8,175 research outputs found
Five new species of Homalotylus Mayr (Hymenoptera: Encyrtidae) - from India with a key to Indian species
No full textTirunagaru, Krishnachaitanya, Sagadai, Manickavasagam, Kumar, Abhinav (2016): Five new species of Homalotylus Mayr (Hymenoptera: Encyrtidae) - from India with a key to Indian species. Journal of Natural History 50: 2369-2387, DOI: 10.1080/00222933.2016.1193650, URL: http://dx.doi.org/10.1080/00222933.2016.119365
Figure 4. H. varicolorus F in Five new species of Homalotylus Mayr (Hymenoptera: Encyrtidae) - from India with a key to Indian species
No full textFigure 4. H. varicolorus F#: (a) Habitus image, (b) antenna, (c) fore wing, (d) ovipositor.Published as part of Tirunagaru, Krishnachaitanya, Sagadai, Manickavasagam & Kumar, Abhinav, 2016, Five new species of Homalotylus Mayr (Hymenoptera: Encyrtidae) - from India with a key to Indian species, pp. 2369-2387 in Journal of Natural History 50 on page 2381, DOI: 10.1080/00222933.2016.1193650, http://zenodo.org/record/399305
Figure 6. H. noyesi F in Five new species of Homalotylus Mayr (Hymenoptera: Encyrtidae) - from India with a key to Indian species
No full textFigure 6. H. noyesi F#: (a) Habitus image, (b) antenna, (c) fore wing, (d) ovipositor.Published as part of Tirunagaru, Krishnachaitanya, Sagadai, Manickavasagam & Kumar, Abhinav, 2016, Five new species of Homalotylus Mayr (Hymenoptera: Encyrtidae) - from India with a key to Indian species, pp. 2369-2387 in Journal of Natural History 50 on page 2385, DOI: 10.1080/00222933.2016.1193650, http://zenodo.org/record/399305
Elliptic Fibrations on a Generic Jacobian Kummer Surface
Get PDFWe describe all the elliptic fibrations with section on the Kummer surface X of the Jacobian of a very general curve C of genus 2 over an algebraically closed field of characteristic 0, modulo the automorphism group of X and the symmetric group on the Weierstrass points of C. In particular, we compute elliptic parameters and Weierstrass equations for the 25 different fibrations and analyze the reducible fibers and Mordell-Weil lattices. This answers completely a question posed by Kuwata and Shioda in 2008.National Science Foundation (U.S.) (Grant DMS-0757765)National Science Foundation (U.S.) (Grant DMS-0952486)Solomon Buchsbaum AT&T Research Fun
Decentralized Nonlinear Control for Power Systems Using Normal Forms and Detailed Models
No full textThis paper proposes a decentralized method for nonlinear control of oscillatory dynamics in power systems. The method is applicable for ensuring both transient stability and small-signal stability. The method uses an optimal control law, which has been derived in the general framework of nonlinear control using normal forms. The model used to derive the control law is the detailed subtransient model of synchronous machines, as recommended by the IEEE. Minimal approximations have been made in either the derivation or the application of the control law. The developed method also requires the application of the dynamic state estimation technique. As the employed control and estimation schemes only need local measurements, the method remains completely decentralized. The method has been demonstrated as an effective tool to prevent blackouts by simulating a major disturbance in a benchmark power system model and its subsequent control using the proposed method.</p
Multiplicative excellent families of elliptic surfaces of type E[subscript 7] or E[subscript 8]
No full textWe describe explicit multiplicative excellent families of rational elliptic surfaces with Galois group isomorphic to the Weyl group of the root lattices E[subscript 7] or E[subscript 8]. The Weierstrass coefficients of each family are related by an invertible polynomial transformation to the generators of the multiplicative invariant ring of the associated Weyl group, given by the fundamental characters of the corresponding Lie group. As an application, we give examples of elliptic surfaces with multiplicative reduction and all sections defined over Q for most of the entries of fiber configurations and Mordell–Weil lattices described by Oguiso and Shioda, as well as examples of explicit polynomials with Galois group W(E[subscript 7]) or W(E[subscript 8]).National Science Foundation (U.S.) (Career Grant DMS-0952486)Solomon Buchsbaum AT&T Research Fun
Algorithmic design of self-assembling structures
No full textWe study inverse statistical mechanics: how can one design a potential function so as to produce a specified ground state? In this article, we show that unexpectedly simple potential functions suffice for certain symmetrical configurations, and we apply techniques from coding and information theory to provide mathematical proof that the ground state has been achieved. These potential functions are required to be decreasing and convex, which rules out the use of potential wells. Furthermore, we give an algorithm for constructing a potential function with a desired ground state
Review on Distribution System State Estimation Considering Renewable Energy Sources
No full textPower system state estimation (PSSE) is critical for accurately monitoring and managing electrical networks, especially with the increasing integration of renewable energy sources (RESs). This review aims to explicitly evaluate and compare state estimation techniques specifically adapted to handle RES-related uncertainties, providing both theoretical insights and clear practical guidance. It categorizes and analytically compares physical-model-based, forecasting-aided, and neural network-based approaches, summarizing their strengths, limitations, and ideal application scenarios. The paper concludes with recommendations for method selection under different practical conditions, highlighting opportunities for future research
Decentralized Dynamic State Estimation in Power Systems Using Unscented Transformation
Get PDF04/02/15 meb. Accepted version, Ok to add.This paper proposes a decentralized algorithm for real-time estimation of the dynamic states of a power system. The scheme employs phasor measurement units (PMUs) for the measurement of local signals at each generation unit, and subsequent state estimation using unscented Kalman filtering (UKF). The novelty of the scheme is that the state estimation at one generation unit is independent from the estimation at other units, and therefore the transmission of remote signals to a central estimator is not required. This in turn reduces the complexity of each distributed estimator, and makes the estimation process highly efficient, accurate and easily implementable. The applicability of the proposed algorithm has been thoroughly demonstrated on a representative model
Electrical vehicle load modelling for distribution system considering future scenarios
No full textElectric vehicles (EVs) are a valuable means of reducing our reliance on traditional fossil fuel based transportation. In recent years, the market share of EVs is increasing, which raises some important questions: what is the impact of EVs on the electrical load of our electricity distribution systems, and how can we adequately model it? Some researches have been done to model the EV loads and influence, but they are limited in applications due to complexity and requirements of data. This paper proposes a model for EV loads which takes into account diversity of EV loads and difficulties in applications, and provides analysis of the EV loads in modern and future grids. Efficacy of the proposed model has been demonstrated using real EV-datasets, which provides valuable statistical analysis
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