An approximation algorithm is an efficient algorithm that finds an approximate solution with a provable approximation guarantee. The standard measure of the quality of an approximation algorithm is its approximation factor. The approximation factor of an algorithm is the worst case ratio between the value (cost) of the solution the algorithm finds and the value (cost) of the optimal solution. T...

background: to determine a cut-off point of tpsa and psad to prevent unnecessary invasive cancer-diagnosing tests in the community. methods: this study was performed on 688 consecutive patients referred to our center due to prostatism, suspicious lesions on digital rectal examination and/or elevated serum psa levels. all patients underwent transrectal ultrasound guided biopsies and obtained psa...

having observed the costly failures of different cutoff walls, that had been constructed according to the mix design specified by reputable consultants in iran, a research programme was conducted to study the effects of constituent materials on the properties of plastic concrete. the main properties, such as compressive strength, biaxial and triaxial strains, permeability, and modulus of elasti...

a study was conducted to standardize production and postharvest handling of lily (lilium longifolium l. cv. mero star). in production trial, three plant densities viz.10, 20 and 30 cm between plants in 60 cm spaced rows and two planting depths viz.7.5 and 15 cm were compared. increased plant growth, yield and quality was recorded when plants were grown at a close spacing of 10 cm with 15 cm pla...

We prove that in an undirected graph there are at most O(n 2) cuts of size strictly less than 3=2 of the size of the minimum cut.

We compare two multicommodity ow problems, the maximum sum of ow, and the maximum concurrent ow. We show that, for a given graph and a given set of k commodities with speci ed demands, if the minimum capacity of a multicut is approximated by the maximum sum of ow within a factor of , for any subset of commodities, then the minimum cut ratio is approximated by the maximum concurrent ow within a ...

'The great appear great, because we are on our knees. Let us rise!,' wrote Larkin. Jean Faugier ( 1 ) described the 'tall poppy syndrome' and spoke of 'bold, nonconformist', brightly- coloured flowers being chopped down mercilessly by farmers just because they were different and stood above the rest in the wheatfields.