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Nowadays, smart meters are deployed in millions of residential households to gain significant insights from fine-grained electricity consumption data. The information extracted from smart meter data enables utilities to identify the socio-demographic characteristics of electricity consumers and then offer them diversified services. Traditionally, this task is implemented in a centralized manner with the assumption that utilities have access to all the smart meter data. However, smart meter data are measured and owned by different retailers in the retail market who may not be willing to share their data. To this end, a distributed electricity consumer characteristics identification method is proposed based on federated learning, which can preserve the privacy of retailers. Specifically, privacy-perseverance principal component analysis (PCA) is exploited to extract features from smart meter data. On this basis, an artificial neural network is trained in a federated manner with three weighted averaging strategies to bridge between smart meter data and the socio-demographic characteristics of consumers. Case studies on the Irish Commission for Energy Regulation (CER) dataset verify that the proposed federated method has comparable performance with the centralized model on both balanced and unbalanced datasets.

Semantic metadata standards pave the way for interoperability by providing building operators and application developers with common schemes to describe building resources. Applications can query building metadata models to retrieve the set of entities and relationships they need to operate, instead of hard-coding references to specific points and objects from the underlying data sources. Currently, querying such models requires the developer to be very specific when formulating queries in order to obtain meaningful answers (or any answer). The developer is inevitably expected to be familiar with the systems and components of the buildings being queried, as well as the schema used to represent them. The variety of buildings - both in the composition of their subsystems and in how they happen to be modeled - means that the developer will need to use multiple queries in order to retrieve necessary results. This is complex, time-consuming and error-prone. To address this limitation, we investigate query relaxation as a technique to facilitate discovery of meaningful building resources in a collection of ontology-based buildings data. We evaluate our query relaxation approach over a set of Brick models and demonstrate its use in the context of real-world building applications., BuildSys '21: Proceedings of the 8th ACM International Conference on Systems for Energy-Efficient Buildings, Cities, and Transportation, ISBN:978-1-4503-9114-6

Resume Introduction La dermatose auto-immune a la progesterone (DAIP) est due a une hypersensibilite a la progesterone endogene survenant parfois chez des patientes prealablement sensibilises a la progesterone exogene (pilule et sterilet). Elle se caracterise par une eruption recidivante survenant au cours de la phase luteale du cycle menstruel ou le taux de progesterone est le plus eleve. L’aspect clinique de la DAIP peut etre confondu avec d’autres dermatoses. Nous en rapportons une observation de DAIP chez une jeune femme. Observation Une femme de 23 ans consultait pour une eruption papulo-vesiculeuse prurigineuse du tronc evoluant par poussees depuis la puberte et non amelioree par les dermocorticoides et les antihistaminiques. Les lesions debutaient quelques jours avant les menstruations et disparaissent spontanement apres. Le diagnostic de DAIP a ete confirme par la positivite de l’IDR a la progesterone et la reponse favorable a une contraception orale bloquant l’ovulation sans recidive au cours des cycles menstruels ulterieurs. Discussion Il s’agit d’une dermatose auto-immune rare. Le diagnostic repose sur des criteres precis notamment la rythmicite des lesions en phase lutheale, la positivite des tests a la progesterone et la reponse favorable aux medicaments bloquant l’ovulation. L’etiopathogenie est floue, la reponse positive aux differents tests de sensibilisation a la progesterone suggere des mecanismes etiopathogeniques divers a mediation cellulaire et/ou hormonale. Conclusion La DAIP est generalement benigne, mais le caractere recidivant a chaque cycle menstruel peut devenir invalidant retentissant sur la qualite de vie des patientes. Les formes severes peuvent mettre en jeu le pronostic vital necessitant parfois le recours a une ovariectomie bilaterale.

Resume La tumeur a cellules granuleuses ou tumeur d’Abrikossoff est une tumeur benigne rare qui siege principalement au niveau de la tete et du cou avec atteinte preferentielle de la muqueuse buccale. Deux fillettes âgees de 8 et 12 ans, sans antecedent, presentaient des lesions nodulaires pigmentees siegeant respectivement au niveau de la region scapulaire gauche et en regard de la crete iliaque gauche. L’examen histologique et l’etude immuno-histochimique de la biopsie cutanee confirmaient le diagnostic de tumeur a cellules granuleuses. Dans les 2 cas, une exerese chirurgicale avec des marges de 2 cm etait realisee. Aucune recidive n’etait notee apres un recul de 6 et 2 mois. La tumeur d’Abrikossoff est une tumeur d’origine schwannienne predominant normalement chez les femmes de race noire, âgees de 20 a 60 ans et siegeant principalement au niveau de la muqueuse buccale. L’atteinte de l’enfant est plus rare et exceptionnelle dans sa forme cutanee pure. L’histologie montre une proliferation de cellules de grande taille a cytoplasme abondant granulaire et a noyaux de petite taille, hyperchromatiques et reguliers. En immuno-histochimie, les cellules tumorales expriment la proteine S100, la neuron specific enolase (NSE) et la vimentine. Le traitement consiste en une exerese complete afin d’eviter la recidive.

We report new (e,2e) and (e,3e) experiments for ionization of argon under unexplored kinematics characterized by large energy transfer to the target and where the two 'atomic' electrons carry the same kinetic energy. This opens the possibility of competition and interference between direct 3p-outer shell double ionization (DI) and indirect DI via an Auger emission from the 2p shell. The (e,2e) results are found to be in reasonably good agreement with state-of-the-art theoretical models for 2p-single ionization. The importance of the other competing processes, namely direct 3p-DI and/or Auger relaxation, not included in the models is highlighted. The measured (e,3e) angular correlation pattern displays a rich structure, partly resulting from final state interactions where the outgoing electrons tend to minimize their Coulomb repulsion. The rapprochement with the (e,2e) results allows the assignment of some of the observed peaks to given ionization mechanisms, either the two-step 2 direct 3p-DI, or a 2p-single ionization followed by an Auger emission.

We study the electron impact double ionization of argon in the case where two, or else, three of the outgoing electrons (one scattered and two ejected) have the same energy. Each electron in the final (continuum) state is described by a Coulomb wave and account is taken for the interaction between these three electrons. We also include exactly all the exchange effects for the first time. The results of our model are compared to the recent experiments of Catoire et al (2004, Photonic, Electronic and Atomic Collisions ed R Schuch et al (Phys. Scr. T110 228–32); 2005, Electron and Photon Impact Ionization and Related Topics ed B Piraux (Bristol: Institute of Physics) p 53).

The International Symposium on (e,2e), Double Photoionization and Related Topics, and the 13th International Symposium on Polarization and Correlation in Electronic and Atomic Collisions were held concurrently in Buenos Aires, Argentina, from 20 to 28 July 2005. Here, the papers presented at the meetings are reported.

We report new coplanar (e, 2e) measurements for ionization of He and Ar under kinematics characterized by large energy transfer and close to minimum momentum transfer from the projectile to the target. These kinematics have remained rather unexplored to date due to the smallness of the corresponding cross sections. They could be investigated here thanks to the high sensitivity of our multi-collection spectrometer. The experimental results are used as a sensitive test of state-of-the-art available theoretical models for multi-electron atoms, namely the BBK and a hybrid DWBA+R-matrix (close coupling) models. An overall satisfactory agreement with experiment is obtained for the hybrid DWBA results for both targets. However, a close inspection of the remaining discrepancies calls for further refinement of the theory.

A complete analysis of our recent (e, 3e) experiments on helium at 601 eV incident energy (Lahmam-Bennani et al 2003 Phys. Rev. A 67 010701) is conducted by using an approximate 6C model which accounts for the interaction between all four particles (the scattered electron, the two ejected electrons and the nucleus) in the final state. An accurate wavefunction for the initial state is also used. The agreement between experiments and theory is not always good even though most peaks and dips can be explained. Comparison is also made with the results of the first Born-BBK approximation as well as with approximate second Born results.

A second Born treatment is applied to study the (e, 3e) and (e, 3 − 1e) reactions for H2 targets. The results of this approximation are compared to the (e, 3 − 1e) experimental data obtained at about 600 eV impact energy. Several single-centre wavefunctions are used to describe the initial state and excited states of the molecule. Even if the second Born approximation is able to explain part of the experimental results the agreement is not good, similar to the case of the double ionization of helium (Gotz et al 2003 J. Phys. B: At. Mol. Opt. Phys. 36 L77).

The second Born approximation is applied to study the (e, 2e) reaction for H2 targets. The results of this approximation are compared to a new set of experimental data obtained at about 600 eV impact energy, as well as to previous experiments performed at larger (~4 keV) or smaller (250 eV) energy. Several single-centre wavefunctions are used to describe the initial state and excited states of the molecule. A generally good agreement is obtained with the experiments and with recent calculations.

Over the past two decades impressive progress has been made in the theoretical and the experimental study of the multiple excitation and of the complete fragmentation of four-body Coulomb systems. The double ionization of atoms by charged particle impact is employed routinely to prepare and to explore the Coulomb four-body excited states (the two ionized electrons and the scattered charged projectile moving in the field of the residual ion). The spectrum of this four-body system can be determined experimentally by resolving simultaneously the momentum vectors of all particles. Such a multi-coincidence measurement entails however low counting rates which makes the experimental realization a challenging task. This work gives a brief overview on recent achievements in multi-detection techniques and outlines the various methods to carry out the double ionization experiments induced by electron impact. The advantages and the limits of the various experimental approaches are pointed out. On the theoretical side, serious difficulties are encountered which are prototypical for the theoretical treatment of many-body correlated systems: (A) With increasing number of interacting particles (and hence of degrees of freedom) a direct numerical evaluation of the four-body Green's function, which encompasses the entire spectrum of the system, becomes a challenge. (B) Due to the non-integrable character of interacting many particle systems, an analytical approach can only be approximate. In this report we discuss in details the various methods that have been put forward to deal with the four-body problem, including: perturbative many-body treatments (first and second order theories) and non-perturbative methods as well as pure numerical approaches. Due to the complicated structure of the four-particle continuum spectrum we present and discuss simple qualitative arguments to explain the main features (peaks and dips) that are observed in the experiments. The limitations of these simple methods are illustrated by contrasting the predictions with full numerical calculations and with experimental data. Future directions and possible applications are also discussed.

The coplanar (e, 3e) relative cross sections for double ionization of argon have been measured at an electron impact energy of E0 = 561.4 eV and under equal energy sharing among the two 'ejected' electrons, Eb = Ec = 9 eV. The scattering angle is fixed to ?a = 1.5?, corresponding to a momentum transfer K = 0.4 au to the target. The experimental results have been compared with calculations in the first Born approximation, which include only first-order processes in the target?projectile interaction. The comparison shows severe deviations between the experimental and theoretical results. These deviations are much larger than the ones previously observed in helium under comparable kinematics. To fill this gap between theory and experiment, a decisive improvement in the theory is needed. This can be achieved by improving the first-order calculations and by including higher-order processes such as the two-step mechanism, or even new mechanisms, for instance the simultaneous ejection of the pair of target electrons.

New coplanar (e, 3e) experiments for double ionization (DI) of helium (1s2) and argon (3p2) at about 600 eV incident energy, and under moderate momentum transfer to the target (~0.8 au), are presented. It is shown that, when the data are sorted according to the Bethe-ridge condition (i.e. the magnitude of the momentum transfer is equal to that of the sum momentum of the emitted electrons), the (e, 3e) angular distributions clearly bear the signature of the target initial two-electron momentum density, |ψ(p1,p2)|2. We show, for the first time in DI, the different signature due to the s or p character of the ionized electrons. For He, the results are qualitatively compared with a state-of-the-art first-order theory.

(e,2e) experimental studies are reviewed. As a tribute to Chris Brion, the emphasis is put on the experimental birth and infancy of electron momentum spectroscopy, as well as on early, well established achievements in (e,2e) dynamics studies. The limits of our understanding of these processes are drawn and exemplified through selected results.

The relative cross sections of Ar double ionization by electron impact have been measured in an (e, 3e) experiment at low incident energy E0 = 561.4 eV, at a scattering angle θa = 6.5° and with equal energy sharing among the two `ejected' electrons, Eb = Ec = 9 eV. The experimental results are compared with calculations in the first Born approximation, which include the shake-off and two-step 1 mechanisms in the target-projectile interaction. The symmetry breaking about the direction of the momentum transfer and the appearance of a small feature near the main ones show that the non-first-order effects (such as two-step 2 mechanism) play an important role. These effects are enhanced in the present experiments with respect to the former ones (El Marji et al 1997 J. Phys. B: At. Mol. Opt. Phys. 30 3677) with higher collision energy, E0 = 5563 eV, which is in agreement with an earlier theoretical estimate by McGuire.

New coplanar (e, 3-1e) experiments on double ionization (DI) of helium and molecular hydrogen at about 600 eV incident energy, and with asymmetric energy sharing among the two ejected electrons are presented. The results are compared with state-of-the-art first-order theories, and are discussed in terms of DI mechanisms. Evidence is given of the great importance of second- or higher-order effects in the projectile-target interaction, even at the high incident energy considered.

Using a multiparameter multicoincidence spectrometer, we have measured the coplanar (e,3e) angular distributions following the double ionization of helium at an incident energy of ’5.6 keV and under a small projectile’s scattering angle of 0.45°. The two ejected electrons have been detected with equal energies Eb 5Ec510 eV. The absolute value of the cross section is determined with an accuracy of 25%. The origin of dips and peaks in the spectra is exposed by analyzing the corresponding theoretical calculations. These calculations have been done using a four-body final-state wave function for the three electrons moving in the field of He 21 . The dipolar limit is investigated and the manifestation of the deviation from this limit are pointed out. General features and possible trends for other targets are proposed. @S1050-2947~99!02805-X# PACS number~s!: 34.80.Ht, 34.80.Dp I. INTRODUCTION Recently, there has been an increased activity in the study of the double ionization ~DI! processes under photon or electron impact. This progress has been fueled by the spectacular advances in the development of very sophisticated, high sensitivity new spectrometers @1‐5# that render possible the energy and angle-resolved simultaneous detection of two or three final-state electrons. Thus, in such measurements the energy and momentum transferred to the target, the energies and momenta of all the final-channel electrons are simultaneously determined. Apart from the spin degrees of freedom these measurements yield, in the case of the He target, the ultimate information obtainable on the collision dynamics and provide hence the most sensitive probe for theoretical approaches. The challenge and promise in the theoretical investigations of these processes lie in the modeling and understanding of the inherently nonseparable many-body interacting systems ~in the case of electron impact DI, the final state consists of three electrons moving in the field of He 21 ) and in the treatment of the particular difficulties associated with the infinite range of the Coulomb potentials.

Experimental results are presented for (e, 2e) ionization of the Ar(2p) orbital in a highly asymmetric geometry. Despite the magnitude of the momentum transfer being only 0.5 au, it is found that the triple differential cross section is not symmetric about the direction of momentum transfer. We have performed distorted-wave Born approximation calculations which not only do not show the observed symmetry breaking but are also little different from the first Born results. This suggests that distortion of the fast electron by the atom is not significant. We conclude that a new mechanism must be invoked to explain the data which depends on a two- or higher-step process.

A new spectrometer for the coincidence study of (e,2e) single ionization, and e,(3-1)e or (e,3e) double ionization by electron impact is described. The system is based on two double toroidal analyzers for the ejected electrons and a cylindrical electrostatic analyzer for the scattered electrons. It allows angular and energy distributions of the ejected electrons to be measured over almost the totality of the collision plane, using dual two-dimensional position sensitive detectors. The design and operation of the spectrometer is described with a special emphasis on the imaging properties of the system. The performance (energy and angular resolutions,…) and the calibration of the spectrometer are discussed and sample results for (e,2e), e,(3-1)e and (e,3e) experiments on the rare gases are presented.

Using a new multi-parameter multi-coincidence spectrometer, we have measured relative, coplanar (e, 3e) angular distributions for the double ionization of neon at impact energy, under a small scattering angle, , and equal energy sharing among the two `ejected' electrons, . The general features of the distributions are outlined and compared with similar measurements on argon (El Marji et al 1997 J. Phys. B: At. Mol. Opt. Phys. 30 3677). It is found that the distributions are dominated by the simultaneous backward emission of both ejected electrons. On the basis of qualitative arguments, this may be attributed, as in argon, to a double-hit process (a so-called `two step 2' mechanism). However, additional structures are found for neon, which are not present for argon, namely a forward emission of both ejected electrons. Though their origin could not be explained in terms of intuitive double-ionization mechanisms, they clearly indicate that the recoil ion actively participates during the collision.

Using a new multiparameter multicoincidence spectrometer, we measure coplanar angular distributions from the double ionization of argon at impact energy, under a small scattering angle, , and equal energy sharing among the two `ejected' electrons, . The absolute scale for the cross sections is determined within a factor of 2. General features and possible trends of the distributions are outlined. The data are discussed in terms of double ionization mechanisms and it is proposed here, using qualitative arguments, that the angular distributions are dominated by a double hit process (the so-called `two-step 2' mechanism). Such predominance is shown to be due to the chosen kinematical conditions, characterized by both an energy selectivity (equal ejected electrons energies) and a spatial selectivity (ejected electrons observed in opposite half-planes).

The experimental advances in the study of electron impact double ionization using double coincidence e,(3-1)e or triple coincidence (e,3e) techniques are reviewed. The recent advent and extension of multianalysis and multidetection systems have allowed a second generation of (e,3e) spectrometers to be born. Their most pertinent characteristics are described. Illustrative results from both e,(3-1)e and (e,3e) experiments are discussed, showing all the promising potential of these highly differential studies for the detailed investigation of the fundamentals of the double ionization process.

Recent electron-impact double ionization (e, 3 - 1e) experiments on helium are investigated theoretically. An ab initio calculation has been performed on the basis of the first Born approximation using different correlated wavefunctions for the initial bound-state and a correlated double-continuum wavefunction which satisfies the exact asymptotic boundary conditions for the final state with two slow electrons. The results of this calculation are compared with those of other theories.

Results of an argon e, (3 - 1)e double-ionization experiment with an incident energy of 5.5 keV are presented. The two emitted electrons, with energies of 96 and 17.5 eV, are observed in coincidence, and several angular distributions were measured simultaneously using a dual-position multidetection system. The observations provide clear indication for a shake-off mechanism being responsible of the double-ionization process under the kinematics considered.