
coupling leading to different gauge groups.Comment: 34 page
The ABCDEF's of Matrix Models for Supersymmetric Chern-Simons Theories
We consider N = 3 supersymmetric Chern-Simons gauge theories with product
unitary and orthosymplectic groups and bifundamental and fundamental fields. We
study the partition functions on an S^3 by using the Kapustin-Willett-Yaakov
matrix model. The saddlepoint equations in a large N limit lead to a constraint
that the long range forces between the eigenvalues must cancel; the resulting
quiver theories are of affine Dynkin type. We introduce a folding/unfolding
trick which lets us, at the level of the large N matrix model, (i) map quivers
with orthosymplectic groups to those with unitary groups, and (ii) obtain
non-simply laced quivers from the corresponding simply laced quivers using a
Z_2 outer automorphism. The brane configurations of the quivers are described
in string theory and the folding/unfolding is interpreted as the
addition/subtraction of orientifold and orbifold planes. We also relate the
U(N) quiver theories to the affine ADE quiver matrix models with a
Stieltjes-Wigert type potential, and derive the generalized Seiberg duality in
2 + 1 dimensions from Seiberg duality in 3 + 1 dimensions.Comment: 30 pages, 5 figure
5d quivers and their AdS(6) duals
We consider an infinite class of 5d supersymmetric gauge theories involving
products of symplectic and unitary groups that arise from D4-branes at orbifold
singularities in Type I' string theory. The theories are argued to be dual to
warped AdS(6)x S4/Zn backgrounds in massive Type IIA supergravity. In
particular, this demonstrates the existence of supersymmetric 5d fixed points
of quiver type. We analyze the spectrum of gauge fields and charged states in
the supergravity dual, and find a precise agreement with the symmetries and
charged operators in the quiver theories. We also comment on other brane
objects in the supergravity dual and their interpretation in the field
theories.Comment: 29 pages, 15 figure
Gauge Fluxes in F-theory and Type IIB Orientifolds
We provide a detailed correspondence between G_4 gauge fluxes in F-theory
compactifications with SU(n) and SU(n)x(1) gauge symmetry and their Type IIB
orientifold limit. Based on the resolution of the relevant F-theory Tate models
we classify the factorisable G_4-fluxes and match them with the set of
universal D5-tadpole free U(1)-fluxes in Type IIB. Where available, the global
version of the universal spectral cover flux corresponds to Type IIB gauge flux
associated with a massive diagonal U(1). In U(1)-restricted Tate models extra
massless abelian fluxes exist which are associated with specific linear
combinations of Type IIB fluxes. Key to a quantitative match between F-theory
and Type IIB is a proper treatment of the conifold singularity encountered in
the Sen limit of generic F-theory models. We also shed further light on the
brane recombination process relating generic and U(1)-restricted Tate models.Comment: 53 pages, 3 figures; v2: Refs added; v3: minor corrections to match
version published in JHE
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