A Privacy-Preserving and Accountable Billing Protocol for Peer-to-Peer Energy Trading Markets

This paper proposes a privacy-preserving and accountable billing (PA-Bill) protocol for trading in peer-to-peer energy markets, addressing situations where there may be discrepancies between the volume of energy committed and delivered. Such discrepancies can lead to challenges in providing both privacy and accountability while maintaining accurate billing. To overcome these challenges, a universal cost splitting mechanism is proposed that prioritises privacy and accountability. It leverages a homomorphic encryption cryptosystem to provide privacy and employs blockchain technology to establish accountability. A dispute resolution mechanism is also introduced to minimise the occurrence of erroneous bill calculations while ensuring accountability and non-repudiation throughout the billing process. Our evaluation demonstrates that PA-Bill offers an effective billing mechanism that maintains privacy and accountability in peer-to-peer energy markets utilising a semi-decentralised approach.Comment: 6-pages, 1 Figure, Accepted for International Conference on Smart Energy Systems and Technologies (SEST2023

Continuous variable private quantum channel

In this paper we introduce the concept of quantum private channel within the continuous variables framework (CVPQC) and investigate its properties. In terms of CVPQC we naturally define a "maximally" mixed state in phase space together with its explicit construction and show that for increasing number of encryption operations (which sets the length of a shared key between Alice and Bob) the encrypted state is arbitrarily close to the maximally mixed state in the sense of the Hilbert-Schmidt distance. We bring the exact solution for the distance dependence and give also a rough estimate of the necessary number of bits of the shared secret key (i.e. how much classical resources are needed for an approximate encryption of a generally unknown continuous-variable state). The definition of the CVPQC is analyzed from the Holevo bound point of view which determines an upper bound of information about an incoming state an eavesdropper is able to get from his optimal measurement.Comment: upper bound on information Eve can get was revised and substantially lowered (chapter IV), part of chapter III rewritten, several typos correcte

Capacities of Grassmann channels

A new class of quantum channels called Grassmann channels is introduced and their classical and quantum capacity is calculated. The channel class appears in a study of the two-mode squeezing operator constructed from operators satisfying the fermionic algebra. We compare Grassmann channels with the channels induced by the bosonic two-mode squeezing operator. Among other results, we challenge the relevance of calculating entanglement measures to assess or compare the ability of bosonic and fermionic states to send quantum information to uniformly accelerated frames.Comment: 33 pages, Accepted in Journal of Mathematical Physics; The role of the (fermionic) braided tensor product for quantum Shannon theory, namely capacity formulas, elucidated; The conclusion on the equivalence of Unruh effect for bosons and fermions for quantum communication purposes made clear and even more precis

Chiral metamaterials with negative refractive index based on four "U" split ring resonators

A uniaxial chiral metamaterial is constructed by double-layered four "U" split ring resonators mutually twisted by 90 degrees. It shows a giant optical activity and circular dichroism. The retrieval results reveal that a negative refractive index is realized for circularly polarized waves due to the large chirality. The experimental results are in good agreement with the numerical results.Comment: 4 pages, 4 figures, Published as cover on AP

Context-dependent seed dispersal by a scatter-hoarding corvid

1. Corvids (crows, jays, magpies and nutcrackers) are important dispersers of large-seeded plants. Studies on captive or supplemented birds suggest that they flexibly adjust their scatter-hoarding behavior to the context of social dynamics and relative seed availability. Because many corvid-dispersed trees show high annual variation in seed production, context-dependent foraging can have strong effects on natural corvid scatter-hoarding behavior. 2. We investigated how seed availability and social dynamics affected scatter-hoarding in the island scrub jays (Aphelocoma insularis). We quantified rates of scatter-hoarding behavior and territorial defense of 26 colormarked birds over a three-year period with variable acorn crops. 3. We tested whether caching parameters were correlated with variation in annual seed production of oaks as predicted by the predator dispersal hypothesis, which states that caching rates and distances should vary with seed abundance in ways that benefit tree fitness. We also tested whether antagonistic interactions with conspecifics would affect scatter-hoarding adversely, as found in experimental studies. 4. Caching behavior varied with acorn availability. Caching distances correlated positively with annual acorn crop size, increasing by as much as 40% between years. Caching rates declined over time in years with small acorn crops, but increased when crops were large. Acorn foraging and caching rates were also negatively correlated with rates of territorial aggression. Overall foraging rates, however, were not associated with aggression, suggesting that reduced dispersal rates were not simply due to time constraints. 5. Our field results support laboratory findings that caching rates and distances by scatter-hoarding corvids are context-dependent. Furthermore, our results are consistent with predictions of the predator dispersal hypothesis and suggest that large seed crops and social interactions among scatter-hoarders affect dispersal benefits for oaks and other masting tree species

X-ray Scintillation in Lead Halide Perovskite Crystals

Current technologies for X-ray detection rely on scintillation from expensive inorganic crystals grown at high-temperature, which so far has hindered the development of large-area scintillator arrays. Thanks to the presence of heavy atoms, solution-grown hybrid lead halide perovskite single crystals exhibit short X-ray absorption length and excellent detection efficiency. Here we compare X-ray scintillator characteristics of three-dimensional (3D) MAPbI3 and MAPbBr3 and two-dimensional (2D) (EDBE)PbCl4 hybrid perovskite crystals. X-ray excited thermoluminescence measurements indicate the absence of deep traps and a very small density of shallow trap states, which lessens after-glow effects. All perovskite single crystals exhibit high X-ray excited luminescence yields of >120,000 photons/MeV at low temperature. Although thermal quenching is significant at room temperature, the large exciton binding energy of 2D (EDBE)PbCl4 significantly reduces thermal effects compared to 3D perovskites, and moderate light yield of 9,000 photons/MeV can be achieved even at room temperature. This highlights the potential of 2D metal halide perovskites for large-area and low-cost scintillator devices for medical, security and scientific applications

Low-energy elastic electron scattering from isobutanol and related alkyl amines

Normalized experimental differential and integral cross sections for vibrationally elastic scattering of low-energy electrons from isobutanol (C_4H_9OH)are presented. The differential cross sections are measured at incident energies from 1 to 100 eV and scattering angles from 5° to 130°. These cross sections are compared to earlier experimental and theoretical results for isobutanol and n-butanol, as well as to results for smaller alcohols and for alkanes. Further comparisons are made with calculated cross sections for isobutylamine (C_4H_9NH_2)and for smaller amines, including ethylamine (C_2H_5NH_2), dimethylamine (CH_3NHCH_3)the two C_3H_7NH_2 isomers n-propylamine and isopropylamine, and ethylene diamine (NH_2C_2H_4NH_2). The calculated cross sections are obtained using the Schwinger multichannel method. The comparisons illuminate the role of molecular structure in determining the angular distribution of resonantly scattered electrons

Simultaneous measurement of the muon neutrino charged-current cross section on oxygen and carbon without pions in the final state at T2K

Authors: K. Abe,56 N. Akhlaq,45 R. Akutsu,57 A. Ali,32 C. Alt,11 C. Andreopoulos,54,34 L. Anthony,21 M. Antonova,19 S. Aoki,31 A. Ariga,2 T. Arihara,59 Y. Asada,69 Y. Ashida,32 E. T. Atkin,21 Y. Awataguchi,59 S. Ban,32 M. Barbi,46 G. J. Barker,66 G. Barr,42 D. Barrow,42 M. Batkiewicz-Kwasniak,15 A. Beloshapkin,26 F. Bench,34 V. Berardi,22 L. Berns,58 S. Bhadra,70 S. Bienstock,53 S. Bolognesi,6 T. Bonus,68 B. Bourguille,18 S. B. Boyd,66 A. Bravar,13 D. Bravo Berguño,1 C. Bronner,56 S. Bron,13 A. Bubak,51 M. Buizza Avanzini ,10 T. Campbell,7 S. Cao,16 S. L. Cartwright,50 M. G. Catanesi,22 A. Cervera,19 D. Cherdack,17 N. Chikuma,55 G. Christodoulou,12 M. Cicerchia,24,† J. Coleman,34 G. Collazuol,24 L. Cook,42,28 D. Coplowe,42 A. Cudd,7 A. Dabrowska,15 G. De Rosa,23 T. Dealtry,33 S. R. Dennis,34 C. Densham,54 F. Di Lodovico,30 N. Dokania,39 S. Dolan,12 T. A. Doyle,33 O. Drapier,10 J. Dumarchez,53 P. Dunne,21 A. Eguchi,55 L. Eklund,14 S. Emery-Schrenk,6 A. Ereditato,2 A. J. Finch,33 G. Fiorillo,23 C. Francois,2 M. Friend,16,‡ Y. Fujii,16,‡ R. Fujita,55 D. Fukuda,40 R. Fukuda,60 Y. Fukuda,37 K. Fusshoeller,11 C. Giganti,53 M. Gonin,10 A. Gorin,26 M. Guigue,53 D. R. Hadley,66 J. T. Haigh,66 P. Hamacher-Baumann,49 M. Hartz,62,28 T. Hasegawa,16,‡ S. Hassani,6 N. C. Hastings,16 Y. Hayato,56,28 A. Hiramoto,32 M. Hogan,8 J. Holeczek,51 N. T. Hong Van,20,27 T. Honjo,41 F. Iacob,24 A. K. Ichikawa,32 M. Ikeda,56 T. Ishida,16,‡ M. Ishitsuka,60 K. Iwamoto,55 A. Izmaylov,26 N. Izumi,60 M. Jakkapu,16 B. Jamieson,67 S. J. Jenkins,50 C. Jesús-Valls,18 M. Jiang,32 P. Jonsson,21 C. K. Jung,39,§ X. Junjie,57 P. B. Jurj,21 M. Kabirnezhad,42 A. C. Kaboth,48,54 T. Kajita,57,§ H. Kakuno,59 J. Kameda,56 D. Karlen,63,62 S. P. Kasetti,35 Y. Kataoka,56 Y. Katayama,69 T. Katori,30 Y. Kato,56 E. Kearns,3,28,§ M. Khabibullin,26 A. Khotjantsev,26 T. Kikawa,32 H. Kikutani,55 H. Kim,41 S. King,30 J. Kisiel,51 A. Knight,66 T. Kobata,41 T. Kobayashi,16,‡ L. Koch,42 T. Koga,55 A. Konaka,62 L. L. Kormos,33 Y. Koshio,40,§ A. Kostin,26 K. Kowalik,38 H. Kubo,32 Y. Kudenko,26,∥ N. Kukita,41 S. Kuribayashi,32 R. Kurjata,65 T. Kutter,35 M. Kuze,58 L. Labarga,1 J. Lagoda,38 M. Lamoureux,24 D. Last,43 M. Lawe,33 M. Licciardi,10 R. P. Litchfield,14 S. L. Liu,39 X. Li,39 A. Longhin,24 L. Ludovici,25 X. Lu,42 T. Lux,18 L. N. Machado,23 L. Magaletti,22 K. Mahn,36 M. Malek,50 S. Manly,47 L. Maret,13 A. D. Marino,7 L. Marti-Magro,56,28 T. Maruyama,16,‡ T. Matsubara,16 K. Matsushita,55 V. Matveev,26 C. Mauger,43 K. Mavrokoridis,34 E. Mazzucato,6 N. McCauley,34 J. McElwee,50 K. S. McFarland,47 C. McGrew,39 A. Mefodiev,26 C. Metelko,34 M. Mezzetto,24 A. Minamino,69 O. Mineev,26 S. Mine,5 M. Miura,56,§ L. Molina Bueno,11 S. Moriyama,56,§ Th. A. Mueller,10 L. Munteanu,6 S. Murphy,11 Y. Nagai,7 T. Nakadaira,16,‡ M. Nakahata,56,28 Y. Nakajima,56 A. Nakamura,40 K. Nakamura,28,16,‡ S. Nakayama,56,28 T. Nakaya,32,28 K. Nakayoshi,16,‡ C. E. R. Naseby,21 T. V. Ngoc,20,¶ K. Niewczas,68 K. Nishikawa,16,* Y. Nishimura,29 E. Noah,13 T. S. Nonnenmacher,21 F. Nova,54 P. Novella,19 J. Nowak,33 J. C. Nugent,14 H. M. O’Keeffe,33 L. O’Sullivan,50 T. Odagawa,32 T. Ogawa,16 R. Okada,40 K. Okumura,57,28 T. Okusawa,41 S. M. Oser,4,62 R. A. Owen,45 Y. Oyama,16,‡ V. Palladino,23 V. Paolone,44 M. Pari,24 W. C. Parker,48 S. Parsa,13 J. Pasternak,21 M. Pavin,62 D. Payne,34 G. C. Penn,34 L. Pickering,36 C. Pidcott,50 G. Pintaudi,69 C. Pistillo,2 B. Popov,53,** K. Porwit,51 M. Posiadala-Zezula,64 A. Pritchard,34 B. Quilain,10 T. Radermacher,49 E. Radicioni,22 B. Radics,11 P. N. Ratoff,33 C. Riccio,39 E. Rondio,38 S. Roth,49 A. Rubbia,11 A. C. Ruggeri,23 C. Ruggles,14 A. Rychter,65 K. Sakashita,16,‡ F. Sánchez,13 G. Santucci,70 C. M. Schloesser,11 K. Scholberg,9,§ M. Scott,21 Y. Seiya,41,†† T. Sekiguchi,16,‡ H. Sekiya,56,28,§ D. Sgalaberna,11 A. Shaikhiev,26 A. Shaykina,26 M. Shiozawa,56,28 W. Shorrock,21 A. Shvartsman,26 M. Smy,5 J. T. Sobczyk,68 H. Sobel,5,28 F. J. P. Soler,14 Y. Sonoda,56 S. Suvorov,26,6 A. Suzuki,31 S. Y. Suzuki,16,‡ Y. Suzuki,28 A. A. Sztuc,21 M. Tada,16,‡ M. Tajima,32 A. Takeda,56 Y. Takeuchi,31,28 H. K. Tanaka,56,§ H. A. Tanaka,52,61 S. Tanaka,41 Y. Tanihara,69 N. Teshima,41 L. F. Thompson,50 W. Toki,8 C. Touramanis,34 T. Towstego,61 K. M. Tsui,34 T. Tsukamoto,16,‡ M. Tzanov,35 Y. Uchida,21 M. Vagins,28,5 S. Valder,66 Z. Vallari,39 D. Vargas,18 G. Vasseur,6 W. G. S. Vinning,66 T. Vladisavljevic,54 V. V. Volkov,26 T. Wachala,15 J. Walker,67 J. G. Walsh,33 Y. Wang,39 D. Wark,54,42 M. O. Wascko,21 A. Weber,54,42 R. Wendell,32,§ M. J. Wilking,39 C. Wilkinson,2 J. R. Wilson,30 K. Wood,39 C. Wret,47 K. Yamamoto,41,†† C. Yanagisawa,39,‡‡ G. Yang,39 T. Yano,56 K. Yasutome,32 N. Yershov,26 M. Yokoyama,55,§ T. Yoshida,58 M. Yu,70 A. Zalewska,15 J. Zalipska,38 K. Zaremba,65 G. Zarnecki,38 M. Ziembicki,65 E. D. Zimmerman,7 M. Zito,53 S. Zsoldos,30 and A. Zykova26 (T2K Collaboration)This paper reports the first simultaneous measurement of the double differential muon neutrino chargedcurrent cross section on oxygen and carbon without pions in the final state as a function of the outgoing muon kinematics, made at the ND280 off-axis near detector of the T2K experiment. The ratio of the oxygen and carbon cross sections is also provided to help validate various models’ ability to extrapolate between carbon and oxygen nuclear targets, as is required in T2K oscillation analyses. The data are taken using a neutrino beam with an energy spectrum peaked at 0.6 GeV. The extracted measurement is compared with the prediction from different Monte Carlo neutrino-nucleus interaction event generators, showing particular model separation for very forward-going muons. Overall, of the models tested, the result is best described using local Fermi gas descriptions of the nuclear ground state with RPA suppression

Optimizing the Performance of Streaming Numerical Kernels on the IBM Blue Gene/P PowerPC 450 Processor

Several emerging petascale architectures use energy-efficient processors with vectorized computational units and in-order thread processing. On these architectures the sustained performance of streaming numerical kernels, ubiquitous in the solution of partial differential equations, represents a challenge despite the regularity of memory access. Sophisticated optimization techniques are required to fully utilize the Central Processing Unit (CPU). We propose a new method for constructing streaming numerical kernels using a high-level assembly synthesis and optimization framework. We describe an implementation of this method in Python targeting the IBM Blue Gene/P supercomputer's PowerPC 450 core. This paper details the high-level design, construction, simulation, verification, and analysis of these kernels utilizing a subset of the CPU's instruction set. We demonstrate the effectiveness of our approach by implementing several three-dimensional stencil kernels over a variety of cached memory scenarios and analyzing the mechanically scheduled variants, including a 27-point stencil achieving a 1.7x speedup over the best previously published results