19,468 research outputs found
Slicing and dicing the information space using local contexts
In recent years there has been growing interest in faceted grouping of documents for Interactive Information Retrieval (IIR). It is suggested that faceted grouping can offer a flexible way of browsing a collection compared to clustering. However, the success of faceted grouping seems to rely on sufficient knowledge of collection structure. In this paper we propose an approach based on the local contexts of query terms, which is inspired by the interaction of faceted search and browsing. The use of local contexts is appealing since it requires less knowledge of the collection than existing approaches. A task-based user study was carried out to investigate the effectiveness of our interface in varied complexity. The results suggest that the local contexts can be exploited as the source of search result browsing in IIR, and that our interface appears to facilitate different aspects of search process over the task complexity. The implication of the evaluation methodology using high complexity tasks is also discussed
Solving Hard Computational Problems Efficiently: Asymptotic Parametric Complexity 3-Coloring Algorithm
Many practical problems in almost all scientific and technological
disciplines have been classified as computationally hard (NP-hard or even
NP-complete). In life sciences, combinatorial optimization problems frequently
arise in molecular biology, e.g., genome sequencing; global alignment of
multiple genomes; identifying siblings or discovery of dysregulated pathways.In
almost all of these problems, there is the need for proving a hypothesis about
certain property of an object that can be present only when it adopts some
particular admissible structure (an NP-certificate) or be absent (no admissible
structure), however, none of the standard approaches can discard the hypothesis
when no solution can be found, since none can provide a proof that there is no
admissible structure. This article presents an algorithm that introduces a
novel type of solution method to "efficiently" solve the graph 3-coloring
problem; an NP-complete problem. The proposed method provides certificates
(proofs) in both cases: present or absent, so it is possible to accept or
reject the hypothesis on the basis of a rigorous proof. It provides exact
solutions and is polynomial-time (i.e., efficient) however parametric. The only
requirement is sufficient computational power, which is controlled by the
parameter . Nevertheless, here it is proved that the
probability of requiring a value of to obtain a solution for a
random graph decreases exponentially: , making
tractable almost all problem instances. Thorough experimental analyses were
performed. The algorithm was tested on random graphs, planar graphs and
4-regular planar graphs. The obtained experimental results are in accordance
with the theoretical expected results.Comment: Working pape
Trends and Opportunities in Agriculture An Executive Interview with Lowell Catlett
Agriculture will change more in the next decade than it did in the last century. Lowell Catlett is a futurist sharing his knowledge and insight on the new trends and technologies shaping the future of agriculture and how those working in this sector can take advantage of new opportunities.innovation, communication, opportunity, technology, Research and Development/Tech Change/Emerging Technologies, Teaching/Communication/Extension/Profession, Q10, Q16,
Global Supply Chain: An Executive Interview with Mary Shelman
Mary Shelman discusses forces driving higher food prices and some of the changes which are impacting the global food supply chain. Shelman coordinates Harvard Business School’s premier Agribusiness Seminar attended annually by more than 200 CEOs and top managers from global firms. She also organizes and teaches similar programs in Europe, Latin America and Asia. Her research focuses on the forces shaping global agribusiness. Her experience bridges academia, as an author and teacher of dozens of case studies on strategic change and challenges in global agribusiness firms, with industry experience.global food supply chain, food prices, markets, Agribusiness, Demand and Price Analysis, Marketing, Q10, Q11, Q13,
Managing Global Climate Change An Executive Interview with Carole Brookins
Carole Brookins is an international consultant known for her work as a policy and trade strategist on issues concerning the global political economy and its effect on the food and agriculture sector. She currently serves on the board of several corporate and non- profit organizations concerned with global food system issues and is currently helping to develop solutions which can offset the effects of global climate change through the reduction and management of carbon emissions—an issue of increasing importance in future food marketing and world trade. This interview was conducted by Doug Jose is a Professor and Extension Farm Management Specialist in the Department of Agricultural Economics at the University of Nebraska- Lincoln and host of the Market Journal, a weekly televised program on agriculture. This interview occurred during the 18th Annual World Forum and Symposium in Monterey, California, in June, 2008.global climate change, food marketing, Carbon Exchange Market, transportation, Agricultural and Food Policy, Food Security and Poverty, Marketing, Research and Development/Tech Change/Emerging Technologies, Resource /Energy Economics and Policy, Q10, Q13, Q16,
The political economy of innovation; an institutional analysis of industrial policy and development in Brazil
This dissertation examines Brazilian industrial policies during the administrations of President Lula (2003-2010) and questions if innovation has truly been the main driver of those instruments. It provides a brief overview on the intersections of politics, economics, innovation and institutions as well as the main choices, incentives and alliances of the Brazilian government, which are illustrated by the Innovation Law, PITCE, PDP and campaign financing of President Lula's 2002 and 2006 candidacies. By adding to the analysis Brazil's exports, its balance of trade and the expenditures of BNDES, this research indicates a disconnect between the intentions and the results of the industrial policy. China and “low-tech” businesses seem to have become the real drivers of the government's agenda; the first for its importance to the Brazilian economy and the latter for its influence with government. Finally, while recognizing some positive results, it presents an alternative model based on a “high-tech” natural resources vision of development which could convert the current challenges into opportunitiesBrazil; development; institutions; innovation; industrial policy
A Lighthouse Effect in Eta Carinae
We present a new model for the behavior of scattered time-dependent,
asymmetric near-UV emission from the nearby ejecta of {\eta} Car. Using a 3-D
hydrodynamical simulation of {\eta} Car's binary colliding winds, we show that
the 3-D binary orientation derived by Madura et al. (2012) is capable of
explaining the asymmetric near-UV variability observed in the Hubble Space
Telescope Advanced Camera for Surveys/High Resolution Camera (HST ACS/HRC)
F220W images of Smith et al. (2004b). Models assuming a binary orientation with
i ~ 130 to 145 degrees, {\omega} ~ 230 to 315 degrees, PAz ~ 302 to 327 degrees
are consistent with the observed F220W near-UV images. We find that the hot
binary companion does not significantly contribute to the near-UV excess
observed in the F220W images. Rather, we suggest that a bore-hole effect and
the reduction of Fe II optical depths inside the wind-wind collision cavity
carved in the extended photosphere of the primary star lead to the
time-dependent directional illumination of circum-binary material as the
companion moves about in its highly elliptical orbit.Comment: 14 pages, 4 figures, 1 table. Accepted for publication in ApJ
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