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Analytical Physics
Published in Dana Crowe, Alec Feinberg, Design for Reliability, 2017
Diffusion is defined as the migration of atoms or mass transport. It is well known that atoms in gases and liquids are very mobile. For example, when a bottle of perfume is opened, it can be smelled in adjacent rooms quickly, sometimes almost immediately. It is not well known whether atoms in solids also are mobile and can move readily from one area to another. This phenomenon is used in the production of quarters and galvanized steel. For the case of the quarters, a metal sandwich is made with a copper/nickel alloy surrounding a copper center. The copper diffuses both ways and produces a metallurgical bond. A detrimental aspect of diffusion is Kirkendall voiding, where one atom in a metal-to-metal joint diffuses so quickly that vacancies (holes in the lattice) accumulate at the backside of the diffusion line and weaken the material.
Calculations
Published in Joe Cieszynski, David Fox, Electronics for Service Engineers, 2012
A quarter written as 14 is a fraction. If a cake is taken and divided equally into four pieces, and one of these pieces is given to you, you will have one fourth of the cake. One fourth is called a quarter which is written as 14. There are four quarters 44 in the cake or, if referring to numbers only, the whole which equals 1. How many fiftieths are there in one whole or 1? The answer is fifty. From the examples used so far it can be seen that the lower of the two numbers of a fraction describes how many parts the whole has been divided into:
Order-Fulfillment and Across-the-Dock Objectives and Their Impact on Your Company's Profit and Customer Service
Published in David E. Mulcahy, John P. Dieltz, Order-Fulfillment and Across-the-Dock Concepts, Design, and Operations Handbook, 2003
David E. Mulcahy, John P. Dieltz
During a review meeting with your financial manager, you obtain the past fiscal year dollar value for each controllable expense item. If the past fiscal year dollar expense figures do not cover 12 or 13 months, the order-fulfillment or across-the- dock manager uses the required periods from the previous fiscal year to obtain or estimate a total for the present fiscal year periods. You also obtain the next fiscal year calendar or schedule for each month and quarter end dates. The schedule of these calendar end dates indicates each of the 13 period calendar end dates. Each period consists of 4 weeks. Three quarters of the calendar year consist of 3 periods or 12 weeks. One quarter has 4 periods or 16 weeks. The financial manager determines the 16-week quarter position on the fiscal calendar.
Characterization of physical and mineralogical properties of anthracite and bituminous coal tailings
Published in International Journal of Coal Preparation and Utilization, 2021
Min Liew, Ming Xiao, Shimin Liu
Figure 10 (a) and (b) show the tailings grains selected for mineral composition analysis. Attention is paid to the coal grains with non-separable impurities in this study. As shown in Figures 11 and 12, the detected carbons account for 77.50% and 73.55% in the total weight of the coal grains for the anthracite and the bituminous coal tailings, respectively. Although the coal grain sizes of the anthracite and bituminous coal tailings samples vary by a great extent, their percentages of carbon in weight are almost the same (about three quarters of the overall mass). Figures 13 and 14 show the mineral composition analysis using an impurity grain in the anthracite and bituminous coal tailings, respectively. When comparing the mineral compositions of the coal grains and impurities in both tailings samples, the amounts of Silica (SiO2) and Aluminum oxide (Al2O3) increase drastically when the percentages of carbon in the impurities decrease. Since the percentage of impurities in coal grains is low, the non-separable impurities attached to the coal grains need not be removed as long as the overall energy value meets client requirements. However, separable impurities (i.e. the impurity grains) may need to be removed given the insignificant amount of carbons in them.
Recommending collaborations with newly emerged services for composition creation in cloud manufacturing
Published in International Journal of Computer Integrated Manufacturing, 2021
SCR and all the baselines are evaluated from January 2006 for ten consecutive years. For a given time interval , collaborative services are recommended to each service that newly emerged in that time interval. With collaborations recorded by the end of (+1)-th time interval act as the ground truth for the evaluation, MAP@L and NDCG@L are calculated. The evaluation is performed repeatedly when the length of a time interval varies from one to four quarters of a year. For example, when the time interval length is set to one quarter of a year, the recommendation scheme is performed every 3 months in a CMfg platform, and the average value of MAP@L and NDCG@L over the 40 consecutive time intervals are reported. In this way, all the methods are sufficiently compared with multiple settings of recommending frequency.
A change point approach to analysing the match activity profiles of team-sport athletes
Published in Journal of Sports Sciences, 2019
David M. Corbett, Alice J. Sweeting, Sam Robertson
Time series analysis methodologies are built upon the assumptions of stationarity, absence of seasonality and absence of trend (Cryer & Chan, 2008). Stationarity refers to the consistency of mean, variance and autocorrelation over time (Cryer & Chan, 2008). The Dickey-Fuller test for stationarity was applied to all velocity time series’ and returned an average test statistic of −19.87, a lag order of 39 and a p-value of <0.01, suggesting the velocity time series was stationary (Tanaka, 2017). Seasonality refers to a time series, where data points periodically fluctuate at fixed intervals (Atchison, Berardi, Best, Stevens, & Linstead, 2017). Due to the uneven length of quarters in AF, the velocity time series’ do not violate the assumption of seasonality. The inability of linear approaches in the literature to determine a linear change in physical output as a function of time within matches, demonstrates an absence of trend (Dillon et al., 2017). This suggests that instantaneous velocity files do not violate any of the assumptions for time series analysis and can be analysed without any transformations.