2,002 research outputs found

    Evaluating Advanced Search Interfaces using Established Information-Seeking Models

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    When users have poorly defined or complex goals, keyword searching may not provide sufficient support. Subsequently, more advanced systems are being developed to support richer modes of search. This paper presents a formative framework for evaluating advancing search systems, which are providing more versatile environments that become increasingly hard to compare. This is done by quantifying their strengths and weaknesses in supporting user tactics and varying user conditions. This framework combines established models of users, user needs, and user behaviours to achieve this. The framework is applied to evaluate three advanced search interfaces and shows promising results

    Evaluating advanced search interfaces using established information-seeking model

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    When users have poorly defined or complex goals search interfaces offering only keyword searching facilities provide inadequate support to help them reach their information-seeking objectives. The emergence of interfaces with more advanced capabilities such as faceted browsing and result clustering can go some way to some way toward addressing such problems. The evaluation of these interfaces, however, is challenging since they generally offer diverse and versatile search environments that introduce overwhelming amounts of independent variables to user studies; choosing the interface object as the only independent variable in a study would reveal very little about why one design out-performs another. Nonetheless if we could effectively compare these interfaces we would have a way to determine which was best for a given scenario and begin to learn why. In this article we present a formative framework for the evaluation of advanced search interfaces through the quantification of the strengths and weaknesses of the interfaces in supporting user tactics and varying user conditions. This framework combines established models of users, user needs, and user behaviours to achieve this. The framework is applied to evaluate three search interfaces and demonstrates the potential value of this approach to interactive IR evaluation

    Experience in Social Affective Applications: Methodologies and Case Study

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    New forms of social affective applications are emerging, bringing with them challenges in design and evaluation. We report on one such application, conveying well-being for both personal and group benefit, and consider why existing methodologies may not be suitable, before explaining and analyzing our proposed approach. We discuss our experience of using and writing about the methodology, in order to invite discussion about its suitability in particular, as well as the more general need for methodologies to examine experience and affect in social, connected situations. As these fields continue to interact, we hope that these discussions serve to aid in studying and learning from these types of application

    Predation Risk and Elk-Aspen Foraging Patterns

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    Elk-aspen foraging patterns may be influenced by cover type, distance from roads or trails, the type of user on road or trail (park visitor, human hunter, or predator), and two general states of aspen condition (open-grown or thicket). Pellet group and browse utilization transects in the Canadian Rockies showed that elk were attracted to roads used by park visitors and avoided by wolves, and that elk possibly avoided aspen and conifer patches near backcountry trails used by wolves. In high predation risk landscapes, aspen stands were dense, lightly browsed, and rarely entered by elk. As risk decreased, elk density and aspen browsing increased proportionally faster on edges of aspen stands compared to the interior of aspen stands. In low risk landscapes, edge and interior plots were intensively used, and stands had a low density of heavily browsed stems. Regeneration of aspen stands likely requires low densities of risk-sensitive elk

    Designing for Schadenfreude (or, how to express well-being and see if you're boring people)

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    This position paper presents two studies of content not normally expressed in status updates—well-being and status feedback—and considers how they may be processed, valued and used for potential quality-of-life benefits in terms of personal and social reflection and awareness. Do I Tweet Good? (poor grammar intentional) is a site investigating more nuanced forms of status feedback than current microblogging sites allow, towards understanding self-identity, reflection, and online perception. Healthii is a tool for sharing physical and emotional well-being via status updates, investigating concepts of self-reflection and social awareness. Together, these projects consider furthering the value of microblogging on two fronts: 1) refining the online personal/social networking experience, and 2) using the status update for enhancing the personal/social experience in the offline world, and considering how to leverage that online/offline split. We offer results from two different methods of study and target groups—one co-workers in an academic setting, the other followers on Twitter—to consider how microblogging can become more than just a communication medium if it facilitates these types of reflective practice

    Operator-Based Truncation Scheme Based on the Many-Body Fermion Density Matrix

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    In [S. A. Cheong and C. L. Henley, cond-mat/0206196 (2002)], we found that the many-particle eigenvalues and eigenstates of the many-body density matrix ρB\rho_B of a block of BB sites cut out from an infinite chain of noninteracting spinless fermions can all be constructed out of the one-particle eigenvalues and one-particle eigenstates respectively. In this paper we developed a statistical-mechanical analogy between the density matrix eigenstates and the many-body states of a system of noninteracting fermions. Each density matrix eigenstate corresponds to a particular set of occupation of single-particle pseudo-energy levels, and the density matrix eigenstate with the largest weight, having the structure of a Fermi sea ground state, unambiguously defines a pseudo-Fermi level. We then outlined the main ideas behind an operator-based truncation of the density matrix eigenstates, where single-particle pseudo-energy levels far away from the pseudo-Fermi level are removed as degrees of freedom. We report numerical evidence for scaling behaviours in the single-particle pseudo-energy spectrum for different block sizes BB and different filling fractions \nbar. With the aid of these scaling relations, which tells us that the block size BB plays the role of an inverse temperature in the statistical-mechanical description of the density matrix eigenstates and eigenvalues, we looked into the performance of our operator-based truncation scheme in minimizing the discarded density matrix weight and the error in calculating the dispersion relation for elementary excitations. This performance was compared against that of the traditional density matrix-based truncation scheme, as well as against a operator-based plane wave truncation scheme, and found to be very satisfactory.Comment: 22 pages in RevTeX4 format, 22 figures. Uses amsmath, amssymb, graphicx and mathrsfs package

    How can we all help conserve nature?

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    When we speak about conserving nature, we are really talking about taking care of our future, because nature provides essential resources for our survival and enjoyment. We asked an international group of scientists working on different environmental issues worldwide to identify important practical actions that we can all do to help conserve nature. We obtained nearly 100 responses and grouped them into three main categories: (1) Actions to reduce our ecological footprint; (2) Actions to conserve nature; and (3) Actions that help us connect with nature. We briefly explain actions that can be performed daily to reduce our impact on nature, and provide some useful links for further readin

    Multi Visualization and Dynamic Query for Effective Exploration of Semantic Data

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    Semantic formalisms represent content in a uniform way according to ontologies. This enables manipulation and reasoning via automated means (e.g. Semantic Web services), but limits the user’s ability to explore the semantic data from a point of view that originates from knowledge representation motivations. We show how, for user consumption, a visualization of semantic data according to some easily graspable dimensions (e.g. space and time) provides effective sense-making of data. In this paper, we look holistically at the interaction between users and semantic data, and propose multiple visualization strategies and dynamic filters to support the exploration of semantic-rich data. We discuss a user evaluation and how interaction challenges could be overcome to create an effective user-centred framework for the visualization and manipulation of semantic data. The approach has been implemented and evaluated on a real company archive

    High-Temperature Superconducting Level Meter for Liquid Argon Detectors

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    Capacitive devices are customarily used as probes to measure the level of noble liquids in detectors operated for neutrino studies and dark matter searches. In this work we describe the use of a high-temperature superconducting material as an alternative to control the level of a cryogenic noble liquid. Lab measurements indicate that the superconductor shows a linear behaviour, a high degree of stability and offers a very accurate determination of the liquid volume. This device is therefore a competitive instrument and shows several advantages over conventional level meters.Comment: 13 pages, 11 figures. Accepted for publication in JINS

    Electronic damping of molecular motion at metal surfaces

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    A method for the calculation of the damping rate due to electron-hole pair excitation for atomic and molecular motion at metal surfaces is presented. The theoretical basis is provided by Time Dependent Density Functional Theory (TDDFT) in the quasi-static limit and calculations are performed within a standard plane-wave, pseudopotential framework. The artificial periodicity introduced by using a super-cell geometry is removed to derive results for the motion of an isolated atom or molecule, rather than for the coherent motion of an ordered over-layer. The algorithm is implemented in parallel, distributed across both k{\bf k} and g{\bf g} space, and in a form compatible with the CASTEP code. Test results for the damping of the motion of hydrogen atoms above the Cu(111) surface are presented.Comment: 10 pages, 3 figure
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