energy method of evaluation is widely employed in analyzing problems associated with sustainable agriculture. in this study, energy ratio (er) of dryland wheat for three regions of eghlid township was quantified. the total cropping area of eghlid is nearly 8282 hectares comprised of: khosrowshirin (5000 ha), sedeh (1682 ha) and dezhkord (1600 ha). the corresponding values of wheat yield in thes...

It is commonly accepted that tree form has an impact on the productivity of single-grip harvesters. However, it remains unclear, which elements of tree form are significant and to what degree they impact harvesting productivity. This is of particular importance in hardwood dominated stands, where hardwood trees often exhibit complex and variable stem and crown architecture that can complicate a...

This article discusses the relationship between mathematical proof and the digital computer from the viewpoint of the 'sociology of proof': that is, an understanding of what kinds of procedures and arguments count for whom, under what circumstances, as proofs. After describing briefly the first instance of litigation focusing on the nature of mathematical proof, the article describes a variety ...

We propose a practical verification framework for preemptive OS kernels. The framework models the correctness of API implementations in OS kernels as contextual refinement of their abstract specifications. It provides a specification language for defining the high-level abstract model of OS kernels, a program logic for refinement verification of concurrent kernel code with multi-level hardware ...

Using separation logic, this paper presents three Hoare logics (corresponding to different notions of correctness) for the simple While language extended with commands for heap access and modification. Properties of separating conjunction and separating implication are mechanically verified and used to prove soundness and relative completeness of all three Hoare logics. The whole development, i...

(51) We apply 8I to (51) and prove (49). P and t are deened inductively over the structure of sequent trees. In the base case, we have P and t such that (47) is 8x (T(x) T(x)). Consider now the step case. We write (47) in the following form. (52) where P x 1 ; :::; x n ] does not contain occurrences of T. We assume the hypotheses of (52) and derive Tac(x 1) ^ ::: ^ Tac(x m). From (29) we obtain...

Formal reasoning on Peer-to-Peer (P2P) systems is an intimidating task. This paper focuses on broadcast algorithms for Content Addressable Network (CAN). Since these algorithms run on top of complex P2P systems, finding the right level of abstraction in order to prove their functional correctness is difficult. This paper presents a mechanized model for both CAN and broadcast protocols over thos...