183,666 research outputs found
Assessing Ageing Condition of Mineral Oil-Paper Insulation by Polarization/Depolarization Current
No full textAccurately assessing the ageing status of oil-paper insulation in transformer is essential and important. Polarization and Depolarization Current (PDC) technique is effective in assessing the condition of oil-paper insulation system. Though the PDC behaviour of mineral oil-paper insulation has been widely investigated, there is no report about how to make the quantitative analysis of mineral oil-paper insulation ageing condition by PDC. The PDC characteristics of mineral oil-paper insulation samples were investigated over the ageing period at 110°C. A new method for assessing the ageing condition of mineral oil-paper insulation by calculating the depolarization charge quantity was proposed. Results show that the depolarization charge quantity of mineral oil-paper insulation sample is very sensitive to its ageing condition. The stable depolarization charge quantity could be used to predict the ageing condition of mineral oil-paper insulation
A Comparative Study of Moisture and Temperature Effect on the Frequency Dielectric Response Behaviour of Pressboard Immersed in Natural Ester and Mineral Oil
No full textIt is important to investigate the dielectric behaviour of natural ester-paper insulation as the number of transformer choosing natural ester as its insulation oil is increasing. A comparative study of the influence of moisture and temperature on the frequency dielectric response of pressboard immersed in natural ester and mineral oil was provided. X-Y model simulation was used to indicate the difference between the frequency domain spectroscopy (FDS) characteristics of transformer main insulation system using natural ester-pressboard and mineral oil-pressboard, respectively. Compared to the mineral oil impregnated pressboard with lower moisture content, the natural ester impregnated pressboard with lower moisture content has higher E'r and tan? values in the lower frequency region at various temperatures. While there is no significant difference existing in the E'r and tan? curves of mineral oil impregnated pressboard and natural ester impregnated pressboard with higher moisture content in the lower frequency. X-Y model simulation results show that the dielectric loss difference between natural ester-paper insulation system and mineral oil-paper insulation system with the lower moisture content is more obvious at higher temperature
A constructive proof of a unimodular transformation theorem for simplices
Full text linkMatrices;Linear Programming;Integer Programming
Infinite Dimensional Symmetries of Self-Dual Yang-Mills Theories.
Full text linkWe construct infinite dimensional symmetries of the Chalmers-Siegel action describing the self-dual sector of non-supersymmetric Yang-Mills. The symmetries are derived by virtue of a canonical transformation between the Yang-Mills fields and new fields that map the Chalmers-Siegel action to a free theory which has been used to construct a Lagrangian approach to the MHV rules. We describe the symmetries of the free theory in a quite general way which are an infinite dimensional algebra in the group algebra of isometries.
We dimensionally reduce the symmetries of the action to write down symmetries of the Hitchin system and further, we extend the construction to the supersymmetric, self-dual theory.
We review recent developments in the approach to calculating N=4 Yang-Mills scattering amplitudes using symmetry arguments. Super-conformal symmetry and the recently discovered dual super-conformal symmetry have been shown to be related as a Yangian algebra and moreover, anomalous terms appearing in their action on amplitudes lead to deformations of the generators which gives rise to recursive relationships between amplitudes
Fault Detection and Classification in Analogue Integrated Circuits using Robust Heteroscedastic Probabilistic Neural Networks
No full text
FAKTOR-FAKTOR YANG MEMPENGARUHI RETENSI STAF DI KALANGAN GENERASI Z PADA INDUSTRI PERBANKAN
Full text linkPenelitian ini bertujuan untuk mengeksplorasi faktor-faktor yang memengaruhi retensi tenaga kerja Generasi Z di industri perbankan Indonesia. Bagi sebuah organisasi yang ingin bertahan dan berkembang, penting untuk memenuhi kebutuhan stafnya. Penelitian ini berfokus pada faktor-faktor yang mempengaruhi keputusan Generasi Z untuk tetap bekerja di sektor perbankan. Agar perusahaan mampu mempertahankan generasi muda, mereka perlu memahami kebutuhan khusus dan motivasi generasi ini. Pendekatan kuantitatif digunakan dalam pengumpulan data dengan menyebarkan kuesioner survei kepada responden. Dari 600 kuesioner yang dibagikan, 385 kuesioner berhasil dikembalikan, menghasilkan tingkat respons sebesar 64 persen dengan metode sampel acak. Sasaran utama studi ini adalah karyawan Bank X di Indonesia yang berasal dari kelompok Generasi Z. Penelitian ini diharapkan dapat menambah wawasan yang ada tentang retensi karyawan serta memberikan panduan bagi organisasi perbankan dalam merancang strategi yang lebih efektif untuk mempertahankan karyawan Generasi Z.Kata kunci: Retensi Karyawan; Generasi Z; Budaya Organisasi; Pelatihan dan Pengembangan; Job-Fit
Nahm’s equation and the search for classical solutions in Yang-Mills theory
Full text linkThe history of the theory of magnetic monopoles in classical electrodynamics and unified gauge theories is reviewed, and the Atiyah-Ward and Atiyah-Drinfe1d-Hitchin-Man in constructions of exact classical solutions to the self-dual Yang-Mills equations are described. It is shown that the one-dimensional self-dual equation introduced by Nahm can be reformulated as a Rieraann-Hi1bert problem through the twister transform previously used by Ward for monopole and instanton fields, and a general formula for the patching matrix is derived. This is evaluated in some special cases, and a few simple examples are given where Nahm's equation can be solved by this method. An attempt is made to generalize the ADHM construction to treat non self dual Yang-Mills fields, with only partial success. The one-dimensional analogue of the second-order Yang-Mills equation, the so-called non self dual Nahm equation, is investigated, paying particular attention to a simple ansatz in which translation of the fields is equivalent to a mere scale transformation of the matrices T(_i)(Z). For these 'separable solutions' the matrices satisfy certain cubic equations, whose solution space depends critically on the nature of the Lie algebra under consideration. It is shown that corresponding to certain Riemannian symmetric pairs there are one-parameter families of 'interpolating solutions' to the cubic equations, which join oppositely oriented bases of a Lie subalgebra. The associated matrix-valued functions T(_i)(z) therefore interpolate between solutions of 'selfdual' and 'antiselfdual' Nahm equations
Three dimensions of biodiversity: New perspectives and methods
No full textAlthough the knowledge and understanding of biodiversity is rapidly increasing, very little of the total biodiversity is currently considered in applied conservation actions. In this sense, it is crucial to integrate independent fields of biodiversity models and perspectives with conservation issues, in particular, the views that address the links between biodiversity, ecosystem services and human well-being, species interaction, and focal charismatic species. This study overcomes the lack of framework necessary for this integration, and proposes three perspectives and approaches to assess biodiversity. The first perspective is biodiversity potential. It considers the correlation between renewable resources in local ecosystems and biodiversity potential, in terms of the possibility of maintaining a high degree of biodiversity. The energy cost is evaluated using both static and dynamic methods, based on the measure of the emergy of local renewable resources and of the total emergy throughput needed by components in ecosystem food webs, respectively, also highlighting the link between biodiversity and ecosystem services, species interactions via energy transfer respectively. The second perspective considers the contribution of biodiversity to human well-being, such as domestication. In this approach, we assess the contribution of biodiversity to humans by calculating the emergy of non-renewable resources required to domesticate animals or plants into agricultural products. The third perspective highlights the significance of local focal charismatic species to global biodiversity conservation. Taking rare species as an example, the emergy required to maintain rare species per unit area is used as a quantitative indicator of the role of local rare species in maintaining global biodiversity. By measuring biodiversity from these three perspectives (potential, contribution and significance) simultaneously, biodiversity conservation strategies are addressed for different regions. Taking China as a case study, it shows that the provinces featuring high potential, low contribution and low significance can moderately increase biodiversity development. The provinces with high significance to global biodiversity should strengthen conservation to halt biodiversity loss. The areas exhibiting overexploitation of biodiversity should in turn restrict biodiversity exploitation. The general approaches proposed in this study could be applied to different cases, situations and species, promoting the integration to biodiversity conservation actions at different scales. © 2021 The Author(s
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