this article aims to study an important principle in discourse analysis, which belongs to paul grice, the contemporary philosopher. he believes that in addition to giving and taking information during a conversation, people also show their cooperation with each other, and so he suggests the ‘cooperative principle’ which contains some principles of subtext. since the cooperative principle is wit...

introduction: studying the hydrological cycle, especially in large scales such as water catchments, is difficult and complicated despite the fact that the numbers of hydrological components are limited. this complexity rises from complex interactions between hydrological components and environment. recognition, determination and modeling of all interactive processes are needed to address this i...

introduction of human development index (hdi) by undp in early 1990 followed a surge in use of non-parametric and parametric indices for measurement and comparison of countries performance in development, globalization, competition, well-being and etc. the hdi is a composite index of three indicators. its components are to reflect three major dimensions of human development: longevity, knowledg...

university of tehran administers a test known as the university of tehran english proficiency test (the utept) to phd candidates on a yearly basis. by definition, the test can be considered a high-stakes one. the validity of high stakes tests needs to be known (roever, 2001). as mesick (1988) maintains, if the validity of high stakes tests are not known, it might have some undesirable consequen...

the main design criteria of ballasted railway tracks include rail deflections, rail bending stresses, rail wheel contact stresses, sleeper bending moments and ballast sleeper contact pressures. numerous criteria have been defined for the design of ballasted railway tracks owing to the various mechanical properties of track components and their complex interaction. therefore, railway track desig...