Showing papers on "String (computer science) published in 1978"

Algorithms for Loop Matchings

Abstract: A simplified (two-base) version of the problem of planar folding of long chains (e.g., RNA and DNA biomolecules) is formulated as a matching problem. The chain is prescribed as a loop or circular sequence of letters A and B, n units long. A matching here means a set of A-B base pairings or matches obeying a planarity condition: no two matches may cross each other if drawn on the interior of the loop. Also, no two adjacent letters may be matched. We present a dynamic programming algorithm requiring $O( {n^3 } )$ steps and $O( {n^2 } )$ storage which computes the size of the maximum for the given A-B base sequence and which also allows reconstructing a particular folded form of the original string which realizes the maximum matching size. The algorithm can be adapted to deal with sequences with larger alphabets and with weighted matchings.An algorithm is also presented for a modified problem closer to the biochemical problem of interest: We demand that every match must be adjacent to another match, forcing ...

The reference string indexing method

Abstract: The motivation for the reference string indexing method may be derived from the intention to retrieve any piece of information by specifying arbitrary parts of it. Common restrictions such as the usage only of a certain set of descriptors or (complete) keywords in document retrieval systems or the specification of only certain (inverted) attributed values for queries in formatted files should be removed without loosing performance necessary for interactive usage.

Pronounceability and Statistical "Englishness" as Determinants of Letter Identification

Abstract: The statistical "Englishness" of letter strings, assessed by a measure based on letter-cluster frequencies, exerts a significant effect on report accuracy, independent of string pronounceability, despite previous suggestions to the contrary. This claim is supported by an experiment on tachistoscopic recognition of a set of nonword strings for which rated pronounceability and "Englishness" vary orthogonally. Implications for a theory of word recognition are discussed.

Syntactic Error Correction in Programming Languages

Abstract: A technique for syntactic error correction, called pattern mapping, is developed. A pattern is used to describe how to map or change one string into another. Using a preconstructed list of patterns, for each detected error, the first pattern with successful mapping is found and a correction is made based on this pattern.

String storage and searching for data base applications: Implementation on the INDY backend kernel

Abstract: User and hardware cost trends dictate that data base systems should provide more complete functionality, simplicity of use, and reliability by increasing the amount of hardware present in the system. These goals are accomplished with a simple hardware arrangement within a one-dimensional cellular storage system called INDY. The INDY backend kernel is intended as a powerful tool for implementing all data models. The INDY cellular storage array is intended to provide functionality that is difficult to implement efficiently using a conventional hardware arrangement. It allows a simple implementation of improved data independence at high speeds. INDY simultaneously satisfies the time windows of future hardware technologies and user requirements.The importance of strings as a mechanism for defining abstract data types for data base languages is discussed in more detail in another paper. In that paper, a language called STRING is introduced which allows names of data objects to be semantically defined as variable-length strings and compared based on string pattern membership. This paper is concerned with the implementation of string storage and searching required by the STRING language. Implementation of higher level structures and searching requirements (such as sets, rows, tables and hierarchies) on the INDY kernel is treated elsewhere.

Continuous solutions of the problem of a string vibrating against an obstacle

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Kana-chinese character converter

Abstract: PURPOSE: To make a conversion speed high and reduce erroneous conversions by retrieving segmented phonetic elements from a combination storage unit and discriminating the propriety of words. CONSTITUTION: A Kana (japanese syllabary) code string is generated by input part 1 correspondingly to the Kana-described Japanese sentence (input Kana string) which is inputted form a Kana keyboard by an operator, and is supplied to phonetic read segmenting part 2, and is segmented to every phonetic element according to a fixed rule. The Kana code string segmented in this manner is supplied to Kana- Chinese character conversion control part 3, and Kana code strings to be converted are supplied to collating circuit 4, and words are read out from storage unit 5 on a basis of element combination while using phonetic elements, which are segmented by phonetic delimiter marks, of the Kana code string as minium units, thereby performing collation. The property of a part of speech of read words is used to discriminate each propriety to output only a proper conversion result. COPYRIGHT: (C)1979,JPO&Japio

An Elementary Evaluation of the Catalan Numbers

Abstract: 2. The derivation. Consider any product of n + 1 terms. We insist on putting in the final set of parentheses for the final operation, so we have n pairs of parentheses. For example, when n = 2, we have the products ((ab)c) and (a(bc)). It is remarkable, though well known in Logic and Computer Science, that only the left or only the right parentheses are necessary. Indeed, if we omit the right (left) parentheses and replace all the left (right) parentheses by some operator symbol, say X, then we have the Polish (reverse Polish) notation of 1Fukasiewicz. For example, when n=2, the products above have the Polish forms XXabc and XaXbc and the reverse Polish forms abXcX and abcXX. Henceforth we shall only deal with the reverse Polish forms, which are more convenient. Any product of n + 1 terms or operands gives a unique reverse Polish string of n + 1 operands and n operators. A simple induction verifies that we have more operands than right parentheses occurring in any initial segment of a product. Thus the same relation must hold for operands and operators in the corresponding reverse Polish string. We say a string of n + 1 operands and n operators, is well-formed if this is the case. Given a well-formed string, we can recover the product of n + 1 terms as follows. Read the string from left to right. The first symbol must be an operand and we write this down. Continuing, if the next symbol is an operand, we write it at the right of the last symbol written. If the next symbol is an operator, we write a parenthesis about the last two operands and consider the parenthesized expression as a new operand, replacing the enclosed two. Since the string is well-formed, we will get a correctly parenthesized product as the result of continuing this process. So we have a bijection between the products of n + 1 operands and the well-formed strings of n + 1 operands and n operators.

String mounting apparatus

Abstract: The invention as described herein consists of a string mounting apparatus as may be used with stringed musical instruments to improve the quality of the sounds emanating therefrom and to provide high quality reproductions of sounds as the musical instrument is played.

Tunable string holder for musical instrument

Abstract: A string holder for a string instrument comprises a support which is secured for the string instrument and formed with a plurality of generally parallel longitudinal guides in each of which a respective support block can be displaced through a relatively long longitudinal distance. This block can be locked at any location along the respective guide. Each of the blocks carries a two-arm lever one of whose arms is secured to the respective string and the other of whose arms is acted on by a screw for displacement of the one arm through a relatively short distance for fine tuning of the distance between bridge and anchor point for the respective string.

Kite string reel structure

Abstract: A kite string reel structure of such hollow internal configuration that a hand of a user may be removably disposed therein, and the hand when clenched grasping a transverse handle within the reel structure to support the latter in a desired position where the other hand of the user may be employed to wrap kite string on the reel or pay out kite string therefrom When the reel structure is disposed in a substantially parallel direction to the kite string when a kite is being flown, the pull on the kite string will automatically cause a rapid pay out of kite string from the reel

Automatic centering of character strings

Abstract: In a word processor a string of characters entered serially via a keyboard into a plurality of positions are centered about a particular point on a line of a record medium by providing a storage medium having a plurality of addressed cells which are serially assigned to the positions on the line of the record medium, the cell addresses ranging between first and second values. The cell assigned to the position which includes the particular point receives the first character of the string while all subsequent data characters are considered as pairs of data characters. One data character of the pair is entered into the memory cell having an address one unit closer to the first value than the address of the memory cell in which the previous character was loaded and for the other data character of the pair the contents of each memory cell is shifted to the memory cell having an address one unit closer to the second value and such other data character of the pair is loaded into the memory cell in which the one data character was initially loaded. Thereafter, the contents of the loaded memory cells are serially transferred to the display device.

A word recognition method from a classified phoneme string in the Lithan speech understanding system

Abstract: In this paper, we describe an optimum matching method between a classified phoneme string and a phoneme string of a lexical entry in a word dictionary. This method is performed by using a phoneme similarity matrix and a dynamic programming technique. A classified segment consists of the first candidate, second candidate, reliability and duration. The effect of coarticulation is normalized in this matching procedure. We also describe a word spotting method in continuous speech by modifying this method.

The Copying Power of One-State Tree Transducers

Abstract: One-state deterministic top-down transducers (or tree homomorphisms) cannot handle ''prime copying'', i.e. their class of output (string) languages is not closed under the operation L ( -> { (w)^f(n) | w in L, f(n) >= 1 } ) , where f is any integer function whose range contains numbers with arbitrary large prime factors (such as a polynomial). The exact amount of nonclosure under these copying operations is established for several classes of input (tree) languages. These results are relevant to the extended definable (or restricted parallel level) languages, to the syntax-directed translation of context-free languages and to the tree transducer hierarchy.

Post marketing drug surveillance, another string to the bow.

Abstract: Interest in post marketing surveillance of new drugs has been growing steadily for the past few years and has attracted the attention of Governments, the Pharmaceutical Industry and the Profession. There is agreement between these three that such surveillance is necessary even more so in the light of recent experience with Practolol but as yet no firm decision has been made as to the correct way in which this should be done. Views have been expressed in the three articles in the B .M.J . [1, 2, and 3]. Several individuals have presented schemes and most of these can be found in the proceedings of a recent symposium in Honolulu [4]. I should like to present some of the work we have been carrying out at Deddington Health Centre and outline our philosophy on drug research in the community because we feel it is apposite and complimentary to the many suggestions advanced so far. It was decided three years ago that to look at two variables, the drug and the patient, in each new situation or when a new drug was to be studied was not ideal so we decided to attempt to define one variable the patient as accurately as possible and to store and build on this information for future reference before a new drug was introduced. 7,300 records were analysed and relevant information placed on the OCHP [5] computer facility. Problem lists were created for each patient and when they attended afterwards these were updated and new problems added. Diagnostic categories, symptoms, signs or just problems are coded using OXMIS [6] coding and free recording has been allowed, firstly because problems with new drugs may not be easily categorised and secondly we can easily edit out at a later date information which is irrelevant. In our experience if too great a restriction is placed on recording then relevant information is lost because it is initially considered too trivial or unimportant. This process also enabled groups who regularly receive drugs from our dispensary, or fresh groups to be identified and placed on a recall register which is automatically generated by the computer. The second phase of this investigation was to identify groups who would qualify by their clinical picture to receive the particular drugs under study. So far, the areas investigated are bronchitis, hypertension (two studies: one in the over 60s and the other in the 20 to 60 age group) and allergy. Using the over-60 hypertensive study as an example, every patient (1,300) is being examined initially by a S. R. N. 1 assistant who records blood pressure on a random sphygmomanometer, completes a questionnaire and then presents this information each week to the G.P., a cardiologist and a geriatrician. The patients are then categorised and patients with problems or those receiving hypotensive therapy are seen by the consultant who decides if a placebo washout would harm the patient or if a problem exists which would exclude the patient from receiving a Betablocker. Each patient then has a battery of investigations and is admitted to a double blind randomised clinical trial. So far, 1,000 patients have been examined and about 400 qualify for the study and over 150 are receiving treatment. Thus, our intention is to admit as many patients in our community to this study and follow them long term. It is felt that if other centres could be identified who would be willing to carry out a similar profiling of patients and about 30,000 problem lists created and maintained then this would be a useful adjunct to monitored release. Admittedly very small incidence side effects would not be identified but total population studies of this type and the close control imposed