34064761
A Parallel Execution of Functional Logic Language with Lazy Evaluation
39501622
A logic programming approach to hybrid knowledge representation
A new hybrid system called Sphinx is presented which combines classification-based reasoning with logic programming technique. It consists of two major components: a terminological component and an assertional one. The former uses a frame-based knowledge representation scheme based on classification and the latter is a theorem prover based on Horn logic. The assertional component can also handle a first-order query language and wh-questions. A new knowledge base maintenance mechanism based on the negation as failure inference rule enables Sphinx to support incremental assertions and retractions. In addition, Sphinx provides explanation capability to help the user in developing and debugging knowledge bases.
1326236
History Sensitive String for Multiple Alphabets
In most cases, to represent characters in a computer, conventional code systems such as ASCII, EBCDIC, or BCD, whose code-length is uniform, have been used. In some countries, where the native language is not English, people can easily adapt their alphabet to these code systems by simply replacing the Enghsh alphabet with the alphabet of their native language. In other countries, especially in Korea and Japan, a straightforward application of the conventional code system is not possible. This is because, to compose a sentence, people customarily intermix words each of which may be constructed by different alphabets. For example, in Korea, they have an alphabet for their native language called Hangul. Hangul is a complete language by which Koreans can communicate with each other. However, Korean culture was influenced by China and more recently by the western countries. This results in widespread usage of four different types of documents in Korea. Documents may be written in Hangul only, Hangul with Chinese words, Hangul with English words, and Hangul with both Chinese and English words. Even in these cases, Hangul is the main alphabet. Another example of the applications of multiple alphabets in a single text are the high level language programs in Korean environment where the program language is a popular high level language such as PASCAL, C, or LISP, but variable names or data in the program may consist of Korean characters [7,9]. In this case, the main alphabet is English. Another example using heterogeneous characters is the use of attributes such as color, size, or font in high quality text editors. In such cases, characters from multiple alphabets should be used in a computer. Since each alphabet may have characteristics different from each other, some coding methods for multiple alphabets can be considered. When the sizes of the alphabets are significantly different from each other, employment of codes of a uniform length is prohibitively expensive. There are two different techniques to encode the multiple alphabets into a single code system. In the following sections, two coding methods of multiple alphabets are generalized, and their advantages and disadvantages are analyzed.
3145493
KPSP: A Knowledge Programming System based on Prolog
29923826
A Relational Dataflow Database Machine Based on Hierarchical Ring Network
32944410
SPHINX - A Hybrid Knowledge Representation System
398600
What's new on the web?: the evolution of the web from a search engine perspective
We seek to gain improved insight into how Web search engines shouldcope with the evolving Web, in an attempt to provide users with themost up-to-date results possible. For this purpose we collectedweekly snapshots of some 150 Web sites over the course of one year,and measured the evolution of content and link structure. Our measurements focus on aspects of potential interest to search engine designers: the evolution of link structure over time, the rate ofcreation of new pages and new distinct content on the Web, and the rate of change of the content of existing pages under search-centric measures of degree of change.Our findings indicate a rapid turnover rate of Web pages, i.e.,high rates of birth and death, coupled with an even higher rate ofturnover in the hyperlinks that connect them. For pages that persistover time we found that, perhaps surprisingly, the degree of contentshift as measured using TF.IDF cosine distance does not appear to beconsistently correlated with the frequency of contentupdating. Despite this apparent non-correlation, the rate of content shift of a given page is likely to remain consistent over time. That is, pages that change a great deal in one week will likely change by a similarly large degree in the following week. Conversely, pages that experience little change will continue to experience little change. We conclude the paper with a discussion of the potential implications ofour results for the design of effective Web search engines.
400964
Searching the Web
We offer an overview of current Web search engine design. After introducing a generic search engine architecture, we examine each engine component in turn. We cover crawling, local Web page storage, indexing, and the use of link analysis for boosting search performance. The most common design and implementation techniques for each of these components are presented. For this presentation we draw from the literature and from our own experimental search engine testbed. Emphasis is on introducing the fundamental concepts and the results of several performance analyses we conducted to compare different designs.
122713
Joint transmitter and receiver optimization in additive cyclostationary noise
A joint optimization of transmitter and receiver is considered for strictly band-limited linear modulations in additive cyclostationary noise. Under the assumptions that the period of the cyclostationarity of the noise is the same as the inverse of the symbol transmission rate and that the noise has a positive-definite autocorrelation function, the optimum transmitter and receiver waveforms that jointly minimize the mean-squared error at the output of the linear receiver are derived with the data sequence modeled as a wide-sense stationary (WSS) colored random process and the channel modeled as a linear time-invariant system with a general frequency-selective impulse response. Numerical results show that this joint optimization technique leads to a significant performance improvement over the systems with receiver-only optimization and the systems with no transmitter and receiver optimizations.
171503
Parallel crawlers
In this paper we study how we can design an effective parallel crawler. As the size of the Web grows, it becomes imperative to parallelize a crawling process, in order to finish downloading pages in a reasonable amount of time. We first propose multiple architectures for a parallel crawler and identify fundamental issues related to parallel crawling. Based on this understanding, we then propose metrics to evaluate a parallel crawler, and compare the proposed architectures using 40 million pages collected from the Web. Our results clarify the relative merits of each architecture and provide a good guideline on when to adopt which architecture.
516682
Efficient Crawling Through URL Ordering
In this paper we study in what order a crawler should visit the URLs it has seen, in order to obtain more "important" pages first. Obtaining important pages rapidly can be very useful when a crawler cannot visit the entire Web in a reasonable amount of time. We define several importance metrics, ordering schemes, and performance evaluation measures for this problem. We also experimentally evaluate the ordering schemes on the Stanford University Web. Our results show that a crawler with a good ordering scheme can obtain important pages significantly faster than one without.