EXACT ANALYSIS OF OS MODIFIED VERSIONS WITH NONCOHERENT INTEGRATION

This paper deals with the exact detection analysis of the Ordered-Statistic(OS) processor along with OS Greatest Of(OSGO) and OS Smallest Of(OSSO) modified versions, for M postdetection integrated pulses when the operating environment is nonhomogeneous. Analytical results are presented in multiple-target case as well as in regions of clutter power transitions. The primary and the secondary interfering targets are assumed to be fluctuating in accordance with the SWII target fluctuation model. As the number of noncoherently integrated pulses increases,lower threshold values and consequently better detection performances are obtained in both homogeneous and multiple target background models. However, the false alarm rate performance of OSSO-CFAR(Constant False Alarm Rate) scheme at clutter edges is worsen with increasing the postdetection integrated pulses. As predicted, the OSGO-CFAR detector accommodates the presence of spurious targets in the reference window, given that their number is within its allowable range in each local window, and controls the rate of false alarm when the contents of the reference cells have clutter boundaries.

NEW HMM ALGORITHM FOR TOPOLOGY OPTIMIZATION

A new hybrid MMA-MGCMMA （HMM） algorithm for solving topology optimization problems is presented. This algorithm combines the method of moving asymptotes （MMA） algorithm and the modified globally convergent version of the method of moving asymptotes （MGCMMA） algorithm in the optimization process. This algorithm preserves the advantages of both MMA and MGCMMA. The optimizer is switched from MMA to MGCMMA automatically, depending on the numerical oscillation value existing in the calculation. This algorithm can improve calculation efficiency and accelerate convergence compared with simplex MMA or MGCMMA algorithms, which is proven with an example.

Parameter evaluation for soil erosion estimation on small watersheds using SWAT model

This research was undertaken for the evaluation of soil erosion using the semi-distributed basin scale SWAT model for four subcatchments of the Dhrabi River Catchment(DRC),which is located in the Pothwar Plateau region.Two subcatchments(catchment-25 and-31)are characterized by gullies while the other two(catchment-27 and-32)are managed with terraced landuse system.The performance of the model was satisfactory with coefficient of determination(R^(2))=0.67 to 0.91 and Nash-Sutcliffe efficiency(ENS)=0.54 to 0.85 for both surface runoff and sediment yield during the calibration(2009-2010)and validation(2011)periods.The PUSLE factor was found to be the most sensitive parameter during model calibration.It was observed that all of the rainfall-runoff events occurred during the monsoon season(June to September).The estimated annual sediment loss ranged from 2.6 t/hm^(2) to 31.1 t/hm^(2) over the duration of the simulation period for the non-terraced catchments,in response to annual precipitation amounts that were between 194.8 mm to 579.3 mm.In contrast,the predicted annual sediment levels for the terraced catchments ranged from 0.52 t/hm^(2) to 10.10 t/hm^(2) due to similar precipitation amounts.The terraced catchments resulted in 4 to 5 times lower sediment yield as compared to non-terraced catchments.The results suggest that there is a huge potential for terraces to reduce soil erosion in the DRC specifically and Pothwar area generally,which have proven to be an efficient approach to establishing soil and water conservation structures in this region.