Additional suggestions for X-ray quantitative analysis of high-volume filter samples
Abstract It has been observed that reference intensity constants for natural aerosols used in X-ray quantitative analysis of high-volume filter samples varies significantly according to the geological history and surface weathering conditions of the source rock or soil. Reference intensity values pertaining to compounds from actual geologic outcrops or soil types within the sampling area should be used in order for the highest accuracy to be obtained. Two “approximation” computations are suggested for circumstances where the more elaborate procedures involving matrix and transmission corrections may not be justified. The first, least accurate approximation, uses the Chung (1975) equation directly; the second and “better” approximation uses a simple beam transmission correction and the Chung equation in a one-step iteration. Very good agreement between the better approximation and the complete refinement procedure is observed for the several analyses presented.
This study presents a profit maximization model that adopts the number of requests for image or voice transferring services on a network as decision variables for when to switch a second server on and off based on the costs of using a second server and of users waiting. A Markovian queue with a number of servers depending upon queue length and finite capacity is discussed. The data of interarrival time and service times of requests are collected by observing a queuing system. An empirical Bayesian method is then applied to estimate the traffic intensity of the system, which denotes the need for host computers. The mean number of transfer requests in the system and the queue length of transfer requests are calculated as the characteristic values of the system.