Number Generator Research Articles

Stochastic and quasistochastic computations

The work contains a brief survey of research related to stochastic and quasistochastic methods of computation carried out in recent years by the author and his colleagues. The areas of research include, in particular, substantiation of multiplicative generators of pseudorandom numbers, Monte Carlo methods for solving nonlinear equations, complexity estimation, stochastic stability and parallelism of stochastic and quasistochastic algorithms. This area of research is of utmost current interest in view of the rapid development of multiprocessor computing machinery.

ARC-FRACTAL AND THE DYNAMICS OF COASTAL MORPHOLOGY

In this paper, we present an idea of creating fractals by using the geometric arc as the basic element. This approach of generating fractals, through the tuning of just three parameters, gives a universal way to obtain many novel fractals including the classic ones. Although this arc-fractal system shares similar features with the well-known Lindenmayer system, such as the same set of invariant points and the ability to tile the space, they do have different properties. One of which is the generation of pseudo-random number, which is not available in the Lindenmayer system. Furthermore, by assuming that coastline formation is based purely on the processes of erosion and deposition, the arc-fractal system can also serve as a dynamical model of coastal morphology, with each level of its construction corresponds to the time evolution of the shape of the coastal features. Remarkably, our results indicate that the arc-fractal system can provide an explanation on the origin of fractality in real coastline.

Exploring pseudo- and chaotic random Monte Carlo simulations

Computer simulations are an increasingly important area of geoscience research and development. At the core of stochastic or Monte Carlo simulations are the random number sequences that are assumed to be distributed with specific characteristics. Computer-generated random numbers, uniformly distributed on (0, 1), can be very different depending on the selection of pseudo-random number (PRN) or chaotic random number (CRN) generators. In the evaluation of some definite integrals, the resulting error variances can even be of different orders of magnitude. Furthermore, practical techniques for variance reduction such as importance sampling and stratified sampling can be applied in most Monte Carlo simulations and significantly improve the results. A comparative analysis of these strategies has been carried out for computational applications in planar and spatial contexts. Based on these experiments, and on some practical examples of geodetic direct and inverse problems, conclusions and recommendations concerning their performance and general applicability are included.

Mop: An Efficient Algorithm for Mining Frequent Pattern with Subtree Traversing

Mining frequent patterns in database has emerged as an important task in knowledge discovery and data mining. In this paper, we present an efficient algorithm called Mop for fast frequent pattern discovery. Mop utilizes a new kind of data structure called OP_tree (ordered pattern tree) and some particular properties of frequent patterns to facilitate the process of mining frequent patterns. An OP_tree is a special frequent pattern tree, where the children of any node are sorted according to the supports of corresponding items. Efficiency of Mop is achieved with three techniques: (1) it adopts OP_tree to store a large database to avoid repetitive database scans, (2) it finds all frequent 2-patterns in the construction of OP_tree to avoid the costly generation of a large number of candidate 2-patterns, (3) the supports of candidate k-patterns (k>2) can be obtained by traversing a few of specific subtrees of the OP_tree, which greatly reduces the search space and avoid multi-scans of a database. We experimentally compare our algorithm with the Apriori algorithm and the FP-growth algorithm on one real database and one synthetical database. The experimental results show that Mop is about an order of magnitude faster than the Apriori algorithm. Mop also outperforms the FP-growth algorithm, especially when support threshold is very low and databases are quite large.

Generation of Random Numbers by Means of Optical Manipulator

Generation of Random Numbers by Means of Optical Manipulator

METHOD OF ELLIPTIC CURVES IMPOSITION IN CRYPTOGRAPHIC PROTECTION TASKS OF GRAPHIC INFORMATION

In the articles offered the newest methods of cryptographic defence of informative resources are based on the features of algorithms of elliptic curves and methods of the asymmetric enciphering, the algorithm of generation of random numbers is worked out based on ciphered information and various types of images.

Thoracic Epidural Analgesia With Levobupivacaine for 6 Postoperative Days Attenuates Sympathetic Activation After Thoracic Surgery

To investigate the impact of 2 postoperative analgesic regimens on heart rate variability in patients who underwent thoracotomy. A prospective, randomized trial. A single-institutional study in a university hospital. Fifty patients who underwent thoracotomy under combined general anesthesia and thoracic epidural analgesia divided by a number generator into 2 equal groups (A and B). In group A, postoperative analgesia consisted of thoracic epidural analgesia with levobupivacaine for 6 postoperative days. In group B, on the 3rd postoperative day this regimen was changed to patient-controlled intravenous morphine. Heart rate variability recordings were performed on the day before surgery, after the epidural, after operation, and on every postoperative day. Statistical analysis used chi-square and Student t tests (Bonferroni correction). In both groups, the low-frequency component of the analyzed recordings declined after epidural and after surgery. In group A, the low-frequency component was significantly lower compared with baseline from the 2nd postoperative day onward, whereas in group B it was significantly higher compared with A on the 4th and 6th postoperative days. In both groups, the changes in high frequency were statistically insignificant. Intergroup comparisons of the low-/high-frequency ratio showed statistical difference on the last day of observation. There was no difference between the groups in hemodynamic variables and visual analog scale/10 scores. Postoperatively decreased cardiac sympathetic outflow continues with epidural analgesia, whereas it is abolished by the change to intravenous patient-controlled morphine.

Concession Schedules and Terrorist Risk Aversion

The purpose of this paper is to address some problems that derive from the economic analysis of negotiations between governments and terrorists (or terrorist organisations). The analysis demonstrates three things. First, a government’s concessions cannot unambiguously decrease the terrorist organisation’s risk aversion. Second, a government’s concession of immunity from prosecution can unambiguously decrease the terrorist organisation’s risk aversion. Third, the incentive structures imposed by the terrorist organisation can influence the risk preferences of its agents and may act to offset or reinforce the incentives or concessions offered by governments during negotiations. In addition, the paper presents a novel theoretical-analytical framework that facilitates the generation of a number of new insights into terrorist behaviour. This is a ‘contingent claims’ framework.

Do home numeracy and literacy practices of Greek and Canadian parents predict the numeracy skills of kindergarten children?

Children’s experiences with early numeracy and literacy activities are a likely source of individual differences in their preparation for academic learning in school. What factors predict differences in children’s experiences? We hypothesised that relations between parents’ practices and children’s numeracy skills would mediate the relations between numeracy skills and parents’ education, attitudes and expectations. Parents of Greek (N = 100) and Canadian (N = 104) five‐year‐old children completed a survey about parents’ home practices, academic expectations and attitudes; their children were tested on two numeracy measures (i.e., KeyMath‐Revised Numeration and next number generation). Greek parents reported numeracy and literacy activities less frequently than Canadian parents; however, the frequency of home numeracy activities that involved direct experiences with numbers or mathematical content (e.g., learning simple sums, mental math) was related to children’s numeracy skills in both countries. For Greek children, home literacy experiences (i.e., storybook exposure) also predicted numeracy outcomes. The mediation model was supported for Greek children, but for Canadian children, the parent factors had both direct and mediated relations with home practices.

THE EFFECT OF BUOYANCY ON VORTEX SHEDDING AND ENTROPY GENERATION OF A HEATED SQUARE CYLINDER

The effect of buoyancy on vortex shedding and entropy generation phenomena of a heated square cylinder has been studied numerically for assisting and opposing mixed convection flows. The present analysis is valid when the buoyancy force effects are small compared to forced convection effects. The mixed convection flow problem is formulated by two-dimensional incompressible flow, with the buoyancy term represented by Boussinesq approximation. The hyperbolic grid generation method is applied to provide an efficient mesh system for the flow. The governing equations are transformed into an orthogonal transformed plane and are solved in stream function and vorticity form using high-accuracy finite difference schemes. Results show that the strength of the vortex shedding is increased with increasing Reynolds number. The effect of buoyancy reduces or stops the vortex shedding phenomena for assisting mixed convection flows with the combination of Reynolds and Richardson numbers. The effect of buoyancy increases the strength of the vortex shedding as the Richardson number increases for opposing mixed convection flows. Heat transfer characteristics and entropy generation are reported for various combinations of Reynolds and Richardson numbers. The effect of buoyancy increases the average Nusselt number and entropy generation for assisting mixed convection flows, and we see the opposite trend for opposing mixed convection flows. The reported average Nusselt number values match very well with the numerical and experimental values available from the literature. © 2010 by Begell House, Inc.

Efficient conformational sampling of multiconformational cyclic molecules: application to 1,4,7,10,13-Pentaoxacyclopentadecane

The result of an exhaustive search of low-energy conformers of 1,4,7,10,13-Pentaoxacyclopentadecane is presented. The search method combines the generation of large number of trial conformers using local nonstochastic deformations known as the Conflex method, which is coupled to AMBER force field as the minimizer. The extent of the conformational space sampled was evaluated from the view point of the number of duplicates of each conformer, generation of inclusion type structures without considering the substrate and the spread of the allowed torsion angles visited during the search. It is shown that the conformational search is exhaustive and efficient as conformers, which the metal coordinated crown ether complexes adopt, were generated. Free energies using the AMBER structures were calculated using the model of Cramer and Truhlar. The study suggests that 1,4,7,10,13-Pentaoxacyclopentadecane exists as a mixture of conformers in solution. The results show the efficiency of the method and could be the method of choice in the design of synthetic macrocyclic receptors.

Lucky numbers: Spatial neglect affects physical, but not representational, choices in a Lotto task

Spatial neglect can be characterized by a “magnetic attraction” towards the right side of a visual stimulus array and a selection of stimuli from that hemispace. This study examined whether these distinctive characteristics in visuo-motor space are also evident in representational number space. Given that numbers are thought to be represented along a left-to-right oriented mental number line, an affinity for the spontaneous selection of larger numbers was anticipated for neglect patients. Contrary to this expectation, neglect patients ( n = 20) picked a similar range of numbers compared to controls ( n = 17) when generating a number between 1000 and 10 000 and when playing an imaginary lottery game. There was, however, a positive correlation between the biases for the imaginary lottery, number generation and a number bisection task – demonstrating that exploration asymmetries along the mental number line are consistent within individuals across tasks. Some of the patients selected smaller numbers in all of these tasks, confirming reports of dissociations between physical and numerical-representational forms of neglect. Conversely, only four (20%) of the patients could reliably be classified as demonstrating a neglect in number space. When filling out a physical lottery ticket, the neglect patients showed the expected bias towards picking numbers placed on the right-hand side of the ticket. These results demonstrate that the magnetic attraction towards the right side of mental representations is rather weak and that representational forms of neglect only occasionally co-exist with neglect in physical space.

Function of microRNA during neuromuscular junction development

Concurrent session 2: Developmental neurobiology Program/Abstract # 11 The evolution of chemosensory perception in insects Leslie B. Vosshall Howard Hughes Medical Institute, New York, NY USA Lab. Neurogenet. Behav., Rockefeller Univ., New York, NY, USA The detection of environmental cues is critical for insects to find relevant food sources, potential mates, and suitable oviposition sites. The species-related information carried by chemical cues is perceived and processed through the chemosensory system. Recent data from our group and others in the field show that insects have acquired an evolutionarily distinct olfactory system, that although anatomically homologous to that in vertebrates, uses novel structural and molecular mechanisms to detect odors. This presentation will cover the latest comparative data on the development and function of chemosensory systems in insects compared to vertebrates. doi:10.1016/j.ydbio.2009.05.017 Program/Abstract # 12 Id2 is essential for regulating growth and patterning of the vertebrate retina Rosa A. Uribe, Jeffrey M. Gross Mol. Cell and Dev. Biol., Univ. of Texas at Austin, Austin, TX, USA While much is known about the neuronal organization of the retina and the temporal sequence of neurogenesis, the intrinsic cellular and molecular mechanisms mediating these processes remain elusive. The Inhibitor of Differentiation (Id) family of proteins inhibits differentiation in multiple cell contexts, presumably by keeping cells in a proliferative, stem cell-like state. Although previous studies have described Id2 expression in the retina, its function during retinal development has not been well characterized. Using morpholino knockdown, we show that reduction of Id2 protein leads to microphthalmia and defects in neuronal differentiation within the retina. Id2 loss of function (LOF) retinas contain ganglion cells, but all other differentiated retinal neuron subtypes are absent. While retinal specification markers are expressed normally, the expression of retinal differentiation transcription factors is diminished in Id2 LOF retinas, suggesting that Id2 function is required downstream of cell fate specification and prior to terminal differentiation. While apoptosis is not increased in Id2 LOF retinas, cell cycle analyses using flow cytometry and BrdU incorporation assays reveals that cells in Id2 LOF retinas remain in the S phase of the cell cycle, suggesting that microphthalmia in Id2 LOF embryos results from an inability to progress through the cell cycle. Interestingly, overexpression of Id2 leads to increased eye size with no effect on retinal differentiation or patterning. Taken together, these observations support a model where Id2 regulates both cell cycle progression and retinal differentiation to influence retinal growth and development. doi:10.1016/j.ydbio.2009.05.018 Program/Abstract # 13 Function of microRNA during neuromuscular junction development David Van Vactor, Carlos M. Loya, Cecilia S. Lu, Tudor A. Fulga Department of Cell Biology, Harvard Medical School, Boston, MA, USA Abstract#13will bepresentedas scheduled, butwill not bepublished due to lack of license agreement between authors and publisher.13will bepresentedas scheduled, butwill not bepublished due to lack of license agreement between authors and publisher. doi:10.1016/j.ydbio.2009.05.019 Program/Abstract # 14 Feedback regulation of neurogenesis Rosa Gonzalez-Quevedo, Dorothy F. Sobieszczuk, Alexei Poliakov, Yoonsung Lee, Kenneth D. Poss, David G. Wilkinson Div. Dev. Neurobiol., MRC-NIMR, Mill Hill, UK Department of Cell Biol., Duke Univ. Med. Ctr., Durham, NC, USA Generation of appropriate numbers of neurons and glia during development of the nervous system requires the correct balance between maintaining neural progenitors versus the differentiation of cells. This balance is regulated by a network of activators and inhibitors. Within regions of active neurogenesis, the amountof cell differentiation is limited by widely expressed inhibitors and by short-range lateral inhibition. In specific parts of the vertebrate nervous system, neurogenesis is also regulated by large scale patterning mechanisms that generate distinct neurogenic and non-neurogenic zones. We will discuss two novel feedback mechanisms that regulate different aspects of neuronal differentiation. First, we have investigated how nonneurogenic zones are generated in segment centres in the zebrafish hindbrain, confining neurogenesis to zones adjacent to boundaries. We show that this spatial patterning of neurogenesis is achieved by signalling from specific early-generated neurons to progenitor cells. A second feedback mechanism has been found in studies of primary Developmental Biology 331 (2009) 388–389

Manipulating the Caenorhabditis elegans genome using mariner transposons

Tc1, one of the founding members of the Tc1/mariner transposon superfamily, was identified in the nematode Caenorhabditis elegans more than 25 years ago. Over the years, Tc1 and other endogenous mariner transposons became valuable tools for mutagenesis and targeted gene inactivation in C. elegans. However, transposition is naturally repressed in the C. elegans germline by an RNAi-like mechanism, necessitating the use of mutant strains in which transposition was globally derepressed, which causes drawbacks such as uncontrolled proliferation of the transposons in the genome and accumulation of background mutations. The more recent mobilization of the Drosophila mariner transposon Mos1 in the C. elegans germline circumvented the problems inherent to endogenous transposons. Mos1 transposition strictly depends on the expression of the Mos transposase, which can be controlled in the germline using inducible promoters. First, Mos1 can be used for insertional mutagenesis. The mobilization of Mos1 copies present on an extrachromosomal array results in the generation of a small number of Mos1 genomic insertions that can be rapidly cloned by inverse PCR. Second, Mos1 insertions can be used for genome engineering. Triggering the excision of a genomic Mos1 insertion causes a chromosomal break, which can be repaired by transgene-instructed gene conversion. This process is used to introduce specific changes in a given gene, such as point mutations, deletions or insertions of a tag, and to create single-copy transgenes.

종자 특이 프로모터와 대두 Ferritin 유전자에 의한 벼 종실의 철분강화

The recombinant DNAs, pGBF, pGTF, and pZ4F, using soybean ferritin gene have constructed with the promoters derived from seed proteins, glutelin, globulin, and zein. The recombinant ferritin genes were transformed into rice plant by Agrobacterium-mediated transformation. Iron contents and agronomic traits have been evaluated in the transgenic progenies. The embryogenic calli survived from second selection medium were regenerated at the rates of 19.2% with pGBF, 15.0% with pGTF, and 18.4% with pZ4F in Donganbyeo and 6.7% with pGBF, 11.7% with pGTF, and 3.4% with pZ4F in Hwashinbyeo. The introduction of ferritin gene in putative transgenic rice plants was confirmed by PCR and Southern blot analysis and also the expression of ferritin gene was identified by Northern blot and Western blot analysis. The iron accumulation in transgenic rice grains of the transgenic rice plant, T1-2, with zein promoter and ferritin gene contained 171.4 ppm showing 6.4 times higher than 26.7 ppm of Hwashinbyeo seed as wild type rice, but the transgenic plants with globulin and glutelin showed a bit higher iron contents with a range from 2.1 to 3.0 times compare to wild type grain. The growth responses of transgenic plants showed the large variances in plant height and number of tillers. However, there were some transgenic plants having similar phenotype to wild type plants. In the T1 generation of transgenic plants, plant height, culm length, panicle length, and number of tillers were similar to those of wild type plants, but ripened grain ratio ranged from 53.3% to 82.2% with relatively high variation. The transgenic rice plants would be useful for developing rice varieties with high iron content in rice grains.

A Note on the Generative Power of Axon P Systems

Axon P systems are a class of spiking neural P systems. In this paper, the axon P systems are used as number generators and language generators. As a language generator, the relationships of the families of languages generated by axon P systems with finite and context-free languages are considered. As a number generator, a characterization of the family of finite sets can be obtained by axon P systems with only one node. The relationships of sets of numbers generated by axon P systems with semilinear sets of numbers are also investigated. This paper partially answers some open problems formulated by H. Chen, T.-O. Ishdorj and Gh. Păun.

Advantages of COS-1 monkey kidney epithelial cells as packaging host for small-volume production of high-quality recombinant lentiviruses

The HEK293T human embryonic kidney cells have been used widely as a packaging host for transfection-based production of recombinant lentiviruses. The present study describes advantages of using COS-1 African green monkey kidney cells versus HEK293T cells as a packaging host for small-volume production of high-quality recombinant lentiviruses. The particle performance index, defined as the ratio of infection-competent viral particles to the total number of particles, was three- to four-fold greater in transfection supernatants generated using COS-1 cells than that generated using HEK293T cells. Adhesion of HEK293T cells to the cell culture-treated plastic surface was weak, causing significant HEK293T cell contamination in the transfection supernatants produced by laboratory automation using the 96-well cell culture plates. In contrast, COS-1 cells adhered strongly to the plastic surface, and cell contamination was not detected in the transfection supernatants. These results suggest that COS-1 cells may be a useful alternative packaging host for use for automated generation of large numbers of high-quality lentivirus reagents, particularly because they eliminate the need for additional purification steps to remove viral particles from cell culture supernatant.

Spectral test and spectral distance for multiplicative generators with moduli 2 p

Multiplicative generators of pseudorandom numbers with moduli 2p and full periods are studied in terms of the probabilistic interpretation of spectral test.

Correlation of effector function with phenotype and cell division after in vitro differentiation of naive MART-1-specific CD8+ T cells

Adoptive transfer of antigen-specific CD8+ T cells may represent an effective strategy for immunotherapy of tumors such as melanoma, but is limited by the number and functionality of in vitro expanded T cells. Here, we document that although ELAGIGILTV-specific CD8+ T cells from different donors initially possessed a naive phenotype, after antigen-induced in vitro expansion two distinct phenotypes correlating with cell proliferation rate emerged in the different donors. Those cultures achieving fewer cumulative population doublings (CPDs) were cytotoxic and displayed a CD45RA+CCR7- phenotype. In contrast, cultures reaching higher CPDs were non-cytotoxic T cells with a CD45RA-CCR7- phenotype. Thus, the generation of larger numbers of ELAGIGILTV-specific CD8+ T cells correlates negatively with the acquisition of a CD45RA+CCR7- phenotype and cytotoxic capacity. A better understanding of the differentiation pathways of cytotoxic T cells to obtain optimally efficient cells for adoptive transfer will allow the development of new immunotherapy protocols.

Wiener–Hopf solution of rewetting of an infinite cylinder with internal heat generation

The two-dimensional quasi-steady conduction equation governing conduction controlled rewetting of an infinite cylinder with heat generation has been solved by Wiener–Hopf technique. The analytical solution yields the quench front temperature as a function of various model parameters such as Peclet number, Biot number and dimensionless heat generation rate. Also, the dry out heat generation rate is obtained by setting the Peclet number equal to zero, which gives the maximum permissible heat generation so as to prevent the dry out of the coolant.