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241.
Bosonization of degenerate fermions yields insight both into Landau-Fermi liquids, and into non-Fermi liquids. We begin our review with a pedagogical introduction to bosonization, emphasizing its applicability in spatial dimensions greater than one. After a brief historical overview, we present the essentials of the method. Well known results of Landau theory are recovered, demonstrating that this new tool of many-body theory is robust. Limits of multidimensional bosonization are tested by considering several examples of non-Fermi liquids, in particular the composite fermion theory of the half-filled Landau level. Nested Fermi surfaces present a different challenge, and these may be relevant in the cuprate superconductors. We conclude by discussing the future of multidimensional bosonization. 相似文献
242.
We study the effect of the topology of industrial relationship (IR) between the companies in a stock exchange market on the universal features in the market. For this we propose a stochastic model for stock exchange markets based on the behavior of technical traders. From the numerical simulations we measure the return distribution, P(R), and the autocorrelation function of the volatility, C(T), and find that the observed universal features in real financial markets are originated from the heterogeneity of IR network topology. Moreover, the heterogeneous IR topology can also explain Zipf–Pareto’s law for the distribution of market value of equity in the real stock exchange markets. 相似文献
243.
Hyeong In Choi Sungjin Lee Hwan Pyo Moon Nam-Sook Wee Daehoon Kim Song-Hwa Kwon 《Entropy (Basel, Switzerland)》2021,23(7)
It is known that a variant of Ising model, called Seeded Ising Model, can be used to recover the information content of a biometric template from a fraction of information therein. The method consists in reconstructing the whole template, which is called the intruder template in this paper, using only a small portion of the given template, a partial template. This reconstruction method may pose a security threat to the integrity of a biometric identity management system. In this paper, based on the Seeded Ising Model, we present a systematic analysis of the possible security breach and its probability of accepting the intruder templates as genuine. Detailed statistical experiments on the intruder match rate are also conducted under various scenarios. In particular, we study (1) how best a template is divided into several small pieces called partial templates, each of which is to be stored in a separate silo; (2) how to do the matching by comparing partial templates in the locked-up silos, and letting only the results of these intra-silo comparisons be sent to the central tallying server for final scoring without requiring the whole templates in one location at any time. 相似文献
244.
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246.
Young Kwon song 《代数通讯》2013,41(4):1649-1663
Maximal commutative subalgebras of the algebra of n by n matrices over a field k very rarely have dimension smaller than n. There is a (B, N)-construction which yields subalgebras of this kind. The Courter's algebra that is of this kind was shown a (B, N)-construction where B is the Schur algebra of size 4 and N = k 4. That is, the Courter's algebra is isomorphic to B ? (k 4)2, the idealization of (k 4)2. It was questioned how many isomorphism classes can be produced by varying the finitely generated faithful B-module N. In this paper, we will show that the set of all algebras B ? N 2 fall into a single isomorphism class, where B is the Schur algebra of size 4 and N a finitely generated faithful B-module. 相似文献
247.
An analysis of subspace migration that occurs in the limited-view inverse scattering problem is considered herein. Based on the structure of singular vectors associated with the nonzero singular values of the multi-static response matrix, we establish a relationship between the subspace migration imaging function and Bessel functions of integer order of the first kind. The revealed structure and numerical examples show why subspace migration is applicable for imaging of small scatterers in limited-view inverse scattering problems. 相似文献
248.
Hyun-Joung Kwon Jeong-Ah Seo Takashi Iwahashi Yukio Ouchi Doseok Kim Hyung Kook Kim Yoon-Hwae Hwang 《Current Applied Physics》2013,13(1):271-279
This study examined the acoustic phonon mode of ionic liquids consisting of 1-alkyl-3-methyl-imidazolium family (CnMIM) cations with n values ranging from 2 to 10 and bis(trifluoromethylsulfonyl)amide (TFSA) anion in the temperature range from 300 K to 100 K. [CnMIM]+[TFSA]? showed depolarized (VH) components of Brillouin peaks at temperatures below the glass transition temperature when n is larger than 4. On the other hand, in the case of ionic liquids with different anions, such as [C4MIM]+[BF4]?, [C4MIM]+[PF6]? and [C8MIM]+[BF4]?, the VH component of Brillouin peaks was not observed in the temperature range investigated. The dielectric loss spectra showed that the temperature dependence of alkyl chain domain relaxation of all ionic liquids followed the Arrhenius law and showed an increase in activation energy at the temperature where the VH component of Brillouin peak appeared. These results suggest that the observed depolarized component of Brillouin peak might originate from uniquely induced polarization in the 2nd domain composed of head groups of cations and anions. 相似文献
249.
~66 nm thick CdS film with a hexagonal structure was uniformly generated via a low temperature-processed chemical bath deposition at 80 °C using a complexing agent of ethylenediaminetetraacetic acid and its crystal structure, surface morphology, optical transmittance, and Raman scattering property were measured. Grown CdS film was used as a channel layer for the fabrication of bottom-gate, top-contact thin-film-transistor (TFT). The TFT device with 60 °C-dried channel layer exhibited a poor electrical performance of on-to-off drain current ratio (Ion/Ioff) of 5.1 × 103 and saturated channel mobility (μsat) of 0.10 cm2/Vs. However, upon annealing at 350 °C, substantially improved electrical characteristics resulted, showing Ion/Ioff of 5.9 × 107 and μsat of 5.07 cm2/Vs. Furthermore, CdS channel layer was chemically deposited in an identical way on a transparent substrate of SiNx/ITO/glass as part of transparent TFT fabrication, resulting in Ion/Ioff of 5.8 × 107 and μsat of 2.50 cm2/Vs. 相似文献
250.
Ali Hussain Jin Soo Kim Tae Kwon Song Myong Ho Kim Won Jong Kim Sang Su Kim 《Current Applied Physics》2013,13(6):1055-1059
Lead-free non-stoichiometric (K0.470Na0.545)(Nb0.55Ta0.45)O3 (KNNT) textured ceramics were prepared by a reactive templated grain growth method using NaNbO3 (NN) templates. The Plate-like NaNbO3 (NN) templates were synthesized from bismuth layer-structured Bi2.5Na3.5Nb5O18 (BNN) particles by a topochemical microcrystal conversion (TMC) method. Using 5 wt% of NN templates, textured KNNT ceramics were fabricated, and their crystal structure, microstructure, dielectric and piezoelectric properties were compared with non-textured KNNT ceramics prepared by a conventional solid state reaction method. The textured KNNT ceramics exhibited high grain orientation and high dielectric constant. In addition, piezoelectric properties of textured KNNT ceramics were improved, giving a high piezoelectric coefficient d33 = 390 pC/N and piezoelectric coupling coefficient kp = 0.60. 相似文献