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Letteratura scientifica selezionata sul tema "Information retrieval"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 16 novembre 2024

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Articoli di riviste sul tema "Information retrieval"

1

Jalali, Ali, Shannon Hicks-Jalali, Robert J. Sica, Alexander Haefele e Thomas von Clarmann. "A practical information-centered technique to remove a priori information from lidar optimal-estimation-method retrievals". Atmospheric Measurement Techniques 12, n. 7 (18 luglio 2019): 3943–61. http://dx.doi.org/10.5194/amt-12-3943-2019.

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Abstract. Lidar retrievals of atmospheric temperature and water vapor mixing ratio profiles using the optimal estimation method (OEM) typically use a retrieval grid with a number of points larger than the number of pieces of independent information obtainable from the measurements. Consequently, retrieved geophysical quantities contain some information from their respective a priori values or profiles, which can affect the results in the higher altitudes of the temperature and water vapor profiles due to decreasing signal-to-noise ratios. The extent of this influence can be estimated using the retrieval's averaging kernels. The removal of formal a priori information from the retrieved profiles in the regions of prevailing a priori effects is desirable, particularly when these greatest heights are of interest for scientific studies. We demonstrate here that removal of a priori information from OEM retrievals is possible by repeating the retrieval on a coarser grid where the retrieval is stable even without the use of formal prior information. The averaging kernels of the fine-grid OEM retrieval are used to optimize the coarse retrieval grid. We demonstrate the adequacy of this method for the case of a large power-aperture Rayleigh scatter lidar nighttime temperature retrieval and for a Raman scatter lidar water vapor mixing ratio retrieval during both day and night.

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2

Zhou, Minqiang, Bavo Langerock, Mahesh Kumar Sha, Nicolas Kumps, Christian Hermans, Christof Petri, Thorsten Warneke et al. "Retrieval of atmospheric CH<sub>4</sub> vertical information from ground-based FTS near-infrared spectra". Atmospheric Measurement Techniques 12, n. 11 (25 novembre 2019): 6125–41. http://dx.doi.org/10.5194/amt-12-6125-2019.

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Abstract. The Total Carbon Column Observing Network (TCCON) column-averaged dry air mole fraction of CH4 (XCH4) measurements have been widely used to validate satellite observations and to estimate model simulations. The GGG2014 code is the standard TCCON retrieval software used in performing a profile scaling retrieval. In order to obtain several vertical pieces of information in addition to the total column, in this study, the SFIT4 retrieval code is applied to retrieve the CH4 mole fraction vertical profile from the Fourier transform spectrometer (FTS) spectrum at six sites (Ny-Ålesund, Sodankylä, Bialystok, Bremen, Orléans and St Denis) during the time period of 2016–2017. The retrieval strategy of the CH4 profile retrieval from ground-based FTS near-infrared (NIR) spectra using the SFIT4 code (SFIT4NIR) is investigated. The degree of freedom for signal (DOFS) of the SFIT4NIR retrieval is about 2.4, with two distinct pieces of information in the troposphere and in the stratosphere. The averaging kernel and error budget of the SFIT4NIR retrieval are presented. The data accuracy and precision of the SFIT4NIR retrievals, including the total column and two partial columns (in the troposphere and stratosphere), are estimated by TCCON standard retrievals, ground-based in situ measurements, Atmospheric Chemistry Experiment – Fourier Transform Spectrometer (ACE-FTS) satellite observations, TCCON proxy data and AirCore and aircraft measurements. By comparison against TCCON standard retrievals, it is found that the retrieval uncertainty of SFIT4NIR XCH4 is similar to that of TCCON standard retrievals with systematic uncertainty within 0.35 % and random uncertainty of about 0.5 %. The tropospheric and stratospheric XCH4 from SFIT4NIR retrievals are assessed by comparison with AirCore and aircraft measurements, and there is a 1.0 ± 0.3 % overestimation in the SFIT4NIR tropospheric XCH4 and a 4.0 ± 2.0 % underestimation in the SFIT4NIR stratospheric XCH4, which are within the systematic uncertainties of SFIT4NIR-retrieved partial columns in the troposphere and stratosphere respectively.

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3

Rubin, Ohad, e Jonathan Berant. "Retrieval-Pretrained Transformer: Long-range Language Modeling with Self-retrieval". Transactions of the Association for Computational Linguistics 12 (2024): 1197–213. http://dx.doi.org/10.1162/tacl_a_00693.

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Abstract Retrieval-augmented language models (LMs) have received much attention recently. However, typically the retriever is not trained jointly as a native component of the LM, but added post-hoc to an already-pretrained LM, which limits the ability of the LM and the retriever to adapt to one another. In this work, we propose the Retrieval-Pretrained Transformer (RPT), an architecture and training procedure for jointly training a retrieval-augmented LM from scratch and applying it to the task of modeling long texts. Given a recently generated text chunk in a long document, the LM computes query representations, which are then used to retrieve earlier chunks in the document, located potentially tens of thousands of tokens before. Information from retrieved chunks is fused into the LM representations to predict the next target chunk. We train the retriever component with a semantic objective, where the goal is to retrieve chunks that increase the probability of the next chunk, according to a reference LM. We evaluate RPT on four long-range language modeling tasks, spanning books, code, and mathematical writing, and demonstrate that RPT improves retrieval quality and subsequently perplexity across the board compared to strong baselines.

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4

Fournier, N., P. Stammes, M. de Graaf, R. van der A, A. Piters, M. Grzegorski e A. Kokhanovsky. "Improving cloud information over deserts from SCIAMACHY Oxygen A-band measurements". Atmospheric Chemistry and Physics 6, n. 1 (25 gennaio 2006): 163–72. http://dx.doi.org/10.5194/acp-6-163-2006.

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Abstract. The retrieval of column densities and concentration profiles of atmospheric trace gas species from satellites is sensitive to light scattered by clouds. The SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) instrument on the Envisat satellite, principally designed to retrieve trace gases in the atmosphere, is also capable of detecting clouds. FRESCO (Fast Retrieval Scheme for Clouds from the Oxygen A-band) is a fast and robust algorithm providing cloud information from the O2 A-band for cloud correction of ozone. FRESCO provides a consistent set of cloud products by retrieving simultaneously effective cloud fraction and cloud top pressure. The FRESCO retrieved values are compared with the SCIAMACHY Level 2 operational cloud fraction of OCRA (Optical Cloud Recognition Algorithm) but, also, with cloud information from HICRU (Heidelberg Iterative Cloud Retrieval Utilities), SACURA (SemiAnalytical CloUd Retrieval Algorithm) and the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument. The results correlate well, but FRESCO overestimates cloud fraction over deserts. Thus, to improve retrievals at these locations, the FRESCO surface albedo databases are decontaminated from the presence of desert dust aerosols. This is achieved by using the GOME Absorbing Aerosol Index. It is shown that this approach succeeds well in producing more accurate cloud information over the Sahara.

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Lokhande, Kalyani, e Dhanashree Tayade. "English-Marathi Cross Language Information Retrieval System". International Journal of Advanced Research in Computer Science and Software Engineering 7, n. 8 (30 agosto 2017): 112. http://dx.doi.org/10.23956/ijarcsse.v7i8.34.

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Nowadays, diﬀerent types of content in diﬀerent languages are available on World Wide Web and their usage is increasing rapidly. Cross Language Information Retrieval (CLIR) deals with retrieval of documents in another language than the language of the requested query. Various researchers worked on Cross Language Information Retrieval systems for Indian languages using diﬀerent translation approaches. There is still CLIR system to be developed which allow user to retrieve Marathi documents when English query is given. In the proposed English to Marathi Cross Language Information Retrieval system, translation is based on query translation approach. The proposed system retrieves Marathi documents depending on matching terms in query. The performance of the proposed system is improved by query pre-processing and query expansion using WordNet.

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6

Frankenberg, C., O. Hasekamp, C. O'Dell, S. Sanghavi, A. Butz e J. Worden. "Aerosol information content analysis of multi-angle high spectral resolution measurements and its benefit for high accuracy greenhouse gas retrievals". Atmospheric Measurement Techniques Discussions 5, n. 2 (16 aprile 2012): 2857–85. http://dx.doi.org/10.5194/amtd-5-2857-2012.

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Abstract. New generations of space-borne spectrometers for the retrieval of atmospheric abundances of greenhouse gases require unprecedented accuracies as atmospheric variability of long-lived gases is very low. These instruments, such as GOSAT and OCO-2, typically use a high spectral resolution oxygen channel (O2 A-band) in addition to CO2 and CH4 channels to discriminate changes in the photon path-length distribution from actual trace gas amount changes. Inaccurate knowledge of the photon path-length distribution, determined by scatterers in the atmosphere, is the prime source of systematic biases in the retrieval. In this paper, we investigate the combined aerosol and greenhouse gas retrieval using multiple satellite viewing angles simultaneously. We find that this method, hitherto only applied in multi-angle imagery such as from MISR, greatly enhances the ability to retrieve aerosol properties by 2–3 degrees of freedom. We find that the improved capability to retrieve aerosol parameters significantly reduces interference errors introduced into retrieved CO2 and CH4 total column averages. Instead of focussing solely on improvements in spectral and spatial resolution, signal-to-noise ratios or sampling frequency, multiple angles reduce uncertainty in space based greenhouse gas retrievals more effectively and provide a new potential for dedicated aerosols retrievals.

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Frankenberg, C., O. Hasekamp, C. O'Dell, S. Sanghavi, A. Butz e J. Worden. "Aerosol information content analysis of multi-angle high spectral resolution measurements and its benefit for high accuracy greenhouse gas retrievals". Atmospheric Measurement Techniques 5, n. 7 (27 luglio 2012): 1809–21. http://dx.doi.org/10.5194/amt-5-1809-2012.

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Abstract (sommario):

Abstract. New generations of space-borne spectrometers for the retrieval of atmospheric abundances of greenhouse gases require unprecedented accuracies as atmospheric variability of long-lived gases is very low. These instruments, such as GOSAT and OCO-2, typically use a high spectral resolution oxygen channel (O2 A-band) in addition to CO2 and CH4 channels to discriminate changes in the photon path-length distribution from actual trace gas amount changes. Inaccurate knowledge of the photon path-length distribution, determined by scatterers in the atmosphere, is the prime source of systematic biases in the retrieval. In this paper, we investigate the combined aerosol and greenhouse gas retrieval using multiple satellite viewing angles simultaneously. We find that this method, hitherto only applied in multi-angle imagery such as from POLDER or MISR, greatly enhances the ability to retrieve aerosol properties by 2–3 degrees of freedom. We find that the improved capability to retrieve aerosol parameters significantly reduces interference errors introduced into retrieved CO2 and CH4 total column averages. Instead of focussing solely on improvements in spectral and spatial resolution, signal-to-noise ratios or sampling frequency, multiple angles reduce uncertainty in space based greenhouse gas retrievals more effectively and provide a new potential for dedicated aerosols retrievals.

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8

Shi, Chong, Makiko Hashimoto e Teruyuki Nakajima. "Remote sensing of aerosol properties from multi-wavelength and multi-pixel information over the ocean". Atmospheric Chemistry and Physics 19, n. 4 (26 febbraio 2019): 2461–75. http://dx.doi.org/10.5194/acp-19-2461-2019.

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Abstract. In this study, we investigate the feasibility of a multi-pixel scheme in the inversion of aerosol optical properties for multispectral satellite instruments over the ocean. Different from the traditional satellite aerosol retrievals conducted pixel by pixel, we derive the aerosol optical thickness (AOT) of multiple pixels simultaneously by adding a smoothness constraint on the spatial variation of aerosols and oceanic substances, which helps the satellite retrieval, with higher consistency from pixel to pixel. Simulations are performed for two representative oceanic circumstances, open and coastal waters, as well as the land–ocean interface region. We retrieve the AOT for fine, sea spray, and dust aerosols simultaneously using synthetic spectral measurements, which are from the Greenhouse Gases Observing Satellite and Thermal and Near Infrared Sensor for Carbon Observation – Cloud and Aerosol Imager (GOSAT∕TANSO-CAI), with four wavelengths ranging from the ultraviolet to shortwave infrared bands. The forward radiation calculation is performed by a coupled atmosphere–ocean radiative transfer model combined with a three-component bio-optical oceanic module, where the chlorophyll a concentration, sediment, and colored dissolved organic matter are considered. Results show that accuracies of the derived AOT and spectral remote-sensing reflectance are both improved by applying smoothness constraints on the spatial variation of aerosol and oceanic substances in homogeneous or inhomogeneous surface conditions. The multi-pixel scheme can be effective in compensating for the retrieval biases induced by measurement errors and improving the retrieval sensitivity, particularly for the fine aerosols over the coastal water. We then apply the algorithm to derive AOTs using real satellite measurements. Results indicate that the multi-pixel method helps to polish the irregular retrieved results of the satellite imagery and is potentially promising for the aerosol retrieval over highly turbid waters by benefiting from the coincident retrieval of neighboring pixels. A comparison of retrieved AOTs from satellite measurements with those from the Aerosol Robotic Network (AERONET) also indicates that retrievals conducted by the multi-pixel scheme are more consistent with the AERONET observations.

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Wood, Norman B., e Tristan S. L'Ecuyer. "What millimeter-wavelength radar reflectivity reveals about snowfall: an information-centric analysis". Atmospheric Measurement Techniques 14, n. 2 (4 febbraio 2021): 869–88. http://dx.doi.org/10.5194/amt-14-869-2021.

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Abstract. The ability of single-frequency, millimeter-wavelength radar reflectivity observations to provide useful constraints for retrieval of snow particle size distribution (PSD) parameters, snowfall rates, and snowfall accumulations is examined. An optimal estimation snowfall retrieval that allows analyses of retrieval uncertainties and information content is applied to observations of near-surface W-band reflectivities from multiple snowfall events during the 2006–2007 winter season in southern Ontario. Retrieved instantaneous snowfall rates generally have uncertainties greater than 100 %, but single-event and seasonal snow accumulations from the retrieval results match well with collocated measurements of accumulations. Absolute fractional differences are mainly below 30 % for individual events that have more substantial accumulations and, for the season, 12.6 %. Uncertainties in retrieved snowfall rates are driven mainly by uncertainties in the retrieved PSD parameters, followed by uncertainties in particle model parameters and, to a lesser extent, the uncertainties in the fall-speed model. Uncertainties attributable to assuming an exponential distribution are negligible. The results indicate that improvements to PSD and particle model a priori constraints provide the most impactful path forward for reducing uncertainties in retrieved snowfall rates. Information content analyses reveal that PSD slope is well-constrained by the retrieval. Given the sensitivity of PSD slope to microphysical transformations, the results show that such retrievals, when applied to radar reflectivity profiles, could provide information about microphysical transformations in the snowing column. The PSD intercept is less well-constrained by the retrieval. While applied to near-surface radar observations in this study, the retrieval is applicable as well to radar observations aloft, such as those provided by profiling ground-based, airborne, and satellite-borne radars under lighter snowfall conditions when attenuation and multiple scattering can be neglected.

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P, Jennifer. "Indexing Techniques on Information Retrieval". International Journal of Psychosocial Rehabilitation 24, n. 1 (20 gennaio 2020): 1716–20. http://dx.doi.org/10.37200/ijpr/v24i1/pr200271.

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Più fonti

Tesi sul tema "Information retrieval"

1

Bartow, Paul J. "Information retrieval /". Online version of thesis, 1991. http://hdl.handle.net/1850/12169.

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2

Lui, Chang. "Synatic Information Retrieval". Thesis, University of Ulster, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516287.

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Dunlop, Mark David. "Multimedia information retrieval". Thesis, University of Glasgow, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358626.

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4

Keim, Michelle. "Bayesian information retrieval /". Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/8937.

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5

Brucato, Matteo. "Temporal Information Retrieval". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/5690/.

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Morgenroth, Karlheinz. "Kontextbasiertes Information-Retrieval : Modell, Konzeption und Realisierung kontextbasierter Information-Retrieval-Systeme /". Berlin : Logos, 2006. http://deposit.ddb.de/cgi-bin/dokserv?id=2786087&prov=M&dok_var=1&dok_ext=htm.

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7

Koenders, Michael. "FROM MUSIC INFORMATION RETRIEVAL (MIR) TO INFORMATION RETRIEVAL FOR MUSIC (IRM)". Thesis, The University of Sydney, 2016. http://hdl.handle.net/2123/16914.

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This thesis reviews and discusses certain techniques from the domain of (Music) Information Retrieval, in particular some general data mining algorithms. It also describes their specific adaptations for use as building blocks in the CACE4 software application. The use of Augmented Transition Networks (ATN) from the field of (Music) Information Retrieval is, to a certain extent, adequate as long as one keeps the underlying tonal constraints and rules as a guide to understanding the structure one is looking for. However since a large proportion of algorithmic music, including music composed by the author, is atonal, tonal constraints and rules are of little use. Analysis methods from Hierarchical Clustering Techniques (HCT) such as k-means and Expectation-Maximisation (EM) facilitate other approaches and are better suited for finding (clustered) structures in large data sets. ART2 Neural Networks (Adaptive Resonance Theory) for example, can be used for analysing and categorising these data sets. Statistical tools such as histogram analysis, mean, variance as well as correlation calculations can provide information about connections between members in a data set. Altogether this provides a diverse palette of usable data analysis methods and strategies for creating algorithmic atonal music. Now acting as (software) strategy tools, their use is determined by the quality of their output within a musical context, as demonstrated when developed and programmed into the Computer Assisted Composition Environment: CACE4. Music Information Retrieval techniques are therefore inverted: their specific techniques and associated methods of Information Retrieval and general data mining are used to access the organisation and constraints of abstract (non-specific musical) data in order to use and transform it in a musical composition.

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Graf, Erik. "Human information processing based information retrieval". Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/5188/.

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This work focused on the investigation of the question how the concept of relevance in Information Retrieval can be validated. The work is motivated by the consistent difﬁculties of deﬁning the meaning of the concept, and by advances in the ﬁeld of cognitive science. Analytical and empirical investigations are carried out with the aim of devising a principled approach to the validation of the concept. The foundation for this work was set by interpreting relevance as a phenomenon occurring within the context of two systems: An IR system and the cognitive processing system of the user. In light of the cognitive interpretation of relevance, an analysis of the learnt lessons in cognitive science with regard to the validation of cognitive phenomena was conducted. It identiﬁed that construct validity constitutes the dominant approach to the validation of constructs in cognitive science. Construct validity constitutes a proposal for the conduction of validation in scenarios, where no direct observation of a phenomenon is possible. With regard to the limitations on direct observation of a construct (i.e. a postulated theoretic concept), it bases validation on the evaluation of its relations to other constructs. Based on the interpretation of relevance as a product of cognitive processing it was concluded, that the limitations with regard to direct observation apply to its investigation. The evaluation of its applicability to an IR context, focused on the exploration of the nomological network methodology. A nomological network constitutes an analytically constructed set of constructs and their relations. The construction of such a network forms the basis for establishing construct validity through investigation of the relations between constructs. An analysis focused on contemporary insights to the nomological network methodology identiﬁed two important aspects with regard to its application in IR. The ﬁrst aspect is given by a choice of context and the identiﬁcation of a pool of candidate constructs for the inclusion in the network. The second consists of identifying criteria for the selection of a set of constructs from the candidate pool. The identiﬁcation of the pertinent constructs for the network was based on a review of the principles of cognitive exploration, and an analysis of the state of the art in text based discourse processing and reasoning. On that basis, a listing of known sub-processes contributing to the pertinent cognitive processing was presented. Based on the identiﬁcation of a large number of potential candidates, the next step consisted of the inference of criteria for the selection of an initial set of constructs for the network. The investigation of these criteria focused on the consideration of pragmatic and meta-theoretical aspects. Based on a survey of experimental means in cognitive science and IR, ﬁve pragmatic criteria for the selection of constructs were presented. Consideration of meta-theoretically motivated criteria required to investigate what the speciﬁc challenges with regard to the validation of highly abstract constructs are. This question was explored based on the underlying considerations of the Information Processing paradigm and Newell’s (1994) cognitive bands. This led to the identiﬁcation of a set of three meta-theoretical criteria for the selection of constructs. Based on the criteria and the demarcated candidate pool, an IR focused nomological network was deﬁned. The network consists of the constructs of relevance and type and grade of word relatedness. A necessary prerequisite for making inferences based on a nomological network consists of the availability of validated measurement instruments for the constructs. To that cause, two validation studies targeting the measurement of the type and grade of relations between words were conducted. The clariﬁcation of the question of the validity of the measurement instruments enabled the application of the nomological network. A ﬁrst step of the application consisted of testing if the constructs in the network are related to each other. Based on the alignment of measurements of relevance and the word related constructs it was concluded to be true. The relation between the constructs was characterized by varying the word related constructs over a large parameter space and observing the effect of this variation on relevance. Three hypotheses relating to different aspects of the relations between the word related constructs and relevance. It was concluded, that the conclusive conﬁrmation of the hypotheses requires an extension of the experimental means underlying the study. Based on converging observations from the empirical investigation of the three hypotheses it was concluded, that semantic and associative relations distinctly differ with regard to their impact on relevance estimation.

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9

Abdulahhad, Karam. "Information retrieval modeling by logic and lattice : application to conceptual information retrieval". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENM014/document.

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Cette thèse se situe dans le contexte des modèles logique de Recherche d'Information (RI). Le travail présenté dans la thèse est principalement motivé par l'inexactitude de l'hypothèse sur l'indépendance de termes. En effet, cette hypothèse communément acceptée en RI stipule que les termes d'indexation sont indépendant les un des autres. Cette hypothèse est fausse en pratique mais permet tout de même aux systèmes de RI de donner de bon résultats. La proposition contenue dans cette thèse met également l'emphase sur la nature déductive du processus de jugement de pertinence. Les logiques formelles sont bien adaptées pour la représentation des connaissances. Elles permettent ainsi de représenter les relations entre les termes. Les logiques formelles sont également des systèmes d'inférence, ainsi la RI à base de logique constitue une piste de travail pour construire des systèmes efficaces de RI. Cependant, en étudiant les modèles actuels de RI basés sur la logique, nous montrons que ces modèles ont généralement des lacunes. Premièrement, les modèles de RI logiques proposent normalement des représentations complexes de document et des requête et difficile à obtenir automatiquement. Deuxièmement, la décision de pertinence d->q, qui représente la correspondance entre un document d et une requête q, pourrait être difficile à vérifier. Enfin, la mesure de l'incertitude U(d->q) est soit ad-hoc ou difficile à mettre en oeuvre. Dans cette thèse, nous proposons un nouveau modèle de RI logique afin de surmonter la plupart des limites mentionnées ci-dessus. Nous utilisons la logique propositionnelle (PL). Nous représentons les documents et les requêtes comme des phrases logiques écrites en Forme Normale Disjonctive. Nous argumentons également que la décision de pertinence d->q pourrait être remplacée par la validité de l'implication matérielle. Pour vérifier si d->q est valide ou non, nous exploitons la relation potentielle entre PL et la théorie des treillis. Nous proposons d'abord une représentation intermédiaire des phrases logiques, où elles deviennent des noeuds dans un treillis ayant une relation d'ordre partiel équivalent à la validité de l'implication matérielle. En conséquence, nous transformons la vérification de validité de d->q, ce qui est un calcul intensif, en une série de vérifications simples d'inclusion d'ensembles. Afin de mesurer l'incertitude de la décision de pertinence U(d->q), nous utilisons la fonction du degré d'inclusion Z, qui est capable de quantifier les relations d'ordre partielles définies sur des treillis. Enfin, notre modèle est capable de travailler efficacement sur toutes les phrases logiques sans aucune restriction, et est applicable aux données à grande échelle. Notre modèle apporte également quelques conclusions théoriques comme: la formalisation de l'hypothèse de van Rijsbergen sur l'estimation de l'incertitude logique U(d->q) en utilisant la probabilité conditionnelle P(q|d), la redéfinition des deux notions Exhaustivité et Spécificité, et finalement ce modèle a également la possibilité de reproduire les modèles les plus classiques de RI. De manière pratique, nous construisons trois instances opérationnelles de notre modèle. Une instance pour étudier l'importance de Exhaustivité et Spécificité, et deux autres pour montrer l'insuffisance de l'hypothèse sur l'indépendance des termes. Nos résultats expérimentaux montrent un gain de performance lors de l'intégration Exhaustivité et Spécificité. Cependant, les résultats de l'utilisation de relations sémantiques entre les termes ne sont pas suffisants pour tirer des conclusions claires. Le travail présenté dans cette thèse doit être poursuivit par plus d'expérimentations, en particulier sur l'utilisation de relations, et par des études théoriques en profondeur, en particulier sur les propriétés de la fonction Z
This thesis is situated in the context of logic-based Information Retrieval (IR) models. The work presented in this thesis is mainly motivated by the inadequate term-independence assumption, which is well-accepted in IR although terms are normally related, and also by the inferential nature of the relevance judgment process. Since formal logics are well-adapted for knowledge representation, and then for representing relations between terms, and since formal logics are also powerful systems for inference, logic-based IR thus forms a candidate piste of work for building effective IR systems. However, a study of current logic-based IR models shows that these models generally have some shortcomings. First, logic-based IR models normally propose complex, and hard to obtain, representations for documents and queries. Second, the retrieval decision d->q, which represents the matching between a document d and a query q, could be difficult to verify or check. Finally, the uncertainty measure U(d->q) is either ad-hoc or hard to implement. In this thesis, we propose a new logic-based IR model to overcome most of the previous limits. We use Propositional Logic (PL) as an underlying logical framework. We represent documents and queries as logical sentences written in Disjunctive Normal Form. We also argue that the retrieval decision d->q could be replaced by the validity of material implication. We then exploit the potential relation between PL and lattice theory to check if d->q is valid or not. We first propose an intermediate representation of logical sentences, where they become nodes in a lattice having a partial order relation that is equivalent to the validity of material implication. Accordingly, we transform the checking of the validity of d->q, which is a computationally intensive task, to a series of simple set-inclusion checking. In order to measure the uncertainty of the retrieval decision U(d->q), we use the degree of inclusion function Z that is capable of quantifying partial order relations defined on lattices. Finally, our model is capable of working efficiently on any logical sentence without any restrictions, and is applicable to large-scale data. Our model also has some theoretical conclusions, including, formalizing and showing the adequacy of van Rijsbergen assumption about estimating the logical uncertainty U(d->q) through the conditional probability P(q|d), redefining the two notions Exhaustivity and Specificity, and the possibility of reproducing most classical IR models as instances of our model. We build three operational instances of our model. An instance to study the importance of Exhaustivity and Specificity, and two others to show the inadequacy of the term-independence assumption. Our experimental results show worthy gain in performance when integrating Exhaustivity and Specificity into one concrete IR model. However, the results of using semantic relations between terms were not sufficient to draw clear conclusions. On the contrary, experiments on exploiting structural relations between terms were promising. The work presented in this thesis can be developed either by doing more experiments, especially about using relations, or by more in-depth theoretical study, especially about the properties of the Z function

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Romano, Nicholas C., Dmitri G. Roussinov, Jay F. Nunamaker e Hsinchun Chen. "Collaborative Information Retrieval Environment: Integration of Information Retrieval with Group Support Systems". HICSS, 1999. http://hdl.handle.net/10150/105688.

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Artificial Intelligence Lab, Department of MIS, University of Arizona
Observations of Information Retrieval (IR) system user experiences reveal a strong desire for collaborative search while at the same time suggesting that collaborative capabilities are rarely, and then only in a limited fashion, supported by current searching and visualization tools. Equally interesting is the fact that observations of user experiences with Group Support Systems (GSS) reveal that although access to external information and the ability to search for relevant material is often vital to the progress of GSS sessions, integrated support for collaborative searching and visualization of results is lacking in GSS systems. After reviewing both user experiences described in IR and GSS literature and observing and interviewing users of existing IR and GSS commercial and prototype systems, the authors conclude that there is an obvious demand for systems supporting multi-user IR.. It is surprising to the authors that very little attention has been given to the common ground shared by these two important research domains. With this in mind, our paper describes how user experiences with IR and GSS systems has shed light on a promising new area of collaborative research and led to the development of a prototype that merges the two paradigms into a Collaborative Information Retrieval Environment (CIRE). Finally the paper presents theory developed from initial user experiences with our prototype and describes plans to test the efficacy of this new paradigm empirically through controlled experimentation.

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Libri sul tema "Information retrieval"

1

Lin, Hongfei, Min Zhang e Liang Pang, a cura di. Information Retrieval. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-88189-4.

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Grossman, David A., e Ophir Frieder. Information Retrieval. Dordrecht: Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-1-4020-3005-5.

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Fuhr, Norbert, a cura di. Information Retrieval. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-76981-8.

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Zhang, Shichao, Tie-Yan Liu, Xianxian Li, Jiafeng Guo e Chenliang Li, a cura di. Information Retrieval. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01012-6.

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5

Wen, Jirong, Jianyun Nie, Tong Ruan, Yiqun Liu e Tieyun Qian, a cura di. Information Retrieval. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-68699-8.

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Gker, Aye, e John Davies, a cura di. Information Retrieval. Chichester, UK: John Wiley & Sons, Ltd, 2009. http://dx.doi.org/10.1002/9780470033647.

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Braslavski, Pavel, Ilya Markov, Panos Pardalos, Yana Volkovich, Dmitry I. Ignatov, Sergei Koltsov e Olessia Koltsova, a cura di. Information Retrieval. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-41718-9.

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Dou, Zhicheng, Qiguang Miao, Wei Lu, Jiaxin Mao e Guang Jia, a cura di. Information Retrieval. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-56725-5.

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Zhang, Qi, Xiangwen Liao e Zhaochun Ren, a cura di. Information Retrieval. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-31624-2.

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Hersh, William. Information Retrieval. New York, NY: Springer New York, 2009. http://dx.doi.org/10.1007/978-0-387-78703-9.

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Capitoli di libri sul tema "Information retrieval"

1

Klinke, Harald. "Information Retrieval". In Digital Humanities, 268–78. Stuttgart: J.B. Metzler, 2017. http://dx.doi.org/10.1007/978-3-476-05446-3_19.

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Shahi, Dikshant. "Information Retrieval". In Apache Solr, 39–56. Berkeley, CA: Apress, 2015. http://dx.doi.org/10.1007/978-1-4842-1070-3_3.

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Shekhar, Shashi, e Hui Xiong. "Information Retrieval". In Encyclopedia of GIS, 577. Boston, MA: Springer US, 2008. http://dx.doi.org/10.1007/978-0-387-35973-1_636.

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Harvey, Charles, e Jon Press. "Information Retrieval". In Databases in Historical Research, 147–87. London: Macmillan Education UK, 1996. http://dx.doi.org/10.1007/978-1-349-24392-1_6.

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Riggert, Wolfgang. "Information Retrieval". In Betriebliche Informationskonzepte, 75–126. Wiesbaden: Vieweg+Teubner Verlag, 2000. http://dx.doi.org/10.1007/978-3-322-89195-2_3.

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Carneiro, Davide, Paulo Novais e José Neves. "Information Retrieval". In Conflict Resolution and its Context, 141–62. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-06239-6_7.

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Amati, Giambattista. "Information Retrieval". In Encyclopedia of Database Systems, 1–6. New York, NY: Springer New York, 2017. http://dx.doi.org/10.1007/978-1-4899-7993-3_915-2.

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Darwish, Kareem. "Information Retrieval". In Natural Language Processing of Semitic Languages, 299–334. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-45358-8_10.

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Linckels, Serge, e Christoph Meinel. "Information Retrieval". In X.media.publishing, 81–100. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-17743-9_5.

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Levy, Allan H., e David P. Lawrance. "Information Retrieval". In Aspects of the Computer-based Patient Record, 146–52. New York, NY: Springer New York, 1992. http://dx.doi.org/10.1007/978-1-4757-3873-5_15.

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Atti di convegni sul tema "Information retrieval"

1

Ball, Liezl, e Theo Bothma. "The capability of search tools to retrieve words with specific properties from large text collections". In ISIC: the Information Behaviour Conference. University of Borås, Borås, Sweden, 2020. http://dx.doi.org/10.47989/irisic2030.

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Introduction. With the increase in the availability of digital text collections for humanities researchers, tools to enable enhanced retrieval are required. If words with very specific properties could be retrieved from a text collection more accurate linguistic and other analyses can be made. There are a range of properties and metadata that could be specified for retrieval, from morphological data up to bibliographic data. Furthermore, the bibliographic data should not only be on item level but extended to the text-level. For example, in an anthology each section could be encoded with the author of that section. Such extended metadata will enable fine-grained retrieval. Method. In this study, current tools were evaluated to determine to what extent they allow users to retrieve words with specific properties from a text collection. Analysis. The analysis is limited to the following criteria: interface design, metadata, search options, filtering and search results. Results. Currently, it is not possible for a user to retrieve words with specific properties from a text collection. Conclusion. An extended set of metadata should be used to encode text to enable retrieval of words on a fine-grained level.

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Li, Zhanjun, Victor Raskin e Karthik Ramani. "Developing Ontologies for Engineering Information Retrieval". In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-34530.

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When engineering content is created and applied during the product lifecycle, it is often stored and forgotten. Since search remains text-based, engineers do not have the means to harness and reuse past designs and experiences. On the other hand, current information retrieval approaches based on statistical methods and keyword matching are not directly applicable to the engineering domain. We propose a new computational framework that includes an ontological basis and algorithms to retrieve unstructured engineering documents while handling complex queries. The results from the preliminary test demonstrate that our method outperforms the traditional keyword-based search with respect to the standard information retrieval measurement.

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"Information Retrieval". In 2021 Fifth International Conference on Information Retrieval and Knowledge Management (CAMP). IEEE, 2021. http://dx.doi.org/10.1109/camp51653.2021.9498026.

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Poulon, Astrid, e Christophe Vaudry. "Information retrieval". In the 15th French-speaking conference on human-computer interaction. New York, New York, USA: ACM Press, 2003. http://dx.doi.org/10.1145/1063669.1063713.

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"Information retrieval". In 2016 Third International Conference on Information Retrieval and Knowledge Management (CAMP). IEEE, 2016. http://dx.doi.org/10.1109/infrkm.2016.7806334.

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6

"Information Retrieval". In 2018 Fourth International Conference on Information Retrieval and Knowledge Management (CAMP). IEEE, 2018. http://dx.doi.org/10.1109/infrkm.2018.8464804.

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7

Yim, Sungshik, e David Rosen. "Case-Based Retrieval Approach of Supporting Process Planning in Layer-Based Additive Manufacturing". In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-35309.

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The process planning task for a given design problem in additive manufacturing can be greatly enhanced by referencing previously developed process plans. In this research, a case-based retrieval method, called the DFM (Design For Manufacturing) framework, that retrieves previously formulated process plans is proposed to support process planning. To support the DFM Framework, we have developed an information model (ontology) of manufacturing process knowledge in the domain of additive manufacturing processes, including design requirements, process plans, and rules that map requirements to plans. Description Logic (DL) is identified as an appropriate mathematical formalism to encode the ontology and realize the computational mapping between the design and manufacturing domains. Storage and retrieval algorithms are presented that, first, structure the repository of previous DFM problems and, second, enable DFM problems to be retrieved.

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Vitsentiy, Vitaliy. "A stochastic programming approach to optimization of information retrieval". In International Workshop of "Stochastic Programming for Implementation and Advanced Applications". The Association of Lithuanian Serials, 2012. http://dx.doi.org/10.5200/stoprog.2012.22.

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The researDupach problem of optimization of the expected relevance of retrieved documents in search sessions with feedback is considered in this paper. This problem is solved by planning the interaction with the user with endogenous reduction of uncertainty by means of stochastic programming. An approach to build the model based on topic models of documents that takes into account past history of retrieved documents and user feedback values in the current decision is proposed. The experiments with a simulated database of documents shown a significant improvement in retrieval effectiveness over the traditional approach.

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Tzanetakis, George. "Music information retrieval". In the seventeen ACM international conference. New York, New York, USA: ACM Press, 2009. http://dx.doi.org/10.1145/1631272.1631450.

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Lupu, Mihai. "Patent information retrieval". In the 35th international ACM SIGIR conference. New York, New York, USA: ACM Press, 2012. http://dx.doi.org/10.1145/2348283.2348536.

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Rapporti di organizzazioni sul tema "Information retrieval"

1

Jha, Somesh, Vitaly Shmatikov e Matthew Fredrikson. Private Information Retrieval. Fort Belvoir, VA: Defense Technical Information Center, dicembre 2010. http://dx.doi.org/10.21236/ada536856.

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Knoblock, Craig A., Yigal Arens e Chu-Nan Hsu. Cooperating Agents for Information Retrieval. Fort Belvoir, VA: Defense Technical Information Center, maggio 1994. http://dx.doi.org/10.21236/ada285887.

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Hoeferlin, David M., e Stephen A. Thorn. Crosslingual Audio Information Retrieval Development. Fort Belvoir, VA: Defense Technical Information Center, aprile 2009. http://dx.doi.org/10.21236/ada539725.

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Newitt, L. R., G. V. Haines e R. L. Coles. The magnetic information retrieval program. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1990. http://dx.doi.org/10.4095/225655.

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Bader, Brett William, Peter Chew, Ahmed Abdelali e Tamara Gibson Kolda. Cross-language information retrieval using PARAFAC2. Office of Scientific and Technical Information (OSTI), maggio 2007. http://dx.doi.org/10.2172/908061.

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Liu, Xiaoyong, e W. B. Croft. Statistical Language Modeling for Information Retrieval. Fort Belvoir, VA: Defense Technical Information Center, gennaio 2005. http://dx.doi.org/10.21236/ada440321.

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Franz, Martin, J. S. McCarley e Wei-Jing Zhu. English-Chinese Information Retrieval at IBM. Fort Belvoir, VA: Defense Technical Information Center, gennaio 2006. http://dx.doi.org/10.21236/ada456312.

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Lynch, C. Using the Z39.50 Information Retrieval Protocol. RFC Editor, dicembre 1994. http://dx.doi.org/10.17487/rfc1729.

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Newitt, L. R., e G. V. Haines. An interactive magnetic information retrieval program. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1985. http://dx.doi.org/10.4095/315221.

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Newitt, L. R., e G. V. Haines. An interactive magnetic information retrieval program. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1985. http://dx.doi.org/10.4095/225672.

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