Micromachined High-Aspect-Ratio Parylene Spring and Its Application to Low-Frequency Accelerometers

A new microfabrication technology for high-aspect-ratio parylene structure has been developed for soft spring applications. Free-standing parylene beams with widths of 10–40 µm and aspect ratios of 10–20 have been successfully fabricated. Since parylene has a small Young's modulus, a high-aspect-ratio beam with a spring constant of the order of 1 × 10^(-3) N/m has been realized. The large yield strain of parylene enables a test structure to have a large-amplitude oscillation of 600 µm_(p-p), without any failure of the high-aspect-ratio springs. An early prototype of in-plane capacitive accelerometer was also developed. It was found that its resonant frequency is as low as 37 Hz, and the noise spectral density is 64 µg/(Hz)^(0.5)

MHV amplitudes at strong coupling and linearized TBA equations

The maximally helicity violating (MHV) amplitudes of ${\cal N} =4$ super Yang-Mills theory at strong coupling are obtained by solving auxiliary thermodynamic Bethe ansatz (TBA) integral equations. We consider a limit where the TBA equations are linearized for large chemical potentials and masses therein. By solving the linearized equations, we derive analytic expansions of the 6-point MHV amplitudes in terms of the ratio of the chemical potential $A$ and the mass $M$. The expansions are valid up to corrections exponentially small in $A$ or inversely proportional to powers of $A$. The analytic expansions describe the amplitudes for small conformal cross-ratios of the particle momenta in a standard basis, and interpolate the amplitudes with equal cross-ratios and those in soft/collinear limits. The leading power corrections are also obtained analytically. We compare the 6-point rescaled remainder functions at strong coupling and at 2 loops for the above kinematics. They are rather different, in contrast to other kinematic regions discussed in the literature where they are found to be similar to each other.Comment: 41 pages, 9 figures; (v2) a reference added, typos corrected, minor revision

Strategy towards the "Big Bang": The Industrial Bank of Japan's approach

The Japanese “Big Bang” is a broad reform plan for Japan’s financial system announced in November 1996 by Prime Minister Ryutaro Hashimoto. The goal of this ambitious financial liberalization plan is to revamp Japan’s financial markets and industry which have been adversely affected by the bursting of the bubble economy or, in other words, to make Tokyo an international market comparable to those of New York and London by the year 2001

Quantum Wronskian approach to six-point gluon scattering amplitudes at strong coupling

We study the six-point gluon scattering amplitudes in N=4 super Yang-Mills theory at strong coupling based on the twisted Z_4-symmetric integrable model. The lattice regularization allows us to derive the associated thermodynamic Bethe ansatz (TBA) equations as well as the functional relations among the Q-/T-/Y-functions. The quantum Wronskian relation for the Q-/T-functions plays an important role in determining a series of the expansion coefficients of the T-/Y-functions around the UV limit, including the dependence on the twist parameter. Studying the CFT limit of the TBA equations, we derive the leading analytic expansion of the remainder function for the general kinematics around the limit where the dual Wilson loops become regular-polygonal. We also compare the rescaled remainder functions at strong coupling with those at two, three and four loops, and find that they are close to each other along the trajectories parameterized by the scale parameter of the integrable model.Comment: 30 pages, 8 figures; (v2) a reference adde

Aging, Saving, and Public Pensions in Japan

We analyze the impact of population aging on Japan's household saving rate and on its public pension system and the impact of that system on Japan's household saving rate and obtain the following results: first, the age structure of Japan's population can explain the level of, and past and future trends in, its household saving rate; second, the rapid aging of Japan's population is causing Japan's household saving rate to decline and this decline can be expected to continue; third, the pay-as-you-go nature of the public pension system, combined with rapid population aging, created considerable intergenerational inequities and increased the saving rates of cohorts born after 1965, which in turn slowed the decline in Japan's household saving rate; and fourth, the 2004 public pension reform alleviated the intergenerational inequities of Japan's public pension system somewhat but will in the long run exacerbate the downward trend in Japan's household saving rate.

Aging, Saving, and Public Pensions in Japan

We analyze the impact of population aging on Japan's household saving rate and on its public pension system and the impact of that system on Japan's household saving rate and obtain the following results: first, the age structure of Japan's population can explain the level of, and past and future trends in, its household saving rate; second, the rapid aging of Japan's population is causing Japan's household saving rate to decline and this decline can be expected to continue; third, the pay-as-you-go nature of the public pension system, combined with rapid population aging, created considerable intergenerational inequities and increased the saving rates of cohorts born after 1965, which in turn slowed the decline in Japan's household saving rate; and fourth, the 2004 public pension reform alleviated the intergenerational inequities of Japan's public pension system somewhat but will in the long run exacerbate the downward trend in Japan's household saving rate.

Aquaporin-4 Functionality and Virchow-Robin Space Water Dynamics: Physiological Model for Neurovascular Coupling and Glymphatic Flow.

The unique properties of brain capillary endothelium, critical in maintaining the blood-brain barrier (BBB) and restricting water permeability across the BBB, have important consequences on fluid hydrodynamics inside the BBB hereto inadequately recognized. Recent studies indicate that the mechanisms underlying brain water dynamics are distinct from systemic tissue water dynamics. Hydrostatic pressure created by the systolic force of the heart, essential for interstitial circulation and lymphatic flow in systemic circulation, is effectively impeded from propagating into the interstitial fluid inside the BBB by the tightly sealed endothelium of brain capillaries. Instead, fluid dynamics inside the BBB is realized by aquaporin-4 (AQP-4), the water channel that connects astrocyte cytoplasm and extracellular (interstitial) fluid. Brain interstitial fluid dynamics, and therefore AQP-4, are now recognized as essential for two unique functions, namely, neurovascular coupling and glymphatic flow, the brain equivalent of systemic lymphatics

Ridge Regression, Hubness, and Zero-Shot Learning

This paper discusses the effect of hubness in zero-shot learning, when ridge regression is used to find a mapping between the example space to the label space. Contrary to the existing approach, which attempts to find a mapping from the example space to the label space, we show that mapping labels into the example space is desirable to suppress the emergence of hubs in the subsequent nearest neighbor search step. Assuming a simple data model, we prove that the proposed approach indeed reduces hubness. This was verified empirically on the tasks of bilingual lexicon extraction and image labeling: hubness was reduced with both of these tasks and the accuracy was improved accordingly.Comment: To be presented at ECML/PKDD 201

Micromachined high-aspect-ratio parylene beam and its application to low-frequency seismometer

A new microfabrication technology for high-aspect-ratio Parylene structure is developed for soft spring applications and applied to in-plane seismometer which covers low frequency (<1 Hz) and small acceleration range. Parylene beams having 10-40 /spl mu/m wide and an aspect ratio of 10-30 were successfully fabricated. Since Parylene has a small Young's modulus and is non-brittle material, high-aspect-ratio robust beam having spring constant on the order of 1 x 10^(-3) N/m was realized. A prototype capacitive seismometer was also made, and its resonant frequency and noise spectral density was respectively measured to be 37 Hz and 45 µg / √Hz Since the Brownian noise is only 25 ng µg / √Hz, seismometer having much lower noise floor may be feasible using this new technology