Extracting the cutoff frequency in the gravitational-wave spectrum of black hole-neutron star mergers

The location of the cutoff in the gravitational-wave spectrum of black hole-neutron star mergers is correlated strongly with the neutron-star radius for the case that the neutron star is disrupted by the black hole during the merger. However, the modulation which appears in the spectrum due to the mode mixing makes it difficult to measure the cutoff frequency if gravitational waves are observed from inclined direction or the binary is precessing. In this letter, we show that the cutoff frequency can be measured even in such situations with a method we have recently proposed to reconstruct the face-on waveforms only from the strain observed from a particular direction. We show that the systematic error in the measurement of the neutron-star radius can be reduced to $\lesssim 5\%$ for the case that tidal disruption of the neutron star occurs significantly.Comment: 6 pages, 2 figure

Extracting the orbital axis from gravitational waves of precessing binary systems

We present a new method for extracting the instantaneous orbital axis only from gravitational wave strains of precessing binary systems observed from a particular observer direction. This method enables us to reconstruct the co-precessing frame waveforms only from observed quantities for the ideal case that the signal-to-noise ratio is high enough to analyze the waveforms directly. Specifically, we do not assume knowledge of the time evolution of the instantaneous orbital axis and the co-precessing waveforms before analyzing the data in our method. We test and measure the accuracy of our method using the numerical relativity simulation data of precessing binary black holes taken from the SXS Catalog. We show that the direction of the orbital axis is extracted within $\approx0.02~{\rm rad}$ error from gravitational waves emitted during the inspiral phase. The co-precessing waveforms are also reconstructed with high accuracy; the mismatch (assuming white noise) between them and the original co-precessing waveforms is typically a few times $10^{-3}$ including the merger-ringdown phase, and can be improved by an order of magnitude focusing only on the inspiral waveform. In this method, the co-precessing frame waveforms are not only the purely technical tools for understanding the complex nature of precessing waveforms but also direct observables.Comment: 12 pages, 8 figures, 1 table, published in PR

Design of a Taxation System to Promote Electric Vehicles in Singapore

Part 2: Design, Manufacturing and Production Management; International audience; Electric vehicles offer a potential low-carbon alternative to todays gasoline-powered vehicles. In line with global trends, Singapore has expressed interest in promoting electric vehicles on its shores. This paper investigates the effects of taxation, namely tax rebates and carbon taxes, on the penetration of electric vehicles in Singapore. A consumer vehicular preference model was constructed using the logit model, and the effects on the economy determined through an inputoutput analysis. Multi-objective optimization is then used to find the optimal tax rate. Results indicate that a tax rebate minimizes the negative impact on the economy at a low penetration rate of electric vehicles, whereas a carbon tax minimizes the negative impact on GDP at a high penetration rate of above 60%. Document type: Part of book or chapter of boo

Efficacy of FimA antibody and clindamycin in silkworm larvae stimulated with Porphyromonas gulae

Objective: Porphyromonas gulae, a major periodontal pathogen in animals, possesses fimbriae that have been classified into three genotypes (A, B, C) based on the diversity of fimA genes encoding fimbrillin protein (FimA). P. gulae strains with type C fimbriae were previously shown to be more virulent than other types. In this study, we further examined the host toxicity mediated by P. gulae fimbriae by constructing recombinant FimA (rFimA) expression vectors for each genotype and raised antibodies to the purified proteins. Methods and Results: All larvae died within 204 h following infection with P. gulae type C at the low-dose infection, whereas type A and B did not. Among fimA types, the survival rates of the larvae injected with rFimA type C were remarkably decreased, while the survival rates of the larvae injected with rFimA type A and type B were greater than 50%. Clindamycin treatment inhibited the growth of type C strains in a dose-dependent manner, resulting in an increased rate of silkworm survival. Finally, type C rFimA-speci?c antiserum prolonged the survival of silkworm larvae stimulated by infection with P. gulae type C strain or injection of rFimA type C protein. Conclusion: These results suggested that type C fimbriae have high potential for enhancement of bacterial pathogenesis, and that both clindamycin and anti-type C rFimA-specific antibodies are potent inhibitors of type C fimbriae-induced toxicity. This is the first report to establish a silkworm infection model using P. gulae for toxicity assessment

Cost Analysis of eVTOL Configuration Design for an Air Ambulances System in Japan

Electric-vertical-takeoff-and-landing (eVTOL) aircraft, known as urban air mobility or flying cars, are being considered for widespread use as air taxis, emergency medical transportation, sightseeing vehicles, and rural transportation, owing to their reduced-size, low-cost, and low-noise characteristics. In this study, we conduct an interview at a Japanese hospital that currently uses a helicopter for medical emergencies to output the mission profile. Due to current battery-technology limitations, the new air ambulance, which will deliver a doctor to a patient, is conceived as having 2 passengers, including the pilot. Two eVTOL configurations are studied: a fixed-wing craft and a multi-rotor. The purpose of this study is to develop a cost model for a new air ambulance through a combination of 3 approaches: top-down, bottom-up, and parametric. The cost model is constructed to analyze the production cost of each configuration, broken down into the capital expense and direct operating cost. The result shows that the multi-rotor’s production cost is lower than the fixed-wing craft. The direct operating cost of a fixed-wing craft at high flight hours is higher than that of the multi-rotor. Scenario analysis shows a result that the capacity difference of a battery has a significant difference in the cost in the years 2020 and 2030 due to the high cost of battery replacement

A Nonlinear Growth Analysis of Integrated Device Manufacturers' Evolution to the Nanotechnology Manufacturing Outsourcing

With the increasing cost of setting up a semiconductor fabrication facility, coupled with significant costs of developing a leading nanotechnology process, aggressive outsourcing (asset-light business models) via working more closely with foundry companies is how semiconductor manufacturing firms are looking to strengthen their sustainable competitive advantages. This study aims to construct a market intelligence framework for developing a wafer demand forecasting model based on long-term trend detection to facilitate decision makers in capacity planning. The proposed framework modifies market variables by employing inventory factors and uses a top-down forecasting approach with nonlinear least square method to estimate the forecast parameters. The nonlinear mathematical approaches could not only be used to examine forecasting performance, but also to anticipate future growth of the semiconductor industry. The results demonstrated the practical viability of this long-term demand forecast framework