A monoalphabetic cipher uses fixed substitution over the entire message, whereas a polyalphabetic cipher uses a number of substitutions at different positions in the message, where a unit from the plaintext is mapped to one of several possibilities in the ciphertext and vice versa.

In the simplest case, the difference between two haplotypes is assessed by counting the number of locations where they have different bases: This is referred to as the number of substitutions ( other kinds of differences between haplotypes can also occur, for example the insertion of a section of nucleic acid in one haplotype that is not present in another ).

The difference between organisms is usually re-expressed as a percentage divergence, by dividing the number of substitutions by the number of base pairs analysed: the hope is that this measure will be independent of the location and length of the section of DNA that is sequenced.

* There is no limit to the number of substitutions a player or team can make.

Because these substitutions do not require a change in the number of rings, they occur more frequently than the other substitutions.

Due to the high number of simultaneous substitutions requested by Canadian broadcasters, portions of programming are sometimes lost.

The substituted amphetamines consist of the same structure with one or more substitutions ; prevalent examples include cathinone, DOM, ephedrine, MDMA, methamphetamine, methcathinone, and methylphenidate, though a large number of such compounds have been synthesized.

The minimum string distance ( MSD ) is the number of " primitives " which is the number of insertions, deletions, or substitutions to transform one string into another.

While 14 clubs is a maximum, it is not a minimum ; players are free to use any lesser number of clubs they think will be useful, so substitutions for the common omissions above are not always made ; a player may simply choose to play without a 5-wood or 2-4 irons, instead using a 4-wood and moving directly to their 5-iron as desired distance decreases ( a 4-wood in a skilled golfer's hands averages 200 yards ; a 5-iron in the same player's hands would be about 160, which is a large gap but not unplayable ).

Due to the number of bounty jumpers taking advantage of being substitutes for those drafted, the Confederate Congress withdrew the law making substitutions possible in December 1863.

Branches A & C have a high number of substitutions.

Typically, a branch length of a phylogenetic tree is expressed as the expected number of substitutions per site ; if the evolutionary model indicates that each site within an ancestral sequence will typically experience x substitutions by the time it evolves to a particular descendant's sequence then the ancestor and descendant are considered to be separated by branch length x.

The expected number of substitutions per site per year is often indicated with the Greek letter mu ( μ ).

A model is said to have a strict molecular clock if the expected number of substitutions per year μ is constant regardless of which species ' evolution is being examined.

An important implication of a strict molecular clock is that the number of expected substitutions between an ancestral species and any of its present-day descendants must be independent of which descendant species is examined.

For example, even though rodents are genetically very similar to primates, they have undergone a much higher number of substitutions in the estimated time since divergence in some regions of the genome.

Many useful substitution models are time-reversible ; in terms of the mathematics, the model does not care which sequence is the ancestor and which is the descendant so long as all other parameters ( such as the number of substitutions per site that is expected between the two sequences ) are held constant.

The total of 9 free parameters is often further reduced to 8 parameters plus, the overall number of substitutions per unit time.

Mechanistic models describe all substitutions as a function of a number of parameters which are estimated for every

The completeness of the connections provide that, for N people, there are Af lines of communication between the pairs, which can become a large number ( 1,225 ) for a party of fifty guests.

That is how the real routine of resistance goes on, and its strength is directly proportionate to the number of insignificant people who can let themselves be taken to pieces, piece by piece, without quitting.

She can decrease the number of temptations.

The Peace Corps can either begin in very low gear, with only preparatory work undertaken between now and when Congress finally appropriates special funds for it -- or it can be launched now and in earnest by executive action, with sufficient funds and made available from existing Mutual Security appropriations to permit a number of substantial projects to start this summer.

Since broadcast frequencies are very limited in number, these objectives are to some extent inconsistent in that not all of them can be fully realized, and to the extent that each is realized, there is a corresponding reduction of the possibilities for fullest achievement of the others.

During nighttime hours, because of the intense skywave propagation then prevailing, no large number of stations can be permitted to operate on one of these channels, if the wide area service for which these frequencies are assigned is to be rendered satisfactorily by the dominant stations which must be relied upon to render it.

Additional class 2, assignments for daytime operation can be made without causing destructive interference to the class 1, stations or to each other, and by their operation provide additional service on these channels and additional local outlets for a large number of communities.

If your state has no provisions for the numbering of pleasure boats, you must apply for a number from the U.S. Coast Guard for any kind of boat with mechanical propulsion rated at more than 10 horsepower before it can be used on Federal waterways.

As America on wheels was responsible for an industry of motor courts, motels, and drive-in establishments where you can dine, see a movie, shop, or make a bank deposit, the ever-increasing number of boating enthusiasts have sparked industries designed especially to accommodate them.

The depth gauge rod can now be set, and any number of holes bored to exact and identical depth.

In your sales force, will a smaller number of higher-priced, high-quality salesmen serve you best, or can you make out better with a larger number of lower-paid salesmen??

We found that wherever you can use two teams on a job, five men, not four, is the magic number ''.

A binomial experiment can produce random variables other than the number of successes.

In the following paper it is shown that in a certain definite sense, exactly an odd number of squares can be inscribed in every such curve which does not contain an infinite number of inscribed squares.

Furthermore, one can find a neighborhood of Q in which the difference function is monotone, for since it is analytic it can have only a finite number of extrema in any interval.

It is planned to double the number of teams and to make use of improved equipment in a second demographic inquiry in 1960, so that the inquiry can be carried through in one year and the results published more expeditiously.

In the Steiners have busy lives without visiting relatives only context can indicate whether visiting relatives is equivalent in meaning to paying visits to relatives or to relatives who are visiting them, and in I looked up the number and I looked up the chimney only the meanings of number and chimney make it clear that up is syntactically a second complement in the first sentence and a preposition followed by its object in the second.

Second, as we increase the number of desegregated school districts and schools themselves, how can we achieve this action through school board action??

At the same time, every device that can be employed to reduce the number of variables is of the greatest value, and it is one of the attractive features of dynamic programming that room is left for ingenuity in using the special features of the problem to this end.

List the number of hours the family can be expected to work each month.

If in any one calculation Ptolemy had had to invoke 83 epicycles all at once, while Copernicus never required more than one third this number, then ( in the sense obvious to Margenau ) Ptolemaic astronomy would be simpler than Copernican.

Secretary of War Baker, blindfolded, put his hand into a large glass bowl and drew the initial number of those to be called.

Although the United States and the U.S.S.R. have been arguing whether there shall be four, five or six top assistants, the most important element in the situation is not the number of deputies but the manner in which these deputies are to do their work.

and it is still very far from certain how valid the party's claim is that in `` a growing number of kolkhozes '' the peasants are finding it more profitable, to surrender their private plots to the kolkhoz and to let the latter be turned into something increasingly like a state farm.

The whole program must be conceived of as an effort, stretching over a considerable number of years, to alter the basic social and economic conditions in the less developed world.

The resulting setup, it was declared, `` would be similar to that which is in successful operation in a number of metropolitan counties as large or larger than Rhode Island ''.

This apparatus will also be used to measure transition probabilities of a large number of other elements.

These data are not of the precision obtainable by the methods previously mentioned, but the vast number of approximate values available will be useful in many areas.

There is little doubt that the number of those who wish to serve will be far greater than our capacity to absorb them.

These expenditures are estimated to be $12.1 billion, an increase of $187 million over 1960, reflecting additional longevity pay of career personnel, more dependents, an increased number of men drawing proficiency pay, and social security tax increases ( effective for the full year in 1961 compared with only 6 months in 1960 ).

Rather, such assignments are made, as they must be, on the basis of certain overall rules and standards, representing to some extent a statistical approach to the problem, taking into account for each situation some of the variables ( e.g., power and station separations ) and averaging out others in order to achieve the balance which must be struck between protection against destructive interference and the assignment of a number of stations large enough to afford optimum radio service to the Nation.

Such additional daytime class 2, assignments are appropriate if optimum use is to be made of these frequencies, and the Commission has over the years made a large number of them.

In addition, production machinery must in many cases be designed to handle with equal efficiency both natural fibers and the increasing number of synthetics, as well as blends.

The number of locking bars required depends on how many false moves must be prevented.

It is a number without which the equation cannot be solved correctly.