Large Image Fast Compositing Based on Uniform Sample

In order to understand how the algorithms underlying neural computation are implemented within any neural system, it is necessary to understand details of the anatomy, physiology and global organization of the neurons from which the system is constructed. Information is represented in neural systems by patterns of activity that vary in both their spatial extent and in the time domain. One of the great challenges to microscopists is to devise methods for imaging these patterns of activity and to correlate them with the underlying neuroanatomy and physiology. We have addressed this problem by using a combination of three dimensional reconstruction techniques, quantitative analysis and computer visualization techniques to build a probabilistic atlas of a neural map in an insect sensory system. The principal goal of this study was to derive a quantitative representation of the map, based on a uniform sample of afferents that was of sufficient size to allow statistically meaningful analyses of the relationships between structure and function.

Download Full-text

Transportation container for pre-processing cytogenetic assays in radiation accidents

Scientific Reports ◽

10.1038/s41598-021-89832-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jian Gu ◽

Brett Duane ◽

Mikhail Repin ◽

David J. Brenner ◽

Frederic Zenhausern

Keyword(s):

Cell Culture ◽

Linear Correlation ◽

Alkaline Batteries ◽

Radiation Accidents ◽

Shipping Container ◽

Dose Curve ◽

Uniform Sample ◽

Clear Dose Response ◽

Transportation Container ◽

High Linear Correlation

AbstractWe report a shipping container that enables a disruptive logistics for cytogenetic biodosimetry for radiation countermeasures through pre-processing cell culture during transportation. The container showed precise temperature control (< 0.01 °C) with uniform sample temperature (< 0.1 °C) to meet the biodosimetry assay requirements. Using an existing insulated shipping box and long shelf life alkaline batteries makes it ideal for national stockpile. Dose curve of cytogenetic biodosimetry assay using the shipping container showed clear dose response and high linear correlation with the control dose curve using a laboratory incubator (Pearson’s correlation coefficient: 0.992). The container’s ability of pre-processing biological samples during transportation could have a significant impact on radiation countermeasure, as well as potential impacts in other applications such as biobanking, novel molecular or cell-based assays or therapies.

Download Full-text

Approximate Mining of Frequent -Subgraph Patterns in Evolving Graphs

ACM Transactions on Knowledge Discovery from Data ◽

10.1145/3442590 ◽

2021 ◽

Vol 15 (3) ◽

pp. 1-35

Author(s):

Muhammad Anis Uddin Nasir ◽

Cigdem Aslay ◽

Gianmarco De Francisci Morales ◽

Matteo Riondato

Keyword(s):

Sample Size ◽

State Of The Art ◽

Empirical Evaluation ◽

Connected Subgraph ◽

Dynamic Graphs ◽

High Quality ◽

Complexity Bounds ◽

Approximation Quality ◽

Uniform Sample ◽

Waiting For Godot

“Perhaps he could dance first and think afterwards, if it isn’t too much to ask him.” S. Beckett, Waiting for Godot Given a labeled graph, the collection of -vertex induced connected subgraph patterns that appear in the graph more frequently than a user-specified minimum threshold provides a compact summary of the characteristics of the graph, and finds applications ranging from biology to network science. However, finding these patterns is challenging, even more so for dynamic graphs that evolve over time, due to the streaming nature of the input and the exponential time complexity of the problem. We study this task in both incremental and fully-dynamic streaming settings, where arbitrary edges can be added or removed from the graph. We present TipTap , a suite of algorithms to compute high-quality approximations of the frequent -vertex subgraphs w.r.t. a given threshold, at any time (i.e., point of the stream), with high probability. In contrast to existing state-of-the-art solutions that require iterating over the entire set of subgraphs in the vicinity of the updated edge, TipTap operates by efficiently maintaining a uniform sample of connected -vertex subgraphs, thanks to an optimized neighborhood-exploration procedure. We provide a theoretical analysis of the proposed algorithms in terms of their unbiasedness and of the sample size needed to obtain a desired approximation quality. Our analysis relies on sample-complexity bounds that use Vapnik–Chervonenkis dimension, a key concept from statistical learning theory, which allows us to derive a sufficient sample size that is independent from the size of the graph. The results of our empirical evaluation demonstrates that TipTap returns high-quality results more efficiently and accurately than existing baselines.

Download Full-text

Predictive view of the value relevance of earnings in India

Journal of Financial Reporting and Accounting ◽

10.1108/jfra-08-2021-0219 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Hajam Abid Bashir ◽

Manish Bansal ◽

Dilip Kumar

Keyword(s):

Capital Investment ◽

Stock Return ◽

Value Relevance ◽

Stock Exchange ◽

Predictive Ability ◽

Cash Flows ◽

Data Set ◽

Content Type ◽

Uniform Sample ◽

Reported Earnings

Purpose This study aims to examine the value relevance of earnings in terms of predicting the value variables such as cash flow, capital investment (CI), dividend and stock return under the Indian institutional settings. Design/methodology/approach The study used panel Granger causality tests to examine causality relationships among variables and panel data regression models to check the statistical associations between earnings and value variables. Findings Based on a data set of 7,280 Bombay Stock Exchange-listed firm-years spanning over ten years from March 2009 to March 2018, the results show higher sensitivity of earnings toward cash flows, CI, divided and stock return and vice-versa. Further, the findings deduced from the empirical results demonstrate that earnings are positively related to value variables. Overall, the results established that earnings are value-relevant and have predictive ability to forecast the value variables that facilitate investors in portfolio valuation. The results are consistent with the predictive view of the value relevance of earnings. Several robustness checks confirm these results. Originality/value This study brings new empirical evidence from a distinct capital market, India, and provides a new facet to the value relevance debate in terms of its prediction view. The study is among earlier attempts that jointly measure the ability of earnings in forecasting different value variables by taking a uniform sample of firms at the same period. Hence, the study provides a comprehensive view of the predictive ability of reported earnings.

Download Full-text

Trivariate Empirical Mode Decomposition via Convex Optimization for Rolling Bearing Condition Identification

Sensors ◽

10.3390/s18072325 ◽

2018 ◽

Vol 18 (7) ◽

pp. 2325 ◽

Cited By ~ 2

Author(s):

Yong Lv ◽

Houzhuang Zhang ◽

Cancan Yi

Keyword(s):

Convex Optimization ◽

Empirical Mode Decomposition ◽

Dimensional Space ◽

Real Data ◽

Rolling Bearing ◽

Low Rank ◽

Data Matrix ◽

Mode Decomposition ◽

Uniform Sample ◽

Local Mean

As a multichannel signal processing method based on data-driven, multivariate empirical mode decomposition (MEMD) has attracted much attention due to its potential ability in self-adaption and multi-scale decomposition for multivariate data. Commonly, the uniform projection scheme on a hypersphere is used to estimate the local mean. However, the unbalanced data distribution in high-dimensional space often conflicts with the uniform samples and its performance is sensitive to the noise components. Considering the common fact that the vibration signal is generated by three sensors located in different measuring positions in the domain of the structural health monitoring for the key equipment, thus a novel trivariate empirical mode decomposition via convex optimization was proposed for rolling bearing condition identification in this paper. For the trivariate data matrix, the low-rank matrix approximation via convex optimization was firstly conducted to achieve the denoising. It is worthy to note that the non-convex penalty function as a regularization term is introduced to enhance the performance. Moreover, the non-uniform sample scheme was determined by applying singular value decomposition (SVD) to the obtained low-rank trivariate data and then the approach used in conventional MEMD algorithm was employed to estimate the local mean. Numerical examples of synthetic defined by the fault model and real data generated by the fault rolling bearing on the experimental bench are provided to demonstrate the fruitful applications of the proposed method.

Download Full-text

Exact Formulae for Variances of Functionals of Convex Hulls

Advances in Applied Probability ◽

10.1017/s0001867800006698 ◽

2013 ◽

Vol 45 (04) ◽

pp. 917-924

Author(s):

Christian Buchta

Keyword(s):

Convex Hull ◽

Asymptotic Distribution ◽

Convex Polygon ◽

Convex Hulls ◽

Affine Invariance ◽

Uniform Sample

The vertices of the convex hull of a uniform sample from the interior of a convex polygon are known to be concentrated close to the vertices of the polygon. Furthermore, the remaining area of the polygon outside of the convex hull is concentrated close to the vertices of the polygon. In order to see what happens in a corner of the polygon given by two adjacent edges, we consider—in view of affine invariance—n points P 1,…, P n distributed independently and uniformly in the interior of the triangle with vertices (0, 1), (0, 0), and (1, 0). The number of vertices of the convex hull, which are close to the origin (0, 0), is then given by the number Ñ n of points among P 1,…, P n , which are vertices of the convex hull of (0, 1), P 1,…, P n , and (1, 0). Correspondingly, D̃ n is defined as the remaining area of the triangle outside of this convex hull. We derive exact (nonasymptotic) formulae for var Ñ n and var . These formulae are in line with asymptotic distribution results in Groeneboom (1988), Nagaev and Khamdamov (1991), and Groeneboom (2012), as well as with recent results in Pardon (2011), (2012).

Download Full-text

An Optical Model for Quantitative Raman Microspectroscopy

Applied Spectroscopy ◽

10.1177/0003702819895299 ◽

2020 ◽

Vol 74 (6) ◽

pp. 684-700 ◽

Cited By ~ 2

Author(s):

Joseph Razzell Hollis ◽

David Rheingold ◽

Rohit Bhartia ◽

Luther W. Beegle

Keyword(s):

Optical Model ◽

Solid Phase ◽

Pyrolytic Graphite ◽

Sample Volume ◽

Raman Intensity ◽

Complex Samples ◽

Uniform Sample ◽

Pass Through ◽

The Individual ◽

Spectrometer Slit

Raman spectroscopy is an invaluable technique for identifying compounds by the unique pattern of their molecular vibrations and is capable of quantifying the individual concentrations of those compounds provided that certain parameters about the sample and instrument are known. We demonstrate the development of an optical model to describe the intensity distribution of incident laser photons as they pass through the sample volume, determine the limitations of that volume that may be detected by the spectrometer optics, and account for light absorption by molecules within the sample in order to predict the total Raman intensity that would be obtained from a given, uniform sample such as an aqueous solution. We show that the interplay between the shape and divergence of the laser beam, the position of the focal plane, and the dimensions of the spectrometer slit are essential to explaining experimentally observed trends in deep ultraviolet Raman intensities obtained from both planar and volumetric samples, including highly oriented pyrolytic graphite and binary mixtures of organic nucleotides. This model offers the capability to predict detection limits for organic compounds in different matrices based on the parameters of the spectrometer, and to define the upper/lower limits within which concentration can be reliably determined from Raman intensity for such samples. We discuss the potential to quantify more complex samples, including as solid phase mixtures of organics and minerals, that are investigated by the unique instrument parameters of the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) investigation on the upcoming Mars 2020 rover mission.

Download Full-text

The Lx–Luv–Lradio relation and corona–disc–jet connection in optically selected radio-loud quasars

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1411 ◽

2020 ◽

Vol 496 (1) ◽

pp. 245-268 ◽

Cited By ~ 2

Author(s):

S F Zhu (朱世甫) ◽

W N Brandt ◽

B Luo (罗斌) ◽

Jianfeng Wu (武剑锋) ◽

Y Q Xue (薛永泉) ◽

...

Keyword(s):

Black Holes ◽

Black Hole ◽

Small Scale ◽

Spectral Slope ◽

Physical Processes ◽

X Ray ◽

Accretion Flow ◽

Radio Jets ◽

Spectrum Radio ◽

Uniform Sample

ABSTRACT Radio-loud quasars (RLQs) are more X-ray luminous than predicted by the X-ray–optical/UV relation (i.e. $L_\mathrm{x}\propto L_\mathrm{uv}^\gamma$) for radio-quiet quasars (RQQs). The excess X-ray emission depends on the radio-loudness parameter (R) and radio spectral slope (αr). We construct a uniform sample of 729 optically selected RLQs with high fractions of X-ray detections and αr measurements. We find that steep-spectrum radio quasars (SSRQs; αr ≤ −0.5) follow a quantitatively similar $L_\mathrm{x}\propto L_\mathrm{uv}^{\gamma }$ relation as that for RQQs, suggesting a common coronal origin for the X-ray emission of both SSRQs and RQQs. However, the corresponding intercept of SSRQs is larger than that for RQQs and increases with R, suggesting a connection between the radio jets and the configuration of the accretion flow. Flat-spectrum radio quasars (FSRQs; αr > −0.5) are generally more X-ray luminous than SSRQs at given Luv and R, likely involving more physical processes. The emergent picture is different from that commonly assumed where the excess X-ray emission of RLQs is attributed to the jets. We thus perform model selection to compare critically these different interpretations, which prefers the coronal scenario with a corona–jet connection. A distinct jet component is likely important for only a small portion of FSRQs. The corona–jet, disc–corona, and disc–jet connections of RLQs are likely driven by independent physical processes. Furthermore, the corona–jet connection implies that small-scale processes in the vicinity of supermassive black holes, probably associated with the magnetic flux/topology instead of black hole spin, are controlling the radio-loudness of quasars.

Download Full-text

The convex hull of a uniform sample from the interior of a simple d-polytope

Journal of Applied Probability ◽

10.1017/s0021900200027261 ◽

1989 ◽

Vol 26 (02) ◽

pp. 259-273 ◽

Cited By ~ 3

Author(s):

Barthold F. Van Wel

Keyword(s):

Convex Hull ◽

Asymptotic Expression ◽

Expected Number ◽

Simple Polytope ◽

Uniform Sample ◽

Sample Points

An asymptotic expression is given for the expected number of vertices of the convex hull of a uniform sample from the interior of a d-dimensional simple polytope. This extends a result derived by Rényi and Sulanke for sample points in the plane.

Download Full-text

Stellar Magnetic Dynamos and Activity Cycles

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314002038 ◽

2013 ◽

Vol 9 (S302) ◽

pp. 190-193

Author(s):

Nicholas J. Wright

Keyword(s):

Coronal Emission ◽

X Ray ◽

Rotation Periods ◽

Early Results ◽

Uniform Sample ◽

Activity Cycles ◽

Blind Search ◽

The Relationship ◽

Interface Type ◽

Stellar Dynamo

AbstractUsing a new uniform sample of 824 solar and late-type stars with measured X-ray luminosities and rotation periods we have studied the relationship between rotation and stellar activity that is believed to be a probe of the underlying stellar dynamo. Using an unbiased subset of the sample we calculate the power law slope of the unsaturated regime of the activity – rotation relationship as LX / Lbol ∝ Roβ, where β = − 2.70 ± 0.13. This is inconsistent with the canonical β = − 2 slope to a confidence of 5σ and argues for an interface-type dynamo. We map out three regimes of coronal emission as a function of stellar mass and age, using the empirical saturation threshold and theoretical super-saturation thresholds. We find that the empirical saturation timescale is well correlated with the time at which stars transition from the rapidly rotating convective sequence to the slowly rotating interface sequence in stellar spin-down models. This may be hinting at fundamental changes in the underlying stellar dynamo or internal structure. We also present the first discovery of an X-ray unsaturated, fully convective M star, which may be hinting at an underlying rotation - activity relationship in fully convective stars hitherto not observed. Finally we present early results from a blind search for stellar X-ray cycles that can place valuable constraints on the underlying ubiquity of solar-like activity cycles.

Download Full-text