Complex vortex flow patterns around bridge piers, especially during floods, cause scour process that can result in the failure of foundations. Abutment is a complex three-dimensional phenomenon difficult to predict with traditional formulas obtained using empirical approaches such as regressions. This paper presents test standalone Kstar model five novel hybrid algorithm bagging (BA-Kstar), dag...

KSTAR is an advanced tokamak with fully superconducting coils for the steady state research, which began in December 1995 and was completed in July 2008. As a single science project, it has been marked as the largest construction project in the history of Korea. During the construction period, we encountered several challenges, such as technical issues, cost overrun and schedule slippage. Never...

The neutral beam injection (NBI) system is designed to provide the ion heating and current drive for the high performance operation and long pulse operation of the Korean Superconducting Tokamak Advanced Research (KSTAR). The KSTAR NBI consists of two beam lines. Each beam line contains three ion sources of which one ion source has been designed to deliver more than 2.5 MW of deuterium neutral ...

Predictive modeling of KSTAR operation scenarios are performed with the aim of developing high performance steady state operation scenarios. Various transport codes are employed for this study. Firstly, steady state operation capabilities are investigated with time dependent simulations using a free-boundary transport code. Secondly, reproducibility of high performance steady state operation sc...

Accurate prediction of stable alluvial hydraulic geometry, in which erosion and sedimentation are equilibrium, is one the most difficult but critical topics field river engineering. Data mining algorithms have been gaining more attention this due to their high performance flexibility. However, an understanding potential for these provide fast, cheap, accurate predictions geometry lacking. This ...

The cryogenic system for the KSTAR superconducting magnets has been commissioned. It consists of a cold box, distribution boxes (DB) and cryogenic transfer lines. The cold box and DB #1 provide 600 g/s of supercritical helium to cool the superconducting (SC) magnets, their SC bus-lines, and the magnet support structures. It also provides 17.5 g/s of liquid helium to the current leads and suppli...

After the successful accomplishment of vacuum commissioning assisted by vacuum vessel baking and glow discharge cleaning, KSTAR had shifted to the cool-down phase in April 2, 2008 and completed cooling of all superconducting coils and structures down to the operation temperature of 4.5K for about a month by the helium refrigerator system with 9KW cooling capacity. For the next a month, all supe...

s. We show that strong edge magnetic shear which is generic to divertor plasmas makes the shearing of turbulence eddys in toroidal geometry more effective. From calculations of the shearing rates for KSTAR edge parameters, we conclude that the enhanced magnetic shear at the diverted KSTAR plasma edge facilitates shear suppression of turbulence and ensuing H-mode transition.

Four-array system of soft X-ray diagnostics was installed on KSTAR tokamak. Each array has 32 viewing chords of two photo-diode array detectors with spatial resolution of 2 cm. To estimate signals from the soft X-ray radiation power, typical ne, Te, and argon impurity line radiation profiles in KSTAR are chosen. The photo-diodes were absolutely calibrated as a function of the incident photon en...

KSTAR is an advanced tokamak with fully superconducting coils for the steady state plasma research. The detailed engineering design and infrastructure setup for R & D have been completed in 2001. In March 2008, after the construction period of seven years, the KSTAR assembly has been completed, by connecting the cryogenic transfer lines between the tokamak and the cryogenic distribution system....