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1
Kollár, János. "Semi-Normal Log Centres and Deformations of Pairs." Proceedings of the Edinburgh Mathematical Society 57, no. 1 (December 19, 2013): 191–99. http://dx.doi.org/10.1017/s0013091513000801.
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AbstractWe show that some of the properties of log canonical centres of a log canonical pair also hold for certain subvarieties that are close to being a log canonical centre. As a consequence, we obtain that, in working with deformations of pairs where all the coefficients of the boundary divisor are bigger than ½, embedded points never appear on the boundary divisor.
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Lingas, Andrzej, and Anil Maheshwari. "A Simple Optimal Parallel Algorithm for Reporting Paths in a Tree." Parallel Processing Letters 07, no. 01 (March 1997): 3–11. http://dx.doi.org/10.1142/s0129626497000036.
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We present optimal parallel solutions to reporting paths between pairs of nodes in an n-node tree. Our algorithms are deterministic and designed to run on an exclusive read exclusive write parallel random-access machine (EREW PRAM). In particular, we provide a simple optimal parallel algorithm for preprocessing the input tree such that the path queries can be answered efficiently. Our algorithm for preprocessing runs in O( log n) time using O(n/ log n) processors. Using the preprocessing, we can report paths between k node pairs in O( log n + log k) time using O(k + (n + S)/ log n) processors on an EREW PRAM, where S is the size of the output. In particular, we can report the path between a single pair of distinct nodes in O( log n) time using O(L/ log n) processors, where L denotes the length of the path.
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López-García, María Nieves, Miguel Angel Sánchez-Granero, Juan Evangelista Trinidad-Segovia, Antonio Manuel Puertas, and Francisco Javier De las Nieves. "Volatility Co-Movement in Stock Markets." Mathematics 9, no. 6 (March 11, 2021): 598. http://dx.doi.org/10.3390/math9060598.
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The volatility and log-price collective movements among stocks of a given market are studied in this work using co-movement functions inspired by similar functions in the physics of many-body systems, where the collective motions are a signal of structural rearrangement. This methodology is aimed to identify the cause of coherent changes in volatility or price. The function is calculated using the product of the variations in volatility (or price) of a pair of stocks, averaged over all pair particles. In addition to the global volatility co-movement, its distribution according to the volatility of the stocks is also studied. We find that stocks with similar volatility tend to have a greater co-movement than stocks with dissimilar volatility, with a general decrease in co-movement with increasing volatility. On the other hand, when the average volatility (or log-price) is subtracted from the stock volatility (or log-price), the co-movement decreases notably and becomes almost zero. This result, interpreted within the background of many body physics, allows us to identify the index motion as the main source for the co-movement. Finally, we confirm that during crisis periods, the volatility and log-price co-movement are much higher than in calmer periods.
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ADDARIO-BERRY, LOUIGI, NICOLAS BROUTIN, and GÁBOR LUGOSI. "The Longest Minimum-Weight Path in a Complete Graph." Combinatorics, Probability and Computing 19, no. 1 (June 22, 2009): 1–19. http://dx.doi.org/10.1017/s0963548309990204.
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We consider the minimum-weight path between any pair of nodes of the n-vertex complete graph in which the weights of the edges are i.i.d. exponentially distributed random variables. We show that the longest of these minimum-weight paths has about α* log n edges, where α* ≈ 3.5911 is the unique solution of the equation α log α − α = 1. This answers a question posed by Janson [8].
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Catanzaro, G., M. Gangi, M. Giarrusso, M. Munari, and F. Leone. "HD 226766: a hierarchical SB3 system with two twin Am stars." Monthly Notices of the Royal Astronomical Society 487, no. 1 (May 14, 2019): 919–27. http://dx.doi.org/10.1093/mnras/stz1312.
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ABSTRACT In this paper, we present a detailed revision of the orbital parameters and the first quantitative abundance analysis of the spectroscopic triple system HD 226766. By means of a simultaneous fit of the radial velocities of all the three components, we derived precise orbital parameters for the system, in particular inner pair has P(d) = 31.9187 ± 0.0001, e = 0.28 ± 0.01, and MA/MB = 1.03 ± 0.03, while the C component orbits around the inner pair with a period of P(d) = 1615 ± 59 in a very eccentric orbit (e = 0.54 ± 0.11). From the fit of the Hβ and Hα profiles, we determined the effective temperatures and surface gravities of each component of the inner pair: Teff = 8600 ± 500 K and log g = 3.8 ± 0.2 for HD 226766 A and Teff = 8500 ± 400 K and log g = 4.0 ± 0.2 for HD 226766 B. In the hypothesis that component C is a main sequence star (log g = 4.0) we derived Teff = 8000 ± 500 K. Rotational velocities have been estimated by modeling the profiles of metallic lines: v sin i = 13 ± 1 km s−1 for inner pair and v sin i = 150 ± 20 km s−1 for the C component. We find that the inner pair is heterogeneous from the point of view of the chemical composition: both stars are very similar and show chemical anomalies typical of Am stars. With some hypothesis about the masses of the components, we estimated the orbital inclination angle for the inner binary, i = (47 ± 1)○, and for the outer orbit, i = (54 ± 19)○.
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Onaka, Susumu, and Kunio Hayashi. "Description of Changes in Crystal Orientations by the Elements of Logarithm of a Rotation Matrix." Scanning 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/4893956.
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The logarithmlnRof rotation matrixRis a skew symmetric tensor consisting of three independent elements of real numbers. In addition to the Euler angles and the axis/angle pair, the elements oflnRcalled the log angles are also the set of three parameters ofR. In this paper, we will show that the concept of the log angles is also useful to discuss changes in crystal orientations. The changes inRas a function of the position are given by the changes in the log angles. As an example, orientation changes caused by arrays of dislocations in a plastically deformed Cu single crystal are discussed.
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Tanaka, Hiromu. "Semiample perturbations for log canonical varieties over an F-finite field containing an infinite perfect field." International Journal of Mathematics 28, no. 05 (March 21, 2017): 1750030. http://dx.doi.org/10.1142/s0129167x17500306.
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Let [Formula: see text] be an [Formula: see text]-finite field containing an infinite perfect field of positive characteristic. Let [Formula: see text] be a projective log canonical pair over [Formula: see text]. In this note, we show that, for a semi-ample divisor [Formula: see text] on [Formula: see text], there exists an effective [Formula: see text]-divisor [Formula: see text] such that [Formula: see text] is log canonical if there exists a log resolution of [Formula: see text].
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NAIR, R. "Pair correlations of the leVeque sequence on the polydisc." Mathematical Proceedings of the Cambridge Philosophical Society 145, no. 1 (July 2008): 197–203. http://dx.doi.org/10.1017/s0305004108001229.
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AbstractWe consider a system of “forms” defined for ẕ = (zij) on a subset of $\Bbb C^d$ by where d = d1 + ⋅ ⋅ ⋅ + dl and for each pair of integers (i,j) with 1 ≤ i ≤ l, 1 ≤ j ≤ di we denote by $(v_{ij}(k))_{k=1}^{\infty}$ a strictly increasing sequence of natural numbers. Let ${\Bbb C}_1$ = {z ∈ ${\Bbb C}$ : |z| < 1} and let ${\underline X} \ = \ \times _{i=1}^l \times _{j=1}^{d_i}X_{ij}$ where for each pair (i, j) we have Xij = ${\Bbb C}\backslash {\Bbb C}_1$. We study the distribution of the sequence on the l-polydisc $({\Bbb C}_1)^l$ defined by the coordinatewise polar fractional parts of the sequence Xk(ẕ) = (L1(ẕ)(k),. . ., Ll(ẕ)(k)) for typical ẕ in ${\underline X}$ More precisely for arcs I1, . . ., I2l in $\Bbb T$, let B = I1 × ⋅ ⋅ ⋅ × I2l be a box in $\Bbb T^{2l}$ and for each N ≥ 1 define a pair correlation function by and a discrepancy by ΔN = $\sup_{B \subset \Bbb T^{2l}}${VN(B) − N(N−1)leb(B)}, where the supremum is over all boxes in $\Bbb T^{2l}$. We show, subject to a non-resonance condition on $(v_{ij}(k))_{k=1}^{\infty}$, that given ε > 0 we have ΔN = o(N$(log N)^{l + {1\over 2}}$(log log N)1+ε) for almost every $\underline x(\underline z)\in \Bbb T^{2l}$. Similar results on extremal discrepancy are also proved. Our results complement those of I. Berkes, W. Philipp, M. Pollicott, Z. Rudnick, P. Sarnak, R Tichy and the author in the real setting.
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Janjic, Tomislav, Gordana Vuckovic, and Milenko Celap. "Application of the log k pair linearity rule and proportionality rule to the RPP mobile phase scales estimation on cyano-silica column." Journal of the Serbian Chemical Society 66, no. 3 (2001): 173–78. http://dx.doi.org/10.2298/jsc0103173j.
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On the basis of literature-reported log k values, the Log k pair linearity rule and the Proportionality rule were found to be also valid in the case of cyano-silica sorbent, whenmethanol, acetonitrile or propane-2-olwere used as modifiers. The RPPscales, reflecting the solvent strength, are in good linear relationship with the experimentally determined log k values. Furthermore, in the case of methanol and acetonitrile, the linear dependence: log k = f(mol%of modifier) was also established. In the function obtained in a such way, the intercept and the slope exhibit an approximate linear dependence. Finally, in the case of methanol, the experimentally obtained log k values are in a satisfactory agreement with the values calculated by the above equation.
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HSU, F. R., R. C. CHANG, and R. C. T. LEE. "PARALLEL ALGORITHMS FOR COMPUTING THE CLOSEST VISIBLE VERTEX PAIR BETWEEN TWO POLYGONS." International Journal of Computational Geometry & Applications 02, no. 02 (June 1992): 135–62. http://dx.doi.org/10.1142/s0218195992000093.
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In this paper, we are concerned with the closest visible vertex pair problem, which is defined as follows: we are given two simple non-intersecting polygons P and Q with m and n vertices respectively, we are asked to find a closest visible pair of vertices between P and Q. We shall show that we can solve this problem in O( log (m+n)) time with O(m+n) processors in the CREW PRAM model.
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Janjic, Tomislav, Gordana Vuckovic, and Milenko Celap. "Application of the log k pair linearity rule and proportionality rule to the RPP mobile phase scales estimation on diol-silica column." Journal of the Serbian Chemical Society 65, no. 10 (2000): 733–42. http://dx.doi.org/10.2298/jsc0010733j.
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By the application of the Log ? pair linearity rule and the Proportionality rule to the previously published log ? values for 27 compounds, obtained on diol-silica columns with acetonitrile, methanol and tetrahydrofuran as modifiers, the existence of common RPP scales was established. The obtained correlation coefficients of the linear function log k = f(RPP) were better than 0.9900 for 26 compounds in the first, 21 in the second and 20 in the third case. In addition, in the case of the two first modifiers a linear correlation between the obtained RPP values and mol % of modifier in the mobile phase was found. On the basis of this, the following simple linear function: log k= f(mol % of modifier) was proposed as a criterion for log k values judgment in practical work. A linear correlation was also established between intercept and slope of the function, in spite of the fact that the investigated compounds essentially differ in their descriptors.
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Angel, Omer, Abbas Mehrabian, and Yuval Peres. "The string of diamonds is nearly tight for rumour spreading." Combinatorics, Probability and Computing 29, no. 2 (November 4, 2019): 190–99. http://dx.doi.org/10.1017/s0963548319000385.
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AbstarctFor a rumour spreading protocol, the spread time is defined as the first time everyone learns the rumour. We compare the synchronous push&pull rumour spreading protocol with its asynchronous variant, and show that for any n-vertex graph and any starting vertex, the ratio between their expected spread times is bounded by $O({n^{1/3}}{\log ^{2/3}}n)$. This improves the $O(\sqrt n)$ upper bound of Giakkoupis, Nazari and Woelfel (2016). Our bound is tight up to a factor of O(log n), as illustrated by the string of diamonds graph. We also show that if, for a pair α, β of real numbers, there exist infinitely many graphs for which the two spread times are nα and nβ in expectation, then $0 \le \alpha \le 1$ and $\alpha \le \beta \le {1 \over 3} + {2 \over 3} \alpha $; and we show each such pair α, β is achievable.
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Namikawa, Yoshinori. "A finiteness theorem on symplectic singularities." Compositio Mathematica 152, no. 6 (April 15, 2016): 1225–36. http://dx.doi.org/10.1112/s0010437x16007387.
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An affine symplectic singularity$X$with a good$\mathbf{C}^{\ast }$-action is called a conical symplectic variety. In this paper we prove the following theorem. For fixed positive integers$N$and$d$, there are only a finite number of conical symplectic varieties of dimension$2d$with maximal weights$N$, up to an isomorphism. To prove the main theorem, we first relate a conical symplectic variety with a log Fano Kawamata log terminal (klt) pair, which has a contact structure. By the boundedness result for log Fano klt pairs with fixed Cartier index, we prove that conical symplectic varieties of a fixed dimension and with a fixed maximal weight form a bounded family. Next we prove the rigidity of conical symplectic varieties by using Poisson deformations.
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DeCosta, D. P., and J. A. Pincock. "Intramolecular electron transfer in the photochemistry of substituted 1-naphthylmethyl esters of benzoic acids." Canadian Journal of Chemistry 70, no. 7 (July 1, 1992): 1879–85. http://dx.doi.org/10.1139/v92-235.
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Direct excitation of the esters 5 in methanol solvent leads to rapid intramolecular exciplex formation (kex = 1010 s−1 for X = CH3O, Y = CN) with electron transfer from the naphthalene to the benzoate ring. This process dominates the usual fluorescence and reaction of the excited singlet state. The rate of this process can be varied over 103 by suitable change in the substituents X and Y. The electron-transfer rates can be correlated with the two-parameter Hammett equation: log kex = 8.48 − 1.5σ+ + 0.77σ. For cases where the rate of exciplex formation is slow, the usual homolytic carbon–oxygen bond cleavage occurs from the excited singlet state. The eventual products result from the ion pair since the rate of electron transfer in the radical pair to form the ion pair is considerably faster than the rate of decarboxylation of the benzoyloxy radical.
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Wagner, P. D., G. Hedenstierna, G. Bylin, and L. Lagerstrand. "Reproducibility of the multiple inert gas elimination technique." Journal of Applied Physiology 62, no. 4 (April 1, 1987): 1740–46. http://dx.doi.org/10.1152/jappl.1987.62.4.1740.
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Although measurement errors in the multiple inert gas elimination technique have a coefficient of variation of approximately 3%, small biological fluctuations in ventilation, blood flow, or other variables must contribute additional variance to this method of assessing ventilation-perfusion (VA/Q) mismatch. To determine overall variance of computed indices of VA/Q mismatch, an analysis of variance was carried out using a total of 400 duplicate pairs of inert gas samples obtained from canine (N = 118) and human (N = 282) studies in the past 2 years. In both sets VA/Q mismatch ranged from minimal (2nd moment of ventilation and blood flow distributions, log SDV and log SDQ, respectively approximately equal to 0.3 each) to severe (log SDV and log SDQ approximately equal to 2.0). Differences between duplicate log SD values were computed and found to be a constant fraction of the mean log SD of each duplicate pair, averaging 13% for both canine and human ventilation and blood flow data. The resultant coefficient of variation for a single measurement of log SD about its mean averaged 8.6% for all data combined. This analysis demonstrates excellent reproducibility of these dispersion indices over a wide range of conditions, and if the mean of duplicate values is used, thus reducing variability by square root 2 to 6.1%, log SD can be estimated with an approximately 95% confidence limit of +/- 12%.
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de Fernex, Tommaso, and Christopher D. Hacon. "Singularities on normal varieties." Compositio Mathematica 145, no. 2 (March 2009): 393–414. http://dx.doi.org/10.1112/s0010437x09003996.
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AbstractIn this paper we generalize the definitions of singularities of pairs and multiplier ideal sheaves to pairs on arbitrary normal varieties, without any assumption on the variety being ℚ-Gorenstein or the pair being log ℚ-Gorenstein. The main features of the theory extend to this setting in a natural way.
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LAI, CHING-JUI. "BOUNDING VOLUMES OF SINGULAR FANO THREEFOLDS." Nagoya Mathematical Journal 224, no. 1 (October 17, 2016): 37–73. http://dx.doi.org/10.1017/nmj.2016.21.
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Let $(X,\unicode[STIX]{x1D6E5})$ be an $n$-dimensional $\unicode[STIX]{x1D716}$-klt log $\mathbb{Q}$-Fano pair. We give an upper bound for the volume $\text{Vol}(X,\unicode[STIX]{x1D6E5})=(-(K_{X}+\unicode[STIX]{x1D6E5}))^{n}$ when $n=2$, or $n=3$ and $X$ is $\mathbb{Q}$-factorial of $\unicode[STIX]{x1D70C}(X)=1$. This bound is essentially sharp for $n=2$. The main idea is to analyze the covering families of tigers constructed in J. McKernan (Boundedness of log terminal fano pairs of bounded index, preprint, 2002, arXiv:0205214). Existence of an upper bound for volumes is related to the Borisov–Alexeev–Borisov Conjecture, which asserts boundedness of the set of $\unicode[STIX]{x1D716}$-klt log $\mathbb{Q}$-Fano varieties of a given dimension $n$.
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Robichaud, P. R., J. W. Wagenbrenner, R. E. Brown, P. M. Wohlgemuth, and J. L. Beyers. "Evaluating the effectiveness of contour-felled log erosion barriers as a post-fire runoff and erosion mitigation treatment in the western United States." International Journal of Wildland Fire 17, no. 2 (2008): 255. http://dx.doi.org/10.1071/wf07032.
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Between 1998 and 2002, six sites were established immediately after large wildfires in the western United States to determine the effectiveness of contour-felled log erosion barriers in mitigating post-wildfire runoff and erosion. In each pair of matched, burned, and small watersheds (1–13 ha), one was treated with contour-felled log erosion barriers and one was left untreated as a control. For 4 to 6 post-fire years, runoff and sediment yields were measured and correlated with rain properties. High-intensity rainfall produced most of the measured runoff and sediment yields except in the southern California site, where long-duration rain events produced most of the runoff and erosion. For small rain events (less than the 2-year return period for the 10-min duration), the runoff, peak flows, and sediment yields were lower in the treated watersheds than in the control watersheds, but there was no treatment effect for rain events with larger return periods. Improper installation and degradation over time reduced the effectiveness of contour-felled log erosion barriers. Rainfall characteristics and installation procedures should be carefully considered before choosing contour-felled log erosion barriers for post-fire hillslope stabilisation.
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AUGUSTINE, JOHN, DAVID EPPSTEIN, and KEVIN A. WORTMAN. "APPROXIMATE WEIGHTED FARTHEST NEIGHBORS AND MINIMUM DILATION STARS." Discrete Mathematics, Algorithms and Applications 02, no. 04 (December 2010): 553–65. http://dx.doi.org/10.1142/s1793830910000887.
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We provide an efficient reduction from the problem of querying approximate multiplicatively weighted farthest neighbors in a metric space to the unweighted problem. Combining our techniques with core-sets for approximate unweighted farthest neighbors, we show how to find approximate farthest neighbors that are farther than a factor (1 - ∊) of optimal in time O( log n) per query in D-dimensional Euclidean space for any constants D and ∊. As an application, we find an O(n log n) expected time algorithm for choosing the center of a star topology network connecting a given set of points, so as to approximately minimize the maximum dilation between any pair of points.
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Kim, Sungil, Kwang Hyun Kim, Baehyun Min, Jungtek Lim, and Kyungbook Lee. "Generation of Synthetic Density Log Data Using Deep Learning Algorithm at the Golden Field in Alberta, Canada." Geofluids 2020 (January 31, 2020): 1–26. http://dx.doi.org/10.1155/2020/5387183.
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This study proposes a deep neural network- (DNN-) based prediction model for creating synthetic log. Unlike previous studies, it focuses on building a reliable prediction model based on two criteria: fit-for-purpose of a target field (the Golden field in Alberta) and compliance with domain knowledge. First, in the target field, the density log has advantages over the sonic log for porosity analysis because of the carbonate depositional environment. Considering the correlation between the density and sonic logs, we determine the sonic log as input and the density log as output for the DNN. Although only five wells have a pair of training data in the field (i.e., sonic and density logs), we obtain, based on geological knowledge, 29 additional wells sharing the same depositional setting in the Slave Point Formation. After securing the data, 5 wells among the 29 wells are excluded from dataset during preprocessing procedures (elimination of abnormal data and min–max normalisation) to improve the prediction model. Two cases are designed according to usage of the well information at the target field. Case 1 uses only 23 of the surrounding wells to train the prediction model, and another surrounding well is used for model testing. In Case 1, the Levenberg–Marquardt algorithm shows a fast and reliable performance and the numbers of neurons in the two hidden layers are of 45 and 14, respectively. In Case 2, the 24 surrounding wells and four wells from the target field are used to train the DNN with the optimised parameters from Case 1. The synthetic density logs from Case 2 mitigate an underestimation problem in Case 1 and follow the overall trend of the true density logs. The developed prediction model utilises the sonic log for generating the synthetic density log, and a reliable porosity model will be created by combining the given and the synthetic density logs.
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Gleaton, James, Ping Sa, and Sami Hamid. "Asymptotic Properties of MLE's for Distributions Generated from an Exponential Distribution by a Generalized Log-Logistic Transformation." Journal of Probability and Statistical Science 20, no. 1 (October 3, 2022): 204–27. http://dx.doi.org/10.37119/jpss2022.v20i1.543.
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ABSTRACT. A generalized log-logistic (GLL) family of lifetime distributions is one in which any pair of distributions are related through a GLL transformation, for some (non-negative) value of the transformation parameter k (the odds function of the second distribution is the k-th power of the odds function of the first distribution). We consider GLL families generated from an exponential distribution. It is shown that the Maximum Likelihood Estimators (MLE’s) for the parameters of the generated, or composite, distribution have the properties of strong consistency and asymptotic normality and efficiency. Data simulation is also found to support the condition of asymptotic efficiency.
Keywords Generalized log-logistic exponential distribution; asymptotic properties of MLE’s; simulation
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Strupczewski, Witold G., Krzysztof Kochanek, Iwona Markiewicz, Ewa Bogdanowicz, Stanislaw Weglarczyk, and Vijay P. Singh. "On the tails of distributions of annual peak flow." Hydrology Research 42, no. 2-3 (April 1, 2011): 171–92. http://dx.doi.org/10.2166/nh.2011.062.
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This study discusses an application of heavy-tailed distributions to modelling of annual peak flows in general and of Polish data sets in particular. One- and two-shape parameter heavy-tailed distributions are obtained by transformations of random variables. The correct selection of a flood frequency model with emphasis on heavy-tailed distribution discrimination is then discussed. If a distribution is wrongly assumed, the error, in the upper quantile, arising as a result, depends on the method of parameter estimation and is shown analytically for three methods. Asymptotic and sampling values (got by simulation) were assessed for the pair log-Gumbel (LG) as a false distribution and log-normal (LN) as a true distribution. Comparing the upper quantiles of various distributions with the same values of moments, it is found that heavy-tailed distributions do not consistently provide higher flood frequency estimates than do soft-tailed distributions. Based on L-moment ratio diagrams and the test of linearity on log–log plots, it is concluded that Polish datasets of annual peak flows should be modelled using soft-tailed distributions, such as the three-parameter Inverse Gaussian, rather than heavy-tailed distributions.
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MORRIS, IAN D. "Lyapunov-maximizing measures for pairs of weighted shift operators." Ergodic Theory and Dynamical Systems 39, no. 1 (May 4, 2017): 225–47. http://dx.doi.org/10.1017/etds.2017.22.
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Motivated by recent investigations of ergodic optimization for matrix cocycles, we study the measures of the maximum top Lyapunov exponent for pairs of bounded weighted shift operators on a separable Hilbert space. We prove that, for generic pairs of weighted shift operators, the Lyapunov-maximizing measure is unique, and show that there exist pairs of operators whose unique Lyapunov-maximizing measure takes any prescribed value less than $\log 2$ for its metric entropy. We also show that, in contrast to the matrix case, the Lyapunov-maximizing measures of pairs of bounded operators are, in general, not characterized by their supports: we construct explicitly a pair of operators and a pair of ergodic measures on the 2-shift with identical supports, such that one of the two measures is Lyapunov-maximizing for the pair of operators and the other measure is not. Our proofs make use of the Ornstein $\overline{d}$-metric to estimate differences in the top Lyapunov exponent of a pair of weighted shift operators as the underlying measure is varied.
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KUSAKARI, YOSHIYUKI, HITOSHI SUZUKI, and TAKAO NISHIZEKI. "A SHORTEST PAIR OF PATHS ON THE PLANE WITH OBSTACLES AND CROSSING AREAS." International Journal of Computational Geometry & Applications 09, no. 02 (April 1999): 151–70. http://dx.doi.org/10.1142/s021819599900011x.
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Given obstacles and crossing areas together with two pairs of terminals on the plane, our algorithm finds a pair of rectilinear paths which connect the pairs of terminals, neither pass through any obstacle nor cross each other except in the crosssing areas, and minimize the total length, where all obstacles and crossing areas are assumed to be axis-parallel rectangles. The algorithm takes O(n log n) time and O(n) space, where n is the total number of obstacles and crossing areas.
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Laurinčikas, Antanas. "Zeros of the Riemann zeta-function in the discrete universality of the Hurwitz zeta-function." Studia Scientiarum Mathematicarum Hungarica 57, no. 2 (June 2020): 147–64. http://dx.doi.org/10.1556/012.2020.57.2.1460.
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AbstractLet 0 < γ1 < γ2 < ··· ⩽ ··· be the imaginary parts of non-trivial zeros of the Riemann zeta-function. In the paper, we consider the approximation of analytic functions by shifts of the Hurwitz zeta-function ζ(s + iγkh, α), h > 0, with parameter α such that the set {log(m + α): m ∈ } is linearly independent over the field of rational numbers. For this, a weak form of the Montgomery conjecture on the pair correlation of {γk} is applied.
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Tseng, L. H., P. Heffernan, and D. T. Lee. "Two-Guard Walkability of Simple Polygons." International Journal of Computational Geometry & Applications 08, no. 01 (February 1998): 85–116. http://dx.doi.org/10.1142/s0218195998000060.
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A pair of points s and g on the boundary of a simple polygon P admits a walk if two guards can simultaneously walk along the two boundary chains of P from s to g such that they are always visible to each other. The walk is a counter-walk if one guard moves from s to g while the other moves from g to s in the same direction along the boundary and they are always visible to each other. The (counter-)walk is straight if no backtracking is necessary during the (counter-)walk. In this paper, we show that, given a polygon with n vertices, to test if there exists (s,g) that admits a (straight) (counter-)walk can be solved in time O(n log n) and in linear space. Also we compute all (s,g)'s that admit a (straight) walk in O(n log n) time and all vertex pairs that admit a (straight) counter-walk in O(n log n + m), where m is O(n2).
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Abrahamsen, Mikkel, Panos Giannopoulos, Maarten Löffler, and Günter Rote. "Geometric Multicut: Shortest Fences for Separating Groups of Objects in the Plane." Discrete & Computational Geometry 64, no. 3 (August 11, 2020): 575–607. http://dx.doi.org/10.1007/s00454-020-00232-w.
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Abstract We study the following separation problem: Given a collection of pairwise disjoint coloured objects in the plane with k different colours, compute a shortest “fence” F, i.e., a union of curves of minimum total length, that separates every pair of objects of different colours. Two objects are separated if F contains a simple closed curve that has one object in the interior and the other in the exterior. We refer to the problem as geometrick-cut, as it is a geometric analog to the well-studied multicut problem on graphs. We first give an $$O(n^4\log ^3\!n)$$ O ( n 4 log 3 n ) -time algorithm that computes an optimal fence for the case where the input consists of polygons of two colours with n corners in total. We then show that the problem is NP-hard for the case of three colours. Finally, we give a randomised $$4/3\cdot 1.2965$$ 4 / 3 · 1.2965 -approximation algorithm for polygons and any number of colours.
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Ouzounov, Atanas. "LTSD and GDMD features for Telephone Speech Endpoint Detection." Cybernetics and Information Technologies 17, no. 4 (November 27, 2017): 114–33. http://dx.doi.org/10.1515/cait-2017-0045.
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AbstractThis paper proposes a new contour-based speech endpoint detector which combines the log-Group Delay Mean-Delta (log-GDMD) feature, an adaptive twothreshold scheme and an eight-state automaton. The adaptive thresholds scheme uses two pairs of thresholds - for the starting and for the ending points, respectively. Each pair of thresholds is calculated by using the contour characteristics in the corresponded region of the utterance. The experimental results have shown that the proposed detector demonstrates better performance compared to the Long-Term Spectral Divergence (LTSD) one in terms of endpoint accuracy. Additional fixed-text speaker verification tests with short phrases of telephone speech based on the Dynamic Time Warping (DTW) and left-to-right Hidden Markov Model (HMM) frameworks confirm the improvements of the verification rate due to the better endpoint accuracy.
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AMATO, NANCY M. "DETERMINING THE SEPARATION OF SIMPLE POLYGONS." International Journal of Computational Geometry & Applications 04, no. 04 (December 1994): 457–74. http://dx.doi.org/10.1142/s0218195994000240.
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Given simple polygons P and Q, their separation, denoted by σ(P, Q), is defined to be the minimum distance between their boundaries. We present a parallel algorithm for finding a closest pair among all pairs (p, q), p ∈ P and q ∈ Q. The algorithm runs in O ( log n) time using O(n) processors on a CREW PRAM, where n = |P| + |Q|. This algorithm is time-optimal and improves by a factor of O ( log n) on the time complexity of previous parallel methods. The algorithm can be implemented serially in Θ (n) time, which gives the first optimal sequential algorithm for determining the separation of simple polygons. Our results are obtained by providing a unified treatment of the separation and the closest visible vertex problems for simple polygons.
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Vasyl'kiv, Ya V., and M. Ya Kravec. "Integral mean of Green’s potentials and their conjugate." Carpathian Mathematical Publications 5, no. 1 (June 17, 2013): 19–29. http://dx.doi.org/10.15330/cmp.5.1.19-29.
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The best possible estimates for Lebesgue integral means $m_q(r,F)\; (1\le q<+\infty)$ for the pair of functions $F= g+i\:\breve{g}$, here $g$ - Green's potential, $\breve{g}$ - function conjugate to $g$, was obtained. It generalizes well-known results of Ya.V. Vasyl'kiv and A.A. Kondratyuk for logarithms $\log\; B$ of Blaschke products $B$ in terms of counting function $n(r,0,B)\; (0<r<1)$ of their zeroes.
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HUANG, Y. M., and M. SARRAFZADEH. "A PARALLEL ALGORITHM FOR MINIMUM DUAL-COVER WITH APPLICATION TO CMOS LAYOUT." Journal of Circuits, Systems and Computers 01, no. 02 (June 1991): 177–204. http://dx.doi.org/10.1142/s0218126691000045.
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In a pair of planar graphs (G, Gd), with Gd being the dual graph of G, a sequence of distinct edges is a dual-Euler trail if it is a trail both in G and in Gd. A set of disjoint dual-Euler trails that simultaneously cover G and Gd is called a dual-cover. We present an O( log n) time and O(n) processors algorithm, in PRAM model, based on the graph separator theory, for obtaining a minimum cardinality dual-cover in a pair of series-parallel graphs (G, Gd), where n is the total number of edges. We employ the proposed algorithm to obtain a minimum-area VLSI layout of CMOS functional cells. Our algorithm, when implemented in a serial environment performs better than previous algorithms and produces more compact layouts.
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Takahashi, Jun-Ya, Hitoshi Suzuki, and Takao Nishizeki. "Shortest Non-Crossing Rectilinear Paths in Plane Regions." International Journal of Computational Geometry & Applications 07, no. 05 (October 1997): 419–36. http://dx.doi.org/10.1142/s0218195997000259.
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Let A be a plane region inside an outer rectangle with r rectangular obstacles, and let k terminal pairs lie on the boundaries of the outer rectangle and one of the obstacles. This paper presents an efficient algorithm which finds "non-crossing" rectilinear paths in the plane region A, each connecting a terminal pair without passing through any obstacles, and whose total length is minimum. Non-crossing paths may share common points or line segments but do not cross each other in the plane. The algorithm takes time O(n log n) where n = k + r.
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BOUSQUET, NICOLAS, LOUIS ESPERET, ARARAT HARUTYUNYAN, and RÉMI DE JOANNIS DE VERCLOS. "Exact Distance Colouring in Trees." Combinatorics, Probability and Computing 28, no. 2 (July 24, 2018): 177–86. http://dx.doi.org/10.1017/s0963548318000378.
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For an integer q ⩾ 2 and an even integer d, consider the graph obtained from a large complete q-ary tree by connecting with an edge any two vertices at distance exactly d in the tree. This graph has clique number q + 1, and the purpose of this short note is to prove that its chromatic number is Θ((d log q)/log d). It was not known that the chromatic number of this graph grows with d. As a simple corollary of our result, we give a negative answer to a problem of van den Heuvel and Naserasr, asking whether there is a constant C such that for any odd integer d, any planar graph can be coloured with at most C colours such that any pair of vertices at distance exactly d have distinct colours. Finally, we study interval colouring of trees (where vertices at distance at least d and at most cd, for some real c > 1, must be assigned distinct colours), giving a sharp upper bound in the case of bounded degree trees.
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Lee, Lawrence H., Adam J. Arnold, Cutberto A. Santillan, Monica B. Emelko, Sarah E. Dickson, and Jen-Shih Chang. "Bench-Scale Disinfection of Bacteria and Viruses with Pulsed Arc Electrohydraulic Discharge." Water Quality Research Journal 43, no. 1 (February 1, 2008): 77–84. http://dx.doi.org/10.2166/wqrj.2008.010.
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Abstract Pulsed arc electrohydraulic discharge (PAED) offers concurrent treatment of chemical and microbial target compounds in water by several mechanisms. Here, Escherichia coli, Bacillus subtilis spore, and MS2 bacteriophage inactivation by PAED were investigated using two bench-scale reactors (0.7 and 3 L). A plasma channel was created between a pair of iron electrodes set 0.5 mm apart in these reactors. Pulsed applied voltage was supplied at approximately 0.3 kJ/pulse (~100 µsec). In the 0.7-L reactor, median E. coli, B. subtilis, and MS2 reductions of 2.4-, 4.6-, and 3.7-log, respectively, were observed after approximately 80 seconds of treatment in water with a conductivity of 14.7 mS; reductions of 2.8-, 4.0-, and 3.7-log, respectively, were observed in treated drinking water filter effluent (conductivity of 610 µS). In the 3-L reactor, at a conductivity of 500 to 600 µS, 1.9- and approximately 0.9-log median reductions of E. coli and B. subtilis were achieved after 500 pulses (~3,300 sec); and, at a conductivity of 4.3 mS, median E. coli reductions of 0.5-log were achieved after 50 pulses (400 sec). Further work is necessary to elucidate the primary mechanism(s) of disinfection acting in the PAED system and how they relate to the reactor design, applied power requirements, and disinfection of specific target microorganisms.
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PACH, JÁNOS, NATAN RUBIN, and GÁBOR TARDOS. "On the Richter–Thomassen Conjecture about Pairwise Intersecting Closed Curves." Combinatorics, Probability and Computing 25, no. 6 (May 4, 2016): 941–58. http://dx.doi.org/10.1017/s0963548316000043.
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A long-standing conjecture of Richter and Thomassen states that the total number of intersection points between any n simple closed Jordan curves in the plane, so that any pair of them intersect and no three curves pass through the same point, is at least (1−o(1))n2.We confirm the above conjecture in several important cases, including the case (1) when all curves are convex, and (2) when the family of curves can be partitioned into two equal classes such that each curve from the first class touches every curve from the second class. (Two closed or open curves are said to be touching if they have precisely one point in common and at this point the two curves do not properly cross.)An important ingredient of our proofs is the following statement. Let S be a family of n open curves in ℝ2, so that each curve is the graph of a continuous real function defined on ℝ, and no three of them pass through the same point. If there are nt pairs of touching curves in S, then the number of crossing points is $\Omega(nt\sqrt{\log t/\log\log t})$.
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Helwig, Ulf, Fiona Braegger, Karel Kostev, and Carsten Schmidt. "Comparative Analysis of the 3-Year Persistence Rate with Second-Line Vedolizumab and Tumor Necrosis Factor-α Inhibitors in Patients with Inflammatory Bowel Disease Followed in Gastroenterology Practices in Germany." Digestive Diseases 38, no. 6 (2020): 466–73. http://dx.doi.org/10.1159/000506121.
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<b><i>Background:</i></b> Our goal was to investigate the 3-year persistence rates with second-line vedolizumab and tumor necrosis factor-α (TNF-α) inhibitors (i.e., adalimumab, golimumab, infliximab) in patients with inflammatory bowel disease (IBD) who were followed in gastroenterology practices in Germany. <b><i>Methods:</i></b> This study included patients aged ≥18 years who had received prescriptions for second-line biological drugs in Germany between 2014 and 2017 (<i>n</i> = 5,150) retrieved from the longitudinal prescription database. Vedolizumab users were matched to adalimumab, golimumab, and infliximab users based on age, sex, and index year. The primary outcome of the study was the rate of persistence with vedolizumab compared with the rate of persistence with adalimumab, golimumab, and infliximab within 3 years of second-line therapy initiation in IBD patients. Persistence was estimated as therapy time without discontinuation, with discontinuation being defined as at least 90 days without any prescription for the biological drug of interest. <b><i>Results:</i></b> After matching patients who had received vedolizumab with those who had received adalimumab, the rate of persistence after 3 therapy years was 30.3% for vedolizumab and 27.9% for adalimumab (log-rank <i>p</i> = 0.005). The corresponding figures were 27.8 and 20.8% in the vedolizumab-golimumab matched-pair analysis (log-rank <i>p</i> < 0.001) and 29.5 and 25.2% in the vedolizumab-infliximab matched-pair analysis (log-rank <i>p</i> value = 0.008). Vedolizumab was associated with a significant 0.85-, 0.72-, and 0.86-fold decrease in the risk of discontinuation within 3 years of therapy initiation compared to adalimumab, golimumab, and infliximab, respectively. <b><i>Conclusions:</i></b> Treatment persistence was higher for vedolizumab than for TNF-α inhibitors up to 3 years after initiating second-line biological therapy.
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BIESEN, WIM VAN, RAYMOND C. VANHOLDER, NIC VEYS, ANNEMIEKE DHONDT, and NORBERT H. LAMEIRE. "An Evaluation of an Integrative Care Approach for End-Stage Renal Disease Patients." Journal of the American Society of Nephrology 11, no. 1 (January 2000): 116–25. http://dx.doi.org/10.1681/asn.v111116.
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Abstract. Studies analyzing the outcome of integrative care of end-stage renal disease (ESRD) patients, whereby patients are transferred from one renal replacement modality to another according to individual needs, are scant. In this study, we analyzed 417 files of 223 hemodialysis (HD) and 194 peritoneal dialysis (PD) patients starting renal replacement therapy between 1979 and 1996, to evaluate the effect of such an approach. Analysis was done for survival of patients on their first modality, for intention-to-treat survival (counting total time on renal replacement therapy, but with exclusion of time on transplantation), and for total survival. Log rank analysis was used and correction for risk factors was performed by Cox proportional hazards regression. Intention-to-treat survival and total survival were not different between PD and HD patients (log rank, P > 0.05). Technique success was higher in HD patients compared to PD patients (log rank, P = 0.01), with a success rate after 3 yr of 61 and 48%, respectively. Thirty-five patients were transferred from HD to PD and 32 from PD to HD. Transfer of PD patients to HD was accompanied by an increase in survival compared to those remaining on PD (log rank, P = 0.001), whereas, in contrast, transfer of patients from HD to PD was not (log rank, P = 0.17). Survival of patients remaining more than 48 mo on their initial modality was lower for PD patients (log rank, P < 0.01). A matched-pair analysis between patients who started on PD and who were transferred to HD later (by definition called integrative care patients), and patients who started and remained on HD, showed a survival advantage for the integrative care patients. These results indicate that patient outcome is not jeopardized by starting patients on PD, at least if patients are transferred in a timely manner to HD when PD-related problems arise.
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Rotter, M. L., W. Koller, G. Wewalka, H. P. Werner, G. A. J. Ayliffe, and J. R. Babb. "Evaluation of procedures for hygienic hand-disinfection: controlled parallel experiments on the Vienna test model." Journal of Hygiene 96, no. 1 (February 1986): 27–37. http://dx.doi.org/10.1017/s0022172400062501.
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SUMMARYControlled parallel experiments were performed on the Vienna test model for the evaluation of procedures for hygienic hand-disinfection in three laboratories (Vienna, Mainz, Birmingham). The degerming activity of four procedures, each taking 1 min, was assessed repeatedly and compared with that of a standard disinfection procedure (ST) using isopropanol 60 % (v/v). The mean log reductions (mean log RF) for each procedure were as follows: n−propanol 50% (v/v) 4·85 and 5·14 in Vienna (V) and Mainz (M) respectively, ethanol 70 % (v/v) + chlorhexidinegluconate 0·5% (w/v), 4·01 (V), 3·76 (M) and 4·00 in Birmingham (B). Washing procedures were less effective, mean log RF 's of 3·19 (V), 3·49 (M) and 3·04 (B) were obtained with povidone-iodine soap, and 2·91 (V), 3·37 (M) and 3·27 (B) with a liquid phenolic soap. Analysis of variance on the data from Vienna and Mainz revealed significant differences of means not only between procedures (‘preparations’) but also on repeat testing. To compensate for the influence of variables such as test subjects, laboratory and day, the Vienna test model provides a method of standardization by testing a ST in parallel with the test procedure (P).Standardization of the results was obtained by pair-wise substraction, log . Analysis of variance on the resulting values demonstrated that comparability of the results between laboratories and on repeat testing was achieved. The relative variation of the measurements within the laboratories ranged from 0·9 to 4·2%. As assessed by power-analysis, a disinfection procedure will be detected as significantly (P= 0·1) inferior to the standard processes in 95 of 100 experiments if it produces a mean log RF that is at least 0·55–0·65 log units smaller than that of the standard.
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Boettcher, Erin, Neeraj Gupta, Hsiao-Wen Chen, Mandy C. Chen, Gyula I. G. Józsa, Gwen C. Rudie, Sebastiano Cantalupo, et al. "Discovery of a Damped Lyα Absorber Originating in a Spectacular Interacting Dwarf Galaxy Pair at z = 0.026." Astrophysical Journal Letters 926, no. 2 (February 1, 2022): L33. http://dx.doi.org/10.3847/2041-8213/ac5250.
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Abstract We present the discovery of neutral gas detected in both damped Lyα absorption (DLA) and H i 21 cm emission outside of the stellar body of a galaxy, the first such detection in the literature. A joint analysis between the Cosmic Ultraviolet Baryon Survey and the MeerKAT Absorption Line Survey reveals an H i bridge connecting two interacting dwarf galaxies (log (M star/M ⊙) = 8.5 ± 0.2) that host a z = 0.026 DLA with log[N(H i)/cm−2] = 20.60 ± 0.05 toward the QSO J2339−5523 (z QSO = 1.35). At impact parameters of d = 6 and 33 kpc, the dwarf galaxies have no companions more luminous than ≈0.05L * within at least Δv = ±300 km s−1 and d ≈ 350 kpc. The H i 21 cm emission is spatially coincident with the DLA at the 2σ–3σ level per spectral channel over several adjacent beams. However, H i 21 cm absorption is not detected against the radio-bright QSO; if the background UV and radio sources are spatially aligned, the gas is either warm or clumpy (with a spin temperature to covering factor ratio T s /f c > 1880 K). Observations with VLT-MUSE demonstrate that the α-element abundance of the ionized interstellar medium (ISM) is consistent with the DLA (≈10% solar), suggesting that the neutral gas envelope is perturbed ISM gas. This study showcases the impact of dwarf–dwarf interactions on the physical and chemical state of neutral gas outside of star-forming regions. In the SKA era, joint UV and H i 21 cm analyses will be critical for connecting the cosmic neutral gas content to galaxy environments.
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Kashyap, Des R., Lina M. Botero, William L. Franck, Daniel J. Hassett, and Timothy R. McDermott. "Complex Regulation of Arsenite Oxidation in Agrobacterium tumefaciens." Journal of Bacteriology 188, no. 3 (February 1, 2006): 1081–88. http://dx.doi.org/10.1128/jb.188.3.1081-1088.2006.
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ABSTRACT Seminal regulatory controls of microbial arsenite [As(III)] oxidation are described in this study. Transposon mutagenesis of Agrobacterium tumefaciens identified genes essential for As(III) oxidation, including those coding for a two-component signal transduction pair. The transposon interrupted a response regulator gene (referred to as aoxR), which encodes an ntrC-like protein and is immediately downstream of a gene (aoxS) encoding a protein with primary structural features found in sensor histidine kinases. The structural genes for As(III) oxidase (aoxAB), a c-type cytochrome (cytc 2), and molybdopterin biosynthesis (chlE) were downstream of aoxR. The mutant could not be complemented by aoxSR in trans but was complemented by a clone containing aoxS-aoxR-aoxA-aoxB-cytc 2 and consistent with reverse transcriptase (RT) PCR experiments, which demonstrated these genes are cotranscribed as an operon. Expression of aoxAB was monitored by RT-PCR and found to be up-regulated by the addition of As(III) to cell cultures. Expression of aoxAB was also controlled in a fashion consistent with quorum sensing in that (i) expression of aoxAB was absent in As(III)-unexposed early-log-phase cells but was observed in As(III)-unexposed, late-log-phase cells and (ii) treating As(III)-unexposed, early-log-phase cells with ethyl acetate extracts of As(III)-unexposed, late-log-phase culture supernatants also resulted in aoxAB induction. Under inducing conditions, aoxS expression was readily observed in the wild-type strain but significantly reduced in the mutant, indicating that AoxR is autoregulatory and at least partially controls the expression of the aox operon. In summary, regulation of A. tumefaciens As(III) oxidation is complex, apparently being controlled by As(III) exposure, a two-component signal transduction system, and quorum sensing.
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DILLENCOURT, MICHAEL B., DAVID M. MOUNT, and NATHAN S. NETANYAHU. "A RANDOMIZED ALGORITHM FOR SLOPE SELECTION." International Journal of Computational Geometry & Applications 02, no. 01 (March 1992): 1–27. http://dx.doi.org/10.1142/s0218195992000020.
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A set of n distinct points in the plane defines [Formula: see text] lines by joining each pair of distinct points. The median slope of these O(n2) lines was proposed by Theil as a robust estimator for the slope of the line of best fit for the points. We present a randomized algorithm for selecting the k-th smallest slope of such a set of lines which runs in expected O(n log n) time. An efficient implementation of the algorithm and practical experience with the algorithm are discussed.
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Pramod Kumar Mishra. "Theoretical estimate of the probability for macromole formation." JOURNAL OF ADVANCED APPLIED SCIENTIFIC RESEARCH 2, no. 4 (December 15, 2021): 1–8. http://dx.doi.org/10.46947/joaasr242020103.
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We estimate the polymerization probability of a macromolecule, where the macromolecule is made of distinct monomers; and there are different values of the fugacity for the addition of the monomers in the chain to form an infinitely long linear macromolecule of distinct monomers. The lattice model of the random walk has been used to mimic the conformations of an ideal chain in two and three dimensions, and this ideal chain is the macromolecules of distinct monomers. It has been shown through analytical estimates that the flexible macromolecules may be easily formed than the stiff macromolecules for both two and three dimensional cases. In the case of stiff chain, the ratio of the critical value of monomer fugacity is nothing but the log-log ratio of the Boltzmann’s weight corresponding to the monomers affinity corresponding to its conjugate monomer pair; and it is due to a fact that the stiff chain has small value of the entropy.
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Bowker, Karen E., Alan R. Noel, and Alasdair P. MacGowan. "Pharmacodynamics of Minocycline against Staphylococcus aureus in an In Vitro Pharmacokinetic Model." Antimicrobial Agents and Chemotherapy 52, no. 12 (June 2, 2008): 4370–73. http://dx.doi.org/10.1128/aac.00922-07.
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ABSTRACT Free drug serum concentrations of minocycline associated with the doses given to humans (100 mg every 12 hours for 24 hours) were simulated in an in vitro hollow-fiber pharmacokinetic model. Four strains of methicillin (meticillin)-resistant Staphylococcus aureus (MRSA), United Kingdom EMRSA 15 and 16 plus a pair of blood culture isolates before and after long-term minocycline treatment, were employed. The minocycline MICs for these four strains were 0.04 mg/liter, 0.19 mg/liter, 0.06 mg/liter, and 0.75 mg/liter. The antibacterial effect (ABE) of minocycline was measured using the area under the bacterial kill curve to 24 h (AUBKC) and the log change in viable count at 24 h (d24). The ABEs of minocycline with and without the addition of rifampin (rifampicin) were compared to those of vancomycin, and dose escalation and fractionation were used to determine the dominant pharmacodynamic index and its size. Minocycline alone produced a 1.5- to 2.0-log10-unit reduction in viable count for the strains with MICs of <0.2 mg/liter, while the addition of rifampin increased the ABE for these strains (P < 0.05). Vancomycin simulations produced a reduction in viable counts of 2.8 to 4.5 log units at 24 h, which was equivalent to the minocycline-plus-rifampin combination. Free area under the concentration-time curve (AUC)/MIC was best related to AUBKC or d24 using a sigmoid maximal effect (Emax) model with r 2 of 0.92 and 0.87, respectively, and the AUC/MIC ratios for no change and −1-log-unit, −2-log-unit, and −3-log-unit drop at 24 h were 33.9, 75.9, 1,350, and >2,000, respectively. Fractionation of the dose at free AUC/MICs associated with human doses showed no difference between once, twice, or three times a day dosing. In contrast, fractionation of the dose at a free AUC associated with a static effect indicated that once daily dosing was superior. These data show that minocycline is an AUC/MIC-driven agent at human exposures and that the addition of rifampin may offer benefit in terms of MRSA killing.
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Bhandari, Devendra, Fur-Chi Chen, and Roger C. Bridgman. "Detection of Salmonella Typhimurium in Romaine Lettuce Using a Surface Plasmon Resonance Biosensor." Biosensors 9, no. 3 (July 28, 2019): 94. http://dx.doi.org/10.3390/bios9030094.
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Leafy vegetables have been associated with high-profile outbreaks causing severe illnesses. Timely and accurate identification of potential contamination is essential to ensure food safety. A surface plasmon resonance (SPR) assay has been developed for the detection of Salmonella Typhimurium in leafy vegetables. The assay utilizes a pair of well characterized monoclonal antibodies specific to the flagellin of S. Typhimurium. Samples of romaine lettuce contaminated with S. Typhimurium at different levels (between 0.9 and 5.9 log cfu/g) were pre-enriched in buffered peptone water. Three SPR assay formats, direct assay, sequential two-step sandwich assay, and pre-incubation one-step sandwich assay were evaluated. All three assay formats detect well even at a low level of contamination (0.9 log cfu/g). The SPR assay showed a high specificity for the detection of S. Typhimurium in the presence of other commensal bacteria in the romaine lettuce samples. The results also suggested that further purification of flagellin from the sample preparation using immunomagnetic separation did not improve the detection sensitivity of the SPR assay. The functional protocol developed in this study can be readily used for the detection of S. Typhimurium in leafy vegetables with high sensitivity and specificity.
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Nilsson, DE, and R. Modlin. "A MYSID SHRIMP CARRYING A PAIR OF BINOCULARS." Journal of Experimental Biology 189, no. 1 (April 1, 1994): 213–36. http://dx.doi.org/10.1242/jeb.189.1.213.
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Like other mysid shrimps, the tropical shallow-water species Dioptromysis paucispinosa possesses compound eyes of the refracting superposition type. In the rear of each eye, pointing backwards, is a single conspicuous facet almost three times the diameter of those in the rest of the eye. Underlying the large facet is an equally enlarged single crystalline cone, projecting an upright image onto a specialized retina of 120 densely packed and extremely narrow rhabdoms. This peculiar arrangement constitutes an acute zone which operates as a simple eye within a compound eye. Calculations of spatial sampling frequency and photon catch indicate that the centre of the acute zone resolves more than six times better than the normal eye, but it requires intensities more than a log unit higher ­ figures not unlike those of modern compact binoculars. The fact that the acute zone covers a visual field of 15­20°, with a large binocular overlap, strengthens the analogy with a pair of binoculars. The resolution of the acute zone is also remarkable in absolute terms: a rhabdom axis separation of 0.64° rivals foveal vision in large insects, although the entire eye of Dioptromysis measures only 0.4 mm. With the normal posture of the shrimp, the acute zone points backwards, about 12° above the horizon. Difficulties in understanding the animal's use of such an acute zone were resolved by the discovery of large coordinated eye movements. The eyestalk can be rotated around its axis by at least 130°. This makes the acute zone aim forwards and upwards, which is a more sensible direction for spotting and pursuing prey. The acute zone is probably held in the rest position aiming backwards only to avoid having an important part of the forward visual field constantly occupied by an eye region of inferior sensitivity.
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Manner, Jussi, Simon Berg, Martin Englund, Back Tomas Ersson, and Anders Mörk. "Innovative productivity improvements in forest operations: a comparative study of the Assortment Grapple using a machine simulator." Journal of Forest Science 66, No. 11 (November 30, 2020): 443–51. http://dx.doi.org/10.17221/104/2020-jfs.
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Because of generally small log piles, loading forwarders during thinning is time consuming. The Assortment Grapple, an innovative grapple with an extra pair of claws which facilitates the handling of two assortments during one loading crane cycle, has been designed to decrease forwarders’ loading time consumption. A standardized experiment was performed in a virtual thinning stand using a machine simulator with the objectives to form guidelines for working with the Assortment Grapple and to analyse its development potential. Four experienced operators participated in the study. According to the results, the Assortment Grapple’s accumulating function is beneficial only when there are no remaining trees between piles loaded during the same crane cycle. In such cases, none of participating operators lost time, and 3 of 4 operators saved time notably. The problem with the remaining trees is the extra time required to steer the crane tip around them. Therefore, a harvester should place those log piles that are later to be forwarded together in the same space with no remaining trees between the piles. Furthermore, we recommend that the Assortment Grapple’s usability will be improved by adding an own rocker switch on the forwarder’s controls to command the extra claws.
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AKBULUT, SELMAN. "TOPOLOGY OF MULTIPLE LOG TRANSFORMS OF 4-MANIFOLDS." International Journal of Mathematics 24, no. 07 (June 2013): 1350052. http://dx.doi.org/10.1142/s0129167x13500523.
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Given a 4-manifold X and an imbedding T2 × B2 ⊂ X, we describe an algorithm X ↦ Xp,q for drawing the handlebody of the 4-manifold obtained from X by (p, q)-logarithmic transforms along the parallel tori. By using this algorithm for relatively prime (p, q), we obtain a simple handle picture of the Dolgachev surface E(1)p,q, from that we deduce that the exotic copy [Formula: see text] of [Formula: see text] differs from the original one by a codimension zero simply connected Stein submanifold Mp,q. This gives examples of infinitely many small Stein manifolds which are exotic copies of each other (rel boundaries). Also by using the description of S2 × S2 as a union of two cusps glued along their boundaries, and by using this algorithm, we show that a pair of log transforms along the tori in these cusps gives back S2 × S2 or [Formula: see text].
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Akyel, Tugba, and Massimo Lanza de Cristoforis. ""Microscopic behavior of the solutions of a transmission problem for the Helmholtz equation. A functional analytic approach"." Studia Universitatis Babes-Bolyai Matematica 67, no. 2 (June 8, 2022): 383–402. http://dx.doi.org/10.24193/subbmath.2022.2.14.
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"Let $\Omega^{i}$, $\Omega^{o}$ be bounded open connected subsets of ${\mathbb{R}}^{n}$ that contain the origin. Let $\Omega(\epsilon)\equiv \Omega^{o}\setminus\epsilon\overline{\Omega^i}$ for small $\epsilon>0$. Then we consider a linear transmission problem for the Helmholtz equation in the pair of domains $\epsilon \Omega^i$ and $\Omega(\epsilon)$ with Neumann boundary conditions on $\partial\Omega^o$. Under appropriate conditions on the wave numbers in $\epsilon \Omega^i$ and $\Omega(\epsilon)$ and on the parameters involved in the transmission conditions on $\epsilon \partial\Omega^i$, the transmission problem has a unique solution $(u^i(\epsilon,\cdot), u^o(\epsilon,\cdot))$ for small values of $\epsilon>0$. Here $u^i(\epsilon,\cdot) $ and $u^o(\epsilon,\cdot) $ solve the Helmholtz equation in $\epsilon \Omega^i$ and $\Omega(\epsilon)$, respectively. Then we prove that if $\xi\in\overline{\Omega^i}$ and $\xi\in \mathbb{R}^n\setminus \Omega^i$ then the rescaled solutions $u^i(\epsilon,\epsilon\xi) $ and $u^o(\epsilon,\epsilon\xi)$ can be expanded into a convergent power expansion of $\epsilon$, $\kappa_n\epsilon\log\epsilon$, $\delta_{2,n}\log^{-1}\epsilon$, $ \kappa_n\epsilon\log^2\epsilon $ for $\epsilon$ small enough. Here $\kappa_{n}=1$ if $n$ is even and $\kappa_{n}=0$ if $n$ is odd and $\delta_{2,2}\equiv 1$ and $\delta_{2,n}\equiv 0$ if $n\geq 3$."
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Belomyttsev, M. Yu, and V. G. Molyarov. "CREEP RESISTANCE OF FERRITIC-MARTENSITIC STEEL 16Cr12MoWSiVNbB (EP-823)." Izvestiya. Ferrous Metallurgy 62, no. 4 (June 20, 2019): 290–302. http://dx.doi.org/10.17073/0368-0797-2019-4-290-302.
Full textAbstract:
Base characteristics of ferritic-martensitic heat resisting steels with 12 % of chrome are parameters of their strength and creep resistance at temperatures of 600 – 750 °С. Steel 16Cr12MoWSiVNbB (EP-823) is considered as the basic material for manufacturing environments fuel rods (TVEL) of a developed reactor with natural safety of BRESTtype. In the literature, there are data about its mechanical characteristics for tensile tests in a range of temperatures of 20 – 750 °С and the limited characteristics of rupture strength. Data on its creep velocity is absent. Laws of creep of steel EP-823 were investigated on metal of three heats with weight of 3 kg. The compression tests at air were applied for cylindrical samples of 5 ÷ 6 mmat temperatures of 600 – 760 °С and stresses of 70 – 310 MPa. The base of compression tests did not exceed 11 hours. The structure after quenching and tempering consisted of tempered martensite and 6 – 12 vol. % of delta-ferrite, the grain size was less 20 μm. It is shown, that the description of creep tests results in double logarithmic (log (σ) – log (έ)) coordinates provides the best concurrence of results of approximation and experiment, than in half-logarithmic (σ – log (έ)). The analysis of parametrical dependences on Hollomon’s PS = (T/1000)[CS – log (έ) and to Larsen-Miller’s PE = (T/1000)[СE – log (σ)] has allowed to find the equations for creep velocity for the set pressure level of 100 – 220 MPa in the form of log (έ) = –19,355 + 9,17 (T/1000) log (σ) and ultimate strength of creep under the set admissions for creep velocity of 0,01 – 1 %/hour in the form of log (σ) = 4,304 – – 0,109 (T/1000) [20 – log (έ)]. Calculations of ultimate strength of creep and creep velocity on pair models and models of Hollomon (Larsen-Miller) give close results, but the preference should be given the second ones as these models consider all three varied factors. Data of control tests under the scheme of a tensile in the same conditions are cited. It is shown, that between results of tests on compression and on tensile at definition of durability characteristics, there is the linear dependence expressed by the equation σ0.2 at compression = 1.3σ0.2 at tensile. At the analysis of creep it has been established, that creep velocity for steel of one grade (09Cr12W3NbB) and for one heat at different type of loading (tensile or compression) have similar values while creep velocities for steel of one grade (EP-823), but of different heats even at one type of loading – compression, can differ substantially.
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Giacometti, Arnaud, Patrick Marcel, Elsa Negre, and Arnaud Soulet. "Query Recommendations for OLAP Discovery-Driven Analysis." International Journal of Data Warehousing and Mining 7, no. 2 (April 2011): 1–25. http://dx.doi.org/10.4018/jdwm.2011040101.
Full textAbstract:
Recommending database queries is an emerging and promising field of research and is of particular interest in the domain of OLAP systems, where the user is left with the tedious process of navigating large datacubes. In this paper, the authors present a framework for a recommender system for OLAP users that leverages former users’ investigations to enhance discovery-driven analysis. This framework recommends the discoveries detected in former sessions that investigated the same unexpected data as the current session. This task is accomplished by (1) analysing the query log to discover pairs of cells at various levels of detail for which the measure values differ significantly, and (2) analysing a current query to detect if a particular pair of cells for which the measure values differ significantly can be related to what is discovered in the log. This framework is implemented in a system that uses the open source Mondrian server and recommends MDX queries. Preliminary experiments were conducted to assess the quality of the recommendations in terms of precision and recall, as well as the efficiency of their on-line computation.