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On the Efficacy of Fourier Series Approximations for Pricing European Options  [PDF]
A. S. Hurn, K. A. Lindsay, A. J. McClelland
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.517267
Abstract: This paper investigates several competing procedures for computing the prices of vanilla European options, such as puts, calls and binaries, in which the underlying model has a characteristic function that is known in semi-closed form. The algorithms investigated here are the half-range Fourier cosine series, the half-range Fourier sine series and the full-range Fourier series. Their performance is assessed in simulation experiments in which an analytical solution is available and also for a simple affine model of stochastic volatility in which there is no closed-form solution. The results suggest that the half-range sine series approximation is the least effective of the three proposed algorithms. It is rather more difficult to distinguish between the performance of the half-range cosine series and the full-range Fourier series. However there are two clear differences. First, when the interval over which the density is approximated is relatively large, the full-range Fourier series is at least as good as the half-range Fourier cosine series, and outperforms the latter in pricing out-of-the-money call options, in particular with maturities of three months or less. Second, the computational time required by the half-range Fourier cosine series is uniformly longer than that required by the full-range Fourier series for an interval of fixed length. Taken together, these two conclusions make a case for pricing options using a full-range range Fourier series as opposed to a half-range Fourier cosine series if a large number of options are to be priced in as short a time as possible.
Distal locking in femoral intramedullary nailing system: Is one cross screw sufficient?  [PDF]
S. V. Karuppiah, A. J. Johnstone
Journal of Biomedical Science and Engineering (JBiSE) , 2012, DOI: 10.4236/jbise.2012.510073
Abstract: Introduction: The indications for intramedullary nail fixation of fractures of the femoral shaft have been greatly expanded by techniques of interlocking nailing. However, distal locking screw fixation remains the most technically demanding and problematic portion of the procedure and maybe responsible for as much as one-half of the exposure of the surgeon’s hands to radiation during the procedure. Objective: This biomechanical study was undertaken to compare the stability of using one distal locking cross screw versus two cross screws in femoral fractures fixed with intramedullary nailing (IMN) system. Materials: A composite model made from a stainless steel IMN (12 mm × 1 mm) was connected to a load cell (Instron machine). Axial forces upto 2 kN (3 times body weight) was applied or until a maximum displacement of 1 mm was reached. The distal locking end of the intramedullary nail was secured with stainless steel cylinders of different dimensions 50 mm × 5 mm, 75 mm × 5 mm and 100 mm × 3 mm to represent the proximal femoral diaphysis, diaphyseo-metaphyseal junction and distal femoral metaphyseal respectively. The distal locking end of the intramedullary nail was attached to the cylinder with a dedicated single or two rods (5 mm diameter), made from stainless steel, to represent the distal locking cross screw. Results: In the 50 mm cylinder, the mean stiffness (±standard deviation) of the system using either single or two screws were similar i.e. 3298 ± 144 N/mm. But in the 75 mm and 100 mm cylinders, the mean stiffness of the fracture model with two distal locking cross screws fixation was 2.059 ± 96 N/mm and 0.816 ± 122 N/mm and with single distal locking cross screw fixation were 0.643 ± 142 N/mm and 0.289 ± 88 N/mm respectively. Conclusion: Single distal locking cross screw fixation provide poorer fracture stability compared to two distal locking cross screws when used to fix distal femoral metaphyseal fractures.
On the Real Einstein Beauty E = Kmc2  [PDF]
A. J. Babchin, M. S. El Naschie
World Journal of Condensed Matter Physics (WJCMP) , 2016, DOI: 10.4236/wjcmp.2016.61001
Abstract: The paper suggests that E = mc2 may be open to misinterpretation and that in this form it is not what Einstein advanced first. It is further suggested to return to the slightly less compact formula E = Kmc2 where a < K < 1 which has the merit of accounting for the measured ordinary energy density of the cosmos (K = 1/22) and the conjectured missing dark energy density of the universe (K = 21/22) from the view point of economical notation.
Enhanced Spore Production of Bacillus subtilis Grown in a Chemically Defined Medium  [PDF]
S. M. S. Monteiro, J. J. Clemente, M. J. T. Carrondo, A. E. Cunha
Advances in Microbiology (AiM) , 2014, DOI: 10.4236/aim.2014.48049
Abstract: Spores of Bacillus subtilis are being used as probiotics and competitive exclusion agents for animal consumption. Commercial production media often include relatively expensive components of animal origin that are a potential source for the presence of adventious agents, therefore undesirable for use in production scale. In this study a new animal-free component, chemically defined medium, was tested for B. subtilis spore production. Medium composition was optimized with respect to vitamin composition, carbon, nitrogen and calcium concentrations. A fed-batch bioprocess was developed, being the effect on sporulation of the carbon to nitrogen ratio at the end of the exponential growth phase studied. The developed strategy consisted of an initial and a final batch phase and an intermediate fed-batch phase with the addition of a feeding solution containing glucose and calcium and the addition of a feeding solution of ammonium sulphate, using an exponential and a constant feeding profile, respectively. Using the fed-batch strategy, it was possible to achieve a maximum spore production of 3.6 × 1010 spores/mL, corresponding to a 5 folds increase when compared to the preliminary batch experiments.
Evaluation of Multiusers’ Interference on Radiolocation in CDMA Cellular Networks  [PDF]
A. J. Bamisaye, M. O. Kolawole, V. S. A. Adeloye
Wireless Sensor Network (WSN) , 2010, DOI: 10.4236/wsn.2010.22013
Abstract: Radiolocation has been previously studied for CDMA networks, the effect of Multiple Access Interference has been ignored. In this paper we investigate the problem of Radiolocation in the presence of Multiple Access Interference. An extensive simulation technique was developed, which measures the error in location estimation for different network and user configurations. We include the effects of lognormal shadow and Rayleigh fading. Results that illustrate the effects of varying shadowing losses, number of base stations involved in position location, early-late discriminator offset and cell sizes in conjunction with the varying number of users per cell on the accuracy of radiolocation estimation was presented.
Short term effects of fire intensity and fire regime on vegetation dynamic in a tropical humid savanna (Lamto, central Côte d’Ivoire)  [PDF]
A. B. N’Dri, J. Gignoux, A. Dembele, S. Konate
Natural Science (NS) , 2012, DOI: 10.4236/ns.2012.412134
Abstract: We tested the effects of different fire regimes (with different fire date and fuel load) on grass growth, tree debarking and topkill in a Guinea savanna of West Africa. Different fire intensities were simulated on two plots of 3.72 ha each, delimited in two shrubby savanna of the Lamto reserve (C?te d’Ivoire). Two fire regimes were applied, the mid-season fire (January) and the late fire (April). Two fuel levels (single: C1 and double: C2) have been used. For each fire regime, fire intensity was determined. It increases with the fuel quantity (1259 ± 356 kW·m–1 and 3380 ± 1472 kW·m–1 respectively for C1 and C2). The regrowth speed of grasses is also dependent on the fuel quantity (grasses). It increases with it and is higher after the mid-season fire than the late fire. The average intensity of the mid-season fire (2966 ± 2233 kW·m–1) is not significantly different from that of the late fire (1673 ± 1124 kW·m–1). Damages or debarking caused by fire on adult trees were recorded and are linked to fire intensity. Those damages appear to initiate the external cavity observed on trees, known to be detrimental to tree trunk mechanical resistance. They generally affect adult trees of Crossopteryx febrifuga species which is also the most commonly hollowed species. Mid-season fire remains the recommanded fire regime because it insures a faster regrowth of grasses which leads to the maintenance of equilibrium between grasses and trees.
Seed Germination and Effects of Three Watering Regimes on the Growth of Dialium guineense (Wild) Seedlings  [PDF]
O. Olajide, A. A. Oyedeji, G. S. Tom, J. Kayode
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.520321
Abstract: The effectiveness of three pre-germination treatments in breaking dormancy of the seeds of Dialum guineense and effects of three watering regimes on the growth performance of the seedlings were investigated. The pre-germination treatments were: soaking in hot water for 10 seconds and cooling down in cold water (T1), soaking in cold water for 24 hours (T2), soaking in running water for 48 hours (T3) and control (T4), while watering regimes include: watering once daily in the morning (W1), watering once every two days in the morning (W2) and watering once every three days in the morning (W3). The results showed that germination occurred first at 5 days after sowing (5 DAS) among the seeds soaked in cold water for 24 hours before sowing (T2), while the untreated seeds (control) took the longest period of 12 days before germination occurred. T1 had the highest germination value of 49.6% while T3 had the least of 31.2%. The effects of watering regimes were found to be significantly different on stem-collar diameter, leaf area and total dry weight (P < 0.05). The least significant difference (LSD) test showed that W2 and W3 supported the best growth performance. It is concluded from the results that T2
Fabrication of End Quenched Machine: Hardenability Evaluation  [PDF]
A. A. Yekinni, J. O. Agunsoye, S. A. Bello, I. O. Awe, S. I. Talabi
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2014, DOI: 10.4236/jmmce.2014.22014
Abstract: The Jominy end quench machine was designed, manufactured and tested. The manganese steel was developed. The as-cast manganese steels were quenched in water at different austenising temperatures and hardenability test was carried out on the samples cut at different distances from the quenched surface with the use of the manufactured Jominy end quench machine. The optical microscope was used to investigate the microstructure of the cut samples. Results revealed that the Jominy end quench machine worked effectively with short cycle time and improved water management system. The extremely rapid cooling prevents the decomposition of the chromium carbides. However, the hardness values of the samples decreased with increase in the distance from the quenched surface and the size of the chromium carbides increased with austentic temperatures which is responsible for reduction in the hardness values of the quenched samples at higher austentinic temperature. The manufactured Jominy end quench machine has advantages of improved water management system and short processing time over the existing ones.
Alternative dark energy models: an overview
Lima, J. A. S.;
Brazilian Journal of Physics , 2004, DOI: 10.1590/S0103-97332004000200009
Abstract: a large number of recent observational data strongly suggest that we live in a flat, accelerating universe composed of ~ 1/3 of matter (baryonic + dark) and ~ 2/3 of an exotic component with large negative pressure, usually named dark energy or quintessence. the basic set of experiments includes: observations from sne ia, cmb anisotropies, large scale structure, x-ray data from galaxy clusters, age estimates of globular clusters and old high redshift galaxies (ohrg's). it is now widely believed that such results provide the remaining piece of information connecting the inflationary flatness prediction (wt = 1) with astronomical observations. from a theoretical viewpoint, they have also stimulated the current interest for more general models containing an extra component describing this unknown dark energy, and simultaneously accounting for the present accelerating stage of the universe. in this review we present a simplified picture of the main results and discuss briefly some difficulties underlying the emerging dark energy paradigm.
CAMBIOS EN LA DISTRIBUCIóN Y ABUNDANCIA DE LAS GARRAPATAS Y SU RELACIóN CON EL CALENTAMIENTO GLOBAL
Cortés,J. A;
Revista de la Facultad de Medicina Veterinaria y de Zootecnia , 2010,
Abstract: the climatic change could be affect the frequency and distribution of the vector populations, like ticks, in many different places around the world, nowadays. nevertheless, there is a number of factors explaining changes in the incidences of vector-borne diseases, e.g., rapid growth of human population, socio-economic conditions, changes of landscape, and international trading. i am presenting basic concepts about changes of the climate in a biological and epidemiological context. it has been documented that microorganisms transmission rates are higher with shorter life cycles of ticks. i am hereby presenting the main strategies designed to limit migration and abundance of tick populations. although tick control within farm animals uses chemical acaricides, several strategies could be added by an integrated pest management program. it poses an effective and sustainable alternative.
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