in this thesis our aim is to construct vector field in r3 for which the corresponding one-dimensional maps have certain discontinuities. two kinds of vector fields are considered, the first the lorenz vector field, and the second originally introced here. the latter have chaotic behavior and motivate a class of one-parameter families of maps which have positive lyapunov exponents for an open in...

one very decisive factor in students’ academic destiny is the result they get at final term examinations. because of its importance, both students and teachers are curiously anxious about them. as normally it is the case, these final term tests are prepared hurriedly in short time by teachers which result in students’ dissatisfaction, complaining on how the test was different from their expecta...

abstract biometric access control is an automatic system that intelligently provides the access of special actions to predefined individuals. it may use one or more unique features of humans, like fingerprint, iris, gesture, 2d and 3d face images. 2d face image is one of the important features with useful and reliable information for recognition of individuals and systems based on this ...

the changes in todays world organization, to the extent that instability can be characterized with the most stable organizations called this afternoon. if you ever change management component, an additional value to the organization was considered, today, these elements become the foundation the organization is survival. the definition of the entrepreneur to identify opportunities to exploit a...

the present study was carried on to investigate the use of face-keeping strategies in reaction to complaints by male and female in two different cultures, persian and american english. to see if apology strategies are affected by cultural, contextual preferences and gender of interlocutors in two distinct languages of persian and american english. the hypotheses to be tested were 1) ifids, acce...

asymmetric polyethersulfone (pes) microfiltration flat sheet membranes were composed by the phase inversion method (pim) and were used as supports. composite membranes were fabricated by coating silicone rubber as selective layer. effect of different concentrations of pes and pdms and different solvent such as nmp, dmf and dms effects as pes solvents and support thickness and different coagulat...

دسته ای از ترکیبات شیمیائی که مخصوصا با گسترش زندگانی جدید (ماشینی)اهمیت فرآینده ای پیدامی کنند، افزودنیهای مختلف غذائی میباشند که در صنایع مربوطه بکار گرفته می شوند بکارگیری بخشی از این موا تحت عنوان طعم دهنده ها بمنظور تامین طعم و مزه طبیعی درفرآورده های صنعتی تقریبا اجتناب ناپذیر گشته و همگام با توسعه تولیدات روبه توسعه می رود. یک شناخت سیستماتیک و جامع از خواص و آثار اینگونه مواد طبیعتا مست...

in current study, 63 samples of bat populations collected from differ regions were used for evaluating the geographic variations. twenty cranial and dental characters for traditional morphometric and landmarks method on the ventral, dorsal skull and mandible for geometry morphometric studies were used. statistical analyses of traditional morphometric and geometry morphometric data indicated low...

the issue of curriculum and syllabus evaluation and revision has been in center of attention right from when curriculum came into attention of educational institutions. thus everywhere in the world in educational institutions curricula and syllabi are evaluated and revised based on the goals, the needs, existing content, etc.. in iran any curriculum is designed in a committee of specialists and...

the main purpose of this study was to investigate any relationship between high school efl teachers metaphorical understandings of their role in class and their self-efficacy beliefs. teachers metaphors were elicited through two different prompts: one picturing what they believed a language teacher should be like in class, and the other demonstrating what they are actually like in class; such...