مشخصات پژوهش

عنوان	Determine the Difference between Bias and Unbias Comparison in Economic Statistical Design of T2–FRS and T2-VSS Control Charts
نوع پژوهش	مقاله ارائه شده کنفرانسی
کلیدواژه‌ها	T Control Chart, Economic Statistical Design (ESD), Fixed Ratio Sampling (FRS), Variable Sampling Sizes (VSS), Unbias, Genetic Algorithm(GA).
چکیده	The Hotelling's 2 T control chart, is the most widely used multivariate procedure for monitoring two or more related quality characteristics. Recently, the variable sampling sizes (VSS) control scheme has been proved to have a very good performance on detecting small to moderate shifts when it is compared to the fixed ratio sampling (FRS) 2 T control scheme. Moreover, it is shown that the VSS scheme is more economical than the FRS scheme. It is applied the cost model proposed by Lorenzen and vance (1986). Furthermore, it is assumed that the length of time that the process remains in control is exponentially distributed which allows applied the Markov chain approach for developing the cost model. It is applied genetic algorithm to determine the optimal values of model parameters by minimizing the cost function. This paper studies unbias comparison between Economic Statistical design T 2  FRS and 2 T VSS control charts with respect to the expected cost per unit time.
پژوهشگران	محسن ترابیان (نفر اول)، اصغر سیف (نفر دوم)