Toshihiro Sakamoto

Learn More
a r t i c l e i n f o A crop yield estimation model using time-series MODIS WDRVI was developed. The main feature of the proposed model is the incorporation of crop phenology detection using MODIS data, called the " Shape-Model Fitting Method ". MODIS WDRVI taken 7–10 days before the corn silking stage had strong linear correlation with corn final grain(More)
[1] Water column stratification increased at climatic transitions from cold to warm periods during the late Quaternary and led to anoxic conditions and sapropel formation in the deep eastern Mediterranean basins. High-resolution data sets on sea-surface temperatures (SST) (estimated from U 37 k 0 indices) and d 18 O of planktonic foraminifer calcite (d 18 O(More)
In this study, an inexpensive camera-observation system called the Crop Phenology Recording System (CPRS), which consists of a standard digital color camera (RGB cam) and a modified near-infrared (NIR) digital camera (NIR cam), was applied to estimate green leaf area index (LAI), total LAI, green leaf biomass and total dry biomass of stalks and leaves of(More)
statistics district level. In particular, the annual changes in the spatiotemporal patterns of the estimated silking stage had a high level of agreement with those of the NASS-derived statistics. These results suggested that the TSF method could provide local-scale information of corn phenological stages, which had an advantage over the NASS-derived(More)
We developed a crop scheduling model for rice cultivation in the Vietnam Mekong Delta (VMD), focusing on the adaptive behavior of crop planning to various water resource constraints. In addition, we also examined the effects of environmental change on rice cultivation in the last decade. In the VMD, multiple rice cropping is practiced under a variety of(More)
In migration analysis of the brown planthopper, Nilaparvata lugens (Stål), in a tropical region, it is difficult to know the arrival timing of the immigrants because rice plants in different growth stages are simultaneously cultivated, and local insects may already occur in destination areas. Due to this analytical difficulty, additional information is(More)
We discovered naturally collimated beam of surface acoustic wave (SAW) on balls and developed ball SAW sensor. It has an unique advantage of ultra-multiple roundtrips more than 100 turns. We achieved for the first time, sensing range of hydrogen from 10 ppm (0.001%) to 100 % with a single sensor element, essential for hydrogen stations fuel cell(More)
The taxonomy of optical emission detected during the critical first few minutes after the onset of a γ-ray burst (GRB) defines two broad classes: prompt optical emission correlated with prompt γ-ray emission 1 , and early optical afterglow emission uncorrelated with the γ-ray emission 2. The standard theoretical interpretation attributes prompt emission to(More)
We developed a new layer structure of domain wall displacement detection (DWDD) optimized for a blue laser diode (LD) and confirmed that acceptable characteristics could be obtained. We tested readout and recording with a blue LD on this DWDD disk and confirmed that the jitter did not exceed 15% for bit lengths longer than 0.125 /spl mu/m at the track pitch(More)
  • 1