Results 41 to 50 of about 13,614 (252)

Detecting Topological Order with Ribbon Operators

, 2016
We introduce a numerical method for identifying topological order in two-dimensional models based on one-dimensional bulk operators. The idea is to identify approximate symmetries supported on thin strips through the bulk that behave as string operators ...
Bridgeman, Jacob C., Flammia, Steven T., Poulin, David   +2 more
core   +1 more source

Understanding Engagement in Collaborative Governance Networks Through Motivation, Learning, and Values

Environmental Policy and Governance, EarlyView.
ABSTRACT Collaborative governance networks are increasingly central to local climate action, yet research offers limited understanding of the personal, psychological, and informal factors that sustain engagement within them. This paper examines how such networks facilitate meaningful and lasting participation through an in‐depth study of Malmö Works, a
Gustav Osberg
wiley   +1 more source

Security domain modeling and suppression of commutation failure for LCC-HVDC considering AC-DC coupling

Energy Conversion and Management: X
In line-commuted converter based high voltage direct current (LCC-HVDC), commutation failure (CF) is a main source of danger. The CF is usually suppressed by regulating the single electrical quantity.
Shoudong Xu, Jinxin Ouyang, Mingyu Pang, Taiyu Xiao, Chao Xiao   +4 more
doaj   +1 more source

Wigner Oscillators, Twisted Hopf Algebras and Second Quantization

, 2008
By correctly identifying the role of central extension in the centrally extended Heisenberg algebra h, we show that it is indeed possible to construct a Hopf algebraic structure on the corresponding enveloping algebra U(h) and eventually deform it ...
B. Chakraborty, Bopp F., Dirac P. A. M., F. Toppan, P. G. Castro   +4 more
core   +2 more sources

Robust Control Using a Matrix Converter to Enhance Wind Turbine Systems

Energy Science &Engineering, EarlyView.
This study uses a more efficient and effective solution to improve the operational performance of a wind turbine‐based power system. This system uses a doubly fed induction generator and relies on a matrix converter and fractional‐order proportional–integral controller.
Sihem Ghoudelbourk, Habib Benbouhenni, Adil Yahdou, Zakaria Mohamed Salem Elbarary, Nicu Bizon   +4 more
wiley   +1 more source

Research on transient AC overvoltage suppression method of DC sending end based on novel fast-excitation MCR

International Journal of Electrical Power & Energy Systems
The growing reliance on high-power high-voltage direct current (HVDC) transmission systems has intensified challenges associated with transient AC overvoltage induced by commutation failures resulting from converter operation characteristics.
Xiyu Yin, Xiaoyue Chen, Linyu Zhang, Shan Li, Yujie Ding, Rui Song, Chunlai Li   +6 more
doaj   +1 more source

Heterotic compactifications on SU(2)-structure backgrounds

, 2009
In this paper we study the reduction of heterotic string theory on SU(2)-structure backgrounds. We compute the bosonic low-energy gauged N=2 supergravity specified by the Killing vectors corresponding to the gauged isometries.
, , , Andrei Micu, B. Spanjaard, B. Wecht, C.M. Hull, D. Joyce, Danny Martínez-Pedrera, H. Samtleben, H. Triendl, I. Benmachiche, J. Bovy, J.P. Gauntlett, Jan Louis, K. Becker, K. Dasgupta, M. Cvetič, M. Graña, M. Haack, M. Rocek, N. Kaloper, N.J. Hitchin, N.J. Hitchin, O. Aharony, R.A. Reid-Edwards, S. Chiossi, S. Gurrieri, S. Salamon, V. Cortes   +29 more
core   +1 more source

The politics of impact: How political ideology shapes perceptions of the environmental impact of individual actions

Journal of Consumer Psychology, EarlyView.
Abstract Although consumers who engage in the same sustainable behaviors objectively have the same environmental impact, this research finds that people's perceptions of that impact are subjective and systematically shaped by political ideology. Seven studies demonstrate that conservatives tend to perceive their sustainable actions to have less of a ...
Aylin Cakanlar, Katherine White, Remi Trudel   +2 more
wiley   +1 more source

CSR disclosure and investment efficiency in MENA countries: The moderating role of CSR committee

Strategic Change, EarlyView.
ABSTRACT Corporate social responsibility disclosure (CSRD) is often recognized as a transparency mechanism that allows companies to communicate their commitment to CSR. However, CSRD may also exacerbate agency conflicts. This study addresses these two contrasting perspectives by investigating the impact of CSRD on investment efficiency and exploring ...
Mohamed Malek Belhoula, Imen Khanchel, Naima Lassoued, Rouba Jebri   +3 more
wiley   +1 more source

Current-limit control method to prevent subsequent commutation failure of LCC-HVDC based on adaptive trigger voltage

International Journal of Electrical Power & Energy Systems, 2020
Abstract With the wide construction of the line-commuted converter-based high-voltage direct current (LCC-HVDC), a large-scale AC/DC hybrid grid pattern has gradually formed. LCC-HVDC is prone to subsequent commutation failure (SCF) during the recovery process of first commutation failure (FCF).
Jinxin Ouyang, Zhen Zhang, Mingyu Pang, Junjun Ye, Xiaofu Xiong   +4 more
openaire   +1 more source