999 research outputs found
The Gallant-Lambert-Vanstone Decomposition Revisited
No full textThe Gallant-Lambert-Vanstone method accelerates the computation of scalar multiplication [k]P of a point (or a divisor) P of prime order r on some algebraic curve (or its Jacobian) by using an efficient endomorphism phi on such curve. Suppose phi has minimal polynomial h(x) = Sigma(d)(i=0) a(i)x(i) is an element of Z[x], the question how to efficiently decompose the scalar k as [k] P = Sigma(d-1)(i=0)[k(i)]phi(i) (P) with max(i) log vertical bar k(i)vertical bar approximate to 1/d log r has drawn a lot of attention. In this paper we show the link between the lattice based decomposition and the division in Z[phi] decomposition, and propose a hybrid method to decompose k with max(i) vertical bar k(i)vertical bar <= 2((d-5)/4) d(dN(h))((d-1)/2)r(1/d), where N(h) = Sigma(d-1)(i=0) a(i)(2). In particular, we give explicit and efficient GLV decompositions for some genus 1 and 2 curves with efficient endomorphisms through decomposing the Frobenius map in Z[phi], which also indicate that the complex multiplication usually implies good properties for GLV decomposition. Our results well support the GLV method for faster implementations of scalar multiplications on desired curves.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000345588100013&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Computer Science, Theory & MethodsEICPCI-S(ISTP)
Active suspensions in thin films: Nutrient uptake and swimmer motion
Get PDFA numerical study of swimming particle motion and nutrient transport is conducted for a semidilute to dense suspension in a thin film. The steady squirmer model is used to represent the motion of living cells in suspension with the nutrient uptake by swimming particles modelled using a first-order kinetic equation representing the absorption process that occurs locally at the particle surface. An analysis of the dynamics of the neutral squirmers inside the film shows that the vertical motion is reduced significantly. The mean nutrient uptake for both isolated and populations of swimmers decreases for increasing swimming speeds when nutrient advection becomes relevant as less time is left for the nutrient to diffuse to the surface. This finding is in contrast to the case where the uptake is modelled by imposing a constant nutrient concentration at the cell surface and the mass flux results to be an increasing monotonic function of the swimming speed. In comparison to non-motile particles, the cell motion has a negligible influence on nutrient uptake at lower particle absorption rates since the process is rate limited. At higher absorption rates, the swimming motion results in a large increase in the nutrient uptake that is attributed to the movement of particles and increased mixing in the fluid. As the volume fraction of swimming particles increases, the squirmers consume slightly less nutrients and require more power for the same swimming motion. Despite this increase in energy consumption, the results clearly demonstrate that the gain in nutrient uptake make swimming a winning strategy for micro-organism survival also in relatively dense suspensions.Process & EnergyMechanical, Maritime and Materials Engineerin
Erratum to Fischer et al. "Inhibitor development in nonsevere haemophilia across Europe" (Thromb Haemost 2015; 114: 670-675).
No full text[This corrects the article DOI: 10.1160/TH14-12-1044.]. In the Original Article by Fischer et al. "Inhibitor development in non- severe haemophilia across Europe" (Thromb Haemost 2015; 114: 670-675), the author R. Hollingsworth was omitted by mistake. Please find the corrected list of authors here: Fischer K, Iorio A, Lassila R, Peyvandi F, Calizzani G, Gatt A, Lambert T, Windyga J, Gilman EA, Hollingsworth R, Makris M, on behalf of the EUHASS participants
Wrestling with Japanese Tribalism Emerging Collaborative Opportunities For India and Japan
Get PDFJapanese firms, with their strong technology base and high domestic factor costs, have the potential of teaming with India, with its more basic infrastructure and eight times the population. Japan's poorly-performing excess capital could fuel India's strongly-developing middle class and robust entrepreneurialism. Especially promising are collaborative information technology projects. What stands in the way of a greatly expanded relationship? Much of the blockage stems from Japan's insularism, an impetus here labeled tribalism. A hopeful dimension is that this tribalism can be clearly defined as archaic, recognized as detrimental, and then toned-down. Further points for development include an active campaign to encourage diversity in Japan, teaming up to provide alternatives to investment in neighboring China, and agitating for representation on the UN Security Council. India can help initiate all these processes, and can in turn benefit from a Japan reaching out for regional economic partnerships.homogeneity; tribalism; UN Security Council; partnership; immigration; trade; e-Japan strategy
tgcd: An R package for analyzing thermoluminescence glow curves
No full textAbstractThermoluminescence (TL) glow curves are widely used in dosimetric studies. Many commercial and free-distributed programs are used to deconvolute TL glow curves. This study introduces an open-source R package tgcd to conduct TL glow curve analysis, such as kinetic parameter estimation, glow peak simulation, and peak shape analysis. TL glow curves can be deconvoluted according to the general-order empirical expression or the semi-analytical expression derived from the one trap-one recombination center (OTOR) model based on the Lambert W function by using a modified Levenberg–Marquardt algorithm from which any of the parameters can be constrained or fixed. The package provides an interactive environment to initialize parameters and offers an automated “trial-and-error” protocol to obtain optimal fit results. First-order, second-order, and general-order glow peaks (curves) are simulated according to a number of simple kinetic models. The package was developed using a combination of Fortran and R programming languages to improve efficiency and flexibility
Inverse laplace transform for transient-state fluid line network simulation
Get PDFInverse Laplace transform methods have a long history in the development of time-domain fluid line models. This paper presents a study combining the new Laplace-domain input/output (I/O) model derived from the network admittance matrix with the Fourier series expansion numerical inverse Laplace transform (NILT) to serve as a time-domain simulation model. A series of theorems are presented demonstrating the stability of the I/O model, which is important for the construction of the NILT method. In the previous work by the first author, the Fourier series expansion algorithm was studied, where qualitative relationships between the parameters and numerical errors were analyzed, and reliable parameter heuristics were developed. These heuristics are used for a series of numerical examples dealing with networks of 11, 35, 51, and 94 pipes by using five different pipe models. The examples are used as the basis from which the accuracy and numerical efficiency of the proposed NILT are compared to the standard method of characteristics (MOCs) model for transient pipeline networks. Findings show that, for all case studies considered, the proposed NILT is numerically efficient for the pipe types involving convolution operations, and it is accurate for networks composed of both linear and nonlinear pipe types.Aaron C. Zecchin, Martin F. Lambert and Angus R. Simpso
Erratum to: Sub-gap defect density characterization of molybdenum oxide: An annealing study for solar cell applications (Nano Research, (2020), 13, 12, (3416-3424), 10.1007/s12274-020-3029-9)
No full textRef. [56] was unfortunately wrong, Instead of [56] Corless, R. M.; Gonnet, G. H.; Hare, D. E. G.; Jeffrey, D. J.; Knuth, D. E. On the Lambert W function. Adv. Comput. Math. 1996, 5, 329–359. It should be changed to Biswas, R. K.; Khan, P.; Mukherjee, S.; Mukhopadhyay, A. K.; Ghosh, J.; Muraleedharan, K. Study of short range structure of amorphous Silica from PDF using Ag radiation in laboratory XRD system, RAMAN and NEXAFS. J. Non. Cryst. Solids 2018, 488, 1–9. Some entries in Table 2 were unfortunately misprinted.Photovoltaic Materials and DevicesElectrical Sustainable Energ
Informal gold mining and mercury pollution in Brazil
Get PDFThe Amazon region has been responsible for a major share of Brazilian gold production in recent years. The region has witnessed a sizable gold rush comparable only to the California gold rush last century. The gold rush has spawned a powerful informal mining sector and has attracted many people - some who have come to the region in search of wealth and some who were already there but were displaced from other, unsuccessful economicactivities. What these people encounter at the mining sites are dreadful living and working conditions. Gold mining also causes substantial environmental problems, which may persist whether gold deposits do or not. The author discusses the environmental effects of gold mining in the region, focusing on mercury pollution. Mercury, an important input in gold extraction, is being discharged into the atmosphere and the rivers at alarming rates. The environmental costs of the present extraction, is being discharged into the atmosphere and the rivers at alarming rates. The environmental costs of the present extraction technology will be faced primarily by future generations, because of natural chemical processes. Although removing the mercury already discharged from the Amazonian environment may be an enormous task, at least future discharges should be curtailed through the use of appropriate technology, environmental education, and a combination of command and control measures and market-based incentives. The author describes the gold extraction process and the extent of mercury use and contamination. He analyzes key elements of the environmental problem, especially the informal miner and the fish economy. Finally, he suggests a combination of command and control regulations and market-based incentives adapted to the informal gold mining economic environment. He emphasizes the need for an education campaign about the perils of using mercury and the availability of more appropriate, and inexpensive, alternative extraction technologies.Mining&Extractive Industry (Non-Energy),Montreal Protocol,Water and Industry,Coastal and Marine Resources,Primary Metals
"R-BEST" Rationale: Impact of a Research Based Elementary Science Teaching Rationale Paper on Beginning Elementary Teachers
No full textThe first year of elementary teaching can be overwhelming, often resulting in a decline in teachers’ sense of their own effectiveness. Teaching science in particular can be difficult for newcomers, as they may feel unfit to teach a difficult topic with which they may have little experience. Some researchers have suggested that a research-based rationale, understood as a statement of purpose, strategy, goals, and evaluation, can make teachers more confident and increase their self-efficacy. This paper asks what impact a research-based elementary science teaching (R-BEST) rationale has on a teacher’s first year of teaching elementary science and what improvements could be made with this assessment method at the pre-service level so that the impact can be made greater. The author interviewed first year teachers who completed an elementary science methods course in Fall 1996 to obtain their views on the effectiveness of the R-Best rationale which they had to write to complete the course. Demographic data was collected and participants were asked open-ended questions so they could identify what was most important to them. A majority of respondents thought the assignment of writing and defending an R-BEST rationale paper was beneficial to them and had a strong impact on how they viewed and taught science. A majority of respondents also felt comfortable in teaching science and had high self-confidence.SUNY BrockportEducation and Human DevelopmentMaster of Science in Education (MSEd)Education and Human Development Master's These
Continental reworking during overprinting orogenic events, southern Prince Charles Mountains, east Antarctica
No full text© The Author 2009. Published by Oxford University Press. All rights reserved.In situ electron microprobe monazite dating and mineral equilibria modelling of amphibolite-granulite-facies metapelites from the southern Prince Charles Mountains, East Antarctica has been carried out to unravel the P-T conditions, spatial extent and structural style of two overprinting orogenic records. This study shows that: (1) rocks of the northern Palaeoproterozoic Lambert Complex were pervasively reworked at peak conditions (6·5-7·1 kbar and 790-810°C) during the Early Neoproterozoic Rayner orogenic event; (2) rocks of the southern Lambert Complex experienced pervasive deformation and metamorphism at peak conditions (5·8-6·1 kbar and 625-635°C) during Early Palaeozoic Prydz orogenic activity; (3) in regions of the Lambert Complex reworked during the Rayner orogenic event, Prydz-aged orogenesis was highly localized. The distribution of orogenic activity pertaining to the Rayner and Prydz orogenic events in the southern Prince Charles Mountains can be attributed to (1) the development of a southward directed (current coordinates) orogenic front that propagated from an Early Neoproterozoic collision between India and Antarctica, and (2) rock fertility (i.e. availability of free fluid) during Early Palaeozoic intraplate orogenesis that was driven by far-field stresses generated by a collision of India-Antarctica with the Mawson Craton. © The Author 2009. Published by Oxford University Press. All rights reserved.G. Phillips, D. E. Kelsey, A. F. Corvino and R. A. Dutc
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