[word=are] [lemma=□]? | □
[word=are] [lemma=determine]? | □
The use of reflection phase gratings to diffuse sound helps create a listening environment in the home and elsewhere that allows a listener to experience an old-fashioned concert-hall ambience . Architectural acoustics designers have only three ingredients they can use to conjure up every imaginable type of acoustic environment ; namely , absorption , reflection , and diffusion . " The basic patterns on the curved surface are not different from those on a flat surface , " the researchers reported . The answer is in the way waves cancel or reinforce each other , depending on whether the crest of one wave meets the trough or crest of another wave . In economics , however , it 's useful to characterize the size distribution of firms more precisely than that . In his unpublished autobiographical writings , Euler noted , " True , [ Bernoulli ] was very busy and so refused flatly to give me private lessons ; but he gave me much more valuable advice to start reading more difficult mathematical books on my own and to study them as diligently as I could ; if I came across some obstacle or difficulty , I was given permission to visit him freely every Saturday afternoon and he kindly explained to me everything I could not understand . For the coloring shown above , the three red numbers 1 , 5 , 9 form an arithmetic progression with a common difference of 4 . Bush is proposing a few high-profile spending boosts , such as an increase in the maximum Pell grant for low-income students , from the current $ 4,050 to $ 4,600 . Each of the other digits also turns up with approximately the same frequency , showing no significant departure from predictions . Sales figures through Dec. 23 from 16,000 conventional supermarkets , not including big-box stores such as Wal-Mart or Costco , showed an overall 14 percent drop in spinach sales from a year ago , according to the Perishables Group . His purchase of an Apple II personal computer in 1979 provided him with the tool he needed to develop his mathematical art ideas further . A number is said to be " absolutely normal " if its digits are normal not only to base 10 but also to every integer base greater than or equal to 2 . For each of the two versions of the game , Robinove drew 100 initial hands , totaling 700 letters , then looked at the vowel frequency . Ceiling reflections produce very similar signals at each ear . Moreover , every number appears exactly once , so the EKG sequence is a permutation of the positive integers . No sampling procedure can fully capture every detail of an analog signal . Another such avenue is the use of data-mining techniques , applied to electronic sales data now readily available to most retailers , to assess how sales of one product influence those of another in a different category and , hence , affect total profitability . For moderate fluctuations , for instance , an erratically driven car can trigger a train of density waves , which move upstream like shock waves . " As a columnist for a Texas newspaper over the last , fleeting six-plus years , it always has been the greatest compliment ( although it almost has never been intended that way ) when a reader would write to compare me ( I shrink in abject humility , even as I type this ) to Molly , a friend of going on 40 years . " I have n't closed the door on others , but I recognize it would be easier on me , easier on her and easier on the family , and those are the people that are important in a marriage , " he said of his desire to meet and marry someone with Coptic roots . A digital camera periodically photographs a set of six Lava Lite lamps , each one generally in a different stage of activity . In those days , there were no graphing calculators ( or even pocket calculators ) , and all plotting was done by hand , point by point , on sheets of graph paper .