Showing papers on "Division (mathematics) published in 2014"

Concerted control of Escherichia coli cell division

Abstract: The coordination of cell growth and division is a long-standing problem in biology. Focusing on Escherichia coli in steady growth, we quantify cell division control using a stochastic model, by inferring the division rate as a function of the observable parameters from large empirical datasets of dividing cells. We find that (i) cells have mechanisms to control their size, (ii) size control is effected by changes in the doubling time, rather than in the single-cell elongation rate, (iii) the division rate increases steeply with cell size for small cells, and saturates for larger cells. Importantly, (iv) the current size is not the only variable controlling cell division, but the time spent in the cell cycle appears to play a role, and (v) common tests of cell size control may fail when such concerted control is in place. Our analysis illustrates the mechanisms of cell division control in E. coli. The phenomenological framework presented is sufficiently general to be widely applicable and opens the way for rigorous tests of molecular cell-cycle models.

Electro-optical frequency division and stable microwave synthesis

Abstract: Optical frequency division by using frequency combs has revolutionized time keeping and the generation of stable microwave signals. We demonstrate optical frequency division and microwave generation by using a tunable electrical oscillator to create dual combs through phase modulation of two optical signals that have a stable difference frequency. Phase-locked control of the electrical oscillator by means of optical frequency division produces stable microwaves. Our approach transposes the oscillator and frequency reference of a conventional microwave frequency synthesizer. In this way, the oscillator experiences large phase noise reduction relative to the frequency reference. The electro-optical approach additionally relaxes the need for highly linear photodetection of the comb mode spacing. As well as simplicity, the technique is also tunable and scalable to higher division ratios.

Encrypted integer division and secure comparison

Abstract: When processing data in the encrypted domain, homomorphic encryption can be used to enable linear operations on encrypted data. Integer division of encrypted data however requires an additional protocol between the client and the server and will be relatively expensive. We present new solutions for dividing encrypted data in the semi-honest model using homomorphic encryption and additive blinding, having low computational and communication complexity. In most of our protocols we assume the divisor is publicly known. The division result is not only computed exactly, but may also be approximated leading to further improved performance. The idea of approximating the result of an integer division is extended to similar results for secure comparison, secure minimum, and secure maximum in the client-server model, yielding new efficient protocols with demonstrated application in biometrics. The exact minimum protocol is shown to outperform existing approaches.

Adaptive storage reliability management

Abstract: A storage controller identifies a storage location within a storage division that corresponds to a high error rate. In response, the storage controller may refresh data stored on the storage division by relocating data from the storage division and/or initializing (e.g., erasing) the storage division. In some embodiments, the storage division is selectively refreshed by relocating data from the storage location(s) having high error rates, while deferring a full relocation of other data from the storage division. The storage division may be selectively refreshed based on reliability characteristics of the storage division, such as the remaining data retention time calculated for the storage division.

Joint Video Frame Set Division and Low-Rank Decomposition for Background Subtraction

Abstract: The recently proposed robust principle component analysis (RPCA) has been successfully applied in background subtraction. However, low-rank decomposition makes sense on the condition that the foreground pixels (sparsity patterns) are uniformly located at the scene, which is not realistic in real-world applications. To overcome this limitation, we reconstruct the input video frames and aim to make the foreground pixels not only sparse in space but also sparse in time. Therefore, we propose a joint video frame set division and RPCA-based method for background subtraction. In addition, we use the motion as a priori knowledge which has not been considered in the current subspace-based methods. The proposed method consists of two phases. In the first phase, we propose a lower bound-based within-class maximum division method to divide the video frame set into several subsets. In this way, the successive frames are assigned to different subsets in which the foregrounds are located at the scene randomly. In the second phase, we augment each subset using the frames with a small quantity of motion. To evaluate the proposed method, the experiments are conducted on real-world and public datasets. The comparisons with the state-of-the-art background subtraction methods validate the superiority of our method.

An Approximate Method for Comparing Modular Numbers and its Application to the Division of Numbers in Residue Number Systems

Abstract: This paper presents a new method and algorithms for dividing modular numbers on the basis of the use of dividend and divisor values relative with respect to the full range of a residue number system. The proposed modular division algorithm uses elementary operations of register shift and addition, which makes the algorithm very simple and fastest to date.

Upper and lower bounds of symmetric division deg index

Abstract: Symmetric division deg index is one of the 148 discrete Adriatic indices that showed good predictive properties on the testing sets provided by International Academy of Mathematical Chemistry.

Display device and control method thereof

Abstract: PROBLEM TO BE SOLVED: To provide a technique capable of suppressing deterioration in visibility of a still image caused by performing local dimming control.SOLUTION: A display device of the present invention comprises: display means for displaying an image on a screen; light emission means capable of separately controlling light emission with respect to each of a plurality of division areas constituting the screen; acquisition means for acquiring a feature amount of an image displayed in the division area according to each of the division areas; and control means for controlling light emission by the light emission means. The control means controls the light emission of the light emission means so as to allow it to emit light, with respect to a video area only displaying a video among the plurality of division areas, at luminance on the basis of a feature amount of the video area, and with respect to a mixed area displaying both of a video and a still image among the plurality of division areas, at prescribed luminance.

Flexible displayer and manufacturing method thereof

Abstract: The invention relates to the technical field of flexible display, and discloses a flexible displayer and a manufacturing method thereof. The flexible displayer comprises a first flexible substrate, a pixel defining layer and a cathode. The pixel defining layer is made of resin materials. First division walls are provided with protruding structures, and first channels provided with openings deviating from the first flexible substrate and extending along the length direction of the first division wall are formed by the protruding structures. Second division walls are provided with protruding structures, and second channels provided with openings deviating from the first flexible substrate and extending in the length direction of the second division walls are formed by the protruding structures. The parts, directly facing the first division walls, of the cathode are provided with bends corresponding to the first channels, and the parts, directly facing the second division walls, of the cathode are provided with bends corresponding to the second channels. When the flexible displayer is bent along the first division walls or the second division walls, the cathode can release stress borne by the cathode, and the quality of the flexible displayer is improved.

Method for dividing screen freely and mobile terminal

Abstract: The invention provides a method for dividing a screen freely. The method comprises the steps of receiving a screen division command, including, a contact type screen division command and/or a non-contact type screen division command, and dividing the screen into at least two screen areas based on the screen division command, wherein each screen area has a regular shape and/or an irregular shape. The invention also provides a mobile terminal. With the adoption of the invention, free screen division of an interface shown by a mobile terminal can be realized.

Estimating the division rate of the growth-fragmentation equation with a self-similar kernel

Abstract: We consider the growth-fragmentation equation and we address the problem of estimating the division rate from the stable size distribution of the population, which is easily measured, but non-smooth. We propose a method based on the Mellin transform for growth-fragmentation equations with self-similar kernels. We build a sequence of functions which converges to the density of the population in division, simultaneously in several weighted spaces, as the measurement error goes to 0. This improves the previous results for self-similar kernels and allows us to understand the partial results for general fragmentation kernels. Numerical simulations confirm the theoretical results. Moreover, our numerical method is tested on real biological data, arising from a bacteria growth and fission experiment.

Stochasticity in the symmetric division of plant cells: when the exceptions are the rule

Abstract: Long before most of the molecular aspects of cell division were uncovered, L. V. Heilbrunn remarked that: “it is easier to make a new theory of cell division than to test an old one” and promised his readers to limit his treatment of cell division to “the factual facts regarding the physical changes which take place during mitosis” (Heilbrunn, 1928). Heilbrunn's barb was directed, first and foremost, to the theories or empirical rules put forward to explain how cells select a plane of division. A perusal of the cell biology literature in the decades preceding Heilbrunn's comment suffices to appreciate the author's cynicism toward cell division theories. By the end of the nineteenth century, at least five different rules had been formulated to predict how cells select a division plane. Of these, the most widely cited rules for plant cells were the Rectangular Section formulated by Sachs (1878) and the Principle of Minimal Area promoted by Berthold (1886) although often attributed to Errera (1888). The presence of exceptions to these rules led to many more “improved” rules and fueled a heated debate that spilled well into the twentieth century. An intriguing feature of this story is that despite the explosion of cell biology research in the twentieth century, the nineteenth century obsession with cell division rules rapidly receded; and ultimately vanished before the tests Heilbrunn so eagerly desired were performed. Although many biologists have cited this early work in reviews (e.g., Smith, 2001; Kwiatkowska, 2004; Dumais, 2007), the classical division rules have laid essentially dormant for a full century. The reasons why these rules were never tested must be sought in the particular mind-set of twentieth century biology. The most important factor is probably the geometrical nature of the rules which did not resonate well with the molecularly-oriented biology of the last century. Certainly, reducing cell division to a geometrical problem adds little to the “factual facts regarding the physical changes which take place during mitosis.” Yet, it is probable that even the most abstract division rule would not have been neglected for so long if it had predicted with great accuracy the selection of division planes in plant cells. Thus, another factor seems to have played an important role: the fact that even within the confine of a specific tissue, cell division seems to escape the determinism embodied by the classical rules. The frequent exceptions to the predicted division planes must have invalidated the division rules to the eye of most biologists. We recently argued that these exceptions may in fact be confirmation of another, more subtle, division rule (Besson and Dumais, 2011). Here we briefly retrace the history leading to this new rule while, at the same time, highlighting the strange turn of events that greatly delayed the acceptance of stochasticity in this particular area of cell biology.

Moving object extraction method based on optical flow method and superpixel division

Abstract: The invention discloses a moving object extraction method based on superpixel division and an optical flow method, and mainly solves the problems of more noises, high-frequency information loss, inaccurate boundary and the like of the existing moving object extraction method The implementation steps of the method are as follows: (1), inputting an image, and pre-dividing the image into a superpixel set S to obtain a mark sheet I 2; (2), taking images of two adjacent frames in a video sequence and determining a rough position of a moving object by a Horn-Schunck optical flow method; (3), using the optical flow method to obtain the speed u in the horizontal direction and the speed v in the vertical direction, wherein V is speed amplitude of the optical flow method; (4) performing median filtering, Gauss filtering, binarization operation and morphology opening and closing operation on the optical flow result V to obtain V4; (5) using a superpixel division result to further correct the optical flow result, and extracting to obtain the accurate moving object Superpixels belonging to a moving area are extracted accurately Simulation experiments show that compared with the prior art, the moving object extraction method has the advantages of simple operation, small noise, clear boundary and the like, and can be used for extracting the moving object in the video sequence

Clock generation circuit, processor system using same, and clock frequency control method

Abstract: A microcomputer includes a register that stores division ratio setting information, a frequency divider that determines first and second division ratios based on the division ratio setting information, frequency-divides a first clock having a first frequency at the first division ratio, and frequency-divides a second clock having a second frequency at the second division ratio, and a CPU. The first and second division ratios are determined in such a manner that a frequency of the first clock that is frequency-divided at the first division ratio and a frequency of the second clock that is frequency-divided at the second division ratio are made equal to each other.

Division algebras with infinite genus

Abstract: To what extent does the maximal subfield spectrum of a division algebra determine the isomorphism class of that algebra? It has been shown that over some fields a quaternion division algebra's isomorphism class is largely if not entirely determined by its maximal subfield spectrum. However in this paper, we show that there are fields for which the maximal subfield spectrum says little to nothing about a quaternion division algebra's isomorphism class. We give an explicit construction of a division algebra with infinite genus. Along the way we introduce the notion of a "linking field extension," which we hope will be of independent interest. We go on to show that there exists a field K for which (1) there are infinitely many nonisomorphic quaternion division algebras with center K, and (2) any two quaternion division algebra with center K are pairwise weakly isomorphic. In fact we show that there are infinitely many nonisomorphic fields satisfying these two conditions.

Applied and Computational Mathematics Division, Summary of Activities for Fiscal Year 2013

Abstract: This report summarizes the technical work of the Applied and Computational Sciences Division of NIST’s Information Technology Laboratory. Part I (Overview) provides a high-level overview of the Division’s activities, including highlights of technical accomplishments during the previous year. Part II (Features) provides further details on five projects of particular note this year. This is followed in Part III (Project Summaries) by brief synopses of all technical projects active during the past year. Part IV (Activity Data) provides listings of publications, technical talks, and other professional activities in which Division staff members have participated. The reporting period covered by this document is October 2012 through December 2013. For further information, contact Ronald F. Boisvert, Mail Stop 8910, NIST, Gaithersburg, MD 208998910, phone 301-975-3812, email boisvert@nist.gov, or see the Division’s web site at http://www.nist.gov/itl/math/index.cfm. Cover Visualization: Slice along the z=0 plane of the fourth wave function characterizing the interaction of two nonreactive polar RbCs molecules. Results computed using the system PHAML developed by the NIST Applied and Computational Mathematics Division. See page 64. Acknowledgements: Thanks to Catherine Graham and Ginger White for assisting in the compilation of Parts III and IV of this document. Disclaimer: Certain commercial entities, equipment, or materials may be identified in this document in order to describe an experimental procedure or concept adequately. Such identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the entities, materials, or equipment are necessarily the best available for the purpose. Summary of Activities for Fiscal Year 2013 iii

Operational momentum in multiplication and division

Abstract: Biases are commonly seen in numerical cognition. The operational momentum (OM) effect shows that responses to addition and subtraction problems are biased in the whole-number direction of the operation. It is not known if this bias exists for other arithmetic operations. To determine whether OM exists in scalar operations, we measured response bias in adults performing symbolic (Arabic digits) and non-symbolic (dots) multiplication and division problems. After seeing two operands, with either a multiplication (×) or division (÷) sign, participants chose among five response choices. Both non-random performance profiles and the significant contribution of both operands in a multiple regression analysis predicting the chosen values, suggest that adults were able to use numerical information to approximate the outcomes in both notations, though they were more accurate on symbolic problems. Performance on non-symbolic problems was influenced by the size of the correct choice relative to alternatives. Reminiscent of the bias in addition and subtraction, we found a significant response bias for non-symbolic problems. Non-symbolic multiplication problems were overestimated and division problems were underestimated. These results indicate that operational momentum is present in non-symbolic multiplication and division. Given the influence of the size of the correct choice relative to alternatives, an interaction between heuristic bias and approximate calculation is possible.

Scalability of few-mode fibers for mode-division-multiplexed systems

Abstract: We investigate the impact of the increase of the number of LP modes supported by few-mode fibers on their main characteristics, pointing out the limiting factors of this increase.

Mobile terminal and screen division method thereof

Abstract: The invention provides a mobile terminal which comprises a first touch module used for receiving touch operation and displaying a visual object, a second touch module arranged adjacently to the first touch module and used for receiving the touch operation, a processing module used for controlling the first touch module to display at least two divided screen areas based on the touch operation successively received by the first touch module and the second touch module. The invention also provides a screen division method of the mobile terminal. With the adoption of the invention, the screen division operational steps are simplified, and free screen division for an interface shown by the mobile terminal is realized.

Fish-eye image correction method based on multistep correction

Abstract: The invention introduces a fish-eye image correction method based on multistep correction, and aims at overcoming the disadvantages of image magnification and loss of edge information caused by a normal correction model in the prior art. A correction model is established based on multistep correction. A size zooming factor, based on a polynomial model, of a fish-eye image is established; the fish-eye image is corrected for the first time by utilizing the size zooming factor; interpolation is carried out on the image corrected for the first time in a neighborhood interpolation method; a division model based on a backward mapping method is established; and via the division model, the image after interpolation is corrected for the second time to obtain a secondary corrected image. The fish-eye image is corrected via the correction model, the problems including loss of edge information, image magnification, distortion and incomplete correction of the corrected images are solved, most information of a fish-eye lens is completely reserved, and the condition that the edge of the image is fuzzy is changed.

The scheme of a novel methodology for zonal division based on power transfer distribution factors

Abstract: One of the methodologies that carry out the division of the electrical grid into zones is based on the aggregation of nodes characterized by similar Power Transfer Distribution Factors (PTDFs). Here, we point out that satisfactory clustering algorithm should take into account two aspects. First, nodes of similar impact on cross-border lines should be grouped together. Second, cross-border power flows should be relatively insensitive to differences between real and assumed Generation Shift Key matrices. We introduce a theoretical basis of a novel clustering algorithm (BubbleClust) that fulfills these requirements and we perform a case study to illustrate social welfare consequences of the division.

The Scheme of a Novel Methodology for Zonal Division Based on Power Transfer Distribution Factors

Abstract: One of the methodologies that carry out the division of the electrical grid into zones is based on the aggregation of nodes characterized by similar Power Transfer Distribution Factors (PTDFs). Here, we point out that satisfactory clustering algorithm should take into account two aspects. First, nodes of similar impact on cross-border lines should be grouped together. Second, cross-border power flows should be relatively insensitive to differences between real and assumed Generation Shift Key matrices. We introduce a theoretical basis of a novel clustering algorithm (BubbleClust) that fulfills these requirements and we perform a case study to illustrate social welfare consequences of the division.

Equipment cabinet air conditioner

Abstract: The invention discloses an equipment cabinet air conditioner, which is used for adjusting the temperature in an equipment cabinet, and comprises an internal circulating heat exchange system and an external circulating heat exchange system. The internal circulating heat exchange system comprises an evaporation heat exchanger, an evaporation fan, and an inner shell for accommodating the evaporation heat exchanger and the evaporation fan. The external circulating heat exchange system has a condensation heat exchanger which includes an accommodating space for accommodating a refrigerant medium; heat dissipating fins for dissipating heat by using natural convection are arranged at one side deviated from the internal circulating heat exchange system, and the side deviated from the internal circulating heat exchange system is exposed outside the equipment cabinet so as to enable the heat dissipating fins to be directly contacted with air; and the internal circulating heat exchange system is positioned in the equipment cabinet. At least two sets of the heat dissipating fins are arranged in the longitudinal extension direction; and the upper and lower two sets of the heat dissipating fins are divided by at least one division gap. Through the condensation heat exchanger for dissipating heat through natural convection, the equipment cabinet air conditioner reduces the part cost, conveniently cleans the condensation heat exchanger, effectively prevents the attenuation of the refrigeration capacity after the long-time operation, can largely save energy and reduce consumption, and is reliably operated.

Binary division algorithm and high speed deconvolution algorithm (Based on Ancient Indian Vedic Mathematics)

Abstract: The performance of any processor solely depends upon its power, area and delay. In order to get an effective processor, its power, area and delay should be less. Division is always considered to be bulky and one of the most difficult operations in arithmetic and hence all the implementations of division algorithms in VLSI architecture have higher orders of time and space complexities. Vedic Mathematics on the other hand offers a new holistic approach to mathematics. Its range extends from the most concrete values of numerical computation to the most abstract aspects of the dynamics of intelligence. In this work we have implemented an optimized binary division architecture using sutras of Vedic Mathematics which are Nikhilam Sutra and Parvartya Sutra. This work discusses about these two algorithms of division and their application for calculating deconvolution. Both the algorithms have been implemented with improved results of time delay and are with fewer complexities. The proposed division algorithm is coded in Verilog, synthesized and simulated using Xilinx ISE design suit 14.2. Simulated results for proposed Vedic divider circuit shows a reduction in delay of 19% than the conventional method.

Division and evaluation method for fracture and hole type reservoir flow units

Abstract: The invention provides a division and evaluation method for fracture and hole type reservoir flow units. The division and evaluation method for the fracture and hole type reservoir flow units comprises the steps that the standards for dividing flow unit types in an underground reservoir body are determined according to the changing rate of the hurst index after water appears in an oil well and the storage characteristics of the underground reservoir body of a fracture and hole type reservoir; the statistical result of weighted average porosity of the underground reservoir body of all the flow unit types is used as the unified standard for dividing the flow unit types, and the flow unit type division on a whole fracture and hole type reservoir area is carried out by utilizing the unified standard; characteristic parameters reflecting oil well productivity contribution are selected according to flowing laws of fluid of each flow unit type, and the flow units belonging to the corresponding flow unit types are evaluated by utilizing the characteristic parameters. According to the division and evaluation method for the fracture and hole type reservoir flow units, the fact that the units with identical storage characteristics and the flowing laws of the fluid can be divided as the same flow unit is facilitated, the evaluation standard is beneficial for forming efficient developing modes aiming at different flow units for researching the distribution characteristics of remaining oil.