Congestion is an important issue that requires the efficiency of decision-making units (DMUs). We first classify conventional congestion into congestion (newly defined) and technical inefficiency, based on prior research and real applications. Modified definitions and mathematical expression of congestion, managerial inefficiency, and technical inefficiency are proposed to better illustrate the...

I examine inefficiencies in Japanese water utility companies. Efficiency in this context is defined as a firm’s capacity to maximize output given a fixed level of inputs. The findings suggest that the average operation rate, customer density and size variables are associated with lower levels of inefficiency (or higher levels of efficiency), while water purification (a conditioning variable cap...

Widespread introduction and early initiation of antiretroviral therapy significantly improves the prognosis in people living with HIV — an increase number CD4+ T-lymphocytes, incidence HIV-related diseases mortality rate decreases. Despite suppression replication, a fraction ART-treated patients fails to achieve normalization T-cell counts. These have increased risk clinical progression AIDS no...