Query Expansion Techniques for Enterprise Search

Although web search remains an active research area, interest in enterprise search has waned. This is despite the fact that the market for enterprise search applications is expected to triple within the next six years, and that knowledge workers spend an average of 1.6 to 2.5 hours each day searching for information. To improve search relevancy, and hence reduce this time, an enterprise- focused application must be able to handle the unique queries and constraints of the enterprise environment. The goal of this thesis research was to develop, implement, and study query expansion techniques that are most effective at improving relevancy in enterprise search. The case-study instrument used in this investigation was a custom Apache Solr-based search application deployed at a local medium-sized manufacturing company. It was hypothesized that techniques specifically tailored to the enterprise search environment would prove most effective. Query expansion techniques leveraging entity recognition, alphanumeric term identification, intent classification, collection enrichment, and word vectors were implemented and studied using real enterprise data. They were evaluated against a test set of queries developed using relevance survey results from multiple users, using standard relevancy metrics such as normalized discounted cumulative gain (nDCG). Comprehensive analysis revealed that the current implementation of the collection enrichment and word vector query expansion modules did not demonstrate meaningful improvements over the baseline methods. However, the entity recognition, alphanumeric term identification, and query intent classification modules produced meaningful and statistically significant improvements in relevancy, allowing us to accept the hypothesis

Soil carbon in the South Atlantic United States: Land use change, forest management, and physiographic context

Evidence-based forest carbon (C) management requires identifying baseline patterns and drivers of soil organic carbon (SOC) stocks, and their responses to land use change and management, at scales relevant to landowners and resource professionals. The growth of datasets related to SOC, which is the largest terrestrial C pool, facilitates use of synthesis techniques to assess SOC stocks and changes at management-relevant scales. We report results from a synthesis using meta-analysis of published studies, as well as two large databases, in which we identify baseline patterns and drivers, quantify influences of land use change and forest management, and provide ecological context for distinct management regimes and their SOC impacts. We conducted this, the fourth in a series of ecoregional SOC assessments, for the South Atlantic States, which are disproportionately important to the national-scale forest C sink and forest products industry in the U.S. At the ecoregional level, baseline SOC stocks vary with climatic, topographic, and soil physical factors such as temperature and precipitation, slope gradient and aspect, and soil texture. Land use change and forest management modestly influence SOC stocks. Reforestation on previously cultivated lands increases SOC stocks, while deforestation for cultivation has the opposite effect; for continuously forested lands, harvesting is associated with SOC increases and prescribed fire with SOC declines. Effects of reforestation are large and positive for upper mineral soils (+30%) but not detectable in lower mineral soils. Negative effects of prescribed fire are due to significant C losses from organic horizons (-46%); fire and harvest have no impacts on upper mineral soils but both increase SOC in lower mineral soils (+8.2 and +46%, respectively, with high uncertainty in the latter). Inceptisols are generally more negatively impacted by prescribed fire or harvest than Ultisols, and covariance between inherent factors (including soil taxonomy) and management impacts indicates how interior vs. coastal physiographic sections differ in their management regimes and SOC trends. In the cooler, wetter, topographically rugged interior hardwood forests, which have larger baseline SOC stocks, prescribed fire and even light harvesting generally decrease SOC; in contrast, intensively managed coastal plain pine plantations begin with small initial SOC stocks, but exhibit rapid gains over even a single rotation. This covariance between place (physiography) and practice (management regime) suggests that distinct approaches to forest C management may be complementary to other ecological or production goals, when implemented as part of wider (e.g., state-level) forest C or climate policy

Exploring the role of machismo in gender discrimination: a comparison of Mexico and the US.

This conceptual paper explores how the construct of machismo can influence gender-based discrimination across two cultures; Mexico and the U.S. First, the relevant literature on machismo is reviewed and the construct clarified. Secondly, evidence is presented which indicates that masculine gender roles are not innate, but rather heavily influenced by cultural factors. Hofstede\u27s cultural dimensions are used to develop propositions about the effect of masculinity on gender-based discrimination. We suggest propositions designed to explain how programs aimed at eliminating or reducing gender-based discrimination might be impacted by high levels of cultural masculinity

Photochemistry at the surface of gold nanoprisms from surface-enhanced raman scattering blinking

cited By 8International audienceIn this work, we investigate the optical properties of triangular gold nanoprisms synthesized following a one-pot chemical process and using triethylene glycol (TREG) and polyvinylpyrrolidone (PVP) as solvent and capping agents. The nanoprisms sustain a strong localized surface plasmon resonance (LSPR) which is exploited in surface-enhanced Raman scattering (SERS) by the PVP and TREG molecules present at the nanoparticle surface. The work is focused on the temporal fluctuations of the SERS signal. The assignment of the observed Raman features is based on density functional theory calculations, performed for various interaction states between the PVP or the TREG molecules and the gold surface, in a simple model system. The SERS blinking is analyzed quantitatively using the autocorrelation of spectrally selected temporal SERS traces. We also use SERS covariance maps in order to investigate the cross-correlation between the relevant Raman features. We show that the fluctuations of the PVP and TREG SERS signals are not random. We found that the Raman features associated with the CO stretching vibrations are fingerprints of the interaction between the organic molecules and the nanoparticle surface. In particular, we observe quasi-periodic adsorption/desorption events of the PVP molecules that reveal their dynamical interaction with the gold surface. From the SERS covariance maps, we also point out correlations between the TREG and PVP signals which we interpret as occasional exchange of the two molecular species. The dependence of the SERS blinking on the detuning between the Raman excitation and the surface plasmon resonance is also investigated. We show that the optical excitation plays an important role in the photoinduced chemical processes that occur close to the nanoparticle surface