Persistence of Natural Disasters on Children's Health: Evidence from the Great Kanto Earthquake of 1923

This study uses a catastrophic earthquake in 1923 to analyze the long-term effects of a one-off disaster on children's health. I find that fetal exposure to Japan's Great Kanto Earthquake had stunting effects on girls in the devastated area. Disaster relief spending helped remediate stunting among boys by late primary school ages, whereas it did not ameliorate girls' stunting, suggesting a biased remediation mechanism before birth and compensating investment after birth. While the maternal mental stress via strong vibrations played a role in the adverse health effects, the maternal nutritional stress via physical disruption also enhanced those effects

Relation of Origins of Primitive Chaos

A new concept, primitive chaos, was proposed, as a concept closely related to the fundamental problems of sciences themselves such as determinism, causality, free will, predictability, and time asymmetry [{\em J. Phys. Soc. Jpn.} {\bf 2014}, {\em 83}, 1401]. This concept is literally a primitive chaos in such a sense that it leads to the characteristic properties of the conventional chaos under natural conditions. Then, two contrast concepts, nondegenerate Peano continuum and Cantor set, are known as the origins of the primitive chaos. In this study, the relation of these origins is investigated with the aid of a mathematical method, topology. Then, we can see the emergence of interesting concepts such as the relation of whole and part, and coarse graining, which imply the essence of our intrinsic recognition for phenomena

Suppression of common-mode voltage in a PWM rectifier/inverter system

This paper proposes a PWM rectifier/inverter system capable of suppressing not only supply harmonic currents but also electromagnetic interference (EMI). An active common-noise canceler (ACC) developed for this system is characterized by sophisticated connection of a common-mode transformer which can compensate for common-mode voltages produced by both PWM rectifier and inverter. As a result, the size of the common-mode transformer can be reduced to 1/3, compared with the previously proposed ACC. A prototype PWM rectifier/inverter system (2.2 kW) has been implemented and tested. Some experimental results show reduction characteristics of the supply harmonic current and EMI</p