A brief discussion is reported on advantages and disadvantages offered by serial computers as com... more A brief discussion is reported on advantages and disadvantages offered by serial computers as compared with parallel computers and on different number representations in serial machines. A particular advantage is illustrated, as regards overflow cheking, of the representation in which the most significant digit of a number is used to indicate the sign and negative numbers are represented by their 2's complement. The advantages are examined of using a discretely variable word length.
... Dark Age (revisited) The futuristic essay which inspired the plot of the novel "The ... more ... Dark Age (revisited) The futuristic essay which inspired the plot of the novel "The Death of ... I have used the term "dark age" to describe this coming widespread crisis. The early medieval centuries from, say, 500 to 1100 are often called "Dark Ages" in the history books. ...
This paper addresses the distribution of digits in the positional representation of powers of int... more This paper addresses the distribution of digits in the positional representation of powers of integers, a problem with a long history, and presents a complete solution when the representation base is a prime number. For any given base and exponent, the powers are viewed as a semi-infinite array whose rows are indexed by the nonnegative integers and whose columns are indexed by the representation positions. By using arguments of elementary number theory, the positions of the array are classified in a manner permitting their enumeration. Since each column is a periodic sequence, the distribution is expressed in terms of the number of occurrences (frequency) of each digit in a period.
A brief discussion is reported on advantages and disadvantages offered by serial computers as com... more A brief discussion is reported on advantages and disadvantages offered by serial computers as compared with parallel computers and on different number representations in serial machines. A particular advantage is illustrated, as regards overflow cheking, of the representation in which the most significant digit of a number is used to indicate the sign and negative numbers are represented by their 2's complement. The advantages are examined of using a discretely variable word length.
... Dark Age (revisited) The futuristic essay which inspired the plot of the novel "The ... more ... Dark Age (revisited) The futuristic essay which inspired the plot of the novel "The Death of ... I have used the term "dark age" to describe this coming widespread crisis. The early medieval centuries from, say, 500 to 1100 are often called "Dark Ages" in the history books. ...
This paper addresses the distribution of digits in the positional representation of powers of int... more This paper addresses the distribution of digits in the positional representation of powers of integers, a problem with a long history, and presents a complete solution when the representation base is a prime number. For any given base and exponent, the powers are viewed as a semi-infinite array whose rows are indexed by the nonnegative integers and whose columns are indexed by the representation positions. By using arguments of elementary number theory, the positions of the array are classified in a manner permitting their enumeration. Since each column is a periodic sequence, the distribution is expressed in terms of the number of occurrences (frequency) of each digit in a period.
Il Rev Charles Elliott, mio trisavolo, pubblicò nel 1851 un libro antischiavista "La Bibbia e ... more Il Rev Charles Elliott, mio trisavolo, pubblicò nel 1851 un libro antischiavista "La Bibbia e la schiavitù" che forse ispirò il discorso i Abraham Lincoln a Peoria, Ill. del 1855.
This is a tract against violence and against faith -- monotheistic religions have prompted violen... more This is a tract against violence and against faith -- monotheistic religions have prompted violence from time immemorial
Innovazione in Europa; fattori chiave: ricerca, sviluppo, cultura. Analisi comparate e strategie,... more Innovazione in Europa; fattori chiave: ricerca, sviluppo, cultura. Analisi comparate e strategie, di Roberto Vacca, 25/5/2016 L'analisi del rappoto annuale INNO SCOREBOARD 2015 della Commissione Europea sullo stato dell'innovazione tecnico-scientifica dei 38 Paesi EU mostra che i leader eccellono nel rapporto fra investimenti privati e investimenti pubblici in ricerca e sviluppo-Altro fattore vitale è la cultura media. Stimolare gli imprenditori a raddoppiare le risorse dedicate alla ricerca e innalzare i livellj di cultura media sono prerequisiti alla crescita del PIL pro capite e alla riduzione della disoccupazione.
The metaphor of stopping time suggests disregard for difference in calendar age. Old people dispo... more The metaphor of stopping time suggests disregard for difference in calendar age. Old people dispose of valuable memories & experience: if they are awake and alert (suggestions of how to), they should be enrolled to solve problems. Symbiosis with up to date youngsters is also a big asset. I analyze recent Chinese success in this context. At all ages we are subject to burnout - how to avoid it & how to know more, innovate, forecast, grow.
Violenza potenziale massima è data dagli arsenali nucleari; le 3 religioni monoteiste hanno ispir... more Violenza potenziale massima è data dagli arsenali nucleari; le 3 religioni monoteiste hanno ispirato violenze gravi solo in parte attenuate, ma occasionalmente riaccese da gruppi terroristi.
Dal 1959 il tasso CO2 atmosferico cresce secondo curve logistiche (Volterra) valide su intervall... more Dal 1959 il tasso CO2 atmosferico cresce secondo curve logistiche (Volterra) valide su intervalli di 17 anni con derivata positiva crescente e asintoti inferiori a 500 ppm
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