String (computer science)

About: String (computer science) is a research topic. Over the lifetime, 19430 publications have been published within this topic receiving 333247 citations. The topic is also known as: str & s.

Constant-round coin-tossing with a man in the middle or realizing the shared random string model

Abstract: We present the first constant-round non-malleable commitment scheme and the first constant-round non-malleable zero-knowledge argument system, as defined by Dolev, Dwork and Naor (1991). Previous constructions either used a non-constant number of rounds, or were only secure under stronger setup assumptions. An example of such an assumption is the shared random string model where we assume all parties have access to a reference string that was chosen uniformly at random by a trusted dealer. We obtain these results by defining an adequate notion of non-malleable coin-tossing, and presenting a constant-round protocol that satisfies it. This protocol allows us to transform protocols that are non-malleable in (a modified notion of) the shared random string model into protocols that are non-malleable in the plain model (without any trusted dealer or setup assumptions). Observing that known constructions of a non-interactive non-malleable zero-knowledge argument systems in the shared random string model (De Santis et. al., 2001) are in fact non-malleable in the modified model, and combining them with our coin-tossing protocol we obtain the results mentioned above. The techniques we use are different from those used in previous constructions of non-malleable protocols. In particular our protocol uses diagonalization and a non-black-box proof of security (in a sense similar to Barak's zero-knowledge argument (2001)).

Burst tries: a fast, efficient data structure for string keys

Abstract: Many applications depend on efficient management of large sets of distinct strings in memory. For example, during index construction for text databases a record is held for each distinct word in the text, containing the word itself and information such as counters. We propose a new data structure, the burst trie, that has significant advantages over existing options for such applications: it uses about the same memory as a binary search tree; it is as fast as a trie; and, while not as fast as a hash table, a burst trie maintains the strings in sorted or near-sorted order. In this paper we describe burst tries and explore the parameters that govern their performance. We experimentally determine good choices of parameters, and compare burst tries to other structures used for the same task, with a variety of data sets. These experiments show that the burst trie is particularly effective for the skewed frequency distributions common in text collections, and dramatically outperforms all other data structures for the task of managing strings while maintaining sort order.

Language input architecture for converting one text form to another text form with tolerance to spelling, typographical, and conversion errors

Abstract: A language input architecture converts input strings of phonetic text to an output string of 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. 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 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.

Associating geographic-related information with objects

Abstract: Techniques for associating geographic-related information with objects are described. In one implementation, a search is conducted on a keyword string of one or more keywords descriptive or otherwise representative of a geographically-relevant object. If a location is identified, geographic-related semantic information of the location is associated with the geographically-relevant object. In some cases, multiple possible locations may be identified as a result of searching the keyword string. If multiple locations are identified, a probable location is determined and then geographic-related semantic information of the probable location is associated with the geographically-relevant object described by the keyword string.

Solar power generation apparatus and control method therefor

Abstract: When a ground fault occurs in some solar battery string, this solar battery string may be disconnected and operation of a solar power generation system may be continued. If the open-circuit voltage of the solar battery string is high, a safety problem arises. If the open-circuit voltage is decreased, the conversion efficiency decreases. Therefore, an intermediate switch is provided midway along the solar battery string. When a ground fault occurs, this solar battery string where the ground fault has occurred is divided into substrings.