Multifractality meets entanglement: relation for non-ergodic extended states

In this work we establish a relation between entanglement entropy and fractal dimension $D$ of generic many-body wave functions, by generalizing the result of Don N. Page [Phys. Rev. Lett. 71, 1291] to the case of {\it sparse} random pure states (S-RPS). These S-RPS living in a Hilbert space of size $N$ are defined as normalized vectors with only $N^D$ ($0 \le D \le 1$) random non-zero elements. For $D=1$ these states used by Page represent ergodic states at infinite temperature. However, for $0<D<1$ the S-RPS are non-ergodic and fractal as they are confined in a vanishing ratio $N^D/N$ of the full Hilbert space. Both analytically and numerically, we show that the mean entanglement entropy ${\mathcal{S}_1}(A)$ of a subsystem $A$, with Hilbert space dimension $N_A$, scales as $\overline{\mathcal{S}_1}(A)\sim D\ln N$ for small fractal dimensions $D$, $N^D< N_A$. Remarkably, $\overline{\mathcal{S}_1}(A)$ saturates at its thermal (Page) value at infinite temperature, $\overline{\mathcal{S}_1}(A)\sim \ln N_A$ at larger $D$. Consequently, we provide an example when the entanglement entropy takes an ergodic value even though the wave function is highly non-ergodic. Finally, we generalize our results to Renyi entropies $\mathcal{S}_q(A)$ with $q>1$ and to genuine multifractal states and also show that their fluctuations have ergodic behavior in narrower vicinity of the ergodic state, $D=1$.Comment: 7 pages, 4 figures, 92 references + 9 pages, 9 figures in appendice

Declarative process modeling in BPMN

Traditional business process modeling notations, including the standard Business Process Model and Notation (BPMN), rely on an imperative paradigm wherein the process model captures all allowed activity flows. In other words, every flow that is not specified is implicitly disallowed. In the past decade, several researchers have exposed the limitations of this paradigm in the context of business processes with high variability. As an alternative, declarative process modeling notations have been proposed (e.g., Declare). These notations allow modelers to capture constraints on the allowed activity flows, meaning that all flows are allowed provided that they do not violate the specified constraints. Recently, it has been recognized that the boundary between imperative and declarative process modeling is not crisp. Instead, mixtures of declarative and imperative process modeling styles are sometimes preferable, leading to proposals for hybrid process modeling notations. These developments raise the question of whether completely new notations are needed to support hybrid process modeling. This paper answers this question negatively. The paper presents a conservative extension of BPMN for declarative process modeling, namely BPMN-D, and shows that Declare models can be transformed into readable BPMN-D models. © Springer International Publishing Switzerland 2015

Vibration analysis of the civic tower in Rieti

In the last decades the definition of a suitable monitoring system for identifying the dynamic behavior of structures has had a central position in the civil engineering research area. The vibration analysis leads to the recognition of the reference state of structures which is essential to determine the integrity level when extreme events occur, such as earthquakes. The latest seismic events occurred in the world have shown the essential role of the new passive seismic techniques which aim to protect structures and the importance of supervising the building construction operations and the adopted improvement measures. In this work the structural monitoring of the civic tower located in Rieti is presented. In the tower a non-conventional TMD has been installed via an inter-story isolation system at the top floor by means of High Damping Rubber Bearings (HDRB). The general goal is to define a monitoring system suitable with this experimental case through the vibration analysis. Several aspects will be taken into account: the choice of sensors setup, the measured quantities and the extraction of structural information. Firstly this will allow to define the structure’s reference state featured by frequencies, damping ratios and mode shapes. Moreover the effective design of the monitoring system would lead to the characterization of the dynamic behavior of the structure equipped with a passive vibration control system. Different tests have been carried forward: ambient vibration test (AVT), forced vibration test (FVT) with vibrodyne and seismic test (ST). The AVT and the FVT enable to define the monitoring system and check the reliability of the adopted identification tools, among which an Output Only algorithm stands out: the Observer Kalman Filter System Id. On the other hand the ST will point out some preliminary information about the dynamic behaviour of the structure equipped with a non conventional Tuned Mass Damper referring it to higher levels of vibrations

Preliminary validation of an indirect method for discharge evaluation of Pertuso Spring (Central Italy)

This paper deals with the results of the first year of the Environmental Monitoring Plan, related to the catchment project of Pertuso Spring, which is going to be exploited to supply an important water network in the South part of Roma district. The study area is located in the Upper Valley of the Aniene River (Latium, Central Italy), in the outcrop of Triassic-Cenozoic carbonate rocks, and belong to an important karst aquifer. Pertuso Spring is the main outlet of this karst aquifer and is the one of the most important water resource in the southeast part of Latium Region, used for drinking, agriculture and hydroelectric supplies. Karst aquifer feeding Pertuso Spring is an open hydrogeological system aquifer characterized by complex interactions and exchanges between groundwater and surface water which influence the aquifer water budget. Thus, evaluation of groundwater discharge from this karst spring can be affected by difficulties in performing measurements because of the insufficient knowledge about water transfer processes in the hydrological cycle and geometry of drainage conduits. The aim of this paper is to assess the interactions between karst aquifer feeding Pertuso Spring and Aniene River based on stream discharge measurements and water geochemical tracer data in order to validate an indirect method for karst spring discharge evaluation. As a matter of fact, in this paper, there are presented the results of the application of Magnesium as a reliable tracer of karst spring discharge. This indirect method is based on the elaboration of surface water discharge measurements in relationship with Mg2+ concentration values, determined as for groundwater, coming from Pertuso Spring, as for surface water sample, collected upstream and downstream of Pertuso Spring, along Aniene River streamflow. The application of Magnesium as an environmental tracer provides a means to evaluate discharge of Pertuso Spring, as it came up to be a marker of the mixing of surface water and groundwater. On the other hand, the Magnesium ion concentration provides information for the identification of groundwater flow systems and the main hydrogeochemical processes affecting the composition of water within the karst aquifers

Graceful exit via polymerization of pre-big bang cosmology

We consider a phenomenological modification of the Pre Big Bang scenario using ideas from the resolution of curvature singularities in Loop Quantum Cosmology. We show that non-perturbative Loop modifications to the dynamics, arising from the underlying polymer representation, can resolve the graceful exit problem. The curvature and the dilaton energy stay finite at all times, in both the string and Einstein frames. In the string frame, the dilaton tends to a constant value at late times after the bounce.Comment: 7 pages, 8 figures. Some clarifications added. To appear on Phys. Rev.

Model and Design of a Power Driver for Piezoelectric Stack Actuators

A power driver has been developed to control piezoelectric stack actuators used in automotive application. A FEM model of the actuator has been implemented starting from experimental characterization of the stack and mechanical and piezoelectric parameters. Experimental results are reported to show a correct piezoelectric actuator driving method and the possibility to obtain a sensor-less positioning contro

Housing system and welfare of buffalo (Bubalus bubalis) cows

Twenty-eight buffalo cows were used to evaluate the effect of housing system on a range of behavioural and physiological variables. Fourteen cows were group-housed in a loose open-sided barn with a concrete floor and 10 m2 per head as space allowance (group IS). Fourteen others were group-housed in a similar barn but they could also benefit from an outdoor yard with 500 m2 per head as space allowance, free access to potholes for wallowing and spontaneous vegetation (group TS). Animals were subjected to six sessions of instantaneous scan sampling at 10-day intervals. Behavioural variables were expressed as proportions of subjects observed in each category of posture and activity. Phytohaemagglutinin (PHA) was used to perform a skin test based on non-specific delayed type hypersensitivity, whereas 20 mg of ovalbumin were injected subcutaneously to evaluate humoral immune response. Blood samples for evaluation of cortisol concentration were collected immediately prior to exogenous porcine ACTH injection and 1, 2 and 4 h after. The metabolic status of the animals and milk production were also monitored. The proportion of idling animals was higher in group IS than in group TS (P< 0·001). More IS buffalo cows were observed eating at the manger than TS animals (P< 0·001). A higher proportion of TS animals were observed in the sun (P< 0·001). Grazing and bathing activities were recorded only for TS animals. Our findings suggest that buffalo cows kept in intensive conditions and having no access to ample yards and potholes may extend their periods of idling with negative effects on the state of welfare. Immune responses, metabolite concentrations and milk production were not affected by treatment, whereas cortisol levels were higher in IS animals (P< 0·05). The provision of a housing system similar to natural conditions was able to improve the welfare of buffalo cows as indicated by the expression of some species-specific natural behaviours. Such conditions were also associated with lower adrenal cortex response to ACTH injection, possibly as a consequence of the higher degree of initiative allowed to TS cows

Extraocular muscle sampled volume in Graves' orbitopathy using 3-T fast spin-echo MRI with iterative decomposition of water and fat sequences

Abstract Background: Current magnetic resonance imaging (MRI) techniques for measuring extraocular muscle (EOM) volume enlargement are not ideally suited for routine follow-up of Graves’ ophthalmopathy (GO) because the difficulty of segmenting the muscles at the tendon insertion complicates and lengthens the study protocol. Purpose: To measure the EOM sampled volume (SV) and assess its correlation with proptosis. Material and Methods: A total of 37 patients with newly diagnosed GO underwent 3-T MRI scanning with iterative decomposition of water and fat (IDEAL) sequences with and without contrast enhancement. In each patient, the three largest contiguous coronal cross-sectional areas (CSA) on the EOM slices were segmented using a polygon selection tool and then summed to compute the EOM-SV. Proptosis was evaluated with the Hertel index (HI). The relationships between the HI value and EOM-SV and between HI and EOM-CSA were compared and assessed with Pearson’s correlation coefficient and the univariate regression coefficient. Inter-observer and intra-observer variability were calculated. Results: HI showed a stronger correlation with EOM-SV (P&lt;0.001; r¼0.712, r2¼0.507) than with EOM-CSA (P&lt;0.001; r¼0.645 and r2¼0.329). The intraclass correlation coefficient indicated that the inter-observer agreement was high (0.998). The standard deviation between repeated measurements was 1.9–5.3%. Conclusion: IDEAL sequences allow for the measurement EOM-SV both on non-contrast and contrast-enhanced scans. EOM-SV predicts proptosis more accurately than does EOM-CSA. The measurement of EOM-SV is practical and reproducible. EOM-SV changes of 3.5–8.3% can be assumed to reflect true volume changes

State-of-the-art all-silicon sub-bandgap photodetectors at telecom and datacom wavelengths

Silicon-based technologies provide an ideal platform for the monolithic integration of photonics and microelectronics. In this context, a variety of passive and active silicon photonic devices have been developed to operate at telecom and datacom wavelengths, at which silicon has minimal optical absorption - due to its bandgap of 1.12 eV. Although in principle this transparency window limits the use of silicon for optical detection at wavelengths above 1.1 μm, in recent years tremendous advances have been made in the field of all-silicon sub-bandgap photodetectors at telecom and datacom wavelengths. By taking advantage of emerging materials and novel structures, these devices are becoming competitive with the more well-established technologies, and are opening new and intriguing perspectives. In this paper, a review of the state-of-the-art is presented. Devices based on defect-mediated absorption, two-photon absorption and the internal photoemission effect are reported, their working principles are elucidated and their performance discussed and compared