Width Histogram Research Articles

Utilizing Entropy-Based Method for Rainfall Network Design in Huaihe River Basin, China

The nonstationary characteristics caused by significant variation in hydrometeorological series in the context of climate change inevitably have a certain impact on the selection of an optimal gauging network. This study proposes an entropy-based, multi-objective, rain gauge network optimization method to facilitate the design of a 43 stations-based network in Huaihe River Basin (HRB), China. The first goal of this study is to improve the accuracy of gauge-related information estimation through the selection and comparison of discretization methods. The second goal of this study is to quantify the impact of trend-caused nonstationarity on optimal network design using the sliding window method. This study compares the divergence of three kinds of discretization methods, including the floor function-based approach, Scott’s equal bin width histogram (EWH-Sc) approach, and Sturges’s equal bin width histogram (EWH-St) approach. The matching degree of the variance and marginal entropy of the observed series is computed to select the most suitable of the above three discretization methods. The trend-caused nonstationarity in 75% of all stations in the HRB could definitely influence the final results of the optimal rain-gauge network design using the sliding window method. Therefore, in future studies of rain-gauge network optimization, it is necessary to carry out uncertainty research according to local conditions in view of climate change and human activities.

Constructing outlier-free histograms with variable bin-width based on distance minimization

We propose a new method of constructing a variable bin width histogram that can accommodate the unbalanced distribution of the samples yet retaining, as a whole, the good aspect of both equal width (EW) and equal-area (EA) histograms that are being used popularly for data visualization and analysis. We formulate this as an optimal change point detection problem in which the bin boundaries are determined by minimizing the sum of the absolute error or the squared error in each bin. The former is based on Distance Minimization (DM) and new, and the latter is based on Variance Minimization (VM) and is considered the state-of-the-art. The constructed histograms can effectively be used to detect and visualize hidden outliers/anomalies by applying the interquartile range method in each bin. The final histograms are obtained by adjusting bin boundaries and heights accordingly after removing the detected outliers/anomalies. We further propose a method to annotate the constructed bins if the data for annotation is given for each sample as a set of nominal variables, using z-score with respect to their distribution within each bin. We applied our method to both real vinyl greenhouse datasets and two different sets of three synthetic datasets, and confirmed that both DM and VM methods work as intended, both can represent the sample distribution with a smaller number of bins than those by EW and EA methods, The use of interquartile range method can detect anomalies as well as outliers, and the terms selected for annotation are interpretable and reasonable. EW and EA methods have contrasting properties. DM and VM methods lie in between, but the former is closer to EA method and the latter to EW method. DM method runs substantially faster than VM method and performs slightly better than VM method in outlier detection and annotation tasks.

A comprehensive experimental study on the role of matrix structure on the multiple cracking behavior of PVA-ECC

In this study, the effect of W/B ratio and mineral additive types on the role of fiber–matrix synergy in PVA-ECC was comprehensively investigated with the aid of micro-mechanical design theory. The effects of rheological properties, failure cross-section fiber distribution, natural flaw size distributions on tensile performance were investigated, and the relationships among these parameters were researched. For maximum tensile stress, crack analysis were performed with DIC technique and crack width histograms were determined. Moreover, the relationships between tensile performance and compressive strength have been investigated. According to the results, it was determined that the combined effect of W/B ratio and mineral additive type in PVA-ECC had a significant effect on both the rheological and mechanical results, and their relationships were compared. Fiber distribution and flaw size distribution should also be considered together to explain the difference in tensile performance of different/same ECC mixtures. It has been determined that the current micromechanical theory PSH criteria are insufficient to provide saturated multiple crack behavior, and therefore need to be updated. In the investigation of crack pattern of ECC, crack width distribution rather than average crack width was found to be a more realistic approach.

HBOS-CNV: A New Approach to Detect Copy Number Variations From Next-Generation Sequencing Data.

Copy number variation (CNV) is a genomic mutation that plays an important role in tumor evolution and tumor genesis. Accurate detection of CNVs from next-generation sequencing (NGS) data is still a challenging task due to artifacts such as uneven mapped reads and unbalanced amplitudes of gains and losses. This study proposes a new approach called HBOS-CNV to detect CNVs from NGS data. The central point of HBOS-CNV is that it uses a new statistic, the histogram-based outlier score (HBOS), to evaluate the fluctuation of genome bins to determine those of changed copy numbers. In comparison with existing statistics in the evaluation of CNVs, HBOS is a non-linearly transformed value from the observed read depth (RD) value of each genome bin, having the potential ability to relieve the effects resulted from the above artifacts. In the calculation of HBOS values, a dynamic width histogram is utilized to depict the density of bins on the genome being analyzed, which can reduce the effects of noises partially contributed by mapping and sequencing errors. The evaluation of genome bins using such a new statistic can lead to less extremely significant CNVs having a high probability of detection. We evaluated this method using a large number of simulation datasets and compared it with four existing methods (CNVnator, CNV-IFTV, CNV-LOF, and iCopyDav). The results demonstrated that our proposed method outperforms the others in terms of sensitivity, precision, and F1-measure. Furthermore, we applied the proposed method to a set of real sequencing samples from the 1000 Genomes Project and determined a number of CNVs with biological meanings. Thus, the proposed method can be regarded as a routine approach in the field of genome mutation analysis for cancer samples.

Characterization, detection, and counting of metal nanoparticles using flow cytometry

There is a need to accurately detect, characterize, and quantify nanoparticles in suspensions. This study helps to understand the complex interactions between similar types of nanoparticles. Before initiating a study of metal nanoparticles, five submicron PS beads with sizes between 200 nm and 1 µm were used to derive a reference scale that was useful in evaluating the flow cytometer for functionality, sensitivity, resolution, and reproducibility. Side scatter intensity (SSC) from metal nanoparticles was obtained simultaneously from 405 nm and 488 nm lasers. The 405 nm laser generally yielded histogram distributions with smaller CVs, less side scatter intensity, better separation indices between beads and decreased scatter differences between different sized particles compared with the 488 nm laser. Submicron particles must be diluted to 10(6) and 10(7) particles/mL before flow cytometer analysis to avoid coincidence counting artifacts. When particles were too concentrated the following occurred: swarm, electronic overload, coincidence counting, activation of doublet discrimination and rejection circuitry, increase of mean SSC histogram distributions, alterations of SSC and pulse width histogram shape, decrease and fluctuations in counting rate and decrease or elimination of particulate water noise and 1 µm reference bead. To insure that the concentrations were in the proper counting range, the nanoparticle samples were mixed with a known concentration of 1 µm counting beads. Sequential dilutions of metal nanoparticles in a 1 µm counting bead suspension helped determine the diluted concentration needed for flow cytometer analysis. It was found that the original concentrated nanoparticle samples had to be diluted, between 1:10,000 and 1:100,000, before characterization by flow cytometry. The concentration of silver or gold nanoparticles in the undiluted sample were determined by comparing them with a known concentration (1.9 × 10(6) beads/mL) of 1 µm polystyrene reference beads.

A note on the e–a histogram

The e–a histogram dominates, under square error loss, a fixed bin width histogram when both are assigned the same number of bins. That is, the fixed bin width histogram is inadmissible and the dominating alternative is the e–a histogram.

Design of low-power hybrid digital pulse width modulator with piecewise calibration scheme

A low-power hybrid digital pulse width modulator (DPWM) is proposed in the paper. Owing to the piecewise calibration scheme, the delay time of delay line is locked to target frequency. The delay line consists of two piecewise lines with different control codes. The delay time of each cell in one sub-delay-line is longer than the last significant bit (LSB) of DPWM, while the delay time of each cell in the other sub-delay-line is shorter than LSB. Optimum linearity is realised with minimum standard cells. Simulation results show that the differential nonlinearity and integral nonlinearity are improved from 5.1 to 0.4 and from 5 to 1.3, respectively. The DPWM is fully synthesised and fabricated in a 90-nm CMOS process. The proposed DPWM occupies a silicon area of 0.01 mm2, with 31.5 μw core power consumption. Experimental results are shown to demonstrate the 2-MHz, 10-bit resolution implementation. Pulse width histogram is firstly introduced to characterise the linearity of the DPWM.

Velocities and Linewidths in the Network and Cell Interiors of a Polar Coronal Hole Compared with the Quiet Sun

The relative Doppler velocities and linewidths in a polar coronal hole and the nearby quiet-Sun region have been obtained from the {\it Solar and Heliospheric Observatory} (SOHO)/{\it Coronal Diagnostic Spectrometer} (CDS) observations using emission lines originating at different heights in the solar atmosphere from the lower transition region (TR) to the low solar corona. The observed region is separated into the network and the cell interior and the behavior of the above parameters were examined in the different regions. It has been found that the histograms of Doppler velocity and width are generally broader in the cell interior as compared to the network. The histograms of Doppler velocities of the network and cell interior do not show significant difference in most cases. However, in the case of the quiet Sun, the Doppler velocities of the cell interior are more blueshifted than those of the network for the lowermost line He {\sc ii} 304 {\AA}, and an opposite behavior is seen for the uppermost line Mg {\sc ix} 368 {\AA}. The histograms of line width show that the network--cell difference is more prominent in the coronal hole. The network has significantly larger linewidth than the cell interior for the lowermost TR line He {\sc ii} 304 {\AA} for the quiet Sun. For coronal hole, this is true for the three lower TR lines He {\sc ii} 304 {\AA}, O {\sc iii} 599 {\AA}, and O {\sc v} 630 {\AA}. Also obtained are the correlations between the relative Doppler velocity and the width. A mild positive correlation is found for the lowermost transition region line He {\sc ii} 304 {\AA} which further decreases or become insignificant for the intermediate lines. For the low coronal line, Mg {\sc ix} 368 {\AA}, the correlation becomes strongly negative.

Wind and drifting-snow gust factor in an Alpine context

AbstarctWind-transported snow is a common phenomenon in cold windy areas, creating snowdrifts and contributing significantly to the loading of avalanche release areas. It is therefore necessary to take into account snowdrift formation both in terms of predicting and controlling drift patterns. Particularly in an Alpine context, drifting snow is a nonstationary phenomenon, which has not been taken into account in physical modeling carried out in wind tunnels or in numerical simulations. Only a few studies have been conducted to address the relation between wind gusts and drifting-snow gusts. Consequently, the present study was conducted at the Lac Blanc pass (2700ma.s.l.) experimental site in the French Alps using a snow particle counter and a cup anemometer in order to investigate drifting-snow gusts. First, it was shown that the behavior of the wind gust factor was coherent with previous studies. Then the definition of wind gust factor was extended to a drifting-snow gust factor. Sporadic drifting-snow events were removed from the analysis to avoid artificially high drifting-snow gust factors. Two trends were identified: (1) A high 1 s peak and a mean 10 min drifting-snow gust factor, greater than expected, were observed for events that exhibited a gamma distribution on the particle width histogram. The values of drifting-snow gust factors decreased with increasing gust duration. (2) Small drifting-snow gusts (i.e. smaller than or of the same order of magnitude as wind gusts) were also observed. However, in this case, they were systematically characterized by a snow particle size distribution that differed from the two-parameter gamma probability density function.

Line Width Distributions in Single-Molecule Spectroscopy Due to Optical Saturation

The paper deals with distributions of spectroscopic line widths of single molecules as measured in disordered solids at low temperatures. The influence of the random orientation of the dye molecules and, hence, of the different amount of power broadening on the fluorescence excitation spectra is investigated. The resulting line width distributions are calculated as a function of laser intensity and of the detection efficiency of the apparatus. It turns out that, for linearly polarized laser light, power broadening tends to give rise to asymmetric distributions that have a steep slope at narrow widths and a longer tail at broad widths. Possible implications for experimental line width histograms are discussed.

Variance and width of absorption lines of single molecules in low temperature glasses

We consider the line shapes of single molecules in low temperature glasses due to dipole–dipole interaction between the molecules and other particles of the system. Motivated by computer simulations, we employ a simplified formula for the absorption lines and derive an analytic expression for the distribution of the variance of such absorption lines. The simplest version of this distribution—derived for pointlike particles without cutoff of the interaction at small distances—already accounts for the qualitative features of width histograms measured experimentally or gained by computer simulation. We further analyze the effect of the minimal approach distance between the chromophore and the perturbing particles and employ an approximate relation between the variance and the full width at half maximum of the absorption lines. We find that the main characteristics of the histogram of widths stem from the (homogeneous) distribution of interactions in space and do not reflect the distribution of the internal parameters of the underlying model.

Adaptation and variability of spike discharge of auditory nerve

The response of afferent fibers in gerbil auditory nerve to constant intensity tone bursts was observed. The rapidly declining rate during the first 10 ms appears to have lower variability than the response during the steady state. That is, PST histograms appear smoother during the rapid adaptation phase than at later times. We tested this impression by calculating pulse‐number distributions. Histograms of bin width T were constructed by dividing the response record of single fibers into N subsets. The mean and variance of the number of spikes in each bin of the subset PST histograms were calculated, for various values of N and T. We observed that the variance‐to‐mean ratio was relatively constant and independent of (declining) firing rate during the adapting response, except for the onset 1‐ms bin. At high intensities the probability of firing approached unity during the onset 1‐ms window, so that the variance approached zero. At all later times, the ratio was near unity, consistent with a Poisson process with a relative refractory period.

Quadratic integration: Theory and application to the electronic structure of platinum

In this paper we present a general computational technique for deriving fine histogram representations of singular k-dependent integrals for any crystalline solid. Detailed consideration is given to the errors involved in such integrals, and in their representations. Comparisons are made to previous work and the special advantage of each technique is emphasized. Applications of the quadratic (QUAD) technique are made to platinum using the combined interpolation scheme showing the total, band and basis function ( S-part) density of states. These densities of states are based on histograms of width 0.001 Ry, 1 000 000 Monte Carlo points in 1/48th of the Brillouin zone, and have an intrinsic accuracy of better than 1%. The extrinsic accuracy of the platinum band structure used here is somewhat poorer than 1%, and the special problems of materials with a steep derivative in the density of states at the Fermi energy is considered. Comparisons with the temperature and magnetic field dependent susceptibility and the specific heat data suggest that enhancement effects in platinum are small.

A morphometric study of the ant species,Myrmecia dispar (Clark) (Hymenoptera: Formicidæ)

Myrmecia dispar (Clark) workers and queens show monomorphic polymorphism with limited size variation. Significant differences were found for the mean values of certain characters of workers between some colonies. Frequency histograms of head width against the number of workers in a colony varied considerably, with little or no definite pattern for the smaller colonies and ranging from unimodal to bimodal histograms for the larger colonies. Highly significant, positive, correlation values were obtained for all measured characters in each colony. Partial correlation analysis revealed much of this correlation to be due to similar growth coefficients. Regression analysis indicated that the characters head width and pronotal width were linearly related.