This paper is about using range-only data to navigate an autonomous underwater vehicle (AUV). We assume the vehicle is equipped with conventional long base line (LBL) transceiver which measures acoustic time of flights (TOFs) between vehicle and small submerged transponders. Using only range data and no prior information other than approximate water column depth, we solve for both transponder l...

A nonlinear least squares fitting algorithm is used to estimate both snow depth and snow density for a snow-layer above a flat ground reflector. The product of these two quantities, snow depth and density, provides an estimate of the snow water equivalent. The input to this algorithm is a simple ray model that includes a speculary reflected signal along with a direct signal. These signals are t...

The ability of soil venting to inexpensively remove large amounts of volatile organic compounds (VOCs) from contaminated soils is well established. However, the time required using venting to remediate soils to low contaminant levels often required by state and federal regulators has not been adequately investigated. Most field studies verify the ability of a venting system to circulate air in ...

J. Burge, M. A. Peterson, and S. E. Palmer (2005) reported that an ordinal cue to depth can influence the perception of metric depth in stereoscopic displays. They argued that when a familiar figure--a face--is placed stereoscopically closer than a background there is greater perceived depth relative to the ground than when the face shape is placed stereoscopically further and becomes the groun...

Ground water and surface water create a range of problems in lignite mining utilizing surface mining methods. In order to create a safe and economic mining environment, it is essential to carry out mining after dewatering the rock mass surrounding the lignite mines by advance dewatering techniques. This paper briefly describes the ground water regimes including pressure gradients associated wit...

Chlorinated solvents are the most prevalent organic contaminants found in ground water (Stroo et al. 2003), and in the dissolved phase they are typically mobile and recalcitrant, particularly trichloroethylene (TCE) and tetrachloroethylene (PCE). Schwille (1984, 1988) was the first to recognize that chlorinated solvent plumes (i.e., zones of dissolved phase contaminants) are caused by immobile ...

to assess the pollution trend of southwest ground water aquifer of tehran by nitrite and nitrate, in february 1999, out of 300 wells within this area, 99 wells were selected according to simple random sampling without replacement, analysed by colorimetric and ultraviolet spectrophotometric screening standard methods, respectively. the conclusion asserted is that with a confidence limit of 95%, ...

The drops are used to control the descents,  stabilize the bed level, and control the upstream water level in sloping channels with less slope than the ground slope. The current study presents a numerical analysis of hydraulic characteristics in the vertical drop using computational fluid dynamics. At first, the laboratory models were used for verification and choosing the best model of turbule...