A semantics-based framework is presented for the definition and manipulation of class hierarchies for object-oriented languages. The framework is based on the notion of observable of a class, i.e., an abstraction of its semantics when focusing on a behavioral property of interest. We define a semantic subclass relation, capturing the fact that a subclass preserves the behavior of its superclass...

Tabled evaluation has been proved an effective method to improve several aspects of goal-oriented query evaluation, including termination and complexity. Several “native” implementations of tabled evaluation have been developed which offer good performance, but many of them require significant changes to the underlying Prolog implementation, including the compiler and the abstract machine. Appr...

abstract the purpose of this paper is estimation of the effective factors on tea supply in gilan province by using time series data during 1360-1390 in the form of nerlove model. according to the results, explanatory variables of the model could describe 97 percent of dependent variable (product supply) changes. the results show that the guaranteed price index of green tea leaf with elasticity ...

Organic agriculture (OA) includes a comprehensive production management system that is considered as one of the strategies to reduce negative impacts of industrial agriculture in many countries. This research was identifying factors affecting the development of OA in Ardabil province. A descriptive– correlation survey approach was used in this study. Participants were agricultural specialists o...

The present paper is about the detection of cross seas based on ERS-2/SAR wave mode data and comparison to WAM model. A case of cross seas observed by ERS-2/SAR was analyzed for its generation and development by wave mode data together with the WAM model two-dimensional (2-D) spectra. The sea surface elevation is estimated from these wave mode data with cross sea features using a CMOD type tilt...