viroids are smallest, single-stranded, circular, highly structured plant pathogenic rnas that do not code for any protein. viroids belong to two families, the avsunviroidae and the pospiviroidae. members of the pospiviroidae family adopt a rod-like secondary structure. in this study the most stable secondary structures of citrus viroid variants that reported from fars province were drawn. the m...

We study the consequences of the introduction of widespread limited liability for corporations, with particular reference to the liability reforms introduced in Great Britain during the nineteenth century. In the view that is most widely accepted, by reducing transactions costs associated with screening and monitoring in capital markets , limited liability increases eciency of capital markets a...

Norms have been promoted as a coordination mechanism for controlling agent behaviours in open MAS. Thus, agent platforms must provide normative support, allowing both norm-aware and non norm-aware agents to take part in MAS that are controlled by norms. In this paper, the most relevant proposals on the denition of norm enforcement mechanisms are analysed. These proposals present several drawbac...

Proxy ring (anonymous proxy) signatures allow an entity to delegate its signing capability to a group of entities (proxy group) such that only one of the members in the proxy group can generate a proxy signature on behalf of the delegator while privacy of the proxy signer is protected. Identity-based versions of proxy ring signatures employ identity strings in place of randomly generated public...

A new tree code method for simulating planetesimal dynamics is presented. A self-similarity argument is used to restrict the problem to a small patch of a ring of planetesimals at 1 AU from the Sun. The code incorporates a sliding box model with periodic boundary conditions and surrounding ghost particles. The tree is self-repairing and exploits the attened nature of Keplerian disks to maximize...

This paper presents a speed-up learning method for logic programs, which accelerates a program by composing macro clauses based on partial structures of proof trees. Many systems have been proposed for composing useful macros, e.g., some of them select macros that connects two peaks in a heuristic function. Another employs heuristics that select useful macros. Although they work well in some do...

19 a very stringent regulation. Thus, the ecient equilibrium|the economic dispatch|is realized in a way that resembles how centralized economies were expected to realize ecient allocations. The diculties with this centralized approach, in terms of information collection and incentive incompatibilities, have yet to be addressed in the specic context of transmission access. Most proposals on tran...

In this paper, an iterative method is proposed for solving matrix equation $sum_{j=1}^s A_jX_jB_j = E$. This method is based on the global least squares (GL-LSQR) method for solving the linear system of equations with the multiple right hand sides. For applying the GL-LSQR algorithm to solve the above matrix equation, a new linear operator, its adjoint and a new inner product are dened. It is p...

In the real world there are groups which composed of independent units. The conventional data envelopment analysis(DEA) model treats groups as units, ignoring the operation of individual units within each group.The current paper, investigates parallel system network approach proposed by Kao and modifies it. As modied Kao' model is more eligible to recognize ecient groups, a new ranking method i...