Showing papers on "String (computer science) published in 2000"

Text Classification using String Kernels

Abstract: We introduce a novel kernel for comparing two text documents. The kernel is an inner product in the feature space consisting of all subsequences of length k. A subsequence is any ordered sequence of k characters occurring in the text though not necessarily contiguously. The subsequences are weighted by an exponentially decaying factor of their full length in the text, hence emphasising those occurrences which are close to contiguous. A direct computation of this feature vector would involve a prohibitive amount of computation even for modest values of k, since the dimension of the feature space grows exponentially with k. The paper describes how despite this fact the inner product can be efficiently evaluated by a dynamic programming technique. A preliminary experimental comparison of the performance of the kernel compared with a standard word feature space kernel [6] is made showing encouraging results.

STRING: a web-server to retrieve and display the repeatedly occurring neighbourhood of a gene

Abstract: The repeated occurrence of genes in each other’s neighbourhood on genomes has been shown to indicate a functional association between the proteins they encode. Here we introduce STRING (search tool for recurring instances of neighbouring genes), a tool to retrieve and display the genes a query gene repeatedly occurs with in clusters on the genome. The tool performs iterative searches and visualises the results in their genomic context. By finding the genomically associated genes for a query, it delineates a set of potentially functionally associated genes. The usefulness of STRING is illustrated with an example that suggests a functional context for an RNA methylase with unknown specificity. STRING is available at http://www.bork.embl-heidelberg.de/STRING

An improved error model for noisy channel spelling correction

Abstract: The noisy channel model has been applied to a wide range of problems, including spelling correction. These models consist of two components: a source model and a channel model. Very little research has gone into improving the channel model for spelling correction. This paper describes a new channel model for spelling correction, based on generic string to string edits. Using this model gives significant performance improvements compared to previously proposed models.

Grammar-based codes: a new class of universal lossless source codes

Abstract: We investigate a type of lossless source code called a grammar-based code, which, in response to any input data string x over a fixed finite alphabet, selects a context-free grammar G/sub x/ representing x in the sense that x is the unique string belonging to the language generated by G/sub x/. Lossless compression of x takes place indirectly via compression of the production rules of the grammar G/sub x/. It is shown that, subject to some mild restrictions, a grammar-based code is a universal code with respect to the family of finite-state information sources over the finite alphabet. Redundancy bounds for grammar-based codes are established. Reduction rules for designing grammar-based codes are presented.

Efficient concurrent zero-knowledge in the auxiliary string model

Abstract: We show that if any one-way function exists, then 3-round concurrent zero-knowledge arguments for all NP problems can be built in a model where a short auxiliary string with a prescribed distribution is available to the players. We also show that a wide range of known efficient proofs of knowledge using specialized assumptions can be modified to work in this model with no essential loss of efficiency. We argue that the assumptions of the model will be satisfied in many practical scenarios where public key cryptography is used, in particular our construction works given any secure public key infrastructure. Finally, we point out that in a model with preprocessing (and no auxiliary string) proposed earlier, concurrent zero-knowledge for NP can be based on any one-way function.

Information management, retrieval and display system and associated method

Abstract: The system searches through an informational resource, such as one or more documents (18), or a stream of information and displays the search results in a format based on a user-selected display criteria or hierarchy (32). The display hierarchy will allow the user to effectively obtain items of interest. The system performs a method for retrieving information that includes the steps of: (a) dividing the informational resource into finite elements; (b) assigning a categorical tag to each of the elements; (c) generating a searchable database record (23) for each element where each record includes at least one string contained within the element; (d) supplying a search string; (e) searching the database for records containing the search string; (f) arranging the results in a hierarchal structure according, at least in part, to the data in the categorical tags assigned to the elements returned by the search; and (g) displaying the results in the hierarchical structure.

A communication terminal having a predictive editor application

Abstract: A communication terminal having a display; a keypad having a plurality of keys associated with several letters each; processor means controlling the display means in accordance with the operation of the keypad The communication terminal has a predictive editor program for generating an output containing words matching a received string of ambiguous key strokes Furthermore the communication terminal has on editor application controlled by the processor means for editing a text based on the predictive editor programs interpretation of key strokes The editor application comprises means for storing string of entered words, means for storing a sequence of key stokes, said sequence is updated upon the occurrence of a new key stroke, and being used as input to the predictive editor program, means for storing a list of matching words received from said predictive editor program The processor means combines the text string and one word from the list of matching words for displaying in the display of at least a part of said text string and one word from the list of matching words, said one word from the list of matching words is marked in comparison to the remaining part of the text string and added to the text string upon acknowledgement by the user The terminal comprises means for acknowledging a word suggested by said predictive editor program, and said acknowledging means includes a key on the keypad indicating that a word suggested by said predictive editor program is a part of a compound word, said editor application fixes the suggested word as an acknowledged part of the compound word, resets said sequence of key strokes serving as input for said predictive editor program in order to determine another part of the compound word independently of the acknowlegded part of the compound word

Methods and associated apparatus for downhole data retrieval, monitoring and tool actuation

Abstract: A system of downhole communication and control is provided in methods and associated apparatus for data retrieval, monitoring and tool actuation. In a described embodiment, an item of equipment installed in a tubular string has a first communication device associated therewith. A tool conveyed into the tubular string has a second communication device therein. Communication is established between the first and second devices. Such communication may be utilized to control operation of the tool, retrieve status information regarding the item of equipment, supply power to the first device and/or identify the item of equipment to the tool.

Speech synthesis with prosodic model data and accent type

Abstract: A speech synthesizing method includes determining the accent type of the input character string, selecting the prosodic model data from a prosody dictionary for storing typical ones of the prosodic models representing the prosodic information for the character strings in a word dictionary, based on the input character string and the accent type, transforming the prosodic information of the prosodic model when the character string of the selected prosodic model is not coincident with the input character string, selecting the waveform data corresponding to each character of the input character string from a waveform dictionary, based on the prosodic model data after transformation, and connecting the selected waveform data with each other. Therefore, a difference between an input character string and a character string stored in a dictionary is absorbed, then it is possible to synthesize a natural voice.

Method and apparatus for integrating resolution services, registration services, and search services

Abstract: An input request may be processed by a device such as a network access apparatus, servlet, applet, stand-alone executable program, or a user interface element such as a microphone, text box object or location field of a web browser. When such an input request is determined to include a valid domain name, it may then be determined whether to perform a search request with the input as a literal string. A search request may be initiated by selecting an exact phrase option from a listbox or by surrounding the input with a delimiter such as the quote sign (e.g., “example.com”) to process the detected domain name as a literal string, otherwise a domain name detected from input may be processed as a registration and/or resolution request. When it is determined that the input is instead processed as a resolution and/or registration request, then the resolvability and/or availability of the domain name may be determined. When the domain name is determined to be not resolvable, then the domain name may be processed as a registration request.

System and method for placing active tags in HTML document

Abstract: The method and the information processing system dynamically creates an HTML document with at least one embedded hyperlink code therein. The HTML document is based upon a source document provided by a manufacturer or a supplier of services. Typically, the system and the method is operable in a client-server computer environment. A database is provided on the server computer system which database associates location data of a plurality of data strings in the source document with hyperlink addresses. The location data in the database maps at least one predetermined data string in the source document. An HTML document, based upon the source document, is published with an image tag on, in or near the predetermined data string. As an example, the string may be a “part number” or a string of words “SONY PLAYSTATION II.”. The published HTML document has an image tag on, at or near the part number and a map attribute command which supplies or generates an HTML location data unique to the image tag location in the HTML document when the browser calls the server's common gateway interface (CGI). The image tag URL points to the database on the server. The server, via the database provides a corresponding hyperlink address, associated with the unique location data correlated to the HTML location data, to the browser on the client computer system. The method and the system then publishes and embeds in the original or initial HTML document at, on or near the predetermined data string or part number an active hyperlink tag (an embedded code) with the corresponding hyperlink address obtained from the database.

String stability analysis of adaptive cruise controlled vehicles

Abstract: A framework for string-stability analysis is formulated in this paper. First, uniform string will be analyzed. We will then present analysis results on strings of mixed vehicles. A String-Stability Margin (SSM) index is defined in this paper to give a quantitative measurement of any ACC design. Simulation results using MATLAB and a microscopic traffic simulator will also be given to demonstrate the effectiveness of ACC systems on traffic smoothness.

System and method for lossless data compression and decompression

Abstract: Systems and methods for providing lossless data compression and decompression are disclosed which exploit various characteristics of run-length encoding, parametric dictionary encoding, and bit packing to comprise an encoding/decoding process having an efficiency that is suitable for use in real-time lossless data compression and decompression applications In one aspect, a method for compressing input data comprising a plurality of data blocks comprises the steps of: detecting if the input data comprises a run-length sequence of data blocks; outputting an encoded run-length sequence, if a run-length sequence of data blocks is detected; maintaining a dictionary comprising a plurality of code words, wherein each code word in the dictionary is associated with a unique data block string; building a data block string from at least one data block in the input data that is not part of a run-length sequence; searching for a code word in the dictionary having a unique data block string associated therewith that matches the built data block string; and outputting the code word representing the built data block string

System and method for referencing object instances and invoking methods on those object instances from within a speech recognition grammar

Abstract: A system and method for referencing object instances of an application program, and invoking methods on those object instances from within a recognition grammar. A mapping is maintained between at least one string formed using characters in the character set of the recognition grammar and instances of objects in the application program. During operation of the disclosed system, when either the application program or script within a recognition grammar creates an application object instance, a reference to the object instance is added to the mapping table, together with an associated unique string. The unique string may then be used within scripting language in tags of the rule grammar, in order to refer to the object instance that has been “registered” by the application program in this way. A tags parser program may be used to interpret such object instance names while interpreting the scripting language contained in tags included in a recognition result object. The tags parser program calls the methods on such object instances directly, eliminating the need for logic in the application program to make such calls in response to the result tag information.

Universal lossless compression via multilevel pattern matching

Abstract: A universal lossless data compression code called the multilevel pattern matching code (MPM code) is introduced. In processing a finite-alphabet data string of length n, the MPM code operates at O(log log n) levels sequentially. At each level, the MPM code detects matching patterns in the input data string (substrings of the data appearing in two or more nonoverlapping positions). The matching patterns detected at each level are of a fixed length which decreases by a constant factor from level to level, until this fixed length becomes one at the final level. The MPM code represents information about the matching patterns at each level as a string of tokens, with each token string encoded by an arithmetic encoder. From the concatenated encoded token strings, the decoder can reconstruct the data string via several rounds of parallel substitutions. A O(1/log n) maximal redundancy/sample upper bound is established for the MPM code with respect to any class of finite state sources of uniformly bounded complexity. We also show that the MPM code is of linear complexity in terms of time and space requirements. The results of some MPM code compression experiments are reported.

Observation and Analysis of Suzuki String Teaching.

Abstract: This study is an examination of teacher and student behavior in 48 violin and cello lessons taught by 12 expert Suzuki string teachers. One representative excerpt of work on a repertoire piece that...

Method and apparatus for defining search queries and user profiles and viewing search results

Abstract: A user interface for querying and displaying records form a database employs a physical metaphor for the process of constructing queries and viewing results. In one embodiment, the search criteria are shown as strings of beads in a three-dimensional scene, each bead representing a criterion and each string representing a different category. For example the criteria, drama, action, suspense, and horror may be included in a category of genre. Criteria are selected to form a query by moving corresponding beads to a query string. User preference profiles can be constructed in the same way. Profiles can be saved and represented as bead strings that can be used in further interactions in the same manner as criteria beads. Results are displayed in a three-dimensional scene also. The accuracy of the match between retrieved records and the query correspond to the placement of results, also represented as beads, along the Z-axis of the scene.

Input of symbols

Abstract: A mobile phone has a display and a keypad which comprises a plurality of keys. Each key has associated with it a plurality of different symbols. The keypad is used to enter symbols in the form of Pinyin strings ( 25 ) into the display which are then used to determine a candidate list ( 26 ) of Chinese characters which are presented in the display. Symbols are entered into the display by pressing respective keys once or more than one times in rapid succession. Selection of a symbol is only permitted if it corresponds to a valid Pinyin string ( 25 ), either in isolation or in combination with one or more symbols entered in a previous selection. Characters chosen from the candidate list are entered into a message ( 24 ) in the display.

Method for producing summaries of text document

Abstract: A computer method for preparing a summary string (19) from a source document of encoded text (17). The method comprises comparing a training set of encoded text documents (10) with manually generated summary strings (11) associated therewith to learn probabilities (13) that a given summary word or phrase will appear in summary strings (19) given a source word or phrase appears in encoded text documents (17) and constructing from the source document a summary string containing summary words or phrases (19) having the highest probabilities of appearing in a summary string (19) based on the learned probabilities established in the previous step.

Language input architecture for converting one text form to another text form with modeless entry

Abstract: A language input architecture converts input strings of phonetic text (e.g., Chinese Pinyin) to an output string of language text (e.g., Chinese Hanzi) in a manner that minimizes typographical errors and conversion errors that occur during conversion from the phonetic text to the language text. The language input architecture has a search engine, one or more typing models, a language model, and one or more lexicons for different languages. Each typing model is trained on real data, and learns probabilities of typing errors. The typing model is configured to generate a list of probable typing candidates that may be substituted for the input string based on probabilities of how likely each of the candidate strings was incorrectly entered as the input string. The probable typing candidates may be stored in a database. The language model provides probable conversion strings for each of the typing candidates based on probabilities of how likely a probable conversion output string represents the candidate string. The search engine combines the probabilities of the typing and language models to find the most probable conversion string that represents a converted form of the input string. By generating typing candidates and then using the associated conversion strings to replace the input string, the architecture eliminates many common typographical errors. When multiple typing models are employed, the architecture can automatically distinguish among multiple languages without requiring mode switching for entry of the different languages.

The ups and downs of protein topology; rapid comparison of protein structure.

Abstract: Protein topology can be described at different levels. At the most fundamental level, it is a sequence of secondary structure elements (a "primary topology string"). Searching predicted primary topology strings against a library of strings from known protein structures is the basis of some protein fold recognition methods. Here a method known as TOPSCAN is presented for rapid comparison of protein structures. Rather than a simple two-letter alphabet (encoding strand and helix), more complex alphabets are used encoding direction, proximity, accessibility and length of secondary elements and loops in addition to secondary structure. Comparisons are made between the structural information content of primary topology strings and encodings which contain additional information ("secondary topology strings"). The algorithm is extremely fast, with a scan of a large domain against a library of more than 2000 secondary structure strings completing in approximately 30 s. Analysis of protein fold similarity using TOPSCAN at primary and secondary topology levels is presented.

Utterance verification in continuous speech recognition: decoding and training procedures

Abstract: This paper introduces a set of acoustic modeling and decoding techniques for utterance verification (UV) in hidden Markov model (HMM) based continuous speech recognition (CSR). Utterance verification in this work implies the ability to determine when portions of a hypothesized word string correspond to incorrectly decoded vocabulary words or out-of-vocabulary words that may appear in an utterance. This capability is implemented here as a likelihood ratio (LR) based hypothesis testing procedure for, verifying individual words in a decoded string. There are two UV techniques that are presented here. The first is a procedure for estimating the parameters of UV models during training according to an optimization criterion which is directly related to the LR measure used in UV. The second technique is a speech recognition decoding procedure where the "best" decoded path is defined to be that which optimizes a LR criterion. These techniques were evaluated in terms of their ability to improve UV performance on a speech dialog task over the public switched telephone network. The results of an experimental study presented in the paper shows that LR based parameter estimation results in a significant improvement in UV performance for this task. The study also found that the use of the LR based decoding procedure, when used in conjunction with models trained using the LR criterion, can provide as much as an 11% improvement in UV performance when compared to existing UV procedures. Finally, it was also found that the performance of the LR decoder was highly dependent on the use of the LR criterion in training acoustic models. Several observations are made in the paper concerning the formation of confidence measures for UV and the interaction of these techniques with statistical language models used in ASR.

Optimal amnesic probabilistic automata or how to learn and classify proteins in linear time and space.

Abstract: Statistical modeling of sequences is a central paradigm of machine learning that finds multiple uses in computational molecular biology and many other domains. The probabilistic automata typically built in these contexts are subtended by uniform, fixed-memory Markov models. In practice, such automata tend to be unnecessarily bulky and computationally imposing both during their synthesis and use. Recently, D. Ron, Y. Singer, and N. Tishby built much more compact, tree-shaped variants of probabilistic automata under the assumption of an underlying Markov process of variable memory length. These variants, called Probabilistic Suffix Trees (PSTs) were subsequently adapted by G. Bejerano and G. Yona and applied successfully to learning and prediction of protein families. The process of learning the automaton from a given training set S of sequences requires theta(Ln2) worst-case time, where n is the total length of the sequences in S and L is the length of a longest substring of S to be considered for a candidate state in the automaton. Once the automaton is built, predicting the likelihood of a query sequence of m characters may cost time theta(m2) in the worst case. The main contribution of this paper is to introduce automata equivalent to PSTs but having the following properties: Learning the automaton, for any L, takes O (n) time. Prediction of a string of m symbols by the automaton takes O (m) time. Along the way, the paper presents an evolving learning scheme and addresses notions of empirical probability and related efficient computation, which is a by-product possibly of more general interest.

Searching monophonic patterns within polyphonic sources

Abstract: The string matching problem for strings in which one should find the occurrences of a pattern string within a text, is well-studied in the past literature. The problem can be solved efficiently, e. g., by using so-called bit-parallel algorithms. We adapt the bit-parallel approach to music information retrieval. We consider a situation where the pattern is monophonic and the text (the musical source) is polyphonic, that is, the pattern is a sequence of symbols, while the source is a sequence of sets of symbols (i.e., chords). The application of the bit-parallel approach is straightforward, if the transposition invariance is not allowed in the matching. However, the problem becomes trickier with transposition invariance, a necessary property in practice. We present algorithms for both cases. Our main contribution is a linear-time transposition-invariant filtering-algorithm for static music databases. We show by experiments that, if the average size of the chords keeps reasonably low, our filtering method clearly outperforms a straightforward approach.

Document image decoding using an integrated stochastic language model

Abstract: A text recognition system represents the decoded message of a document image as a path through an image network. A method for integrating a language model into the network selectively expands the network to accommodate the language model only for certain ones of the paths in the network, effectively managing the memory storage requirements and computational complexities of integrating the language model efficiently into the network. The language model generates probability distributions indicating the probability of a certain character occurring in a string, given one or more previous characters in the string. Selectively expanding the image network is achieved by initially using upper bounds on the language model probabilities on the branches of an unexpanded image network. A best path search operation is then performed to determine an estimated best path through the image network using these upper bound scores. After decoding, only the nodes on the estimated best path are expanded with new nodes and with branches incoming to the new nodes that accommodate new language model scores reflecting actual character histories in place of the upper bound scores. Decoding and selectively expanding the image network are repeated until the final output transcription of the text image has been produced.

Voice and telephone keypad based data entry for interacting with voice information services

Abstract: This invention relates in general to methods for receiving and interpreting an alphanumeric input string entered on a telephone keypad using one keystroke per input string character. The set of matching objects in a database are selected and sorted and presented to the user as an ordered list from which the user may select the desired item on the list through a further numeric keystroke entry or through a spoken selection that is matched against a restricted voice recognition grammar for improved recognition accuracy. In an alternative embodiment, the matching objects in the database are selected and sorted and the response associated with each matched object is presented in sorted sequence.

Evolutionary systems: a language generating device inspired by evolving communities of cells

Abstract: We introduce a language generating device based on string operations suggested by the evolution of cell populations, called evolutionary system. Cells are represented by strings which describe their DNA sequences. The cell community evolves according to gene mutations and cell divison defined by operations on strings. The paper deals with the generative power of these mechanisms (a characterization of the class of recursively enumerable languages is presented) and the dynamics of the string population. A connection between the growth function of D0L systems and the population growth relation of evolutionary systems is also given.

Automatically expanding abbreviated character substrings

Abstract: A server machine receives an input string of characters from a client machine, and the string includes at least one abbreviated substring preceded and followed by word delimiters. Each abbreviated substring represents an expanded substring. The server machine automatically finds one of the abbreviated substrings based on the preceding and following word delimiters, determines that it is one of a set of abbreviated substrings, and produces an expanded version of the string of characters with the abbreviated substring replaced by its expanded substring. The case of the beginning character of the expanded substring can be the same as that of abbreviated substring. The expanded substring can depend on time, such as the current time.