Stacked Profiles Research Articles

A modeling pattern for layered system interfaces

AbstractCommunications between systems is often initially represented at a single, high level of abstraction, a link between components. During design evolution it is usually necessary to elaborate the interface model, defining it from several different, related viewpoints and levels of abstraction. This paper presents a pattern to model such multi‐layered interface architectures simply and efficiently, in a way that supports expression of technical complexity, interfaces and behavior, and analysis of complexity. Each viewpoint and layer of abstraction has its own properties and behaviors. System elements are logically connected both horizontally along the communication path, and vertically across the different layers of protocols. The performance of upper layers depends on the performance of lower layers, yet the implementation of lower layers is intentionally opaque to upper layers. Upper layers are hidden from lower layers except as sources and sinks of data. The system elements may not be linked directly at each horizontal layer but only via a communication path, and end‐to‐end communications may depend on intermediate components that are hidden from them, but may need to be shown in certain views and analyzed for certain purposes.This architectural model pattern uses methods described in ISO 42010 [1], Recommended Practice for Architectural Description of Software‐intensive Systems and CCSDS 311.0‐M‐1 [2], Reference Architecture for Space Data Systems (RASDS). A set of useful viewpoints and views are presented, along with the associated modeling representations, stakeholders and concerns. These viewpoints, views, and concerns then inform the modeling pattern. This pattern permits viewing the system from several different perspectives and at different layers of abstraction. An external viewpoint treats the systems of interest as black boxes and focuses on the applications view, another view exposes the details of the connections and other components between the black boxes. An internal view focuses on the implementation within the systems of interest, either showing external interface bindings and specific standards that define the communication stack profile or at the level of internal behavior. Orthogonally, a horizontal view isolates a single layer and a vertical viewpoint shows all layers at a single interface point between the systems of interest. Each of these views can in turn be described from both behavioral and structural viewpoints.

TheXMMCluster Survey: testing chameleon gravity using the profiles of clusters

The chameleon gravity model postulates the existence of a scalar field that couples with matter to mediate a fifth force. If it exists, this fifth force would influence the hot X-ray emitting gas filling the potential wells of galaxy clusters. However, it would not influence the clusters' weak lensing signal. Therefore, by comparing X-ray and weak lensing profiles, one can place upper limits on the strength of a fifth force. This technique has been attempted before using a single, nearby cluster (Coma, $z=0.02$). Here we apply the technique to the stacked profiles of 58 clusters at higher redshifts ($0.1<z<1.2$), including 12 new to the literature, using X-ray data from the XMM Cluster Survey (XCS) and weak lensing data from the Canada France Hawaii Telescope Lensing Survey (CFHTLenS). Using a multi-parameter MCMC analysis, we constrain the two chameleon gravity parameters ($\beta$ and $\phi_{\infty}$). Our fits are consistent with general relativity, not requiring a fifth force. In the special case of $f(R)$ gravity (where $\beta = \sqrt{1/6}$), we set an upper limit on the background field amplitude today of $|f_{\rm{R0}}| < 6 \times 10^{-5}$ (95% CL). This is one of the strongest constraints to date on $|f_{\rm{R0}}|$ on cosmological scales. We hope to improve this constraint in future by extending the study to hundreds of clusters using data from the Dark Energy Survey.

Photonic crystal with triangular stack profile

The enhanced localized reflectivity at a plane where the refractive index derivatives are discontinuous is increased using a periodic triangular stack. This optical system is studied using three different methods: a slowly varying refractive index approximate solution, numerical solutions to the nonlinear amplitude equation and the exact analytical solution using a matrix formalism. The field intensity within a photonic crystal with a periodic triangular profile is evaluated as a function of penetration depth and wavelength. These results are compared with the standard binary layered structures.

VIDE: The Void IDentification and Examination toolkit

We present vide, the Void IDentification and Examination toolkit, an open-source Python/C++ code for finding cosmic voids in galaxy redshift surveys and NN-body simulations, characterizing their properties, and providing a platform for more detailed analysis. At its core, vide uses a substantially enhanced version of zobov (Neyinck 2008) to calculate a Voronoi tessellation for estimating the density field and performing a watershed transform to construct voids. Additionally, vide provides significant functionality for both pre- and post-processing: for example, vide can work with volume- or magnitude-limited galaxy samples with arbitrary survey geometries, or dark matter particles or halo catalogs in a variety of common formats. It can also randomly subsample inputs and includes a Halo Occupation Distribution model for constructing mock galaxy populations. vide uses the watershed levels to place voids in a hierarchical tree, outputs a summary of void properties in plain ASCII, and provides a Python API to perform many analysis tasks, such as loading and manipulating void catalogs and particle members, filtering, plotting, computing clustering statistics, stacking, comparing catalogs, and fitting density profiles. While centered around ZOBOV, the toolkit is designed to be as modular as possible and accommodate other void finders. vide has been in development for several years and has already been used to produce a wealth of results, which we summarize in this work to highlight the capabilities of the toolkit. vide is publicly available at http://bitbucket.org/cosmicvoids/vide_public and http://www.cosmicvoids.net.

Probing the gas content of radio galaxies through H I absorption stacking

Using the WSRT, we carried out shallow HI absorption observations of a flux-selected (S > 50 mJy) sample of 93 radio AGN with available SDSS redshifts between 0.02 < z < 0.23. We study the gas properties of radio AGN down to fluxes not systematically explored before using, for the first time, stacking of extragalactic HI absorption. Despite the shallow observations, we obtained a direct detection rate of ~29%, comparable with deeper studies. Detections are found at every flux level, showing that HI absorption detections are not biased toward brighter sources. The stacks of detections and non-detections reveal a clear dichotomy in the presence of HI, with the 27 detections showing an average peak {\tau} = 0.02, while the 66 non-detections remain undetected with an upper limit {\tau} < 0.002. Separating the sample into compact and extended AGN increases the detection rate, {\tau}, and FWHM for the compact sample. The dichotomy for the stacked profiles of detections and non-detections still holds between these two groups. We argue that orientation effects connected to a disk-like distribution of HI can be partly responsible for the dichotomy, however some of our galaxies must be genuinely depleted of cold gas. A fraction of the compact sources are confirmed by previous studies as likely young radio sources. These show an even higher detection rate of 55%. Along with their high integrated optical depth and wider profile, this reinforces the idea that young radio AGN are particularly rich in atomic gas. Part of our motivation is to probe for the presence of HI outflows. However, the stacked profiles do not reveal any significant blueshifted wing. Our results are particularly relevant for future surveys. The lack of bias toward bright sources is encouraging for the search of HI at lower radio fluxes. The results also represent a reference point for search for HI absorption at higher redshifts.

Comparative Experimental and Technical-Economical Evaluation of a 1kWel Vs. 2.5kWel Tubular SOFC System for Residential Applications

In the frame of a common project on the development of prototype micro-cogeneration systems for household applications, ENEA and FCLAB have characterized a 1kWel and a 2.5kWel tubular-type SOFC technology-based unit respectively. Spanning the entire operational window of the two systems (within boundary conditions set by safe and durable operation, i.e. limitations on fuel utilization, oxygen-to-carbon ratio, stack and exhaust temperature profiles) the performance and efficiency characteristics of the two systems have been fully mapped. Thus, a technical-economical evaluation can take place for a calculated assessment of the optimal allocation of the two scales of systems.

Galactic accretion and the outer structure of galaxies in the CDM model

We have combined the semi-analytic galaxy formation model of Guo et al. (2011) with the particle-tagging technique of Cooper et al. (2010) to predict galaxy surface brightness profiles in a representative sample of ~1900 massive dark matter haloes (10^12--10^14 M_sol) from the Millennium II Lambda-CDM N-body simulation. Here we present our method and basic results focusing on the outer regions of galaxies, consisting of stars accreted in mergers. These simulations cover scales from the stellar haloes of Milky Way-like galaxies to the 'cD envelopes' of groups and clusters, and resolve low surface brightness substructure such as tidal streams. We find that the surface density of accreted stellar mass around the central galaxies of dark matter haloes is well described by a Sersic profile, the radial scale and amplitude of which vary systematically with halo mass (M_200). The total stellar mass surface density profile breaks at the radius where accreted stars start to dominate over stars formed in the galaxy itself. This break disappears with increasing M_200 because accreted stars contribute more of the total mass of galaxies, and is less distinct when the same galaxies are averaged in bins of stellar mass, because of scatter in the relation between M_star and M_200. To test our model we have derived average stellar mass surface density profiles for massive galaxies at z~0.08 by stacking SDSS images. Our model agrees well with these stacked profiles and with other data from the literature, and makes predictions that can be more rigorously tested by future surveys that extend the analysis of the outer structure of galaxies to fainter isophotes. We conclude that it is likely that the outer structure of the spheroidal components of galaxies is largely determined by collisionless merging during their hierarchical assembly

Comparison of H i and optical redshifts of galaxies – the impact of redshift uncertainties on spectral line stacking

Accurate optical redshifts will be critical for spectral co-adding techniques used to extract detections from below the noise level in ongoing and upcoming surveys for HI, which will extend our current understanding of gas reservoirs in galaxies to lower column densities and higher redshifts. We have used existing, high quality optical and radio data from the SDSS and ALFALFA surveys to investigate the relationship between redshifts derived from optical spectroscopy and neutral hydrogen (HI) spectral line observations. We find that the two redshift measurements agree well, with a negligible systematic offset and a small distribution width. Employing simple simulations, we determine how the width of an ideal stacked HI profile depends on these redshift offsets, as well as larger redshift errors more appropriate for high redshift galaxy surveys. The width of the stacked profile is dominated by the width distribution of the input individual profiles when the redshift errors are less than the median width of the input profiles, and only when the redshift errors become large, ~150 km/s, do they significantly affect the width of the stacked profile. This redshift accuracy can be achieved with moderate resolution optical spectra. We provide guidelines for the number of spectra required for stacking to reach a specified mass sensitivity, given telescope and survey parameters, which will be useful for planning optical spectroscopy observing campaigns to supplement the radio data.

The cosmological information of shear peaks: beyond the abundance

We study the cosmological information of weak lensing (WL) peaks, focusing on two other statistics besides their abundance: the stacked tangential-shear profiles and the peak-peak correlation function. We use a large ensemble of simulated WL maps with survey specifications relevant to future missions like Euclid and LSST, to explore the three peak probes. We find that the correlation function of peaks with high signal-to-noise (S/N) measured from fields of size 144 sq. deg. has a maximum of ~0.3 at an angular scale ~10 arcmin. For peaks with smaller S/N, the amplitude of the correlation function decreases, and its maximum occurs on smaller angular scales. We compare the peak observables measured with and without shape noise and find that for S/N~3 only ~5% of the peaks are due to large-scale structures, the rest being generated by shape noise. The covariance matrix of the probes is examined: the correlation function is only weakly covariant on scales < 30 arcmin, and slightly more on larger scales; the shear profiles are very correlated for theta > 2 arcmin, with a correlation coefficient as high as 0.7. Using the Fisher-matrix formalism, we compute the cosmological constraints for {Om_m, sig_8, w, n_s} considering each probe separately, as well as in combination. We find that the correlation function of peaks and shear profiles yield marginalized errors which are larger by a factor of 2-4 for {Om_m, sig_8} than the errors yielded by the peak abundance alone, while the errors for {w, n_s} are similar. By combining the three probes, the marginalized constraints are tightened by a factor of ~2 compared to the peak abundance alone, the least contributor to the error reduction being the correlation function. This work therefore recommends that future WL surveys use shear peaks beyond their abundance in order to constrain the cosmological model.

Evidence of soils and palaeosols in the Poznań Formation (Neogene, Polish Lowland)

A succession of stacked paleosol profiles was recognized in open pits in the western Wielkopolska region (Poland). Field observations and micromorphological studies made it possible to distinguish the following pedostructures, formed in contrasting environments: soil horizons, crystallaria, concretions, redoximorphic structures, Fe-Mn globulae and slickensides. In both soils (Holocene) and paleosols (Pleistocene or/and Pliocene?), surface horizons are present (horizon A), marked by rhizocretions. There are two separate carbonate soils. One of them contains calcite concretions and gypsum pedofeatures, presumably formed in arid or semi-arid conditions. Two of the soil profiles are probably truncated, and only subsurface horizons are present (horizon B). In some cases, paleosols are separated by sediment layers slightly influenced by pedogenesis (horizon BC). Carbonate soils (Bk) indicate water deficit during their formation. The presence of horizons with slickensides (Bss) indicates intervals with contrasting seasonal climates (wet and dry cycles). The profiles were influenced by gleying processes which caused redistribution of iron oxides and formation of iron and iron-manganese concretions. The pedostructures recognised reflect different climatic conditions as well as humidity changes during the time of their formation.

Planckintermediate results

Taking advantage of the all-sky coverage and broadfrequency range of the Planck satellite, we study the Sunyaev-Zeldovich (SZ) and pressure profiles of 62 nearby massive clusters detected at high significance in the 14-month nominal survey. Careful reconstruction of the SZ signal indicates that most clusters are individually detected at least out to R500. By stacking the radial profiles, we have statistically detected the radial SZ signal out to 3 × R500, i.e., at a density contrast of about 50–100, though the dispersion about the mean profile dominates the statistical errors across the whole radial range. Our measurement is fully consistent with previous Planck results on integrated SZ fluxes, further strengthening the agreement between SZ and X-ray measurements inside R500. Correcting for the effects of the Planck beam, we have calculated the corresponding pressure profiles. This new constraint from SZ measurements is consistent with the X-ray constraints from XMM-Newton in the region in which the profiles overlap (i.e., [0.1–1] R500), and is in fairly good agreement with theoretical predictions within the expected dispersion. At larger radii the average pressure profile is slightly flatter than most predictions from numerical simulations. Combining the SZ and X-ray observed profiles into a joint fit to a generalised pressure profile gives best-fit parameters [P0,c500,γ,α,β ] = [6.41,1.81,0.31,1.33,4.13 ] . Using a reasonable hypothesis for the gas temperature in the cluster outskirts we reconstruct from our stacked pressure profile the gas mass fraction profile out to 3 R500. Within the temperature driven uncertainties, our Planck constraints are compatible with the cosmic baryon fraction and expected gas fraction in halos.

Investigation of the weathering layer using seismic refraction and highresolution seismic reflection methods, NE of Riyadh city

Five seismic refraction and five high-resolution seismic reflection (HRSR) profiles were carried out in northeastern part of Riyadh city to investigate depth of the weathering layer. Results obtained from seismic refraction survey reveal the depths of weathering layer at 12, 25, 17, 12, and 16 m, respectively. On the other hand, HRSR stack sections illustrate the depths of weathering layer at 14, 28, 20, 13, and 18 m, respectively. The weathering layer is composed of alluvial sediments and gravel, which is underlain by a sequence of limestone and dolomite layer. Seismic results from site no. 2 have been found to be in good agreement with lithological information reported from the adjacent water well. The HRSR data generally reveal better signal-to-noise ratio and enhanced resolution compared to the refraction data. Although, the HRSR data failed in achieving high-quality common midpoint (CMP) stacking profile at site no. 3, it provide an improved image of the subsurface features than the refraction data, recognizing it as a potential seismic technique.

Scheduling heterogeneous multi-cores through Performance Impact Estimation (PIE)

Single-ISA heterogeneous multi-core processors are typically composed of small (e.g., in-order) power-efficient cores and big (e.g., out-of-order) high-performance cores. The effectiveness of heterogeneous multi-cores depends on how well a scheduler can map workloads onto the most appropriate core type. In general, small cores can achieve good performance if the workload inherently has high levels of ILP. On the other hand, big cores provide good performance if the workload exhibits high levels of MLP or requires the ILP to be extracted dynamically. This paper proposes Performance Impact Estimation (PIE) as a mechanism to predict which workload-to-core mapping is likely to provide the best performance. PIE collects CPI stack, MLP and ILP profile information, and estimates performance if the workload were to run on a different core type. Dynamic PIE adjusts the scheduling at runtime and thereby exploits fine-grained time-varying execution behavior. We show that PIE requires limited hardware support and can improve system performance by an average of 5.5% over recent state-of-the-art scheduling proposals and by 8.7% over a sampling-based scheduling policy.

Research on velocity and acceleration geophones and their acquired information

Based on the research of two geophone types (10 Hz moving-coil velocity and piezoelectric acceleration) and their velocity and acceleration parameters, frequency response functions have been determined, as well as the differences between them. Also, shock-vibration tests have been accomplished, not only to explain the two shock response signal differences, but also to analyze the response signal characteristics and its ability to carry information. In addition, seismic data acquisition experiments have been carried out under comparable conditions in the field. A contrast analysis of shot gathers and stack profiles acquired with the two geophone types is given in this paper. The results show that the acceleration signal from the acceleration geophone has a better advantage in terms of high signal-to-noise ratio, high accuracy, high resolution, and quantity of information to better meet current and future requirements for seismic exploration.

A PRECISE CLUSTER MASS PROFILE AVERAGED FROM THE HIGHEST-QUALITY LENSING DATA

We outline our methods for obtaining high precision mass profiles, combining independent weak-lensing distortion, magnification, and strong-lensing measurements. For massive clusters the strong and weak lensing regimes contribute equal logarithmic coverage of the radial profile. The utility of high-quality data is limited by the cosmic noise from large scale structure along the line of sight. This noise is overcome when stacking clusters, as too are the effects of cluster asphericity and substructure, permitting a stringent test of theoretical models. We derive a mean radial mass profile of four similar mass clusters of high-quality HST and Subaru images, in the range R=40kpc/h to 2800kpc/h, where the inner radial boundary is sufficiently large to avoid smoothing from miscentering effects. The stacked mass profile is detected at 58-sigma significance over the entire radial range, with the contribution from the cosmic noise included. We show that the projected mass profile has a continuously steepening gradient out to beyond the virial radius, in remarkably good agreement with the standard Navarro-Frenk-White form predicted for the family of CDM-dominated halos in gravitational equilibrium. The central slope is constrained to lie in the range, -dln{\rho}/dln{r}=0.89^{+0.27}_{-0.39}. The mean concentration is c_{vir}=7.68^{+0.42}_{-0.40} (at a mean virial mass 1.54^{+0.11}_{-0.10}\times 10^{15} M_{sun}/h), which is high for relaxed, high-mass clusters, but consistent with LCDM when a sizable projection bias estimated from N-body simulations is considered. This possible tension will be more definitively explored with new cluster surveys, such as CLASH, LoCuSS, Subaru HSC, and XXM-XXL, to construct the c-M relation over a wider mass range.

WiFi Auto Configuration Architecture Using ZigBee RF4CE for Pervasive Environments

This paper presents a novel architecture to provide a simple and easy control and sharing between various CE and IT devices for realizing a smart digital home using RF4CE that is based on IEEE 802.15.4. The proposed architecture is working on RF4CE which is a reliable bidirectional communication standard and also optimizes Zigbee protocol in order to provide a simple and energy efficient networking stack and standard application profiles in creating a multi-vendor interoperable solution for home entertainment and monitoring. In proposed architecture, RF4CE protocol provides a key idea to establish an initial network between devices. After that, the proposed architecture is probing a connection type from devices, and then sharing configuration information to make a zero-configuration, i.e., Wi-Fi connectivity setup. In order to show the feasibility of the proposed architecture, we make a development various H/W prototypes and implementation results demonstrate a mobile terminal can control other devices and provide contents sharing between the devices. Furthermore, based on the RF4CE-based zero-configuration architecture, it can be extended to support smart connectivity in a smart digital home with various wireless technologies like Wi-Fi, Bluetooth, UWB, and so on.

Investigation of the weathering layer using seismic refraction and high-resolution seismic reflection methods, NE of Riyadh city

Five seismic refraction and five high-resolution seismic reflection (HRSR) profiles were carried out in northeastern part of Riyadh city to investigate depth of the weathering layer. Results obtained from seismic refraction survey reveal the depths of weathering layer at 12, 25, 17, 12, and 16 m, respectively. On the other hand, HRSR stack sections illustrate the depths of weathering layer at 14, 28, 20, 13, and 18 m, respectively. The weathering layer is composed of alluvial sediments and gravel, which is underlain by a sequence of limestone and dolomite layer. Seismic results from site no. 2 have been found to be in good agreement with lithological information reported from the adjacent water well. The HRSR data generally reveal better signal-to-noise ratio and enhanced resolution compared to the refraction data. Although, the HRSR data failed in achieving high-quality common midpoint (CMP) stacking profile at site no. 3, it provide an improved image of the subsurface features than the refraction data, recognizing it as a potential seismic technique.

Analysis of complicated structure seismic wave fields

In western China seismic wave fields are very complicated and have low signal to noise ratio. In this paper, we focus on complex wave field research by forward modeling and indicate that density should not be ignored in wave field simulation if the subsurface physical properties are quite different. We use the acoustic wave equation with density in the staggered finite-difference method to simulate the wave fields. For this purpose a complicated geologic structural model with rugged surfaces, near-surface low-velocity layers, and high-velocity outcropping layers was designed. Based on the instantaneous wave field distribution, we analyzed the mechanism forming complex wave fields. The influence of low velocity layers on the wave field is very strong. A strong waveguide occurs between the top and base of a low velocity layer, producing multiples which penetrate into the earth and form strong complex wave fields in addition to reflections from subsurface interfaces. For verifying the correctness of the simulated wave fields, prestack depth migration was performed using different algorithms from the forward modeling. The structure revealed by the stacked migration profile is same as the known structure.

Characterization of the interphase in an aluminium/epoxy joint by using controlled pressure scanning electron microscopy coupled with an energy dispersive X-ray spectrometer

The aim of this work is to introduce the use of low vacuum scanning electron microscopy (LVSEM) coupled with an X-ray energy dispersive spectrometer (EDS) in the field of structural adhesives, more precisely aluminium/epoxy resin assembly. Such assembly is characterized by the creation of an interphase resulting from the metal diffusion inside the resin during cross-linking. As the performance of the final bond is strongly links by the interphase properties, fine characterization of this interphase, in particularity the evaluation of its thickness is essential to understand the macroscopic properties of the adhesive assembly. First, the EDS acquisition parameters were investigated in order to limit the sample/resin damage/degradation due to the incident electrons beam irradiation. Then a specific methodology of stacked profiles was defined to improve the precision of the measures. To evaluate the true Al diffusion profile, the impact of the interaction volume of incident electron in the material on the Al signal variation during the interface crossing was calculated and the effect of the gas pressure on the electron beam characteristic and so on the measured profiles was examinated. According to our developed methodology and data treatments, Al diffusion profile was interpreted and interphase thickness was qualitatively determined by comparison with an experimental baseline. This innovative methodology promotes the use of LVSEM–EDS in the field of adhesive structural assemblies, but also, deals with a comparative study on the effect of the gas pressure on the EDS profile analysis.

Diffraction analysis of perovskite-like oxides containing irregular intergrowths

Features of the X-ray intensity distributions caused by the presence of random and nonrandom stacking faults (irregular intergrowths) in layered perovskite-like oxides are studied by a computer simulation technique. It is shown that, apart from the stacking fault properties, the position, profile and intensity of a diffraction peak are dependent on the ratio between theclattice parameter of the crystal and the thickness of the new structural fragment formed as a result of the stacking fault. A means of characterizing the stacking faults on the basis of the relative positions of pairs of diffraction peaks is presented. The approach is exemplified by the X-ray diffraction study of a disordered single crystal of the system Bi–Sr–Ca–Cu–O.