Window In Space Research Articles

Recent reliable observations and improved tests on synthetic catalogs with spatiotemporal clustering verify precursory decelerating–accelerating seismicity

We examined the seismic activity which preceded six strong mainshocks that occurred in the Aegean (M = 6.4–6.9, 33–43° N, 19–28° E) and two strong mainshocks that occurred in California (M = 6.5–7.1, 32–41° N, 115–125° W) during 1995–2010. We find that each of these eight mainshocks has been preceded by a pronounced decelerating and an equally easily identifiable accelerating seismic sequence with the time to the mainshock. The two preshock sequences of each mainshock occurred in separate space, time, and magnitude windows. In all eight cases, very low decelerating seismicity, as well as very low accelerating seismicity, is observed around the actual epicenter of the ensuing mainshock. Statistical tests on the observed measures of decelerating, qd, and accelerating, qa, seismicity against similar measures calculated using synthetic catalogs with spatiotemporal clustering based on the ETAS model show that there is an almost zero probability for each one of the two preshock sequences which preceded each of the eight mainshocks to be random. These results support the notion that every strong shallow mainshock is preceded by a decelerating and an accelerating seismic sequence with predictive properties for the ensuing mainshock.

The Sun-Shading Technologies of the Existing Traditional Dwellings in China

Shading space is an important characteristic of China's traditional architecture. The traditional dwellings in China are taken as the research object. On the basis of the statement of the classification and function of building shading, this paper focuses on the various shading methods such as eaves shading, function space shading, windows shading, courtyard shading, green shading and building mutual shading in the building layout.

Probabilistic seismic hazard analysis of Tripura and Mizoram states

A probabilistic seismic hazard analysis for the states of Tripura and Mizoram in North East India is presented in this paper to evaluate the ground motion at bedrock level. Analyses were performed considering the available earthquake catalogs collected from different sources since 1731-2010 within a distance of 500 km from the political boundaries of the states. Earthquake data were declustered to remove the foreshocks and aftershocks in time and space window and then statistical analysis was carried out for data completeness. Based on seismicity, tectonic features and fault rupture mechanism, this region was divided into six major seismogenic zones and subsequently seismicity parameters (a and b) were calculated using Gutenberg-Richter (G-R) relationship. Faults data were extracted from SEISAT (Seismotectonic atlas of India, Geological Survey of India, New Delhi, 2000) published by Geological Survey of India and also from satellite images. The study area was divided into small grids of size 0.05A degrees A xA 0.05A degrees (approximately 5 km x 5 km), and the hazard parameters (rock level peak horizontal acceleration and spectral accelerations) were calculated at the center of each of these grid cells considering all the seismic sources within a radius of 500 km. Probabilistic seismic hazard analyses were carried out for Tripura and Mizoram states using the predictive ground motion equations given by Atkinson and Boore (Bull Seismol Soc Am 93:1703-1729, 2003) and Gupta (Soil Dyn Earthq Eng 30:368-377, 2010) for subduction belt. Attenuation relations were validated with the observed PGA values. Results are presented in the form of hazard curve, peak ground acceleration (PGA) and uniform hazard spectra for Agartala and Aizawl city (respective capital cities of Tripura and Mizoram states). Spatial variation of PGA at bedrock level with 2 and 10 % probability of exceedance in 50 years has been presented in the paper.

Window Exchange Umbrella Sampling to Enhance Conformational Sampling and Quantify Energetics in Transmembrane Helix Assembly

The method of window exchange umbrella sampling molecular dynamics (WEUSMD) with a pre-optimized parameter set was recently used to obtain the most probable conformations and the energetics of transmembrane (TM) helix assembly of a generic TM sequence. When applied to glycophorin A TM domain (GpA-TM) using the window potentials along the helix-helix distance, however, tight interfacial packing of GpA-TM resulted in insufficient conformational sampling at short helix-helix separation. To address this sampling issue, we approached in two directions: (i) Extension of WEUSMD into two dimensions with the restraint potentials along the rHH and crossing angle (Ω) to bypass barriers for hidden variables; (ii) Design of another scheme for the window spacing rather than a uniform one to control the average acceptance probability (Pa) between neighboring windows systematically. The two-dimensional WEUSMD results demonstrate that the incomplete sampling in the one-dimensional WEUSMD arises from high barriers along the crossing angle between the GpA-TM helices. In principle, the multi-dimensional WEUSMD is suitable for modeling TM helix assembly. However, for three or higher dimensions, this approach becomes prohibitively intensive. To avoid this issue, one may consider the latter approach, the variable window spacing for WEUSMD, where the (highest) restraint force constant for the window at the shortest rHH geometrically decreases with rHH and the first passage time optimized parameter set is estimated by using an analytic approximation of Pa in general case (different window force constants for the exchange pairs). To demonstrate the improved sampling power of WEUSMD that in turn provides trustworthy potential of mean force, we applied WEUSMD with variable window spacing for the assembly of GpA-TM, and indeed obtained the improved sampling power compared to that with uniform window spacing.

Multiple Correspondence Analysis of Fuzzyfied Task Performance and Psycho-Physiological Test Data: Use in Real Car Following Situations

Abstract This article shows the role that Fuzzy Space Windowing (FSW) and Multiple Correspondence Analysis (MCA) may play in the prospect of analyzing two different data sets separately, first and together, afterwards. This methodology is illustrated with a car-following example with 123 individuals. The first data set contains each individual's psychological profile, obtained through tests and questionnaires (23 variables); the second data set contains the signals acquired from real-life driving situations with an instrumented vehicle (6 time variables). The MCA of the first set yields individual typologies, for example, that conscientious drivers declare fewer errors in driving than impulsive and stressed drivers, or that drivers with high cognitive levels have a tendency to declare more violations than other drivers do. The MCA of the second set highlights inter-driver differences (e.g., speed, headway and pedal use). Other factors, such as infrastructure, also have an impact on driving behavior. For example, drivers have a tendency to drive under the speed limit on urban roads and over the speed limit on highways. A third and final MCA is then performed on the most informative variables found with the two previous MCAs.

Single image orthogonal fringe technique for resolution enhancement of the Fourier transform fringe analysis method

Gradient range and spatial resolution in Fourier Transform Profilometry depend on the size of the filter window in reciprocal space. The proposed methods to date for the elimination of the fundamental frequency and enlargement of the filter window are either too computationally complex or depend on the possibility of using two frames, thus disabling the method's ability to cope with dynamic situations and subjecting the results to possible intensity changes between the two frame acquisitions. This article describes a simple method for using a single crossed fringe pattern to accomplish that objective, greatly improving the previously reported technique, whilst retaining its main advantages.

Multi-domain anomaly detection in spatial datasets

A spatial anomaly captures a phenomenon occurring in a region which is vastly deviant in behavior with respect to the other normal observations. However, in reality this anomaly may impact other phenomena in the region across multiple domains, for example, crime is often linked to other sociopolitical factors or phenomenon such as poverty and education. Similarly, accidents in the region may be linked to other environmental factors such as weather and surface condition. So, finding anomalies across multiple domains is important in various applications. In this paper, we propose an approach for finding such a tangible anomalous window across multiple domains where window refers to the set of contiguous points in space, and since the window is multi-domain, there are several overlapping windows in the same space across domains. Our approach for finding anomalous window across the domains comprises the following steps: (1) single-domain anomaly detection: discovering anomalous window in each domain; (2) association rule mining: discovering relationship between the anomalous windows across domains using association rule mining; and (3) validation: validating the result using (a) Monte Carlo simulation, (b) correlation using lift and (c) ground truth evaluation. In addition, we also provide a probabilistic framework to evaluate the relationships between the spatial nodes as a postprocessing step. Finally, we provide a visualization technique for viewing the multi-domain anomalous window and the probabilistic relationships between the nodes. We provide detailed experimental results and comparisons with other approaches using real-world health ranking [51] and transportation datasets [50] with known ground truth windows. The results show that our approach is effective in finding the anomalies in multiple domains as compared to other approaches.

Microcanonical Phase Diagram of the BEG and Ising Models

The density of states of long-range Blume—Emery—Griffiths (BEG) and short-range Ising models are obtained by using Wang—Landau sampling with adaptive windows in energy and magnetization space. With accurate density of states, we are able to calculate the microcanonical specific heat of fixed magnetization introduced by Kastner et al. in the regions of positive and negative temperature. The microcanonical phase diagram of the Ising model shows a continuous phase transition at a negative temperature in energy and magnetization plane. However the phase diagram of the long-range model constructed by peaks of the microcanonical specific heat looks obviously different from the Ising chart.

Offline: A sharp mind and a strong pen

I owe a debt of thanks to Dr John McLean. In May last year, he wrote with a gift, The Quiet Art: A Doctor's Anthology. This fine volume of quotations was compiled by Liverpool physician, Dr Robert Coope, and published in 1952. The President of the Royal College of Physicians at the time, Russell Brain, asked in his foreword, “Do lawyers in their quieter moments write on the human aspects of torts, or architects turn from calculations of window space and sunlight to compose hymns to Apollo?” His claim was that doctors made a special contribution to literature.

Weighted composition followed and proceeded by differentiation operators from Q k ( p , q ) spaces to Bloch-type spaces

In this paper, we investigate boundedness and compactness of the weighted composition followed and proceeded by differentiation operators from Q k ( p , q ) Open image in new window spaces to Bloch-type spaces and little Bloch-type spaces. Some sufficient and necessary conditions for the boundedness and compactness of these operators are obtained.

Possible origins of a time-resolved frequency shift in Raman plasma amplifiers

Raman amplification is a resonant process in which the energy of a long pump pulse is transferred to a short seed pulse by a plasma wave. There has been a significant effort to identify a window in parameter space within which the interaction is expected to be highly efficient and not degraded by competing instabilities or excessive damping. However, experimental results have thus far failed to approach the theoretical limits. Recent amplified signal spectra display a characteristic blue shift, which evolves within the seed pulse duration and suggests that the mechanism responsible for this shift is also limiting amplification in these experiments. We present the evidence and explore different hypotheses for the origins of the shift—namely localization in density minima along the axis of laser propagation induced by an ion acoustic wave that could arise from the Langmuir decay instability, filamentation which could also modulate the plasma density but in the plane transverse to laser propagation, particle trapping, and additional ionization induced by the amplified seed field.

Adjustable-window grating interferometer based on a Mach-Zehnder configuration for phase profile measurements of transparent samples

This communication describes some details of polarization modulation that are useful in phase-shifting interferometry when applied to phase profile measurements of phase objects. Since non-destructive optical techniques allow surface measurement with high accuracy, a Mach-Zehnder configuration coupled to a 4-f arrangement using phase gratings placed on the Fourier plane was implemented to analyze phase objects. Each beam of the interferometer goes through a birefringent wave plate in order to achieve nearly circular polarization of opposite rotations, with respect to each other. The interference of the fields associated with replicated beams, centered on each diffraction order, is achieved varying the spacing of windows with respect to the grating period. Experimental results are presented for cases of four and nine simultaneously captured interferograms.

Radiative exchange across a window and links to indoor energy demand

This work examines energy exchange between a window and the external environment with emphasis on the role of radiation in determining indoor energy demand. A set of radiometers monitored the flow of solar and longwave radiation to and from a window located in Chicago, IL from December to July. A model of energy exchange between the atmosphere, window and interior space allows estimates of the energy required to maintain indoor temperatures. Energy is lost to the atmosphere by sensible heat transport, longwave emission and reflection of sunlight, where the net effect of radiation is the difference between incoming and outgoing components. Sensible heat transport is the most important contributor to cooling, particularly in winter, while the direct effects of radiation are small, except in June and July. However, longwave radiation has a significant influence on the window's temperature. Radiative processes increase the temperature contrast between the window and the atmosphere, and thereby influence sensible heat transport. For the circumstance analyzed here, the action of solar and longwave radiation during December and January increases the demand for interior heating by a factor of four over what would exist in the absence radiant energy.

Shear dispersion in the thermocline and the saline intrusion

Over the mid-Atlantic shelf of the North America, there is a pronounced shoreward intrusion of the saltier slope water along the seasonal thermocline, whose genesis remains unexplained. Taking note of the observed broad-band baroclinic motion, we postulate that it may propel the saline intrusion via the shear dispersion. Through an analytical model, we first examine the shear-induced isopycnal diffusivity (“shear diffusivity” for short) associated with the monochromatic forcing, which underscores its varied even anti-diffusive short-term behavior and the ineffectiveness of the internal tides in driving the shear dispersion. We then derive the spectral representation of the long-term “canonical” shear diffusivity, which is found to be the baroclinic power band-passed by a diffusivity window in the log-frequency space. Since the baroclinic power spectrum typically plateaus in the low-frequency band spanned by the diffusivity window, canonical shear diffusivity is simply 1/8 of this low-frequency plateau — independent of the uncertain diapycnal diffusivity. Applied to the mid-Atlantic shelf, this canonical shear diffusivity is about 20m2s−1, which is sufficient to account for the observed tracer dispersion or saline intrusion in the thermocline.

Active interlock for the NSLS-II damping wiggler

The NSLS-II is a 3rd generation light source with ultra-low beam emittance that is currently under construction at the Brookhaven National Laboratory. Because the power of the synchrotron radiation from the damping wiggler (DW) is about 64kW, a slight mis-steer can result in severe damage to the vacuum chamber. To avoid such problems, an active interlock system is being considered. The system dumps the beam when it departs from the predefined safe window in the phase space. In this paper, we present simple geometric arguments from which we define the safe window on the basis of betatron amplitudes. This window can be applied to any DW around the ring. For the entrance of the wiggler, we obtained window of Δx=±8.4mm, Δx′=±429μrad and Δy=±2.1mm, Δy′=±449μrad.

Period-three route to chaos induced by a cyclic-fold bifurcation in passive dynamic walking of a compass-gait biped robot

This paper presents a study of the passive dynamic walking of a compass-gait biped robot as it goes down an inclined plane. This biped robot is a two-degrees-of-freedom mechanical system modeled by an impulsive hybrid nonlinear dynamics with unilateral constraints. It is well-known to possess periodic as well as chaotic gaits and to possess only one stable gait for a given set of parameters. The main contribution of this paper is the finding of a window in the parameters space of the compass-gait model where there is multistability. Using constraints of a grazing bifurcation on the basis of a shooting method and the Davidchack–Lai scheme, we show that, depending on initial conditions, new passive walking patterns can be observed besides those already known. Through bifurcation diagrams and Floquet multipliers, we show that a pair of stable and unstable period-three gait patterns is generated through a cyclic-fold bifurcation. We show also that the stable period-three orbit generates a route to chaos.

Fokker–Planck Equations and Maximal Dissipativity for Kolmogorov Operators for SPDE Driven by Lévy Noise

In this paper we consider the Kolmogorov operator Open image in new window in an Hilbert space ℍ related to an SPDE driven by Levy noise. We show that Open image in new window is essentially m-dissipatitive in the space Lp([0, T] × ℍ; ν), p ≥ 1, where ν(dt, dx) = νt(dx)dt and the family {νt}t ∈ [0, T] is a solution of the Fokker–Planck equation given by Open image in new window. The uniqueness of solutions for the Fokker–Planck equation is also proved. These results are generalizations of that in Bogachev et al. (J Funct Anal 256:1269–1298, 2009).

A scale fuzzy windowing comparison applied to multivariate descriptive analysis

Observational and experimental data are often investigated into so that the factor effects and/or variables connections can be assessed quickly and easily via inference tests. This article suggests starting the statistical analysis using a 5-step descriptive procedure: 1 Data characterization, 2 Data coding, 3 Data table drafting, 4 Data table analysis and 5 Result presentation. In order to illustrate this preliminary statistical analysis, two data set examples are considered --one from a small simulated system and one from a large mechatronic system--using two different methods: Principal Component Analysis with usual statistical summaries and Multiple Correspondence Analysis with indicators obtained through fuzzy space windowing. In an Intelligent Data Analysis context, the discussion weighs out the pros and the cons of these approaches, prior to using procedures 5-step inference procedures.

Multivariate analysis of human behavior data using fuzzy windowing: Example with driver–car–environment system

In most human component system studies performed in simulators, several factors (or independent variables) (at least two, i.e., individual and time) and many variables (or dependent variables) are present. Large and complex databases have to be analyzed. Instead of using rather automatic procedures, this article suggest that, for a very first analysis at least, the human being must be present and he/she must choose a method being adapted to the data, which is different to run a method supposing that the data fit such or such model. This article suggests starting the analysis while keeping both the multifactorial (MF) and multivariate (MV) aspects. To achieve this aim, with the possibility to show nonlinear relationships, a MFMV exploration of the experimental database is performed using the pair (fuzzy space windowing, Multiple Correspondence Analysis). Then may come an inference analysis. This long (due to multiple large graphical views) but rich procedure is illustrated and discussed using a car driving study example.

Statistical extraction of volcanic sulphate from nonpolar ice cores

Ice cores from outside the Greenland and Antarctic ice sheets are difficult to date because of seasonal melting and multiple sources (terrestrial, marine, biogenic and anthropogenic) of sulfates deposited onto the ice. Here we present a method of volcanic sulfate extraction that relies on fitting sulfate profiles to other ion species measured along the cores in moving windows in log space. We verify the method with a well dated section of the Belukha ice core from central Eurasia. There are excellent matches to volcanoes in the preindustrial, and clear extraction of volcanic peaks in the post‐1940 period when a simple method based on calcium as a proxy for terrestrial sulfate fails due to anthropogenic sulfate deposition. We then attempt to use the same statistical scheme to locate volcanic sulfate horizons within three ice cores from Svalbard and a core from Mount Everest. Volcanic sulfate is <5% of the sulfate budget in every core, and differences in eruption signals extracted reflect the large differences in environment between western, northern and central regions of Svalbard. The Lomonosovfonna and Vestfonna cores span about the last 1000 years, with good extraction of volcanic signals, while Holtedahlfonna which extends to about AD1700 appears to lack a clear record. The Mount Everest core allows clean volcanic signal extraction and the core extends back to about AD700, slightly older than a previous flow model has suggested. The method may thus be used to extract historical volcanic records from a more diverse geographical range than hitherto.