Small area estimation has received a lot of attention in recent years due to growing demand for reliable small area statistics. Traditional area-specific estimators may not provide adequate precision because sample sizes in small areas are seldom large enough. This makes it necessary to employ indirect estimators based on linking models. Basic area level and unit level models have been extensiv...

Although initially originated as a totally empirical relationship to explain the volume of trade between two partners, gravity equation has been the focus of several theoretic models that try to explain it. Specialization models are of great importance in providing a solid theoretic ground for gravity equation in bilateral trade. Some research papers try to improve specialization models by addi...

abstract use of empirical competition models is one of approaches in integrated weed management strategies. in order to investigation of this approach in simulation of yield loss of bean (phaseolus vulgari. l.) caused by jimson weed (datura stramonium l.) interference, an experiment was conducted in national bean research station, in khomein, in 2007. the experiment design was randomized comple...

Hysteresis has been widely recognized in the soil water relationship. In this paper, a detailed review of hysteresis was performed in relation to its models. So far, different models have been suggested to describe hysteresis in the water retention curve (WRC) that could be categorized into two main groups: conceptual and empirical models. The models in the first group are based on the domain t...

Shear wave velocity is a basic engineering tool required to define dynamic properties of soils. In many instances it may be preferable to determine Vs indirectly by common in-situ tests, such as the Standard Penetration Test. Many empirical correlations based on the Standard Penetration Test are broadly classified as regression techniques. However, no rigorous procedure has been published for c...