Multi-Layer Distributed Storage of LHD Plasma Diagnostic Database

At the end of LHD experimental campaign in 2003, the amount of whole plasma diagnostics raw data had reached 3.16 GB in a long-pulse experiment. This is a new world record in fusion plasma experiments, far beyond the previous value of 1.5 GB/shot. The total size of the LHD diagnostic data is about 21.6 TB for the whole six years of experiments, and it continues to grow at an increasing rate. The LHD diagnostic database and storage system, i.e. the LABCOM system, has a completely distributed architecture to be sufficiently flexible and easily expandable to maintain integrity of the total amount of data. It has three categories of the storage layer: OODBMS volumes in data acquisition servers, RAID servers, and mass storage systems, such as MO jukeboxes and DVD-R changers. These are equally accessible through the network. By data migration between them, they can be considered a virtual OODB extension area. Their data contents have been listed in a “facilitator” PostgreSQL RDBMS, which now contains about 6.2 million entries, and informs the optimized priority to clients requesting data. Using the “glib” compression for all of the binary data and applying the three-tier application model for the OODB data transfer/retrieval, an optimized OODB read-out rate of 1.7 MB/s and effective client access speed of 3?25 MB/s have been achieved. As a result, the LABCOM data system has succeeded in combination of the use of RDBMS, OODBMS, RAID, and MSS to enable a virtual and always expandable storage volume, simultaneously with rapid data access

Effect of the particle brush on polishing performance of surface magnetic polishing using slurry circulation system

ArticleProceedings of the 6th international conference on progress of machining technology. CHEN D. NARUTAKI N. YAMANE. YCHEN W. OCHI A. ed. Xi’an in China, 2002-09, AVIATION INDUSTRY PRESS， 334-339 (2002)conference pape

Study on particle-brush in magnetic field assisted machining : Finishing characteristics of grooves

ArticleProceedings of International Conference on Leading Edge Manufacturing in 21st Century (LEM21). Niigata in Japan, 2003-11, The Japan Society of Mechanical Engineers，385-390(2003)conference pape

Nonstop Lose-Less Data Acquisition and Storing Method for Plasma Motion Images

Plasma diagnostic data analysis often requires the original raw data as they are, in other words, at the same frame rate and resolution of the CCD camera sensor. As a non-interlace VGA camera typically generates over 70 MB/s video stream, usual frame grabber cards apply the lossy compression encoder, such as mpeg-1/-2 or mpeg-4, to drastically lessen the bit rate. In this study, a new approach, which makes it possible to acquire and store such the wideband video stream without any quality reduction, has been successfully achieved. Simultaneously, the real-time video streaming is even possible at the original frame rate. For minimising the exclusive access time in every data storing, it has adopted the directory structure to hold every frame files separately, instead of one long consecutive file. The popular ‘zip’ archive method improves the portability of data files, however, the JPEG-LS image compression is applied inside by replacing its intrinsic deflate/inflate algorithm that has less performances for image data