Folding a Paper Strip to Minimize Thickness

In this paper, we study how to fold a specified origami crease pattern in order to minimize the impact of paper thickness. Specifically, origami designs are often expressed by a mountain-valley pattern (plane graph of creases with relative fold orientations), but in general this specification is consistent with exponentially many possible folded states. We analyze the complexity of finding the best consistent folded state according to two metrics: minimizing the total number of layers in the folded state (so that a "flat folding" is indeed close to flat), and minimizing the total amount of paper required to execute the folding (where "thicker" creases consume more paper). We prove both problems strongly NP-complete even for 1D folding. On the other hand, we prove the first problem fixed-parameter tractable in 1D with respect to the number of layers.Comment: 9 pages, 7 figure

Result of Space Particle Monitor (SPM) on-Orbit Demonstration

Space Particle Monitor (SPM) is a compact, lightweight and low-cost radiation measurement device that applies two PIN silicon semiconductor detectors. SPM was developed in the SERVIS (Space Environment Reliability Verification Integrated System) project under the Ministry of Economy, Trade and Industry (METI), and is mounted on JAXA RAPid Innovative payload demonstration Satellite 1 (RAPIS-1) launched in January 2019. We achieved the full success that the discrimination and energy content of electrons, protons, and heavy ions could be observed. This paper reports on-orbit demonstration results of SPM