Resilience Science for a Resilient Society in Natural Disaster Prone Countries

Recently, many destructive natural disasters occurred in the world. Therefore, the damage reductions and disaster mitigation for resilient society are very important and significant. For the implementation of these issues, we propose the resilience science including science, engineering, medicine, and social science. In social science, there are sociology, economics, psychology, law, pedagogy, etc. After 2011 earthquake in East Japan in which severe tsunami damages in a broad area occurred, the reconstruction and restoration activities in each area have been done; however, the progress speeds are not so rapid generally. One of reasons in which delayed reconstruction and restoration occurred is the shortage of pre-recovery plan and concept of future community in each area. In this chapter, we propose the resilience science for resilient society. The resilience science is based on multidisciplinary research fields, and the resilient society is defined as the society equipped with redundancy, robustness, elasticity, and safety. Especially, human resource cultivation is very important in resilience science for the resilient society. For the bright future, the resilience science for the resilient society based on human resource cultivation is indispensable

Flight Performance of the AKARI Cryogenic System

We describe the flight performance of the cryogenic system of the infrared astronomical satellite AKARI, which was successfully launched on 2006 February 21 (UT). AKARI carries a 68.5 cm telescope together with two focal plane instruments, Infrared Cameras (IRC) and Far Infrared Surveyor (FIS), all of which are cooled down to cryogenic temperature to achieve superior sensitivity. The AKARI cryogenic system is a unique hybrid system, which consists of cryogen (liquid helium) and mechanical coolers (2-stage Stirling coolers). With the help of the mechanical coolers, 179 L (26.0 kg) of super-fluid liquid helium can keep the instruments cryogenically cooled for more than 500 days. The on-orbit performance of the AKARI cryogenics is consistent with the design and pre-flight test, and the boil-off gas flow rate is as small as 0.32 mg/s. We observed the increase of the major axis of the AKARI orbit, which can be explained by the thrust due to thermal pressure of vented helium gas.Comment: 19 pages, 10 figures, and 6 tables. Accepted for publication in the AKARI special issue of the Publications of the Astronomical Society of Japa