239 research outputs found
Automatic classification of web pages into bookmark categories
We describe a technique to automatically classify a web page into an existing bookmark category whenever a user decides to bookmark a page. HyperBK compares a bag-of-words representation of the page to descriptions of categories in the userâs bookmark file. Unlike default web browser dialogs in which the user may be presented with the category into which he or she saved the last bookmarked file, HyperBK also offers the category most similar to the page being bookmarked. The user can opt to save the page to the last category used; create a new category; or save the page elsewhere. In an evaluation, the userâs preferred category was offered on average 67% of the time.peer-reviewe
Achieving user adaptivity in hyperspace with hypercontext
HyperContext is a framework for adaptive and adaptable hypertext. In any hyperspace, each piece of information (e.g., contained in a document or node) is normally juxtaposed by other information via links. Two or more hypertext users may encounter the same document although they may have followed different paths to reach it. Those two users may well describe different aspects of the document as relevant to their needs and requirements. The HyperContext framework allows users to create different interpretations of information in context, which will also be available to future users.peer-reviewe
COLLEGE : a collaborative on-line lecture environment for group and individual eLearning
COLLEGE is a platform for the development and delivery of interactive learning content for individual students or groups and will be built during 2005-2007. Phase I will deliver primarily video- and audio-based learning content together with tools to provide automated assistance and assessment of student progress. Phase II will increase the options for the learning content to include non-time-based media and will increase the level of Just- in-Time support for students. The COLLEGE toolset will be based around virtual metaphors corresponding to traditional tools for learning, recording, interacting with the source of the learning material, and assessment.peer-reviewe
How did I find that : automatically constructing queries from bookmarked web pages and categories
We present âHow Did I Find That?â (HDIFT), an algorithm to find web pages related to categories of bookmarks (book- mark folders) or individual bookmarks stored in a userâs bookmark (or favorites) file. HDIFT automatically generates a query from the selected bookmarks and categories, submits the query to a third-party search engine, and presents the results to the user. HDIFTâs approach is innovative in that we select keywords to generate the query from a book- marked web pageâs parents (other web-based documents that contain a link to the bookmarked web page), rather than from the bookmarked web page itself. Our initial limited evaluation results are promising. Volunteers who participated in the evaluation considered 20% of all query results to be relevant and interesting enough to bookmark. Additionally, 56.9% of the queries generated yielded results sets (of at most 10 results) containing at least one interesting and bookmarkable web page.peer-reviewe
Expanding query terms in context
Query expansion is normally performed using a thesaurus that is either generated from a collection of documents, or is otherwise language specific. We present a technique to discover associations between query terms that are synonyms based on past queries and documents common to multiple result sets, to enable query expansion to occur in context.peer-reviewe
Comparing title only and full text indexing to classify web pages into bookmark categories
Web browser bookmark files are used to retain and organise records of web sites that the user would like to revisit. However, bookmark files tend to be under-utilised, as time and effort is needed to keep them organised. We use two methods to index and automatically classify documents referred to in 80 bookmark files, based on document title-only and full-text indexing, respectively. We evaluate the indexing methods by selecting a bookmark entry to classify from a bookmark file, and recreating the bookmark file so that it contains only entries created before the selected bookmark entry. Classification based on full-text indexing generally outperforms that based on document title only indexing. The ability to recommend the correct category at rank 1 using full-text indexing ranges from 20% to 41%, depending on the number of category members. However, combining the approaches results in a increase to 37% â 59%, but we would need to recommend up to two categories to users. By recommending up to 10 categories, this increases to 58% â 80%.peer-reviewe
How grazing management can maximize erosion resistance of salt marshes
Combining natural saltmarsh habitats with conventional barriers can provide a sustainable and cost-effective alternative for fully engineered flood protection, provided that a minimal salt marsh width can be guaranteed for a long period. Hence, it is essential to understand both the key factors and management options driving the lateral erodibility/stability of salt marshes.We aimed to determine how salt marsh management (i.e. grazing by large vs. small grazers vs. artificial mowing), marsh elevation and marsh age affect soil stability (i.e. soil collapse) and intrinsic lateral erodibility of salt marshes (i.e. particle-by-particle detachment). Soil cores were collected in high and low marshes (above and below 0.5 m MHWL, respectively) of different ages. At these locations, we compared cores from grazed areas to cores inside grazer exclosures, with and without artificial mowing. All cores were exposed to waves in flumes to test their stability and lateral erodibility.All soil cores were characterized by a stable fine-grained layer deposited on top of readily erodible sand. The thickness of the fine-grained layer was a key parameter in reducing salt marsh instability (cliff collapse). This layer thickness increased with marsh age and at lower elevations, but decreased with cattle grazing due to compaction.The erosion resistance of the fine-grained layer increased with (a) large grazers that compacted the soil by trampling, (b) mowing that excluded soil-bioturbating species, and (c) grazing by small grazers that promoted vegetation types with higher root density.Synthesis and applications. Overall, marshes with thinner cohesive and/or fine-grained top layers are more sensitive to lateral erosion than marshes with deep cohesive soils, independently of the management. Grazing and artificial mowing can reduce the erodibility of fine-grained soils, making salt marshes more resilient to lateral erosion. However, compaction by large grazers simultaneously leads to thinner fine-grained layers and lower elevation, potentially leading to more inundation under sea-level rise. Hence, to effectively manage salt marshes to enhance their contribution to coastal protection, we recommend (a) moderate/rotational livestock grazing, avoiding high intensity grazing in sediment-poor systems sensitive to sea-level rise and (b) investigating measures to preserve small grazers.</p
Incremental dimension reduction of tensors with random index
We present an incremental, scalable and efficient dimension reduction
technique for tensors that is based on sparse random linear coding. Data is
stored in a compactified representation with fixed size, which makes memory
requirements low and predictable. Component encoding and decoding are performed
on-line without computationally expensive re-analysis of the data set. The
range of tensor indices can be extended dynamically without modifying the
component representation. This idea originates from a mathematical model of
semantic memory and a method known as random indexing in natural language
processing. We generalize the random-indexing algorithm to tensors and present
signal-to-noise-ratio simulations for representations of vectors and matrices.
We present also a mathematical analysis of the approximate orthogonality of
high-dimensional ternary vectors, which is a property that underpins this and
other similar random-coding approaches to dimension reduction. To further
demonstrate the properties of random indexing we present results of a synonym
identification task. The method presented here has some similarities with
random projection and Tucker decomposition, but it performs well at high
dimensionality only (n>10^3). Random indexing is useful for a range of complex
practical problems, e.g., in natural language processing, data mining, pattern
recognition, event detection, graph searching and search engines. Prototype
software is provided. It supports encoding and decoding of tensors of order >=
1 in a unified framework, i.e., vectors, matrices and higher order tensors.Comment: 36 pages, 9 figure
Social Value of Marine and Coastal Protected Areas in England and Wales.
The U.K. government is committed to establishing a coherent network of marine protected
areas by 2012 and the recentMarine and Coastal Access Act, 2009 will designate
marine conservation zones and provide wider access rights to the coast. To fulfill these
goals, this article argues the need for a clearer, shared understanding of the social
value of protected areas in creating new designations and managing existing ones. Although
marine and coastal environments attract many people and are vitally important
in terms of realized and potential social value, the majority of the public in the United
Kingdom lacks understanding and awareness regarding them. Combined with this, the
social value of marine and coastal protected areas (MCPAs) have been largely ignored
relative to conservation and economics, with the latter invariably taking precedence
in environmental policymaking. Social value reflects the complex, individual responses
that people experience in a given place. Many reasons determine why one area is valued
above another, and this research investigates the social value of MCPAs from a
practitionerâs perspective through a series of interviews. Understanding why we âsociallyâ
value MCPAs will ultimately equip managers with an informed understanding
of these spaces, influence management decisions, and, potentially, policymaking. This
article defines social value in the context of MCPAs in England and Wales from a
practitioner perspective, explores key concepts, and suggests possible improvements in
decision-making
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