In airline industries, the aircraft maintenance cost takes up about 13% of the total operating cost. It can be reduced by a good planning. Spare parts inventories exist to serve the maintenance planning. Compared with commonly used reorder point system (ROP) and forecasting methods which only consider historical data, this paper presents two non-linear programming models which predict impending...

The η → πγγ decay was investigated by the SND detector at VEPP-2M ee collider in the reaction ee → φ → ηγ. Here we present the results and some details of this study. We report an upper limit (90% c.l.) Br(η → πγγ) < 8.4×10−4 as our final result. Our upper limit does not contradict the earlier measurement by GAMS spectrometer. To facilitate future studies a rather detailed review of the problem...

Forensic entomologists use blow fly development to estimate a postmortem interval. Although accurate, fly age estimates can be imprecise for older developmental stages and no standard means of assigning confidence intervals exists. Presented here is a method for modeling growth of the forensically important blow fly Lucilia sericata, using generalized additive models (GAMs). Eighteen GAMs were ...

The origins and some motivational details of a collection of nonlinear mixed complementarity problems are given. This collection serves two purposes. Firstly, it gives a uniform basis for testing currently available and new algorithms for mixed complementarity problems. Function and Jacobian evaluations for the resulting problems are provided via a GAMS interface, making thorough testing of alg...

Scarcity of water resources and huge costs of establishing new hydraulic installations necessitate optimal exploitation from existing reservoirs. Sustainable management and efficient exploitation from existing finite water resources are important factors in water resource management, particularly in the periods of water insufficiency and in dry regions, and on account of competitive allocations...

Generalized additive models (GAMs) have become an elegant and practical option in model building. Estimation of a smooth GAM component traditionally requires an algorithm that cycles through and updates each smooth, while holding other components at their current estimated fit, until specified convergence. We aim to fit all the smooth components simultaneously. This can be achieved using penali...

DIETER is an open-source power sector model designed to analyze future settings with very high shares of variable renewable energy sources. It minimizes overall system costs, including fixed and costs various generation, flexibility coupling options. Here we introduce DIETERpy that builds on the existing version, written in General Algebraic Modeling System (GAMS), enhances it a Python framewor...

This paper offers a synthesis of agricultural household modeling, its evolution and uses; presents a general yet simple agricultural household model, estimated with Mexican village data and programmed using General Algebraic Modeling System (GAMS) software; and uses this model to explore household-level impacts of agricultural policy changes on production and incomes under alternative rural-mar...

f or several decades, the selection of a proper tax base has been among the most serious concerns for the economic policy makers. the computable general equilibrium models analysis provides a comprehensive framework for the investigation of the effects of the adopted policies on the economy of a country. in the present study, using a static computable general equilibrium, the effects of tax re...