Nishimura K.,Research Organization of Information and Systems |
Nakamura T.,Japan National Institute of Polar Research |
Sato T.,Kyoto University |
Sato K.,University of Tokyo
Journal of Atmospheric and Oceanic Technology | Year: 2012
Aspect-sensitive backscattering of the atmosphere causes a small error in an effective line-of-sight direction in vertical beam observations leading to a serious degradation of vertical wind estimates due to contamination by horizontal wind components. An adaptive beamforming technique for a multichannel mesosphere-stratosphere- troposphere (MST) radar is presented, which makes it possible to measure the vertical wind velocity with higher accuracy by adaptively generating a countersteered reception beam against an off-vertically shifted echo pattern. The technique employs the norm-constrained direction-constrained minimization of power (NC-DCMP) algorithm, which provides not only robustness but also higher accuracy than the basic direction-constrained minimization of power algorithmin realistic conditions. Although the technique decreases the signal-to-noise ratio, the ratio is controlled and bound at a specified level by the norm constraint. In the case that a decrease of 23 dBis acceptable in a vertical beam observation, forwhich usually amuch higher signal-to-noise ratio is obtained than for oblique beams, the maximum contamination is suppressed to 1/10 even for themost imbalanced aspect sensitivity. © 2012 American Meteorological Society.
Tanaka Y.,Research Organization of Information and Systems |
Sakamoto Y.,Stevens Institute of Technology |
Honda H.,Japan National Food Research Institute
Proceedings of the Annual Hawaii International Conference on System Sciences | Year: 2014
Twitter is an example of social media, which allows its users to post text messages, known as "tweets," of up to 140 characters. A tweet can include a shortened URL that provides further information that cannot be included in the tweet. Does including URLs in tweets influence the forwarding of the tweets during disasters, in which social media is flooded with unverified information? We conducted an experiment to answer this question. The results showed that posting URLs in disaster-related tweets increased rumor-spreading behavior even though the URLs lacked the hyperlink function. We identified some psychological factors that could explain this effect. We conclude by discussing the vulnerability of social media to rumor transmission in light of our results. © 2014 IEEE.
Yamamoto Y.,Kyushu University |
Yamamoto Y.,Research Organization of Information and Systems |
Watanabe T.,Yale University |
Hoki Y.,Kyushu University |
And 11 more authors.
Genome Research | Year: 2013
In germ cells, early embryos, and stem cells of animals, PIWI-interacting RNAs (piRNAs) have an important role in silencing retrotransposons, which are vicious genomic parasites, through transcriptional and post-transcriptional mechanisms. To examine whether the piRNA pathway can be used to silence genes of interest in germ cells, we have generated knock-in mice in which a foreign DNA fragment was inserted into a region generating pachytene piRNAs. The knock-in sequence was transcribed, and the resulting RNA was processed to yield piRNAs in postnatal testes. When reporter genes possessing a sequence complementary to portions of the knock-in sequence were introduced, they were greatly repressed after the time of pachytene piRNA generation. This repression mainly occurred at the post-transcriptional level, as degradation of the reporter RNAs was accelerated. Our results show that the piRNA pathway can be used as a tool for sequence-specific gene silencing in germ cells and support the idea that the piRNA generating regions serve as traps for retrotransposons, enabling the host cell to generate piRNAs against active retrotransposons. © 2013, Published by Cold Spring Harbor Laboratory Press.
Research Organization Of Information And Systems and Sharp Corporation | Date: 2010-07-01
A video display system of the present invention includes (i) a projector that generates a display image in accordance with a digital video signal and (ii) a screen on which an image generated by the projector is projected and displayed. Provided behind the screen is an infrared-emitting unit that emits infrared light through a video display surface during a period of time in which a picture is being displayed on the screen. This allows invisible light to be emitted through a video display section such as a screen together with a displayed image, thereby degrading the image quality of a re-shot picture and rendering use of re-shot image content impossible.
Research Organization Of Information And Systems and Sharp Corporation | Date: 2011-02-25
Light other than visible light is emitted from a video image display section such as a screen, together with display images, so as to degrade image quality of illegally camcorded video images, thereby making it impossible to use the illegally camcorded image contents. A video image display system includes a projector that generates a display image; and a screen on which the image generated by the projector is projected and displayed. On a backside of the screen, there is provided an infrared ray emitting unit that emits infrared light from a video image display surface during a period while video images are being displayed on the screen. The infrared ray emitting unit includes a wavelength cut filter that substantially does not transmit a predetermined wavelength component close to a visible light region, among the light emitted from the infrared light source