[1] Step‐drawdown tests (SDTs) typically involve pumping a well at a constant rate until a quasi‐steady state (QSS) is observed in the drawdown response. The well is then pumped at a higher constant rate until a new QSS is achieved. The process is repeated for additional flow rates. Analysis involves plotting the QSS drawdowns against their corresponding abstraction rates and fitting a nonlinea...

This paper deals with a constrained investment problem for a defined contribution (DC) pension fund where retirees are allowed to defer the purchase of the annuity at some future time after retirement. This problem has already been treated in the unconstrained case in a number of papers. The aim of this work is to deal with the more realistic case when constraints on the investment strategies a...

Aquifer hydraulic parameters play a critical role in investigating various groundwater hydrology problems (e.g., depletion and transport), the Theis formula for constant-rate pumping tests is commonly used to estimate them. However, rate field usually varies with time due some factors, making classical model unsuitable accurate parameter estimation. To address this issue, we developed novel dim...