1,226 research outputs found
Toponogov comparison theorem for open triangles
Dedicated to Professor Gromoll: The aim of our article is to generalize the
Toponogov comparison theorem to a complete Riemannian manifold with smooth
convex boundary. A geodesic triangle will be replaced by an open (geodesic)
triangle standing on the boundary of the manifold, and a model surface will be
replaced by the universal covering surface of a cylinder of revolution with
totally geodesic boundary. Applications of our theorem are found in our article
"Applications of Toponogov's comparison theorems for open triangles"
(arXiv:1102.4156).Comment: This version 4 (36 pages, no figures) is a version to appear in
Tohoku Mathematical Journa
A Web application to estimate the climate change effects on agriculture in Thailand
A Web application was developed to estimate the effects of climate change on agriculture. We chose the northeast and north of Thailand as the target areas of this application, although most countries in the Asian monsoon region are agricultural areas. Northeastern Thailand is a rainfed farming area where rice and drought-tolerant crops are cultivated. Northern Thailand is a mountainous area where several types of vegetables are cultivated. The application identifies and recommends crops that can be grown based on the simulation results of a crop model DSSAT. The DSSAT was executed 365 times; the start date was moved forward one day each time. The effects of climate change were estimated by inputting meteorological data that reflects the influence of climate change. The most favorable start date and the yield are summarized and displayed as output. Application of this system to grid meteorological data required the shortening of execution time and handling a huge volume of data. These problems were solved using multithreading, StAX and Hadoop. The Web application with witch output data were presented was designed based on the assumption that it would be used by a farmer in the field with a 7-inch tablet.</jats:p
The 3-D image recognition based on fuzzy neural network technology
Three dimensional stereoscopic image recognition system based on fuzzy-neural network technology was developed. The system consists of three parts; preprocessing part, feature extraction part, and matching part. Two CCD color camera image are fed to the preprocessing part, where several operations including RGB-HSV transformation are done. A multi-layer perception is used for the line detection in the feature extraction part. Then fuzzy matching technique is introduced in the matching part. The system is realized on SUN spark station and special image input hardware system. An experimental result on bottle images is also presented
- …