A System Development for Remote Sensing, and Interpretation for Rice Fields in the World Using Satellite Data

Remote Sensing Laboratory, Field Science Center, Graduate School of Agriculture Science, Tohoku University started at April 2004. For the studies and education at the laboratory we are now developing the system of remote sensing and GIS. Our system consists of ordinary PCs, one digitizer and one color laser printer. The PCs are assembled by us for the optimal performance and the low cost. Gigabit LAN connects each PC, and one PC is used as file server to store remote sensing images and GIS data such as digital maps, geocoded satellite images and digital elevation models (DEM). The file server has RAID system for safety storage from HD trouble. We use ARC/GIS as GIS software and many kinds of Remote Sensing software such as, ERDAS/Imagine, ENVI, eCognition, PG-Steamer and SILCAST. Using the developing system, we understand and teach for regional differences of agriculture especially with the interpretation of ASTER data analysis. A kind of project "Determination of Local Characteristics at Global Agriculture Using archive ASTER Data" was started at the middle of November 2005. We establish data processing system and get some results. Paddy rice fields analysis was started at first, we analyze 1) the Shonai Plains in Japan, 2) the Yangtze River delta in Middle-East China, 3) Mekong Delta in South Vietnam, 4) North-east Thai Plaines, Thailand, 5) Sacrament Valley, California, USA. The results of this studies are as follows, 1) Using ASTER images, we can easily understand agricultural characteristics of each local area. 2) ASTER data have high accuracy for location, and the accuracy is suitable for global study without the fine topographical maps, 3) By five years observation of ASTER, there are huge numbers of ASTER scenes, but not enough volumes for cloud free data for seasonal analysis. It means that follow-on program of ASTER is necessary, 4) We need not only paddy field, but also all crop fields and all area, 5) The studies are necessary to international corroboration.Original Pape

Dust from Comet 209P/LINEAR during its 2014 Return: Parent Body of a New Meteor Shower, the May Camelopardalids

We report a new observation of the Jupiter-family comet 209P/LINEAR during its 2014 return. The comet is recognized as a dust source of a new meteor shower, the May Camelopardalids. 209P/LINEAR was apparently inactive at a heliocentric distance rh = 1.6 au and showed weak activity at rh < 1.4 au. We found an active region of <0.001% of the entire nuclear surface during the comet's dormant phase. An edge-on image suggests that particles up to 1 cm in size (with an uncertainty of factor 3-5) were ejected following a differential power-law size distribution with index q=-3.25+-0.10. We derived a mass loss rate of 2-10 kg/s during the active phase and a total mass of ~5x10^7 kg during the 2014 return. The ejection terminal velocity of millimeter- to centimeter-sized particles was 1-4 m/s, which is comparable to the escape velocity from the nucleus (1.4 m/s). These results imply that such large meteoric particles marginally escaped from the highly dormant comet nucleus via the gas drag force only within a few months of the perihelion passage.Comment: 18 pages, 4 figures, accepted on 2014 December 11 for publication in the Astrophysical Journal Letter

Optical Properties of (162173) 1999 JU3: In Preparation for the JAXA Hayabusa 2 Sample Return Mission

We investigated the magnitude-phase relation of (162173) 1999 JU3, a target asteroid for the JAXA Hayabusa 2 sample return mission. We initially employed the international Astronomical Union's H-G formalism but found that it fits less well using a single set of parameters. To improve the inadequate fit, we employed two photometric functions, the Shevchenko and Hapke functions. With the Shevchenko function, we found that the magnitude-phase relation exhibits linear behavior in a wide phase angle range (alpha = 5-75 deg) and shows weak nonlinear opposition brightening at alpha< 5 deg, providing a more reliable absolute magnitude of Hv = 19.25 +- 0.03. The phase slope (0.039 +- 0.001 mag/deg) and opposition effect amplitude (parameterized by the ratio of intensity at alpha=0.3 deg to that at alpha=5 deg, I(0.3)/I(5)=1.31+-0.05) are consistent with those of typical C-type asteroids. We also attempted to determine the parameters for the Hapke model, which are applicable for constructing the surface reflectance map with the Hayabusa 2 onboard cameras. Although we could not constrain the full set of Hapke parameters, we obtained possible values, w=0.041, g=-0.38, B0=1.43, and h=0.050, assuming a surface roughness parameter theta=20 deg. By combining our photometric study with a thermal model of the asteroid (Mueller et al. in preparation), we obtained a geometric albedo of pv = 0.047 +- 0.003, phase integral q = 0.32 +- 0.03, and Bond albedo AB = 0.014 +- 0.002, which are commensurate with the values for common C-type asteroids.Comment: 27 pages, 4 figure, accepted for publication in the Astrophysical Journa

テレワーク ケンキュウ ドウコウ ブンセキ ニホン テレワーク ガッカイシ, 2002-2008 ネン

『テレワーク』が流行語となり、その潜在的な有効性が議論の的になったのは 1990年代の中頃であったが、それ以来、『テレワーク人口』は増加し続けている。このような背景のもと、テレワークの有効性に関する研究と実践方法の提言に関する牽引車としての役割を目的として日本テレワーク学会が設立されたのは1999年であった。学会の発行する学術誌で議論される問題は多岐に亘るため、議論の内容は日本におけるテレワークの全容を反映していると考えるられるだろう。そこで、本研究では、日本テレワーク学会誌における研究動向を分析することにより、日本におけるテレワークの実情を明らかにする。It was in the mid-1990s that the word "telework" became a vogue and its effectiveness and potential came under review in Japan. Since then the number of "teleworkers" has been increasing. Against such background Japan Telework Society has been established since 1999 to act as a vehicle for promoting broad-ranging research for assessing the effectiveness of telework programs and proposing the best practice on the telework. Because issues discussed in the articles published in their journal cover wide variety of topics, they may be considered to reflect the actual aspect of the telework in Japan. So, in this article, trends in issues discussed in the Journal of Japan Telework Society are figured out and an actual aspect of telework in Japan is discussed based on the results of the analysis