1089297
Automatic identification of user goals in Web search
There has been recent interests in studying the "goal" behind a user's Web query, so that this goal can be used to improve the quality of a search engine's results. Previous studies have mainly focused on using manual query-log investigation to identify Web query goals. In this paper we study whether and how we can automate this goal-identification process. We first present our results from a human subject study that strongly indicate the feasibility of automatic query-goal identification. We then propose two types of features for the goal-identification task: user-click behavior and anchor-link distribution. Our experimental evaluation shows that by combining these features we can correctly identify the goals for 90% of the queries studied.
1598607
The infocious web search engine: improving web searching through linguistic analysis
In this paper we present the Infocious Web search engine [23]. Our goal in creating Infocious is to improve the way people find information on the Web by resolving ambiguities present in natural language text. This is achieved by performing linguistic analysis on the content of the Web pages we index, which is a departure from existing Web search engines that return results mainly based on keyword matching. This additional step of linguistic processing gives Infocious two main advantages. First, Infocious gains a deeper understanding of the content of Web pages so it can better match users' queries with indexed documents and therefore can improve relevancy of the returned results. Second, based on its linguistic processing, Infocious can organize and present the results to the user in more intuitive ways. In this paper we present the linguistic processing technologies that we incorporated in Infocious and how they are applied in helping users find information on the Web more efficiently. We discuss the various components in the architecture of Infocious and how each of them benefits from the added linguistic processing. Finally, we experimentally evaluate the performance of a component which leverages linguistic information in order to categorize Web pages.
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.
1739520
Exploiting Geographical Location Information of Web Pages
Many information resources on the web are relevant primarily to limited geographical communities. For instance, web sites containing information on restaurants, theaters, and apartment rentals are relevant primarily to web users in geographical proximity to these locations. In contrast, other information resources are relevant to a broader geographical community. For instance, an on-line newspaper may be relevant to users across the United States. Unfortunately, the geographical scope of web resources is largely ignored by web search engines. We make the case for identifying and exploiting the geographical location information of web sites so that web search engines can rank resources in a geographically sensitive fashion, in addition to using more traditional information-retrieval strategies. In this paper, we first consider how to compute the geographical location of web pages. Subsequently, we consider how to exploit such information in one specific "proof-of-concept" application we implemented in JAVA, and discuss other examples as well.
1720833
Automatic identification of user interest for personalized search
One hundred users, one hundred needs. As more and more topics are being discussed on the web and our vocabulary remains relatively stable, it is increasingly difficult to let the search engine know what we want. Coping with ambiguous queries has long been an important part of the research on Information Retrieval, but still remains a challenging task. Personalized search has recently got significant attention in addressing this challenge in the web search community, based on the premise that a user's general preference may help the search engine disambiguate the true intention of a query. However, studies have shown that users are reluctant to provide any explicit input on their personal preference. In this paper, we study how a search engine can learn a user's preference automatically based on her past click history and how it can use the user preference to personalize search results. Our experiments show that users' preferences can be learned accurately even from little click-history data and personalized search based on user preference yields significant improvements over the best existing ranking mechanism in the literature.
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.
6528301
Energy Efficient Broadcast in Wireless Ad hoc Networks with Hitch-hiking
In this paper, we have proposed a novel concept called Hitch-hiking in order to reduce the energy consumption of broadcast application for wireless networks. Hitch-hiking takes advantage of the physical layer design that facilitates the combining of partial signals to obtain the complete information. The concept of combining partial signals using maximal ratio combiner [13] has been used to improve the reliability of the communication channel but has never been exploited to reduce energy consumption. We propose a centralized heuristic algorithm called Wireless Multicast with Hitch-hiking (WMH) to construct an energy efficient tree using Hitch-hiking and also present a distributed version of the heuristic. We also evaluate the proposed heuristics through simulation. Simulation results show that Hitch-hiking can reduce the transmission cost of broadcast by as much as 50%. Further, we propose and evaluate a protocol called PSBT that reduces energy consumption of broadcast by eliminating redundancy in receive operation. Finally, we propose an algorithm that takes advantage of both Hitch-hiking and PSBT in conserving energy.
29212181
Concurrency and inheritance in actor-based object-oriented languages
Abstract The combination of concurrent and object-oriented programming is a promising paradigm. However, the design of such an integrated language faces a serious problem: concurrent features of the language may interfere with object-oriented features such as inheritance and encapsulation. We present a new concurrency control mechanism for concurrent object-oriented languages based on the actor model, with the aim of avoiding such a problem. The concurrency constraints of an object are expressed with a pair of constructs—behavior abstraction sets and replacement clauses. They are completely separated from the code of methods; moreover, they are the units of inheritance. We introduce a new replacement scheme called lazy replacement for actor-based languages to reduce complexity in expressing the concurrency constraints of objects. We examine the relationship between the proposed concurrency control mechanism and a well-known inheritance mechanism using an experimental language.
9811102
Four-bend top-down global routing
We propose a new global net distribution approach for high-performance m/spl times/m two-dimensional arrays of very large scale integration and multichip-modules. The objective is to route n nets with minimum density of global cells, using a "small" number of bends. There are a number of applications where it is necessary to limit the number of bends on each wire. For example, it is desirable to limit the number of bends on each microstrip (transmission) line, for mismatches of line impedance can cause reflections from the junction points such as bends and vias. Furthermore, for high-performance routing, intersections of wires cause the use of more vias, which in turn require the use of more routing resources (because of the larger via pitch). This is the first paper that addresses a graph-theoretic framework to solve the bend-constrained global routing problem in two-dimensional arrays. In this paper, at each level of an underlying quad-tree, we present a novel four-bend routing algorithm by decomposing the original problem at level i into two subproblems that can be solved exactly based on a two-stage approach of smaller-sized linear program followed by min-cost flow networks. The overall (i.e., entire level of the four-way partition hierarchy) constraint and variable size for the first stage is O(md/sub o/), while the overall run time for the second stage is O(n/sup 3/ log n/sup 2/). The time complexity of such a hierarchical approach is one order of magnitude less than one of constructing a global routing using the min-cost-flow-based flat design approach. Last, we present an extension that permits a limited degree of control over the number of bends. The proposed algorithm can also be used for estimating the wireability in the early design planning stage for high-level synthesis. Experimental results showed the effectiveness of the proposed algorithm.
34064761
A Parallel Execution of Functional Logic Language with Lazy Evaluation
18975029
An asymptotic analysis of band-limited DS/SSMA communication systems
A new asymptotic analysis is presented to establish whether or not commonly used techniques to approximate the performance of direct-sequence spread-spectrum multiple-access (DS/SSMA) systems still apply when the systems are strictly band limited. The results apply to any linear data modulation and spreading scheme. The interference components, including the interchip interference (ICI) of a linear receiver output, are shown to be asymptotically jointly Gaussian random variables conditioned on the phases and delays of the interfering signals. Expressions for the error probabilities of band-limited systems are also developed from this result.