1,187 research outputs found
Query Expansion of Zero-Hit Subject Searches: Using a Thesaurus in Conjunction with NLP Techniques
The focus of our study is zero-hit queries in keyword subject searches and the effort of increasing recall in these cases by reformulating and, then, expanding the initial queries using an external source of knowledge, namely a thesaurus. To this end, the objectives of this study are twofold. First, we perform the mapping of query terms to the thesaurus terms. Second, we use the matched terms to expand the user’s initial query by taking advantage of the thesaurus relations and implementing natural language processing (NLP) techniques. We report on the overall procedure and elaborate on key points and considerations of each step of the process
Facets and Typed Relations as Tools for Reasoning Processes in Information Retrieval
Faceted arrangement of entities and typed relations for representing
different associations between the entities are established tools in knowledge
representation. In this paper, a proposal is being discussed combining both
tools to draw inferences along relational paths. This approach may yield new
benefit for information retrieval processes, especially when modeled for
heterogeneous environments in the Semantic Web. Faceted arrangement can be used
as a se-lection tool for the semantic knowledge modeled within the knowledge
repre-sentation. Typed relations between the entities of different facets can
be used as restrictions for selecting them across the facets
Gunn Effect in Silicon Nanowires: Charge Transport under High Electric Field
Gunn (or Gunn-Hilsum) Effect and its associated negative differential
resistivity (NDR) emanates from transfer of electrons between two different
energy bands in a semiconductor. If applying a voltage (electric field)
transfers electrons from an energy sub band of a low effective mass to a second
one with higher effective mass, then the current drops. This manifests itself
as a negative slope or NDR in the I-V characteristics of the device which is in
essence due to the reduction of electron mobility. Recalling that mobility is
inversely proportional to electron effective mass or curvature of the energy
sub band. This effect was observed in semiconductors like GaAs which has direct
bandgap of very low effective mass and its second indirect sub band is about
300 meV above the former. More importantly a self-repeating oscillation of
spatially accumulated charge carriers along the transport direction occurs
which is the artifact of NDR, a process which is called Gunn oscillation and
was observed by J. B. Gunn. In sharp contrast to GaAs, bulk silicon has a very
high energy spacing (~1 eV) which renders the initiation of transfer-induced
NDR unobservable. Using Density Functional Theory (DFT), semi-empirical 10
orbital () Tight Binding (TB) method and Ensemble Monte Carlo
(EMC) simulations we show for the first time that (a) Gunn Effect can be
induced in narrow silicon nanowires with diameters of 3.1 nm under 3 % tensile
strain and an electric field of 5000 V/cm, (b) the onset of NDR in I-V
characteristics is reversibly adjustable by strain and (c) strain can modulate
the value of resistivity by a factor 2.3 for SiNWs of normal I-V
characteristics i.e. those without NDR. These observations are promising for
applications of SiNWs in electromechanical sensors and adjustable microwave
oscillators.Comment: 18 pages, 6 figures, 63 reference
Direct, residual and cumulative effects of organic manures and biofertilizers on yields, NPK uptake, grain quality and economics of wheat (Triticum aestivum L.) under organic farming of rice-wheat cropping system
Field experiments were conducted at the research farm of the Indian Agricultural Research Institute, New Delhi during rabi (winter) season of 2007-2008 and 2008-2009 on a sandy clay loam soil (typical Ustochrept, 51.46% sand, 23.02% silt and 25.52% clay) of low in organic C (0.57%), medium in available phosphorus (19.87 kg/ha), high in available potassium (247.12 kg/ha) and low in available nitrogen (163.2 kg/ha) and of pH 8. Results revealed that the cumulative effects of farmyard manure (FYM) and green manure (GM) were more effective than their direct and residual effects and GM was significantly superior to FYM for increasing the productivity, nutrient uptake, grain quality and gross and net income of wheat in the rice-wheat cropping system. Further, inoculation of biofertilizers (B) with GM was better than GM alone in its cumulative effect. The combination of GM + FYM was still better than GM or FYM alone in its direct and cumulative effects for increasing productivity and gross return, but net return was significantly reduced due to the higher cost of GM + FYM compared to FYM or GM alone. However, the residual effect of GM + FYM was similar to the cumulative effects of GM or FYM alone. The highest increase in productivity, grain quality and nutrient uptake was recorded with the application of GM + FYM + B. However, net return was significantly reduced due to the higher cost incurred in the combination of GM + FYM + B. It was concluded that the cumulative effect of GM + FYM + B for higher productivity and the cumulative effect of GM + B for higher net return were suitable for wheat in organic farming of the rice-wheat cropping system
Inferring biomarkers for Mycobacterium avium subsp. paratuberculosis infection and disease progression in cattle using experimental data
Available diagnostic assays for Mycobacterium avium subsp. paratuberculosis (MAP) have poor sensitivities and cannot detect early stages of infection, therefore, there is need to find new diagnostic markers for early infection detection and disease stages. We analyzed longitudinal IFN-γ, ELISA-antibody and fecal shedding experimental sensitivity scores for MAP infection detection and disease progression. We used both statistical methods and dynamic mathematical models to (i) evaluate the empirical assays (ii) infer and explain biological mechanisms that affect the time evolution of the biomarkers, and (iii) predict disease stages of 57 animals that were naturally infected with MAP. This analysis confirms that the fecal test is the best marker for disease progression and illustrates that Th1/Th2 (IFN-γ/ELISA antibodies) assays are important for infection detection, but cannot reliably predict persistent infections. Our results show that the theoretical simulated macrophage-based assay is a potential good diagnostic marker for MAP persistent infections and predictor of disease specific stages. We therefore recommend specifically designed experiments to test the use of a based assay in the diagnosis of MAP infections
Pain and mental health - separate and joint associations with sickness absence among young employees
Peer reviewe
Empathic accuracy and aggression in couples: Individual and dyadic links
This study examined links between intimate partner aggression and empathic accuracy – how accurately partners can read one another’s emotions – during highly affective moments from couples’ (N = 109) video recall of laboratory-based discussions of upsetting events. Less empathic accuracy between partners was generally related to higher levels of aggression by both partners. More specific patterns emerged based on the type of aggression and emotion being expressed. Women’s poorer ability to read their partners’ vulnerable and positive emotions was linked to both men’s and women’s greater physical and psychological aggression. Moreover, women’s inaccuracy in reading their partner’s hostility was linked to women’s greater psychological aggression towards the men. Men’s inaccuracy in reading their partner’s hostility was linked to women’s (not men’s) greater physical and psychological aggression. Findings suggest important nuances in the links between empathic inaccuracy and aggression, and implications for prevention and treatment of partner aggression are discussed
The Quantum Socket: Three-Dimensional Wiring for Extensible Quantum Computing
Quantum computing architectures are on the verge of scalability, a key
requirement for the implementation of a universal quantum computer. The next
stage in this quest is the realization of quantum error correction codes, which
will mitigate the impact of faulty quantum information on a quantum computer.
Architectures with ten or more quantum bits (qubits) have been realized using
trapped ions and superconducting circuits. While these implementations are
potentially scalable, true scalability will require systems engineering to
combine quantum and classical hardware. One technology demanding imminent
efforts is the realization of a suitable wiring method for the control and
measurement of a large number of qubits. In this work, we introduce an
interconnect solution for solid-state qubits: The quantum socket. The quantum
socket fully exploits the third dimension to connect classical electronics to
qubits with higher density and better performance than two-dimensional methods
based on wire bonding. The quantum socket is based on spring-mounted micro
wires the three-dimensional wires that push directly on a micro-fabricated
chip, making electrical contact. A small wire cross section (~1 mmm), nearly
non-magnetic components, and functionality at low temperatures make the quantum
socket ideal to operate solid-state qubits. The wires have a coaxial geometry
and operate over a frequency range from DC to 8 GHz, with a contact resistance
of ~150 mohm, an impedance mismatch of ~10 ohm, and minimal crosstalk. As a
proof of principle, we fabricated and used a quantum socket to measure
superconducting resonators at a temperature of ~10 mK.Comment: Main: 31 pages, 19 figs., 8 tables, 8 apps.; suppl.: 4 pages, 5 figs.
(HiRes figs. and movies on request). Submitte
Validation of Lexical Frequency Profiles As a Measure of Lexical Richness in Written Discourse
Technological developments and their utilities in various areas including education have offered great advantages for man. One of the greatest achievements in this trend has been the innovation in computer software like Lexical Frequency Profiles (LFP) and its pedagogical implications either in teaching or measurement. To take the maximum advantages, this study seeks to validate the LFP as a measure of lexical richness in written discourse of Iranian EFL Learners. 50 students majoring in English Translation participated in this study; each of them was encouraged to develop two compositions on general topics in order to establish VocabProfile indexes. To estimate the reliability of the LFP, the VocabProfile indexes of two writings were correlated, but for the validity purpose, first, a productive version of Vocabulary Levels Test (VLT) was administered and second, the students’ compositions were fed into P_Lex software to elicit P_Lex index. After that, VocabProfile indexes were correlated with VLT scores and P_Lex index separately. The findings of the study revealed that students’ VocabProfile indexes written on two different topics correlated significantly with each other. Because of such a significant correlation coefficients, and the LFP indexes are related to VLT active test and P_Lex index, it is conservatively safe to claim that VocabProfile indexes are to some extent reliable and valid measurement instruments but not strong enough to be used as a stand- alone measure for the assessment of lexical richness. Pedagogically speaking, the LPF is suggested as a relatively reliable and valid measure to be used along with other dependable devices in measuring lexical richness in discourses of various types
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