Abstract:
A system plots results of a data search. The system executes one or more search queries to search stored data. The system receives results of the executed one or more search queries, where the results are orderable by at least one search characteristic. The system designates a visual representation for each of the results. The system plots each of the visual representations on a multi-dimensional graphical display, where at least one dimension of the multi-dimensional graphical display corresponds to the at least one search characteristic.

Description:
RELATED APPLICATIONS 
     This application is a continuation of co-pending U.S. patent application Ser. No. 12/622,871, filed on Nov. 20, 2009, which is a continuation of co-pending U.S. patent application Ser. No. 10/813,229, filed Mar. 31, 2004, now U.S. Pat. No. 7,660,822, the disclosures of which are hereby incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to information searching systems and, more particularly, to systems and methods for sorting and displaying searches of aggregated information in multiple dimensions. 
     2. Description of Related Art 
     Existing information searching systems use search queries to search through aggregated data to retrieve specific information that corresponds to the received search queries. Such information searching systems may search information stored locally, or in distributed locations. The World Wide Web (“web”) is one example of information stored in distributed locations. The web contains a vast amount of information and locating a desired portion of that information, however, can be challenging. This problem is compounded because the amount of information on the web and the number of new users inexperienced at web searching are growing rapidly. 
     Search engines attempt to return hyperlinks to web documents in which a user is interested. Generally, search engines base their determination of the user&#39;s interest on search terms (called a search query) entered by the user. The goal of the search engine is to provide links to high quality, relevant results to the user based on the search query. Typically, the search engine accomplishes this by matching the terms in the search query to a corpus of pre-stored web documents. Web documents that contain the user&#39;s search terms are “hits” and are returned to the user. The search engine oftentimes ranks the documents using a ranking function based on the documents&#39; perceived relevance to the user&#39;s search terms. 
     In addition to determining relevance, existing search paradigms may use other dominant characteristics to sort the results of a search. For example, in shopping or product search (e.g., Froogle), users typically like to sort by price. As another example, when searching news stories or USENET/groups, users typically prefer to sort by date or recency. As a further example, when searching images, users may prefer to sort by image quality or image size. As yet another example, in geographic search, users may prefer to sort by distance. With existing search paradigms, users must choose to sort either by relevance or by the alternative characteristic, and can at best toggle between these modes. This creates a frustrating experience for the user in which important sorting dimensions are ignored (e.g., the user retrieves a lot of very cheap products that aren&#39;t what they wanted, or the user gets a lot of very recent articles that are not really about the topic they wanted). Existing search paradigms employed in any type of information searching system, thus, make it very difficult for users to easily find reasonably relevant data while, at the same time, also optimizing at least one other desired characteristic. 
     Accordingly, it would be desirable to implement a search paradigm in an information searching system that permits sorting and display of search results by multiple alternative characteristics. 
     SUMMARY OF THE INVENTION 
     Systems and methods, consistent with the principles of the invention, implement a search paradigm that permits users to search and sort data according to multiple characteristics. Such characteristics may include relevance or another alternative characteristic, such as, for example, price, date, recency, image quality, image size, or geographic distance. Consistent with the principles of the invention, results of a search that sorts by multiple characteristics may be displayed in a document that plots the results of the search in a multi-dimensional graph, with each dimension of the graph corresponding to one of the multiple characteristics. 
     According to one aspect consistent with the principles of the invention, a method of displaying the results of a search is provided. The method includes receiving one or more search queries. The method further includes searching stored data based on the one or more search queries to generate results, where the results are orderable by at least one search characteristic. The method also includes providing a document that includes a multi-dimensional graph of the results of the search, where at least one dimension of the multi-dimensional graph corresponds to the at least one search characteristic. 
     According to another aspect, a method of plotting results of a data search is provided. The method includes executing one or more search queries to search stored data. The method further includes receiving results of the executed one or more search queries, where the results are orderable by at least one search characteristic. The method also includes designating a visual representation for each of the results and plotting each of the visual representations on a multi-dimensional graphical display, where at least one dimension of the multi-dimensional graphical display corresponds to the at least one search characteristic. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, explain the invention. In the drawings, 
         FIG. 1  is a diagram of an overview of an exemplary implementation of the invention; 
         FIG. 2  is a diagram of an exemplary network in which systems and methods consistent with the principles of the invention may be implemented; 
         FIG. 3  is an exemplary diagram of a client and/or server of  FIGS. 1 &amp; 2  in an implementation consistent with the principles of the invention; 
         FIGS. 4A and 4B  are flowcharts of exemplary processing for providing multi-dimensional display documents according to an implementation consistent with the principles of the invention; 
         FIG. 5  is a diagram of an exemplary news search document according to an implementation consistent with the principles of the invention; 
         FIG. 6  is a diagram of an exemplary product search document according to an implementation consistent with the principles of the invention; 
         FIG. 7  is a diagram of an exemplary two-dimensional display document according to an implementation consistent with the principles of the invention; 
         FIG. 8  is a diagram of an exemplary document with news links according to an implementation consistent with the principles of the invention; and 
         FIG. 9  is a diagram of an exemplary news document according to an implementation consistent with the principles of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description of the invention refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. Also, the following detailed description does not limit the invention. 
     Systems and methods consistent with the principles of the invention implement a search paradigm that permits users to search and sort data according to multiple characteristics, such as, for example, relevance, price, date, recency, image quality, image size, or geographic distance. The results of the search may be plotted on a multi-dimensional graph, with each dimension of the graph corresponding to one of the multiple characteristics. 
     A “document,” as the term is used herein is to be broadly interpreted to include any machine-readable and machine-storable work product. A document may include an e-mail, a web site, a file, a combination of files, one or more files with embedded links to other files, a news group posting, a blog, a web advertisement, etc. In the context of the Internet, a common document is a web page. Web pages often include textual information and may include embedded information (such as meta information, images, hyperlinks, etc.) and/or embedded instructions (such as Javascript, etc.). 
     Exemplary System Overview 
       FIG. 1  illustrates a system overview of one exemplary implementation of the invention. As shown in  FIG. 1 , a server  120  may receive one or more data search queries  130  from a client  110  via, for example, a network (not shown). The one or more data search queries  130  may be explicitly provided by a user at the client  110 , or may, for example, be inferred from the user&#39;s past “web browsing” activity. The one or more search queries may be derived in any manner, such as, for example, user selection from a list of related search queries, user selection from a list of “canned” queries, etc. Server  120  may perform a search of aggregated data using the received one or more data search queries. The aggregated data may include data retrieved and aggregated from one or more data sources, such as, for example, news sources, image sources, product sources, or any other type of data source. 
     Server  120  may sort the results of the search using multiple characteristics derived, at least in part, from the received one or more data search queries. For example, in one implementation, server  120  may sort the results of the search based on relevance and one other characteristic, such as, for example, price, data, recency, image quality, image size, or geographic distance. In other implementations, server  120  may sort the results of the search based on multiple characteristics, such as any combination of three or more of the above noted characteristics. Using the results of the search and sort, server  120  may then provide a multi-dimensional display document  140  to client  110 . Multi-dimensional display document  140  may plot the results of the search with each of the multiple characteristics, used to sort the results of the search, being represented as a dimension on the plot. For example, if document  140  includes a two-dimensional plot, then one dimension may be relevance, and another dimension may be price. Multi-dimensional display document  140  may include any number of dimensions (e.g., 2, 3, 4, etc.). 
     Exemplary Network Configuration 
       FIG. 2  is an exemplary diagram of a network  200  in which systems and methods consistent with the principles of the invention may be implemented. Network  200  may include multiple clients  110  connected to multiple servers  120  and  210  via a network  220 . Network  220  may include a local area network (LAN), a wide area network (WAN), a telephone network, such as the Public Switched Telephone Network (PSTN), an intranet, the Internet, a memory device, another type of network, or a combination of networks. Two clients  110  and two servers  120  and  210  have been illustrated as connected to network  220  for simplicity. In practice, there may be more or fewer clients and servers. Also, in some instances, a client may perform the functions of a server and a server may perform the functions of a client. 
     Clients  110  may include client entities. An entity may be defined as a device, such as a wireless telephone, a personal computer, a personal digital assistant (PDA), a laptop, or another type of computation or communication device, a thread or process running on one of these devices, and/or an object executable by one of these devices. Servers  120  and  210  may include server entities that gather, process, search, and/or maintain documents in a manner consistent with the principles of the invention. Clients  110  and servers  120  and  210  may connect to network  220  via wired, wireless, and/or optical connections. 
     In an implementation consistent with the principles of the invention, server  120  may include a search engine  225  usable by users at clients  110 . Server  120  may implement a data aggregation service by crawling a corpus of documents (e.g., web pages) hosted on data source server(s)  210  and store information associated with these documents in a repository of crawled documents. The data aggregation service may be implemented in other ways, such as by agreement with the operator(s) of data source server(s)  210  to distribute their hosted documents via the data aggregation service. Server  120  may additionally provide multi-dimensional plots of data retrieved based on one or more search queries provided by users at clients  110 . Each dimension of a multi-dimensional plot may correspond to a characteristic of the one or more search queries used to sort the searched data. 
     Server(s)  210  may store or maintain documents that may be crawled by server  120 . Such documents may include data related to published news stories, products, images, user groups, geographic areas, or any other type of data. For example, server(s)  210  may store or maintain news stories from any type of news source, such as, for example, the Washington Post, the New York Times, Time magazine, or Newsweek. As another example, server(s)  210  may store or maintain data related to specific product data, such as product data provided by one or more product manufacturers. 
     While servers  120  and  210  are shown as separate entities, it may be possible for one or more of servers  120  and  210  to perform one or more of the functions of another one or more of servers  120  and  210 . For example, it may be possible that two or more of servers  120  and  210  are implemented as a single server. It may also be possible for a single one of servers  120  or  210  to be implemented as two or more separate (and possibly distributed) devices. 
     Exemplary Client/Server Architecture 
       FIG. 3  is an exemplary diagram of a client or server entity (hereinafter called “client/server entity”), which may correspond to one or more of clients  110  and servers  120  and  210 , according to an implementation consistent with the principles of the invention. The client/server entity may include a bus  310 , a processing unit  320 , an optional main memory  330 , a read only memory (ROM)  340 , a storage device  350 , one or more input devices  360 , one or more output devices  370 , and a communication interface  380 . Bus  310  may include one or more conductors that permit communication among the components of the client/server entity. 
     Processing unit  320  may include any type of software, firmware or hardware implemented processing device, such as, a microprocessor, a field programmable gate array (FPGA), combinational logic, etc. Main memory  330  may include a random access memory (RAM) or another type of dynamic storage device that stores information and instructions for execution by processing unit  320 , if processing unit  320  includes a microprocessor. ROM  340  may include a conventional ROM device or another type of static storage device that stores static information and/or instructions for use by processing unit  320 . Storage device  350  may include a magnetic and/or optical recording medium and its corresponding drive. 
     Input device(s)  360  may include one or more conventional mechanisms that permit an operator to input information to the client/server entity, such as a keyboard, a mouse, a pen, voice recognition and/or biometric mechanisms, etc. Output device(s)  370  may include one or more conventional mechanisms that output information to the operator, including a display, a printer, a speaker, etc. Communication interface  380  may include any transceiver-like mechanism that enables the client/server entity to communicate with other devices and/or systems. For example, communication interface  380  may include mechanisms for communicating with another device or system via a network, such as network  220 . 
     As will be described in detail below, the client/server entity, consistent with the principles of the invention, performs certain searching-related operations. The client/server entity may, in some implementations, perform these operations in response to processing unit  320  executing software instructions contained in a computer-readable medium, such as memory  330 . A computer-readable medium may be defined as one or more physical or logical memory devices and/or carrier waves. 
     The software instructions may be read into memory  330  from another computer-readable medium, such as data storage device  350 , or from another device via communication interface  380 . The software instructions contained in memory  330  may cause processing unit  320  to perform processes that will be described later. Alternatively, hardwired circuitry may be used in place of, or in combination with, software instructions to implement processes consistent with the principles of the invention. Thus, implementations consistent with the principles of the invention are not limited to any specific combination of hardware circuitry and software. 
     Exemplary Processing 
       FIGS. 4A and 4B  are flowcharts of exemplary processing for providing multi-dimensional display documents according to an implementation consistent with the principles of the invention. As one skilled in the art will appreciate, the processing exemplified by  FIGS. 4A and 4B  can be implemented in software and stored on a computer-readable memory, such as main memory  330 , ROM  340  or storage device  350  of server  120 . In other implementations, the processing exemplified by  FIGS. 4A and 4B  can be implemented in hardwired circuitry, such as combinational logic, within processing unit  320  of server  120 . 
     Processing may begin with server  120  accessing external data sources (e.g., from server(s)  210 ), fetching the data content stored at the data sources and aggregating the fetched data content in a local memory (act  405 ) ( FIG. 4A ). For example, server  120  may use a web crawler (e.g., web robot) that may access documents hosted by data source server(s)  210 . Data source server(s)  130  may host, for example, data content related to news, products, images, user groups, or other types of data content. The fetched data content may then be indexed and grouped, using conventional indexing and grouping algorithms (act  410 ). 
     Server  120  may then receive one or more search queries from a user at client  110  (act  415 ). Server  120  may support various types of search queries, such as, for example, searches by price, date, recency, image quality, image size or distance. In one implementation, server  120  may use one or more search queries derived in any type of manner. For example, any type of “clickable” query may be used by server  120 . Such “clickable” queries may, include, for example, selections from a list of related queries or selections from categories of queries. In another implementation, search queries entered by the user in the past may be ranked based on recency and frequency and made accessible through a menu placed on a search page for selection by the user. Selecting such a search query may reissue the search query. In a further implementation, one or more search queries may be inferred from the user&#39;s current or past browsing activity (e.g., a data search query may include an inferred set of keywords, etc.). Additionally, any combination of the above search queries may be supported by server  120 . 
     In one implementation of the invention directed to news searching (e.g., Google News), as shown in  FIG. 5 , a user may enter search text in a news search page  500 . News search page  500  may include various search features that permit the user to specify customized search parameters. News search page  500  may support search query forms such as (a) one or more keywords (e.g., ‘with all of the words,’ ‘with the exact phrase,’ ‘with at least one of the words,’ ‘without the words’) (b) topical categories (e.g., ‘topic=sports,’ ‘topic=crime’; (c) geographical categories (e.g., ‘geo=Asia,’ ‘geo=USA’); (d) geographical reporting areas (e.g., U.S. newspapers, European newspapers, etc.); (e) restrictions on the news sources to be considered (e.g., ‘return only articles from the news sources named,’ ‘do not return articles from the new source named’); and/or (g) a time window that defines a start and end of a time interval from which articles may be retrieved. A search query may additionally include any combination of the above forms of search query. 
     In another implementation of the invention directed to product searching, as shown in  FIG. 6 , a user may enter search text in a product search page  600 . Product search page  600  may include various search features that permit the user to specify customized search parameters. Product search page  600  may support search query forms such as (a) one or more keywords (e.g., ‘with all of the words,’ ‘with the exact phrase,’ ‘with at least one of the words,’ ‘without the words’); (b) a product price range (e.g., ‘display products whose price is between’); (c) a specification of where the one or more keywords should occur (e.g., ‘in the product name or description,’ ‘in the product description’); (d) a product category (e.g., ‘return products from the category’); (e) a specification of whether to group by store (e.g., ‘group by store,’ ‘show all products’); (f) a view selection (e.g., ‘list view,’ ‘grid view,’ ‘graph view’); and/or (g) a time window that defines a start and end of a time interval from which product data may be retrieved. A search query may additionally include any combination of the above forms of search query. 
     Server  120  may then store the one or more search queries in local memory (e.g., main memory  330 , ROM  340  or storage device  350 ) (act  420 ). Server  120 , using search engine  225 , may execute the one or more search queries (act  425 ). The results of the executed search queries may be sorted using existing sorting techniques. Such sorting techniques may, for example, sort the results of the executed search queries by relevance. The sorting techniques may further sort the results of the executed search queries by one or more additional characteristics, such as, for example, price, date, recency, image quality, image size, geographic distance, etc. 
     The sorted results of the one or more search queries may be provided to the user as a multi-dimensional display document (act  430 ) ( FIG. 4B ). The multi-dimensional display document may include a multi-dimensional graph of the sorted results of the one or more search queries, where each dimension of the graph corresponds to a characteristic of the executed search. For example, each dimension of the multi-dimensional display may correspond to one of relevance, price, date, recency, image quality, image size, geographic distance or any other appropriate search characteristic. Each search query result may be represented by small summaries, such as, for example, a small thumbnail image, an icon, or a fragment of text (e.g., a single word or short phrase). Since any form of summary may take up non-zero area in the plot of the multi-dimensional display, not all search results may be able to be displayed simultaneously on a single display document. In such a case, the plot may span across multiple pages of the document (i.e., a user may “page” from one page of the document to the next to view all of the results). In some implementations of the invention, the size of each of the summaries of the results may vary (e.g., more relevant equals a bigger icon or image). 
     Because results may not be points on the plot, two results may overlap if centered about their true points. Therefore, consistent with the invention, the results may not have to be positioned exactly on the multi-dimensional plot. Results plotted on a dimension corresponding to relevance, in particular, may have their position shifted to a significant extent along the relevance dimension. So long as the relative ordering along the different dimensions is substantially preserved, some liberties may be taken in order to plot more results on the multi-dimensional display document. Optimal packing to preserve certain constraints of minimizing out-of-position-ness may likely be NP-hard. However, several simple greedy solutions may be possible to shift result positions slightly to fit more results in the multi-dimensional display document, and to make sure that whatever results are displayed may not be too far from their correct positions. In some implementations, for example, most relevant to least relevant results may be positioned accurately, but if there is overlap with a prior result, then results may be “shifted” in the less relevant direction until there is no overlap. Or, alternatively, an overlapping ‘more relevant’ result can be shifted up or down on the other axis up X % of the size of the thumbnails if it will prevent an overlap. However, this shift should be performed only if it also preserves the relative ordering along the other dimension with all currently positioned results. 
     In one implementation, a fixed number of results may be positioned per “page” of the multi-dimensional display document. For example, each “page” may include the N most relevant results, or the N most relevant results and the M results that optimize another dimension (e.g., 10 most relevant and 10 cheapest in price). Displaying the N most relevant results, and the M results that optimize another dimension, provides advantage over a simple list because it simultaneously shows the relevance of the results and the ordering of the results in at least one other dimension. 
     In another implementation, the particular overlaps on the plot might determine what results get displayed (e.g., continue including more results until there is room for no more, or until a threshold on number or relevance is passed). In yet another implementation, more relevant results may be permitted to overlap on top of less relevant results, but the amount of overlap may be permitted to increase only as relevance decreases, so that from the more relevant side of the plot to the less relevant side there is a sort of “fanning-out” with more and more results able to “peek out” from under their “neighbors.” 
     Consistent with some implementations of the invention, natural restrictions may be performed on the range of one or more of the dimensions of the multi-dimensional display document (e.g., price restrictions, date restrictions). Restriction on the range of one or more of the dimensions may be achieved by implementing multiple (e.g., 2, 3, or 4) overlapping ranges that have different granularities (e.g., prices in $100 increments and prices in $20 increments). The user may implement a restriction (e.g., by “clicking” on a range if using a mouse interface) that “zooms” the display in, causing the selected range to “zoom” out to fill substantially the entire display of the multi-dimensional document. 
     In a further implementation, the axes of the plot on the multi-dimensional display document may be scaled. The axes, thus, need not be linear, and any monotonic transformation of an axis may be used (e.g., a logarithmic scale for price or recency). In some instances, if a large gap between clusters of results exists, a monotonic “squeezing” of the space between the results could be used to bring them closer together and fit more results into the plot with less blank space (e.g., a simple piecewise linear transformation could be used that simply uses a different linear scaling for the gap between two clusters of results). This might be useful if the set of results plotted includes the top N results that optimize each axis independently. In another implementation, the multi-dimensional display document may plot multiple dimensions, with none of the dimensions being relevance (e.g., price vs. merchant rating, image quality vs. staleness, date vs. poster reputation, etc.). 
       FIG. 7  illustrates an exemplary two-dimensional display document  700  consistent with one implementation of the invention. Two-dimensional display document  700  depicts a “graph view” of the results of a product search related to ‘digital cameras’ where the y-axis corresponds to ‘price’ and the x-axis corresponds to ‘relevance.’ 
     If the user is using a “mouse,” moving the mouse over a target in the multi-dimensional display document (e.g., a thumbnail image, icon, etc.) may trigger the display of additional information. For example, in the product searching context, thumbnails with no text might be used to represent each product result and, upon “mouse-over” of a particular thumbnail, the title, exact price, and merchant for the offer might be displayed. Another possible representation for product searching might be a thumbnail image with a single word or phrase displayed in close association with the image (e.g., inside of, on top of, or in close proximity to). In certain subdomains (e.g., product categories), domain-specific summaries may be used. For example, in electronics domains, for queries that return many different models, the model number/string may be an appropriate one word label. For a digital camera query, thumbnails of digital cameras may appear with labels such as “S400,” “A70,” “G3,” etc. Accessories may be labeled with the word that describes the category of accessory (e.g., ‘battery,’ ‘case,’ ‘book,’ etc.). The accessory offers could be classified as accessories by price clustering or other classification signals and classified into the domain specific accessory types by another simple classifier. Upon “mouse-over” of the word or phrase, additional information may be displayed. 
     Server  120  may determine whether a user selects a result from the multi-dimensional display document (act  435 ). In one implementation, for example, the user may select a result by “clicking” on an associated image, icon, or text, with a mouse. If the user selects a result from the provided multi-dimensional display document, then server  120  may provide a document(s) that corresponds to the selected result (act  440 ). For example,  FIG. 9  illustrates an exemplary news document  900  that includes a news story  905  that corresponds to a specific selection by a user. According to another exemplary aspect, server  120  may, upon selection of a result, provide a document with one or more links to documents that correspond to the selected result. For example,  FIG. 8  illustrates an exemplary document  800  that includes multiple links  805  corresponding to a news story related to a news search query provided by a user. If the user selects one of the one or more links of the provided document, then server  120  may provide a document(s) that corresponds to the selected link. For example,  FIG. 9  illustrates an exemplary news document  900  that includes a news story  905  that corresponds to a specific link selected by a user. 
     Returning to act  435 , if the user does not select a result from the multi-dimensional display document, then server  120  may determine whether the user selects a “next page” or a restricted range of the multi-dimensional display document (act  445 ). More results may exist then can fit on one page of the multi-dimensional display document, therefore, the user may select a subsequent page to view additional results. The user may further select a restricted range (e.g., by “clicking” on a range if using a mouse interface) to “zoom” the display in, causing the selected range to “zoom” out to substantially fill the entire display of the multi-dimensional display document. Server  120  may provide the selected “next page,” or the restricted range, of the multi-dimensional display document to the user (act  450 ). If the user does not select a “next page” or a restricted range, then processing may return to act  415 , with receipt of another search query(ies) from the user. 
     CONCLUSION 
     Systems and methods consistent with the principles of the invention enable the sorting of search results by multiple different characteristics, and display of those search results on a multi-dimensional graph. Each dimension of the multi-dimensional graph may correspond to one of the multiple characteristics. 
     The foregoing description of preferred embodiments of the present invention provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. For example, while a series of acts have been described with regard to  FIGS. 4A and 4B , the order of the acts may be modified in other implementations consistent with the principles of the invention. Additionally, while aspects of the invention has been described with respect to searching information stored in the world-wide web (WWW), one skilled in the art will recognize that the sorting and displaying of search results in multiple dimensions, consistent with the principles of the invention, may be employed in any other type of information searching system. Also, non-dependent acts may be performed in parallel. 
     It will also be apparent to one of ordinary skill in the art that aspects of the invention, as described above, may be implemented in many different forms of software, firmware, and hardware in the implementations illustrated in the figures. The actual software code or specialized control hardware used to implement aspects consistent with the principles of the invention is not limiting of the present invention. Thus, the operation and behavior of the aspects of the invention were described without reference to the specific software code—it being understood that one of ordinary skill in the art would be able to design software and control hardware to implement the aspects based on the description herein. 
     Further, certain portions of the invention have been described as “logic” that performs one or more functions. This logic may include hardware, such as an application specific integrated circuit or a field programmable gate array, software, or a combination of hardware and software. 
     The scope of the invention is defined by the following claims and their equivalents.